Digital Commons Network^™

A Novel Method Based On Comparison Using Threshold Scale For Cfar Detectors Under Environments With Conditions Of Electromagnetic Interference, Milad Daneshvar, Naser Parhizgar, Pouria Salehi

Turkish Journal of Electrical Engineering and Computer Sciences

Detection of a noisy signal is a complex process. Many radar systems are working in an environment where the signal processing parts cannot overcome the effects of interference sources due to their high power. These sources of conflict may completely erode the signal or may make a mistake in deciding. It may make the return of the echoes of the goals difficult. To solve this problem, the detector processor can use a new algorithm to estimate noise power and then can set the threshold in different positions of the cell under test. The proposed algorithm, by differentiating between homogeneous and …

A Transmission Optimization Algorithm For Smart Load Controllers, Ohyoung Song

Turkish Journal of Electrical Engineering and Computer Sciences

This paper introduces a transmission optimization algorithm for wireless transmissions between smart load controllers and a corresponding gateway in wireless personal area networks, where smart load controllers connect several electrical appliances through their corresponding load interfaces, measure the power consumption from each electrical appliance connected to the load controller, and control on/off switching through its load interface. The aim of this paper is to reduce the traffic load of power consumption data in electrical appliances used in the building area network and the smart grid network. The proposed algorithm allows the smart load controller to efficiently reduce traffic load even …

Ad Hoc Diplomats, Ryan M. Scoville

Faculty Publications

Article II of the Constitution grants the president power to appoint “Ambassadors” and “other public Ministers” with the advice and consent of the Senate. By all accounts, this language requires Senate confirmation for the appointment of resident ambassadors and other diplomats of similar rank and tenure. Yet these are hardly the only agents of U.S. foreign relations. Ad hoc diplomats—individuals chosen exclusively by the president to complete limited and temporary assignments—play a comparably significant role in addressing international crises, negotiating treaties, and otherwise executing foreign policy.

This Article critically examines the appointments process for such irregular agents. An orthodox view …

Improving Side Lobe Level Of X-Band Microstrip Rotman Lens Utilizing Nonuniform Distribution Of Output Ports, Ehsan Zareian Jahromi, Raheleh Basiri, Parvin Salehi, Hamidreza Karami

Turkish Journal of Electrical Engineering and Computer Sciences

A new microstrip Rotman lens with enhanced side lobe level (SLL) is proposed for X-band applications. A proper nonuniform distribution of the initial width of output ports is considered to improve the SLL. The benefit of SLL improvement is not based on using additional attenuators or amplifiers at the output ports. Moreover, an analytical background is presented to investigate the resulting SLL of the proposed structure. The advantage of SLL enhancement is obtained at all noncorner scan angles considering 10 GHz operating frequency. As the middle input port is excited, more than 3 dB of SLL enhancement is achieved at …

A Novel And Unified Approach For Averaged Channel Capacity And Averagedeffective Capacity Analyses Of Diversity Combining And Multihop Transmissionschemes In Flat Fading Environments, Ferkan Yilmaz, Mohamed-Slim Alouini

Turkish Journal of Electrical Engineering and Computer Sciences

n this paper, we introduce an Lp -norm aggregation to present a signal-to-noise ratio expression unified not only for such diversity combining schemes as equal-gain combining, maximal-ratio combining, and selection combining, but also for such transmission techniques as multihop transmission. Accordingly, we propose two moment-generating function-based approaches that both respectively unify the exact analyses of the averaged channel capacity and averaged effective capacity over generalized fading channels with respect to the diversity combining and multihop transmission schemes. Finally, the mathematical formalism is illustrated by numerical special cases and verified by simulations.

Power Electronic Controller With Time Sharing Switching Strategy For Grid Connected Pv Systems, Maria Jenisha Charles, Ammasaigounden Nanjappagounder, Binu Ben Jose Dharmaian Retnam

Turkish Journal of Electrical Engineering and Computer Sciences

The design and implementation of a high-efficiency two-stage power electronic controller for feeding power from a photovoltaic (PV) array to the load/utility grid is proposed. The PV array is connected to the load/utility grid through a boost converter and an inverter. The boost converter is controlled by sinusoidal pulse width modulation (SPWM) pulses so as to get a clamped quasi-sinusoidal waveform at the DC link. The inverter converts the clamped quasi-DC voltage into AC voltage using the SPWM controller. At any time only one switch operates at high frequency, thus yielding reduction in the switching losses of the converters. The …

