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Write a function which will partition a sequence of shots java
write a function which will partition a sequence of shots java quicksort(a: array[int], low: int, high: int) = ( if (!(low < high)) return; mid: int = partition(a, low, high); quicksort(a, low, mid); quicksort(a, mid + 1, high) ) partition(a: array[int], low: int, high: int): int = ( /* Reorder the elements in a into two contiguous groups. Dec 31, 2020 · Use recursion to sort both partitions. Spark groupBy function is defined in RDD class of spark. Note that support for Java 7 is deprecated as of Spark 2. function package. Nov 29, 2014 · Java 8 Collectors. Each call to the function that processes events delivers a single event from a specific partition. This subsequence has length 6; the input sequence has no 7-member increasing subsequences. value, function(value, key, collection){ if (test(value[key], key, collection) === "string"){ matches. When you call the System. Parameters. zip Dec 03, 2006 · There is a function module PRICING which is called by the standard SD transactions to carry out pricing. nio package, which was released in Java SDK, version 1. The solution below correctly solves the problem. 5 As an example, p(5) = 7, and here are all 7 of the partitions of the integer n = 5: 5 = 5 = 4 + 1 = 3 + 2 = 3 + 1+ 1 = 2 + 2+ 1 = 2 + 1+ 1+ 1 = 1 + 1+ 1+ 1+ 1 We take p(n) = 0 for all negative values of n and p(0) is de・]ed to be 1. What is BDK? - BDK, Bean Development Kit is a tool that enables to create, configure and connect a set of set of Beans and it can be used to test Beans without writing a code. For example, "dad" is a palindrome, as its reverse is "dad," whereas "program" isn't, as its reverse is "margorp" that is different from "program. Further, if a subtype can be defined for the reals, to separate positive and negative reals, two functions can be written for the reals, one to return a real when the parameter is positive // Java program for implementation of QuickSort class QuickSort {/* This function takes last element as pivot, places the pivot element at its correct position in sorted array, and places all smaller (smaller than pivot) to left of pivot and all greater elements to right of pivot */ int partition (int arr [], int low, int high) {int pivot = arr [high]; int i = (low-1); // index of smaller element for (int j = low; j < high; j ++) {// If current element is smaller than or // equal to pivot if Dec 23, 2020 · NumPartitions: Int, which returns the number of partitions that you will create it as per the requirements. Examples. Return value An iterator that points to the first element of the second group of elements (those for which pred returns false), or last if this group is empty. On the other hand the default for writes is number of partitions of your output dataset. This site provides free download management system project report. The source here refers to a Collection or Arrays who provides data to a Stream. Lambdas, serious type inference, and the Streams API changed my Java code so deeply that it feels like a new language. By default, Sklearn train_test_split will make random partitions for the two subsets. T - the type of elements in the sequence. The problem is to find the minimum time to get this job done under the constraints that any painter will only paint continuous sections of boards, say board {2, 3, 4} or only board {1} or nothing but not board {2, 4, 5}. These annotations were then added to the database for later investigation by researchers. Aug 14, 2019 · Apparently it's best to write logic against which, as keyCode and charCode are complicated: The event. n = numpartitions (ds); Partition the datastore into the default number of partitions and return the datastore corresponding to the first partition. Given a linked list and a value x, partition it such that all nodes less than x come before nodes greater than or equal to x. Level 3: This is the stage in which you will group some cases and write a test procedure. Precedence rules can be overridden by explicit parentheses. We let the function p(n) denote the number of partitions of the integer n. Even for built-in functions, there is only a certain probability the function will do whatever you intend it to do. java that sorts an array of Comparable objects by by using, as a subroutine, the partitioning algorithm described in the previous exercise: First, pick a random element v as the partitioning element. A single partition can refer to many things, such as classes, use cases, components, or interfaces. They illustrate how the different parts of a system interact with each other to carry out a function, and the order in which the interactions occur when a particular use case is executed. The Scala List class may be the most commonly used data structure in Scala applications. out. And aggregate operations or bulk operations are operations which allow us to express common manipulations on those values easily and clearly. Sometimes there is, but other times you need to write the function. Write only one statement per line. The latter sequences throw an exception on an attempt to iterate them the second time. Now click on save button. Codes are designed by the user and function similarly to layers in AutoCAD. In step 1, we select the last element as the pivot, which is 6 in this case, and call for partitioning, hence re-arranging the array in such a way that 6 will be placed in its final position and to its left will be all the elements less Included in Oracle 7. Writing. Two types of Apache Spark RDD operations are- Transformations and Actions. java, Week2. Sequence numbers for the same partition key generally increase over time; the longer the time period between PutRecord or PutRecords requests, the larger the sequence numbers become. In the post conversion of number to words is done for both international system and Indian system. Write a program to calculate students' average test scores and their grades. In number theory, * a partition of N is a way to write it as a sum of positive integers. SELECT MAX ([Column_Name]) FROM [Source] The Sql Server MAX Function will ignore Null values. The syntax of the SQL Server Max is. In java, while programming, there is a need for manipulating and abstracting files in a program. I have a pipe delimited flat file and created metadata and want to use metadata while working with analytical functions May 02, 2019 · QuickSort is a sorting algorithm, which is commonly used in computer science. Feb 26, 2020 · Java Conditional Statement: Exercise-5 with Solution. Here is a partition function for a random element as a pivot. This is a type of index that is created on the result of a function applied to the column, which could be used in this query. Write a program for Insertion Sort in java. 4. We'll use the Clickstream sample data to demonstrate some partition strategies. If a partition cannot be shown clearly, then the name of a partition is written on top of the name of an activity. Jan 07, 2021 · For date and time formatting, the conversion string is a sequence of two characters: the 't' or 'T' character and the conversion suffix. The function is then called again with the result obtained in step 1 and the next value in the sequence. $ cat numbers2. How to get distinct elements from an array by avoiding duplicate elements? Write a program to get distinct word list from the given file. lang. api. The subsequences are then recombined to yield a sorted sequence. Our goal is to write a program to filter out extraneous pairs from the sequence: When the program reads a pair p q from the input, it should write the pair to the output only if the pairs it has seen to that point do not imply that p is connected to q. A sequence file is a flat file that consists of binary key This example shows how to write a simple function fixUploadedFilesNames() to rename uploaded files back to their original names. The code for C++ contains solid function for quicksort, but Java code contains two separate functions for partition and sort, accordingly. But be cautious about poisoned messages. io. , if an administrator adds new partitions). For Partition algorithm is important per se, therefore it may be carried out as a separate function. Multiple sequence alignment is an important tool to study the evolution and function of homologous proteins. The module for multiple sequence alignments, AlignIO This page describes Bio. May 07, 2020 · Q32. For heterogeneous collections of data where access by name is clearer than access by index, collections. Let's say my Azure Function pulls in a batch of 50 events from that partition into a function. Default is None: reverse: Optional. PARTITION BY expr_list PARTITION BY is an optional clause that subdivides the data into partitions. Flashcards. in partition['validation'] a list of validation IDs Create a dictionary called labels where for each ID of the dataset, the associated label is given by labels[ID] For example, let's say that our training set contains id-1 , id-2 and id-3 with respective labels 0 , 1 and 2 , with a validation set containing id-4 with label 1 . The function get the partition as an `Iterator` and can produce an arbitrary number of result values. This can either be a function pointer or a function object. Level 2: This is the practical stage in which writing cases depend on the actual functional and system flow of the application. You do not have to look up the OID by hand, however, since the regclass data type's input converter will do the work for you. If you omit the clause, the SUM() function will use the ALL clause by default. 1 INTRODUCTION. Java. Write a function which will partition a sequence of labels into minimal subsequences so that no labels appear in more than one subsequence. Quicksort with 3-way partitioning is entropy-optimal. Arguments: children - this is to base the rank on; a change in the value of one the children will trigger a change in rank. The longest increasing subsequence in this example is not unique. The function main also happens to be the entry point of any (standard-compliant) C++ program and must be peak_movie, a MATLAB code which creates a sequence of frames, and then an animation or movie from the data displayed by the peaks() function. Example. txt', 'w' ); nbytes = fprintf (fileID, '%5d %5d %5d %5d ' ,A) nbytes = 96. zip contains classes that read and write jar files. If a string is balanced, return YES. equals(): the standard Java programming equality method. So the main problem is to get the next partition from a given partition. Let's look at COS components to understand how to best store your data for optimum query performance. In order to find the split point, each of the n items needs to be checked against the pivot value. The writerows () method writes all given rows to the CSV file. Syntax Battleship is a war-themed board game for two players in which the opponents try to guess the location of their opponent's warships and sink them. 3 is a UTL_FILE package that can read and write files. c) Add Partition by Right Click near the name "Activity1". This book starts from an introduction to Java and then explains how to write programs that have Graphic User Interface by writing the Tic-Tac-Toe and Ping-Pong games. The result is one plus the previously assigned rank value. com _. The discussion of aggregate functions segues logically into the subject of more-advanced SQL operations that use aggregations and other specific views of your data. You can integrate this RFC into a Web application. Jan 21, 2019 · Here we explain the differences between partition key, composite key and clustering key in Cassandra. java, Week4. The goal is to help students learn to program in the most popular language in the world: Java. This program will write, read object (through member functions) in, from binary file. This is important to implement because Spark application will need to test your Partitioner object against other instances by its own terms when it decides whether two of your RDDs are partitioned the same way as it is The example function, when applied on the sequence (1,2,3,4,5), folds the sequence into the string "start-1-2-3-4-5": valresult:DataStream[String]=windowedStream. The partition of an integer is a