• The KSFM Journal of Fluid Machinery
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• v.12 no.2
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• pp.31-38
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• 2009

The valve performance has been evaluated from the theoretical equation based on design information such as packing thrust, spring preload and friction coefficient(${\mu}$). The accuracy of those data can be lower than that of vendor's initial design data. Especially, the friction coefficient can be degraded with time than the original condition and the valve performance calculated using the previous friction coefficient can not be available. Accordingly, this paper is describing a new performance evaluation method of valve based on diagnostic test data which are acquired from a site valve tested in static and dynamic conditions. Especially, this paper provides a new method using friction coefficient(${\mu}$) which is derived from the diagnostic test data acquired in the valve's design basis condition.

• Journal of the Korea Safety Management & Science
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• v.17 no.2
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• pp.89-96
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• 2015

The weapon systems development has some distinct characteristics in that a big size of government budget (derived from national tax) has been expended frequently and the completion of the development projects seems to take long. Thus, the impact of the potential changes in the required operational capability on the development activities can induce some type of project risks. As such, proper management of project risk has been one of crucial subjects in the weapon systems development. Although a variety of methods can be considered, an approach based on the test and evaluation (T&E) process has been selected in this paper in order to appropriately handle those potential risks. In the study of the underlying T&E process, the safety consideration (for instance, explosiveness) of weapon systems is also included. To achieve the objective of the paper, a step-by-step procedure is first presented in the analysis of the T&E process. Then, to pursue some enhancement on the process, a set of necessary and useful activities are added in terms of risk and safety management. The resultant process is further analyzed and tailored based on a design structure matrix method. The case study of a tank development is also discussed.

• Proceedings of the Korean Society for Information Management Conference
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• 2002.11a
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• pp.23-65
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• 2002

This study is to consider varying factors of internal/external informational and operational environments in libraries, and develop a new evaluation indicators for university libraries in digital environments. In order to do this research, the previous works have been investigated, and the Delphi study and our own analysis have been performed. The main research results are as follows. First, the results through the Delphi method that was to adopted to verify evaluation items and indicators determined by the literature review show that the repressed values for each evaluation category is greater than 3.00. overall average is 4.02. and standard deviation is ranged from 0.40 to 0.62 for each category. This means that the evaluation indicators are valid. Second, the factor analysis was performed to verify the construct validity of evaluation indicators. As a result. the cumulative variance of evaluation indicators consisting of 11 dimensions per factor is 72.733%. In turn, this result shows that the validity of these indicators is very reliable. Third, t-test and one way ANOVA are performed within significance probability 0.05 in order to verify differences in each librarians point of views for the degree of importance in evaluation indicators. The results show that these evaluation indicators are verified to be appropriate since there is no significant difference. Based on the Delphi study and our own analysis. we developed a new evaluation indicators that consists of 7 evaluation categories, 35 evaluation items, and 92 evaluation indicators.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.5
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• pp.882-889
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• 2010

This paper presents a method of finding the optimal operating point minimizing a given objective function with 3 phase power flow equations and operational constraints, called 3 phase optimal power flow (3POPF). 3 phase optimal power flow can provide operation and control strategies for the distribution systems with distributed generation assets, which might be frequently in unbalanced conditions assuming that high penetration rate of renewable energy sources in the systems. As the solution technique for 3POPF, this paper adopts a simulation-based method of particle swarm optimization (PSO). In the PSO based 3POPF, a utility function needs to be defined for evaluation of the degree in operational improvement of each particle's current position. To evaluate the utility function, in this paper, NR-based 3 phase power flow algorithm was developed which can deal with looped distributed generation systems. In this paper, illustrative examples with a 5-bus and a modified IEEE 37-bus test systems are given.

• Land and Housing Review
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• v.15 no.3
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• pp.79-95
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• 2024

Over the past decade, urban regeneration projects have been actively promoted nationwide in South Korea, leading to the establishment of numerous community facilities aimed at fostering community engagement and revitalization. Recently, the need for diagnostic tools to provide appropriate support and guidance for the sustainable operation of these facilities has been increasingly emphasized. However, a comprehensive manual or nationwide standard approach remains lacking. As such, this study aims to propose evaluation criteria and their application methods for the periodic operational assessment of those facilities. First, through a review of previous studies, candidate indicators were identified. After that, preliminary indicators and frameworks were determined through expert consultations, followed by surveys conducted with 65 experts to finalize the evaluation indicators. The survey results highlighted the importance of 'Value Creation (VC)' and 'Operation Management (OM)' as key aspects of facility evaluation. In assessing VC, key factors include enhancing community vitality, strengthening local capacity, providing tailored functions for the community, and contributing to the local economy. In constructing OM, the focus lies on operational system, financial management, operational personnel, and economic viability and sustainability. This study proposes an evaluation framework that includes the final evaluation indicators and available data sources for each indicator, and a pilot test was conducted to verify its applicability. Moreover, the study suggests directions for utilizing the evaluation criteria and methods for applying indicators tailored to the characteristics of individual facilities.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.4
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• pp.602-613
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• 2015

