• The KSFM Journal of Fluid Machinery
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• v.19 no.5
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• pp.12-19
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• 2016

In present study, a parametric study of a centrifugal compressor with inlet treatment has been performed numerically using three-dimensional Reynolds-averaged Navier-Stokes equations. The shear stress transport turbulence model was used for analysis of turbulence. The finite volume method and unstructured grid system were used for the numerical solution. Tested parameters were related to the geometry of the inlet duct. It was found that the application of circumferentially distributed holes in the inlet duct improves operational stability of the compressor compared to that with conventional inlet duct.

• International Journal of Highway Engineering
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• v.14 no.5
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• pp.157-164
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• 2012

PURPOSES: Regional offices of the Ministry of Land, Transport and Maritime Affairs use a computerized system called KAMIS so as to manage road equipment systematically. Road agencies can record number of operating days by equipment, actual working hours, accumulated operating hours (or distance) by equipment, and operating cost. However, KAMIS does not provide critical information, although it is strongly related to efficient road management equipment operation. In other words, road agencies do not know whether they have sufficient equipment to handle their actual work. METHODS: Therefore, this study suggests a methodology to evaluate for operational efficiency of road management equipment using analytical hierarchy process(AHP). First of all, estimated weights related criteria can be produced by AHP, and then use operational history by pieces of equipment. RESULTS: Results show that importance of management work can differ from weather conditions through five areas. CONCLUSIONS: Commonly, this results can imply to help save money for the purchase and maintenance of road management equipment, and they would improve the functional performance of KAMIS.

• Korean journal of food and cookery science
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• v.11 no.3
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• pp.295-302
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• 1995

The purposes of the study were to identify the operational characteristics in employee feeding facilities, and to examine the correlations of productivity and these characteristics. A questionnaire was developed and mailed the 500 dietitians in employee feeding facilities in Seoul and Kyoungki Do. Usable questionnaires were received from 117 respondents for a response rate of 23.4％. The questionnaire was designed to determine the productivity index and to investigate the relationship between operational characteristics and productivity index. The questionnaire was contained 2 parts with a total of 16 statements. Data were analyzed for descriptive statistics and Pearson correlation analysis using SPSS/PC programs. The average productivity indices of 117 facilities were 6.91 meals/hr. Total meals served/week was significantly correlated to the productivity index (r=0.441, p < 0.001). No of average servings per meal, percentage of convenience food use, average minutes for service/day, and employment in professional practice of dietitian were also positively correlated, while food cost was negatively correlated to the productivity.

• Journal of Information Technology Applications and Management
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• v.11 no.3
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• pp.35-62
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• 2004

Recently, IT outsouricng has been one of the major concerns of many companies. This paper explores the relationship between information technology outsourcing risk factors and outsourcing performance. It is based upon a three-phase process utilizing IPO (Input-Process-Output) system. The first phase means the outsourcing planning risks t~at arise from overall environment of outsourcing, organizational refuse, and wrong contracts. The second phase implies outsourcing operational risks, which are occurred while out-sourcing perform and consist of organizational acceptances of outsourcing, partnership and hidden costs. The last phase is outsourcing performance based on four perspective of BSC(Blanced Scored Card). The survey was performed on the IT/IS firms, and the data was collected from 53 service receivers. The result of the analysis are as follows. First, Outsourcing planning risks positively affects the operational risks. Second, Outsourcing operational risks negatively affects the Outsourcing Performance.

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.3 s.18
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• pp.47-58
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• 2004

This paper focuses on the technical information about the development of the submarine operational effectiveness simulation model for the feasibility study stage of the submarine design. The simulation model is classified into simulation control model and system model. Using user input and related performance parameters, it can simulate various scenarios by no change of the program because it includes tactic manager which makes decision about every situation. And the Monte-Carlo simulation mode which provides the stochastic results is available. Through the test simulation, the usefulness of the simulation model was verified. It should be helpful for the analysis of the submarine operational effectiveness by diversified scenarios in the concept design phase..

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.134-136
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• 2002

In April of 2000, the Korea Power Exchange(KPX) was introduced into Korea electricity market. The purpose of this paper is to describe how the system operator indicates operational risks between the transmission planning and the supply and demand growth to make the market "work" and manage the power system in real time. This paper describes the experiences of kpx about the indication of operational risks including, for example, contingency analysis, voltage profile and fault capacity of three-phase short current.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.28 no.1
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• pp.14-21
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• 2020

Here I investigate what effects Operational Control Center(OCC)'s service quality may have on airline staff's job engagement. My analysis reveals that airline OCC's service quality has a meaningful effect on airline staff's service satisfaction, and that service satisfaction mediates a meaningful effect on staff's job engagement. It was suggested that improving OCC's service quality leads to higher staff's job engagement. Accordingly, I suggest methods of improving OCC's service quality. I find that the importance of contributing factors on OCC's service quality are as follows, in order of most to least important: professionalism, assurance, empathy, reliability, organizational culture, and responsiveness. The results of this study are relevant not only for airlines but also for government agencies such as the National Emergency Management Agency, the Korea Forest Service, the National Police Agency and the Korea Coast Guard that operate aircraft and must ensure aviation safety.

• Journal of the Korea Safety Management & Science
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• v.19 no.3
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• pp.43-48
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• 2017

The first tram in korea was commended the operation from 1899 to 1968 as a core role of public transportation. However, tram recently is being recognized as an alternative against a traffic congestion, a super-aged society and an environmental pollution problem. Because of these advantages, we are trying to introduce tram in korea. The efforts to introduce trams have focused on the economic analysis for tram construction. But we must be interested in tram operational safety. Early opening tram accidents could affect a negative impact on the additional tram introduction. We are trying to introduce trams in Daejeon, Wi-Rye and Su-won. In this paper, I want to check the safety issues in tram operation phase.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1012-1014
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• 1998

This paper presents a database design for power system operational planning system of the integrated system for power system operational planning and analysis that will be more economical and stable of power system operation. An alias of the integrated system is Highly Integrated Total Energy System(HITES). We first describe the requirements for the Power System Planning System of HTES. Database design is processed in two phases(conceptual design and physical design), and CDM(Conceptual Data Model) and PDM(Physical Data Model) are generated by Powerdesigner(CASE tool for database design). In the future, the constructed database needs to be tested and tuning.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.95-97
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• 1995

A superconducting current generator, or a superconducting rectifier(SCR) is used as a current source to energize a superconducting magnets in SMES, MRI. We selected a full-wave SCR among various SCR models and analyzed its operational characteristics by computer simulation. In process of pumping the current, the improvement of performance is dependent on how much bigger the open resistance of the switch is in comparison to load coil impedance when one of two switches become active. Faster transfer can he seen in resistive commutation mode by shortening the time elapsed for the resistance to arrive at certain level from zero state. Although recovery time for the switch has no direct effect on current pumping, optimal switch design is needed to increasing operational frequency.