text:
The Print Swap
Feature Shoot Media
Feature Shoot Portfolio Reviews
A Spiritual Journey Exploring the Magnificence of Trees
By Miss Rosen on June 12, 2018
Lake Tree, Beihai Park, Beijing, China, 2008
Bamboo and Tree, Qingkou Village, Yunnan, China, 2013
Huangshan Mountains, Study 13, Anhui, China, 2008
As a young boy growing up in the town of Widnes in northwest England, photographer Michael Kenna discovered a tree at the edge of a field in Victoria Park and made it his own. He and his brothers staked out their respective arboreal homes, hidden from the world, they could escape into the limitless expanses of their imaginations. Those trees became sanctuaries from all that civilization demanded of them, allowing them a space to commune with nature, free and unfettered.
Over the past 35 years, Kenna has dedicated himself to photographing trees all around the globe. Using a Hasselblad to create exquisite black and white silver gelatin prints, Kenna's portraits of trees are like Zen koans: tranquil and enchanting, minimal and moody, and powerfully evocative of life's deepest mysteries.
A selection of these works is on view in 'Philosopher's Tree' by Michael Kenna at Blue Lotus Gallery, Hong Kong, from June 15 through July 1, 2018. The works take us around the world, into different realms where trees have their own unique relationship with the landscape and the environment. Whether in China or Italy, Norway or Brazil, Kenna's relationship to the trees is an unwavering act of devotion.
Here we see some of the grandest flora in its full glory, speaking silent wisdom, knowledge, and understanding of the secrets of life and the interplay between all living creatures on earth. Kenna shares his observations about life among the trees.
Erhai Lake, Study 9, Yunnan, China. 2014
Could you speak about your early experiences among the trees as a child and how this informed your relationship with these majestic beings?
"As a young boy growing up, I had my own favorite tree. Well, it wasn't really mine, but I adopted it. More accurately, I suppose, it adopted me. My four brothers also had their own preferred trees, all conveniently located close to the playground. We would often sit high amongst the branches, shouting across to each other, safe from the prowling wild animals on the ground, the evil space ships attacking us from the sky, or the pirate ships waiting to drag us off. The trees were our safe zones, where we were hidden from the world.
"Occasionally, I would visit my tree alone and spend hours amongst the leaves in flights of fanciful imagination. The tree would then be the center of my universe, as well as my best friend. Recently, while visiting my sister in Widnes, I was delighted to once again renew my acquaintance with these trees. They seemed a bit smaller than in my memory, but otherwise quite unchanged.
"Today I have many more tree friends scattered across the world, which I like to visit whenever possible. I don't climb as much as I used to, but I still like to use my imagination. I have been labeled a 'landscape photographer' and am often asked why I don't make portraits. Of course I do, but of trees.
"When asked why, I usually answer half-jokingly that trees don't need to primp themselves, they never answer back, and always seem happy with the portraits that I make. They are also fiercely independent, graphically beautiful and seem quite happy to wait around in the cold for many hours while I make long time exposures. How could anybody not love photographing a tree?"
Tree in Snowdrift, Yangcao Hill, Wuchang, Heilongjiang, China. 2
Could you speak about what you have discovered about the character and nature of trees having spent so much time in their presence and observing their ways of life?
"I once had a dream that I was a giant chestnut tree. It seemed that as I grew, centuries came and went. I looked down from where I stood and observed generations of people, individuals and families, going about their lives. Our ongoing human stories – often viewed through the subjective prisms of drama, comedy or tragedy – seemed to take on a whole different light when viewed from this new perspective. I think that when I woke-up, I was a changed person and my respect for these sentinels of experience was dramatically increased.
"Towers of dignity, trees silently offer their wisdom to those willing to listen. Research shows that within minutes of being surrounded by trees and green space, our blood pressure drops, our heart rate slows and our stress levels come down. Trees are the longest living organisms on earth and one of the planet's most valuable natural resources. They purify the air we breath, improve the water quality, prevent erosion of soil, provide food and shade, reduce noise pollution, and help slow the rate of global warming. They are also exquisitely beautiful."
What was the inspiration for this body of work: where did the idea take root and how did it begin to develop into a series of photographs?
"For almost 45 years, I have had the distinct honor and privilege to photograph trees in a variety of different countries. I have never consciously made a decision to create a specific body of work on trees. They are just a natural part of my photographic journey. It seems as though I have always photographed trees and will continue to do so. I am very grateful to now be able to offer their portraits as a small token of immense appreciation for their presence in our world. We are all indebted to the trees, they give us so much and ask for so little in return."
Reflected Tree, Hongkun, Anhui, China, 2007
By traversing the globe, did you distinguish any remarkable similarities or differences between the trees in various places?
"I am not a scientist, but according to a comprehensive study of the world's plants by the Botanical Gardens Conservation International (BGCI), there are currently 60,065 species of trees in the world. There are obvious and not so obvious differences, between trees, but I like to think that similarities greatly outweigh differences.
"I suppose it's a bit like the human population. We appear in all sorts of shapes, sizes and colors. We may speak different languages, and have different cultural and/or religious traditions and habits. Ultimately, we are all part of one human being family."
Can you speak about the interplay between long exposure photography and the subject at hand: how does this format allow you to discover deeper aspects of the nature of trees?
"My feeling is that if we spend time with a subject matter, and make a considered photograph, rather than just glancing and making a quick snap, we will generally discover more. It is analogous to meeting someone. A quick exchange and we don't really know the true character of that person. The more time we spend, the more understanding we have. Sometimes it takes a lifetime and we still don't fully understand somebody.
"It often feels to me that our world continues to spin faster and faster. We have so much to do in a day, so many devices to look at, and people to be in touch with on social media. Information is available everywhere, images are constantly being produced and dispersed. Our world is fast paced and multi-facetted; it can exhaust our many senses if we are not consciously aware.
"It is sometimes necessary to slow ourselves down and get out of the mainstream turbulence. There are many ways of doing this: we could meditate, practice yoga or take a long walk, for example. I would suggest that spending some time with trees is always helpful. For my part I make long photographic exposures, most are a matter of minutes but some last up to twelve hours. What a luxury it is not to have to do anything during these periods of time."
Lastly, could you speak about the meaning of the title Philosopher's Tree and how you came to it?
"The Philosopher's Tree actually existed. I photographed it on a number of occasions in Northern Japan. It was a large Poplar tree that sat in the middle of a farmer's field near Biei, Hokkaido. Standing about 30 meters tall and with a diameter of almost two meters, its name referred to the resemblance it had to a philosopher lost in thought, with its head tilting to one side. It was a striking and glorious tree.
"Unfortunately, it was cut down in February 2016. The farmer cited the age of the tree (Poplars grow quickly, but have a short life span), and the many trespassing tourists and photographers who would tramp through the crops during the growing seasons to see the tree, despite the many signs asking them not to. It was a sad end for this glorious tree.
"I was extremely fortunate to have met and photographed The Philosopher's Tree before it was no longer there. Even now, in it's absence this particular tree remains influential in my life. It reminds me to continually acknowledge that every tree, every thing, every body has a life span, which we should celebrate."
"Desmond Tutu once wrote: 'We are fragile creatures, and it is from this weakness, not despite it, that we discover the possibility of true joy.' Trees are our teachers and we can all gain some wisdom from them. We just have to learn how to slow down, be in the moment, wait a little, and listen."
Huangshan Mountains, Study 26, Anhui, China. 2009
Wanaka Lake Tree, Study 1, Otago, New Zealand. 2013
All images: © Michael Kenna
Michael Kenna's Deeply Spiritual Photos of Japan Unveiled in New Book
Photo du Jour: Tranquility in China
Thievery in the Redwood Forests of Humboldt County, California
These Surreal Landscapes Will Inspire You to See the World
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text:
Q: Commuting Grothendieck topologies. Let $T_1$ and $T_2$ be two Grothendieck topologies on the same small category $C$, and let $T_3 = T_1 ∪ T_2$ (by which I mean the smallest Grothendieck topology on C containing $T_1$ and $T_2$).
Assume that every $T_3$ cover has a refinement of the form $\stackrel{f_1}{\to} \stackrel{f_2}{\to}$ where $f_2$ is a $T_2$ cover and $f_1$ is a $T_1$ cover (this is true for example, if $T_1$ is the Nisnevich topology, and $T_2$ is the topology consisting of proper cdh covers; in this case $T_3$ is the cdh topology).
If $F$ is a $T_1$-sheaf, is its $T_2$-sheafification still a $T_1$-sheaf (and therefore a $T_3$-sheaf)?
I can show this is true if $F$ is a $T_2$ separated $T_1$ sheaf, but I want to remove this condition.

A: How about this for a counter-example: We take the category
$$ A \stackrel{f_2}{\to} B \rightrightarrows C \stackrel{f_1}{\to} D $$
where there is a unique morphism from $A$ to $C$ and from $B$ to $D$. The only $T_1$ cover is $f_1$ and the only $T_2$ cover is $f_2$.
This category and these topologies satisfy my conditions.
Consider the $T_1$ sheaf $F$:
$F(A) = $ a singleton set $\underline{0} = ${$0$}.
$F(B) = $ a two element set $\underline{1} = ${$0, 1$}.
$F(C) = $ a singleton set $\underline{0} = ${$0$}.
$F(D) = \varnothing$ the empty set.
$$ \underline{0} \leftarrow \underline{1} \leftleftarrows \underline{0} \leftarrow \varnothing $$
The two morphisms $F(B) \leftleftarrows F(C)$ are the two distinct morphims $\underline{1} \leftleftarrows \underline{0}$. This is a $T_1$ sheaf.
Then the $T_2$ separated presheaf (which happens to already by a $T_2$ sheaf) associated to this $T_1$ sheaf is
$$ \underline{0} \leftarrow \underline{0} \leftleftarrows \underline{0} \leftarrow \varnothing $$
which is no longer a $T_1$ sheaf.

redpajama_set_name: RedPajamaStackExchange


text:
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redpajama_set_name: RedPajamaCommonCrawl


