• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.359-360
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• 2019

본 논문에서는 2018년에 성횡한 악성코드에 대한 피해 사례를 살펴본 후 이를 적극적으로 대응하기 위한 방안을 살펴본다. 특히 가상통화 거래소에 대한 해킹 사고 및 가상화폐에 대한 지속적인 해킹 시도가 탐지되면서 관련 소식들이 언론에 지속적으로 보도되었다. 또한 이와 관련하여 PC 및 서버 자원을 몰래 훔쳐 가상통화 채굴에 사용하는 크립토재킹 공격기법도 함께 주목받았다. 랜섬웨어 부문은 갠드크랩 관련 보도가 대부분을 차지할 정도로 국내에서 지속적으로 이슈가 되었다. 또한 미국 법무부에서 최초로 북한 해커조직의 일원을 재판에 넘기면서 해커 그룹에 대한 관심이 집중되기도 했다. 2018년 전반적으로 이러한 가상통화 거래소 해킹, 크립토재킹, 랜섬웨어, 해커 그룹의 4가지 키워드를 도출하였으며, 이 중 해커 그룹은 북한과 중국의 경우를 나누어 총 5가지 주제를 통해 악성코드에 대한 주요 이슈들을 살펴본다. 본 논문에서는 이러한 악성코드의 공격을 근본적으로 해결할 수 있는 방안으로 클라이언트 측에 USB형태의 BBS(Big Bad Stick) 하드웨어를 통하여 제안하는 환경을 제안하고 안전한 서비스가 제공됨을 증명하여 본 연구가 새로운 보안성을 갖춘 시스템임을 보인다.

• Journal of the Korean Society of Radiology
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• v.83 no.6
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• pp.1286-1297
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• 2022

Purpose To assess the usefulness of various metal artifact reduction (MAR) methods in patients with hip prostheses. Materials and Methods This retrospective study included 47 consecutive patients who underwent hip arthroplasty and dual-energy CT. Conventional polyenergetic image (CI), orthopedic-MAR (OMAR), and virtual monoenergetic image (VMI, 50-200 keV) were tested for MAR. Quantitative analysis was performed in seven regions around the prostheses. Qualitative assessments included evaluation of the degree of artifacts and the presence of secondary artifacts. Results The lowest amount of image noise was observed in the O-MAR, followed by the VMI. O-MAR also showed the lowest artifact index, followed by high-keV VMI in the range of 120-200 keV (soft tissue) or 200 keV (bone). O-MAR had the highest contrast-to-noise ratio (CNR) in regions with severe hypodense artifacts, while VMI had the highest CNR in other regions, including the periprosthetic bone. On assessment of the CI of pelvic soft tissues, VMI showed a higher structural similarity than O-MAR. Upon qualitative analysis, metal artifacts were significantly reduced in O-MAR, followed by that in VMI, while secondary artifacts were the most frequently found in the O-MAR (p < 0.001). Conclusion O-MAR is the best technique for severe MAR, but it can generate secondary artifacts. VMI at high keV can be advantageous for evaluating periprosthetic bone.

• Management & Information Systems Review
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• v.16
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• pp.1-35
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• 2005

The Virtual organization is a alternative organization for redesigning the classical organization. With the advantages of the quickness of decision making and also connection with other organization, it can be well prepared for the consumer's need. With recent increased interest in virtual organization, there are many companies that consider the virtual organization as practical use. However, it is still in an early stage of the research and the concept has not been established for the virtual organization. The purpose of this research is to systematize the understanding of the virtual organization for the future organizational model. The differences of existing organizational structure can be compared with these three reasons of practical use for the virtual organization, the development of information technology, the importance of strategic choice and unreliable environment. Also, the framework for the virtual organization can be presented with its profiles. The use of this research can be appeared by analyzing the given framework from the companies that are already made practical application of the virtual organization. For the future, this research will give the direction and its viewpoint how this will be used for achieving the competitive advantage of companies and practical use for actual aspects with the pursuit of this research.

