• Computers and Concrete
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• 제24권6호
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• pp.541-553
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• 2019

Alkali-silica reaction (ASR) in concrete can induce degradation in its mechanical properties, leading to compromised serviceability and even loss in load capacity of concrete structures. Compared to other properties, ASR often affects the modulus of elasticity more significantly. Several empirical models have thus been established to estimate elastic modulus reduction based on the ASR expansion only for condition assessment and capacity evaluation of the distressed structures. However, it has been observed from experimental studies in the literature that for any given level of ASR expansion, there are significant variations on the measured modulus of elasticity. In fact, many other factors, such as cement content, reactive aggregate type, exposure condition, additional alkali and concrete strength, have been commonly known in contribution to changes of concrete elastic modulus due to ASR. In this study, an artificial intelligent model using artificial neural network (ANN) is proposed for the first time to provide an innovative approach for evaluation of the elastic modulus of ASR-affected concrete, which is able to take into account contribution of several influence factors. By intelligently fusing multiple information, the proposed ANN model can provide an accurate estimation of the modulus of elasticity, which shows a significant improvement from empirical based models used in current practice. The results also indicate that expansion due to ASR is not the only factor contributing to the stiffness change, and various factors have to be included during the evaluation.

• Journal of information and communication convergence engineering
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• 제18권3호
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• pp.183-187
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• 2020

The general Wi-Fi network connection structure is that a number of IoT (Internet of Things) sensor nodes are directly connected to one AP (Access Point) node. In this structure, the range of the network that can be established within the specified specifications such as the range of signal strength (RSSI) to which the AP node can connect and the maximum connection capacity is limited. To overcome these limitations, multiple middleware bridge technologies for dynamic scalability and load balancing were studied. However, these network expansion technologies have difficulties in terms of the rules and conditions of AP nodes installed during the initial network deployment phase In this paper, an intelligent edge computing IoT device is developed for constructing an intelligent autonomous cluster edge computing network and applying it to real-time road danger context aware and notification system through an intelligent risk situation recognition algorithm.

• 수산해양교육연구
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• 제26권4호
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• pp.760-768
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• 2014

Yet logistics base in China has a refrigerated storage facilities installed areas, the number of those is very limited and is generally insufficient. According to these especial points, a new construction cold chain logistics network design strategy is required from how to use the existing refrigerated warehouses to new issue. For example, however refrigerated storage facility is supplied, can it satisfy all demand of this area? Then does it have optimized location of this area? If future demand expansion, adding that already other refrigerated storage facilities matter? Or, add another refrigerated facilities, optimum cold chain established a network matter? So on. Above problems can be occurred. In order to solve facing many of these issues of distribution network, northeast area in China has been selected as a subject, and we designed a new cold chain distribution network.

• 대한전기학회논문지:시스템및제어부문D
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• 제51권2호
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• pp.69-77
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• 2002

Speaker verification can be classified in two categories, text-dependent speaker verification and text-independent speaker verification. In this paper, we discuss text-dependent speaker verification. Text-dependent speaker verification system determines whether the sound characteristics of the speaker are equal to those of the specific person or not. In this paper we obtain the speaker data using a sound card in various noisy conditions, apply a new Hidden LMS (Least Mean Square) adaptive algorithm to it, and extract LPC (Linear Predictive Coding)-cepstrum coefficients as feature vectors. Finally, we use a competitive learning neural network for speaker verification. The proposed hidden LMS adaptive filter using a neural network reduces noise and enhances features in various noisy conditions. We construct a separate neural network for each speaker, which makes it unnecessary to train the whole network for a new added speaker and makes the system expansion easy. We experimentally prove that the proposed method improves the speaker verification performance.

