• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2006년도 한국컴퓨터종합학술대회 논문집 Vol.33 No.1 (D)
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• pp.319-321
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• 2006

본 논문에서는 블록 FEC(Forward Error Correction) 알고리즘을 적용한 IEEE 802.11e MAC(Medium Access Control)의 블록전송모드(Block Transfer Mode)의 성능을 분석한다. 성능 향상을 위해서 IEEE 802.11e MAC은 TXOP(Transmission Opportunity)시간 동안 특정 스테이션(station)에게 독점적인 전송 기회를 부여하며, 이 기간동안 하나의 블록 즉 연속적으로 여러 개의 데이터 프레임(frame)을 전송한다. 수신자는 블록내의 각 프레임에 수신 여부를 블록 ack (block Acknowledgment)방식, 즉 하나의 ack 패킷이 모든 수신 프레임의 일련번호를 모아 알려 준다. 그러나 오류가 빈번한 무선 채널 환경에서는 블록 ack 방식을 사용하더라도 빈번한 재전송으로 인해 채널의 성능이 현저히 감소한다. 이러한 문제를 해결하기 위해 심볼 단위로 오류를 복원하는 블록 FEC 알고리즘을 적용할 수 있는데, 본 논문에서는 802.11e에서 FEC 알고리즘을 적응하는 두 가지 방식의 성능을 해석적으로 분석한다. 즉 두 가지 방식은 프레임 당 블록 FEC를 적용하는 방법과 전체 블록 내의 프레임을 하나의 데이터로 간주하여 FEC를 적용하는 방식이다. 본 논문에서는 이 들 두 가지 방식의 채널 성능 향상 정도와 블록 ack만을 사용한 경우의 성능을 수식적으로 계산한다. 실험에 의하면 BER이 $10^{-4}$인 채널 환경에서 블록 FEC를 적용한 방식이 블록 ack를 사용한 방식에 비해 약 1.5%의 성능향상을 보인다.

• 한국실내디자인학회논문집
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• 제22권6호
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• pp.68-78
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• 2013

The purpose of this study is to investigate Seonyudo Park and Kkummaru in terms of haptic space. This is an attempt to escape from the limits of optical space that identifies the space with abstract concepts. Haptic perception of the space refers to feeling the space with all the senses through non-hierarchical interactions. Time of the haptic space is revealed by Deleuze's crystalline description and Bergson's pure recollection that is not useful to identify objects. According to two concepts, the running present forks into the past and the future, and the nature of time appears at the point of indiscernibility in which the past, present, and future coexist. Thought on time about the architecture provides a valid point of view to understand the relationship of visitor's sensory experience of space, recollection, and emotion. In this respect, it can be said that Joh sung-yong's two works explored for new areas of architectural experience by building up the potential image of the subject which is placed in the human memory. And then this study shows that two works recover the relationship between the past and the present so that they give an opportunity to consider the meaning of time in the architecture.

• 한국자동차공학회논문집
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• 제16권2호
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• pp.183-190
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• 2008

This paper deals with the characteristics of idle vibration due to the type of constant velocity joints. Based on the kinematics model of constant velocity joints, a offset between the tripod center and tullip center plays a important role in generating unwelcome forces. Moreover, it induced additional forces in lateral direction of a vehicle movement according to the angle of the spider in idle vibration. The difference of mass for each constant velocity joint types affect the natural frequency of the driveshaft and the powertrain. When the static torque is applied to the constant velocity joints, the natural frequencies of the driveshaft are reduced nearby 50Hz. There will be a big opportunity that the dirveshaft and constant velocity joints would be a transfer path of idle vibration at D or R gear range. Experiments indicate that TJ type is better than SFJ and DOJ in idle vibration.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제16권3호
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• pp.359-370
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• 1994

The reconstruction of major head and neck defects must be an integral part of the overall cancer treatment plan. The priorities of surgical treatment of head and neck tumor are 1) local tumor control, 2) relief of pain, 3) avoidance of difficult dressing, 4) provision of oral continence, and 5) ability to swallow and manage saliva. The recent advances in reconstructive surgery including the development of musculocutaneous flaps and microvascular free tissue transfer have allowed the surgical restoration of head and neck tumor defects that previously were not possible. These techniques have provided the opportunity to undertake larger, more aggressive resection while at the same time permitting functional rehabilitation. The timing of reconstruction demands on the nature of the resection, the ability of the ablative and reconstructive teams to coordinate efforts, the overall health of the patients, the patient's needs and wishes. So, we report to emphasize current methods for restoring major head and neck tumor defects after tumor ablation, reviewing for the reconstructive operations, postoperative complications, and postoperative sequelae etc, of patients from Jan, 1990 to Dec, 1993.

• Journal of Information Technology Applications and Management
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• 제23권2호
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• pp.177-194
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• 2016

This study analyzed President Park's speeches and the government's industry policy in the field of information security using cognitive map. The relationship analysis between policy tool variables and policy goal variables was employed to derive revitalization strategy of information security. This paper found that entrepreneurship revitalization has very strong causality with expansion of domestic market and global market. But, on the other hand, HR development has very weak causality with job creation and future growth driver because the labor market in the information security industry is poor and its transfer rate to other industry is very high. This study showed that this cognitive map could be characterized by a scarcity of feedback loops and a strong emphasis on the positive loops in the structure of virtuous circle. In this paper, we also constructed a comprehensive cognitive map on the policy vision of information security, showing that there are a risk of cyber threat, an opportunity of new fusion security market, information security reinforcing circle, global economic circle, and domestic market circle.

