• Journal of the Institute of Electronics Engineers of Korea TE
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• v.39 no.2
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• pp.124-133
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• 2002

In this thesis. we present the cyber lecture system based on XML 3-tier that uses the communication network as the internet. The system was designed to analysis the existing cyber lecture system and its details and to examine web system architecture and XML 3-tier model. With the designed system, we developed the cyber lecture system. We tested the existing system for performance and problem, then we improved the method of the cyber lecture system used by XML 3-tier Model. The cyber lecture system is offered the handiness of the cyber lecture system using web interface.

• The Journal of Information Technology
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• v.3 no.3
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• pp.39-55
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• 2000

Internet Trade is the new type of business transaction, which sells and advertises the product and services by using the Internet, which is spreaded rapidly to the world. Under these circumstance, our country should discuss the proper position and role as the center in the trade amount in the world trade market, and face the irresistible changes of trade environment. First, in the institution and legal aspect. Second, the price payment system of the internet trade. Third, the so-called infra construction, the physical sector for activating the internet trade, the comprehensive plan of super-highway information communication net work by the government authorities is expected to be promoted. There is no perfect solution that internet trade could be completely done in front of monitor and will be solved one by one along with the development of electronic commerce. At last, the government's and industry's joint positive concern and participation in the rapidly changing new world trade trends of internet trade is expected fit for our position in the world.

• Journal of KIISE:Information Networking
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• v.35 no.6
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• pp.521-528
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• 2008

Such conventional maritime communication technologies as radio have short some comings in their transmission quality. It can be overcome by wireless channels provided by satellites such as INMARSAT, which nevertheless suffer from the high costs. In this paper, we propose a novel technology resolving the above problems, featuring in the establishment of maritime communication networks with multi-hop structures. The inter vessel and ship-to- shore networks previously modeled after MANET are remodeled by SANET (Ship Ad Hoc Networks) in the present work. Fan-shaped Search Zone Routing (FSR) protocol also is presented, which utilizes not only static geographical information including the locations of ports and the navigations of courses but also the unique characteristics of ships in terms of mobile nodes. The FSR finds the fan-shaped search zone on which the shortest path is located. The performance of LAR protocol is compared with that of FSR in several ways. First, FSR does not make use of a type of control packets as beaconing data, resulting in a full utilization of the bandwidth of the wireless channels. Second, the delivery rate by the FSR is 100% for the fan-shaped search zone includes at least one route between source and destination nodes on its border line, where as that of LAR has been turned out to be 64%. Third, the optimality of routes searched by the FSR is on a 97% level. Of all, the FSR shows a better performance than LAR by about 50%.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.4
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• pp.267-272
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• 2016

In the era of ultra high speed information communication technology represented by Smart phone and Tablet PC, the disable and the aged people came to be in a position of so-called 'relatively weak people' in the field of information communication due to inconvenience of use and difference in information acquisition and processing ability. Thus, a survey was conducted on Smart phone accessibility items based on previous studies of the disabled with crippled disorder, brain lesions, myelopathy and muscular disabilities having more inconvenience relatively in their use of smart phone due to upper limb dysfunctions. Especially, people with upper limb dysfunctions with relatively weak grip had big inconvenience in the conditions of uses requiring actions such as grabbing and rotating the devices, and due to the characteristics of touch screen input method of Smart phone, they had big inconvenience due to a lack of a guidance for keyboard in input. As a result of questionnaires by the type of disability, it turned out that severe myelopathy causes the most inconvenience in using smart phone.

• The Transactions of the Korea Information Processing Society
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• v.5 no.11
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• pp.2943-2953
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• 1998

As communication networks become very fast, the scope of applications is varied and applications using multi-party communications in which more than one communication station participate, have been increased. In this paper, multicast servers are designed and implemented by two different schemes (centralized multicast server scheme and distributed multicast server scheme). Both scheme contain three operation for joining/leaving of a node, operation for transmitting the name of the group and messages to the server, and operation for a node to read messages and clear shared memory. Based on their implementations, two multicast server schemes are compared in terms of complexity, extendibility, efficiency and real-time aspects. As a result, the average transfer time of the distributed multicast server scheme is shorter than that of the centralized multicast server scheme. Finally, we designed the multi-party real-time communication method to guarantee QoS in multicast.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.1
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• pp.42-47
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• 2020