way of writing it as a sum of positive integers. For example, the sum of DISTINCT of 1, 1, and 2 is 3, while the sum of ALL of 1, 1, and 3 is 4. NumberFormatException: For input string: "null" This call is necessary to perform initialization of the sequence during formatting so that it can be incremented upon completion using the setup steps below. The expressions of the PARTITION BY clause can be column expressions, scalar subquery, or scalar function. Just click continue. NOTE: You only need to implement the given function. Function Description. // / Write a function which will partition a sequence of shots into minimal subsequences so that no shot appears in more than one subsequence. Function Name − This is the actual name of the function. Whether you are looking for essay, coursework, research, or term paper help, or with any other assignments, it is no problem for us. The key of map can be only true and false. False will sort ascending, True will sort descending. Unlike the function rank, dense_rank will not produce gaps in the ranking sequence. Two sums are considered the same if they only differ in the order of their constituent summands. which property normalizes event. For example– If you enter number 123 output should be One hundred twenty three in words. Functions group together script code; control structures, operations, method calls, etc. com is licensed under the MIT License , read this Code License . AlignIO, and although there is some overlap it is well worth reading in The Raspberry Pi is a tiny and affordable computer that you can use to learn programming through fun, practical projects. Nov 23, 2018 · Drawbacks: needs to be used along with other tool(s) to manually write, export, and share a user manual. Which is a primary principle of the Rapid Application Development methodology? One of the primary principles of the Rapid Application Development methodology is early prototyping of the product in the development cycle My professor has me writing a program with the following instructions and I'm a little stuck mentally in getting the output to the screen and to a file. For an explanation of how analytic functions work, see Analytic Function Concepts. Create an instance of Storage Container client; Create an instance using Azure Identity; Consume events from all Event Hub Write a program Centroid. 6. This method accepts a predicate and returns a Collector. I tried to use Numeric. util package. You may assume the following input data is read from a text file. The syntax to a drop a function in Oracle is: DROP FUNCTION function_name; function_name The name of the function that you wish to drop. Let's explore the most common time and date formatting suffix characters with the examples. Rebalances are important because they provide the consumer group with high availability and scalability Sequence Number: The sequence number is a unique 64-bit integer assigned to a message as it is accepted and stored by the broker and functions as its true identifier. Partition keys are basic elements for determining how the data is stored in the table. We can write a Fibonacci function by using recur as well. peak_movie_test pendulum_comparison , a MATLAB code which compares the linear and nonlinear ordinary differential equations (ODE) that represent the behavior of a pendulum of length L under a The trick here is to swap the pivot value to the front of the sequence, partition the rest of the values, and then swap the pivot value back to where it belongs: int partition(int *arr, const int left, const int right) { const int mid = left + (right - left) / 2; const int pivot = arr[mid]; // move the mid point value to the front. Oct 23, 2015 · There are many ways of reversing a String in Java for whatever reason you may have. This article is the first in a three-article sequence that introduces you to some commonly used analytic functions and their associated clauses. The following is the Java Implementation using rightmost element as the pivot. For example, the partitions of the number 5 are: 5; 4+1; 3+2; 2+2+1 Reassignment of partitions to consumers also happen when the topics the consumer group is consuming are modified (e. Custom functions are called from within a SQL statement, like a regular function, and return a single value. For example, given [6, 2, 4, 0, 5, 1, 1, 4, 2, 9] , you should return 2 , as the optimal solution involves jumping from 6 to 5 , and then from 5 to 9 . The fprintf function wrote 96 bytes to the file. Write a program to implement hashcode and equals. Use standard programming structures. 3 the only means of writing a file was to use DBMS_OUTPUT with the SQL*Plus SPOOL command. Write a program to get a line with max word count from the given file. So, we can eliminate this case by choosing random element as a pivot. Sequence operations, like Sequence. 7. Sequences in JavaFX look like arrays in Java. Java has well-defined rules for specifying the order in which the operators in an expression are evaluated when the expression has several operators. Given strings of brackets, determine whether each sequence of brackets is balanced. The call specification tells the database which Java method, or which named function in which shared library, to invoke when a call is made. Java examples (Java sample source code) help to understand functionality of various Java classes and methods as well as various programming techniques in a simple way, which is otherwise very hard to learn by reading tutorials or Java API. _2() methods. txt' using a for loop with in file_object clause, display the numbers, and then display the following data: the sum total of the random numbers picked and the number of random numbers read from the file. Arguments − An argument is like a Functions April 15, 2019 1 Some number sequences An inflnite sequence (or just a sequence for short) is an ordered array a0; a1; a2; :::; an; ::: of countably many real or complex numbers, and is usually abbreviated as (an;n ' 0) or just (an). Functions of n arguments require at least 2 arguments. Before we check palindrome numbers using functions, let us first define our function. After I press play, the sequence would delay for 2 seconds, then release the shutter during the 1 second "long" and go right into the 4 second "intvl" countdown. Pseudorandom means that the numbers are generated in a well-defined way, but the sequence of numbers looks random (satisfies many mathematical properties of random numbers). It makes a call to the partition function from Quicksort. java that reads in a sequence of positions and masses (x i, y i, m i) from standard input and prints out their center of mass (x, y, m). C++ program to write and read an object in/from a binary file. If a built-in function is not available, you can write your own using procedural SQL or Java. Find the syntax of partitioningBy method. Nov 22, 2020 · Hive Partitions is a way to organizes tables into partitions by dividing tables into different parts based on partition keys. Any other number of this series is the sum of the two elements coming before it. 4 or later to successfully compile and execute this program. The ones that are supported in almost all databases are: ROW_NUMBER(): This one generates a new row number for every row, regardless of duplicates within a partition. Moving partition ownership from one consumer to another is called a rebalance. Write a program Partition. It takes a single parameter that is a sequence of String objects called args. One easy way to perform this is to write a function that can convert the fields into positions in an array. We can use the 'chmod' command which stands for 'change mode'. By default the lower bound or the starting index is set to zero. The header <algorithm> defines a collection of functions especially designed to be used on ranges of elements. , 1994), Dalign (Morgenstern, 1999), T-Coffee (Notredame et al. Sep 05, 2020 · The zeroth element of the sequence is 0. The expression1, expression1, etc. For example, using increment operators, you can add 1 to a variable named a like this: a++; An expression that uses an increment or decrement operator is a statement itself. java visualizes quicksort with 3-way partitioning. 1. • Easier to do sequence diagrams as a team. Within a partition, each event includes an offset, sequence number, and the timestamp of when it was enqueued. Complexity: The worst case time complexity of this algorithm is O( n 2 ) , but as this is randomized algorithm, its time complexity fluctuates between O( n 2 ) and O(n (log n) ) and mostly it comes out to be O( n (log n)) . Spark RDD groupBy function returns an RDD of grouped items. They are declared by placing brackets, [], after the type. The following is a list of operators available in EL. Step 3: A message will be displayed 'Function module name is reserved for SAP'. Apr 17, 2009 · Sequences vs Arrays. QuickSort is a divide and conquers algorithm. Use rand_partition instead of partition function in quick_sort function to reduce the time complexity of this algorithm. They cannot refer to expressions or aliases in the select list. Then you/your team developed the screen shots. An activity partition or a swimlane is a high-level grouping of a set of related actions. apache. Today, we will look at a few simple ways of reversing a String in Java. java that takes a positive integer N as a command-line argument and prints out all partitions of N. Write the purpose of the process. 8. However, you can also specify a random state for Jan 02, 2018 · Buckets and partitions play important roles in data organization. Write the initial steps that set the stage for functions. WindowedStream → DataStream. Palindrome in Java Java program to check if a string is a palindrome or not, it's a palindrome if it remains the same on reversal. In this tutorial, you will learn reading and writing Avro file along with schema, partitioning data for performance with Scala example. The idea is to use recursion to solve this problem. Create the shortest function, program, or expression that calculates a sequence of squarefree palindromic numbers. Use a bracket and "if" statements to write the function. Show, in the style of the trace given with partition(), how that method partitions the array E A S Y Q U E S T I O N. For example, the string "Reverse Me" once reversed will be "eM esreveR". Add comments if necessary. partition ( predicate: (Char) -> Boolean): Pair < List < Char >, List < Char > > Splits the original array into pair of lists, where first list contains elements for which predicate yielded true , while second list contains elements for which predicate yielded false . Nov 16, 2020 · The following sections describe the numbering functions that BigQuery supports. This is the Java File Class as we will see in this article. Partition columns are virtual columns, they are not part of the data itself but are derived on load. Place your java code in the directory that makes sense for your function. 