• Journal of the Korean Geographical Society
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• v.46 no.1
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• pp.81-99
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• 2011

The purpose of this paper is to systemize the spatial studies of logistics industry by arranging the partially scattered current studies on spatial studies of logistics industry overall. Logistics industry now builds a complex spatial organization which has been developed to the stages of independent optimization by materials management and physical distribution providing specialized logistics services, logistics, and supply chain management including IT and management step by step. The complex spatial organization of logistics industry has been systematized with geographical space and virtual space, disintegration and integration, and intermediation and disintermediation. The three areas reported a dynamic characteristic overlapped in space. The dynamic characteristic has a dose relationship with interaction between IT and space of economic activities.

• The Journal of the Korea Contents Association
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• v.11 no.7
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• pp.9-20
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• 2011

In this paper, we attempt to realize the diversity of human actions in a virtual world in terms of the basic actions. We utilize the comprehensive knowledge structure of ontology to organize the human actions into an action hierarchy, each action being the root action of its associated hierarchy of specialized actions. Each basic action is implemented by composing the primitive motions and each basic action in turn by reusing those basic actions. Our approach to the development of these actions is focused more on their diversity and brevity than on their visual realism. Based on this design we develop a method to grasp virtual humans' characteristics and reflect those characteristics on their respective action patterns. We also present a mechanism for the agents to adapt their motions to diverse qualitative changes in environment. We apply these methods to such basic actions as walk, run and throw to demonstrate their viability.

• Progress in Medical Physics
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• v.27 no.2
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• pp.93-97
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• 2016

In this study, we evaluate the effect of respiration on the dose distribution in patient target volume (PTV) during intensity-modulated radiation therapy (IMRT) and research methods to reduce this impact. The dose distributions, homogeneity index (HI), coverage index (CVI), and conformity index of the PTV, which is calculated from the dose-volume histogram (DVH), are compared between the maximum intensity projection (MIP) image-based plan and other images at respiration phases of 30%, 60% and 90%. In addition, the reducing effect of complication caused by patient respiration is estimated in the case of a bolus and the expended PTV on the skin. The HI is increased by approximately twice, and the CVI is relatively decreased without the bolus at other respiration phases. With the bolus and expended PTV, the change in the dose distribution of the PTV is relatively small with patient respiration. Therefore, the usage of the bolus and expended PTV can be considered as one of the methods to improve the accuracy of IMRT in the treatment of breast cancer patients with respiratory motion.

• Korean Security Journal
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• no.62
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• pp.9-33
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• 2020

This study presents aspects of the financing of terrorism using virtual-currencies. Fisrt of all, this introduces the conventional threat of the financing of terrorism and the analysis of current legal system regarding virtual-currency in South Korea. Next, the financing of terrorism cases are analyzed. With given analysis, the paper deals with its response and future extensions by technical and institutional aspects. The threats of the financing of terrorism are going higher after the appearance of virtual-currencies such as Bitcoin. There are two typical ways to use virtual-currencies by terrorist groups. One is to conduct public fund-raising in the social network system and the dark web. The other is to hack into virtual-currency exchange network in order to steal virtual currencies for developing the weapon of mass destruction. Specifically South Korea is top three country of trading virtual currencies and has been subject to virtual-currency hacking more than 10 cases. However, many countries including South Korea deal with virtual currencies as only innovative technology and means of investment, not the threats of the financing of terrorism. Under these circumstances, there a the legal contradiction. This article points this limit and absurdity. Also, it shows reasonable alternatives. All in all, given these aspects, the article proposes detailed policy directions.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.600-607
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• 2008

