• 한국치위생학회지
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• 제9권2호
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• pp.111-124
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• 2009

This study analyzes through the review of literature and laws the exposure time, clinical frequency, and radiation exposure of intraoral and extraoral radiography as well as of panoramic radiography performed by dental hygienists in dental clinics, compares the dental radiology curriculums of radiological science and dental hygiene departments, and proposes the expansion of dental hygienists' radiography operations. The radiology curriculums were compared between the radiological science and dental hygiene departments of colleges. For new analysis by radiography for dental diagnosis, the exposure time, radiation absorbed dose, effective dose, and number of days of natural radiation were compared by the type of oral radiation films and radiographical techniques proposed by domestic and international studies. The exposure time of panoramic radiography is 15 seconds and it takes about two minutes for completion, whereas the exposure time of the standard radiography is 0.2~0.8 seconds and it takes 10 times longer for completion of the radiography of full mouth than the panoramic radiography. The standard radiography can cause distortions of radiation at severely curved parts of dental arch and palatopharyngeal reflex. However, panoramic radiography can be performed even for lock jaw patients, causes less inconvenience to patients and is much simpler than the standard radiography. The percentage of dental clinics where radiography is performed by dental hygienists was 92.0%, and the percentage of standard film radiography by dental hygienists was 98% whereas the percentage of panoramic radiography by dental hygienists was 92%. For the absorbed dose which is an indicator of radiation exposure, the When the effective dose which is an indicator of the danger of radiation exposure was converted to the number of days of natural radiation, it was 3.3 days for panoramic radiography, but 13.9 days for the full mouth standard radiography by bisecting angle technique which was 4.2 times longer than the panoramic radiography. There were two colleges that had a dental radiology course with two credits in the departments of radiological science. The credits for dental radiology courses in the department of dental hygiene ranged varied by college, ranging from 3 to 8; on average, the theory course was 2.2 credits and the practice course was 2.02 credits. To summarize the above results, the percentage of dental clinics where panoramic radiography is performed by dental hygienists under the guidance of dentists is high. Panoramic radiography has become an essential facility for dental clinics. It is faster than standard film radiography and less dangerous due to low radiation exposure. Panoramic radiography is a simple mechanical job that does not require training of oral radiography by radiotechnologist. Because panoramic radiography is one of major operations which must be performed at all times in dental clinics, it must be designated as intraoral technique rather than extraoral technique, or legalized for inclusion in the scope of operations of dental hygienists.

• 한국운동역학회지
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• 제23권2호
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• pp.109-116
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• 2013

The purpose of this study was to provide fundamental information for the enhancement of performance through kinematic analysis of cornering according to the radius of curve course in short track speed skating. To perform this study, six skaters: three narrow radius players(N, body mass: $56.0{\pm}7.2$ kg, height: $163.7{\pm}5.1$ cm, age: $21.3{\pm}1.5$ yrs) and three wide radius players(W, body mass: $61.0{\pm}9.5$ kg, height: $169.0{\pm}4.4$ cm, age: $20.0{\pm}1.7$ yrs). Three-dimensional motion analysis was performed on the section from the forth block starting to show the change of radius to the sixth block using eight infrared cameras(sampling frequency of 100 Hz for N and W players). The time of push-off was greater for N than for W(p<.05) while the radius of center of mass was greater for W than for N(p<.05). The flexion and extension of knee and hip joint were greater for N than for W(p<.05). The external rotation of left knee joint was greater for N than for W(p<.05). Based on the findings, a small radius by increasing the range of the flexion and extension of knee and hip joint with greater external rotation of left knee joint would be related to more efficient run at curve. It is expected that these results will be useful in developing a training program for enhancing performance of short track speed skating athletes.

