Digital Communications and Networking Commons^™

การควบคุมคุณภาพการให้บริการโดยใช้แผนราคาในโครงข่ายเข้าถึง, ธนชาติ วีระพันธุ์

Chulalongkorn University Theses and Dissertations (Chula ETD)

ปัจจุบันเทคโนโลยีการสื่อสารทั้งมีสายและไร้สายได้พัฒนาไปอย่างรวดเร็ว ประกอบกับความต้องการที่จะใช้บริการเทคโนโลยีการสื่อสารที่มากขึ้นอย่างต่อเนื่อง แต่ด้วยทรัพยากรที่มีอยู่อย่างจำกัด จึงทำให้เกิดความคับคั่งในระบบโครงข่ายเข้าถึง จึงเป็นสาเหตุทำให้โครงข่ายเกิดการประวิงและยากต่อการควบคุมคุณภาพการให้บริการ เพื่อแก้ปัญหาดังกล่าวจึงนำแผนราคาเข้ามาจูงใจในการเข้าใช้บริการ ในโครงข่าย ในวิทยานิพนธ์ฉบับนี้จำลองระบบด้วยแถวคอย M/M/1 โดยแบ่งรูปแบบของแถวคอยออกเป็น แบบเดี่ยว และ แบบลำดับความสำคัญ โดยกรณีของแถวคอยแบบเดี่ยว เมื่อระบบเกิดความคับคั่ง ทำให้มีการปรับราคา ผู้ใช้บริการที่ไม่ยอมรับราคาที่เปลี่ยนไปจะไม่ได้เข้าสู่ระบบ ส่วนในกรณีของแถว คอยแบบลำดับความสำคัญ เมื่อระบบเกิดความคับคั่ง ทำให้มีการปรับราคา ผู้ใช้บริการที่ไม่ยอมรับ ราคาที่เปลี่ยนไปสามารถเข้าสู่ระบบได้แต่ต้องรอให้ผู้ใช้บริการที่ยอมรับราคาที่เปลี่ยนไปใช้บริการเสร็จ ก่อน นอกจากนั้น แถวคอยลำดับความสำคัญยังแบ่งออกเป็นสองกรณี กรณีแรกคือผู้ใช้บริการ ที่ยอมรับราคาที่เปลี่ยนไปสามารถขัดจังหวะการใช้บริการของผู้ใช้บริการที่ไม่ยอมรับราคาที่เปลี่ยนไป ได้ทันที กรณีที่สองคือผู้ใช้บริการที่ยอมรับราคาที่เปลี่ยนไปต้องรอให้ผู้ใช้บริการที่ไม่ยอมรับราคาที่ เปลี่ยนไปใช้บริการเสร็จก่อน วิทยานิพนธ์ฉบับนี้เสนอการวิเคราะห์ทางคณิตศาสตร์และการจำลองระบบทางคอมพิวเตอร์เพื่อหาค่าที่เหมาะสมของความน่าจะเป็นที่ผู้ใช้บริการจะยอมรับราคาที่ปรับขึ้น ราคาใหม่ที่ปรับขึ้นอย่าง เหมาะสม เวลาประวิงของแพ็กเกตเฉลี่ย เวลาเฉลี่ยที่แพ็กเกตอยู่ในระบบ ความน่าจะเป็นที่เวลา ประวิงของแพ็กเกดจะมีค่ามากกว่าเวลาประวิงของแพ็กเกตที่กำหนด และรายได้ที่คาดหวังเฉลี่ย โดยผลลัพธ์จากการวิเคราะห์ทางคณิตศาสตร์และการจำลองระบบทางคอมพิวเตอร์ที่นำแผนราคามา ประยุกต์ใช้กับรูปแบบของแถวคอยทั้งสองสามารถควบคุมคุณภาพการให้บริการได้ตามค่าที่กำหนด จากการศึกษาด้วยการวิเคราะห์และการจำลองระบบด้วยคอมพิวเตอร์ให้ผลลัพธ์ที่สอดคล้องกัน

New Operations On Intuitionistic Fuzzy Soft Sets Based On First Zadeh's Logical Operators, Florentin Smarandache, Said Broumi, Pinaki Majumdar

Branch Mathematics and Statistics Faculty and Staff Publications

In this paper , we have defined First Zadeh’s implication , First Zadeh’s intuitionistic fuzzy conjunction and intuitionistic fuzzy disjunction of two intuitionistic fuzzy soft sets and some their basic properties are studied with proofs and examples.

