• Title/Summary/Keyword: direct and indirect design

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Effect of Indirect Oxidation on the Design of Sewage/wastewater Reuse System with an Electrolysis Reactor (전기분해 반응조의 간접산화 효과가 하.폐수 재활용 시스템 설계에 미치는 영향)

  • Shin, Choon-Hwan
    • Clean Technology
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    • v.15 no.2
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    • pp.116-121
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    • 2009
  • In this paper, we investigated the effect of an indirect oxidation zone in an electrolysis reactor that used Ti/$IrO_2$ as the anode and SUS 316L as the cathode. Based on our preliminary results, the electrolysis reactor was operated with pole plate interval of 6 mm, current density 1.0 $A/dm^2L$ and electrolyte concentration 15%. The removal efficiency, COD (chemical oxygen demand), was additionally increased by 55% and 12.5${\sim}$15.0% in the direct and indirect oxidation zones, respectively. The removal efficiencies of T-N (total nitrogen) and T-P (total phosphorus) were found to be 88% and 75%, respectively. It was shown that the additional effect of the indirect oxidation zone on the removal was nearly negligible. Also, as the removal of COD,T-N and T-P took place during the initial2${\sim}$5 days of reaction, it was concluded that there was no need to extend the retention time of the electrolysis reactor.

The Relationship between Coolness, Perceived Value and Value Creation: An Empirical Study of Fashion Distribution

  • Truong, Nguyen Xuan;Ngoc, Bui Hoang;Phuong, Pham Thi Lan
    • Journal of Distribution Science
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    • v.19 no.9
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    • pp.101-111
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    • 2021
  • Purpose: This study discusses and discovers the important role of fashion product coolness in affecting consumers' perceived value and consumers' value creation behavior. Accordingly, fashion product coolness exerts a direct effect on perceived value while perceived value has a direct impact on value creation. Besides, fashion product coolness has an indirect effect on value creation through perceived value. Research design, data, and methodology: This study adopts the quantitative research approach by cross-sectional technical on a sample of 319 respondents in Vietnam. PLS-SEM has been used to analyze the survey data. Results: The result indicates that the proposed direct and indirect effects are significant. Specifically, utilitarian "coolness" and hedonic "coolness" have positive impacts on perceived value. The perceived value poses an impact on consumers' value creation behavior, including customer lifetime value and influencer value. Finally, the perceived value links utilitarian "coolness", hedonic "coolness" with customer lifetime value and influencer value. Conclusions: Fashion distribution is playing an increasingly important role in the retail sector of the economy. Fashion distribution activities are greatly influenced by the perceived value of consumers. The findings are supposed to strengthen the beliefs of fashion brands and retailers in the promotion of value creation and consumers' perceived value in the field of fashion distribution.

A study on flow characteristic of a stand type Kimchi refrigerator for optimum design of air flow passage (서랍식 김치냉장고의 최적 유로 설계를 위한 유동특성에 관한 연구)

  • Han, H.R.;Jung, H.Y.;Park, Y.K.;Choi, Y.H.;Lee, Y.W.
    • Journal of Power System Engineering
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    • v.15 no.5
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    • pp.37-42
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    • 2011
  • The normal cooling system of a refrigerator is applied to indirect a cooling methods. But the Kimchi refrigerator is applied to direct the cooling method. Recently when the model was applied to both direct and indirect the cooling methods, the improvement was considerable. With the development of the living standards in Korea, there has been more sensitive dissatisfaction about the taste and the smell of Kimchi. In order to solve these kinds, there is a need to systematic and scientific approach. Based on these, the purpose of this study is to optimize design for improve the storage period of Kimchi refrigerator. In this research, we concentrate on the temperature change and heat transfer characteristics of interior parts of the Kimchi refrigerator due to control cycle of temperature and flow phenomenon of cooling air.

Model Reference Adaptive Control for Linear System with Improved Convergence Rate-parameter Adaptation Method (선형시스템을 위한 개선된 수렴속도를 갖는 기준모델 적응제어)

  • Lim, Kye-Young
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.37 no.12
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    • pp.884-893
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    • 1988
  • Adaptive controllers for linear unknown coefficient system, that is corrupted by disturbance, are designed by parameter adaptation model reference adaptive control(MRAC). This design is stemmed from the Lyapunov direct method. To reduce the model following error and to improve the convergence rate of the design, an indirect-suboptimal control law is derived. Proper compensation for the effects of time-varying coefficients and plant disturbance are suggested. In the design procedure no complete identification of unknown coefficients are required.

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Model Reference Adaptive Control for Linear System with Improved Convergence Rate -SIGNAL SYNTHESIS METHOD- (선형시스템을 위한 개선된수렴속도를 갖는 기준모델 적응제어기- SYNTHESIS METHOD)

  • Lim, Kye-Young
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.37 no.10
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    • pp.733-739
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    • 1988
  • Adaptive controllers for linear system whose nominal values of coefficients only are known, that is corrupted by disturbance, are designed by signal synthesis model reference adaptive control (MRAC). This design is stemmed from the Lyapunov direct method. To reduce the model following error and to improve the conrergence rate of the design, an indirect suboptimal control law is de rived using the Hamilton Jacobi Beellman equation. Proper compensaton for the effects of time varying coefficients and plant disturbance are suggested. In the design procedure no complete identification of unknown coefficients are required.

