• Journal of Wind Energy
• /
• v.14 no.3
• /
• pp.109-119
• /
• 2023

A structural safety evaluation was conducted for the stabbing system for the pre-piling jacket substructure currently being developed in South Korea, considering pile construction errors due to its lateral movement that may occur during construction in the ocean. Based on (1) the maximum stress generated by the stabbing system, (2) the maximum rotational displacement of the guide cone, and (3) the maximum stress generated by the horizontal hydraulic pressure cylinder, the structural safety of the stabbing system was examined under the initial loading condition and three possible load combinations during its construction. In order to evaluate the structural safety of the stabbing system, a concept of stress safety factor (= Yield stress / Max. Von-Mises stress) was used. It was found that the stabbing system considered in this study has a sufficient margin of safety.

• Journal of Korea Multimedia Society
• /
• v.13 no.12
• /
• pp.1814-1819
• /
• 2010

Since 1987, when statistical analyzing guide for thermal life test of Accelerated Life Test(ALT) was proposed as ANSI/IEEE Std 101, this guide has been used widely for many experiment data. Shim(2004) had done Monte Carlo simulation to compare life of two different systems or materials, based on statistic values obtained from ANSI/IEEE Std 101 data. In this study, a profile analysis is proposed for comparing life of two different systems or materials, and some examples using pre-existing data are given.

• Journal of International Society for Simulation Surgery
• /
• v.2 no.2
• /
• pp.80-82
• /
• 2015

The mandibuloplasty for the facial aesthetic reason has been the one of the most popular procedures in aesthetic facial bone surgery in East Asia. Most East Asian women prefer smaller-looking and smooth-shaped facial contour. Prominent mandible angle which are common in Asia would be the main problem for smooth facial contour. In addition, recently, the mandibular body and broad chin shape also are known to be remodeled in order to get the ideal smooth facial shape. However, mandibuloplasty is not that easy to cut because many patients has inward mandibular angle and the visual field in operation is limited. The aim of this trial is to try to provide the prefabricated cutting guide for the symmetric and appropriate mandibuloplasty with the surgeons. Preoperative computed tomography(CT) data were processed for the patient and computer simulation model was produced. Then, mandibuloplasty was done on the computer simulation screen. Based on this data, customized cutting guide was made. This prefabricated cutting guide was used in real mandibuloplasty bilaterally. Premade cutting guide for the mandibuloplasty based on the computer simulation turned out to be very successful in this patient. Individualized approach for each patient could be an ideal way to manage the patients in near future.

• Research in Mathematical Education
• /
• v.26 no.1
• /
• pp.19-30
• /
• 2023

This study analyzes the tasks selected and implemented by pre-service mathematics teachers to support students' development of epistemic actions. Data was collected from 20 students who participated in a mathematics education curriculum theory course during one semester, and multiple data sources were used to gather information about the microteaching sessions. The study focused on the tasks selected and demonstrated during microteaching by pre-service teachers. The results suggest that providing students with a variety of learning opportunities that engage them in different combinations of abductive and deductive epistemic actions is important. The tasks selected by pre-service teachers primarily focused on understanding concepts, calculation, and reasoning. However, the use of engineering tools may present challenges as it requires students to engage in two epistemic actions simultaneously. The study's findings can inform the development of more effective approaches to mathematics education and can guide the development of teacher training programs.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.16 no.6
• /
• pp.203-209
• /
• 2016

Digital tourism is the digital support of the tourist experience before, during and after the tourist activity[1]. The GPS-enabled mobile phones provide location-based mobile applications such as tour guide and storytelling services. In this paper, we propose the smart tour guide service platform based on GIS and develop the mobile application to provide the smart tour guide service. The proposed smart tour guide service platform consists of CMS, the multi-modal navigation system, the tour attraction content creation and management system, the tour commodity creation and management system, the smart search system, and the user terminal. The smart tour guide application supports digital tourism in the pre-tour, during tour, and post-tour using the proposed smart tour guide service platform in the popular tourist attractions in Jeju.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.34 no.2
• /
• pp.125-133
• /
• 2024

Objectives: The aim of this study is to develop a comprehensive Occupational Safety and Health (OSH) guide for maintenance tasks in semiconductor processing, specifically focusing on etching, deposition, and ion implantation processes. Methods: The development of the OSH guide involved a literature review, consultations with industry experts, and field investigations. It concentrates on Maintenance Work (MW) operations in these specialized areas. Results: The result is a detailed OSH guide tailored to MW in etching, deposition, and ion implantation facilities within semiconductor processing. This guide is structured to assist maintenance workers through pre-, during and post-MW phases, ensuring easy comprehension and adherence to safety protocols. It highlights the necessity of safety and health measures throughout the MW process to protect personnel. The guide is enriched with real-life scenarios and visual aids, including cartoons and photographs, to aid in the understanding and implementation of safety and health principles. Conclusions: This OSH guide is designed to enhance the protection of workers engaged in maintenance activities in the electronics sector, particularly in semiconductor manufacturing. It aims to improve compliance with safety and health standards in these high-risk environments.

