• Fire Science and Engineering
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• v.32 no.6
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• pp.40-45
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• 2018

The omnidirectional surveillance camera uses the object detection algorithm to level the object by unit so that broadband surveillance can be performed using a fisheye lens and then, it was a field experiment with a system composed of an omnidirectional surveillance camera and a tracking (PTZ) camera. The omnidirectional surveillance camera accurately detects the moving object, displays the squarely, and tracks it in close cooperation with the tracking camera. In the field test of flame detection and temperature of the sensing camera, when the flame is detected during the auto scan, the detection camera stops and the temperature is displayed by moving the corresponding spot part to the central part of the screen. It is also possible to measure the distance of the flame from the distance of 1.5 km, which exceeds the standard of calorific value of 1 km 2,340 kcal. In the performance test of detecting the flame along the distance, it is possible to be 1.5 km in width exceeding $56cm{\times}90cm$ at a distance of 1km, and so it is also adaptable to forest fire. The system is expected to be very useful for safety such as prevention of intrinsic or surrounding fire and intrusion monitoring if it is installed in a petroleum gas storage facility or a storing place for oil in the future.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.1
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• pp.33-46
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• 2019

Even though Korea is strengthening the support for startups due to the limitations of growth policies focusing on large companies, the survival rate of startups is very low, so that there should be more efforts to increase the survival rate of startups. As the existing startup support institutions have provided only fragmentary supports to startups, it would be necessary to have the comprehensive support institutions. As an alternative, the accelerator providing the comprehensive support such as spatial support, education, mentoring, networking, seed investment, and connection for follow-up investment to the initial startups was legalized in Korea of 2016, based on the registration system. Currently, within less than two year from then, there have been much interest in it enough to have about 136 registered accelerators. In the United States, the accelerator was introduced more than ten years ago. In Korea, however, it is still in the initial stage, so that the researches or social consensus on the accelerator are not sufficient. Thus, this study aims to suggest the measures for the development of accelerator and the consensus on the decision making for the selection of accelerator of startups, by researching which parts are considered when startups in the accelerator stage select the accelerator. As a result of the empirical analysis, the factor that has the greatest influence on decision making factors when startup chooses an accelerator was the subsequent investment attraction. This can be explained to the accelerator as desired, considering the factor that the startup of the initial stage places the most importance on growth as investment. We hope that these research results will be sustainable in future research related to accelerators, in hopes that it will be useful for establishing accelerator policies for domestic startups and direction for revitalizing related industries.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.74-80
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• 2021

This study investigated the process quality level of a K5 gas mask, which recently acquired its operational capability, through statistical process analysis for the mass production stages and their lots. The tensile adhesion strength was the only operating requirement in the manufacturing process of the K5 gas mask. For this purpose, the results of tensile adhesion strength between the lens and facial rubber during the initial and second mass production stages were analyzed using conventional statistical and statistical process analysis methods. The conventional statistical results indicated that the second mass production stage was better than the initial mass production stage. In cases of a control chart and process capability of tensile adhesion strength, the process quality level was also improved by following the mass production stages. The improvement was caused by process stabilization and work skill elevation. These results and methods are expected to be conducted and utilized in the third mass production stage. Moreover, quality improvement of K5 gas mask mass production can be achieved using the Lean 6 sigma procedure, MDAIC (Define, Measure, Analyze, Improve, Control).

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.6
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• pp.511-519
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• 2020

For camera calibration, a checkerboard is generally used to determine the principal point, focal length, and lens distortions. The checkerboard has a planar and three-dimensional shape, and camera calibration parameters are affected by the size of the checkerboard, the placement of the target, and the number of target points. In this study, the accuracies of the types of checkerboards were compared using checkpoints for stereo camera calibration, and the purpose of this study was to propose the best performance checkerboard. The checkerboard with large flat shape showed comparatively high accuracy through comparison with the check points. However, due to the size of the checkerboard, it was inconvenient to move and rotate, and there was a disadvantage in that it was difficult to shoot so that the target points could all appear in the stereo camera. The checkerboard, which was manufactured in a small size in a flat shape, was easy to move and rotate but had the lowest three-dimensional accuracy. The checkerboard with targets with height values had the hassle of having to determine the three-dimensional coordinates of the target points by using observation equipment for camera calibration, but it was small in size, convenient to move and rotate, and showed the highest three-dimensional accuracy.

• Korean Journal of Optics and Photonics
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• v.33 no.6
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• pp.295-302
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• 2022

In this paper, a wedge prism application method was studied to design a full-high-definition (FHD)-class high-resolution flexible endoscope. In the case of the conventional flexible endoscope optical system, the F number is made large or a liquid lens is applied to obtain the same imaging performance in a wide depth of field. However, there is a problem in that the diameter of the optical system increases because an additional light guide and equipment are required. To solve this problem, two wedge prisms were applied to the flexible endoscope optical system to adjust the image distance for each object distance. First, two wedge prisms were symmetrically placed on the designed endoscopic optical system. An image distance satisfying the target imaging performance according to each objective distance was derived. Next, the wedge prism decenter value for controlling the image distance was derived. By combining these two data, a wedge prism decenter value that satisfied the target imaging performance at each object distance was applied in multi configurations. As a result of the optimal design applied with the wedge prism, a target imaging performance of more than 20% of the modulation transfer function for a resolution of 178 cycles/mm was satisfied in the entire depth of field of 100 mm-7 mm.

