• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1183-1184
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• 2006

Core loss of soft magnetic powder cores have been focused on to achieve high efficiency of power supplies. In this study the effects of crystal grain size on core loss were investigated by changing heat treatment conditions. It was found that core loss is influenced by crystal grain size because eddy current loss decreased and hysteresis loss increased by making crystal grain size smaller, and it is also influenced by particle size.

• Phonetics and Speech Sciences
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• v.4 no.3
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• pp.179-186
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• 2012

The aims of this study are to consider auditory physiological characteristics and to confirm audiological evaluation and interpretation in regards to cases of sensorineural hearing loss that observe an abnormal AB gap. Vestibulosaccular hearing occurs when there is an abnormally large air-bone gap (AB gap) in sensorineural hearing loss, also known as pure cochlear conductive hearing loss. Generally, an AB gap is caused by damage to the external and/or middle ear. In conductive hearing loss, loss of air condition hearing occurs due to a loss of resonance in the outer ear and/or impedance mismatching in the middle ear. Most of these types of hearing loss can be treated medically and surgically. However, there is no medical treatment for an AB gap in sensorineural hearing loss and hearing loss can worsen gradually or suddenly. In addition, many studies have reported that head trauma makes hearing loss even more serious. Therefore, in order to differentiate between conductive hearing losses, it is important to check whether or not there is an enlarged vestibular aqueduct by means of temporal bone computerized tomography and/or magnetic resonance imaging.

• Journal of Korean Society for Quality Management
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• v.30 no.3
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• pp.66-78
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• 2002

Process capability indices are being used as indicators for measurements of process capability for SPC of quality assurance system in industries. In view of the enhancement of customer satisfaction, process capability indices in which loss functions are used to deal with the economic loss In the processes deviated from the target, are in an adequate representation of the customer's perception of quality In this connection, the loss function has become increasingly important in quality assurance. Taguchi uses a modified form of the quadratic loss function to demonstrate the need to consider the proximity to the target while assessing its quality. But this traditional quadratic loss function is inadequate to assessing the quality and quality improvement since different processes have different sets of economic consequences on the manufacturing, Thereby, a flexible approach to the development of the loss function needs to be desired. In this paper, we introduce an easily understood loss function, based on reflection of probability density function of the normal distribution. That is, the Reflected Normal Loss function can be adapted to an asymmetric loss as well as to a symmetric loss around the target. We propose that, instead of the process variation, a new capability index, CpI using the Reflected Normal Loss Function that can accurately reflect the losses associated with the process and a new capability index CpI Is compared with the classical indices as $C_{p}$ , $C_{pk}$, $C_{pm}$ and $C_{pm}$ $^{+}$.>.+/./.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.3
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• pp.165-173
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• 2013

Core loss has a major effect on heat generation in synchronous motors with surface-mounted permanent magnets (SPMs). It is essential to perform heat transfer analysis considering core loss in SPM because core loss is seriously affected by torque and speed of motors. In the present study, mechanical loss, core loss and coil loss are evaluated by measuring input and output energies under various driving conditions. For a better understanding heat transfer paths in synchronous motors, we developed a lumped thermal system analysis model. Subsequently, heat transfer analysis has been performed based on acquired energy loss, temperature data and thermal resistance with three types of SPM. It is shown that the torque constants decrease by Max. 10% as speed increase. At the rated torque, the core loss is Max. 10.9 times greater than the coil loss and the hysteresis loss of magnets is dominant in total loss.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.8 s.239
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• pp.956-962
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• 2005

A three-dimensional computation was conducted to make a study about effects of the inlet boundary layer thickness on the total pressure loss in a low-speed axial compressor operating at the design condition ($\phi=85\%$) and near stall condition($\phi=65\%$). Differences of the tip leakage flow and hub corner-stall induced by the inlet boundary layer thickness enable the loss distribution of total pressure along the span to be altered. At design condition, total pressure losses for two different inlet boundary layers are almost alike in the core flow region but the larger loss is generated at both hub and tip when the inlet boundary layer is thin. At the near stall condition, however, total pressure loss fer the thick inlet boundary layer is found to be greater than that for the thin inlet boundary layer on most of the span except the region near hub and casing. Total pressure loss is scrutinized through three major loss categories in a subsonic axial compressor such as profile loss, tip leakage loss and endwall loss using Denton's loss model, and effects of the inlet boundary layer thickness on the loss structure are analyzed in detail.

