• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제7권6호
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• pp.205-220
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• 2018

소프트웨어 결함 예측은 결함이 자주 발생하는 모듈에 집중함으로써 소프트웨어 품질 보증 활동에 귀중한 프로젝트 리소스를 효과적으로 할당하는 데 도움이 될 수 있다. 회사 내에서 수집 된 충분한 기록 데이터를 사용하여 정확한 결함 발생 가능성이 높은 모듈 예측에 대해 WPDP (프로젝트 내 결함 예측)를 사용할 수 있다. 회사가 과거 데이터를 유지하지 못한 경우 CPDP (Cross-Project Defect Prediction) 메커니즘을 기반으로 오류를 예측하는 분류기를 만드는 것이 도움이 될 수 있다. CPDP는 다른 조직에서 수집 한 다른 프로젝트 데이터를 사용하여 분류기를 작성하기 때문에 정확한 분류기를 만드는데 가장 큰 장애물은 소스와 대상 프로젝트 간의 서로 다른 분포이다. 이 문제의 해결을 위해 효과적인 유사도 측정 기술을 식별하는 것이 중요하므로, 본 논문에서는 다양한 유사도 측정 기술을 CPDP 모델에 적용하여 성능을 비교한다. 유사도 가중치의 유효성을 평가하고, 통계적 유의성 검정 및 효과 크기 검정을 통해 결과를 검증한다. 실험 결과, k-Nearest Neighbor (k-NN), LOcal Correlation Integral (LOCI) 및 Range 방법이 유사도 측정 기술 중 상위 3 개에 속했고, 이들을 사용하는 CPDP 예측 성능이 WPDP의 성능과 유사하였다.

• 한국치위생학회지
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• 제9권1호
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• pp.73-84
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• 2009

The purpose of this study was to examine the professional self-concept of dental hygiene students, their satisfaction level with clinical practice and the correlation of the two factors. The subjects in this study were 129 dental hygiene seniors at a college located in the city of J. The selected students had been engaged in a 16-week clinical practice. The findings of the study were as follows: 1. The dental hygiene students investigated got a mean of 3.34 out of possible five points on professional self-concept. As for the subfactors of professional self-concept, they got 3.75, 3.38 and 2.87 respectively on communication, professional work handling and satisfaction level. 2. They got a mean of 3.29 out of possible five points on satisfaction level with clinical practice. As to the subfactors of the satisfaction level, they gave 3.60, 3.50, 3.46, 3.04 and 2.83 to environments for practice, the content of practice, supervision, the length of practice and evaluation respectively. 3. In regard to the relationship of general characteristics to professional self-concept, satisfaction level with the major and social perception of dental hygienist made significant differences to professional self-concept. 4. As for connections between the general characteristics and satisfaction level with clinical practice, satisfaction with clinical practice was significantly different according to satisfaction with the major, satisfaction with the amount of practice and satisfaction with social perception of dental hygienist. 5. There was a significantly positive correlation between professional self-concept and satisfaction level with clinical practice(r=.383, p=.001). In conclusion, how much dental hygienists who are trained to be a dental hygienist are gratified with clinical practice is one of integral factors to affect their development of professional self-concept. Therefore prolonged research efforts should be directed into determining in which way clinical practice should be implemented to develop the professional self-concept of would-be dental hygienists and how to raise their satisfaction with clinical practice.

• 한국과학교육학회지
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• 제15권1호
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• pp.116-125
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• 1995

This study is to consider hypotheses with integral view on the respect of creative thinking. Subjects of this study are Korean students in the 5th grade who participated in the Field Trip Contest of the second Korean Youth Science Festival, an openended inquiry investigation. Objectives of this study are as follows: 1) to measure the inquiry level of the Field Trip Contest activity 2) to find how many hypotheses were made on different types in the inquiry investigation 3) to measure the quality level of hypotheses made in the scientific inquiry investigation 4) to find out the correlation between the 1st and 2nd hypotheses and the final activity score in the two staged scientific investigation In the consequence of it, inquiry level of the Field Trip Contest was very high with good activity topics and openended way of investigation. Hypotheses were made in the prediction, plan, and conclusion parts in the field trip activity report. They used hypothesis-as-prediction typed statements(3.41/team) more than hypothesis-as-explanation(1.28/team) and descriptive hypothesis(0.03/team) types. Content-related hypothesis(5.03/team) and process-related hypothesis(6.16/team) were usually coupled each other. Most of them had difficulties in hypothesis-from-evidence(0.31/team, 10/32 teams) in the comparison of hypothesis-from-simple conjecture(10.62/team). The quality level of content-related hypotheses(0.74point/statement) and process-related hypotheses(1.98point/statement) were very low by the hypothesis-quality scale(Quinn and George, 1975) for the content-related hypotheses and the process-related hypothesis quality scale developed in this study. There was considerable correlation between the activity score and the 1st and 2nd hypothesis in the 2 staged inquiry investigations with the 2nd and 3rd topics($0.41{\ast}$, $0.59{\ast}{\ast}$ repectively).