메타버스 개발을 위한 세계 각국의 행보가 빨라지고 있다. 미국의 <세컨드라이프>를 시작으로 MS와 구글이 차세대 메타버스 개발을 서두르고 있고, 일본에서도 , , 등이 이미 출시되었거나 출시를 앞두고 있다. 이에 발맞춰 메타버스에 관한 연구도 한창인데, 2006년 5월 미국 캘리포니아에서 열린 제1회 메타버스 로드맵 서alt(Metaverse Roadmap Summit)이 대표적이다. 미국미래학협회(ASF)주최로 열린 이 행사에는 미국의 저명한 IT전문가, 게임제작자들이 대거 참가했고, 조직위측은 이날 햇사에서 진행된 수십 시간 분량의 토론을 인터넷에 고시해서 1년동안 각계각층의 의견을 수렴했다. 그리고 1년 후인 2007년 6월 <메타버스 로드맵 3D웹으로 가는길>을 발표됐다. 뿐만 아니라 비슷한 시기에 일본의 <노무라연구소>에서도 IT로드맵을 발표하고 메타버스의 발전전망을 제시했다. 이에 반해 세계최고의 IT기술력을 자랑하는 국내에서는 메타버스에 관한 개발과 연구가 매우 미흡한 실정이다. 이에 본 고에서는 미국의 <메타버스 로드맵>과 일본의 을 중심으로 메타버스의 개념과 발전전망을 살펴보고, 현존하는 가상세계 중 메타버스 개념에 가장 근접했다고 평가받는 린든랩의 <세컨드라이프>의 의의와 한계를 짚어보았다. 또한 제2, 제3의 <세컨드라이프>를 노리고 있는 세계 각 국의 메타버스 개발동향을 분석하고 이를 통해서 차세대 메타버스 개발의 성공조건으로서 풍부한 콘텐츠 제공과 SNS기능의 강화, 미러월드의 발전가능성등에 주목해야 함을 알 수 있었다. 이러한 연구결과는 90년대 온라인게임의 성공 이후 장기간 침체 현상을 보이고 있는 우리의 가상세계 개발연구에 유의미한 시사점을 지닌다고 하겠다.

• The Journal of the Korea Contents Association
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• v.22 no.5
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• pp.81-96
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• 2022

Covid-19 calls for minimizing gatherings of people in spaces such as offices. Organizations are encouraging information-sharing activities among employees by using online platform technology. Recently, Organizations are supporting their work using the metaverse. This study confirms the effect of metaverse presence on the intention to share knowledge by forming the intrinsic motivation of the employees and the moderating effect of the individual's digital technological competence. We presented research hypotheses through previous studies such as virtual reality and tested the hypotheses using 309 samples obtained through surveys. As a result, the social, tele, and self presence of the metaverse increased organizational-related intrinsic motivation(organizational identification, value congruence) and had a positive effect on the intention to share knowledge. In addition, digital technological competence moderated the relationship between value congruence and intention to share knowledge. This study suggests the importance of strategies to enhance the presence of metaverse for organizations to increase work productivity by using metaverse and the need to support individual digital competence reinforcement.

• Review of KIISC
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• v.26 no.3
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• pp.45-49
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• 2016

게임은 독자적인 하나의 가상 세계를 구성하며, 이에 따라 게임을 서비스하는 기업은 별도의 사법체계에 가까운 정보보호 및 보안 체계 및 인력을 유지하는 경우도 많다. 여기에서는 이러한 기업이 가지고 있는 권한을 활용하여 정보보호를 강화하는 방법에 대해 경제이론에 기반하여 사례를 간략하게 분석하였다. 가상 세계에서의 불법적 활동은 개인의 효용극대화라는 경제이론으로도 설명이 가능하며, 이를 볼 때 불법적 활동의 감소는 기대되는 수익의 감소 및 처벌 규모 및 발각확률 상승으로 인한 기대되는 비용의 증가를 통해 정책적으로 대처가 가능하다. 이를 위해 다양한 기술적/보안조직 등에 대한 연구 및 방법론들이 개발되어 있지만, 이를 통하지 않더라도 게임 내 규칙을 변경하거나, 정책적 방향을 통해서도 유사한 효과를 얻을 수 있다. 여기에서는 간략하게 (1) 불법적 이득을 감소시키는 정책 (2) 불법적 활동의 발각확률을 올리는 정책 (3) 불법적 활동에 대한 처벌에 대한 정책이라는 세 가지 측면에서 검토하였으며, 그동안 게임사에서 시도되었고 효과적이었다고 인지되는 여러 사례를 소개하고자 하였다.