Detection Of Hemorrhage In Retinal Images Using Linear Classifiers And Iterative Thresholding Approaches Based On Firefly And Particle Swarm Optimization Algorithms, Kemal Adem, Mahmut Heki̇m, Seli̇m Demi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

We propose a novel iterative thresholding approach based on firefly and particle swarm optimization to be used for the detection of hemorrhages, one of the signs of diabetic retinopathy disease. This approach consists of the enhancement of the image using basic preprocessing methods, the segmentation of vessels with the help of Gabor and Top-hat transformation for the removal of the vessels from the image, the determination of the number of regions with hemorrhages and pixel counts in these regions using firefly algorithm (FFA) and particle swarm optimization algorithm (PSOA)-based iterative thresholding, and the detection of hemorrhages with the help of …

Accurate And Compact Stochastic Computations By Exploiting Correlation, Hamdan Abdellatef, Mohamed Khalil Hani, Nasir Shaikh-Husin

Turkish Journal of Electrical Engineering and Computer Sciences

Recent studies have shown, contrary to what was previously believed, that by exploiting correlation in stochastic computing (SC) designs, more accurate SC circuits with low area cost can be realized. However, if these basic SC circuits or blocks are cascaded in series to form a large complex system, correlation between stochastic numbers (SNs) from one block to the next would be lost; thus, inaccuracies are introduced. In this study, we propose correlating circuits to be used in building complex correlated SC systems. One of the circuits is the correlator that restores lost correlations between two SNs due to previous processing. …

Text Localization And Extraction From Background With Texture And Noise In Digital Images Using Adaptive Thresholding And Convolutional Neural Network, Pukjira Pattaranuprawat

Chulalongkorn University Theses and Dissertations (Chula ETD)

For the past few years, research topics on finding position of text have received more and more attention from researchers because there are still lots of problems that are needed to be solven. We propose a novel method to find the position of text in an image. The first step of the proposed method is to adjust an image by converting a color image to a gray scale image and then use an average filter to improve an image. An average filter is used to make the background smooth and reduce noise. After that an adaptive thresholding is used to …

Graph Representation For Room Layout Matching Using Spectral Embedding, Thamonwan Sa-Ngawong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Graph matching is efficient to search similar layout when the architectural floor plan data size is increasing. Because the computational time of floor plan matching using spectral embedding is only in seconds, so it is one of the popular methods. However, the isomorphism of each floor plan leads to low accuracy in the matching process and it becomes the weakness of this method. Therefore, we propose a graph representation for room layout matching using spectral embedding. Normally, graph representations of the floor plan define nodes as rooms and edges as connections between rooms. Besides, the graph spectral embedding is to …

Architectural Joinery Design To Prevent Water Leakage In A Precast Concrete Detached House, Prokchol Vataniyobol

Chulalongkorn University Theses and Dissertations (Chula ETD)

The precast concrete construction is widely used in Thailand by customers and developers for residential development. For many decades of building with the precast concrete wall system, the common problems of water leakage are the most pressing concerns. This thesis aims to find the issues that lead to the causes of water penetration and propose a solution to prevent water leakage. From the literature review, the sources of water leakage are at the connection location between the precast modules. The water can penetrate through the opening with the four forces: a momentum of the raindrop, capillary action, gravity, and air …

Attributes Of Perceived Values Towards Coffee Shop Industry In Bangkok, Orapin Siprajim

Chulalongkorn University Theses and Dissertations (Chula ETD)

Coffee shop or café is referred to the place where it offers coffee or drinks and some space for customers to sit and relax. It becomes the most visited place for the modern lifestyles. Coffee shops can be found easily in cities, especially Bangkok, Thailand. There are both local individual coffee houses and chained coffee brands in the market, people can choose to visit either of which or both of them. The rapid growth of coffee industry in Bangkok is affecting how each brand could compete with its rival in the market. Customers are the key driver for the business …

A Study Of Marketing Strategy That Xiaomi Used To Dethrone Samsung In India’S Smartphone Market, Htet Myat Aung

Chulalongkorn University Theses and Dissertations (Chula ETD)

This individual study aims to examine the relationship between marketing strategy and firm’s market shares. In this case, the theory of marketing mix will be mainly used to analyze how Xiaomi's market share grew in accordance with Samsung’s situation. Furthermore, I will take macro environment condition into consideration as the factors that have an impact on the firm's future business. Apart from product innovation and modern technology that are essential things for a phone maker to dominate the market, a business needs to have an effective marketing strategy which can drive up the sales volumes followed by acquiring more market …

