• Resources Recycling
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• v.30 no.6
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• pp.12-18
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• 2021

The water-gas shift reaction is the subsequent step using steam for hydrogen enrichment and H₂/CO ratio-controlled syngas from gasification. In this study, a water-gas shift reaction was performed using syngas from an RPF gasification system. The water-gas shift using a catalyst was performed in a laboratory-scale tube reactor with a high temperature shift (HTS) and a low temperature shift (LTS). The effects of the reaction temperature, steam/carbon ratio, and flow rate on H₂ production and CO conversion were investigated. The operating temperature was 250-400℃ for the HTS system and 190-220℃ for the LTS system. Steam/carbon ratios were between 1.5 and 3.5, and the composition of reactant was CO : 40 vol%, H₂ : 25 vol%, and CO₂ : 25 vol%. The CO conversion and H₂ production increased as the reaction temperature and steam/carbon ratio increased. The CO conversion and H₂ production decreased as the flow rate increased due to reduced retention time in the catalyst bed.

• The Journal of the Acoustical Society of Korea
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• v.40 no.5
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• pp.466-472
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• 2021

Speaker Change Detection (SCD) refers to finding the moment when the main speaker changes from one person to the next in a speech conversation. In speaker change detection, difficulties arise due to overlapping speakers, inaccuracy in the information labeling, and data imbalance. To solve these problems, TIMIT corpus widely used in speech recognition have been concatenated artificially to obtain a sufficient amount of training data, and the detection of changing speaker has performed after identifying overlapping speakers. In this paper, we propose an speaker change detection system that considers the speaker overlapping. We evaluated and verified the performance using various approaches. As a result, a detection system similar to the X-Vector structure was proposed to remove the speaker overlapping region, while the Bi-LSTM method was selected to model the speaker change system. The experimental results show a relative performance improvement of 4.6 % and 13.8 % respectively, compared to the baseline system. Additionally, we determined that a robust speaker change detection system can be built by conducting related studies based on the experimental results, taking into consideration text and speaker information.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.425-426
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• 2008

발전소의 제어 시스템은 제어 기간이 길어짐에 따라 제어 기기의 운전 특성이 변화하므로 최초 설계 및 운전때의 성능과는 다른 제어 특성을 나타낸다. 따라서 주기적으로 제어 성능을 평가하고 평가 결과에 따라서 제어 기기의 성능 개선 작업과 제어 시스템의 제어기 상수 최적화 등의 작업을 통하여 제어 성능을 최적으로 유지하여 제어 목적을 달성하도록 하여야한다. 제어성능 평가기법은 제어 목표 값에 대한 추종성을 평가하는 Set Print Analysis 방법을 주로 사용한다. 평가 지표는 Integral Absolute Error(IAE)와 같은 Error Integral 값과 Minimum Variance방법이 실용적으로 사용된다. 본 논문에서는 Non-Minimum Phase 특성으로 인하여 초기 운전 모드에서 정상 운전 모듈로의 원활한 전환이 어려운 수위 제어 시스템에서 제어 전환을 위한 최적 제어기 상수를 구하기 위하여 CPA 방법을 적용하였다. 일반적으로 제어성 평가는 설정치 변화에 대한 추종성을 평가하지만 본 논문에서는 제어 전환 시의 제어성 평가를 통하여 최적의 제어 전환 상수를 구하고자 하였다. 적용 결과, CPA기법은 설정시 추종성뿐만 아니라 제어 과도에서의 제어 전환 변수의 주종성에 적용하여 제어 전환을 최적화하는데도 유용함을 확인하였다.

• Journal of Science and Technology Studies
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• v.16 no.1
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• pp.63-89
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• 2016

The purpose of this article is to re-interpretate 'Post Catch-up Studies' on the Korean innovation system with the framework of 'Transition Studies'. The viewpoints of the vision, research area and system innovation process of Post Catch-up studies are reviewed and reconfigurated. The Transition Studies concepts of Sustainability, Coevolution of industry and society, and transition management are introduced into the Post-catch up Studies and discussed. It is suggested that Post catch-up studies should support sustainability system transition and make use of transition management tools for the sustainable post catch-up innovation and policy.

