• 제목/요약/키워드: engineering performance

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사고 영향 분석을 이용한 성능위주의 내화설계 (Performance Based Design of Passive Fire Protection Using Consequence Analysis)

  • 한동훈;이종호
    • 한국안전학회지
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    • 제19권1호
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    • pp.102-107
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    • 2004
  • Performance based design is a recent evolutionary step in the process of designing fire protection systems. In essence, it is a logical design process resulting in a solution that achieves a specified performance. Sometimes the prescriptive solutions presented in various codes and standards are too expensive or inflexible. Often the solutions do not and enables optimization of a solution for cost and function. In this study, performance based design was carried out to determine the extent of passive fire protection for oil terminal facilities. The results of performance based design were compared with those of prescriptive code based design. Performance based design is not always more economic than prescriptive code based design but provides more reliable and effective design that is fit for the purpose.

3차원 소형축류홴의 공력특성에 대한 난류모델평가 (Evaluation of the Turbulence Models on the Aerodynamic Performance of Three-Dimensional Small-Size Axial Fan)

  • 김장권;오석형
    • 동력기계공학회지
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    • 제18권6호
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    • pp.13-20
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    • 2014
  • The steady-state, incompressible and three-dimensional numerical analysis was carried out to evaluate turbulent models on the aerodynamic performance of a small-size axial fan(SSAF). The prediction performance on the static pressure of all turbulent models is going downhill at the high static pressure and low flowrate region, but has improved at the axial flow region. In consequence, all turbulent models predict the static pressure coefficient with an error performance less than about 4% after the region of the flowrate coefficient of about 0.14. Especially, the turbulent model of SST $k-{\omega}$ shows the best prediction performance equivalent to an error performance less than about 2% on the static pressure.

A-GNSS Performance Test in Various Urban Environments by Using a Commercial Low Cost GNSS Receiver and Service

  • Han, Kahee;Lee, Jung-Hoon;Im, Ji-Ung;Won, Jong-Hoon
    • Journal of Positioning, Navigation, and Timing
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    • 제7권4호
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    • pp.205-215
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    • 2018
  • The recent emergence of new Global Navigation Satellite Systems (GNSS) has resulted in a gradual improvement in the performance of positioning services. This paper verifies the degree of improvement in positioning performance of Assisted-GNSS (A-GNSS) receivers using assistance information compared to standalone-GNSS receivers that do not use assistance information in various urban environments in Korea. For this purpose, field tests are performed in various urban and indoor environments in Korea. The assistance information is provided by u-blox's AssistNow Online and low-cost commercial receivers are used for mobile station receivers. Through experiments, the Time to First Fix (TTFF), acquisition sensitivity, and position accuracy performance improvement are analyzed. The results of the experiments show that using assistance data improved the performance in all experiment locations, and, in particular, a significant performance improvement in terms of TTFF.

Performance measurement of safety-critical systems based on ordinary differential equations and Petri nets: A case study of nuclear power plant

  • Nand Kumar Jyotish;Lalit Kumar Singh;Chiranjeev Kumar
    • Nuclear Engineering and Technology
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    • 제55권3호
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    • pp.861-869
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    • 2023
  • This article proposes a novel approach to measure the performance of Safety-Critical Systems (SCS). Such systems contain multiple processing nodes that communicate with each other is modeled by a Petri nets (PN). The paper uses the PN for the performance evaluation of SCS. A set of ordinary differential equations (ODEs) is derived from the Petri net model that represent the state of the system, and the solutions can be used to measure the system's performance. The proposed method can avoid the state space explosion problem and also introduces new metrics of performance, along with their measurement: deadlock, liveness, stability, boundedness, and steady state. The proposed technique is applied to Shutdown System (SDS) of Nuclear Power Plant (NPP). We obtained 99.887% accuracy of performance measurement, which proves the effectiveness of our approach.

