• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.2
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• pp.104-110
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• 2008

In this paper we proposed a new source-drain structure for N-type MOSFET which can suppress the output resistance reduction of a device in saturation region due to soft break down leakage at high drain voltage when the gate is biased around relatively low voltage. When a device is generally used as a switch at high gate bias the current level is very important for the operation. but in electronic circuit like an amplifier we should mainly consider the output resistance for the stable voltage gain and the operation at low gate bias. Hence with T-SUPREM simulator we designed devices that operate at low gate bias and high gate bias respectively without a extra photo mask layer and ion-implantation steps. As a result the soft break down leakage due to impact ionization is reduced remarkably and the output resistance increases about 3 times in the device that operates at the low gate bias. Also it is expected that electronic circuit designers can easily design a circuit using the offered N-type MOSFET device with the better output resistance.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.6
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• pp.49-56
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• 2000

Due to the rapid increase of long-distance transportation, particular attentions have been paid to truck tires, especially to their dynamic characteristics. In this research, experimental modal analysis on two kinds of light-duty truck tires, i.e., radial tire and bias tire, are performed by using GRFP(global rational fraction polynomial) method to investigate differences of the dynamic behavior of the two tires. The test results have shown that the modal frequencies of bias tire are much higher than the corresponding values of radial tire with a similar mode shape, which is in accordance with the fact that the radial rigidity of bias tire is higher than that of radial tire. And most of the modal decay rates of bias tire are larger than those of radial tire within the scope of this experiment. In the frequency domain range of test, the bias tire has extra modes, which do not occur in the radial tire. This difference is based on the fact that the circumferential rigidity of the bias tire is quire low whereas that of radial tire is so high that the frequencies of the corresponding modes are out of the frequency range of test.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.5
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• pp.93-99
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• 1998

The chirping characteristics of InGaAsP electroabsorption modulatiors have been analyzed. The effective .alpha. parameters for large signal modulation were estimated by comparing the pulse shape after fiber transmission with constant chirping assumption.We investigated the structure and the operating condition of the modulator to improve the chirping characteristics. The .alpha. parameters were calculated as the function of wavelength detuning and the bias voltage. To minimize the chirping performance, high bias voltage and a small wavelength detuning and the bias voltage. To minimize the chirping performance, high bias voltage and a small wavelength detuning were preferred. An negative .alpha. value is achieved at the wavelength detuning below 30meV with a proper bias voltage so that pulse compression effect was expected.

• Journal of the Korean institute of surface engineering
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• v.43 no.3
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• pp.154-158
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• 2010

Numerical analysis is done to investigate the effects of pulse bias on the plasma processing characteristics like ion doping and ion nitriding by using fluid dynamic code with a 2D axi-symmetric model. For 10 mTorr of Ar plasma, -1 kV of pulse bias was simulated. Maximum sheath thickness was around 20 mm based on the electric potential profile. The peak electron temperature was about 20 eV, but did not affect the averaged plasma characteristics of the whole chamber. Maximum ion current density incident on the substrate was 200 $A/m^2$ at the center, but was decreased down to 1/10th at radius 100 mm, giving poor radial uniformity.

• Transactions on Electrical and Electronic Materials
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• v.13 no.1
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• pp.47-49
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• 2012

In this paper, we investigated the anomalous hump in the bottom gate staggered a-IGZO TFTs. During the positive bias stress, a positive threshold voltage shift was observed in the transfer curve and an anomalous hump occurred as the stress time increased. The hump became more serious in higher gate bias stress while it was not observed under the negative bias stress. The analysis of constant gate bias stress indicated that the anomalous hump was influenced by the migration of positively charged mobile interstitial zinc ion towards the top side of the a-IGZO channel layer.

• Journal of Acupuncture Research
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• v.36 no.2
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• pp.59-71
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• 2019

Acupuncture treatment for oculomotor nerve palsy has been increasing recently. This study analyzed randomized controlled trials (RCTs) and case reports, using the Cochrane risk of bias tool to investigate the efficacy of acupuncture therapy for oculomotor nerve palsy. This analysis was performed on March 7, 2019, using online databases (PubMed, Cochrane, NDSL, OASIS, CNKI) where 208 articles were retrieved. Of these, there were 18 case reports and 18 RCTs that matched the inclusion criteria, of which 32 studies used acupuncture as the primary intervention, 1 used pharmacopuncture, 1 used fire-needling, and 1 used electroacupuncture. The most commonly used acupoints were BL1, BL2, ST2, TE23, Ex-HN5, LI4, GB14, ST36, GB20 and GB1. Significant findings were reported in all RCTs. Six adverse events were reported in 3 RCTs, with no effect on the outcome. No side effects were reported in the case reports. The risk-of-bias analysis showed that the articles did not report the experimental protocol used and it was not clear whether the study was blinded. Hence, it was difficult to assess the risk of bias. Analysis of 36 studies showed that acupuncture therapy for oculomotor nerve palsy was effective in many cases. It was difficult to evaluate the potential bias.

