• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.377-378
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• 2020

본 논문에서는 열화에 따른 하이브리드 차량의 연비 특성을 분석하기 위해 시뮬레이션을 통한 연구를 진행하였다. 전기적 특성 실험 기반으로 배터리 내부 파라미터가 열화에 어떤 영향을 미치는지 분석을 하고 이를 기반으로 하이브리드 차량모델을 통해 시뮬레이션을 진행하였다. 분석 결과를 통해 배터리 열화 상태에 따른 State-Of-Charge (SOC) 및 연비효율 그래프의 변화 추이를 비교하였다.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.1
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• pp.35-39
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• 2013

This paper reports numerical study results with respect to the thermal behavior of a natural convection cooled hybrid fin heat sink (HFH). The HFH consists of hybrid fins, hollow pin fins integrated with plate fins. The thermal performance of the HFH was numerically investigated by employing a commercial CFD software package and compared with that of the pin fin heat sink (PFH). Numerical study has found that array-based and mass-based heat transfer coefficients of the HFH are 12% and 37% greater than those of the PFH, respectively. Extended surface area and lighter weight may explain the better thermal performance of the HFH than the PFH.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.4
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• pp.386-392
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• 2008

This paper presents active vibration control performance of a hybrid mount. The proposed hybrid mount is devised by adopting both piezostack as an active actuator and rubber as a passive element. After experimentally identifying actuating force characteristics of the piezostack and dynamic characteristics of the rubber, the hybrid mount was designed and manufactured. Subsequently, a vibration control system with a specific mass loading is constructed, and its governing equations of motion are derived. In order to actively attenuate vibration transmitted from the base, a feedforward controller is formulated and experimentally realized. Vibration control responses are then evaluated in time and frequency domains.

• Composites Research
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• v.18 no.3
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• pp.1-6
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• 2005

Carbon nanofiber exhibits superior and of ien unique characteristics of mechanical, electrical, chemical and thermal properties. Despite of the excellent properties of carbon nanofiber, the properties of carbon nanofiber filled polymer composites were not increased largely. The reason is that it is still difficult to ensure the uniform dispersion of carbon nanofiber in a polymer matrix. In this study, for improvement of the mechanical properties of composites, carbon nanofiber reinforced hybrid composites was investigated. For the dispersion of carbon nanofiber. solution blending method using ultrasonic was used. Dispersion of carbon nanoifiber was observed by scanning electron microscope (SEH). Mechanical properties were measured by universal testing machine(UTM).

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.6
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• pp.487-497
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• 2010

This paper describes the PSIM simulator for the analysis of the series type HEV operation. The traction force of the series type HEV of which engine is electrically coupled with a traction motor is supplied from the traction motor only. The rating of each power train components, such as gear, motor, ESS, ICE/generator, is designed with the Energy-Based Modeling method and the Electrical Peaking Hybrid(ELPH) method. Under driving cycle, the designed series HEV is evaluated with the developed PSIM simulator. A comparison between the conventional braking and the regenerative braking is performed with the average motor input power. And the fuel economy analysis is carried out on the basis of the simulation results.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.499-502
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• 2009

The auto-ignition tests of hybrid rockets with the concentrated hydrogen peroxide as an oxidizer were presented. Auto-ignition, restartability, and instant ignition were successfully demonstrated by injecting decomposed gases from $H_2O_2$ into paraffin or polyethylene fuels. In addition, much faster response time was demonstrated in case of a paraffin, which was 13 and 30 ms at ignition delay and rise time respectively.

• Composites Research
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• v.27 no.1
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• pp.14-18
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• 2014

Carbon Fiber Reinforced Plastic (CFRP) has strong and superb material properties, especially in mechanical and heat-resisting aspects, but the drawback is its high price. In this study, we made a hybrid composite using carbon fiber and basalt fiber, which is expected to attribute to its strong material properties and its financial benefits. We found out that the higher the content of basalt fiber included, the lower the intensity, and carbon's intensity contents of 80% showed the similar intensity level as that of CFRP. Besides it was possible to get a better mechanical properties using the composite that included the mixed fiber, instead of using a composition of separate fibers filed.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2014.06a
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• pp.144-145
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• 2014

기존 디지털 방송은 제한된 데이터 전송율로 인하여 시청자가 요구하는 다양한 데이터 서비스, 고해상도를 가지는 비디오 서비스와 같은 리치 멀티미디어 서비스를 제공하는 것이 현실적으로 어렵다. 그러나, 최근 들어 유무선 인터넷의 속도가 향상되고 소셜 서비스 등 다양한 인터넷 서비스 모델이 등장함에 따라서 통신망을 활용한 하이브리드 멀티미디어 방송 서비스가 제시되어, 방송 서비스가 가지는 특성을 유지하면서 다양한 시청자의 요구를 만족시키는 것이 가능해 졌다. 본 논문에서는 하이브리드 방송 서비스의 일종인 동적 계획 기반 하이브리드 방송 서비스 모델과 이를 가능하게 하는 송신 시스템 구성을 제안한다. 제안된 시스템은 새롭게 추가된 스케줄링 서버를 포함하고 있으며, 이 스케줄링 서버에 의해서 방송 콘텐츠의 비디오 해상도, 제공 시간, 전송 경로 등을 결정하는 것을 특징으로 한다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.271-274
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• 2006

In order to predict the performance of the small-scale Polyethylene-GOX hybrid rocket motor, a typical internal ballistic model was proposed. The model adopted for the present study employed the lumped scale of chamber pressure so that the pressure-time history resulted from the present model was comparable to the test results.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.229-232
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• 2009

DC-shift phenomenon can be observed in Hybrid rocket combustion. This phenomenon makes performance drop which is structure problem or reduce thrust. Understanding of DC-shift phenomenon, the conditions of the hybrid rocket combustion stability can be found. In this paper, the condition of DC-shift was found and made by using acoustic mode and vortex shedding frequency. The conditions of stable combustion was defined from the experimental study of DC-shift phenomenon.