A Hypernet Architecture, Shufeng Huang

Theses and Dissertations--Computer Science

Network virtualization is becoming a fundamental building block of future Internet architectures. By adding networking resources into the “cloud”, it is possible for users to rent virtual routers from the underlying network infrastructure, connect them with virtual channels to form a virtual network, and tailor the virtual network (e.g., load application-specific networking protocols, libraries and software stacks on to the virtual routers) to carry out a specific task. In addition, network virtualization technology allows such special-purpose virtual networks to co-exist on the same set of network infrastructure without interfering with each other.

Although the underlying network resources needed to support …

Efficient Cooperative Mimo Paradigms For Cognitive Radio Networks, Wei Chen, Liang Hong, Xiaoqian Chen

Computer Science Faculty Research

This paper investigates the benefits that cooperative communication brings to cognitive radio networks. We focus on cooperative Multiple Input Multiple Output (MIMO) technology, where multiple distributed single-antenna secondary users cooperate on data transmission and reception. Three cooperative MIMO paradigms are proposed to maximize the diversity gain and significantly improve the performance of overlay, underlay and interweave systems. In the paradigm for overlay systems the secondary users can assist (relay) the primary transmissions even when they are far away from the primary users. In the paradigm for underlay systems the secondary users can share the primary users’ frequency resources without any …

Cross-Domain Password-Based Authenticated Key Exchange Revisited, Liqun Chen, Hoon Wei Lim, Guomin Yang

Research Collection School Of Computing and Information Systems

We revisit the problem of secure cross-domain communication between two users belonging to different security domains within an open and distributed environment. Existing approaches presuppose that either the users are in possession of public key certificates issued by a trusted certificate authority (CA), or the associated domain authentication servers share a long-term secret key. In this article, we propose a generic framework for designing four-party password-based authenticated key exchange (4PAKE) protocols. Our framework takes a different approach from previous work. The users are not required to have public key certificates, but they simply reuse their login passwords, which they share …

Neuromodulation Based Control Of Autonomous Robots On A Cloud Computing Platform, Cameron Muhammad

College of Graduate Studies: Theses & Dissertations

In recent years, the advancement of neurobiologically plausible models and computer networking has resulted in new ways of implementing control systems on robotic platforms. The work presents a control approach based on vertebrate neuromodulation and its implementation on autonomous robots in the open-source, open-access environment of robot operating system (ROS). A spiking neural network (SNN) is used to model the neuromodulatory function for generating context based behavioral responses of the robots to sensory input signals. The neural network incorporates three types of neurons- cholinergic and noradrenergic (ACh/NE) neurons for attention focusing and action selection, dopaminergic (DA) neurons for rewards- and …

Performance Evaluation Of A Technology Independent Security Gateway For Next Generation Networks, Fudong Li, Nathan Clarke, Steven Furnell, Is-Mkwawa Mkwawa

Research outputs 2014 to 2021

With the all IP based Next Generation Networks being deployed around the world, the use of real-time multimedia service applications is being extended from normal daily communications to emergency situations. However, currently different emergency providers utilise differing networks and different technologies. As such, conversations could be terminated at the setup phase or data could be transmitted in plaintext should incompatibility issues exit between terminals. To this end, a novel security gateway that can provide the necessary security support for incompatible terminals was proposed, developed and implemented to ensure the successful establishment of secure real-time multimedia conversations. A series of experiments …

