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The study on the effectiveness of smart home network service for IT underprivileged people and growth service model (IT소외 계층을 위한 실질적 스마트홈네트워크서비스의 영향 및 성장형 서비스모델에 대한 연구)

  • Kim, Byoung-Soo;Ji, Yeong-Soo;Han, Kyeong-Seok
    • Journal of Advanced Navigation Technology
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    • v.15 no.6
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    • pp.1000-1007
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    • 2011
  • Home Networking will be implementing the interactive network by home appliances over wireless/wireline network framwork. That is, Home appliances, which are being operated within home space configure the network through wireline/wireless network infrastructure for interworking and interacitive services by external internet access. Based on home networking, smarthome is home space where can use automatic telecommunication and interactive service by home appliances. we can call smarthome based on home networking infrastructure as the conceptual gateway for evolving future converged space like u-city. From simple home control service to home automation service over home networking infrastructure, smarthome service is evolving to up-to-date intelligent life environment in growth of IT technology. however, its service model development was based on supplier-centered based on advanced IT technology. because of this situation, smarthome service has not been acknowledged IT underprivileged people as well as IT early-adaptor. so, this research paper will consider and try to find out what will be the feasible factors to make the best service for IT underprivileged people.

Development of Satellite and Terrestrial Convergence Technology for Internet Services on High-Speed Trains (Service Scenarios) (고속열차대상의 위성인터넷 서비스 제공을 위한 위성무선연동 기술(서비스 시나리오 관점))

  • Shin, Min-Su;Chang, Dae-Ig;Lee, Ho-Jin
    • Journal of Satellite, Information and Communications
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    • v.2 no.2
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    • pp.69-74
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    • 2007
  • Recently, the demands for the satellite broadband mobile communication services are increased. To provide these services, mobile satellite communication systems for the passengers or crews on the high-speed moving vehicles, are being developed for the last several years especially in the Europe and North America. However, most of these systems can provide only several hundred kbps of transmission rate and this is not enough performance to provide satellite internet service for the group users such as passengers on the high-speed train. Moreover, service availability with these systems is limited to be rather low because they don't have any countermeasure scheme for the N-LOS environment which happens often along the railway. This paper describes mobile broadband satellite communication system, which is on the development, to provide high data-rate internet services to the high-speed trains. This system is applied with the inter-networking scenarios of both satellite/terrestrial network and satellite/gap-filler network so that it can provide seamless service even in the train operating environment, and these inter-networking schemes result in high service availability. And this system also has the countermeasure schemes, such as upper layer FEC and antenna diversity, for the short fading which is occurred periodically on the railway due to the power supplying structures so that it can provide high speed internet services. Mobile DVB-S2 technology which is now being standardized in the DVB is used for the forward-link transmission and DVB-RCS for the return-link.

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The Effect of C Language Output Method to the Performance of CGI Gateway in the UNIX Systems (유닉스 시스템에서 C 언어 출력 방법이 CGI 게이트웨이 성능에 미치는 영향)

  • Lee Hyung-Bong;Jeong Yeon-Chul;Kweon Ki-Hyeon
    • The KIPS Transactions:PartC
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    • v.12C no.1 s.97
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    • pp.147-156
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    • 2005
  • CGI is a standard interface rule between web server and gateway devised for the gateway's standard output to replace a static web document in UNIX environment. So, it is common to use standard I/O statements provided by the programming language for the CGI gateway. But the standard I/O mechanism is one of buffer strategies that are designed transparently to operating system and optimized for generic cases. This means that it nay be useful to apply another optimization to the standard I/O environment in CGI gateway. In this paper, we introduced standard output method and file output method as the two output optimization areas for CGI gateways written in C language in the UNIX/LINUX systems, and applied the proposed methods of each area to Debian LINUX, IBM AIX, SUN Solaris, Digital UNIX respectively. Then we analyzed the effect of them focused on execution time. The results were different from operating system to operating system. Compared to normal situation, the best case of standard output area showed about $10{\%}$ improvement and the worst case showed $60{\%}$ degradation in file output area where some performance improvements were expected.

Implementation of Hybrid Firewall System for Network Security (전산망 보호를 위한 혼합형 방화벽 시스템 구현)

  • Lee, Yong-Joon;Kim, Bong-Han;Park, Cheon-Yong;Oh, Chang-Suk;Lee, Jae-Gwang
    • The Transactions of the Korea Information Processing Society
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    • v.5 no.6
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    • pp.1593-1602
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    • 1998
  • In this paper, a hybrid firewall system using the screening router, dual-homed gateway, screened host galeway and the application level gateway is proposed, The screened host gateway is comjXlsed of screening router, DMZ and bastion host. All external input traffics are filtered by screening router with network protrcol filtering, and transmitted to the bastion host performing application level filtering, The dual homed gateway is an internlediate equipment prohibiting direct access from external users, The application level gateway is an equipment enabling transmission using only the proxy server. External users can access only through the public servers in the DMZ, but internal users can aeee through any servers, The rule base which allows Telnet only lo the adrnilllslratol is applied to manage hosts in the DMZ According to the equipmental results, denial of access was in orderof Web. Mail FTP, and Telnet. Access to another servers except for server in DMZ were denied, Prolocol c1mials of UDP was more than that of TCP, because the many hosts broadcasted to networds using BOOTP and NETBIOS, Also, the illegal Telnet and FTP that transfer to inside network were very few.

