• Title/Summary/Keyword: idle start

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A Study of GDI+MPI Engine Operation Strategy Focusing on Fuel Economy and Full Load Performance using DOE (실험계획법에 의한 가솔린 GDI+MPI 엔진의 연비 및 성능향상 관점에서의 운전영역별 연료분사 전략에 관한 연구)

  • Kim, Dowan;Lee, Sunghwan;Lim, Jongsuk
    • Transactions of the Korean Society of Automotive Engineers
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    • v.22 no.3
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    • pp.42-49
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    • 2014
  • The gasoline direct injection (GDI) system is considerably spreading in automotive market due to its advantages. Nevertheless, since GDI system emit higher particle matter (PM) due to its combustion characteristics, it is difficult to meet strengthened emission regulation in near future. For this reason, a combined GDI with MPI system, so-called, dual injection (DUI) system is being investigated as a supplemental measure for the GDI system. This paper focused on power and fuel consumption effect by injection mode strategy of DUI system in part load and idle engine operating condition. In this study, port fuel injectors are installed on 2.4 liters GDI production engine in order to realize DUI system. And, at each injection mode, DOE (design of experiment) method is used to optimize engine control parameters such as dual injection ratio, start of injection timing, end of injection timing, CAM position and so on. As a consequence, DUI mode shows slightly better or equivalent fuel efficiency compared to conventional GDI engine on 9 points fuel economy mode as well as MPI mode shows less fuel consumption than GDI mode during idle operation. Furthermore, DUI system shows improvement potential of maximum 2.0% fuel consumption and 1.1% performance compared to GDI system in WOT operating condition.

Two Cases of Narcolepsy Patient Portraying a Tendency of a Dull Learning Ability and Mistaken as an Idle Student (학습부진 양상을 보이고 나태한 학생으로 오인된 기면증 환자 2 례)

  • Lee, Seung-Hwan;Kim, Sun-Kook;Kim, Leen;Chung, Young-Cho;Suh, Kwang-Yoon
    • Sleep Medicine and Psychophysiology
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    • v.8 no.2
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    • pp.138-143
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    • 2001
  • Sleepiness is associated with many different conditions and, as a neglected topic, it can be the cause of serious psychological and social disadvantages. In the aspect of learning, additional problems may arise from poor progress in school caused by the effect of sleepiness on concentration, memory, and other cognitive functions. Narcolepsy is by no means the most common cause of excessive sleepiness. Nonetheless, it is not a rarity, especially in young people. The non-specific nature of early features of narcolepsy, combined with very limited awareness that the condition can start in various ways, leads to many misinterpretations. Misinterpretation of narcolepsy symptoms is not confined to the medical profession. Teachers may well be critical of a student with narcolepsy because of their perception of narcolepsy symptoms as laziness, poor motivation, or difficult behavior and dull learning ability. Inappropriate reactions by parents, teachers, and peers, based on misinterpretation of narcolepsy symptoms or the patient's reactions to them, make a difficult situation worse. Especially in Korea, where schooling is focused on college entrance examinations, the problem is very serious and intensified by inappropriate or delayed diagnosis and treatment. Therefore, psychiatrists should be aware that narcolepsy in young adolescents is not rare and that they need to be familiar with its clinical features in both its classic and less obvious forms. Narcolepsy should be suspected if a adolescent's excessive sleepiness can not be explained in other ways. Therefore, we report on two patients who portray the tendency of dull learning ability and are mistaken as idle students. We diagnosed narcolepsy through polysomnography and multiple sleep latency testing. We treated the students with methylphenidate and pemolin. The students showed improvement in learning ability and were able to adapt better to school.

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Development of an IoT-Based Human Interactive Advertising Service for Sharing Economy (공유경제를 위한 IoT 기반의 휴먼 인터랙티브 광고 서비스 구현)

  • Jung, Wonseok;Lee, Chang-Kyo;Ko, Wan-Jin;Seo, Jeongwook
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2019.05a
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    • pp.413-415
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    • 2019
  • In this paper, we develop IoT-HiAS(IoT-Human Interactive Advertising Service) for sharing economy. The HiAS device shooting the front of the device via a webcam and recognizes the person in real time through the SSD model using MobileNet. If the number of persons above the set threshold is recognized by counting the recognized person, the advertisement is reproduced on the idle resource through the beam projector. At the same time as the advertisement is reproduced, the captured image of the advertisement start time in the front of the device and the number of recognized persons are sends the IoT server of an oneM2M-compliant HiAS server using the IoT client. When the advertisement is finish, the webcam is shooting the front of the device and the image is sends the IoT server. We implemented the IoT-based human interactive advertising service by transmitting the received data to the advertiser and the advertising producers through the SNS(Social Network Service) agent of the HiAS server.

