• International Journal of Ocean System Engineering
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• 제3권2호
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• pp.77-89
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• 2013

The propeller performance has been investigated using a benchmark Duisburg Test Case ship with RANSE. First, the hydrodynamic characteristics of propeller in case of open water have been analyzed by a commercial CFD program and the results are compared with those of experimental data. Later, the flow around the bare hull has been solved and the frictional resistance value and form factor of the ship have been obtained and compared with those of ITTC57 formulation and experimental results for validation. The free surface effect has been ignored. A good agreement has been obtained between the results of RANSE and experiments at both stages. Then the ship - propeller interaction problem was solved by RANSE and the differences in thrust, torque and efficiency of propeller as compared with the open-water numerical results have been discussed.

• 한국초등수학교육학회지
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• 제21권3호
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• pp.443-460
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• 2017

본 연구에서는 문헌 연구 및 초등학교 교사 300명을 대상으로 한 설문 결과의 통계적 분석을 바탕으로 수학 교수 효능감 측정 도구를 개발하였다. 수학 교수 효능감을 구성하는 요인으로는 수학 수업 효능감, 수학 효능감을 선정하였다. 본 연구에서 개발된 설문 문항의 신뢰도는 주성분분석(Principal Components Analysis) 기법을 이용하여 검증하였다. 타당도 검증은 문헌 연구 및 수학 교과 전문 교사의 검토를 중심으로 실시되었다. 이와 같은 절차를 바탕으로 본 연구에서는 13문항으로 구성된 초등학교 교사의 수학 교수 효능감 측정 도구를 개발하였다.

• 대한방사성의약품학회지
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• 제1권2호
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• pp.98-103
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• 2015

Good manufacturing Practice (GMP) regulation for diagnostic and therapeutic radiopharmaceuticals was prepared at 2014. The mandatory GMP regulation becomes effective on $1^{st}$, July 2015,with two years of grace periods. Korean radiopharmaceuticals GMP regulation was consisted of quality management, personnel, premise and facility, documentation, production, quality control and self-audit and they have a very similar structure to European Union and PIC/S GMP regulation. Here, we describe detailed description of GMP regulation each part and application to radiopharmaceuticals production. And we also compare Korea, Japan and USA radiopharmaceuticals GMP regulation. GMP is a method to maintain quality of radiopharmaceuticals in daily production and it must be embedded on the manufacturing operation and management.

• Child Health Nursing Research
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• 제29권1호
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• pp.37-50
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• 2023

Purpose: This study aimed to validate the Child Healthy Lifestyle Profile as an instrument for screening healthy behaviors in school-aged children in South Korea. Methods: Self-reported questionnaires were administered to 454 students, comprising elementary-school students (n=221) and child cancer survivors (n=233). Reliability and validity were assessed using Cronbach's α, exploratory factor analysis (EFA), and confirmatory factor analysis (CFA). Results: Cronbach's α, as a reliability test, was 0.87. Varimax rotation yielded nine factors with eigenvalues greater than 1 in the EFA, which explained 61.0% of the total variance. In the CFA, both convergent and discriminant validities were acceptable. Therefore, the Child Healthy Lifestyle Profile was validated as an assessment tool for Korean school-aged children. Conclusion: Based on the results of this study, the Child Healthy Lifestyle Profile was identified as a reliable and valid instrument for assessing healthy lifestyles in elementary-school children in South Korea.

• 방송공학회논문지
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• 제27권7호
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• pp.1011-1020
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• 2022

Recent high-performance panoptic segmentation models are based on transformer architectures. However, transformer-based panoptic segmentation methods are basically slower than convolution-based methods, since the attention mechanism in the transformer requires quadratic complexity w.r.t. image resolution. Also, sine and cosine computation for positional embedding in the transformer also yields a bottleneck for computation time. To address these problems, we adopt three modules to speed up the inference runtime of the transformer-based panoptic segmentation. First, we perform channel-level reduction using depth-wise separable convolution for inputs of the transformer decoder. Second, we replace sine and cosine-based positional encoding with convolution operations, called conv-embedding. We also apply a separable self-attention to the transformer encoder to lower quadratic complexity to linear one for numbers of image pixels. As result, the proposed model achieves 44% faster frame per second than baseline on ADE20K panoptic validation dataset, when we use all three modules.