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A Study on a Real Time Presentation Method for Playing of a Multimedia mail on Internet (인터넷상의 동영상 메일을 재생하기 위한 실시간 연출 기법 연구)

  • Im, Yeong-Hwan;Lee, Seon-Hye
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.4
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    • pp.877-890
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    • 1999
  • In this paper, a multimedia mail including video, sound, graphic data has been proposed as the next generation mail of the text based mail. In order to develop the multimedia mail, the most outstanding problem is the fact that the multimedia data are too huge to send them to the receiving end directly. The fact of big data may cause many problems in both transferring and storing the data of the multimedia mail. Our main idea is to separate between a control program for the multimedia presentation and multimedia data. Since the size of a control program is as small as a plain text mail, it has no problem to send it attached to the internet mail to the receiver directly. Instead, the big multimedia data themselves may remain on the sender's computer or be sent to a designated server so that the data may be transferred to the receiver only when the receiver activates the play of the multimedia mail. In this scheme, our research focus is paced on the buffer management and the thread scheduling for the real time play of the multimedia mail on internet. Another problem is to provide an easy way of editing a multimedia presentation for an ordinary people having no programming knowledge. For the purposed, VIP(Visual Interface Player) has been used and the results or multimedia mail implemented on LAN has been described.

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Adaptive Error Control Scheme for Supporting Multimedia Services on Mobile Computing Environment (이동 컴퓨팅 환경에서 멀티미디어 서비스 지원을 위한 적응적 에러 제어 기법)

  • Jeon Yong-Hun;Kim Sung-Jo
    • The KIPS Transactions:PartC
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    • v.13C no.2 s.105
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    • pp.241-248
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    • 2006
  • Mobile computing has such characteristics as portability, wireless network, mobility, etc. These characteristics cause various problems to mobile terminals like frequent disconnection, high error rate, and varying network status. These problems motivate us to develop an adaptive error control mechanism for supporting multimedia service in mobile computing environment. In this paper, we propose the Adaptive Error Control(AEC) scheme using client's buffer size and current error rate. After categorizing the status into four groups according to client's buffer size and current error rate, this scheme applies an appropriate error control scheme to each status. In this scheme, thresholds of buffer size and error rate are determined by the data transmission time, play rate and average VOP size, and by the probability of error for a sequence of packets. The performance of proposed scheme is evaluated by flaying MPEG-4 files on an experimental client/server environment, respectively. The results show that error correcting rate is similar to other schemes while the time for correcting error reduce a little. In addition, the size of data for correcting error is decreased by 23% compared with FEC and Hybrid FEC, respectively. Theses results demonstrate that the proposed scheme is more suitable in mobile computing environment with small bandwidth and varying environment than existing schemes.

