• Journal of Korea Multimedia Society
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• v.6 no.1
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• pp.15-27
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• 2003

Recently, the volume of data is increasing rapidly in server for multimedia service, according to development of multimedia application environment. In recent research for storage technology the technology like of the SAN(Storage Area Network) advantages in scalibility of storage devices, and can read data from multiple disk arrays through RAID 0, 5. The RAID 0 and 5 translate to logical address to physical address using equation, but in case of adding disks at the system with equation -based mapping, the problem that we must rearrange the whole data in the previous disks happens. We use the mapping table to solve this problem in recent, but we can not load the whole mapping table in main memory because it occupies too large space. Therefore the extra I/Os are demanded to evaluate real physical address of data, so total performance of the system is degraded. In this paper, we propose the mapping method that supports the scalibility in RAID 0 or 5 system. The proposing method applies small metadata, so- called SZIT and simple equation, so it is possible that we make translate logical address to physical address rapidly and it is scalable in disk extending simultaneously Our suggesting method, if we add disks to the striping system for expanding of storage capacity, has an advantage of never stop service. So, SZlT-based mapping method can do online-disk-expanding in real-time service.

• The KIPS Transactions:PartD
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• v.10D no.7
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• pp.1085-1092
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• 2003

The rapid growth of high speed multimedia services demands the large capacity of the server's storage that maintains the multimedia contents. Among the server's devices, the low I/O speed and physical or logical failure of storage device decrease the total performance of system. The continuous increase of multimedia contents require the flexibility of storage capacity. In order to solve the these problems, we propose the uses of software RAID and LVM techniques that provide the performance improvement and reliability of storage device and the flexibility of storage device respectively. In the LINUX 2.4 kernel, we implemented the reliable and flexible storage device and evaluated the performance of it.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.9
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• pp.457-464
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• 2005

In this paper a 3D memory system that allows 17 access types at an arbitrary position is introduced. The proposed memory system is based on two main functions: memory module assignment function and address assignment function. Based on them, the memory system supports 17 access types: 13 Lines, 3 Rectangles, and 1 Hexahedron. That is, the memory system allows simultaneous access to multiple data in any access types at an arbitrary position with a constant interval. In order to allow 17 access types the memory system consists of memory module selection circuitry, data routing circuitry for READ/WRITE, and address calculation/routing circuitry In the point of view of a developer and a programmer, the memory system proposed in this paper supports easy hardware extension according to the applications and both of them to deal with it as a logical three-dimensional away In addition, multiple data in various across types can be simultaneously accessed with a constant interval. Therefore, the memory system is suitable for building systems related to ,3D applications (e.g. volume rendering and volume clipping) and a frame buffer for multi-resolution.

• Computers and Concrete
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• v.25 no.5
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• pp.479-484
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• 2020

This work performed to analyses the impact of hooked end steel fibres on the mechanical properties of high performance concrete. The mechanical properties considered incorporate compressive strength, split tensile strength and flexural strength. Taking in to thought parameters, such as, volume fraction of fibres, fibre aspect ratio and grade of concrete, a logical strategy called Taguchi technique was utilized to discover the ideal blend of factors. L9 Orthogonal Array (OA) of Taguchi network comprising of three variables and three dimensions is utilized in this work. The evaluations of concrete considered were M60, M80 and M100. M60 contained 15% of metakaolin as bond swap though for M80 it was 5% of metakaolin and for M100 it was 10% metakaolin and 10% of silica smolder. The volume portion of fiber was fluctuated by 0.5%; 1% and 1.5% and the viewpoints proportions considered were 50, 60 and 80. The test outcomes demonstrate that incorporation of steel fibres enhance significantly the the strength characteristics of concrete, predominantly the splitting tensile strength and flexural strength. In light of relapse investigation of the test information scientific models were produced for compressive strength, split tensile strength and flexural strength of the steel fibre-reinforced high performance concrete.

