• Journal of Ocean Engineering and Technology
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• v.2 no.2
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• pp.122-129
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• 1988

Recently with the rapid development in marine and shipbuliding industries such as marine structures, ship and chemical plants, there occurs much interest in the study of corrosion fatigue characteristics which was closed up an important role in mechanical design. In this study, the 5086 Al-alloy was tested by use of rotary bending fatigue tester. The retardation effect of overload on the corrosion fatigue crack propagation in sea environment was quantitatively studied. 1) Retardation effect of corrosion fatigue crack propagation is most eminent when overload ratio is 1.52, overload magnitude corresponds to about 77% and 55% of yield strength and tensile strength respectively. 2) After overload ratio 1.52 was used, retardation of corrosion fatigue crack growth rate is largely retarded and quasi-threshold stress intensity factor range($\Delta\textrm{K}_{th}$) appears. 3) According to m of experimental constant, retardation effect of corrosion fatigue crack propagation corresponds to about 25% of constant stress amplitude when overload ratio is 1.52. 4) When overload ratio 1.52 was used, retardation parameter (RP) decreases to about 0.43 and corrosion sensitivity (S)decreses to about 2.1.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.2
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• pp.369-373
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• 2010

Modem electronic circuits are of importance for the function of communication, traffic systems and security systems. An intentional threat to these systems could be of big casualties and economic disasters. This paper has shown damage effect of microcontroller device with coupling caused by UWB-HPEM(Ultra Wideband-High Power Electromagnetics). The UWB measurements were done at an Anechoic Chamber using a RADAN UWB voltage source, which can generate a transient impulse of about 180 kV. The susceptibility level for microcontroller has been assessed by effect of various operation line lengths. The results of susceptibility analysis has showed that the effect of the reset line length on the MT(Ma1function Threshold) is larger than the effect of the different line length(Data, Power, Clock). With the knowledge of these parameters electronic system can be designed exactly suitable concerning the system requirements. Based on the results, susceptibility of microcontroller can be applied to protection plan to elucidate the effects of microwaves on electronic equipment.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.953-956
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• 2009

We have investigated the effect of light on amorphous silicon thin film transistors based photo-sensor applications. We have analyzed the instability caused by electrical gate bias stresses under the light illumination and the effect of photo-induced quasi-annealing on the instability. Threshold voltage ($V_{TH}$) under the negative gate bias stress with light illumination was more decreased than that under the negative gate bias stress without light illumination even though $V_{TH}$ caused by the light-induced stress without negative gate bias was shifted positively. These results are because the increase of carrier density in a channel region caused by the light illumination has the enhanced effect on the instability caused by negative gate bias stress. The prolonged light illumination led to the recovery of shifted VTH caused by negative gate bias stress under the light illumination due to the recombination of trapped hole charges.

• The Journal of Korean Physical Therapy
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• v.19 no.6
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• pp.43-47
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• 2007

Purpose: This study examined the effect of electro-acupuncture stimulation of the infraspinatus and teres major on the shoulder function reduction. The subjects consisted of 20 female patients with a shoulder dysfunction. Methods: The 20 female patients with shoulder dysfunction participated voluntary in this research. 10 minute electro-acupuncture stimulation (frequency: 5Hz, Intensity: below the pain threshold) with Infra-red therapy, 3 times per week given to the patients' Trigger point of the infraspinatus and teres major. The Visual Analog Scale (VAS), Apley's Scratch Test and Global Perceived Effect Scale (GPES) were examined before alter six applications. Results: There was a significant decrease in the VAS (p<0.05) and Apley's Scratch Test (p<0.05). In addition, there was statistically significant increase in the Global Perceived Effect Scale (p<0.05). Therefore, the infraspinatus and teres major is a very important muscle for the shoulder function. Conclusion: This data will be used to develop a treatment method for patients with a shoulder dysfunction. These results suggest that the electro-acupuncture stimulation into the infraspinatus and the teres major Trigger point is an effective intervention for patients with shoulder dysfunction and pain.

