Computer Sciences Commons^™

การปรับปรุงการแยกฉากหลังบนพื้นหลังสีเขียวไม่สม่ำเสมอแบบทันที, วรายุ จริยาวัฒนรัตน์

Chulalongkorn University Theses and Dissertations (Chula ETD)

วัตถุประสงค์หลักของงานวิจัยนี้คือปรับปรุงการแยกฉากหลังบนพื้นหลังสีเขียวที่ไม่สม่ำเสมอแบบทันที ในวิธีการพื้นฐาน แต่ละพิกเซลจะถูกคำนวณว่าเป็นฉากหลังโดยใช้ค่าขีดจำกัดเดียวกันทั้งภาพเพียง 2 ค่า แต่ในความเป็นจริง วิธีการนี้มีปัญหาในหลาย ๆ กรณี เช่น พื้นหลังไม่ได้เป็นสีเดียวกันทั้งหมด หรือมีเงาของนักแสดงทอดลงไปที่พื้นหลัง เป็นต้น ดังนั้นการใช้ค่าขีดจำกัดเดียวกันหมดทั้งภาพจึงไม่เหมาะสมสำหรับกรณีดังกล่าว งานวิจัยนี้จึงใช้การประมาณความหนาแน่นเคอร์เนลมาช่วยในการหาค่าขีดจำกัดของแต่ละพิกเซลในภาพ เพื่อให้ทุก ๆ พิกเซลในภาพมีขีดจำกัดที่เหมาะสม และยังมีความเร็วในการประมวลผลที่สามารถออกอากาศสดได้ที่ 60 เฟรมต่อวินาที สำหรับความละเอียดระดับ Full HD

Mining And Analysis Of Real-World Graphs, Armita Abedijaberi

Doctoral Dissertations

"Networked systems are everywhere - such as the Internet, social networks, biological networks, transportation networks, power grid networks, etc. They can be very large yet enormously complex. They can contain a lot of information, either open and transparent or under the cover and coded. Such real-world systems can be modeled using graphs and be mined and analyzed through the lens of network analysis. Network analysis can be applied in recognition of frequent patterns among the connected components in a large graph, such as social networks, where visual analysis is almost impossible. Frequent patterns illuminate statistically important subgraphs that are usually …

Reputation And Credit Based Incentive Mechanism For Data-Centric Message Delivery In Delay Tolerant Networks, Himanshu Jethawa

Masters Theses

"In a Data-centric Delay Tolerant Networks (DTNs), it is essential for nodes to cooperate in message forwarding in order to enable successful delivery of a message in an opportunistic fashion with nodes having their social interests defined. In the data-centric dissemination protocol proposed here, a source annotates messages (images) with keywords, and then intermediate nodes are presented with an option of adding keyword-based annotations in order to create higher content strength messages on path toward the destination. Hence, contents like images get enriched as there is situation evolution or learned by these intermediate nodes, such as in a battlefield, or …

Solidification Rate Detection Through Solid-Liquid Interface Tracking, Wei Luo

Masters Theses

”Studying the melt pool dynamics in laser powder bed fusion (LPBF) additive manufacturing is vital to predict the microstructure of the built part. High-speed synchrotron hard X-ray imaging is an advanced technique to monitor the LPBF process in situ and in real time. However, it is very challenging to track the solid-liquid interface due to the low image contrast, high image noise and unstable intensity of the image sequences.

In this paper, we propose an solid-liquid interface detector with human interaction to track the interface to compute the solidification rate of the melt pool. The proposed method includes six independent …

Multiple Security Domain Non Deducibility In The Freedm Smart Grid Infrastructure, Manish Jaisinghani

Masters Theses

"The building block of today's world are not materials, but, computers and algorithms with communication networks between physical entities. A cyber physical system (CPS) is a system in which the cyber and physical entities of the system work together towards a common goal, for example a water treatment facility or an electricity distribution system. These cyber physical infrastructures affect day to day lives of people and hence become target point for the attackers to disrupt normal daily life. Owing to the complexity of a cyber physical system, the attacks have themselves become sophisticated and harder to detect. These sophisticated attacks …

Cloud Transactions And Caching For Improved Performance In Clouds And Dtns, Dileep Mardham

Masters Theses

"In distributed transactional systems deployed over some massively decentralized cloud servers, access policies are typically replicated. Interdependencies ad inconsistencies among policies need to be addressed as they can affect performance, throughput and accuracy. Several stringent levels of policy consistency constraints and enforcement approaches to guarantee the trustworthiness of transactions on cloud servers are proposed. We define a look-up table to store policy versions and the concept of "Tree-Based Consistency" approach to maintain a tree structure of the servers. By integrating look-up table and the consistency tree based approach, we propose an enhanced version of Two-phase validation commit (2PVC) protocol integrated …

