• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2622-2624
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• 2005

화력발전소 보일러의 급수량은 유출되는 증기량에 맞추어 자동 조절된다. 유출 증기량이 변하는 상황에서도 이에 상응하는 급수량은 실시간으로 조절되어야 한다. 증기량과 급수량에 차이가 있으면 보일러의 보유 수량과 드럼의 수위가 변하게 되므로, '드림수위를 일정하게 유지하는 것'이 급수량제어의 목표라고 할 수 있다. 본 논문은 실제 운용되고 있는 설비를 대상으로 고찰한 내용이며, 급수펌프 구동력으로는 중기터빈을 사용한다. 증기터빈과 급수펌프는 같은 축으로 연결되어있으며, 급수량 조절은 급수펌프의 회전속도를 제어함으로써 이루어진다. 터빈에 사응되는 증기는, 고압과 저압 2종류이며, 저압 증기가 부족한 경우에 고압증기를 사용하는 구성으로 되어있다. 증기 밸브의 유량 특성에는 비선형성을 많이 포함하고 있었다. 이 외에도 급수펌프가 갖는 비선형성을 분석하였으며, 이 특성들을 모두 종합한 '증기터빈 속도제어기 튜닝 곡선'을 제시하였다

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.7
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• pp.350-358
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• 2000

Based on the results in the first-part paper, PSS tuning methods including the determination of PSS gain and compensation of phasor lagging are investigated in this second part. In the phase compensation, PSS should compensate phase lagging, resulted from power system-generator-excitation system loop, to provide damping torque in equal phase with the generator speed. Also, PSS gain should be determined to provide maximum damping torque as much as possible without the other modes unstable. In this paper, gain tuning method using the root-locus and the phase compensation of PSS at the one machine with infinite bus system are presented. The differences between PSS tuning at the tuning condition and at the least-stable condition are also discussed.

• Journal of Auto-vehicle Safety Association
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• v.13 no.4
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• pp.20-25
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• 2021

This paper is the result of a research on hybrid tuning technology developed to improve the actual fuel efficiency and reduce emissions of in-use light-duty diesel trucks. In this study, a hybrid powertrain was constructed by inserting an electric motor between the diesel engine and manual transmission of an internal combustion engine vehicle and installing a battery. To verify the safety, a test was conducted based on the Korean tuning regulations. In particular, since there has been no case of tuning an internal combustion engine vehicle into a hybrid vehicle in Korea, it was necessary to carry out all procedures to receive tuning approval. The approval process consists of a technical review, safety verification test, and application for tuning approval. As a result, the test vehicle was approved for tuning because both the technical review and vehicle test results were suitable. Therefore, this study confirmed the safety of diesel hybrid tuning technology, and laid the foundation for the research and development of technologies to tune into an eco-friendly vehicle as well as the activation of related industries.

• International Journal of Highway Engineering
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• v.8 no.3 s.29
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• pp.129-141
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• 2006

The vertical soil pressure developed in the granular layer of asphalt pavement system is influenced by various factors, including the wheel load magnitude, the loading speed, and asphalt pavement temperature. This research observed the distribution of vertical soil pressure in pavement supporting layer by investigating measured data from soil pressure gage in the KHC Test Road. The existing specification of subbase and subgrade compaction was also evaluated with measured vertical pressure. The finite element analysis was conducted to verify the accuracy of results with measured data because it can maximize research capacity without significant field test. The test data was collected from A5, A7, A14, and A15 test sections at August, September, and November 2004 and August 2005. Those test sections and test data were selected because they had best quality. The size of influence area was evaluated and the vertical pressure variation was investigated with respect to load level, load speed, and pavement temperature. The lower speed, higher load level, and higher pavement temperature increased the vertical pressure and reduced the area of influence. The finite element result showed the similar trend of vertical pressure variation in comparison with measured data. The specification of compaction quality for subbase and subgrade is higher than the level of vertical pressure measured with truck load so that it should be lurker investigated.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.141-146
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• 2012

This paper introduces development of multi-rotor system and vision based autonomous landing system. Multi-rotor platform is modeled by rigid body motion with Newton Euler concept. Also Multi-rotor platform is simulated and tuned by LQR control algorithm. Vision based Autonomous Landing system uses a single camera that is mounted Multi-rotor system. Augmented reality algorithm is used as marker detection algorithm and autonomous landing code is test with GCS for the precision landing.