In OFDM-based very high-speed communication systems, FFT/IFFT processor should have several properties of low-area and low-power consumption as well as high throughput and low processing latency. Thus, radix-2k MDF (multipath delay feedback) architectures by adopting pipeline and parallel processing are suitable. In MDF architecture, the feedback memory which increases in proportion to the input signal word-length has a large area and power consumption. This paper presents a feedback memory size reduction method of radix-22 MDF IFFT processor for OFDM applications. The proposed method focuses on reducing the feedback memory size in the first two stages of MDF architectures since the first two stages occupy about 75% of the total feedback memory. In OFDM transmissions, IFFT input signals are composed of modulated data and pilot, null signals. In order to reduce the IFFT input word-length, the integer mapping which generates mapped data composed of two signed integer corresponding to modulated data and pilot/null signals is proposed. By simulation, it is shown that the proposed method has achieved a feedback memory reduction up to 39% compared to conventional approach.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2003.11a
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• pp.101-114
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• 2003

홈 유비퀴터스 네트워크란 PC, 휴대 전화, 디지털TV, 냉장고, 에어컨, 개인 휴대 정보 단말기(PDA), 게임기 등 가정 내의 정보기기들 사이에 통합된 네트워크를 형성해 데이터를 공유할 수 있는 환경을 구성한 것이다. 홈 네트워크 서비스를 가능케 한 요인은 기술적 측면에서 가전기기의 디지털화 및 초고속망의 보급, 수요측면에서 가전기기를 통한 다양한 서비스를 이용하고자 하는 소비자의 요구, 공급측면으로 포화된 정보통신기기 시장에서 새로운 수요창출이 필요한 환경 등으로 요약될 수 있다. 이와 같이 현재 정보통신산업은 지금까지 구축된 정보통신 인프라를 바탕으로 새롭게 등장한 홈 네트워크 서비스 분야에 주목하고 있다. 홈 네트워크는 정보통신기술을 가전기기에 융합시킴으로써 새로운 서비스를 창출한다는 점에서 정보통신산업은 물론, 기존의 백색가전 산업까지 포괄하여 관련 산업의 전후방 효과가 매우 크다. 본 연구에서는 홈 네트워크 서비스에 관련한 핵심 속성을 분석하고, 핵심 속성에 대한 소비자의 선호를 분석하는 실증연구를 수행하였다. 현재 홈 네트워크 시장이 본격적으로 형성되지 않아 현시선호(revealed preference) 자료의 구득이 불가능하므로, 소비자에게 향후 제공될 수 있는 서비스 특성을 지닌 가상적인 제품 조합을 제시하고, 이에 대해 소비자가 실제 시장에서와 같은 구매행위를 가정하도록 한 후, 각 제품 조합에 대한 선호 순위를 매기게 함으로써 소비자의 진술선호(stated preference)를 측정하는 컨조인트(conjoint) 방법론을 사용하였다. 이러한 분석을 통해서 홈 네트워크 서비스의 각 속성에 대한 소비자의 선호구조를 파악하고 지불의 사액(Willingness To Pay, WTP)을 분석하도록 한다. 본 연구의 결과를 이용하여 향후 전개될 홈 네트워크 서비스 및 관련시장의 발전 방향을 전망해 보고 이에 따른 기업이나 정부차원의 대응전략을 파악하고자 한다.육구에서는 큰 변화를 나타내고 있지 않았다(p<0.05). 운동과 비운동시킨 참돔의 지질 함량의 변화는 운동시킨 참돔은 운동으로 인한 에너지 소비로 인하여 함량이 유의적으로 감소했으며(r=-0.35), 비운동사육구에서는 절식으로 인하여 지질함량이 감소하였다(r=-0.38). 파괴강도와 가장 밀접한 영향을 가지는 콜라겐은 운동과 비운동 모두 사육기간동안 큰 변화는 보이지 않았다. 초기의 파괴강도값은 1.45±0.02kg(운동사육구), 1.36±0.18kg(비운동사육구)이였으며 사육기간동안 운동사육구는 파괴강도값이 증가한 반면, 비운동수조에서는 참돔의 파괴강도는 사육기간동안 큰 유의차가 없었다. 각 성분간의 상관도를 살펴보면, 수분함량과 파괴강도는 상관성을 가졌으며, 지질함량과 파괴강도도 같은 경향은 나타내었다. 운동기간동안의 파괴강도와 콜라겐 사이에는 상관성의 거의 없었다. 이는 운동기간에 따른 파괴강도의 증가가 콜라겐의 함량의 증가보다는 지질함량의 감소와 수분함량의 증가와 같은 성분과의 상관성이 크다고 판단된다. 다음으로는, 운동횟수에 의한 영향으로써 운동시간을 1일 6시간으로 설정하여, 운동횟수를 결정하기 위하여 오전, 오후에 각 3시간씩 운동시키는 방법과 오전부터 6시간동안 운동시키는 두 방법을 이용하여 품질을 비교하였다. 각 조건에 따라 운동시킨 참돔의 수분함량을 나타낸 것으로, 2회(오전 3시간, 오후 3시간)에 나누어서 운동시키기 위한 육의 수분함량은 73.37±2.02%를 나타냈으며, 1회(6시간 운동)운동시키기 위한 육은 71.74±1.66%을 나타내었다. 각각의 운동조건에서 양식된 참돔은 사육초기에는 큰 변화가 없었으나, 사육 5일 이후에는 수분함량이 증가하여 15일에는 76.40±0.14, 75.62±0.98%의 수분함량을 2회와 1회 운동시킨 참돔의 육에서 각각 나타났다. 운동횟수에 따른 지질함량은 2회 운동시킨 참돔은 5.83±2.08, 1회 운동시킨 참돔은 6.72

