• 터널과지하공간
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• 제16권5호
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• pp.387-393
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• 2006

본 연구는 발파 시 발생하는 진동을 저감시키고 발파효율을 증진시키기 위하여 NDC(New Deck Charge) 공법 및 Wide space 공법을 혼합하여 발파를 실시한 사례연구이다. NDC 공법은 종이분리봉을 이용하여 분산장 약을 실시하는 공법으로 발파 시 진동은 저감시키나 공저부에서 발파효과가 저감되는 경향을 보인다. Wide Space 공법은 기존의 일반적인 발파공법에 비해 파쇄입도를 조절하고 발파효율을 높이는데 유리한 공법이다. 본 사례 연구에서는 두 가지 공법을 혼합하여 현장 적용성을 검토한 결과, 진동속도가 감소되고 발파효율이 증가하는 결과를 확인하였으며, 향후 다양한 조건에서 발파를 실시하여 자료를 축적한다면 민원저감 및 공기단축에 기여할 수 있는 유용한 발파패턴을 정립할 수 있을 것으로 사료된다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.751-754
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• 2001

A possibility of using waste plastics as a source of secondary fuel in blast furnace has been of recent interest. The success of this process, however, will be critically dependent upon the optimization of operating systems. for instance, the supply of waste plastics must be reliable as well as economically attractive compared with conventional secondary fuels such as heavy oil, natural gas and pulverized coal. In this work, we put special importance on the improvement of the combustibility of waste plastics as a way to enhance energy efficiency in blast furnace. As experimental variables to approach this target, the effects of plastic particle size, blast temperature, and the level of oxygen enrichment were investigated using a custom-made blast model designed to simulate a real furnace. Lastly, the combustion efficiency of the mixture of waste plastics and pulverized coal was tested. The observations made from these experiments led us to the conclusion that with the increase of both blast temperature and the level of oxygen enrichment, and with the decrease of particle size, the combustibility of waste PE could be improved at a given distance from tuyere. Also it was found that the efficiency of coal combustion decreased with the addition of plastics; however, the combustion efficiency of mixture could be comparable at longer distance from tuyere.

• 한국컴퓨터정보학회논문지
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• 제14권2호
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• pp.139-147
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• 2009

BLAST는 생명정보학 분야에서 가장 많이 사용하는 도구이다. 이 도구는 입력서열을 기존 서열 데이터베이스와 신속히 비교하고 그 기능을 예측한다. 생물학자는 BLAST를 이용하여 실험의 범위, 시간과 비용을 줄일 수 있다. 하지만, 서열 데이터 양이 급격히 증가함에 따라 그 처리 시간도 같이 증가하여 성능개선 방안이 필요하다. 본 논문에서는 대용량 BLAST처리 성능 향상을 위한 PC 기반의 클러스터 인프라 (E-Cluster)를 제시하고 이 기반에서 데이터베이스 분할기법 (Logical Partitioning)과 질의 라우팅 기법(Intra-Query)을 제안한다. 제안된 시스템을 평가하기 위해 다양한 길이의 서열들과 NR 데이터베이스와 비교하여 응답시간(Response Time), 성능 향상(Speedup), 효율(Efficiency) 관점에서 평가한다. 본 실험을 통해 기존 SMP, Cluster, 그리드 기반의 BLAST 시스템보다 성능, 효율이 뛰어남을 확인하였고, 특히 제안한 시스템의 최대 효율은 600%로 매우 높았다.

• 한국콘텐츠학회논문지
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• 제10권7호
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• pp.81-87
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• 2010

본 논문에서는 현재 생물정보학 연구에서 가장 많이 사용하고 있는 BLAST의 문제점을 분석하고 이에 따른 해결책을 제시하기 위하여 그리드 컴퓨팅을 이용한 G-BLAST(Grid Computing을 이용한 Basic Local Alignment Search Tool)를 제안한다. 본 연구에서 제안하고 있는 G-BLAST을 이용한 시스템은 이기종 분산 환경에서 수행이 가능한 서열분석 통합 소프트웨어 패키지이며 기존 서열분석 서비스의 취약점인 검색 성능을 개선하여 BLAST 검색 기능을 강화 하였다. 또한, BLAST 결과를 사용자가 관리 및 분석이 용이하도록 데이터베이스 및 유전체 서열분석 서비스 시스템을 구현하였다. 본 논문에서는 G-BLAST시스템의 성능확인을 위하여 병렬컴퓨팅 성능테스트 기법을 도입하여 구현된 시스템을 기존 BLAST와 속도 및 효율부분에서 비교하여 성능개선을 확인하였으며 서열결과 분석에 필요한 자료를 사용자관점에서 제공해주고 있다.

