• 한국안전학회지
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• 제27권3호
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• pp.57-62
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• 2012

The purpose of this paper is to find dangerous factors of a water purifier when water leaks due to inappropriate use and analyze the patterns of damaged parts in order to provide data for the examination of the cause of the problem. If the water purifier is inspected and managed by a non-specialist, when the FLC(Float Level Controller) at the top is inclined, water leakage may occur to the water purifier. The leaked water flows onto the cables and hoses and enters the thermostat terminal, heater, PCB, power supply connection connector, etc., becoming a dangerous factor that may cause a system failure, fire, etc. Due to the water that entered the input terminal, low noise and white smoke were generated at first. However, the flame gradually propagated due to the continuous inflow of moisture. It was found that when moisture reached the PCB, a carbonized conductive path was formed at the varistor terminal, input terminal, semiconductor device terminal, etc., and the flame became larger, which might result in a fire. From the metal microscope analysis of a damaged condenser terminal, it was found that the amorphous structure unique to copper cable disappeared, and voids, boundary surface and disorderly fine particles occurred. Also, in the case of the connector into which moisture penetrated, fusion and deformation occurred at the cable connection clips. The result of analysis of the power supply cable connector using a thermal image camera showed that most of the heat was generated from the cable connection clips and the temperature at the connection center was normal.

• 한국초전도ㆍ저온공학회논문지
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• 제16권2호
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• pp.29-32
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• 2014

The critical current, $I_c$ of HTS superconducting tapes can be measured by transport or contactless method. Practically, the transport method using the four-probe method is the most common. In this study, a simple test procedure by clipping the voltage lead taps have been introduced instead of soldering which reduces time and effort and thereby achieving a much faster measurement of $I_c$. When using a pair of iron clips, $I_c$ value decreased as compared with the measured one by standard method using soldered voltage taps and varies with the width of the clipped specimen part. However, when using a pure Cu clip, both by clipping and by soldering voltage taps give a comparable result and $I_c$ measured are equal and close to the samples specification. As a result, material to be used as voltage clip should be considered and should not influence the potential voltage between the leads during $I_c$ measurement. Furthermore, the simulation result of magnetic flux during $I_c$ measurement test showed that the decrease of $I_c$ observed in the experiment is due to the magnetic flux density, $B_y$ produced at the clipped part of the sample by the operating current with iron clips attached to the sample.

• 방송공학회논문지
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• 제17권1호
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• pp.1-16
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• 2012

양안식 입체 영상 미디어의 제작 워크플로우 개선을 위해, 본 논문에서는, 제작 및 후-제작 단계에서 발생할 수 있는 다양한 제작 왜곡들이 시청 피로도에 미치는 영향을 주관적 시청 실험을 통해 분석하였다. 주관적 시청 실험의 객관적 지표 생성을 위해 제작 왜곡의 요인들을 분류하여 7가지의 대표적 시청 피로도 유발 요인을 선정하고, 선정된 각 요인 별 시청 실험을 위해 카메라와 피사체의 움직임 정도를 조합하여 4가지 실험 동영상을 제작하였다. 제작된 실험 영상들은 각기 7단계의 제작 왜곡을 부가하여 5초 단위의 시청 실험 콘텐츠 196개를 생성하였으며, 생성된 콘텐츠와 ITU-R BT.1438 권고에 따라 총 101명의 실험 참가자를 모집하여 주관적 시청 실험을 실시하였다. 실시된 시청 실험의 분석 결과는 제작 현장에서 발생할 수 있는 다양한 왜곡에 대한 상대적인 중요도 및 각 오차에 대한 허용 한계 범위 등에 대한 기본 정보를 제공한다.

