• Journal of Korean Institute of Industrial Engineers
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• v.26 no.2
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• pp.155-164
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• 2000

Recently Fiber-optic Micro-cellular Wireless Network is considered to solve frequent handoffs and local traffic unbalance in microcellular systems. In this system, central station which is connected to several microcells by optical fiber manages the channels. We propose an efficient sectorization algorithm which dynamically clusters the microcells to minimize the blocked and handoff calls and to balance the traffic loads in each cell. The problem is formulated as an integer linear programming. The objective is to minimize the blocked and handoff calls. To solve this real time sectorization problem the Tabu Search is considered. In the tabu search intensification by Swap and Delete-then-Add (DTA) moves is implemented by short-term memory embodied by two tabu lists. Diversification is considered to investigate proper microcells to change their sectors. Computational results show that the proposed algorithm is highly effective. The solution is almost near the optimal solution and the computation time of the search is considerably reduced compared to the optimal procedure.

• International Journal of Contents
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• v.6 no.3
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• pp.83-88
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• 2010

Aerobic exercise affects cerebral circulation, action of neurotransmitters, glucose, oxygen, and energetic substances and influence on the central nervous system for cognition. This study suggests that both the intensity of exercise and the level of cognitive task need to be considered. Computerized neurobehavioral testing is a more effective method, compared to conventional methods, of neuropsychological testing when measuring cognition objectively, in cases that we found. The intensity of 80% max HR had effect on more complex tasks such as 3 Digit Addition and Digit Span Backward, and the intensity of 65% max HR had an effect on more simple tasks such as Color Word Vigilance and Digit Span Forward. We can assume that different intensity of aerobic exercise might involve specific areas of the brain as they could have different sensitivities, so further studies measuring regional cerebral blood flow or electroencephalogram are needed to confirm the results.

• Journal of Sensor Science and Technology
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• v.21 no.1
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• pp.21-27
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• 2012

In this study, we designed an embedded system for automatic condensation control(ESCC) of the car. This system heats the car glasses as and when it is needed that makes driving safer and convenient. The system was built on an ATmega128L central processing unit(CPU), using high-performance electrically erasable programmable read-only memory(EEPROM) complex programmable logic device(CPLD) ATF1504AS, using which an ESCC algorithm has been proposed. The source code was written in C language. The algorithm of work was written using the dew-point table. This system not only clears the condensation on the glass but also averts condensation. The designed ESCC system begins working once the input information comes close to the dew-point table information. This device enables a wider field of view, thereby increasing safety.

• 전기의세계
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• v.31 no.5
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• pp.375-382
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• 1982

The optimum control of voltage and reactive power in large system requires large amounts of complicated calculation. If the large power system is controlled by the centralized control scheme, the necessary computing time, memory requirments and data transmission channels increase exponetially, and computer control of the system becomes difficult. Piecewise method which aims at the reduction of the difficulties of centralized control scheme is to decompose a large power system into several subsystems, each of which is controlled by a local computer and the control efforts of each subsystem are coordinated by a central computer. Unless sufficient coordination is made between subsystems, the control quality may become very poor. This paper describes how piecewise method can be applied in the optimal control of voltage and reactive power in large system, and presents effective calaulating algorithm for the solution of the problem. The numerical example for model system is presented here.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.353-362
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• 2008

Operation data and fault data are recorded at the TCMS(Train Control and Monitoring System) of train are very important record for repairs and inspection of train. there are two ways to transfer the data today. one is using memory card and the other is using wireless communications. This paper is proposed about TCMS wireless depot analytical equipment that transfers data recorded in train to depot equipment via wireless method. The TCMS wireless depot equipment configuration is an AP(Access Point) and a central server PC at depot equipment. This method has the advantage of decrease of personnel expenses, collection time and convenience of staffs. This paper is verified about the utility of use, efficient establishment position of an AP at depot, the safety of data receiving, the exactitude of data and the shortening of transmission time. and this equipment is now operating at shin-jeong depot of SeoulMetro.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.2
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• pp.102-114
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• 1987

In this paper, in order to develop the transmission system between the remote subscriber and the central office, the hardware and software implementation of a SMUX(Statistical Multiplexer)which can interleace eleven 16Kbps D-channels over a 64Kbps B-channel is obtained. As a result of this study, the high speed data transmission by the use of a dynamic buffer memory management algofithm for statistical multiplexing is realized. Especially a software architectur for interruption is proposed in order to improve performance of the transmission system more efficiently.

