• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1841-1848
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• 2010

Electric railway system consist of rolling stock, track, signal and streetcar line system. ATP(Automatic Train Protection) system in railway signaling system is the important one grasping the position and velocity of a train. The wayside transmitter of ATP system is installed between rails. Recently, the research about increasing train speed has been developed in total departments of the railroad systems. The study on the information transmission between on-board transmitter and wayside transmitter is required for increasing the train speed in the ATP system. When the train speed is increased as to same transmissi on distance, the problem on information transmission occurs because the transmission time is decreased. In case that the transmission distance is extended, the transmission time is decreased with respect to the train speed. Therefore, we have to define the standard magnetic intensity as to the train speed in order to transmit correctly telegram. In this paper, the transmission distance for the telegram is suggested on the basis of the train speed. Also, the standard magnetic intensity from the wayside transmitter to on-board transmitter is proposed by using transmission distance regarding the train speed in the ERTMS/ETCS system by using Matlab program.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.10
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• pp.1803-1808
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• 2010

Electric railway system consists of rolling stock, track, signal and catenary system. ATP system in railway signaling system is the important one grasping the position and velocity of a train. The wayside device of ATP system is installed between rails. Recently, the research about increasing train speed has been developed in total departments of the railroad systems. The study on the information transmission between on-board device and wayside device is required for increasing the train speed in the ATP system. When the train speed is increased as to same transmission distance, the problem on information transmission occurs because the transmission time is decreased. In case that the transmission distance is extended, the transmission time is decreased with respect to the train speed. Therefore, we have to define the standard magnetic field intensity as to the train speed in order to transmit correctly telegram. In this paper, the transmission distance for the telegram is suggested on the basis of the train speed. Also, the standard magnetic field intensity from the wayside device to on-board device is proposed by using transmission distance regarding the train speed in the ERTMS/ETCS system by using Matlab program. Also, BER according to the train speed is presented by calculating electric field intensity from the magnetic field intensity.

• Journal of Drive and Control
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• v.10 no.2
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• pp.30-36
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• 2013

Tractor is a farm vehicle that is designed to provide a high tractive effort at low speed. It is used for versatile agricultural tasks such as hauling a trailer, tillage, mowing and construction work. Most older tractors use a manual transmission. However, as the intensity of work increases, tractors equipped with automatic transmission become popular due to the work convenience. In order to give the operator a large degree of control in field work, 24 gears with automatic 8-speed and manual 3-speed are arranged in transmission. This paper deals with the gear train that is designed for 8-speed automatic transmission by the engagement of multi-disk clutches. The gear ratio for each speed as well as power transmission mechanism is analyzed through velocity analysis. In addition, constraints of mesh gear ratio are derived by investigating the power flow path in velocity diagram for the given 8-speed gear ratio.

• Journal of Biosystems Engineering
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• v.16 no.3
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• pp.239-247
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• 1991

This study was conducted to investigate the feasbility of continuously variable V-belt transmission(CVVT) as automatic power transmission system of combine harvesters. An experimental set-up for testing the performance of CVVT and the automatic transmission system was designed and used to analyze the power transmission characteristics of CVVT. The transmission efficiency of CVVT was increased logarithmically with increase of the load of driven shaft, but was not affected by the speed ratios of transmission. More than 80% of transmission efficiency was obtained in the 25N-m load and more of driven-shaft, and the maximum efficiency was 88~91%. When rapid speed change of the CVVT was attempted, the speed of driven shaft was stabilized within about 0.4 seconds after shift operation in both cases of increasing and decreasing of the speed.

• Wind and Structures
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• v.34 no.4
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• pp.335-353
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• 2022

The current work numerically investigates the transient force and dynamic response of an overhead transmission tower-line structure caused by the passage of a high-speed train (HST). Taking the CRH2C HST and an overhead transmission tower-line structure as the research objects, both an HST-transmission line fluid numerical model and a transmission tower-line structure finite element model are established and validated through comparison with experimental and theoretical data. The transient force and typical dynamic response of the overhead transmission tower-line structure due to HST-induced wind are analyzed. The results show that when the train passes through the overhead transmission tower-line structure, the extreme force on the transmission line is related to the train speed with a significant quadratic function relationship. Once the relative distance from the track is more than 15 m, the train-induced force is small enough to be ignored. The extreme value of the mid-span dynamic response of the transmission line is related to the train speed and span length with a significant linear functional relationship.