Cyber-Physical Security Of An Electric Microgrid, Prashanth Palaniswamy

Masters Theses

"Cyber-physical systems (CPSs) are physical systems that are controlled or monitored by computer-based systems. CPSs are a combination of computation, networking, and physical processes. As CPSs are a combination of various diverse components, they are vulnerable to several security threats. Moreover, there are many different security domains (not just high/low, nor necessarily hierarchical). This paper utilizes previously developed multiple security domain nondeducibility (MSDND) to uncover potential integrity vulnerabilities in an electric microgrid. Invariants are manually generated using the insights obtained through MSDND analysis and use linear regression to automate the generation of invariants. The vulnerabilities are then mitigated, to the …

An Approach For Formal Analysis Of The Security Of A Water Treatment Testbed, Sai Sidharth Patlolla

Masters Theses

"This thesis focuses on securing critical infrastructures such as chemical plants, manufacturing units, and power generating plants against attacks that disrupt the information flow from one component to another. Such systems are controlled by an Industrial Control System (ICS) that includes controllers communicating with each other, and with physical sensors and actuators, using a communications network.

Traditional security models partition the security universe into two worlds, secure and insecure, but in the real world the partitions often overlap and information is leaked even through the physical observation which makes it much harder to analyze a Cyber physical system (CPS). To …

A Network Tomography Approach For Traffic Monitoring In Smart Cities, Ruoxi Zhang

Masters Theses

"Various urban planning and managing activities required by a Smart City are feasible because of traffic monitoring. As such, the thesis proposes a network tomography-based approach that can be applied to road networks to achieve a cost-efficient, flexible, and scalable monitor deployment. Due to the algebraic approach of network tomography, the selection of monitoring intersections can be solved through the use of matrices, with its rows representing paths between two intersections, and its columns representing links in the road network. Because the goal of the algorithm is to provide a cost-efficient, minimum error, and high coverage monitor set, this problem …

Card: Concealed And Remote Discovery Of Iot Devices In Victims' Home Networks, Sammie Lee Bush

Masters Theses

"Smart devices are becoming more common in the standard households. They range from lights to refrigerators and their functionality and applications continues to grow with consumer demand. This increase in networked, complex devices has also brought an increase in vulnerabilities in the average consumer's home. There now exists an Internet of Things (IoT) ecosystem that creates new attack vectors for adversaries to spread malware, build botnets, and participate in other malicious activities. We will overview some of these new attack vectors as well as go over a framework that would allow an adversary to target a user's home network and …

Analyzing Large Scale Trajectory Data To Identify Users With Similar Behavior, Tyler Clark Percy

Masters Theses

"In today's society, social networks are a popular way to connect with friends and family and share what's going on in your life. With the Internet connecting us all closer than ever before, it is increasingly common to use social networks to meet new friends online that share similar interests instead of only connecting with those you already know. For the problem of attempting to connect people with similar interests, this paper proposes the foundation for a Geo-social network that aims to extract the semantic meaning from users' location history and use this information to find the similarity between users. …

Precise Energy Efficient Scheduling Of Mixed-Criticality Tasks & Sustainable Mixed-Criticality Scheduling, Sai Sruti

Masters Theses

"In this thesis, the imprecise mixed-criticality model (IMC) is extended to precise scheduling of tasks, and integrated with the dynamic voltage and frequency scaling (DVFS) technique to enable energy minimization. The challenge in precise scheduling of MC systems is to simultaneously guarantee the timing correctness for all tasks, hi and lo, under both pessimistic and optimistic (less pessimistic) assumptions. To the best of knowledge this is the first work to address the integration of DVFS energy conserving techniques with precise scheduling of lo-tasks of the MC model.

