• Korean Journal of Construction Engineering and Management
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• v.11 no.5
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• pp.75-83
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• 2010

Construction industries is a labor intensive industries. According to Korea Productivity Center, most OECD members indicate high labor productivity more than Korea labor productivity in construction industries. First of all, for increasing labor productivity work efficiency and work condition should be managed by administrator in work site. Especially, work condition could be controlled by the management behaviors of administrator in work site such as work management type. This indicates that work management type could influence strongly work condition. But although that work management type could influence work condition is the characteristic of construction work is recongized to many people, the quantitative analysis on the relationship between work condition and work management type is not enough. Therefore the purpose of this study is to analyze the Influence of Work Management Type on Work Condition.

• Journal of the Ergonomics Society of Korea
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• v.26 no.3
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• pp.1-9
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• 2007

The purpose of this study was going to research relation of job stress and society psychologic stress according to general characteristic, work characteristic, health characteristic and personality characteristic for the occupational therapist in the working domestic rehabilitation therapy with hospital and welfare center occupational therapist. The research was 91 of withdrawal questionnaire among 102 occupational therapist from 1. November 2005 to 31. December 2005. In the result of analysis the given question for the ninety one occupational therapist showed just normal group 25% 23 person, potential stress group 47% 43 person, and the rest 28% 25 person high risk group. The result shows significance different in general characteristic of job stress about age, final scholarship and marriage. Job stress was included income, working time, office form and working position etc. Health special job stress was significance different according to sleep time. So we have to know a fact of job stress of occupational therapist and prevent of loss of business services. And we have to endeavoring removals factor of stress and good office culture fixation.

• Nuclear Engineering and Technology
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• v.55 no.8
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• pp.2757-2772
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• 2023

The fluid retention effect of the Volume Control Tank (VCT) leads to a long time delay in Reactor Coolant System (RCS) concentration during the boration process. A coupled model combining a lumped-parameter sub-model and a computational fluid dynamics sub-model is currently used to investigate the concentration dynamic characteristic of RCS during the boration process. This model is validated by comparison with experimental data, and the predicted results show excellent agreement with experimental data. We provide detailed fields in VCT and concentration variations of RCS to study the interaction between mixing in VCT and the transient responses of RCS. Moreover, the impacts of the inlet flow rate, inlet nozzle diameter, original concentration, and replenishing temperature of VCT on the RCS concentration characteristic are studied. The inlet flow rate and nozzle diameter of VCT remarkably affect the RCS concentration characteristic. Too-large or too-small inlet flow rates and nozzle diameters will lead to unacceptable long delays. In this work, the optimal inlet flow rate and nozzle diameter of VCT are 5 m³/h and 58.8 mm, respectively. Besides, the impacts of the original concentration and replenishing temperature of VCT are negligible under normal operating conditions.

• Journal of the Korea institute for structural maintenance and inspection
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• v.2 no.3
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• pp.176-187
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• 1998

The Dismantlement and Construction of the buildings have the characteristic of floating change with repetition within a Time Schedule which has fixed resources, that is, Manpower, Materials and Equipments, and involve many disaster factors in performing each processes. But as these factors are variable, a work supervisor should be able to understand data analysed distinctive factors of each activities systematically, organizationally, and scientifically, and diagrammatic information media so that he can control any complex and situation beyond forecast. Thus this study is intended to be a barometer of weighing if the existing process schedule has taken security into consideration by making the characteristics of organization and action of Work package per process in a building field with more factors like these into a network system and is intended to minimize construction disasters by systematizing this into a Transformational Network.