2. The figure at the right shows how the two-dimensional (a,b) space is divided by this partition, and the points are test cases that we might choose to completely cover the partition. Mar 19, 2018 · Quick3way. ds = datastore ( 'mapredout. Jul 31, 2019 · The idea is to get the next partition using the values in the current partition. Visualization. Java2K is not a deterministic programming language, but a probabilistic one. " Jul 27, 2017 · Appendix A: Operator Precedence in Java. The number in parentheses is the number of arguments each takes. With this option set, we prevent allocating a sequence in the event that the view already exists. isBalanced has the following parameter(s): Apr 16, 2020 · For this we need to implement the construction operator, which is sort of inverse mapping — while mapping a function over a sequence of inputs produces a sequence of outputs of that function applied to each input, Backus' construction maps a sequence of functions over one input to produce a sequence of results of each function to that input, e. Scala supports functional programming approach. Tuples implement all of the common sequence operations. The Random class is found in the java. See full list on mkyong. The first one picks the rightmost element as the pivot and the second one picks the middle element as the pivot. Messages 1–9 process in a few milliseconds, but message 10 is taking a few minutes to process. Capitalize the initial keyword of each main direction. The package java. Auto Sequence also allows for reversing the sequence once complete (RNG, RTB, RFLLTB, LNG). Python String partition() The partition() method splits the string at the first occurrence of the argument string and returns a tuple containing the part the before separator, argument string and the part after the separator. If we sort the array in ascending order, the k th element of an array will be the k th smallest element. Determine formulas that describe how to calculate an output from an input in each interval. public static int partition (int low, int high) { int pivot = a [low]; int i = low - 1; int j = high + 1; while (i < j) { for (i++; a [i] < pivot; i++); for (j--; a [j] > pivot; j--); if (i < j) swap (i, j); } return j; } Notice that in this code, the array being sorted is a static int array named a. FILE_TYPE; BEGIN Cheap essay writing sercice If you need professional help with completing any kind of homework, Online Essay Help is the right place to get it. f i b (f i b i n d e x (n)) == n Exercise 7 Dec 02, 2015 · In spark, groupBy is a transformation operation. In the above code where we choose the last element as a pivot, it may lead to the worst case of quick sort. 2 days ago · For example, f(a, b, c) is a function call with three arguments, while f((a, b, c)) is a function call with a 3-tuple as the sole argument. In this section we will guide on how to go ahead with the wireframe sketching. It's your responsibility to handle this event. msgflags - 0, or one of: RD_KAFKA_MSG_F_COPY - librdkafka will immediately make a copy of the payload. Now if you wish to capture the behavior of system you should use screen shots which will complement the use-case alread available. Java users also need to call special versions of Spark's functions when creating pair RDDs. Apr 09, 2015 · The factorial of a positive integer n is defined as the product of the sequence n, n-1, n-2, …1. . Source code in Mkyong. key: Optional. push(value[key]); } }); return allValues. , can only refer to the columns derived by the FROM clause. Aug 19, 2015 · Mkyong. //C code for random pivot partition function. Contributing Functions. Write a recursive function fib_indexfib (), which returns the index of a number in the Fibonacci sequence, if the number is an element of this sequence, and returns -1 if the number is not contained in it, i. We store every partition in an array p[]. Java program… Continue reading HyperSQL supports a wide range of built-in functions and allows user-defined functions written in SQL and Java languages. AUTO_PARTITION_SEQ string option (available as of Phoenix 4. Once you have created your function in Oracle, you might find that you need to remove it from the database. Hackerrank. For Example , in the above scenario the user id field can have a maximum of 10 characters, so entering data > 10 should behave the same way. txt: package net. Numbering functions are a subset of analytic functions. Martin Mystery (2003-2006) is a French/Canadian animated series based on the Italian comic book Martin Mystere, animated by the studio that brought you Totally Spies!. The following code snippet is an example of the source data schema in JSON format: Sep 12, 2020 · Partitions data into num_partitions tensors using indices from partitions. It also shows a sample application, a Java Servlet, which runs as a Java EE application using Oracle Business Rules (this describes using Oracle Business Rules without a SOA composite). Let's look at an example of how to drop a function in Oracle. 2. All the hash partitions hold an equal number of rows. Records sequence is maintained at the partition level. 4. Sequence but it has some issues and it is there with Sequence(Date, int, int) signature. Version 1: Rightmost element as pivot. A paper and pencil version of the game dates back to World War I, but most people are familiar with the game through the plastic board game that was first marketed by the Milton Bradley Company in 1967. Custom functions perform like Drill primitive operations. Until it isn't. A sequence diagram is a form of interaction diagram which shows objects as lifelines running down the page, with their interactions over time represented as messages drawn as arrows from the source lifeline to the target lifeline. To contribute a Java function that you have written, do the following: Check the existing javadoc to make sure that the function does not already exist as described in Accessing Functions. For instance, [0, 4, 6, 9, 11, 15] or [0, 4, 6, 9, 13, 15] are other increasing subsequences of equal length in the same input sequence. codejava. If you had a products table with the following data: Feb 21, 2007 · Thus, if i understand your question (and mine!) you should have already created the use-case (lets assume you had). Aggregate Functions. mapPartition {in => in map {(_, 1)}} Filter We can say that recursion is "defining a problem in terms of itself" as it involves a function calling itself with a base case to terminate the infinite loop. Using the command, we can set permissions (read, write, execute) on Jul 28, 2019 · 5. The types of the first two, ByteBuffer and ShortBuffer, are new to the java. Apr 09, 2020 · 1. push(value[key]); }else{ misMatches. Solutions of more than 380 problems of Hackerrank across several domains. There is already an algorithm that breaks the video up into shots and labels them. 1. Oct 09, 2013 · The SQL:2003 standard ranking functions are awesome companions and useful tools every now and then. Similarly, a partition defined using FROM ('a', MINVALUE) TO ('b', MINVALUE) allows any rows where the first partition key column starts with "a". append f = fs . The worst pivot creates an empty partition (for example, if the pivot is the first or last element of a sorted array). The idea is this: instead of an infinite sequence (for example: \(2, 3, 5, 8, 12, \ldots\)) we look at a single function which encodes the sequence. This section of the article will include the following functions: MIN() MAX() COUNT() SUM() AVG() MIN() Function. Note that the SUM() function ignores NULL values. Each shot is labeled with a letter. Fork and This class is very simple: Java users can construct a new tuple by writing new Tuple2(elem1, elem2) and can then access its elements with the . Since this is a more complicated function to understand, let's look at an example that includes data to demonstrate what the function outputs. Using the the COND and the REDUCE operator the factorial function can be implemented as shown below. * * @param <T> the type of the input elements * @param <K> the output type of the key mapping function * @param <U> the output type of the value mapping function * @param <M> the type of the resulting {@code Map} * @param keyMapper a mapping function to produce keys * @param CREATE STREAM raw_quotes(ticker varchar key, bid int, ask int, bidqty int, askqty int) WITH (kafka_topic='stockquotes', value_format='avro', partitions=1); CREATE STREAM vwap WITH (kafka_topic = 'vwap', partitions = 1) AS SELECT ticker, vwap(bid, bidqty, ask, askqty) AS vwap FROM raw_quotes; Jan 31, 2009 · The Kronecker delta function δ(x, y) = 1 if x = y and 0 otherwise. Start with detailed screen sketches to render clarity to the requirements. Quick-sort partitions an input sequence based on a pivot value that is computed from the values in the sequence. In this blog, I shall explain how to write a custom RFC function module to carry out the Pricing using the standard function module PRICING. which for keyboard key input. Example Oct 08, 2020 · Defining a periodic sequence and failing to reference it via the SEQUENCE_NUMBER() function will also result in the error: java. 2D Brownian motion. Note that a scalar subquery and scalar function always returns a single value. map, Sequence. Dec 02, 2020 · If this is set to RD_KAFKA_PARTITION_UA (UnAssigned) then the configured partitioner function will be used to select a target partition. User-defined functions are covered in the SQL-Invoked Routines chapter. Topic: Producer writes a record on a topic and the consumer listens to it. Join the global Raspberry Pi community. The book "Java for Kids" was written by Yakov Fain, Java Champion. Math Solver. Note: If function group is not already made, you could create it from Goto > Function group > Create Group from the initial screen of SE37. Oct 08, 2017 · By default you read data to a single partition which usually doesn't fully utilize your SQL database. database to assign putative functions to each sequence. However, the API won't let you forget one thing: its first and foremost concern is parallelization. Here is the initial GUI, its plot, and its data table: Why use sequence diagrams? Why not code it? 17 • A good sequence diagram is still above the level of the real code (not all code is drawn on diagram) • Sequence diagrams are language-agnostic (can be implemented in many different languages) • Non-coders can read and write sequence diagrams. csv 1,2,3,4,5,6 7,8,9,10,11,12. Assume that the partition function runs in O(n) time for an n-element vector/vector-segment. Below, we have a pictorial representation of how quick sort will sort the given array. Let's consider an array with values {9, 7, 5, 11, 12, 2, 14, 3, 10, 6}. Jan 09, 2021 · If execution of a function invoked as part of the algorithm throws an exception and ExecutionPolicy is one of the standard policies, std::terminate is called. A = magic (4); fileID = fopen ( 'myfile. Default is False Write an array of data, A, to a file and get the number of bytes that fprintf writes. Link to code. Similarly, if one condition in a partition doesn't work, then none of the others will work. Analytic functions not only operate The ALL clause causes the SUM() function to calculate the sum of all values, including duplicates. The first field listed is the partition key, since its hashed value is used to determine the node to store the data. Nov 11, 2016 · Write a recursive program Quick. The next element is 1. You can partition the CUST table by using hash, where a hash function is applied to the partition key of each row and, based on the output, the row is placed in an appropriate partition. Nov 08, 2011 · Enter the function group and short text. Example: max() Let's look at another example from the Java library: the integer max() function, found in the Math class. At runtime, based on a pseudo-RNG, the actual implementation is choosen. java that represents a particle undergoing a Brownian motion in two dimensions. With this function, you don't need to divide the dataset manually. There are k painters available and each takes 1 unit time to paint 1 unit of board. Scholarships Question: Can Use Java Or C++ Or Almost Any Programming Language. 