• Title/Summary/Keyword: Ha39

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The Relationship between Soot Concentration and Operating Condition regarding Cavity Shapes in a D. I. Diesel Engine (직분식 디젤엔진에서 CAVITY 형상에 따른 Soot의 농도와 운전조건과의 관계 연구)

  • Lee, Sang-Suk;Lee, Tae-Won;Ha, Jong-Yu1
    • Journal of the Korean Society of Combustion
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    • v.3 no.1
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    • pp.31-39
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    • 1998
  • The local instantaneous flame temperature and soot concentration in a D. I. diesel engine were measured using a two-color method. The proposed method based on the continuous spectra! radiation from the soot particles in the flame is applicable to industrial Diesel engines without major modifications of their main characteristics because of simplicity and relative ease of application. Measurements were performed at two locations inside the combustion chamber of a D. I. diesel engine. Effects of different engine speeds and loads, fuel injection timings, combustion chamber shapes on flame temperature and KL factor, which is qualitatively proportional to soot concentrations, were examined. Flame temperature change were observed with increasing engine speed and load. The higher the flame temperature is, the lower the KL factor is.

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A Study on Stabilization of Walking and Working Motion of Biped Robot (보행로봇의 워킹 및 작업동작 안정화에 관한 연구)

  • Ha, Eon-Tae;Shim, Hyeon-Seok;Park, In-Man;Lee, Sang-Hyeok;Cha, Bo-Nam;Park, Seong-Jun
    • Journal of the Korean Society of Industry Convergence
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    • v.19 no.1
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    • pp.39-41
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    • 2016
  • In the paper, we propose an stable walking algorithm of biped robot on the ground and working motion stabilization algorithm against external disturbances. We propose obstacle hurdling, incline walking, and going-up stairs algorithm by using infrared sensors and F/T sensors. Also, posture stabilization algorithm against external forces is designed using F/T sensors. Infrared sensors are used to detect the obstacles in he working environment and F/T sensors are used to obtain the ZMP of biped robot. The experimental results show that the biped robot performs obstacle avoidance, obstacle hurdling, walking on the inclined plane by using the proposed walking moton stabilization algorithm.

Actual State and Practical Use of the Factory-Style Plant Production System in Germany (독일의 공장적 식물생산시스템의 현황 및 실용화)

  • Geyer, Bernd
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 1996.05a
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    • pp.11-39
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    • 1996
  • Produktionsanlagen in der Art von Pflanzenfabriken fur Gemuse haben in Nordeuropa eine lange Tradition. Der Aufbau derartiger Anlagen begann in Norwegen bereits 1980. Er war unmittelbar mil der Entwicklung hydroponischer Verfahren zur Produktion von Gemiise, insbesondere mit der Nutrient-Film-Technology verbunden. Derzeit gibt es in Nord- und Mitteleuropa (Norwegen, Finnland, Schweden, Danemark, Holland, Belgien und Deutschland) etwa 15 Gemusefabriken fur die Produktion von Kopf-und Blattsalaten sowie Krautern. (omitted)

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A Study for Implementation of Density Measurement Equipment for Asphalt Pavement based on the electromagnetic capacitance

  • Park, Young-Ho;Kim, Gun-Kyun;Nor, Jeong-Keun;Ha, Jae-Kwon
    • International Journal of Contents
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    • v.6 no.4
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    • pp.39-42
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    • 2010
  • In this paper we developed density measurement equipment for Asphalt Pavement based on the electromagnetic capacitance. This kind of Non-Nuclear Density Gauges technology and products is used or studied in USA, Finland, Sweden as standardization of authorized method for pavement density measurement. Effective permitivity of pavement asphalt is characterized in electromagnetic capacitance by the asphalt material, mixed ratio, and harden grade of pavement asphalt. We can get a density value of asphalt by replacing value of electromagnetic capacitance with standard density value and characteristic transformation curve. We are conformed that measurement data according to temperature, humidity, and real field asphalt of our density measurement equipment can be a precise value.

The height variation of F2 peak density using Anyang Ionosonde measurements for GNSS ionospheric model

  • Kim, Eo-Jin;Chung, Jong-Kyun;Kim, Yong-Ha;Cho, Jung-Ho
    • Bulletin of the Korean Space Science Society
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    • 2008.10a
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    • pp.24.3-24.3
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    • 2008
  • The signals transmitted from satellites of Global Navigation Satellite System (GNSS) interact with the plasma of the ionosphere. To study the impact of the ionospheric plasma on GNSS applications a comprehensive knowledge of the ionosphere is required. Especially the correct measurement of the ionosphere such as the peak height of the F2 layer peak electron density (hmF2) is important for the GNSS ionospheric model. Anyang ionosonde station ($37.39^{\circ}N$, $126.95^{\circ}E$) has been operating from October 2000 and the accumulated data for 8 years may allow us to obtain climatological characteristics of middle latitude ionospheric F region for GNSS application. We analyzed the variations of the hmF2 and NmF2 over Anyang station for different conditions of solar activity, geomagnetic activity, season, and local time, and we compared our results with the IRI model.