Evaluating Electronic Market Designs: The Effects Of Competitive Arousal And Social Facilitation On Electronic Group Buying, Yuecheng Yu, Karl R. Lang, Alex Pelaez

Research Collection School Of Computing and Information Systems

This article presents an evaluation approach foralternative electronic market designs and examines theimpact of competitive arousal under time pressure onmarket performance in a group-buying setting. Drawingon theory from economics, decision theory, andinformation systems, we present a competitive arousalmodel for a social buying setting that posits thatintroducing competitive arousal among buyers reducesbuyer profits and that social facilitation can mitigate thesecosts through better task completion and time tocompletion rates. Using an economic experiment, wefound that rivalry has a negative effect on buyer profitsbut also that competitive arousal increases the efficiencyof social facilitation in terms of group formation. Wediscuss the implications of these …

A Study On Countermeasures Against Steganography: An Active Warden Approach, Qilin Qi

Department of Computer Electronics and Engineering: Dissertations, Theses, and Student Research

Digital steganography is a method used for hiding information in digital images. It can be used for secure communication. There have been many robust digital steganography methods invented in recent decades. The steganographic message can be inserted in multimedia cover signal such as audio, image and video. However, this technique also may be used by malicious users to transmit dangerous information through the Internet beyond the control of security agencies. How to detect and/or block potentially dangerous information transmission on the Internet through billions of multimedia files while not affecting innocent multimedia communications becomes a challenging problem. Existing steganalysis methods …

Tascked: The Sanity Promoting Task Manager, Jake Tobin

Computer Science and Software Engineering

Personal task managers or various forms of to-do lists are abundant in our modern computing age. With the explosion of mobile computing technology, it is easier than ever to take notes digitally and make the data seemingly instantly available anywhere on the Internet. There is a fairly well defined core set of features in personal task managers available for public consumption, but it seems nothing that is publicly available provides feedback to the user or suggestions based on user history. Tascked is a task management solution, which records user history and solicits user feedback on progress. This allows the system …

Testing Virtual Machines For Cadrc Server Hosting, Robin Verweij

Computer Science and Software Engineering

No abstract provided.

Broadcasting With Prediction And Selective Forwarding In Vehicular Networks, Jainjun Yang, Zongming Fei

Computer Science Faculty Publications

Broadcasting in vehicular networks has attracted great interest in research community and industry. Broadcasting on disseminating information to individual vehicle beyond the transmission range is based on inter-vehicle communication systems. It is crucial to broadcast messages to other vehicles as fast as possible because the messages in vehicle communication systems are often emergency messages such as accident warning or alarm. In many current approaches, the message initiator or sender selects the node among its neighbors that is farthest away from it in the broadcasting direction and then assigns the node to rebroadcast the message once the node gets out of …

Attitudes And Behaviors In Online Communities: Empirical Studies Of The Effects Of Social, Community, And Individual Characteristics, Richard Kumi

Graduate Theses and Dissertations

Online communities and communities of practice bring people together to promote and support shared goals and exchange information. Personal interactions are important to many of these communities and one of the important outcomes of personal interactions in online communities and communities of practice is user-generated content. The three essays in the current study examines behavior motivation in online communities and communities of practice to understand how Social and personal psychological factors, and user-generated influence attitudes, intentions and behaviors in online communities.

The first essay addresses two research questions. First, how does Social capital influence exchange and combination behaviors in online …

Analysis Of Social Networks In A Virtual World, Gregory Thomas Stafford

Graduate Theses and Dissertations

As three-dimensional virtual environments become both more prevalent and more fragmented, studying how users are connected via their avatars and how they benefit from the virtual world community has become a significant area of research. An in-depth analysis of virtual world Social networks is needed to evaluate how users interact in virtual worlds, to better understand the impact of avatar Social networks on the virtual worlds, and to improve future online Social networks.