8) when set on a base table determines the sequence used to automatically generate a WHERE clause with the first PK column and the unique identifier from the sequence for child views. net Java - Methods - A Java method is a collection of statements that are grouped together to perform an operation. Buckets (or Clusters): Data in each partition may in turn be divided into Buckets based on the value of a hash function of some column of the Table. This article explains the usage of these two functions in conjunction to retrieve partitioned data in very specific ways. For completeness we'll include a partition function at the end of this document. There is an extremely powerful tool in discrete mathematics used to manipulate sequences called the generating function. To do this, simulate two indepedent Brownian motions X(t) and Y(t), and plot (X(t), Y(t)). getPartition(key: Any): Int, which returns the partition ID ranging from (0 to numPartitions-1) for a given key. See full list on ryanstutorials. Proposition. java is an implementation of this method. Checkout the UDF code as described in Accessing Functions. However, as the output cannot have the file name, mapping is required for a better results. util. Custom functions are reusable SQL functions that you develop in Java to encapsulate code that processes column values during a query. partition = function (collection, test){ var allValues = []; var matches = []; var misMatches = []; _. Apr 10, 2020 · Streams can be defined as a sequence of elements from a source that supports aggregate operations on them. The PARTITION BY and ORDER BY conditions of all SQL analytic queries is applied to split the data into accumulations and within each group. If we Transforms a parallel partition in a single function call. To write a Spark application in Java, you need to add a dependency on Spark. Nov 29, 2017 · They also illustrate the action-response sequence. Scala Functions. The sequence to sort, list, dictionary, tuple etc. It must return a string: YES if the sequence is balanced or NO if it is not. 46 and later. Color You can load the menu examples or you can type a function into the expression box. All Functions have two different implementations. A function can be used to check out a current condition in the world and make a decision about whether (or not) a method is called. Conjugate partitions are used in many bijective proofs of results about partitions; here is one basic example. main . For Example: - Consumers are responsible for storing their own offset values outside of the Event Hubs service. com See full list on alvinalexander. Also, if you click Empty Table you will be presented with a blank table where you can open a csv file for plotting and analysis. Merge-sort partitions the input sequence based on its length, which is assumed to be a power of two, since a binary tree is employed. The Auto Sequence would increment from one line to the next based on the Tags (LNG, LTB, LFLRTB, RNG). AlignIO , a new multiple sequence Alignment Input/Output interface for BioPython 1. For example, multiplication and division have a higher precedence than addition and subtraction. That's because the increment […] Mar 07, 2019 · Spark provides built-in support to read from and write DataFrame to Avro file using "spark-avro" library. Rename these partitions to "Shipping", "Online Sales", and "Accounting" as seen in the following picture. Oct 04, 2019 · The ordering is first based on the partition index and then the ordering of items within each partition. Dec 14, 2020 · Activity partition/swimlane. A sketch is basic in nature, making explicit what the user will see on each screen. Popular algorithms for creating multiple sequence alignment include ClustalW (Thompson et al. Jul 13, 2016 · Partition function for random element as pivot. Input: The input to the function/method consists of an argument - inputList, a list of characters representing the sequence of shots. subds = partition (ds,n,1); Read the data in subds. Exercises. Imagine I have a series of events that all land in the same Event Hub partition. Use blocks to structure steps. We will start by looking at the most traditional method with the least help from external Java classes. Please Note: – Feb 12, 2020 · We can write generic logic which can be used to find the kth smallest element as well. Let's talk about this run function a little more. Then select Add UML -> Activity Partition. Write a data type BrownianParticle. data. The sequence to be operated on by a sequence-function call is specified by a regclass argument, which is just the OID of the sequence in the pg_class system catalog. Instead of variables like X and Y appearing, I use functions over the whole image such as HGradient(). A Function to execute to decide the order. Partition-Even-Odd must be an in-place algo- Welcome to the world of Java examples, organized by categories and Java packages. If you want to make sure the consumer processes every message at least once, you need to write your own code with retry logic. Oct 20, 2020 · The OVER and PARTITION BY functions are both functions used to portion some particular results set according to specified criteria. filter(collection. You can also use the SQL CALL statement to call such a method or routine. CREATE FUNCTION f(p <ref cursor type>) RETURN rec_tab_type PIPELINED PARALLEL_ENABLE(PARTITION p BY [{HASH | RANGE} (<column list>) | ANY ]) IS BEGIN END; The PARTITION…BY phrase in the PARALLEL_ENABLE clause specifies which one of the input cursors to partition and what columns to use for partitioning. A Boolean. _1() and . It is possible to write all data in one shot. You can find me on hackerrank here. If no partitions are specified, it is considered the entire sequence set is one huge partition. charCode. The screen design sketch illustrates the chain of sequence. The test You can specify one or more columns or expressions to partition the result set. Recursion is important concept in computer science and very powerful tool in writing algorithms. In order to aid researchers in the further analysis of the annotated sequences, a A window function computes a value for each row in the window. If you do need to have the function on the column in the WHERE clause, consider creating a function-based index on the column. An}. When it is enabled, Ignite always stores all the data on disk, and loads as much data as it can into RAM for processing. 0 and may be removed in Spark 2. Let's have some overview first then we'll understand this operation by some examples in Scala, Java and Python languages. Writing functions General syntax. In every iteration. Over the years, a lot of people have criticised the SQL language for a variety of reasons. , 2002), muscle (Edgar, 2004) and many others. If you are using Java 8, Spark supports lambda expressions for concisely writing functions, otherwise you can use the classes in the org. Close the file. Included in Oracle 7. We initialize p[] as n where n is the input number. Finally, BLAST2GO was run on these BLAST results in order to assign a GO (Gene Ontology) to each sequence. A sequence (an) can be viewed as a function f from Python String isdigit() The isdigit() method returns True if all characters in a string are digits. Optional Function Scope − You can use keyword local to limit the scope of the function or ignore the scope section, which will make it a global function. partitioningBy is a method that partitions the element of stream always in two part. I've just tried a coding challenge to write a function that returns the length of the shortest possible left partition of an array of numbers, all of whose elements are less than all of the elements in the corresponding right partition. Pre-alpha versions of Tkhtml Hv3 do not correctly interpret the Function class constructor. I solved it by shuffling the input before handling it, and it passed. Write a Java program that keeps a number from the user and generates an integer between 1 and 7 and displays the name of the weekday. java, Week3. Only submit a zip not a rar file. we first print p[] and then update p[] to store the next partition. Definitely, for more advanced formatting we can use DateTimeFormatter which has been available since Java 8. For example String[] declares a sequence of Strings. Data must be treated precisely and in a proper form. Simulate diffusion of particles in a fluid. You can define the logic on which basis partition will be determined. The number of elements in each partition depends on the degree-of-parallelism and previous operations. e. Along with this declare and define another function to find reverse of number, say int reverse(int num);. For aggregate functions, users can use any existing aggregate function as a window function. Conversion of an optical image to a video signal in the vidicon tube was originally accomplished by scanning the stored image with an electron beam. Screen shot near the end of the program named turn02. keyCode and event. Google Drive & Google Docs represent the other side – they can't be used for capturing or editing screenshots and images but are helpful in writing, storing, and sharing your user instruction manuals. Any help is thankful. A Transformation is a function that produces new RDD from the existing RDDs but when we want to work with the actual dataset, at that point Action is performed. Image Transcriptionclose. filter etc, generally preserve that property of a sequence, and again it's documented for an operation if it doesn't. Write a program Checkerboard. This method needs to trigger a spark job when this RDD contains more than one partitions. Dec 31, 2019 · Rather than being a function, range is actually an immutable sequence type. You should preserve the original relative order of the nodes in each of the two partitions. You will have a total of three partitions. All published articles are simple and easy to understand and well tested in our development environment. Complete the function isBalanced in the editor below. write - The Write permissions refer to a user's capability to write or modify a file or directory. Java Writing to Text File Example In the following example, a FileWriter is used to write two words "Hello World" and "Good Bye!" to a file named MyFile. Sequence number is assigned by Amazon Kinesis Data Streams when a data producer calls PutRecord or PutRecords API to add data to an Amazon Kinesis data stream. inline fun CharArray. io; import java. The output will contain results from lower bound i. Sequences are immutable, just like arrays. This problem has been solved! See To guarantee strictly increasing sequence numbers for the same partition key, use the SequenceNumberForOrdering parameter, as shown in the PutRecord Example code sample. Write a SQL query to get the third highest salary of an employee from employee_table? SELECT TOP 1 salary FROM( SELECT TOP 3 salary FROM employee_table ORDER BY salary DESC) AS emp ORDER BY salary ASC; Q33. e 10, but excluding 10. Including the partition clause divides the query result set into partitions, and the window function is applied to each partition separately. user> (defn count-down [result n] (if (= n 0) result (recur (conj result n) (dec n)))) # 'user/count-down user> (count-down [] 5) [5 4 3 2 1] Here is another example of the use of recur. Internships. The output should be the length of each subsequence. Here are some screen shots using the Gauss modified mixed sin example. Otherwise, return NO. Jan 14, 2016 · Few people remain who can testify as to what life was like inside a Nazi death camp, but something about "Son of Saul" — a Holocaust movie unlike any other — feels intuitively true. Spark RDD Operations. The best pivot creates partitions of equal length (or lengths differing by 1). 3. namedtuple() may be a more appropriate choice The pattern matching syntax adds various alternatives. Figure 23. Identify the intervals where different rules apply. Develop an efficient in-place algorithm called Partition-Even-Odd(A) that parti-tions an array A in even and odd numbers. mat' ); Get the default number of partitions for ds. Codes are used in a unique way within J-Field. spark. For example, for input A = h7,17,74,21,7,9,26,10i, the result might be A = h74,10,26,17,7,21,9,7i. Join the first sorted partition, the pivot, and the second sorted partition. You can store function value, pass function as an argument and return function as a value from other function. Jul 15, 2015 · Spark SQL supports three kinds of window functions: ranking functions, analytic functions, and aggregate functions. In addition to the built in API documentation, there is a whole chapter in the Tutorial on Bio. The algorithm must terminate with A containing all its even elements preceding all its odd elements. e 0 to the upper bound i. FILE_TYPE; BEGIN How To: Given a piecewise function, write the formula and identify the domain for each interval. Java has a special class to address these operations. If it tried again to partition this group to 2 groups of 4 it will fail clearly. java and Week5. For partitioned entities, the topmost 16 bits reflect the partition identifier. The directory you intend writing to has to be in your INIT. recur re-binds it's arguments to new values and call the function with the new values. These create 3D texture effects. 5. FileWriter; import java. A call specification declares a Java method or a third-generation language (3GL) routine so that it can be called from PL/SQL. (Among other things this means that you must be using Java version 1. Sep 14, 2019 · An equivalence relation partitions the objects into equivalence classes or connected components. 