• 대한간호학회지
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• 제15권2호
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• pp.5-15
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• 1985

This study was conducted for the purpose of fin-ding out the variance explaining the medical facilities utilization behavior, which is defined adaptation behavior Process by focal, contextual, residual stimuli in Roy's Adaptation Model. What kinds of characteristics can explain adaptation behavior in Roy's Model? And which is the relative importance of input variables? For this analysis, stepwise multiple regression and path analysis was used. The data come from the 1981 Baseline Household Interview Survey in remote rural area. The findings of the analysis can be summarized as follows: First, Total variance of independant variables for adaptation behavior, that is medical facilities utilization including clinic, drug store, health center, herb medicine was shown 16.2 percent. The most important variable which explain the dependent variable was the occurance of illness with the Ra of value 0.112. The illness symptom, living level, regular care source was shown important variables with relatively high the R²value and significant beta coefficient. Second, in the path analysis of variables which is selected important variables, the occurance of illness was shown variable which has the highest direct effect which 0.297 path coefficient. Also the education level of household was shown variable which has the highest indirect effect through living level and the occurance of illness in causal model. Third, This analysis suggests that the occurance of illness belonging focal stimuli are more influenced than others. To sum up, It is seem to the occurance of illness, illness symptom belonging focal stimuli have high explanation ability through direct effect, education level of household among contextual stimuli have explanation ability through indirect effect.

• 대한전기학회논문지:전력기술부문A
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• 제55권5호
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• pp.185-190
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• 2006

The security analysis relates to the ability of the electric systems to survive sudden disturbances such as electric short circuits or unanticipated loss of system elements. It is composed of both steady state and dynamic security analyses, which are not two separate issues but should be considered together. In steady state security analysis including voltage security analysis, the analysis checks that the system is operated within security limits by OPF (optimal power flow) after the transition of a new operating point. On the other hand, dynamic security analysis deals that the transition will lead to an acceptable operating condition. Transient stability, which is the ability of power systems to maintain synchronism when subjected to a large disturbance, is a principal component in dynamic security analysis. Usually any loss of synchronism will cause additional outages. They make the present steady state analysis of the post-contingency condition inadequate for unstable cases. This is the reason of the need for dynamics of systems. Probabilistic criterion can be used to recognize the probabilistic nature of system components and shows the possibility of system security. A comprehensive conceptual framework for probabilistic static and dynamic assessment is presented in this paper. The simulation results of the Western System Coordinating Council (WSCC) system compare an analytical method with Monte-Carlo simulation (MCS). Also, a case study of the extended IEEE Reliability Test System (RTS) shows the efficiency of this approach.

• 한국태양에너지학회 논문집
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• 제35권1호
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• pp.29-34
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• 2015

The photovoltaic ribbon attached the flux reduces the solar module manufacturing process and the pollution. This paper presents an analytical method for solving the continuous flux drying system of photovoltaic ribbon. Also, some experiments of the drying of photovoltaic ribbon are carried out in order to design the drying system. Numerical results indicate the air temperature, the air velocity, the air pressure and the timewise temperature variation of ribbon during drying process. In case of the drier process length is short, 400mm, the photovoltaic ribbon is wet. Thus, another study of drying system is necessary to improve the drying ability. As a result, multi-stage drier system is proposed and shown to be good drying ability.

• 한국산업보건학회지
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• 제23권3호
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• pp.243-249
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• 2013

Objectives: This study assessed the status of domestic industrial hygiene laboratories using data from on-site investigation for revision of quality control systems in 2012-2013. Methods: The target laboratories were 60 industrial hygiene laboratories chosen by random selection and nationwide distribution which had participated in on-site investigations for revision of quality control systems from March 2012 to August 2013. The investigation was performed on-site following standard quality control procedures. The score between each group was compared using Mann-Whitney and Kruskal-Wallis tests, and the correlation between analytical career, sex, academic major of analyst and score of analytical performance was expressed as Spearman's rank correlation coefficient. Results: The assessment revealed that the items to be improved, in sequence, were effort at staff training (score 65.5), ability to calculate data (score 73.4), establishment of internal quality control guidelines (score 75.7), laboratory facilities (score 77.1), degree of understanding and skill at gas chromatography (score 77.1). Analysis performance showed a positive correlation with career of analyst (r=0.56, p<0.01). Conclusions: The practice of on-site investigation for quality control systems showed the current status of industrial hygiene laboratories in the first trial. There were many laboratories which needed improvement and development of analytical systems. This assessment can provide information for the systematic operation and improvement of facilities at each laboratory. Further practice of this investigation will lead to a proficiency testing and accreditation system for autonomous quality control as is the practice in many countries, rather than mandatory practice by legal regulation.

