• 한국재료학회지
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• 제28권5호
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• pp.286-294
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• 2018

Hot-press forming(HPF) steel can be applied successfully to auto parts because of its superior mechanical properties. However, its resistances to aqueous corrosion and the subsequent hydrogen embrittlement(HE) decrease significantly when the steel is exposed to corrosive environments. Considering that the resistances are greatly dependent on the properties of coating materials formed on the steel surface, the characteristics of the corrosion and hydrogen diffusion behaviors regarding the types of coating material should be clearly understood. Electrochemical polarization and impedance measurements reveal a higher corrosion potential and polarization resistance and a lower corrosion current of the Al-coating compared with Zn-coating. Furthermore, it was expected that the diffusion kinetics of the hydrogen atoms would be much slower in the Al-coating, and this would be due mainly to the much lower diffusion coefficient of hydrogen in the Al-coating with a face-centered cubic structure. The superior surface inhibiting effect of the Al-coating, however, is degraded by the formation of local cracks in the coated layer under severe stress conditions, and therefore further study will be necessary to gain a clearer understanding of the effect of cracks formed on the coated layer on the subsequent corrosion and hydrogen diffusion behaviors.

• Human Ecology Research
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• 제51권3호
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• pp.307-319
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• 2013

The purposes of this study are to examine the differences of gender role identity according to general characteristics, parenting behavior, and family function, and to find out the main predictors of gender role identity, in order to further test the mediating effects of family function between parenting behavior and gender role identity among middle school students. Six hundred-fifty 3rd graders from three middle schools in Busan participated in this study. The results showed that the significant variables for predicting the masculinity of gender role identity include family cohesion, and parenting behaviors (father's reasoning, mother's over-expectation) and monthly household income, respectively. The significant variables for predicting femininity were family cohesion, and father's intrusive parenting behaviors, father's educational background and the mother's affection, respectively. The results indicated that for masculinity, family cohesion played the full mediator with the father's monitoring behavior and the partial mediator with the father's reasoning behavior. Similarly, for the mother's reasoning and affection, family cohesion played a full mediator. For femininity, the family cohesion played the full mediator with the father's affection and the partial mediator with the mother's affection. Similarly, for androgyny, the family cohesion played a role of full mediator with the father's monitoring, reasoning, affection and mother's reasoning and affection. In other words, the parents'positive parenting behaviors affected the family cohesion, and in turn, had an impact on the formation of the gender role identity.

• 대한금속재료학회지
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• 제49권5호
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• pp.355-361
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• 2011

Creep behaviors of the Zr-1.Nb-0.5Cu (HANA-6) alloy strips with different orientations were investigated. Anisotropy was observed in the samples depending on their physical orientations due to the formation of texture in their microstructures. The creep strain rate was increased as the test stress and temperature increased. The rate was higher along the rolling-direction than in the transverse-direction irrespective of annealing conditions. However, the samples with $45^{\circ}$ direction showed different behaviors depending on the annealing temperature. When strips were finally annealed at $600^{\circ}C$ for 10 min, the primary creep rate of the $45^{\circ}$ strip was the highest among the various orientations although the saturated creep rate was the lowest. In the case of final annealing at $660^{\circ}C$ for 4 h, the highest creep rate occurred throughout the creep test in the $45^{\circ}$ strip. It is considered that the fraction of (100) planes along the direction of creep deformation affect the creep rates.

• Corrosion Science and Technology
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• 제22권3호
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• pp.201-213
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• 2023

Corrosion management of an aircraft and its engine relies on rinsing and cleaning using tap water. Few studies have reported effects of tap water species on corrosion behaviors of structural materials. In this study, a series of experiments were conducted based on the design of experiment. Solutions with different levels of chloride and sulfate ions were prepared using a full factorial design. Two structural materials (aluminum alloy and steel) were used for an alternate immersion test. Weight loss was then measured. In addition, a silver specimen was utilized as a sensor for chloride deposition measurement. The silver specimen was examined using the electrochemical reduction method, XPS, and SEM-EDS. Surface analysis revealed that levels of chloride and sulfate ions were sufficient for the formation of silver chloride and silver surface. Statistical analysis of weight loss and chloride deposition rate showed significant differences in measured values. Concentration of chloride ions greatly affected corrosion behaviors of structural materials. Sulfate ion hindered the adsorption reaction. These results emphasize the importance of controlling ion concentration of tap water used for cleaning and rinsing an aircraft.

• 간호행정학회지
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• 제9권1호
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• pp.19-30
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• 2003

Purpose : The concept of organizational socialization has been regarded as an abstract concept of organizational learning process and it has been used as strategy for the organizational goal attainment. New graduated nurses' organizational socialization has been a very important process for learning knowledge, skills and behaviors in hospital setting. This study was to analyze and clarify the meaning of the concept of Organizational Socialization. Method : This study use the process of Walker & Avant's concept analysis. Results : The critical attributes of organizational socialization were identified as : 1) Internalization of Value and belief of organization; 2) Learning of organizational rules and modes of living; 3) Improvement of job performance; 4) Maintenance of supportive relationship; 5) Formation of occupational identity. The antecedents of organizational socialization consist of those facts that 1) negative feeling of role; 2) difficulties of interpersonal relationship; 3) unskilled work performance. And the consequences of organizational socialization consist of those facts that 1) organizational commitment; 2) job satisfaction; 3) intention of leave work setting; 4) improvement of job performance; 5) improvement of decision making; 6) maintenance of supportive relationship. Conclusion : Through this concept analysis, the concept of organizational socialization is defined as internalization of value and belief of organization, learning of organizational rules and modes of living, improvement of job performance, maintenance of supportive relationship and formation of occupational identity.