3D. append for item in it : ( t if pred ( item ) else f )( item ) return fs , ts Write a function to return the minimum number of jumps you must take in order to get from the start to the end of the array. BSc IT CS PROJECT DOCUMENTATION information technology students, MCA PROJECTS, BCA PROJECTS, MSc computer science PROJECTS, B Tech bachelor of technology in CS and M Tech students. It would then take a shot right at the end of the countdown and go back to "long" and repeat itself until the "N" (which is counting down from 12, runs down to zero). Drop Function. What is the need for group functions in SQL? Group functions work on the set of rows and returns one result per group. Once you have completed all of the programs and you are ready to submit, compress all source files into a single zip file for submission, do not include your report in the zip file. Hint: model your program after Average. A squarefree number is one which is not evenly divisible by a square number (i. Possible implementation The LISTAGG function can be used in Oracle/PLSQL. The Random class includes the following constructor and methods: Nov 25, 2019 · train_test_split is a function in Sklearn model selection for splitting data arrays into two subsets: for training data and for testing data. For example, a partition defined using FROM (0, MAXVALUE) TO (10, MAXVALUE) allows any rows where the first partition key column is greater than 0 and less than or equal to 10. In scala, functions are first class values. For a description of how numbering functions work, see the Numbering Function Concepts. g. For instance: IDEs cannot easily guess what auto completion options to offer, because as long as you don't specify the FROM clause, there are no tables in scope (yet):… dense_rank() - Computes the rank of a value in a group of values. Nov 13, 2020 · Level 1: In this level, you will write the basic cases from the available specification and user documentation. First give a meaningful name to our function, say isPalindrome(). The available ranking functions and analytic functions are summarized in the table below. TECH IT BSC COMPUTER SCIENCE PROJECT ON COLLEGE MANAGEMENT SYSTEM FOR BCA MCA IN ASP. If the algorithm fails to allocate memory, std::bad_alloc is thrown. It returns a Collector that stores the values in a Map. It is recommended to watch event. In addition, there is no need for additional memory Jan 16, 2020 · Scala List FAQ: Can you share some Scala List class examples?. For instance, the mapToPair() function should be used in place of the basic map Required. Write what you mean, not how to program it. Computation restarts for each partition. push(matches, misMatches); } Dec 14, 2020 · A Parting Shot Here it is with all the mypy --strict typing goodness added: from typing import List , Any , Callable , Iterable , TypeVar , Tuple T = TypeVar ( 'T' ) def partition ( pred : Callable [[ T ], bool ], it : Iterable [ T ]) \ -> Tuple [ List [ T ], List [ T ]]: ts : List [ T ] = [] fs : List [ T ] = [] t = ts . Show that the number p (n, k) p(n,k) p (n, k) of partitions of a positive integer n n n into exactly k k k parts equals the number of partitions of n n n whose largest part equals k k k. Figure 23 shows a screen shot of the airplane as it coming out of its last roll moving in a clockwise direction, getting ready to level out and fly over the camera. Sequence numbers monotonically increase and are gapless. Feb 11, 2016 · In most video systems, the output from the scan lines is formatted serially, or in sequence, as a single linear signal rather than as many parallel signals. Sequence Files. Initially, the function is called with the first two items from the sequence and the result is returned. Do Jan 08, 2021 · Clojure defines many algorithms in terms of sequences (seqs). These functions can then be called when needed, and the code contained within them will be run. This process keeps repeating until there are items in the sequence. /***** * Compilation: javac Partition * Execution: java Partition N * * Print out all partitions of a positive integer N. Johnson 85 83 77 91 76 Once that program is done, need to write a program that reads from a file named 'random. Furthermore, the factorial of 0 is defined as being 1. We'll define a method findKthElementByQuickSelect() which will return the k th element in the sorted array. java that takes a command-line argument n and plots an n-by-n checkerboard with red and black squares. Nov 25, 2020 · Next, in this article on SQL Commands, let us look into the various Aggregate Functions provided in SQL. execute - The Execute permission affects a user's capability to execute a file or view the contents of a directory. A partition of N is a way to write N as a sum of positive integers. The result is \(n\log n\). Shiny app with sequence of pages. IOException; /** * This program demonstrates how to write characters to a text file. 0. Jun 19, 2008 · What happens in your solution (or our) if the function first took {1, 1, 2} and deleted them, then what remains is {2, 3, 3}. This chapter describes how to use Oracle JDeveloper to create a rule-enabled non-SOA Java Enterprise Edition (EE) application. however, i am not sure. If not, it returns False. It is important the file names are correct. fclose (fileID); Section 5. Nov 13, 2020 · Data in each partition must behave in the same way, therefore only one condition needs to be tested. For example, in a program, there may be a need for a file read or write action. Which control structure most likely uses the information returned from the function to evaluate whether (or not) to call a method? If/Else Loop Do in order Do together Jan 05, 2021 · Sequence diagrams, commonly used by developers, model the interactions between objects in a single use case. The series revolves around typical teens Martin Mystery, his step-sister Diana Lombard and their pal Java the Caveman, as they're sent on various missions by a secret organization known as "The Center" to investigate paranormal Jul 06, 2020 · The writerow () method writes a row of data into the specified file. I can't remember a single for-loop that I had to write with Java 8 (well, except within a Spliterator — more on that later). The SQL MAX Function is an Aggregate Function that finds the Maximum value from the total rows or records selected by the SELECT Statement. in the same way as a normal script. Nov 09, 2018 · Within the tMap on any column or variable you can open the expression builder wizard where you get access to hundreds of Talend functions, and if you can't find a Talend function that meets your needs then you can fall back on a native Java function (don't fear, if you don't know Java just Google it). Whether or not you use SequenceNumberForOrdering , records that Kinesis Data Streams receives through a GetRecords call are strictly ordered by sequence number. Dec 23, 2020 · Each shot is labeled with a letter. Write a program for Bubble Sort in java. As an exercise, write a function that returns the nth Fibonacci number using recursion. A seq is a logical list, and unlike most Lisps where the list is represented by a concrete, 2-slot structure, Clojure uses the ISeq interface to allow many data structures to provide access to their elements as sequences. Syntax . For example, Given 1->4->3->2->5->2 and x = 3, return 1->2->2->4->3->5. It provides rich set of built-in functions and allows you to create user defined functions also. fold("start",(str,i)=>{str+"-"+i}) Aggregations on windows. o Ass1. Partition is helpful when the table has one or more Partition keys. It creates two empty arrays to hold elements less than the pivot value and elements more significant than the pivot value, and then recursively sort the sub-arrays. The function name and the parameter list together constitute the function signature. Quick3wayBars. To analyze the quickSort function, note that for a list of length n, if the partition always occurs in the middle of the list, there will again be \(\log n\) divisions. Apr 13, 2019 · Week1. Dec 09, 2016 · The SQL language is very intuitive. NET JAVA AND PHP WITH SOURCE CODE. Oct 17, 2020 · We have to paint n boards of length {A1, A2, . Therefore, it's very helpful to know how create lists, merge lists, select items from lists, operate on each element in a list, and so on. The {@code Map} * is created by a provided supplier function. Ignite Persistence, or Native Persistence, is a set of features designed to provide persistent storage. int partition(int arr[], int left, int right) { int i = left, j = right; int tmp; By writing three separate functions with the same name, the programmer has the convenience of not having to remember different names for each type of data. Oracle SUM() function Declare recursive function to check palindrome. The syntax of the reduce() function is as follows: UML 2 Tutorial - Sequence Diagram Sequence Diagrams. OVER clause requirements: PARTITION BY ROW_NUMBER() OVER(PARTITION BY Emp_ID ORDER BY Emp_ID) RANK() OVER(PARTITION BY Emp_ID ORDER BY Emp_ID). This functional implementation of the factorial function nicely resembles the definition. 1 Generating Functions. Google Drive & Google Docs. java. println() method, for example, the s The function shall not modify its argument. B. Listing 13 also shows the declaration of three instance variables. IGNOU Projects, SMU Projects. This post shows how you can write a Java program to convert numbers to words. DECLARE fileHandler UTL_FILE. A range is any sequence of objects that can be accessed through iterators or pointers, such as an array or an instance of some of the STL containers. This program will write, read time in, from the file using fstream, fstream is the set of classes with member function, that are used to communicate (read, write and more) with the files. , 2000), POA (Lee et al. . d) Create another partition. Automated the process of adding solutions using Hackerrank Solution Crawler. In brief, each table requires a unique primary key. Next, partition the array into a left subarray containing all elements less than v, followed by a middle subarray Increment (++) and decrement (—) operators in Java programming let you easily add 1 to, or subtract 1 from, a variable. com is providing Java and Spring tutorials and code snippets since 2008. For any other ExecutionPolicy, the behavior is implementation-defined. For example the page_views table may be bucketed by userid, which is one of the columns, other Sep 29, 2020 · Saving the CSV Files: Writing to CSV/TSV files are also quite easy. Stream keeps the order of the data as it is in the source. Aggregates the contents of a window. This app demonstrates how to write a Shiny app that has a sequence of different pages, where the user can navigate to the next/previous page. The MIN function returns the smallest value of the selected column in a table. Before Oracle 7. Nov 23, 2012 · This post shows two versions of the Java implementation. So the first item in the first partition gets index 0, and the last item in the last partition receives the largest index. write a function which will partition a sequence of shots java
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redpajama_set_name: RedPajamaCommonCrawl


text:
Bequaertinia leontovitchi es un coleóptero de la familia Chrysomelidae.

Fue descrita científicamente por primera vez en 1940 por Laboissiere.

Referencias

leontovitchi

redpajama_set_name: RedPajamaWikipedia


text:
Diese Seite auf Deutsch
Alexander Alexandrovich Alekhine
* 31 October 1892 Moscow † 24 March 1946 Estoril, Portugal
Buried in Montparnasse Cemetery, Paris (Lev Polugaevsky was buried here as well).
The grave was heavily damaged by a severe storm on 26/12/1999 and has been restored later on.
Photograph by Michael Negele (in November 1990):
We received the following photographs and detailed information from our French member Alain Biénabe (Bordeaux).
Photos © Denis Teyssou (2004/7).
Alekhine was buried in Lisbon on April 16, 1946.
In 1956, his ashes were transferred to the Montparnasse Cemetery in Paris (Section 8).
This tomb was erected on March 25, 1956 by FIDE President Folke Rogard (Sweden), Vyacheslav Ragosin (USSR), Marcel Berman Vice President (France), World Champion Mikhail Botvinnik (USSR), Gian Carlo dal Verme (Italy) and Pierre Dierman (Belgium).