• Advances in environmental research
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• 제3권1호
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• pp.45-69
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• 2014

The groundwater has been a major source of water supply throughout the ages. Around 50% of the rural as well as urban population in the developing countries like India depends on groundwater for drinking. The groundwater is also an important source in the agriculture and industrial sector. In many parts of the world, groundwater resources are under increasing threat from growing demands, wasteful use and contamination. A good planning and management practices are needed to face this challenge. A key to the management of groundwater is the ability to model the movement of fluids and contaminants in the subsurface environment. It is obvious that the contaminant source activities cannot be completely eliminated and perhaps our water bodies will continue to serve as receptors of vast quantities of waste. In such a scenario, the goal of water quality protection efforts must necessarily be the control and management of these sources to ensure that released pollutants will be sufficiently attenuated within the region of interest and the quality of water at points of withdrawal is not impaired. In order to understand the behaviour of contaminant transport through different types of media, several researchers are carrying out experimental investigations through laboratory and field studies. Many of them are working on the analytical and numerical studies to simulate the movement of contaminants in soil and groundwater of the contaminant transport. With the advent of high power computers especially, a numerical modelling has gained popularity and is indeed of particular relevance in this regard. This paper provides the state of the art of contaminant transport and reviews the allied research works carried out through experimental investigation or using the analytical solution and numerical method. The review involves the investigation in respect of both, saturated and unsaturated, porous media.

• 분석과학
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• 제28권1호
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• pp.1-7
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• 2015

4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a tobacco specific nitrosamine found only in tobacco products. The ability to monitor biomarker concentrations is very important in understanding environmental tobacco smoke (ETS). In this study, an efficient and sensitive method for the analysis of NNK in dust was developed and validated using liquid chromatography tandem mass spectrometry. Dust was collected with filter paper soaked in methanol. The standard solution and dust sample were diluted with 100 mM ammonium acetate and extracted using dichloromethane. Our calibration curves ranged from 25 to $10^4pg/mL$. Excellent linearity was obtained with correlation coefficient values between 0.9996 and 1.0000. The limit of detection (LOD) was 5 pg/mL ($S/N{\geq}3$) and the retention time was 10 min. The limit of quantification (LOQ) was 25 pg/mL, and the acceptance criteria was the rate of 98-103% (80-120% at levels up to $3{\times}LOQ$). The coefficient of variations (CV) was 2.8%. Accuracies determined from dust samples spiked with four different levels of NNK racurves ranged that from 25 to 104 pg/mL. Excellent linearity was obtained between 92.1% and 114%. The precision of the method was acceptable (5% of CV). The recovery rates of the whole analytical procedure at low, medium, and high levels were 105.7-116.5% for NNK. The carry-over effects during LC-MS/MS analysis were not observed for NNK. This manuscript summarizes the scientific evidence on the use of markers to measure ETS.

• Geomechanics and Engineering
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• 제30권1호
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• pp.11-26
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• 2022

One of the most important issues in tunneling, is the squeezing phenomenon. Squeezing can occur during excavation or after the construction of tunnels, which in both cases could lead to significant damages. Therefore, it is important to predict the squeezing and consider it in the early design stage of tunnel construction. Different empirical, semi-empirical and theoretical-analytical methods have been presented to determine the squeezing. Therefore, it is necessary to examine the ability of each of these methods and identify the best method among them. In this study, squeezing in a part of the Alborz service tunnel in Iran was estimated through a number of empirical, semi- empirical and theoretical-analytical methods. Among these methods, the most robust model was used to obtain a database including 300 data for training and 33 data for testing in order to develop a machine learning (ML) method. To this end, three ML models of Gaussian process regression (GPR), artificial neural network (ANN) and support vector regression (SVR) were trained and tested to propose a robust model to predict the squeezing phenomenon. A comparative analysis between the conventional and the ML methods utilized in this study showed that, the GPR model is the most robust model in the prediction of squeezing phenomenon. The sensitivity analysis of the input parameters using the mutual information test (MIT) method showed that, the most sensitive parameter on the squeezing phenomenon is the tangential strain (ε_θ^α) parameter with a sensitivity score of 2.18. Finally, the GPR model was recommended to predict the squeezing phenomenon in tunneling projects. This work's significance is that it can provide a good estimation of the squeezing phenomenon in tunneling projects, based on which geotechnical engineers can take the necessary actions to deal with it in the pre-construction designs.

