• Proceedings of the KAIS Fall Conference
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• 2008.05a
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• pp.186-188
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• 2008

태양광, 풍력 등의 대체에너지전원의 개발 및 보급이 증가하는 추세에서 이들 소규모 전원이 도입되는 배전계통의 환경 및 여건을 정비하는 것이 무엇보다 시급하고도 중요한 사항이라고 생각된다. 이들 배전계통의 환경 가운데 가장 중요한 것 중의 하나가 수용가의 전압을 일정한 범위 내로 유지하는 것이다. 전력회사에서는 하계의 피크 부하기간 중에 지정된 고압선로의 직하와 말단의 전압을 측정하여 규정전압(전등 : 220${\pm}$6%, 동력 : 380${\pm}$10%)이내에 유지되는 가를 평가하여 산업자원부에 보고하도록 전기사업법에 규정되어 있을 정도로 중요한 목표관리 대상이다. 따라서, 배전계통의 전압조정 기술은 상당히 중요한 기술이므로, 본 논문에서는 분산전원이 배전계통에 연계되어 운용되는 경우, 전압조정장치의 동작을 시뮬레이션 할 수 있는 시뮬레이터를 개발하여 수용가의 전압을 평가하고 개선하는 시스템을 개발하였다.

• Proceedings of the Korea Contents Association Conference
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• 2019.05a
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• pp.323-324
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• 2019

오늘날 관광업은 나날이 한 도시의 중요한 경제 수입 업종이 되고 있으며, 관광업은 지방의 경제 발전에 대체적인 작용을 한다. 사인시스템에서 중요한 공공시설로서, 없어서는 안 되는 작용을 하고 있다. 관람객들은 사인시스템을 통해 목적지를 찾는 데 필요한 시간을 단축할 수 있고, 관광지에 대한 전반적인 인상도 높일 수 있다. 고대 고성 안내 사인시스템에 대한 연구와 완벽을 통해서 옛 고성로 하여금 더욱 좋은 개발 기회를 얻게 하다. 이곳을 찾은 사람들이 역사와 문화에 대해 더 잘 알게 해 준다고 말했다. 본 논문의 연구 대상은 중국 남북의 역사문화관광지 중에서 선발한 AAAA급 이상의 관광지이다. 본 연구의 연구 대상으로 선정된 4개 관광지는 리장고성, 관도고성, 선양고궁. 첫째, 관련 문헌을 통해 사인디자인과 관련된 요소를 파악, 이들 요소를 바탕으로 설문 조사의 관련 문항을 제작했다. 둘째, 관광지마다 현장조사를 하고 관련 사진을 수집해 설문조사의 기초 자료로 활용했다. 네 개의 관광지의 사인시스템에 대해 설문조사를 실시하다. 셋째, 설문조사 결과를 집계한다.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.2
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• pp.45-51
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• 2022

In this paper, an universal reduced input system that can represent Korean text message, English alphabet letter, special characters, and numbers is develpoed. The reduced keyboard input system has 5 number keys and 4 special function keys to reduce the complexity of inserting characters for the severely disabled. Also, mobile application is developed for the use of easy communication for the disabled.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.1393-1396
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• 2009

인터넷 서비스를 사용하기 위해서 사용자들은 이름과 주민등록번호로 실명 인증을 받은 후에 ID를 부여 받았으나, 최근 보안상 문제로 주민등록번호 대체 수단인 I-PIN 서비스를 사용하고 있다. 그리고 하나의 ID로 통합하여 인터넷 서비스를 받을 수 있는 OpenID 서비스가 국내에서도 시행중이지만 사용자 인증이 없어 악성 댓글과 스팸 등으로 악용될 수 있다. 본 논문에서는 OpenID에서 회원가입을 할 때 I-PIN을 사용하여 사용자 인증을 하는 기법을 제안하고 기존의 OpenID와 I-PIN을 적용한 OpenID를 비교분석을 통하여 보안적인 측면이 강화된 것을 확인할 수 있다.

• Journal of the Korea Concrete Institute
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• v.17 no.1 s.85
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• pp.77-84
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• 2005

The steel slag, a by-product which is produced by refining pig iron during the manufacture of steel, is mainly used as road materials after aging. It is necessary to age steel slag for long time in air because the reaction with water and free-CaO in steel slag could make the expansion of volume. This problem prevents steel slag from being used as aggregate for concrete. However, steel slag used in this study was controled by a air-jet method which rapidly cools substance melted at a high temperature. The rapidly-chilled method would prevent from generation of free-CaO in steel slag. This study dealt with the influence of the using rate of rapidly-chilled steel slag on flow, dosage of SP, W/C ratio, and strength of mortar by statistical experimental design. Also, the results of this experiment were approved by statistical analysis methods, such as analysis of variance and F-testing. As results of F-testing, this paper proved at $1\%$ level of significance that the more the using rate of rapidly-chilled steel slag increased, the more this affected the enhancement of flow, the decrease of dosage of SP and W/C ratio, and the development of compressive strength. Also, considering the fluidity and compressive strength of mortar, it is desirable to use $75\%$ of rapidly-chilled steel slag for river sand.

