• Title, Summary, Keyword: group penalty

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The Optimal Controller Design of Buck-Boost Converter by using Adaptive Tabu Search Algorithm Based on State-Space Averaging Model

  • Pakdeeto, Jakkrit;Chanpittayagit, Rangsan;Areerak, Kongpan;Areerak, Kongpol
    • Journal of Electrical Engineering and Technology
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    • v.12 no.3
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    • pp.1146-1155
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    • 2017
  • Normally, the artificial intelligence algorithms are widely applied to the optimal controller design. Then, it is expected that the best output performance is achieved. Unfortunately, when resulting controller parameters are implemented by using the practical devices, the output performance cannot be the best as expected. Therefore, the paper presents the optimal controller design using the combination between the state-space averaging model and the adaptive Tabu search algorithm with the new criteria as two penalty conditions to handle the mentioned problem. The buck-boost converter regulated by the cascade PI controllers is used as the example power system. The results show that the output performance is better than those from the conventional design method for both input and load variations. Moreover, it is confirmed that the reported controllers can be implemented using the realistic devices without the limitation and the stable operation is also guaranteed. The results are also validated by the simulation using the topology model of MATLAB and also experimentally verified by the testing rig.

Positive Effect of Non-directive College Introductory Physics Laboratory (비지시적 대학 일반 물리 실험의 긍정적 효과)

  • Kim, Eun-Sook;Hwang, Kyung-Soo
    • Journal of The Korean Association For Science Education
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    • v.17 no.1
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    • pp.55-64
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    • 1997
  • Experiments done in traditional physics laboratories have been criticized for giving too detailed instruction so that student could follow the experimental procedure without understanding. This type of experiment is often called "cookbook experiment." Cookbook experiment was known to be little help to understand the physics concepts and to increase student interest. To solve these problems with traditional cookbook experiment, non-directive introductory physics laboratory was designed and tried with the freshmen of Department of Physics Education of Seoul National University. Non-directive laboratory was characterized by the lack of step by step instruction for students to follow. The instruction students received consisted of the goal of experiment, a short introduction, and a list of suggested materials to be used. Student designed the experimental procedure and decided what material they wanted to use. One group submitted one lab report as a group to encourage cooperation among students. Lab report could be written in any form students wanted and no penalty point was given to poor data or inappropriate theory, etc to encourage taking risks. Penalty points were given if the students did not get involved during class hours. Student received extra point for being creative and / or working hard. Teaching assistants used Socratic dialogue in helping students to find their own way instead of explaining what they had to do. Students' interest about the non-directive experiment was studies at the of the semester. A questionnaire was made for students to answer. The questionnaire consisted of four categories, the equipment and the laboratory, the experimental procedure, the lab report, and teaching assistant. For each category, student were asked to explain the differences from other laboratory classes, features they liked and the reasons why they do, features they did not like and why they did not. At the end of the questionnaire, students were asked what hey wanted to change and what they did not. They also could put any opinion they had other than the questions asked. Student overall opinion was very positive. All the students said they liked the lack of detailed experimental procedure because it gave them the feeling of achievement, made them feel challenged and think in more diverse and creative ways. Students liked the lab report because group report forced them to discuss more and the free form lab report helped them to focus on the what they did. Student responses about the teaching assistant was also positive but not as enthusiastic as the experimental procedure or lab report. However students recognised that the role of the teaching assistant was as a guide, a supporter, or a facilitator.

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Implementation of Simulated Annealing for Distribution System Loss Minimum Reconfiguration (배전 계토의 손실 최소 재구성을 위한 시뮬레이티드 어닐링의 구현)

  • Jeon, Young-Jae;Choi, Seung-Kyo;Kim, Jae-Chul
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.4
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    • pp.371-378
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    • 1999
  • This paper presents an efficient algorithm for loss reduction of distribution system by automatic sectionalizing switch operation in large scale distribution systems of radial type. Simulated Annealing algorithm among optimization techniques can avoid escape from local minima by accepting improvements in cost, but the use of this algorithm is also responsible for an excessive computation time requirement. To overcome this major limitation of Simulated Annealing algorithm, we may use advanced Simulated Annealing algorithm. All constaints are divided into two constraint group by using perturbation mechanism and penalty factor, so all trail solutions are feasible. The polynomial-time cooling schedule is used which is based on the statistics calculation during the search. This approaches results in saving CPU time. Numerical examples demonstrate the validity and effectiveness of the proposed methodology.

