Poster Presenters for the Graduate Center Computer Science Student Workshop 2014

Poster Abstracts

Automatic Kronecker Product Model Based Detection of Repeated Patterns in 2D Urban Images by Juan Liu
Repeated patterns (such as windows, tiles, balconies and doors) are prominent and significant features in urban scenes. Therefore, detection of these repeated patterns becomes very important for city scene analysis. This paper attacks the problem of repeated patterns detection in a precise, efficient and automatic way, by combining traditional feature extraction followed by a Kronecker product low- rank modeling approach. Our method is tailored for 2D images of building facades. We have developed algorithms for automatic selection of a representative texture within facade images using vanishing points and Harris corners. After rectifying the input images, we describe novel algorithms that extract repeated patterns by using Kronecker product based modeling that is based on a solid theoretical foundation. Our approach is unique and has not ever been used for facade analysis. We have tested our algorithms in a large set of images.

Knowledge Discovery and Predictive Modeling of Protein-drug Binding Kinetics by Integrating Machine Learning and Molecular Dynamics Simulation by See Hong Chiu
Machine learning provides a cost-effective and timesaving approach to discovering hidden patterns and predicting significant outcomes from data. It has succeeded in predicting binding affinity of novel ligand-protein interactions in equilibrium conditions. However, few works have been done to study ligand-protein unbinding events, which are directly correlated with the biological activity of ligands. In this paper, we combine mechanism-based physical modeling and machine learning to predict drug-target residence time, which is a measure how long a drug will bind to its receptor in non-equilibrium conditions. Using HIV protease inhibitors as an example, we identified and selected features based on decomposed residue pair-wise energy and normal model changes upon ligand bindings.

Surveillance Event Detection System by Chucai Yi
We present a general event detection system evaluated by the Surveillance Event Detection (SED) task of TRECVID 2012 campaign. The proposed system is evaluated on all the seven event categories of the SED task. In our system, a sliding temporal window is employed as the detection unit, which is represented by a histogram of spatial-temporal features including STIP-HOG/HOF and SURF/MHI-HOG. We also investigate the spatial priors of various events by estimating spatial distributions of actions under different camera views in the training data. As non-linear SVMs usually have superior performances but in general are much slower in both training and testing, we therefore employ explicit feature maps to approximate large scale non-linear SVMs by linear ones. In order to deal with highly imbalanced data, our system performs detection by a set of cascade linear SVMs that are learned corresponding to specific events and camera views.

Where am I? -Indoor Localization and Navigation for the Visually-impaired People by Feng Hu
In this poster we propose a localization and navigation system for visually-impaired people in indoor environment with portable omnidirectional lens mounted on smart phone a nd remote GPU-enabled server. Concise short omnidirectional video features are extracted and represented in the smart phone front end, and transmitted to the server end, where database is built and great computation capability is provided. Vertical lines features from HSI  and HSI gradient space are used as video clips representation and key-words searched in database for coarse localization. Refined navigation information are obtained from camera pose estimation and moving parameter estimation process. Data parallelism and task parallelism property are observed from the database and estimation process, thus task can be accelerated by GPU. Experiments on synthetic data and real data are carried out and demonstrate the fastness and robustness of the system.

Sensor Selection Problem by Nooreddin Naghibolhosseini
The sensor network is a group of special objects that can sense the environment and are able to produce spacial information about the environment. Each sensor in a sensor network is an independent device with some energy resource and some information gathering mechanism and transmitting capability. The information gathering mechanism can be any mechanism that can sense the environment and provide information. For example a sensor might be a camera that can see certain range and can cover center areas. The sensor might be a wireless device enable of sensing a some object in some distance or maybe something that can measure the temperature or humidity of the environment. A sensor might be a person with access to a telephone line. A sensor network can be made by putting multiple sensors on an environment and these sensors can collaborate with each other to perform better in the sensor network.
In our model of the sensor network. Each sensor has a cost and a value. and We have a budget to select number of sensors in the environment. The interesting subject in the sensor network is the capability of prediction. Each sensor in the sensor network may predict some other sensors with some probability. For example if we use humidity sensor network then sensor A may predict the value of the sensor B in 20 percent of times. This means if the sensor A shows high humidity sensor B may show the high humidity in 20% of times. The value of sensor A and sensor B might be different because maybe the information of location of the sensor A is more important than the information of the location of the sensor B. We have evaluate some algorithms and found new results.

Sustenance against RL-based Sybil attacks in Cognitive Radio Networks using Dynamic Reputation System by Kenneth Ezirim
Sybil attacks are known form of denial-of-service attacks that are common-place in Dynamic Spectrum Access networks. In this paper, we formulate novel threat and defense mechanisms for the Sybil attack problem in Cognitive Radio Net- works (CRN). We present potential identity sampling strategies that a malicious Sybil attacker can use to enhance its attack capability and impact without being detected. We investigate how a Sybil attacker can leverage reinforced learning to improve its performance. We also formulate a novel dynamic reputation mechanism to defend against such threat that relies on the nodes’ reporting in an intelligent and adaptive manner. Results obtained shows that a Sybil attacker can improve its performance using RL learning technique. It also demonstrates that the use of the dynamic reputation mechanism can considerably reduces the effectiveness of Sybil attacks and improve the accuracy of spectrum decisions.

Using a Topological Descriptor to Investigate Structures of Virus Particles by Lucas Oliveira
An understanding of the three-dimensional structure of a biological macromolecular complex is essential to fully understand its function. A component tree is a topological and geometric image descriptor that captures information regarding the structure of an image based on the connected components determined by different grayness thresholds. We believe interactive visual exploration of component trees of (the density maps of) macromolecular complexes
can yield much information about their structure. To illustrate how component trees can convey important structural information, we consider component trees of four recombinant mutants of the procapsid of a bacteriophage (cystovirus phi6),
and show how differences between the component trees reflect the fact that each non-wild-type mutant of the procapsid has an incomplete set of constituent proteins.