• Nuclear Engineering and Technology
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• v.49 no.1
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• pp.92-102
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• 2017

The analysis of steam generators as an interface between primary and secondary circuits in light water nuclear power plants is crucial in terms of safety and design issues. VVER-1000 nuclear power plants use horizontal steam generators which demand a detailed thermal hydraulics investigation in order to predict their behavior during normal and transient operational conditions. Two phase flow field simulation on adjacent tube bundles is important in obtaining logical numerical results. However, the complexity of the tube bundles, due to geometry and arrangement, makes it complicated. Employment of porous media is suggested to simplify numerical modeling. This study presents the use of porous media to simulate the tube bundles within a general-purpose computational fluid dynamics code. Solved governing equations are generalized phase continuity, momentum, and energy equations. Boundary conditions, as one of the main challenges in this numerical analysis, are optimized. The model has been verified and tuned by simple two-dimensional geometry. It is shown that the obtained vapor volume fraction near the cold and hot collectors predict the experimental results more accurately than in previous studies.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.4-6
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• 2002

최근 폭발적으로 증가하는 대량의 정보를 효율적으로 관리하기 위해서 서버에 개별적으로 연결되던 저장장치를 고속의 전용 네트워크에 직접 연결하고 이를 여러 서버가 공유하는 SAN(Storage Area Network)이 등장했다. SAN을 보다 효과적으로 활용할 수 있도록 SAN 운영체제들은 여러 저장장치를 하나의 커다란 저장장치로 보이게 하는 저장장치 가상화를 지원한다. 저장장치 가상화의 핵심적인 역할을 하는 것이 바로 논리볼륨 관리자이다. 논리볼륨 관리자는 논리주소 블록을 실제 디스크의 물리블록으로 매핑시키는 매핑 관리자를 통해 가상화를 실현한다. 이 논문에서는 효율적인 논리볼륨 관리자를 위해 매핑 관리자와 자유공간 관리자의 기능 향상에 대한 방법을 찾고 이를 반영한 매핑 관리자와 자유공간 관리자를 설계하고 구현한다. 더불어 이 논문의 매핑 관리기법은 특정 시점의 볼륨이미지를 유지할 수 있는 스냅샷과 시스템을 정지시키지 않고 SAN에 디스크를 추가할 수 있는 온라인 재구성 기능을 지원한다.

• 한국항공운항학회:학술대회논문집
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• 2016.05a
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• pp.89-94
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• 2016

This paper is to investigate how each cases(recurrent cases) is to be classified and what each parties should prepare to solve their cases by civil law system and so on. We could find the increased volume (or quantity) of transportation by air recently and have to worry about the sky-rocketed cases of unfulfilled navigation management(aviation service) proportionately inevitably. So we knew that some cases of disputes are solved by unreasonable demand, unilateral concession or irrational decision without any logical or legal criterion, because both sides(passenger and carrier) do not recognize the situation correctly and have any preparation for the legal settlement. Therefore we should prepare the classification work and comprehend about the legal effect(fulfillment retardation of duty, fulfillment impossibility of duty and imperfect fulfillment in our civil law system) of each cases. We can grasp the legal relationship with a carrier and a passengers by the legal analysis more efficiently and save (or help) energy and time of concerned parties.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1553-1557
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• 2005

High performance and reliability of the storage system to handle a very large amount of data has been become very important. Many techniques have been applied on the various application systems to establish very large capacity storage that satisfy the requirement of high I/O speed and physical or logical failure protection. We applied RAID and LVM to construct a storage system for the global data center which needs a very reliable large capacity storage system. The storage system is successfully established and equipped on the latest Linux application server.

• Journal of information and communication convergence engineering
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• v.5 no.4
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• pp.369-373
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• 2007

RFID systems large volume of data, it can lead to slower queries. To achieve better query performance, we can partition into active and some nonactive data. In this paper, we propose two approaches of partitioning for efficient query support. The one is average period plus delta partition and the other is adaptive average period partition. We also present the system architecture to manage active data and non-active data and logical database schema. The data manager check the active partition and move all objects from the active store to an archive store associated with an average period plus data and an adaptive average period. Our experiments show the performance of our partitioning methods.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.955-956
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• 2009

이 Paper는 Server 솔루션에서 사용되는 RAID 컨트롤러가 Disk 상의 에러(Error)를 처리하는 behavior를 분석하고 이를 개선할 수 있는 방법을 제안한다. RAID Level 중에 가장 기본인 RAID 0는 주로 Internet portal site의 Search Engines 이나 Media streaming Servers, 그리고 HD 영상 편집 시스템에서 사용된다. 그러나 Fault tolerance가 지원되지 않기 때문에 Data Volume(logical Disk)의 보존성이 약한 취약점을 가지고 있다. 따라서 이것을 개선하고 Data 보존성을 높일 수 있는 방안을 제시한다.