• Title/Summary/Keyword: TVM

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Extraction of optimal time-varying mean of non-stationary wind speeds based on empirical mode decomposition

  • Cai, Kang;Li, Xiao;Zhi, Lun-hai;Han, Xu-liang
    • Structural Engineering and Mechanics
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    • v.77 no.3
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    • pp.355-368
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    • 2021
  • The time-varying mean (TVM) component of non-stationary wind speeds is commonly extracted utilizing empirical mode decomposition (EMD) in practice, whereas the accuracy of the extracted TVM is difficult to be quantified. To deal with this problem, this paper proposes an approach to identify and extract the optimal TVM from several TVM results obtained by the EMD. It is suggested that the optimal TVM of a 10-min time history of wind speeds should meet both the following conditions: (1) the probability density function (PDF) of fluctuating wind component agrees well with the modified Gaussian function (MGF). At this stage, a coefficient p is newly defined as an evaluation index to quantify the correlation between PDF and MGF. The smaller the p is, the better the derived TVM is; (2) the number of local maxima of obtained optimal TVM within a 10-min time interval is less than 6. The proposed approach is validated by a numerical example, and it is also adopted to extract the optimal TVM from the field measurement records of wind speeds collected during a sandstorm event.

Overview of Vietnamese traditional medicine

  • Trinh Hien Trung
    • Bulletin of Food Technology
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    • v.18 no.3
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    • pp.91-97
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    • 2005
  • Nowaday, in Vietnam there are two types of medical services which have coexisted. These are Western medicine or Tay Y and Eastern medicine or Dong Y (this is also known as Oriental medicine). Dong Y is includes Chinese traditional medicine (TCM) or Thuoc Bac and Vietnamese traditional medicine (TVM) or Thuoc nam. In its’ history, Vietnam was dominated by feudal China in more than 1000 years, so that Vietnamese people was impacted much by Chinese thought, culture and medicine of course. Traditional Chinese and Traditional Vietnamese Medicine differ in practice, though they share the same theoretical foundation. Their relationship can be observed by the influence of TCM theories on the TVM which are Yin and Yang, Five Elements. In practice, TCM practitioners usually spend more time giving their patients a sort of theoretical explanation of what's going on, whereas TVM practitioners would use a more practical approach and concentrate less on theory. TVM was popular in common life of working people, generally using ingredients readily available nearby and involving a minimum of processing. Most knowledge was passed unselfconsciously from one generation to the next. It can be said that Vietnamese people are based on theories of TCM and available tropical plant sand animals native to Vietnam to built and develop TVM with it’s own character. The following are some plants are using in normal life of Vietnamese people as food or drink with well-being effect(1,2).

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Experimental Study for Torsional Vibration Monitoring System Development of Diesel Engine (디젤엔진의 비틀림진동 모니터링 시스템 개발을 위한 실험적인 연구)

  • 이돈출;김상환;장석기
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11b
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    • pp.640-646
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    • 2001
  • The torsional vibration monitoring system(TVM) for large diesel engines was developed and applied by manufacturers of torsional vibration damper, flexible coupling and diesel engine since 1990s. And demands of TVM have been steadily increased to operate safely engine and to extend maintenance interval of damper and flexible coupling. In this paper, the experimental methods and algorithms of TVM development which used the existing PC, turning wheel and speed sensors in ship are introduced.

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TVM-based Performance Optimization for Image Classification in Embedded Systems (임베디드 시스템에서의 객체 분류를 위한 TVM기반의 성능 최적화 연구)

  • Cheonghwan Hur;Minhae Ye;Ikhee Shin;Daewoo Lee
    • IEMEK Journal of Embedded Systems and Applications
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    • v.18 no.3
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    • pp.101-108
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    • 2023
  • Optimizing the performance of deep neural networks on embedded systems is a challenging task that requires efficient compilers and runtime systems. We propose a TVM-based approach that consists of three steps: quantization, auto-scheduling, and ahead-of-time compilation. Our approach reduces the computational complexity of models without significant loss of accuracy, and generates optimized code for various hardware platforms. We evaluate our approach on three representative CNNs using ImageNet Dataset on the NVIDIA Jetson AGX Xavier board and show that it outperforms baseline methods in terms of processing speed.

A Study on the Speed-instructions for Increasing Speed of the Train in High Speed Railway (고속철도 증속에 따른 폐색 표준 속도 수립에 대한 연구)

  • Bang, Yung;Kim, Hyun-Min;Cho, Shin-Young;Cho, Yong-Gi
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.1081-1099
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    • 2010
  • The TVM 430 system manufactured by Ansaldo STS in France is currently used in ground signalling system for Kyungbu HSR. It transmits the speed information to the on-board signalling system in the form of continuous signal via the track, and the rolling stock in Kyungbu HSR runs with 300km/h max. operating speed by using the corresponding information. Looking from the recent international trends in HSR, reducing the travelling time and increasing of the line capacity is promoting via the improvement of train speed. In case of TGV Est, they are realizing the normal operation with 320km/h max. operating speed by using TVM SEI signalling system, which is similar to TVM 430. Furthermore, in case Honam HSL, which is under construction, is looking over faster speed than the limited one of Kyungbu HSR(i.e. over 300km/h). In this paper, it is assumed that the existing TVM 430 ground signalling system is used and train speed is improved, therefore the number of block section to be increased depending on the increase of train speed and the standard speed to be used in this case is drawn via the simulation of the train model and described the method accordingly.

