• Title/Summary/Keyword: Multi-start

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The Applicability Study of SYMHYD and TANK Model Using Different Type of Objective Functions and Optimization Methods (다양한 목적 함수와 최적화 방법을 달리한 SIMHYD와TANK 모형의 적용성 연구)

  • Sung, Yun-Kyung;Kim, Sang-Hyun;Kim, Hyun-Jun;Kim, Nam-Won
    • Journal of Korea Water Resources Association
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    • v.37 no.2
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    • pp.121-131
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    • 2004
  • SIMHYD and TANK model are used to predict time series of daily rainfall-runoff of Soyang Dam and Youngcheon Dam watershed. The performances of SIMHYD model with 7 parameters and TANK model with17 parameters are compared. Three optimization methods (Genetic algorithm, Pattern search multi-start and Shuffled Complex Evolution algorithm) were applied to study-areas with 3 different types of objective functions. Efficiency of TANK model is higher than that of SIMHYD. Among different types of objective function, Nash-sutcliffe coefficient is found to be the most appropriateobjective function to evaluate applicability of model.

Performance Analysis of OFDM for Wireless Communication Applications (이동 무선 통신 응용을 위한 OFDM의 성능 해석)

  • 김창선;김성곤;변건식
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.2
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    • pp.251-256
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    • 2001
  • In this study, a OFDM mode, unlike traditional single carrier mode, is that a great number of carrier in multi-channel environment is transmitted by modulating objective Data parallel in order to execute high speed Data translation and make frequency orthogonal to offer high spectrum efficiency As a result, this method is adopted to a variety of fields and is being actively studied. In this papers, the efficiency of OFDM wireless-communication systems is evaluated by modulation methods through computer simulation. M-PSK and M-QAM are used as modulation methods. The simulation is executed in a real channel and a virtual channel included multi-path, AWGN, Peak Power clipping, Frame Start Time Error. As a result of simulation, it is confirmed that M-OAM method is superior to M-PSK in OFDM systems in terms of the transmission methods.

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Optimum Design of Integer and Fractional-Order PID Controllers for Boost Converter Using SPEA Look-up Tables

  • Amirahmadi, Ahmadreza;Rafiei, Mohammadreza;Tehrani, Kambiz;Griva, Giovanni;Batarseh, Issa
    • Journal of Power Electronics
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    • v.15 no.1
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    • pp.160-176
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    • 2015
  • This paper presents a method of designing optimal integer- and fractional-order proportional-integral-derivative (FOPID) controllers for a boost converter to gain a set of favorable characteristics at various operating points. A Pareto-based multi-objective optimization approach called strength Pareto evolutionary algorithm (SPEA) is used to obtain fast and low overshoot start-up and dynamic responses and switching stability. The optimization approach generates a set of optimal gains called Pareto set, which corresponds to a Pareto front. The Pareto front is a set of optimal results for objective functions. These results provide designers with a trade-off look-up table, in which they can easily choose any of the optimal gains based on design requirements. The SPEA also overcomes the difficulties of tuning the FOPID controller, which is an extension to the classic integer-order PID controllers and potentially promises better results. The proposed optimized FOPID controller provides an excellent start-up response and the desired dynamic response. This paper presents a detailed comparison of the optimum integer- and the fractional-order PID controllers. Extensive simulation and experimental results prove the superiority of the proposed design methodology to achieve a wide set of desired technical goals.

Shipyard Skid Sequence Optimization Using a Hybrid Genetic Algorithm

  • Min-Jae Choi;Yung-Keun Kwon
    • Journal of the Korea Society of Computer and Information
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    • v.28 no.12
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    • pp.79-87
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    • 2023
  • In this paper, we propose a novel genetic algorithm to reduce the overall span time by optimizing the skid insertion sequence in the shipyard subassembly process. We represented a solution by a permutation of a set of skid ids and applied genetic operators suitable for such a representation. In addition, we combined the genetic algorithm and the existing heuristic algorithm called UniDev which is properly modified to improve the search performance. In particular, the slow skid search part in UniDev was changed to a greedy algorithm. Through extensive large-scaled simulations, it was observed that the span time of our method was stably minimized compared to Multi-Start search and a genetic algorithm combined with UniDev.

