공정 폐스크랩 방열패드의 펄핑을 통한 재생 실리콘 제진패드특성에 관한 연구

이석문,구현숙,김성훈 한국폐기물자원순환학회(구 한국폐기물학회) 2014 한국폐기물자원순환학회 춘계학술발표논문집 Vol.2014 No.-

IT 제품의 슬림화 및 고해상도화에 따른 기판의 발열 문제의 해결수단으로 방열패드가 널리 사용되고 있으나, 제조공정에서 발생되는 폐방열패드는 대부분 소각을 통해 폐기 처리됨에 따라 정부시책에 반하여 문제가 발생하며 소각시 발생되는 Gas 유해성분 등도 문제시 되고 있으며, 폐실리콘 방열패드를 이용한 제품의 생산, 폐기 단계에 따른 환경부하를 근본적으로 해결하고 비용을 최소화하기 위한 재활용 기술이 요구되고 있다. 본 연구는 고부가가치의 재생 실리콘 제진패드 생산을 위해 마이크로칩 재활용 시스템을 통해 종래 고무제진패드보다 제진특성이 우수한 친환경 실리콘 제진패드 생산 공정을 제안하고 펄핑 기술에 필요한 공정기술을 확립하여 수요처에서 요구하는 재생 제진특성을 실현하기 위해, 폐방열패드의 입자크기를 1.5mm~5mm로 미세 분쇄한 후 실리콘 바인더와 고무경도 향상제인 Silicone H-oil 및 제진성능 향상제 실리카 분말을 혼합 교반하여 슬러리를 만든 후, 열성형 프레스를 이용하여 온도: 90~100℃, 가압시간: 2~5분, 압력: 50~70Kg/㎤ 조건의 건조성형 공정을 거쳐 최종 크기로 절단하는 제조공정을 통해 제진특성이 우수한 친환경 재생실리콘 제진패드를 구현하였다. 이와 같은 재생공정을 통해 경도 Shore A 50, 압축영구줄음율 38%, 열전도도 1.0, 내전압 5kV를 가진 난연성 UL94V-0급의 실리콘 제진패드 시제품 제작을 통해 PDP, LED TV의 기판보호용 제진패드에 적합한 특성을 얻었다.

Air Substrate를 이용한 이중 대역 마이크로스트립 안테나

이석문,김희중,하천수,Lee, Seok-Moon,Kim, Hee-Joong,Ha, Cheun-Soo 한국전자파학회 2007 한국전자파학회논문지 Vol.18 No.9

본 논문에서는 air substrate를 이용하여 웨지 모양의 방사 패치에 슬롯을 부가하여 이중 대역 특성을 갖는 안테나에 관하여 연구하였다. 웨지 모양으로 경사진 형태의 air substrate 안테나는 대역폭을 증가시킬 수 있으며, 급전 프로브의 길이가 짧아지므로 긴 프로브 급전에서 발생되는 리액턴스 성분을 줄일 수 있다. 또한, 방사 패치에 위치한 슬롯은 사용 주파수에 따라 리액턴스 성분이 변하게 되므로 안테나의 공진 주파수가 변하게 되며, 이로서 이중 대역(셀룰러 대역과 PCS 대역) 특성을 얻을 수 있다. 안테나의 대역폭, 입력 임피던스 등에 영향을 미치는 슬롯의 길이와 위치는 시뮬레이션을 통해 최적치를 얻었으며, 안테나를 제작하여 실험한 결과 -10 dB 대역폭은 셀룰러 대역과 PCS 대역 등 두 대역을 만족하였고, -15 dB 수준의 교차 편파 특성을 보였다. 이러한 결과들로써 본 연구에서 제안된 안테나는 셀룰러 대역과 PCS 대역의 기지국 안테나로서 이용될 수 있음을 확인하였다. In this paper, we study the characteristics of dual band microstrip antenna with the wedge-shaped radiation patch added the slot using air substrate. Wedge-shaped patch antenna with air substrate is avoided the large probe reactance associated with a thick substrate owing to the use of short probe and good impedance matching over a wide frequency range can be obtained. Slot on the antenna radiator varies the reactance component according to the employed frequency and affect the resonance freaqency of the antenna, therefore the antenna can resonate at the dual band(cellular and PCS band). The slot length and position have an effect on the bandwidth and input impedance of the antenna are optimized by simulation. From the experiment results for the fabricated antenna, -10 dB of $S_{11}$ is content with the allocated bandwidth of Cellular and PCS system and - 15 dB of cross polarization level. From the results of this paper, it has been confirmed that the proposed antenna can be used as the base station antenna fur Cellular and PCS band.

고층아파트의 주거동 배치유형에 따른 개방적 특성 분석 연구 - 점형, 평행형, 중정형 배치형식을 중심으로

이석문,함정도,김원필 대한건축학회 2005 대한건축학회논문집 Vol.21 No.9

High-rise apartment housing type has genetically been conduced to various problems such as excessive high density, closed open view, monotonous building shape, and worse daylighting condition in specific building blocks. Recent public interests in well-being of residential life are now toward open view quality and other environmental housing elements. The aims of this research is intended to analyze the characteristics of open view according to the allocation technique and building block types of apartment buildings which eventually increases the quality of surrounding environments. It extensively examined the openness through computer simulation in order to seek appropriate planning methods for the better openness without dropping the level of density when creating the site plan. The research results found that court type of building blocks indicated low-level openness caused by the blocking of adjacent units, while parallel type showed no differences. Consequently, tower type sited by pointed direction founded to give high-level openness. Generally the study implied that the index of facade-area ratio has certain level of limitation in measuring openness in specific areas, suggesting that mixed allocation of various building type be practical plan alternative for the better openness.

