• Journal of KIISE:Databases
• /
• v.27 no.1
• /
• pp.53-63
• /
• 2000

The mobile computing service market is increasing rapidly due to the development of low-cost wireless network technology and the high-performance mobile computing devices. In recent years, several methods have been proposed to effectively deal with restrictions of the mobile computing environment such as limited bandwidth, frequent disconnection and short-lived batteries. Amongst those methods, much study is being done on the caching method - among the data transmitted from a mobile support station, it selects those that are likely to be accessed in the near future and stores them in the local cache of a mobile host. Existing cache replacement methods have some limitations in efficiency because they do not take into consideration the characteristics of user mobility and spatial attributes of geographical data. In this paper, we show that the value and the semantic of the data, which are stored in the cache of a mobile host, changes according to the movement of the mobile host. We argue it is because data that are geographically near are better suited to provide an answer to a users query in the mobile environment. Also, we define spatial location of geographical data has effect on, using the spatial attributes of data. Finally, we propose two new cache replacement methods that efficiently support user mobility and spatial attributes of data. One is based on the location of data and the other on the meaningful region of data. From the comparative analysis of the previous methods and that they improve the cache hit ratio. Also we show that performance varies according to data density using this, we argue different cache replacement methods are required for regions with varying density of data.

• Proceedings of the Korean Information Science Society Conference
• /
• 1999.10c
• /
• pp.466-468
• /
• 1999

현재 인터넷 프로토콜인 IPv4의 주소 부족 등의 문제를 해결하기 위해 차세대 인터넷 프로토콜 IPv6에 대한 연구가 활발히 진행되고 있다. 그러나 새로운 프로토콜 IPv6 상에서 기존의 다른 상위 프로토콜 및 응용이 어떠한 영향을 받게 될지는 의문이다. 한편, IPv6 상에서 새로운 프로토콜 및 응용을 개발할 때에 많은 시험이 요구된다. 이와 같은 이유로 인해 새로운 통신 프로토콜에 있어서 모니터링은 필수적이다. 그러나 지금까지의 많은 모니터링 라이브러리들은 텍스트에 기반하고 있으며, 그래픽 데이터를 제공하는 도구들도 대부분 통계정보의 제공에 초점을 두고 있다. 이를 두고 프로토콜이 그 표준에 따라 정확한 원리에 맞게 동작하는 지를 파악하는 데는 큰 도움이 되지 않고 있다. 이에 본 연구에서는 대상 프로토콜의 실제적인 동작 과정이나 원리를 알 수 있도록 그래픽 기반의 사용자 친화적 모니터링 도구를 제작한다. 이를 위해, 먼저 IPv6가 다른 프로토콜에 영향을 미칠 수 있는 사항들을 분석한다. 다음으로 본 교에 구축되어 있는 IPv6 호스트에 모니터링에 필요한 환경을 구축하고, Java Applet을 이용한 모니터 프로그램을 제작한다. 현재 개발하는 모니터 프로그램은 TCP의 슬라이딩 윈도우(Sliding Window) 기법에 관련된 사항을 모니터링 해주는 것으로 그 범위를 한정한다. 개발된 도구를 이용하여 IPv6 상에서 FTP가 TCP를 이용하여 파일을 전송하는 경우의 모니터링을 실시하고, 그 결과를 분석 제시한다. 이로써, 개발된사용자 친화적 모니터링 도구가 얼마나 쉽게 슬라이딩 윈도우 기법을 이해시켜 주고, 내포된 의미를 파악할 수 있게 해주는지를 알 수 있다.한 것으로 연구되었다. 정상조 직에 비해 산소가 부족하여 염기성대사(anaerobic metabolism)를 많이 함으로 그 부산물인 유산 (lactic acid)이 많이 생성됨으로 정상조직보다 pH가 낮아 암 조직이 정상조직에 비해 고온온열치료에 더 잘 듣는 원인이 된다. 3) 영양이 부족한 상태의 세포는 고온온열치료에 훨씬 예민하다. 4) 암조직은 혈관상태가 정상조직에 비해 좋지 않음으로 정상조직보다 쉽게 가온이 되며, 일단 가온된 온도는 잘 식지 않음으로 정상조직에 비해 훨씬 효율적이다. 5)고 온온열치료는 4$0^{\circ}C$~43.5 $^{\circ}C$정도에서만 이 작용이 일어남으로 정상인체에서 43$^{\circ}C$이상의 가온 은 쉽지 않음으로 이 효과는 암조직에서 주고 일어나게 된다. 6)고온온열치료는 방사선치료 후에 생기는 손상의 재생을 억제함으로 방사선의 치료효과를 높인다. 7)38.5$^{\circ}C$~41.5$^{\circ}C$의 낮 은 온도에서도 암조직의 산소 상태를 호전시켜 방사선 치료효과를 증대시키는 역할을 한다.alization)가 나타난다. 그러나 무의식에 대칭화만 있는 것은 아니며, 의식의 사고양식인 비대칭도 어느 정도 나타나며, 대칭화의 정도에 따라, 대상들이 잘 구분되어 있는 단계, 의식수준의 감정단계, 집단 내에서의 대칭화 단계, 집단간에서의 대칭화 단계, 구분이 없어지는 단계로 구분하였다.systems. We believe that this taxonomy is a significant contribution because it ad

