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Cheap, Accurate RFID Tracking of Museum Visitors for Personalized Content Delivery
Timothy Baldwin and Lejoe Thomas Kuriakose, University of Melbourne, Australia
In this project, we explored the deployment of RFID-based technologies to observe visitors' behaviour in a museum to record what exhibits they visit and when. This data has tremendous potential to enhance museum visits through personalizing information via dynamic interfaces, or profiling the visitor to make recommendations for future activity inside or outside the museum. The outcomes of the project demonstrate the viability of (passive) RFID technologies for museum visitor tracking and provide empirical validation of the near-human tracking accuracy of the system in two different environments.
Keywords: tracking, RFID, exhibit engagement, personalized content delivery, visitor location, evaluation
Automatically tracking the location of objects has been an area of interest for several years in various fields. While GPS has revolutionized outdoor location-based services, there is no de facto standard for high-precision indoor localization. Indoor position-based systems have been slow to take off for a number of reasons, including high cost, complexity, administrative difficulties and limited accuracy. GPS-like technologies for indoor-based location tracking still lack positioning accuracy, so alternative cost-effective location-based services must be considered. Obvious candidates in terms of the availability and maturity of the underlying technology are RFID, Bluetooth and Wireless LAN (Hightower and Borriello, 2001).
Our study is focused on tracking the location of visitors in a museum environment. We explore the deployment of passive RFID-based technologies for this purpose, primarily because of the affordability of passive RF tags and readers. Our underlying motivation in tracking visitors is to use the information as a basis for learning about patterns of exhibit/gallery interaction, and ultimately to provide personalized information to visitors (Bohnert et al., 2008a, Bohnert et al., 2008b). Much of the work on RFID-based tracking in museum environments has relied on the visitor physically swiping an RFID tag at predetermined locations in the museum space (see Section 4). This has obvious disadvantages in terms of unobtrusiveness (the physical act of swiping detracts from the museum experience) and reliability of the data (there's no guarantee the visitor will continue to swipe the tag throughout the museum visit). Our approach makes use of the same RFID technology, but assesses the feasibility of tracking unobtrusively, without any action on the part of the visitor. The system described in this paper detects and records a set of triples of tag ID, reader ID and timestamp, representing that a given visitor was at a particular reader at the indicated time; the position can be inferred from the predetermined location of each RFID.
This study is a part of the Kubadji project (http://www.kubadji.org), a research collaboration involving the University of Melbourne, Monash University and Melbourne Museum. The goal of the project is to develop technologies to dynamically deliver personalized information to visitors in diverse, information rich, physical environments, focusing on museums. The contribution of this research is to explore the viability of unobtrusive tracking technologies to support the physical deployment of the developed technologies in a physical space. As part of this, we propose a number of evaluation methodologies to encourage greater cross-comparison of tracking technologies.
The remainder of this paper is structured as follows. First, we survey location-sensing techniques for indoor-based location tracking and their basic technological basis. We then survey relevant work on RFID-based tracking in museums, before presenting the technical details of our approach, along with the system architecture and details. Finally, we detail a tracking experiment where we compare the proposed method with human tracker performance in a physical tracking setting, and discuss and analyze the results.
2. Location Sensing Technologies
There exist three basic techniques for location sensing: triangulation, scene analysis, and proximity. In this section, we detail the proximity technique as it is the underlying principle behind RFID-based systems.
2.1. Proximity
Proximity-based location-sensing techniques work by determining how close an object is to a known location. The object's presence is detected in a given field of range. The three general approaches to sensing proximity are:
Detecting physical contact: this is the most basic form of proximity sensing, and relies on physical contact between an object and a sensor; examples include touch sensors, pressure sensors and capacitive field detectors.
Monitoring wireless access points: these monitor a mobile device when it is within the range of wireless access point.
Observing electronic IDs: scanning devices detect electronic IDs such as electronic card logs or identification tags (e.g. RFID tags).
In each case, the position of the mobile object can be inferred from the predetermined location of the sensing device.
2.2. Location-sensing system properties
For any location-sensing system, the following properties must be considered.
2.2.1. Accuracy
To determine the accuracy of a location sensing system, the error distribution incurred when locating objects must be assessed, along with relevant dependencies such as the density of infrastructural elements. For our purposes, we are interested in gauging whether we are able to achieve "sufficient" levels of accuracy with the proposed location sensing technology, relative to gold-standard human tracking. Separately, we are engaged in research to ascertain the impact of loss of tracking accuracy on services relevant to the aims of the Kubadji project,;namely, personalized content delivery and recommendation.
2.2.2. Scalability
The scalability of a location-sensing system is determined relative to its coverage per unit of infrastructure, and the number of objects the system can locate per unit of infrastructure over a given time interval. Time is an important factor due to the limited bandwidth available in sensing objects. RFID-based technologies can tolerate a maximum number of communications before the channel becomes congested. Beyond this point, there is either an increase in locational latency or a loss in accuracy due to the system calculating an object's position less frequently.
Systems can often expand scalability by increasing the number of infrastructure components. Some of the hurdles to scalability are infrastructure cost and middleware complexity.
2.2.3. Recognition
Recognition is the ability to automatically identify located objects, e.g. to enable a specific action based on its ID. For example, an airport luggage handling mechanism needs to route luggage to the correct flight or baggage claim carousel.
Recognition can be achieved by assigning unique names or GUIDs to objects. In the case of RFID, RF tags are equipped with a unique tag identifier. Once an object has been identified by its GUID, the infrastructure can access a centralized database to look up the name, type or other semantic information about the object.
Cost can be assessed in several ways:
1. Time, including factors such as installation overhead and system administration needs.
2. Space, including the amount of installed infrastructure and the hardware's size and form factor.
3. Capital, including factors such as the price per mobile unit or infrastructure elements and the salary of support personnel.
This section provides a brief summary of related work in tracking objects of interest.
3.1. Detecting visitor movement by differential air pressure sensing
Pantel et al. (2008) described an approach that detects gross movement and room transitions by sensing differential air pressure from a single point in a building. It utilizes existing central heating, ventilation and air conditioning (HVAC) systems. The building or space as a whole forms a closed circuit for air circulation, and HVAC provides a centralized airflow source and therefore a central point for monitoring.
Variation in airflow in a monitored space caused by human movement, particularly obstruction of doorways, results in static pressure changes in the HVAC air handler unit. The proposed system detects this type of pressure variation via sensors mounted on the air filter and calculates exactly where exactly certain movements are occurring in the monitored space. In experiments by the authors, the system was shown to be able to classify unique transition events with up to 75-85% accuracy.
Although it makes use of a central monitoring point to classify human movement, such an approach cannot be utilized in a museum environment because the spaces are often large and open plan, complicating the detection of human movement. In addition, museums are usually not closed spaces (visitors are constantly entering and exiting the museum), it is questionable whether the system would scale to large volumes of visitor traffic, and there is no facility to identify which individual is associated with a given movement.
3.2. WLAN-based tracking and information management
Savidis et al. (2008) proposed the combination of different location-aware systems to locate an object, based on both explicit 2D positioning technologies such as WLAN (e.g. the Ekahau system: http://www.ekahau.com/) and implicit 2D positioning from sensory modules such as RFID (which provides binary classification of whether an object is located within a given field) and infrared (which provides field-based or linear "tripwire" information). The idea is to utilize any available medium to extract position information regarding an object of interest and use software to resolve the ambiguities. Notable aspects of the proposed system are spatial content editing with mixed mode administration, system-initiated information based on location and user triggered data exploration - an efficient technique for lending out devices with minimal delay - and integrated usage of various location-sensing technologies such as WLAN, GPS and infrared beacons.
3.3. Recognition of viewing activity using electrooculography
Bulling et al. (2008) proposed a method for detecting eye movements of people using wearable electrooculography. The relevance of eye movements to this research is that we ideally wish to know not where visitors are physically located, but what is occupying their attention, for which purposes we need to know what they are looking at. See Section 6.3 for further discussion of this point.
The approach of Bulling et al. can be used in combination with RFID to precisely determine what exactly visitors are looking at and where they are physically positioned. RFID only provides their physical positioning, of course, and if two exhibits are close to each other, the RFID approach cannot easily pinpoint which they are nearest to. Additionally, it is entirely possible that they are located next to one exhibit but looking at a second exhibit.
The proposed method uses electrooculography as a measurement technique for recognition of user activity and attention. It consists of sensors worn on the body and thus can be implemented as a wearable system. In terms of intrusiveness and cost, however, this method has limited applicability in the museum domain.
4. RFID Technology in Museums
This section describes how RFID-based technology has been deployed in museums around the world.
eXspot is a customized RFID application which was prototyped in the Exploratorium in San Francisco, USA (Hsi and Fait, 2005). The system consists of an RFID reader package mounted on museum exhibits along with a wireless network connecting these readers to dynamically generated Web pages. The visitors each carry an RF tag in the form of a card or necklace, based on which eXspot tracks which exhibits they visited. The exhibit information is later available on a personalized Web page which each visitor can access via the Internet. The eXspot RFID readers also make it possible for visitors to trigger digital cameras to take their pictures. eXpot makes all this possible by having the reader constantly query its field for the presence of RF tags. When a visitor carrying an RF tag approaches the vicinity of a reader, the tag is read and its ID is sent over mote radio to a network base station. Similar to our system, a database is used to stored triples of time, exhibit ID, and tag ID.
Also at the Exploratorium, Fleck et al. (2002) had visitors swipe RFID cards to "bookmark" features of the museum to follow up on post-visit.
The Museum of Natural History in Aarhus, Denmark made use of RFID technology to provide a visitor learning and interaction tool called TaggedX. In an interactive exhibition called "Flying", 50 stuffed bird exhibits were fitted with RFID chips. Visitors carried PDAs fitted with RFID readers which actively scanned for RF-tagged exhibits. On detecting an exhibit, the PDA presented the visitor with quizzes, audio and video relevant to that exhibit.
