In previous studies, the pressure distribution on optical mirror surface was measured by CFD analysis assuming various external air conditions on optical structures designed using knowledge-based design techniques. In this study, the KBD model was verified by comparing the pressure data from the mirror surface obtained through CFD analysis with the pressure values from the wind tunnel test of the actual model.

염분은 해양의 밀도를 결정하는 중요한 변수이자 전지구 물의 순환을 나타내는 주요 인자 중 하나이다. 해상 염분 관측은 선박을 이용한 현장조사, Argo 플로트, 부이를 통한 조사가 주로 수행되어 왔다. 2009년 염분관측 인공위 성이 발사한 이래로, 위성 염분자료를 이용하여 전 지구 해역에서 표층 염분 관측이 가능해졌다. 그러나 위성 염분자료는 다양한 오차를 포함하기 때문에 연구 자료로 활용하기에 앞서 정확도 검증과정이 필요하다. 따라서 본 연구에서는 2015년 4월부터 2020년 8월까지 Soil Moisture Active Passive (SMAP) 위성 염분자료와 이어도 해양과학기지에서 제공하는 실측 염분자료 간의 정확도 및 오차특성을 비교 분석하였다. 총 314개의 일치점을 생산하였으며, 염분의 평균제 곱근오차 및 평균편차는 각각 1.79, 0.91 psu로 제시되었다. 전반적으로 위성 염분이 실측 염분보다 과대추정 되는 것으로 나타났다. 위성 염분의 오차는 계절, 표층 수온, 풍속과 같은 다양한 해양 환경적 요인에 의존성을 보였다. 여름철 위성 염분과 실측 염분의 차이는 0.18 psu 이하로 저수온보다는 고수온에서 위성 염분의 정확도가 증가하였다. 이는 센서의 민감도에 따른 결과였다. 마찬가지로 5 m s−1 이상 풍속 조건에서 오차가 줄어들었다. 본 연구결과는 연안에서 위성 염분자료를 활용할 경우에는 특정한 연구 목적에 적합한지 확인하여 제한적으로 사용하여야 함을 제시한다.

In a series of recent launch tests, North Korea has been improving the firepower of its missiles that can target South Korea. North Korea’s missiles and submarines are capable of threatening targets in South Korea and are likely faster and more covert than the systems previously seen in North Korea. The advanced threats require that ROK Navy should not only detect them earlier than ever but also response quicker than ever. In addition to increasing threats, the number of young man that can be enlisted for military service has been dramatically decreasing. To deal with these difficulty, ROK navy has been making various efforts to acquire a SMART warship having enhanced defense capability with fewer human resources. For quick response time with fewer operators, ROK Navy should improve the efficiency of systems and control tower mounted on the ship by promoting the Ship System Integration. Total Ship Computing Environment (TSCE) is a method of providing single computing environment for all ship systems. Though several years have passed since the first proposal of TSCE, limited information has been provided and domestic research on the TSCE is still in its infancy. In this paper, we apply TSCE with open architecture (OA) to solve the problems that ROK Navy is facing in order to meet the requirements for the SMART ship. We first review the level of Ship System Integration of both domestic and foreign ships. Then, based on analyses of integration demands for SMART warship, we apply real time OA to design architecture for TSCE from functional view and physical view. Simulation result shows that the proposed architecture has faster response time than the response time of the existing architecture and satisfies its design requirements.

목적 : 본 연구의 목적은 교육적 모델에 기반을 두고 교사, 학생, 학부모, 학교 관계자 등과 협력적 팀 접근을 이루어 서비스를 제공하기 위해 학교작업치료사에게 요구되는 지식, 기술, 특성 등에 관한 핵심 역량을 규명하여 학교작업치료사에게 필요한 역량지표를 개발하고 타당화 하는데 있다. 연구방법 : 본 연구는 학교작업치료 경험이 있는 작업치료사 8명을 델파이 위원으로 구성하여 2차에 걸쳐 델파이 조사를 시행하였다. 1차에서는 학교작업치료사의 역량에 관하여 개방형 설문을 통해 의견을 수집한 뒤 전문가 자문의원 5명의 자문을 통해 2차 델파이 설문지를 작성하였다. 2차 델파이 조사에서는 역량에 대해 적합도와 중요도 각각의 내용타당도를 확인하고, 델파이 조사결과에 대해 전문가 자문의원 5명에게 자문을 받은 후에 최종 역량 지표룰 도출하였다. 결과 : 1차 델파이 결과 39개의 지표가 도출되었으며, 2차 델파이 결과 내용타당도 비율이 낮게 나온 7개 문항에 대해서 전문가 자문을 거쳐 수정 및 통합하여 최종 36개 지표가 도출되었다. 3개의 역량군은 전문지식, 직무기술, 개인적 특성이었으며 각각 14개, 11개, 11개의 항목이 역량지표로 도출되었다. 결론 : 본 연구는 학교작업치료사가 갖추어야 할 역량에 대하여 전문지식과 직무를 파악하고 타 전문가와 소통하는 작업치료사로서 필요한 기술과 개인적 특성을 파악하는데 의미가 있다. 의료적 모델이 아닌 사회적․교육적 모델에 기반을 둔 학교작업치료사의 역량을 도출하여 향후 학교작업치료사의 전문성 함양을 위한 교육과정의 기틀을 마련하고, 특수교육대상자의 학교생활 참여를 지원하기 위해 교사 등과 협력적 팀을 이루어 접근하기 위한 중요한 기초자료를 제공할 수 있을 것이다.