• 한국컴퓨터정보학회논문지
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• 제15권10호
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• pp.209-220
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• 2010

본 연구는 유아들의 컴퓨터 활용에 대한 실태 및 능력을 알아보기 위하여 성별 및 연령별로 나누어 설문조사를 실시하였다. 연구대상은 김포시에 소재한 K 대학의 유아교육과 학생들이 1개월간 실습한 실습 장소에 다니고 있는 유아들을 대상으로 총 378명의 설문지를 본 연구의 분석에 사용하였다. 본 연구결과 분석에 의하면 여아가 남아보다 한글읽기와 쓰기, 숫자 활동, 외국어 혹은 음악 미술활동 등의 교육적 목적으로 더 많이 사용하고 있었는데 여아들의 경우에 음악이나 미술활동을 위해 컴퓨터 활용을 남아들보다 많이 하고 있는 것으로 나타났다. 반면에 만화영화 나게임, 인터넷 검색 등의 흥미, 오락을 위한 컴퓨터 사용은 남아가 여아보다 높게 나타났다. 컴퓨터의 그림 지시를 이해하고 다룰 수 있는 능력과 친구와 이메일 주고받거나 채팅, 그림을 그릴 수 있는 능력, 인터넷 쇼핑, 홈페이지 제작등의 수준 높은 활용능력은 여아가 남아보다 우월한 것으로 나타났다. 반면 컴퓨터 게임능력은 남아가 여아보다 크게월등한 것으로 나타났다. 설문의 분석결과 유아교육용 응용소프트웨어개발은 남아는 흥미위주 및 게임형식의 응용프로그램을 여아는 음악 및 미술적요소를 활용한 응용프로그램을 활용하는 것이 바람직해 보이고 연령별로는 1-2세에서는 컴퓨터를 같이하는 사람의 적극적인 도움이 필요한 응용프로그램을, 3-4세에서는 일부의 도움을 필요로 하는 응용프로그램을 6-7세에서는 스스로 할 수 있는 응용프로그램으로 성별 및 나이에 적합한 응용프로그램이 필요하다.

• 한국초등수학교육학회지
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• 제19권4호
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• pp.625-647
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• 2015

예비교사가 수학 수업을 어떻게 이해하고 비평하는지는 수업전문성 개발의 기초가 되므로 중요하다. 본 연구는 예비교사들이 교육실습 과정 중 현직교사의 시범 수업을 참관한 후 작성한 수업 비평을 토대로, 비평 수준 및 특징을 분석한 것이다. 특히 비평에 포함된 수학 내용뿐만 아니라 주체, 견지, 근거, 대안을 토대로 비평 수준을 종합적으로 분석하였다는 점이 유의미하다. 연구 결과, 예비교사들의 비평 수준은 1수준(소감형), 2수준(점검형), 3수준(분석형) 중 대부분 2수준에 머물러 있음을 알 수 있었다. 비평 수준틀에 대한 중다회귀분석결과 비평 수준에 가장 큰 영향력을 미치는 요인은 견지(見地)였다. 한편 예비교사들의 비평을 통하여 교육실습 과정에서의 수업 참관이 수학 수업과 관련된 신념과 교사로서의 이미지 형성에 중요한 영향을 끼친다는 것을 알 수 있었다. 이와 같은 결과를 토대로 수학 수업에 대한 비평 및 교육실습과 관련하여 교사의 전문성 신장을 도모할 수 있는 시사점을 도출하였다.

• 대한화학회지
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• 제63권6호
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• pp.459-472
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• 2019

이 연구는 논의-기반 모델링 전략을 적용한 일반화학실험 수업에서 글쓰기 대상에 따른 과학 글쓰기가 예비 화학교사들의 모델링 능력 및 모델링에 대한 인식에 미치는 영향을 알아보는 것을 목적으로 하였다. 또한 이와 함께 예비 화학교사들의 화학개념 이해에 미치는 영향도 알아보았다. 이를 위해서 사범대학 화학교육과에 재학 중인 예비 화학교사 1학년 18명을 대상으로 11개 주제의 논의-기반 모델링 전략을 적용한 일반화학실험 수업을 진행하였다. 화학개념 이해는 사전과 사후의 화학개념 이해 검사 점수에 대한 효과크기를 비교하였다. 모델링 능력은 예비 화학교사들이 제시하는 모델을 설명, 표상화, 의사소통의 3가지 영역으로 구분하여 집단의 효과크기를 분석하였으며, 모델링에 대한 인식을 알아보기 위해서 설문조사를 실시하였다. 분석결과, 예비 화학교사의 화학개념 이해와 모델링 능력은 글쓰기 대상인 독자의 수준이 낮은 경우, 효과가 더 큰 것으로 나타났으며 글쓰기 대상에 따른 집단에서 모델링에 대한 인식은 차이가 없는 것으로 나타났다. 하지만 모델링 과정을 경험함에 따라 예비 화학교사들의 응답이 더 구체적으로 변해가는 것을 확인할 수 있었다.