• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.756-761
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• 2007

This papered is concerned with the crashworthiness characteristics analysis of the non-step bus when it is crashed or roll-over analysis. Computer simulations is implemented using LS-Dyna explicit code which can effectively analysis dynamic response with the lapse of time. We construct a FEM model of the non-step bus under development according to the safety rules used in Europe for composite non-step buses. The crash energy and absorption rate are evaluated to understand crashworthiness characteristic of the composite non-step bus. Body deformation is also examined whether the survival space is secured for passengers.

• 한국자동차공학회논문집
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• 제6권6호
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• pp.1-6
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• 1998

A leaf spring plays an important role in a passenger bus. Since characteristic of a leaf spring has a hysteresis behaviour, modeling technique for a leaf spring is an important issue for passenger bus analysis. In this paper, modeling technique for a leaf spring is presented. First, non-linear FEM model of a leaf spring is constructed then it is used to make an approximated model to be used in dynamic analysis. The modeling procedure is ex-plained in step by step approach. Then, this model is applied to dynamic analysis of a mini-bus with flexible body and non-linear dynamic force element. The results are compared with test data.

• 전기학회논문지P
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• 제63권4호
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• pp.361-367
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• 2014

This paper is related to a new solar power conditioner for a built-in step-up chopper function. In the first step-up chopper proposed solar PV power conditioner for mutually connected in series with the input voltage of the bypass diodes are respectively connected to the positive terminal should install the mutual boosting chopper diode connected in series with the boost chopper switching element between the two power supply and at the same time the first and the second was connected to a second diode and a resonance inductor and a snubber capacitor in series with each other. And the common connection point between the bypass diode and the step-up chopper and the step-up chopper diode common connection point of the switching elements of the input voltage was set to the boost inductor for storing energy. In addition, between the step-up chopper and the step-up chopper diode and a switching element of a joint connection point of the first auxiliary diode and the second common connection point of the auxiliary diode was provided, the resonance capacitor. Between the step-up chopper and the step-up chopper diode and a switching element of a joint connection point and the common connection point of the resonance inductor snubber capacitor and connecting the third secondary diode, between two power supply lines is characterized by configuring the DC link capacitor bus lines in parallel. Therefore, it is possible to suppress the switching loss through, DC link bus lines, as well as there could seek miniaturization and weight reduction of the power conditioner itself by using a common capacitor of the non-polar non-polar electrolytic capacitor having a capacitor, the service life of the circuit can be extended and it is possible to greatly reduce the loss can be greatly improve the reliability of the product and the operation of the product itself.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2019년도 전력전자학술대회
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• pp.11-13
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• 2019

This paper proposes a novel high step-up non-isolated DC-DC converter, suitable for regulating dc bus in various inherent low voltage micro sources especially for photovoltaic (PV) and fuel cell sources. This novel high voltage Non-isolated Boost DC-DC converter topology is best replacement, where high voltage conversion ratio is required without the transformer and also need continuous input current. Since the proposed topology utilizes the stack-based structure, the voltage gain, and the efficiency are higher than other conventional non-isolated converters. Switches in this topology is easier to control since its control signal is grounding reference. Also, there is no need of extra gate driver and extra power supply for driver circuit, which reduces the cost and size of system. In order to show the feasibility and practicality of the proposed topology principle operation, steady state analysis and simulation result is presented and analyzed in detail. To verify the performance of proposed converter and theoretical analysis 360W laboratory prototype is implemented.

• Journal of Power Electronics
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• 제15권6호
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• pp.1438-1445
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• 2015

A new DC-DC power converter is researched for renewable energy and battery hybrid power supplies systems in this paper. At the charging mode, a renewable energy source provides energy to charge a battery via the proposed converter. The operating principle of the proposed converter is the same as the conventional DC-DC buck converter. At the discharging mode, the battery releases its energy to the DC bus via the proposed converter. The proposed converter is a non-isolated high step-up DC-DC converter. The coupled-inductor technique is used to achieve a high step-up voltage gain by adjusting the turns ratio. Moreover, the leakage-inductor energies of the primary and secondary windings can be recycled. Thus, the conversion efficiency can be improved. Therefore, only one power converter is utilized at the charging or discharging modes. Finally, a prototype circuit is implemented to verify the performance of the proposed converter.

• 대한교통학회지
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• 제32권2호
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• pp.152-161
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• 2014

현재 KHCM이 출판될 당시와 현재의 대중교통 환경이 달라져 승하차시간 산정방법이 달라질 필요가 있다고 판단된다. 이에 본 연구에서는 승하차시간에 영향을 주는 승하차수, 입석자수, 상면지상고를 변수로 총승하차시간값을 도출하는 모형을 다중회귀모형을 통해 분석하였다. 그 결과 총승차시간의 경우는 승하차수, 입석자수, 상면지상고 순으로 영향력의 차이가 있었으며, 총하차시간의 경우는 하차자수, 상면지상고 순으로 분석되었고, 두 개의 모형에서의 독립변수들은 모두 종속변수와 양의 상관관계를 가지는 것으로 나타났다. 모형을 통해 예측된 순수 승하차시간은 기존의 버스정류장은 물론 TOD를 고려한 신도시 등의 신설 버스정류장 용량 산정에 유용할 것으로 판단된다.

• 대한토목학회논문집
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• 제33권1호
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• pp.241-249
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• 2013

"교통약자의 이동편의 증진법"이 제정됨에 따라, 각 지자체에서는 교통약자의 이동권을 보장하고자 다양한 노력을 해오고 있다. 그러나, 지역여건 및 교통수단 특성 등 교통약자의 교통수단 도입과 관련한 주변 상황은 고려되지 않아 교통약자 이동편의 증진 시책은 그 실효성이 매우 미흡한 상태이다. 따라서, 본 연구에서는 부산광역시를 대상으로 행정동별 경사도와 저상버스 운행여건, 특별교통수단 이용실태 등 교통약자의 교통수단 이용특성을 고찰하였다. 또한, 교통약자의 교통수단 이동지수 개념을 도입하여 지역별 교통약자의 교통수단 이용여건을 수량화하여 비교분석함으로써 지역특성에 부합하는 교통약자의 교통수단 이용편의 증진방안을 제시하였다.