In order to design a diesel engine system and predict its performance, it is necessary to analyze the gas flow of the intake and exhaust system. A gas flow analysis in three-dimensional (3D) format needs a high-resolution workstation and enormous time for analysis. Therefore, the method of characteristics (MOC) was used for a gas flow analysis with a fast calculation time and a low-resolution workstation. An experiment was conducted on a single cylinder diesel engine to measure pressure in cylinder, intake pipe and exhaust pipe. The one-dimensional (1D) gas flow was analyzed under the same conditions as the experiment. The engine speed, valve timing and compression ratio were the same conditions and the intake pressure was inputted as the experimental results. Bent pipe such as an exhaust port that cannot be realized in 1D was omitted. As results of validation, the cylinder pressure showed accuracy, but the exhaust pipe pressure exhibited inaccuracy. This is considered as an error caused by the failure to implement a bent pipe such as an exhaust port. When analyzed in 3D, calculation time required 61 hours more based on a model of this study. In the future, we intend to implement a bent pipe that cannot be realized in 1D using 3D and prepare a method to supplement reliability by using 1D-3D coupling.

Because the inner environment of greenhouse has a direct impact on crop production, many studies have been performed to develop technologies for controlling the environment in the greenhouse. However, it is difficult to apply the technology developed to all greenhouses because those studies were conducted through empirical experiments in specific greenhouses. It takes a lot of time and cost to develop the models that can be applicable to all greenhouse in real situation. Therefore studies are underway to solve this problem using computer-based simulation techniques. In this study, a model was developed to predict the inner environment of glass greenhouse using CFD simulation method. The developed model was validated using primary and secondary heating experiment and daytime greenhouse inner temperature data. As a result of comparing the measured and predicted value, the mean temperature and uniformity were 2.62°C and 2.92%p higher in the predicted value, respectively. R2 was 0.9628, confirming that the measured and the predicted values showed similar tendency. In the future, the model needs to improve by applying the shape of the greenhouse and the position of the inner heat exchanger for efficient thermal energy management of the greenhouse.

In this study, we developed a learning progression for the structure of the solar system using multi-tier supply form items and validated its appropriateness. To this end, by applying Wilson’s (2005) construct modeling approach, we set up ‘solar system components,’ ‘size and distance pattern of solar system planets,’ and ‘solar system modeling’ as the progress variables of the learning progression and constructed multi-tier supply form items for each of these variables. The items were applied to 150 fifth graders before and after the classes that dealt with the ‘solar system and star’ unit. To describe the results of the assessment, the students’ responses to each item were categorized into five levels. By analyzing the Wright map that was created by applying the partial credit Rasch model, we validated the appropriateness of the learning progression based on the students’ responses. In addition, the validity of the hypothetical pathway that was established in the learning progression was verified by tracking changes in the developmental level of students before and after the classes. The results of the research are as follows. The bottom-up research method that used multi-tier supply form items was able to elaborately set the empirical learning progression for the conceptualization of the structure of the solar system that is taught in elementary school. In addition, the validity of the learning progression was high, and the development of students was found to change with the learning progression.

본 연구는 초기 조현병 환자를 대상으로 Duraiswamy 등(2007)이 개 발한 요가 프로그램을 한국의 실정에 맞는 요가 프로그램으로 개발 및 타당화하고자 하는 것을 목적으로 하였다. 이를 위하여 프로그램의 관련 당사자인 의사, 간호사, 프로그램 개발 전문가를 대상으로 프로그램에 대한 내용타당도를 검증하였다. 본 연구의 목적을 달성하기 위한 구체적인 연구문제는 첫째, Duraiswamy 등(2007)이 개발한 조현병 환자 대상 요가 프로그램의 구성개념의 타당도를 확인하는 것이었다. 둘째, 델파이 전문가 의견을 종합한 한국판 조현병 환자 대상 요가 프로그램 을 구성하는 것이었다. 그 결과, 기존의 25개 항목으로 구성된 총 60분 프로그램에서 총 6개 항목, 총 15분으로 새롭게 만들어진 한국판 조현병 환자 대상 요가 프로그램을 구성하고 타당화 하였다. 최종 프로그램은 1) 긴장풀기 운동, 2) 아사나, 3) 호흡운동으로 구성되어 있으며, 1) 긴장풀기 운동은 손 뻗으며 호흡하기, 산토끼 자세, 막대자세, 2) 아사 나는 IRT 즉시 이완 기술, 3) 호흡운동은 부위별 호흡, 나다요가로 구성되었다. 본 연구의 결과를 통해 개발된 프로그램의 활용은 조현병 환자들이 생활에서 경험하는 스트레스에 적절하게 대처할 수 있도록 중재하는 데에 도움을 줄 수 있을 것으로 기대한다.