The Tech Museum of Innovation in San Jose, USA implemented RFID technologies in one of its exhibitions after experimenting with barcode readers and paper tags. Visitors were given wristbands embedded with RFIDs that activate exhibits and trigger interaction with displays. Currently, they issue RFID-embedded tickets that allow users to bookmark information in interactive kiosks for post-visit access.
In perhaps the most closely-related research in the museum domain, Kanda et al. (2007) implemented an active RFID-based system to allow visitors to the Osaka Science Museum in Osaka, Japan to interact with robot exhibits. They separately used the collected data to estimate visitor trajectories and analyze visiting patterns. Compared to this research, active RFID has the advantage of tags regularly emitting a signal, allowing for more fine-grained analysis of visitor movements. Its primary disadvantage is cost, with a single unit costing thousands of dollars. It is thus not scalable to large numbers of visitors.
In summary, the primary use of RFID technologies in museums has been to support personalized in situ visitor interaction or to record which exhibits a visitor viewed, for use in post-visit content delivery. Our research differs in that we use RFID technologies explicitly for visitor tracking purposes, and evaluate the accuracy of our proposed method relative to human trackers.
5. Overview of Our Approach
This research focuses on the utilization of RFID to unobtrusively track museum visitors. Our immediate interests in the tracking data are to:
predict a visitor's future pathway in the museum,
recommend exhibits of potential interest to the visitor, and
personalize content delivered to those visitors (Bohnert et al., 2008a, Berkovsky et al., 2008).
There are no doubt other applications for the data, however, and the proposed system is compatible with the tracking functionalities of eXspot and the Tech Museum of Innovation, e.g. In essence, our interest is in developing a low-cost, scalable system which involves minimal instrumentation of the museum visitor and no explicit action on part of the visitor.
In the interests of determining the true accuracy of our tracking system, we put particular focus on comparing the performance of our system with that of human trackers in museum-like environments, based on two exhibit engagement "modalities": simple exhibit proximity, and visitor gaze. To this end, we propose a series of evaluation metrics for evaluating tracking accuracy.
Below, we first outline the system architecture of the RFID-based tracking system, and then describe the tracking software used by the human trackers.
5.1. System architecture and implementation
This section describes the system architecture and implementation of our RFID-based system. The system architecture consists of a set of RFID readers in known, fixed locations, and a central server monitoring the readers and logging visitor activity. When a tag is in the vicinity of a reader, the server records the timestamp, reader ID, and tag ID of the tag. An overview of the architecture is shown in Figure 1.
Fig 1: Architecture of our tracking system (the dotted rectangles represent the range of each RFID reader; the black dot in Area2 represents an RF tag)
The server runs services such as the RFID location tracker and a tool for storing and visualizing visitor tracks. The RFID location tracker is implemented in .NET using C# and makes use of Skyetek protocol Version 3 (STPV3) to communicate with the Skyetek RFID readers. It performs the function of detecting and reading tags in the vicinity of each reader. It does this via Skyetek APIs for the .NET (C#) platform. Each reader is located in a fixed location. When a tag is detected, the tag ID, reader ID, and timestamp are stored in the tracker database, which also contains exhibit details. The database used is Microsoft SQL Server 2005. The tags used are passive RF tags, which have the advantage of being cheap and not requiring battery power to function, but the disadvantage of needing to be in very close proximity to an RFID reader in order to be detected. To trace the location of a particular tag which is associated with a visitor, we developed Location Matrix View, also in the .NET platform. This provides a location matrix of a given tag, from which it is possible to infer the sequence of exhibits visited, the time spent at each exhibit, and so on. Location Matrix View also provides a way to extract a location matrix in the form of an Excel file.
The RFID readers used in this research are SkyeModule M9 by Skyetek, a multiprotocol UHF (862-955 Mhz) RFID reader platform. It is possible to adjust the RF power output of the readers from the server, which determines the range of the reader.
In our implementation, we connected the readers to the server via a USB interface. For a large-scale deployment this would obviously not scale well. It would be possible to overcome this restriction by connecting multiple RFID readers to a multiplexor, which could in turn be connected by any one of the host interfaces on the server.
Prior to commencement of live tracking, we implemented the following optimizations. First, we preconfigured the Skyeware software to recognize only ISO18000-6B RF tags, as this was the only tag type used in experiments. This improves performance because the reader is not burdened with auto-detecting the tag type, and is a valid assumption in a museum environment, where we have control over what types of tags we make available to visitors. Second, we set the RF output power of the three SkyModule M9 RFID readers to 27dBm to attain the maximum range of 1m. Third, we used antennas with linear polarization, which has the advantage of providing good range,but at the expense of tags needing to be at a specific orientation to the antenna. Finally, we placed 5 separate tags vertically in a single clear plastic badge holder, which visitors wore around their neck. The reason for using multiple tags was to increase the probability of tag detection; by using a neck-worn badge holder, we were able to ensure that the tags were vertically aligned and avoid tag rotation.
5.2. Software for manual tracking
The human trackers used the GeckoTracker software to manually track visitors to two mini-galleries (Bohnert and Zukerman, 2009). GeckoTracker is a cross-platform Java-based client which renders a map of a physical space, with exhibits realized as clickable regions. The human tracker tracks a single visitor at a time, and logs each exhibit 'interaction' by clicking on the corresponding region at the start of the interaction, and clicking that region again on completion of the interaction. Similar to the RFID-based tracking software, GeckoTracker generates a series of 4-tuples representing the visitor ID, exhibit ID, timestamp, and click event (on or off).
The clickable map is rendered from an SVG (scalable vector graphics) representation of the space, including region-based representation of each exhibit. We generated the SVG images in Inkscape.
GeckoTracker was run on a Linux-based laptop PC and a Windows-based tablet PC.
Fig 2: A screenshot of the GeckoTracker interface, with exhibits highlighted
Figure 2 is a screenshot of the GeckoTracker interface for Gallery 1 (see Section 6), with the three exhibits highlighted.
6. Experiments
In this section, we present our tracking experiments, in which we compare the accuracy of the proposed RFID-based tracking system with two human trackers, each using the GeckoTracker software.
6.1. Tracking setup
The experiments were carried out in two mini-galleries, set up in two independent spaces. We accepted one visitor at a time into a given mini-gallery, and had the system and each of the human trackers independently track their movements, generating three independent tracks per visitor, which formed the basis of our evaluation. Additionally, we explored two different modalities for exhibit engagement: (1) physical proximity, based on the assumption that proximity to an exhibit equates with interest in it; and (2) visitor gaze, where a visitor is considered to engage with an exhibit for the length of time they maintain eye contact with it. The two human trackers were asked to alternate between these two tracking modalities between one visitor and the next, ensuring that a given modality was used as the basis for tracking throughout a given visit, and also that the two human trackers based their track on the same modality for a given visitor. Physical proximity-based tracking is intended to mirror the operation of the RFID-based tracker, and designed to directly measure the accuracy of the automatic tracker based on its native modality. Visitor gaze-based tracking, on the other hand, is intended to be a more faithful representation of the true interest of the visitor, and is the actual procedure used by Melbourne Museum when manually assessing exhibit engagement (e.g. in newly-opened galleries). Clearly, the RFID-based tracker is unable to return direct readings for the gaze-based modality. Intuitively, therefore, we would expect the human trackers to have higher agreement with the RFID-based tracker for the physical proximity modality than the visitor gaze modality. The question we are asking in empirically evaluating the RFID-based tracker based on the two separate modalities is what the relative difference is for the two models of visitor engagement with a given exhibit, or conversely, whether simple physical proximity is an adequate model of true exhibit interest.
(a) Gallery 1 map (b) Gallery 2 map
Fig 3: Maps of the two mini-galleries used in our tracking experiments
(coloured regions indicate exhibit locations)
We conducted our experiments across two mini-galleries: Gallery 1 and Gallery 2. Each mini-gallery contained (the same) three exhibits, named Exhibit 1, Exhibit 2 and Exhibit 3, as detailed in Figure 3. The exhibits were prepared with the intention of mimicking a real museum environment, and contained information on the three heterogeneous themes of Godzilla monsters, vegetables and joinery, respectively, in the form of a printed set of PowerPoint-style slides in each case. The printed slides were mounted on a self-standing poster board in the same layout across the two mini-galleries. An RFID reader with single dedicated antenna was mounted at the centre of each of the exhibits. The reason we prepared only three exhibits was a purely logistical one: we had access to the hardware for only three readers of the type described above.
Visitors (all graduate students in the Department of Computer Science and Software Engineering at the University of Melbourne, not directly associated with this research) were invited to visit one of the mini-galleries (only one visit was recorded per visitor). The only instructions they were given were that they were to act as they would in visiting a gallery in a museum, including being given the option of carrying a camera with them to take pictures. They were then asked to place the badge holder containing the RF tags (see Section 5.1) around their neck, and were allowed to browse through the exhibits at their own pace in whatever manner they chose.
We first tracked 8 visitors in Gallery 1, before relocating the exhibits to Gallery 2 and tracking a further 7 (unique) visitors. The reason we used two separate spaces (with the same set of exhibits) was to control for the effects of the physical space on visitor behaviour and the accuracy of the RFID-based tracker. Gallery 1 was selected to be a smaller space with high reflexivity, possibly impacting on the accuracy of RFID antennae. Gallery 2 was a much larger, more regularly-shaped space, more like an open-plan gallery in an actual museum.
6.2. Evaluation methodology
On completion of the tracking, we had a total of 3 tracks (two human and one machine) for each of the 15 visitors. We were unable to identify a standard evaluation methodology for tracking experiments of this type, and thus chose to develop our own evaluation metrics. In each case, we evaluate a given pairing of tracks for a given visitor; namely, the pairing of the two human trackers, and the pairing of the RFID-based tracker with the "intersection" of the human trackers. The human pairing is intended to be an upper bound estimate of the best-possible tracking performance we could expect to achieve, based on the assumption that humans are "gold standard" trackers. The machine-human pairing, on the other hand, is intended to provide a relative evaluation of how close to human performance the machine is able to get. We calculate the 'intersection' of the human trackers by computing the time intervals where both trackers have recorded that the visitor is engaged with a given exhibit. For example, consider the two triples from human tracker 1 and human tracker 2, respectively:
(Exibit1, 00:00:05, 00:00:35) [start time = 5 seconds into visit, end time = 35 seconds into visit]
(Exibit1, 00:00:15, 00:01:00)
The intersection would be calculated as:
(Exibit1, 00:00:15, 0:00:35)
as this is the duration where both trackers are in agreement that the visitor is engaged with the exhibit.
We developed a total of two evaluation metrics, based on either: (1) the simple sequence of exhibits in each of the two tracks under consideration (ignoring the time spent engaging with each exhibit); or (2) the timed sequence of exhibits, where the relative agreement in the duration (and start and end points) of engagement with a given exhibit is taken into account.
6.2.1. Edit Distance
