• IMMUNE NETWORK
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• 제7권4호
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• pp.179-185
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• 2007

Background: Adenovirus (Ad) vectors have been widely used for many gene therapy applications because of their high transduction ability and broad tropism. However, their utility for cancer gene therapy is limited by their poor transduction into cancer cells lacking the primary receptor, coxsackievirus and adenovirus receptor (CAR). Methods: To achieve CAR-independent gene transfer via Ad, we pretreated Ad with 1,2-dioleoyl-3-trimethylammonium propane (DOTAP) and analyzed their transduction efficiency into cancer cells in vitro and in vivo comparing with the virus alone. Results: Treatment of DOTAP significantly increased adenoviral gene transfer in tumor cells in vitro. Moreover, DOTAP at an optimum dose $(10{\mu}g/ml)$ enhanced IL-12 transgene expression by fivefold in tumor, and twofold in serum after intratumoral injection of adenovirus expressing IL-12N220L (Ad/IL-12N220L). In addition, cotreatment of DOTAP decreased tumor growth rate in the Ad/IL-12N220L-transduced tumor model, finally leading to enhanced survival rate. Conclusion: Our results strongly suggest that DOTAP could be of great utility for improving adenovirus-mediated cancer gene therapy.

• 산업경영시스템학회지
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• 제33권3호
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• pp.137-145
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• 2010

The objective of this paper is to evaluate the equilibrium price between PSTN and VoIP telephony services in the case of non-linear utility function. Currently there are two types of wired phone services we are known PSTN (Public Switched Telephone Network) and VoIP (Voice over Internet Protocol). The PSTN telephony which provide high quality service and VoIP which provides relatively low quality service form a vertically differentiated oligopoly. Therefore, the evaluation of the equilibrium price between PSTN and VoIP services is very important to wired phone service providers. The equilibrium price depends on the state of the service cost function has been proved different value. This paper was evaluated each equilibrium price for the state of the linear cost function and non-linear cost function. Subsequently, this paper analyzed the demand of both services and the equilibrium profit which can maximize the profit of both service providers.

• 한국병원경영학회지
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• 제12권2호
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• pp.25-42
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• 2007

To identify characteristics of elderly inpatients who had long term hospitalization in a general hospital, this study categorized into two groups who were hospitalized for less than 30 days and a group hospitalized for more than 30 days. To compare the groups the independent variables were the sociodemographical characteristics, the medical care utility characteristics, and the disease characteristics and finally analyzed factors affecting the hospitalization period. The data of 18,727 inpatients who were older than 65 years of age by the year 2005 were used and the data were analyzed using SPSS for Windows 12.0. With the results, it is necessary to provide intensive and positive management to elderly inpatients who belong to the more than 30 days group and also necessary to share roles and functions of hospital by medical network with local hospitals and clinics in order to manage long-term elderly inpatients and offer continuous post-management to discharged patients by encouraging them to use a long-term care center or by implementing an early discharge program. This study should provide many studies on how to manage the period of hospitalization efficiently on long-stay elderly inpatients in the future.

• ETRI Journal
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• 제34권3호
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• pp.341-351
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• 2012

We deal with a resource allocation problem for multimedia service discrimination in wireless networks. We assume that a service provider allocates network resources to users who can choose and access one of the discriminated services. To express the rational service selection of users, the utility function of users is devised to reflect both service quality and cost. Regarding the utility function of a service provider, total profit and efficiency of resource usage have been considered. The proposed service discrimination framework is composed of two game models. An outer model is a repeated Stackelberg game between a service provider and a user group, while an inner model is a service selection game among users, which is solved by adopting the Kalai-Smorodinsky bargaining solution. Through simulation experiments, we compare the proposed framework with existing resource allocation methods according to user cost sensitivity. The proposed framework performed better than existing frameworks in terms of total profit and fairness.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1998-1999
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• 2007

Before applying the HTS(High Temperature Superconductor) power devices to a real utility network, system analysis should be carried out by some simulation tools. PSCAD/EMTDC simulation tool is one of the most popularized useful analysis tools for electrical power system. Unfortunately the model component for HTS coil is not provided in PSCAD/EMTDC simulation tool. In this paper, EMTDC model component for HTS coil has been developed considering real characteristics of HTS coil like critical current, temperature and magnetic field. The developed model component of HTS coil could be used for power system application. Using the developed model component for HTS coil, we can easily do the simulation of HTS power devices application test in utility with the various inductance, quench current, inner magnetic field, and temperature values, for instances; SMES(Superconducting Magnetic Energy Storage) system, superconducting motor, transformer, and FCL(Fault Current Limiter)

• 한국게임학회 논문지
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• 제19권2호
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• pp.23-32
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• 2019

VR 콘텐츠의 대중화가 더딘 것은 시각적인 새로운 경험 즉, '흥미' 이상의 '효용'을 만들어내지 못했기 때문이다. 가상현실 콘텐츠의 효용은 기능적 현실감에서 출발하며 그것을 증진시키기 위해서 사실적인 인터랙션이 요구된다. 본 연구는 구체적으로 네트워크 플레이, 캐릭터 인공지능, 햅틱 구현의 3가지 방법을 제시하고 있다. 가설을 확인하기 위하여 기획에서부터 콘텐츠 제작, 플레이 테스트, 기술 검증까지 야구를 소재로 한 VR 콘텐츠 제작의 전 단계를 수행하였다. 최종 결과물에 대한 사용자 및 평가 기관의 테스트를 통하여 사실적인 시각 효과와 플레이 연출, 진동에 의한 타격감까지 콘텐츠의 현실감을 높이는 데 기여한 것으로 평가되었다.

