• 한국통신학회논문지
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• 제37A권11호
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• pp.986-992
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• 2012

중첩 융합 네트워크 환경 하에서의 무선 이동통신시스템의 성능개선이 급격히 증가하는 무선 트래픽의 처리를 위해 매우 중요한 이슈로 떠오르고 있다. 그러므로 단말기의 기능성이 좋아짐에 따라 스마트한 지능을 기반으로 자원의 효과적 활용에 적합한 개별 이종네트워크의 특성분석과 특성을 반영하는 시스템측면의 최적화가 매우 중요하다고 할 수 있다. 본 논문에서는 기지국의 소형화와 지능화가 진행되는 가운데 기지국 hotelling과 같은 기지국 집중화를 통한 통합적 최적화가 가능하므로 이에 대응한 이중 가상 셀 시스템에 대해 살펴보고 활용도 측면의 특성을 분석하였다.

• 한국컴퓨터정보학회논문지
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• 제18권1호
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• pp.55-62
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• 2013

본 논문은 어린이나 노약자, 손이 불편한 장애우 등이 컴퓨터의 타자 실력을 증가시키기 위한 타자게임을 설계 구현하였다. 이 게임의 구성은 화면에 임의의 단어가 나타나는 한글이나 영문의 단어를 정해진 시간 안에 올바르게 치면 점수가 증가되고, 틀리게 치게 되면 점수가 감점되며, 올바르게 입력을 하면 앞서가는 벌레나 곤충을 잡을 수 있도록 따라가는 방식으로 되어 있다. 틀린 단어를 입력하면 앞서가는 벌레와 거리가 더 멀어지게 되며, 정해진 시간 안에 많은 단어의 입력을 하여 올바른 입력을 하면 앞서가는 벌레와 충돌되어 벌레를 없앨 수 있는 기능을 제공한다. 이는 두되 계발을 촉진시키면서 키보드의 단어 입력과 같은 타자 실력을 증가시키기 위함이다. 흥미를 유발하면서도 타자 실력과 키보드의 글자의 위치를 암기할 수 있는 장점이 있으며 정서적으로도 도움이 될 것으로 기대된다.

• 지식경영연구
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• 제22권4호
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• pp.157-172
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• 2021

정보보호 기업은 1990년도 후반에서 2000년도 초반에 설립되었는데 다른 주요한 기반 산업에 비하면 그 역사가 휠씬 짧다. 그럼에도 불구하고 정보보호 산업은 급속하게 발전하고 있다. 4차 산업혁명과 관련한 첨단 기술의 발전에 힘입어 정보보호 산업의 비중은 점점 크질 것으로 예상된다. 2019년에 발생한 COVID-19가 2020년 전세계로 확산되면서 비대면 서비스와 디지털 전환 가속되었다. 이용자에 대한 사이버 위협도 증가되고 있어 분야별 차별화된 보안이 필요한 상황이다. 하지만 정보보호 인력의 부족, 국내 기업의 보안 역량의 미흡, 국내 정보보호 시장 협소 등으로 인하여 새로운 사이버보안 위협을 대응하기에는 한계가 있다. 본 연구는 정보보호 기업의 외부 환경 요인인 정부의 정보보호 제도의 운영, 정부의 영향력, 정부의 지원, 정보보호 기업간 파트너십 등과, 내부 환경 요인인 최고경영층의 지원, 재무상태, 인적자원 등이 조직 역량, 혁신 역량에 미치는 영향을 분석하였다. 또한 조직 역량, 혁신 역량이 재무적 성과와 비재무적 성과에 영향을 미치는지를 실증 데이터를 이용하여 분석하였다. 본 연구의 결과는 정보보호 정책과 시사점을 제시하고 정보보호산업의 경쟁력을 강화하는 기초자료로 활용될 수 있을 것이다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.69.5-69
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• 2001

Computer simulations are widely used to analyze passenger safety in traffic accidents. ATB(articulated total body) is a computer simulation model developed to predict gross human body response to such dynamic environments as vehicle crashes and pilot ejections. ATB, whose code is open, has high flexibility and application capability that users can easily insert defined modules and functions. ATB is, however, inconvenient as it was coded in FORTRAN and it needs a formatted input file. Moreover, it takes much time to make input files and to modify coding errors. This study aims to increase user friendliness by adding a preprocessor program, WINATB(WiNdow ATB), to the conventional ATB. WINATB programmed in Visual C++ and OpenGL uses ATB IV as a dynamic solver ...

