• Title/Summary/Keyword: average speed

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An experimental study on characteristics of exhaust emission due to vehicle driving pattern in urban area (도심지 주행패턴에 의한 배출물특성에 관한 실험적 연구)

  • 한영출
    • Journal of the korean Society of Automotive Engineers
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    • v.8 no.3
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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.

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PC-based low speed control of a servo motor using instantaneous speed detection (PC 기반의 순시속도 검출에 의한 서보 모터의 저속 제어)

  • 류재규;박정일;이석규
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.377-382
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    • 1993
  • The low speed control of a servo motor using instantaneous speed detection method is described. To estimate the instantaneous speed from the average speed, the speed estimator of the first or second order is used. We confirm that these estimatorsimprove the speed control performance of a servo system with experiments.

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Dynamic Traffic Light Control Scheme Based on VANET to Support Smooth Traffic Flow at Intersections (교차로에서 원활한 교통 흐름 지원을 위한 VANET 기반 동적인 교통 신호등 제어 기법)

  • Cha, Si-Ho;Lee, Jongeon;Ryu, Minwoo
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.18 no.4
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    • pp.23-30
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    • 2022
  • Recently, traffic congestion and environmental pollution have occurred due to population concentration and vehicle increase in large cities. Various studies are being conducted to solve these problems. Most of the traffic congestion in cities is caused by traffic signals at intersections. This paper proposes a dynamic traffic light control (DTLC) scheme to support safe vehicle operation and smooth traffic flow using real-time traffic information based on VANET. DTLC receives instantaneous speed and directional information of each vehicle through road side units (RSUs) to obtain the density and average speed of vehicles for each direction. RSUs deliver this information to traffic light controllers (TLCs), which utilize it to dynamically control traffic lights at intersections. To demonstrate the validity of DTLC, simulations were performed on average driving speed and average waiting time using the ns-2 simulator. Simulation results show that DTLC can provide smooth traffic flow by increasing average driving speed at dense intersections and reducing average waiting time.

A Study on Driver's Physiological Response in Train Simulator (열차 시뮬레이터 조작 시 운전자의 생체신호 변화에 대한 연구)

  • Jang, Hye-Yoen;Jang, Jae-Ho;Kim, Tea-Sik;Han, Chang-Soo;Han, Jung-Soo;Ahn, Jae-Yong
    • Journal of the Ergonomics Society of Korea
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    • v.25 no.4
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    • pp.129-135
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    • 2006
  • he purpose of this study is to measure bio-signal to investigate the driver's physiological response change under real situation using train simulator. The train simulator used in this study is KTX model and according to changes of driving situation, The bio-signal controlled by autonomic nervous system, such as GSR(Galvanic Skin Response), SpO2(Saturation percent O2), HR(Heart Rate), ECG(Electrocardiograph), EEG(Electroencephagram) and movement and response of eye were measured. Statistically significant difference in bio-signal data and eye movement activity pattern were investigated under several different driving speeds using analysis of variance (p<0.05). The GSR and HR value measured in average and mission speed operation is higher than in high-speed operation. β wave of EEG in average speed operation become more activated than in high speed operation. In accordance with a characteristic of rail vehicle, movement and response of eye in high-speed operation requiring relatively simple maneuver become less activated than in either average or mission speed operations. Conclusively, due to more careful driving controls in average and mission speed operation are required than in high-speed operation, level of mental and physical stresses of train driver was increased and observed through changes of bio-signal and eye movement measured in this study.

