• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.4
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• pp.1302-1320
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• 2015

In cloud, everything can be provided as a service wherein a large number of users submit their jobs and wait for their services. hus, scheduling plays major role for providing the resources efficiently to the submitted jobs. The brainwave of the proposed ork is to improve user satisfaction, to balance the load efficiently and to bolster the resource utilization. Hence, this paper roposes an Adaptive Multilevel Scheduling System (AMSS) which will process the jobs in a multileveled fashion. The first level ontains Preprocessing Jobs with Multi-Criteria (PJMC) which will preprocess the jobs to elevate the user satisfaction and to itigate the jobs violation. In the second level, a Deadline Based Dynamic Priority Scheduler (DBDPS) is proposed which will ynamically prioritize the jobs for evading starvation. At the third level, Contest Mapping Jobs with Virtual Machine (CMJVM) is roposed that will map the job to suitable Virtual Machine (VM). In the last level, VM Scheduler is introduced in the two-tier VM rchitecture that will efficiently schedule the jobs and increase the resource utilization. These contributions will mitigate job iolations, avoid starvation, increase throughput and maximize resource utilization. Experimental results show that the performance f AMSS is better than other algorithms.

• Journal of the Korea Society of Computer and Information
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• v.8 no.3
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• pp.53-60
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• 2003

In these day, Digital Contents is authorized in forms of HTML and various kind of multi-media by an enterprise and/or organization. At this circumstances, it is very hard or impossible to search a contents between them. Futhermore, you may have to change your contents service systems to extend to cover more user services needs. On this paper, we propose a new architecture to get extendability and empowered interoperability without any maintenance, update or changes. And we introduce the OMG's CORBA to make fault resilient system and to provide a load balancing using a distributed process mechanism. Even more, we adopted the SyncML specification. It can help us to make it real to synchronize between DBMS at real-time. So all these are support easy content synchronization and user-friendness.

• Journal of Korea Multimedia Society
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• v.13 no.2
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• pp.287-297
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• 2010

Authentication is needed to use safe devices in the home network environment. In this authentication, there are an ID base form and Certification base form. In case of an ID base form, it is difficult to apply to the multi domain environment and in case of an Certification base form, because the way that contains and stores the certificate demand on devices, additional setting of the user is needed for transfer of ownership and purchase of new devices, and more. Because both ways attend an individual authentication for devices, the ways exist overhead as the frequent authentication for a lot of devices in service aspects of user needs. To arrange these problems, in this paper, the authentication information of devices can be securely stored and managed in the java card and a processing time of the authentication could be improved better then the existing technique by authenticating a group of service.

• Architectural research
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• v.24 no.2
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• pp.29-40
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• 2022

The transition from manufacturing to service-based economies in highly developed societies during the post-industrial period resulted in the decline of the industrial landscape, leaving it abandoned or underutilized. In pursuit of revitalizing the obsolete industrial space, innovative design techniques based on adaptive reuse are applied to retrofit modern functions to create a new cultural space and preserve the historical, symbolic, and cultural importance of the abandoned industrial facilities. Design considerations based on facade redesign have proven to be one of the most adopted techniques that can help in recreating a new function for the vacant industrial buildings and integrating them into the present-day urban fabric. This paper examines the facade renovation elements used for the adaptive reuse of 15 abandoned industrial buildings presently used as multi-purpose facilities in South Korea. Through a questionnaire survey, this study analyzes the respondents' preference for different facade renovation elements in the 15 sites according to age and gender. The study found that both genders showed similar preference patterns between most elements. But on some elements, females were keener and expressed a stronger opinion than males. There were much more females than males who perceived color and material as the most important exterior elements. The findings of this study can be used for the adaptive reuse of industrial buildings according to user preferences for different facade renovation elements.

• Journal of KIISE:Databases
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• v.30 no.6
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• pp.585-592
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• 2003

In the spatial database systems, it is necessary to manage spatial objects that have two or more aspatial information with different security levels on the same layer. If we adapt the polyinstantiation concept of relational database system for these spatial objects, it is difficult to process the representation problem of spatial objects and to solve the security problem that is service denial and information flow by access of subject that has a different security level. To address these problems, we propose a polyinstantiation method for security management of spatial objects in this paper. The proposed method manages secure spatial database system efficiently by creating spatial objects according to user's security level through security-level-conversion-step and polyinstantiation-generation-step with multi-level security policy. Also, in case of user who has a different security level requires secure operations, we create polyinstance for spatial object to solve problems of service denial and information flow.

