• Radiation Oncology Journal
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• v.11 no.2
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• pp.363-367
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• 1993

A retrospective analysis was peformed on 42 patients with carcinoma of the uterine cervix who were treated with external beam (EB) radiation therapy alone at the Department of Therapeutic Radiology, Seoul National University Hospital from March 1979 to December 1988. After whole pelvic field irradiation of 50Gy, all the patients received additional booster dose of 12-22Gy to the primary tumor Thirty one received EB radiotherapy alone because of poor geometry for intracavitary application,5 because of medical problems and 6 because of other reasons. Five year locoregional control rate and five year survival rate were $34.5\%\;and\;35.4\%,$ respectively. Five year survivals were $66.7\%,\;36.4%,\;32.8\%\;and\;25.0\%$ for stage IIA, IIB, IIIB and IVA, respectively. The response one month after treatment well correlated with prognosis. The incidence of grade 2 and 3 complication was $12\%\;and\;10\%,$ respectively. There was tendency of increased complication with advanced stage.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.9A
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• pp.755-761
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• 2005

In this paper, we proposed a channel estimation method by impulse signal train in OFDM. In order to estimate the channel response, 4 impulse signals are generated and transmitted during one OFDM (Orthogonal Frequency Division Multiplexing) symbol. The intervals between the impulse signals are all equal in time domain. At the receiver, the impulse response signals are summed and averaged. And then, the averaged impulse response signal is zero padded and fast Fourier transformed to obtain the channel estimation. The BER performance of the proposed method is compared with those of conventional estimation method using the long training sequence in fast fading environments. The simulation results show that the proposed method improves by 3 dB in terms of Eb/No, compared with the conventional method.

• Journal of Life Science
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• v.13 no.1
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• pp.105-109
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• 2003

Epoxide hydrolase (EH) gene from Aspergillus niger #33 was cloned from cDNA library generated by reverse transcriptase-polymerase chain reaction (RT-PCR). The nucleotide sequence analysis revealed that the deduced amino acid sequence was almost similiar to that of A. niger LCP521 previously reported. The cloned EH gene was transformed into Saccharomyces cerevisiae and expressed by addition of galactose. The recombinant S. cerevisiae showed hydrolytic activity toward racemic phenyl oxirane substrate based on chiral GC analysis, and can be used as a potential biocatalyst for the preparation of chiral phenyl oxirane.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.10
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• pp.1-7
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• 2007

In WCDMA systems the down-link power allocation directly affects the cell deployment capacity, coverage, and system performances. Down-link power should be controlled at minimum but still satisfy the mobile stations' required signal to noise ratio. This paper mathematically proves that the down-link power allocation depends on the number of active mobile stations accessed to the base station. Therefore this paper proposes the dynamic down-link power allocation should be implemented to the WCDMA cellular systems.

• Journal of the Korean School Mathematics Society
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• v.19 no.2
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• pp.123-151
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• 2016

The purpose of this study is to analyze the existing studies about the effect on private tutoring and EBS broadcasting which is considered as the alternative which was presented by education authorities. And this study attempts to measure the degree of the effects of private tutoring and EBS engagement on mathematics achievement using various quantitative methodologies. T-test and OLS multiple regression indicates some selection-bias which has positive direction compared to the PSM method closed to experimental design. So, it will be required to consider the methodology which measures the exact effect of institution or participation when we conduct the observational studies.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.11a
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• pp.92-95
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• 2012

대한민국에서 3DTV 방송서비스는 더 이상 '미래방송서비스'가 아니다. EBS는 올해 4월 지상파 DTV 주파수에서 세계최초로 2D/3D 혼용방송서비스를 실시하였으며, 오는 10월 15일에는 APC(Automatic Program Controller)와 연동하여 방송스케줄에 따라 자동으로 3D 방송을 송출하는 시스템을 구축하여 2차 시범방송을 진행할 예정이다. 이렇게 3D 방송을 위한 기술적 준비는 차근차근 이루어지고 있음에 반하여, 3D 방송서비스에 대한 시청자의 호응은 그다지 크지 않다. 이것은 방송되는 3D 콘텐츠의 양과 질이 부족하기 때문으로 풀이된다. 이 같은 3D 방송서비스의 장애요소에 착안하여, 본 논문에서는 3D 콘텐츠 제작효율을 높이고, 만들어지는 3D 방송콘텐츠의 품질을 높이기 위한 하나의 방법으로서, 제작현장에서 활용할 수 있는 3D 콘텐츠 제작과 밀접한 관련이 있는 새로운 참조지표인 '입체충실도(Depth Fidelity)'를 정의하여 제안하고자 한다. 입체충실도를 도출하기 위해 우선 양안식(兩眼式) 3D 입체영상의 특징을 분석하였고, 시청자 체감 가상깊이를 계산하여 활용하였다. 또한 연구를 통해 도출한 입체충실도 계산 알고리즘이 적용된 EBS 입체계산기(Stereoscopic Calculator) 애플리케이션을 개발하여 안드로이드 스마트폰에서 이용할 수 있도록 함으로써, 카메라감독과 프로듀서 등 방송제작 현업 스태프들이 연구결과를 활용할 수 있도록 했다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.732-734
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• 2005