As Hurricane Ike picks up speed and grows into a bigger storm, the city of Houston and Harris County Emergency Management are beginning to evacuate residents. Handicapped residents, senior citizens and others with special needs are being evacuated this morning. Also, residents of low lying areas in the Houston area and Harris County will also start evacuating today following a mandatory evacuation order that has been issued. Hurricane Ike is expected to make landfall somewhere south of the Galveston and will bring with Hurricane 4 power winds and big wave surges. A mandatory evacuation order is also in place for the entire Galveston island and was issued by the Mayor of Galveston.
Governor Rick Perry of Texas has already put the National Guards of Texas on standby to help with the emergency situation created by the approaching hurricane Ike. He has also issued a disaster declaration for about 88 counties of Texas that are most likely to affected by the Hurricane. FEMA and other federal agencies are working hard to make sure that all emergency preparation are in place following President Bush's declaration of emergency in the State of Texas.
Mayor Bill White Of Houston and a Harris County Judge Ed Emmett have issued orders for mandatory evacuations of residents living in Harris County zip codes 77586 (Zone A), 77058, 77059, 77062, 77520, 77546, 77571, 77598 (Zone B) beginning at noon today.
Here is a Houston Area Zip Code map showing Houston Evacuation Zones and Harris County Evacuation Zones. Click on the map to view it in detail.
Also, please continue to check newly added evacuation zones and zip codes at City Of Houston's website houstonhidefromthewind.org.


text:
Q: tex4ebook: unable to include picture using \includegraphics and package \usepackage The preamble of the tex file:
%% LyX 2.3.3 created this file.  For more info, see http://www.lyx.org/.
%% Do not edit unless you really know what you are doing.
\documentclass[letterpaper,oneside,english,oldfontcommands]{memoir}
\usepackage[T1]{fontenc}
\usepackage[latin9]{inputenc}
\setcounter{secnumdepth}{3}
\setcounter{tocdepth}{3}
\usepackage{amsmath}
\usepackage{graphicx}
\makeatletter

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% LyX specific LaTeX commands.

\special{papersize=\the\paperwidth,\the\paperheight}
\makeatother
\usepackage{babel}
\begin{document}

**The latex code block dealing with including graphics:**

\begin{figure}
\centering
\includegraphics[scale=0.5]{Integration.png}
%\par\end{centering}
\end{figure}

**The tex4ebook command when executed goes like this:**

tex4ebook -s test2.tex -f epub3 mathml
[STATUS]  tex4ebook: Conversion started
[STATUS]  tex4ebook: Input file: test2.tex
This is pdfTeX, Version 3.14159265-2.6-1.40.20 (MiKTeX 2.9.7250 64-bit)
entering extended mode
This is pdfTeX, Version 3.14159265-2.6-1.40.20 (MiKTeX 2.9.7250 64-bit)
entering extended mode
This is pdfTeX, Version 3.14159265-2.6-1.40.20 (MiKTeX 2.9.7250 64-bit)
entering extended mode

**dvipng: Fatal error, PK file C:\Users\srirams05\AppData\Local\MiKTeX\2.9\fonts/pk/cx/jknappen/ec/dpi576\ecrm1000.pk ends prematurely**

        1 file(s) copied.
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        1 file(s) copied.
HTML Tidy for Windows released on 25 March 2009
        1 file(s) copied.
[STATUS]  tex4ebook: Conversion finished

The only issue with the EPUB outout is that the figure is missing. If the LaTeX code block above dealing with the figure is removed there is no issue... I suspect that the issue is with dvipng and MikTeX...
I am using the tex4ebook provided with MikTex 2.9.

A: It seems that the PNG file is wrongly recoginzed and TeX4ht tries to include it as an EPS file. This causes the invocation of dvipng. Try to place this file, graphics.4ht to the directory with your document:
% graphics.4ht (2019-11-25-09:03), generated from tex4ht-4ht.tex
% Copyright 1997-2009 Eitan M. Gurari
% Copyright 2009-2019 TeX Users Group
%
% This work may be distributed and/or modified under the
% conditions of the LaTeX Project Public License, either
% version 1.3c of this license or (at your option) any
% later version. The latest version of this license is in
%   http://www.latex-project.org/lppl.txt
% and version 1.3c or later is part of all distributions
% of LaTeX version 2005/12/01 or later.
%
% This work has the LPPL maintenance status "maintained".
%
% The Current Maintainer of this work
% is the TeX4ht Project <http://tug.org/tex4ht>.
%
% If you modify this program, changing the
% version identification would be appreciated.

   \expandafter\let\csname includegraphics \endcsname\includegraphics
\def\includegraphics{\expandafter\protect\csname includegraphics \endcsname}
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    \@ifnextchar"{\edef\Gin@base{\expandafter\grf:removequote\Gin@base}\grf:thrashname}{\grf:thrashname}}
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   \noBoundingBox\empty \global\let\noBoundingBox\:UnDef\fi}
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    \let\@latex@error\grp:warning \let\@ehc\empty}
\append:defIII\:tempc{\b:graphics\grf:gobble\leavevmode grf:gobble}
\HLet\Gin@setfile\:tempc
\NewConfigure{graphics*}[2]{%
   \expandafter\ifx \csname :.#1\endcsname\relax
      \pend:defIII\n:Gin@setfile:{\csname :.#1\endcsname}%
   \fi
   \def\:temp{#2}\ifx \:temp\empty
     \expandafter\let\csname :.#1\endcsname\:UnDef
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   \PictureOff\expandafter\grf:fixquotes\Gin@base\relax#1\PictureOn \G:cnfg \let\G:cnfg\relax}
\let\G:cnfg\relax

\let\old:GreadEps\Gread@eps
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\def\if:boundingbox#1#2{\ifdim\Gin@req@width=\Gin@nat@width\ifx\noBoundingBox\UnDefined#1\else#2\fi\else#1\fi}

\Hinput{graphics}
\endinput

It is the current code responsible for the graphics inclusion.


text:
Developing Connections in India and a new regional conference
Two expert seminars have been convened by Professor Margaret Barrett (ISME President 2012 – 2014) who continues to work on this project. The second expert seminar on music education was held in New Delhi in December 2015. Undertaken in conjunction with project partners ISME, SEMPRE, The Indira Ghandi National Centre for the Arts, and The University of Queensland, the seminar was extremely successful and identified a range of strategies for increasing ISME's presence and impact in India. Significant outcomes of the meeting included the development of the New Delhi Statement on Music Education and Engagement (See attached). This statement was presented to Dr Manesh Sharma, India's National Minister for Culture and endorsed by him. The statement was also presented to Minister Sisodia, Delhi Minister for Education, who also endorsed the statement. In continuing work members of the seminar are working to establish the Indian Alliance for Music under the leadership of Vikram Sampath. Dr Adam Greig, Director of the KM Conservatory of Music has undertaken to host the first ISME Regional Conference in India in December 2017 at the Chennai campus of the KMCM.
New Delhi Statement on Music Education and Engagement Download


Another book to help you start your next company.
This is the 19th book in the series Learning Together and Leading Together where we are going through the Personal MBA plan curated by Josh Kaufman. Our goal is to get through 99 books this year. Do we read the whole book? Nope. We digest the summary(s) of the book and I give my thoughts and you give your thoughts. Feel free to follow along and comment if you would like.
The best summary I found on this book was by ActionableBooks.com and is quoted below.
What if everything you thought about creating a business was outdated?
That's the premise behind the book Rework, written by 37Signals's Jason Fried and David Heinemeier Hansson. 37Signals is responsible for the profitable web applications Basecamp, Backpack, Highrise, and Campfire. The company also created Ruby on Rails, a web application framework which is the backbone for most of the web 2.0 world.
But they're not like any other business. They say plenty of things which both inspire and anger, especially when it comes to starting a business. They say things like: You don't need to obsess about planning. You need less than you think. Workaholics aren't heroes. Meetings can poison. Emulate chefs and drug dealers. Forget estimates. Forget the competition. Avoid seed money. Avoid traditional marketing. Forgo the reliance on resumes and formal education. Make something that truly matters and don't be another carbon copy.
Rework is fearless. It's conversational without any mundane "biz-speak," and it's backed by Fried and Heinemeier Hansson's own successes during their 10+ years in business.
This book reaches out to both starting entrepreneurs and seasoned ones. It also reaches out to those who are "thinking about it," and to those still haunted by the myths of what it really takes to succeed in business… any business. This isn't limited to tech companies.Rework is an alternative take to starting anything in the business world.
Using 37Signals and other successful companies as case studies, Rework examines what happens when you rethink and rework the way a business is born and built. The authors' opinion is strong: Anyone can start. First, get rid of the myths and excuses.
There's a new business paradigm, admits 37Signals. They thrive because they did what many people were afraid to do: Ignore the real world. This sole conviction is the most powerful takedown from which the rest of book springs forth.
How do you start a business today? You first start by not believing this place called the real world.
37Signals have defied the real world by doing many things that can scare traditional businesses: They've intentionally stayed lean and small. They've attracted millions of customers without salespeople or advertising. They've forgone long-term planning and estimates. They've preferred to out-teach competitors, rather than outsell or outspend. They've lived by their own anti-real world advice and still remain profitable today.
Do you really need a long-term plan?
Do you really need outside money?
Do you really need people with a formal education?
Do you really need to wait for inspiration?
If this is really your life's work, what's wrong with starting, creating, and co-creating with what you have, right now? Can't you start small and grow along the way?
What 37Signals advocates is casting away excuses: What's good enough so that you can simply get started, or even launch?
When you estimate and plan down to every detail, you're really guessing. When you seek outside money, you're likely to give up control. When you limit talent only to resumes and formal education, you miss the discovery of talent everywhere else. When you wait for inspiration, or the "right time," neither seem to stick around for long.
Ideas are plentiful. Inspiration is extinguishable. Anyone can have an idea, but what matters is what you do and how well you execute.
There's also the idea of aiming for less mass and avoiding growth for the sake of growth. Some big companies wish to be leaner and more flexible, but can't, since they've sealed their fate with tech lock-ins, excess staff, long-term contracts and unforeseeable road maps. If they try to make critical changes, it can take years. They wind up talking, meeting, but not doing.
How much do you really need? Start out lean, keep mass low. Good enough is just fine. That way, you have room to improvise. It's easier to execute decisions regarding your product line and feature sets, when you come to work expecting to adapt and change. You can make mistakes, fix them quickly, and simply get on with it.
The world is populated by some truly inspiring companies; companies we can learn from and emulate. But, (sadly) the world is also loaded with some uninspiring, Jurassic era, legacy companies that may appear healthy, but are actually rotting from the inside. You might've worked for one of them.
They stand for something, but their words are disconnected from the reality of the experience.
They apologize or talk to you like robots.
Their cultures and bureaucracies treat their employees like children.
They are more governed by rule books than human beings.
They are full of "dead-weight" delegators, processes, and other unneeded mass.
The Rework guys demonstrate that a lot of these negative effects can actually hinder good intentions. One of those intentions – the ideas of hiring "Rockstars" to build reputation and credibility – can completely backfire. "Instant culture" isn't possible. Not in a lasting way, at any rate. Real cultures develop through time and consistent behavior. There's nothing wrong with Rockstars… but grow them, don't necessarily hire for them. Start with your environment. A talented team can't thrive if the work environment is poisonous to begin with.
Everyone's capable of great work, not just rockstars, ninjas, or jedis. Rockstar environments emerge when you detox the work environment and give employees what they deserve. Get rid of mere order delegators and phony policies that create nothing meaningful but illusions of control and agreement.
There's more in the book about growing, nurturing, and thriving as a business: Better ways to handle competitors. Better ways to hire. Better ways to make progress. Better ways to evolve your product, service, and even your team. But ignoring excuses and fearful justifications always come first. Rework is a potent reminder that, to build a great business today, you have to take down the past.
You can rework and redefine the real world. Just get going and start creating. You need less than you think.
I wanted to quote the entire book on this blog but I feel that would not be appropriate. Which means you should go get this book. Does ActionableBooks.com do a great job on the summary above? Yes. And if you are not reading their summaries then you need to be.
ReWork is a game-changing book. It is a book that will stretch you as a person and as an entrepreneur. It is one of the books that will make you think. You won't agree with it on every idea. You will find yourself arguing with yourself throughout it. To me this is what a great business book does. It is beyond principles but gets to the questions.
I am in the process of helping launch another company. This book was a great reminder in how that company should measure things today. We won't be about the real world but hopefully be about something much greater.
Have you read this book yet? What do you think is the most controversial idea in the book?
Rework is a very quick and easy read. So few words that some might feel cheated. It does make a couple of very good point though: The Internet truly has changed the way we do business. The way large corporations work is anachronistic and the authors describe this in a fresh way.