The first evaluation metric, based on the simple sequence of exhibits, is edit distance (a.k.a. Levensthein distance). First, for each tracking mode (i.e. RFID, human tracker 1 or human tracker 2), we generate a list of triples of the form (Exhibit ID, start time, end time) for each visitor (ignoring the time spent at each exhibit). We then calculate the edit distance between a given pairing of exhibit sequences; that is, the minimal number of insertion, deletion and substitution operations required to transform one sequence into the second, first for the pairing of the two human trackers and then for the intersection of the two human trackers readings and the RFID based readings. For example, let us consider the two sequences, E1,E2,E3,E4 (i.e. Exhibit 1 followed by Exhibit 2, and so on) and E2,E1,E3,E4,E5. Starting from the first sequence, it is possible to generate the second by: (1) substituting E2 for E1 (generating E2,E2,E3,E4), (2) substituting E1 for the second E2 (generating E2,E1,E3,E4), and (3) inserting E5 at the end of the sequence (generating E2,E1,E3,E4,E5). The reader can hopefully confirm that this is the minimum number of basic edit operations needed to transform the first sequence into the second (and also that the result is symmetric). As a result, the edit distance between the two strings is calculated to be 3 (2 substitutions and 1 insertion). In practice, we use the standard dynamic programming algorithm to calculate edit distance.
Edit distance returns a non-negative integer. The lower this number, the greater the agreement between the two tracks (noting that identical tracks will have an edit distance of 0).
6.2.2. Paired t-test
The second evaluation metric is based on a two-tailed paired t-test, over a pair of timed sequences of exhibits. The paired t-test is a parametric hypothesis test for comparing paired samples; i.e., two sets of observations over a common sample space. In order to apply it to our tracking data, we need the two timed sequences to be fully aligned. Assume, for example, we have the following track for human tracker 1:
(Exhibit 1,0:00:05,0:00:35) [start time = 5 seconds into visit, and end time = 35 seconds into visit]
(Exhibit 1,0:00:40,0:00:55)
and the following track for human tracker 2:
The two sequences are of different length, and cannot be 'paired' cleanly. We resolve this by aligning the two sequences by calculating the pairings with the highest overlap (essentially overlaying the two sequences onto a timeline and aligning a given observation to the observation in the second track with the highest time overlap, resolving ties via a greedy search mechanism to ensure a single observation is mapped to at most one observation of non-zero overlap in the second track). In our example above, we would arrive at the following alignment:
Human tracker 1
We then convert the start/end times for each observation into durations, and for unpaired observations, insert a zero-duration observation:
(Exhibit 1,0:00:30)
We normalize the durations by calculating the arithmetic mean for each pair of observations, and calculating the relative deviation from the mean for each observation, by subtracting the mean from the original value and dividing the result by the mean. This would result in the following normalized values:
(Exhibit 1,-0.20)
(Exhibit 1,0.20)
Finally, we perform a two-tailed paired t-test over the two arrays of normalized values, and return the t value. For the detailed mathematics, we refer the reader to a statistics textbook. In our example, the final t value is 0.59. Similarly to edit distance, the higher the t value, the greater the difference between the two tracks (but here, two identical tracks will produce a divide by 0 error, which we can interpret as 0 for the sake of stability).
6.3. Results and analysis
We present the results of our tracking experiment for Gallery 1 and Gallery 2 in Tables 1 and 2, respectively, based on our two evaluation metrics, separating out the two tracking modalities (gaze and distance).
Edit distance
Paired t-test
HT1 vs. HT2
HT vs. RFID
Table 1: For Gallery 1, the average edit distance and t value (based on the paired t-test) for human tracker 1 vs. human tracker 2 (HT1 vs. HT2), and human tracker intersection vs. RFID-based readings (HT vs. RFID), for the gaze and distance tracking modalities
First, we observe that the RFID-based tracker always performs worse than human performance (i.e. the human trackers agree with each other to a greater degree than they agree with the RFID-based tracker), a predictable trend given that humans provide the gold-standard for the task. More importantly, the relative agreement with the human trackers for the RFID-based tracker is almost unchanged between the distance and gaze modalities. This leads to the surprising conclusion that the RFID-based tracker is equally capable of emulating proximity-based tracking as it is gaze-based tracking, which is a very promising result for the proposed technology. Recall also that the RFID-based tracker is a proximity-based technology, making it doubly surprising that it should work so well. Returning to our research question in Section 6.1, it would appear that proximity is a relatively good proxy for the gaze modality, and that proximity-based technologies offer a cheap means of gaze-based tracking. Comparing our human-human upper bound performance between distance- and gaze-based tracking, we see relatively little difference for Gallery 1 but a larger difference in terms of the t value for Gallery 2. In fact, for Gallery 2, the t-test suggests that there is very little separating human and machine performance. A primary cause of this result is one particularly "excitable" visitor who continually looked back and forth between exhibits and the trackers, and attempted to engage the trackers in conversation on the objectives of the research and what they were doing. This particular visit was tracked based on gaze, and the continual changes in gaze and approaches from the visitor led to markedly lower agreement for this one visitor. We included this in our results, but in practice this is somewhat of an anomaly and not indicative of what we would expect to observe in a real-world museum.
Comparing the results for Gallery 1 and Gallery 2, the edit distance was appreciably higher in Gallery 2, and conversely, the t value was appreciably higher in Gallery 1. The reason for the relatively low edit distance in Gallery 1 was the restricted space and particular layout of the exhibits, which tended to cause the visitors to visit the exhibits in the same order, and never return to an exhibit they had already visited. Overall tracks were thus shorter, meaning that the mean edit distance value was lower. In Gallery 2, the open plan meant that there was more variation in the path followed, and more revisiting of exhibits by visitors. The longer tracks thus led to higher edit distances. The reason for the t value dropping appears to relate to the trackers becoming more familiar with the tracking methodology and software, and more precise in their start and end times for exhibit engagement. While we predicted that the higher density of reflexive surfaces in Gallery 1 could lead to a drop in performance, this was not evident in our RFID readings.
The primary cause of errors for the RFID-based tracker was false negatives; i.e. the tracker failing to sense a visitor when s/he was in the proximity of a given exhibit. In particular, there were no readings for one visitor, probably as a result of their body blocking the UHF signals. In our experimental setting, we deliberately chose not to provide any explicit feedback to the user on whether they were being sensed or not. In fact, there was no direction to the visitors as to the purpose of the badge holder. In an actual museum setting where the tracking is tied to a service, it would be more pertinent to provide real-time feedback to the user to ensure they were tracked successfully and as a result got the maximum benefit from the service. We expect this would avoid pathologically bad cases such as this. What it does point to is the fact that while humans are not 100% consistent (as seen in the fact that we did not have 0 edit distance and t values for either gallery), they are at least consistent in the relative level of noise in their observations across visitors. That is, we did not observe any instances where the level of agreement between the human trackers was appreciably higher for one particular visitor or one of the two mini-galleries (other than the space-related effect described above). The RFID-based tracker, on the other hand, worked well overall, but had poor worst-case performance.
A secondary cause of the results for the RFID-based tracker being artificially bad was momentary drop out in the UHF signal when a visitor remained in front of a given exhibit, meaning that two separate instances of exhibit were recorded. Under both our evaluation metrics, this leads to a penalty in the final edit distance or t value. While we do not present the results there, we experimented with smoothing methods (based on a sliding window approach) to reduce such noise in the data, and achieved very slight improvements in our results.
7. Conclusions and Future Work
In this paper, we propose a tracking architecture based on RFID technology, targeted particularly at museum spaces. We deployed the proposed system in a mini-gallery and used it to track visitors relative to exhibits. To evaluate the tracking accuracy of the system, we carried out a direct comparison with human trackers, based on two evaluation metrics and two separate tracking modalities (distance and gaze). Our results indicate that the RFID-based tracker is surprisingly accurate, and equally capable of emulating distance- and gaze-based tracking.
Although the results were promising, they also showed that RFID is susceptible to environmental interference and suffers from a complete loss of tracking output, for instance, when a tag is obstructed. Further research is required to determine the level of user awareness required to minimize such effects. We are also interested in testing the scalability of the proposed methodology, with more exhibits, and more importantly, more visitors at a time. Additionally, we hope to carry out more systematic exploration of the effect of the physical space (e.g. reflective surfaces, restricted spaces, and physical obstructions) on tracking accuracy.
We would like to acknowledge the efforts of the following individuals: Karl Grieser in curating the exhibits used in this research; Fabian Bohnert for providing considerable technical assistance with GeckoTracker and input on the evaluation; Lars Kulik, Egemen Tanin and members of the SUM Lab for various technical discussions and prods in the right direction; members of the Department of Computer Science and Software Engineering for being willing "guinea pig" visitors; and Carolyn Meehan for her support and domain expertise throughout.
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Bohnert, F., I. Zukerman, S. Berkovsky, T. Baldwin and E. Sonenberg (2008a). Using Collaborative Models to Adaptively Predict Visitor. In Proceedings of the 5th International Conference on Adaptive Hypermedia and Adaptive Web-Based Systems. Hanover, Germany, pp. 42–51.
Bohnert, F., I. Zukerman, S. Berkovsky, T. Baldwin and L. Sonenberg (2008b). Using Interest and Transition Models to Predict Visitor Locations in Museums. AI Communications, 21(2-3), pp. 195–202.
Bulling, A., J.A. Ward, H. Gellersen and G. Tröster (2008). Robust Recognition of Reading Activity in Transit using Wearable Electrooculography. In Proceedings of Pervasive 2008. Sydney, Australia, pp. 19–37.
Fleck, M., M. Frid, T. Kindberg, E. O'Brien-Strain, R. Rajani and M. Spasojevic (2002). Rememberer: A Tool for Capturing Museum Visits. In Proceedings of UbiComp 2002. Goteborg, Sweden, pp. 48–55.
Hightower, J. and G. Borriello (2001). A Survey and Taxonomy of Location Systems for Ubiquitous Computing. University of Washington, Department of Computer Science and Engineering, Seattle, USA.
Hsi, S. and H. Fait (2005). "RFID Enhances Visitors' Museum Experience at the Exploratorium,".Communications of the ACM, 48(9), pp. 60–65.
Kanda, T., M. Shiomi, L. Perrin, T. Nomura, H. Ishiguro, and N. Hagita (2007). "Analysis of People Trajectories with Ubiquitous Sensors in a Science Museum". In Proceedings of the 2007 IEEE International Conference on Robotics and Automation (ICRA2007). Rome, Italy, pp. 4846–4853.
Patel, S.N., M.S. Reynolds and G.D. Abowd (2008). "Detecting Human Movement by Differential Air Pressure Sensing in HVAC System Ductwork: An Exploration in Infrastructure Mediated Sensing". In Proceedings of Pervasive 2008. Sydney, Australia, pp. 1–18.
Savidis, A., M. Zidianakis, N. Kazepis, S. Dubulakis, D. Gramenos, and C. Stephanidis (2008). "An Integrated Platform for the Management of Mobile Location-aware Information Systems". In Proceedings of Pervasive 2008. Sydney, Australia, pp. 128–145.
Baldwin, T. and L.T. Kuriakose, Cheap, Accurate RFID Tracking of Museum Visitors for Personalized Content Delivery. In J. Trant and D. Bearman (eds). Museums and the Web 2009: Proceedings. Toronto: Archives & Museum Informatics. Published March 31, 2009. Consulted http://www.archimuse.com/mw2009/papers/baldwin/baldwin.html


