• 제목/요약/키워드: small scale model

검색결과 1,219건 처리시간 0.028초

국내 중소건설업체의 효율성 평가에 관한 연구 (A Study on the Evaluation of Efficiency in the Korean Small and Medium sized Construction Firms)

  • 김혁;유한주;송광석
    • 품질경영학회지
    • /
    • 제38권3호
    • /
    • pp.463-474
    • /
    • 2010
  • In this study, we evaluate the efficiency of Construction Industry using Data Envelopment Analysis(DEA). Since the Construction Industry has been traditionally operated through competition, it is important to measure the efficiency. In this paper, we empirically analyze the Efficiency of the 50 Korean Construction Industry. In detail, we used the scale of efficiency in order that efficiency cannot be affected by the total technical efficiency of each company and the scale of DMU by applying CCR or BBC model. Also, we analyzed the changes of measurement DEA model score. we adopted the basic DEA, RTS Region and MPSS(Most Productive Scale Size) method which are combined with efficiency measurement model in order to analyze the operational status. Furthermore, by complementing the shortfalls of the scale efficiency value of the DEA Model, RTS Region Model can be recommended to be appropriate in the evaluation of ideal input/output Quantity. In particular, input variables are total assets, construction capacity, the technical staff and output variables are sales volume, operating income. The result of RTS Region and MPSS shows that 9 DMUs of the efficiency frontier in the Construction Industry are analyzed to be relatively efficient DMUs, and 41 DMUs are analyzed to be inefficient DMUs, and finally inefficient DMUs are separated with Region 1 and Region 6.

디젤 엔진 운전 조건에서 분무 연소 과정과 난류 화염 구조 특성에 대한 해석 (Characteristization of Spray Combustion and Turbulent Flame Structures in a Typical Diesel Engine Condition)

  • 이영재;허강열
    • 한국연소학회지
    • /
    • 제14권3호
    • /
    • pp.29-36
    • /
    • 2009
  • Simulation is performed to analyze the characteristics of turbulent spray combustion in a diesel engine condition. An extended Conditional Moment Closure (CMC) model is employed to resolve coupling between chemistry and turbulence. Relevant time and length scales and dimensionless numbers are estimated at the tip and the mid spray region during spray development and combustion. The liquid volume fractions are small enough to support validity of droplets assumed as point sources in two-phase flow. The mean scalar dissipation rates (SDR) are lower than the extinction limit to show flame stability throughout the combustion period. The Kolmogorov scales remain relatively constant, while the integral scales increase with decay of turbulence. The chemical time scale decreases abruptly to a small value as ignition occurs with subsequent heat release. The Da and Ka show opposite trends due to variation in the chemical time scale. More work is in progress to identify the spray combustion regimes.

  • PDF

농촌 소유역 수환경 개선을 위한 유역관리 협의체 구성방안 - 함평천 사례를 중심으로 - (Framework of Watershed Management Organization Consortium for Water Environment Improvement of Small Rural Watershed)

  • 이기완;김영주;윤광식
    • 농촌계획
    • /
    • 제11권4호
    • /
    • pp.59-65
    • /
    • 2005
  • Proper management of small rural watershed is important since it does affect water quality improvement of larger scale watershed. Therefore, effective small watershed management guideline including participatory program of local people is required to achieve water environment improvement. Feasibility of water quality goal, short and long-term watershed management plan and funding sources were investigated by field monitoring of Hampyungchun watershed which has characteristics of rural stream, and literature review. The relevant parties and their roles fer watershed management were identified and suggested. A hybrid model, that is mixture of government driven model and NGO model, is recommended for watershed management organization in this study.

Reynolds number and scale effects on aerodynamic properties of streamlined bridge decks

  • Ma, Tingting;Feng, Chaotian
    • Wind and Structures
    • /
    • 제34권4호
    • /
    • pp.355-369
    • /
    • 2022
  • Section model test, as the most commonly used method to evaluate the aerostatic and aeroelastic performances of long-span bridges, may be carried out under different conditions of incoming wind speed, geometric scale and wind tunnel facilities, which may lead to potential Reynolds number (Re) effect, model scaling effect and wind tunnel scale effect, respectively. The Re effect and scale effect on aerostatic force coefficients and aeroelastic characteristics of streamlined bridge decks were investigated via 1:100 and 1:60 scale section model tests. The influence of auxiliary facilities was further investigated by comparative tests between a bare deck section and the deck section with auxiliary facilities. The force measurement results over a Re region from about 1×105 to 4×105 indicate that the drag coefficients of both deck sections show obvious Re effect, while the pitching moment coefficients have weak Re dependence. The lift coefficients of the smaller scale models have more significant Re effect. Comparative tests of different scale models under the same Re number indicate that the static force coefficients have obvious scale effect, which is even more prominent than the Re effect. Additionally, the scale effect induced by lower model length to wind tunnel height ratio may produce static force coefficients with smaller absolute values, which may be less conservative for structural design. The results with respect to flutter stability indicate that the aerodynamic-damping-related flutter derivatives 𝘈*2 and 𝐴*1𝐻*3 have opposite scale effect, which makes the overall scale effect on critical flutter wind speed greatly weakened. The most significant scale effect on critical flutter wind speed occurs at +3° wind angle of attack, which makes the small-scale section models give conservative predictions.

