• 제목/요약/키워드: Dual Energy

검색결과 1,043건 처리시간 0.027초

이중분사식 수소기관의 비정상 열부하 해석에 관한 연구 (A Study on Unsteady Thermal Loading of Hydrogen Engine with Dual Injection)

  • 위신환;김윤영;김홍준;이종태
    • 한국수소및신에너지학회논문집
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    • 제12권2호
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    • pp.147-155
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    • 2001
  • To measure of thermal loading in the combustion chamber of hydrogen engine with dual injection, instantaneous wall-surface temperature and unsteady heat flux of the cylinder head are measured and analyzed. The maximum wall surface temperature is shown in direct injection region which has large heat supplied. Partial and spatial temperatures have slight deviation in transient region of injection, though injection method change suddenly. All of thermal characteristics such as instantaneous temperature, temperature swing and heat flux of hydrogen engine with dual injection are remarkably higher than those of gasoline engine. It means necessity of additional countermeasure of thermal loading.

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복합 열원 공조시스템의 최적 제어 알고리즘 (Optimal Control Algorithm for the Dual Source Chiller Air Conditioning System)

  • 한도영;김진
    • 설비공학논문집
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    • 제16권9호
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    • pp.881-888
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    • 2004
  • Control algorithms for a dual source chiller air conditioning system were developed. These are control algorithms for the supply air temperature control, the supply header chilled water temperature control, the chiller chilled water temperature control, and the cooling tower water temperature control. These algorithms were analyzed by using a dynamic simulation program. Simulation results showed the energy savings and the satisfactory controls of an absorption and centrifugal chiller air conditioning system. Therefore, control algorithms developed for this study may effectively be used for the improved controls of the dual source chiller air conditioning system.

진가태극권 동작에 대한 음양논적인 연구 -태극초세를 중심으로- (Study on the Dual Principle of the Negative-Positive Toward 'the Motion of ChenJia Taijiquan')

  • 김경철
    • 동의생리병리학회지
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    • 제18권6호
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    • pp.1598-1601
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    • 2004
  • I studied on the dual principle the negative-positive toward 'the motion of Taijiquan'. The results are as follows. The grade of comprehension on the dual principle for the negative-positive for human-body is equal to the comprehension on Taijiquan. YeoBiSae is judged abstractly for the image of MuGeug and GiSae for the image of TaeGeug on the motion of Taijiquan progressing program. The motion of Taijiquan is divided up the extension and contraction. In the motion of Taijiquan, the extension exercises make use of positive energy and DogMaeg(독맥), the contraction exercises make use of negative energy and ImMaeg(임맥).

A DSP-Based Dual Loop Digital Controller Design and Implementation of a High Power Boost Converter for Hybrid Electric Vehicles Applications

  • Ellabban, Omar;Mierlo, Joeri Van;Lataire, Philippe
    • Journal of Power Electronics
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    • 제11권2호
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    • pp.113-119
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    • 2011
  • This paper presents a DSP based direct digital control design and implementation for a high power boost converter. A single loop and dual loop voltage control are digitally implemented and compared. The real time workshop (RTW) is used for automatic real-time code generation. Experimental results of a 20 kW boost converter based on the TMS320F2808 DSP during reference voltage changes, input voltage changes, and load disturbances are presented. The results show that the dual loop control achieves better steady state and transient performance than the single loop control. In addition, the experimental results validate the effectiveness of using the RTW for automatic code generation to speed up the system implementation.

Improved Dual-Path Energy Recovery Circuit using a Current Source and a Voltage Source for High Resolution and Large-Sized Plasma Display Panel

  • Yi, Kang-Hyun;Moon, Gun-Woo
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2008년도 하계학술대회 논문집
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    • pp.544-546
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    • 2008
  • An improved dual-path energy recovery circuit (ERC) using a current source and a voltage source for plasma display panel (PDP) is proposed. The proposed ERC uses the voltage source to charge a panel and the current source to discharge the panel. Thus, the proposed circuit can make the panel charge to $V_S$ and discharge to 0V, fully and it is possible to achieve zero voltage switching (ZVS) of all switches in H-bridge inverter and zero current switching (ZCS) of all switches in the ERC. Moreover, it has less conduction and switching loss in ERC devices by the dual energy recovery paths for charging and discharging the panel. Furthermore, it has features of canceling the gas discharge current, high performance and the low cost ERC components. The operation principle and features of the proposed ERC are presented in detail and verified with 42-inch SD PDP.