• Korean Journal of Poultry Science
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• v.30 no.1
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• pp.49-54
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• 2003

This study was carried out to investigate the effects of the inoculated diet with Paecilomyces japonica on weight gain, feed efficiency and cordycepin contents in the breast and thigh meats of broilers. One hundred and twenty broiler chicks were divided into four dietary groups ; 1) control (basal diet), 2) T1 (substituted with 5% inoculated diet), 3) T2 (substituted with 10% inoculated diet) 4) T3 (substituted with 20% inoculated diet) during 4 weeks. Cordycepin contents of inoculated diet with Pacilomyces japonica was significantly higher than before inoculation (P<0.05). Body weight gain and feed efficiency were highest in T1 group when fed starter diet (P<0.05) but these were lowest in T3 group fed when fed finished diet (P<0.05). Body weight gain and feed efficiency were the lowest in T2 group for overall period than other groups. Cordycepin contents of breast and thigh meats were significantly higher in Pacilomyces japonica groups than control at 5 weeks of age (P<0.05). However, it was similar among the T1, T2 and T3 groups. These results indicated that body weight gain and feed efficiency tended to increase in birds fed replaced 5% inoculation diet Cordycepin contents of breast and thigh meats would be increased significantly in birds fed inoculated diet (P<0.05).

• Journal of the Mineralogical Society of Korea
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• v.17 no.4
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• pp.365-383
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• 2004

Granitic rocks in the southeastern Gyeongsang Basin can be classified into three groups. The group I contains various mafic microgranular enclave (MME) and/or mafic clot which implies magma mixing or mingling. The group II show the feature of shallow depth emplacement at low pressure, and the group III is characterized by A-type granite implying extensional tectonic environment. Mineralogical characteristics of the granitic rocks have showed systematic variations in perthite exsolution temperatures and biotite compositions according to their rock facies, although they do not show any distinctively different trend in geography and textures or rock facies. Amphiboles from Group I are calcic-amphibole and they were formed at 0.4 ～ 2.8 kb in pressure based on the amphibole geobarometry. Amphiboles from group ill are riebeckite, whileas amphiboles were not observed in Group II. The chemical composition of biotite defined in clusters showing a continuous spectrum between group I to ferric-annite of group ill. The composition of plagioclase generally plotted in albite, oligoclase, and andesine area without any distinctive differences among their geography or rock facies. The exsolution temperatures by perthite geothermometry are calculated as $300～400^{\circ}C$ in Group I, and 500～$600^{\circ}C$ in equigranular granite of group II and alkali-feldspar granite of group III.

• The Journal of Engineering Geology
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• v.19 no.3
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• pp.313-321
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• 2009

The relationship between precipitation and groundwater level and the correlation between the moving average of precipitation and goundwater level were analyzed for the Han river watershed in Korean peninsular. Fourteen regions in the watershed were selected and there were somewhat different patterns of seasonal fluctuation of groundwater level data. The groundwater level data tends to decrease in dry spell and increase in wet spell however the range between maximum and minimum values is quite different for each gauging point. We could have stronger correlation between groundwater level for fractured rock aquifer and the moving average of precipitation than the groundwater level for alluvial aquifer. The critical infiltration, which is the maximum daily infiltration averaged throughout watershed, value is turned out to have the range of 10 to 90 mm. We could have stronger correlation when we consider critical infiltration and modify the original precipitation data than we use original precipitation data. We also could have higher correlation coefficient when we consider snowmelt effect for the watershed that has considerable snow event.

• Journal of the Korea Concrete Institute
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• v.23 no.2
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• pp.203-209
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• 2011

The cement industry is expected to face a major set-back in the near future due to its large energy consumption and $CO_2$ production, causing global warming. In order to overcome these environmental problems, this research has bee carried out to find a cement substitute material. One possible cement substitute material is Zeolite cement. In this study, the materialistic characteristics of Zeolite cement mortar were evaluated. Natural Zeolite cement mortar was prepared using alkali activation (NaOH) instead of water ($H_2O$) to determine achievable strength and appropriate mixing ratio. Based on the mixing ratio, functional material was added to alkali active agent to harden Zeolite mortar to develop a highly functional construction material. The study result showed that pure Zeolite cement mortar achieved compressive strength of 42 MPa in 7 days depending on the mixing amount of alkaline catalyst and the hardening temperature, showing high efficiency and possibility as a new construction material.

• Journal of the Korean Wood Science and Technology
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• v.40 no.4
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• pp.287-293
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• 2012

This study was carried out in order to compare nail shear strength between domestic plywood and imported OSB for structural sheathing members as infill wall of wooden construction. The differences of nail shear strength between parallel-to-grain direction and perpendicular-to-grain direction of sheathing material to frame material were distinct at the plywood composition. The shear strengths of plywood and OSB with nail met current design values. The plywood of P-4 type, which uses MLH at surface layer and constructs 7 ply, showed greater than OSB regardless of grain direction of sheathing material to frame material. When the plywood as sheathing material to frame material was used, it was found out that the overall construction of perpendicular-to-grain direction of plywood had greater nail shear strengths than the construction of parallel-to-grain.