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Subrosa 2 : An Experimental Evaluation Of Timing Analysis Attacks And Defenses In Anonymity Systems, Payap Sirinam Jan 2012

Subrosa 2 : An Experimental Evaluation Of Timing Analysis Attacks And Defenses In Anonymity Systems, Payap Sirinam

Computer Science and Engineering Theses - Archive

A circuit-based low-latency anonymous communication service such as Tor helps Internet users hide their IP addresses and thereby conceal their identities when communicating online. However, this kind of service is vulnerable to timing analysis attacks that can discern the relationship between incoming and outgoing messsages in order to find correlations between them. The attacker can use this information to reveal the idenity of the internet users without knowing the IP addresses concealed in the anonymous communication services.Dependent link padding (DLP) is a scheme propsed to enable anonymity systems to resist these attacks. However, DLP adds high overhead from dummy packets …

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An Extensible Self-Adapting Dissemination Framework For High-Speed Continuous Xml Streaming Data, Anthony E. Okorodudu Jan 2012

An Extensible Self-Adapting Dissemination Framework For High-Speed Continuous Xml Streaming Data, Anthony E. Okorodudu

Computer Science and Engineering Dissertations - Archive

The efficient dissemination of data has become increasingly important with recent advances in technology that provide us immediate access to information at our fingertips. The insatiable demand for data has increased significantly with the popularity and widespread use of smart phones and tablets throughout the world. This thesis is focused on efficient push-based means of disseminating data to a large number of interested clients using a network of co-operating machines, called brokers.There have been extensive studies in optimizing both XML filtering and XPath-based subscription management in publish/subscribe systems with the aim of disseminating data in a timely fashion. Much less …

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Energy-Efficient Protocols And Systems For Wireless Sensor Networks And Smart Environments, Giacomo Ghidini Jan 2012

Energy-Efficient Protocols And Systems For Wireless Sensor Networks And Smart Environments, Giacomo Ghidini

Computer Science and Engineering Dissertations - Archive

In a wireless sensor network, small computing devices, called sensors, sense the surrounding environment and relay the sensed data to a base station over a multi-hop wireless network, eventually processing them en-route. Wireless sensor networks and other devices, such as smartphones, smart meters, and smart appliances, cooperate in smart environments to obtain information about the environment, and then use this information to improve the experience of the users. Since most of these systems rely on battery power, there is a need for energy-efficient solutions for their operation. The objective of this dissertation is to design algorithms and protocols to improve …

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System For Interpretation Of Reviewer Feedback On Social Web, Shrikant Desai Jan 2012

System For Interpretation Of Reviewer Feedback On Social Web, Shrikant Desai

Computer Science and Engineering Theses - Archive

The increasing popularity of social media web sites such as Amazon, Yelp and others has influenced our online decision making. Before making selection decisions on movies and restaurants, we investigate its reviewer feedback. Social media web sites provide reviewer feedback in the form of ratings, tags, and user reviews. However, overwhelming feedback details will leave the user in a quandary as to decide whether the item is desirable or not. Potential buyers either make a snap judgment based on the aggregate ratings/tags or spend a lot of time in reading reviews.In this thesis, we build a system that can analyse …

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Learning Partially Observable Markov Decision Processes Using Abstract Actions, Hamed Janzadeh Jan 2012

Learning Partially Observable Markov Decision Processes Using Abstract Actions, Hamed Janzadeh

Computer Science and Engineering Theses - Archive

Transfer learning and Abstraction are among the new and most interesting research topics in AI and address the use of learned knowledge to improve learning performance in subsequent tasks. While there has been significant recent work on this topic in fully observable domain, it has been less studied for Partially Observable MDPs. This thesis addresses the problem of transferring skills from the previous experiences in POMDP models using high-level actions (Options) in two different kind of algorithms: value iteration and expectation maximization. To do this, this thesis first proves that the optimal value function remains piecewise-linear and convex when policies …

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Selective Grouping Algorithm For Low Latency Anonymous Systems, Vishal Gupta Jan 2012

Selective Grouping Algorithm For Low Latency Anonymous Systems, Vishal Gupta

Computer Science and Engineering Theses - Archive

Low latency anonymous communications are prone to timing analysis attacks. It is a technique by which the adversary can de-anonymize the user by correlating packet timing patterns. A recent proposal to stop these attacks is called Dependent Link padding. However, it creates high dummy packets overhead in the network. In this work we propose selective grouping, a padding scheme that protects users in an anonymity system from those attacks with minimal overhead. The aim is to decrease overhead by dividing users in different groups while maintaining good anonymity. The key idea of our approach is to group clients with similar …

