• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.847-858
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• 2015

Control strategy and corresponding parameters have significant impacts on the overall technical and economic characteristics of composite energy storage systems (CESS). A better control strategy and optimized control parameters can be used to improve the economic and technical characteristics of CESS, and determine the maximum power and stored energy capacity of CESS. A novel coordinated control strategy is proposed considering the coordination of various energy storage systems in CESS. To describe the degree of coordination, a new index, i.e. state of charge coordinated response margin of supercapacitor energy storage system, is presented. Based on the proposed control strategy and index, an optimization model was formulated to minimize the total equivalent cost in a given period for two purposes. The one is to obtain optimal control parameters of an existing CESS, and the other is to obtain the integrated optimal results of control parameters, maximum power and stored energy capacity for CESS in a given period. Case studies indicate that the developed index, control strategy and optimization model can be extensively applied to optimize the economic and technical characteristics of CESS. In addition, impacts of control parameters are discussed in detail.

• Steel and Composite Structures
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• 제1권3호
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• pp.283-294
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• 2001

In the present work a constitutive model is developed which permits the assessment of the structural performance through a criterion based on cumulative damage. For it, a damage index is defined and is evaluated through the application of the Miner's rule in low-cycle fatigue. However, the damage index is not considered as a posteriori variable since is incorporated explicitly as an internal variable in the constitutive equations which produces a direct coupling between the damage and the structural mechanical behaviour allowing the possibility of considering as a whole different coupled phenomena. For the elaboration of this damage model, the concepts of the mechanics of continuum medium are applied on lumped dissipative models in order to obtain a coupled simplified model. As a result an elastoplastic model coupled with damage and fatigue damage is obtained.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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• pp.1102-1105
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• 1993

A fuzzy expert system for prediction and mitigation of sludge bulking was developed for an activated sludge process which treats waste water from a food industry. The developed system is able not only to infer the degree of progress of sludge bulking but also to generate remedial operation guides which may be sent to the local controllers as remote set points. One of the important consequences through this study is the BI (Bulking Index) inferred by the bulking prediction expert system was found to have a close correlation with the SVI (Sludge Volume Index) which is a practical measure of degree of bulking but needs tedious chores for its measurement.

• 산업경영시스템학회지
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• 제3권3호
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• pp.59-66
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• 1980

The purpose of this paper to study on measuring method in technical progress. Technology is combination method of raw material and capital, land, labour. The first step to technical Progress is COBB-DOUGLAS production function, so technical progresses are important role in economic growth and development. General production function from Y=f(K, L, T) and COBB-DOUGLAS production function Y=${AK^I}{L^b}$ is first condition. Technical progress is saving of production factor In capital saving, labour saving, neutral saving. Marred Hicks Robinson has Insist on technical progress by each view of production factor, but, what is most excellent measuring method of technical progress\ulcorner I : productivity index method. II : Gross Production function method. Productivity method used in every products level in weight values, gross method function method used in production factor attributed to products. Above two measuring method has delicate problem in each input factor, substitution relation and production factor simultaneously linked each others This basic problem based on technical progress is not solubable in this time.

• 한국경영과학회지
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• 제29권3호
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• pp.79-98
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• 2004

Despite its contribution to the Korean medical service industry the question of how efficiently the Korean public hospitals have operated has been unresolved. This study gauges and analyzes the overall efficiency and the Malmquist productivity index in the industry over the period 1992 through 2001. In addition to cost efficiency. we also measure technical, allocative, pure technical and scale efficiencies. Furthermore. the Malmquist index is decomposed into efficiency and frontier changes. We identify several important factors which seem to have strong relationship with various inefficiency estimates. The results indicate that on average the public hospitals has wasted a significant amount of resources and costs over the period. Unlike many other industries, the low level of cost efficiency of the public hospital industry is mainly due to allocative inefficiency rather than technical inefficiency. The Maimquist productivity indices seem both due to the frontier change and efficiency change, but with more effect by the former. The results also indicate that the turnover of hospital beds has played an important role in determining efficiency and productivity of this important industry.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 추계학술대회
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• pp.39-39
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• 2018

The Schizandra chinensis (Korean name : omija) is a fruit native to northeast Asia that is cultivated in South Korea and China. Using 1,938 valid patents of 6 group countries, we analyzed the patent trend based on year, countries, applicants, and technology. The technologies are categorized the 10 sub-technologies such as medicine, quasi-drugs, food, feed, cosmetics, cultivation, genome, manufacture, preprocessing, and etc. The technology level and competitiveness are analyzed using patent index such as cites per patent, patent impact index, patent family size and technology strength. In Korea, patent number rapidly increasing and individual technical level is lower than other countries. However, overall technical competitiveness is estimated high due to multiple patents. We suggest that cosmetics and cultivation fields are most likely to be developed in future omiza technology development in Korea. Our study will provides to the information of technical trend to support performing of new projects for omija plant.