In this thesis, the utilization based schedulability tests and sufficient conditions for such …

Smart Augmented Reality Instructional System For Mechanical Assembly, Ze-Hao Lai

Masters Theses

"Quality and efficiency are pivotal indicators of a manufacturing company. Many companies are suffering from shortage of experienced workers across the production line to perform complex assembly tasks such as assembly of an aircraft engine. This could lead to a significant financial loss. In order to further reduce time and error in an assembly, a smart system consisting of multi-modal Augmented Reality (AR) instructions with the support of a deep learning network for tool detection is introduced. The multi-modal smart AR is designed to provide on-site information including various visual renderings with a fine-tuned Region-based Convolutional Neural Network, which is …

Classification Of Eeg Signals Of User States In Gaming Using Machine Learning, Chandana Mallapragada

Masters Theses

"In this research, brain activity of user states was analyzed using machine learning algorithms. When a user interacts with a computer-based system including playing computer games like Tetris, he or she may experience user states such as boredom, flow, and anxiety. The purpose of this research is to apply machine learning models to Electroencephalogram (EEG) signals of three user states -- boredom, flow and anxiety -- to identify and classify the EEG correlates for these user states. We focus on three research questions: (i) How well do machine learning models like support vector machine, random forests, multinomial logistic regression, and …

Improved Crpd Analysis And A Secure Scheduler Against Information Leakage In Real-Time Systems, Ying Zhang

Masters Theses

"Real-time systems are widely applied to the time-critical fields. In order to guarantee that all tasks can be completed on time, predictability becomes a necessary factor when designing a real-time system. Due to more and more requirements about the performance in the real-time embedded system, the cache memory is introduced to the real-time embedded systems.

However, the cache behavior is difficult to predict since the data will be loaded either on the cache or the memory. In order to taking the unexpected overhead, execution time are often enlarged by a certain (huge) factor. However, this will cause a waste of …

Black Business Owners Overcoming Barriers In Texas, Henry Williams

Walden Dissertations and Doctoral Studies

Black entrepreneurs in the state of Texas reported that they did not achieve the same level of success as nonminority enterprises. Many Black entrepreneurs have obtained education from top tier institutions and have the managerial experiences, skills, and working knowledge that facilitate business success, but they are not able to sustain business growth. The purpose of this phenomenological study was to explore the lived experiences of Black Texan entrepreneurs. This research was established using the conceptual framework of human capital. The overarching research question concerned the lived experiences of Black Texas entrepreneurs who were not as successful in business as …

Strategies Certified Project Management Professionals Use To Prevent Counterproductive Behavior, Lisa Annika Christin Hansson-Vazquez

Walden Dissertations and Doctoral Studies

Project managers who fail to apply strategies to prevent counterproductive work behavior in information technology projects could negatively affect users, budget costs, timelines, or projects. The purpose of this multiple case study was to explore strategies that project managers used to prevent counterproductive work behavior that put project success at risk. Social learning theory was the conceptual framework for this study. Data were collected through document review of published Project Management Institute (PMI) material as well as semistructured interviews with 10 project managers who were members of a PMI chapter in the southeastern United States, and who held a project …

Artificial Intelligence And It Professionals, Sunil Mithas, Thomas Kude, Jonathan W. Whitaker

Management Faculty Publications

How will continuing developments in artificial intelligence (AI) and machine learning influence IT professionals? This article approaches this question by identifying the factors that influence the demand for software developers and IT professionals, describing how these factors relate to AI, and articulating the likely impact on IT professionals.

Bibliography For Interstices 2018: Beyond Human: Emotion And Ai, Kristin Laughtin-Dunker

Library Displays and Bibliographies

An annotated list of materials in the Leatherby Libraries to accompany the Interstices 2018: Beyond Human: Emotion and AI event held at Chapman University in February 2018. The event featured Lisa Joy, co-creator and executive producer of HBO’s Emmy winning hit series Westworld, Jon Gratch, Director for Virtual Human Research at the University of Southern California’s (USC) Institute for Creative Technologies and Caroline Bainbridge, a Professor of Psychoanalysis and Culture in the Department of Media, Culture and Language at the University of Roehampton London. The Leatherby Libraries also hosted two book club discussions of The Positronic …

Pseudorehearsal In Actor-Critic Agents With Neural Network Function Approximation, Vladimir Marochko, Leonard Johard, Manuel Mazzara, Luca Longo

Articles

Catastrophic forgetting has a significant negative impact in reinforcement learning. The purpose of this study is to investigate how pseudorehearsal can change performance of an actor-critic agent with neural-network function approximation. We tested agent in a pole balancing task and compared different pseudorehearsal approaches. We have found that pseudorehearsal can assist learning and decrease forgetting.

