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FDTD 방법을 이용한 간단한 건물 구조의 광대역 차폐 효과에 관한 연구 (Study on Wideband Shielding Effects of Simple Building Structures Using FDTD Method)

  • 조제훈;하상규;박성민;추광욱;주세훈;김형동;정경영
    • 한국전자파학회논문지
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    • 제24권7호
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    • pp.748-751
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    • 2013
  • 본 논문은 유한 차분 시간 영역(FDTD: Finite-Difference Time-Domain)법을 이용하여 간단한 건물 구조의 광대역 복사성 펄스 결합에 관한 연구를 수행하였다. 이를 위해 건물을 콘크리트와 유리로 구성하였으며, 각 물질의 전기적 특성을 수치적으로 모델링하였다. 본 논문에서는 본 연구팀에서 개발한 분산 FDTD 알고리즘을 이용하여 건물의 전자파 특성 해석을 수행하고, 건물 구조에 따른 차폐 효과를 50 MHz~1 GHz 대역에서 분석하였다.

Phase Transition and Metalization of DRI According to the Quality of Iron Oxide

  • Yun, Young Min;Jung, Jae Hyun;Seo, Sung Kwan;Chu, Yong Sik
    • 한국세라믹학회지
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    • 제52권5호
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    • pp.389-394
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    • 2015
  • Direct reduced iron was made using an electric furnace. The reduction ratio of direct reduced iron varied depending on the grade of iron ore. Coal played an important role as a reducing agent in making the direct reduced iron. The coal must contain a suitable amount of volatile components having high calorie values and low impurity content. In this study, oxidized pellets were directly reduced using anthracite as a reductant in an electric furnace. Direct reduction behaviors of hematite and magnetite pellets were confirmed in a coal-based experiment. Reduction behaviors were demonstrated by analyzing the chemical compositions, measuring the reducibility, and observing the phase changes and microstructure. The superior reducibility of hematite pellets can be ascribed to their high effective diffusivity, which is due to their high porosity. The quickly after reducing for 40min and achieves a high value at the end of the reduction.

규석 분말도에 따른 ALC의 물리적 특성 변화 (Physical Properties of ALC with Various Fineness of Quartzite)

  • 추용식;정의종;송훈;이종규;김영곤;강대구
    • 한국세라믹학회지
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    • 제47권5호
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    • pp.407-411
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    • 2010
  • ALC was fabricated using cement, lime and quartzite by hydrothermal reaction. ALC has low strength and brittleness on account of inner pores. The studies for resolving these problems were driven by many researchers. Among these researches, the controls of quartzite fineness have been studied for unsuitable properties of ALC. This study experimented with variation of 90 ${\mu}m$ residue for obtain good physical properties. It was found that 90 ${\mu}m$ residue influenced on physical properties of ALC. The lower amount of 90 ${\mu}m$ residue, the higher compressive and bending strength. But the continuing decrease of 90 ${\mu}m$ residue did not cause the increase of strength. In order to application of these results in process, the states of process and hydrothermal products will be considered.

제철 산업부산물인 석회석 슬러지의 배연탈황 공정 적용에 관한 연구 (A Study on the Application Limestone Sludge to the Flue Gas Desulfurization Process)

  • 서성관;추용식;심광보;이종규;송훈;윤영민
    • 한국세라믹학회지
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    • 제51권6호
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    • pp.575-583
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    • 2014
  • The flue gas desulfurization (FGD) process is currently the most effective process utilized to remove sulfur dioxide from stack gases of coal-fired plants. However, FGD systems use a lot of limestone as desulfurizing agent. In this study, we use limestone sludge, which is a by-product of the steel industry, to replace the desulfurizing agent of the FGD system. The limestone particle size is found to be unrelated to the desulfurizing rate; the gypsum purity, however, is related. Limestone sludge mixes with limestone slurry delivered at a constant rate in a desulfurizing agent with organic acid are expected to lead to a high desulfurization efficiency and high quality by-product (gypsum).

한약 독성 금기 정보 검색 서비스 (A Searching Service of Toxic and Contraindicating Information of Medicinal Materials in Traditional Korean Medicine)

  • 김상균;장현철;김진현;김철;예상준;송미영
    • 한국한의학연구원논문집
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    • 제17권3호
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    • pp.69-76
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    • 2011
  • Objectives : Our study aims to help users take the medicinal materials in a desirable manner by providing toxic and contraindicating information, based on the ontology of medicinal materials in traditional Korean medicine (TKM). Methods : The toxic and contraindicating data are extracted for 160 medicinal materials from 67 books published in Korea and China. The extracted data are linked to the medicinal material in the ontology, respectively. Results : We in this paper construct an ontology for toxic and contraindicating data of medicinal materials in traditional Korean medicine (TKM), extending our conventional ontology. Based on the ontology, we devised a web-based searching tool that enables users to share the toxic and contraindicating information of medicinal materials. Conclusions : The contents in our ontology are facts based on the books, while the addition of clinical knowledge may elaborate the ontology. Moreover, the addition of easy explanations for terminologies in our ontology is required to help users which are not familiar to TKM.

