• 한국안전학회지
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• 제28권5호
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• pp.66-70
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• 2013

This study examined the relative effects of education and eco-IVIS(in-vehicle information system) to reduce fuel consumption and greenhouse gas emissions. Also the study investigated the increasing of driving workload when drivers interact with intervention technique. Thirty participants randomly assigned into two groups(training and eco-IVIS) and conducted driving before and after the each intervention technique. While driving, we observed three driving behaviors: Frequency of excessive RPM, percent of speeding, and mean fuel efficiency. Also the Driver Activity Load Index was used to rate participants' subjective ratings of driving workload. Although the results showed positive impact of both education and eco-IVIS to increasing the eco-driving behaviors, eco-IVIS was more effective than education. However, we found comparable level of driving workload in the education and eco-IVIS.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 F
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• pp.2534-2536
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• 1999

This paper suggested a new sensorless driving strategy for brushless de motor which can improve the conventional degradation of highspeed operating performances, lowspeed operating performances and starting performances caused by applying general single pwm switching frequency. By varying PWM switching frequency during operating time, the proposed method can get some desired upper performances. For confirming the validity of the proposed method, the sensorless driving system is implemented with an rPM module and 87c196MC micro controller.

• 오토저널
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• 제8권3호
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• pp.46-54
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• 1986

Driving pattern of gasoline passenger car was measured and analyzed at some areas(6urban area routes, 4 radial routes, 4 circular routes)in Seoul city. Measured items were vehicle speed, engine speed, intake manifold vacuum, and fuel consumption. Driving pattern data were reappearanced with engine dynamometer. Results of this investigation might be summarized as below; 1. When we compared urban area route with radial or circular route in rush hour, it was found that the average vehicle speed was measured to be lower about 25% and fuel consumption to be higher about 12% in urban area route. 2. Average vehicle speed was measured to be higher about 30% and driving resistance output to be higher about 25% in non-rush hour, but average fuel economy was increased a little. 3. On the bases of average fuel economy and characteristics of exhaust emissions, optimum driving vehicle speed was found about 60 km/h in the 4th(top)and about 40km/h in the 3rd in driving of experimental engine. 4. Idling frequency and exhaust emissions of CO,HC were related to idling closely. But exhaust emission of NOx, which had nothing to do with idling frequency, had relation to acceleration time ratio.

• Journal of Power Electronics
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• 제14권2호
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• pp.217-225
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• 2014

This paper deals with the optimization of the driving techniques for the ZVT synchronous buck converter proposed in [1]. Two new gate drive circuits are proposed to allow this converter to operate by only one control signal as a 12V voltage regulator module (VRM). Voltage-driven method is applied for the synchronous rectifier. In addition, the control signal drives the main and auxiliary switches by one driving circuit. Both of the circuits are supplied by the input voltage. As a result, no supply voltage is required. This approach decreases both the complexity and cost in converter hardware implementation and is suitable for practical applications. In addition, the proposed SR driving scheme can also be used for many high frequency resonant converters and some high frequency discontinuous current mode PWM circuits. The ZVT synchronous buck converter with new gate drive circuits is analyzed and the presented experimental results confirm the theoretical analysis.

• 한국산업융합학회 논문집
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• 제10권4호
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• pp.227-233
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• 2007

In case of design of a rectifier to supply high current, To select switching frequency of semiconductor switches affect absolutely the design of the LC filter value in an power conversion circuit. The conventional rectifier by using MOSFET is no use in high current equipments because of small drain-source current. To solve this problem, this paper proposes to design of high capacity rectifier by parallel driving of MOSFET in the single half bridge DC-DC converter. This method can be able to develop high current rectifier by distributed drain-source current. The proposed scheme is able to expect a decrease in size, weight and cost of production by decreasing the LC filter value and increasing maximumly the switching frequency. The validity of the proposed parallel driving strategy is verified through computer-aided simulations and experimental results.

