• Journal of the Korea Convergence Society
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• v.9 no.4
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• pp.9-14
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• 2018

Recently, as the internet speed is getting faster, in the cloud environment, the service receiving device is changing from a general PC to a compact device such as a mobile phone or a tablet PC. Since handheld devices such as mobile phones or tablet PCs are often used in wireless rather than wired, there are many problems that personal information may be exposed maliciously from a third party. In this paper, we propose a user privacy protection scheme through a duplicate duplicate key generation process which can safely protect user 's privacy from third party among cloud services being served through various wireless media. The proposed scheme is used to synchronize the duplicated key between the server and the intermediary device, and aims at shortening the time of the authentication process protecting the user 's privacy. In this case, the proposed scheme uses Interleave() function and random number to synchronize the server and the intermediary device, so it can safely prevent the malicious attack of the third party.

• Journal of Korea Multimedia Society
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• v.7 no.5
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• pp.689-697
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• 2004

Rapid advances in mobile computing and the availability of wireless communications will soon provide mobile users with the ability to access data regardless of the location of the user or of the data. SRA(Static Replica Allocation) that is traditional scheme has been used for the replication method on the server. This replicates the data on the replica server after a moving host has been transferred to the cell. This strategy is simple and can easily relocate data. However, if a mobile user does not exist in the cell, the replicated data can be deleted in order to maintain data consistency. In addition to, if the mobile host leaves from replicated cell, it is difficult to access data in terms of replication route. Therefore, this paper proposes a new method of relocation based on data consistency strategy called USRAC(User Selection Replica Allocation based on Consistency) and also analyzes access cost according to the moving rate of mobile users, according to the access rate of mobile hosts, and according to the number of cells of mobile users and mobile hosts.

• The Transactions of the Korea Information Processing Society
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• v.6 no.10
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• pp.2587-2596
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• 1999

Recently, by the extension of skills like LAN, the wireless telecommunication network and the satelite services make it possible for the mobile computer users to access a database. A method to use the replicated database on a server to get new data without missing any information has been being studied. So far we have used the Static Replica Allocation(SRA) for the replication which is the method of the replication on the server. This method is to replicate the data on the replica server after a moving host is transferred to a cell. Since the network of the SRA is very good, and if there are few moving users, no trouble will happen. But if there is no moving users in a cell, the data will not be shared. Therefore, this paper is about the study of the method of relocation after replicating the data to the cells for the users(User Select Replica Allocation : USRA). We also analyze the access rate and the possibility which are closely related to the moving frequency of the mobile hosts and the numbers of the cells. As a result, We show that the 120% lower access cost and the 40%∼50% gains are achieved from the low mobility

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.10a
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• pp.93-95
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• 1996

A replication server is considered to be one of the most effective tools to cope with the problems that may be caused by the complex data replications in distributed database systems. In the distributed environment, locking a table is inevitable and it is the main reason to coerce the system practically. This paper presents an Asynchronous Replicator Scheme (ARS) that basically utilizes the system log as files named differential files to refresh the distributed data files with complicated queries, and that it prevents (normally, huge) base tables from being locked. We take join operations as the complicated queries, not only because the join operation covers almost all the operations, but also because it is one of the most time-consuming and data intensive operations in query processings.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10a
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• pp.187-190
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• 2000

전형적인 멀티미디어 시스템은 클라이언트-서버 구조로 이루어지고 있다. 사용자의 요청에 따라 요청된 데이터를 갖고 있는 적절한 서버를 찾는 방법을 확장성 있게 지원하기 위해 계층적 관리 구조가 제시되었다. 이 접근방법에서는 중간 계층에서 영역 관리자가 사용자의 요청을 전달해 줌으로 인해서, 사용자 요청에 대한 거부 확률을 효과적으로 줄일 수 있다. 그러나 load balancing 을 이루기 위한 계층적 관리 구조에서는 정적 복제 방식을 사용함으로 인해서 사용자 요청에 대한 거부 확률이 최소화되지 못하였다. 따라서, 본 연구에서는 계층적 관리구조에 멀티미디어 데이터가 요청되는 패턴에 따라 동적으로 변화하는 동적 복제 방식을 도입할 것을 제안하고, 실험을 통하여 제안된 방법은 기존의 방법과 비교하였다.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.250-252
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• 1999

모빌 컴퓨팅에서는 모빌 호스트의 위치와 상태관리를 위하여 디폴트 서버기법이 널리 사용되는데, 모빌 호스트로 전송되는 데이터는 먼저 디폴트 서버로 보내진 후 다시 모빌 호스트가 위치하는 로칼 서버로 전송된다. 디폴트 서버기법에 기반을 둔 SDN(single Default Notification)기법에서는 클라이언트가 모빌 호스트와의 연결요청을 하면 쿼리 서버를 통해 해당 디폴트 서버에 모빌 호스트의 위치 및 상태를 문의한 후 통신이 이뤄진다. 그러나 쿼리 횟수가 많고 디폴트 서버와의 거리가 멀거나 기지국의 수가 많을 경우 디폴트 서버와의 통신 오버헤드가 커지며, 디폴트 서버에 결함이 발생할 경우 해당 모델 호스트와의 연결이 불가능해진다. 본 논문에서는 위와 같은 문제점을 해결하기 위해 디폴트 서버와의 통신 비용을 줄이기 위한 디폴트 서버 중첩 기법을 제안한다.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.10
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• pp.746-758
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• 2006