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WDM Transmission Using Dispersion Compensation in Optical Transmission Links with Nonuniform Residual Dispersion per Span

  • Lee, Seong-Real
    • Journal of information and communication convergence engineering
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    • v.9 no.6
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    • pp.753-757
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    • 2011
  • The possibility of implementing nonuniform residual dispersion per span (RDPS) in optical links with net residual dispersion (NRD) controlled by precompensation and postcompensation for 960 Gbps WDM transmissions is studied and discussed. The fiber optic communication links investigated in this paper consist of inline dispersion management (DM) for each fiber spans and optical phase conjugator (OPC) at mid-way of total transmission length in order to compensate for WDM signal distortions due to group velocity dispersion (GVD) and nonlinearities. It is confirmed that the effect of nonuniform RDPS distribution on system performance is not significant. It is also confirmed that the optimal NRD is obtained to be one of two values of +10 ps/nm or -10 ps/nm, which depend on the deciding of NRD controlled by precompensation or postcompensation, and the exact RDPS configurations. The effective NRD ranges resulting eye opening penalty (EOP) below 1 dB are independent on the exact RDPS distribution for relative low launch power. Therefore, results show the possibility of implementing the flexible optical links to expand network construction for WDM transmission of high bit-rate capability.

A Survey on the Visitor's Cognition of Visitor Reservation System in National Park - The Case Study of Soraksan National Park - (국립공원 탐방예약제 시행에 대한 탐방객 의식 조사 - 설악산국립공원 탐방객을 대상으로-)

  • 이주수;조중현;김용근
    • Korean Journal of Environment and Ecology
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    • v.17 no.1
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    • pp.92-100
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    • 2003
  • The purpose of this study is to survey and analyze of the visitor's cognition of Visitor-Reservation System in Soraksan National Park. To accomplish the purpose, a questionnaire survey was employed in Soraksan National Park. The contents of questionnaire consist of the socioeconomic characteristics and the types of visiting, the activity, the cognition of Visitor-Reservation System. 166 samples of total 170 respondents were used for final analysis. As a result of the analysis, the socioeconomic characteristics and the type of visiting were showed similar trends with results from other National Park visitor survey Most of respondents recognized the enforcement Visitor-Reservation System and A majority of respondents affirmatively recognized the introduction Visitor-Reservation System. Most of respondents wanted an easy method reservation and cancel in enforcement Visitor-Reservation System. Besides Most of respondents recognized negative conception on regulation(nature-rest system, facility-reservation system etc) of National Park Authority(N.P.A). About expanding enforcement Visitor-Reservation System of National Park's preservation, 'Agree Group' was almost equal with 'Disagree Group'. About more effect operate the Visitor-Reservation System Most of respondents were agree to introduce penalty.

The solar cell modeling using Lambert W-function (Lambert W 함수를 이용한 태양전지 모델링)

  • Bae, Jong-Guk;Kang, Gi-Hwan;Kim, Kyung-Soo;Yu, Gwon-Jong;Ahn, Hyung-Geun;Han, Deuk-Young
    • 한국태양에너지학회:학술대회논문집
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    • pp.278-281
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    • 2011
  • This system can predict the maximum output about all illumination levels so that the PV system designer can design the system having the best efficiency. For the output prediction exact about the solar cell, that is the device the basis most in the PV system, the basis has to be in order to try this way. The solution based on Lambert W-function are presented to express the transcendental current-voltage characteristic containing parasitic power consuming parameters like series and shunt resistances. A simple and efficient method for the extraction of a single current-voltage (I-V) curve under the constant illumination level is proposed. With the help of the Lambert W function, the explicit analytic expression for I is obtained. And the explicit analytic expression for V is obtained. This analytic expression is directly used to fit the experimental data and extract the device parameters. The I-V curve of the solar cell was expressed through the modeling using Lambert W-function and the numerical formula where there is the difficulty could be logarithmically expressed This method expresses with the I-V curve through the modeling using Lambert W-function which adds other loss ingredients to the equation2 as to the research afterward. And the solar cell goes as small and this I-V curve can predict the power penalty in the system unit.

