• Title/Summary/Keyword: Performance scale

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Characteristics of Absorption Heat Transfer on Micro-Scale Hatched Tubes with Different Surface Roughness (미소해칭 전열관의 표면거칠기에 따른 흡수열전달 특성)

  • 조현철;김춘동;김익생;박찬우;강용태
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.8
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    • pp.641-647
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    • 2002
  • Objectives of this paper are to investigate the effect of roughness of micro-hatching tubes on the absorption performance and to develop on experimental correlation of Nusselt as a function of the roughness. Three different micro-scale hatched tubes and a bare tube were tested in the present experiment. $H_{2}O/LiBr$ solution is used as working fluid. It was found that absorption performance of micro-scale hatched tubes were improved upto 2 times with an error band of ${\pm}25%$ compared with the bare tube. An experimental correlation of Nusselt was developed as a function of the roughness.

Model-Ship Correlation Study on the Powering Performance for a Large Container Carrier

  • Hwangbo, S.M.;Go, S.C.
    • Journal of Ship and Ocean Technology
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    • v.5 no.4
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    • pp.44-50
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    • 2001
  • Large container carriers are suffering from lack of knowledge on reliable correlation allowances between model tests and full-scale trials, especially at fully loaded condition, Careful full-scale sea trial with a full loading of containers both in holds and on decks was carried out to clarify it. Model test results were analyzed by different methods but with the same measuring data to figure out appropriated correlations factors for each analysis methods, Even if it is no doubt that model test technique is one of the most reliable tool to predict full scale powering performance, its assumptions and simplifications which have been applied on the course of data manipulation and analysis need a feedback from sea trial data for a fine tuning, so called correlation factor. It can be stated that the best correlation allowances at fully loaded condition for both 2-dimensional and 3-dimensional analysis methods are fecund through the careful sea trial results and relevant study on the large size container carriers.

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Performance Simulation of Part Load Operation for 2MWe Circulating Fluidized Bed Boiler (2MWe 순환유동상 보일러의 부분 부하 운전 성능 모사)

  • Kim, Taehyun;Choi, Sangmin;Hyun, Ju-soo
    • 한국연소학회:학술대회논문집
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    • 2012.04a
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    • pp.35-36
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    • 2012
  • Part load operation usually covers large periods of the total operation time on the economic ground and electricity demand in small-scale boilers. Performance analysis of part load behavior is very important for the purpose of boiler operation optimization. A simple thermal calculation approach is applied to predict performance of a pilot-scale circulating fluidized bed (CFB) boiler at part load operation. Verification has been carried out by comparing between calculation results an operation data of the boiler.

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A study on the performance of wastewater treatment with the pilot-scale reactor (Pilot 규모의 반응기를 이용한 폐수처리에 관한 연구)

  • 서명교;최윤찬;서정호;노종수;이근복;김의용
    • Journal of Environmental Health Sciences
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    • v.22 no.4
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    • pp.10-15
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    • 1996
  • Treatment of a synthetic wastewater was made for the purpose of evaluating the performance of a pilot scale of an IFBBR. The particles used in this experiment were circular shaped polystyrene whose density was lower than that of water. The reactor volume was 400 l and the SCOD removal efficiency was more than 90% at HRT of 5 hrs. The IFBBR was successfully operated for 5 months without any significant problems. And it whs certained that IFBBR had a potential capability for treating wastewater.

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Comparative Performance Evaluation of Advanced Daylighting Glazing Systems by Scale Model Measurements (축소모형을 이용한 가변 유리투과체의 채광유형별 성능평가 비교)

  • Jeong, In Young;Kim, Jeong Tai
    • KIEAE Journal
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    • v.4 no.3
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    • pp.27-35
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    • 2004
  • The conventional way to acquire sufficient amount of daylight in interiors is to provide large openings with clear glass. The use of clear glass on the whole facade, however, might cause a sort of visual problem because of the harness of direct sun and brighter sky surface than expected. They should be filtered in opticalway or bounced in the architectural. One of the common solutions for the problem might be the use of photometric glasses with various transmittances for the glass walls. This paper deals with performance data related to the impact of various transmittal glazing materials for window systems in terms of daylighting. A series of scale model measurements was carried out with the fundamental configuration of a commonly used all-glass facades. Additionally some experimental performance index was issued for the better expression of the need of natural lighting.

A Comparative Study of the Success Factors of Quality on Business Performance : Focused on Business Scale (품질성공요소가 경영성과에 미치는 영향에 관한 비교연구 : 기업규모를 중심으로)

  • Ko, Young-Hak;Chung, Young-Bae
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.35 no.3
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    • pp.225-233
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    • 2012
  • The purpose of this study is to observe effect on a result of a business performance depending on the business scale and the success factors of quality. Verified hypothesis of the quality of success factors and business performance are conducted in order to conduct this research. The results of hypothesis testing can be summarized as follows : First, depending on the size of the company, quality of corporate success factors in the management and significant positive was verified to be in effect. Second, depending on the size of the small business companies' human resource management, product/process is significantly positive in effect and medium companies' quality information, quality of suppliers in the commercialization of technology is significantly positive in effect. Third, depending on the size of the small business companies' human resource management, product/process financial performance is significantly positive in effect and mid-sized companies, suppliers in the quality significantly positive show the influence of financial performance. The results of measurement through the size of the enterprise and the successful factors of quality impacts on business performance directly.