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Similarity Measures And Indexing Methods For Time Series And Multiclass Recognition, Alexandra Stefan Jan 2012

Similarity Measures And Indexing Methods For Time Series And Multiclass Recognition, Alexandra Stefan

Computer Science and Engineering Dissertations - Archive

This thesis investigates the problem of similarity search in multimedia databases. A key application domain of the proposed work is pattern classification, with emphasis on classification of gestures, handshapes, faces, and time series. A secondary application of the proposed work is efficient similarity search in large biological databases of protein sequences.More specifically, the thesis makes contributions both by defining novel similarity measures, that are used to identify the best database matches, and by proposing methods to improve efficiency. On the topic of similarity measures, the thesis contributes a method for measuring similarity in a database of videos from American Sign …

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Micromachined Devices For In Vitro Biomedical Applications, Uday Shankar Tata Jan 2012

Micromachined Devices For In Vitro Biomedical Applications, Uday Shankar Tata

Electrical Engineering Dissertations - Archive

Cell migration is a central process in the development and maintenance of tissues. Any deviation in the process can have serious consequences, such as atherosclerosis and cancer metastasis. During cancer metastasis, chemokines produced at secondary sites form chemical gradients and attract the cancer cells from primary sites. One of the primary limitations for the study of cancer cell migration has been the lack of a suitable cost-effective assay for cell migration with easy translatability to clinical situations. To address these issues, a microfluidic device was designed for assaying of cancer cell migration towards different chemoattractants. The device was created with …

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Thermal Effects And Analysis Of High Frequency Devices In Analog Integrated Circuit Design, Ardasheir Sayek Rahman Jan 2012

Thermal Effects And Analysis Of High Frequency Devices In Analog Integrated Circuit Design, Ardasheir Sayek Rahman

Electrical Engineering Dissertations - Archive

Heterojunction Bipolar Junction Transistors (HBTs) are used in various high frequency applications in modern day technology. These devices produce high trans-conductance which is need for high frequency application. Their gain is significantly larger than complimentary metal-oxide-semiconductor (CMOS) devices which also imply there is high current within the devices. Since HBTs are very compact structure, the thermal heating generated within the devices needs to be characterized. This thesis explores the thermal effects from self heating in the static and time domains of the devices using 3D dimensional simulation and mathematical modeling using heat flow equation. The study concentrates on the thermal …

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The Art Of Microchannel Molding In Microscope Glass Slides, Sree Bhupathiraju Jan 2012

The Art Of Microchannel Molding In Microscope Glass Slides, Sree Bhupathiraju

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

This research is an effort to develop a new process by combining engineering principles with the history of glass art molding to develop clear micro-level test features in glass, for bio-medical and drug experiments dealing with cells, tissue, and micro-level organisms. Most of the present research in the bio-medical field involving micro-level cell and brain tissue testing is done using expensive glass or developed using Polydimethylsiloxane (PDMS) as the main material. Disadvantages of PDMS is that, over time the cell or blood tissue reacts with polymers causing a reduction in clarity making it difficult for a research scientist to observe …

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Shaping And Maintenance Of Low-Latency Anonymity Systems, Harsha Doreswamy Jan 2012

Shaping And Maintenance Of Low-Latency Anonymity Systems, Harsha Doreswamy

Computer Science and Engineering Theses - Archive

Surveillance of users on the Internet is growing. This makes it increasingly important to protect users' identity when they communicate online, especially for users like journalists, whistleblowers, and military officials. Anonymity systems can conceal users' identities and provide anonymity for their online activities. Low-latency anonymity systems like Tor are designed to provide support for applications like Web browsing, video streaming, and online chat. To make the commutation between source and destination unlinkable, Tor routes all the traffic through three Tor relays, which are spread across the globe. These three relays are usually chosen without considering the delay to get from …

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Choices And Consequences: A Game-Based Risky Behavior Prevention Program, Amanda Michelle Vines Jan 2012

Choices And Consequences: A Game-Based Risky Behavior Prevention Program, Amanda Michelle Vines

Computer Science and Engineering Theses - Archive

Serious games have been defined as a mental contest played with a computer in accordance to specific rules that use entertainment to further government or corporate training, education, health, public policy and strategic communication objectives. There have been various studies done to gauge the effectiveness of serious games to teach and engage. In collaboration with professors in social work and computer science, we have designed a multiplayer, social, serious game called Choices and Consequences (C&C) in an effort to better reach the audience of pre-teens and teens in order to reduce the risk taking behaviors of youth today. The game …