text:
<?php

class CommentsTest extends apiBuzzTest {

  private $activityId = false;

  public function setUp() {
    if (! $this->activityId) {
      // find an activity in the @publicstream with comments that we can test with
      $activities = $this->buzz->listActivities('@public', '@me', 100);
      if (isset($activities['items']) && count($activities['items'])) {
        foreach ($activities['items'] as $activity) {
          if (isset($activity['links']['replies'][0]) && (int)$activity['links']['replies'][0]['count'] > 0) {
            $this->activityId = $activity['id'];
            break;
          }
        }
      }
    }
    if (! $this->activityId) {
      throw new Exception("Could not find a buzz post with comments attached to it in the test user's public stream");
    }
  }

  public function testListAndGetComments() {
    // check the basic comments feed for the activity selected activity
    $comments = $this->buzz->listComments('@self', '@me', $this->activityId, 20);
    $this->assertArrayHasKey('kind', $comments);
    $this->assertEquals('buzz#commentFeed', $comments['kind']);
    $this->assertArrayHasKey('links', $comments);
    $this->assertArrayHasKey('title', $comments);
    $this->assertArrayHasKey('updated', $comments);
    $this->assertArrayHasKey('id', $comments);
    $this->assertArrayHasKey('items', $comments);
    $this->assertTrue(is_array($comments['links']));
    $this->assertTrue(is_array($comments['items']));

    $comment = $comments['items'][0];
    $this->evaluateComment($comment);

    // test getComments()
    $comment = $this->buzz->getComments('@self', $comment['id'], $this->activityId);
    $this->evaluateComment($comment);
  }

  /**
   * @depends testListAndGetComments
   */
  public function testInsertUpdateAndDeleteComments() {
    // test insert
    $comment = $this->buzz->insertComments('@self', $this->activityId, array('data' => array('content' => 'Testing insertComment()')));
    $this->evaluateComment($comment);
    $this->assertEquals('Testing insertComment()', $comment['content']);
    $this->assertEquals('Testing insertComment()', $comment['originalContent']);

    // test update
    $comment = $this->buzz->updateComments('@self', '@me', $comment['id'], $this->activityId, array('data' => array('content' => 'Testing updateComment()')));
    $this->evaluateComment($comment);
    $this->assertEquals('Testing updateComment()', $comment['content']);
    $this->assertEquals('Testing updateComment()', $comment['originalContent']);