• 통상정보연구
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• 제8권4호
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• pp.391-411
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• 2006

The present Study investigated on effect of working time and physical work environment on job satisfaction, and is based on a representative survey carried out in the 15 European Union Member States in 2,000 on behalf of the European Foundation for the Improvement of Living and Working Conditions by Infratest Burke Sozialforschung and a consortium of national fieldwork institutes. In the course of the survey, a total of 21,703 people drawn from the economically active populations in the 15 countries were questioned about their working time, overtime, weekend work, physical work environment, social support of supervisor and co-worker and job satisfaction. Regression analysis and subgroup analysis were employed to examine the hypotheses. It was found that weekend work, overtime and physical work environment associate negatively with job satisfaction. Social support of supervisor and co-worker moderated only relation between working time and job satisfaction. The results provide support for prior quantitative studies partly. Based on these significant research findings, theoretical implications were discussed.

• 전기학회논문지P
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• 제57권2호
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• pp.91-95
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• 2008

The large AC generator fault may lead to large impacts or perturbations in power system. The generator protection control systems in Korea have been imported and operated through a turn-key from overseas entirely. Therefore a study of the generator protection field has in urgent need for a stable operation of the imported goods. In present, the algorithm using the current ratio differential relaying based DFT for stator winding protection or a fault detection had been applied that of internal fault protection of a generator. the DFT used for the analysis of transient state signal conventionally had defects losing a time information in the course of transforming a target signal to frequency domain. In this paper, the discrete wavelet transform (DWT) was applied a fault detection of the generator being superior to a transient state signal analysis and being easy to real time realization. The fault signals after executing a terminal fault modeling collect using a MATLAB package, and calculate the wavelet coefficients through the process of a muiti-level decomposition (MLD). The proposed algorithm for a fault detection using the Daubechies WT (wavelet transform) was executed with a C language and the commend line function for the real time realization after analyzing MATLAB's graphical interface. The advanced technique had improved faster a speed of fault discrimination than a conventional DFR based on DFT.

• Journal of Preventive Medicine and Public Health
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• 제15권1호
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• pp.179-186
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• 1982

The methods controlling the confounding factors were discussed using the data of secondary infertility with induced abortion. Mantel-Haenszel method and logistic model were applied in the analysis to find out which factors were confounding and/or effect modification variables. In the logistic analysis, the main effect of induced abortion, spontaneous abortion, age and interaction effect between induced abortion and spontaneous abortion were chosen as independent variables being regressed into logistic functions. Spontaneons abortion was interpreted as a potential confounder and at the same time potential effect modifier and age was interpreted as potential confounder. Spontaneous abortion was shown to be more important influencing factor than age to the secondary infertility. In the course of logistic analysis, the problem of parameter estimation and hypothesis testing, assessing the fitness of a model, and selection of the best model were briefly explained. For the program of logistic model, FUNCAT Procedure of SAS package was chosen.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2006년도 추계학술대회
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• pp.427-430
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• 2006

Clustering for gene expression data without filtering out noise genes may be distorted or derived inappropriate inference. Identifying significant genes and deleting noise before major analysis is necessary fur meaningful discovery from genes expression pattern. We proposed a new method of finding significant genes using factor analysis which is done on transposed data matrix. We construct significance score that is sum of factor loadings for declared significant number of factor, and set threshold through replication. Our proposed method works well for simulated time-course data for finding significant genes even though variance level gets larger.

• The Korean Journal of Ecology
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• 제21권5_1호
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• pp.427-433
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• 1998

The standing crop and net production were estimated in Moojaechi on Mt. Jungjok. By using the decay model of organic carbon, absolute year of bog peat was calculated. Pollen analysis to bog peat revealed vegetational history and climate change around Moojaechi. The time required for amount of the accumulated peat in the bog was estimated in terms of the balance of the accumulation and decay of organic carbon of the deposit peat. Absolute year of the peat surveyed in this study was about 314 years. Pollen of Pinus was predominant in all the pollen zone, Geamineae and Cyperaceae increased in lower pollen zone while Pinus in upper pollen zone. This showes that climate of the past was probably more humid than that of present. In addition, middle pollen zone showed warming trend which is suggested by high pollen concentration of Quercus, Juglans, Carpinus and Corylus. It suggests that overall environment and vegetation were changed from warmer and more humid to dry condition in Moojaechi and it is considered as the course of boggy ground formation by retrogressive successions.