• Journal of The Korean Society of Integrative Medicine
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• v.8 no.4
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• pp.1-11
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• 2020

Purpose : The purpose of this meta-analysis was to examine the effects of microcurrent on inflammatory musculoskeletal diseases. Methods : Domestic databases (RISS, NDSL, KISS, DBpia, and Kmbase) were searched for studies that conducted clinical trials associated with microcurrent and its impact on inflammatory musculoskeletal diseases. A total of 606 studies published between 2002 and 2019 were identified, with 8 studies satisfying the inclusion data. The studies were classified according to patient, intervention, comparison, and outcome (PICO). The search outcomes were items associated with blood component, pain, and function. The 8 studies that were included in the study were evaluated using R meta-analysis (version 4.0). The quality of 7 randomized control trials was evaluated using Cochrane risk of bias (ROB). The quality of 1 non-randomized control trial was evaluated using risk of bias assessment tool for non-randomized studies (RoBANS). Effect sizes were computed as the corrected standard mean difference (SMD). A random-effect model was used to analyze the effect size because of the high heterogeneity among the studies. Egger's regression test was carried out to analyze the publishing bias. Results : The following factors had a large effect size involving microcurrent on inflammatory musculoskeletal diseases: blood component (Hedges's g=-2.46, 95 % CI=-4.20~-0.73), pain (Hedges's g=3.51, 95 % CI=2.44~4.77), and function (Hedges's g=3.06, 95 % CI: 1.53~4.58). Except for function (t=1.572, p=.191), Egger's regression test showed that the publishing bias had statistically significant differences. Conclusion : This study provides evidence for the effectiveness of microcurrent on inflammatory musculoskeletal diseases in terms of blood component, pain, and function. However, due to the small sample sizes used in the included studies, the results of our study should be interpreted cautiously, especially considering the publishing bias.

• Korean Journal of Materials Research
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• v.4 no.1
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• pp.9-23
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• 1994

Epitaxial $CoSi_2$ layer has been grown on NaCl(100) substrate at low deposition temperature($200^{\circ}C$) by multitarget bias cosputter deposition(MBCD). The phase sequence and crystallinity of deposited silicide as a function of deposition temperature and substrate bias voltage were studied by X-ray diffraction(XRD) and transmission electron microscopy(TEM) analysis. Crystalline Si was grown at $200^{\circ}C$ by metal induced crystallization(M1C) and self bias effect. In addition to, the MIC was analyzed both theoretically and experimentally. The observed phase sequence was $Co_2Si \to CoSi \to Cosi_2$ and was in good agreement with that predicted by effective heat of formation rule. The phase sequence, the CoSi(l11) preferred orientation, and the crystallinity had stronger dependence on the substrate bias voltage than the deposition temperature due to the collisional cascade mixing, the in-situ cleaning, and the increase in the number of nucleation sites by ion bombardment of growing surface. Grain growth induced by ion bombardment was observed with increasing substrate bias voltage at $200^{\circ}C$ and was interpreted with ion bombardment dissociation model. The parameters of $E_{Ar}\;and \alpha(V_s)$ were chosen to properly quantify the ion bombardment effect on the variation in crystallinty at $200^{\circ}C$ with increasing substrate bias voltage using Langmuir probe.

• Journal of the Korean Data and Information Science Society
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• v.24 no.6
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• pp.1543-1550
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• 2013

In this paper, we study Bayesian estimation for the finite population proportion in binary data under selection bias. We use a Bayesian nonignorable selection model to accommodate the selection mechanism. We compare four possible estimators of the finite population proportions based on data analysis as well as Monte Carlo simulation. It turns out that nonignorable selection model might be useful for weekly biased samples.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2365-2367
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• 2000

The deterministic errors of semiconductor gyros and accelerometers must be estimated and compensated to develop the low-cost IMU using them. Generally, the dominant errors of the low-cost IMU are bias and misalignment errors. Bias is sensitive to temperature. Therefore, in this paper, the effect on temperature of bias is analyzed and temperature compensation are carryed out. It is shown by experiment that the compensation is efficient.