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Three tardies in a card marking will result in a Responsibility Room assignment which will be served during lunch.
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Planner, writing utensil, assignments and all classroom materials including textbook, folders, notebook or paper, and calculator.


text:
Song and hymn requests, June 2016
Following Mary's month in May, some people call June the month of the Sacred Heart. This is because it includes the feasts of:
the Sacred Heart of Jesus (40 days after Pentecost) and
the Immaculate Heart of Mary (the Saturday after that).
So hymns like Sweet Heart of Jesus Font of Love and Mercy have been very popular, along with some of the lesser known Sacred Heart hymns, such as O Sacred Heart of Jesus and All Ye who Seek a Comfort Sure.
A new edition of Selected Hymns from the Catholic Hymn Book - Nigeria has been released. It has click-able links between the hymn titles and copyright information in section two and the hymn text in section three - making it a lot easier to use.
This edition also fixes a formatting issue in section two of the original, which saw some of the copyright info left off the page. The new version is available on Kindle now - click here. (Or here in the UK / Ireland).
If you would like to get this book on a format other than Kindle, please leave a message in the Comments section near the bottom of this page.
Last month's hymn and song research requests
There were 23 research requests during May, 10 for songs which were already written up, 12 which had an information page done for them during the month, and one which has been added to the list to be written up "one day". Looking at the details ...
A Mhuire Mhathair
Information about this Irish-language hymn about Mary is available here.
Blessings on our King
Information about this hymn by Australian priest Frank Andersen is available here.
Come Ye that Love the Lord
This request, from a person who heard the hymn in Ghana, is for sheet music in the key of C, for the tune COME WE THAT LOVE THE LORD by Robert Lorwy which this hymn is usually set to.
Looking through the various published versions in Hymnary, it appears that it is most often set in the key of F, or occasionally G or A-flat.
If you know of any versions where it is set in C, or would be willing to transpose the original version for the requestor, please leave a message in the Comments box at the bottom of the page.
Deep in the Spirit
Information about this hymn by Australian priest Frank Andersen - which was requested in May last year, too is now available here.
Father I Thank You for Your Goodness
Information about this song of thanksgiving is available here.
The person who requested this hymn learned it in Episcopal church in Denver Colorado during the 1970s. Because they provided some of the first verse, I'm pretty sure that they are looking for the English hymn Go Tell Everyone.
Holy Spirit Come Into our Lives
Information about this hymn by American composer Ken Canedo is now available here.
I Cannot Come
Information about this song by Miriam Therese Winter is available here.
May is the Month of Mary
Very little information has been found about this hymn, which seems to have been part of an English primary school religious education programme during the mid 20th century. There is now a page about it here - hopefully I'll be able to find out more information about it.
Men to Match my Mountains
Some information about this song by Sonny Salsbury is available here. If you know any more about it, eg where it was published, the full lyrics, where to get sheet music etc, then please leave a message in the Comments box near the bottom of the page.
O Mary When Our God chose You
Information about this Marian hymn is now available here.
On Eagles Wings - Joncas
Information about this hymn by Jan Michael Joncas is now available here.
Queen of the May
Information about this hymn, which is very popular every May, is available here.
See the Paraclete Descending
Information about this Pentecost hymn is available here.
This children's' song was published in 2007 - an information page about it is now available here.
Spirit of God in the Clear Running Water
Information about this hymn by Medical Mission sister Miriam Therese Winter is now available here.
Take my Hand and Use it as Your Own
This request is most likely for the folk-style hymn was written by Sebastian Temple, Take my hands and Make them as Your Own. An information page about it is now available.
The Deer's Cry
In information page about Shaun Davey's setting of St Patrick's Breastplate is now available here.
The Spirit is a Movin'
This hymn was written in America during the 1960s - and was requested by a reader who recently heard it in church in Fiji. Informaation about it is now available here
The Sun is Shining Brightly
This requested just included the phrase "the sun is shining brightly" - it is probably for the hymn The Lovely Month of May.
This folk-style hymn about the Visitation was written by Miriam Therese Winter and first published in 1968.
The Wonders He Has Done
This request from a read in Papua New Guinea is most likely for Frank Andersen's song The Wonders He has done in Every Age - for which an information page is now available.
We Form One Church
This song by American priest and song-writer Willard F. Jabusch was included in the 20th Century Folk Hymnal, Volume 3. An information page about it is available here.
When I Cross that River
An information page about this Southern Baptist gospel song is available here.
One person has been in touch because they want to buy the music books for Scripture in Song volume 1 and volume 2. Unfortunately these books are long since out of print, so they aren't available from regular shops/sources. The best way to get them is probably to use a second-hand goods website: I'm pretty sure that I got my copies from TradeMe in New Zealand. Amazon or its UK/Ireland version may help too. The secret with buying rare-but-not-very-valuable books from 2nd-hand websites is to either visit regularly, or to set up alerts which notify you if particular books or types of book are listed.
Another option is to check 2nd-hand bookstores and charity shops (less organised, non-chain-store ones are usually best) or book sales run by Christian organisations: for example this blogger has had a lot of ""finds"" from the Lifeline booksales in Brisbane, Australia.
Don't see your request?
Every month, there are a number of requests which just don't have enough information to track down the intended hymn or song. If you made a request but don't see it listed here, then you might like to try again. this time, including some phrases that aren't likely to be included in other hymns.
Getting updates about requested songs and hymns
If you subscribe to the GodSongs.net mailing list, you will get an email when new hymns and hymnal-listing are added, and when new newsletters are posted:
Please note that shortly after you subscribe, Feedburner will send you a verification-request message - be sure to click on the link, so your subscription is complete.
Are you looking for a hymn or song?
Are you searching for the words or sheet music for a particular song or hymn - especially from the last 50 or so years?
The Hymn Finder tool is your first port of call. It is a customized search tool, which lets you search for any words from the hymn - and looks for them in a set of websites that are known to contain hymns. This means that you get results which are hymns - instead of sermons and newsletters which just contain snippets, or pages about totally different topics which just happen to contain those words.
If this doesn't help, then submit a request using the hymn research request tool, and it will be responded to in next month's newsletter.
https://www.godsongs.net/2016/06/newsletter-song-and-hymn-requests-june-2016.html
[url=https://www.godsongs.net/2016/06/newsletter-song-and-hymn-requests-june-2016.html]Song and hymn requests, June 2016[/url]
Labels: Newsletters


