• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1509_1510
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• 2009

This paper presents the design and simulation results of ohmic contact RF MEMS silicon switch with a high isolation at high frequencies along with the position of a contact part, initial off-state and intermediate off-state including the state where a contact part is placed right over a signal line of coplanar waveguide (CPW). The ohmic contact part is connected with comb drives made of high resistivity single crystalline silicon. The released contact part is $30{\mu}m$ apart from the edge of signal line on the glass substrate along the lateral direction (x-direction) at initial off-state. The electrostatic force of the comb electrode creates the x-directional movement thus initial state is converted to the intermediate off-state. The initial off-state of the switch results in isolations of -31 dB, -24 dB and reflections of -0.45 dB, -0.67 dB at 50 GHz and 110 GHz, respectively. It shows the isolation degradation when the contact part moves right over the signal line of CPW like an initial off-state of a conventional MEMS switch. The isolations and reflections are -31 dB, -24 dB and -0.50 dB, -1.31 dB at 50 GHz and 110 GHz, respectively at the intermediate off-state.

• 대한조선학회논문집
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• 제44권5호
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• pp.534-541
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• 2007

This paper suggests the mathematical method for the estimation of the required engine output for WIG crafts. The engine size of a WIG craft Is a key parameter in the design stage, because WIGs should overcome the hump drag during the take-off. Therefore, it is very important for a WIG designer to estimate required power and state change during take-off. The mathematical method was developed based on the steady planing state model of a planing boat. Through numerical calculations on various take-off states, it was found that the suggested method could give reasonable estimation of required power and state change during take-off.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2019년도 춘계학술대회
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• pp.283-284
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• 2019

In the last decades patient's suffering with Parkinson's disease is increasing at a rapid rate and as per prediction it will grow more rapidly as old age population is increasing at a rapid rate through out the world. As the performance of wearable sensor based approach reached to a new height as well as powerful machine learning technique provides more accurate result these combination has been widely used for assessment of various neurological diseases. ON state is the state where the effect of medicine is present and OFF state the effect of medicine is reduced or not present at all. Classification of ON/OFF state for the Parkinson's disease is important because the patients could injure them self due to freezing of gait and gait related problems in the OFF state. in this paper wearable sensor based approach has been used to collect the data in ON and OFF state and machine learning techniques are used to automate the classification based on the gait pattern. Supervised machine learning techniques able to provide 97.6% accuracy while classifying the ON/OFF state.

• 대한전자공학회논문지SD
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• 제37권12호
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• pp.29-34
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• 2000

금속유도 측면 결정화에 의해 제작된 다결정 실리콘 박막 트랜지스터(Thin Film Transistor; TFT)의 전기적 스트레스의 효과에 대해 연구하였다. MILC로 제작된 TFT에 전기적 스트레스가 인가될 때, off-state 전류가 100배에서 10000배까지 감소한다. 그러나 전기적 스트레스를 인가한 소자를 관상로에서 열처리를 할 경우 열처리온도가 증가할 수록 off-state 전류가 다시 증가했다. 열처리온도에 따른 off-state 전류의 의존성으로부터 MILC 다결정 실리콘 박막내 트랩준위의 활성화에너지(0.34eV)를 얻어냈다.

• Wind and Structures
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• 제35권1호
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• pp.21-34
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• 2022

Gust factor is an important parameter for the conversion between peak gust wind and mean wind speed used for the structural design and wind-related hazard mitigation. The gust factor of typhoon wind is observed to show a significant dispersion and some differences with large-scale weather systems, e.g., monsoons and extratropical cyclones. In this study, insitu measurement data captured by 13 meteorological towers during a strong typhoon Morakot are collected to investigate the statistical characteristics, height and wind speed dependency of the gust factor. Onshore off-sea and off-land winds are comparatively studied, respectively to characterize the underlying terrain effects on the gust factor. The theoretical method of peak factor based on Gaussian assumption is then introduced to compare the gust factor profiles observed in this study and given in some building codes and standards. The results show that the probability distributions of gust factor for both off-sea winds and off-land winds can be well described using the generalized extreme value (GEV) distribution model. Compared with the off-land winds, the off-sea gust factors are relatively smaller, and the probability distribution is more leptokurtic with longer tails. With the increase of height, especially for off-sea winds, the probability distributions of gust factor are more peaked and right-tailed. The scatters of gust factor decrease with the mean wind speed and height. AS/NZ's suggestions are nearly parallel with the measured gust factor profiles below 80m, while the fitting curve of off-sea data below 120m is more similar to AIJ, ASCE and EU.

