• Title/Summary/Keyword: unit load system

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Evaluation of Pollutant Load Unit Factor for Calculating Pollutants Emission in Aquacultural Farms (양식계 오염원 배출량 산정을 위한 원단위 설정)

  • Park, Jae Hong;Park, Bae Kyoung;Rhew, Doug Hee;Lee, Jae Kwan
    • Journal of Korean Society on Water Environment
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    • v.29 no.5
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    • pp.656-665
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    • 2013
  • This research was conducted to investigate pollutant load unit factor from aquacultural farms. Pollutant load unit factors were investigated on the 13 kinds of fish type, i.e., Trout, Leather Carp, Eel, Carp, Cartfish, Freshwater Eel, Crucian Carp, Colored Carp, Sturgeon, Marsh Snail, Sweetfish, Pond Snail, Eriocheir Sinensis. Water qualities in aquacultural farms were investigated wide range of values by fish type and pollutant items. High BOD and COD values were observed at the Leather Carp (Ponded water system), Cartfish (Ponded water system) and Freshwater Eel (Recirculating System). TOC and DOC values were relatively high at the Freshwater Eel (Recirculating System) and Eriocheir Sinensis (Extensive). Eel (Ponded water system) and Freshwater Eel (Recirculating System) produced high concentrated nutrient pollutants, i.e., T-N, T-P. Pollutant load unit factors are dependent on fish type, aquacultural type, water quality items, etc. If some fishes have similar basic unit values, those could be applied for TMDLs as a group of fish having same pollutant load unit. The water quality concentrations of post treatment facilities' (mainly reservoir tank) effluent were higher than those of fish raising bath because of extracting pollutant from sediment in the reservoir tank. Therefore, it needs to the management and regulations about post treatment facilities.

A Situations and Improvements on the Rail Freight System (철도화물수송체계의 현황과 개선방안)

  • 이용상
    • Journal of the Korean Society for Railway
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    • v.7 no.1
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    • pp.37-48
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    • 2004
  • In this paper, I explain the situations and problems which are focused on the rail freight system. We have a many problems, which have been showed the long freight logistics time, and inadequate fare system. And rail freight system does not have a efficient marketing system, and unit load system. Therefore rail freight has been decreased modal share, which is estimated from 9.65% in 1995 to 6.25% in 2001(ton base). Recently, EU nations and America rail freight system reveals a good outcome, which keeps the balance in the black. The main factors which go into the black, is the enlargement the investment in rail freight and efficient management focusing on the unit load system, fare system, and personnel management. I suggest the several improvement ways, which will be helpful to advance the rail freight system. Fistly, I suggest the speed up the freight rail and efficient fare system. Secondly, I propose the unit load system and the regulation the truck focusing on curtailment of the social cost. Lastly, I make an overture of establishment the comprehensive logistics system.

A Study on the Digital Unit Development for Turbine Load Set Control (Turbine Load Set 조정을 위한 Digital Unit 개발)

  • Moon Yong-Seon;Jeong Ho-Jin;Kang Sung-Ryul;Choi Hyeong-Yoon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.3
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    • pp.498-503
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    • 2005
  • As important device that decide output load in superannuated thermoelectric power plant which do Turbine Load Set Motor device. This generation of electric power system operated Set Up Range Motor according to Set Up value that operator manufactures by hand circumvolve, and generation of electric power output load derision is consisted by internal action including Motor Therefore, in this research passively output load operated Turbine Motor Drive equipment that can have existing Turbine Load Set Motor Performance developing Digital Drive Unit device design. Also control algorithm implementation and existing Turbine Load Set Motor Drive and connection possibility through designed controlling system to connect basis function that decide development output load with Digital Drive Unit that designed also with existing Motor Drive Unit and can be operated.

Optimal Redundant Units and Load in Parallel Systems (병렬 시스템에서의 최적 중복부품수와 최적 부하수준)

  • 윤원영;김귀래
    • Journal of the Korean Operations Research and Management Science Society
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    • v.23 no.1
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    • pp.97-107
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    • 1998
  • This paper is concerned with a parallel system that sustains a time-independent load and consists of n components with exponential lifetimes. It is assumed that the total load is shared by the working components and the failures of components increase higher failure rates in the surviving components according to the relationship between the load and the fialure rates. The power rule model among several load-failure rate relationships is considered. We consider the system efficiency meausre as the expected profit earned by the system per unit time. The high load causes high gain but it also occurs frequent system failures. The expected profit per unit time is used as criterion to evaluate the system efficiency. The goal of system engineer is to determine the optimal load and redundant units maximizing the expected profit per unit time. First, the system reliability function is obtained and the optimization problem of the load-sharing parallel system is considered. Given the redundant units, the existence of the optimal load can be proved analytically and given the load, the optimal redundant units can be solved also analytically. The optimal load and redundant units are obtained simultaneously by numerical computation. Some numerical examples are studied.

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A Study on Driving Motor Performance Comparison for Load Efficiency Improvement of a Bicycle Locker System (자전거 거치대 잠금장치의 부하시 효율개선을 위한 구동모터성능비교에 관한 연구)

  • Han, Ki-Soo;Won, Sung-Hong
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.62 no.4
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    • pp.175-180
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    • 2013
  • This paper presents the design and implementation of a Bicycle Locker System. Generally DC motor has been used to control a Bicycle Locker System, but DC motor system requires frequent maintenances and its power efficiency is comparatively poor especially under heavy load conditions. In order to improve this difficulties, this paper adopts BLDC motor for a Bicycle Locker System and its motor controller is developed. The performances of locker units are compared between DC motor unit and BLDC motor unit. The motor power consumptions between two motors are discussed. Test results verify that power efficiency of the suggested BLDC drive unit is considerably improved compared to the DC drive unit with load condition.