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text:
Short-pulse controlled optical switch using external cavity based single mode Fabry-Pérot laser diode
Bikash Nakarmi, Tran Quoc Hoai, Yong-Hyub Won, and Xuping Zhang
Bikash Nakarmi,1,2,* Tran Quoc Hoai,3 Yong-Hyub Won,1,3 and Xuping Zhang2
1Electrical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
2Institute of Optical Communication Engineering, Nanjing University, Nanjing, China
3Information and Communication Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
*Corresponding author: bikash@kaist.ac.kr
B Nakarmi
T Hoai
Y Won
X Zhang
Bikash Nakarmi, Tran Quoc Hoai, Yong-Hyub Won, and Xuping Zhang, "Short-pulse controlled optical switch using external cavity based single mode Fabry-Pérot laser diode," Opt. Express 22, 15424-15436 (2014)
Realization of all-optical multi-logic functions and a digital adder with input beam power management for multi-input injection locking in a single-mode Fabry-Pérot laser diode (OE)
All-optical 4x10 Gbps NAND gate using single mode Fabry-Pérot laser diode (OE)
All-optical flip-flop based on the bistability of injection locked Fabry-Perot laser diode (OE)
Extinction ratios
Light beams
Long period gratings
Single mode lasers
Tunable diode lasers
Fabry-Perot (120.2230)
Lasers, injection-locked (140.3520)
All-optical devices (230.1150)
Switching (250.6715)
Original Manuscript: May 8, 2014
Revised Manuscript: June 10, 2014
Manuscript Accepted: June 10, 2014
2. Operating principle
3. Experimental setup and results
We propose and demonstrate a novel scheme for short pulse controlled all-optical switch using external cavity based single mode Fabry- Pérot laser diode (SMFP-LD). The proposed scheme consists of control unit and switching unit as two essential blocks. The basic principle of the proposed scheme is the optical bistability property of SMFP-LD for the control unit and the suppression of the dominant beam of SMFP-LD with injection locking for the switching unit. We also present the analysis of hysteresis width and rising/falling time with change in wavelength detuning which helps to find the optimum wavelength detuning value and power of light beams at different stages of the proposed scheme that gives wide input dynamic power range, high ON/OFF contrast ratio, and low rising/falling time. Input data of 10 Gb/s Non Return to Zero (NRZ) signal is switched at output ports depending upon the control signal generated by the control unit, which comprises of optical SR latch. Output waveforms, clear eye diagrams with extinction ratio of about 11 dB, rising/falling time of about 30 ps and 40 ps, and bit error rate (BER) are measured to validate proposed scheme. No noise floor is observed at output ports up to BER of 10−12 and the maximum power penalty recorded is about 1.7 dB at a BER of 10−9 which shows good performance of the proposed short pulse controlled optical switch using SMFP-LDs.
Optical signal processing and controlling has received considerable attention since it addresses various challenges such as information acquisition, transmission, storage and processing, and meets the demands of high speed and large capacity requirement of optical communication system. Additionally, optical signal possesses benefit of comparatively less electro-magnetic interference, less cross talk, no heat dissipation, no short circuit problems and many others [1, 2]. The technology advancement of high quality optical fiber has enabled the development of communication networks in present condition. It has not only improved communication but also has played a vital role for the development of related technology and other optical signal processing and controlling schemes. Optical computing which plays a significant role on the communication networks has been also developed as an integral part of it. Compared to the present electronics counterparts, photonics still need focus and extensive research and development on the improvement of efficient integration technology, power consumption, all-optical memory system and cost. Despite the present limitations, all-optical technology shows promising applications in the field of fast signal processing, higher accuracy sensing, control system in hazardous situations, and electromagnetic interference free system. One of these scenario is represented by optical interconnection between chip to chip used for short range photonics interconnection to improve the high performance computing [3]. The successful implementation of the optical interconnection in reality as in the PERCS (Productive, Easy-to-use, reliable Computing system) [4] and OSMOSIS (Optical shared memory supercomputer interconnect system) [5] have shown the feasibility and necessity of optical network. Optical bistability, an essential property for the realization of optical memory, have been analyzed by different research groups in many different approaches for the realization of optical buffers and RAM [6–10].
Optical switch is one of the important building block for the optical signal processing and communication system. Various techniques and components such as Mach-Zenhder interferometer, erbium doped fiber with long-period fiber gratings, semiconductor optical amplifier (SOA) have been used for the demonstration of optical switch and overcoming the limitation of each other [11–14]. Among various components, SOAs have shown promising developments on designing various optical units including switch. SOAs require high biasing current and are expensive [15]. To overcome the higher cost and high driving current requirements, optical units such as gates and switches have been proposed using commercially available multi-mode Fabry-Pérot laser diodes (MMFP-LD) [16–18] and especially designed single mode Fabry-Pérot laser diodes [19–21]. But all these techniques require input control signal to be high for the entire period of data to be blocked at the output ports.
In this paper, we propose and experimentally demonstrate an idea of controlling the switch using SMFP-LDs with short pulses input as a control signal. Only short pulses at the input control blocks are enough to switch and block input data at output ports. The switching window can be varied easily by implementing different periods of short pulses at the input of control signal. The control block is composed of optical SR unit which works on the bistability of SMFP-LD and the switching unit works on the principle of the injection locking with suppression of the dominant mode of the SMFP-LD. The hysteresis width analysis in injection locking of SMFP-LD with different wavelength detuning is done to find the optimum input power for the different stage of proposed switch which helps to provide the high dynamic range for the control unit and power efficient solution. Additionally, the effect of wavelength detuning on rising/falling time is also analyzed to provide minimum rising/falling time at the output ports. The proposed idea is verified experimentally by using 10 Gb/s data to be switched at output ports depending upon the short pulse applied on the control unit. The different duration of short pulse are implemented to show the performance of the proposed short pulse control switch. The 3.5 Gb/s NRZ data are used to provide the different duration of control pulse and to analyze the output performance with different pulse width of input control signal. Clear output waveforms, eye diagrams with extinction ratio of more than 11 dB, rising/falling time of about 30/40 ps and no noise floor up to BER of 10−12 are obtained at output ports.
The proposed scheme of short pulse controlled optical switch consist of two units, control unit and switching unit, as shown in Fig. 1. The control and switching unit work on optical bistability, injection locking, and gain modulation of SMFP-LDs [22–24]. In [23], optical logic units and comparator circuit using SMFP-LDs have been demonstrated but do not provide any insight and analysis about short pulse switching technique, effect of wavelength detuning on hysteresis width, and rising/falling time. In this paper, we analyze the effect of wavelength detuning on optical bistability and rising/falling time, and implement the results in demonstrating short pulse controlled switch using SMFP-LDs, which does not require input signals to be high for the entire duration of data transfer. SMFP-LDs, which are used in this scheme are specially designed and developed in our laboratory, have a dominant self-locked single longitudinal mode with high side mode suppression ratio [25]. The SMFP- LD is obtained by eliminating the inclinations of 6° to 8° of the coupling fiber present in conventional FP-LDs, thereby, forming an external cavity between laser diode and the fiber. The SMFP-LD consists of a FP-LD chip with a multi-quantum well of 300 µm and an external cavity length of 4 mm. By varying the temperature, the mode matching condition is achieved for both the cavities. The refractive index of the active region changes with the change in temperature. As a result, there is a change in optical path length in the laser diode providing the optimal mode matching condition for the single mode oscillation. This single mode oscillation can be tuned to another mode by varying the operating temperature, which gives the wavelength tunability of the dominant mode of the SMFP-LD. The required temperature stability is maintained with the commercially available temperature electric cooler (TEC) which has a temperature stability of 0.01°C. The self-locking mode of SMFP-LD is tunable to a wide range of wavelength of about 10 nm by varying the operating temperature. SMFP-LD shows similar characteristics as that of the MMFP-LDs with the injection of external beam. The difference between SMFP-LDs and MMFP-LDs is that the former does not need any external probe beam for signal processing.
Fig. 1 Basic block diagram of proposed short-pulse controlled optical switch.
Control unit has two inputs which are used to generate the control signal for switching input data at outputs based on the input control pulse applied. The control unit is composed of SR latch which gives the output based on the set and reset signal at the input. The output of SR latch, Q, which is the control signal for switching and blocking the input data at the output port 1 of switching unit, will be high with the implementation of set beam at the input of control unit. Output Q will maintain the same logic output, high, even when the set beam is removed. Output at Q will be logic 0 only when another control input beam, reset, is high with set as low. Hence the input data applied to switching unit will be switched to the output port 1 when Q is logic 0. Similarly the input data will be switched to the output port 2 when is logic 0.