    // test delete
    $this->buzz->deleteComments('@me', $comment['id'], $this->activityId);
  }

  private function evaluateComment($comment) {
    $this->assertArrayHasKey('kind', $comment);
    $this->assertEquals('buzz#comment', $comment['kind']);
    $this->assertArrayHasKey('id', $comment);
    $this->assertArrayHasKey('published', $comment);
    $this->assertArrayHasKey('updated', $comment);
    $this->assertArrayHasKey('actor', $comment);
    $this->assertArrayHasKey('content', $comment);
    $this->assertArrayHasKey('links', $comment);
    $this->assertTrue(is_array($comment['links']));
    $this->assertTrue(is_array($comment['actor']));
  }

}

redpajama_set_name: RedPajamaGithub


In plants, a hybrid is the result of cross-breeding between two different non-hybrid plants. There are several reasons for hybridization, including increased productivity or disease resistance in food plants, and improved color or other visual attributes in decorative plants. Huge improvements in agriculture and horticulture have been made possible by combining or concentrating the characteristics of non-hybrid plants. Modern varieties of wheat, for example, are the result of thousands of years of hybridization--bread wheat (Triticum aestivum) is a hexaploid hybrid of three wild grasses. Some wheat species have two sets of chromosomes (diploid), but many have four sets of chromosomes (tetraploid) or even six sets (hexaploid).
The first offspring of a hybrid cross is known as a F1 hybrid, which is short for Filial 1. It is the first generation resulting from the crossing of two distinctly different parents.
The seed of F1 hybrids will not reliably produce plants with the same features. Plants grown from the seed of F1 hybrids may have the characteristics of one parent, both parents, or an unpredictable combination of the two. To produce F1 hybrid seed, it is necessary to repeat the cross-pollination of the parent plants every season.
Non-hybrid plants are known as heirloom or open-pollinated (OP) varieties. An heirloom is an open-pollinated plant that has been passed down through generations of farmers or gardeners. Just how old a plant must be to qualify as an heirloom is hotly debated, but most agree that an heirloom must have existed as a stable variety before the 1945 to 1951 period when commercial hybrids were first widely used in agriculture and horticulture.
The primary advantages of hybrids are the characteristics that result from the cross. In food plants, these include increased productivity, more uniform shape and size of the fruit, consistent (and sometimes faster) development to maturity, resistance to (or at least tolerance of) diseases, improved ability to withstand hot or cold temperatures, or a delayed bolting to seed that allows an extended harvest period.
In horticulture, the advantages of hybrids can include the production of larger and more colorful flowers, more consistent blooming patterns, and more uniform growth. The hybrid creation of new colors and more attractive bloom shapes results in the introduction of exciting new cultivars every year.
Many hybrid plants have one additional advantage, technically called heterosis but commonly known as hybrid vigor. A hybrid will often produce more or grow more vigorously than either of its parents. There are competing theories about what causes it, but plant breeders and growers agree that it exists.
Hybrid vigor is the opposite of inbreeding depression, where the repeated breeding of related individuals results in a decline in plant performance.
Non-hybrid open-pollinated and heirloom vegetable varieties are valued for their taste and unique appearance. For example, some gardeners insist that hybrid tomatoes lack the "real" tomato taste of heirloom varieties.
The seeds of non-hybrids can be saved from year to year, because those varieties will breed "true," unlike hybrids. Farmers all over the world traditionally save seed from which to grow next year's crop. These varieties have become adapted to certain climates, soils and other growing conditions, and are economically important to farmers in developing nations.
Non-hybrids are, of course, the parents of hybrids. When an heirloom variety is lost, its unique combination of characteristics is forever lost to the gene pool.


text:
Q: Changes to variable value don't persist in if statement in JavaScript I'm setting the value of a variable inside the setAndCheck function to 1 by calling it with defined string. The value is set, but when I call the function later to check the value later, it seems like that the change has not been applied and therefore the related if statement is not executed.
The job of the function is to assign 1 to argument if called with appropriate and then it's called to check whether it's been set and return 1. If it's not then it just returns 0 at the end.
function setAndCheck(arg) {
  var first_one = 0;
  var second_one = 0;
  if (arg == "setIt1")
    first_one = 1;
  else if (arg == "setIt2")
    second_one = 1;
  else if (arg == "checkIt1" && first_one)
    return 1;
  else if (arg == "checkIt2" && second_one)
    return 1;
  return 0;
}

I expected the output of 1 after setting both variables with "setIt1" and "setIt2". But the function still returns 0 which means the variables have the value of 0 when called with "checkIt1" or "CheckIt2".

A: Every time you define a variable inside a function, that variable gets reset whenever you call that function again since you are redeclaring it. To make the variable persist you need to make it available in the global-scope by putting it outside your function.
     var first_one = 0;
     var second_one = 0;

    function setAndCheck(arg){
      if (arg == "setIt1")
      first_one=1;
      else if (arg == "setIt2")
      second_one=1;
      else if (arg == "checkIt1" && first_one)
        return 1;
      else if (arg == "checkIt2" && second_one)
        return 1;
      return 0;
    }

A:
I call the function later to check the value later, it seems like that
  the change has not been applied and therefore the related if statement
  is not executed.

Every time the function will b e called it will again create the variable. So the value will never be saved.
You can create the variable outside the function and then assign the value.
Next time you need not to call the function but directly use the value

A: Well, as far as I can see, the problem lies in the fact that you declare and initialize the variables inside the scope of the function.
Let's take it from the beginning.

*

*The function is called with arg "setIt1". first_one and second_one are
set to 0, then first_one is set to 1.

*The function is called with arg "setIt2". first_one and second_one
are reset to 0, then second_one is set to 1.

*The function is called with arg "checkIt1. first_one and second_one are reset to 0, so (arg == "checkIt1" && first_one) returns false, thus resulting in the function returning 0.

edit: The second problem is that local variables (variables declared inside a function cease to exist when the function ends. So every time the function is executed and exits, both first_one and second_one disappear. The only way to keep the values is to declare first_one and second_one before calling the function.

redpajama_set_name: RedPajamaStackExchange


Harmon was one of the glamorous stars who set the red dress trend during the Academy Awards. The actress wore a formfitting gown with a ruffled train and diamond drop earrings to the In Style viewing party at STK in Los Angeles.
Blanchett finished her look with metallic accessories from Roger Vivier.
Meester stood tall in sandals from Sergio Rossi.