Current State And Guidelines For Development Of Thai Teachers Teaching In English Program In Thailand, Chonnikarn Wongsawat

Chulalongkorn University Theses and Dissertations (Chula ETD)

Although a number of previous studies have explored the current state and guidelines for development of teachers teaching in English Program, little research has been conducted regarding beliefs and practices of Thai teachers in the program. This study aimed to investigate the issues addressed above from 34 Thai teachers teaching in English Program at Saunkularb Wittayalai Thonburi School and Saint Gabriel’s College. The results of a questionnaire and a semi-structured interview showed that the teachers’ educational background was consistent with their responsible subject and the majority of the teachers had 1 – 5 years of teaching experience in English Program. …

The Role Of Input Frequency On The Acquisition Of English Adjectival Suffixes By L1 Thai Learners, Chalit Chiarakiat

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study examined the acquisition of English adjectival suffixes by L1 Thai learners to test whether input frequency, which refers to frequency of occurrences in corpora of English usage (Almulla, 2015; Biber, 1993), influenced the perception of the targeted English adjectival suffixes. Based on the input frequency framework (J. Bybee, 2010; J. L. Bybee & Beckner, 2010; Croft & Cruse, 2004), it was hypothesized that type frequency (suffix frequency) as well as token frequency (word frequency) would have a positive effect on the perception. A Grammaticality Judgement Test which incorporated type and token frequency counts from the MorphoQuantics corpus was …

An Analysis Of A Digital Game As Resource Of Autonomous English Language Learning, Panich Wongkhwansane

Chulalongkorn University Theses and Dissertations (Chula ETD)

The research aims to analyze an online digital game features and investigate students’ perceptions toward the game; whether or not they think the game is a context where the opportunities of English language learning and practicing could be provided. Five main game features were analyzed based on the games’ characteristics promoting language learning. In addition, in order to investigate the students’ perceptions, three participants were interviewed as a group. The data were collected through the semi-structured and individual follow-up interview, and analyzed using qualitative approach. The findings indicated that, provided int the game, there are five major features which could …

Exploring Critical Reading In The English Textbooks For Thai Students, Mintra Suratha

Chulalongkorn University Theses and Dissertations (Chula ETD)

The study aims to explore components of critical reading skills in which support the development of critical reading ability in textbooks used by Thai students. 14 textbooks were gathered and used in this research. The instrument used was core critical reading skills checklist for upper secondary school English textbooks. Content analysis and descriptive statistics were employed to analyze result derived from the checklist. The result showed that textbook sample composed of different degrees of critical reading components. Some skills can be found in almost every textbook, while some skills can hardly be found. Moreover, the order of skills presented in …

The Socio-Economic Impact Of Iuu-Fishing : The Case Of Eu Give Yellow Card To Thailand, Chaniga Dharmasaroja

Chulalongkorn University Theses and Dissertations (Chula ETD)

Marine resources are a very important resource for global existence. If there is no organized management, it can damage the marine resources. Therefore, the European Union considers Illegal, Unregulated and Unreported (IUU) Fishing, which is a fishery that obstructs Violation or destruction of conservation measures in any fishing area And non-compliance with the requirements for fishery data collection, as well as not reporting fishery and fishery or false data reporting to responsible agencies From illegal fishing, the IUU may cause future marine resources to be depleted. However, Thailand has a large export value to the European Union. But Thailand is …

The European Union Solidarity In Relation To Covid - 19 Situation., Wanisa Bunlue

Chulalongkorn University Theses and Dissertations (Chula ETD)

This independent_study submitted in partial fulfillment of the requirements for the degree of Master of Arts in European Studies Inter-Department of European Studies, This paper aim to study and examine the situation of the European Union Solidarity in relation to the Coronavirus or the Covid – 19 situations. The outbreak of the corona virus or the COVID-19 crisis around the world, is something that no one has never expected to happen in this century, as there are currently infected people in 185 countries. According to nowadays, the European Union is one of the most successfully union in tern of economic, …

The Impacts Of Us Macroeconomic Announcements On Thai Bond Markets, Jaturapat Thanaboot

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study investigates the impact of US macroeconomic announcements both in terms of announcement day and surprise on Thai bond markets. More specifically, this paper analyses the different impacts of 16 US macroeconomic announcements on Thai bond markets. Using daily total returns on short- and long-term government bonds including investment-grade bond, I find that the overall US macroeconomic announcement days lower subsequent volatility in Thai bond markets while US macroeconomic announcement surprises raise volatility. Furthermore, after separating between types of US macroeconomic announcements, US inflation announcement days seem raise Thai bond market volatility while most of the negative US macroeconomic …