• Nuclear Engineering and Technology
• /
• v.50 no.6
• /
• pp.963-970
• /
• 2018

The U.S. Nuclear Regulatory Commission, Regulatory Guide 1.20 needs to perform a comprehensive vibration assessment program for reactor internals during preoperational and startup testing for nuclear power plants and extended power uprate. Although the measurement program is one of the core programs, it is rarely carried out except for a first-of-a-kind or a unique design. This article describes measurement results of vibration and stress for the comprehensive vibration assessment program for an APR-1400 reactor internals. The measurement was performed at an upper guide structure during the pre-core hot functional test of Shin Kori unit 4 reactor internals because the Shin Kori unit 3 and 4 are the first construction project for the APR-1400, and the upper guide structure assembly was to design change compared with the valid prototype. We confirmed that all measured results are within the test acceptance criteria. It means that the structural integrity of the APR-1400 reactor internals was secured for the flow-induced vibration.

• Journal of Korean Elementary Science Education
• /
• v.38 no.2
• /
• pp.287-304
• /
• 2019

Teaching with technology has been widespread in practical classroom settings, and increased the needs to enhance pre-service teachers' capability with a variety of technologies. The purpose of this study is focused on designing and implementing a training program to develop pre-service teachers' Technological Pedagogical Content Knowledge(TPACK) which promotes them use technologies tactically in integrated science classes. Based on the theoretical framework of TPACK and Practitioner's Guide to TPACK, the authors developed ten periods of lessons comprised instructional skills in elementary science education. Subsequently, the program was applied into a teacher trainee course in Korea. The results of this study indicate that the TPACK training program for pre-service teachers significantly influenced on attitude toward convergence, TPACK, and science teaching efficacy of the engaged participants. The developed program, meanwhile, caused a significant TPACK improvement of female participants of the teachers college more effectively. Furthermore, it mitigated the gap between science and humanity tracks coming from their high schools. Consequently, there are possibilities to improve pre-service teachers' teaching strategies for integrated classes, if they have opportunities to review the comprehensibility of technological, pedagogical, content knowledge, and intersected areas with metacognitive perspectives.

• Structural Engineering and Mechanics
• /
• v.18 no.4
• /
• pp.429-440
• /
• 2004

Remotely Operated Vehicle of 6000-meters is a new conceptual equipment made to replace the manned systems for investigating the deep-sea environment, and all of the ROV systems in operational condition strongly depend on the connecting cables. In this point of view dynamics of the ROV cable system is very important for operational and safety aspects as a cable generally encounters great tension. Researches have been executed on this problem, and most of papers have been mainly focused on the operational condition of ROV system in deep sea. This paper presents the dynamic cable response analysis during ROV launching condition rather than the operational one in order to provide the design guide of a ROV cable system in this circumstance, considering the coupling effects between cable and wave-induced ship motion. To obtain the variations of cable tensions during a ROV launching, a pre-stressed harmonic response analysis was carried out. Wave-induced tensions of the cable during ROV launching were obtained in real sea states using FE modeling, and the basic design guide of a ROV cable system was obtained.

• Journal of Korean Elementary Science Education
• /
• v.38 no.1
• /
• pp.87-101
• /
• 2019

The purpose of this study was to investigate elementary school teachers' perception and the status of education program on science museum field trips by using a questionnaire (188 teachers) and interview (6 teachers). The results of the research are as follows. First, factors influencing elementary school teachers who choose the science museum as a place for field trips were 'student's interest', 'teacher's own experience related to the science museum', 'science curriculum', 'suggestions from a fellow teacher', 'space available for field work' and so on. Second, 82% of the respondents conducted pre-education program, but they mainly conducted safety education. Third, the teacher conducted post-education program less than pre-education program. In the post-education program, the most activities were to express and share knowledge and experience gained from the science museum. Fourth, 52.2% of the teachers provided tasks or activity sheets during science museum field trips. Fifth, the teachers mainly served as safety guide. In addition, the teachers thought that safety guide was the most important role of teacher in science museum field trips. Sixth, the teachers thought that the method of viewing the science museum's collection, which emphasizes the role of docent rather than the teacher, was more educational.