• 한국산업정보학회논문지
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• 제26권4호
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• pp.33-46
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• 2021

대한민국 지진관측 사상 최대인 규모 5.8 지진이 2016년 경주에서 발생하였고, 두 번째로 큰 규모 5.4의 지진이 포항에서 연이어 발생하였다. 정부나 지자체는 그간 경험하지 못했던 지진이 발생하자 긴급 재난 문자 발송, 대응 정보 전달 등의 지진 대응 업무에 대한 문제들이 노출됐고, 현장에 있는 국민은 적절한 정보를 전달받지 못해 대응 과정에서 혼란이 가중되었다. 이 같은 상황을 해결하기 위해서는 지진 발생 직후 국민에게 필요한 정보를 신속히 전달하는 지진 대응 서비스가 필요하다. 국립재난안전연구원에서는 지진 발생 직후 지진 상황 및 장소에 따라 맞춤형 정보를 신속히 전달하는 모델인 지진동 경보기 기반 지진 안심서비스 기술을 개발하고 있다. 본 논문에서는 지진 발생 직후, 현장에 있는 국민에게 필요한 정보를 전달함으로써 원활하게 대응하도록 도와주는 지진동 경보기와 이를 활용한 지진 안심서비스 기술을 소개한다. 또한, 이 기술에 대한 사용자 수요와 의견을 조사·분석하여, 기술보급과 실용성을 높이기 위한 향후 R&D 방향과 정책적 방안을 제시한다.

• 한국인터넷방송통신학회논문지
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• 제19권6호
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• pp.175-181
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• 2019

소형 레이더 센서에 적용할 목적으로 W-대역의 핵심부품인 MMIC 칩을 송신기 특성에 맞게 국내설계하고 0.1㎛ GaAs pHEMT 공정으로 제작하여 이를 해외 구매한 MMIC 칩과 성능 비교하였으며, 국내개발 MMIC 중에서 저잡음 증폭기의 잡음지수, 스위치의 삽입손실 그리고 하향변환 혼합기 MMIC 칩의 이미지제어 성능은 상용칩 보다 우수한 특성을 보임을 확인할 수 있었다. 국내개발 MMIC 칩을 W-대역의 도파관 저손실 전이구조 설계 및 임피던스 정합을 통해 송신부 및 수신부에 적용하여 제작 후 성능 검증하였으며, 제작한 송신부 출력은 26.9 dBm로 측정되어 분석 결과보다 우수한 결과를 보였고 수신부의 잡음지수는 9.17 dB로 분석 결과와 근사한 측정 결과를 보였다. 결과적으로 형 레이더 센서의 송수신기에 국내 개발 MMIC 칩을 적용하는 경우, 해외 구매 MMIC 칩 적용 시보다 성능이 향상될 것으로 기대된다.

• 한국인터넷방송통신학회논문지
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• 제21권3호
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• pp.29-34
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• 2021

소형 레이더 센서에 적용할 목적으로 W-대역의 핵심부품인 전력증폭 MMIC 칩 및 스위치 및 저잡음 증폭 MMIC 통합 칩을 국내설계하고 각각 OMMIC사의 60nm GaN 공정과 Winsemi.사의 0.1㎛ GaAs pHEMT 공정으로 제작하고 이를 모듈화하였다. 국내개발 MMIC 중에서 W-대역 전력증폭 MMIC는 송신모듈로 제작후 출력 값 27.7 dBm로 측정되었고, 스위치와 저잡음증폭 통합 MMIC는 수신모듈로 제작후 잡음지수는 9.17 dB로 분석 결과와 근사한 측정 결과를 보였다. 또한 온도 시험을 통해서 그 결과를 분석하였는데 송신모듈은 고온에서 상온과 출력에서 1.6 dB 편차를 보였고 수신모듈은 고온과 저온 모두 포함하여 2.7 dB의 편차를 보였으나 상온과 비교하여서는 1.4 dB 상승하였다. 온도시험까지를 포함하는 결과를 확인한 바와 같이 소형 레이더 센서의 송수신기에 W-대역 국내 개발 MMIC 칩을 적용 가능할 것으로 판단된다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제35권5호
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• pp.310-315
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• 2013

Micromorphometric and histological examinations were conducted with a collected tissue specimen nine months after sinus bone graft using autogenous tooth bone graft material (AutoBT). As a result of micro-computed tomographic analysis, the total bone volume (graft material+new bone) was 76.45%, and the proportion of new bone was 45.4%. The bone mineral density and the average Hounsfield Unit of new bone were 0.26 and 1,164.69, respectively. The histological examination showed that AutoBT particles were united well with new bone. AutoBT was considered to have excellent bone healing ability after sinus graft and bone density that can resist repneumatization.