• Proceedings of the Korea Information Processing Society Conference
• /
• 2000.10a
• /
• pp.677-680
• /
• 2000

웹이 등장하면서 지금까지 인터넷 상에서 텍스트와 이미지를 이용하여 정보를 표현하고 전달하는 방법이 가장 많이 사용되어왔다. 그러나 웹 관련 기술의 비약적인 발달과 네트워크 속도의 증가 및 인터넷의 급속한 보급으로 단순한 텍스트와 이미지 중심의 HTML 문서를 이용한 정보의 전달이 아닌 멀티미디어 데이터를 이용한 정보의 표현과 전달이 점차 증대되고 있다. 이에 따라 멀티미디어 데이터를 전송하기 위한 스트리밍 프로토콜도 등장하였다. 최근에는 컴퓨터의 성능 증가 및 네트워크 속도의 증가(초고속 통신 서비스의 보급)에 의해 멀티미디어 데이터의 전송이 가능하게됨으로써 기존의 공중파나 CATV 방송국의 형태 지니고 인터넷 상에서 실시간 생방송 서비스와 VOD(Video On Demand) 서비스를 제공하는 인터넷 방송국이 급속하게 생겨나고 있다.[11] 인터넷 방송은 동영상과 오디오의 실시간 전달을 가능하게 하는 멀티미디어 스트리밍 기술과 멀티미디어를 실시간으로 전송할 수 있는 실시간 전송 프로토콜을 기반으로 발전하고 있다. 인터넷 상에서 멀티미디어 스트리밍 서비스를 하는 대부분의 인터넷 방송은 스트리밍 서버로서 RealNetworks사의 RealSystem과 Microsoft사의 WMT(Windows Media Technologies)를 사용하고 있다. 본 논문은 Real Server와 WMT의 비교 분석을 통해 실시간 전송 프로토콜을 지원하고, 멀티미디어 스트리밍 기술을 지원하는 자바를 기반으로 한 분산 서버 구조의 스트리밍 서버, 서버간의 부하를 제어하는 미들웨어, 멀티미디어 스트림을 재생할 수 있는 클라이언트를 설계하고 구현한다. 방법에 대해서 자세히 살펴보고 실제 SQL Server 7.0 환경에서 구축된 공간 엔진 및 OLE DB 제공자 컴포넌트의 구현 예에 대하여 살펴볼 것이다. 혈액내방사선 조사량이 안전용량 범위(200rad)에 속하며 48시간 후 체내잔류량은 서양인과 큰 차이가 없었다.비출현의 소견을 보이는 악성종양 환자의 골 신티그람 53개중 44개 (83.0%)에서 척추 및 늑골에 미만성, 또는 다발성 침습이 관찰되었다. 또 골전이 부위를 두개골, 척추, 견대부, 늑골, 골반, 사지의 근위부 장골의 6개 부위로 나누어 분석할 경우 49개(92.5%)에서 3부위 이상에 전이가 발견되었고, 35개(66.0%)에서 4부위 이상에 전이가 발견되었으며, 5부위 이상, 6개 부위에 모두 전이가 발견된 것은 각각 20개 (37 7%), 11개(20.8%)이었다. 이상의 성적으로 보아 악성종양 환자의 골 신피그라피에서 신장 영상의 비출현은 종양의 광범위한 골전이를 간접적으로 시사하는 소견으로 생각된다. 여러 악성종양중 전립선암에서 신장 영상 비출현의 빈도가 가장 높았으며, 특히 위암에서 골전이 및 신장 영상 비출현의 빈도가 높음은 주목할 만한 것이라 하겠다.출한 결과 인,규소 증가와 자가영양성 미소플랑크톤(ANP)증가에 미치는 요인이 해안과 외해에서 동일하게 가장 큰 설명력을 보였다. N:P 비도 해안에서 36.4, 외해에서 32.6을 보이고 있어 인이 상당히 부족한 것으로 나타났다. 따라서 조사해역은 인이 식물플랑크톤 성장에 중요한 제한요인으로 작용하고 있다고 판단된다.의 회전. 전위력의 강도, 적용시점, 그리고 키, 체중등의 신체적 요인 등이 있으나 능숙한 기계사