• Journal of Oral Medicine and Pain
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• v.30 no.4
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• pp.465-473
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• 2005

The purpose of this study was to evaluate the desensitizing effects of a Nd:YAG laser (Sunlase, SUNRISE Technologies, Inc., USA) irradiation on cervically exposed hypersensitive dentine. 45 patients was irradiated with pulsed Nd:YAG laser (1.5 W, 20 Hz, 75 mJ/pulse, 4 minutes) as the experimental group, 27 patients was mock irradiated as the control group. The degree of sensitivity to the thermal and tactile stimuli were determined qualitatively with an evaporative stimulus defined as two times air blast at a distance of 3 mm from each site to be tested and with a mechanical stimulus as a slightly scratching the cervical site with a dental explorer. A qualitative registration of the degree of discomfort was determined according to a numerical pain scale(NPS) in an 11-point scale in which 0= "no pain" and 10="most excruciating pain imaginable". Recordings were assessed before treatment, immediately after, 1 and 2 weeks after treatment. Pain tolerance threshold and pulp vitality were evaluated with electric pulp tester before and immediately after treatment. 1. Desensitizing of hypersensitive dentine with Nd:YAG laser irradiation was more effective than that with mock irradiation. 2. The placebo effect of mock irradiation was recognized for severe sensitive teeth($NPS\;{\geqq}\;6$), but not for moderate sensitive teeth(NPS < 6). 3. Laser irradiation did not affect the pain tolerance threshold and pulp vitality of the hypersensitive teeth. 4. Desensitizing effect of laser irradiation for the hypersensitive teeth had been continuing at least 2 weeks. It was concluded that desensitizing of hypersensitive dentine with a Nd:YAG laser is effective and the maintenance of the positive result was more prolonged than the placebo effect.

• Journal of Ginseng Research
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• v.42 no.2
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• pp.183-191
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• 2018

Background: Ginseng saponin has long been used as a traditional Asian medicine and is known to be effective in treating various kinds of pain. Ginsenoside Rf is one of the biologically active saponins found in ginseng. We evaluated ginsenoside Rf's antinociceptive and anti-inflammatory effects, and its mechanism of action on adrenergic and serotonergic receptors, in an incisional pain model. Methods: Mechanical hyperalgesia was induced via plantar incision in rats followed by intraperitoneal administration of increasing doses of ginsenoside Rf (vehicle, 0.5 mg/kg, 1 mg/kg, 1.5 mg/kg, and 2 mg/kg). The antinociceptive effect was also compared in a Positive Control Group that received a ketorolac (30 mg/kg) injection, and the $Na{\ddot{i}}ve$ Group, which did not undergo incision. To evaluate the mechanism of action, rats were treated with prazosin (1 mg/kg), yohimbine (2 mg/kg), or ketanserin (1 mg/kg) prior to receiving ginsenoside Rf (1.5 mg/kg). The mechanical withdrawal threshold was measured using von Frey filaments at various time points before and after ginsenoside Rf administration. To evaluate the anti-inflammatory effect, serum interleukin $(IL)-1{\beta}$, IL-6, and tumor necrotizing $factor-{\alpha}$ levels were measured. Results: Ginsenoside Rf increased the mechanical withdrawal threshold significantly, with a curvilinear dose-response curve peaking at 1.5 mg/kg. $IL-1{\beta}$, IL-6, and tumor necrotizing $factor-{\alpha}$ levels significantly decreased after ginsenoside Rf treatment. Ginsenoside Rf's antinociceptive effect was reduced by yohimbine, but potentiated by prazosin and ketanserin. Conclusion: Intraperitoneal ginsenoside Rf has an antinociceptive effect peaking at a dose of 1.5 mg/kg. Anti-inflammatory effects were also detected.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.5
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• pp.876-884
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• 2017

The current-voltage characteristics of Silicon(Si), Germanum(Ge), and hetero tunnel field-effect transistors(TFETs) with source-overlapped gate structure was investigated using TCAD simulations in terms of tunneling. A Si-TFET with gate oxide material $SiO_2$ showed the hump effects in which line and point tunneling appear simultaneously, but one with gate oxide material $HfO_2$ showed only the line tunneling due to decreasing threshold voltage and it shows better performance than one with gate oxide material $SiO_2$. Tunneling mechanism of Ge and hetero-TFETs with gate oxide material of both $SiO_2$ and $HfO_2$ are dominated by point tunneling, and showed higher leakage currents, and Si-TFET shows better performance than Ge and hetero-TFETs in terms of SS. These simulation results of Si, Ge, and hetero-TFETs with source-overlapped gate structure can give the guideline for optimal TFET structures with non-silicon channel materials.