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Effect of Value Timing on Residual Gas Fraction and Combustion Characteristics at Part Load Condition in an SI Engine (가솔린 엔진의 밸브타이밍 변화가 부분부하 조건에서 잔류가스량 및 연소특성에 미치는 영향)

  • 김철수;송해박;이종화;유재석;조한승
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.4
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    • pp.26-33
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    • 2000
  • In-cylinde flow and mixture formation are key contributors to both idle stability and combustion stability at part load condition in SI engine. The real time measurements of air-fuel ration and in- cylinder residual gas fraction are particularly important to obtain a better understanding of the mechanisms for combustion and emissions especially during cold start and throttle transient condition. This paper reports the cycle resolved measurements of residual gas fraction and equivalence ration near speak plug with value timing change and their effects on combustion characteristics at part load. The results showed that the effect of intake value opening on the residual gas fraction was smaller than that of exhaust valve closing because of the decreases of exhaust gas reverse flow from exhaust port. The variation of equivalence ratio near spark plug increased with the increase of value overlap and it closely related with heat release rate and combustion stability

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Novel Estimation Technique for the State-of-Charge of the Lead-Acid Battery by using EKF Considering Diffusion and Hysteresis Phenomenon (확산 및 히스테리시스 현상을 고려한 확장칼만필터를 이용한 새로운 납축전지의 충전상태 추정방법)

  • Duong, Van-Huan;Tran, Ngoc-Tham;Park, Yong-Jin;Choi, Woojin
    • The Transactions of the Korean Institute of Power Electronics
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    • v.19 no.2
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    • pp.139-148
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    • 2014
  • State-of-charge (SOC) is one of the significant indicators to estimate the driving range of the electric vehicle and to control the alternator of the conventional engine vehicles as well. Therefore its precise estimation is crucial not only for utilizing the energy effectively but also preventing critical situations happening to the power train and lengthening the lifetime of the battery. However, lead-acid battery is time-variant, highly nonlinear, and the hysteresis phenomenon causes large errors in estimation SOC of the battery especially under the frequent discharge/charge. This paper proposes a novel estimation technique for the SOC of the Lead-Acid battery by using a well-known Extended Kalman Filter (EKF) and an electrical equivalent circuit model of the Lead-Acid battery considering diffusion and hysteresis characteristics. The diffusion is considered by the reconstruction of the open circuit voltage decay depending on the rest time and the hysteresis effect is modeled by calculating the normalized integration of the charge throughput during the partial cycle. The validity of the proposed algorithm is verified through the experiments.