Welding is the most convenient method for fabricating steel materials to build ships and offshore structures. However, welding using high heat processes inevitably produces welding displacements on welded structures. To mitigate these, heavy industries introduce various welding techniques such as back-step welding and skip-step welding. These techniques effect on the change of the distribution of high heat on welded structures, leading to a reduction of welding displacements. In the present study, various cases using different and newly introduced welding techniques are numerically simulated to ascertain the most efficient technique to minimize welding displacements. A numerical simulation using a finite element method based on the inherent strain, interface element and multi-point constraint function is introduced herein. Based on several simulation results, the optimal welding technique for minimizing welding displacements to build a general ship grillage structure is finally proposed.

Objective: To evaluate item-factor structures of the 15 sensory items from the Survey of Pathways to Diagnosis and Services (Pathways) and examine the best fitting model. Methods: The study subjects were 1,968 children aged 6-17 years, who had ever been diagnosed with Autism Spectrum Disorder (ASD) and/or Intellectual Disability (ID). Factor analyses and item response theory models were used to determine the best fitting item-factor structure of the sensory items. The Strengths and Difficulties Questionnaires (SDQ) was used to test the concurrent validity of the sensory severity estimates. Results: A bifactor MIRT model (a general and four sensory factors) was selected as the best fitting model. All items statistically fitted to the bifactor model (p > .01) and showed moderate correlations with all five subscales of the SDQ (r s = .31 ~.51, p < .0001). The general sensory score differentiated the four different diagnostic groups (ASD, ID, ASD with ID, and no current symptoms) [F (3,1961) = 207.4, p < .0001]. Conclusion: The Pathways sensory items yielded reliable estimates of the general and each corresponding sensory factor by applying a bifactor MIRT model. The sensory score can be used as a valid sensory measure in the population survey.

본 연구는 코칭역량에 대한 선행연구들을 검토, 정리, 분석하여 코칭역량 구성요인을 살펴 보고 이를 측정할 척도문항을 개발하는데 목적이 있다. 이를 위해, 코칭역량 선행연구 분석 및 초점집단면담(FGI)을 진행하여 코칭역량 구성요인을 도출하고 105문항을 제작하였다. 코칭전문가에게 2차례에 걸친 내용타당도 검증을 실시하여 예비문항 95문항을 도출하고 일반인 120명을 대상으로 예비설문을 실시하였다. 수집된 데이터로 탐색적 요인분석을 통해 척도 정교화를 진행하여 최종 66개의 문항을 도출하였다. 최종 문항으로 일반인 207명을 대상으로 본 조사를 실시하였고, 기술적 통계분석과 탐색적 요인분석으로 7개의 하위요인에 34개 문항을 추출하였다. 추출된 문항으로 확인적 요인분석을 실시하여 모형적합도를 살펴보았으며, 수렴 타당성과 판별타당성을 확보하였다. 연구결과 자율성, 낙관주의, 희망, 관계성, 질문, 경청, 피드백 역량으로 명명한 최종 7개 요인 34개 문항의 코칭역량 척도를 확정하였다. 본 연구에서 개발한 코칭역량 척도는 전문 코치 양성이나 코칭프로그램의 효과성 측정에 기초를 제공하고자 하는데 의의가 있다.

Given the view of tests as mechanisms within a language policy framework (Shohamy, 2006), Korean proficiency tests are not only used as a way to measure language knowledge, but rather as tools to impose national ideologies about langage use and diversity. The field of Korean language testing needs to embrace sociopolitical dimensions, and engage what is going on value and consequence in test development and validation. By drawing upon a combined approach of Messick’s (1989) validity framework, Fairclough’s (2001) Critical Discourse Analysis (CDA), Bachman and Palmer’s Assessment Use Arugment (AUA), this study aims to illustrate how the practice of testing can be discursively interpreted as a multilayered phenomenon, constituted through discourse. It discussed the applicability of AUA’s two claims (decisions, consequences) to the validation of Korean language proficiency or related certification testing for immigrants with foci of value implications and consequences. The interconnectedness of test validation and CDA is modelled through the procedure of Faircough’s (2001) analytic methodology. In an effort to illustrate that language testing is discursively value-laded, this study not only offer a theoretical and methodological addition to the current inquiry of test validation, but also re-emphasize that language testing is sociopolitically driven from a discursive angle.