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Image Restoration Using Partial Differential Equation (편미분 방정식을 이용한 이미지 복원)

  • Joo, Ki-See
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.12
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    • pp.2271-2282
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    • 2006
  • This paper is concerned with simulation issues arising in the PDE-based image restoration such as the total variation minimization(TVM) and its generalizations. In particular, we study the issues of staircasing and excessive dissipation of TVM-like smoothing operators. A strategy of scaling the algebraic system and a non-convex minimization are considered respectively for anti-staircasing and anti-diffusion. Furthermore, we introduce a variable constraint parameter to better preserve image edges. The resulting algorithm has been numerically verified to be efficient and reliable in denoising. Various numerical results are shown to confirm the claim.

Compatibility on Speed Profile between ATC Signaling and TVM 430 ATC Signaling (ATS 기존선 신호 방식과 TVM430 ATC 신호 방식의 속도 profile에 따른 Compatibility)

  • Kim, Yong-Kyu;Kang, Ki-Sok
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.1423-1425
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    • 2000
  • 경부고속전철(KTX)의 운행은 서울-동대구간은 고속선에 의한 고속 운행을 실행하는 반면, 동대구-부산간은 기존선 전철화 및 선로 개량 사업을 통해 기존선을 운행한다. 그 결과 남서울, 북대전, 남대전, 및 북대구의 기존선과 고속선 연결부 인터페이스는 가장 중요한 검토 및 연구 대상으로, 기존선과 고속선 간의 속도 형상에 대한 호환성은 KTX 차량의 적절한 운행을 결정하는 기본 요소이며 또한 필수 요소로 작용한다. 따라서 본 연구에서는 기존선과 고속선 신호 시스템의 호환성에 따른 속도 천이를 분석한다.

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Development of Optimal Train Operation System in Bottle-neck Section According to the Opening of High Speed Railway in Seoul Metropolitan Area (수도권 고속철도개통에 따른 고속선 병목구간 최적열차운행 체계 연구)

  • Chun, Chunggeun;Chung, Sungbong;NamKung, Baekkyu
    • Journal of the Korean Society for Railway
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    • v.15 no.6
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    • pp.631-637
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    • 2012
  • New Opening of Suseo-Pyeongteak High Speed Railway (HSR) will be a new leap in the Korean railway history. However if this section of HSR line around Seoul Metropolitan Area opens, the confluence of new HSR and existing HSR line in Pyeongteak-Osong section will cause a bottle neck problem. In other words, the opening of Suseo-Pyeongteak HSR line will make the capacity of track reach the limit and the section of railroad between Pyeongteak and Osong will be saturated. This will also make such troubles as restricting the number of train which stops at Cheonan-Asan station. In this study, based on the train assignment theory of TVM430 signal system, the methods of calculating headway and number of train are reviewed and the plan for application of optimal operation pattern during peak hour between Pyeongteak-Osong section is also suggested. To remove the bottle neck problem in this HSR section, 3 alternatives are suggested and the expected effects and problems of each alternative are also analyzed. The results show that the troubles caused by excess of track capacity can be removed without any additional cost if the minimum headway in operating system for HSR is adopted in this section. In the future, if these alternatives are considered to the long-term plan for operating train and signal systems, this will improve the efficiency of train operation, which can remove the bottle neck in the HSR line.

Influence analysis to the ATC signal by using sand on the rail in the High-speed Train(KTX) (살사 동작시 고속차량(KTX) ATC 차상장치의 신호흐름 분석)

  • Yun, Cha-Jung;Lee, Tae-Hoon;Cho, Yong-Gee
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.1029-1030
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    • 2008
  • 철도에서는 열차가 출발할 때 착력을 향상시키기 위해 레일과 차륜사이에 모래를 살사하게 되는데 이때 ATC(Automatic Train Control : 열차자동제어장치) 신호파형에 영향을 줄 수 있다는 판단에 따라 시험운행하면서 ATC 차상장치인 TVM 430의 CRNB 보드 내에서 살사동작 후 신호파형을 측정하고 분석하였다. 이로 인해 다중화 되어 있는 차상장치 시스템의 동작상태와 살사재료별 ATC 신호파형에 미치는 영향성을 파악할 수 있었으며 향후 살사로 인해 발생되는 문제점 등의 연구에 활용될 수 있을 것으로 판단된다.

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Effect Analysis for Track Circuit affected by Track Structure and Material (궤도구조 및 재료가 궤도회로에 미치는 영향 분석)

  • Park, Dae-Geun;Kim, Jung-Hun;Kim, Jae-Hak;Kang, Young-Jong
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.1724-1728
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    • 2008
  • Track circuit is transmitted throughout the rails. In order to insure safe and reliable operation of track circuits, the track and the environment should respect mandatory electrical characteristics. In addition, for cab signalling through track Circuit as per TVM 430, these electrical characteristics should insure the transmission to the train. Track circuits have several operation and safety functions. They can detect the train position and broken rails. When track circuits are used as track to train transmission, they also have to be powered enough to be captured by the train sensors.

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