• Journal of Satellite, Information and Communications
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• v.12 no.2
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• pp.51-55
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• 2017

This paper aims to maximize the energy harvesting rate and channel capacity in RF-energy harvesting networks (RF-EHNs) under the constraints of maximum transmit power and minimum quality of service (QoS) in terms of rate capacity for each user. We study a multi-user RF-EHN with frequency division multiple access (FDMA) in a Rayleigh channel. An access point (AP) simultaneously transmitting wireless information and power in the RF-EHN serves a subset of active users which have a power-splitting antenna. To gauge the network performance, we define energy efficiency (EE) and propose an optimization solution for maximizing EE with Lagrangian dual decomposition theory. In simulation results, we confirm that the EE is effectively maximized by the proposed solution with satisfying the given constraints.

• Journal of the Korea Society for Simulation
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• v.14 no.4
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• pp.107-116
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• 2005

The multi user communications that is called as the multicast service should be applied into the evolving mobile networks. In this paper, we propose a fast multicast management scheme for mobile terminals in HMIPv6 (Hierarchical Mobile IPv6) based mobile networks. In HMIPv6 based mobile networks, we consider the mobile terminal mobility that the multicast management scheme during mobile handover is used for the multicast routing changing. The changing impact to the multicast routing Is determined from handovers in intra AR, and in inter AR or MAP. In this paper, we propose multicast supporting schemes that the tunneling scheme is used in intra AR handover, and the previous subscription scheme is used in inter AR handover for considering the changing impact of the multicast routing.

• Annual Conference of KIPS
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• 2024.05a
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• pp.869-870
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• 2024

다양한 형태의 다수 에이전트가 서비스하는 환경에서 사용자가 요청하는 서비스 명령은 단순할수록 사용성이 좋다. 하나의 서비스는 다양한 로봇이 유기적으로 수행해야 하며, 사용자가 서비스 명령에 대해 요구사항을 추가하면 이를 다수 로봇이 적절하게 처리하는 방법이 필요하다. 본 논문에서는 사용자가 요청한 서비스에 대해 로봇의 동작은 노드로, 동작 간의 관계는 에지로 표현하고 이를 통해 스케줄링 하는 방법론을 제공한다. 실험 결과, 다수 로봇 환경에서 사용자의 요구사항을 동적으로 대응하며 효율적으로 서비스가 수행됨을 확인하였다.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.6
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• pp.205-212
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• 2015

SSH provides a secure, encrypted communication channel between two end point systems using public key encryption. But SSH brute force attack is one of the most significant attacks. This kind of attack aims to login to the SSH server by continually guessing a large number of user account and password combinations. In this paper, we analyze logs of SSH brute force attacks in 2014 and propose a failed-log based detection mechanism in high performance computing service environment.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.9
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• pp.279-292
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• 2014

Energy aware server cluster aims to reduce power consumption at maximum while keeping QoS(quality of service) as much as energy non-aware server cluster. In the existing methods of energy aware server cluster, they calculate the minimum number of active servers needed to handle current user requests and control server power mode in a fixed time interval to make only the needed servers ON. When loads change rapidly, QoS of the existing methods become degraded because they cannot increase the number of active servers so quickly. To solve this QoS problem, we classify load change situations into five types of rapid growth, growth, normal, decline, and rapid decline, and apply five different thresholds respectively in calculating the number of active servers. Also, we use a flexible scheme to adjust the above classification criterion for multi threshold, considering not only load change but also the remaining capacity of servers to handle user requests. We performed experiments with a cluster of 15 servers. A special benchmarking tool called SPECweb was used to generate load patterns with rapid change. Experimental results showed that QoS of the proposed method is improved up to the level of energy non-aware server cluster and power consumption is reduced up to about 50 percent, depending on the load pattern.