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Optimal Seismic Reliability of Bridges Based on Minimum Expected Life Cycle Costs (최소기대비용에 기초한 교량의 최적내진신뢰성)

  • 조효남;임종권;심성택
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1999.10a
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    • pp.249-256
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    • 1999
  • This study is intended to propose a systematic procedure for the development of the reliability-based seismic safety and cost-effective Performance criteria for design and upgrading of long span PC bridges. In the paper, a set of cost function models for life cycle cost analysis of bridges is proposed. The total life cycle cost functions consist of initial cost and direct/indirect damage costs considering repair/replacement costs, human losses and property damage costs, road user costs, and indirect regional economic losses. The damage costs are successfully expressed in terms of Park-Ang median global damage indices and damage probabilities. The proposed approach is successfully applied to model bridges in both regions of a moderate seismicity area like Seoul, Korea and a high one like Tokyo, Japan. It may be expected that the proposed approach can be effectively utilized for the development of cost-effective performance criteria for design and upgrading of various types of bridges as well as long span PC bridges.

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SIMULATOR FOR EVALUATION OF VARIOUS FUZZY CONTROL METHODS

  • Hayashi, Kenichiro;Muta, Itsuya;Hoshino, Tsutomu;Ohtsubo, Akifumi
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.949-952
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    • 1993
  • As well-known, fuzzy control has been recognized to be of great usefulness in many engineering fields. However, the present design methods of fuzzy control systems depend on trial and error the thing that limits its usefulness. Therefore, an effective and convenient support tools for design and evaluation are greatly needed as well as the establishment of the design methods and guidling. From these backgrounds, we have developed a fuzzy control simulator[1, 2] which has various fuzzy control methods such as "direct method", "indirect method" and "fuzzy-PID method". This paper deals especially with the "direct method" function of the simulator. The simulator was developed for personal computers and programed in C language.

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Comparative study on the prediction of speed-power-rpm of the KVLCC2 in regular head waves using model tests

  • Yu, Jin-Won;Lee, Cheol-Min;Seo, Jin-Hyeok;Chun, Ho Hwan;Choi, Jung-Eun;Lee, Inwon
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.13 no.1
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    • pp.24-34
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    • 2021
  • This paper predicts the speed-power-rpm relationship in regular head waves using various indirect methods: load variation, direct powering, resistance and thrust identity, torque and revolution, thrust and revolution, and Taylor expansion methods. The subject ship is KVLCC2. The wave conditions are the regular head waves of λ/LPP = 0.6 and 1.0 with three wave steepness ratios at three ship speeds of 13.5, 14.5 and 15.5 knots (design speed). In the case of λ/LPP = 0.6 at design speed, two more wave steepness ratios have been taken into consideration. The indirect methods have been evaluated through comparing the speed-power-rpm relationships with those obtained from the resistance and self-propulsion tests in calm water and in waves. The load variation method has been applied to predict propulsive performances in waves, and to derive overload factors (ITTC, 2018). The overload factors have been applied to obtain propulsive efficiency and propeller revolution. The thrust and revolution method (ITTC, 2014) has been modified.

Optimum Life-Cycle Cost Design of Steel Bridges (강교의 생애주기비용 최적설계)

  • Cho, Hyo-Nam;Lee, Kwang-Min;Kim, Jung-Ho;Choi, Young-Min;Bong, Youn-Jong
    • Journal of Korean Society of Steel Construction
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    • v.15 no.4 s.65
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    • pp.341-358
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    • 2003
  • This paper proposed a general formulation of Life-Cycle Cost (LCC) models and LCC effective design system models of steel bridges suitable for practical implementation. An LCC model for the optimum design of steel bridges included initial cost and direct/indirect rehabilitation costs of a steel bridge as well as repair/replacement costs, loss of contents or fatality and injury losses, road user costs, and indirect socioeconomic losses. The new road user cost model and regional socioeconomic losses model were especially considered because of the traffic network. Illustrative design examples of an actual steel box girder and an orthotropic steel deck bridge were discussed to demonstrate the LCC effectiveness of the design of steel bridges. Based on the results of the numerical investigation, the LCC-effective optimum design of steel bridges based on the proposed LCC model was found to lead to a more rational, economical, and safer design compared with the initial cost-optimum design and the conventional code-based design.

The plastic design of dart location from the viewpoint of visual-spatial division (시각적 공간분할로 본 Dart 위치의 조형적 설계)

  • 정옥임
    • Journal of the Ergonomics Society of Korea
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    • v.6 no.1
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    • pp.33-40
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    • 1987
  • To study the body trunk basic to Clothing construction, and study the peculiarities of visual spatial division, necessary items are measured indirectly from 216 unmarried women from 19 to 24 years old by a photographic net-work method. In so doing, the problem of Fashion Design in establishing the location of Darts for Basic Dress is not considered. The following results are obtained. 1) Indirect measuring method, is obtained approximate to actual size, with an error of .+-. 2.8cm. 2) In the modeling plan of Dart location viewed from the visual-spatial division in Basic Dress, it is concluded that Darts are to be placed at the point of 1/3k+1/5k form the waist. From the aesthetic point of wiew, it is more appealling for darts to be placed at the point of 6cm .+-. 0.6cm right or left of center. 3) From direct measurement dart location can be set based on bust point width, and from indirect measurement, dart location can be set based on waist width.

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