Food Distribution System in Vietnam: Nash Equilibrium and Channel Choice of Small Scale Farmers

  • NGO, Chi Thanh
    • 유통과학연구
    • /
    • 제19권1호
    • /
    • pp.61-73
    • /
    • 2021
  • Purpose: The transition from a traditional to a modern food distribution system induces several adjustments on the supply side since supermarkets must collect food on a larger scale and with higher quality standards. This situation becomes a real challenge for small scale farmers to access supply in a modern distribution channel. This gives rise to an original solution: supplying supermarkets through farmer associations or cooperatives. Based on this context of Vietnam linking to the case of distribution science, the paper proposes an industrial organization model of the food processing system in developing countries. The model presents the competitive relationship between two competing distribution systems: a traditional and a modern one. The former is composed of several retailers that sell their products on the traditional market while the latter is based on cooperatives that collect food and negotiate with supermarkets. The current study is to discuss the conditions under which the evolution of the food distribution system occurs by using the proposed model. Research design, data, and methodology: Based on the proposed model, the study explored the quantity flow from small producers to consumers through a Nash equilibrium and address the question of farmer repartition by a free-entry equilibrium. Results: The result shows that there is a unique positive equilibrium in the food market with participation of cooperative associations; Since farmers serve cooperative associations, they not only receive quantity incentive prices but also share profits within their organization. Conclusions: This study shows a unique distribution equilibrium where the profits of farmers working for middlemen and cooperatives are maximized. Further insights were discussed.

Pose Estimation with Binarized Multi-Scale Module

  • Choi, Yong-Gyun;Lee, Sukho
    • International journal of advanced smart convergence
    • /
    • 제7권2호
    • /
    • pp.95-100
    • /
    • 2018
  • In this paper, we propose a binarized multi-scale module to accelerate the speed of the pose estimating deep neural network. Recently, deep learning is also used for fine-tuned tasks such as pose estimation. One of the best performing pose estimation methods is based on the usage of two neural networks where one computes the heat maps of the body parts and the other computes the part affinity fields between the body parts. However, the convolution filtering with a large kernel filter takes much time in this model. To accelerate the speed in this model, we propose to change the large kernel filters with binarized multi-scale modules. The large receptive field is captured by the multi-scale structure which also prevents the dropdown of the accuracy in the binarized module. The computation cost and number of parameters becomes small which results in increased speed performance.

원자로 연료봉내 대형 와유동에 의한 원자로 냉각제 시스템의 난류 증진 (Turbulent Enhancement of the Cooling System of Nuclear Reactor by Large Scale Vortex Generation in a Nuclear Fuel Bundles)

  • 전건호;박종석;최영돈
    • 설비공학논문집
    • /
    • 제12권11호
    • /
    • pp.1004-1011
    • /
    • 2000
  • Experimental and computational studies were carried out to confirm the turbulent enhancement of the cooling system of nuclear reactor by large scale vortex generation in nuclear fuel bundle. The large scale vortex motions were generated by rearranging the inclination angles of mixing vanes to the coordinate directions. Axial development of mean and turbulent velocities in the subchannels were measured by the 2-color LDV system. Eddy diffusivity heat flux model and $k-varepsilon$ model were employed to analyze the turbulent heat and fluid flows in the subchannel. The turbulence generated by split mixing vanes has small length scales so that they maintain only about $10 D_H$ after the spacer grid. On the other hand, the turbulences generated by the large scale vortex continue more and remain up to $25 D_H$after the spacer gird.

  • PDF

소규모 제조기업의 효율적 재고관리를 위한 재고속성에 관한 연구 (A Study on the Properties of Inventory for Efficient Inventory Control at Small-scale Manufacturing Company)

  • 김기범;남곤;정용문;허세민
    • 한국산학기술학회논문지
    • /
    • 제21권12호
    • /
    • pp.449-455
    • /
    • 2020
  • 재고관리는 고객주문에 대한 대응수준을 결정짓는 중요한 관리항목 중의 하나이다. 고객의 니즈가 다양화해짐에 따라 생산하는 품목의 수가 증가하고 제품 수명주기가 단축됨에 따라 제조기업에 있어 재고관리의 중요성은 높아지고 있다. 그러나 소규모 제조기업에 있어 재고관리를 위해 IT시스템에 투자하는 것은 현실적으로 어려운 부분이 많다. 이에 본 연구에서는 소규모 제조기업에서 쉽고 빠르게 적용할 수 있는 재고관리 방법론을 다루고자 한다. 우선 재고속성의 개념을 정의하고, 재고의 월령과 수량에 따라 양성과 악성으로 구분할 수 있는 분석 방법론을 제안한다. 다음으로 재고속성에 따라 제품 보관 창고 내의 위치를 관리하기 위한 기준을 제안한다. 그리고 인테리어 벽지 제조기업을 대상으로 제안한 방법론을 적용함으로써 기존의 재고관리 방식의 비효율성을 인식하고, 재고관리에 대한 새로운 기준을 세울 수 있음을 검증한다. 본 연구에서 제안한 재고관리 방법론은 소규모 제조기업의 현장개선 활동의 일환으로 즉시 적용할 수 있는 관리 항목으로, 재고관리 활동을 통해 장기재고로 인한 낭비요인을 줄이고 창고의 여유 보관용량을 확보할 수 있을 것으로 기대한다.

