• Title/Summary/Keyword: Demands

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A study on the development of the engine/hydraulic pump control system of excavator (굴삭기의 엔진 및 유압펌프 제어시스템의 개발에 관한 연구)

  • 하석홍;윤영환;이일영;조겸래;이진걸;황봉동
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10a
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    • pp.675-680
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    • 1990
  • According to the recent increase of demands for multi-function and economics on hydraulic excavator, it is required that excavator should have simple operation, higher and operational efficiency. However, it is difficulty for current hydraulic system to satisfy demands fully. This study shows that new control system improves power transmission efficiency, work capability of engine and hydraulic system of current excavator.

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무연탄 수요예측 및 공장규모 결정에 관한 사례연구

  • 오형술;김명수;박동권;김용택
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1990.04a
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    • pp.111-124
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    • 1990
  • All most factories producing briquets in Seoul are currently located at residential districts. The coal dusts scattered from these factories are making serious problems in living. To get rid of this environmental pollution, moving thesis factories to places of mining coals is considered now. For doing this project, first, annual briquet demands are forecasted using regression analysis and then, optimal factory capacities to be built are obtained based on forecast demands using LP. To validate factory capacities obtained above simulation is conducted using SLAM II.

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A study on profitability of train schedule planning (열차공급계획의 수익성 분석에 관한 연구)

  • Woo Hee-Moon;Jang Seong-Yong;Kim Dong-hee
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.1538-1545
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    • 2004
  • In the train schedule plan corresponds to a master plan for transport services. This service plan must be constructed to minimize operational cost or maximize revenue considering transportation demands and resource capacities in the operation company, and it includes several sub-planning activities such as train operation frequency plan, train schedule plan, train capacity assignment plan, and rolling stock requirement plan. In this paper, we present profitability evaluation system for the current train schedule plan. The proposed system can be used for evaluating profitability by estimating train service revenue considering customer demands.

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Investigation on Recently Developed Reinforced Soil Wall System (국내 보강토옹벽 신기술 조사 연구)

  • Lee, Kwang-Wu;Cho, Sam-Deok
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.158-167
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    • 2008
  • Reinforced earth wall system has been popularized since its introduction to Korean civil engineering society in early 1980's. Nowadays, the increased use of reinforced earth wall for the purpose of obtaining more land brings several additional demands such as environmental-friendly, better stable and constructible, and economical system. This paper introduces some recently developed reinforced earth wall systems with consideration of the current demands.

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Characteristics of Near Field Earthquakes and its effect on Seismic demands (Near Field 지진의 특징과 구조응답에 대한 영향)

  • 배미혜;권오성;한상환
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2002.04a
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    • pp.208-213
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    • 2002
  • Near field ground motions contain distinct, large amplitude pulses in both velocity and displacement. This paper presents an investigation on the characteristics of near filed earthquakes and their effects on seismic demands. For this purpose 20 sets of near field ground motion and 20 sets of far filed ground motion are compared with respect to Linear Elastic Response Spectrum(LERS), Response Modification Factor(R), Inelastic Response Spectrum(IRS), and performance point of Capacity Spectum Method(CSM).

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A Study on Analyzing Demands for Professional Librarians in Domestic and Foreign Countries (국내.외 전문사서 수요분석 연구)

  • Noh, Young-Hee;Ahn, In-Ja;Hoang, Gum-Sook
    • Journal of the Korean Society for Library and Information Science
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    • v.42 no.2
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    • pp.189-208
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    • 2008
  • This study aims to deane prototypes of professional librarians as well as their job requirements by analyzing international demands for librarianship. Demands analysis starts with examining librarian job posting websites in the US, UK and Canada, followed by inquiring incumbent librarians in Korea. As for the job requirements. the study parallels definitions by IFLA and ALA with job announcements by hiring institutions. As a result, we identified 21 professional librarian prototypes by subject(7), task(12) and object(2), and defined the job requirements as 1) MLS or equivalent school knowledge with undergraduate degree of library science, and/or at least six years of relevant business experience, or 2) at least nine-rear experience as a second-level full-time librarian with two-rear experience and/or professional training in the job relevant field.

A Case Study on the Development and Implementation of a Elementary Science Differentiated Instruction-Learning Program for the Gifted Underachievers (미성취 영재를 위한 초등 과학 개별화 교수-학습 프로그램의 개발과 적용 사례 연구)

  • Jeong, Seong-Hee;Cheon, Ok-Myung;Kang, Seong-Joo
    • Journal of Korean Elementary Science Education
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    • v.34 no.4
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    • pp.394-405
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    • 2015
  • The purpose of this study was to develop and apply a differentiated instruction-learning reflecting various characteristics and demands of the gifted underachievers, and thereby help to develop the study attitude and study achievement of the gifted underachievers. To achieve the purpose, a case study on five gifted underachievers who are in $6^{th}$ grade of elementary school was conducted. By collecting and analyzing a variety of data including standardized tests, interviews with teachers, students, and parents, and observation journals, this researcher examined the characteristics and demands of the gifted underachievers. For the development of the program, differentiated strategies were designed according to students' interest and concern, their multiple-intelligence, and their learning styles. As a result of the application of them, a program with a total of 20 sections was finally developed. The result of the application for the differentiated instruction-learning program revealed improvements in their academic achievements. In addition, it was found that their learning motives were improved. The program was also found to affect their self-concept and their attitude toward learning. The study showed that developing an education program for the gifted underachievers should begin from the analysis of each student's characteristics. Also, it was found that a differentiation strategy could become an alternative to apply various characteristics and demands of the gifted underachievers to the development of a program. The gifted underachievers' intellectual and definitive characteristics were changed even by the short-term mediation. Therefore, the new issue about educating the gifted is to provide a differentiated instruction-learning program fitting their characteristics and demands and help them exert their potential as best as they could.