QUANTITATIVE ANALYSIS ON PROJECT PERFORMANCE ANALYSIS AND DELIVERY METHODS

  • Seta Ohanesian;Jin-Lee Kim;Tang-Hung Nguyen;Ok-Kyue Kim
    • 국제학술발표논문집
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    • The 5th International Conference on Construction Engineering and Project Management
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    • pp.332-337
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    • 2013
  • Various project delivery methods have been utilized by owners over the years to maximize project performance. The design-build delivery method is being increasingly used due to the advantages it can offer to an engineering construction industry. Numerous studies have advocated the use of design/build over the traditional design/bid/build delivery approach. This study represents comprehensive analysis of 40 projects from the construction industry and shows that design/build method may not provide all the benefits to project performance. This study found timesaving was a definitive advantage of design/build project delivery, but the positive effects of cost changes was not convincing. Based on the results of the study, the project management expertise and experience of the contractor may have a greater impact on project performance outcomes than focusing on project delivery strategy only.

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섬유종류 및 혼입량에 따른 고성능콘크트의 폭열저감에 관한 실험적 연구 (An Experimental study on Reduction Effect to Explosive spalling of high performance concrete by Fiber Type and Volume Fraction of Fiber)

  • 나철성;신관수;김영선;권영진;김규용;김무한
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 2005년도 공동추계학술논문발표회 논문집
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    • pp.81-85
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    • 2005
  • Recently, fire resistance of high performance concrete for explosive spalling was issued as high performance concrete was vulnerable to the explosive spalling in initial fire. Therefore, in this study, an experiment about reduction effect to explosive spalling of high performance concrete is performed by adding several polymer fiber with various volume fraction, an then final fiber and volume fraction of that which reduce the explosive spalling of high performance concrete is presented. As the result of this study, the most fitted fiber volume fraction of reducing effect for explosive spalling at high performance concrete is under the 0.1%, as consider the flowability and efficiency.

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ROADWAY PERFORMANCE EVALUATION USING FUNCTION ANALYSIS METHOD OF VALUE ENGINEERING

  • Jong-Hyun Park;Yong-Jang Lee;In-Su Jung;Chan-Sik Lee
    • 국제학술발표논문집
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    • The 3th International Conference on Construction Engineering and Project Management
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    • pp.1528-1533
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    • 2009
  • Infrastructure is provided to the user through long-term project period and large-scale working expenses. Existing facilities are getting old as time goes by. Accordingly, proper maintenance is required and generally more maintenance cost than initial invested cost is needed during life cycle. Therefore, a specific plan that just increases the value of facilities is required by evaluating performance of facilities and inputting minimum maintenance cost. Value engineering that increases the value of object by systemically analyzing Life Cycle Costs and function is actively promoted at the design phase of construction. These efforts can increase the performance of facilities at the maintenance phase of infrastructure. This study is to search how to evaluate the performance of Roadway by utilizing function analysis, as a core part of VE in the maintenance phase. In order to this a new evaluation criteria were proposed by adding an evaluation items to the existing criteria through the research of old documents, status of roadway maintenance and function analysis of VE. The results of this study may promote the effective performance evaluation to determine a resolution of roadway congestion in future. A succeeding study using the proposed evaluation criteria will be required.

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EPAR V2.0: AUTOMATED MONITORING AND VISUALIZATION OF POTENTIAL AREAS FOR BUILDING RETROFIT USING THERMAL CAMERAS AND COMPUTATIONAL FLUID DYNAMICS (CFD) MODELS