Three Decades Of Universal Design - Defining Moments, Margaret Kinsella

Articles

This paper contributes to the growing research on incorporating Universal Design in the Higher Education landscape by presenting a Practitioner's Perspective on Universal Design as delivered in the Institute of Technology, Blanchardstown (ITB) in the first year of a creative digital media degree as part of the first year experience. This first year experience is a transition time for many students and has many complexities; while being an exciting and fulfilling time, the transition can also be challenging and isolating. Through Universal Design, the aim is to enable students to 'Get connected' and 'Stay connected'. Universal Design for Learning is …

A Javascript Framework Comparison Based On Benchmarking Software Metrics And Environment Configuration, Jefferson Ferreira

Dissertations

JavaScript is a client-side programming language that can be used in multi-platform applications. It controls HTML and CSS to manipulate page behaviours and is widely used in most websites over the internet. JavaScript frameworks are structures made to help web developers build web applications faster by offering features that enhance the user interaction with the web page. An increasing number of JavaScript frameworks have been released in recent years in the market to help front-end developers build applications in a shorter space of time. Decision makers in software companies have been struggling to determine which frameworks are best suited for …

Investigation Into The Predictive Power Of Artificial Neural Networks And Logistic Regression For Predicting Default In Chit Funds, Ciara Kerrigan

Dissertations

This study evaluated the performance of an artificial neural network (ANN) multi-layer perceptron model and a logistic regression logitboost (LR) model to predict default in chit funds. The two types of default investigated were late payment of 30 days and late payment of 90 days. The dataset was broken up into training and validation datasets using random sampling and K folds cross validation was used on the training dataset to assess performance of the tuning parameters. The validation dataset was used to compare performance of both algorithms. Principle component analysis (PCA) was used to reduce the feature set while still …

Exploring The Features To Classify The Musical Period Of Western Classical Music, Arturo Martínez Gallardo

Dissertations

Music Information Retrieval (MIR) focuses on extracting meaningful information from music content. MIR is a growing field of research with many applications such as music recommendation systems, fingerprinting, query-by-humming or music genre classification. This study aims to classify the styles of Western classical music, as this has not been explored to a great extent by MIR. In particular, this research will evaluate the impact of different music characteristics on identifying the musical period of Baroque, Classical, Romantic and Modern. In order to easily extract features related to music theory, symbolic representation or music scores were used, instead of audio format. …

Non-Linear Machine Learning With Active Sampling For Mox Drift Compensation, Tamara Matthews, Muhammad Iqbal, Horacio Gonzalez-Velez

Conference papers

Abstract—Metal oxide (MOX) gas detectors based on SnO2 provide low-cost solutions for real-time sensing of complex gas mixtures for indoor ambient monitoring. With high sensitivity under ideal conditions, MOX detectors may have poor longterm response accuracy due to environmental factors (humidity and temperature) along with sensor aging, leading to calibration drifts. Finding a simple and efficient solution to correct such calibration drifts has been the subject of numerous studies but remains an open problem. In this work, we present an efficient approach to MOX calibration using active and transfer sampling techniques coupled with non-linear machine learning algorithms, namely neural networks, …

Algorithms For Reconstruction Of Gene Regulatory Networks From High -Throughput Gene Expression Data, Wenping Deng

Dissertations, Master's Theses and Master's Reports

Understanding gene interactions in complex living systems is one of the central tasks in system biology. With the availability of microarray and RNA-Seq technologies, a multitude of gene expression datasets has been generated towards novel biological knowledge discovery through statistical analysis and reconstruction of gene regulatory networks (GRN). Reconstruction of GRNs can reveal the interrelationships among genes and identify the hierarchies of genes and hubs in networks. The new algorithms I developed in this dissertation are specifically focused on the reconstruction of GRNs with increased accuracy from microarray and RNA-Seq high-throughput gene expression data sets.

The first algorithm (Chapter 2) …

ระบบนำทางหุ่นยนต์ด้วยหลายตัวนำทางย่อยและหลายแผนที่ย่อย, สุขุม สัตตรัตนามัย

Chulalongkorn University Theses and Dissertations (Chula ETD)

การใช้งานหุ่นยนต์อัตโนมัติในเขตเมืองที่มีความหลากหลายของลักษณะพื้นที่สูงเป็นงานท้าทายที่ต้องการโปรแกรมนำทางและรูปแบบแผนที่ที่แตกต่างกันในแต่ละบริเวณ การปฏิบัติงานของหุ่นยนต์ในโลกจริงต้องเจอกับสิ่งแวดล้อมที่มีการเปลี่ยนแปลงอย่างต่อเนื่อง เช่น ฝนตกหรือความคับคั่งของบริเวณที่ต้องนำทาง ส่งผลให้ต้องปรับแผนเส้นทาง ในงานวิจัยนี้นำเสนอระบบนำทางหุ่นยนต์ในโลกจริงซึ่งเป็นรูปแบบใหม่ของการสลับการทำงานระหว่างโปรแกรมนำทางหลายตัวอย่างเหมาะสม เพื่อให้สามารถจัดการกับพฤติกรรมของหุ่นยนต์และสภาพแวดล้อมที่ท้าทายได้ ระบบที่นำเสนอในงานวิจัยนี้เป็นผลลัพธ์ของการติดตั้งหุ่นยนต์จริงในระบบซึ่งมีผู้ใช้งานและสภาพแวดล้อมจริง