Equity Term Structure Of Property Funds And Reits In Thailand, Chenchai Chotchuangnava

Chulalongkorn University Theses and Dissertations (Chula ETD)

The equity term structure of property funds and REITs in Thailand is upward-sloping. This result contradicts with various studies suggesting that the term structure of risk premia is decreasing. A tenet of those studies is that, by holding long-term equity, investors are willing to forego a part of the compensation to avoid immediate risks which seems to be reverse for property funds and REITs in Thailand. There is evidence that the correlation between size and return is positive. Unlike U.S. REIT, the momentum factor has no application to explain the difference in excess returns. High turnover property funds and REITs …

Costly Signal In Open Market Repurchase: Evidence In Thailand, Thanawat Anavachapongpan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Several studies argue that open market share repurchase has the lowest power to signal the inside information to the market. In this study I explore the market reaction to the announcement of stock repurchase plan with the firm’s characters argued in prior literature that they can increase the market confident. Referred from prior literatures, the stated motivation in the press release, insider “BUY” prior announcement, percentage of majority shareholder, and the amount of repurchasing plan are introduced to reflect the level of information signal sent by management. I find that investors have skepticism with an information sent via open market …

Is There Risk Reduction In Conglomerate Acquisition?, Paskamon Luntavanich

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study examines risk effect in conglomerate acquisitions through portfolio diversification framework. We find that based on asset diversification potential, acquirers’ risks are expected to decline when they engage in diversifying acquisitions. Interestingly, our result suggests that focus acquisitions are also associated with firms’ risk decrease. With this finding, it indicates that asset diversification potential is also pronounced even when the two assets, i.e., firms from similar industry are combined together. In addition, our results suggest that risks are expected to decline more when diversified firms make further diversifying acquisitions than focus acquisitions but this evidence could not be observed …

Do Investors React To Purchase Price Allocation?, Nonthawan U-Thisanonth

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study examines the influence of Purchase Price Allocation (PPA) on investors’ decision making in Thailand by utilising the completed M&A deals which the acquirers listed on the Stock Exchange of Thailand and are over 50% owned after transactions during 2010 – 2019. I investigate how purchase price allocation to goodwill impacts on stock return reaction surrounding the announcement of final PPA information and inspect an association between percentage of goodwill allocated to the identifiable intangible assets and potential earnings per share (EPS) dilution. However, I do not find the supporting evidence to indicate that the investors react to the …

Which Types Of Investor Investment Flow Affect Thailand Stock Market Index, Net Teeramungcalanon

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study examines the effect of types of investor investment flow on Thailand Stock Market Index returns. Daily data on investment types, namely, foreign investors, institutional investors, proprietary investors, and retail investors from the Stock Exchange of Thailand for the period 2015 to 2020 is used. The results from the OLS model show that proprietary investors dominate the SET index. We also conduct a Granger causality test to understand the relationship between the SET index and investor investment flow. This study also examines the relation between SET volatility and investor behavior. The result shows that when the SET index has …

Impact Of Growth In International Tourism Industry Contributed To Co2 Emission In Cambodia, Philippines And Thailand, Juthamard Laohawattanajinda

Chulalongkorn University Theses and Dissertations (Chula ETD)

Tourism is generally considered a clean industry, one of the reasons is tourism increasing investment in traveling facilities, instead of investment in factories. Furthermore, increasing tourism development relies on the protection of the natural environment and ecology. However, tourism development, like all industrial development, also comes with the higher demand in energy consumption and lack of management in the tourism industry resulting in environmental degradation The paper investigated the effect of environmental degradation in both aspects of destination factors and tourist factors based on the EKC hypothesis by incorporating trade openness and CO2 emission in Cambodia, Philippines, and Thailand which …

Is A Self-Employment Skilled Employment? - A Case Study Of Self-Employed With Bachelor’S Degree In Thailand, Kemmika Labkim

Chulalongkorn University Theses and Dissertations (Chula ETD)

In the paper, the research will be focused on self-employed occupations with a bachelor's degree in Thailand to look at the skills require for the self-employed to be hired. The researcher looks further into the Thai labor force survey conducted in 2016, the latest source. The survey shows in detail of self-employed occupations in Thailand with degrees with the total number of 2,284 people in 196 different occupations which counted only those who graduate from bachelor's and above. Hence, in this paper, the researcher looks upon three different sources of information: 2016 Thai labor force National Survey, the skill required …