His tomb, where his name is engraved in Cyrillic and Roman, shows a chessboard:
The inscription reads (translated):
Alexander Alekhine
Chess genius of Russia and France
1st November 1892 - 25 March 1946
World chess champion from 1927 to 1935 and from 1937 to his death
Grace Alekhine née Wishar (1876-1956)
The tomb is surmounted by a bas-relief of Alekhine at chess (sculpture by A. Baratz):
Destroyed in 1999/12 (after a storm and a tree falling on the grave), it was rebuilt exactly and with the same materials.
It was completed in early 2003, with support and funding of the Cultural Service of the Russian Embassy (they paid the bill on their own: more than 20 000 euros).
Our Italian member Santo Daniele Spina has sent us his article La tomba di Alekhine, published in L'Italia Scacchistica no. 1205, December 2008, p. 489:
Photograph by Arcangelo Blandini in Archivio Aldo Clementi.
A PDF of the article with two additional pictures:
Una foto originale della tomba di Alekhine
en.wikipedia.org/wiki/File:Alekhine_tombe.jpg
commons.wikimedia.org/wiki/File:Detail_of_grave_of_Alexander_Alekhine..._
www.findagrave.com/cgi-bin/fg.cgi?page=pv&GRid=7312


text:
A Second Look at Susquehanna Sediment
December 6th, 2019 by Adam Voiland
A MODIS image of the mid-Atlantic on November 6, 2019. Credit: NASA Earth Observatory
In November 2019, we highlighted this Landsat 8 image showing a glut of sediment flowing down the Susquehanna River into Chesapeake Bay. It was a striking, timely image, but one of the realities of publishing new content every day is that sometimes good information comes in after a deadline has passed.
In this case, Mark Trice, a water quality expert with the Maryland Department of Natural Resources, pointed out a few things about Susquehanna sediment after our story was out that seem worth passing on.
Mark Trice in his Maryland DNR office. The body of water on the map behind his left shoulder is Chesapeake Bay and the Atlantic Ocean. Image courtesy of Mark Trice.
Among them: a link to a recent report that synthesizes and summarizes what scientists have learned about the ecological effects of high sediment flows on the Susquehanna River and the role of the Conowingo Dam. While the dam trapped most sediment and associated nutrient pollution (nitrogen and phosphorus) when it was first built, enough material has piled up behind the dam now that significant amounts of sediment and nutrients now flow past it during storms. A University of Maryland press release summarized the findings this way:
Most sediment and particulate nutrient impacts to the Bay occur during high-flow events, such as during major storms, which occur less than 10 percent of the time. Loads delivered to the upper Chesapeake Bay during low flows have decreased since the late 1970s, while loads during large storm events have increased. Most of these materials are retained within the upper Bay but some can be transported to the mid-Bay during major storm events, where their nutrients could become bioavailable.
The potential impact of reservoir sediments to Bay water quality are limited due to the low reactivity of scoured material, which decreases the impact of total nutrient loading even in extreme storms. Most of this material would deposit in the low salinity waters of the upper Bay, where rates of nitrogen and phosphorus release from sediments into the water are low.
"While storm events can have major short-term impacts, the Bay is actually really resilient, which is remarkable," said the study's lead author Cindy Palinkas, associate professor at the University of Maryland Center for Environmental Science. "If we are doing all of the right things, it can handle the occasional big input of sediment."
Trice's colleagues at the Maryland Department of Natural Resources (DNR) underscored the Bay's resiliency to sediment as well when I asked about the recent event. "Although these high flow events routinely occur, the Bay is resilient and continues to show improvement due to the commitment by the Bay watershed partners to have all pollution reduction strategies implemented by 2025 to have a healthy Chesapeake Bay," said Bruce Michael of Maryland DNR.
Also worth mentioning: the 2019 water year (October 1, 2018, to September 30, 2019) brought a record-breaking flow of freshwater into the Bay, Trice noted. "The annual average freshwater flow into the Chesapeake Bay during water year 2019 was 130,750 cubic feet per second, which is the highest annual amount since 1937, the first year for which data are available," the U.S Geological Survey said.
Chart credit: U.S. Geological Survey
Finally, thank you to Virginia Tech geology professor Brian Romans (@clasticdetritus) for pointing out something about the image that is unrelated to sediment but fascinating: the line of cities and suburbs running from Baltimore, Md., to Richmond, Va., marks the boundary between two key geologic zones: the flat Coastal Plain to the east and the more rugged Piedmont to the west. Interestingly, many cities are located along this "fall line" because rapids prevented boats from traveling any farther upstream when they were first settled.
Satellites Probe Droppings for Clues About Penguin Populations
December 12th, 2018 by Adam Voiland
NASA Earth Observatory map by Joshua Stevens, using Landsat data from the U.S. Geological Survey and calculations from Lynch, H. J., & Schwaller, M. R.
Last year, we published a story explaining how scientists had used satellite images of rocks stained pink with guano to discover several unexpectedly large colonies of Adélie penguins on the Danger Islands. Now the researchers are back with a new announcement: Using Landsat data, they have analyzed how the size of that penguin population has changed since 1982. They also used Landsat's deep archive of satellite imagery to analyze what the penguins eat and whether their diets have changed over the past three decades.
"While the Adélie population [on the Danger Islands] is massive, it was even larger in the past," said Heather Lynch of Stony Brook University. "We believe the population peaked in the late 1990s and has been on a slow steady decline ever since." The scientists are still working out what may have caused the 10 to 15 percent decline in the population, but they think it is probably related to changing environmental conditions.
NASA Earth Observatory images by Joshua Stevens, using Landsat data from the U.S. Geological Survey and calculations from Lynch, H. J., & Schwaller, M. R. (2014).
Adélie penguins are particularly sensitive to changes in climate because they require ice-free land areas to breed and access to open water. They also need enough sea ice to support populations of key food sources. The researchers thought that changing diets would accompany the decline in population, but by analyzing the spectral signatures of all the guano stains found in cloud-free Landsat image of the islands since 1982, they were surprised to discover the penguins' diets have stayed the same.
Penguin guano ranges from white to pink to dark red. White guano is from eating mostly fish; pink and red is from mostly eating krill. The University of Connecticut's Casey Youngflesh, however, noticed some intriguing regional patterns in what Adélie penguins eat. Colonies in West Antarctica tend to eat more krill, while colonies in East Antarctic consume more fish. The reasons for the difference are not clear, though Youngflesh is looking into the possibility that differences in the Antarctic silverfish population may be a factor.
Discovering the big colonies on the Danger Islands has also opened up a new pathway for figuring out when penguins first arrived. By digging through layers of guano-stained pebbles during a recent field expedition and dirt and dating them with radiocarbon techniques, Michael Polito of Louisiana State University worked out that penguins must have arrived on the Danger Islands about 2,900 years ago, thousands of years earlier than previous evidence suggested.
Credits: Heather Lynch, Stony Brook University.
Expect to hear even more guano-stained discoveries in the future. "We are only just scratching the surface of what we can do in terms of tracking seabirds from space," said Lynch. "We should be able to extend the technique to snow petrel, boobies, and cormorants."
Lynch put the total number of penguins on the Danger Islands at roughly 1.5 million (individual birds) — more than live on all the rest of the Antarctic Peninsula combined.
Read more about the Danger Island Adélie penguins from NASA and MAPPPD.
What Caused Twin Mega-Avalanches in Tibet?
February 6th, 2018 by Adam Voiland
In July 2016, the lower portion of a valley glacier in the Aru Range of Tibet detached and barreled into a nearby valley, killing nine people and hundreds of animals. The huge avalanche, one of the largest scientists had ever seen, sent a tongue of debris spreading across 9 square kilometers (3 square miles). With debris reaching speeds of 140 kilometers (90 miles) per hour, the avalanche was remarkably fast for its size.
(NASA Earth Observatory image by Joshua Stevens, using modified Copernicus Sentinel 2 data processed by the European Space Agency. Image collected on July 21, 2016.)
Researchers were initially baffled about how it had happened. The glacier was on a nearly flat slope that was too shallow to cause avalanches, especially fast-moving ones. What's more, the collapse happened at an elevation where permafrost was widespread; it should have securely anchored the glacier to the surface.
Two months later, it happened again — this time to a glacier just a few kilometers away. One gigantic avalanche was unusual; two in a row was unprecedented. The second collapse raised even more questions. Had an earthquake played a role in triggering them? Did climate change play a role? Should we expect more of these mega-avalanches?
(NASA Earth Observatory image by Joshua Stevens and Jesse Allen, using ASTER data from NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. Image collected on October 4, 2016.)
Now scientists have answers about how these unusual avalanches happened. There were four factors that came together and triggered the collapses, an international team of researchers reported in Nature Geoscience. The scientists analyzed many types of satellite, meteorological, and seismic data to reach their conclusions. They also sent teams of researchers to investigate the avalanches in the field.
First, increasing snowfall since the mid-1990s caused snow to pile up and start working its way toward the front edge of the glaciers (a process known as surging). Second, a great deal of rain fell in the summer of 2016. As a result, water worked its way through crevasses on the surface and lubricated the undersides of the glaciers. Third, water pooled up underneath the glaciers, even as the edges remained frozen to the ground. Fourth, the glaciers sat on a fine-grained layer of siltstone and clay that became extremely slippery.
Notice the large amounts of silt and clay in the path of the first avalanche. (Photo taken on July 15, 2017, by Adrien Gilbert/University of Oslo)
Earth Observatory checked in with Andreas Kääb (University of Oslo), lead author of the study, to find out more about how the avalanche happened and what it means.
These glaciers were not on a steep slope, but the avalanche moved quite quickly. How did that happen?
Strong resistance by the frozen margins and tongues of the glaciers allowed the pressure to build instead of enabling them to adjust. The glaciers were loading up more and more pressure until the frozen margins suddenly failed. Local people reported a load bang. Once the margins failed, there was nothing at the glacier bed to hold it back, just water-soaked clay.
Your study notes that there was "undestroyed grassy vegetation on the lee side of the hills, suggesting that the fast-moving mass had partially jumped over it." Are you saying the avalanche was airborne? If so, is that unusual?
