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Comparative study of some algorithms for global optimization (광역최적화 방법론의 비교 연구)

  • Yang, Seung-Ho;Lee, Hyeon-Ju;Lee, Jae-Uk
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2006.11a
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    • pp.693-696
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    • 2006
  • Global optimization is a method for finding more reliable models in various fields, such as financial engineering, pattern recognition, process optimization. In this study, we compare and analyze the performance of the state-of-the-art global optimization techniques, which include Genetic Algorithm (DE,SCGA), Simulated Annealing (ASA, DSSA, SAHPS), Tabu & Direct Search (DTS, DIRECT), Deterministic (MCS, SNOBIT), and Trust-Region algorithm. The test functions for the experiments are Benchmark problems in Hedar & Fukushima (2004), which are evaluated with respect to efficiency and accuracy. Through the experiment, we analyse the computational complexity of the methods and finally discuss the pros and cons of them.

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Analysis of Authentication Systems for Future Internet Service Environments (미래 인터넷 서비스 환경을 위한 인증 시스템 분석)

  • Park, Seung-Chul
    • Journal of Information Technology Services
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    • v.10 no.2
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    • pp.163-176
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    • 2011
  • In the current Internet environment, there may exist a number of independently-operating authentication systems even within a single organization, according to the service types and service providing entities. Current silo-style isolated authentication system model has revealed critical problems in the aspects of usability, cost-effectiveness, extensibility and flexibility, and privacy protection. Recently, several next generation authentication systems have been actively developed by leading industrial and standardization institutions. This paper firstly analyzes the problems of current Internet authentication system environments. And then, the underlying idea, operating procedures, and pros and cons of the newly developed next generation authentication systems are analyzed so as to provide the selection guidelines for the new authentication systems and drive further development directions for future Internet authentication systems.

Dietary Supplements : Current Controversies in the United States

  • Kim, Jeong-Seon
    • Journal of Nutrition and Health
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    • v.30 no.6
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    • pp.727-732
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    • 1997
  • Dietary supplements are generally defined as concentrated sources of nutrients prescribed in addition to the daily diet to increase nutrient intake. These supplements are usually in the form of tablets, capsules, pills, powders, or liquids. Sales of dietary supplements are roughly $4 billion per year in the United States. Nearly 4 out of every 10 adults use dietary supplements regularly. This article is to report the pros and cons in the use of dietary supplements and a brief overview of current law, proposed regulations, and related activities in the United States. It provides what information should be known to the public before federal regulations governing health claims are made . These regulations may decide whether health food industries or pharmaceutical companies can make claims about the function of nutrients.

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Recent Industrial Developments of VPN(Virtual Private Network) (VPN의 최근 산업계 동향)

  • Hwang, S.O.;Choi, Y.B.;Lee, J.S.;Yoon, K.S.;Kim, M.J.
    • Electronics and Telecommunications Trends
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    • v.14 no.6 s.60
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    • pp.74-86
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    • 1999
  • VPN (Virtual Private Network) is an effort to get some of the advantages of public network – cost saving, scalability, flexibility, and efficient network management as well as some advantages of private dedicated network – fast speed and less security threats. We introduce protocols to implement VPN, pros and cons of VPN, and its application areas. We also explain some tasks and classification criteria that should be considered in deploying VPN, available commercial products and recent industrial trends of VPN.

A Simple Method for Predicting Lateral Earth Pressure in Consideration of Construction Speed of Embankment (성토 재하속도를 고려한 측방토압의 간이예측법)

  • Im, Eun-Sang;Kim, Hyoung-Soo;Kim, Tae-Hoon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.1055-1060
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    • 2005
  • In evaluating the stability of underground structures and designing prevention methods against the lateral flow, it is necessary to predict the amount and the distribution of the lateral earth pressure acting on these retaining structures. However, because the lateral deformation of real ground is a very complex phenomenon influenced by interaction between volumetric deformation bringing an increase of stability of ground and shear deformation causing failure of ground, any appropriate methods for estimating the lateral earth pressure in consideration of the geotechnical properties of ground and the construction conditions in embankment have not been developed as yet. Therefore, a prediction method, which considers effects of a construction speed of embankment, using the Boussinesq's solution based on the elasticity theory without using complex numerical analyses such as finite element analyses is proposed in this research.