위탁급식전문업체의 급식소 식수 규모별 노동생산성 비교 분석에 따른 인력산정 모델 개발 (Development of Standardized Model of Staffing Demand through Comparative Analysis of Labor Productivity by Foodservice's Meal Scale in Contract Foodservice Management Company)

  • 박문경;조선경;차진아;양일선
    • Journal of Nutrition and Health
    • /
    • 제39권4호
    • /
    • pp.417-425
    • /
    • 2006
  • The purpose of this study were to a) investigate operation of human resource in contract foodservice management company (CFMC), b) identify the staffing indices for the establishment an labor productivity for CFMC, and c) develop standardized model of staffing demand as foodservice's scale in CFMC. The data was collected using FS intra-net system from 138 contract-managed foodservice operations in A CFMC and statistical analysis was completed using the SAS/win package (ver. 8.0) for description analysis, ANOVA, Duncan multiple comparison, pearson correlation analysis, and regression analysis. The types of operation were included factory (45%), small scale operation (26%), office (11%), department store (10%), training institute (4%), and hospital (3%). The distribution of foodservice scale was classified by meal served was as follows; 'less than 500 meals (47%)', 'from 500 to 1500 meals (25%)', 'from 1500 to 2500 meals (17%)', and 'more than 2500 meals (12%)'. There was two types of contract method, fee-contract (53%) and profit-and-loss contract (46%) Some variables were significantly high operation indices such as selling price, food cost, monthly sales, net profit and others were significantly low operation indices such as labor, meal time a day in the small foodservice on meal scale (p<.001). The more foodservice was large, the more human resource was disposed on dietitian, cook, cooking employee altogether (p<.001). Foodservice in A CFMC was divided into 2 groups by 500 meals a day, according to comparative analysis of labor productivity as meal scale per working hour, meal scale a day and operation indices as meal per foodservice employee, meal per cooking employee (p<.001). The regression equation model was developed as 'the number of employees=1.82+0.014 ${\times}$ meal served' in the operation of less than 500 meals, 'the number of employees=9.42+0.013 ${\times}$ meal scale a day -0.94 ${\times}$ meal scale per working hour' in the operation over 500 meal scale using labor productivity indices and operation indices. Therefore, CFMC could be enhanced efficiency of human resource arrangement using the standardized model of staffing demand and would be increased effectiveness of profit.

3D Animation 제작 파이프라인 연구 - 국내 소규모 3D애니메이션 제작을 중심으로 - (A study on the System Process of Production pipeline of 3D animation)

  • 양성수
    • 한국콘텐츠학회:학술대회논문집
    • /
    • 한국콘텐츠학회 2008년도 춘계 종합학술대회 논문집
    • /
    • pp.198-202
    • /
    • 2008
  • 대규모 3D 컴퓨터애니메이션의 제작공정은 제작기술의 발전과 예산의 대규모화로 인해 그 구조가 더욱 복잡화, 세분화, 되고 있으며, 프로덕션타입, 제작규모, 제작방식과 같은 유형에 따라 제작 파이프라인의 형태가 다양하게 변화되고 있다. 하지만, 소규모 제작업체에서는 제작 파이프라인의 개념과 그 구성에 대한 변화와 발전이 미비하여 이에 대한 재조명이 필요할 때이다. 이러한 연구의 배경을 주목하여 본 연구는 국내 소규모 3D애니메이션의 제작 파이프라인에 대한 이해를 돕고, 소규모 국내 프로덕션 실정에 맞는 3D애니메이션 제작 파이프라인의 구성 방안을 모색 하고자하는데 그 목적을 가진다. 본 연구에서 제시하는 소규모 3D애니메이션의 제작 파이프라인 구성 모델과 방법론은 프로젝트의 성향이나 주변 환경에 따라 충분히 변화 가능한 것이기 때문에 절대적인 것만은 아니며, 3D 컴퓨터애니메이션 제작 파이프라인의 구성을 위해서는 그 목적을 충분히 이해하고, 프로덕션내의 작업자간의 정보의 공유가 충분히 이루어질 수 있도록 소규모 프로덕션의 환경을 고려하여 상황에 맞추어 구성 할 수 있는 방법이 될 것이라고 생각한다.

  • PDF