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Compressed-sensing (CS)-based Image Deblurring Scheme with a Total Variation Regularization Penalty for Improving Image Characteristics in Digital Tomosynthesis (DTS) (디지털 단층합성 X-선 영상의 화질개선을 위한 TV-압축센싱 기반 영상복원기법 연구)

  • Je, Uikyu;Kim, Kyuseok;Cho, Hyosung;Kim, Guna;Park, Soyoung;Lim, Hyunwoo;Park, Chulkyu;Park, Yeonok
    • Progress in Medical Physics
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    • v.27 no.1
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    • pp.1-7
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    • 2016
  • In this work, we considered a compressed-sensing (CS)-based image deblurring scheme with a total-variation (TV) regularization penalty for improving image characteristics in digital tomosynthesis (DTS). We implemented the proposed image deblurring algorithm and performed a systematic simulation to demonstrate its viability. We also performed an experiment by using a table-top setup which consists of an x-ray tube operated at $90kV_p$, 6 mAs and a CMOS-type flat-panel detector having a $198-{\mu}m$ pixel resolution. In the both simulation and experiment, 51 projection images were taken with a tomographic angle range of ${\theta}=60^{\circ}$ and an angle step of ${\Delta}{\theta}=1.2^{\circ}$ and then deblurred by using the proposed deblurring algorithm before performing the common filtered-backprojection (FBP)-based DTS reconstruction. According to our results, the image sharpness of the recovered x-ray images and the reconstructed DTS images were significantly improved and the cross-plane spatial resolution in DTS was also improved by a factor of about 1.4. Thus the proposed deblurring scheme appears to be effective for the blurring problems in both conventional radiography and DTS and is applicable to improve the present image characteristics.

PMD Tolerance of 10 Gbps Modulated Signals due to SOA-Induced Chirp in SOA Booster Amplifiers

  • Jang, Ho-Deok;Kim, Kyoung-Soo;Lee, Jae-Hoon;Jeong, Ji-Chai
    • Journal of the Optical Society of Korea
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    • v.12 no.4
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    • pp.232-239
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    • 2008
  • We investigated how the polarization-mode dispersion (PMD) tolerance was degraded by semiconductor optical amplifier (SOA)-induced chirp for the 10 Gb/s nonreturn-to-zero (NRZ), duobinary NRZ, return-to-zero (RZ), and carrier-suppressed RZ (CS-RZ) modulation formats. The power penalty was calculated as a measure of the system performance due to PMD for a given SOA-induced chirp. Considering only first-order PMD, all modulation formats have a similar PMD tolerance regardless of SOA-induced chirp. On the other hand, when both first- and second-order PMD are considered, the PMD tolerance of all modulation formats with the exception of the CS-RZ modulation format are degraded by SOA-induced chirp. Among all modulation formats considered here, the NRZ modulation format has the PMD tolerance with the highest sensitivity to SOA-induced chirp. When the peak-to-peak chirp induced by SOAs is $0.28{\AA}$, its PMD tolerance is degraded up to 4 dB for a differential group delay (DGD) of 50 ps. However, the PMD tolerance of the CS-RZ modulation format is largely unaffected by SOA-induced chirp.

