• 한국안전학회지
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• 제30권4호
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• pp.39-45
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• 2015

This paper deals with development of integrity evaluation instrument for the power line surge protective device. A reliable power supply is an essential element in the developed information and communication society by highly advances in IT technology. However, the lightning incidence also increased with the recent extreme weather events. In Korea, in order to protect the electrical system from lightning surge, SPD(Surge Protective Device) has been used for these past 30 years. However, the method of diagnosing the safety of the SPD in the industry is insufficient. In this paper, SPD integrity evaluation system was composed of a variable DC power source unit, voltage-current sensor and the embedded controller. In order to measure V-I characteristics of MOV, 3 type samples were degraded by impulse current generator. After impulse tests, the varistor voltage of all samples and nonlinearity coefficient were decreased. It confirmed the utility of the developed equipment by this experimental test and the reliability of SPD is expected for surge accident prevention when applied to industrial plant.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.114-121
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• 2004

The sensor and measuring instrument that are used for the infrastructure is discussed the reliability problem from the various environment factors. In the domestic infrastructure, the low reliability products are produced, because of lack of the pertinent test methods and equipments. To improve the practical use and accuracy of the sensor, it raises the measurement reliability about the sensor and measurement instrument. In this study, the variance of the displacement value according to temperature was investigated using the LVDT for the infrastructure. The experimental results showed that a sensor is affected by environment factor such as temperature.

• 대한디지털의료영상학회논문지
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• 제10권1호
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• pp.21-28
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• 2008

Diagnostic display monitor QA according to AAPM TG18 is usually performed by PACS administrator, product manager and reading doctor, and for acceptance testing and periodic quality control evaluation, a combination of visual and quantitative tests can be used, as outlined in sections 5 and 6 of 'assessment of display performance for medical imaging systems'. Although many display tests can be performed visually, a more objective and quantitative evaluation of display performance requires special test tools. The required instruments vary in their complexity and cost, depending on the context of the evaluation(research, acceptance testing, or quality control) and how thorough the evaluation needs to be. Objective and reliable assessment of many display characteristics can be performed with relatively inexpensive equipment, So, we made 'AAPM TG18 guiding instrument' to ues variable purpose of the evaluation of 'geometrical distortions(quantitative"', 'veiling glare(visual)' and 'sensor calibration'. The spatial measurements for the quantitative evaluation of geometric distortions, and the measurement of the veling-glare ring response function which provides information regarding the spatial extent of the luminance spread, can be performed using the TG18 guiding instrument can be used to sensor calibration to standardize the basic rate of 0% luminance when periodic calibration.

• 영어어문교육
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• 제18권1호
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• pp.171-195
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• 2012

While noticing that there is insufficient interest in the assessment of EFL learners' vocabulary levels or sizes, the researchers developed two tests identical in form (Forms A and B) to assess the lexical knowledge of Korean university learners at the $1^{st}{\sim}10^{th}$ 1,000 word bands by adapting a pre-established vocabulary levels test (VLT). Of equal concern was to investigate if the VLT was equally a valid and reliable instrument to be used on measuring the lexical knowledge of EFL learners. The participants were 804 university freshmen enrolled in a General Education English Course from four different colleges. The learners were asked to respond to either Form A or B. While scores generally fell towards the lower frequency bands, multiple regression found the Korean College Scholastic Ability Test (CSAT) to be a significant variable for predicting the learners' vocabulary sizes. From a methodological perspective, however, noticeable differences between Forms A and B could be found with item response theory analysis. The findings of the study provide suggestions on how future VLT for testing EFL learners may have to be redesigned.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.550-553
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• 2002

A source meter is a basic instrument to perform a measurement of DC characteristic of semiconductor devices. the source meter can be used as variable voltage source, variable current source, voltage meter, or current meter. The accuracy of the low current measurement can be improved with the compensation of leakage current and charge and discharge current. In the low current measurement, the RC time constant is extremely big, so the measurement speed is very low. In this thesis, the analysis of the behavior of the measurement current according to the RC time constant and output capacitance and the method to accelerate the measurement speed.