Knowing When Not To Answer: Positional Peptide Sequencing With Encoder-Decoder Networks, Korrawe Karunratanakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

การถอดรหัสเปปไทด์นั้นเป็นองค์ประกอบสำคัญสำหรับการศึกษาโปรตีน โดยทั่วไปแล้วการวิเคราะห์ข้อมูล mass spectrum นั้นจะศึกษาเพียงสายของกรดอะมิโนที่ปรากฏอยู่ในฐานข้อมูลเท่านั้น ทำให้การค้นหาสายเปปไทด์แบบใหม่ที่อาจเกิดจากการกลายพันธุ์นั้นทำได้ยาก วิถีการถอดรหัสด้วยดีโนโวแก้ไขข้อจำกัดนี้ด้วยการถอดรหัสสายเปปไทด์โดยตรงจากข้อมูล mass spectrum โดยใช้ความรู้เกี่ยวกับกระบวนการแตกตัวของไอออน ทำให้ไม่จำเป็นต้องใช้ฐานข้อมูลโปรตีนช่วย อย่างไรก็ดี วิธีดังกล่าวยังมีข้อจำกัดด้านความแม่นยำและต้องการการตรวจทานโดยผู้เชี่ยวชาญ วิทยานิพนธ์ฉบับนี้นำเสนอวิธีการถอดรหัสเปปไทด์ด้วยวิธีการดีโนโวแบบใหม่ชื่อ SMSNet โดยใช้โมเดล deep learning เข้าช่วย โดยยังสามารถทำนายกรดอะมิโนได้อย่างครอบคลุมในระดับความแม่นยำของกรดอะมิโนที่ 95% งานฉบับนี้เสนอขั้นตอน ถอดรหัส ตัดออก และสืบค้น เพื่อตัดผลทำนายในตำแหน่งที่มีความกำกวมออกและใช้ข้อมูลจากฐานข้อมูลโปรตีนช่วยเพื่อให้ทำนายสายเปปไทด์ได้ถูกต้องทั้งเส้น นอกจากนี้ งานนี้ได้นำเสนอการใช้ rescorer ในการแก้ไขคะแนนความมั่นใจสำหรับผลทำนายในแต่ละตำแหน่ง ซึ่งส่งผลให้สามารถแยกกลุ่มคะแนนความมั่นใจสำหรับคำตอบที่ถูกต้องและคำตอบที่ผิดได้ดียิ่งขึ้น เมื่อประกอบทุกขั้นตอนวิธีในงานวิจัยฉบับนี้เข้าด้วยกันพบว่า SMSNet สามารถทำนายสายเปปไทด์ได้ในประสิทธิภาพที่ใกล้เคียงกับการทำนายด้วยฐานข้อมูลในการทดลองจริง

Autonomous Vehicle Communication Using Blockchain, Reid Barber

Honors Theses

With recent advancements in machine learning and interest in expanding the smart city, various technology companies and car manufacturers have begun pour- ing billions of dollars into research and development of autonomous vehicles. While many companies are hard at work developing their own driverless cars, it is important to begin planning how these cars will communicate with one another and other in- frastructure. Because the safety of passengers and pedestrians are heavily dependent on these communications, the careful design and implementation of these networks is crucial. Blockchain is another technology that has amassed a great deal of attention in recent …

Effective Strategies For Managing Continuous Consultant Turnover In It Project Teams, Nicholas K. Jury

Walden Dissertations and Doctoral Studies

Information Technology project managers have found that collective turnover of consultants lowers code quality, increases knowledge loss and negatively impacts team performance. Within the last decade, companies have begun to see that offshore consultants have a turnover rate greater than 26%, more than double the rates for the rest of the IT consulting industry. Collective turnover also puts additional pressure on the project team, causing work exhaustion and thus additional turnover. The purpose of this single case study was to explore strategies that 6 successful project managers utilized to limit and reduce the impact of collective turnover of their hybrid …