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An experimental study on the reduction method of earth pressure acting on the cut-and-cover tunnel lining (개착식 터널의 라이닝에 작용하는 토압경감대책에 관한 실험적 연구)

  • Kim, Sang-Yoon;Im, Jong-Chul;Park, Lee-Keun;Bautista, Ferdinand E.
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.952-957
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    • 2004
  • Cut and Cover Method is generally used in shallow tunnels and tunnel entrances with thin soil cover. In this type of cons0truction, backfilling is considered to be the most important process. In this process even though the backfill material is thoroughly compacted, compaction and self-weight due to vehicular vibration and pressure exerted by the soil cause the backfill material to undergo self-compression which leads to settlement. The settlement of the backfill material subjects the tunnel lining under excessive earth pressure which cause cracking and deformation. In the model test performed installation of geotextile on the sides and top of the tunnel was able to reduce the earth pressure acting on the tunnel lining.

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A Basic Research for Connection Type of Green Frame (Green Frame 접합방식 기초연구)

  • Kim, Keun-Ho;Joo, Jin-Kyu;Lim, Chae-yeon;Kim, Sun-Kuk
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.11a
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    • pp.171-172
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    • 2011
  • Green column and green beam, key structural members of green frame, have the characteristics of post-lintel structure, thanks to the steel frame in the connection, enabling prompt and precise installation. The connection of green frame can be divided into 4 types, depending on its shape, and each type is associated with different characteristics and construction methods. Notably, as the connection between green columns have differing types and sequences of work, subject to the connection method in use, a connection method optimized for relevant site conditions need to be selected. Therefore, this study analyzed pros and cons of 4 different types of green frame connection methods. The results set forth herein will provide basic data for subsequent studies to comparatively analyze the performance and constructibility of different green frame connection methods.

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In-Vehicle Network Technologies (차량 내 네트워크 기술)

  • Lee, Seongsoo
    • Journal of IKEEE
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    • v.22 no.2
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    • pp.518-521
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    • 2018
  • IVN (in-vehicle network) connects various electronic modules in the vehicles. It requires real-time, low noise, high reliability, and high flexibility. It includes CAN (controller area network), CAN-FD (CAN flexible data rate), FlexRay, LIN (local interconnect network), SENT (single edge nibble transmission), and PSI5 (peripheral sensor interface 5). In this paper, their operation priciples, target applications, and pros and cons are explained.

Compliance Technologies of Electromagnetic Compatibility in Automotive Electronic Systems (전장 시스템의 전자파 적합성 대응 기술)

  • Shin, Youngsan;Lee, Seongsoo
    • Journal of IKEEE
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    • v.22 no.2
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    • pp.506-509
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    • 2018
  • Recently, number of components and operation frequency rapidly increase in automotive systems. This often leads to EMI (electromagnetic interference) where automotive systems suffer from malfunctions induced by electromagnetic wave. This paper surveys various EMC (electromagnetic compatibility) compliance technologies such as EMI filter, EMI shielding materials, and spread spectrum clock generator. Their pros and cons are also explained.

Bitcoin and Its Energy Usage: Existing Approaches, Important Opinions, Current Trends, and Future Challenges

  • Mir, Usama
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.8
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    • pp.3243-3256
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    • 2020
  • Recent years have shown a great interest of public in buying and selling of crypto/digital currency. With hundreds of digital currencies in financial market, bitcoin remains the most widely used, adapted, and accepted currency around the world. However, the critics of bitcoin still consider it a threat to modern day power usage. This paper discusses the important pitfalls, pros, and cons related to bitcoin's energy consumption. The paper begins by highlighting the flexibilities cryptocurrency can bring to online money transfers compared to traditional 'fiat' architecture. Then, the focus of the paper entirely remains on listing various facts related to bitcoin's energy utilization including a brief description of several emerging approaches for energy optimization. This paper is concluded by revealing key current challenges associated to bitcoin's energy usage.