• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.04b
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• pp.12-13
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• 2008

Organic field-effect transistors (OFETs) are of interest for use in widely area electronic applications. We fabricated a copper phthalocyanine (CuPc) based field-effect transistor with different metal electrode. The CuPc FET device was made a top-contact type and the substrate temperature was room temperature. The source and drain electrodes were used an Au and Al materials. The CuPc thickness was 40nm, and the channel length was $50{\mu}m$, channel width was 3mm. We observed a typical current-voltage (I-V) characteristics in CuPc FET with different electrode materials.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.494-495
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• 2007

Organic field-effect transistors (OFETs) are of interest for use in widely area electronic applications. We fabricated a copper phthalocyanine (CuPc) based field-effect transistor with different metal electrode. The CuPc FET device was made a top-contact type and the substrate temperature was room temperature. The source and drain electrodes were used an Au and Al materials. The CuPc thickness was 40nm, and the channel length was $50{\mu}m$, channel width was 3mm. We observed a typical current-voltage (I-V) characteristics in CuPc FET with different electrode materials.

• Tribology and Lubricants
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• v.24 no.5
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• pp.241-249
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• 2008

This paper describes the tribological effects on the nonlinear behavior of a spur gear pair with one-way clutch according to the direct contact elastic deformation model over a wide range of speeds, considering the hydrodynamic effects. The effects of various lubrication parameters, such as viscosity, film width, and friction, on the nonlinear dynamic behavior were analyzed. Forces due to the entraining velocity and the hydrodynamic friction were about two orders smaller than normal forces over the whole speed range. While the viscosity has a strong effect on the behavior of gear pair systems, friction has very little effect on torsional behavior. The inclusion of the hydrodynamic effect facilitates nonlinearity by increasing the overlap and damping, as well as decreasing elastic deformation and tooth reaction forces.

• International Journal of Korean Welding Society
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• v.1 no.1
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• pp.71-77
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• 2001

The characteristics of the fume generation in a flux cored arc welding were investigated using the fume collection chamber developed. The Korean Standard concerning the method for the evaluation of the fume generation rate(FGR) was updated by the evaluation method obtained through this study. It was found that the effect of humidity in the test environment should be considered and the automatic welding method had to be employed for the purpose of the exact evaluation of the fume generation rate. The results showed that the fume generation rate was influenced by the welding parameters. The important factors were the welding current arc voltage, travel speed, and contact tip to work distance(CTWD) that affected the heat input as well as the torch angle and the shielding gas flow rate that influenced the shielding effect. The fume generation rate increased as the heat input increased and the shielding effect decreased. It was also observed that the effect of the welding current is much grater than the other welding parameters.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.2
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• pp.15-26
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• 2009

Purpose: To compare and analyze the ocular changes after wearing conventional and 2-weeks cosmetic tinted contact lens, which were made of different material and fabrication method. Methods: Thirty five university students, age of twenties, participated in this study. With daily wearing schedule, they had worn temporary cosmetic tinted lens for 2 weeks and conventional tinted lens for two month in their right and left eye, respectively. Subjective symptoms and objective signs were graded by using CCLRU scales and corneal thickness were measured after 1 day and 2 months wearing, and under or over 5 hours wearing in a day, respectively. Results: Major subjective symptoms found in the student wearing cosmetic tinted contact lens for a 1 day and 2 months were dryness, redness, foreign body sensation and itchiness. It was also found that those symptoms were more severe in left eye (conventional cosmetic tinted contact lens) than right eye (2-weeks cosmetic tinted contact lens). However, symptoms of redness in both eyes showed statistically significant difference in the case of 1 day and 2 months wearing and under or over 5 hours wearing in a day (p=0.000). After 2 months wearing, left eye with conventional cosmetic tinted contact lens showed limbal redness (p=0.000) and bulbar conjunctival redness (p=0.012) with statistically significance, whereas there was no significant difference in both eyes before lens wear. Left eye showed statistically significant changes in all objective signs, but right eye showed palpebral conjunctival redness, corneal staining and conjunctival staining. Therefore, it was concluded that conventional cosmetic tinted contact lens may be more effective on ocular changes after wearing of lens. A statistically significant changes in both eyes after wearing lens were found that corneal thickness increased about $5{\mu}m$ (p=0.001) in right eye whereas $7{\mu}m$ (p=0.004) in left eye. Conclusions: A statistically significant number of participants in this study preferred to wearing of high Dk/t temporary cosmetic tinted contact lens made by sandwich method which resulted in less ocular changes and may give more healthy and safe ocular conditions.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.13 no.2
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• pp.165-181
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• 2000

Sinichengpaeum has been widely used in the oriental medical treatment of nasal diseases. These studies were performed done to investigate the effect of Sinicheng- paeum on the anti-allergic action We studied the vascular permeability response induced by the histamine and serotonin injection(allergy Ⅰ type), homologous PCA provoked by the IgE-like antibody against EWA(allergy Ⅳ type), contact dermatitis induced by picryl chloride(allergy Ⅳ type), delayed type hypersensitivity response to SRBC (allergy Ⅳ type), and the amount of eosinophil and IgE. The results were as follows: 1. The effect of Sinichengpaeum on vascular permeability responses to intradermal histamine and serotonin were significant. 2. In the homologous PCA provoked by the IgE-like antibody against white egg albumin, Sinichengpaeum showed a significant effect. 3. In the delayed type hypersensitivity responses to picryl chloride, Sini-chengpaeum provoked a significant effect. 4. After reaction provoked by picryl chloride, Sinichengpaeum showed an insignficant effect on amount of eosinophil, but a significant effect in IgE amount. 5. In the delayed type hypersensitivity responses to SRBC, Sinichengpaeum provoked a significant effect. 6. After reaction provoked by SRBC, Sinichengpaeum showed a significant effect on amount of cosinophil, but an insignificant effect in IgE amount.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.13 no.1
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• pp.60-77
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• 2000

