• 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.

• Corrosion Science and Technology
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• 제6권4호
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• pp.186-192
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• 2007

Carbonation is one of the most important factors causing the corrosion of reinforcement concrete. Nevertheless, experimental studies on the concrete carbonation have not been carried out sufficiently because of the slow process of carbonation process. Therefore, this study adopts an experimental system exploiting a vacuum instrument that has been recently developed to accelerate carbonation instead of existing experimental system to conduct rapid carbonation tests on Portland cement and fly-ash cement concretes. Test results revealed that, compared to water-cement ratio of 40%, the carbonation depth increases from 103% to 138% for an increase of water-cement ratio from 45% to 60%. These results are larger than the carbonation depths obtained by mathematical model, and such difference is increasing with larger water-cement ratios. The results also indicated that larger fly-ash contents lead to sharp increase of the carbonation depth, which is in agreement with previous experimental researches. The adoption of the new accelerated carbonation test system enabled to shorten effectively the time required to produce experimental data compared to the existing carbonation test method. The experimental data obtained in this study together with ongoing acquisition of data using the new carbonation test method are expected to contribute in the understanding of the carbonation process of concrete structures in Korea.

• 한국정보과학회논문지:시스템및이론
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• 제28권10호
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• pp.541-547
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• 2001

코이를 기초로 설계된 칩을 테스팅 하기 위해서는 각 코어로의 테스트 데이터 접근을 위해 완전히 분리 링 필요하다. 부분 분리 링은 코어를 둘러싸고 있는 분리 링의 크기를 줄이고 분리 링으로써의 역할을 모두 수행한다. 본 논문에서는 기존의 방법들보다 부분 분리 링의 크기를 더욱 작게 하고 해법을 찾는 데 걸리는 시간보다 줄일수 있는 효율적인 방법을 제시한다. 이를 위해 테스트 가능도에 기반을 둔 효율적인 순위 결정 기법을 적용하였으며 SOC 테스팅의 특성을 살린 정렬 기법을 적용하였다. 실험결과에서 기존의 방법들보다 본 논문에 제시된 방법이 실제로 유용하다는 것을 보여준다.

• 한국전자통신학회논문지
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• 제10권4호
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• pp.513-519
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• 2015

정적분석방식은 소프트웨어 코드분석방식중의 하나이다. 국제철도신호시스템 소프트웨어 관련규격 IEC 62279에서는 소프트웨어 안전성 레벨에 따라 총 9가지 분석방법을 조합하여 사용할 것을 권고하고 있다. 본 논문에서는 도시철도 차 지상간 열차운행 정보 통신장치 연구개발에서 소프트웨어 품질을 향상하기 위하여 세 가지 정적분석방식에 대하여 연구하고, LDRA 툴을 이용하여 사례 연구를 진행하였다. 따라서 철도신호시스템 소프트웨어개발주기에 필요한 시간을 단축하여 안전성 관련 소프트웨어의 효율적인 개발에 도움을 주고자 한다.

• 대한전자공학회논문지SD
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• 제48권1호
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• pp.39-49
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• 2011

터보 코드는 반복 복호를 하기 때문에 긴 복호시간을 필요로 한다. 고속 통신을 하기 위해서는 복호 시간을 줄여야 하며 이는 병렬 처리를 통해 해결할 수 있다. 하지만 병렬 처리 시 메모리 경합이 발생할 수 있는데 이는 복호기의 성능을 저하시킨다. 이러한 메모리 정합을 피하기 위해 2006년 QPP 인터리버가 제안되었다. 본 논문에서는 QPP 인터리버에 적합하며 비교적 적은 지연 시간을 갖고 회로의 크기도 줄인 MDF 기법을 제안한다. 그리고 MDF 기법을 사용한 MAP 복호 모듈의 설계를 보인다. 구현한 복호기는 Xilinx 사의 FPGA에 타켓팅하였으며 최대 80Mbps의 처리율을 보인다.