국제동향 - 새로운 Unit Load System의 꿈

  • Seo, Byeong-Ryun
    • Pallet News
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    • s.78
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    • pp.3-15
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    • 2015
  • 본 원고는 지난 2015년 6월 25일 중국 상하이에서 열린 제 10차 아시아파렛트시스템연맹(APSF) 정기총회 발표 원고로 서병륜 회장(APSF명예회장, KPCA회장, LogisALL그룹 회장)이 '새로운 Unit Load System의 꿈' 이라는 주제로 발표 하였습니다.

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The Probabilistic Production Simulation with Energy Limited Units Using the Mixture of Cumulants Approximation (에너지 제약을 갖는 발전기를 고려한 경우의 Mixture of Cumulants Approximation법에 의한 발전시뮬레이션에 관한 연구)

  • 송길영;김용하
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.40 no.12
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    • pp.1195-1202
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    • 1991
  • This paper describes a newly developed method of production simulation by using the Mixture of Cumulant Approximation (MOCA). In this method, the load is modelled as random variable (r.v.) which can be interpreted in terms of partitioning the load into various categories. We can consider the load shape of multi-modal characteristics. The number of load category and demarcation points of each load category are calculated automatically by using interpolation and least square method. Each generating unit of a supply system is modelled as r.v. of unit outage capacity according to the number of unit outage subset. Since the computation burden of each subset's moments increases exponentially as units are convolved to the system, we further derive the specific recursive formulae. In simulating the energy limited units, hydro unit simulation is performed using Energy Invariance Property and the simulation of pumped storage unit is modelled as compulsory and economic operations. The proposed MOCA method is applide to the test systems and the results are compared with those of cumulant and Booth Baleriaux method. It is verified that the MOCA method is considerably reliable and stable both pathological and well behaved system.

Unit-load Method for the Estimation of Non-point Pollution Loads by Subcategorizing the Land-use Category Reflected in the National Land Register Data : A Case Study of Kyeongan Watershed in South korea (경안천 유역 지적공부에 나타난 특정지목의 토지이용 특성 세분화를 통한 비점오염 부하량 산정 개선방안)

  • Lee, Bum-Yeon;Lee, Chang-Hee;Ha, Do;Lee, Su-Woong
    • Journal of Korean Society on Water Environment
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    • v.26 no.4
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    • pp.598-607
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    • 2010
  • One of constraints in the application of unit-load method to estimate non-point pollution loads in the total water pollutant load management system (TWPLMS) is the limited numbers of applicable unit-loads. Since only 7 unit-loads are currently available for total 28 land-use categories in the national land register data, each unit-loads inevitably have to represent several land-use categories regardless of their actual land coverage characteristics. As a way to minimize the problem, this study suggested a nested application of the available unit-loads based on the analysis of high resolution aerial images taken in the Kyeongan watershed. Statistical analysis of three selected land-use categories such as school, apartment complex, and golf course showed that there exit significant (95% confidence level) relationships between the registered land-uses and actual land coverages. The school and apartment complex currently considered as 100% ground have only 65% and 80% of ground characteristics, respectively. Golf course, which is considered as 100% pasture, has about 5% of ground area. This indicates that the unit-load method using in TWPLMS can give over estimated non-point pollutant loads for the school and apartment complex (19.8~54.4%) but under estimation for the golf course (80.9%).

Performance Analysis of Water-to-Air Heat Pump System under Water Temperature and Load Ratio (열원 및 부하조건에 따른 물-공기 히트펌프 시스템의 성능분석)

  • Cho, Yong;Lee, Dong Keun
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.05a
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    • pp.194.2-194.2
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    • 2011
  • Heating and cooling performance has been analyzed for the water-source heat pump system using raw water from Daechung reservoir. During heating operation from March to May, water temperature is not good condition for a heat source due to the higher atmospheric temperature. Avearged heating load ratio is only 14.3%, and the averaged unit COP and system COP are estimated to be 2.46 and 2.15 respectively. The COP is affected considerably by the water temperature, and the unit COP is increased from 2.16 at $5^{\circ}C$ to 2.95 at $11^{\circ}C$. Cooling performance is analyzed with the measured data from June to August. During cooling operation, raw water has lower temperature by 4. $5^{\circ}C{\sim}4.7^{\circ}C$ than the atmosphere. The load ratio is 39.2%, and the averaged unit COP and system COP are estimated to be 7.25 and 6.13 respectively. The heating COP is affected by the load ratio rather than water temperature. The COP is increased for 20%~40% load ratio, while is decreased for 40%~60% load ratio. It is estimated that the compressor operation combination for 3 (two constant speed and one inverter) compressors is changed for the load ratio.

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A Research on Logistics System for Agro-Food (농식품 물류체계에 관한 연구)

  • Ha, Young-Sun
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.13 no.1
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    • pp.29-32
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    • 2007
  • In a comparison the Logistics system for Agro-food of Korea and the Logistic system of Europe and Japan, the more developed countries of Europe have better systems. This well-formed rationalization of Logistics on Agro-food, and perfectly-equipped packaging system measurements for Agro-food make 100% pallet freight possible. Also, this means that a unit load system has been achieved. In Japan, the Logistic system is mainly accomplished by auction. However, it has been rapidly changing into the same type as the developed countries these days. Logistic system in Korea is also mainly accomplished by auction under the influence of Japan. However it also has been rapidly changing in to the same type as the developed countries these days. In the future, Korea has to build up international competitiveness in the face of FTA(Free Trade Agreement) era. This can happen by having better-organized Agro-food Logistics system and unit load system which results in accurate packaging system measurements.

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