• 한국정보통신학회논문지
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• 제6권4호
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• pp.582-588
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• 2002

본 연구에서는 브러시리스 직류 전동기(BLDCM)에 대한 효율적인 센서리스 운전 기법을 제시한다. 제시된 기법은 인버터 스위칭 주파수(4KHz, 6KHz, 8KHz)를 회전속도에 따라 적절히 가변함으로서 넓은 속도 범위에서 운전성능과 효율을 향상시킬 수 있다. 실험결과들은 제시된 기법이 제형파 역기전력을 갖는 BLDCM의 센서리스 운전특성을 효율 적으로 개선 할 수 있음을 보여주고 있다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(5)
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• pp.179-182
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• 2000

We have proposed a new driving method of AC PDPs for high resolution and high luminance, in which address pulses shorter than 1 $\mu$sec and increase address time, make it possible to drive 2100 scan lines The proposed driving scheme also allows high sustain frequency, leading to improved luminance. The experiment with a 4-inch color AC PDP with 30$\times$58 pixels realized a high luminance of 850cd/$m^2$ when the sustain voltage of 140v with the frequency of 125KHz is applied to the panel, and showed the possibility of the proposed driving scheme for high luminance and high resolution AC PDPs with 2100 lines.

• Journal of Biosystems Engineering
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• 제26권1호
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• pp.11-20
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• 2001

Experiments under the stationary and harvesting condition, were performed in order to investigate the vibration characteristics of a head-feeding combine. 6 degrees of freedom components of acceleration at the location of the center of the gravity, and 3 degrees of freedom components of acceleration at the location of the operator seat were measured independently. The vibration characteristics of the combine were estimated with the power spectral density of the time series data of accelerations. From this research, the following results were obtained. 1. Vibration of a head-feeding combine under the stationary condition(engine, thresher and cutter are driven without harvesting) is mainly influenced by the engine. Further, 1/3, 1/2 (sub-harmonic) frequency components of the engine are observed besides engine driving frequency component(45Hz). 2. Vibration of a head-feeding combine under the harvesting condition is influenced by the engine, threshing unit and driving unit. Namely, some kinds of vibration frequency components in harvesting are observed compared with stationary condition. Further, sub-harmonic frequency components of the engine are observed besides engine driving frequency component as same as stationary condition. From these results, it may be concluded that vibration of a head-feeding combine is characteristics of semi-periodic and nonlinear vibration.

• 한국심리학회지 : 문화 및 사회문제
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• 제12권1호
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• pp.81-102
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• 2006

본 연구는 운전자의 조심성에 초점을 두고 고령운전자와 청소년운전자의 운전확신수준과 운전행동과의 관계를 알아보았다. 우선, 운전확신수준을 측정하기 위한 도구를 제작하여 사용하였으며, 조사대상자들의 운전경력, 주행거리, 위반경험, 사고경험을 함께 조사하였다. 조사대상자는 만 25세 이하 청소년운전자와 만 65세 이상 고령운전자 325명이었으며, 고령운전자의 자료는 1:1 인터뷰를 통하여 수집하였다. 먼저, 운전확신수준의 구조를 알아보고자 요인분석을 실시하고, 고령운전자와 청소년운전자의 운전확신수준을 비교하였다. 그리고 고령운전자와 청소년운전자의 운전확신수준과 운전행동과의 관계를 알아보았다. 운전확신수준은 '운전상황', '안전운전', '운전능력', '주의'의 네 요인으로 이루어져 있었으며, 고령운전자의 운전확신수준은 청소년운전자의 운전확신수준보다 낮은 것으로 나타났다. 고령운전자 집단에서는 운전확신수준과 운전경력, 위반경험이 강한 상관관계를 가지고 있었고, 청소년운전자의 운전확신수준은 운전경력, 주행거리, 위반경험, 사고경험과 강한 상관관계를 가지고 있는 것으로 나타났다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
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• pp.48-51
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• 2000

플라즈마 디스플레이 패널의 발광효율을 개선하기 위하여 sustain 구간의 파형을 변화시킨 새로운 구동파 형을 제안하였다. 제안된 sustain 파형은 기존의 구형파에 기울기를 가진 ramp 형태의 파형을 덧붙여 줌으로써 Self-Erasing을 유도하는 파형이다. 기존에 제안된 Self-Erasing을 이용한 구동방식은 높은 구동주파수(>150kHz)에서만 발광효율이 개선되는 반면, 본 논문에서 제안하는 파형은 낮은 구동주파수(25kHz)에서도 30％정도의 발광효율이 개선되었다. 본 논문의 결과로부터 주파수, 듀티, 기울기 등의 다양한 구동조건에서의 연구가 진행된다면 더 큰 발광효율개선이 기대된다.