• 컴퓨터교육학회논문지
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• 제14권5호
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• pp.1-8
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• 2011

본 연구에서는 전문계 고등학교 학생들의 알고리즘 시간효율성에 관한 개념 이해 수준을 확인하고 빈번하게 발생하는 오개념 유형들을 확인하고자 하였다. 선행연구에서 확인된 세 가지 유형의 오개념들을 토대로 9개의 오개념 측정 문항을 개발하였으며, 프로그래밍 관련 과목을 이수한 51명의 전문계 고등학교 학생들을 대상으로 조사를 실시하였다. 연구결과, 알고리즘 시간효율성에 관한 개념 이해도는 매우 낮은 수준으로 나타났으며, 견고하고 반복적으로 발생되는 여러 유형의 오개념들을 확인하였다. 마지막으로, 확인된 오개념들을 과학적 개념으로 변화시키기 위한 교육적 전략인 시뮬레이션 및 알고리즘 효율성 평가 틀의 활용 방안과 함께 교육과정 개선의 필요성을 제안하였다.

• 한국산학기술학회논문지
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• 제19권4호
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• pp.123-131
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• 2018

본 연구는 ${\bigcirc}{\bigcirc}$ 고속국도 공사 중 발생된 이암 절토 사면의 붕괴 요인 분석 및 대책방안을 제시하였다. 기반암인 이암에 대해 실내시험을 수행하고, 국제 기준에 의거해 공학적인 특성을 규명하였다. 그리고 설계 시 수행되었던 사면안정해석을 재검토 하였다. 또한, Swelling-Slaking 현상으로 인해 기반암인 이암의 강도열화특성을 고려한 안정해석을 추가적으로 수행하였다. 기반암인 이암에 대해 Swelling-Slaking Test 결과, 풍화내구성은 낮음-보통으로 나타났으며, 팽창변형률은 매우 낮음으로 나타났다. 설계 안정해석 검토 결과, 이암의 공학적 특성을 고려하지 않고, 한계평형해석을 이용해 실제와 상이한 결과가 나타났다. 강도열화특성을 고려한 추가안정해석 결과, 사면의 붕괴지점과 안정해석의 최대전단변형률 발생지점이 동일하게 나타났으며, 건기시 우기시 모두 기준 안전율을 만족하지 못하였다. 붕괴 사면의 대책방안으로는 사면경사완화공법이 가장 적절하였다. 유한요소해석을 통해 완화 경사를 산정하였다. 완화 경사의 현장 적용성을 위해 시추공영상촬영과 비교한 결과, 미고결된 이암의 대부분이 제거되는 것으로 나타나 미고결된 이암으로 인한 추가적인 붕괴 위험성은 현격히 저하되는 것으로 나타났다.

• 대한간호학회지
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• 제33권5호
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• pp.562-569
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• 2003

Purpose: The purpose of this longitudinal prospective study was to assess changes in fatigue and quality of life for a 6-week course of radiotherapy. Method: A descriptive and longitudinal design was used to this study. Twenty-three subjects receiving radiotherapy from a radiotherapy clinic of a general hospital completed the questionnaires. Fatigue was measured using Lee's scale(1999) and quality of life using Yang's scale(2002) weekly for 6 weeks. Result: Fatigue significantly increased(F=6.043, p=.000), and quality of life significantly decreased (F=3.938, p=.003) and physical symptoms also significantly increased(F=2.432, p=.039) during a 6-week radiotherapy. Multiple regression analysis revealed that fatigue at the first week and physical symptoms at the 6th week were the significant affecting variables(60.1% of the variance) on fatigue. And 63.2% of the variance in quality of life was explained by quality of life and fatigue at the first week and body weight change for 6 weeks radiotherapy. Conclusion: Based on these results, the fatigue and quality of life at the beginning time of radiotherapy have a lasting impact throughout the course of treatment. It suggests that nurses provide patients with information about the occurrence of fatigue during radiotherapy and the practical methods of intervening physical symptoms.