A Study on the Sailing Speed of Ancient Ships - especially on the average speed and the effect of the wind, the tide, and the man-power at the oar - (고대 선박의 항해속도 연구 - $\ll$고려도경$\gg$을 중심으로-)

  • Yoon, Il-Young
    • Journal of National Security and Military Science
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    • s.7
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    • pp.155-231
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    • 2009
  • Xu-Jing(徐競) an official of the Song(宋), a medieval Kingdom of China, wrote a book titled $\ll$Koryo Tu Jing(高麗圖經)$\gg$ which explains his travel to the Koryo as a member of diplomatic mission in 1123. $\ll$Koryo Tu Jing$\gg$ is the record of his personal experience in Koryo with many explanatory illustrations and especially contains 5 months' voyage record of his diplomatic fleet. His fleet set sail at a port located in the Ding Hai Xian(定海縣), Ming Zhou(明州) via a few islands of Koryo [Hyup Kye San(俠界山) , the Kun San Do(群山島) , the Ja Yon Do(紫燕島) , the Keup Su Mun(急水門) in Kang Hwa Gun(江華郡) and the Hap Gul(蛤窟) ] and finally arrived the Port Ye Song Hang(禮成港) . According to the Xu-Jing's record his fleet sailed the sea with the help of the favorable seaward winds and tides as the usual way of ancient sailing. The Xu- Jing's Fleet sailed the sea between the Mei Cen(梅岑), Ming Zhou(明州) of China and the Hyup Kye San(俠界山) of Koryo from about 5:00 a.m., May 24th(of the lunar calendar) to about 5:00 p.m., June 2nd. At this section, the average speed of the seaward winds was 19.45km/h and the average speed of the fleet which sailed only by the power of the winds was 6.29km/h. This means that 32.3% of the favorable seaward winds' speed was equal to the speed of the ancient fleet which sailed only by the power of the favorable seaward winds. The fleet sailed the sea between the Ja Yon Do(紫燕島) and the Keup Su Mun(急水門) from about 9:00 a.m., June 10th to about 1:00 p.m., the same day. At this section the fleet sailed by the power of tides in addition to the favorable seaward winds without oaring. The average speed of the winds was not different from that of former section and the average speed of the tides was 1.937km/h. And at this section the average speed of the fleet increased by 0.41km/h than that of the former section. This means that 21.1% of the speed of the tides was equal to the increased speed of the ancient fleet by virtue of the tides. The fleet sailed the sea between Keup Su Mun(急水門) and the Hap Gul(蛤窟) from about 1:00 p.m., June 10th to about 3:00 p.m., the same day. At this section, there were no seaward winds and the fleet sailed only by the powers of tides and oaring. And at this section, the tide increased the average speed of the fleet by 0.3114km/h and the fleet could sail at the speed of 4.3km/h. So we can conclude that the average speed of ancient fleet without any influences of the seaward winds and tides was 3.98 km/h. We can make use of the various sailing speeds of ancient fleets when judging their maritime activities. If we make use of the various sailing speeds of the ancient fleets as calculated in this article, we will be able to get various important informations about the certain ancient fleet's maritime maneuver. For example, we can infer the sailing routs of a certain fleet and the time when the fleet passed a certain spot by making use of the various sailing speeds of the ancient fleet. In this article I did not take account of the shapes of ships that consist of the ancient fleets and the sizes of the various ships and fleets. It was because that such factors would not change the foresaid conclusions seriously.

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Assessment of Long-Term Effectiveness of Speed Monitoring Displays on Speed Variation (어린이보호구역에 과속경보시스템 적용에 따른 장기적 속도변화 평가)

  • Lee, Sang-Soo
    • Journal of the Korean Society of Safety
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    • v.21 no.3 s.75
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    • pp.107-113
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    • 2006
  • Speeding is one of major causes of frequent and severe traffic accidents in school zones. In this paper, the long-term effectiveness of speed monitoring displays (SMD) on speed variability was investigated through a field study in a school zone environment. The performance difference was discussed with several dependent variables including average speed, 85th percentile speed, and distribution of speed. Study results showed that the speed of vehicles began to reduce where the driver recognized the presence of an SMD, and about 12.4 percent (5.8km/h) of average speed was reduced at the SMD location. This speed reduction was observed throughout the day regardless of time of day. Statistical tests showed that the speed difference was statistically significant. In addition, analysis results of speed distribution showed that the number of speeding vehicle was greatly reduced after the SMD was installed, and 85th percentile speed also decreased from 54.3km1h to 45.0km/h. Therefore, it was concluded that the application of SMD produced a positive impact on the driver's behavior for a long period of times.