• 대한인간공학회지
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• 제31권1호
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• pp.63-76
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• 2012

Objective: The main objective of this study is to propose a user-centered assessment metric for ubiquitous services. Background: As the ubiquitous era took off, the interactions between ubiquitous services and users have come to take an important position. It is essential to conceptualize a new assessment model that considers human-system interaction capability with a user-centered design perspective. Method: The evaluation model for the interactivity of ubiquitous service was approached from the concept of usability and inter-personality of services. As a validation study, suggested assessment metric was utilized to evaluate the u-Home service. Priority weighting of each assessment metric was derived using the quantification type-I analysis. Results: To evaluate interactivity, this study suggested a quantitative metric for user testing performed after classifying the interactivity characteristics to contextualization; ubiquity; user experience; and service capability. Conclusion: This study suggest the metric for the ubiquitous service that are experienced in real life, and introduced the concept of ubiquitous service interactivity. Application: The suggested evaluation metric can be used to evaluate interactivity level of ubiquitous service and identify the potential problem and usability requirements at the early stage of service development.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권8호
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• pp.1754-1769
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• 2013

For the purpose of enhancing the spectrum efficiency, cognitive radio (CR) technology has been recently proposed as a promising dynamic spectrum allocation paradigm. In CR, spectrum sensing is the key capability of secondary users in a cognitive radio network that aims for reducing the probability of harmful interference with primary users. However, the individual CRs might not be able to carry out reliable detection of the presence of a primary radio due to the impact of channel fading or shadowing. This paper studies the cooperative spectrum sensing scheme as means of optimizing the sensing performance in AWGN and Rayleigh channels. Results generated from simulation provide evidence of the impact of channel condition on the complementary receiver operating characteristic (ROC). Based on the results, it was found that with constant local SNRs at the secondary users, the probability of missed detection ($P_m$) of cooperative spectrum sensing in a cognitive radio network, calculated using a closed form expression, can be significantly minimized. Thus, the paper illustrates that improvement of the detection performance of the CR network can be achieved by establishing a centralized cooperation among neighboring cognitive radio users. Finally, verification of the validity of the fusion schemes utilized for combining the individual CR decisions is provided.

• International Journal of Contents
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• 제5권3호
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• pp.50-56
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• 2009

Internet is being used for several activities by a great range of users. These activities include communication, e-commerce, education, and entertainment. Users are required to register regarding website in order to enroll web activities. However, registration can be done by automated hacking software. That software make false enrollments which occupy the resources of the website by reducing the performance and efficiency of servers, even stop the entire web service. It is crucial for the websites to have a system which has the capability of differing human users and computer programs in reading images of text. Completely Automated Public Turing Test to Tell Computers and Human Apart (CAPTCHA) is such a defense system against Optical Character Recognition (OCR) software. OCR can be defined as software which work for defeating CAPTCHA images and make countless number of registrations on the websites. This study proposes a new CAPTCHA context that is Korean CAPTCHA by means of the method which is splitting CAPTCHA images into several parts with random rotation values, and drawing random lines on a grid background by using Korean characters only. Lines are in the same color with the CAPTCHA text and they provide a distortion of image with grid background. Experimental results show that Korean CAPTCHA is a more secure and effective CAPTCHA type for Korean users rather than current CAPTCHA types due to the structure of Korean letters and the algorithm we are using: rotation and splitting. In this paper, the algorithm of our method is introduced in detail.

• 한국멀티미디어학회논문지
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• 제7권12호
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• pp.1754-1764
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• 2004

Lately mobile handheld devices such as Personal Digital Assistant (PDA) and cellular phones are getting more popular for personal web surfing. However, today most mobile handheld devices have relatively poor web browsing capability due to their low performance so their users have to suffer longer communication latency than those of desktop Personal Computers (PCs). In this paper, we propose an effective pre-refresh mechanism for embedded web browser of mobile handheld devices to reduce this problem. The proposed mechanism uses the idle time to pre-refresh the expired web objects in an embedded web browser's cache memory. It increases the utilization of Central Processing Unit (CPU) power and network bandwidth during the idle time and consequently reduces the client's latency and web browsing cost. An experiment was done using a simulator designed by us to evaluate the efficacy of the proposed mechanism. The experiment result demonstrates that it has a good performance to make web surfing faster.

• 제어로봇시스템학회논문지
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• 제13권8호
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• pp.735-742
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• 2007

The importance of the interaction capability of a robot increases as the application of a robot is extended to a human's daily life. In this paper, a portable mediate interface Handybot is developed with various interaction channels to be used with an intelligent home service robot. The Handybot has a task-oriented channel of an icon language as well as a verbal interface. It also has an emotional interaction channel that recognizes a user's emotional state from facial expression and speech, transmits that state to the robot, and expresses the robot's emotional state to the user. It is expected that the Handybot will reduce spatial problems that may exist in human-robot interactions, propose a new interaction method, and help creating rich and continuous interactions between human users and robots.