• Imaging Science in Dentistry
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• 제43권4호
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• pp.253-259
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• 2013

Purpose: Radiographs is an integral part of patient management in dentistry, despite their detrimental effects. As the literature pertaining to radiation protection among Indian dental practitioners is sparse, exploring such protection is needed. Materials and Methods: All private dental practitioners in Mangalore, India were included in the study. A structured, pre-tested, self-administered questionnaire was employed to assess the knowledge, attitudes, practices, previous training, perceptions towards the need to spread awareness, and willingness to gain and implement knowledge about radiation hazards and protection. Information regarding each respondent's age, gender, education, and type and duration of practice was collected. Results: Overall, 87 out of 120 practitioners participated in the study. The mean knowledge, attitude, and practice scores were $9.54{\pm}2.54$, $59.39{\pm}7.01$, and $5.80{\pm}3.19$, respectively. Overall, 25.3% of the respondents had undergone training in radiation protection, 98.9% perceived a need to spread awareness, and 94.3% were willing to improve their knowledge. Previous training showed a significant correlation with age, sex, and duration of practice; attitude was significantly correlated with education and type of practice; and knowledge scores showed a significant correlation with type of practice. Conclusion: Although the knowledge and practices of respondents were poor, they had a positive attitude and were willing to improve their knowledge. Age, sex, and duration of practice were associated with previous training; education and type of practice with attitude scores; and type of practice with knowledge scores. The findings of this study suggest a policy is needed to ensure the adherence of dental practitioners to radiation protection guidelines.

• Wind and Structures
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• 제17권1호
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• pp.43-68
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• 2013

The fluctuating wind induced vibration is one of the most important factors which has been taken into account in the design of long-span bridge due to the low stiffness and low natural frequency. Field measurement characteristics of sustained wind on structure site can provide accurate wind load parameters for wind field simulation and structural wind resistance design. As a suspension bridge with 1490 m main span, the Runyang Suspension Bridge (RSB) has high sensitivity to fluctuating wind. The simultaneous and continuously wind environment field measurement both in mid-span and on tower top is executed from 2005 up to now by the structural health monitoring system installed on this bridge. Based on the recorded data, the wind characteristic parameters, including mean wind speed, wind direction, the turbulence intensity, the gust factors, the turbulence integral length, power spectrum and spatial correlation, are analyzed in detail and the coherence functions of those parameters are evaluated using statistical method in this paper. The results indicate that, the turbulence component of sustain wind is larger than extremely strong winds although its mean wind speed is smaller; the correlation between turbulence parameters is obvious; the power spectrum is special and not accord with the Simiu spectrum and von Karman spectrum. Results obtained in this study can be used to evaluate the long term reliability of the Runyang Suspension Bridge and provide reference values for wind resistant design of other structures in this region.

• 한국안전학회지
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• 제36권3호
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• pp.74-80
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• 2021

Korea Atomic Energy Research Institute (KAERI) has been operating an integral effects test facility, the Advanced Thermal-Hydraulic Test Loop for Accident Simulation (ATLAS), according to APR1400 for transient experimental and design basis accident simulation. Moreover, based on the experimental data, the domestic standard problem (DSP) program has been conducted in Korea to validate system codes. Recently, through DSP-05, the performance of the passive auxiliary feedwater system (PAFS) in the event of multiple steam generator tube rupture (MSGTR) has been analyzed. However, some errors exist in the reference input model distributed for DSP-05. Furthermore, the calculation results of the heat loss correlation for the secondary system presented in the technical report of the reference indicate that a large difference is present in heat loss from the target value. Thus, in this study, the reference model is corrected using the geometric information from the design report and drawings of ATLAS. Additionally, a new heat loss correlation is suggested by fitting the results of the heat loss tests. Herein, MSGTR-PAFS accident analysis is performed using MARS-KS 1.5 with the improved model. The steady-state calculation results do not significantly differ from the experimental values, and the overall physical behavior of the transient state is properly predicted. Particularly, the predicted operating time of PAFS is similar to the experimental results obtained by the modified model. Furthermore, the operating time of PAFS varies according to the heat loss of the secondary system, and the sensitivity analysis results for the heat loss of the secondary system are presented.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제29권3호
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• pp.423-439
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• 2015

