• Title/Summary/Keyword: Performance Issues

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Leg-By-Leg-Based Finite-Control-Set Model Predictive Control for Two-Level Voltage-Source Inverters

  • Zhang, Tao;Chen, Xiyou;Qi, Chen;Lang, Zhengying
    • Journal of Power Electronics
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    • v.19 no.5
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    • pp.1162-1170
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    • 2019
  • Finite-control-set model predictive control (FCS-MPC) is a promising control scheme for two-level voltage-source inverters (TL-VSIs). However, two main issues arise in the classical FCS-MPC method: an exponentially-increasing computational time and a low steady-state performance. To solve these two issues, a novel FCS-MPC method has been proposed for n-phase TL-VSIs in this paper. The basic idea of the proposed method is to carry out the FCS-MPC scheme of TL-VSIs for one leg by one leg, like a "pipeline". Based on this idea, the calculations are reduced from exponential time to linear time and its current waveforms are improved by applying more switching states per sampling period. The cases of three-phase and five-phase TL-VSIs were tested to verify the effectiveness of proposed method.

Trends in Ultra Low Power Intelligent Edge Semiconductor Technology (초저전력 엣지 지능형반도체 기술 동향)

  • Oh, K.I.;Kim, S.E.;Bae, Y.H.;Park, S.M.;Lee, J.J.;Kang, S.W.
    • Electronics and Telecommunications Trends
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    • v.33 no.6
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    • pp.24-33
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    • 2018
  • In the age of IoT, in which everything is connected to a network, there have been increases in the amount of data traffic, latency, and the risk of personal privacy breaches that conventional cloud computing technology cannot cope with. The idea of edge computing has emerged as a solution to these issues, and furthermore, the concept of ultra-low power edge intelligent semiconductors in which the IoT device itself performs intelligent decisions and processes data has been established. The key elements of this function are an intelligent semiconductor based on artificial intelligence, connectivity for the efficient connection of neurons and synapses, and a large-scale spiking neural network simulation framework for the performance prediction of a neural network. This paper covers the current trends in ultra-low power edge intelligent semiconductors including issues regarding their technology and application.

Private Blockchain-Based Secure Access Control for Smart Home Systems

  • Xue, Jingting;Xu, Chunxiang;Zhang, Yuan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.12
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    • pp.6057-6078
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    • 2018
  • Smart home systems provide a safe, comfortable, and convenient living environment for users, whereby users enjoy featured home services supported by the data collected and generated by smart devices in smart home systems. However, existing smart devices lack sufficient protection in terms of data security and privacy, and challenging security and privacy issues inevitably emerge when using these data. This article aims to address these challenging issues by proposing a private blockchain-based access control (PBAC) scheme. PBAC involves employing a private blockchain to provide an unforgeable and auditable foundation for smart home systems, that can thwart illegal data access, and ensure the accuracy, integrity, and timeliness of access records. A detailed security analysis shows that PBAC could preserve data security against various attacks. In addition, we conduct a comprehensive performance evaluation to demonstrate that PBAC is feasible and efficient.

Development of a Functional Complexity Reduction Concept of MMIS for Innovative SMRs

  • Gyan, Philip Kweku;Jung, Jae Cheon
    • Journal of the Korean Society of Systems Engineering
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    • v.17 no.2
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    • pp.69-81
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    • 2021
  • The human performance issues and increased automation issues in advanced Small Modular Reactors (SMRs) are critical to numerous stakeholders in the nuclear industry, due to the undesirable implications targeting the Man Machine Interface Systems (MMIS) complexity of (Generation IV) SMRs. It is imperative that the design of future SMRs must address these problems. Nowadays, Multi Agent Systems (MAS) are used in the industrial sector to solve multiple complex problems; therefore incorporating this technology in the proposed innovative SMR (I-SMR) design will contribute greatly in the decision making process during plant operations, also reduce the number MCR operating crew and human errors. However, it is speculated that an increased level of complexity will be introduced. Prior to achieving the objectives of this research, the tools used to analyze the system for complexity reduction, are the McCabe's Cyclomatic complexity metric and the Henry-Kafura Information Flow metric. In this research, the systems engineering approach is used to guide the engineering process of complexity reduction concept of the system in its entirety.

A STUDY ON CULTURAL PRACTICES IN CONSTRUCTION CONTRACTING ORGANIZATIONS IN MALAYSIA

  • H. Abdul-Rahman;Wang Chen;Halimatun. Othman
    • International conference on construction engineering and project management
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    • 2007.03a
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    • pp.169-178
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    • 2007
  • This paper has investigated the cultural practices influencing business performance and integrity in selected Malaysian contractors and has discussed culture related issues to improve the management of cultural capitals in the Malaysian construction industry. Issues of current enterprise culture and applicable cultural practices, leadership styles, enterprise axiology and integrity, cultural practices and loyalty, and identification of organizational culture are discussed during the semi-structured interviews and questionnaire survey. Conclusions has been drawn that the people oriented and task oriented management style have a similar quantity of supporters in Malaysian contractors. The integrity and profit are respectively identified as the enterprise axiology in the ethical and economic perspective. The monkey culture is considered as the most applicable type for the cultural practice and the current enterprise cultures applied in the Malaysian contractors are mostly positive to both the organizations and society.