Control unit comprises of two SMFP-LDs in the cascaded form where the output of SMFP-LD1 and set pulse are inputted to SMFP-LD2. It is noted that the set pulse is at the same wavelength as that of the self-injected mode of SMFP-LD1, λ1. This configuration helps to set the output of control unit i.e. Q as "1" even with lesser amount of power at set beam, which makes the configuration more efficient in terms of power requirement. The control output is obtained through SMFP-LD2. The output is divided into two and passed through different band pass filters, BPFs tuned at the wavelength of λ1 and λ2 which give opposite logic state of each other. These two beams Q and Q¯ act as control signals for the corresponding output ports of the proposed switch with SMFP-LD3 and SMFP-LD4. Since control signals to switching unit are always in opposite logic state, the input data signal is either outputted to port 1 or port 2 based on the low/high state of Q and Q¯.
Figure 2 shows the spectrum schematic of the proposed short pulse controlled optical switch. Figure 2(a)-2(i) shows the spectrum schematic of self-injected SMFP-LD2 with dominant mode at the wavelength of λ2. At the initial condition both set and reset beams are logic "0". At the initial condition, SMFP-LD2 has input beam of λ1 which is the dominant mode of the SMFP- LD1. The power of λ1 is managed in such a way that it is enough to injection lock the side mode of SMFP-LD2 but it is not sufficient enough to suppress the dominant mode of SMFP-LD2, λ2 as shown in Fig 2(a)-2(ii). The dominant mode of SMFP-LD2 will be suppressed only when there is a presence of additional beam which can be obtained from the set signal and is injected in the same wavelength as that of the dominant mode of SMFP-LD1 (λ1 = λs). As set beam uses the same wavelength as that of dominant mode of SMFP-LD1, small amount of power on the set pulse λs is sufficient enough to suppress the dominant mode of SMFP-LD2 as shown in Fig. 2(a)-(iii). It is noted that in order to suppress the dominant mode of SMFP-LD2, both beams; dominant mode of SMFP-LD1 and set beam are required. With previous state of suppression of the dominant mode of SMFP-LD2, the self-injected dominant beam of SMFP-LD1 alone is enough to hold on to the same state of λ2 as shown in Fig. 2(a)-2(iv). The suppressed state of λ2 will be in the same state until the reset beam is set to logic "1". This gives the set sate of SR latch by providing Q which is in the wavelength of λ1 as logic high and Q¯ which is in the wavelength of λ2 as logic low. Two outputs from SMFP-LD2 with Q and Q¯ work as a control signal for the switching unit. With reset signal as logic "1", the dominant mode of SMFP-LD1 will be suppressed and hence the input to the SMFP-LD2, which is after the BPF tuned at λ1, is logic "0" as shown in Fig. 2(a)-2(v). Hence the output from SMFP-LD2 will be logic "0" at Q and logic "1" at Q¯. In this case also, even with the removal of reset beam the output will maintain the same state since λ2 cannot be suppressed only with the presence of the λ1 which is shown in Fig. 2(a)-2(vi).
Fig. 2 Spectrum schematic of (a) control unit and (b) switching unit, of the proposed short pulse-controlled switch.
Two output state of Q and Q¯ depend on the input control signals S and R which is used to pass the input signal either through port 1 or port 2. Since the configuration of the control unit for switching is SR latch the input control signals S and R are not required to be continuously in logic "1" state for transferring or blocking the data through output ports. Only a short pulse at the input S and R is sufficient enough for the operation of the switching unit. The switching unit works on injection locking and gain modulation of SMFP-LD which is illustrated in Fig. 2(b). Figure 2(b)-2(i) and 2(b)-2(ii) show the spectrum of dominant mode of SMFP-LD3 and injection locked SMFP-LD by data signal λdata which suppresses the dominant mode of SMFP-LD3, respectively. Furthermore, the gain or power of the injected data signal can be modulated by injecting another beam known as pump beam which is either Q or Q¯ in the proposed scheme. When the control signal Q or Q¯ is present the gain of the data signal will be suppressed based on the gain modulation principle. The amount of gain suppression depends on the power of the control signal which is directly proportional to the wavelength detuning of control signal to the corresponding mode of the SMFP-LD.
In order to find the optimum power and wavelength detuning for different beams of the proposed scheme, we analyzed the hysteresis width of the optical bistability, the suppression of the dominant mode of SMFP-LD, and rising/falling time of output signal which are shown in Fig. 3. The effect of wavelength detuning on the stability of injection locking with a single injected mode has been analyzed in [21] and it is shown that the negative wavelength detuning will result in unstable locking regime. However, with more than single injected locked modes, the negative wavelength detuning has relatively small region of instability but the negative wavelength detuning cannot provide bistability [26]. Hence, we have only considered the effect of positive wavelength detuning on hysteresis width in optical bistability and rising/falling time of output ports. The effect of positive wavelength detuning on optical bistabilty shown in Fig. 3(a) is matched with the theoretical analysis presented on [26]. One of the notable things that we have observed is the change in the width of the hysteresis. Figure 3(a)-3(i) and 3(a)-(3ii) shows the hysteresis curve with wavelength detuning of 0.02 nm and 0.04 nm. We can see that the hysteresis loop width is small in both cases and the power of the dominant mode drops sharply compared to that of Fig. 3(a)-3(ii) and 3(a)-3(iv) which have higher wavelength detuning. In addition, some noticeable issues are counterclockwise hysteresis with detuning of 0.02 nm, and a butterfly hysteresis loop with the increase in wavelength detuning to 0.04 nm. In Fig. 3(a)-3(iii), the wavelength detuning is maintained at 0.08 nm. When the injected power is set initially to a value of −6 dBm (marker1), the power of the dominant mode is about −5 dBm level. However, as the injected power is increased to −5.1 dBm, the dominant mode is fully suppressed as SMFP- LD is locked at the injected wavelength. On the contrary, decreasing the injected beam power below −5.1 dBm after the injection locking with suppression of dominant mode, the output of dominant mode maintain low output state (state of marker 2 and 3). The dominant mode will remain suppressed until the input injected beam is less than −6.2 dBm. On slightly decreasing the injected power from −6.2 dBm (marker 4), the dominant mode returns back to the unsuppressed mode and back to initial state (marker 1 again) gaining the power at the dominant mode and completes the hysteresis loop. It is noticeable that the corresponding modulation depth as a value of high-output to low-output states can reach a high level of 40 dB from Fig. 3(a)-3(iii). In addition, when the wavelength detuning is increased to 0.12 nm, the hysteresis loop width is further extended, which is illustrated in Fig. 3(a)-3(iv). It is observed that the optical bistability shown in Fig. 3(a) exhibits a transition from counterclockwise to clockwise hysteresis by the way of a butterfly hysteresis when the wavelength detuning is increased from 0.02 nm to 0.12 nm.
Fig. 3 Wavelength detuning effect on (a) hysteresis width (i) 0.02 nm (ii) 0.04 nm (iii) 0.08 nm and (iv) 0.12 nm, and (b) rising/falling time of output.
The effect of change in wavelength detuning on rising/falling time of the output port is illustrated in Fig. 3(b). The NRZ input signal is used for the analysis of the rising/falling time in SMFP-LD. Wavelength detuning is varied from the range of 0 nm to 0.14 nm. It is observed that the rising and falling time both increases with the increase in the wavelength detuning and the falling time is higher than rising time in SMFP-LDs. From Fig. 3(a), we observed that the increase in wavelength detuning increases the hysteresis width which in turn increases the rising and falling time of output of the SMFP- LD. With this result we can conclude that the higher wavelength detuning is preferred for the latch operation compared to the switching operation as wavelength detuning shows the directly proportional relationship with rising/falling time. Hence in our proposed approach, we used the higher wavelength detuning of 0.12 nm for the control unit which comprises of SR latch and lower wavelength detuning of 0.04 nm to the switching unit.
The experimental set up for the proposed short pulse controlled all-optical switch is shown in Fig. 4. SMFP-LD1 and SMFP-LD2 generate control signals which are used to control the switching of input data from port 1 and port 2 via SMFP-LD3 and SMFP-LD4, respectively. SMFP-LD1 is cascaded to SMFP-LD2 in order to make it work as a SR flip-flop, which provides control signal for switching ports; Port 1 and Port 2. SMFP-LD3 and SMFP-LD4 work on the injection locking property and are used as a switching unit to switch the input data to output ports, according to the control signal. The logic state of control signal is determined based on the state of S, R and the previous control output state. Tunable lasers (TL), TL1 and TL2 are used to modulate short pulses which are control signals for switching input data to output port 1 or output port 2. Pulse pattern generators (PPG), PPG1 and PPG2 are used to generate 16 bit 3.5 Gb/s NRZ data and are optically modulated by the modulator, MOD, for controlling switching of input data to output ports. Data with different bit sequence are used to show the switching of input data signals at the output ports for different time interval with different input pulse width. The minimum width of pulse used for set and reset bit is about 250 ps. With S and R beam present for 250 ps, the proposed scheme can perform the switching operation to switch the input data to either output port 1 or output port 2 and maintain the data output to the same port even when the short pulse applied to control signal is absent until another control signal is applied. It shows the distinct difference between proposed short pulses controlled switch which require the control signal to be ON only for a short duration compared to the conventional optical switch which requires the control signal to be ON for the entire period of the switching operation.
Fig. 4 Experimental setup of the proposed short pulse-controlled switch using self-injected single mode Fabry-Pérot laser diode.
TL3 is used to modulate 10 Gb/s NRZ input data signal generated by PPG3 which is to be switched at the output ports, either to port 1 or port 2 based on the control pulse S and R. Polarization controllers (PC), PC1, PC2 and PC7 are used to minimize the loss in the Mach-Zehnder modulator where as other PCs are used to obtain the TE polarized light only to be injected on respected SMFP-LDs since SMFP-LDs works on the injection locking principle which is based on the TE polarized light. With TM polarized light source, absorption modulation phenomenon occurs [27]. SMFP-LD1, SMFP-LD2, SMFP-LD3, and SMFP-LD4 have threshold current of 9 mA, 11 mA, 13 mA, and 11 mA, and are biased with the biasing current of 14 mA, 17 mA, 20 mA, and 20 mA under the operating temperature of 21°C, 23.5°C, 26.7°C, and 17.5°C, respectively. Under these operating conditions, SMFP-LD1 to SMFP-LD4 have the dominant self-injection locked mode at the wavelength of 1546.2 nm, 1541.24 nm, 1544.2 nm, and 1539.84 nm with the side mode suppression ratio (SMSR) of 38.2 dB, 29.7 dB, 35.14 dB and 38.61 dB, respectively. BPF1 is used to pass the dominant mode of the SMFP-LD1, which is injected to SMFP-LD2. BPF2 and BPF3 are used to pass the wavelength of λ1 and λ2, which are control signals for SMFP-LD3 and SMFP-LD4. BPF4 and BPF5 are used at the output ports; Port1 and Port 2, which ensure only the wavelength of data signals are present on output ports.