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Routing And Channel Assignment Schemes For Interference Avoidance In Wireless Mesh Networks, Fawaz Saleem Bokhari Jan 2012

Routing And Channel Assignment Schemes For Interference Avoidance In Wireless Mesh Networks, Fawaz Saleem Bokhari

Computer Science and Engineering Dissertations - Archive

This dissertation presents efficient routing and channel assignment schemes for interference avoidance in wireless mesh networks (WMNs). The most significant contributions of this dissertation are the development and design of two routing algorithms that help in improving network throughput by selecting less interference paths both for single and multiple radio WMNs and the design of an intelligent channel assignment scheme which increases the overall network capacity by assigning partially overlapped channels having less interference among neighboring ones for multi radio multi channel wireless mesh networks (MRMC-WMNs). For single radio single channel WMNs, we propose AMIRA (Ant Mesh routing for InteRference …

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Nanomembrane Surface Emitting Light Sources, Santhad Chuwongin Jan 2012

Nanomembrane Surface Emitting Light Sources, Santhad Chuwongin

Electrical Engineering Dissertations - Archive

Crystalline semiconductor nanomembranes (NM), which are transferable, stackable, bondable and manufacturable, offer unprecedented opportunities for unique electronic and photonic devices for vertically stacked high density photonic/electronic integration, high performance flexible electronics and flexible photonics. High quality single crystalline silicon NMs (Si NM) have been transferred onto various foreign substrates, such as glass and flexiblePolyethylene terephthalate (PET) plastics, based on low temperature transfer and stacking processes, developed by various groups. In the last few years, significant progress has been made by Ma's group on record high-speed flexible electronics, and high performance flexible Germanium (Ge) photodetectors, based on transferable Si/SiGe NMs. Many …

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Optimization And Reinforcement Learning Techniques In Multi-Agent Graphical Games And Economic Dispatch, Mohammed Abouheaf Jan 2012

Optimization And Reinforcement Learning Techniques In Multi-Agent Graphical Games And Economic Dispatch, Mohammed Abouheaf

Electrical Engineering Dissertations - Archive

This work discusses optimization and reinforcement learning techniques in power system Economic Dispatch and Multi-Agent graphical games. Power System Economic Dispatch (ED) is one of the power system energy management tools that is used to allocate required power generation to a number of generating units to meet the active load demand [109]. The operation cost of the power utilities depends on the fuel cost of the generating units. By optimizing the objective functions that depend on the fuel cost, the Economic Dispatch results in fuel cost savings, [25]. The generation cost functions are either smooth or non-smooth based on the …

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Improving Quality Of Service In Xml Data Stream Processing Using Load Shedding, Ranjan Dash Jan 2012

Improving Quality Of Service In Xml Data Stream Processing Using Load Shedding, Ranjan Dash

Computer Science and Engineering Dissertations - Archive

In recent years, we have witnessed the emergence of new types of systems that deal with large volumes of streaming data. Examples include nancial data analy- sis on feeds of stock tickers, sensor-based environmental monitoring, network tra c monitoring and click stream analysis to push customized advertisements or intrusion detection. Traditional database management systems (DBMS), which are very good at managing large volumes of stored data, fall short of serving this new class of appli- cations, which require low-latency processing on live data from push-based sources. Data Stream Management Systems (DSMS) are fast emerging to address this new type of …

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Reducing The Complexity Of Reinforcement Learning In Pomdps By Decomposition Into Decision And Perceptual Processes, Rasool Fakoor Jan 2012

Reducing The Complexity Of Reinforcement Learning In Pomdps By Decomposition Into Decision And Perceptual Processes, Rasool Fakoor

Computer Science and Engineering Theses - Archive

Markov Decision Processes (MDPs) and Partially Observable Markov Decision Processes (POMDPs) are very powerful and general frameworks to model decision and decision learning tasks in a wide range of problem domains. As a result, they are widely used in complex and real-world situations such as robot control tasks. However, the modeling power and generality of the frameworks comes at a cost in that the complexity of the underlying models and corresponding algorithms grows dramatically as the complexity of the task domain increases. To address this , this work presents an integrated and adaptive approach that attempts to reduce the complexity …

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Measurements Of A Latency-Biased Expander Topology In The Tor Anonymity System, Subhasish Dutta Chowdhuri Jan 2012

Measurements Of A Latency-Biased Expander Topology In The Tor Anonymity System, Subhasish Dutta Chowdhuri

