• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.579-586
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• 2011

During a reactor normal operation, a primary coolant was designed to remove the fission reaction heat of the reactor. When one pump is failure and the other pump shall supply the cooling water to cool the reduced power, it is necessary to estimate how much flow will be supplied to cool the reactor. We carried a flow net work analysis for two parallel pumping system as based on the piping net work of the primary cooling system in HANARO. As result, it is estimated that the flow of one pump increased than the rated flow of the pump below the cavitation critical flow.

• IE interfaces
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• v.6 no.1
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• pp.99-112
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• 1993

This study deals with analysis of material from in Tube manufacturing line. This line is a multi product flow ship type production line, which consists of 5 steps of work station. Some work stations involve in unnecessary moving activities of workers and much work in-process storage due to the non-systematic material flow with respect to the different lot size production of multi-items. To improve productivity for this line, one alternative is considered such as grouping two work stations by using GT and JIT concepts. Also, feasibility analysis for this alternative is performed using and simulation model built by SIMAN IV simulation language.

• 유체기계공업학회:학술대회논문집
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• 2000.12a
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• pp.110-115
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• 2000

The mean streamline analysis using the empirical loss correlations has been developed for performance prediction of industrial mixed-flow fan impellers in the present study. New simple, but effective, models for the additional Euler input work characteristic and an internal recirculation loss due to internal flow reversal under the low flowrate conditions are proposed in this paper. Comparison of overall performance predictions with six sets of test data of mixed-flow fans is accomplished to demonstrate the accuracy of the proposed models. Predicted performance curves by the present set of loss models agree fairly well with experimental data for a variety of mixed-flow fan impellers over the entire operating conditions. The prediction method presented herein can be used efficiently in the conceptual design phase of mixed-flow fan impellers.

• Korean Journal of Childcare and Education
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• v.9 no.2
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• pp.97-115
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• 2013

The present study examined the relationships between work related flow (i.e., absorption, work enjoyment, and intrinsic work motivation) and role conflict causes (i.e., teacher's belief, teaching and interaction with young children, comradeship, relationships with parents, workload, supervision, and social awareness of the job). A canonical correlation analysis was performed on the data from a sample of 154 childcare teachers. The results are as follows (1) there was a reciprocal-causal relationship between teachers' role conflict causes and their work-related flow; (2) canonical function 1 showed that absorption and work enjoyment are strongly associated to a teacher's belief and supervision of conflict causes; and (3) canonical function 2 showed that intrinsic motivation has a relatively strong relationship with workload and supervision of conflict causes. It can be concluded that it is important for childcare teachers to have sufficient job resources to promote their flow at work. Further research is needed for investigation of teacher's flow at various conditions of work.

• Journal of Mechanical Science and Technology
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• v.20 no.9
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• pp.1475-1482
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• 2006

Wet compression means the injection of water droplets into the compressor of gas turbines. This method decreases the compression work and increases the turbine output by decreasing the compressor exit temperature through the evaporation of water droplets inside the compressor. Researches on wet compression, up to now, have been focused on the thermodynamic analysis of wet compression where the decrease in exit flow temperature and compression work is demonstrated. This paper provides thermodynamic and aerodynamic analysis on wet compression in a centrifugal compressor for a microturbine. The meanline dry compression performance analysis of centrifugal compressor is coupled with the thermodynamic equation of wet compression to get the meanline performance of wet compression. The most influencing parameter in the analysis is the evaporative rate of water droplets. It is found that the impeller exit flow temperature and compression work decreases as the evaporative rate increases. And the exit flow angle decreases as the evaporative rate increases.

• Journal of the Ergonomics Society of Korea
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• v.29 no.5
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• pp.763-770
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• 2010

The use of web widgets on desktop and mobile devices has been increasing rapidly. Web widgets provide access to activities and information from various sources across the web. As the number of supported widgets increases, managing widgets and finding relevant or interesting widgets becomes more complex. In addition, interacting with widgets in web service systems can be difficult, especially for novice users. Up to this point, there has been little research on web widget usability. This paper performs an experimental study regarding user interfaces of web widgets based on the mouse tracking and work-flow analysis. In the experiment, four sites providing widget services are chosen - iGoogle, Netvibes, My yahoo, and Wizard. The experiment participants perform three assigned tasks in the chosen sites, and their mouse operations are recorded using Camtasia, a screen casting software. Mouse tracking analysis is performed based on the recorded data in order to analyze common user behaviors. In addition, work-flow diagrams representing the operational flows to carry out the given tasks in each web site are constructed so as to visually and systematically analyze detailed usage patterns. The experimental study results presented in this paper can contribute to developing guidelines for highly usable and accessible interface design of web widgets.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.277-278
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• 2003

Cyclone separators are widely used for cleaning gas streams or for catalyst recovery. For many years, the complexity of the gas flow pattern in cyclones has been a matter of many experimental and theoretical work. At present, precise flow measurements have been performed by means of LDA and hot-wire anemometry (Patterson and Munz, 1996; Hoekstra et al., 1999; Peng et al., 2002). In the theoretical work, Computational fluid dynamics (CFD) codes are frequently employed for simulating cyclone gas-particle flows(Hoekstra et al., 1999). (omitted)

• Korean Journal of Construction Engineering and Management
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• v.2 no.4 s.8
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• pp.48-61
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• 2001

This study aims at improving work reliability. It proposes a way to overcome the limitations of current scheduling methods by providing a new framework, CPAM(Construction Process Analysis Model) based on the lean principles. It suggests methods which improve work reliability and production effectiveness with variability control methods. Also it suggests methods which reduce inventories of materials and equipment and WIP(Work In Process) using two techniques; Lookahead Schedule and Weekly Work Plan. The contribution of this research also includes that it assumes planning as a process of reducing uncertainty and maximizing throughput, counter-posing plan reliability to resource redundancy as alternative strategies for managing in conditions of uncertain work flow.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.738-746
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• 2009

The purpose of this study is to develop the web-based system for work performance analysis(WPAS). The need of work performance analysis system has already been suggested in many previous researches on the computerization of the performance measurement in the construction site by using the indicators such as time, cost and quality. However, they had focused on measuring or analyzing the result when the project would be over. The WPAS suggests three indicators - work reliability, work effectiveness and work efficiency - to manage the performance of the construction site. It can help the manager more easily recognize the status of on-going work in the construction site by measuring and analyzing the work reliability rate, the work effectiveness and work efficiency every day. This research includes the procedures for WPAS measurement process, database structure of WPAS which was analyzed by the IDEF0 and the data flow diagram. Finally, this research introduces the result of WAPS's case studies and validation in the Korean construction site.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.442-445
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• 2003

The purpose of this study is to present an improved lift-up & procurement work flow for effectiveness of resources increase in building construction. The current lift-up & procurement work flow has some waste factors; complicated information system, connection lack with process and decision-making delay. Therefore the study applied the value stream mapping methodology for improvement of current lift-up & procurement work flow. The main contents of the study are as follows; 1) A problem of current work flow were analyzed through current state mapping(CSM). 2) An improved work flow was suggested through future state mapping(FSM). 3) An improvement effect analysis of information system and lift-up planning The study recommends that continuous improvement of lift-up & procurement work flow and efficient management of information in building construction.