Two control signals S and R are injected at the wavelength of 1546.2 and 1549.82 nm with the wavelength detuning of 0.12 nm with the respective SMFP- LD1 and SMFP-LD2. The 0.12 nm wavelength detuning is used for the control signal since from the analysis of Fig. 3(a), we found higher wavelength detuning gives wider hysteresis width which is desired for the SR latch operation. Set beam and dominant mode of SMFP-LD1 have the same wavelength so that even the set signal power of about −16 dBm with the presence of dominant mode of SMFP-LD1 (when R = 0) is sufficient enough to suppress the dominant mode of SMFP-LD2 for the Set state. This low power of set signal is possible due to the larger hysteresis width, since there is a large difference between the input power required for injection locking and releasing. Depending upon S and R pulse applied at the input of control unit, the modulated data which are inputted to both switching wings are either outputted to port 2 or port 1.
Figure 5(a) shows the spectrum diagram of the control unit that generates signals which are used for switching the inputted data to output ports. Figure 5(a)-5(i) and Fig. 5(a)-5(ii) show the spectrum output of SMFP-LD1 and SMFP-LD2 under the normal biasing condition of SMFP-LDs without any input beam injected to both SMFP-LDs. Figure 5(a)-5(iii) shows spectrum output of SMFP-LD2 without any input pulse S and R applied. But in this case, there is a presence of the dominant mode of SMFP-LD1 which is injected to SMFP-LD2. The power of the dominant mode of SMFP-LD1 is managed in such a way that the power is sufficient enough to weakly injection lock SMFP-LD2 but is not enough to suppress the dominant mode of SMFP-LD2. In order to suppress it, both inputs to SMFP-LD2, set signal, S, and output from SMFP-LD1, which is the dominant mode of SMFP-LD1, should be logic high. SMFP- LD2 is injection locked at the wavelength of λ1, 1546.86 nm as shown in Fig. 5(iv) which gives logic high input to SMFP-LD3 and logic zero input to SMFP-LD4. With this condition, 10 Gb/s input data which is modulated by TL3 is outputted to output port 2. In this case, the data signal inputted to SMFP-LD4 is not suppressed since the injection locking phenomena does not occurred with the signal λ2 as it is logic "0". The reverse phenomenon occurs at the output port 1 with no data signal since there is the presence of input beam to SMFP-LD3, λ1, which suppresses the input data signal of 10 Gb/s. Both output ports will maintain the same state even with the removal of set beam because the power of λ1 is sufficient enough to maintain the suppression of dominant mode of SMFP-LD2 due to the presence of dominant mode of SMFP-LD1 as shown in Fig. 5(a)-5(v).
Fig. 5 Spectrum diagram for the control unit of proposed short pulse controlled optical switch: SR latch. (a) For the set state and data output at port 2 (b) for reset state and data output at port 1.
We found that with 0.12 nm wavelength detuning of λ1 to the corresponding side mode of SMFP-LD2, the minimum power needed to suppress the dominant mode is about −9 dBm (measured after coupler) and −12 dBm is required to maintain in the locked-state. Hence the self-injected mode of SMFP-LD1 should be less than −9 dBm but higher than −12 dBm. With control inputs S = 1 and R = 0, the data inputted to SMFP-LD3 will be suppressed and hence no data output is obtained at the output port 1 but the inputted data to SMFP-LD4 will be outputted to port 2 as shown in Fig. 6(a). This state will be maintained even later when S = 0 and R = 0, until R = 1 since the control signals, which are used to control the switching units, are the outputs from the S and R latch. Figure 6(a) includes spectrum diagram of the SMFP-LD4 with dominant mode at the wavelength of 1544.2 nm [Fig. 6(a)-6(i)], which is suppressed due to the presence of input data signal at the wavelength of 1551.02 nm [Fig. 6(a)-6(ii)]. Since there is an absence of λ2, data will be obtained at port 2. In presence of λ2 (when S = 0 and R = 1) obtained from BPF3, gain of the data signal can be modulated by λ2, which is the control signal for switching the data to output Port 2. The contrast ratio of 28.04 dB is measured for the output port 2 [Fig. 6(a)-6(iii)].
Fig. 6 Spectrum diagram for the switching unit of proposed short pulse controlled optical switch (a) port 2 (b) port 1.
Similarly, the output of Port 1 is obtained from SMFP-LD3 after passing through BPF2. The dominant mode of SMFP-LD3, 1539.84 nm, [Fig. 6(b)-6(i)] is suppressed by the injection of data signal at the wavelength of 1551.02 nm [Fig. 6(b)-6(ii)]. When reset control beam is logic 1, both inputs to SMFP-LD2, set beam and dominant mode of SMFP-LD1 are logic zero as the dominant mode of SMFP-LD1 is suppressed due to the presence of reset beam and S is set to "0". Hence SMFP-LD2 gives high output at the wavelength of λ2, as shown in Fig. 5(b)-5(i), because both the inputs to SMFP-LD2 are logic 0. The output of SMFP-LD2 has the output of λ2 beam which suppresses input data at the output port 2 as shown in Fig. 6(b)-6(iii) whereas there will be the presence of data output at output port 1 since the beam injected to SMFP-LD3, λ1 is logic 0. The data will be outputted to the output port 1 even latter when R = 0 and S = 0 as shown in Fig. 5(b)-5(ii) and Fig. 6; until the set beam is "1" with reset beam is "0".
Figure 7 shows oscilloscope traces at different stages of the proposed short pulse controlled optical switch. PPG1 and PPG2 are arranged to generate different duration of set and reset pulse, and accordingly the output state of Q and Q¯ changes which are the control signals for controlling input data to be blocked or passed through output ports. We can see that even when the set or reset pulse is made logic 0 after the logic 1 state, the control signal for switch, Q and Q¯ maintain the same state.
Fig. 7 Waveform diagram of input control signals, output of control units, input data, switched output data, rising/falling time of outputs and eye daigram of proposed short pulse controlled switch with 500 ps/div, 50 ps/div and 20 ps /div, respectively.
For example, even though the set pulse is "0" with previous state of S = 1 and R = 0, the logic state of Q and Q¯ is maintained with logic state 1 and 0 respectively and vice-versa which controls the data transfer to output ports. When S beam is logic 1, 10 Gb/s NRZ input data is switched at the output port 2 and it maintains same state until the reset beam is logic 1. This shows the proposed optical switch can perform well even with a short pulse of control signals S and R. The minimum pulse duration used in the experiment is 280 ps for input S and R. Clear waveforms with rising/falling time of 31.6 ps/35.2 ps for output port 1 and 36 ps/41.7 ps for output port 2 with 10 Gbps 16 bit NRZ signal, eye diagrams with an extinction ratio of 12.33 dB for output port 1 and 11.47 dB for output port 2 with 10 Gb/s 231 − 1 pseudo random bit sequence input data signal are observed. Figure 8 shows no noise floor up to BER of 10−12 and maximum power penalty of about 1.7 dB is measured at the BER of 10−9. The clear output waveforms, rising/falling time, eye diagrams, and BER plot show the good performance of proposed short pulse controlled optical switch and proves the proposed switch using single mode Fabry-Pérot laser diodes.
Fig. 8 BER plot of output ports of proposed short pulse controlled optical switch.
We have proposed and demonstrated a novel approach of short pulse controlled optical switch using self-injected single mode Fabry-Pérot laser diode along with the analysis of wavelength detuning effect on hysteresis width and rising/falling time of SMFP-LD. The analysis provides the information for choosing the wavelength detuning and hence the optimal power for the different beams to be used in the proposed idea. The minimum pulse duration of 280 ps are used for switching 10 Gb/s input data at the output ports. The output of the proposed scheme is verified with clear waveforms, eye diagrams with extinction ratio of more than 11 dB for both output ports, less rising/falling time of about 30 ps and 40 ps, and maximum power penalty of about 1.7 dB at BER of 10−9. Since SMFP-LDs are used in the proposed scheme, there is no need of additional probe beam and high biasing current as required in SOAs and other methods. Besides SMFP-LDs cost less than other active device used for the switching purpose which we believe is cost effective and power efficient. The maximum input data rate of 10 Gb/s can be further increased by increasing the relaxation oscillation of solitary lasers, which can be obtained by engineering the cavity length, the injected power and the injected current. The demonstrated short pulse optical switch can be used for power saving architecture and controlling applications, where there is a need to control the output with pulses. The calculation of total power consumption and its footprint on power saving along with the integration issues of device is already under research, which will provide more benefits to the applications in optical networks with short pulse controlled optical switch using SMFP-LDs.
1. Y. Liu, E. Tangdiongga, Z. Li, H. de Waardt, A. M. J. Koonen, G. D. Khoe, X. Shu, I. Bennion, and H. J. S. Dorren, "Error-free 320-Gb/s all-optical wavelength conversion using a single semiconductor optical amplifier," J. Opt. Soc. Am. B 25, 103–108 (2007).
2. E. Tangdiongga, H. C. H. Mulvad, H. de Waardt, G. D. Khoe, A. M. J. Koonen, and H. J. S. Dorren, "SOA- based clock recovery and demultiplexing in a lab trial of 640-Gb/s OTDM transmission over 50-km fibre link," Proceedings of European Conference and Exhibition on Optical Communication, (Berlin, 2007), pp. 57–58.
3. J. T. Kim, J. J. Ju, S. Park, M. S. Kim, S. K. Park, and M. H. Lee, "Chip-to-chip optical interconnect using gold long-range surface plasmon polariton waveguides," Opt. Express 16(17), 13133–13138 (2008). [CrossRef] [PubMed]
4. K. J. Barker, A. Benner, R. Hoare, A. Hoisie, A. K. Jones, D. K. Kerbyson, D. Li, R. Melhem, R. Rajamony, E. Schenfeld, S. Shao, C. Stunkel, and P. Walker, "On the feasibility of optical circuit switching for high performance computing systems," Proceedings of ACM/IEEE Supercomputing, (Seattle, WA, 2005), pp. 16. [CrossRef]
5. R. Hemenway, R. Grzybowski, C. Minkenberg, and R. Luijten, "Optical packet-switched interconnect for super-computer applications," J. Opt. Netw. 3(12), 900–914 (2004). [CrossRef]
6. D. M. Gvozdić, M. M. Krstić, and J. V. Crnjanski, "Switching time in optically bistable injection-locked semiconductor lasers," Opt. Lett. 36(21), 4200–4202 (2011). [CrossRef] [PubMed]
7. M. M. Krstić, J. V. Crnjanski, and D. M. Gvozdić, "Injection power and detuning-dependent bistability in Fabry Pérot laser diodes," IEEE J. Quantum Electron. 18(2), 826–833 (2012). [CrossRef]