Thermal Characteristics of Rotating Anode X-ray Tube with Emissivity in Aging Process for Digital Radiography

이석문 한국진공학회 2015 Applied Science and Convergence Technology Vol.24 No.5

We investigated the thermal characteristics of rotating anode X-ray tube to develop it for digital radiography by using computer simulation. The target which is the area of the anode struck by electrons is the most important component to get a long life of X-ray tube. So we analyze the thermal characteristics of the target and rotor assembly according to their emissivity by using ANSYS transient thermal simulation and then compare with the measured data of the target temperature operating in aging process of X-ray tube. Especially, keeping the lead coated layer as the role of metal lubricant on ball bearing enables to prevent the noise in rotating anode. The simulation result showed that its temperature was under the melting point of the lead in X-ray tube for digital radiography with 1.2 mm large focal spot 0.6 mm small focal spot and 150 kV tube voltage. We also investigated the relationship between the diameter of the anode shaft and the temperature of the anode and rotor assembly. It has been confirmed that the smaller anode shaft could be good for the rotor thermal characteristics.

육혈 험방

이석문,Lee, Seok-Mun 대한한약협회 1998 大韓漢藥 Vol.2 No.-

공동주택 주거동 형태에 따른 개방성 비교분석 연구 - 입면건폐율과 컴퓨터시뮬레이션을 중심으로 -

이석문,김원필,함정도 대한건축학회 2005 대한건축학회논문집 Vol.21 No.11

Apartment, the most common housing type in Korea nowadays is causing various problems such as excessive concentration of population, traffic jam, monotonous view, and 'heat-island' phenomenon in specific areas. This study is focussing on the allocation technique of apartment buildings which eventually increases the quality of surrounding environments. It deals with the issues regarding problems caused by highly dense population including the openness within housing complexes. The study explores characteristics of openness by building blocks and allocation types of buildings that forms the residential complex in order to seek appropriate methods for the improvement of openness without changing the level of density when creating the site plan. For this purpose, selected housing complexes were classified as 116 types of building blocks and simplified model which does not consider open space created from super-structure details, pillars of lower grounds and balcony types were simulated to examine facade-area ratio. The extensive research found that appropriate mix of building blocks in site planning, on the condition of the same density and design, could improve openness without modifying distances among blocks and building stories. Furthermore, the study proposed that considerate mix of building blocks from the stand point of openness is the viable plan alternatives without adjusting density level.

FeSiCr에 Fe50Ni가 첨가된 폴리머 복합 시트의 전자파 흡수 특성

이석문,김상문,Lee, Seok-Moon,Kim, Sang-Mun 한국전기전자재료학회 2014 전기전자재료학회논문지 Vol.27 No.7

In this paper, we studied the magnetic composite sheets for electromagnetic wave noise absorber of quasi-microwave band by using soft magnetic FeSiCr and Fe50Ni flakes with the thickness of about $1{\mu}m$ and polymer. The magnetic hysteresis curve including saturation magnetization and residual magnetization and the complex permeability characteristics of the composite sheets were investigated to clarify the mixing effect on electromagnetic wave absorption properties. The saturation magnetization was decreased about 10% while the residual magnetization was increased about 15% and the real parts of complex permeability at below 500 MHz were increased 0.6~4 while those values at above 500 MHz were decreased 0.4~2.5 according to the change of contents of FeSiCr and Fe50Ni powders. As a result, the reflection loss can be moved to the lower frequency from 2~3 GHz to 1~1.5 GHz as the contents of Fe50Ni flaky powder into FeSiCr flaky powder was increased up to 50%.

금석문 탁본전에 붙혀

전라금 석문연구회 전라금석문연구회 2005 탁본전시회 도록 Vol.2005 No.1

동학농민혁명 기념제를 중심으로

이석문 열린전북 2002 열린전북 Vol.2002 No.4

산업체 참여형 캡스톤디자인 & 현장실습 연계 모형 연구: 경북 Y대학 전자공학과 사례를 중심으로

이석문,서영석,Lee, Seok-moon,Suh, Young-suk 한국실천공학교육학회 2022 실천공학교육논문지 Vol.14 No.1

Universities should provide experiential learning in subject and non-course subjects so that students can graduate with job competency related to their major and the experiential learning includes capstone design implemented on campus and field training conducted by companies. In particular, the decrease in industry participation in short-term (4 weeks) and mid-term field training (8 weeks) due to the implementation of standard field training introduced from the second half of 2021 is making it more difficult for students to gain practical experience. To solve this problem, in this paper, we propose an industry-participatory capstone design & field practice linkage model that combines capstone design and professional practice to solve the technical difficulties of companies. Participating students find solutions to corporate difficulties in the capstone design process and produce prototypes for solutions during the field practice period, focusing on the case of the department of electronic engineering at Gyeongbuk Y University. We believe that it is one of the good models of industry-university cooperation education in which universities and industries win-win.