• 한국자동차공학회논문집
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• 제15권1호
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• pp.99-105
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• 2007

It is very important to clarify the 3-D angular flow characteristics of in-cylinder bulk motion in the developing process of variable induction system. In-cylinder flow induced by variable induction system is very complex, so we can not describe the in-cylinder bulk flow characteristics using the conventional swirl or tumble coefficient. In this study, we introduced the new 3-D angular flow index, angular flow coefficient($N_B$), for in-cylinder bulk flow characteristics. And also, to confirm the index, we carried out the steady flow rig test for intake port of test engine varying valve lift on the test matrix.

• 한국멀티미디어학회논문지
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• 제24권3호
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• pp.448-459
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• 2021

In this paper, we propose a method of predicting the next-day stock price fluctuations of 10 KOSDAQ-listed companies in 5G, autonomous driving, and electricity sectors by training SVM, XGBoost, and LightGBM models from macroeconomic·financial market indicators, technical indicators, social interest indicators, and daily positive indices extracted from online news. In the three experiments to find out the usefulness of social interest indicators and daily positive indices, the average accuracy improved when each indicator and index was added to the models. In addition, when feature selection was performed to analyze the superiority of the extracted features, the average importance ranking of the social interest indicator and daily positive index was 5.45 and 1.08, respectively, it showed higher importance than the macroeconomic financial market indicators and technical indicators. With the results of these experiments, we confirmed the effectiveness of the social interest indicators as alternative data and the daily positive index for predicting stock price fluctuation.

• Current Optics and Photonics
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• 제7권2호
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• pp.136-146
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• 2023

Based on calculations using the macroscopic Maxwell's equations with mesoscopic boundary conditions, light absorption by a layered metal-insulator-metal (MIM) metamaterial system embedded in three different environments is investigated. Increasing the top metal thickness shifts the broad absorption band to lower dielectric-constant regions and longer wavelengths, for either TM or TE waves. Boosting the dielectric-layer thickness redshifts the broadband absorption to regions of larger dielectric constant. In air, for the dielectric-constant range of 0.86-3.40, the absorption of the system exceeds 98% across 680-1,033 nm. In seawater with optimized dielectric constant, ≥94% light absorption over 400-1,200 nm can be achieved; particularly in the wavelength range of 480-960 nm and dielectric-constant range of 0.82-3.50, the absorption is greater than 98%. In an environment with even higher refractive index (1.74), ≥98% light absorption over 400-1,200 nm can be achieved, giving better performance. The influence of angle of incidence on light absorption of the MIM system is also analyzed, and the angle tolerance for ≥90% broadband absorption of a TM wave is up to 40° in an environment with large refractive index. While the incident-angle dependence of the absorption of a TE wave is nearly the same for different circumstances, the situation is different for a TM wave.

• 펄프종이기술
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• 제31권4호
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• pp.69-75
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• 1999

This study was performed to investigated the application of mixed resins for corrugated container board. The corrugated container board yields a sandwich structure in which a linerboard material is glued to a corrugated medium . Now, manufacturing corrugated container boards don't provide sufficient strength, and result in box failure during shipping . Therefore improvement of box strength is necessary . In this study, we intend to improve box strength by improving corrugated medium strength with mixed resins and to find the optimum treatment condition of this resins. First, we tried to mixed resins as Starch+CMC, Starch_Irea, CMC+Urea, Second, investigated to applicability of this resins for corrugated medium , and the third, measured tensile index, burst index, and edgewise compression index on liner, medium paper, and single faced corrugated container board. In this test results, we obtained that the improvement ratios of tensile index in liner and medium paper were approximately 80-185%, 60-118% , respectively. The respecting improvement ratios of edgewise compression index of single faced corrugated container board was approximately 91-124%, relatively. In addition, we concluded that optimum condition in mixing ratio was 1 :3 with CMC + Urea and the ap[plication amounts was 9% on materials. Fro manufacture of corrugated container board, optimum condition in mixing ratio was 1 : 3 with 5% CMC +Urea , because of considering to improvement of strength on cost.