Inelastic behavior of systems with flexible base

  • Fernandez-Sola, Luciano R.;Huerta-E catl, Juan E.
    • Earthquakes and Structures
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    • v.14 no.5
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    • pp.411-424
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    • 2018
  • This study explores the inelastic behavior of systems with flexible base. The use of a single degree of freedom system (ESDOF) with equivalent ductility to represent the response of flexible base systems is discussed. Two different equations to compute equivalent ductility are proposed, one which includes the contribution of rigid body components, and other based on the overstrength of the structure. In order to asses the accuracy of ESDOF approach with the proposed equations, the behavior of a 10-story regular building with reinforced concrete (RC) moment resisting frames is studied. Local and global ductility capacity and demands are used to study the modifications introduced by base flexibility. Three soil types are considered with shear wave velocities of 70, 100 and 250 m/s. Soil-foundation stiffness is included with a set of springs on the base (impedance functions). Capacity curves of the building are computed with pushover analysis. In addition, non linear time history analysis are used to asses the ductility demands. Results show that ductility capacity of the soil-structure system including rigid body components is reduced. Base flexibility does not modify neither yield and maximum base shear. Equivalent ductility estimated with the proposed equations is fits better the results of the numerical model than the one considering elastoplastic behavior. Modification of beams ductility demand due to base flexibility are not constant within the structure. Some elements experience reduced ductility demands while other elements experience increments when flexible base is considered. Soil structure interaction produces changes in the relation between yield strength reduction factor and structure ductility demand. These changes are dependent on the spectral shape and the period of the system with fixed and flexible base.

The Load Forecasting in Summer Considering Day Factor (요일 요인을 고려한 하절기 전력수요 예측)

  • Han, Jung-Hee;Baek, Jong-Kwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.8
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    • pp.2793-2800
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    • 2010
  • In this paper, we propose a quadratic (nonlinear) regression model that forecasts daily demands of electric power in summer. For cost-effective production (and/or procurement) of electric power, forecasting demands of electric power with accuracy is important, especially in summer when temperature is high. In the literature, temperature and daily demands of preceding days are typically employed to construct forecasting models. While, we consider another factor, day of the week, together with temperature and daily demands of preceding days. For validating the proposed model, we demonstrate the forecasting accuracy in terms of MAPE(Mean Absolute Percentage Error) and MPE(Maximum Percentage Error) using field data from KEPCO(Korea Electric Power Corporation) in comparison with two forecasting models in the literature. When compared with the two benchmarks, the proposed forecasting model performs far better providing MAPE and MPE not exceeding 3.08% and 8.99%, respectively, in summer from 2005 to 2009.

Consumer Demands for Prepared Frozen or Refrigerated Foods and Industry′s Response to Consumer Demands (조리냉동 및 냉장식품에 대한 도시주부의 이용실태 및 인식정도와 식품제조업체의 의식구조 조사에 관한 연구)

  • 곽동경;이경애;류은순
    • Korean journal of food and cookery science
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    • v.9 no.3
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    • pp.230-238
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    • 1993
  • The objectives of this study were to provide the basic data for the consumer education and for the new product development by surveying housewives'demands concerning prepared frozen or refrigerated foods and by surveying industry's practices and opinions concerning new product development. 804 housewives and 14 manufacturing companies of prepared frozen or refrigerated foods were surveyed. Data from housewives were analyzed by using SPSS-X progrm in terms of $x^2$-test, one-way ANOVA, t-test. The results of study are summarized as follows : 1. Frozen dumpling, frozen meat, surimi, ham and sausage were identifed as the most frequently used food items by housewives. The mean storage period for either prepared frozen or refrigerated foods was less than 15 days. 2. Housewives with higher educational background showed the greater concerns in packing and sanitary conditions, convenience in cooking procedures and brand name of the product than their counterparts. 3. Most housewives'purchasing motive for prepared frozen or refrigerated foods was the convenience of the cooking procedures(71.1%). Among the member of family, children(72.8%) specially liked prepared frozen or refrigerated foods. 4. Housewives'demands for prepared frozen or refrigerated foods were 'price reduction'and 'nutrition fortification'. These were in accordance with the companys'opimons. 5. Most wanting new product developments from the housewives perspectives were beverages (37.7%), stir-fried menu items(36.1%), pan-fried menu items(34.0%), stewed menu items(30.3%) and soups(20.4%). In case of stew and soups, the industry did not have a plan to develop those menu items.

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