온라인 증권거래 서비스의 고객만족 요인에 대한 실증적 연구

  • Choe, Don-Hwang;Hong, Jae-Beom;Yang, Jeong-Sik
    • Proceedings of the Korea Association of Information Systems Conference
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    • 2005.05a
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    • pp.161-175
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    • 2005
  • 본 연구에서는 온라인 증권거래 서비스 품질과 고객만족 나아가 고객행동을 분석한 연구이다. 이를 위해 설문조사를 실시하였으며 조사원이 직접 증권사 객장을 방문하여 운라인 증권거래경험이 있는 고객을 대상으로 설문조사를 실시하였다. 이를 위해 40개 증권사, 420여개설문이 회수되었다. 분석결과, 첫째, 온라인 증권거래를 이용하는 고객층을 분석하면, 여성보다는 남성이 온라인 증권거래를 활발히 이용하고 있으며 연령별로는 40대, 50대, 30대 순으로 나타났으며 직업은 대부분 근로생활자가 많이 활용하고 있는 것으로 나타났으며 전체 50%이상이 매일 접속하고 거래하는 것으로 나타났으며 운영 규모는 1천만원이하가 다수로 나타났다. 둘째, 온라인 증권거래 서비스 품질요인으로 지각된 신뢰성, 지각된 편의성, 지각된 유형성, 지각된 응답성 순으로 고객만족에 영향을 미치는 것으로 나타났다. 지각된 신뢰성은 약속된 서비스를 정확하게 수행하는 능력에 대한 지각으로 나타내며, 지각된 편의성은 온라인증권거래를 이용하기에 얼마나 용이한 지에 대한 지각을 나타낸다. 지각된 유형성은 물적 시설, 장비, 사람, 의사소통 도구의 외형과 같은 부분에 대한 지각을 나타내는 것이다 지각된 응답성은고객을 돕고 즉각적인 서비스를 제공하려는 의지에 대한 지각을 나타낸다. 마지막으로 고객만족은 재이용이나 구전의도에 긍정적인 효과를 미치는 것으로 나타났다. 이러한 결과는 고객지향적인 온라인 증권거래 서비스 시스템 구축 및 운영이 이용확대에 중요한 요인임을 제시한다. 본 연구는 온라인 증권거래에 대한 고객만족의 탐색적인 연구로써 보다 심도 있는 연구를 위한 기초를 제공하였다는 점과 온라인 증권거래 성과측정요소로써 고객만족에 영향을 미치는 요인을 제시했다는 점에서 의미를 지닌다.에 의해 유도된 single-strand 절단을 억제하였다. 이상과 같이 간세포 일차배양에서 양파추출물은 t-BHP에 의해 유발된 간독성, 간세포 생존율 감소, 지질과산화를 농도 의존적으로 억제시켰고 또한 t-BHP에 의해 억제된 GSH-Px, GSH-Rd 및 catalase의 활성을 증가시켰다. 이와 같이 양파추출물의 간보호 및 항산화 효과는 항산화 효소, 특히 catalase의 활성 증가와 hydroxyl radical에 의해 유도된 산화억제 및 이에 따른 지질과산화 억제에 기인하는 것으로 사료된다.chno-economic paradigm)의 시각에서 제시하는 한국경제의 성장 ${\cdot}$ 고용 ${\cdot}$ 분배를 위한 정책방향은 다음과 같은 동태적발전과정으로 요약할 수 있다 : 기초과학연구능력 확충 ${\rightarrow}$ 소화 ${\cdot}$ 흡수 ${\cdot}$ 개량 ${\rightarrow}$ 토착화 능력의 배양 ${\rightarrow}$ 자체기술개발, 선진기술 도입, 산업간 및 산업내 기술확산, 국제기술협력 ${\rightarrow}$ 기술혁신의 촉진 ${\rightarrow}$ 총요소생산성과 기업경쟁력(자원 및 역량, 프로세스 경쟁력, 품질경쟁력, 시장경쟁력, 고객성과, 시장성과, 재무성과)의 제고 ${\rightarrow}$ 가격경쟁력(임금, 금리, 물류비용, 환율 등)과 비(非)가격경쟁력(디자인, 에프터서비스, 품질, 운송 등)의 제고 ${\rightarrow}$ 국가경쟁력의 제고 ${

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Fine Grained Resource Scaling Approach for Virtualized Environment (가상화 환경에서 세밀한 자원 활용률 적용을 위한 스케일 기법)

  • Lee, Donhyuck;Oh, Sangyoon
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.7
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    • pp.11-21
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    • 2013
  • Recently operating a large scale computing resource like a data center becomes easier because of the virtualization technology that virtualize servers and enable flexible resource provision. The most of public cloud services provides automatic scaling in the form of scale-in or scale-out and these scaling approaches works well to satisfy the service level agreement (SLA) of users. However, a novel scaling approach is required to operate private clouds that has smaller amount of computing resources than vast resources of public clouds. In this paper, we propose a hybrid server scaling architecture and related algorithms using both scale-in and scale-out to achieve higher resource utilization rate for private clouds. We uses dynamic resource allocation and live migration to run our proposed algorithm. Our propose system aims to provide a fine-grain resource scaling by steps. Thus private cloud systems are able to keep stable service and to reduce server management cost by optimizing server utilization. The experiment results show that our proposed approach performs better in resource utilization than the scale-out approach based on the number of users.