text:
117 – Case Study: Newcastle Architect Matt & Wife Caroline
Renovating by yourself is great, but renovating with your life partner is a gift. Today, I have Matt Hull and Caroline Dando, a couple who renovate for profit together after graduating from The School Of Renovating. They will share their renovating journey as a couple, their strategies, and their plans for the growth of their reno business.
Listen to Episode 117: Case Study: Newcastle Architect Matt & Wife Caroline
Podcast: Download (Duration 20:27 — 19MB)
[00:00:35] A Newcastle architect's skill
[00:01:37] About Matt
[00:03:28] Passing on information and knowledge to the next generation of architects
[00:04:14] Strong interest and passion for interior design
[00:04:59] Properties in portfolios
[00:06:13] Renovation bucket
[00:06:59] The second project at Carrington
[00:08:01] We all love numbers
[00:08:23] Renovating a family home
[00:09:26] A different skillset
[00:10:11] Renovating as a couple
[00:11:06] The power of passion and natural inclination
[00:12:45] Once you are interested in something, your attitude changes
[00:13:37] Trying to set the wheels in motion
[00:14:28] Renovate and hold
[00:15:52] Getting to where you want to go much quicker
[00:16:49] Purchasing a property with a land component
[00:17:55] The impact of renovating to Newcastle architect, Matt and Caroline's lives
Design Pad Architecture Renos. More photos in the show notes.
Images from: Design Pad Architecture
Newcastle Architect Matt and Caroline Dando
"It's given us the confidence to project that vision to work out how we can get there, implement it, get it done, and then end up with a product that does sell for the money that we thought it might."
Well, hello everyone! It's Bernadette, back with another episode of She Renovates. I've got Newcastle architect Matt and Caroline here today. Matt and Caroline got married straight after they did the Bootcamp and they were set on changing their property journey using renovating. Matt is an architect based in Newcastle. Excluding Matt and David, a lot of architects aren't really willing to look outside their field to see if there's education out there that will make a difference and that's where I think Matt is quite smart. He has been willing to be open-minded about it.
Bernadette Janson: I'm really curious to really talk to you about what your journey has been like and whether you've achieved the results you've wanted to? What impact it's had on your first four years of married life? Before we start, Matt, do you want to just share a little bit about your business. What you do in Newcastle?
Matt Hull: Like you said I'm a local architect in Newcastle, registered. And I've been living here since I came up to study from Sydney in 1991 and fell in love with the place. I could see the potential of Newcastle back in the early 90s. It was completely undervalued, I think.
We are now in a position in Newcastle where other people have seen that potential and realize that. So that's why I stayed in Newcastle and started my own practice. It was a lot easier to get a foothold in the industry, get to know people, network, and implement my architectural skills with builders and clients.
I come from a building background. My father was a builder and I did study some engineering at Wollongong. So having that background, I've tried to implement the practical side of building with all of the theory and the practice within the architecture school at Newcastle to come up with an approach that is somewhat proactive in terms of delivering a product that is buildable and affordable.
I'd like to get builders, introduce them to potential clients early on in this stage of design so that they can start to have a bit of a relationship and see if they can work together and also make sure that the project is in line with their budget.
Newcastle is really good in that term, in those terms that you can get to know people and your reputation can precede yourself but, it's important to keep that networking going. And that's basically how I've survived as an architect.
Bernadette Janson: That's interesting. So do you lecture at the university?
Matt Hull: I did lecture in the past for a number of years there and that was really good to be involved with passing on information and knowledge to the next generation of architects. I'm dedicated to my practice now. I work entirely as a sole practitioner and we've been looking at our projects and thinking about how do we achieve our goals within things such as the guidelines for development and the pragmatics of how do you achieve those goals. How do you build the thing constructed? The university was a good lesson because it kept me engaged with the next generation. It was very inspiring really.
Bernadette Janson: Well, that's excellent! So we've got a bit of where you're from, what about you Caroline?
Caroline Dando: I work full time. I work for a marketing agency in Newcastle and I've been in marketing for quite a few years. But I have had for a long time, a strong interest and passion for interior design, and like many of your students, I watched all the design programs and devour those.
Eventually, our path would see me, hopefully, transition away from full-time work and into more of a project management role with our renos. But that's still a long-term plan yet to be implemented.
Bernadette Janson: Let's see where you at. You might be closer than you think. So tell me, so when you first came through you each had a home and I think you had another one as well, is that correct?
Caroline Dando: Yeah. So we had three between us when we met. So we were very fortunate in that respect. So one of those was a small two-bedroom unit in Mayfield. One was a cottage in Carrington, two bedrooms, and the third is a house in Maryville, which is a four-bedroom home. I think he would probably say at this point in time.
Fortunately for us, we did have those properties in our portfolios and they had also appreciated and value. So for us, working, starting on those properties was pretty low risk. So we decided after The School Of Renovating that we would start with the smallest project first. And so we started with the unit in Mayfield. So there were various constraints around that because it's a unit but we replaced the kitchen, we replaced the bathroom and basically did a cosmetic reno throughout. So that was in 2018.
Bernadette Janson: So was that a hold to rent out?
Caroline Dando: It had been rented but we decided that after the renovation that we would sell it, so we put it on the market and we looked at the figures. We used The School Of Renovating feasibility spreadsheet and basically took this snapshot of the value before we started work on it. And then use that to measure our budget against and that projected profit from that. According to that spreadsheet, we made a profit on that project once we came to sell it.
That profit has gone into our renovation bucket, which we then were able to use on the next project, which is the one that we just sold in Carrington. So we did that in 2019- 2020.
Bernadette Janson: Okay. And that was a unit again, wasn't it?
Caroline Dando: A house. So it was a freestanding house, a little miner's cottage, you'd call it. Again, two bedrooms, one bathroom. We replaced the kitchen, we replaced the bathroom. It was a slightly larger project, even that we swapped the position of the kitchen. So we traded the kitchen and dining room positions because there was a bigger dining room at a much, much smaller kitchen.
We were able to change the layout there quite a bit, which added a good deal of value in the end. It also meant that the dining room then flowed out onto a back deck. Which we created and was a really nice aspect out to the back of the property there as well. Yeah, that one went really well as well. Again, we took a snapshot at the time of just prior to renovation and were able to make a profit on that one as well. But when that money's going into the bucket.
Bernadette Janson: So when you say took a snapshot, you mean?
Caroline Dando: Evaluation, yes.
Bernadette Janson: Do you mind sharing what your profits were or can you remember? Because we all love numbers.
Caroline Dando: Yeah. So it was around $50,000 profit on the first one. The second one was more around 70,000.
Bernadette Janson: Awesome! Beautiful.
Caroline Dando: That's given us a nice little chunk to move on to project number three.
Bernadette Janson: Okay. And have you started project number three?
Caroline Dando: It's in the pipeline.
Bernadette Janson: So is this your house? Your family home?
Matt Hull: Yeah, it will be.
Bernadette Janson: Yeah.
Matt Hull: Currently it's tenanted. We live in a unit that we bought off-plan six years ago. We'll eventually move into the house once it's completed and that will be our forever home.
Bernadette Janson: Okay. Beautiful.
Caroline Dando: I did a lot of work on the first two particularly Matt who was there to be every day. On tools and trainees. This time we've engaged a builder who will obviously bring his own tradies with him. This is a complete transformation when knocking the back off the house, adding another story at the back. So yeah, it's a much bigger project for us.
Bernadette Janson: Wow.
Caroline Dando: We've got more confidence now because of the two that we did before to be able to take this one on with confidence in our ability to oversee.
Bernadette Janson: It's funny because I was saying something to David, we did the place at Bondi with him and we're doing this little place in Darlinghurst at the moment. He had gone over I think to set up for demolition and he really didn't do what I'd expected him to do to prepare, like in terms of protecting the common areas and all that sort of stuff. And I had a go at him and he said, "mom, you've got to realize that in a normal project, I don't have this level of involvement. I don't build because that's not my role." And I thought, "actually, yeah, you're right." So it's really interesting. I personally thought it might've been an absolute walk in the park, but obviously, it's a different skillset.
Matt Hull: Yes, very much.
Bernadette Janson: How has it been for you as a couple?
Caroline Dando: If we go back to the first project, which was the unit that was a real testing ground to see how we work together as a couple. If it hadn't worked, we'd have been arguing every day. We probably wouldn't have gone on to do anymore. But we both slipped into our own kind of roles based on our strengths and what we can bring to each project. So obviously that skillset is very different from mine. He can see the big picture, he thinks about functionality, you know the orientation of the property. Then I'll look at other things, colour schemes, tile choices. I could spend all day looking at those things. I also look after budgeting, which is one of my strong suits as well. So we both found our niche and yeah, that's allowed us to go quite well together.
Bernadette Janson: That's really good.
Matt Hull: The aspects of the project where we could become quite passionate about, and it really helped that Caroline can visualise, she's got great spatial awareness. So when we talked about various aspects of each project, we understood one another, you can do some drawings in 3d, and then you're talking about the same issues and coming to an agreement based on a full appreciation of what the implications are in terms of buildability. What's the outcome? How do people move through space? How does that help? How does the light get into the room? What does it feel like? What does it look out onto? Are there trees? Is there landscaping? So, you can take that approach with every aspect of a house. And it's really great to be working with someone who appreciates that level of thought.
Bernadette Janson: That's really interesting too. The other thing that is really worth pointing out is that's powered by passion and natural inclination, which a lot of women have, but don't realize the potential of it.
Caroline Dando: Yeah. And I think too it's great to do as a couple because as you would know, it becomes all-consuming. You really are chopping up your veggies for dinner and talking about various aspects of the project, or should we choose this? What about that training? This section of the project's running late, we need to pick up the pace on that. Even last night after dinner, we sat down and we were looking at vanities. It just so great being able to share that with a partner is great.
Bernadette Janson: It is. And it's really important to have common interests although I have the problem that our youngest child, in particular, if we talk about renovations at the dinner table, cause everyone's renovating, she says that she puts a ban on conversations over renovating for good. So I had to fix that. She's first out of Uni and she's just got a job. As soon as she's been there long enough to get a loan, she and I are going and doing a project. And she'll get way more money than she currently has.
Matt Hull: Once we are interested in something, our attitude changes.
Bernadette Janson: It does, doesn't it? Yeah certainly with kids. I know with Hannah, she was always shares, shares, shares until she did her first reno and now, we're doing another one. She's renovating her own house, so we've managed to corrupt them all.
I'm really interested in the fact that Caroline's interested in replacing her income. Once that's over what will be the next project?
Caroline Dando: So we have been discussing that over the last probably three, four weeks. Actually, I've been talking to a financial planner, we've been looking to talking to an accountant and a mortgage broker just to try and set a plan in place. As I said earlier having the three properties that we have renovated already in our portfolio, we buy them in and that sort of thing. So we're trying to set the wheels in motion now and put plans in place about how we go about purchasing the next property.
What does it look like? So far we're thinking that we would like to buy something still locally that we would renovate and then hold. We possibly do what we would like to do and if budget may determine whether we can or we cannot. But we're actually thinking about even looking at places that are basically knocked down and rebuild. And maybe if the land size was big enough maybe a duplex or something like that on there because that obviously would make the best use of Matt's architectural skills. Even buying an older property that we renovate and then hold is an option for us as well. So we thought over the next few years, while I'm still working and interest rates are low. Our earning capacity is still high. It's a good time to buy and hold, leverage the properties to be able to buy more.
Once we do finish, the next project, which is the house that we're going to be living in, we should be able to draw down on the equity that we've accrued in that. To help us along in that journey. So over the next five years, it's probably going to be a phase of buy, renovate and hold. And then after that, if I can start to transition away from work, it might be buying renovate and flip. And I just do that part-time or full-time.
Bernadette Janson: So if I can put my two bob's worth in?
Caroline Dando: Yeah, absolutely.
Bernadette Janson: I would look at properties that have renovation potential on big blocks, but where you can renovate the house and sell it off. And you've got the block to build your duplex on. You could keep all three, but sometimes that sort of binds you up in terms of your borrowing capacity to move on. But that way you're increasing your equity quickly. And the other thing is you're keeping the new properties. So you're not your know Doesn't matter how well you renovate it. It's never going to compare with new, doesn't have the same depreciation, particularly if you're new.
So that might be something that you think about. I personally think that if I was in your shoes, that would be the way I was heading, especially that you've got Matt because he can play such a big part in that, the, in that process in terms of the subdivision. I definitely think it would get you to where you want to go much quicker.
Matt Hull: Yeah, thank you.
Bernadette Janson: The Chalmers Street team, we've just finished that they're talking about hitting Newcastle way because we're just seeing so many great deals. We're thinking Newcastle or Wollongong, but yeah, I definitely want to go for something that's got a land component in it. Particularly Newcastle's okay but if you're in an area that you don't really know, you're just talking about a house or an apartment you haven't got much leeway of things go a little bit pear-shaped.
So by having that, like stacking that other strategy on board, it's like a little insurance policy, but of course, you need to know what you're doing which you have the advantage that you've got the expert in the house.
Caroline Dando: Yeah.
Bernadette Janson: So what do you think the niche effect of your renovating journey has been in terms of how you feel about what you do?
Matt Hull: Sorry about the noise. They're doing some work outside there.
Bernadette Janson: Newcastle, I just love- I think it probably does have a little bit of a detrimental effect because now a lot of the houses are on such tiny blocks, but I love the way they're so progressive around the development. It's really great for us.
Matt Hull: So to answer your question.
Matt Hull: Just a moment, what was the question again?
Bernadette Janson: What has been the impact of you turning to renovating to enrich your property journey?
Matt Hull: I think the confidence in almost each of us had a strategy before we started buying houses and we bought in areas that we thought as individuals would be up and coming, we bought them at the time when those suburbs didn't have much appeal at all.
That's why the properties were cheaper. And we've taken that approach as to where do we want to end up? What does our market want to buy? So it's given us the confidence to project that sort of vision to work out how we can get there, implement it, get it done, and then end up with a product that does sell for the sort of money that we thought it might.
And also we were able to stick to those numbers. So it's given us confidence that we can now have conferences that we plan for the future and we know how to get there and we can achieve those goals.
Bernadette Janson: That makes my heart sing. It gives me goosebumps. It's awesome. I think I have asked you everything I need to ask you. Is there anything else you want to say?
Matt Hull: If you're in Newcastle and need an architect, give me a call.
Bernadette Janson: Absolutely. Yeah, definitely.
Listen, thank you so much for being on the podcast. You are going to be invaded by The School Of Renovating students because we've got quite a few that are heading your way. We've already got some there. Yeah, we've got quite a several that have already done project successfully done projects there. We're really making our mark on the Newcastle landscape, which is really nice. Yeah. And it's a lovely city. You're very lucky to be there.
Okay, so that's it for today. Now, if you haven't already done so please come over to iTunes and leave us a review, give us any suggestions that you would like for future episodes and we will be so grateful. We read them all and we are so appreciative of you for making the effort. So thank you.

