• Journal of the Korean institute of surface engineering
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• v.47 no.4
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• pp.147-154
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• 2014

Formation behavior of PEO (Plasma Electrolytic Oxidation) films on AZ31 Mg alloy was studied in aqueous solutions containing various concentrations of hydroxide ion ($OH^-$) and silicate ion ($SiO_3{^{2-}}$) by voltage-time curves, and corrosion resistance of the PEO film-covered specimen was investigated by immersion test in 0.5 M NaCl solution. From the analyses of the voltage-time curves, it is suggested that two different types of anions are essentially needed for the formation of PEO films on AZ31 Mg alloy: film formation agent and local film breakdown agent. $SiO_3{^{2-}}$ ion acts only as a film formation agent but $OH^-$ ion acts not only as a film formation agent but also film breakdown agent. The PEO films prepared on AZ31 Mg alloy in alkaline silicate solution showed very good corrosion resistance without any pitting or filiform corrosions up to 480 h of immersion in 0.5 M NaCl.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.5
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• pp.547-554
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• 2018

Itching is a common clinical symptom of skin disease that significantly affects a patient's quality of life. Transient receptor potential vanilloid 1 (TRPV1) receptors of keratinocytes and peripheral nerve fibers in skin are involved in the regulation of itching as well as pain. In this study, we investigated whether curcumin, which acts on TRPV1 receptors, affects histamine-induced itching in mice, using behavioral tests and electrophysiological approaches. We found that histamine-induced itching was blocked by topical application of curcumin in a concentration-dependent manner. In ex-vivo recordings, histamine-induced discharges of peripheral nerves were reduced by the application of curcumin, indicating that curcumin acts directly on peripheral nerves. Additionally, curcumin blocked the histamine-induced inward current via activation of TRPV1 (curcumin $IC_{50}=523nM$). However, it did not alter chloroquine-induced itching behavior in mice, which is associated with transient receptor potential ankyrin 1 (TRPA1). Taken together, our results suggest that histamine-induced itching can be blocked by topical application of curcumin through the inhibitory action of curcumin on TRPV1 receptors in peripheral nerves.

• Journal of Korean Society for Quality Management
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• v.44 no.3
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• pp.649-660
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• 2016

Purpose: The purpose of this study is to find empirical studies the causal relationship among positive defining representation, negative defining representation, surface acting, deep acting, dissatisfaction of job, and intention of job transfer. Methods: The collected data through the survey by customer satisfaction team of "A" company call center. Results: The result of this study is that emotion and behavior norm influence on deep act of expressing both positive impacts of the employees. Conclusion: Feelings of corporate representation norm is psychologically of employees that because it affects even also must facilitate the surface acts and internal acts of employees and job dissatisfaction at the same time due to emotional dissonance and emotional exhaustion and turnover are hidden on the back emotion norms in the contact department, it should be aware of the need to address the emotional problems. Companies need to develop a variety of programs with attention to addressing the emotional difficulties experienced by workers.

• Journal of Korean society of Dental Hygiene
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• v.16 no.5
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• pp.751-758
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• 2016

Objectives: The purpose of the study is to investigate the influence of emotional labor on job burnout in dental hygienists based on the moderating effect of employee support. Methods: A self-reported questionnaire by Likert 5 point scale was completed by 219 dental hygienists in Ulsan and Gyeongbuk from March 15 to April 9, 2016. The study instruments consisted of emotional labor, job burnout og Maslach Burnout Inventory, and employee support. Data were analyzed by descriptive analysis, Pearson's correlation, multiple regression analysis, and hierarchical regression analysis using SPSS 18.0 program. Results: Surface acting had a positive influence on achievement and negative influence on impersonal chemistry. Inner acting had a positive influence on emotional burnout and achievement. Employee support had a moderating effect on emotional labor and job burnout. Conclusions: The strategy of emotional labor management for dental hygienists is very important for job burnout solution.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.132-135
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• 2002

MI(Magneto-Impedance) sensor which is made by thin films has significantly high detecting sensitivity in weak magnetic field. It also has a merit to be able to build in the low power system. Its structure is simple, which makes it easier to prepare a miniature. In this study, its magnetic permeability and anisotropy field($H_{k}$) as a function of a thickness of sputtered amorphous CoZrNb films with zero-magnetostriction and soft magnetic property are investigated. In order to make a uniaxial anisotropy, film was subjected to the post annealing in a static magnetic field with 1KOe intensity at 250, 300, and $320^{\circ}C$ respectively for 2 hours. Magnetic properties of film are measured by using a MH loop tracer. Its magnetic permeability of a film is measured over the frequency range 1 MHz to 750MHz. And, it was examined on the permeability and impedance to design the MI sensor which acts at 50MHz by thickening a CoZrNb film relatively, and fabricated the MI sensor which acts at the 50MHz.