8. G. T. Kanellos, D. Fitsios, T. Alexoudi, C. Vagionas, A. Miliou, and N. Pleros, "Bringing WDM Into Optical Static RAM Architectures," J. Lightwave Technol. 31(6), 988–995 (2013). [CrossRef]
9. P. Maniotis, D. Fitsios, G. T. Kanellos, and N. Pleros, "Optical Buffering for Chip Multiprocessors: A 16GHz Optical Cache Memory Architecture," J. Lightwave Technol. 31(24), 4175–4191 (2013). [CrossRef]
10. Z. Zang and Y. Zhang, "Low-switching power (<45mW) optical bistability based on optical nonlinearity of ytterbium-doped fiber with a fiber Bragg grating pair," J. Mod. Opt. 59(2), 161–165 (2012). [CrossRef]
11. M. Jamali, V. Ahmadi, and M. Razaghi, "Optical self-switching based on a semiconductor- optical-amplifier-assisted Sagnac interferometer," J. Opt. Soc. Am. B 30(10), 2576–2583 (2013). [CrossRef]
12. H. Ju, S. Zhang, D. Lenstra, H. de Waardt, E. Tangdiongga, G. Khoe, and H. J. S. Dorren, "SOA-based all-optical switch with subpicosecond full recovery," Opt. Express 13(3), 942–947 (2005). [CrossRef] [PubMed]
13. Z. Zang and W. Yang, "Theoretical and experimental investigation of all-optical switching based on cascaded LPFGs separated by an erbium-doped fiber," J. Appl. Opt. 109, 103106 (2011).
14. Z. Zang and Y. Zhang, "Analysis of optical switching in a Yb3+-doped fiber Bragg grating by using self-phase modulation and cross-phase modulation," Appl. Opt. 51(16), 3424–3430 (2012). [CrossRef] [PubMed]
15. J. M. Martinez, J. Herrera, F. Ramos, and J. Marti, "All-optical Address Recognition Scheme for Label Swapping Networks," IEEE Photon. Technol. Lett. 18(1), 151–153 (2006). [CrossRef]
16. J. P. Wang, B. S. Robinson, S. J. Savage, S. A. Hamilton, E. P. Ippen, R. Mu, H. Wang, J. Sarathy, and B. B. Stefanov, "Efficient performance optimization of SOA-MZI devices," Opt. Express 16(5), 3288–3292 (2008). [CrossRef] [PubMed]
17. L. Y. Chan, P. K. A. Wai, L. F. K. Lui, B. Moses, W. H. Chung, H. Y. Tam, and M. S. Demokan, "Demonstration of an all-optical switch by use of a multiwavelength mutual injection-locked laser diode," Opt. Lett. 28(10), 837–839 (2003). [CrossRef] [PubMed]
18. M. Uddin, J. S. Cho, and Y. H. Won, "All-optical multicasting NOT and NOR logic gates using gain modulation in an FP-LD," IEICE Electron. Express 6(2), 104–110 (2009). [CrossRef]
19. L. Y. Chan, K. K. Qureshi, P. K. A. Wai, B. Moses, L. F. K. Lui, H. Y. Tam, and M. S. Demokan, "All-optical bit-error monitoring system using cascaded inverted wavelength converter and optical NOR gate," IEEE Photon. Technol. Lett. 15(4), 593–595 (2003). [CrossRef]
20. Y. D. Jeong, J. S. Cho, Y. H. Won, H. J. Lee, and H. Yoo, "All-optical flip-flop based on the bistability of injection locked Fabry-Perot laser diode," Opt. Express 14(9), 4058–4063 (2006). [CrossRef] [PubMed]
21. B. Nakarmi, M. Rakib-Uddin, T. Q. Hoai, and Y. H. Won, "A simple controlled all-optical ON/OFF switch using gain modulation in single mode Fabry-Prot laser diode," IEEE Photon. Technol. Lett. 24, 212–214 (2011). [CrossRef]
22. B. Nakarmi, M. Rakib-Uddin, and Y. H. Won, "Realization of all-optical multi-logic functions and a digital adder with input beam power management for multi-input injection locking in a single-mode Fabry-Pérot laser diode," Opt. Express 19(15), 14121–14129 (2011). [CrossRef] [PubMed]
23. B. Nakarmi, Y. H. Won, and X. Zhang, "External cavity based single mode Fabry-Prot laser diode and its application towards all-optical digital circuits," Proceedings of SPIE Photonics Asia, (Beijing, 2012), pp. 57–58.
24. E. K. Lau, H. K. Sung, and M. C. Wu, "Frequency response enhancement of optical injection-locked lasers," IEEE J. Quantum Electron. 44(1), 90–99 (2008). [CrossRef]
25. Y. D. Jeong, Y. H. Won, S. O. Choi, and J. H. Yoon, "Tunable single-mode Fabry-Perot laser diode using a built-in external cavity and its modulation characteristics," Opt. Lett. 31(17), 2586–2588 (2006). [CrossRef] [PubMed]
26. M. Krstić, J. Crnjanski, M. Masšanović, L. Johansson, L. Coldren, and D. Gvozdić, "Multivalued stability map of an injection-locked semiconductor laser," IEEE J. Quantum Electron. 19(4), 1501408 (2013). [CrossRef]
27. H. Yoo, Y. D. Jeong, Y. H. Won, M. Kang, and H. J. Lee, "All-optical wavelength conversion using absorption modulation of an injection-locked Fabry-Pérot laser diode," IEEE Photon. Technol. Lett. 16(2), 536–538 (2004). [CrossRef]
Y. Liu, E. Tangdiongga, Z. Li, H. de Waardt, A. M. J. Koonen, G. D. Khoe, X. Shu, I. Bennion, and H. J. S. Dorren, "Error-free 320-Gb/s all-optical wavelength conversion using a single semiconductor optical amplifier," J. Opt. Soc. Am. B 25, 103–108 (2007).
E. Tangdiongga, H. C. H. Mulvad, H. de Waardt, G. D. Khoe, A. M. J. Koonen, and H. J. S. Dorren, "SOA- based clock recovery and demultiplexing in a lab trial of 640-Gb/s OTDM transmission over 50-km fibre link," Proceedings of European Conference and Exhibition on Optical Communication, (Berlin, 2007), pp. 57–58.
J. T. Kim, J. J. Ju, S. Park, M. S. Kim, S. K. Park, and M. H. Lee, "Chip-to-chip optical interconnect using gold long-range surface plasmon polariton waveguides," Opt. Express 16(17), 13133–13138 (2008).
K. J. Barker, A. Benner, R. Hoare, A. Hoisie, A. K. Jones, D. K. Kerbyson, D. Li, R. Melhem, R. Rajamony, E. Schenfeld, S. Shao, C. Stunkel, and P. Walker, "On the feasibility of optical circuit switching for high performance computing systems," Proceedings of ACM/IEEE Supercomputing, (Seattle, WA, 2005), pp. 16.
R. Hemenway, R. Grzybowski, C. Minkenberg, and R. Luijten, "Optical packet-switched interconnect for super-computer applications," J. Opt. Netw. 3(12), 900–914 (2004).
D. M. Gvozdić, M. M. Krstić, and J. V. Crnjanski, "Switching time in optically bistable injection-locked semiconductor lasers," Opt. Lett. 36(21), 4200–4202 (2011).
M. M. Krstić, J. V. Crnjanski, and D. M. Gvozdić, "Injection power and detuning-dependent bistability in Fabry Pérot laser diodes," IEEE J. Quantum Electron. 18(2), 826–833 (2012).
G. T. Kanellos, D. Fitsios, T. Alexoudi, C. Vagionas, A. Miliou, and N. Pleros, "Bringing WDM Into Optical Static RAM Architectures," J. Lightwave Technol. 31(6), 988–995 (2013).
P. Maniotis, D. Fitsios, G. T. Kanellos, and N. Pleros, "Optical Buffering for Chip Multiprocessors: A 16GHz Optical Cache Memory Architecture," J. Lightwave Technol. 31(24), 4175–4191 (2013).
Z. Zang and Y. Zhang, "Low-switching power (<45mW) optical bistability based on optical nonlinearity of ytterbium-doped fiber with a fiber Bragg grating pair," J. Mod. Opt. 59(2), 161–165 (2012).
M. Jamali, V. Ahmadi, and M. Razaghi, "Optical self-switching based on a semiconductor- optical-amplifier-assisted Sagnac interferometer," J. Opt. Soc. Am. B 30(10), 2576–2583 (2013).
H. Ju, S. Zhang, D. Lenstra, H. de Waardt, E. Tangdiongga, G. Khoe, and H. J. S. Dorren, "SOA-based all-optical switch with subpicosecond full recovery," Opt. Express 13(3), 942–947 (2005).
Z. Zang and W. Yang, "Theoretical and experimental investigation of all-optical switching based on cascaded LPFGs separated by an erbium-doped fiber," J. Appl. Opt. 109, 103106 (2011).
Z. Zang and Y. Zhang, "Analysis of optical switching in a Yb3+-doped fiber Bragg grating by using self-phase modulation and cross-phase modulation," Appl. Opt. 51(16), 3424–3430 (2012).
J. M. Martinez, J. Herrera, F. Ramos, and J. Marti, "All-optical Address Recognition Scheme for Label Swapping Networks," IEEE Photon. Technol. Lett. 18(1), 151–153 (2006).
J. P. Wang, B. S. Robinson, S. J. Savage, S. A. Hamilton, E. P. Ippen, R. Mu, H. Wang, J. Sarathy, and B. B. Stefanov, "Efficient performance optimization of SOA-MZI devices," Opt. Express 16(5), 3288–3292 (2008).
L. Y. Chan, P. K. A. Wai, L. F. K. Lui, B. Moses, W. H. Chung, H. Y. Tam, and M. S. Demokan, "Demonstration of an all-optical switch by use of a multiwavelength mutual injection-locked laser diode," Opt. Lett. 28(10), 837–839 (2003).
M. Uddin, J. S. Cho, and Y. H. Won, "All-optical multicasting NOT and NOR logic gates using gain modulation in an FP-LD," IEICE Electron. Express 6(2), 104–110 (2009).
L. Y. Chan, K. K. Qureshi, P. K. A. Wai, B. Moses, L. F. K. Lui, H. Y. Tam, and M. S. Demokan, "All-optical bit-error monitoring system using cascaded inverted wavelength converter and optical NOR gate," IEEE Photon. Technol. Lett. 15(4), 593–595 (2003).
Y. D. Jeong, J. S. Cho, Y. H. Won, H. J. Lee, and H. Yoo, "All-optical flip-flop based on the bistability of injection locked Fabry-Perot laser diode," Opt. Express 14(9), 4058–4063 (2006).
B. Nakarmi, M. Rakib-Uddin, T. Q. Hoai, and Y. H. Won, "A simple controlled all-optical ON/OFF switch using gain modulation in single mode Fabry-Prot laser diode," IEEE Photon. Technol. Lett. 24, 212–214 (2011).
B. Nakarmi, M. Rakib-Uddin, and Y. H. Won, "Realization of all-optical multi-logic functions and a digital adder with input beam power management for multi-input injection locking in a single-mode Fabry-Pérot laser diode," Opt. Express 19(15), 14121–14129 (2011).
B. Nakarmi, Y. H. Won, and X. Zhang, "External cavity based single mode Fabry-Prot laser diode and its application towards all-optical digital circuits," Proceedings of SPIE Photonics Asia, (Beijing, 2012), pp. 57–58.
E. K. Lau, H. K. Sung, and M. C. Wu, "Frequency response enhancement of optical injection-locked lasers," IEEE J. Quantum Electron. 44(1), 90–99 (2008).
Y. D. Jeong, Y. H. Won, S. O. Choi, and J. H. Yoon, "Tunable single-mode Fabry-Perot laser diode using a built-in external cavity and its modulation characteristics," Opt. Lett. 31(17), 2586–2588 (2006).
M. Krstić, J. Crnjanski, M. Masšanović, L. Johansson, L. Coldren, and D. Gvozdić, "Multivalued stability map of an injection-locked semiconductor laser," IEEE J. Quantum Electron. 19(4), 1501408 (2013).
H. Yoo, Y. D. Jeong, Y. H. Won, M. Kang, and H. J. Lee, "All-optical wavelength conversion using absorption modulation of an injection-locked Fabry-Pérot laser diode," IEEE Photon. Technol. Lett. 16(2), 536–538 (2004).
Ahmadi, V.
Alexoudi, T.
Bennion, I.
Chan, L. Y.
Cho, J. S.
Choi, S. O.
Chung, W. H.
Coldren, L.
Crnjanski, J.
Crnjanski, J. V.
de Waardt, H.
Demokan, M. S.
Dorren, H. J. S.
Fitsios, D.
Grzybowski, R.
Gvozdic, D.
Gvozdic, D. M.
Hamilton, S. A.
Hemenway, R.
Herrera, J.
Hoai, T. Q.
Ippen, E. P.
Jamali, M.
Jeong, Y. D.
Johansson, L.
Ju, H.
Ju, J. J.
Kanellos, G. T.
Kang, M.
Khoe, G.
Khoe, G. D.
Kim, J. T.
Kim, M. S.
Koonen, A. M. J.
Krstic, M.
Krstic, M. M.
Lau, E. K.
Lee, H. J.
Lee, M. H.
Lenstra, D.
Li, Z.
Liu, Y.
Lui, L. F. K.
Luijten, R.
Maniotis, P.
Marti, J.
Martinez, J. M.
Masšanovic, M.
Miliou, A.
Minkenberg, C.
Moses, B.
Mu, R.
Mulvad, H. C. H.
Nakarmi, B.
Park, S. K.
Pleros, N.
Qureshi, K. K.
Rakib-Uddin, M.
Ramos, F.
Razaghi, M.
Robinson, B. S.
Sarathy, J.
Savage, S. J.
Shu, X.
Stefanov, B. B.
Sung, H. K.
Tam, H. Y.
Tangdiongga, E.
Uddin, M.
Vagionas, C.
Wai, P. K. A.
Wang, H.
Wang, J. P.
Won, Y. H.
Wu, M. C.
Yang, W.
Yoo, H.
Yoon, J. H.
Zang, Z.
Zhang, S.
Zhang, X.
Zhang, Y.
IEEE J. Quantum Electron. (3)
IEEE Photon. Technol. Lett. (4)
IEICE Electron. Express (1)
J. Appl. Opt. (1)
J. Lightwave Technol. (2)
J. Mod. Opt. (1)
J. Opt. Netw. (1)
J. Opt. Soc. Am. B (2)
Opt. Lett. (3)