• Journal of radiological science and technology
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• v.39 no.3
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• pp.313-321
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• 2016

Placenta accrete patients whose mother mortality rates are rather high due to massive bleeding during childbirth need to have Prophylactic placement of Internal Iliac Artery Balloon Occlusion Catheters procedure to reduce amount of blood loss and inoperative transfusion. Nevertheless, studies for mothers inevitably exposed to dose during PIIABOCs procedure have not been published many yet. Therefore, this study is to investigate exact information on radiation dose exposed to fetus during PIIABOCs procedure. Average effective dose of fetus per organ is 2.38~8.83 mGy, measured highest at beam center and followed by eyeball, stomach and bladder. The result showed that the longer fluoroscopy time is used, the closer beam center is and the thicker abdominal thickness is, the more effective dose on fetus is increasing. When using the collimator and protection shown to decrease the effective dose and when using higher the patient table shown to decrease the effective dose. It has been reported that the threshold of deterministic effect is about 100mGy. Deterministic effect was regarded as a factor that would influence on fetus exposed by medical radiation than stochastic effect. Consequently, it concluded that dose exposed on fetus in PIIABOCs procedure was approximately 10% of threshold of deterministic effect with effective dose of 0.49~18.27 mGy.

• Journal of Environmental Health Sciences
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• v.39 no.1
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• pp.90-98
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• 2013

Objectives: Many studies have shown that air pollution and temperature have adverse effects on mortality and morbidity. But the interactive effect between air pollution and temperature on mortality has been rarely investigated. This study aims to explore whether temperature modifies the associations between ambient particulate matter less than $10{\mu}m$ in diameter ($PM_{10}$) and mortality in Seoul, Korea. Methods: The time-series analysis examined the effect of the interaction between $PM_{10}$ and temperature on mortality from 1999 to 2010 in Seoul. In order to examine the interactive effect between $PM_{10}$ and temperature on mortality, we fitted a response surface model controlling the time-trends and meteorological variables. The effects of $PM_{10}$ were stratified by temperature stratum to quantitatively estimate the $PM_{10}$-health outcome associations. Results: When temperature was low (below the threshold temperature), the percentage increases per $10{\mu}g/m^3$ increase of $PM_{10}$ increased 0.38% (95% Confidence Interval[CI]: 0.09~0.68%) and 0.31% (95% CI: - 0.07~0.68%) of mortality in the all age group and ${\geq}65$ year age group, respectively. When temperature was high (above the threshold temperature), the percentage increases per $10{\mu}g/m^3$ increase of $PM_{10}$ increased 1.09% (95% CI: 0.47~1.72%) and 1.35% (95% CI: 0.65~2.06%) for mortality in the all age group and ${\geq}65$ year age group, respectively. Conclusion: The results of this study showed strong modification by temperature in the association between $PM_{10}$ and mortality. We recommend that public health strategies to minimize adverse health impact of heat and $PM_{10}$ should be considered in control and prevention measures for air pollution and weather-related health impacts.

• 한국사회정책
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• v.23 no.1
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• pp.25-59
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• 2016

This paper analyses the policy effect of minimum housing standards, using the fact that Seoul set the minimum housing standards in 1998. Because the whole country except Seoul did not set the minimum housing standards in 1998, we could find this situation as a quasi-experiment. In order to identify the policy effect of minimum housing standards, I compare decreasing amounts in the number of households below the threshold between Seoul and comparison regions from 1995 to 2000, using Differences-in-Differences method. I draw estimate of one-to-one comparison, using Gyeonggi province as a comparison region, and OLS estimate, utilizing the whole nation except Seoul as a comparison region, respectively, and compare two estimates. The former and the latter suggest that the setting of Seoul minimum housing standard in 1998 account for decreasing the number of households under the minimum housing standard, by about 216,638 and 325,149, respectively. The latter is statistically significant at the 0.001 level and the former is in the 95% confidence level of the latter. Therefore we could conclude that the setting of minimum housing standards contributes significantly to achieve the policy objectives, a decrease in the number of households, which are below the threshold.