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Water Balance and Nutrient Losses of Paddy Fields Irrigated from a Pumping Station (양수장지구 구획논 물수지와 영양염류 유출부하)

  • Choi, Jin-Kyu;Koo, Ja-Woong;Son, Jae-Gwon;Cho, Jae-Young;Yoon, Kwang-Sik;Han, Kuk-Heon
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2001.10a
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    • pp.394-398
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    • 2001
  • The study was carried out to investigate the water balance and losses of nutrients from paddy fields during cropping period. The size of paddy fields was 95 ha and the fields were irrigated from a pumping station. The runoff loading was the highest in June because of the high concentrations of nutrients due to applied fertilizer. When the runoff losses of nutrients were compared to applied chemical fertilizer, it was found that 39.1 % to 42.5 % of nitrogen lost via runoff while runoff losses of phosphorus account for 6.3 % to 8.0 % of the total applied amount during cropping period. When the ratio was calculated between nutrients losses by infiltration and the applied of chemical fertilizer, two year results showed 9.1 % to 10.7 % for nitrogen and 0.2 % for phosphorus, respectively.

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A study on an algorithm based on sensitivity method for alleviating overloads in power networks (송전선로 과부하를 해소하기 위한 민감도에 근거한 알고리즘 연구)

  • Lee, Byung-Ha;Baek, Jung-Myoung
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2007.05a
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    • pp.286-290
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    • 2007
  • In this paper, a new algorithm based on sensitivity method for alleviating overloads in power networks is presented to find the switching branches effectively. Preferentially the switching of shunt reactive devices such as shunt reactor and shunt capacitors is performed. If overloads are not eliminated, the ranking of switching branches is calculated according to the algorithm based on sensitivity method and the switching of the ranked branches is performed in the order of ranking until overloads are eliminated. In order to show the effects of this algorithm, it is applied to a small scale power system of IEEE 39-bus test system.

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Probabilisitic Reliability Evaluation considering the small signal stability constraints with Monte Carlo simulation (소신호 안정도를 고려한 확률론적 신뢰도 평가 및 몬테카를로 시뮬레이션을 통한 신뢰도 평가 tool의 구현)

  • Jang, Gwang-Soo;Kim, Yu-Chang;Jung, Ha-Sub;Pakr, Jong-Keun
    • Proceedings of the KIEE Conference
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    • 2006.07a
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    • pp.3-4
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    • 2006
  • 본 논문에서는 계통의 불확실성을 고려한 확률론적인 방법으로 전력계통의 신뢰도를 평가한다. 발전기 3 state modeling 및 부하의 정규분포 곡선으로 확률론 신뢰도 평가 모델을 가정하였다. 그리하여 Adequacy 및 계통의 전압 및 송전선제약 조건 외에도, 소신호 안정도 항목을 추가하여 보다 동적인 측면에서의 신뢰도 평가가 이루어지도록 하였다. 이러한 평가 방법의 결과에 의하여 각 평가 항목간의 비율을 비교하였으며, 이를 통한 PSS의 설치 위치 선정의 근거를 마련하였다. 모의 방법은 Monte Carlo Simulation방법을 사용하였으며, WSCC 3기 9모선과 New England 10기 39모선을 모의계통으로 하였다.

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A Study on Integrated Small Signal Stability Analysis of Power Systems (계통의 종합적 미소신호 안정도해석에 관한 연구)

  • Nam, Ha-Kon;Song, Sung-Geun;Kim, Yong-Gu;Shim, Kwan-Shik
    • Proceedings of the KIEE Conference
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    • 1998.11c
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    • pp.1033-1036
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    • 1998
  • In this research project, two aspects of small signal stability are studied: improvement in Hessenberg method to compute the dominant electromechanical oscillation modes and siting FACTS devices to damp the low frequency oscillation. Fourier transform of transient stability simulation results identifies the frequencies of the dominant oscillation modes accurately. Inverse transformation of the state matrix with complex shift equal to the angular speed determined by Fourier transform enhances the ability of Hessenberg method to compute the dominant modes with good selectivity and small size of Hessenberg matrix. Any specified convergence tolerance is achieved using the iterative scheme of Hessenberg method. Siting FACTS devices such as SVC, STACOM, TCSC, TCPR and UPFC has been studied using the eigen-sensitivity theory of augmented matrix. Application results of the improved Hessenberg method and eigen-sensitivity to New England 10-machine 39-bus and KEPCO systems are presented.

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A study on aggregation method using relation index of state variables in the power system (상태변수들의 관계지수를 이용한 전력시스템 축약기법 연구)

  • Lee, Byung-Ha;Oh, Min-Hyuk
    • Proceedings of the KIEE Conference
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    • 2006.11a
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    • pp.339-341
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    • 2006
  • Increasing interconnection of power plants in modern large electric power system has made power system dynamic studies much more complex. For effective analysis of the power system, model reduction and aggregation is required. In this paper, a new relation index is presented to identify the coherent generators in the large scale power system. In order to demonstrate the effects of this relation index, it is applied to a small scale power system of IEEE 39-bus test system and the simulation results are presented.

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