• KEPCO Journal on Electric Power and Energy
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• 제3권1호
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• pp.9-16
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• 2017

The performance test is conducted for the purpose of determining the accurate thermal performance of the power generation facility or deriving the factors of thermal efficiency degradation. Compared to the acquisition method of power plant thermal performance test data by compensating cable or transmission cable, performance test using wireless instrument can acquire digital data in order to shorten the period due to installation and demolition of instrument and enhance safety of workers and relatively accurate data can be acquired thereby improving work efficiency. Wireless instruments have already been introduced to the market a long time ago, and some of them are used in industry such as petrochemical industry. However, there is no example which has been conducted for performance test of power generation facilities. In order to apply power generation facilities, a reliable system capable of acquiring performance data smoothly without affecting the control system is required. The wireless measurement system can eliminate the measurement defects and errors such as the damage due to the movement of the connecting cable, the extension due to the extension of the shield wire, the contact failure at the contact point between the measuring sensor and the connecting wire, This method has the advantage of collecting relatively accurate performance test data.

• 전기학회논문지P
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• 제64권4호
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• pp.297-302
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• 2015

Replacing a manual switch installed in a feeder for a distribution system with an automatic one increases the reliability of the electric power system. This is because the automatic switch can shorten the duration of a fault the customer experiences by splitting the faulty section faster than the manual one does. However, improving the reliability of the distribution system may increase investment costs. Here, the investment costs include automatic switch cost, replacement work cost and labor cost. For this reason, importance should be attached to the proper balance between the increase of the investment costs and the improvement of the reliability of the distribution system. This article analyzed reliability index and economics when manual switches installed in a feeder (RBTS Bus2 model) was replaced by automatic ones. In addition, it attempted to draw the optimum rate of automation of manual switches by automatic ones using the GRG optimization method, considering the current economic requirements.

• 전기학회논문지
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• 제67권10호
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• pp.1358-1363
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• 2018

As the usage of the Internet grows and digital media become more diversified, it has become much easier for digital contents to be distributed and shared. This makes easier to access the desired digital contents. On the other hand, there is an increasing need to protect the copyright of digital works. There are some prevalent ways to protect ownership, but they accompany several disadvantages. Among those ways, watermarking methods have the advantage of ensuring invisibility, but they also have a disadvantage that they are vulnerable to external attacks such as a noise and signal processing. In this paper, we propose the detecting method of illegal contents that is robust against external attacks to protect digital works. We extract HSV and LBP features from images and use Euclidian-based hashing techniques to shorten the searching time on high-dimensional and near-duplicate videos. According to the results, the proposed method showed higher detection rates than that of the Watermarking techniques in terms of the images with fabrications or deformations.

• 한국정밀공학회지
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• 제20권5호
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• pp.225-231
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• 2003

The injection molding is a traditional manufacturing method that can make plastic parts by just one time in mold. Therefore, the injection molding has become one of a manufacturing method, which is widely applied in a producing of plastic products. Nowadays, to use of plastic parts has increased and plastic product-model using term has been shorten. By these reasons, using term of a injection mold has fast been reduced. These produced molds will be disused and leaved in a storage after a regular term to use it. These leaved molds are sometime sold as scrap iron. But, these molds have lots parts for recycling except special parts for example, cavities, cores and eject pins, etc. In this research, we investigated when the cavity and core of in injection mold would be changed, the injection mold could be recycled. We suggested the structures and standardizations for recycling of a moldbase. We also developed a program in which can be used when the recycling moldbase design in the Auto-CAD with the recycling standards. We called this program as the Recy-Mold. For the availability of the program and moldbase structure fur the recycling standards, we experimented a used mold for automobile lens, which was remanufactured by the recycling standard. The results of this test showed feasibility for the recycling mold.

• 한국자동차공학회논문집
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• 제7권6호
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• pp.182-197
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• 1999

Described in this paper is an optimal driving control algorithm which focused on the improvement of fuel economy and the minimization of pollutant emissions in the parallel type hybrid drivertrain system for transit bus. For the energy balance among components such as engine, induction machine and buttery, the algorithm for power split ration determine is proposed. When it is implemented in the hybrid electric control unit(HECU) , using the sub-optimal method and the approximate technique , it is possible to save the memory , to shorten the calculation time, and to achieve the efficient driving actually. A Shift strategy for automated manual transmission is the other side of the driving control algorithm. It enables to select the optimal gear by using several shift maps which were predefined from the proposed method in this paper, As a results of driving simulation, it is proved that these algorithms make the hybrid drivetrain system to reduce fuel consumption and emissions considerably and to have the ability to the efficient use of battery.