Computer Science and Engineering Theses - Archive

Anonymous communication systems protect the privacy of their users by hiding who is communicating with whom. With the widespread use of the Internet, anonymity systems are all the more essential to support applications having strong privacy requirements such as intelligence gathering, military communications, or e-voting protocols. Anonymity systems must balance security and performance to remain popular with their users. In this work, we perform measurements on anonymity systems to improve their performance. We use the Vivaldi network coordinate system to efficiently map out the relative delays between hosts. Using this data, we create an overlay expander network topology that is …

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Point Of Gaze Applications For Assistive Interaction, Jonathan Walter Rich Jan 2012

Point Of Gaze Applications For Assistive Interaction, Jonathan Walter Rich

Computer Science and Engineering Theses - Archive

Eye tracking has many useful applications in human-machine interfaces and assistive technologies. Traditional input methods, such as the keyboard and mouse, are not practical in certain situations and can be completely ineffective for users with physical disabilities. Since many computing interfaces contain a strong visual component, it follows that knowledge of the user's point of gaze (PoG) can be extremely useful. Several approaches to PoG tracking have been described with various results and associated costs. Commercially available tracking devices have proven to be very useful for some disabled users, though often the systems can be cost prohibitive. Many computing applications …

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An Experiment In Developing Small Mobile Phone Applications Comparing On-Phone To Off-Phone Development, Tuan Anh Nguyen Jan 2012

An Experiment In Developing Small Mobile Phone Applications Comparing On-Phone To Off-Phone Development, Tuan Anh Nguyen

Computer Science and Engineering Theses - Archive

TouchDevelop represents a radically new mobile application development model, as TouchDevelop enables mobile application development on a mobile device. I.e., with TouchDevelop, the task of programming say a Windows Phone is shifted from the desktop computer to the mobile phone itself. We describe a first experiment on independent, non-expert subjects to compare programmer productivity using TouchDevelop vs. using a more traditional approach to mobile application development.

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Development Of A Detached Vital Sign Home Monitoring Management System, Anderson John Jan 2012

Development Of A Detached Vital Sign Home Monitoring Management System, Anderson John

Computer Science and Engineering Theses - Archive

Patients coping with chronic illnesses are often inconvenienced with routine doctor visits for the sole purpose of conducting basic vital sign monitoring. Such visits tend to be disruptive, and are more so when the patient requires a lengthy commute or has a mobility disability. As technology progresses, advances in low powered integrated circuits and network connectivity has opened the doors to a new world of remote patient monitoring. This thesis explores the possibility of using low powered technology to develop a patient monitoring system that's completely detached, thus allowing patients to move around their homes while the monitoring continues. We …

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Solid-State Devices For Detection Of Dna, Protein Biomarkers And Cells, Waseem Asghar Jan 2012

Solid-State Devices For Detection Of Dna, Protein Biomarkers And Cells, Waseem Asghar

Electrical Engineering Dissertations - Archive

Nanobiotechnology and BioMEMS have had tremendous impact on biosensing in the areas of cancer cell detection and therapeutics, disease diagnostics, proteomics and DNA analysis. Diseases are expressed on all levels including DNA, protein, cell and tissue. Therefore it is very critical to develop biosensors at each level. The power of the nanotechnology lies in the fact that we can fabricate devices on all scales from micro to nano. This dissertation focuses on four areas: 1) Development of nanopore sensors for DNA analysis; 2) Development of micropore sensors for early detection of circulating tumor cells (CTCs) from whole blood; 3) Synthesis …

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Precision And Mobility Analysis For Microrobot Design And Control, Muhammed Rasid Pac Jan 2012

Precision And Mobility Analysis For Microrobot Design And Control, Muhammed Rasid Pac

Electrical Engineering Dissertations - Archive

The emerging field of microrobotics extends from manipulation of nanostructures to 3D assembly of micromachines, and to control of motile bacteria as manipulation tools. Microrobots are not necessarily small themselves but the smallest scale in which they operate is measured in micrometers. Microrobots have to be precise, fast, and flexible to be useful as top-down manufacturing tools. As the relative magnitudes of uncertainties and errors with respect to the operational precision of robots grow towards smaller scales, the requirement for better precision increases. Hence, the concepts of precision analysis and precision-based design are important steps in microrobotic system development. In …

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Prominent Streaks Discovery On Blog Articles, Jijo John Philip Jan 2012

Prominent Streaks Discovery On Blog Articles, Jijo John Philip

Computer Science and Engineering Theses - Archive

We are surrounded by data in various forms such as instant messages, Twitter tweets, Facebook status updates, news, media, blogs and much more. Extracting meaning from such a massive collection of unstructured data would lead to interesting stories. Examples of such stories can be ``\emph{Who was the most popular actor in a particular month}''or ``\emph{Which diseases were people most concerned about in year 2008}''. In this thesis, we propose to discover popular entities mentioned in blog articles based on the concept of prominent streak. Given a sequence of values for a named entity (e.g., a person, a place, etc.), where …