• Journal of information and communication convergence engineering
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• 제8권4호
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• pp.387-392
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• 2010

This study focuses on improving MIMO-OFDM systems by combining a wireless communication architecture known as vertical BLAST(bell laboratories layered space-time) or V-BLAST and STTC(space time trellis coding). In this paper, the combination is done by introducing STTC in each V-BLAST layer. Moreover, this architecture uses multiple antennas that are grouped into small number of antennas which makes it less complex to decode by decoding every group. Whereas, in traditional V-BLAST, all the antennas form one group and they are decoded together at the receiver, therefore, this increases the complexity as the number of antennas is getting high. We compare the bit error rate performance of this system with MIMO-OFDM that uses convolutional coding instead of STTC. Under the same spectral efficiency, the simulation results prove that joining V-BLAST with STTC improves MIMO-OFDM systems performance.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.755-758
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• 2001

Most of the waste plastics are incinerated and landfilled now, leading to much environmental problems. The technology of injection into the blast furnace was developed as a useful recycling method of waste plastics, and applied to the actual operation in several ironmaking companies. We carried out the test operation to inject continuously the two kinds of waste plastics through four tuyeres of the Foundry blast furnace in POSCO by 130 ton of total amount. From this test operation, we analyzed the coke replacement ratio, the permeability, the heat load and other changes of furnace conditions with the injection of waste plastics into the blast furnace. Some trials based upon the theoretical approaches were applied to examine the efficiencies of blast furnace.

• 한국응용곤충학회지
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• 제22권2호
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• pp.74-83
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• 1983

Yield losses due to diseases and insect pests were mentioned and emphasized the efficiency of resistant cultivars in curving the yield losses and increasing chemical efficiency. Present status of resistance breeding for blast, bacterial leaf blight viruses, brown planthopper and white backed planthopper were introduced and the resistance sources for those are discussed. Breeding strategies for above items were presented. Specially for the blast resistance, discussions were made in some detail. With brief future prospects of resistance breeding in Korea, a suggestion was made for pathologists to make clear about whether the blast spores will be brought from mainland China as we see with Bph and Wbph or not.

• 드라이브 ㆍ 컨트롤
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• 제19권1호
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• pp.8-15
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• 2022

The demand for the re-painting of steel bridges is increasing, but surface treatment is still centered on human resources for on-site re-painting processes. Worker safety accidents continue to occur because the work is performed in a narrow space. Recently, PS balls with excellent surface treatment have been used for blasting, but the working environment is poor due to the large amount of dust generated. In this study, an effective surface treatment method using impeller blasting equipment was developed. The correlation between steel ball size, impeller rotation speed, and exposure time was studied to optimize the efficiency of the surface treatment.

• 대한산업공학회지
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• 제23권4호
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• pp.687-698
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• 1997

In this paper, a Variation of Blast with Go-Back-N(V-BGBN) protocol is proposed, which differs from Blast with Go-Back-N(BGBN) and Blast with Full Retransmission on Error(BFRE) protocols in the retransmission strategy of packets. Performances of these three protocols under correlated packet errors are analyzed. Throughput efficiency of an arbitrary packet is obtained under the assumption that the round trip delay and the packet length are respectively constant. Recursive formula and difference equations are used as analytical tools. Correlation of packet errors is modelled by a two state Markov chain. The throughput efficiencies under these protocols are compared. V-BGBN protocol is shown to be superior to other two protocols in high speed network.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문 발표회
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• pp.5-8
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• 2003

As a part of efforts to obtain high quality and economical efficiency of concrete, blast-furnace slag has been utilized by means of cement replacement. Therefore superior performance can be ensured, environmental pollution can be prevented and economical advantage can be obtained with utilization by cement replacement. But the studies on the blast-furnace slag are not systematic and reasonable. So, it was planed that basic data in regard to technique of manufacturing and economic improvement of concrete is showed with experimental comparison and investigation of engineering properties of concrete utilizing blast-furnace, industry by-product, as cement replacement in this study.