• Journal of Technology Innovation
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• v.22 no.3
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• pp.193-223
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• 2014

Socio-technical systems are receiving growing attention as a core concept in the process of searching for proper solutions to sustainable growth. In this paper, we review the way for governing socio-technical transitions from a governmental perspective. Based upon the governance studies and transition research, we set social coordination and locus of transition pressures as transition contexts to differentiate transition policy governance. We propose four types of policy governance for sustainable socio-technical transitions: leading, facilitative, coordinative and persuasive. Analysis on four case based upon this typology shows different transition polices of each transition pathway in analytical aspect. It provides basic criteria for policy makers to design effective transition policies in normative aspect. Also, this paper can contribute to closing the gap between transition research and governance studies.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.4
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• pp.167-189
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• 2022

In the case of SAE autonomous driving levels 2 and 3, since complete autonomous driving is impossible, the take-over process is essential, and take-over time(TOT) is the most important factor in determining the safety of the autonomous driving system. Accordingly, research on TOT is being actively conducted, but each research is independently conducted and general conclusions that integrate various research results are required. Therefore, in this study, the factors affecting TOT were analyzed using meta-analysis, which integrates the results of individual studies and presents an integrated opinion. As a result of meta-analysis, a total of 10 influencing factors were selected, and most of them were related to the non-driving related task(NDRT) type. In addition, implications for the future research direction of take-over and NDRT were presented.

• Journal of Korea Technology Innovation Society
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• v.17 no.2
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• pp.355-379
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• 2014

For the transition to the low carbon society, it is inevitable but difficult journey that the new energy technology spread co-exists with formal social system. The objective of offshore wind power plant that has been implemented by the government is to connect large capacity new renewable energy to the central electric power system. Therefore, for the successful introduction of offshore wind power system, the transition of the formal social technology system should be companied. This study analysis the energy system transition about niche strategy adjustment using Multiple Level Perspectives & Strategic Niche Management. It also multi level analyzes and structuralizes the process that new technology, as a research result, evolves through connecting and communicating with formal regime and landscape. Also, adjusting Strategic Niche Management, it diagnoses the obstructive factors in the initial stage of niche experiment and found the major reasons why offshore wind power test plant had been delayed. Through this study, it reaches to the practical implication that offshore niche technology could grow stably in the energy system and various policies.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.787-790
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• 2003

전통적인 원격 평가 시스템들은 학생 개개인의 특성과 성향을 고려하지 않기 때문에 단순하고 획일적이라는 문제점을 갖고 있다. 돈 논문에서는 이러한 문제점을 해결하고 비디오를 통한 평가를 위하여 장면전환검출과 사용자 프로파일을 이용한 원격 비디오 평가 시스템을 제안하고 구현한다 비디오 문제 출제를 위한 장면 전환 검출을 통하여 키 프레임과 문제 출제 구간을 추출한다. 문제 출제 방법은 평가에 사용자 프로파일의 적용을 위하여 카테고리 기반 시스템과 키워드 기반 시스템을 합성한 방법을 이용하였다. 이 시스템을 통하여 학생들은 자신의 부족한 영역을 보충하고 관심 영역을 유지할 수 있으며 학업 성취도를 향상시킬 수 있다 사용자 프로파일을 이용한 본 시스템은 사용자의 문제 풀이 결과에 따라 영역별 문제 수를 조절하고 평가의 질과 효율성을 최대화시킨다.

• Proceedings of the Korean System Dynamics Society
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• 2000.02a
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• pp.97-114
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• 2000

시스템 다이내믹스 연구에 있어서 피드백 루프는 시스템의 구조와 행태를 연결시키는 핵심적인 개념적 도구이다. 특히 여러 개의 피드백 루프로 구성된 복잡한 시스템에 있어서, 지배적 피드백 루프(dominant feedback loop) 및 그 전환(shift)은 시스템의 행태를 결정짓는 구조적 원인을 제공한다. 그러나 지배적 피드백 루프에 대한 연구는 아직까지 그 발견방법에 관한 알고리즘 연구에 머물러 있는 상태이다. 지배적 피드백 루프는 시스템의 급격한 변화를 예상하는 단초가 된다는 점에서, 지배적 피드백 루프를 어떻게 인식할 것이냐는 정부의 정책결정에 있어서나 기업의 의사결정에 있어서 중요한 문제라고 할 수 있다. 본 논문에서는 지배적 피드백 루프 및 그 전환에 대한 의사결정자의 인식에 관하여 살펴보고 어떠한 인지적 편향이 있는지에 관하여 검토하고자 한다.

• Journal of the Economic Geographical Society of Korea
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• v.19 no.4
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• pp.743-763
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• 2016

This paper aims to figure out properties of housing system under the socialist market economy, which is formed after China's Reform and Opening-up. The characteristics of Chinese housing system under socialist market economy are actually a subtype of capitalist housing model because of the existing clear commodity housing market and the weakness of public land ownership. Furthermore, the government is leading agent of the capitalistic transition and marketization. Also this government-driven marketization has specialty on the feature based on the socialist tradition such as public land ownership.