Yes, for a small part of the avalanche path. We see this for other large-volume, high-speed avalanches, and it really illustrates the massive amount of energy released. You need quite high speeds in order for debris to jump. For us, the phenomenon is important as validation for the speeds obtained from the seismic signals the avalanches triggered and the avalanche modeling that we did.
Would you say these collapses were a product of climate change?
Climate change was necessary, but other factors that had nothing to do with climate were also critical. The increasing mass of the glaciers since the 1990s and the heavy rains and meltwater in 2016 are connected to climate change. The type of bedrock and the way the edges were frozen to the ground had nothing to do with climate change.
Can we expect to see more big glacial collapses as the world gets warmer?
It's not clear. Climate change could increase or, maybe even more likely, decrease the probability of such massive collapses. Most glaciers on Earth are actually losing mass (not gaining, like the two glaciers in Tibet were). Also, if permafrost becomes less widespread over time and glacier margins melt, it is less likely that pressure will build up in that way that it did in this case.
I know you used several types of satellite data as part of this analysis. Can you mention a few that yielded particularly useful information?
We used a lot of different sources of data: Sentinel 1 and 2, TerraSAR-X/TanDEM-X, Planet Labs, and DigitalGlobe WorldView. Landsat 8 was absolutely critical because it gave the first and critical indication of the soft-bed characteristics. The entire Landsat series was instrumental for checking the glacier history since the 1980s. We also used declassified Corona data back to the 1960s.
Are these sorts of avalanches likely to happen in other parts of the world?
Honestly, I have no clue at the moment, but we would be much less surprised next time. We know now that this type of collapse can happen under special circumstances. (It happened once before in the Caucasus at Kolka Glacier.) One thing that should be investigated is whether there are other glaciers—especially polythermal ones—with these very fine-grained materials underneath them.
Three dimensional CNES Pléiades image of the avalanches. Processed by Etienne Berthier. Via Twitter.
Research Roundup: Atmospheric Rivers
October 27th, 2017 by Adam Voiland
Atmospheric rivers stretched from Asia to North America in October 2017. Learn more.
If you live on the West Coast of North America, you have probably heard meteorologists talk about "atmospheric rivers" — the narrow, low-level plumes of moisture that often accompany extratropical storms and transport large volumes of water vapor across long distances. When atmospheric rivers encounter land, they can drop tremendous amounts of rain and snow. That can be good for replenishing reservoirs and for quenching droughts, but these remarkable meteorological features can also trigger destructive floods, landslides, and wind storms.
During the past decade, atmospheric rivers have fueled a flood of another type: scientific research papers. Prior to 2004, fewer than 10 studies mentioned atmospheric rivers in any given year; in 2015, about 200 studies were published on the matter. The availability of increasingly sophisticated satellite and aircraft data has fueled the trend, according to a recent article in the Bulletin of the American Meteorological Society. Here's a sampling of what scientists have learned about these rivers in the sky.
They Can Bring Rains, Winds, And Lots of Damage
In a study led by Duane Waliser of NASA's Jet Propulsion Laboratory and published in Nature Geoscience, researchers showed that atmospheric rivers are among the most damaging storm types in the middle latitudes. Of the wettest and windiest storms (those ranked in the top 2 percent), atmospheric rivers were associated with nearly half of them. Waliser and colleagues found that atmospheric rivers were associated with a doubling of wind speed compared to all storm conditions.
They Shift With The Seasons
During the winter, atmospheric rivers in the Pacific generally shift northward and westward, Bryan Mundhenk of Colorado State University and colleagues concluded in a study. They also found that the El Niño/Southern Oscillation (ENSO) cycle can affect the frequency of atmospheric river events and shift where they occur. The research was based on data processed by MERRA, a NASA reanalysis of meteorological data from satellites.
They Aren't Just a West Coast Thing
Atmospheric rivers are a global phenomenon and responsible for about 22 percent of all water runoff. One recent study from a University of Georgia team underscored that the U.S. Southeast sees a steady stream of atmospheric rivers. "They are more common than we thought in the Southeast, and it is important to properly understand their contributions to rainfall given our dependence on agriculture and the hazards excessive rainfall can pose," said Marshall Shepherd of the University of Georgia. Other studies note that atmospheric rivers have contributed to anomalous snow accumulation in East Antarctica and extreme rainfall in the Bay of Bengal.
Climate Change Could Alter Them
A recent study led by Christine Shields of the National Center for Atmospheric Research suggests that climate change could push atmospheric rivers in the Pacific toward the equator and bring more intense rains to southern California. The modeling calls for smaller increases in rain rates in the Pacific Northwest. Another ensemble of models shows a 35 percent increase in the number of days with landfalling atmospheric rivers in western North America.
Satellites Are Key to Studying Their Precipitation
While there are few ground-based weather stations in the open ocean to tally how much rain falls, satellites such as those included in the Global Precipitation Measurement (GPM) mission can estimate precipitation rates from above. "Satellites have proven valuable over both the ocean and land, though uncertainties are often larger over land because of complicating factors like the terrain and the presence of snow on the surface," said Ali Behrangi, the author of a study that assessed the skill of different satellite-derived measurements of precipitation rates.
Salt, Bleach, and Heat for Oceans Day
June 9th, 2017 by Mike Carlowicz
In recognition of World Oceans Day (June 8) and this week's UN Oceans Conference, here are some recent highlights from ocean science…
1.4 Million Pixels of Salt
The Gulf of Mexico, like any sea, is rich in dissolved salts. Unlike most seas, the Gulf also sits atop a big mound of salt. Left behind by an ancient ocean, salt deposits lie beneath the Gulf seafloor and get pressed and squeezed and bulged by the heavy sediments laying on top of them. The result is pock-marked, almost lunar-looking seafloor. The many mounds and depressions came into clearer relief this spring with the release of a new seafloor bathymetry map compiled from oil and gas industry surveys and assembled by the U.S. Bureau of Ocean Energy Management.
3D Water Babies
NASA's Scientific Visualization Studio took a look back at conditions in the Pacific Ocean in 2015-16, which included the arrival and departure of both El Nino and La Nina. The 3D visualizations were derived from NASA's Modern-Era Retrospective Analysis for Research and Applications (MERRA) dataset, a global climate modeling effort that is built from remote sensing data.
In other Nino news, a research team led by NASA Langley scientists found that the strong 2015-2016 El Niño lofted abnormal amounts of cloud ice and water vapor unusually high into the atmosphere, creating conditions similar to what could happen on a larger scale in a warming world.
Not the Kind of Brightening You Want to See
For past few years, warm ocean temperatures in the western Pacific Ocean have wrecked havoc on the Great Barrier Reef. Extreme water temperatures can disrupt the symbiotic partnership between corals and the algae that live inside their tissues. This leads the colorful algae to wash out of the coral, leaving them bright white in what scientists refer to as "bleaching" events. The health of coral reefs is usually monitored by airborne and diver-based surveys, but the European Space Agency recently reported that scientists have been able to use Sentinel 2 data to identify a bleaching event on the Great Barrier Reef. Such satellite monitoring could prove especially useful for monitoring reefs that are more remote and not as well studied as those around Australia.
Eyeing the Fuel for Hurricane Season
On June 1, the beginning of Atlantic Hurricane Season, the National Oceanic and Atmospheric Administration released a map of sea surface temperatures in the Caribbean, the Gulf of Mexico, and the tropical North Atlantic Ocean. The darkest orange areas indicate water temperatures of 26.5°C (80°F) and higher — the temperatures required for the formation and growth of hurricanes. Forecasters are expecting a hurricane season that is a bit more active than average.
(Finger)Prints of Tides
In a new comprehensive analysis published in Geophysical Research Letters, a French-led research team found that global mean sea level is rising 25 percent faster now than it did during the late 20th century. The increase is mostly due to increased melting of the Greenland Ice Sheet. A big part of the study was a reanalysis and recalibration of data acquired by satellites over the past 25 years, which are now better correlated to surface-based measurements. The study found that mean sea level has been increasing by 3 millimeters (0.1 inches) per year. The American Geophysical Union published a popular summary of the study.
What Do Satellites Tell Us About Trees?
June 2nd, 2017 by Pola Lem
Tropical forests, such as those in Gabon, Africa, are an important reservoir of carbon. (Photography courtesy of Sassan Saatchi, NASA/JPL-Caltech.)
Old-growth forests are vital because they capture large amounts of carbon and provide homes to hundreds of species. In the Eastern United States, trees in these minimally disturbed ecosystems tend to be more than 120 years old.
Can satellites help pinpoint this "old-growth" and quantify its value? That was the question Joan Maloof posed to a group of researchers during a talk at NASA Goddard Space Flight Center in May 2017. As head of the Old-Growth Forest Network and a professor at Salisbury University, Maloof aims to identify stands of old-growth forests for conservation. A large part of her job involves explaining why these areas are important—something satellite data can help show.
As it turns out, satellites have already told us much about trees. A 2012 story from NASA Earth Observatory described some of the remote sensing methods researchers use:
Scientists have used a variety of methods to survey the world's forests and their biomass. […] With satellites, they have collected regional and global measurements of the "greenness" of the land surface and assessed the presence or absence of vegetation, while looking for signals to distinguish trees from shrubs from ground cover.
In January 2017, a paper in Science Advances tracked intact forest landscapes between 2000 and 2013. (Intact forest landscapes were defined as areas larger than 500 square kilometers with no signs of human activity in Landsat imagery). This new research underscores the importance of such landscapes. The study's authors identified several key findings:
Dividing up forest landscapes with roads and development can hinder their ability to store carbon
Forest wildlands (forests least affected by human activity) have the highest conservation value
Large forest wildlands store more carbon than small forest wildlands; they are at risk of deforestation
The global extent of intact forests declined by 7 percent 2000 and 2013.
For more information on trees and satellites, check out the NASA Earth Observatory feature, "Seeing Forests for the Trees and the Carbon: Mapping the World's Forests in Three Dimensions."
Rivers on Earth, Titan, and Mars
May 31st, 2017 by Adam Voiland
Rivers on three planetary bodies: the dry Parana Valles on Mars (left), the Nile River on Earth (middle), and Vid Flumina on Titan (right). Image by Benjamin Black using NASA data.