• KIPS Transactions on Computer and Communication Systems
• /
• v.3 no.7
• /
• pp.219-230
• /
• 2014

In the cloud computing environment, cloud service users purchase and use the virtualized resources from cloud resource providers on a pay as you go manner. Typically, there are two billing plans for computing resource allocation adopted by large cloud resource providers such as Amazon, Gogrid, and Microsoft, on-demand and reserved plans. Reserved Virtual Machine(VM) instance is provided to users based on the lengthy allocation with the cheaper price than the one of on-demand VM instance which is based on shortly allocation. With the proper mixture allocation of reserved and on-demand VM corresponding to users' requests, cloud service providers are able to reduce the resource allocation cost. To do this, prior researches about VM allocation scheme have been focused on the optimization approach with the users' request prediction techniques. However, it is difficult to predict the expected demands exactly because there are various cloud service users and the their request patterns are heavily fluctuated in reality. Moreover, the previous optimization processing techniques might require unacceptable huge time so it is hard to apply them to the current cloud computing system. In this paper, we propose the cloud brokering system with the adaptive VM allocation schemes called A3R(Adaptive 3 Resource allocation schemes) that do not need any optimization processes and kinds of prediction techniques. By using A3R, the VM instances are allocated to users in response to their service demands adaptively. We demonstrate that our proposed schemes are able to reduce the resource use cost significantly while maintaining the acceptable Quality of Service(QoS) of cloud service users through the evaluation results.

• KIPS Transactions on Computer and Communication Systems
• /
• v.2 no.7
• /
• pp.283-292
• /
• 2013

In order to ensure high performance, all the servers in an existing server cluster are always On regardless of number of real-time requests. They ensure QoS, but waste server power if some of them are idle. To save energy consumed by servers, the server power mode control was developed by shutdowning a server when a server is not needed. There are two types of server power mode control depending on when a server is actually turned off if the server is selected to be off: static or dynamic. In a static mode, the server power is actually turned off after a fixed time delay from the time of the server selection. In a dynamic mode, server power is actually turned off if all the services served in the server are done. This corresponds to a turn off after a variable time delay. The static mdoe has disadvantages. It takes much time to find an optimal shutdown time manually through repeated experiments. In this paper, we propose a dynamic shutdown method to overcome the disadvantages of static shutdown. The proposed method allows to guarantee user QoS with good power-saving because it automatically approaches an optimal shutdown time. We performed experiments using 30 PCs cluster. Experimental results show that the proposed dynamic shutdown method is almost same as the best static shutdown in terms of power saving, but better than the best static shutdown in terms of QoS.

• KIPS Transactions on Computer and Communication Systems
• /
• v.2 no.1
• /
• pp.15-26
• /
• 2013

IP-based Wireless Sensor Networks (IP-WSNs) are gaining importance for their broad range of applications in health-care, home automation, environmental monitoring, industrial control, vehicle telematics and agricultural monitoring. In all these applications, mobility in the sensor network with special attention to energy efficiency is a major issue to be addressed. Because of the energy inefficiency of networks-based mobility management protocols can be supported in IP-WSN. In this paper we propose a network based mobility supported IP-WSN protocol called Multicasting-based inter-Domain Mobility Management Scheme in Sensor-based Fast Proxy Mobile IPv6 Networks (mSFP). Based on [8,20], We present its network architecture and evaluate its performance by considering the signaling and mobility cost. Our analysis shows that the proposed scheme reduces the signaling cost, total cost, and mobility cost. With respect to the number of IP-WSN nodes, the proposed scheme reduces the signaling cost by 7% and the total cost by 3%. With respect to the number of hops, the proposed scheme reduces the signaling cost by 6.9%, the total cost by 2.5%, and the mobility cost by 1.5%. With respect to the number of IP-WSN nodes, the proposed scheme reduces the mobility cost by 1.6%.