• 한국초전도ㆍ저온공학회논문지
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• 제8권3호
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• pp.54-58
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• 2006

In this paper, authors developed a real-time simulation algorithm for the power device application of HTS(High Temperature Superconducting) wire by using Real Time Digital Simulator(RTDS). At present, in order to extend the power capacity of some area where has a serious problem of power quality. especially metropolitan complex city, there are so many problems such as right of way for power line routes. space for downtown substations. and the environmental protection, etc. HTS technology can be useful to overcome this problem. Recently, according to the advanced HTS technology, the power application is being researched well. Simulation is required for safety before installation of HTS power cable, a fabrication model used at the power system simulation. This paper describes a real time digital simulation method for the application of HTS wire to power device. For the simulation analysis, test sample of HTS wire was actually manufactured. And the transient phenomenon of the HTS wire was analysed in the simulated utility power grid. This simulation method is the world first trial in order to obtain much better information for installation of HTS power device into a utility network.

• 한국물환경학회지
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• 제28권2호
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• pp.202-212
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• 2012

Due to the deterioration of water supply network and the deficiency of raw water, the water utility of local governments have performed various projects to improve their revenue water ratio. However, it is very difficult to estimate the cost for maintaining the revenue water ratio at higher level after completing the project, because local governments have different conditions affecting the operating and maintenance cost of water supply network. The purpose of this study is to present a procedure to estimate the operating and maintenance cost required to maintain the target revenue water ratio of the water supply network. For this purpose, we estimated the cost used only for operation and maintenance of water supply network of 164 local governments with the aid of K-Mean Clustering Analysis and the data from 40 representative local governments. Then, the regression analysis was performed to find relationship between revenue water ratio and the operating and maintenance cost with two different data sets generated by two classification methods; the first method classifies the local governments by means of k-means clustering, and the other classifies the local governments according to the index standardized by the operating and maintenance cost per unit length of water mains per revenue water ratio. The results shows that the method based on the index standardized by the cost and revenue water ratio of each government produces more reliable results for finding regression equations between revenue water ratio and the operating and maintenance cost only for water supply network. The estimated regression equations for each group can be used to estimate the cost required to keep the target revenue water ratio of the local government.

• 한국컴퓨터정보학회논문지
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• 제15권1호
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• pp.119-128
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• 2010

지난몇 년간 소셜 네트워크(Social network) 서비스는 급속도로 성장해 왔으며 향후 수년간이러한 추세는 지속될 전망이다. 이에 따라 해당기업, 공공기관에서는 다량의 소셜 네트워크 데이터를 보유하게되었으며, 이 데이터를 배포하여 각종 연구 기관에서 인구통계, 통계분석 등의 연구 목적에 사용할 수 있다. 그러나 배포되는 소셜 네트워크 데이터는 외부정보와 결합되어 개인프라이버시 노출의 문제를 초래할 수 있다. 소셜 네트워크 데이터 소유자는 데이터를 배포하기 전 개인을 식별할 수 있는 명시적 정보를 삭제하거나 암호화해야 함은 물론 외부정보와 결합되어 개인프라이버시 노출의 문제를 발생시킬 가능성이 있는 데이터 또한 수정해야 한다. 데이터 수정 과정에서 수정되는 데이터의 양이 적을수록 데이터의 유용성은 높아진다. 본 논문에서는 소셜 네트워크 프라이버시 보호 기법과 관련된 기존 연구가 고려하지 않은 내용정보 고려 및 구조정보 왜곡을 보완하는 새로운 기법을 제안한다. 또한 다양한 실험 결과를 통해 소셜 네트워크의 여러 환경에서 제안 기법의 확장성 및 타당성을 알아본다.

• Journal of Electrical Engineering and Technology
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• 제8권2호
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• pp.215-222
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• 2013

Electrical power distribution systems are critical links between the utility and customer. In general, power distribution systems have unbalanced feeders due to the unbalanced loading. The devices that dependent on balanced three phase supply are affected by the unbalanced feeders. This necessitates the balancing of feeders. The main objective of reconfiguration is to balance the loads among the phases subject to constraints such as load flow equations, capacity and voltage constraints and to reduce the real power loss, while subject to a radial network structure in which all loads must be energized. Therefore, the distribution system reconfiguration problem has been viewed as multi-objective problem. In this paper, the hybrid heuristic algorithm has been used for reconfiguration, which is the combination of fuzzy and greedy algorithms. The purpose of the introduction of greedy is to refrain the searching for the period of phase balancing. The incorporation of fuzzy helps to take up more objectives amid phase balancing in the searching. The effectiveness of the proposed method is demonstrated through modified IEEE 33 bus and modified IEEE 125 bus radial distribution system.