단말기에서의 SDR 기술

  • 김선영;강법주;김창주
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.10 no.3
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    • pp.48-57
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    • 1999
  • 안테나 단에서 직접 수신 신호의 디지털화가 이루어지고 그 해당 신호의 처리는 고속 디지털 신호처리기 내에서 소프트웨어로 수행되는 방식을 SWR(Software Radio)이라 한다. 그러나 현재의 기술 수준을 감안하여 보다 현실적인 SDR(Software Defined Radio) 정의가 필요하게 되었다. SDR이란 수신신호의 디지털화가 안테나 이하의 임의의 단(IF단)에서 이루어지는 무선으로 정의된다. 물론 A/D변환기등의 기술이 더욱 발전되면 궁극적으로는 SWR로 진화될 것이다. 그러면 SDR은 왜 필요한 것일까? 현재 사용중인 이동통신 단말기의 단점은 어느 한 표준 또는 방식에 종속되어 언제 어디서나 임의의 시스템에 접속되어 사용하기에는 많은 기술 종속적인 문제 및 제약을 내포하며, 사용방식에 따른 시스템의 유연성이 없고, 상용 서비스 도중에 발생되는 단말기 문제의 해결(recall service)이 어렵고, 많은 기술료를 지불해야 한다는 것이다. 부연하면 CDMA 셀룰라의 경우 퀄컴 등의 특정한 회사에 의해 기술이 폐쇠되어, 정보의 흐름이 자유스럽지 못할 뿐더러, 이로 인해 기술진화가 보다 빠르게 진행되지 못하고, 전세계적으로 많은 새로운 우수 제품의 출연에 제약이 가해진다는 것이다. 따라서 SDR(Software Defined Radion)을 도입, 하드웨어 및 소프트웨어를 개방형 구조(open architecture)로 개발한다면 정보의 흐름을 자유롭게 할 수 있고, 이로 인하여 세계적으로 다양한 신제품의 개발이 촉진되고 결과적으로 전세계 시장이 커지게 되는 일석이조의 효과를 얻을 수 있게 된다. 또한 이 같은 개방형 단말기 개발의 필요성은 최근 시장동향으로 볼 때, 기존의 단말기 회사 입장에서는 새로운 수익 모델이 필요한 시점이고, 또한 2002년경에 판매되는 단말기의 80%정도는 멀티모드타입 단말기일 것으로 예측되는 점, 그리고 금년말까지 100개 회사 이상이 SDR 포럼 멤버로 가입할 것으로 예측되는 점, 무선 인터넷 폭발적인 성장으로 복합 멀티미디어 단말기 시대가 다가오는 점 등으로 미루어 볼 때, 고객의 서비스 가치선택에 역점을 둔 기술을 중시해야 한다는 점에서 더욱 설득력을 지닌다. 따라서 이 같은 목적과 3세대 이동통신 및 인터넷 사용자의 증가, 반도체기술의 발전에 힘입어, 과거 군용 시스템에서 이용되던 SWR 기술을 상용시스템 특히 3세대 이동통신에 적용하려는 연구가 활발히 진행되고 있다. '96년 SDR 포럼이 결성되었는데, 목적은 휴대형 장치(hand-held devices), 기지국(base stations), 차량형 장치(mobile stations)를 포함하는 다중모드(multi-mode), 다중대역(multi-band) SDR을 위한 개방형 구조의 표준을 정하기 위함이다. 이 같이 public forum에 의한 표준(open architecture standard)이 정해지면 그 다음은 이를 어떻게 구현할 것인가가 문제가 될 것이다. 본고에서는 먼저 SDR 단말기 요구사항을 살펴보고, 이 요구사항들을 만족하는 SDR 단말기 구조, SDR 계층참조 모델, 그리고 기존의 단말기 구조와 SDR 계층참조 모델의 연관관계에 대해 살펴보고, 크게 두가지 종류의 단말기 즉 사용 SDR 단말기와 군용 SDR 단말기에 대해 살펴보고, 설계 절차 및 현재 시점에서 단말기 구현을 위해 해결해야 하는 기술적 과제를 살펴보고 결론을 언급한다.

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A Study on Integrated Binding Service Strategy Based on Name/property in Wide-Area Object Computing Environments (광역 객체 컴퓨팅 환경에서 이름/속성기반의 통합 바이딩 서비스 방안)

  • Jeong, Chang-Won;Oh, Sung-Kwun;Joo, Su-Chong
    • The KIPS Transactions:PartA
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    • v.9A no.2
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    • pp.241-248
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    • 2002
  • With the structure of tilde-area computing system which Is specified by a researching team in Vrije University, Netherlands, lots of researchers and developers have been progressing the studies of global location and interconnection services of distributed objects existing in global sites. Most of them halve focused on binding services of only non-duplicated computational objects existing wide-area computing sites without any consideration of duplication problems. But all of objects existing on the earth rave the duplicated characteristics according to how to categorize their own names or properties. These objects with the same property can define as duplicated computational objects. Up to now, the existing naming or trading mechanism has not supported the binding services of duplicated objects, because of deficiency of independent location service. For this reason, we suggest a new model that can not only manages locations of duplicated objects In wide-area computing environments, but also provide minimum binding time by considering both the optimal selection of one of duplicated objects and load balance among distributed systems. Our model is functionally divided into 2 parts, one part to obtain an unique object handle of duplicated objects with same property as a naming and trading service, and the other to search one or more contact addresses by a node manager using a liven object handle, as a location service For location transparency, these services are independently executing each other. Based on our model, we described structure of wide-area integrated tree and algorithms for searching and updating contact address of distributed object on this tree. finally, we showed a federation structure that can globally bind distributed objects located on different regions from an arbitrary client object.