• Annual Conference on Human and Language Technology
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• 2011.10a
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• pp.72-76
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• 2011

본 논문은 한국전자통신연구원 언어처리연구팀에서 2004년까지 개발하였던 웹문서 자동번역 시스템을 2006년부터 매년 도메인별로 상용화에 성공한 사례를 기술한 것이다. 상용화가 가능하였던 주요 요인 중 하나인 도메인 특화 방법을 소개하며 이 도메인 특화 방법이 시기별로 개선되어 진화되는 모습을 기술한다. 즉 2004년의 웹문서 영한 자동번역기를 2006년에 특허문서 영한 자동번역기로 특화할 때 사용한 도메인 특화 방법이 '초기 도메인 특화 방법'이라 할 수 있는데, 이 초기의 도메인 특화 방법에 번역지식 및 번역엔진 모듈의 반자동 튜닝 방법과 자동화된 평가 방법을 추가하여 2007년에 '개선된 도메인 특화 방법'을 개발하였다. 이 '개선된 도메인 특화 방법'은 2007년에 특허문서 영한 자동번역기를 기술논문 영한 자동번역기로, 2008년에 기술논문 영한 자동번역기를 IT웹신문 영한 자동번역기로, 2009년에 IT 웹신문 영한 자동번역기를 전자우편 및 기업문서 영한 자동번역기로, 그리고 2010년에 전자우편 영한 자동번역기를 메신저 영한 자동번역기로 구현할 때 사용하였으며 그 효과는 신규 도메인용 영한 번역기를 개발하는 기간을 점차적으로 줄이게 하였으며 구현 프로세스에 일관성을 제공하였다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.3
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• pp.34-41
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• 2011

This paper presents a wide tuning range, fine-resolution DCO (Digitally Controlled Oscillator) with an active inductor. In order to control the frequency of the DCO, the transconductance of the active inductor is tuned digitally. In addition, the DCO gain needs to be calibrated digitally to compensate for gain variations. To cover the wide tuning range, an automatic three-step coarse tuning scheme is proposed. The DCO total frequency tuning range is 1.4 GHz (2.1 GHz to 3.5 GHz), it is 58 % at 2.4 GHz. An effective frequency resolution is 0.14 kHz/LSB. The proposed DCO is implemented in 0.13 ${\mu}m$ CMOS process. The total power consumption is 6.6 mW from a 1.2 V supply voltage. The phase noise of the DCO output at 2.4 GHz is -120.67 dBc/Hz at 1 MHz offset.

• Annual Conference on Human and Language Technology
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• 1996.10a
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• pp.489-496
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• 1996

자연어 처리에서 언어에 대한 지식은 전자사전과 문법규칙으로 구성되어 서로 상보적 관계에 있고, 각 어휘에 대한 품사 및 기타 자질-값에 의해 매개된다. 이러한 언어지식을 전통적인 방법에서는 국어자료의 분석에 경험이 많은 언어전문가의 직관에 다분히 의존하여 정의하였고, 말뭉치를 이용한 자동 획득 기법에서는 태그세트를 먼저 설정하고, 이 태그를 원시 말뭉치에 부착하여 태깅된 말뭉치로부터 자동으로 통계적 분석을 통하여 획득한다. 그런데 두가지 접근방법이 가지고 있는 공통적인 문제점은 품사나 자질-값의 정의 및 할당기준, 선악의 평가기준, 튜닝에 대한 적극적 대처 등이 마련되어 있지 않다는 점이다. 이 연구에서는 이러한 문제점의 발생원인을 말뭉치 분석 과정에서 살펴보고, 품사 및 자질-값의 설정과 할당기준을 마련하는 방법론 및 이를 적극적으로 지원하는 도구를 설계한다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.2
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• pp.87-93
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• 2010

This paper presents a low-power, wide tuning range VCO with automatic two-step negative-Gm calibration loop to compensate for the process, voltage and temperature variation. To cover the wide tuning range, digital automatic negative-Gm tuning loop and analog automatic amplitude calibration loop are used. Adaptive body biasing (ABB) technique is also adopted to minimize the power consumption by lowering the threshold voltage of transistors in the negative-Gm core. The power consumption is 2 mA to 6mA from a 1.2 V supply. The VCO tuning range is 2.65 GHz, from 2.35 GHz to 5 GHz. And the phase noise is -117 dBc/Hz at the 1 MHz offset when the center frequency is 3.2 GHz.

• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.747-754
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• 2004

Database administrators should be aware of performance characteristics of database systems in order to manage database system effectively. The usages of system resources in database systems could be quite different under database workloads. The objective of this paper is to identify and analyze performance characteristics of database systems in different workloads, which could help database tuners tune database systems Under the TPC-C and TPC-W workloads, which represent typical workloads of online transaction processing and electronic commerce respectively, we investigated usage types of resource that are determined by fourteen performance indicator, and are behaved in response to changes of four tuning parameters (data buffer, private memory, I/O process, shared memory). Eight out of the fourteen performance indicators cleary show the performance differences under the workloads. Changes of data buffer parameter give a influences to database system. The tuning parameter that affects the system performance significantly is the database buffer size in the both workloads.