• The Journal of Korean Institute of Communications and Information Sciences
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• 제38B권11호
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• pp.902-910
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• 2013

The most representative research network in Korea, KREONET, has developed DynamicKL, an advance reservation based Network Service Agent (NSA) for user driven virtual circuit services. DynamicKL provides reservation, provisioning, release, termination, and inquiry web services for network resources by using an open standard network service interface (NSI), as well as web services for network resources by using a GUI interface. In addition, it has the RICE interface to support a protection management function per VC for virtual circuits and reservations. In this article, a protection management per VC for provisioned VCs and reservations is addressed in the DynamicKL framework, as a contribution to the VC protection management issue, which results in more manageable and reliable VC services compared to other advance reservation frameworks. An administrator can detect successful or unsuccessful VC protections in the event of a primary link failure and successful or unsuccessful VC retrievals after a primary link repair, by using RICE.

• Journal of Digital Convergence
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• 제12권3호
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• pp.227-235
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• 2014

Mobile virtualization is an approach to mobile device management in which two virtual platforms are installed on a single wireless device. A smartphone, a single wireless device, might have one virtual environment for business use and one for personal use. Mobile virtualization might also allow one device to run two different operating systems, allowing the same phone to run both RTOS and Android apps. In this paper, we propose the techniques to virtualize the cores of a multicore, allowing the reassign any number of vCPUs that are exposed to a OS to any subset of the pCPUs. And then we also propose the real-time scheduling method to assigning the vCPUs to the pCPU. Suggested technology in this paper solves problem that increases time of real-time process when interrupt are handled, and is able more to fast processing than previous algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제31권9A호
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• pp.837-843
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• 2006

IEEE802.15.3 and IEEE802.15.4 have defined the hybrid MAC protocols based on TDMA and CSMA where a multi-frame TDMA structure is employed so that multiple data frames can be transmitted within one timeslot to guarantee minimum delay bounds of isochroous traffic. However, TDMA has an intrinsic problem that cannot dynamically allocate optimal length of timeslot to each station. Therefore the idle timeslot can be produced by stations when each transmission queue is instantaneously empty during its timeslot, which would waste lots of timeslots especially in the multi-frame TDMA systems. In this paper, we propose a more flexible multiple-access scheme for the multi-frame TDMA system based on the concept of virtual slot which is accessible by every station with the highest priority for slot owner and lower priority for other stations. Finally, our simulation results from various environments show that proposed scheme can achieve magnitude improvement of total system throughput and average message delay by maximizing channel utilization.

• Journal of the Korea Society for Simulation
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• 제28권1호
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• pp.1-9
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• 2019

Recently, as the importance of warehouses has increased, much efforts are being made to improve the picking process in order to cope with a small amount of high frequency and fast delivery. This study proposes an algorithm to assign orders to pickers in the situation where Single Order Picking policy is used. This algorithm utilizes five attributes related to picking such as picking processing time, elapsed time after receipt of order, inspection/packing workstation situation, picker error, customer importance. A measure of urgency is introduced so that the units of measure for each attribute are the same. The higher the urgency, the higher the allocation priority. In the proposed algorithm, the allocation policy can be flexibly adjusted according to the operational goal of the picking system by changing the weight of each attribute. Simulation experiments were performed on a hypothetical small logistics warehouse. The results showed excellent performance in terms of system throughput and flow time.

• Journal of the Institute of Electronics and Information Engineers
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• 제51권9호
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• pp.103-108
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• 2014

In the virtualized server systems, a scheduler in a hypervisor is responsible to assign physical resources for virtual machines. However, the traditional scheduler is hard to provide optimized resource allocation considering the amount of I/O requests. Especially, the drawback hinders performance of software load balancer which runs on virtual machines to distribute I/O requests from the clients. In this paper, we propose a new architecture to improve the performance of software load balancer using multiprocess. Our architecture aims to improve hardware resource utilization and overall performance of the server systems which utilize virtualization technology. Experimental results show the effectiveness of the proposed architecture for the various cases.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제31권10C호
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• pp.981-990
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• 2006

In this paper, we introduce the concept of a subcarrier-based virtual multiple antennas (SV-MIMO) for OFDM cellular systems, where the multiple antenna techniques are performed on a set of subcarriers, not on the actual multiple antennas. The virtual multiple antenna system can support multiple users simultaneously as well as reduce inter-cell interference (ICI) form adjacent cells with a single antenna. Also, this technique is easily extended to multiple antenna environments. The virtual multiple antenna techniques can be divided into a virtual smart antenna technique and a virtual MIMO technique. Especially, this method effectively reduces ICI at cell boundary with frequency reuse factor equal to 1, and can support flexible resource allocation depending on the amount of interference. It is shown by simulation that the proposed method is superior to conventional method under the same condition of data transmission.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국해양정보통신학회 2003년도 춘계종합학술대회
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• pp.237-240
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• 2003

Efficient memory management is one of the most crucial requirement of lava virtual machine. In Java, memory is allocated everytime when a new instance of class is created or when a method is called. The allocated memory is freed when the instance is no longer used, or when the called method is returned. In this paper we have examined the memory management scheme applied to the simpleRTJ lava virtual machine. The simpleRTJ has such a distinguished characteristic in its memory management scheme that the size of all instances are forced to be the same and the size of stack frames of all methods be the same, respectively. We present in this paper the scheme thoroughly and analyze its anticipated performance qualitatively.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제16권3호
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• pp.482-488
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• 2012

Desktop is offered to each individual in Educational environments of school or academy, as the users are increasing, the more Desktop is required for each person. Huge Desktop accession resulted in many problems including difficulty of management, Software and Hardware cost rising, cramped places, power consumption increasing and etc. To solve those problems, we focus into uprising technology solution, such as Multi Computer, Desktop Virtualization, and DaaS(Desktop as a Service). In this paper, existing problems that can dramatically improve the private cloud computing for desktop virtualization with the requirements of the system were analyzed.

• Journal of the Korea Society of Computer and Information
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• 제12권2호
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• pp.29-36
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• 2007

In the Java a profiler interface such as JVM TI is provided for communication between a Java virtual machine and a profiler. The JVM TI specification, however does not require an implementation of a profiler interface. Consequently the JVM without an implementation of a profiler interface cannot use a profiler with the JVM TI. For solving the problem, we propose a technique which analyzes heap usage without a profiler interface. This technique inserts codes to extract heap usage into source files in the Java. We implemented a code inserter to verify the proposed technique. We experimented with Java programs that are frequently used and opened. the experimental result presents the number of created objects. the maximum number of allocated objects, and the used pattern of the objects.

• Annual Conference of KIPS
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• 한국정보처리학회 2017년도 춘계학술발표대회
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• pp.50-52
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• 2017

클라우드 컴퓨팅 시장의 지속적 성장과 가상화의 인기로 세계적 VDI 시장은 꾸준한 성장률을 보이고 있다. 또한 의료, 교육, 금융 등의 폭넓은 분야에서 VDI 서비스가 활용될 전망이다. 하지만 기존 VDI 서비스는 고정적인 자원 할당으로 사용자 워크로드 맞춤형 자원이 제공되지 못하는 문제점이 있다. 따라서 본 논문에서는 기존 VDI에 비해 실행속도가 빠른 컨테이너의 장점을 살려 VDI를 컨테이너화 하고, 사용자 워크로드 맞춤형으로 자원을 분배하기 위해 VDI 컨테이너 자원 사용량 데이터로 K-means 알고리즘을 통한 군집 분석 기반의 워크로드 분류 방법을 제시하였다.