• KIEE International Transactions on Power Engineering
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• v.2A no.4
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• pp.160-165
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• 2002

This paper describes a proposed performance criteria and evaluation procedures for transmission system planning in Korea. Performance criteria of the transmission system are expected to be used as a guideline for investment into a transmission network. Moreover, performance evaluation procedures, which are based on current practices and widely accepted theories, are suggested to achieve fair and acceptable results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.6
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• pp.509-516
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• 1991

In this paper, we propose on objective evaluation model of telephone transmission qulity in order to estimate a satisfaction score regarding speech quality in a relephone network. As the degradantion factors of telephone transmission quality, this model takes into account transmission loss, noise, distortion, talker echo and sidetone. A performance index[PI] is introduced for five psychological factors affecting telephone speech qualty, and a Mean Opinion Score(MOS) is estimated from the sum of all Pis. The simulation results indicate theat the MOS obtained from the objective evaluation model is in good agreement with that of subjective evaluation.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.1002-1008
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• 2014

This paper describes insulation design and its reliability evaluation of ${\pm}80kV$ HVDC XLPE cable. Recently, the construction of HVDC transmission system, which is combined overhead line with underground cable, has been completed. This system is installed with existing 154 kV AC transmission line on the same tower. In this paper, the lightning transient analysis is firstly reviewed for selection of basic impulse insulation level and nominal insulation thickness. Then the electrical performance tests including load cycle test and superimposed impulse test based on CIGRE TB 496 are performed to evaluate the reliability of newly designed HVDC cable. There is no breakdown for ${\pm}80kV$ HVDC XLPE cable during electrical performance test. Finally, this system is installed in Jeju island based on successful electrical performance test (Type test). After installation tests are also successfully completed.

• International Journal of Quality Innovation
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• v.10 no.1
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• pp.115-126
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• 2009

Video transmission effectiveness in the Ad Hoc network is becoming important recently, if different routing protocols are applied. Some researchers conclude that the reactive protocols are better for file transfer protocol (FTP) and constant bit rate (CBR) or hypertext transfer protocol (HTTP) transmission in an Ad Hoc wireless network but the performance report of video transmission is not much. This study adopts Qualnet (Network Simulator) as a simulation tool for environmental designing and performance testing, and employs an experimental design with eight groups. Our experiment shows that: (1) The performance of AODV (reactive) protocol is better than DSDV, ZRP and DSR when the transmission load has only one video stream; (2) Proactive (DSDV) and Hybrid protocols (ZRP) are better for a smaller Ad Hoc network when it transmits a video stream with some applications (VoIP, FTP and CBR). We conclude that packet loss rate is sensitive to the quality of video transmission and it has negative relationship with Peak Signal-to-Noise Ratio (PSNR) value. In addition, our experiment also shows that PSNR is a simple Metric for the performance evaluation of video transmission.

• Journal of Digital Contents Society
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• v.9 no.3
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• pp.433-439
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• 2008

A moving picture in online game is one of major ways to advertise online games, which gives a lot of help in playing game. In this case, a moving picture is compressed to variable bit rate for efficient storage use and network resource efficiency. Adaptable bandwidth allocation technique builds a transmission plan of a game moving picture. And, then some frames are discarded when transmission rate by the transmission plan is larger than available transmission rate, until transmission rate satisfies available transmission rate. Thus, performance evaluation factors in adaptable bandwidth allocation technique may be dependent on discarding order of a frame which transmission rate is much influenced. In this paper, in order to show the performance, a CBA algorithm, an MCBA algorithm, an MVBA algorithm, [6] and [7] algorithm were applied to a transmission plan in the adaptable band width allocation technique using various frame discard methods and performance evaluation factors were compared in among smoothing algorithms.