Multi-Purpose Hybrid Recommendation System on Artificial Intelligence to Improve Telemarketing Performance

  • Hyung Su Kim;Sangwon Lee
    • Asia pacific journal of information systems
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    • v.29 no.4
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    • pp.752-770
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    • 2019
  • The purpose of this study is to incorporate telemarketing processes to improve telemarketing performance. For this application, we have attempted to mix the model of machine learning to extract potential customers with personalisation techniques to derive recommended products from actual contact. Most of traditional recommendation systems were mainly in ways such as collaborative filtering, which predicts items with a high likelihood of future purchase, based on existing purchase transactions or preferences for products. But, under these systems, new users or items added to the system do not have sufficient information, and generally cause problems such as a cold start that can not obtain satisfactory recommendation items. Also, indiscriminate telemarketing attempts can backfire as they increase the dissatisfaction and fatigue of customers who do not want to be contacted. To this purpose, this study presented a multi-purpose hybrid recommendation algorithm to achieve two goals: to select customers with high possibility of contact, and to recommend products to selected customers. In addition, we used subscription data from telemarketing agency that handles insurance products to derive realistic applicability of the proposed recommendation system. Our proposed recommendation system would certainly solve the cold start and scarcity problem of existing recommendation algorithm by using contents information such as customer master information and telemarketing history. Also. the model could show excellent performance not only in terms of overall performance but also in terms of the recommendation success rate of the unpopular product.

Multi-Vector Defense System using Reverse Proxy Group and PMS(Patch Management System) Construction (Reverse Proxy Group과 PMS를 이용한 멀티벡터(Multi-Vector) DDoS 공격 방어시스템 구축 방안)

  • Kim, Min-Su;Shin, Sang-Il;Kim, JongMin;Choi, KyongHo;Lee, Daesung;Lee, DongHwi;Kim, Kuinam J.
    • Convergence Security Journal
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    • v.13 no.1
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    • pp.79-86
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    • 2013
  • The objective of DDoS Attacks is to simply disturb the services. In recent years, the DDoS attacks have been evolved into Multi-Vector Attacks which use diversified and mixed attacking techniques. Multi-Vector Attacks start from DDoS Attack and Malware Infection, obtain inside information, and make zombie PC to reuse for the next DDoS attacks. These forms of Multi-Vector Attacks are unable to be prevented by the existing security strategies for DDoS Attacks and Malware Infection. This paper presents an approach to effectively defend against diversified Multi-Vector attacks by using Reverse Proxy Group and PMS(Patch Management Server).

A Study on the Improvement of the Blind Zones in View of Safety Laws and Regulations for the New Multi­purpose Business (신종 다중이용업소의 안전기준 사각지대 개선에 관한 연구)

  • Park, Jongkeun
    • Journal of the Korean Society of Safety
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    • v.34 no.3
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    • pp.89-95
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    • 2019
  • Currently, the legal framework for installation of safety facilities has not been implemented for new multi-purpose business excluding 23 multi-purpose business types, and therefore, there is a high likelihood of large number of casualties in case of fire accident. At present, the new multi-purpose business can start its operation only with administrative actions of the licensing agencies and registration to the tax agency, and it is difficult that the fire department, which is a competent safety management department, makes intervention them in the same way as before. In addition, as the licensing agency has no authority to restrict the business due to insufficient implementation of safety facilities, a lot of civil complaints occur, which causes difficulties in changing concerned laws and regulations rapidly. In this study, it is considered to analyze the legal system, status of safety management of multi-purpose business, type of new multi-use facility and characteristics of fire risk. Based on such analysis results, this study will suggest the improvement plan to solve the blind zones in the safety management, which enables the multi-purpose business to be operated within the legal framework.

