• Korean Journal of Optics and Photonics
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• v.11 no.4
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• pp.239-245
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• 2000

In this paper, the fundamental properties of diffractive optical element were investigated. Also, this work deals with theoretical approaches for achromatization in DOE's optical system based on thin lens theory. It is found that achromatization could be satisfied by one hybrid lens only, which is composed of a diffractive and a refractive element. In order to have compact optical system, we used the tele-photo type lens composed of a positive and a negative power elements instead of retro-focus lens. From the Gaussian brackets and Seidel aberration theory, the initial design was numerically obtained. The aberration properties of an initial design was aplanat and flat field. In order to correct the chromatic aberrations, refractive and diffractive elements were used on front element. This hybrid lens is also useful for correction of higher order aberrations. Compared to conventional design composed of refractive lenses only, this approach dramatically improved the compactness of the optical system. Finally, residual aberration balancing results in a lens with focal length of 3.89 mm and overall length of 5.19 mm, which has enough performance over an f-number of 4.0. Also, it is expected to fulfill all the requirements of a digital still camera lens. This optical system is superior to the current refractive lens system in the number of elements, weight, and aberration properties. rties.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.12 no.1
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• pp.38-45
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• 2018

The purpose of this study was to investigate the effects of an increase in self - determination experience on the behavior of young children with autism spectrum disorder by telepresence robot. As for research method, the study used AB design, two selected children engaged in activities with a telepresence robot in free play time in the morning. The activities were conducted in 19 sessions, twice a week, 15 to 40 minutes each. To investigate the effect of the activity on the child's behavior was observed using the behaviors of free play time and work time in the afternoon. All the process was recorded by a camera and then analyzed by frequency recording. The results of the study are as follows. First, the participation of young children with autism spectrum disorder in free play time increased. Second, choice-making or preference behavior of young children with autistic spectrum disorder were increased. This study suggests that increasing the self-determination experience of young children with autism spectrum disorders using telepresence robots increases their participation and increases their choice-making or preference behavior.

• The Journal of Korean Physical Therapy
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• v.27 no.4
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• pp.207-213
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• 2015

Purpose: The aim of the current study was to investigate EMG activity on dynamic balance of subjects with functional lumbar instability following fatigue of low back. Methods: The subjects (24 university students) were divided into 2 groups; functional lumbar instability group (6 males and 6 females) and lumbar stable group (7 males and 5 females) who could complete a questionnaire and undergo a prone instability test. All participants were evaluated for distribution of muscle activity using the TeleMyo DTSTM system. Dynamic balance was tested by Y balance test. This study was conducted for measurement of EMG activity on dynamic balance with the difference between FLIG and control group following muscle fatigue. Results: The functional lumbar instability group (FLIG) showed a significantly lower YBT score (%) of anterior, posterolateral direction on Y-balance test (YBT) in dynamic balance than the lumbar stable group (LSG) (p<0.05). The FLIG was significantly lower than the LSG in anterior direction in EMG activity(%) of MF, RA, ES, GMX, GME, RF, and posteromedial direction in EMG activity(%) of IO, ES and then posterolateral direction in EMG activity(%) of IO, ES in dynamic balance (p<0.05). There was significant correlation of MF, RA, and GMX in anterior reach direction (p<0.05) and ES, GME (p<0.01) and IO, ES in posteromedial reach direction (p<0.05) and EO, ES, GMX in posterolateral reach direction (p<0.05) there was positive correlation. Conclusion: This study showed that FLIG effected EMG activity by dynamic balance following muscle fatigue. Further study is needed for measurement of various ages and work with lumbar instability for clinical application.

• The Korean Society of Law and Medicine
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• v.20 no.2
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• pp.141-171
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• 2019

Nurses are medical personnels under the Medical Service Act and perform medical practice such as medical assistance at medical institutions. The nurse, a medical personnel, provides emergency medical service to emergency patients in the pre-hospital emergency medical system as a 119 rescuer based on the Act on 119 Rescue and Emergency Medical Services. The scope of practice of nurses is comprehensively defined in the Medical Service Act and specified through precedents. In contrast, The scope of work of emergency medical technician is listed in detail. It is understood that nurses in the pre-hospital emergency medical service system have a wider scope of practice than emergency medical technician. In particular, the scope of practice of nurses as emergency medical personnel in the pre-hospital emergency medical system should be interpreted differently within the medical institution, considering the urgency of the patient, being transferred to the emergency medical institution, and the specificity of medical direction through tele-communication.

