• Journal of Technology Innovation
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• v.15 no.1
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• pp.115-144
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• 2007

This paper is concerned with figuring out a scheme to facilitate UML utilization through examining the factors which affect the intention to use UML. For this, we conducted a survey of those factors among software engineers in IT service companies. In order to examine the factors affecting the intention to use UML, we developed a model by combining the Technology Acceptance Model and the Innovation Attributes Theory, which have been proved to explain well about the acceptance of new technologies and services. Statistical analysis shows that the subjective norm which is one of social factors has significant influence on the career consequences, and also on the compatibility when the result of UML utilization is demonstrable. The career consequences, the compatibility and the ease of use are found to have significant influence on the usefulness perception of UML utilization, implying that the recognition that one's future career can be affected in the long term by UML utilization is important in shaping how one perceives the usefulness along with the compatibility with one's current task type and the ease of use. The usefulness and the compatibility are evaluated to be the factors that have significant influences on the intention to use UML.

• Korean Institute of Interior Design Journal
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• v.18 no.2
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• pp.71-79
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• 2009

It is the youth period that the personality is shaping gradually. The residential environments have influence on the young ego. Especially residential design should include more youth friendly design elements than any other facilities. The purpose of this study was to provide the youth friendly design elements about the space design of apartment through analysis of youth's needs. This study was progressed to the survey method about five districts of apartment design competitions in 2007. The collected cases are analyzed by using statistics software SPSS for windows release 11.0. The result of the study was as below. First, the youth satisfaction of current residential space got more satisfied as floor space got larger. Second, most of youth uses them own room that is satisfied with their floor space for sleeping, inviting friends, studying, playing activities. Third, generally youth preferred to place their own room not far from the restroom, but the result of distance between master room and entrance was classified depend on sex, personal inclination, and residence environment, also generally satisfied with volume of their room. Fourth, for the restroom, although it is too small that satisfied with bath facilities relatively. And cast, youth's preferred room for extra was 'movie/music room', 'game room' and 'dress room' which is higher preference than 'study room'.

• Current Optics and Photonics
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• v.4 no.3
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• pp.229-237
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• 2020

In this study, a beam-coupling system is designed to improve the coupling efficiency of achip-integrated spectrometer when the waveguide is arranged in a linear and discrete manner. In the proposed system the beam is shaped to be anti-Gaussian, to deposit adequate energy in the edge waveguides. The beam is discretely coupled to the corresponding waveguide by a microlens array, to improve the coupling efficiency, and is compressed by a toroidal lens to match the linear discrete waveguides. Based on the findings of this study, the coupling efficiency of the spectrometer is shown to increase by a factor of 2.57. Accordingly, this study provides a reference basis for the improvement of the coupling efficiency of other similar spectrometers.

• Journal of Korean Academy of Nursing
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• v.23 no.3
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• pp.453-466
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• 1993

Quantitative methodology has been the predominent methodology utilized in research in nursing. However since the 1970s qualitative methodology has also emerged as a useful methodology and has been utilized by many researchers. But in the use of this methodology, the philosophical, epistemelogical, and theoretical backgrounds have been neglected by many researchers. This paper reports a review of the literature on methodologies, quanitative and qualitative, used in nursing, and makes suggestions for future research directions. It explains why qualitative methodology has emerged as as effective methodology in nursing and discusses how the qualitative methodology differs from the quanitative one. A comparison of the two is made based on perspectives of humane being and human behavior as well as the development of nursing science. This paper also presents several views on change in nursing science, since viewpoint not only influences the determination of the current stage of nursing science but also the shaping of the future directions of nursing science and research. Scientific revolution by Kuhn, the evolutionary perspective by Toulmin, the transition of research tradition by Laudan. and convolutionary processes are presented. However, this paper indicates that it is too early to adopt these points of view, because the history of nursing science is too short. It suggests that nursing needs pluralism in philosophy, paradigms and theory, as well as in methodology. Although we experience paradoxes in adopting different perspectives in nursing, it is wise for us to continue to include a variety of viewpoints including those to which we are not accustomed, such as qualitative methodology, since we are not yet able to decide what is best for the development of nursing science.

