• 한국자동차공학회논문집
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• 제21권3호
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• pp.105-112
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• 2013

In this paper, EV (Electric Vehicle) and ICE (Internal Combustion Engine) vehicle simulators are developed to compare maximum driving range of EV and ICE vehicle according to different driving patterns. And, simulations are performed for fourteen constant velocity cases (20, 30, 40, ${\ldots}$, 150 km/h) and four different driving cycles. From the simulation results of constant velocity, it is found that the decreasing rate of maximum driving range for EV is larger than the one for ICE as both the vehicle velocity and the driving power increase. It is because the battery efficiency of EV decreases as both the velocity and the driving power increase, whereas the engine and transmission efficiencies of ICE vehicle increase. From the results of four driving cycle simulation, the maximum driving range of EV is shown to decrease by 50% if the average driving power of driving cycle increases from 10 to 20kW. It is because the battery efficiency decreases as the driving power increases. In contrast, the maximum driving range of ICE vehicle also increases as the average driving power of driving cycle increases. It is because the engine and transmission efficiencies also increase as the driving power increases.

• 한국수소및신에너지학회논문집
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• 제28권1호
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• pp.56-62
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• 2017

Although most electricity production contributes to air pollution, the vehicle organizations and environmental agency categorizes all EVs as zero-emission vehicles because they produce no direct exhaust or emissions. Currently available EVs have a shorter range per charge than most conventional vehicles have per tank of gas. EVs manufacturers typically target a range of 160 km over on a fully charged battery. The energy efficiency and driving range of EVs varies substantially based on driving conditions and driving habits. Extreme outside temperatures tend to reduce range, because more energy must be used to heat or cool the cabin. High driving speeds reduce range because of the energy required to overcome increased drag. Compared with gradual acceleration, rapid acceleration reduces range. Additional devices significant inclines also reduces range. Based on these driving modes and climate conditions, this paper discusses the performance characteristics of EVs on energy efficiency and driving range. Test vehicles were divided by low / high-speed EVs. The difference of test vehicles are on the vehicle speed and size. Low-speed EVs is a denomination for battery EVs that are legally limited to roads with posted speed limits as high as 72 km/h depending on the particular laws, usually are built to have a top speed of 60 km/h, and have a maximum loaded weight of 1,400 kg. Each vehicle test was performed according to the driving modes and test temperature ($-25^{\circ}C{\sim}35^{\circ}C$). It has a great influence on fuel efficiency amd driving distance according to test temperature conditions.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.892-896
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• 2001

Recently, many indoor driving ranges are being built near residential areas because golf is one of the popular sports. Consequently, environmental noise occurs in the residential areas. This study is to predict the noise near the indoor golf driving range by the computer simulation(commercial software Raynoise 3.0) for various cases of noise control methods.

• 대한기계학회논문집A
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• 제38권1호
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• pp.37-44
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• 2014

본 연구에서는 전기이륜차의 1회충전주행거리를 알아보기 위해 도로 주행시험과 차대동력계(Chassis Dynamometer) 주행시험을 하였다. 도로주행시험은 대전시(Daejeon Metropolitan City)의 도로 중 대표적인 3가지 루트에서 주행시험을 하였다. 차대동력계를 이용한 CVS-40모드 주행시험의 경우 도로 부하조건을 다양하게 설정하여 CVS-40 모드주행을 실시하였다. 본 연구를 통하여 도로에서의 전기이륜차의 1회 충전주행거리(Per-Charge Range Testing)를 확인하고, 차대동력계 도로부하 설정방법에 따른 주행거리 및 에너지소비효율을 측정하였다. 이를 통해 실도로 주행시험과 차대동력계 주행시험을 비교하여, 차대동력계 실험에서도 전기이륜차 1회충전주행거리시험이 실도로에서의 주행조건과 근접한 결과를 갖는 도로부하 설정에 대해 연구하였다.