A Study on Weight of SWOT Factors for Korea Food Service Franchise Entrepreneur (국내 외식프랜차이즈의 창업을 위한 SWOT요인의 중요도에 관한 연구)

  • Choi, Chae-Bong;Lee, Sang-Suk
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.12 no.5
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    • pp.141-162
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    • 2017
  • The International Monetary Fund (IMF) crisis introduced a system for easy layoffs. With recent economic downturn, employees have been asked to retire early and less new jobs have become available. More small businesses as a result have been started. The purpose of this research is to study weight and ranking on SWOT factors of korea food service franchise industry using the SWOT analysis. The Analytic Hierarchy Process (AHP) and Analytic Network Process (ANP) were used to analyze the SWOT found by the surveys. First, the SWOT analysis shows that the franchise owners and the expert group view the industry positively overall and there are more strengths, opportunities than weaknesses, threats. While there are negatives and threats to the industry overall, many people think that there are more opportunities and positive aspects. Second, the franchise owners rank proven business model and platform (S3) as the strongest strength of food service franchise businesses while the expert group ranks management supports (S2) from headquarters as the strongest strength. Third, the expert group and franchise owner group indicate that the weight on unfair franchise contracts with headquarters(W3) and high penalty from breaking a franchise agreement(W4) are 60% of weaknesses. Fourth, both the expert group and franchise owner group indicate that change in people's lifestyle, value system and consumption pattern(O3) as the most important opportunity. Fifth, both groups indicate that changes in consumption pattern(T1) due to ever changing food service industry as the biggest threat. It is ranked higher than the entry of korea food service franchises.

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Modelling Pasture-based Automatic Milking System Herds: The Impact of Large Herd on Milk Yield and Economics

  • Islam, M.R.;Clark, C.E.F.;Garcia, S.C.;Kerrisk, K.L.
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.7
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    • pp.1044-1052
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    • 2015
  • The aim of this modelling study was to investigate the effect of large herd size (and land areas) on walking distances and milking interval (MI), and their impact on milk yield and economic penalties when 50% of the total diets were provided from home grown feed either as pasture or grazeable complementary forage rotation (CFR) in an automatic milking system (AMS). Twelve scenarios consisting of 3 AMS herds (400, 600, 800 cows), 2 levels of pasture utilisation (current AMS utilisation of 15.0 t dry matter [DM]/ha, termed as 'moderate'; optimum pasture utilisation of 19.7 t DM/ha, termed as 'high') and 2 rates of incorporation of grazeable complementary forage system (CFS: 0, 30%; CFS = 65% farm is CFR and 35% of farm is pasture) were investigated. Walking distances, energy loss due to walking, MI, reduction in milk yield and income loss were calculated for each treatment based on information available in the literature. With moderate pasture utilisation and 0% CFR, increasing the herd size from 400 to 800 cows resulted in an increase in total walking distances between the parlour and the paddock from 3.5 to 6.3 km. Consequently, MI increased from 15.2 to 16.4 h with increased herd size from 400 to 800 cows. High pasture utilisation (allowing for an increased stocking density) reduced the total walking distances up to 1 km, thus reduced the MI by up to 0.5 h compared to the moderate pasture, 800 cow herd combination. The high pasture utilisation combined with 30% of the farm in CFR in the farm reduced the total walking distances by up to 1.7 km and MI by up to 0.8 h compared to the moderate pasture and 800 cow herd combination. For moderate pasture utilisation, increasing the herd size from 400 to 800 cows resulted in more dramatic milk yield penalty as yield increasing from c.f. 2.6 and 5.1 kg/cow/d respectively, which incurred a loss of up to $AU 1.9/cow/d. Milk yield losses of 0.61 kg and 0.25 kg for every km increase in total walking distance (voluntary return trip from parlour to paddock) and every one hour increase in MI, respectively. The high pasture utilisation combined with 30% of the farm in CFR in the farm increased milk yield by up to 1.5 kg/cow/d, thereby reducing loss by up to $0.5/cow/d (c.f. the moderate pasture and 800 cow herd scenario). Thus, it was concluded that the successful integration of grazeable CFS with pasture has the potential to improve financial performance compared to the pasture only, large herd, AMS.