• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1835-1838
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• 2002

This paper presents the statistical analysis and the effects of the ionospheric scintillation to the satellite communication system. By receiving 1.694 GHz carrier wave of telemetry signal transmitted from Geostationary Meteorological Satellite (GMS-5) at both of King Mongkut's Institute of Technology Ladkrabang, Bangkok. and Chiang Mai University, Thailand, in order to study the characteristics of Ionospheric scintillation in case of different geomagnetic latitude Position; the statistical analysis of S$_4$, fade duration. message reliability and fade rate can be obtained . The data was analyzed from february 2000 to January 2001

• Journal of Power Electronics
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• v.2 no.1
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• pp.25-31
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• 2002

Servo drives with microcomputer control provide the possibility of using modern and sophisticated control algorithms. As an additional feature it is possible to implement parallel and/or redundant software and hardware structures to realise safe motion or similar security functions. Unfortunately microcomputer control also has some impact on the behaviour of servo drives. Control algorithm, cycle time, sensors and interface have to be perfectly synchronised. Special control schemes are necessary on the line side (power supply) to meet the actual requirements concerning EMC. This contribution presents experiences and results obtained from a modern digital drive system pointing out the influences of low and high accuracy position sensors and the interdependencies mentioned above.

• Proceedings of the Korean Magnestics Society Conference
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• 2002.12a
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• pp.12-12
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• 2002

We present the new jaw tracking system that utilizes five degrees of freedom of head and lower jaw. The proposed method does not disturb the physiology because the system does not need to fix magnetic field sensors or clutch on the patient's body or mouth. The impact of this result goes beyond the conventional optical and magnetic tracking system of jaw movement [1][2]. Position accuracy within 1mm and reasonable cost is necessary for practical use of the jaw tracking system. (omitted)

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.8
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• pp.731-737
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• 2012

In this paper the usage of Bluetooth in networked control systems is described. ACL links and commonly used serial port profile built on top of ACL links are analyzed and their problems such as unpredictable latency are discovered. SCO link packet scheduling, latency estimation and setup procedure are examined. SCO link is suggested as proper link for NCS, due to its low latency and low variance. Smith predictor use for latency compensation is described and its impact on control performance is estimated. A number of experiments on DC motor position control are performed and control performance of system utilizing SCO link with and without Smith predictor is proved to be higher than control performance of system utilizing ACL link.

• JSTS:Journal of Semiconductor Technology and Science
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• v.10 no.2
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• pp.100-106
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• 2010

The impact of surface quantization on device parameters of a Si metal oxide semiconductor (MOS) capacitor has been analyzed in the present work. Variation of conduction band bending, position of discrete energy states, variation of surface potential, and the variation of inversion carrier concentration at charge centroid have been analyzed for different gate voltages, substrate doping concentrations and oxide thicknesses. Oxide thickness calculated from the experimental C-V data of a MOS capacitor is different from the actual oxide thickness, since such data include the effect of surface quantization. A correction factor has been developed considering the effect of charge centroid in presence of surface quantization at strong inversion and it has been observed that the correction due to surface quantization is crucial for highly doped substrate with thinner gate oxide.

• Journal of the Korea Society of Computer and Information
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• v.22 no.6
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• pp.25-32
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• 2017

We are living in networks which are regarded as a society. However, it is difficult to designate a specific position or the impact over sociological relationships and virtual links. In this paper, we conceptualize two themes of the network as Physical Network and Virtual Network, and observe their cross-network effects. New concept called Networked Community (NC) is then introduced to walk through both PN and VN by using the element of connections say connectivity feature. Through modeling NC by the theme of network transposition and egocentric network, we try to comprehend all possible networks for detecting the problems and solutions by using both sides' idea. Experimental results show that we can model real-world problems and then analyze them through NC by measurable and structural manner.

• Nuclear Engineering and Technology
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• v.36 no.6
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• pp.497-511
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• 2004

A PSV (pressurizer safety valve) popping test carried out in the early phases of a refueling outage may trigger a test-induced LOCA(loss of coolant accident) if a PSV fails to fully close and is stuck in a partially open position. According to a KSNP (Korea standard nuclear power plant) low power and shutdown PSA (probabilistic safety assessment), the failure of a high pressure safety injection (HPSI) accompanied by the failure of a PSV to fully close was identified as a dominant accident sequence with a significant impact on low power and shutdown risks (LPSR). In this study, we aim to investigate and verify a new means for mitigating this type of accident using a thermal-hydraulic analysis. In particular, we explore the applicability of an aggressive cool-down combined with operator actions. The results of the various sensitivity studies performed there will help reduce LPSR and improve Refueling outage safety.

• Journal of the Optical Society of Korea
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• v.6 no.3
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• pp.108-116
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• 2002

Lasing modes of laser-diode-pumped fiber grating lasers are analyzed by coupled-mode theory. First, a power series solution of the coupled-mode equations is derived under the assumption of an exponentially-decreasing longitudinal modal gain profile for a laser-diode-pumped grating section, followed by determination of the transfer matrix for such a section. Based on these results, an eigenvalue equation for oscillation is then derived and solved numerically for the lasing modes of uniform and phase-shifted fiber grating lasers. Comparisons made with the uniform-gain results indicate that, surprisingly, the lasing mode characteristics are not as significantly altered as might be expected in most cases, even for a highly nonuniform gain profile. In the case of a phase-shifted grating, the phase-shift position appears to have a much greater impact on determining the threshold gain, the modal field distribution, and the front-to-back output power ratio.

• Research in Mathematical Education
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• v.18 no.2
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• pp.149-170
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• 2014

The Vietnamese language has a specific property related to the zero in the name-number system. This study was conducted to examine the impact of linguistic differences and of the zero's position in a number on a transcoding task (verbal number into Arabic number). Vietnamese children and French-speaking Belgian children, from grades 3 to 6, participated in the study. The success rate and the type of errors they made varied, depending on their grade and language. At Grade 4, Vietnamese children showed performances equivalent to Grade 6 Belgian children. Our results confirmed the support provided by language to the understanding and performances in a transcoding task. Results also showed that a syntactic zero is easier to manipulate than a lexical zero for Vietnamese children. The relative influence of language and the source of errors are discussed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11b
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• pp.1089-1092
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• 2001

In order to measure the vibration of a ribbed clindrical shell, the principle of reciprocity has been implemented. An accelerometer was fixed at the position defined as the excitation point. An impact hammer was used to tap at the response array points (64 points) located along the circumference of the shell. The frequency response function was reciprocally measured at each point in turn. The response data was processed to obtain the frequency/wavenumber spectrum. From the spectrum the characteristics of wave propagation on the ribbed cylindrical shell have been observed.