redpajama_set_name: RedPajamaCommonCrawl


The end of the school year is finally here for my little man. Pre-K graduation is next week and I have to say, the flood gates will be released. Gavin had an amazing year and I really wanted to show his teachers and therapists how much we appreciate all their hard work and patience.
I thought about what to buy his teachers, a gift card, flowers, personalized notecards. These are all nice, but not memorable. So, I went to the source that has virtually every idea out there, Pinterest.
I found the crayon idea and thought, bingo! This would be the perfect gift.
Print out a large font in a light shadow (so the letter won't appear behind the crayons). Cut the paper to fit the shadow box. On a separate piece of paper, line up the crayons first and then cut them. Transfer the cut crayons and glue them to the card stock. Let it dry and then put it in the shadow box. So simple and easy to do!
I decided to put a spin on this idea for his occupational therapists, so I decided to use materials that they often use in their sessions.
This would be a great project for medical art as well. Child life specialists can provide loose parts and medical materials for kids to explore and create.
I'm stealing this!! So cool. What font did you use to print the letters?
Thanks Tonya! I used font Times New Roman at size 650. Have fun!


I called it "The Atom" because it's a test for both smooth walking as well as changing a characters size. The feet kinda get cut off but it doesn't really show up so much that it should be counted in the CC.
Anyway, it needs way more frames per step, check out some tutorials on walks, there are loads.
If he is proud of his animation and wants to give it a name, let him be.
You need easing, and more smoothing.
my eyes exploded like an atom bomb .
also the walk is awful. he lifts his leg too high and it looks very sloppy, not enough frames ber step and its very hard footed (i.e. should be smoother).
Thanks for comments. SO major notes are.
Meh I just had an idea for a quick animation(once I get better) where the stick shrinks and grows while he fights his enemies. Thought it might be cool.


