• 한국치위생학회지
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• 제16권5호
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• pp.759-766
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• 2016

Objectives: The purpose of the study was to investigate the impact of dental fear on the oral health related quality of life in teenagers. Methods: A self-reported questionnaire by Likert 5 point scale was completed by 900 high school students in J area from March 10 to April 20, 2014. The questionnaire consisted of general characteristics of the subjects, dental fear survey, and oral health related quality of life. Data were analyzed by t-test and One-way ANOVA using SPSS 12.0 program. Results: Oral symptoms had no significant differences in mother's education and family economic status. Emotional well-being factors had no significant difference in age, religion, school performance, and family economic strength. Dental fear was closely related to emotional well-being, Oral symptoms, social stabilities, functional limit and mental stabilities. Explanation power of the model was 29.1%. Conclusions: It is very important to explain the dental fear procedure to teenagrers before dental surgery and this will enhance the oral health related quality of life in teenagers.

• 한국정밀공학회지
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• 제33권5호
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• pp.401-407
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• 2016

This paper describes the derivation methodology of the working torque predictive model that can be used in the initial design stages of the impact hammer tool. The working torque control mechanism is designed, taking into account various factors, such as the force of the spring and friction. Firstly, the analysis dynamic model for working environments was modeled as an additional bush and spring, and verified by comparing the test results of the working torque. Secondly, the main performance parameters of the working torque were theoretically defined by analyzing the operating mechanism. The equation to predict the working torque was derived using the dynamic analysis results according to the value changes of the parameters. The prediction equation of the working torque was validated by comparing the predicted results with the experimental data. The error difference between the experimental data and the predictive model results was found to be 8.62%.

• 전산구조공학
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• 제10권3호
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• pp.233-240
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• 1997

본 연구에서는 다양한 구조 및 하중조건에 대하여 중차량의 주행에 의한 충격효과를 분석하였다. 중차량 주행시의 다주형 강판형교의 동적해석에서는 노면조도 및 차륜-바닥판 사이의 상호작용을 고려하였다. 진입로와 교량바닥판의 노면형상은 각 노면조도에 따라 지수 스펙트럴 밀도 함수를 사용하여 생성시켰으며, 교량바닥판과 차륜사이의 상관력을 좀더 합리적으로 반영하기 위해 개선된 후처리기법을 사용하여 보정하였다. 또한 교량진입부에서 발생할 수 있는 바닥판과 진입로사이의 단차조건도 분석하였다. 현행 도로교 표준 시방서에 준하여 설계된 다양한 교량들에 대하여 동적거동에 중요한 영향을 미치는 구조인자들(경간장, 주형간격 등)의 영향을 체계적으로 검토하였다. 다양한 주행속도에 따른 단일주행에 의한 기본적인 하중상태 뿐만 아니라 동일차선 및 인접차선을 주행하는 다수 차량의 하중조건도 검토하였다.

• 디지털융복합연구
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• 제19권10호
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• pp.119-132
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• 2021

본 연구는 기업가정신에 있어 성별 간 차이가 나타나는 현상 자체가 아닌 기업가정신의 성별 차이를 발생시키는 사회적 맥락의 영향을 확인하는 데에 초점을 둔다. 구체적으로 본 연구는 글로벌 기업가정신 트렌드 리포트(GETR)의 20개국 데이터를 사용하여 사회적 맥락이 성별과 기업가정신 간 관계에 미치는 조절효과를 검증하였다. 사회적 맥락의 함의와 관련된 가설검증을 위하여, 본 연구에서는 Hofstede의 문화차원 요인인 권력 거리, 개인주의, 남성성, 불확실성 회피와 제도적 요인인 양성평등, 사회보장을 사회적 맥락을 반영하는 구체적 변수로 사용하였다. GLM을 사용한 실증분석 결과 성별은 기업가 정신에 독립적으로 영향을 미치지 않았으며, 성별은 각각 권력 거리, 개인주의, 불확실성 회피, 양성 평등, 사회 보장 변수와 상호 작용하여 유의한 영향을 미치는 것으로 나타났다. 이와 같은 본 연구의 결과는 기업가정신의 성별 차이가 각 성별에 내재된 고유의 특성에 기인한 것이 아니라, 개인이 속한 그 국가의 사회적 맥락 수준에 따라 나타날 수 있음을 시사한다.

• 한국포장학회지
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• 제21권2호
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• pp.61-65
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• 2015

Agricultural products packaged for transportation are put in the various dangerous environments owing to the damage factors like vibration, shock, compression, climate etc. under the distribution process. On fruits packaging for transportation, especially, the shock and vibration is considered as the most important damage factors. A major cause of shock damage to fruits is drops during manual handling. Especially, the damages of fruits during the parcel delivery service are very serious. The parcel delivery services of fruits are increasing and contribute to increasing of farm house earning. Also, the freight vehicle is mostly used to transport the fruits. Shock and impact generated by the freight vehicle may give serious damage to fruits. The optimum packaging design of parcel delivery service of fruits during transportation is required to reduce the fruits damages. In order to design the packaging system for parcel delivery service of fruits considering the transportation environment, the comprehension of characteristics for vibration and shock generated by manual handling and acting on transportation vehicles under various road conditions and loading methods is required. This research was performed to analyze the shock characteristics, acceleration level and power spectral density (PSD) during the parcel delivery service of fruits. The overall level of recommended PSD profile in a specific transportation of parcel delivery service for fruits was $0.63G_{rms}$.

