• 한국지반공학회논문집
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• 제25권7호
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• pp.11-21
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• 2009

본 논문은 사질토 지반에서 천층터널의 신개념 고성능 지보시스렘을 연구하였으며 새로운 지보시스템의 메카니즘 제안과 기존의 지보시스템과의 비교 분석을 시행하였다. 새로운 지보시스템인 선지보 시스템은 터널의 굴착전에 지반을 보강해주는 효과와 터널의 지보력을 증가시켜주는 여러 가지 장점이 있다. 본 연구에서는 선지보 시스템의 시공순서를 분석하고 터널 시공시 선지보 시스템의 적용성을 검증하기위해 수치해석을 수행하였다. 신개념 지보시스템을 분석한 결과, 신개념 고성능 터널지보시스템은 천층터널에서의 적용성이 뛰어나며, 터널 입 출구, 토사터널, 연약지반에서의 적용성 또한 뛰어난 것으로 판단되어졌다.

• Journal of Computing Science and Engineering
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• 제2권4호
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• pp.394-411
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• 2008

The data in automation and control systems can be achieved not only from different field devices but also from different OPC (OLE for Process Control) servers. However, current OPC clients can only read and decode the simple data from OPC servers. They will have some problems to acquire structured data and exchange the structured data. In addition to the large network control systems, the OPC clients can read, write, and subscribe to thousands of data points from/to OPC servers. Due to that, the most important factor for building a high performance and scalable industrial control system is the ability to transfer the process data between server and client in the most efficient and fastest way. In order to solve these problems, we propose a means to implement the OPC DA (Data Access) server supporting the OPC complex data, so that the OPC DA clients are able to read and decode any type of data from OPC servers. We also propose a method for caching the process data in large industrial control systems to overcome the limitation of performance of the pure OPC DA system. The performance analysis and discussion indicate that the proposed system has an acceptable performance and is feasible in order for applying to real-time industrial systems today.

• 한국정보과학회논문지:시스템및이론
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• 제29권4호
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• pp.232-243
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• 2002

TLB(translation lookaside buffer) 성능 향상을 위한 전형적인 방법으로 TLB로 하여금 더 많은 엔트리 수를 지원하는 방법, 페이지 크기를 증대시키는 방법, 그리고 다중 페이지 크기를 지원하는 방법이다. 현재 TLB 성능을 높이기 위한 가장 좋은 방법으로 다중 페이지 크기를 지원하는 연구가 효과적이다. 다중 페이지 크기를 지원하는 방법들 중에서 가장 적합한 것은 운영체제나 컴파일러로부터 일정한 정보를 받아서 가장 적합한 페이지 크기를 TLB에 할당하는 것이다. 그러나 운영체제의 시스템 영역에서 는 이러한 방식이 가능하나 사용자 영역에서는 현실적으로 이러한 방식을 지원하기 어렵기 때문에 우리는 사용자 영역까지 운영체제의 지원 없이 이중 페이지를 지원할 수 있는 새로운 TLB 구조를 제안하고자 한다. 고성능을 보장하기 위한 방법으로 이중페이지를 하드웨어 방식으로 지원하는 방식을 제시하고, 또한 저전력의 효과를 높이기 위하여 하나의 완전 연관 TLB를 두 개의 서버 TLB로 나누는 방식을 사용하였다. 이러한 두 가지 방식을 내장형 프로세서에 적합하도록 하나로 집적화 하여 저전력과 고성능의 효과를 모두 얻을 수 있었다. 시뮬레이션 결과에 따르면 적은 엔트리만을 사용하고도 높은 성능 향상효과를 얻을 수 있으며 또한 완전 연관 TLB에 비해 거의 50%이상 소비전력을 줄이는 효과를 얻을 수 있다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.277-280
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• 1998

As user's demands for high-speed data traffic are recently increased, ABR services are considered as one of important service requirements in ATM networks. Unfortunately, a number of existing ATM switching systems have structural drawbacks as to support ABR services because these switching systems have been developed to support realtime(rt) services such as CBR and rt-VBR services. To support ABR services in the existing ATM switching systems, new traffic control mechanisms for ABR services are required. This paper proposes a method for supporting ABR services in ATM swithcing systems without back-pressure mechanisms and evaluates the performance of the proposed method using simulation.