Current Internet services do not consider the service level interoperability because each service is developed with its own interface, which is not compatible with other services. This means that characteristics of Internet services are autonomous and heterogeneous. Moreover each service has its own access method, data representation, and data structure. This will make it difficult for NGN services to be converged. For the convergence scenarios of NGN services, interoperability among different applications shall be supported in service layers in various network environments. In order to realize this, integration function in applications is necessary. And, it is also required that NGN services shall consider to adopt the conventional E-business framework such as ebXML in order to create value added services.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.4
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• pp.298-302
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• 2004

An electronic commerce model is proposed which distributes digital content in mobile environment. This model resolves the problems caused by various digital content and complex distribution structure. The online distribution systems under the wireless environment include many different factors from the conventional offline and wired networks. Furthermore, the multimedia content may be propagated more easily and illegally. The scheme to protect the rights and profits of people related to the copyrights of digital content is needed. In this paper a framework for electronic commerce of content distribution under the wireless environment based on MPEG-21 is proposed. This model can be applied to the digital rights management system and utilized to protect the rights of trading entities in online distribution of electronic commerce.

• Applied Chemistry for Engineering
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• v.25 no.5
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• pp.503-509
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• 2014

The carbon/porous silica composite membrane was fabricated in a simple manner, which could be successfully for the simultaneous separation and production of chiral epoxides and 1,2-diols, based on their differences in hydrophilic/hydrophobic natures. The chiral Co(III)-$BF_3$ salen catalyst adopted in the membrane reactor system has given the very high enantioselectivity and recyclability in hydrolysis of terminal epoxides such as ECH, 1,2-EB, and SO. The optically pure epoxide and the chiral catalyst were collected in the organic phase after hydrolysis reaction. The hydrophilic water-soluble 1,2-diol product hydrolyzed by chiral salen diffused into the aqueous phase through the SBA-16 or NaY/SBA-16 silica composite layer during the reaction. The water acted simultaneously as a reactant and a solvent in the membrane system. One optical isomer was obtained with high purity and yield, and furthermore the catalysts could be recycled without observable loss in their activity in the continuous flow-type membrane reactor.

• Journal of the Korea Concrete Institute
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• v.23 no.2
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• pp.245-252
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• 2011

Currently, the design guidelines for the prevention of progressive collapse are not available in Korea due to the lack of study efforts in progressive collapse resistance evaluation of RC flat plate system. Therefore, in this study, three types of analysis were conducted to evaluate the progressive collapse resistance of a RC flat plate system. A linear static analysis was carried out by comparing the demand-capacity ratio (DCR) differences of the systems using the alternate load path method, which is the guideline of GSA. A dynamic behavior was investigated by checking the vertical deflection after removal of the column using the linear dynamic analysis. Lastly, a maximum load factor was investigated using the nonlinear static analysis. The finite element (FE) analyses were conducted using various parameters to analyze the results obtained using effective beam width (EB) model and plate element FEM (PF) model. This study results showed that the strength contributions of the slab in the EB models are underestimated compared to those obtained from the PF models. Therefore, a detailed FE analysis considering the slab element is required to thoroughly estimate the progressive collapse resisting capacity of flat plate system. The scenario of the corner column (CC) removal is the most dangerous conditions where as the scenario of the inner column (IC) removal is the least dangerous conditions based on the consideration of various parameters. The analysis results will allow more realistic evaluations of progressive collapse resistance of RC flat plate system.