Experimental studies were done to research effects of Leejungtang and Leejungtanggamibang on the anti-allergic effects. We studied the vacular permeability response induced by histamine and serotonin, homologous PCA provoked by IgE-like antibody against EWA, contact dermatitis induced by picryl chloride and delayed type hypersensitivity response to SRBC. The results were obtained as follows: 1. In effects of the Leejungtang and Leejungtanggamibang on the vascular permeability responses to intradermal serotonin, the Leejungtang revealed insignificant effect and Leejungtanggamibang revealed significantly inhibitory effect. 2, In effects of the Leejungtang and Leejungtanggamibang on the vascular permeability responses to intradermal histamine, the Leejungtang revealed insignificant effect and Leejungtanggamibang revealed significantly inhibitory effect. 3. In the homologous PCA provoked by IgE-like antibody against white albumin, the Leejungtang revealed insignificant effect and Leejungtanggamibang revealed significantly inhibitory effect. 4. In the delayed type hypersensitivity responses to picryl chloride, the Leejungtang revealed insignificant effect and Leejungtanggamibang revealed significantly inhibitory effect. 5. In the delayed type hypersensitivity responses to sheep red blood cell the Leejungtang revealed insignificant effect and Leejungtanggamibang revealed significantly inhibitory effect.

• The Journal of Dong Guk Oriental Medicine
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• v.8 no.1
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• pp.77-91
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• 1999

After allergic contact dermatitis elicitated by Dinitrochlorobenzene(DNCB) treatment, ICR female mice administered Yunkyopaedocksangamibang(YPGM) extract were observed to investigate the effect of YPGM on allergic contact dermatitis. This study investigated that contact hypersensitivity assay, abdominal skin morphologic changes including mast cells. At contact hypersensitivity assay, the right ear swelling in YPGM group were probability decreased than DNCB group. At observation of abdominal skin morphologic change, the infiltration of lymphocyte, lymphocyte insertion to epithelium, enlarged capillary, angiogenesis, and damages of epithelium as cytoplasmic vacuolation and enlarge of inter cellular space in YPGM were diminished than DNCB group. The number of mast cell was increased both DNCB and YPGM group. The shape of mast cell in DNCB group was mainly appeared degranulated type, but granulated type in YPGM group. The number of serotonin positive cell was increased both DNCB and YPGM group. The shape of serotonin positive cell in DNCB group was mainly appeared degranulated type, but granulated type in YPGM group. As results indicated that the YPGM extract administration work on the mitigation of skin damages in mouse with allergic contact dermatitis.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.415.2-415.2
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• 2016

Triboelectric nanogenerator (TENG) is one of ways to convert mechanical energy sound, waves, wind, vibrations, and human motions to available electrical energy. The principal mechanism to generate electrical energy is based on contact electrification on material surface and electrostatic induction between electrodes. The performance of TENG are dependent on amount of the input mechanical energy and characteristics of triboelectric materials. Furthermore, the whole TENG system including mechanical structure and electrical system can effect on output performance of TENG. In this work, we investigated the effect of gear train on output performance and power conversion efficiency (PCE) of TENG under a given input energy. We applied the gear train on mechanical structure to improve the contact rate. We measured the output energy under a constant input energy by controlling the size of the working gear. We prepared gears with gear ratios (rin/rw) of 1, 1.7, and 5. Under the constant input energy, the voltage and current from our gear-based TENG system were enhanced up to the maximum of 3.6 times and 4.4 times, respectively. Also, the PCE was increased up to 7 times at input frequency of 1.5 Hz. In order to understand the effect of kinematic design on TENG system, we performed a capacitor experiment with rectification circuit that provide DC voltage and current. Under the input frequency of 4.5 Hz, we obtained a 3 times enhanced rectifying voltage at a gear ratio of 5. The measured capacitor voltage was enhanced up to about 8 fold in using our TENG system. It is attributed that our gear-based TENG system could improve simultaneously the magnitude as well as the generation time of output power, finally enhancing output energy. Therefore, our gear-based TENG system provided an effective way to enhance the PCE of TENGs operating at a given input energy.

• Journal of Digital Convergence
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• v.13 no.12
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• pp.401-411
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• 2015

The main object of the study is to investigate the relationship between depressive symptom and poverty and to analyze the interaction effect between poverty and informal social relationship on depressive symptom. The data for the study is survey data on Life of elderly in Chuncheon Area in 2014. The sample size of the survey is 2,023 and because of missing data, the analysis contains data for 1,934 persons. The survey is conducted by the face to face interview with the questionnaire. Results of the analysis are as follows. First, the poverty shows positive relationship with depressive symptom. Second, the level of contact with children and support exchange with friends show negative relationship with depressive symptom. Third, There is interaction effect between poverty and level of contact with children on depressive symptom.