• KIPS Transactions on Computer and Communication Systems
• /
• v.2 no.7
• /
• pp.303-310
• /
• 2013

As the role of software increases in computing environments, issues in software security become more important problems. Dynamic taint analysis is a technique to trace and manage tainted data originated from unreliable sources during the execution of a program. This analysis can be applied to software security verification as well as software behavior understanding, testing unexpected errors, or debugging. In the previous researches, they focussed only to show the analysis results of dynamic taint analysis, and they did not logically describe propagation process of tainted data and analysis procedures. So, there were difficulties in understanding the analysis procedures or applying to other analysis. In this paper, by theoretically describing the analysis procedure, we logically show how the propagation process of tainted data can be traced, and present a theoretical model for dynamic taint analysis. In addition, we verify the correctness of the proposed model by implementing an analyser, and show that propagation of tainted data can be traced by the model. The proposed model can be applied to understand the analysis procedures of data flows in dynamic taint analysis, and can be used as an base knowledge for designing and implementing analysis method, which applies such analysis method.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.9
• /
• pp.458-465
• /
• 2020

Technological advances in artificial intelligence are affecting many industries, such as telecommunications, logistics, security, and healthcare, and research and development related to economic, efficiency, linkage with commercial technologies are the current focus. Predicting the changes in the future battlefield environment and ways of conducting war from a strategic point of view, as well as designing/planning the direction of military development for a leading response is not only a basic element to prepare for comprehensive future threats but also an indispensable factor that can produce an optimal effect over a limited budget/time. From this perspective, this study was conducted as part of a technology-driven plan to discover potential future technologies with high potential for use in the defense field and apply them to R&D. In this study, based on research data collected in a defense future technology investigation, the future new technology that requires further research was predicted by considering the redundancy with existing defense research projects and the feasibility of technology. In addition, an empirical study was conducted to verify the significance between the future new defense technology and the evaluation indicators in the AI field.

• Journal of KIISE:Information Networking
• /
• v.32 no.2
• /
• pp.220-235
• /
• 2005

Internet Service Quality has been constantly the center of attention to Internet Service Providers. The KII project plan (Korea Information Infrastructure) aims to build broadband backbone networks mainly through optical fiber cables and ATM switches and to Provide the government ministries, local authorities and non-profit organizations with high-speed, highly capable broadband access to these networks at reasonable rates. The KB service model, however, is different from other Internet Service models much in the same way SP (Service Provider) and NP (Network Provider) differ from each other. In this paper, we evaluate KII service according to various customer satisfaction indicators under the methodologies and categories as put forth in both the ACSI (American Customer Satisfaction Index) and SEM (Structural Equation Model). We use a structural equation model (SEM) to demarcate the Korea Information Infrastructure Customer Satisfaction Index (KIICSI) in relation to network service quality. The results of our study suggest some strategies for the KII Project need to be modified and effectively implemented in order to increase the satisfaction level of the KII customers.

• Journal of Digital Convergence
• /
• v.15 no.5
• /
• pp.13-25
• /
• 2017

The purpose of this study is to suggest the direction of O2O industry policy for solving the conflict problems with the traditional industry stakeholder and for enhancing the regulations as new industry development is inevitable. We make use of TAIDA that is one of scenario methods to accomplish the purpose and suggest the direction of policy. First, it is needed to prepare directly by government the environment that new business models are able to emerge easily with various consulting services and information supports like public system servers and IT infra, it is practical support policy. Second, positive legal application for new business and making the law for new business are needed in legal issues situation as soon as possible. Third, the conflicts with old and new industry would be managed to the direction of "predictable" progressively. Incongruity among laws, safety and security problems, and the conflict of stakeholder are urgent. Because of the limit in this study, it is expected that O2O industry is categorized in detail aligned to the characteristics and that new policies along to the separate industry areas are developed by the following study.