• 한국사회복지학
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• 제42권
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• pp.83-106
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• 2000

The purpose of this study is to identify the common factors that affect adolescents, drinking and delinquency. Previous studies have supported that parenting is the most important variable to explain adolescents' drinking and delinquency. For study, 497 adolescents from middle schools and high schools in Inchon city, Korea, were recruited. Instrument for measurement consists of affective-tie and supervision regarding parenting, drinking, and delinquency. Stepwise multiple regression was used as a main statistical analysis. According to the results, even though there is some association between drinking and delinquency, this study found that the most strong predictable variable in explaining adolescents' drinking and delinquency is parenting. That is to say, effective parenting can contribute to prevent adolescents's drinking and delinquency. Therefore, this study suggests that social services and programs to support effective parenting should be provided.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.1041-1043
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• 1993

A robust position control scheme for a Brushless Direct Drive Motor(BLDDM) is presented. To obtain the robustness under the load variation, a Variable Structure Controller(VSC) is used. However, the VSC has a chattering problem and require the full state informations. To overcome this problem, in this paper, the sliding mode observer is used for compensating the load disturbance and estimating the motor velocity. As a result, the VSC for a BLDDM posision control is designed by using only position measurment and the chattering problem is greatly reduced. To show the validaty of the proposed scheme, the simulation study is carried out.

• 대한원격탐사학회지
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• 제19권1호
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• pp.1-9
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• 2003

MODIS LAI product has been one of key variable for analyzing the quantitative aspects of terrestrial ecology at global scale. This study was designed to validate MODIS global LAI product for regional application. To examine the quality of MODIS LAI data, we developed a reference LAI surface that was derived by relating the ground LAI measurements to Landsat ETM+ reflectance. The study area, the Kwangneung Experiment Forest in Korea, covers mixed deciduous and coniferous species of temperate forest. Ground measurements of LAI were conducted at 30 sample plots by using a photo-optical instrument during the growing season of 2002. Ground measured LAI data were then related to the ETM+ reflectance to produce a continuous map of LAI surface over the study area. From the comparison between the MODIS LAI and the reference LAI, it was found that the MODIS LAI values were slightly higher at the forestland. Considering the limitations of producing the reference LAI surface and the uncertainty of the input variable for the MODIS LAI algorithm, such small discrepancy mal not be significant.

• 성인간호학회지
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• 제12권1호
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• pp.112-121
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• 2000

The purpose of this study was to define the degree of the resourcefulness and the health-promoting behavior of cancer patients, to identify the relationship between the resourcefulness and the health promoting behaviors and to provide the basis for strategic nursing intervention. This study was conducted by an exploratory survey. Data were collected by self-reported questionnaires from 97 cancer patients in a university hospital in Tae-Gu from September to December of 1998. The sample data were collected by using a convenient sampling method. The following instruments were used in the study after some adaptation : Park Chai Soon's Health Promoting Lifestyle Profile, Oh Pok Ja's instrument for health promotion behavior and the Rosenbaum self-control schedule(SCS). The reliability of instruments was tested with Chronbach'alph(.79-.89). Data was analyzed by using the SAS program. T-test, ANOVA, and Pearson's coefficients of correlation. The results of this study were as follows: First, the average score of the resourcefulness variable was 22.20; the range of the score was from -30 to +81 The average score of the performance in the health promoting behavior variable was 96.13; the range of the score was from 39 to 137 Second, the resourcefulness variable was significantly different from such demographic factors as gender and perceived health status, but there was no statistically significant difference between the demographic factors and the health promoting behavior variable, except that of perceived health status. Third, the performance in health promoting behavior of cancer patients was significantly correlated with the resourcefulness of cancer patients(r= .50) In conclusion, resourcefulness was identified to be an important variable that could contribute to promote health-promoting behavior.

• 성인간호학회지
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• 제27권4호
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• pp.375-383
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• 2015

Purpose: The purpose of this study was to identify the relationship of resiliency and symptom experience and depression. Subjects (N=152) were patients with chronic obstructive pulmonary disease (COPD).admitted to D University Medical Center in B City. Methods: Data collection was conducted from July 20 to August 25, 2013. The levels of symptom, resilience, and depression were measured using a seven question symptom experience measuring instrument, a 25-question resilience instrument, and a 15-question Short Geriatric Depression Scale (SGDS). The collected data were analyzed by descriptive analysis, Pearson's correlation coefficients, and path analysis using SPSS/Win 19.0 and AMOS 5.0. Results: There was a significant negative correlation between symptom and resilience, a significant positive correlation between symptom and depression, and a significant negative correlation between resilience and depression. Symptom showed a direct effect on depression and an indirect effect on depression scores through resilience as a mediating variable. Conclusion: It is necessary to develop nursing intervention programs to relieve symptom in COPD patients, and to develop appropriate resilience enhancement programs to reduce their depression.