• Journal of Information Processing Systems
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• 제13권2호
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• pp.348-359
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• 2017

Nowadays most vehicles are equipped with a variety of electronic devices to improve user convenience as well as its performance itself. In order to efficiently interconnect these devices with each other, Controller Area Network (CAN) is commonly used. However, the CAN requires reconfiguration of the entire network when a new device, which is capable of supporting both of transmission and reception of data, is added to the existing network. In addition, since CAN is based on the collision avoidance using address priority, it is difficult that a new node is assigned high priority and eventually it results in transmission delay of the entire network. Therefore, in this paper we propose a new system component, called CAN coordinator, and design a new CAN framework capable of supporting plug and play functionality. Through experiments, we also prove that the proposed framework can improve real-time ability based on plug and play functionality.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권1호
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• pp.280-294
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• 2023

Unmanned aerial vehicles (UAVs) and millimeter-wave frequencies play key roles in supporting 5G wireless communication systems. They expand the field of wireless communication by increasing the data capacities of communication systems and supporting high data rates. However, short wavelengths, owing to the high millimeter-wave frequencies can cause problems, such as signal attenuation and path loss. To address these limitations, research on high directional beamforming technologies continue to garner interest. Furthermore, owing to the mobility of the UAVs, it is essential to track the beam angle accurately to obtain full beamforming gain. This study presents a beam tracking method based on the unscented Kalman filter using hybrid beamforming. The simulation results reveal that the proposed beam tracking scheme improves the overall performance in terms of the mean-squared error and spectral efficiency. In addition, by expanding analog beamforming to hybrid beamforming, the proposed algorithm can be used even in multi-user and multi-stream environments to increase data capacity, thereby increasing utilization in new-radio multiple-input multiple-output orthogonal frequency-division multiplexing systems.

• 농업과학연구
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• 제38권3호
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• pp.541-547
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• 2011

Korean building industry was developed by concrete and steel construction. However, concrete and steel have some problems which low carbon storage capability and difficulty of recycling. According to many studies, timber has high carbon storage capability, high recycling capability and sustainable supporting capability. Focus on this factors of timber, make new wall structure as Green Timber Wall panels and check the shear performance to use wall system in housing construction such as light-weight timber construction and nondearing wall on other construction. In the results, B-4-B and B-4-S show similar modulus of shear stiffness on the table. GH-4-GH has slip shape failure mode between Green Timber Wall boards. GH-4-GV has most stable characteristic curve than other specimens.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.953-958
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• 2002

The finishing method of concrete floor using automatic surface finisher is one of new technologies in concrete floor construction. The development of high technologies in construction will increase in order to satisfy the demand to construct high quality building. Using this method, it is possible to increase the quality of building as well as to reduce the labor work in site. In this paper, a system which can be used to finish the concrete floor using automatic surface finisher, is presented and its structural capacities are evaluated. The system is composed of rail which guides the surface vibrator and absorbs the volume change of concrete, and a device supporting the rail. From the experimental work for these devices, it was shown that the support and rail had suitable strength to resist the automatic surface finisher. For design purpose, also, effective span of supports was tabulated.

• 한국정보처리학회논문지
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• 제7권4호
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• pp.1201-1210
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• 2000

In order to tolerate faults which may occur during the execution of distributed tasks in high-performance parallel computer systems, tasks are duplicated on different processors. In this paper, by utilizing the task duplication based scheduling algorithm, a new task scheduling algorithm which duplicates each task on more than two different processors with the minimum schedule length is presented, and the number of processors required for the duplication is analyzed with the ratio of communication cost to computation time and the workload of the system. A simulation with various task graphs reveals that the number of processors required for the full-duplex fault-tolerant task scheduling with the obtainable minimum schedule length increases about 30% to 75% when compared with that of the task duplication based scheduling algorithm.

• 한국CDE학회논문집
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• 제11권5호
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• pp.351-358
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• 2006

Recently, the development of new structural model in fixed partial denture system is required to be started from the conceptual design with low cost, high performance and quality. In this point, a FEM based design of partial denture is used to investigate stress distribution on the durable shape. In this paper, the structural performances of partial dentures were analyzed under three biting forces. The periodontal embedding model is introduced on behalf of the detailed supporting tissue, which is composed of dentin, cortical bone, cancellous bone and periodontal ligament. Using topology optimization, the optimal reinforcement layout of connector was obtained and the detail shape in the fixed partial denture was designed.