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Artificial Intelligence in Aviation (항공분야의 인공지능)

  • Hyun, WooSeok
    • Korean journal of aerospace and environmental medicine
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    • v.29 no.2
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    • pp.59-66
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    • 2019
  • Artificial Intelligence (AI) born in 1956 is a general term that implies the use of a computer to make intelligent machines with minimal human intervention. AI is a topic dominating diverse discussions on the future of professional employment, change in the social standard and economic performance. In this paper, I describe fundamental concepts underlying AI and their significance to various fields including aviation and medicine. I highlight issues involved and describe the potential impacts and challenges to the industrial fields. While many benefits are expected in human life with AI integration, problems are needed to be identified and discussed with respect to ethical issues and the future roles of professionals and specialists for their wider application of AI.

Exploring the Challenges and Strategies for Combating Advertising Fraud and Preserving Brand Reputation in the Korean Advertising Landscape

  • Seung-Chul Yoo;Yoontaek Sung
    • International Journal of Advanced Culture Technology
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    • v.11 no.1
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    • pp.306-311
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    • 2023
  • As digital advertising continues to dominate the advertising industry and experience substantial growth, associated criminal activities such as advertising fraud and brand safety risks have become increasingly prevalent. Despite the severity and extent of these crimes, the response in Korea has been lackluster, often perceiving them merely as losses in advertising expenses incurred by corporations. However, it is important to note that these issues have direct repercussions on the end-consumer in the form of increased prices for goods and services. Furthermore, illegal and intrusive advertisements not only cause inconvenience to the viewer, but may also indiscriminately target cognitively vulnerable groups, such as children and the elderly, with the intention of manipulating advertising metrics and artificially inflating performance indicators. In this study, we aim to explore the concept and significance of advertising fraud and brand safety, and to evaluate the current measures taken in the Korean market. Additionally, we will delve into the implications of related policies and emphasize the necessity of digital advertising literacy in addressing these issues.

Complementary FET-The Future of the Semiconductor Transistor (Complementary FET로 열어가는 반도체 미래 기술)

  • S.H. Kim;S.H. Lee;W.J. Lee;J.W. Park;D.W. Suh
    • Electronics and Telecommunications Trends
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    • v.38 no.6
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    • pp.52-61
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    • 2023
  • With semiconductor scaling approaching the physical limits, devices including CMOS (complementary metal-oxide-semiconductor) components have managed to overcome yet are currently struggling with several technical issues like short-channel effects. Evolving from the process node of 22 nm with FinFET (fin field effect transistor), state-of-the-art semiconductor technology has reached the 3 nm node with the GAA-FET (gate-all-around FET), which appropriately addresses the main issues of power, performance, and cost. Technical problems remain regarding the foundry of GAA-FET, and next-generation devices called post-GAA transistors have not yet been devised, except for the CFET (complementary FET). We introduce a CFET that spatially stacks p- and n-channel FETs on the same footprint and describe its structure and fabrication. Technical details like stacking of nanosheets, special spacers, hetero-epitaxy, and selective recess are more thoroughly reviewed than in similar articles on CFET fabrication.

An Exploratory Study on Issues Related to chatGPT and Generative AI through News Big Data Analysis

  • Jee Young Lee
    • International Journal of Advanced Culture Technology
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    • v.11 no.4
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    • pp.378-384
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    • 2023
  • In this study, we explore social awareness, interest, and acceptance of generative AI, including chatGPT, which has revolutionized web search, 30 years after web search was released. For this purpose, we performed a machine learning-based topic modeling analysis based on Korean news big data collected from November 30, 2022, when chatGPT was released, to August 31, 2023. As a result of our research, we have identified seven topics related to chatGPT and generative AI; (1)growth of the high-performance hardware market, (2)service contents using generative AI, (3)technology development competition, (4)human resource development, (5)instructions for use, (6)revitalizing the domestic ecosystem, (7)expectations and concerns. We also explored monthly frequency changes in topics to explore social interest related to chatGPT and Generative AI. Based on our exploration results, we discussed the high social interest and issues regarding generative AI. We expect that the results of this study can be used as a precursor to research that analyzes and predicts the diffusion of innovation in generative AI.

Quantifying Risk Factors on Cost Performance By Characterizing Capital Facility Projects

  • Jang, Myung-Hoon;Cha, Hee-Sung
    • Korean Journal of Construction Engineering and Management
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    • v.7 no.4 s.32
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    • pp.177-183
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    • 2006
  • Risk-based estimation has been successfully introduced into the construction industry. By incorporating historical data associated with probability analysis, risk-based estimate is an effective decision support aid in considering whether to launch a particular project. The industry challenges, however, especially related with management issues, such as labor shortage, wage growth, and supply chain complexity, have often resulted in poor cost performance. The insufficient assessing the project characteristics (i.e., resource availability, project complexity, and project delivery method) can be the main reasons in the poor cost performance. Because the accuracy level of cost performance prediction can be enhanced by extensive evaluation of the subject project characteristics, a new approach for predicting cost performance in an earlier stage of a project can improve the Industry substantiality, in other words, value maximization. The purpose of this paper is to develop a new methodology in developing a risk-based estimate tool by incorporating extensive project characteristics. To do this, an extensive industry survey was conducted from both private and public sectors in building industry in Korea. In addition, significant project characteristics were identified in terms of cost performance indicator. Although the data collection is limited to Korean industry the suggested approach provides the industry with a straightforward methodology in risk management. As many researchers maintained that front-end planning efforts are crucial in achieving the successful outcome in building projects, the new method for risk-based estimation can Improve the cost performance as well as enhance the fulfillment in terms of business sustainability.