• Laser Solutions
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• v.4 no.2
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• pp.47-57
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• 2001

This study deals with the laser cutting of stencil for the PCB. The most important aim of this study is to determine optimal conditions which make good-qualify stencil in Nd:YAG laser cutting. We made an experiment according to various variables (power. type of mask. gas pressure, cutting speed, and pulse width) and analyzed the cutting characteristics (surface roughness, kerf width. dross) . Each variable has optimal value for good-qualify cut edge under fixed condition. And neural network after learning experimental data with a million time iteration could predict surface roughness of cut edge under arbitrary condition approximately.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.342-352
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• 2003

Idle NVH characteristics are one of the most important aspects among the vehicle performances. Vehicle developers are devoted to improve vehicle interior noise and steering wheel and seat vibrations. In order to improve the idle quality, noise and vibration transfer path should be carefully evaluated. Also, effects of various components related to the idle performance should be confirmed. A general procedure for improving the idle qualify is described in detail. The relationship among cylinder pressure characteristics, crankshaft rotational speed variation, and vehicle vibrations is also investigated. Influences of drive shaft, torque converter, air conditioning system, vehicle structure including engine mount system, and idle control parameters on the vehicle idle quality are studied. Weak points of typical vehicles on the idle qualify are identified. Some of improvement measures are proposed and verified.

• The Journal of the Acoustical Society of Korea
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• v.25 no.3
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• pp.129-136
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• 2006

For the environmental noise assessments. A weighted equivalent noise level (LeqA) is used to measure the time varying environmental noise. However, it is not appropriately reflect various environmental noise features and human emotions. The human perception of the noise is affected largely by the psychoacoustic characteristics of noise as well as the sound pressure level In this study, the effective factors of noise qualify are analyzed using the subjective assessment and statistical analysis of environmental noise, such as road traffic noise. construction site noise, noise in daily living. and other. The analysis methodology is composed to three steps as follows : firstly, the values of the sound qualify metrics of various noise sources were analyzed. And to classify the noise sources, we conducted a cluster analysis using sound quality metrics. Secondly, subjective jury testing was carried out using the methods of paired comparisons and semantic differential. Finally, the correlation between the subjective parameters and the noise quality metrics were analyzed. As a result. the human perception characteristics of the various environmental noise are described in some physical parameters of the noise qualify metrics.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2007.04a
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• pp.219-222
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• 2007

• 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 Korea Society of Computer and Information
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• v.1 no.1
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• pp.65-82
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• 1996

The assurance of software product. which Is different to other products. is very complex because of Its characteristics. The use of objective development standards or guidelines and the confirmation to meet user's requirements are Important to achieve the software quality system. Moreover correct understanding of qualitv standards and continuous applications of check-points for qualify audit are necessary. ISO 9000 series. which are International standards. were made for the qualify assurance. Among them. ISO 9000-3 is the quality management and quality assurance standards for applying ISO 9001 to the design. development. supply. installation and maintenance of software. The newly revised ISO/CD 9000-3：1995 contains a lot of enforced changes within ISO 9001 framework - quality standards for manufactured products. This paper analyses the revised ISO 9000-3 by comparing it to ISO 9001. and derives quality audit points to use for qualify audit In future.

• Journal of the Korea Society of Computer and Information
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• v.11 no.4 s.42
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• pp.197-206
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• 2006

One of the most significant characteristics of JPEG2000. the emerging still image standards. is the ROI (Region of Interest) coding. JPEG2000 provides a number of ROI coding mechanisms and ROI parameters. To apply them to an application, it must select the applicable values. In this paper, we evaluate how the ROI coding mechanisms and the ROI parameters influencing JPEG2000 qualify affect the ROI quality and the whole image quality. The ROI coding mechanisms are Maxshift and Implicit. and the parameters are tile size and ROI size, codeblock size, number of DWT decomposition levels and ROI importance. The bigger the tile size, the better the quality. The bigger the ROI size, the ROI importance and the number of DWT decomposition levels, the worse the qualify. In code block $32{\times}32$ of Maxshift and Implicit, it has the best qualify.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.14 no.24
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• pp.133-139
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• 1991

If the specifications of product. in general. art determined too wide. the precision of product becomes diminished. Otherwise it costs dearly to keep the precision. Therefore, It is realistic to consider various factors in determining specification of qualify characteristics TAGUCH Idefines quality of an object as "Quality is the loss that a product causes to society after being shipped. other than any losses caused by its intrinsic function". Particularly, to improve the performances of product TAGUCHI focuses his attention on the product design and process design which enable the functional characteristics of product to he robust to noises. In this paper, by the TAGUCHI's loss function, the characteristics which affect the variation of a product performance are classified into the scrappable characteristics and the reworkable characteristics when the target values of functional characteristics have been determined. And we will determine the tolerance of each characteristic which minimize the quality cost by the cost function which considers the economic factors and probability features of each characteristic.cteristic.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.1
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• pp.49-59
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• 2005

The evaporation heat transfer experiments are conducted with the shell and plate heat exchanger (S&PHE) without oil in the refrigerant loop using R-410A. An experimental refrigerant loop has been established to measure the evaporation heat transfer coefficient h. of R-410A in a vertical S&PHE. Two vertical counter flow channels were formed in the S&PHE by three plates haying a corrugated trapezoid shape of a $45^{\circ}C$ chevron angle. UP flow of the boiling R-410A in one channel receives heat from the hot down flow of water in the other channel The effects of the refrigerant mass flux. average heat flux. refrigerant saturation temperature and vapor qualify are explored in detail. Similar to the case of a plate heat exchanger. even at a very low Reynolds number, the flow in the S&PHE remains turbulent. The Present data shows that the evaporation heat transfer coefficients of R-410A increased with the vapor qualify. The results indicate a rise in the refrigerant mass flux caused an increase in the h.. Raising the imposed wall heat flux is found to slightly improve h., while h, is found to be lower at a higher refrigerant saturation temperature. Based on the present data. empirical correlation of the evaporation heat transfer coefficient is proposed.

• Research in Community and Public Health Nursing
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• v.17 no.3
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• pp.364-375
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• 2006

Purpose: The purpose of the study was to investigate burden and the qualify of life in caregivers who are taking care of home-based rare and incurable disease patients. Methods: The subjects of this study were 300 caregivers of rare and incurable disease patients registered at five health centers in Seoul. A survey was conducted by mail and visit in person during the period from the 25th of March to the 12th of May 2005. Collected data were analyzed through t-test, ANOVA, Pearson's correlation coefficient. Result: The mean burden of caregivers was 3.42, and the mean qualify of life of caregivers was 2.71. Burden and QoL showed significant differences according to caregivers' characteristics such as sender, age, relation to the patient, academic qualification, religion, occupation, monthly household income and perceived health condition. Caregivers' burden was in an inverse correlation with their quality of life. Conclusions: According to the results of this study, rare and incurable disease caregivers' burden and their quality of life were in a significant correlation with each other. In order to improve caregivers' quality of life by reducing their burden, we need to reestablish comprehensive policies for rare and incurable disease management including nursing intervention strategies for caregivers.