• Structural Engineering and Mechanics
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• v.59 no.3
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• pp.403-430
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• 2016

This paper studies the dynamics of the lineal-located time-harmonic moving-with-constant-velocity load which acts on the hydro-elastic system consisting of the elastic plate, compressible viscous fluid - strip and rigid wall. The plane-strain state in the plate is considered and its motion is described by employing the exact equations of elastodynamics but the plane-parallel flow of the fluid is described by the linearized Navier-Stokes equations. It is assumed that the velocity and force vectors of the constituents are continuous on the contact plane between the plate and fluid, and impermeability conditions on the rigid wall are satisfied. Numerical results on the velocity and stress distributions on the interface plane are presented and discussed and the focus is on the influence of the effect caused by the interaction between oscillation and moving of the external load. During these discussions, the corresponding earlier results by the authors are used which were obtained in the cases where, on the system under consideration, only the oscillating or moving load acts. In particular, it is established that the magnitude of the aforementioned interaction depends significantly on the vibration phase of the system.

• International Journal of Railway
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• v.5 no.2
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• pp.93-101
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• 2012

Owing to the lightening of railway vehicles and increased operation speeds, the reduction of running safety in the presence of crosswind is becoming an important problem. In particular, the running safety tends to decrease when vehicles run on curved track. When a crosswind acts on a vehicle negotiating a curve from the outer side, flange climbing can occur. In this study, a full-vehicle model was constructed using the multi-body simulation software SIMPACK, and a simulation of a bogie vehicle with two-axle trucks negotiating a curve was carried out to examine the running safety under the condition where a crosswind acts on the vehicle from the outer side of the curve. As a result, it was verified that the derailment coefficient of the first wheelset becomes large in the exit transition curve and the coefficient of the third wheelset does in the entrance transition curve, and this trend becomes pronounced at low operation speeds in the presence of a stronger crosswind. It was also shown that the critical derailment coefficients obtained by modified Nadal's formula considering the effect of attack angle become close to the actual derailment coefficients at the timing that flange climbing occurs.

• Corrosion Science and Technology
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• v.2 no.3
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• pp.109-116
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• 2003

It is well known that SSCC (sulfide stress corrosion cracking) is caused by drastic ingression of hydrogen during the service and accumulation of hydrogen near the potential crack initiation site in the material. It is important to characterize the hydrogen trapping behavior to evaluate the service performance of the high strength pipeline steels. In this study. the relationship between the hydrogen trapping behavior and SSCC susceptibility is evaluated in terms of alloy composition, microstructure and carbide behavior. The hydrogen trapping behavior was measured by electrochemical hydrogen permeation test cell (Devanathan cell). The SSCC susceptibility is evaluated by constant extension rate test and constant strain lest method. The hydrogen trapping behavior is affected greatly by microstructure and nature of carbide particles. The fine TiC, and NbC in the matrix of ferritic structure acts as strong irreversible trap sites whereas the bainitic structure acts as reversible trap site. The SSCC susceptibility is closely related to not only the hydrogen trapping behavior but also the loading condition. As the activity of reversible trap site increases, SSCC susceptibility decreases under static loading condition below yield strength, whereas SSCC susceptibility increases under dynamic loading condition or above yield strength. As the activity of irreversible trap site increases. SSCC susceptibility increases regardless of loading condition. It is cased by the mixed effect of dislocation on hydrogen diffusion and trapping behavior.

• Journal of Korea Society of Industrial Information Systems
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• v.11 no.3
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• pp.82-89
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• 2006

Optical transmission system related to network infra of ubiquitous is a essential bridge technique between metro network and access point. So, it is need to develop this technique. In this paper, we develop 1Gbps SNMP optical transmitter/receiver system based on 1 core ring-type WDM PON. The developed system can reduce number of optic fiber and doesn't need extra transmitter/receiver. Also, this system can extend nodes owing to many node per wavelength, acts rapidly against security cutting, and acts independent of protocols.

• Proceedings of the Ginseng society Conference
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• 1998.06a
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• pp.216-223
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• 1998

Cyclic nucleotide phosphodiesterases (PDEs) represent the unique enzymatic system degrddinf cAMP and cGMP which play a major role in the regulation of cell physiology. To investigate a possible molecular mechanism of ginsenosides, their activities were evaluated on PDEs which are recently described is new therapeutic targets. PDEs are classified into 7 families according to their genes (PDEI to PDE7) and are differently distributed in tissues. The IC50 values of ginsenosides were determined on PDEI to PDE 5 chromatographically isolatetl from bovine aorta. The results show that total ginseng saponin extract preferentially inhibits PDE 1 and PDE4 at concentrations nearby 200 ug/ml. Protopanaxadiol (PPD) fraction acts preferentially on PDE4 with and IC50 value of 100 nlml and inhibits also PDEI and PDE5 at 14 to 2 fold higher concentrations, respectively. Protopanaxatriol (PPT) fraction preferentially inhibits PDE 1 with and IC50 value of 170 ug/ml. Compound Rgl, originated from PPT fraction, and RC3 (5) represent the most active compounds towards PDE 1 with IC50 values around 80 UM. However Rg3 (R), epimer of Rgl (5) has no effect on the various PDEs tested, excepted on PDE3 rich is sligthly sensitive Compound Rbl, originated from PPD, acts on both PDEI and PDE4. It if two fold less active than Rgl and Rg3 (5) on PDEI. Taken together, these results mainly suggest that PDEI and PDE4 inhibitions could be a molecular mechanism which would participate in ginsenoside mechanisms, especially the effect of PPD on blood vessel and on CNS.