SHORT-TERM WIND SPEED FORECAST BASED ON ARMA MODEL IN JEJU ISLAND (제주도에서의 ARMA 모델을 기반으로한 단기 풍속 예측)

  • Do, Duy Phuong N.;Lim, Jintaek;Lee, Yeonchan;Oh, Ungjin;Choi, Jaeseok
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.329-330
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    • 2015
  • From the results of previous my paper [10] in 2015 year of economic and electrical power storage research conference in Naju, this paper describes an application of autoregressive and moving average (ARMA) model to forecast hourly average wind speed (HAWS) in Jeju island. The models are used to build up short-term forecast of hourly average wind speed by the weighted sum of previous wind speed values.

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A Study on the Relation of Urban Heat Island and Air Pollution in Seoul Area (서울지역의 도시열섬현상과 대기오염도의 관계에 관한 연구)

  • 장영기;김정욱
    • Journal of Korean Society for Atmospheric Environment
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    • v.7 no.1
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    • pp.49-53
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    • 1991
  • Relations of urban heat island and air pollution are analyzed by using $SO_2$ concentration data (winter season in 1985) from 10 sites of Seoul area and differences of wind speed and air temperature in urban and rural area. Urban heat island is developed when daily mean wind speed at urban site is lower than 1.5m/sec or in the interval of 3.0 $\sim$ 3.5m/sec. When differences between urban and rural air temperature is greater than the overall average of those differences, $SO_2$ concentrations of those above-average differences are 1.3 $\sim$ 1.8 times higher than those of below-average differences. The trends are shown obviously at north-eastern area of Seoul (Gilum Dong, Ssangmun Dong, Myeonmog Dong). When intensity of Urban Heat Island is weak, $SO_2$ concentration was reduced in propotion to a rise of wind speed. But $SO_2$ concentration is on the partial increase in spite of a rise of wind speed when intensity of urban heat island is strong.

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Development of a Turning Radius Measurement System using DGPS for Agricultural Tractors (DGPS를 이용한 농용트랙터 선회반경 측정 시스템 개발)

  • Kim, Yu-Yong;Lim, Jong-Guk;Shin, Seoung-Yeop;Kim, Hyeok-Ju;Kim, Byoung-Gap;Kim, Hyeong-Kwon
    • Journal of Biosystems Engineering
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    • v.35 no.2
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    • pp.85-90
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    • 2010
  • This study was carried out to develop turning radius measuring method and device of using a DGPS speed sensor for agricultural tractors. The measurement system consisted of a DGPS speed sensor, a data acquisition device, a touch panel, a photo sensor, a radio modem and a notebook computer. Three methods were developed: average of turning speed-time method, integral of turning speed-time method, and speed-heading angular velocity method. Best method was average of turning speed-time method which could be used with a maximum error 2.7 cm.

Resonance Frequency Analysis to Laser Welding Condition by Time-average ESPI (Time-average ESPI에 의한 레이저용접 조건에 따른 공진주파수 특성 분석)

  • 이유황;김경석;정성욱;최태호
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.10a
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    • pp.245-249
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    • 2004
  • This paper describes the vibration characteristics of Nd:YAG laser welding plates analyzed time-average Electronic Speckle Pattern Interferometry(ESPI). In laser welding, the travel speed has influence on a mechanical properties, such as elastic modules, response frequencies and so on, which is resulted on a residual stress of the welding zone. the response frequencies related to elastic modules are determined by time-average ESPI and the results, as compared to each condition, are used to estimate optimal condition of travel speed.

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