As one of the mission payloads to be verified through the cube satellite mission of Cube Laboratory for Space Technology Experimental Project (STEP Cube Lab), we developed a hinge driving separation nut-type holding and releasing mechanism. The mechanism offers advantages, such as a large holding capacity and negligible induced shock, although its activation principle is based on a nylon cable cutting mechanism triggered by a nichrome burn wire generally used for cube satellite applications for the purpose of holding and releasing onboard appendages owing to its simplicity and low cost. The basic characteristics of the mechanism have been measured through a release function test, static load test under qualification temperature limits, and shock measurement test. In addition, the structural safety and operational functionality of the mechanism module under launch and on-orbit environments have been successfully demonstrated through a vibration test and thermal vacuum test.

• Journal of the Korea Convergence Society
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• v.5 no.4
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• pp.15-20
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• 2014

This paper discusses the creative capstone design education in Kongju National University and introduce a new operational capstone design education method. The result products are evaluated by self-evaluation and performance assessment that is based on the operational method and procedure of the project. The capstone design teams are comprised of 2~3 students with a individual major accomplishments. All teams are satisfied the criteria of evaluation. And their's self-satisfaction and questionaries are totally 3.88~4.44 point out of 5. Compared with the conduct of previous capstone design project that was not the industry affiliate, it provides students with industrial experience in design and development of industrial solution. And industrial partner must provide funds for student team to design, fabrication and test in next time.

• Earthquakes and Structures
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• v.22 no.1
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• pp.65-82
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• 2022

This paper presents a structural performance assessment of a historical masonry clock tower both using numerical and experimental process. The numerical assessment includes developing of finite element model with considering different types of soil-structure interaction systems, identifying the numerical dynamic characteristics, finite element model updating procedure, nonlinear time-history analysis and evaluation of seismic performance level. The experimental study involves determining experimental dynamic characteristics using operational modal analysis test method. Through the numerical and experimental processes, the current structural behavior of the masonry clock tower was evaluated. The first five experimental natural frequencies were obtained within 1.479-9.991 Hz. Maximum difference between numerical and experimental natural frequencies, obtained as 20.26%, was reduced to 4.90% by means of the use of updating procedure. According to the results of the nonlinear time-history analysis, maximum displacement was calculated as 0.213 m. The maximum and minimum principal stresses were calculated as 0.20 MPa and 1.40 MPa. In terms of displacement control, the clock tower showed only controlled damage level during the applied earthquake record.

• Journal of the Korean Society of Systems Engineering
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• v.16 no.1
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• pp.25-35
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• 2020

The South Korean Navy is making efforts to acquire vessels that the new technology of the 4th industry is applied, and as a part of these efforts, it has a plan to mount and operate an Unmanned Surface Vehicle(USV) on a vessel that will be introduced later. However, the recent studies have focused on only development of common platforms and mission equipment for the USV, and have not sufficiently analyzed studies and operatinoal requirements on mother ship that will operate the mounted USV. Hence, this study analyzed and presented requirements of mother ship with the mounted USV in order to operate effectively it when the future medium and large vessels to be acquired by the South Korean Navy intent to operate the USV.

• Proceedings of the KSRS Conference
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• v.2
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• pp.797-799
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• 2006

The Electro-optical camera subsystem as a payload of a satellite system consists of OM (optical module) and CEU(camera electronics unit), and most performances of the camera subsystem depend a lot on the CEU in which TDI CCDs(Time Delayed Integration Charge Coupled Device) take the main role of imaging by converting the light intensity into measurable voltage signal. Therefore it is required to specify and design the CEU very carefully at the early stage of development with overall specifications, design considerations, calibration definition, test methods for key performance parameters. This paper describes the overview of CEU development. It lists key requirement characteristics of CEU hardware and design considerations. It also describes what kinds of calibration are required for the CEU and defines the test and evaluation conditions in verifying requirement specifications of the CEU, which are used during acceptance test, considering the fact that CEU performance results change a lot depending on test and evaluation conditions such as operational line rate, TDI level, and light intensity level, so on.