• ETRI Journal
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• 제43권4호
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• pp.603-616
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• 2021

Over the last few years, autonomous vehicles have progressed very rapidly. The odometry technique that estimates displacement from consecutive sensor inputs is an essential technique for autonomous driving. In this article, we propose a fast, robust, and accurate odometry technique. The proposed technique is light detection and ranging (LiDAR)-based direct odometry, which uses a spherical range image (SRI) that projects a three-dimensional point cloud onto a two-dimensional spherical image plane. Direct odometry is developed in a vision-based method, and a fast execution speed can be expected. However, applying LiDAR data is difficult because of the sparsity. To solve this problem, we propose an SRI generation method and mathematical analysis, two key point sampling methods using SRI to increase precision and robustness, and a fast optimization method. The proposed technique was tested with the KITTI dataset and real environments. Evaluation results yielded a translation error of 0.69%, a rotation error of 0.0031°/m in the KITTI training dataset, and an execution time of 17 ms. The results demonstrated high precision comparable with state-of-the-art and remarkably higher speed than conventional techniques.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1495-1498
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• 2008

We proposed driving method with variable integration time for ambient light sensing. One operation period of the proposed driving method consists of several sub-integration periods with variable integration time which can enlarge dynamic range of ambient light sensing circuit. Temperature dependent characteristic of p-intrinsic-metal (p-i-m) diode can be compensated using the proposed driving method.

• 유공압시스템학회논문집
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• 제5권2호
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• pp.1-7
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• 2008

To improve the performance of the bent axis type axial piston pump driven by the tapered piston, it is necessary to know the driving characteristics and mechanism of the tapered piston and the cylinder block. Since each piston not only rotates on its axis and reciprocates in the cylinder bore, but also revolves around the axis of the driving shaft, it is difficult to analyze the driving mechanism theoretically. The theoretical mechanism far the bent axis type axial piston pump is studied by using the geometrical method. The driving range of the tapered piston is determined by theoretical equations. The results show that the cylinder block is driven by one tapered piston in a limited range and the core parameters such as driving factor of the piston and the ahead delay angle influenced performance of the bent axis type axial piston pump.

• 한국콘텐츠학회논문지
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• 제13권8호
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• pp.409-419
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• 2013

본 연구에서는 골프연습장 이용고객들이 인식하는 서비스품질, 서비스가치, 고객만족, 재구매행동과의 구조적관계를 규명하는 데 그 목적이 있다. 연구대상은 K도 C시, P광역시, U광역시에 소재하고 있는 골프연습장 8곳의 이용고객을 모집단으로 선정하였으며, 편의표본추출법을 사용하여 총 374명을 유효 표본으로 선정하여 본 연구의 자료로 이용하였다. 조사도구는 SPSS 12.0과 AMOS 5.0 통계패키지를 이용하여 요인분석, 신뢰도분석, 상관관계분석, 빈도분석, 탐색적 요인분석, 확인적 요인분석, 구조방정식 모형분석을 이용하였으며, 결론은 다음과 같다. 첫째, 골프장 서비스품질은 서비스가치에 긍정적인 영향을 미친다. 둘째, 골프장 서비스품질은 고객만족에 긍정적인 영향을 미친다. 셋째, 서비스가치는 고객만족에 긍정적인 영향을 미친다. 넷째, 서비스가치는 재구매행동에 긍정적인 영향을 미친다. 다섯째, 고객만족은 재구매행동에 긍정적인 영향을 미친다.

• 전자공학회논문지B
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• 제32B권10호
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• pp.1280-1285
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• 1995

In this paper the optimized overlap driving scheme for improving the reduction problem of the operating voltage range occured by the overlap driving scheme proposed precedently and increasing the contrast ratio of screen image in the simple matrix LCDs is proposed. The characteristic estimation of the proposed method was performed in a condition that the number of scan electrodes was 120 and the threshold voltage of LC pixel was 2V and the overlap rate of scan signal was varied from 0% to 40% . As a result of estimation compared with the overlap driving scheme proposed precedently, this new method was certified as a method which it could increase the operating voltage range of the LC pixel by 16% in 20% overlap condition and it's operating voltage range was also increased very much with the increase of the overlap rate. Consequently this newly proposed method was certified as a method which it could maintain the improvement effect of the operating characteristics obtained by the overlap driving scheme proposed precedently with the big improvement in the contrast ratio of screen image.

• 한국소음진동공학회논문집
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• 제21권11호
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• pp.1005-1012
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• 2011

Diverse sports are appearing due to the enhanced quality of life and improved cultural standards of the present society. In particular, as golf gains greater popularity from the public, many golf ranges are being constructed near residential areas. However, the hitting noise generated by golf disrupt the pleasant living environment of neighboring residents to generate strong disputes related with noise. In this perspective, this study analyzed the characteristics and dispersion of sound pressure level according to the frequency of hitting noises generated in golf driving ranges and used this data to predict the range of effect through computer simulation. Thus, it is stipulated that these research results can be used as useful data for establishing effective plans in the future during civil complaints reported in relation to hitting noises in golf driving ranges.