• Journal of Ocean Engineering and Technology
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• v.2 no.2
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• pp.37-45
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• 1988

A dynamically positioned vessel must be capable of maintaining a specified position and direction by controlling the thruster devices. The motions of a vessel are often assuned to tne sum of low frequency(LF)motions and high frequency(HF)motions. The former is mainly due to wind, current and second order wave forces, while the latter is mainly due to first order wave forces. In order to avoid the high frequency thruser modulation, the control system must include filters to estimate the low frequency motions from the measured motion signals, This paper presents a control system based on Kalman filtering technique and optimal control tyeory. Using the combined kalmam filter, LF motion estimates and HF ones are achieved from the motion measurement of the vessel. The estimated low frequency motions are used as inputs to the dynamic positioning system. The thruster modulation is minimized using the optimal control theory; Linear Quadratic Gaussian(LQG)controller. The performances of the Kalman filter and the dynamic positioned vessel are investigated by computer simulation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.2
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• pp.21-28
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• 1998

A new technique for shaping the line current and reducing the total hannonic distortion in a threephase rectifier is introduced. A review of the problems inherent in a three-phase diode rectifier feeding capacitive load and the possible solutions are first presented. The proposed 3 bidirectional switches and their operation are presented. The main features of this paper are low cost, high efficiency and simplicity. A simulation and experiment results show its good action.action.

• ETRI Journal
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• v.37 no.3
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• pp.460-470
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• 2015

Orthogonal frequency-division multiplexing (OFDM) is one of the most widely used technologies in current wireless communication systems and standards. Cognitive radio (CR) provides a robust solution to the problem of spectrum congestion as it offers opportunistic usage of frequency bands that are not occupied by primary users. Due to the underlying sensing, spectrum shaping, scaling, and interoperable capabilities of OFDM, it has been adapted as a best transmission technology for CR wireless systems. However, the performance of an OFDM-based CR wireless system is affected by the existence of narrowband interference (NBI) from other users. Further, due to carrier frequency offset in NBI sources, NBI energy may spread over all subcarriers of an OFDM signal. In this paper, a fixed Amplify-and-Forward (AF) relay that operates at a frequency band that is different from that of direct mode is introduced to suppress the effect of NBI. Analytical expressions are derived for outage probability in direct, AF-relay, and incremental relaying modes. The outage performance of the proposed AF relay-based CR network is proven to be better than that of direct mode.

• Journal of the Ergonomics Society of Korea
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• v.30 no.1
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• pp.117-125
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• 2011

While human error happens repeatedly in the semiconductor industry in Korea, which has brought a tremendous loss from manpower, welfare etc., there are limitations to human error prevention activities. When a semiconductor company introduces new machines and facilities from Japan or Germany, the companies often do not consider human factors in the design. Also, semiconductor companies are so occupied with promoting increased productivity, their attention to human errors has been pushed aside. Negative aspects of technical exchange associated with safety management are one aspect of the industry's nature. A semiconductor company recently began acknowledging on the back of TQM(Total Quality Management) that human error has a decisive effect on the safety. There are a number of uncontrollable and hard to handle event sets because the nature of these events with a human error may often be threatened or very intensive. It is strongly required that systemic studies should be performed to grasp the whole picture of a current situation for hazard factors. This study aims to examine the human error approach through the case of human error prevention field activities in a semiconductor industry compared with the activities and experience in nuclear power plants.

• Journal of Electrical Engineering and Technology
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• v.3 no.2
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• pp.152-161
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• 2008

This paper deals with a new wave shaping technique for cost effective harmonic mitigation in ac-dc converter feeding Vector Controlled Induction Motor Drives(VCIMD's) for improving power quality at the point of common coupling(PCC). The proposed harmonic mitigator consists of a polygon connected autotransformer based twelve-pulse ac-dc converter and a small rating passive shunt filter tuned for $11^{th}$ harmonic frequency. This ac-dc converter eliminates the most dominant $5^{th},\;7^{th},\;and\;11^{th}$ harmonics and imposes the reduction of other higher order harmonics from the ac main current, thereby improving the power quality at ac mains. The design of autotransformer is carried out for the proposed ac-dc converter to make it suitable for retrofit applications, where presently a 6-pulse ac-dc converter is used. The effect of load variation on VCIMD is also studied to demonstrate the effectiveness of the proposed ac-dc converter in a wide operating range of the drive. Experimental results obtained on the developed laboratory prototype of the proposed harmonic mitigator are used to validate the model and design of the ac-dc converter.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1167-1169
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• 1996

As electrical discharge machinery(EDM) is industrial process which is manufactured by discharge energy, by producing discharge, EDM process finished material at the little micrometer air gap. Especially, EDM is used for the characteristic of heat-resisting material, it puts to use air-space industrial element, confusing shaping material such as jet engine, rocket elements. Working performance. is changed by environment of working, discharge current voltage and duration of discharge pulse. Evaluation of performance working is work speed, clearance smoothing of product surface, wasting of pole. In this paper, this machine is compensated by adaptive controller which corrects the weak points of classical machine which is observed and operated working condition by user in hands. The previous purpose is main object in this thesis. The adaptive controller automatically detect abnormal condition and working conditions. To improve performance, surface smoothing and working speed, the adaptive controller uses fuzzy control strategy. To evaluate performance, this controller is implemented by microprocessor i80c196 and is applied real experimental machine.