Many objects existing on wide area environments have the replication characteristics according to how to categorize using their own names or properties. From the clients' requests, the existing naming and trading services have not supported with the binding service for replicated solver object with the same service type. For this reason, we present an integrated model that can support the selection of replicated object and dynamic binding services on wide-area computing environments. This model suggests provides not only location management of replicated objects but also active binding service which enables to select a least-loaded object on the system to keep the balance of load between systems. In this purpose, constructing both the service plan and model for support solver object's binding with replication property on wide area computing environments has been researched. In this paper, we showed the test environment and analyzed the performance evaluation of client/server binding procedures via integrated binding service in federation model and verified our model under the condition to see whether load balance can be applied to our model. For the performance evaluation of suggested wide area integrated binding service federation model, evaluated the integrated binding service of each domain and analyzed the performance evaluation of process for non-replication object's under federation model environment. Also, we analyzed the performance evaluation of the federation model between domains for wide area environment. From the execution results, we showed the federation model provides lowers search-cost on the physical tree structure of network.

• Genomics & Informatics
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• v.19 no.4
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• pp.47.1-47.12
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• 2021

Kaposi's sarcoma-associated herpesvirus (KSHV) is one of the few human oncogenic viruses, which causes a variety of malignancies, including Kaposi's sarcoma, multicentric Castleman disease, and primary effusion lymphoma, particularly in human immunodeficiency virus patients. The currently available treatment options cannot always prevent the invasion and dissemination of this virus. In recent times, siRNA-based therapeutics are gaining prominence over conventional medications as siRNA can be designed to target almost any gene of interest. The ORF57 is a crucial regulatory protein for lytic gene expression of KSHV. Disruption of this gene translation will inevitably inhibit the replication of the virus in the host cell. Therefore, the ORF57 of KSHV could be a potential target for designing siRNA-based therapeutics. Considering both sequence preferences and target site accessibility, several online tools (i-SCORE Designer, Sfold web server) had been utilized to predict the siRNA guide strand against the ORF57. Subsequently, off-target filtration (BLAST), conservancy test (fuzznuc), and thermodynamics analysis (RNAcofold, RNAalifold, and RNA Structure web server) were also performed to select the most suitable siRNA sequences. Finally, two siRNAs were identified that passed all of the filtration phases and fulfilled the thermodynamic criteria. We hope that the siRNAs predicted in this study would be helpful for the development of new effective therapeutics against KSHV.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06d
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• pp.124-126
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• 2006

Mobile Ad hoc networking is an emerging technology and in these days many applications are being developed to run on these networks. In these networks lookup services are very important because all nodes do not have same resources in term of memory and computing power. Nodes need to use different services offered by different servers. Reliable and efficient scheme should be available for lookup services due to limited bandwidth and low computing power of devices in mobile ad hoc networks. Due to mobility and rapid change in network topology, lookup mechanism used in wired network is not appropriate. Service discovery mechanism can be divided into two main categories Centralized and Distributed. Centralized mechanism is not reliable as there is no central node in these networks. Secondly centralized mechanism leads toward single point failure. We can handle the service discovery mechanism by distributing server's information to each node. But this approach is also not appropriate due to limited bandwidth and rapid change in network. In this paper, we present reliable lookup service scheme which is based on distributed mechanism. We are not using replication approach as well due to low bandwidth of wireless networks. In this scheme service discovery mechanism will be handled through different lookup servers. Reliability is the key feature of our proposed scheme.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.200-205
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• 2005

전통적인 컴퓨터 시스템은 클라이언트-서버 구조로 클라이언트가 데이터를 요청하면 데이터를 관리하는 서버가 이를 제공한다. 이러한 구조에서 데이터를 요청하는 사용자 수 증가하면 단일 서버(single server)만으로는 모든 사용자의 요청을 처리할 수 없기 때문에 다중 서버로 서비스를 제공하는 방법들이 제안되었다. 다중 서버를 가지는 시스템은 모든 데이터에 대해서 균등한 사용자 요청이 들어오면 최적의 성능을 내지만, VoD(Video On Demand) 서비스와 같이 인기 많은 데이터(hot data)에 대한 요구와 인기 없는 데이터(cold data)에 대한 요구가 현저하게 차이가 나면 인기 많은 데이터를 가지고 있는 서버는 사용자요청을 제대로 처리하지 못하는 반면에 인기 없는 데이터만을 가지는 서버는 시스템 자원을 낭비하는 단점을 가진다. 이 논문은 NS 카드를 장착한 시스템에서 인기 많은 비디오데이터를 QoS와 저장공간의 효율을 위해 부분 컨텐츠 복제 기법을 제안한다. 이 방법은 기존의 전체 컨텐츠를 복제하여 서비스하는 방법과는 달리 컨텐츠의 부분을 복제하고 서비스 시점에서 나머지 부분을 복제함으로써 사용자의 서비스 지연시간이 늘어나지 않으면서 저장공간의 효율성을 높일 수 있다.