• 로봇학회논문지
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• 제17권3호
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• pp.359-364
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• 2022

This study presents a nonlinear model predictive control (NMPC)-based obstacle avoidance and whole-body motion planning method for the mobile manipulators. For the whole-body motion control, the mobile manipulator with an omnidirectional mobile base was modeled as a nine degrees-of-freedom (DoFs) serial open chain with the PPR (base) plus 6R (arm) joints, and a swept sphere volume (SSV) was applied to define a convex hull for collision avoidance. The proposed receding horizon control scheme can generate a trajectory to track the end-effector pose while avoiding the self-collision and obstacle in the task space. The proposed method could be calculated using an interior-point (IP) method solver with 100[ms] sampling time and ten samples of horizon size, and the validation of the method was conducted in the environment of Pybullet simulation.

• Educational Technology International
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• 제14권1호
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• pp.109-136
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• 2013

We conducted an empirical study with 8 middle school students in Korea to investigate the usability and usefulness of our self-designed Digital Textbook. The Stimulated Recall (SR) Method using Morae software was utilized to analyze the learners' task behaviors and mental operations while using the Digital Textbook to learn English. Collected qualitative data indicated several problems in terms of the usability and usefulness of the Digital Textbook. The findings are summarized and some implications are discussed for further revision of the Digital Textbook and validation of the SR method as a usability-usefulness test tool.

• Educational Technology International
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• 제10권1호
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• pp.41-57
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• 2009

Cognitive presence, a sense of "being there" cognitively, has recently been considered as an important indicator for students' engagement in e-learning. There is, however, no widely accepted scale to measure the level of cognitive presence since most studies have put their effort to set and clarify the conceptual framework with qualitative methodology. This study reviewed existing theories on cognitive presence and related fields extensively and developed a new self-report scale for measuring the conceived level of cognitive presence. The reliability and validity of the scale was tested against 723 undergraduate students in two consecutive studies, 418 in the preliminary and 305 in the follow-up study. Three major constructs to measure the perceived level of cognitive presence were: 1) clear understanding, 2) knowledge construction, and 3) learning management. This paper reports the final results of the two independent studies.

• 한국재난정보학회:학술대회논문집
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• 한국재난정보학회 2023년 정기학술대회 논문집
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• pp.99-100
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• 2023

최근 중대재해처벌법의 목적은 건설업 주체 구성원들의 안전불감증을 방지하기 위해 CEO의 안전참여 문화를 강조하고 있다. 선행연구에서는 리더의 감성 수준이 높을수록 업무 능력에 긍정적인 영향을 미치며, 감성능력을 요구하는 추세라고 주장하였다4). 본 연구에서 경영자 (CEO) 리더십 및 안전관리 연구에 사용할 수 있는 감성안전 측정으로 건전하고 간단한 EI 측정개발도구에 대해 신뢰도를 검증한다. Schutte Self-Report Emotional Intelligence Test (SSEIT)의 감정 조절 모델을 적용하면 리더와 안전관리자의 EI가 안전업무 수행과 태도에 긍정적인 영향을 미쳐야 한다. 또한 건설 안전관리 직업의 재해피해가능성스트레스 감정 노동이 EI-활용훈련 결과 감정조절이 가능하다는 것을 제안한다.

• Asia pacific journal of information systems
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• 제31권2호
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• pp.141-184
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• 2021

While a great body of information systems (IS) literature has discussed mobile banking (m-banking) services, most of these studies have focused on the adoption or acceptance phases of this technology; with little attention was given to users' intension to continue using such technology. This paper aims at investigating the most important factors that predict users' continuous intension to use m-banking services in the post-adoption phase. This paper presents a conceptualization and validation of an extended expectation-confirmation model (ECM). A total of 303 Kuwaiti users of m-banking services participated in this study. Partial least squares (PLS) of structure equation modelling (SEM) technique was used to analyze the data. The results mainly showed that users' continuous intension to use m-banking services is significantly influenced by perceived trust, satisfaction, self-efficacy, performance expectancy and effort expectancy. Theoretical and practical contributions as well as the research limitations and future directions are discussed.