• 한국신뢰성학회지:신뢰성응용연구
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• 제8권4호
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• pp.193-204
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• 2008

In this paper, we proposed availability evaluation of network in mobile communication network that have hand off structure. Radio mobile communication network is essential hand off action to keep communication that is no discontinuance by transfer of terminal. Part by state and hand off state ago hand off by transfer of terminal and communication network is estimated performance according to the hand off rate and hand off completion rate of system. we applied MS, SM, MM communication structure in radio CORBA for network availability evaluate. System availability in mobile communication network that can repair that propose in this study uses the hand off rate and hand off completion rate of system by transfer of terminal and availability of whole system did evaluate.

• International Journal of Industrial Entomology and Biomaterials
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• 제26권1호
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• pp.13-21
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• 2013

Boil-off loss ratio is one of the most important economic traits to be considered during the course of silkworm breeding. The boil-off loss ratio varies among the breeds and seasons. The present study was undertaken with 5 oval and 5 peanut breeds and twenty five hybrids involving these parents to select the promising hybrids with desired boil-off loss ratio. Accordingly, studies were undertaken to estimate the heterosis and heterobeltiosis. It was observed that majority of the hybrids revealed negative heterosis for boil-off loss ratio which is desirable. Based on the heterosis and heterobeltiosis, among all the hybrids, the hybrid APBRO5 ${\times}$ APBRD5 exhibited highest negative heterosis for boil-off loss ratio and also exhibited highest EI value (64.5) for the quantitative and qualitative traits. Based on the hybrids performance, boil-off loss ratio, heterosis and heterobeltiosis and evaluation index, the hybrids viz. APBRO5 ${\times}$ APBRD5, APBRO1 ${\times}$ APBRD1 and APBRO3 ${\times}$ APBRD4 were identified for commercial exploitation.

• Ocean Systems Engineering
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• 제4권1호
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• pp.63-82
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• 2014

Declutching control is applied to a hemispherical wave energy converter with direct linear electric Power-Take-Off systems oscillating in heave direction in both regular and irregular waves. The direct linear Power-Take-Off system can be simplified as a mechanical spring and damper system. Time domain model is applied to dynamics of the hemispherical wave energy converter in both regular and irregular waves. And state space model is used to replace the convolution term in time domain equation of the heave oscillation of the converter due to its inconvenience in analyzing the controlled motion of the converters. The declutching control strategy is conducted by optimal command theory based on Pontryagin's maximum principle to gain the controlled optimum sequence of Power-Take-Off forces. The results show that the wave energy converter with declutching control captures more energy than that without control and the former's amplitude and velocity is relatively larger. However, the amplification ratio of the absorbed power by declutching control is only slightly larger than 1. This may indicate that declutching control method may be inapplicable for oscillating wave energy converters with direct linear Power-Take-Off systems in real random sea state, considering the error of prediction of the wave excitation force.

• 전자공학회논문지A
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• 제33A권3호
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• pp.96-106
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• 1996

One of the major problems for poly-Si TFTs is the large off state leakage current. LDD (lightly doped drain) and offset gated structures have been employed in order to reduce the leakage current. However, these structures also redcue the oN current significantly due to the extra series resistance caussed by the LDD or offset region. It is desirable to have a device which would have the properties of the offset gated structure in the OFF state, while behaving like a fully gated device in the oN state. Therefore, we propose a new thin film transistor with pnp junction gate which reduce the leakage curretn during the OFF state without sacrificing the ON current during the ON state.

• 한국전기전자재료학회논문지
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• 제31권6호
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• pp.372-376
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• 2018

The effects of off-state bias stress on the characteristics of p-type poly-Si TFT were investigated. To reduce the gate-induced drain leakage (GIDL) current, the off-state bias stress was changed by varying Vgs and Vds. After application of the off-state bias stress, the Vgs causing GIDL current was dramatically increased from 1 to 10 V, and thus, the Vgs margin to turn off the TFT was improved. The on-current and subthreshold swing in the aged TFT was maintained. We performed a technology computer-aided design (TCAD) simulation to describe the aged characteristics. The aged-transfer characteristics were well described by the local charge trapping. The activation energy of the GIDL current was measured for the pristine and aged characteristics. The reduced GIDL current was mainly a thermionic field-emission current.