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.2
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• pp.209-216
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• 2013

In this paper, we design and analyze digital retrodirective array antenna (RDA) system in 60GHz wireless communication for low power consumption and high quality. Digital RDA can automatically make beam toward source without information about the direction of incoming signal, this system is able to do low power communication thanks to increased signal to interference noise ratio (SINR) because making the beam toward source can reduce interference signals. The frequency offset seriously arises when millimetric wave band like 60GHz is used to communicate for high-speed transmission. The proposed system is robustly designed to frequency offset through designing digital phase lock loop in order to solve the problem of frequency offset. In this paper, we analyze the performance of the proposed system according to the number of array antenna and frequency offset. striking space.

• Convergence Security Journal
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• v.19 no.4
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• pp.87-96
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• 2019

Recently, with the rapid development of video equipment and technology, tremendous video information is produced and utilized in military domain to acquire battlefield information or for effective command control. Note that the video playback devices currently used in the military domain ranges from low-performance tactical multi-functional terminals (TMFT) to high-performance video servers and the networks where the video information is transmitted also range from the low speed tactical information and communication network (TICN) to ultra-high speed defense broadband converged networks such as M-BcN. Therefore, there is a need for an efficient streaming technique that can efficiently transmit defense video information in heterogeneous communication equipment and network environments. To solve the problem, this paper proposes a Scalable Video Coding (SVC) and balanced selection algorithm based Peer-to-Peer (P2P) streaming technique and the feasibility of the proposed technique is verified by simulations. The simulation results based on our BitTorrent simulator show that the proposed balanced selection scheme outperforms the sequential or rarest selection algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.7
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• pp.1471-1477
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• 2003

In order to realize the Gbps VPN system, however, newer and more advanced technologies are required to enable wire-rate processing across a wide range of functions and layers. While it is generally accepted that a software soluTion on general-purpose processors cannot scale to process these functionsa wire rate, the KEY POINT is that a software solution on general-purpose processors is the most practical way by which these security allocationscan be developed. Many of these security functions require application layer processing on the content of the packets, and the very nature of application layer software development is characterized by relatively large code size with a high need for portability an flexibility. We have analysed the consideration and specification for realizing Gbps VPN system. from this work. we can obtain a technology of originality.