INVESTIGATION OF RUNNING BEHAVIORS OF AN LPG SI ENGINE WITH OXYGEN-ENRICHED AIR DURING START/WARM-UP AND HOT IDLING

  • Xiao, G.;Qiao, X.;Li, G.;Huang, Z.;Li, L.
    • International Journal of Automotive Technology
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    • v.8 no.4
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    • pp.437-444
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    • 2007
  • This paper experimentally investigates the effects of oxygen-enriched air (OEA) on the running behaviors of an LPG SI engine during both start/warm-up (SW) and hot idling (HI) stages. The experiments were performed on an air-cooled, single-cylinder, 4-stroke, LPG SI engine with an electronic fuel injection system and an electrically-heated oxygen sensor. OEA containing 23% and 25% oxygen (by volume) was supplied for the experiments. The throttle position was fixed at that of idle condition. A fueling strategy was used as following: the fuel injection pulse width (FIPW) in the first cycle of injection was set 5.05 ms, and 2.6 ms in the subsequent cycles till the achieving of closed-loop control. In closed-loop mode, the FIPW was adjusted by the ECU in terms of the oxygen sensor feedback. Instantaneous engine speed, cylinder pressure, engine-out time-resolved HC, CO and NOx emissions and excess air coefficient (EAC) were measured and compared to the intake air baseline (ambient air, 21% oxygen). The results show that during SW stage, with the increase in the oxygen concentration in the intake air, the EAC of the mixture is much closer to the stoichiometric one and more oxygen is made available for oxidation, which results in evidently-improved combustion. The ignition in the first firing cycle starts earlier and peak pressure and maximum heat release rate both notably increase. The maximum engine speed is elevated and HC and CO emissions are reduced considerably. The percent reductions in HC emissions are about 48% and 68% in CO emissions about 52% and 78%; with 23% and 25% OEA, respectively, compared to ambient air. During HI stage, with OEA, the fuel amount per cycle increases due to closed-loop control, the engine speed rises, and speed stability is improved. The HC emissions notably decrease: about 60% and 80% with 23% and 25% OEA, respectively, compared to ambient air. The CO emissions remain at the same low level as with ambient air. During both SW and HI stages, intake air oxygen enrichment causes the delay of spark timing and the increased NOx emissions.

(Methods for Improving ENHHO of CDMA Mobile Communication) (CDMA 이동통신 ENHHO의 성능개선 방안)

  • 최동유;김재섭;이강현;박창균
    • Journal of the Institute of Electronics Engineers of Korea TE
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    • v.39 no.1
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    • pp.55-64
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    • 2002
  • One of the most important things is Hand-0ff(H/O) in mobile phone service. Meantime soft H/O and softer H/O have been used between the same generations(2G$\longleftrightarrow$2G) and there is little problem. With user's needs and the development of communication technology, the system with different generation coexists and pilot beacon and time-periodic beacon are used for H/O between generations(2.5G$\longleftrightarrow$G) to start service, but it is not economic and efficient. To improve such problems, ENHHO developed in April 2001 has recently used. Unfortunately, this method also has the defect of momentary cutoff of communication information during the procedure of H/O in case of mote than 5 pilot signals. Accordingly, we suggest algorithm to improve the problem of ENHHO and examines its propriety by analyzing the results of field survey using the algorithm.

Design of Low Power H.264 Decoder Using Adaptive Pipeline (적응적 파이프라인을 적용한 저전력 H.264 복호기 설계)

  • Lee, Chan-Ho
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.47 no.9
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    • pp.1-6
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    • 2010
  • H.264 video coding standard is widely used due to the high compression rate and quality. H.264 decoders usually have pipeline architecture by a macroblock or a $4{\times}4$ sub-block. The period of the pipeline is usually fixed to guarantee the operation in the worst case which results in many idle cycles and the requirement of high data bandwidth and high performance processing units. We propose adaptive pipeline architecture for H.264 decoders for efficient decoding and lower the requirement of the bandwidth for the memory bus. Parameters and coefficients are delivered using hand-shaking communication through dedicated interconnections and frame pixel data are transferred using AMBA AHB network. The processing time of each block is variable depending on the characteristics of images, and the processing units start to work whenever they are ready. An H.264 decoder is designed and implemented using the proposed architecture to verify the operation using an FPGA.

Growth Factors and Policy Implications of Hokkaido University Research & Business Park in Japan (일본 홋카이도대학 리서치 & 비즈니스파크의 성장요인과 정책적 시사점)

  • Jang, Hoo-Eun
    • Journal of the Economic Geographical Society of Korea
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    • v.25 no.3
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    • pp.339-356
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    • 2022
  • This study focuses on Hokkaido University Research & Business Park in Japan as an example of establishing a regional innovation ecosystem on campus based on the outstanding research and university-industry collaboration capabilities of local universities in non-metropolitan areas with weak foundations for start-ups and corporate growth. Hokkaido University Research & Business Park established a mid-to long-term plan using the idle sites on campus, and was developed through a gradual development process since 2003. The promotion of university-industry collaboration was pursued through an industrial-based approach of establishing a bio-industry cluster considering the characterization of local universities and the foundation of local industries. It also provides various corporate support services through cooperative governance between local industry, universities, research institutes and the government. This strategy for creating Hokkaido University Research & Business Park provides important policy implications for various policies and projects that promote regional development by utilizing university campuses like the campus innovation park project.