HEY YOU GUYS! May the force be with you on this fatherhood adventure. While one does not simply select any Geek Dad item, feel the force and buy or buy not, there is no try... Just buy!
We even have "My Dad is a Geek" shirts for my precioussss ones in onesie and youth sizes.
Does Life of Dad have you covered or what? Heck Yes! GOSH!
Live long and prosper Geeks!


text:
package de.dakror.mbg;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

import org.json.JSONException;
import org.json.JSONObject;

import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
import android.graphics.Color;
import android.os.Build;
import android.os.Bundle;
import android.preference.PreferenceFragment;
import android.preference.PreferenceManager;
import android.support.v4.widget.SwipeRefreshLayout;
import android.support.v4.widget.SwipeRefreshLayout.OnRefreshListener;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

/**
 * @author Maximilian Stark | Dakror
 */
public class MBGStandIns extends Activity implements OnSharedPreferenceChangeListener, OnRefreshListener {
	/**
	 * @author Maximilian Stark | Dakror
	 */
	public static class SettingsFragment extends PreferenceFragment {
		@Override
		public void onCreate(Bundle savedInstanceState) {
			super.onCreate(savedInstanceState);
			addPreferencesFromResource(R.xml.settings);
		}
	}

	/**
	 * @author Maximilian Stark | Dakror
	 */
	public static class SettingsActivity extends Activity {
		@Override
		public void onCreate(Bundle savedInstanceState) {
			super.onCreate(savedInstanceState);
			setContentView(R.layout.acitivity_settings);
		}

		@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
		@Override
		public boolean onNavigateUp() {
			doWarnings(this, false);
			return super.onNavigateUp();
		}
	}

	SwipeRefreshLayout refreshLayout;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);

		setContentView(R.layout.activity_mbgstandins);
		Intent service = new Intent(this, NotificationService.class);
		startService(service);

		refreshLayout = (SwipeRefreshLayout) findViewById(R.id.swiperefresh);
		refreshLayout.setColorSchemeColors(Color.parseColor("#FF6F00"), Color.parseColor("#ffb300"), Color.parseColor("#FFD54F"), Color.parseColor("#FFF8E1"));
		// using http://www.google.com/design/spec/style/color.html#color-color-palette
		refreshLayout.setOnRefreshListener(this);

		try {
			makeTable();
		} catch (JSONException e) {
			e.printStackTrace();
		}
		PreferenceManager.getDefaultSharedPreferences(this).registerOnSharedPreferenceChangeListener(this);

		String pwd = PreferenceManager.getDefaultSharedPreferences(this).getString(getString(R.string.password_id), "");
		String courses = PreferenceManager.getDefaultSharedPreferences(this).getString(getString(R.string.courses_id), "");

		if (pwd.length() == 0 || courses.length() == 0) {
			Intent intent = new Intent(this, SettingsActivity.class);
			startActivity(intent);
		}
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		MenuInflater inflater = getMenuInflater();
		inflater.inflate(R.menu.options_menu, menu);
		return true;
	}

	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
		switch (item.getItemId()) {
			case R.id.menu_refresh:
				onRefresh();
				break;
			case R.id.settings:
				Intent intent = new Intent(this, SettingsActivity.class);
				startActivity(intent);
				break;
		}
		return super.onOptionsItemSelected(item);
	}

	JSONObject data;

	public void makeTable() throws JSONException {
		Set<StandIn> set = new HashSet<StandIn>();
		final ListView listView = (ListView) findViewById(R.id.standins_list);

		String standins = PreferenceManager.getDefaultSharedPreferences(this).getString(getString(R.string.standins_is), null);
		if (standins != null) {
			data = new JSONObject(standins);
			if (doWarnings(this, false)) set.addAll(Util.loadStandIns(data.getJSONArray("courses")));
		}

		final ArrayList<StandIn> list = new ArrayList<StandIn>(set);
		Collections.sort(list);

		final String[] str = new String[list.size() + 1];
		int i = 0;

		if (standins == null) {
			str[0] = "Keine Einträge verfügbar.";
		} else {
			str[i++] = "Vertretungsplan des " + data.getString("date") + ".";
			Set<String> courses = new HashSet<String>(Arrays.asList(Util.getCourses(this).split(",")));
			for (StandIn s : list) {
				s.added = true;
				str[i] = Util.getMessage(courses, s, false);
				i++;
			}
		}

		listView.setAdapter(new BaseAdapter() {
			@Override
			public View getView(int position, View convertView, ViewGroup parent) {
				View view = null;

				if (position > 0) view = setView(str[position], list.get(position - 1).text.length() == 0 ? null : list.get(position - 1).text);
				else {
					String info = data != null ? data.optString("info") : "";
					view = setView(str[position], info.length() > 0 ? info : "für die Klasse(n) / Kurs(e): " + Util.getCourses(MBGStandIns.this).replace(",", ", "));
				}

				view.setOnClickListener(null);

				return view;
			}

			public View setView(String headerText, String subText) {
				View view = ((LayoutInflater) getSystemService(LAYOUT_INFLATER_SERVICE)).inflate(subText == null ? R.layout.standins_textview_alt : R.layout.standins_textview, null);
				TextView header = (TextView) view.findViewById(R.id.standins_textview_header);
				header.setText(headerText);
				if (subText != null) {
					TextView text = (TextView) view.findViewById(R.id.standins_textview_text);
					text.setText(subText);
				}

				return view;
			}

			@Override
			public long getItemId(int position) {
				return position;
			}

			@Override
			public Object getItem(int position) {
				return str[position];
			}

			@Override
			public int getCount() {
				return str.length;
			}
		});
	}

	@Override
	public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
		if (key.equals(getString(R.string.refresh_id))) {
			refreshLayout.setRefreshing(sharedPreferences.getBoolean(key, false));
		}

		if (key.equals(getString(R.string.standins_is))) {
			try {
				makeTable();
			} catch (JSONException e) {
				e.printStackTrace();
			}
		} else {
			doWarnings(this, false);
		}
	}

	public static boolean doWarnings(Context ctx, boolean inetToo) {
		int err = PreferenceManager.getDefaultSharedPreferences(ctx).getInt(ctx.getString(R.string.error_id), 200);
		boolean pwd = PreferenceManager.getDefaultSharedPreferences(ctx).getString(ctx.getString(R.string.password_id), "").length() > 0;
		boolean crs = Util.getCourses(ctx).length() > 0;
		boolean inet = inetToo ? Util.hasConnection(ctx) : true;
		String msg = "";

		if (err == 401) msg = "Das von Ihnen eingegebene Passwort ist falsch.";
		else if (!pwd) msg = "Bitte geben Sie das Passwort ein.";

		if (!crs) msg += "Bitte geben Sie Ihre Klassen / Kurse an.";

		if ((!inet || err == 199) && inetToo) msg = "Nicht mit dem Internet verbunden. Vertretungsplan konnte nicht aktualisiert werden.";
		if (err != 200 && msg.length() == 0) msg = "Es ist ein Fehler aufgetreten. Bitte versuchen Sie es später erneut.";

		if (msg.length() > 0) {
			Toast.makeText(ctx, msg, Toast.LENGTH_SHORT).show();
		}

		PreferenceManager.getDefaultSharedPreferences(ctx).edit().putInt(ctx.getString(R.string.error_id), 200).apply(); // reset error code

		return pwd && crs && inet;
	}

	@Override
	public void onRefresh() {
		if (doWarnings(this, true)) PreferenceManager.getDefaultSharedPreferences(this).edit().putBoolean(getString(R.string.refresh_id), true).apply();
		else refreshLayout.setRefreshing(false);
	}
}

redpajama_set_name: RedPajamaGithub


text:
Tag: online pokies
Written by Kari Weller on July 22, 2019
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