One of the more distinctive things about Earth among the planets is that we have plate tectonics. In other words, the hard, outer shell of the planet (called the lithosphere) is divided into several cool, rigid plates that float atop a hotter, more fluid layer of rock (the asthenosphere). These rigid surface plates do not float placidly: their grinding, colliding, shifting, and diving causes earthquakes, fuels volcanoes, builds mountains, tears open oceans, and constantly remodels and resurfaces the planet.
That is a far cry from what is happening on Mars and Titan, according to a recent study published in Science. Researchers came to that conclusion by carefully analyzing the way rivers cut through each of these planetary bodies. On Earth, countless rivers and streams snake their way across the surface. On Mars, rivers dried up long ago, but evidence of their presence remains etched into the arid surface. On Titan, Saturn's largest moon, rivers of liquid ethane and methane still flow into lakes.
Artist's cross section illustrating the main types of plate boundaries on Earth. (Cross section by José F. Vigil from This Dynamic Planet—a wall map produced jointly by the U.S. Geological Survey, the Smithsonian Institution, and the U.S. Naval Research Laboratory.)
By comparing imagery and data from all three planetary bodies, researchers noticed distinctive bends in the courses of rivers on Earth; these were formed as rivers were forced to wind around mountain ranges. These bends were absent in river networks on Mars and Titan. In an MIT press release, Benjamin Black, a geologist at the City College of New York, explained:
"Titan might have broad-scale highs and lows, which might have formed some time ago, and the rivers have been eroding into that topography ever since, as opposed to having new mountain ranges popping up all the time, with rivers constantly fighting against them."
Read more about the study from New Scientist, Space.com, and the American Association for the Advancement of Science. Read the full study in Science. Read this NASA Earth Observatory story to learn more about how scientists are using satellites to study river width on Earth.
In the triptych at the top of the page, the image of Parana Valles on Mars was acquired by the Viking 1 orbiter on September 13, 1976. The image of the Nile was captured by NASA's Terra satellite on August 10, 2000. NASA's Cassini spacecraft captured the image of Vid Flumina on Titan on September 26, 2012.
While water does not flow on Titan, rivers of methane and ethane flow into lakes near the moon's northern pole. Learn more about this image from the NASA Jet Propulsion Laboratory Photojournal.
Diesel Fumes Take a Toll on Health
May 26th, 2017 by Adam Voiland
Figure by the ICCT based on data from Anenberg et al. 2017.
It is no secret that many diesel cars and trucks emit more pollution under real-world driving conditions than during laboratory certification testing. Many lab tests, for instance, are run with perfectly maintained vehicles on flat surfaces in ideal conditions. In the real world, drivers chug up hills or sit in traffic in bad weather in vehicles well past their prime.
Until this month, nobody had tallied the health effects of all the excess diesel air pollution entering the atmosphere through real-world driving conditions. According to a new study published in Nature, vehicles in eleven major markets (Australia, Brazil, Canada, China, Europe, India, Japan, Mexico, Russia, South Korea, and the United States) emitted about 4.6 million more tons of nitrogen oxides (NOx) in 2015 than official laboratory tests suggested they would. NOx contributes to the accumulation of both ground-level ozone (O3) and fine particulate matter (PM2.5) in the atmosphere.
According to the research team, nearly one-third of heavy-duty diesel vehicle emissions and over half of light-duty diesel vehicle emissions are above the certification limits. On average, light-duty diesel vehicles produce 2.3 times more NOx than the limit; heavy-duty diesel vehicles emit more than 1.45 times the limit.
The authors of the study calculated the health effects for current and future levels of this excess diesel NOx by running a global atmospheric chemistry model that simulates the distribution of PM2.5 and O3. The bottom line: excess NOx caused 38,000 premature deaths in 2015. It could cause as many as 183,600 premature deaths by 2040 as the use of diesel increases.
"We estimate that excess diesel NOx emissions from on-road trucks, buses, and cars leads to upwards of 1,100 premature deaths per year in the U.S.," said Daven Henze, a professor of mechanical engineering at the University of Colorado and member of NASA's Health and Air Quality Applied Sciences Team.
Other key findings from the study:
China suffered the largest health burden from diesel NOx emissions—31,400 deaths, of which 10,700 are attributed to excess NOx—followed by the European Union (28,500 total; 11,500 excess) and India (26,700 total; 9,400 excess).
Light-duty diesel vehicles in the European Union accounted for 6 out of every 10 deaths related to excess diesel NOx.
In the United States, heavy-duty diesel vehicles caused 10 times the impact of light-duty diesel cars.
For more information, read a press release and fact sheet from the International Council on Clean Transportation, a press release from the University of Colorado, and a press release from the University of York. To find out more about global air pollution trends, read A Clearer View of Hazy Skies from NASA Earth Observatory.
This map, based on previous research, shows a model estimate of the average number of deaths per 1,000 square kilometers (386 square miles) per year due to fine particulate matter (PM2.5), a type of outdoor air pollution. Pollution from diesel exhaust is one contributer to PM2.5. Earth Observatory image by Robert Simmon based on data provided by Jason West. Learn more about this map here.
Methane Mystery Gets More Muddled
May 5th, 2017 by Adam Voiland
Model simulation of the hydroxyl radical concentration in the atmosphere. Image by Angharad Stell, University of Bristol.
A mystery about global methane trends just got more muddled. Two studies published in April 2017 suggest that recent increases in atmospheric concentrations of methane may not be caused by increasing emissions. Instead, the culprit may be the reduced availability of highly reactive "detergent" molecules called hydroxyl radicals (OH) that break methane down.
Understanding how globally-averaged methane concentrations have fluctuated in the past few decades—and particularly why they have increased significantly since 2007—has proven puzzling to researchers. As we reported last year:
"If you focus on just the past five decades—when modern scientific tools have been available to detect atmospheric methane—there have been fluctuations in methane levels that are harder to explain. Since 2007, methane has been on the rise, and no one is quite sure why. Some scientists think tropical wetlands have gotten a bit wetter and are releasing more gas. Others point to the natural gas fracking boom in North America and its sometimes leaky infrastructure. Others wonder if changes in agriculture may be playing a role."
The new studies suggest that such theories may be off the mark. Both of them find that OH levels may have decreased by 7 to 8 percent since the early 2000s. That is enough to make methane concentrations increase by simply leaving the gas to linger in the atmosphere longer than before.
Atmospheric methane has continued to increase, though the rate of the increase has varied considerably over time and puzzled experts. (NASA Earth Observatory image by Joshua Stevens, using data from NOAA. Learn more about the image.)
As a press release from the Jet Propulsion Laboratory (JPL) noted: "Think of the atmosphere like a kitchen sink with the faucet running," said Christian Frankenberg, an associate professor of environmental science and engineering at Caltech and a JPL researcher. "When the water level inside the sink rises, that can mean that you've opened up the faucet more. Or it can mean that the drain is blocking up. You have to look at both."
Unfortunately, neither of the new studies is definitive. The authors of both papers caution that high degrees of uncertainty remain, and future work is required to reduce those uncertainties. "Basically these studies are opening a new can of worms, and there was no shortage of worms," Stefan Schwietzke, a NOAA atmospheric scientist, told Science News.
You can find the full studies here and here. The University of Bristol has also published a press release.
Methane emissions related to human activity are on the rise. (NASA Earth Observatory image by Joshua Stevens, using data from CDIAC. Learn more.)
On This Date: The Bingham Canyon Landslide
April 10th, 2017 by Adam Voiland
NASA/EO-1/ALI/Jesse Allen and Robert Simmon. More info about this image here.
Four years ago today, one of the largest non-volcanic landslides in U.S. history began high on the northern wall of Utah's Bingham Canyon mine. During two main bursts of activity that day, several million cubic meters of rock and soil careened deep into the mine's pit.
This was a case where science and the right preparation saved lives. The company that runs the mine had installed an interferometric radar system months before the slide, and it prevented miners from being blindsided. With the radar system in place, mine operators detected changes in the stability of the pit's walls well before the landslide occurred. When the slope finally gave way, all the workers in the pit had already been evacuated. Not one person was injured.
The image above was acquired by the Advanced Land Imager (ALI) on the Earth Observing-1 satellite on May 2, 2013. For more detailed and recent images of the mine pit, see the montage below. Photos A, B, and C — from Rio Tinto Kennecott — show an overview of the pit, the source area, and slide debris in the immediate aftermath of the event. D is an aerial image from the state government of Utah that shows the mine nine months before the landslide. E is part of the ALI satellite image above. F is a second aerial image taken in February 2014. By then, much of the debris had been removed and a new access road had been built.
The montage was originally published in March 2017 by the Journal of Geophysical Research as part of a study authored by Jeffrey Moore of Lawrence Livermore National Laboratory. The University of Utah wrote about the research in a recent blog post:
On April 10, at 9:30 p.m. and again at 11:05 p.m., the slope gave way and thundered down into the pit, filling in part of what had been the largest man-made excavation in the world. Later analysis estimated that the landslide was at the time the largest non-volcanic slide in recorded North American history. Now, University of Utah geoscientists have revisited the slide with a combined analysis of aerial photos, computer modeling, and seismic data to pick apart the details. The total volume of rock that fell during the slide was 52 million cubic meters, they report, enough to cover Central Park with 50 feet of rock and dirt. The slide occurred in two main phases, but researchers used infrasound recordings and seismic data to discover 11 additional landslides that occurred between the two main events. Modeling and further seismic analysis revealed the average speeds at which the hillsides fell: 81 miles per hour for the first main slide and 92 mph for the second, with peak speeds well over 150 mph.
The interferometric radar system is not the only safety technology in place at Bingham Canyon. Drones, GPS, and trained experts keep a vigilant eye out for signs of landslides at this mine. Technology and tactics like this mean landslides cause very few injuries and deaths in the United States even though significant landslide potential exists in many parts of the country. As we recently reported, many other parts of the world (notably Africa and South America) are not nearly so fortunate.
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