Our current efforts are focused on building and exploring the Social network aspects of virtual worlds. In this thesis, we build a Social network of avatars based …

Identifying Emerging Researchers Using Social Network Analysis, Syed Masum Billah

Graduate Theses and Dissertations

Finding rising stars in academia early in their careers has many implications when hiring new faculty, applying for promotion, and/or requesting grants. Typically, the impact and productivity of a researcher are assessed by a popular measurement called the h-index that grows linearly with the academic age of a researcher. Therefore, h-indices of researchers in the early stages of their careers are almost uniformly low, making it difficult to identify those who will, in future, emerge as influential leaders in their field. To overcome this problem, we make use of Social network analysis to identify young researchers most likely to become …

A Novel Defense Mechanism Against Web Crawler Intrusion, Alireza Aghamohammadi

Master's Theses and Doctoral Dissertations

Web robots also known as crawlers or spiders are used by search engines, hackers and spammers to gather information about web pages. Timely detection and prevention of unwanted crawlers increases privacy and security of websites. In this research, a novel method to identify web crawlers is proposed to prevent unwanted crawler to access websites. The proposed method suggests a five-factor identification process to detect unwanted crawlers. This study provides the pretest and posttest results along with a systematic evaluation of web pages with the proposed identification technique versus web pages without the proposed identification process. An experiment was performed with …

Approximate Techniques In Solving Optimal Camera Placement Problems, Jian Zhao, Ruriko Yoshida, Sen-Ching Samson Cheung, David Haws

Statistics Faculty Publications

While the theoretical foundation of the optimal camera placement problem has been studied for decades, its practical implementation has recently attracted significant research interest due to the increasing popularity of visual sensor networks. The most flexible formulation of finding the optimal camera placement is based on a binary integer programming (BIP) problem. Despite the flexibility, most of the resulting BIP problems are NP-hard and any such formulations of reasonable size are not amenable to exact solutions. There exists a myriad of approximate algorithms for BIP problems, but their applications, efficiency, and scalability in solving camera placement are poorly understood. Thus, …

Social Listening For Customer Acquisition, Juan Du, Biying Tan, Feida Zhu, Ee-Peng Lim

Research Collection School Of Computing and Information Systems

Social network analysis has received much attention from corporations recently. Corporations are trying to utilize social media platforms such as Twitter, Facebook and Sina Weibo to expand their own markets. Our system is an online tool to assist these corporations to 1) find potential customers, and 2) track a list of users by specific events from social networks. We employ both textual and network information, and thus produce a keyword-based relevance score for each user in pre-defined dimensions, which indicates the probability of the adoption of a product. Based on the score and its trend, out tool is able to …

An Autonomous Channel Selection Algorithm For Wlans, Fuhu Deng

Doctoral

IEEE 802.11 wireless devices need to select a channel in order to transmit their packets. However, as a result of the contention-based nature of the IEEE 802.11 CSMA/CA MAC mechanism, the capacity experienced by a station is not fixed. When a station cannot win a sufficient number of transmission opportunities to satisfy its traffic load, it will become saturated. If the saturation condition persists, more and more packets are stored in the transmit queue and congestion occurs. Congestion leads to high packet delay and may ultimately result in catastrophic packet loss when the transmit queue’s capacity is exceeded. In this …

An Adaptive Packet Aggregation Algorithm (Aam) For Wireless Networks, Jianhua Deng

Doctoral

Packet aggregation algorithms are used to improve the throughput performance by combining a number of packets into a single transmission unit in order to reduce the overhead associated with each transmission within a packet-based communications network. However, the throughput improvement is also accompanied by a delay increase. The biggest drawback of a significant number of the proposed packet aggregation algorithms is that they tend to only optimize a single metric, i.e. either to maximize throughput or to minimize delay. They do not permit an optimal trade-off between maximizing throughput and minimizing delay. Therefore, these algorithms cannot achieve the optimal network …