• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.12
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• pp.1913-1920
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• 2017

Software Defined Networking creates totally new concept of networking and its applications which is based on separating the application and control layer from the networking infrastructure as a result it yields new opportunities in improving the network security and making it more automated in robust way, one of these applications is Denial of Service attack mitigation but due to the dynamic nature of Denial of Service attack it would require dynamic response which can mitigate the attack with the minimum false positive. In this paper we will propose a new mitigation Framework for DDoS attacks using Software Defined Networking technology to protect online services e.g. websites, DNS and email services against DoS and DDoS attacks.

• Magazine of the Korean Society of Hazard Mitigation
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• v.7 no.4
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• pp.51-57
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• 2007

근래에 해상물동량의 증가로 선박에 의한 해상운송이 늘어나면서 우리나라 연안뿐만 아니라 전 세계 해상의 교통흐름을 복잡하게 만들었다. 특히, 주요 항만 인접해안, 협수로 및 주요 통항로는 더욱 복잡한 교통흐름을 보여주고 있다. 이에 어느때 보다 선박에 의한 해양사고 발생 가능성이 높아졌다. 이 연구에서는 해양사고가 생길 가능성이 가장 높은 해역에서의 원활한 교통흐름과 안전운항을 위해 우리나라 뿐만 아니라 전 세계적으로 설치 운용중인 VTS 시스템에 대해 고찰 하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.11
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• pp.4331-4346
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• 2015

The femtocell network, which is designed for low power transmission and consists of consumer installed small base stations, coexists with macrocells to exploit spatial reuse gain. For its realization, cross-tier interference mitigation is an important issue. To solve this problem, we propose a joint access and power control scheme that requires limited information exchange between the femto and macro networks. Our objective is to maximize the network throughput while satisfying each user's quality of service (QoS) requirement. To accomplish this, we first introduce two distributed interference detection schemes, i.e., the femto base station and macro user equipment based schemes. Then, the proposed scheme dynamically adjusts the transmission power and makes a decision on the access mode of each femto base station. Through extensive simulations, we show that the proposed scheme outperforms earlier works in terms of the throughput and outage probability.

• Computers and Concrete
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• v.19 no.1
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• pp.111-120
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• 2017

This study aimed to design the accelerated life testing (ALT) of concrete, which stimulating the special natural environment maximumly. Its evaluation indexes, such as dynamic elastic modulus, mass and ultrasonic velocity were measured, and the variation of relative mass and relative dynamic elastic modulus of concrete were studied. Meanwhile, the microanalysis method was used. Moreover, an exploratory application of the stochastic approach, the Weibull distribution and the lognormal distribution, were made to assess the durability of concrete structures. The results show that the ALT for simulating natural environment is more close to the service process of concrete structure under actual conditions; The relative dynamic elastic modulus can be used as the dominant durability evaluation parameters, because it is more sensitive to the environmental factors compared with the relative quality evaluation parameters; In the course of the concrete deterioration, the destruction of the salt freezing cycle is the dominant factor, supplemented by other factors; Both of those two stochastic approaches can be used to evaluate the reliability of concrete specimens under the condition of ALT; By comparison, The lognormal distribution method is better to describe the reliability process.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.1
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• pp.100-113
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• 2018

The Proximity Service, which is one of the most popular network capacity improvement methods, uses the frequency reuse in order to increase the frequency efficiency. As a result, inter-cell interference between cellular and proximity service users occurs at a cell edge. In this paper, we proposed a mitigation scheme for inter-cell interference, where we suggested a new function of and eNB with ProSe function exchanging information about ProSe parameters and ProSe user equipment with neighboring cells via the X2 interface. As the first step, the resource which did not cause the inter-cell interference problem were pre-allocated through the frequency sensing in the ProSe direct discovery. As the next step, the inter-cell interference problem was solved by reallocating appropriate resources based on the ProSe application code, the ProSe application QoS, the ProSe application ID and validity timer in ProSe direct communication.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.5
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• pp.9-13
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• 2009

Modal parameters including resonant frequencies and mode shapes are heavily utililized in most damage identification throries for structural health monitoring. However, extracting modal parameters from dynamic responses needs postprocessing which inevitably involves errors in curve-fitting resonants as well as transforming the domain of responses. In this paper, the applicability of a damage identification method based on free vibration responses to the in-sevice responses is experimentally verified. The experiment is performed via applying periodic and nonperiodic moving loads to a simply supported beam and displacement responses are measured. The moving load is simulated using steel balls and a downhill device. The damage identification results show that the in-service response may be applicable to identifying damage in the beam.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.617-620
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• 2008

Because nature disaster would be increased society damage, government has to prepare the system for response to the disaster. In this study we proposed the concept element of response technology and strategy for the flood and typhoon disaster. And we define the emergence service criteria.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.4
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• pp.67-74
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• 2008

Because the fire service demands are increasing and forms are diversified, the first thing you must do is to make up the fire service budget to keep fire service power sufficiently. Such budget allocation leads to supply enough fire service people want and results in social welfare satisfaction. If the budget of fire service is not enough to meet with its power, sufficient security of the fire fighters would be impossible. Also, when the urgent disasters occur, the government cannot cope with them effectively. In fact, loss of many lives and properties took place in some cities and kuns because of that. The purpose of this study is to investigate the influence of fire service budget for fire service force. To do this, this study reviews fire service budget, fire service force. And this study sets up three hypotheses based on the theoretical backgrounds and the past research. The statistical method used for the verification of hypotheses is multiple regression analysis. The analysis showed that fire service budget per head variable was positive significant, fire service budget ratio variable was not significant. Also, public facilities tax variable was negative significant. Therefore, the analysis showed that public facilities tax couldn't fill the role as a earmarked tax.

• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.136.2-136.2
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• 2009

• Journal of Korean Society of Transportation
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• v.34 no.6
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• pp.523-534
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• 2016

The purpose of this study is to develope a method for measuring social benefit by mitigating in-vehicle congestion level in intercity buses. Contingent valuation method and Tobit model are adopted for social benefit evaluation method. One thousand passengers were interviewed with 992 obtained valid samples. Tobit models with age, income level, and bus boarding times as explanatory variables are selected to estimate the willingness to pay for the mitigation of intercity bus in-vehicle congestion. Statistically and logically, two models with age or income level as explanatory variables are turned out to be valid. The intercity bus service supply status and usage are examined and the bus users who have willingness-to-pay for the intercity bus in-vehicle congestion mitigation have been identified. In case of the 'no standing' rules implemented to the intercity bus, the annual economic benefit from the service is estimated to be 14.7 billion won.