본 연구는 대학 신입생의 고등학교 재학 시 선행학습경험, 내신등급, 수능수리영역등급과 대학에서의 대학수학교과성적, 대학학업성취도(GPA) 간의 관계를 보았다. 이를 통해, 고등학교 재학 시의 수학교과 학업능력이 대학 신입생의 대학수학교과성적에 어느 정도 영향을 미치는지 분석하고자 하였다. 연구의 목적을 위해, A대학교 2014학년 1학기에 개설된 '기초미적분학'을 수강한 이과대학 및 공과대학 신입생 193명을 대상으로 설문을 실시하고 성적 등 관련 자료를 활용하였다. 이들 자료는 기술통계, 상관분석, 차이검정, 일원변량분석(ANOVA), 사후검정 및 회귀분석을 실시하였다. 연구결과, 첫째, 연구 대상 대학생의 90% 이상이 고등학교 재학 시 수학교과 선행학습을 한 것으로 나타났으며, 둘째, 선행학습의 효과성에 대한 인식은 필요성 인식보다 유의미하게 낮게 나타났다. 셋째, 대학수학교과성적과 대학학업성취도 간에는 높은 정적 상관관계가 있었으나, 내신등급과 대학학업성취도 간 및 수능수리영역등급과 대학수학교과성적 간에는 미미한 수준의 상관관계만 있었다. 넷째, 고교성적(내신등급, 수능수리영역등급), 선행학습노력, 선행학습만족도, 선행학습필요성이 대학수학학업성취도에 미치는 영향력은 미미한 수준이었다. 연구결과를 바탕으로, 대학수학교과의 학업성취도를 높이기 위한 방안을 제언하였다.

• Smart Structures and Systems
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• 제19권2호
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• pp.225-236
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• 2017

Railroad bridges in North America are an integral but aging part of the railroad network and are typically only monitored using visual inspections. When quantitative information is required for assessment, railroads often monitor bridges using accelerometers. However without a sensor to directly measure displacements, it is difficult to interpret these results as they relate to bridge performance. Digital Image Correlation (DIC) is a non-contact sensor technology capable of directly measuring the displacement of any visible bridge component. In this research, a railroad bridge was monitored under load using DIC and accelerometers. DIC measurements are directly compared to serviceability limits and it is observed that the bridge is compliant. The accelerometer data is also used to calculate displacements which are compared to the DIC measurements to assess the accuracy of the accelerometer measurements. These measurements compared well for zero-mean lateral data, providing measurement redundancy and validation. The lateral displacements from both the accelerometers and DIC at the supports were then used to determine the source of lateral displacements within the support system.

• 소음진동
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• 제6권5호
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• pp.607-616
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• 1996

A combined computational fluid dynamics(CFD)-Kirchhoff method is presented for predicting high-speed impulsive noise generated by a hovering blade. Two types of Kirchhoff integral formula are used; one for the classical linear Kirchhoff formulation and the other for the nonlinear Kirchhoff formulation. An Euler finite difference solver is solved first to obtain the flow field close to the blade, and then this flow field is used as an input to a Kirchhoff formulation to predict the acoustic far-field. These formulas are used at Mach numbers of 0.90 and 0.95 to investigate the effectiveness of the linear and nonlinear Kirchhoff formulas for delocalized flow. During these calculiations, the retarded time equation is also carefully examined, in particular, for the cases of the control surface located outside of the sonic cylinder, where multiple roots are obtained. Predicted results of acoustic far-field pressure with the linear Kirchhoff formulation agree well with experimental data when the control surface is at the certain location(R=1.46), but the correlation is getting worse before or after this specific location of the control surface due to the delocalized nonlinear aerodynamic flow field. Calculations based on the nonlinear Kirchhoff equation using a linear sonic cylinder as a control surface show a reasonable agreement with experimental data in negative amplitudes for both tip Mach numbers of 0.90 and 0.95, except some computational integration problems over a shock. This concliudes that a nonlinear formulation is necessary if the control surface is close to the blade and the flow is delocalized.

• 한국정보통신학회논문지
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• 제5권3호
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• pp.605-611
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• 2001

고수준의 정보 서비스를 제공하기 위해서는 소프트웨어의 고품질화를 추구하여야 한다. 기존에 개발된 품질측정방법들은 모듈내에 포함되어 있는 요인항목들을 서로 다른 관점에서 개별적으로 측정하고있어 통합적인 평가방법이 필요하다. 따라서 본 논문에서는 다수의 측정 방법들을 모두수용 할 수 있는 모델을 제안한다. 제안된 모델은 비율척도들을 선택하고, 러프논리를 이용하여 그들의 중요도를 산출한다. 다음으로 모듈의 품질도를 측정하기 위해서 퍼지적분을 이용하여 척도들의 중요도와 측정값을 종합한다. 마지막으로 척도들과 산출된 품질도의 상관관계를 분석하고, 통계적 방법으로 제안된 모델의 타당성을 보인다.