• 한국지반공학회논문집
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• 제32권12호
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• pp.33-43
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• 2016

노후관로로 인한 지반내 공동형성과 지반이완 메카니즘을 분석하기 위해 현장시험을 수행하였으며 수치해석을 수행하여 현장시험과 비교하였다. 현장시험은 지반내 인위적인 공동을 만들기 위해 얼음을 이용하였으며, 시간경과에 따른 얼음의 융해로 인해 공동형성과 주변지반의 이완을 확인할 수 있었다. 다짐된 토사의 interlocking에 의한 이완 및 공동형성 거동을 고려하기 위하여개별요소법에 근거한 수치해석 프로그램인 PFC 2D를 이용하였다. PFC의 클럼프(clump) 요소를 도입하여 불규칙 형상의 입자를 모사하였으며, 이를 통해 얻은 공동형성과 지반이완 특성을 현장시험 결과와 비교함으로써 지반내 공동형성 및 거동특성을 파악하였다.

• 복식
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• 제58권1호
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• pp.116-132
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• 2008

Continuity and discontinuity is a relative concept, and there are various categories of the continuity and discontinuity in our circumference. In the thought of postmodernism of the late of 20th Century, continuous creations of the difference and the repetition have being regarded as a discontinuity. But, because of that catches the moment occurring qualitative skip though the flowing of the everlasting time, this has been known to a shortsighted viewpoint overlooking characteristic of the qualitative continuity of an organism, which have being created continuous formation for life through the flowing of the time. Therefore, this had studied like this complex social condition and various relationships expressed in modern fashion focusing on permanently creative movements and behaviors equal to the qualitative continuity. This Thesis is following study about continuity, and aims at understanding of those formative characteristics through consideration about characteristics of qualitative continuity. And, this analyzes formative characteristics of the qualitative continuity into 5 sets: enlargement, conversion, structural variability, mutual combination, and deconstruction. This thesis intends to grasp complex modern social phenomenon and modern fashion into qualitative continuity that means continuous formation and the change of various relationships according to recognition about the course toward open thinking.

• 설비공학논문집
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• 제9권3호
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• pp.343-353
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• 1997

This paper presents a theoretical model for predicting transient behaviors during storage process of the cool storage system using the R141b clathrate. Introduction of the lumped capacitance method along with a brine reservoir having large thermal capacity yields a set of simplified energy equations. Based on the Arrhenius equation and the known experimental findings, the formation rate of clathrate for which the degree of subcooling is properly accounted is newly developed. An effective nondimensionalization of the model equations facilitates the closure of modeling as well as parametric study. Calculated results for a specific case not only simulate a typical pattern of temperautre variation in the tank successfully, but also agree reasonably well with available data. The effect of each characteristic parameter on the system performance is also investigated. It is revealed that the dominant among relevant parameters are the activation energy of reaction, the degree of subcoling and the initial mass fraction of refrigerant. Finally, the uncertainty associated with modeling of the shaft work variation appears to need further studies.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권1호
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• pp.91-98
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• 2005

In order to investigate central metabolic changes in Beijerinckia indica, cells were grown on different carbon sources and intracellular flux distributions were studied under varying concentrations of nitrogen. Metabolic fluxes were estimated by combining material balances with extracellular substrate uptake rate, biomass formation rate, and exopolysaccharide (EPS) accumulation rate. Thirty-one metabolic reactions and 30 intracellular metabolites were considered for the flux analysis. The results revealed that most of the carbon source was directed into the Entner-Doudoroff pathway, followed by the recycling of triose-3-phosphate back to Hexose­6-phosphate. The pentose phosphate pathway was operated at a minimal level to supply the precursors for biomass formation. The different metabolic behaviors under varying nitrogen concentrations were observed with flux analysis.

• 한국입자에어로졸학회지
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• 제5권4호
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• pp.171-178
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• 2009

$PM_{2.5}$ is one of critical air pollutants due to its high absorbability of heavy metallic fumes, PAH and bacillary micro organisms. Such a fine particulate matter is often formed through various nucleation processes including condensation. This study attempts to find the nucleation behaviors of $PM_{2.5}$ arisen from coal power stations using a classical heterogeneous Fletcher's theory. The numerical simulation by C-language could approximate the nucleation process of $PM_{2.5}$ from water vapor, of which approach revealed the required energy for embryo formation and embryo size and nucleation rate. As a result of the calculation, it was found that wetting agents could affect the particle nucleation in vapor condensation. In particular, critical contact angle relates closely with the vapor saturation. Particle condensation could be reduced by lowering the angles. The wetting agents aid to decrease the contact angle and surface tensions, thereby may contribute to save the formation energy.