• 한국응용과학기술학회지
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• 제14권1호
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• pp.15-26
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• 1997

There were a dramatic change in technical aspect in Korean detergent industry for past 5${\sim}$6 years. we, detergent industries, have been trying to find out a new way of production and better goods on environment as well as men to decrease domestic wastes and water pollution. In addition, increasing expense for transportation, storage and displaying give us another difficulties. Compact detergents are best method to solve this problems. Detergent ingredients, formulations and process were concentrated to the development of compact detergents. Now, I'll introduce about the recent trends in technical aspect and near future's prospects in Korean detergent industry.

• Journal of Dairy Science and Biotechnology
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• 제40권3호
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• pp.134-142
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• 2022

Protein-enriched dairy powder is widely consumed to promote muscle synthesis. Recently, in Korea, elderly people have also begun consuming protein powder products to prevent muscle loss. However, these protein-enriched powders have poor flowability and hydration properties because of the fine particles of spray-dried milk protein powder. Therefore, in this study, the fluidized bed agglomeration process was used to solve these problems. The rheological and physical properties of milk protein isolate (MPI)/skim milk powder (SMP) mixtures were effectively improved via fluidized bed agglomeration. The particle size of the MPI/SMP mixtures significantly increased from 35.7-58 ㎛ to 118-136 ㎛, the flowability level improved from fair (21.4-26.3) to good (15.7-16.3), and the cohesiveness level changed from intermediate (1.27-1.36) to low (1.18-1.19) after fluidized bed agglomeration. In addition, the wetting time of the agglomerated MPI/SMP mixtures was effectively reduced to 4.67-58.3 s by fluidized bed agglomeration. These findings may be useful for manufacturing protein-enriched dairy powders with good instant properties.

• KIEE International Transactions on Power Engineering
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• 제11A권4호
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• pp.21-26
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• 2001

As competition is introduced in the electricity supply industry, congestion becomes a more important issue. Congestion in a transmission network occurs due to an operating condition that causes limit violations on the transmission capacities. Congestion leads to inefficient use of the system, or causes additional costs (Congestion cost). One way to reduce this inefficiency or congestion cost is to control the transmission flow through the installation of UPFC (Unified Power Flow Controller). This paper also deals with an optimal siting of the UPFC for reducing congestion cost by using shadow prices. A performance index for an optimal siting is defined as a combination of line flow sensitivities and shadow prices. The proposed algorithm is applied to the sample system with a condition, which is concerning the quadratic cost functions. Test results show that the siting of the UPFC is optimal to minimize the congestion cost by the proposed algorithm.

• Tribology and Lubricants
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• 제26권6호
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• pp.317-321
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• 2010

황화주석 박막을 만들기 위해 마그네트론 스퍼터 박막증착 공정을 통해 몰리브텐 유리판위에 주석박막을 만들고, 95% 알곤 +5% 황화수소 가스 혼합물을 사용하여 아닐링 공정을 통해 황화주석 박막을 형성하위에 증착하는것이 좋은 결과를 보여주고있다. 박막면의 화학적 물리적 특성을 전자현미경, X선 분석, X 선회절을 통해 실험하였으며, 아닐링 조건에 따른황화주석 박막의 파장대 반사율의 관계를 측정하였다.

• 열처리공학회지
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• 제26권3호
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• pp.113-119
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• 2013

Grain growth behaviors of hot-rolled AZ31 (Mg-3%Al-1%Zn) and AZ31-0.3%CaO alloys at elevated temperatures have been investigated in order to clarify the effect of CaO addition on grain stability of Mg-Al-based wrought alloy. The grain size of CaO-free alloy increased steeply from 673 K with an increase in annealing temperature from 573 to 773 K, whereas the grains of CaO-containing alloy were relatively stable up to 723 K. The activation energies for grain growth ($E_g$) were 12.2 and 18.3 kJ/mole between 573 and 673 K and 119.2 and 126.9 kJ/mole between 673 and 773 K in the AZ31 and AZ31-0.3%CaO alloys, respectively. This result indicates that grains in the CaO-added alloy possess higher thermal stability than CaO-free alloy. SEM observations on the annealed alloy samples revealed that higher grain stability resulting from CaO addition would be associated with the suppression of grain growth by Ca-related precipitate particles distributed in the microstructure.

• 공학교육연구
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• 제19권2호
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• pp.26-33
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• 2016

A camp program where the theory of inventive problem solving TRIZ is applied to real problems of the industry was developed and taught at a five-day seminar apart from the standard curriculum at a university D in Gyeonggido. This study focuses on the educational effect that the TRIZ method has on the engineering students when their creative problem solving skills are required to solve industry problems on their own with the knowledge from their courses. For five days, the students were educated about TRIZ and assigned a real industry problem "Removal of friction caused by bubble formation in water heating pipelines". By applying TRIZ to the problem, the students developed an "Air removing Air Arrester" which received the evaluation, "with understanding the system architecture and the task objective causes and formation of the problem could be handled which directly helps the company's R&D". In this case, TRIZ offers the students a guideline and knowledge on how to approach problems and as a result the students provided a practical solution. During the process, the TRIZ method instilled confidence in the students and proved to be a motivation. It becomes obvious that this short-term program has a positive effect on students' way of thinking creatively and increasing their problem-solving abilities.