• Journal of Family Relations
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• v.20 no.4
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• pp.105-130
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• 2016

Objectives: The purpose of this study was to explore the moderating effect of stress coping styles on the relationships between loss experiences and depression of the men and women elderly. Method: The subjects of the study were 116 men and 156 women aged over 60 years. For the data analysis, frequency, Cronbach's ${\alpha}$. Pearson's correlation coefficients, and multiple regression were used. Results: The main results were as follows: First, elderly men reported higher role loss experience, relation loss experience, and problem-focused coping styles than elderly women. Also elderly women reported higher bereavement experience than elderly men. Second, there were main effects of health loss experience, economy loss experience, role loss experience, relation loss experience, problem-focused coping style, and emotion-focused coping style on depression of elderly men and women. Third, problem-focused coping styles moderated the relationships between physical health loss experience, economy loss experience, role loss experience and depression in the elderly men group. Last, social support-seeks coping styles moderated the relationships between economy loss experience and depression in the elderly women group. Conclusions: These results were discussed in terms of educational programs related stress coping strategies for the elderly.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.2
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• pp.53-62
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• 2020

The purpose of this study is to estimate the channel water loss of agricultural water supply in the command areas belong to Yechon irrigation channel of Gyeongcheon reservoir located Mungyeong-si, which area experienced a severe drought in 2015. The channel water loss was estimated by comparison of the irrigation water requirements (IWR) and agricultural water supply of the field data from 2012 to 2015. Further analysis was conducted to define the conveyance loss estimated based on the leakage holes and illegal pumping spots investigated through the field survey, and the distribution loss obtained by subtracting conveyance loss from the channel water loss. The annual rainfall decreased gradually, but the contribution of effective rainfall, available rain water to crop, increased to IWR during the study period. These phenomena resulted in the increase of agricultural water supply, and hence made greater the channel water loss simultaneously. The average channel water losses estimated as 36.8 % with 7.1 % of the conveyance loss and 29.7 % of distribution loss respectively. The distribution loss seems to be related to total number of rainy days, and irrigation schedules, while the conveyance loss was caused by irrigation channel aging conditions and illegal intake problems. In order to achieve sustainable agricultural water resources, the channel water loss needs to be reduced through the restoration of aged irrigation facilities and effective water managements in the fields.

• The Journal of Korean Medicine
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• v.37 no.3
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• pp.62-73
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• 2016

Objectives: Dropout and weight regain are common problems in most obesity treatments. The purpose of this study was to review previously published study results of the predictive factors associated with dropout during weight loss treatment and weight loss maintenance after successful weight loss. Methods: Authors searched for the articles related to dropout and weight loss maintenance, published from 2007 to 2016 found on Pubmed, Scopus, RISS, and KISS. A total of 19 articles were finally selected. From the study results, unchangeable and changeable predictors were extracted, and these predictors were examined according to dropout and weight loss maintenance categories. Results: The unchangeable predictors of dropout were younger age, lower education level and female, whereas the changeable predictors of dropout were lower initial weight loss, symptoms of depression and body dissatisfaction. The strongest factor for predicting the dropout was initial weight loss. The unchangeable predictors of weight loss maintenance were old age, male and family history of obesity, whereas the changeable predictors of weight loss maintenance were regular exercise, dietary restraint, self-weighing and low depressive symptoms. Initial weight loss, depressive symptoms, body image, dietary restraint, physical activity, weight loss expectation and social support were considered to be dominant factors for weight loss treatments. Conclusions: Our review results suggest that unchangeable and changeable predictors of dropout and weight loss maintenance should be carefully examined during treatments of obesity.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.256-261
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• 2017

This paper deals with the experimental evaluation on power loss of a double-side permanent magnet synchronous motor/generator (DPMSM/G) applied to a flywheel energy storage system (FESS). Power loss is one of the most important problems in the FESS, which supplies the electrical energy from the mechanical rotation energy, because the power loss decreases the efficiency of energy storage and conversion of capability FESS. In this paper, the power losses of coreless DPMSM/G are separated by the mechanical and rotor eddy current losses in each operating mode. Moreover, the rotor eddy current loss is calculated by the 3-D finite element analysis (FEA) method. The analysis result is validated by separating the power loss as electromagnetic loss and mechanical loss by a spin up/down test.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.5
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• pp.295-304
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• 2004

This paper deals with characteristic analysis method using d-q axis equivalent circuit considering iron loss in a single-phase line-start permanent magnet synchronous motor. The iron loss resistance to account for the iron loss is included in the equivalent circuit to improve the modeling accuracy. Furthermore, for the improved calculation of the iron loss, the iron loss is calculated from the magnetic flux density by 2-dimensional finite element method. The result is represented as the iron loss resistance and connected in parallel with the total induced voltage. Therefore, the currents can be expressed as the summation the output current with the current corresponding to the iron loss. Finally, the steady state characteristic analysis results are compared with the experimental results to verify this approach.