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On Feasibility Of Fingerprinting Wireless Sensor Nodes Using Physical Properties, Xiaowei Mei Jan 2012

On Feasibility Of Fingerprinting Wireless Sensor Nodes Using Physical Properties, Xiaowei Mei

Computer Science and Engineering Theses - Archive

Fingerprinting wireless devices using physical properties has been recently suggested as an alternative for device identification and authentication. It has been found that the clock skew caused by the frequency discrepancy of the quartz crystals in different devices can be used as a reliable source for fingerprinting. Researchers have studied the application of the clock skew-based fingerprinting in sensor networks and claimed that it can detect fake identities, wormholes, and node replicas. However, the study in this paper draws a completely opposite conclusion, i.e., the clock skew of sensor nodes can be easily forged by adversaries to evade the detection. …

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Pushpop: A Card Game, Vishal Subramani Jan 2012

Pushpop: A Card Game, Vishal Subramani

Computer Science and Engineering Theses - Archive

In this thesis we have designed and implemented an Android card game called PushPop. This game is meant to stimulate the interest of kids in math learning. The Android game has cards with mathematical signs instead of the traditional suits. To reach the goal kids have to perform a lot of mathematical operations which helps them learn maths in a fun and effective way. A study was made to classify PushPop into the various games under the research umbrella of Game Theory. After the analysis we conclude that PushPop is a non-co-operative, symmetric, non-zero sum, simultaneously and imperfect information game …

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Comparing Web Application Scanners For Xss Attacks, Dengfeng Xia Jan 2012

Comparing Web Application Scanners For Xss Attacks, Dengfeng Xia

Computer Science and Engineering Theses - Archive

As software industry is paying increasing attention to web application security, various testing tools with black box testing feature have been developed. To better evaluate their performance, researchers have made efforts in several ways. Since XSS attack is one of the major attacks which can bring severe damages to victims, it is meaningful to pay specific attention to its testing process. However, many web application scanner evaluation projects make comparisons about various vulnerability types, and they are not dedicated to XSS issues enough. Their evaluations either use vulnerable applications in real life, or use test cases created by themselves, and …

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A Novel Scheme For Contact Predictions In Opportunistic Networks, Sujoy Kumar Bhattacharya Jan 2012

A Novel Scheme For Contact Predictions In Opportunistic Networks, Sujoy Kumar Bhattacharya

Computer Science and Engineering Theses - Archive

In the opportunistic network (ON) paradigm information is exchanged between two devices as they encounter each other. For such information exchange to take place the devices must know about the presence of other devices in the neighborhood. A very fundamental problem in ON is to predict the occurrence of a future opportunistic contact which is otherwise highly dynamic and unreliable. An accurate predictor which takes into account the long time history can benefit from multiple objectives. Such a predictor switches to the data transfer mode in anticipation of a contact. Also it maximizes the number of opportunistic contacts while spending …

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Shaping Network Topology For Privacy And Performance, Md Monjurul Hasan Jan 2012

Shaping Network Topology For Privacy And Performance, Md Monjurul Hasan

Computer Science and Engineering Theses - Archive

Anonymity systems provide privacy for Internet communication and are becoming popular. Unfortunately, users experience slow Internet connection through existing systems because paths used to route traffic are selected randomly without considering latency between nodes. In our work, we aim to design a better approach for selecting paths in anonymity systems with improved performance and without sacrificing privacy. We consider stratified topologies for our design where nodes are divided into three hops. We propose a scheme to build restricted network topologies on top of a stratified topology that maximizes throughput. First, we use Tabu Search to build latency-aware stratified restricted topologies …

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Control Framework Dynamic Walking Of A Bipedal Robot, Kishan Kumar Bhongale Prabhakar Prasad Jan 2012

Control Framework Dynamic Walking Of A Bipedal Robot, Kishan Kumar Bhongale Prabhakar Prasad

Computer Science and Engineering Theses - Archive

Despite significant progress in recent years, the capabilities of today's Humanoid robots still lack behind the walking abilities of humans in terms of competence, robustness, flexibility, and speed. Furthermore, unknown environmental conditions and related constraints imposed on the robot significantly increase the complexity of locomotion control and decision making for such systems, easily making planning-based approaches intractable. Part of the reason for this is that the control of a humanoid encompasses observation, processing the observed data, and decision making in terms of locomotion gait and body pose parameters. This key information derived from observations and internal robot information finally allows …

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