• Korean Journal of Construction Engineering and Management
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• v.14 no.4
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• pp.164-171
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• 2013

In urban planning, road facility is used not only for the transportation purpose but also for the utility line space purpose such as electrical, gas, tele communication, heating, water, sewer, and so on. However, since these utilities are built by many different groups, it becomes very difficult to communicate each other. Delay in one party can cause another party's schedule delay but they don't commuicate often. Also, some delay in utility work can cause frequent pavement cut. And, this will impact on construction cost, schedule delay, low quality, user complain and cost. This study developed spatiotemporal decision model to prevent prequent utility cut for mega project such as new urban development project. In addition, this study developed utility cut management system to manage utility cut schedule under pavement. Finally, developed system was applied to new urban development project and verified there effectiveness.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.11
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• pp.1741-1747
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• 2010

This work presents a study on the design of an economic service robot hand for tele-presence manipulators. The conceptual design of new robot hand is derived from biomimetics approach. Guided by the analysis of human arm' musculoskeletal structure, the fingers are actuated by cables and actuators in the forearm. High tension in the cables is achieved by screw-nut mechanism driven by DC motors. A set of combination springs is incorporated in each of the screw-nut mechanism for easy control of gripping force. The first prototype revealed difficulties with finger control and coupling problem between gripping force and wrist movement. The solutions to these problems have been derived from the contradiction analysis of TRIZ. The second design has been verified by tests on various objects with different weight and shape for full range of wrist motion.

• Journal of the Korea Convergence Society
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• v.13 no.1
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• pp.89-99
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• 2022

Due to COVID-19, non-face-to-face cultures such as remote classes, remote work, and tele-medicine are spreading. The major contributors to the settlement of such a non-face-to-face society are small and medium SW companies and SW manpower. However, recently as large platform companies and foreign big tech companies hire thousands of SW manpower, SW small and medium-sized companies are experiencing a serious manpower shortage. Therefore, the purpose of this study is to suggest policy alternatives for SMEs to stably secure SW manpower and support continuous business operation. To achieve this purpose, this study examines the current status of the SW industry and manpower, then summarizes related issues and suggests policy alternatives to solve these issues. Those policies include the reinforcement of incentives to support manpower retention such as the Naeil Chaeum deduction system, youth housing union composition, special military service system, recruitment of manpower through the contract semester system of employment conditions, reinforcement of customized education through supplementation of the SW manpower training voucher system, SW field skill standardization, establishment of a governance system for nurturing SW manpower, preparation of countermeasures against the outflow of manpower to large companies, and a win-win cooperation program for large and SME SW manpower.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.1
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• pp.101-116
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• 2019

Technology-based start-up is important in that it encourages innovation, facilitates the development of new products and services, and contributes to job creation. Technology-based start-up activates entrepreneurship when appropriate support is provided within the ecosystem. Thus, understanding the technology-based start-up ecosystem is crucial. The purpose of this study is as follows. First, in Herrmann et al.'s(2015) study, we compare and analyze the ecosystem of each country by selecting representative regions such as Silicon Valley, Tel Aviv, London and Singapore which have the highest ranking in the start-up ecosystem. Second, we try to deeply understand the start-up ecosystem based on in-depth interviews with various stakeholders such as VC investors, start-ups, support organizations, and professors related to the Korean start-up ecosystem. Finally, based on the results of the study, we suggest development and activation of Korean technology-based start-up ecosystem. As a result, the Seoul start-up ecosystem showed a positive evaluation of government support compared to other advanced countries. In addition, it was confirmed that the ratio of tele-work and start-up company working experience of employees was higher than other countries. On the other hand, in Seoul, It was confirmed that overseas market performance, human resource diversity, attracting investment, hiring technological engineers, and the ratio of female entrepreneurs were lower than those of overseas advanced countries. In addition, according to the results of the interview analysis, Seoul was able to find that start-up ecosystems such as individual angel investors, accelerators, support institution, and media are developing thanks to the government's market-oriented policy support. However, in order for this development to continue, it is necessary to improve the continuous investment system, expansion of diversity, investment return system, and accessibility to the global market. A discussion on this issue is presented.