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Blog > Weekly litigation report — Property rights, school choice, free speech, and more
Weekly litigation report — Property rights, school choice, free speech, and more
December 15, 2018 I By JAMES BURLING
Public land stewards reiterate that the president can reduce the size of national monuments
Briefing is now complete on the motion to dismiss Utah Diné Bikéyah v. Trump, a case that challenges the president's ability to reduce the size of national monuments. PLF represents individuals and non-profit organizations that recreate, work, and volunteer on public lands in Utah and who were harmed when the Bears Ears National Monument was established.
This week, PLF filed another brief explaining that one president cannot bind future presidents when he establishes a national monument. We are asking the court to dismiss the case. A decision on the motion to dismiss is expected in the coming months.
The Ninth Circuit is desperate to get rid of PLF's Montana school choice case, but we aren't giving up
Several years ago, in a case called Armstrong v. Walborn, PLF sued the Montana Department of Revenue on behalf of parents educating their son at a private religious school. The Montana legislature had passed a ground-breaking tax credit program that encouraged private donations to a scholarship fund to help families afford private school. The Department of Revenue, however, passed a regulation that banned students from using these privately donated scholarship dollars to attend religious schools.
Our lawsuit claimed that this blatant discrimination violated the religion clauses and the equal protection clause of the U.S. Constitution. The district court, however, dismissed our case without addressing the important constitutional questions we raised. This week, a Ninth Circuit panel affirmed that dismissal. Nonetheless, we are confident in the ongoing fight to vindicate our clients' right to seek redress in federal court.
The importance of PLF's federal case became even more apparent this week, when the Montana Supreme Court in a parallel state case struck down the Montana tax credit scheme.
Widespread support for PLF appeal of unlawful wetlands enforcement
This Monday several supporters filed six amici briefs asking the U.S. Supreme Court to grant cert in Joe Robertson's Clean Water Act appeal in Robertson v. United States. The amici include a group of other PLF clients (The Hawkes Company, Duarte Nursery, and the Sacketts) who recently won cases in the Supreme Court; nationwide trade associations the National Federation of Independent Businesses and the National Association of Home Builders; and policy organizations the Cato Institute, the Center for Constitutional Jurisprudence, and Judicial Watch. Read more about their briefs at our blog post.
EPA issues lackluster new wetlands rules
PLF previously challenged the Obama-era "Waters of the United States" or "WOTUS" rule, arguing in Washington Cattlemen's Association v. EPA that the rule illegally expanded federal control over land that was not subject to federal control. This week the EPA announced its long awaited proposal to revise the 2015 Obama administration regulation, which illegally defined millions of acres of dry land on private property as federally regulated "navigable waters." Sadly, while the new EPA proposal contains a few common-sense reforms, it falls far short of the broad reform President Trump called for in his February 2017 Executive Order. Read more in our blog and news release.
The constitutional right to speak for yourself
PLF filed an amicus brief in the Massachusetts Supreme Judicial Court in support of non-union educators in Branch v. Commonwealth Employment Relations Board. The educators seek the right to have a voice in the terms of their own employment, rather than being "represented" by the union they refuse to join.
Our brief focuses on the need for courts to rigorously scrutinize infringements on the right of free association (and its corollary, the right not to associate) and the injustice that results when people are forced to associate with groups when they do not share—and even expressly oppose—those groups' objectives.
Government cannot define away property rights
We filed this amicus brief asking the Minnesota Supreme Court to recognize the property rights of mining company Minnesota Sands, LLC, in the case of Minnesota Sands v. County of Winona. Minnesota Sands owns leases with various property owners giving it the exclusive right to mine silica sand on those properties. But Winona County's recent zoning ordinance amendment, which bans such activities outright, rendered the leases worthless.
When government regulation eliminates the value of property rights, the government must compensate the property owner. But the Minnesota Court of Appeals held that Minnesota Sands did not really have a property right at all, since it did not take every step necessary to exercise the rights in its lease. The problem is, it cannot take those steps because of the new ban on silica sand mining.
The court below fundamentally misunderstood the nature of a property right. We weighed in to make sure the Minnesota Supreme Court gets it right. For more, see our blog post.
Washington Supreme Court grants Seattle's petition to review PLF victory on first-in-time rule
As you may recall, PLF scored a major victory against Seattle earlier this year in Yim v. City of Seattle, a constitutional challenge to the city's "first-in-time" rule that required landlords to rent to the first person who submitted an adequate application. The trial court agreed with us that this radical landlord-tenant law was an uncompensated taking for private use that violated due process and free speech. The city has now persuaded the state supreme court to review that trial court decision. We're confident that we can persuade the supreme court that Seattle has gone several steps too far.
National Association of Manufactures v. Department of Defense January 22, 2018
Bears Ears National Monument Litigation January 10, 2018
Robertson v. United States July 21, 2017
The Hill: EPA appeals board is unconstitutional without reform January 13, 2020 I By MICHAEL POON
How rock & roll killed communism January 10, 2020 I By JACLYN BOUDREAU
The Times of Northwest Indiana: Indiana Supreme Court's decision on Lake Michigan beach access is unconstitutional. Here's why. January 07, 2020 I By CHRIS KIESER
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Hypogeum of Hal Saflieni: The grand underground 'temple' with acoustic effects
TOPICS:acousticsancient templebig postHal SaflieniHypogeumHypogeum of Hal Saflienilong postMaltamysterious templeNeolithicunderground temple
Posted By: Dattatreya Mandal September 13, 2015
Often claimed as being the world's only known prehistoric underground temple, the branching subterranean complex of Hypogeum of Hal Saflieni in Paola, Malta, is more than 5,000 years old (which makes it older than the Great Pyramid at Giza). Discovered quite unintentionally in 1902, by workers who were digging for a building site, the expanse of the temple was found to be entirely carved from solid limestone. As a matter of fact, the very term hypogeum translates to 'underground' in Greek, and as such Hypogeum of Hal Saflieni goes down to a depth of more than 30 ft below ground. And the surprising part is – this herculean task was painstakingly achieved by only the rudimentary technology available to Stone Age people.
1. A subterranean mega-complex with three levels –
In terms of its sheer scope, the Hypogeum of Hal Saflieni comprises a labyrinth of cavities (both natural and man-made) that are structurally complemented by architectural elements like pillars, lintels (above door openings) and niches. All of these spatial zones are distributed over three levels, with the upper level being the earliest excavation project achieved by the Stone Age dwellers of Malta. To that end, this level was burrowed out from the brow of a hill, and can be accessed from a structure at the ground level. On the other hand, the two lower levels are 'cut' from natural rock (of the 'soft' globigerina limestone variety).
The extraordinary part is – these levels were entirely hewn and the excavated by using pretty rudimentary equipment, including chert, flint and obsidian tools and antlers. And moreover, in spite of the massive nature of their underground project, the Stone Age engineers didn't forget to use practical elements, like strategic opening along the upper-level for induction of natural light into the middle chambers. However, beyond such natural lighting 'windows', the occupants surely also had measures for artificial lighting in the lower spatial zones of the subterranean Neolithic temple.
2. An underground temple imitating ground-based megalithic temples –
One of the most unique features of the giant Hypogeum of Hal Saflieni relates to how its architectural elements tend to mimic the compositions of contemporary, above-ground megalithic temples. Such fascinating aspects include false bays and passages seemingly influenced by trilithon doorways and windows. Even the ceilings of some chambers have carved stone overhanging arrangements that tend to imitate the corbelled masonry (where the masonry work protrudes inwards in a step-wise manner along the top portion of various entrances and walls) found in the roof section of contemporary above-ground temples.
Quite intriguingly, the prevalence of such corbelled works in megalithic temples situated above ground also hints at the fact that many of these buildings were originally roofed over. As for the Hypogeum itself, its bevy of structural modifications are accompanied by artistic designs on the walls. These include recognizable patterns like honeycombs and spirals that are etched on the wall surfaces with the aid of red ochre, a type of mineral pigment. And surprisingly, these wall murals are the only prehistoric specimens found in the whole island of Malta.
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3. The Oracle Chamber and its acoustic property –
The Hypogeum of Hal Saflieni has its fair share of chambers and rooms spread over three levels – so much so that the labyrinth nature of the subterranean temple has dissuaded many an expert from actually measuring the total area of the 'hypogeum'. However beyond extensive structural engineering, the most incredible feature of this Neolithic complex arguably pertains to its incorporation of special acoustic properties. To that end, one of the chambers and its niche are carved out from limestone (and adorned with red ochre patterns), and the space seemingly demonstrates an acoustic magnification scope. According to some, these properties take mysterious, enchanting and even random routes with surprising sounds booming through the dark caverns and the convoluted passages. Such terrifying yet impressive effects have led to the terming of the room as the Oracle Chamber, where the hidden oracles might have communicated to the visitors via their mystical yet daunting voices aided by the auditory flair.
Now, a number of research projects have studied and analyzed this seemingly intentional feat of acoustic engineering. Some researchers (like Maltese composer Ruben Zahra and a research team from Italy) have noted how the sound within the chamber resonates at a frequency of 110 Hz, which is similar to effects of other ancient-made compartments, including the Newgrange in Ireland. Interestingly, a study published by Dr. Ian Cook of UCLA and his team showcased how this particular frequency had its 'emotional' effect on a number of volunteers. This was measured by EEG, and the frequency resonance at 110 Hz was found to affect the activity patterns over the prefrontal cortex. These patterns tended to oddly shift from left to right-sided dominance, thus alluding to the processing of the emotional quotient.
Another project undertaken by the Archaeoacoustics Conference revealed how male voices emanating at two frequencies (114 Hz and 68-70 Hz) can reverberate throughout the whole complex. The same effect was not achieved by female voices, while the continuous utterance of 'oooh' by male voices did the resonant trick. Now, considering all these results, historians and researchers are still not sure if such phenomenons were directly related to some form of sound engineering achieved by the ancient creators of the Hypogeum of Hal Saflieni. However, the possibility still lies with the hypothesis that the underground complex was used for ceremonious ritual chanting.
4. A temple and a tomb?
While we have been harping about the innovative side of the subterranean Hypogeum of Hal Saflieni, there is also a 'darker' side to the mystery beyond fascinating acoustic effects. In that regard, archaeologists have unearthed a wealth of objects over the years from the sanctuary, including a flurry of human bones. As a matter of fact, it is estimated that the underground temple keeps the remains of more than 6,000 people, all stacked in a bizarre manner along the entrance way. Some experts speculate that the ancient people in the proximate lands followed a ritual where they left the body of the dead inside the sanctuary until the flesh decomposed and then completely fell off the bones. These remaining bones were then collected and stacked within the chambers, oddly accompanied by volumes of red ochre. This probably had to with some kind of ritualistic protocol where the living imbued the bones of the dead with the hue of 'blood and life'.
Other archaeological findings include pottery vessels (with intricate artworks), beads, amulets, shell buttons and stone-carved pendants shaped like animals and birds. But the refined sense of workmanship arguably relates to the clay figurines that represent human figures in various poses. The 'Sleeping Lady' (pictured below) aptly demonstrates the high level of workmanship cultivated by the Stone Age sculptors of Malta.
Sources: UNESCO / HeritageMalta / OTSF
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Home » Blog Posts » Architecture » Hypogeum of Hal Saflieni: The grand underground 'temple' with acoustic effects


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