• Informatization Policy
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• v.21 no.1
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• pp.35-56
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• 2014

Information and communication technologies(ICT) allow and force people to work anywhere, anytime using remote databases and application systems available in real-time twenty four hours a day and seven days a week. With the real time nature of ICT, individual work is becoming more and more fragmented. Instead of working on a similar task repeatedly, individuals are required to respond to e-mails and inquiries through social networks, work on planning documents, work on presentation documents, work on spreadsheets, input necessary data on company databases, generate necessary reports from the database, run teleconference, etc., all maybe in a day's work. Work fragmentation may impact negatively on productivity as the flow is interrupted, but it may increase the productivity by allowing people to handle multiple tasks in a shorter time period. This study explores the types of work fragmentation and their characteristics. An online survey was administered to collect data about work fragmentation and work characteristics including autonomy, complexity, flexibility, usage of ICT, etc. 300 cases were used in the analysis. Analysis of k-mean cluster indicated four different types of work fragmentation: concentrated, temporally distributed, spatially distributed, and fully fragmented.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.41-43
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• 2008

This paper presents the characteristic analysis of Double-Sided Linear Synchronous Generator for wave power generation under different operating conditions. FEM is applied to analyze performance of generator at no-load and load with variable resistance. Moreover, the validity of characteristic analysis is confirmed through the experimental work.

• Journal of Mechanical Science and Technology
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• v.19 no.9
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• pp.1821-1832
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• 2005

This study realizes the conceptual method to predict combustion instability in actual full-scale combustion chamber of rocket engines by experimental tests with model (sub-scale) chamber. The model chamber was designed based on the methodologies proposed in the previous work regarding geometrical dimensions and operating conditions, and hot-fire test procedures were followed to obtain stability boundaries. From the experimental tests, two instability regions are presented by the parameters of combustion-chamber pressure and mixture (oxidizer/fuel) ratio, which are customary for combustor designers. It is found that instability characteristics in the chamber with the adopted jet injectors can be explained by the correlation between the characteristic burning or mixing time and the characteristic acoustic time: In each instability region, dynamic behaviors of flames are investigated to verify the hydrodynamically-derived characteristic lengths of the jet injectors. Large-amplitude pressure oscillation observed in upper instability region is found to be generated by lifted-off flames.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.225-230
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• 2002

Machine of textiles let off is equipment supplying constantly fabrics. Nowdays, as it is replaced band - brake type with hydraulic motor driven type, we looked into characteristic of hydraulic solenoid pilot direction valve(SPDV) for controlling acceleration performance of hydraulic motor. This study deals with controlling the initial speed of textiles let off machine. Finally, to control the initial speed of hydraulic motor, we controlled the adjustment screw of SPDV by a hand. Test which was carried out in the laboratory shows that initial speed of textiles let off could be improved by controlling adjustment screw of SPDV. Also, the results of experiment work were compared with dynamic characteristic of other on/off solenoid direction valve(SDV).

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.25-27
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• 1998

In this paper electromagnetic force and its distribution are analyzed on the nonlinear magnetic materials by Finite Element Method. Most of magnetic materials have the nonlinear characteristic, which considerably effects on the magnetic system. And it is necessary to know its distribution at the every Part of the magnetic material in order to design the, magnetic system considering noise, vibration and strain characteristic. The results are obtained by Maxwell stress. virtual work and magnetic charge method and compared with one another.

• Journal of Multimedia Information System
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• v.5 no.2
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• pp.139-142
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• 2018

This work presents a novel architecture of phase locked loop (PLL) with the current compensating scheme to improve phase noise characteristic. The proposed PLL has two charge pumps (CP), main-CP (MCP) and sub-CP (SCP). The smaller SCP current with same time duration but opposite direction of UP/DN MCP current is injected to the loop filter (LF). It suppresses the voltage fluctuation of LF. The PLL has a novel voltage controlled oscillator (VCO) consisting of a voltage controlled resistor (VCR) and the three-stage ring oscillator with latch type delay cells. The VCR linearly converts voltage into current, and the latch type delay cell has short active on-time of transistors. As a result, it improves phase noise characteristic. The proposed PLL has been fabricated with $0.35{\mu}m$ 3.3 V CMOS process. Measured phase noise at 1 MHz offset is -103 dBc/Hz resulting in 3 dBc/Hz phase noise improvement compared to the conventional PLL.