• 조명전기설비학회논문지
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• 제18권4호
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• pp.131-137
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• 2004

전력서비스 중단이 전력소비자에 끼치는 충격은 소비자와 정전 특성에 달려있다 소비자 특성은 인구통계학적인 측면(주거형태와 가족구성원 수)과 전력공급 형태를 포함하는 반면에 정전특성은 발생 빈도, 기간, 시간과 요일을 포함한다. 따라서 이러한 소비자 정전비용의 평가는 상당히 복잡하고 주관적이다. 주거용 소비자들의 경우, 주거용 소비자에 대한 정전의 충격이 가시적이지 않기 때문에 소비자 조사 방법이 가장 적합할 것으로 보인다. 달리 말하면, 가사일과 정전으로 인해 여가의 가치가 각자 다르기 때문이다. 따라서 본 논문에서는 주택 수용가에 대한 정전 비용을 평가하기 위한 방법으로서 수용가 설문조사 방법을 선택하였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 춘계학술대회 논문집
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• pp.247-253
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• 2004

As a large scale port development in coastal waters proceeds step by step and populations in the vicinity of port are getting increased, the issue on "how to dispose the treated municipal water and wastewater in harbor" brings peoples′ concern. The submarine outfall system discharges the primary or secondary treated effluent at the coastline or in deep water, or between these two. The effluent, which has a density similar to that of fresh water, rises to the sea surface forming plume or jet, together with entraining the surrounding sea water and becomes very dilute. We intended in this paper to investigate the impact on dilution of effluent and the behavior of flume under the conditions of the seasonal and spatial temperature variations, which have not been noticeable in designing effective marine outfall system. To predict and analyze the behaviour and dilution characteristics of plume not just with the effluent temperature, but also with the seasonal variation of temperature of surround water and tidal changes, CORMIX(Cornell Mixing Zone Expert System)-GI have been applied. The results should be used with caution in evaluation the mixing zone characteristics of discharged water. We hope to help for the effective operation of outfall system, probable outfall design, protection of water quality, and warm water discharges from a power plant, etc.

• 전기학회논문지
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• 제65권1호
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• pp.65-72
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• 2016

This paper presents the analysis of the analysis of thrust characteristics of linear induction motors(LIMs) according to secondary reaction plate. LIMs are well known as high speed transport systems, which can obtain thrust directly without gears and links, or auxiliary mechanisms. A simple structure, easy maintenance, and less environmental pollution are advantages of LIMs. In transport systems using LIMs, the secondary reaction plate is an important design factor, because it has considerable impact on the cost of the railway as well as the performance of the LIMs. This paper deals analyzed the characteristics of linear induction motor used for moving the vehicle of container scanner. Thrust, efficiency and load characteristic were interpreted with FEM regarding two models whose material of secondary reaction plate was copper and aluminum. It suggested the interpretation of thrust, efficiency and power factor characteristic along slip and compared the operation ability of linear induction motor through characteristics analysis along the load.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.568-572
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• 2001

An industrial vibratory conveyor system is devised for large-scale feeding by the low-power, using natural frequency of the system. The important thing in this system is to determine the natural frequency and to drive by it. The purpose of this study is to build up reliance on the system with changing of element parameters for vibration characteristics of balancing type vibratory conveyor by using F.E.M. modeling. For investigating the natural frequency, modal testing is performed by using impact hammer, accelerometer and LMS/Vibration Analysis System. Experimental results are compared with F.E.M results. The results of the comparisons within the errors of less than 2 percent can verify the reliability of the F.E.M. analysis of the system. Also we can verify that the characteristics of natural frequency have linearly decreased(-6%) as adding the mass($50{\sim}600kg$). We can find that controlling driving frequency is necessary for triggering the natural frequency, but natural frequency is less affected by adding the mass on the balancing weight.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2005년도 춘계 학술대회
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• pp.513-517
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• 2005

This study examined the possibility of using striped field mice as a biological dosimeter or indicator for the environmental radio-surveillance. For this study, the external morphological characteristics and isoenzymic types of dark-striped field mice were studied after they were captured. Among the morphological external characteristics, the dark-brown coat, dark back stripe, head-to-tail length, tail length, and ear length matched the taxonomical characteristics of dark-striped field mice. The analyses on L-lactate dehydrogenase, aspartate aminotransferase, and malate dehydrogenese revealed that one species of dark-striped field mice, called Apodemus agrarius, was inhabitated throughout a wide range of Korea. On the other hand, A. agrarius and ICR mice to analyze their survival rate and frequency of micronuclei in peripheral polychromatic erythrocytes after irradiation (0, 0.5, 1, 3, 5, 7, 9 Gy). The $LD_{50/30}$ of A. agrarius and ICR mice were approximately 5 Gy and 7Gy, respectively. The results of the study reveal that wild A. agrarius have a high potential as a biological monitoring system to determine the impact of radiation effect in areas such as those within the vicinity of nuclear power plants.