• Journal of KSNVE
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• v.7 no.4
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• pp.655-661
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• 1997

Base-isolation of a primary structure generally decrete the seismic response of its own and the secondary structure. It may cause an adverse effect on the seismic response of secondary system when the system is submerged and subject to a considerable hydrodynamic effect. In this paper, it is shown how, and how much, the base isolation of the primary structure can affect the secondary system response in extreme cases through dynamic analysis of a simplified coupled model for a submerged secondary system and a base-isolated primary structure. As an aseismatic design approach to reduce the response of the submerged system, optimization of the fluid gap, which controls the hydrodynamic mass effect, is performed. As an alternative approach in case where the control of fluid gap is unrealistic, application of base isolation to the submerged system is suggested. Effectiveness of various combinations of the primary base and secondary base isolations are compared.

• Current Optics and Photonics
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• v.1 no.4
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• pp.344-350
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• 2017

We present a new design approach and an example design for an image-space telecentric two-mirror system that has a fast f-number and a wide-field line image. The initial design of the telecentric mirror system is a conventional axially symmetric system, consisting of a flat primary mirror with fourth-order aspheric deformation and an oblate ellipsoidal secondary mirror to correct spherical aberration, coma, and field curvature. Even though in the optimized design the primary mirror is tilted, to avoid ray obstruction by the secondary mirror, the image-space telecentric two-mirror system shows quite good imaging performance, for a line imager.

• Journal of the Korean Society for Railway
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• v.2 no.2
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• pp.6-12
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• 1999

In this study, the most important suspension characteristics of railway vehicle, such as primary and secondary stiffness, are optimized to maximize ride qualify. Critical speed, secondary suspension stroke oil tangent track and derailment coefficient on the maximum curvature, are selected as the performance constraints. Piecewise linear curving model is used to evaluate derailment coefficient where it is assumed that wheel/rail contacts occurs at tread or at idealized flange. The combined design procedure is used to optimize above design variables at the same time.

• Journal of the Korean Operations Research and Management Science Society
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• v.32 no.3
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• pp.17-31
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• 2007

In this paper, we consider a service system with bi-functional servers, which can switch between the primary service room and the secondary room. A service policy is characterized by the switching paints which depend on the queue length in the primary service room and the service level requirement constraint of the secondary room. The primary service room is modeled as a Markovian queueing system and the throughput of the primary service room is function of the total number of bi-functional servers. the buffer capacity of the primary service room, and the service policy. There is a revenue obtained from throughput and costs due to servers and buffers. We study the problem of simuitaneously determining the optimal number of servers, buffer capacity, and service policy to maximize profit of the service system, and develop an algorithm which can be successfully applied with the small number of computations.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1715-1719
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• 2004

An in-house supersonic ejector was designed to ensure low pressure and high speed scavenging of resonating cavity of chemical lasers. For given primary flow condition, 100g/s secondary mass flow rate was observed at the design pressure. Performance validation of a supersonic ejector system along with an investigation of effects of supersonic diffuser was conducted. Placement of diffuser at the secondary inlet further reduced diffuser upstream pressure to 1/4-1/5 relieving the local to the primary supply unit. In order to increase the secondary flow, we put two ejectors capable of removing 50g/s each of secondary flows together to deal with higher mass flow. Test of the parallel unit demonstrated the secondary flow rate was proportional to the numbers of individual units that were brought together. Additionally, flow calculations with a commercial code were carried out in every case of experiment and compared with results.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.329-332
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• 1988

In this paper, A analysis method about air gap field of L.I.M. considering Transverse Edge Effect is suggested. Especially, the case of displacement of primary and secondary it can be analysed and criteria for design of L. I. M. is proposed by proving the influance of ratio of width for primary and secondary to the characteristic

• 한국연소학회:학술대회논문집
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• 2005.10a
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• pp.148-155
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• 2005

In this study, Development of 300,000kcal/hr high velocity Injection burner with fuel multi-stage was performed using experiments. The characteristics of NOx emission in multi fuel/air staged combustor have been experimentally studied. The design concept of multi fuel/air staged combustor is creation of two separate flame, a primary flame is largest access air combustion and the secondary flame is complete combustion zone, where most of fuel bums. Experiments were performed on an industrial scale in a laboratory furnace and Liquefied Natural Gas(LNG) was used as primary and secondary fuels. Comparison of outlet NOx and outlet Temperature under various air rate and primary/ secondary fuel ratio was performed. The test demonstrated that NOx emission con be reduced by 70% in accordance with operating conditions.

• Fourth Industrial Review
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• v.2 no.2
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• pp.47-60
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• 2022

Purpose - The purpose of this study is to investigate the role of Teamwork on Engagement among employees of private primary and secondary schools in Plateau State, Nigeria using the dimensions of Teamwork, which are Communication, Leadership, Team Structure, Situation Monitoring, and Mutual Support on Employee Engagement. Research design, data, and methodology - To analyze the relationship among the variables, the study adopted the descriptive and explanatory research design, and a cross-sectional survey method using a survey questionnaire containing 29 items, with a 5-point Likert scale. The samples of 274 employees (both academic and non-academic) were selected using a simple random probability sampling technique. Multiple Regression was used to analyze data with the aid of the statistical package for social sciences (SPSS version 23.0). Result - This shows that Communication, Leadership, and Situation Monitoring have a positive and significant relationship on Employee Engagement, while Team Structure and Mutual Support show a negative direction but still maintained a significant relationship. Conclusion - The management of private primary and secondary schools should pay attention to Communication, Leadership, Team Structure, Situation Monitoring, and Mutual Support among their employees to promote Employee Engagement in the workplace. It also recommends that future studies should be carried out in other sectors.

• Journal of The Korean Association of Information Education
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• v.25 no.3
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• pp.511-525
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• 2021

The purpose of this study is to develop a design guideline to provide user-friendly experience and convenience for the online support system for the curriculum at primary/secondary schools. To achieve the objective, best practices of overseas on the online support system for curriculum as well as prior research were analyzed. In addition, UX/UI usability problems and needs were derived through a survey of 74 professionals and teachers who are monitoring NCIC and high school credit system sites. Based on the analysis of best practices of overseas and survey results, the draft of the design guideline was derived, and Delphi method was conducted by experts to re- vise the design guidelines and evaluate their validity. This study is meaningful in that it suggests the direction of improvement of the system currently being serviced and the direction of the design of the system to be developed in the future, by providing design guidelines that can be generally applied to online support systems that perform tasks related to the curriculum.

• Journal of Korea Game Society
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• v.21 no.4
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• pp.73-84
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• 2021

In this paper, we propose an analysis method that categorizes the Core that essential behaviors in game, the Primary that solves the game problem, and the Secondary that helps the Core and the Primary. The proposed method can analyze the genre similarity and characteristics of the game, the richness of the content, and the proficiency level of the game. case study were conducted to confirm whether the analysis items were consistent with the objective game experience. The results of this study are expected to be helpful in improving game design ability.