Does Decision In Learning Chinese Derive From Economic Reason? (A Case Study Of Airline Industry To An Increasing In Thai Labor Supply With Third Language Skill), Piyawat Jongjiramongkolchai

Chulalongkorn University Theses and Dissertations (Chula ETD)

The achievement of policy “Reform and opening” implemented in 1978 was successfully liberated new China from failure state to an economic superpower in this century. The success of the policy is not only elevating state’s financial status from the line of poverty, but also enhancing the people purchasing power. Being the largest population country in the world, a massive outbound of both Chinese tourists and entrepreneurs becomes a current global phenomena. Thailand has long been a preferable destination among Chinese tourists for decades with more than thirty million averagely of Chinese tourists visiting Thailand, according to data from Ministry of …

The Impact Of Flexible Working Time On Employees' Work-Life Balance: A Case Study Of A Kitchenware Manufacturing Company, Panisra Turakijkajohn

Chulalongkorn University Theses and Dissertations (Chula ETD)

The objective of this study is to examine the effect of flexible working time on the employees’ work-life balance in case of a kitchenware manufacturing company in Bangkok by using data from 104 employees in a kitchenware manufacturing company in Bangkok during June 2020. The result shows that the perception on flexible working time has a positive and significant impact on the work -life balance of the employees. When classifying employees into two sub-groups by age, the perception on the flexibility of working time only has positive effect on work life balance of employees with age more than 30 years …

การศึกษาเชิงเปรียบเทียบข้อกำหนดมาตรฐานการจัดการพลังงานสากล Iso 50001:2018 และกฎหมายการอนุรักษ์พลังงานของประเทศไทย เพื่อการนำไปประยุกต์ใช้สำหรับโรงงานและอาคารควบคุม, กิตติคุณ สินอุปการ

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยชิ้นนี้มีวัตถุประสงค์เพื่อเปรียบเทียบข้อกำหนดมาตรฐานการจัดการพลังงานสากล ISO 50001:2018 กับการจัดการพลังงานตาม พ.ร.บ. การส่งเสริมการอนุรักษ์พลังงาน พ.ศ. 2535 (แก้ไขเพิ่มเติม พ.ศ. 2550) จากการเปรียบเทียบข้อกำหนดพบว่า ISO 50001:2018 มีความใกล้เคียงกับ พ.ร.บ. เป็นอย่างมาก โดยหัวข้อหลักของ ISO 50001:2018 ครอบคลุมข้อกำหนดทั้งหมดของ พ.ร.บ. ทั้งนี้ มีหัวข้อที่แตกต่างจากข้อกำหนดตาม พ.ร.บ. จำนวน 5 หัวข้อหลัก ได้แก่ (1) บริบทขององค์กร (2) การวางแผน (3) การสนับสนุน (4) การจัดหา และ (5) การปรับปรุง ซึ่ง ISO 50001:2018 มีความแตกต่างจาก ISO 50001:2011 จำนวน 2 หัวข้อ ได้แก่ หัวข้อที่ 4.1 ความเข้าใจองค์กรและบริบทขององค์กร และหัวข้อที่ 10.2 การปรับปรุงอย่างต่อเนื่อง สิ่งที่ได้จากการศึกษาทำให้ทราบว่าองค์กรที่ดำเนินการตาม พ.ร.บ. อยู่แล้ว ไม่ว่าจะเป็นโรงงานควบคุม หรืออาคารควบคุม สามารถเข้าสู่มาตรฐาน ISO 50001:2018 ได้ โดยใช้เอกสารเดิมที่จัดทำตามข้อกำหนดของ พ.ร.บ. โดยจะต้องจัดทำเอกสารเพิ่มเติมตามข้อกำหนด 5 หัวข้อ ดังที่กล่าวมาข้างต้น ทั้งนี้ เอกสารทั้งหมดจะต้องจัดทำให้เป็นรูปแบบตามข้อกำหนด ISO 9001 ส่วนองค์กรที่ได้รับการรับรองตาม ISO 50001:2011 และต้องการเข้าสู่ ISO 50001:2018 ต้องจัดทำเอกสารเพิ่มเติม เช่น วิสัยทัศน์องค์กร พันธกิจ เป้าหมาย วัตถุประสงค์ด้านการจัดการพลังงาน รวมถึงการวิเคราะห์ SWOT Analysis เพื่อให้เข้าใจบริบทขององค์กร เป็นต้น