Effects of Head Nurses' Managerial Competencies and Professional Nurse Autonomy in Nursing Performance (수간호사의 관리역량과 전문직 자율성 인식이 간호업무성과에 미치는 영향)

  • Kim, Young Soon;Eo, Yong Sook;Lee, Nae Young
    • Journal of Korean Academy of Nursing Administration
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    • v.20 no.4
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    • pp.437-445
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    • 2014
  • Purpose: The aim in this study was to identify head nurses' nursing performance according to their managerial competencies and professional nurse autonomy. Methods: From January 15 to January 31, 2013 a survey was distributed to 200 head nurses working in 5 tertiary hospitals in B city and J city. The response rate was 80% (160 responses). The survey content included the Managerial Competencies Scale (MCS), Schutzenhofer professional nurse autonomy Scale (SPNA), and Nursing Performance Scale (SPNA). Results: The score for MCS was 4.53, for SPNA, 177.05, and for SPNA, 4.62. Nursing performance was related to managerial competencies (${\beta}=0.741$; p<.001; SE=0.059) and professional autonomy (${\beta}=0.135$; p=.010; SE=0.001). These factors accounted for 64.8~67.3% of the variability in nursing performance. Conclusion: Results indicate that head nurses' performance would be improved through increased nursing managerial competencies and expansion of professional autonomy suggesting a need to develop work systems designed to achieve high managerial competency and professional autonomy in head nurses.

Extrapolation of wind pressure for low-rise buildings at different scales using few-shot learning

  • Yanmo Weng;Stephanie G. Paal
    • Wind and Structures
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    • v.36 no.6
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    • pp.367-377
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    • 2023
  • This study proposes a few-shot learning model for extrapolating the wind pressure of scaled experiments to full-scale measurements. The proposed ML model can use scaled experimental data and a few full-scale tests to accurately predict the remaining full-scale data points (for new specimens). This model focuses on extrapolating the prediction to different scales while existing approaches are not capable of accurately extrapolating from scaled data to full-scale data in the wind engineering domain. Also, the scaling issue observed in wind tunnel tests can be partially resolved via the proposed approach. The proposed model obtained a low mean-squared error and a high coefficient of determination for the mean and standard deviation wind pressure coefficients of the full-scale dataset. A parametric study is carried out to investigate the influence of the number of selected shots. This technique is the first of its kind as it is the first time an ML model has been used in the wind engineering field to deal with extrapolation in wind performance prediction. With the advantages of the few-shot learning model, physical wind tunnel experiments can be reduced to a great extent. The few-shot learning model yields a robust, efficient, and accurate alternative to extrapolating the prediction performance of structures from various model scales to full-scale.

A Basic Study on the Space-Program in Performance Facilities (공연시설의 스페이스프로그램에 관한 기초적 연구)

  • Hwang Mee-Young;Ko Jae-Min
    • Korean Institute of Interior Design Journal
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    • v.15 no.1 s.54
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    • pp.113-120
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    • 2006
  • This study analyzes the space composition and the construction system of performance facilities, and research the area construction ratio of each necessary space to establish the specialized performance facilities. This study aims the exclusive facilities for opera among the various performance facilities at home and abroad. The results are as following, 1) Performance space is divided into Public space, Performance space and Administration space on the basis of user. 2) The difference in the scale of performance facilities depends on the fractionation of performance supporting facilities and the grade of specialty rather than the number of seats. 3) The scale and zoning of space in the performance facilities to be built in the future, it is necessary to consider ensuring the production support space, the organic connection of support space and the integrated public space.

Performance Management of Communication Networks for Computer Intergrated Manufacturing (컴퓨터 통합 생산을 위한 통신망의 성능 관리)

  • Lee, S.
    • Journal of the Korean Society for Precision Engineering
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    • v.11 no.4
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    • pp.126-137
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    • 1994
  • Performance management of computer networks is intended to improve a given network performance in order for more efficient information exchange between subsystems of an integrated large-scale system. Importance of perfomance management is growing as many functions of the large- scale system depend on the quality of communication services provided by the network. The role of performance management is to manipulate the adjustable protocol parameters on line so that the network can adapt itself to a dynamic environment. This can be divided into two subtasks : performance evaluation to find how changes in protocol parameters affect the network performance and decision making to determine the magnitude and direction of parameter adjustment. This paper is the first part of the two papers focusing on conceptual design, development, and evaluation of performance management for token bus networks. This paper specifically deals with the task of performance evaluation which utilizes the principle of perturbation analysis of discrete event dynamic systems. The developed algorithm can estimate the network performance under a perturbed protocol parameter setting from observations of the network operations under a nominal parameter setting.

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