• 제목/요약/키워드: Performance Quantity

검색결과 993건 처리시간 0.025초

정보시스템 감리의 정량화 분석 모델 설계 (Design on Fixed Quantity Analytical Model for Information System Audit)

  • 김희완;이해만;김동수
    • 한국콘텐츠학회논문지
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    • 제11권2호
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    • pp.88-100
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    • 2011
  • 본 논문에서는 정보시스템 감리의 정량화 모델과 세부 수행 절차를 제시하였다. 또한 사업에 심각한 영향을 미칠 수 있는 요인과 업무상 운영 리스크가 크다고 판단되는 점검 항목을 미리 식별하여 우선 순위를 부여할 수 있는 정보시스템 감리 모델을 제시하였다. 이를 통하여 발주자는 객관적이고 수치화된 점수로 평가할 수 있고, 피 감리인과의 감리 평가 결과에 대한 이견을 최소화하여 감리의 신뢰성과 객관성 및 효과성을 향상시킬 수 있다. 본 논문에서 제시한 모델을 응용 시스템 감리 프로젝트에 적용하였다. 적용결과 총평의 평가결과와 동일한 점수를 얻을 수 있었으며, 제안된 모델이 적정함을 검증하였다.

노즐 형상 변경이 소형 CRDI 엔진의 성능에 미치는 영향에 대한 수치 해석적 연구 (Numerical Study on the Effect of Nozzle Geometry on the Small CRDI Engine Performance)

  • 민세훈;서현규
    • 한국분무공학회지
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    • 제20권4호
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    • pp.254-260
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    • 2015
  • The objective of this study is to investigate the effect of multi-hole nozzle on the performance of small CRDI engine. Combustion and exhaust emission characteristics of engine were studied by using CFD simulation with ECFM-3Z combustion model. The conditions of simulation were varied with nozzle geometry, injection timing and injection quantity. In addition, the results were compared in terms of combustion pressure, rate of heat release, $NO_x$ and soot emissions. It was found that combustion pressure was increased when injection timing was advanced. The rate of heat release of 6 hole nozzle was higher than that of 12 hole nozzle since the quantity of fuel impinged at the bottom of piston rim was different under different injection timing conditions. In the case of $NO_x$ emission, 6 hole nozzle generated more $NO_x$ emission than 12 hole nozzle. On the other hand, in the case of soot emission, 12 hole nozzle showed higher value than 6 hole nozzle because injected fuel droplets from multi-hole nozzle were coalesced.

신선·시즌 상품의 최적 주문량 산정 문제에 대한 실증적 분석 : 소매유통업에서 뉴스벤더 모델의 적용 (An Empirical Analysis on Optimal Oder Quantity of Perishable and Seasonal Products : A Practical Application of Newsvendor Model in Retail)

  • 노건호;황승준
    • 산업경영시스템학회지
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    • 제42권1호
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    • pp.41-54
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    • 2019
  • Although retailers deals with a large number of single-term inventory items, but few cases have been considered in the areas of practical decision making. However, recent moves to strengthen fair trade have created a real need for single-period inventory decision-making problems. This study addresses the problem of ordering quantity decisions that are expected to maximize profits using classical newsvendor models. The research target is data on seasonal and perishable products from retail. We also use data from retailers to actually apply the newsvendor model and calculate the results to compare performance. It also suggests solutions for estimating demand for products sold in order to apply newsvendor models that utilize actual demand ratio versus forecast demand. This study would like to examine the effectiveness of this research through data analysis and make some suggestions for applying it to reality.

구체방수 콘크리트의 균열 자가치유 성능 (Self-Healing Performance of Concrete Using Admixture)

  • 이종윤;이한주;이용진
    • 한국안전학회지
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    • 제27권6호
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    • pp.109-114
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    • 2012
  • This study is the things to experiment and evaluate the performance of self-healing water-proofing on the concrete to be using the crystal growth composite waterproofing admixture. The cylinder to be making on the concrete by ${\varnothing}150{\times}300$ mm for evaluating the performance of self-healing water-proofing was aging 90 days and cut on a 50 mm. So, it prompted the crack and applied. After it measured the quantity of water to be flow the water throughout the crack part of the cylinder, it applied the basic formular of Darcy's law and calculated the coefficient of water permeability. So, it verified the performance of self-healing water-proofing on the basis of the changing shape of the water permeability. This experiment is the thing to be applied the general evaluation of the structure to demand the real watertightness on doing for the evaluating of performance of the quantity of water leak and self-healing water-proofing about the various penetration crack.

R134a와 R152a 냉매를 이용한 자동차용 에어컨 시스템의 성능 비교 (Performance Comparison of Automotive Air conditioning System by using R134a and R152a)

  • 김종수;남수병;이대웅;유성연;김진혁
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2006년도 하계학술발표대회 논문집
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    • pp.9-14
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    • 2006
  • This study presented the feasibility of R152a refrigerant as an alternative of R134a which is used in the current automobile air conditioning system. The performance of air conditioning system installed in the actual vehicle was tested using the climate wind tunnel. The experiments were conducted at various refrigerant charge quantities and various driving conditions such as city traffic, highway traffic and parking. Same components and lubricant were used for both R134a and R152a system. The effects of air set values of thermal expansion valve on the performance were also investigated. In case of the R152a system, refrigerant charge quantity can be reduced about 20%, better performance and superior compressor durability is expected due to the lower discharge pressure compared to the R134a system.