부신경절종의 세침 흡인 세포학적 소견 - 1례 보고 - (Fine Needle Aspiration Cytology of Carotid Body Paraganglioma - A Case Report -)

  • 김준미;조영채
    • 대한세포병리학회지
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    • 제4권1호
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    • pp.77-80
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    • 1993
  • 부신경종은 주로 두경부에 발생하는 종양으로서 그 조직학적 소견은 잘 알려져 있으나 세포학적 고찰은 드문 편이다. 저자들은 30세 여자 환자의 경동맥체에 발생한 부신경절종 1례의 세침 흡인 세포학적 소견을 보고하고자 한다. 환자는 3년간 지속된 직경 3cm의 좌측 경부 종괴를 호소하였으며 본 종괴에서 세침 흡인 세포학적 검사를 시행하였다. 종양세포는 집단이나 낱개로 흩어져서 관찰되었는데 중등도의 세포질을 가졌으며 세포경계는 불분명하였다. 핵은 둥글거나 난원형으로서 간혹 거대핵의 관찰되었다. 핵질은 미세한 응집을 보였고 때로 핵소체가 존재하였다. 본 종양은 발생위치와 세포학적 소견이 갑상선에서 전이한 여포암종과 유사하였으며 기타두경부에 발생하는 원발성 및 전이성 병변과의 감별이 요구된다.

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Building Intelligent User Interface Agent for Semantically Reformulating User Query in Medicine

  • Lim, Chae-Myung;Chu, Sung-Joon;Lee, Dong-Hoon;Park, Duck-Whan;Park, Tae-Young;Yang, Jung-Jin
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2003년도 Proceeding
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    • pp.57-64
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    • 2003
  • Achieving the beneficiary goal of recent discovery in human genome project still needs a way to retrieve and analyze the exponentially expanding bio-related information. Research on bio-related fields naturally applies knowledge discovered to the current problem and make inferences to extract new information where shared concepts and data containing information need to be defined and used in a coherent way. In such a professional domain, while the need to help users reduce their work and to improve search results has been emerged. methods for systematic retrieval and adequate exchange of relevant information are still in their infancy. The design of our system aims at improving the quality of information retrieval in a professional domain by utilizing both corpus-based and concept-based ontology. Meta-rules of helping users to make an adequate query are formed into an ontology in the domain. The integration of those knowledge permits the system to retrieve relevant information in a more semantic and systematic fashion. This work mainly describes the query models with details of GUI and a secondary query generation of the system.

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$(POB)_{2}Ir(pic)$의 doping 비율에 따른 White OLED의 색순도 향상에 관한 연구 (Significant Improvements in White OLED Color Purity by Doping Ratio of $(POB)_{2}Ir(pic)$)

  • 김동은;김병상;박재철;장정수;권영수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 제38회 하계학술대회
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    • pp.1373-1374
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    • 2007
  • We has been synthesized $(POB)_{2}Ir(pic)$ as a red emitting materials and evaluated in the organic light emitting diodes (OLED). The layer of $Alq_3$ doped with $(POB)_{2}Ir(pic)$ as emitters has been demonstrated. The structure of the device is ITO/ NPB (40 nm) / $Zn(HPB)_2$ (40 nm)/ $Alq_3$ : $(POB)_{2}Ir(pic)$ (30 nm) / LiF / Al. We varied the doped rate of $(POB)_{2}Ir(pic)$. The doped rate is 0.4 %, 0.6%, 0.8 and 1.2%, respectively. When the doped rate of the $Alq_3$:$ Ir(POB)_{2}(pic)$ was 0.6%, white emission is achieved. The Commission Internationale de l'Eclairage (CIE) coordinates of the white emission are (0.316, 0.331) at an applied voltage of 10.75V.

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시뮬레이터를 활용한 문제중심학습 모듈 개발 및 적용 - Simman을 중심으로 - (Development and Application of PBL Module Using Simulator - Focused on Simman -)

  • 주민선;황윤영;박창승
    • 기본간호학회지
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    • 제13권2호
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    • pp.182-189
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    • 2006
  • Purpose: This research was done to identify how PBL education using a simulator affects nursing students' critical thinking, self-efficacy, and meta-cognition by applying and developing a PBL module using the Simman simulator. Method: With a one group pre-post test design, the research was conducted with a convenience sampling on 66 students in C College on Jeju Island for 8 weeks from August to October, 2005. The collected data on critical thinking, self-efficacy, and meta-cognition were analyzed using T-test. SPSS 10.0 was used to assist analysis. For study-related variables, means and standard deviations were used. Results: The finding of the research showed that most of the students were in favor of use of PBL-in the curriculum with more than 50% of the scores indicating satisfaction with content of the teaching, the teaching method, and self-confidence in nursing. The results also showed that there was an increase in interest among the students regarding campus practical education. Conclusion: As the application of the PBL module using the Simman simulator elicited more interest and satisfaction from the students, it is worth using this simulator as a the teaching method to improve the practical education in nursing.

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소형 공동주택의 하이브리드 환기시스템 성능실험 연구 (A Study on the Performance Evaluation of the Hybrid Ventilation System for Small Apartment Houses)

  • 전주영;김길태;이종성;김상희
    • 설비공학논문집
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    • 제20권10호
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    • pp.696-701
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    • 2008
  • From Feb. 2006, the ventilating systems with air exchange rate of over 0.7times/hour are installed at the apartment houses (over 100 units). Installation cost and maintenance cost are very important factors for ventilating system because consumers have to pay the expenses of that system. Especially small apartment needs more considerations because small apartment is comparatively the economically weak part. The purpose of this study is to the performance evaluation of the hybrid ventilation system for small apartment houses. Hybrid system 1 consists of natural ventilation system and duct type exhaust diffusers. Hybrid system 2 has natural ventilation system and toilet exhaust system with static pressure fan. Infiltration of test apartment houses with ventilation system is under 0.1 times/hour. Mean air age of hybrid system 1 is 1.52 hours and hybrid system 2 is 1.42 hours. Mean ventilation effectiveness of hybrid system 2(93%) is higher than that of hybrid system 1(81%).