• The Mathematical Education
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• v.60 no.1
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• pp.77-110
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• 2021

In this study, a student participation-centered class based on student mathematical thinking as a the meaningful subject was called a student thinking-based math class. And as a way to support these classes, I paid attention to lesson design. For student thinking-based mathematics classes, it is necessary not only to anticipate student thinking and teacher feedback, but also to plan in advance how to properly arrange and connect expected student responses. The student thinking-based lesson design template proposed in this study is a modified three-step(introduction, main topic, summary) lesson design template. The reason for revising the existing design template is that it has limitation that it cannot focus on mathematical thinking. Using the conceptual framework of student thinking-based mathematics lesson as a lens, the difference between the three-step lesson design prepared by pre-service teachers and the students' thinking-based lesson design prepared by the same pre-service teachers was analyzed. As a result of planning lessons using the student thinking-based lesson design, more attention was paid to the cognitive and social engagement of students. In addition, emphasis was placed in the role of teachers as formative facilitator. This study is of significant in that it recognizes the importance of classes focusing on students' mathematical thinking and provides tools to plan math classes based on students' thinking.

• Knowledge Management Research
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• v.21 no.4
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• pp.129-156
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• 2020

The sharing economy is recognized as a new economic system based on the digital service platform, but the sharing economy has yet to be established in Korea due to a lack of social awareness and understanding. There is a need to enhance understanding and awareness of the sharing economy in positive perspective in order to make up business with advanced economies global and explore new markets. In this study, after collecting papers of the sharing economy over the past decade published by each academic field around the world, we reviewed them from academic lens and conducted a comprehensive analysis using meta analysis methodology. Then, we selected papers of MIS field and analyzed the trends of the MIS field research in these papers. As a result we identified the research trend of the sharing economy and the MIS research and drew the necessity of interdisciplinary research between the two studies by examining importance and relevance of MIS research in the sharing economy research. Therefore, we expect that this study contributes to promote interdisciplinary research with neighboring disciplines and to establish a positive social, economical and industrial position in Korea.

• Korean Journal of Play Therapy
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• v.21 no.4
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• pp.427-448
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• 2018

The study examined the mediated-moderation effect of parental reflection levels from maternal childhood experiences by the parents to mother's reaction to negative emotions of their preschoolers by examining it through the lens of parental role satisfaction. The participants in this study were 327 mothers who and their infants aged 3-6 years. They completed questionnaires on the maternal childhood experiences scale, parental reflection scale, parental role satisfaction scale and mother's reaction to negative emotions of their preschoolers scale. The results of the structural equation model analysis are as follows. First, a mediating model revealed that the relationship between maternal childhood experiences by parents and mother's reactions to negative emotions of their preschoolers was mediated by parental role satisfaction. Second, the results revealed the moderation effect of parents reflection levels on the relationship between maternal childhood experiences by parents and parental role satisfaction. Finally, parental reflection levels were also seen to have a mediated moderation effect of parental reflection level from maternal childhood experiences to mother's reaction to negative emotions of their preschoolers through parental role satisfaction. These results indicate the importance of parental reflection and parental role satisfaction.

• Journal of the Korean Society of Earth Science Education
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• v.13 no.3
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• pp.305-316
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• 2020

This study aimed to analyze the conception of an extra-solar planet perceived by university students. To conduct this, we developed an extra-solar planet education program and questionnaires which help to figure out changes between before and after the program, and then applied them to the targeted students. The results of the study are as follows. First, as to the conception of an extra-solar planet, participants understood it merely as a planet outside the solar system before they got training. However, they expanded it to the one revolving around a star that appears outside the solar system based on keywords after the training. Second, they gave brief responses regarding exploration strategies (e.g., observing the extra-solar planet by using the Doppler effect, dietary phenomenon, and gravitational lens) based on indirect experiences they encountered in the media. The responses indicated their lack of concept of the extra-solar planet exploration methods. However, their recognition of the extra-solar planet observation became concrete while students learned about the exploration of the extra-solar planet. Third, they were expanding the importance of the exoplanet observation simply beyond the discovery of extraterrestrial life to the creative process and research methods, including the solar system and the development of humanity. Fourth, they recognized that exoplanet education is necessary for curriculum as it will be able to bring about students' interest and curiosity as well as scientific knowledge if contents related to the extra-solar planet appear in the earth science curriculum.

• Clean Technology
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• v.27 no.1
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• pp.17-23
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• 2021

Black polymer spacers are currently used for physically separating aligned camera lenses in camera modules of mobile phones. However, the mechanical properties of polymer spacers have their limits, especially in the current trend of using more lenses in thinner camera modules. Thus, copper (Cu) becomes a good candidate for those polymer spacers because of its superior mechanical properties and its inherent blackness due to its black surfaced oxides, such as copper (II) oxide (cupric oxide, CuO). The latter property is critical in quality control because the closer the color of a spacer is to black, the less light interference and flaring phenomena can occur. A standard Cu blackening process and its operational conditions were proposed in this study through a comprehensive analysis of previous research and patents. The Cu blackening process is composed of cleaning, deoxidizing, activating, blackening and sealing. The effects of operational parameters, such as the temperature of each unit process and the activator concentration, were then investigated by measuring the blackness of the Cu strips with a colorimeter. The proposed operational conditions were determined by whether the blackness of Cu strips was within the on-spec. value used in the field.