• 한국컴퓨터정보학회논문지
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• 제6권4호
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• pp.131-137
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• 2001

본 논문은 ATM망에서 ATM계층의 셀 전달 트래픽에 대해 실시간으로 측정하고 측정을 통해 수집된 데이터를 토대로 트래픽 특성을 분석하기 위한 도구 설계에 관한 것으로 설계된 도구를 현장에 적용, real-ATM트래픽을 측정하고 분석하여 도구의 효율성을 확인하였는데, 분석 결과 망 자원의 효율을 약 20％～50％ 까지 개선시킬 수 있을 것으로 확인되었으며 분석 파라메터는 현장에 적용하였고, 적용된 파라메터는 품질을 보장하면서 망 자원 효율을 높일 수 있는 것으로 확인되었다. 따라서, 가입자별 트래픽 유형을 일별 주별, 월별, 분기별로 분석할 수 있도록 향후 많은 raw data를 기반으로 데이터베이스 구축이 필요하며 이를 토대로 망 확장 및 신규 망 구축을 위한 설계 분야 및 ATM망의 트래픽 수요 예측에 활용될 수 있을 것이다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1758-1761
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• 1997

The problem of long range capacity expansion planing for chemical processing network under uncertain demand forecast secnarios is addressed. This optimization problem involves capactiy expansion timing and sizing of each chemical processing unit to maximize the expected net present value considering the deviation of net present values and the excess capacity over a given time horizon. A multiperiod mixed integer nonlinear programming optimization model that is both solution and modle robust for any realization of demand scenarios is developed using the two-stage stochastic programming algorithm. Two example problems are considered to illustrate the effectiveness of the model.

• Journal of Astronomy and Space Sciences
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• 제27권4호
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• pp.359-366
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• 2010

In this study, we developed a global ionosphere model based on measurements from a worldwide network of global positioning system (GPS). The total number of the international GPS reference stations for development of ionospheric model is about 100 and the spherical harmonic expansion approach as a mathematical method was used. In order to produce the ionospheric total electron content (TEC) based on grid form, we defined spatial resolution of 2.0 degree and 5.0 degree in latitude and longitude, respectively. Two-dimensional TEC maps were constructed within the interval of one hour, and have a high temporal resolution compared to global ionosphere maps which are produced by several analysis centers. As a result, we could detect the sudden increase of TEC by processing GPS observables on 29 October, 2003 when the massive solar flare took place.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.46-49
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• 2003

This paper proposes a method to solve expansion problem for a transmission network, given future generation and load strategy, and alternative types of lines available, subject to load, reliability and right of way constraints, the problem is formulated as a series of zero one integer programs which are solved by an efficient branch and bound algorithm A study test result on the 63-buses test system shows that the proposed method is practical and efficiently applicable to the transmission expansion planning.

• 대한전기학회논문지
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• 제33권1호
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• pp.9-16
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• 1984

This paper describes the minimum cost expansion planning which is based on the economical aspect under the various conditions on the power system expansion planning. It presents not only linear cost characteristics analysis but also stepwise cost characteristics analysis which satisfies practical condition in the power system. The latter analysis must be handled by integer programming (IP), because the relation between the cost and the capacity has stepwise characteristics. In order to proceed the latter analysis, the solving procedure is illustrated in detais by using branch and bound method which includes the network flow theory and maximum flow-minimum cut theorem.

• 한국멀티미디어학회논문지
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• 제3권6호
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• pp.674-684
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• 2000

병렬처리 과정 중에서 고려되어야할 가장 중요한 점은 프로세서사이에 통신을 어떻게 효율적으로 처리하는가 하는 것이다. 그 중 하나의 접근방법이 익스팬드 그래프를 이용하여 최적의 지연시간을 달성하는 방법이다. 익스팬드 그래프를 기초로 하여 효율적인 네트워크 구성과 수행시간이 빠른 병렬 알고리즘을 개발하기 위한 시도가 이루어져왔다. 병렬알고리즘 수행에서의 중요한 결과인 O(logN)시간의 AKS정렬 알고리즘은 익스팬드를 기초로 한다. 익스팬드 그래프는 다시 집중기(concentrator)와 초집중기(superconcentrator)에 적용될 수 있으며 Margulis가 선형 익스팬드 그래프의 구성하는 방법을 구체적으로 제시한 후 몇 개의 익스팬드가 제시되었다. 그러나 익스팬드 그래프를 이용한 구체적인 구조는 제시하지 않았다. 본 논문에서 hypercube 구조에서의 익스팬드 네트워크 구조를 조사하고 그리고 각 단에서의 확장성을 분석하고 다단으로 확장한다. 본 논문은 hypercube에서의 익스팬드 네크워크의 이론적 분석을 제시한다.