• Journal of Biosystems Engineering
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• v.43 no.1
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• pp.1-13
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• 2018

Purpose: The development of compact tractors that can be used in dry fields, greenhouses, and orchards for pest control, weeding, transportation, and harvesting is necessary. The development and performance evaluation of power transmission units are very important when it comes to tractor development. This study evaluates the performance of a driving power transmission unit of a 50 kW multi-purpose narrow tractor. Methods: The performance of the transmission and forward-reverse clutch, which are the main components of the driving power transmission unit of multi-purpose narrow tractors, was evaluated herein. The transmission performance was evaluated in terms of power transmission efficiency, noise, and axle load, while the forward-reverse clutch performance was evaluated in terms of durability. The transmission's power transmission efficiency accounts for the measurement of transmission losses, which occur in the transmission's gear, bearing, and oil seal. The motor's power was input in the transmission's input shaft. The rotational speed and torque were measured in the final output shaft. The noise was measured at each speed level after installing a microphone on the left, right, and upper sides. The axle load test was performed through a continuous equilibrium load test, in which a constant load was continuously applied. The forward-reverse clutch performance was calculated using the engine torque to axle torque ratio with the assembled engine and transmission. Results: The loss of power in the transmission efficiency test of the driving power unit was 6.0-9.7 kW based on all gear steps. This loss of horsepower was equal to 11-18% of the input power (52 kW). The transmission efficiency of the driving power unit was 81.5-89.0%. The noise of the driving power unit was 50-57 dB at 800 rpm, 70-77 dB at 1600 rpm, and 76-83 dB at 2400 rpm. The axle load test verified that the input torque and axle revolutions were constant. The results of the forward-reverse clutch performance test revealed that hydraulic pressure and torque changes were stably maintained when moving forward or backward, and its operation met the hydraulic design standards. Conclusions: When comprehensively examined, these research results were similar to the main driving power transmission systems from USA and Japan in terms of performance. Based on these results, tractor prototypes are expected to be created and supplied to farmhouses after going through sufficient in-situ adaptability tests.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.11
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• pp.1645-1652
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• 2016

FTN(Faster-Than-Nyquist) signaling is a method of transmitting symbols at rates faster than the Nyquist rate in the same bandwidth by overlapping transmission pulses. The transmission power of the FTN signal is greater than that of the Nyquist signal, because the number of symbols in the FTN signal is larger than that in the Nyquist signal for the same time interval. Hence, to evaluate the performance of an FTN-based transmission system properly, the performance evaluation criterion should be carefully set, and conversion formulas among the criteria which are used in Nyquist-based system should also be applied attentively. In this paper, the performance evaluation criteria of the FTN-based transmission system is analyzed and a valid way to set the criteria is proposed.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.853-856
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• 1999

In this paper, for the performance evaluation of the discrete wavelet multitone based VDSL modem we have studied VDSL system test loops(VDSL0 - VDSL7) that are proposed by ANSI T1E1.4. In addition, we have modeled the damage factors of the transmission channel and evaluated the data transmission performance of VDSL transmultiplexer based on DWMT in conjunction with the VDSL test loops. For each M-PAM signaling we have evaluated the SNRs that satisfy BER 〓 10$^{-7}$ through simulation and measured the maximum possible transmission speed on each VDSL test loop.

• Journal of information and communication convergence engineering
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• v.4 no.3
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• pp.97-100
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• 2006

In this paper, the transmission service for medical image is proposed via IEEE 802.15.4a on WPAN environment. Also, transmission and receiving performance of medical image using TH UWB-IR system is evaluated on indoor multi-path fading environment. On the results, the proposed scheme can solve the problem of interference from the medical equipment in same frequency band, and minimize the loss due to the indoor multi-path fading environment. Therefore, the transmission with low power usage is possible.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.4
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• pp.343-351
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• 2014

Washing machines designed to clean laundry have been more widely used at home as they reduce household labor and boost the quality of life. Technological advances and better standards of life increase demand for laundry washing performance. Energy efficiency regulations and consumer demand for the larger trend, washing machine makers should be done in performance studies to reduce power, and water consumption and the load on power transmission devices. In this study, performance of a fully automatic washing machine with unconstrained transmission is analyzed through experiment and CFD simulation. It is found that the interaction between laundry and transmission change the washing behavior and affect washing performance with regard to the degree of freedom. The results obtained in this study can be used in developing new washing machine transmissions and make them more robust.