• 한국정밀공학회지
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• 제19권7호
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• pp.97-105
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• 2002

The use of rapid prototyping (RP) has reduced time to market, cut total costs and improved product quality by giving design and manufacturing teams the opportunity to verify and fine tune designs before committing them to expensive tooling and fabrication. In order to improve their unique characteristics according to the working principles, Variable Lamination Manufacturing process (VLM-ST) and corresponding CAD/CAM software (VLM-Slicer) is developed. The objective of this study is to improve the accuracy of VLM-ST process, and it can be done by offset fur cutting error correction, cutting path overrun fur sharp edge and reference shape generation for off-line stacking. It has been shown that, through the verification experiments for given practical shapes, the proposed algorithms are effective for diverse categories of three-dimensional shapes.

• 한국디지털정책학회:학술대회논문집
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• 한국디지털정책학회 2005년도 추계학술대회
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• pp.323-335
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• 2005

Globalization of economy brings both opportunities and threats especially for companies in developing countries such as Korea. Globalization is an opportunity because it may expand the size of market for the company where globalization brings a threat for developing global competitiveness. If the company has already built competitive advantage in its business domain, the company can easily transfer market growth to profit improvement. However, if the company has not developed competitive advantage, globalization of economy will give a serious threat for the survivor of the company. The company might lose its own domestic market share. For the less famous brand of product or company name, international expansion is a challenging strategy. The study evaluated organizational performance of companies that try international expansion by utilizing Miles and Snow's strategy typology. We clustered organizations based on their strategy typology (prospector, analyzer, defender, and reactor) in view of the level of product diversification, new product development instances, level of localization, and autonomy of foreign subsidiary. With the strategy typology, we evaluated international strategy in view of product competitiveness, marketing strategy, human resource strategy, and organizational strategy. The regression result demonstrates that the performance of the company is significantly higher when the company employs prospector strategy. We also found out that product quality and emphasis for developed countries in international expansion are the most important factors for success.

• International journal of advanced smart convergence
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• 제7권3호
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• pp.130-139
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• 2018

This study is to analyze the relationship between character and human semantic production through research on character visualization artworks and to develop a creative platform that visually expresses the formative and semantic dynamics of characters using the results will be. The 3D spatial interaction system using the character visualization proposed generates the transformation of the character in real time using the interaction with user and the deconstruction of the character structure. Transformations of characters including the intentions of the viewers provide a dynamic visual representation to the viewer and maximize the efficiency of meaning transfer by producing various related meanings. The method of dynamic deconstruction and reconstruction of the characters provided by this system creates special shapes that viewers cannot imagine until now and further extends the interpretation range of the meaning of the characters. Therefore, the proposed system not only induces an active viewing attitude from viewers, but also gives them an opportunity to enjoy watching the artwork and demonstrate creativity as a creator. This system induces new gestures of the viewer in real time through the transformation of characters in accordance with the viewer''s gesture, and has the feature of exchanging emotions with viewers.

• International Journal of Internet, Broadcasting and Communication
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• 제10권3호
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• pp.73-80
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• 2018

This study introduces an interactive drawing system, a tool that allows user to sketch and draw with his own intentions. The proposed system enables the user to express more creatively through a tool that allows the user to reproduce his original idea as a drawing and transform it using his body. The user can actively participate in the production of the artwork by studying the unique formative language of the spectator. In addition, the user is given an opportunity to experience a creative process by transforming arbitrary drawing into various shapes according to his gestures. Interactive drawing systems use the segmentation of the drawing image as a way to extend the user's initial drawing idea. The system includes transforming a two-dimensional drawing into a volume-like form such as a three-dimensional drawing using image segmentation. In this process, a psychological space is created that can stimulate the imagination of the user and project the object of desire. This process of drawing personification plays a role of giving the user familiarity with the artwork and indirectly expressing his her emotions to others. This means that the interactive drawing, which has changed to the emotional concept of interaction beyond the concept of information transfer, can create a cooperative sensation image between user's time and space and occupy an important position in multimedia society.

• KDI Journal of Economic Policy
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• 제35권1호
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• pp.33-61
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• 2013

본 논문의 목적은 생애별 지원체계를 국가별로 비교하고, 거기서 경제성장과 정부재정의 지속성에 대한 함의를 도출해 내는 데 있다. 가족지원체계는 점차 그 중요성이 줄어듦에도 불구, 한국을 비롯한 몇몇 아시아 국가에서 유의하게 나타났다. 공공지원체계(사회보장)의 경우 한국은 OECD 국가 내에서 매우 낮은 수준을 보였는데, 이러한 낮은 사회보장이 높은 저축률과 자본축적에 기여한 긍정적인 측면은 인정된다. 하지만 지난 10년 동안 한국에서의 사회보장은 매우 빠른 속도로 변화하였다. 한국의 자본시장과 노동시장이 이러한 변화에 어떻게 반응하는 가가 향후 정부의 정책방향을 결정하는 데 중요한 요인이 될 것이다.