• Journal of Advanced Marine Engineering and Technology
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• v.30 no.8
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• pp.843-852
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• 2006

Vibration/noise analysis as well as strength of planetary gear train are considered in order to develop a transmission for a high-speed ship. The vibration model of a gear pair is developed with considering the elastic deformation of the active teeth and the body to be a rigid. Excitation forces of the transmission system are considered as the mass unbalance of the rotors. misalignment and a function of gear transmission error which comes from the modified tooth surface. A Campbell diagram, in which the excitation sources caused by the mass unbalance of the rotors. misalignment and the transmitted errors of the gearing are considered shows that, at the operating speed, there are not the critical speed.

• Journal of Convergence for Information Technology
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• v.10 no.2
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• pp.32-38
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• 2020

In this paper, we analyze the modulation scheme for high speed transmission in visible light communication system, and study non-orthogonal multiplexing, dimming level and transmission power ratio. Conventional visible light communication has a disadvantage in that it is difficult to multi-transmit to increase the transmission speed. Multi-transmission technique is necessary for high-speed transmission at the transmitter. Since general visible light communication has a limitation in multiple transmission, various researches for high-speed transmission have been conducted. In order to solve this problem, this paper proposes a multiple modulation scheme for high-speed visible light communication using non-orthogonal multiplex transmission scheme and a future research direction.

• Information and Communications Magazine
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• v.11 no.2
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• pp.77-89
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• 1994

High speed optical fiber transmission technology has been remarkably improved during the past 20 years. This paper presents recent research status and future technological issues for the future information society, that is, the Tb/s transmission by frequency division multiplexing and the ultra long-distance by optical soliton transmission. Erbium-doped fiber amplifier and recent optical technology have brought optical transmission system of up to 10 Gb/s to the point of commercialization. Taking into account the future super information highway, that is, B-ISDN network, ultra wide-band picture-based information can be provided for many subscribers via existing optical fiber cables. However, to achieve the high speed transmission, the technologies must be developed not only for transmission lines but also for transmission nodes. Since the conventional signal transmission/processing technique using electronics has the limit in its speed, novel photonic technology is being developed for this purpose. On the other hand, optical solitons propagate stably through optical fibers, without pulse broadening effect of the fiber dispersion. Since the pulse broadening effect becomes serious as the transmission speed increases, optical solitons is the important technologies to realize the high speed, long distance transmission.

• The Transactions of the Korea Information Processing Society
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• v.1 no.4
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• pp.479-489
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• 1994

At the present time, it is an important problem that we are to select a transmission line code for the very-high speed optical transmission system which can confidentially transfer the original information signal sequence efficiently, as it is to be the large capacity and the economization for the optical digital transmission system to transfer the information signal sequence at the very-high speed. Therefore, this paper is to select first the proper transmission line codes for the high speed(more than Mb/s) optical transmission system of the proposed two-level unipolar transmission line codes up to date, and to decide a mBIZ (m Binary with One Zero insertion) code as an optimal transmission line code for the very-high speed optical transmission system, resulting from analyzing the performance at the requirements of the transmission line code, such as the maximum consecutive identical digits, the transmission delay time, the increasing rate of clock, the mark rate, the circuit complexity, the supervision of transmission line error, and power spectrum among the selected transmission line codes.

• The Journal of Society for e-Business Studies
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• v.4 no.2
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• pp.41-58
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• 1999

This paper is a study on a model of economic value of transmission speed of Internet Commerce. For this research, this paper searches the factors that influence the transmission speed of Internet and suggests the model for measurement of economic value. The model adopted in this research is CVM(contingent valuation method) using in environment economics and the research area in this paper is concentrated on Internet-based Electronic Commerce. For this purpose, this paper suggests econometrics model that measures customer's payment intention for transmission speed of Internet. This model can be used as the basic tool of feasibility of investment analysis and reasonable pricing on Internet service. For the more, it will be followed empirical study and more careful comprehension for objective validity of this study.