• Journal of Korean Neurosurgical Society
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• 제30권sup1호
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• pp.165-169
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• 2001

Apatient, 51 years old woman, had suffered form headache and decrease of visual acuity. She had $3{\times}3cm$ sized giant aneurysm originated in cavernous and clinoid portion of left ICA(C4,C5) in the cerebral angiography. Before craniotomy, left CCA was exposed and 6F double lumen catheter was inserted in left ICA through the sheath. Pre-operative angiography was done. balloon catheter was positioned at the petrous portion of ICA. Eyebrow approach was done and giant aneurysm was exposed. The proximal blood flow was controlled with balloon dilatation and suction and decompression was tried, then multiple clips were applied. The loss of distal blood flow under intra-operative angiography was notified after clipping. The position of clips were repositioned to preserve blood flow & the rich flow was confirmed at distal part of clipping. In the post-operative cerebral angiography, the same finding was shown.

• Smart Structures and Systems
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• 제18권3호
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• pp.485-500
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• 2016

Stay cables in some cable-stayed bridges suffer large amplitude vibrations under the simultaneous occurrence of rain and wind. This phenomenon is called rain-wind-induced vibration (RWIV). The upper rivulet oscillating circumferentially on the inclined cable surface plays an important role in this phenomenon. However, its small size and high sensitivity to wind flow make measuring rivulet size and its movement challenging. Moreover, the distribution of the rivulet along the entire cable has not been measured. This paper applies the videogrammetric technique to measure the movement and geometry dimension of the upper rivulet along the entire cable during RWIV. A cable model is tested in an open-jet wind tunnel with artificial rain. RWIV is successfully reproduced. Only one digital video camera is employed and installed on the cable during the experiment. The camera records video clips of the upper rivulet and cable movements. The video clips are then transferred into a series of images, from which the positions of the cable and the upper rivulet at each time instant are identified by image processing. The thickness of the upper rivulet is also estimated. The oscillation amplitude, equilibrium position, and dominant frequency of the rivulet are presented. The relationship between cable and rivulet variations is also investigated. Results demonstrate that this non-contact, non-intrusive measurement method has good resolution and is cost effective.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제35권4호
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• pp.377-411
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• 2021

본 연구는 교수학습 맥락에서 수학교사의 중심신념과 주변신념의 탐색을 목적으로 한다. 이러한 목적을 위해 본 연구는 고등학교 현직교사 8명을 대상으로 가상의 수학 수업 동영상을 활용하여 수학적 신념 측면에서 교사 노티싱(noticing)을 분석하였다. 분석결과, 노티싱하는 교사는 동영상 속 수업교사의 교수학습 문제 상황에 대하여 자신의 수학적 신념을 반영하여 비판하고, 교수학습 대안을 제시하였다. 그리고, 본 연구의 노티싱 분석은 '교수학습의 학생참여'와 같은 특정 노티싱 주제에 반영된 교사들의 수학적 신념을 비교하여 교사 개인의 상대적 중심신념과 주변신념을 드러내었다. 이러한 연구 결과를 통하여 본 연구는 노티싱을 활용하여 교수학습 맥락의 제약조건에서 수학교사의 중심신념과 주변신념을 추출하는 모형을 제안하였으며 부가적으로 수학교사의 교수학습-의사결정-전문성을 관찰할 수 있었다.

• PNF and Movement
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• 제12권1호
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• pp.19-25
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• 2014

Purpose: To investigate the effect of action observation training on the muscle onset time and symmetrical use of rectus femoris(RF) and gastrocnemius medialis(GCM) during sit-to-stand (STS). Methods: Sixteen patients with stroke entered a single-blind trial and were randomly assigned to the experimental(Action) or control(Landscape) groups. Those in the Action observation group watched video clips showing specific movement and strategies to STS, wheas those in the control group watched video clips of static pictures showing differnet landscapes. All patients was measured the EMG data in the STS on the affected side and unaffected side. The EMG data were collected from RF and GCM while performing the STS task. The EMG onset time and onset time ratio for the RF and GCM were calculated by dividing the EMG onset time of RF and GCM action on the affected side by these on the unaffected side. Results: Onset time of affected side RF, GCM was significantly faster action observation training group than control group(p<.05). But interventions before and after the symmetry did not show a significant increase. Conclusion: There findings suggest that action observation training has a positive effect on the muscle onset time shortened during STS tasks.