A Study on the Origin of Clothing (의복(衣服)의 기원(起源)에 대한 연구(硏究) - 선사(先史) 시대(時代)를 중심(中心)으로 -)

  • Lee, Ran-Hee
    • Journal of the Korean Society of Costume
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    • v.6
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    • pp.145-160
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    • 1982
  • Wearing a clothes in human living is very rightful and reasonable things. And it's also the necessaries of living. So now, I want look around about origin of clothes from the prehistorical age, how they start and why they need to wear a clothes. As human culture is unknown origin, human clothes origin is also unknown origin, too. So many different people made unlike story about that, and it is very difficult to say correct birth of clothes. It must be reflection by a time, by a place, by a mankind, until this days, the history of human progress is $2,000,000{\sim}3,000,000$ years. And from after the "Old Adam" man understand what is shame and disgrace, so that made them cover of their private parts, also it is a motive of human clothes. Since after pass a long time, the earth has many changes as it were weather, and for take care of human body from cold, people start make clothes and it's a second object of wearing a clothes. And third object of wearing clothes is after opportunity of development human culture, people desire for an aesthetic sence and for full-fill that feeling they start make a beautiful clothes with accessories and it is motive and a purpose of a human start wear a clothes. So I can say, for origin birth of clothes is 1. Protect of human body. 1) be adapted for different weather and different circumstance. 2) take care self from outside injurg. 2. Decorate for aesthetic sence. 1) Theory of Amulets. 2) Theory of symbolism. 3) Theory of Sex attraction. 4) Aesthetic Theory. 5) Theory of chastity. 6) Multi-theory And material for clothes they made from natural wilds like leaves, fur, skin of wood. skin of fishes and feather etc. But after develop of human knowledge people invent fiber, and use a knitted goods and woven stuff also first of all. They start use those kind that they just cover of their private parts as a belt and astring with leaves and a beast skins. But until this days it's taken big development with human knowledge and most important influence of develop was weather. So modern clothes for present days, must care with. physicology, preservation of health, living activity, dressing, morals, and etiquette etc.

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Design of Water Gas Shift Reactor for Rapid Start-Up in 200 W Portable Fuel Cell System (200 W급 휴대용 연료전지 시스템의 빠른 기동 특성을 위한 수성 가스 반응기 설계)

  • Choi, Jong-Rock;Lee, Sungchul
    • Korean Chemical Engineering Research
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    • v.51 no.4
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    • pp.455-459
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    • 2013
  • The fuel processor for the portable fuel cell includes multi-step processes consisting of hydrogen generator, heat generator and several CO clean-up stages. One of requirements of the fuel processor for portable fuel cell system is a rapid start-up time. Especially, the warm-up time for WGS reactor is crucial factors for total start-up time. In this paper, active heating protocol, which is the heating protocol of WGS reactor supplied by the oxidation of CO rich reformate in the initial stage, is used for a rapid start-up. The air stream fed to the inlet of WGS reactor rapidly oxidize the CO rich reformate in the WGS reactor. Therefore, CO concentration in reformate quickly stabilized at the desired concentration without CO surges.

A Multi Small Humanoid Robot Control for Efficient Robot Performance (효율적인 전시공연을 위한 멀티 소형 휴머노이드 로봇제어)

  • Jang, Jun-Young;Lin, Chi-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.12
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    • pp.8933-8939
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    • 2015
  • In this paper, we designed a multi humanoid robot control method for performing an exhibition that will maximize the efficiency and user convenience and implementation. In recent years, an increasing number of case and to take advantage of the robots in the field performances and exhibitions, plays, musicals, orchestra performances are also various genres. In concert with the existing small humanoid exhibition to source from outside by using a computer and MP3 player and play, while pressing the start button of communication equipment for the show to start the robot began performing with the zoom. Thus, due to the dual source and robot operation and synchronization does not work well is the synchronization of the start of the concert sound starting point of the robot and robot motion and sound are reproduced separately were frequently occurs when you need to restart the show. In addition, when the center of gravity or lose the robots who were present during the performance problems such as performance or intervene to restart the show. In order to overcome this, in this paper, Multi-small humanoid robot was designed to control the efficiency and the user of the GUI-based human interface S/W to maximize convenience, Zigbee communication to transmit a plurality of data in al small humanoid It was used. In addition, targeting a number of the small humanoid robot demonstrated the effectiveness and validity of the user's convenience by gender actual implementation.