  • Youngjib Ham;Mani Golparvar-Fard
    • 국제학술발표논문집
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    • The 5th International Conference on Construction Engineering and Project Management
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    • pp.279-286
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    • 2013
  • This paper introduces a new method for identification of building energy performance problems. The presented method is based on automated analysis and visualization of deviations between actual and expected energy performance of the building using EPAR (Energy Performance Augmented Reality) models. For generating EPAR models, during building inspections, energy auditors collect a large number of digital and thermal imagery using a consumer-level single thermal camera that has a built-in digital lens. Based on a pipeline of image-based 3D reconstruction algorithms built on GPU and multi-core CPU architecture, 3D geometrical and thermal point cloud models of the building under inspection are automatically generated and integrated. Then, the resulting actual 3D spatio-thermal model and the expected energy performance model simulated using computational fluid dynamics (CFD) analysis are superimposed within an augmented reality environment. Based on the resulting EPAR models which jointly visualize the actual and expected energy performance of the building under inspection, two new algorithms are introduced for quick and reliable identification of potential performance problems: 1) 3D thermal mesh modeling using k-d trees and nearest neighbor searching to automate calculation of temperature deviations; and 2) automated visualization of performance deviations using a metaphor based on traffic light colors. The proposed EPAR v2.0 modeling method is validated on several interior locations of a residential building and an instructional facility. Our empirical observations show that the automated energy performance analysis using EPAR models enables performance deviations to be rapidly and accurately identified. The visualization of performance deviations in 3D enables auditors to easily identify potential building performance problems. Rather than manually analyzing thermal imagery, auditors can focus on other important tasks such as evaluating possible remedial alternatives.

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학습성과 수행평가를 위한 루브릭 개발과 적용에 관한 연구 (A Study on the Development and Application of Rubrics for Performance Assessment in Terms of Promoting Program Learning Outcomes)

  • 신민희
    • 공학교육연구
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    • 제15권5호
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    • pp.108-118
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    • 2012
  • The purpose of this study was to provide analytic rubrics for measuring teamwork(PO6), communication and presentation skills(PO7), and life-long learning(PO8) based on theoretical concepts of performance assessment and rubrics. Also, this study analyzed data about performance assessment and rubics from courses offered through college of engineering. Participants were 34 senior engineering students who took the course 'Technical writing and presentation'. In the second week of the course, students were given the pre-test instrument which was developed for measuring students' understanding of program outcomes for this study. After performing project activities using rubrics, students were encouraged to complete the post-test instrument and the reaction questionnaire during the ninth week. The data were analyzed by using SPSS 14.0 and Microsoft Excel. The research findings are as follows. First, to promote and evaluate program learning outcomes appropriately, performance assessment-based on rubircs should be implemented. Second, in the reaction questionnaire about the rubircs, students answered that using rubircs for performing the project was very useful for understanding the performance procedures and assessment criteria. Third, the mean of understanding of program outcomes of students in post-test was significantly increased than in the pre-test(p<.0001). From the findings, performance assessment and rubrics should be used as evaluation tools at course levels in terms of promoting program learning outcomes for engineering education.

The Role of Industrial Clustering and Manufacturing Flexibility in Achieving High Innovation Capability and Operational Performance in Indonesian Manufacturing SMEs

  • Purwanto, Untung Setiyo;Kamaruddin, Shahrul;Mohamad, Norizah
    • Industrial Engineering and Management Systems
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    • 제14권3호
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    • pp.236-247
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    • 2015
  • This study aims to examine the effects of industrial clustering and manufacturing flexibility on innovation capability and operational performance. This study follow a survey method to collect data pertaining to the phenomena of industrial clustering, manufacturing flexibility, innovation capability, and operational performance by utilizing a single respondent design. A total of 124 Indonesian manufacturing SMEs are taken to test the proposed theoretical model by utilizing covariance-based structural equations modeling approach. It was found that both industrial clustering and manufacturing flexibility was positively associated with operational performance and innovation capability as well. In addition, innovation capability may account for the effects of industrial clustering and manufacturing flexibility on operational performance. This implies that manufacturing SMEs have to reorient their production and operation perspectives, including agglomerate with other similar or related SMEs to develop and utilize their own resources. The SMEs also need to possess some degree of manufacturing flexibility in respond to the uncertain environment and market changes. In addition, the SMEs should put a greater emphasize to use industrial cluster and manufacturing flexibility benefits to generate innovation capability to achieve high performance.