• 대한지역사회영양학회지
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• 제25권6호
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• pp.451-463
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• 2020

Objectives: The purpose of this study was to develop and evaluate booklets and video clips to prevent children from picky eating. Methods: Based on a survey conducted on food preferences of preschool children aged 2 to 5 years, 14 kinds of less preferred vegetables were selected. Accordingly, educational videos, activity books, and teaching-learning guides were produced for preschool children using the 'food bridge' theory, and the educational materials were named "Friendly vegetables". Educational materials were distributed to childcare institutions, and their effectiveness was investigated for preschool children who were instructed on these materials once every 30 days from March to November, 2019. The children were examined for changes in their knowledge of names, colors, taste/texture, methods of cultivation, and preferences for vegetables before and after the instructional course. Results: The awareness of vegetables increased significantly in younger children and the picky eating group. When the assessment was carried out in terms of vegetable knowledge, it was observed that the younger the age or the pickier the in eating food, the more effective the education is compared to the counter part. The preference for vegetables also increased after the instruction compared to the pre-instruction period, but significant changes were seen only in the 2~3 year age group for boys and girls. Also, only the picky group of girls showed changes in preference. The children's average interest in the education materials was 3.85 points out of 5 points. Conclusions: Through this study, we have developed educational materials for standalone use in childcare facilities and confirmed that they have a significant effect on improving awareness and preferences related to vegetables. In summary, the younger the age or the pickier the child in eating food, the more effective the education. It is believed that additional education on mealtime guidance is needed which can alter the eating behavior of preschool children and improve their diet. It is proposed to widen the scope of use of the materials by collecting diverse opinions from child care teachers.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.732-737
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• 2009

Due to various project delivery methods and the complexity of construction projects in the construction industry, developing the framework of construction management for critical, highly complex projects in the construction industry has become problematic. Currently, a set of construction manuals play a pivotal role in planning and managing construction projects as subcontractors try to complete their scope of work according to the instructions of a general contractor. It is challenging for general contractors to write a construction management procedure manual to cover various types of project delivery methods and construction projects. In construction, the construction procedure manuals describe specific actions to be taken through the project. In reality a few contactors own such manuals and their construction schedules include more construction operation activities. Thus, it is hard to estimate the workload and productivity of construction managers because the manual and the schedule do not present the amount of management efforts required to complete a project. This paper proposes a framework to present construction management tasks according to project delivery methods which can be applied to various construction projects. Actions for management tasks were mapped and were integrated with construction activities throughout the project life cycle. The framework can then be used to give specific instructions to project participants, collect management actions, and replicate management actions throughout the project life cycle. The framework can also be can used to visualize complete construction project to analyze and manage construction management activities in each phase of a project in order to enhance productivity and efficiency. The studies of existing construction manuals were carried out to identify construction managers' responsibilities. An artificial intelligence program, CLIPS (C-Language Integrated Production System) was used to search for appropriate actions for impending tasks from a set of predefined actions to be performed for a given situation. The framework would significantly help construction managers to understand interrelations among management tasks or actions within a project. Furthermore, the framework can be embedded into Building Information Modeling (BIM) or Facility Management Systems (FMS) so that designers and constructors would execute constructability review before construction begins.

• 한국항해학회지
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• 제15권2호
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• pp.13-38
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• 1991

This paper intends to develop a Prototype Expert Collision Avoidance System by introducing expert system techniques into the decision block of anti-collision loop. The problem domain of this study is characterized and specified by combining the concepts of anti-collision loop and knowledge -based system for collision avoidance. Domain in knowledge which may originates from the appropriate sources such as the International Regulations for Preventing Collision at Sea 1972, Marine Traffic Laws, and many texts on the subject of anticollision navigation and good seamanship is acquired and formalized into the knowledge-base system using production rule. Finally, a Prototype Expert Collision Avoidance System is built by using the CLIPS, developed by AIS NASA written in and fully integrated with the C language, and some test-and-run results of the system are demonstrated and examined. The author considers the proposed system which is named PECAS to be meaningful as a test bed for a further refined Expert Collision Avoidance System on board the Automated Ship.