• BMB Reports
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• v.42 no.8
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• pp.475-481
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• 2009

Emerging data demonstrate pivotal roles for brain insulin resistance and insulin deficiency as mediators of cognitive impairment and neurodegeneration, particularly Alzheimer's disease (AD). Insulin and insulin-like growth factors (IGFs) regulate neuronal survival, energy metabolism, and plasticity, which are required for learning and memory. Hence, endogenous brain-specific impairments in insulin and IGF signaling account for the majority of AD-associated abnormalities. However, a second major mechanism of cognitive impairment has been linked to obesity and Type 2 diabetes (T2DM). Human and experimental animal studies revealed that neurodegeneration associated with peripheral insulin resistance is likely effectuated via a liver-brain axis whereby toxic lipids, including ceramides, cross the blood brain barrier and cause brain insulin resistance, oxidative stress, neuro-inflammation, and cell death. In essence, there are dual mechanisms of brain insulin resistance leading to AD-type neurodegeneration: one mediated by endogenous, CNS factors; and the other, peripheral insulin resistance with excess cytotoxic ceramide production.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.11a
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• pp.189-192
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• 1999

This paper propose an efficient image description method using circular scanning pattern. The method Is based on the fart that the main information of an image tends to consentrate on its central part. By the method, we ran describe color and spacial information of the mage at a time, efficiently. Therefore, we can reduce the computational expense and memory usage needed to index the image more than the conventional one does.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.135-138
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• 2013

GPGPU(General Purpose Graphics Processing Unit) 병렬처리 시스템인 CUDA(Compute Unified Device Architecture)는 컴퓨터에서의 고속 연산 처리를 위해 많이 사용되어왔다. CUDA에서 연산 처리를 하기 위해서는 CUDA의 특성을 이해해야 한다. CUDA는 CPU(Central Processing Unit)가 처리하는 Host 영역과 GPU(Graphics Processing Unit)가 처리하는 영역인 Device 영역이 존재하며, 이 두 영역간의 데이터 복사를 통해 연산 처리를 진행한다. 이런 구조적인 특성상 메인 메모리에서 GPU 메모리로 입력 데이터를 전달해야 GPU를 이용해 연산을 처리할 수 있는 구조를 가지고 있다. 하지만 이러한 처리 구조로 인해 연산 시간과 별도로 메인 메모리와 GPU 메모리간의 데이터 복사시간이 존재하며, 추가적으로 발생하는 메모리 복사 시간으로 인해 오버헤드가 발생하게 된다. 본 논문에서는 실험을 통해 메모리 복사 시간, 연산의 반복 횟수 그리고 연산의 복잡성이 전체 성능에 어떤 영향을 미치는지 논하고자 한다.

• Architectural research
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• v.23 no.1
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• pp.11-17
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• 2021

A concrete-filled circular steel tube beam was fabricated, and a bending test was performed to analyze its failure modes, displacement ductility, bending-shear strength, and load-central deflection relationship. For the bending test, the installation position of the shape memory alloy (SMA) inside and outside the double-skin steel tube was used, and the rebar installation position, the concrete strength, the mixing of fibers, and the inner-outer diameter ratio as the main parameters. The test results showed that the installation positions of the reinforcements inside and outside the double-skin steel tube and the inner-outer diameter ratio of the steel tube affected the ductility, maximum load, and failure mode. In general, the specimen made of general concrete with SMA installed outside and inside (OI) the double-skin steel tube showed the best results.