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댐콘크리트의 내구성 향상에 관한 실험적 연구 (An Experimental Study on the Improvement of Durability of Dam Concrete)

  • 윤영수;원종필;송영철;우상균;송유신
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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    • pp.415-420
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    • 1999
  • Dam concrete should have sufficient durability in wet and dry repetition and abrasion due to water lever variance and also in freezing and thawing resistance as well as water penetration capacity. This study presents various experimental performance to enhance the durability of face slab concrete in concrete face rockfill dam by varying the fly ash substitution of 0%, 10%, 15% and 20% in cement quantity. The effect on durability corresponding to the increasing amount of fly-ash was evaluated and the optimum quantity of fly-ash subtitution was finally recommended. The results show that 15% fly-ash substituion was found out to be an optimum quantity and demonstrated an excellent performances in durability.

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$\alpha$-레벨 집합 분해에 의한 서보제어용 퍼지추론 연산회로 구현 (Implemented Circuits of Fuzzy Inference Engine for Servo Control by using Decomposition of $\alpha$-Level Set)

  • 홍정표;홍순일
    • 대한전기학회논문지:시스템및제어부문D
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    • 제54권2호
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    • pp.90-96
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    • 2005
  • This paper presents hardware scheme of fuzzy inference engine, based on α-level set decomposition of fuzzy sets for fuzzy control of DC servo system. We propose a method which is directly converted to PWM actuating signal by a one body of fuzzy inference and defuzzification. The influence of quantity α-levels on input/output characteristics of fuzzy controller and output response of DC servo system is investigated. It is concluded that quantity α-cut 4 give a sufficient result for fuzzy control performance of DC servo system. The experimental results shows that the proposed hardware method is effective for practical applications of DC servo system.

3축 가속도 센서를 이용한 자세 및 활동 모니터링 (Posture and activity monitoring using a 3-axis accelerometer)

  • 정도운;정완영
    • 센서학회지
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    • 제16권6호
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    • pp.467-474
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    • 2007
  • The real-time monitoring about the activity of the human provides useful information about the activity quantity and ability. The present study implemented a small-size and low-power acceleration monitoring system for convenient monitoring of activity quantity and recognition of emergent situations such as falling during daily life. For the wireless transmission of acceleration sensor signal, we developed a wireless transmission system based on a wireless sensor network. In addition, we developed a program for storing and monitoring wirelessly transmitted signals on PC in real-time. The performance of the implemented system was evaluated by assessing the output characteristic of the system according to the change of posture, and parameters and acontext recognition algorithm were developed in order to monitor activity volume during daily life and to recognize emergent situations such as falling. In particular, recognition error in the sudden change of acceleration was minimized by the application of a falling correction algorithm

Collins 내동기의 최적 설계조건 (Optimum Design Condition of the Collins Cryocooler)

  • 이상원;김수연;정평석
    • 설비공학논문집
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    • 제4권3호
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    • pp.183-190
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    • 1992
  • The Collins cryocooler is numerically analysed with the optimization technique, and the optimum operating and design conditions are searched. This paper shows that liquefied helium quantity has an external maximum w.r.t. the total mass flow rate, the mass flow rates through expander and the capacities of heat exchangers. The liquefied helium quantity increases as the compressor exit pressure of the cryocooler does. The maximum quantity of liquefied helium and the maximum coefficient of performance have been found to exist in extremum, depending on the ratios of each heat exchanger capicities to the total one. At the optimum condition, the capacity of heat exchanger in high temperature region is larger than that in low temperature region.

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APPLICATION OF KNOWLEDGE MANAGEMENT IN BUILDING AUTOMATION SYSTEM: A CASE STUDY OF SIX BUILDINGS IN KUALA LUMPUR

  • Nurul Afida Isnaini Janipha;Hamimah Adnan;Fadzil Hassan
    • 국제학술발표논문집
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    • The 2th International Conference on Construction Engineering and Project Management
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    • pp.672-683
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    • 2007
  • The rapid development of Kuala Lumpur has seen numerous new and high-rise buildings introducing Building Automation System (BAS). Whilst effective application of Knowledge Management (KM) within BAS is the pre-requisite for the achievement of optimum BAS performance, there has been little research undertaken to investigate if have been the case. This paper presents a research undertaken to get a view of how KM applies in BAS in six (6) selected case-study buildings in Kuala Lumpur, all operating with the 'one-system' M&E workstation control BAS. The emergent findings positively suggest that adequate KM approaches were employed within their BAS management processes, but further studies would be necessary to determine the extent of their application and effectiveness.

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