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A New Soft Switching Dual Input Converter for Renewable Energy Systems

  • Harchegani, Amir Torki;Mahdavi, Mohammad
    • Journal of Power Electronics
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    • 제17권5호
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    • pp.1127-1136
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    • 2017
  • This paper proposes a new soft switching dual input converter for renewable energy systems. Multi-input converters are produced by combining discrete converters. These converters reduce the number of circuit elements, cost, volume and weight of the converter and provide a constant output power in different weather conditions. Furthermore, soft switching techniques can be applied to increase efficiency. In this paper, a Zero Voltage Transition (ZVT) dual input boost converter is presented. Only one auxiliary circuit is used to provide the soft switching condition for all of the semiconductor elements. The proposed converter, which is simulated by ORCAD software, is theoretically analyzed. To confirm the validity of the theoretical analysis, a prototype of proposed converter was constructed. Simulation and experimental results confirm the theoretical analysis. An efficiency comparison shows a one percent improvement at nominal loads.

A Dual-Cell-Gap Transflective Liquid Crystal Display with Identical Response Time in Transmissive and Reflective Regions

  • Zhang, Jian-De;Wang, Qiong-Hua;Li, Da-Hai;Yan, Jin-Ren
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.87-90
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    • 2009
  • A dual-cell-gap transflective liquid crystal display (TR-LCD) with identical response time in the transmissive and reflective regions is demonstrated. In the transmissive region, strong anchoring energy condition is used to decrease the response time, while in the reflective region weak anchoring energy condition is used to increase the response time. The simulated dual-cell-gap TR-LCD has good performances.

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A 40fJ/c-s 1 V 10 bit SAR ADC with Dual Sampling Capacitive DAC Topology

  • Kim, Bin-Hee;Yan, Long;Yoo, Jerald;Yoo, Hoi-Jun
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제11권1호
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    • pp.23-32
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    • 2011
  • A 40 fJ/c-s, 1 V, 10-bit SAR ADC is presented for energy constrained wearable body sensor network application. The proposed 10-bit dual sampling capacitive DAC topology reduces switching energy by 62% compared with 10-bit conventional SAR ADC. Also, it is more robust to capacitor mismatch than the conventional architecture due to its cancelling effect of each capacitive DAC. The proposed SAR ADC is fabricated in 0.18 ${\mu}m$ 1P6M CMOS technology and occupies 1.17 $mm^2$ including pads. It dissipates only 1.1 ${\mu}W$ with 1 V supply voltage while operating at 100 kS/s.

Study on Material Discrimination by Atomic Number Using Dual Energy ${\gamma}$-Rays

  • Gil, Y.M.;Lee, Y.S.;Lee, H.S.;Cho, M.H.;Namkung, W.
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 2005년도 추계학술발표회
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    • pp.769-770
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    • 2005
  • This study aims to demonstrate the practical value of radioscopic differentiation of materials. The dual energy method is proposed for identifying materials according to atomic numbers. The differentiation of materials is achieved by comparing the attenuation ratio of low and high energy photons. We used gamma-rays of 0.662 MeV and 1.25 MeV and NaI(Tl) scintillation detector with a Multi-channel Analyzer (MCA). We also carried out the Monte Carlo simulation for the case of bremsstrahlung radiation from dual electron beams of 4 MeV and 9 MeV.

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Dual-Energy CT for Pulmonary Embolism: Current and Evolving Clinical Applications

  • Yoo Jin Hong;Jina Shim;Sang Min Lee;Dong Jin Im;Jin Hur
    • Korean Journal of Radiology
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    • 제22권9호
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    • pp.1555-1568
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    • 2021
  • Pulmonary embolism (PE) is a potentially fatal disease if the diagnosis or treatment is delayed. Currently, multidetector computed tomography (MDCT) is considered the standard imaging method for diagnosing PE. Dual-energy CT (DECT) has the advantages of MDCT and can provide functional information for patients with PE. The aim of this review is to present the potential clinical applications of DECT in PE, focusing on the diagnosis and risk stratification of PE.