• Korean Journal of Child Studies
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• v.26 no.1
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• pp.329-345
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• 2005

Gender and intelligence of children, parenting practices and socioeconomic status of parents were studied to investigate whether they functioned as protective factors for resilient children. Total of 556 children of 12 years of age were contacted for the study. Teachers were asked to rate the children's interpersonal competence. Children reported their experience of stressful life events on a checklist. Based on the competence scores and the experience of stressful life events, 107 children were classified into adaptive, resilient, and maladaptive group. IQ scores were assessed using an intelligence test for the 107 children. Mothers reported their parenting practices and their socioeconomic status through a questionnaire. Descriptive statistics, chi-squares, t-tests, and one-way ANOVAs were performed to analyze the data. There was no difference in their experience of stressful life events between boys and girls. Girls were rated as being more competent by their teachers. There were more girls in the adaptive and the resilient group and more boys in the maladaptive group. Children in adaptive and the resilient group had higher intelligence scores than the maladaptive group. Mothers of resilient children replied as being warm and acceptive and more refusing and controlling than mothers of the adaptive children Group differences in socioeconomic status of the family were not found. Thus, being a girl and having higher IQ scores were the protective factors for the resilient children.

• Polymer(Korea)
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• v.24 no.5
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• pp.656-663
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• 2000

The Effects of thermal history during the melt spinning process on the mechanical properties and crystallinity of polylactic acid (PLLA) fibers have been studied. Thermal history applied on PLLA during the melt process caused the decrease of number-average molecular weights and this resulted in the lowering of orientation and crystallinity in PLLA fibers. As a result, the longer applied thermal history, the less tensile strength and modulus, and the higher elongation at break. It was also found that primary factor for controlling crystallinity of PLLA fiber was the stress induced crystallization while the thermal induced crystallization had a little effect on the crystallinity of PLLA fibers. However, the thermal induced crystallization turn out to be important in the crystallinity developed by annealing of PLLA fibers.

• Journal of Digital Convergence
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• v.15 no.1
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• pp.117-127
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• 2017

Even well trained personnel may fall victim to panic, and a wrong assessment of the situation can turn a small accident into a huge disaster. At the disaster site, the event is commonly broadcasted in real time and is unfiltered. Thus, the commander of the site must be able to accurately assess the scene while not missing out on key considerations. Despite the necessity of good situational assessment, there is barely any research on this topic. This study utilizes METT-TC(Mission, Enemy, Troops, Terrain and weather, Time available, and Civil considerations) which is used by militaries to assess combat situations, and proposes MORT-TAC(Mission, Object, Resources available, Terrain and weather, Time available, Ability, and Civil considerations) as factors to consider in effectively controlling the disaster site. The standard model is used for assessing disaster scenes by applying the Delphi analytical method on each sub-factor of MORT-TAC.

• Bulletin of the Korean Chemical Society
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• v.24 no.3
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• pp.299-305
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• 2003

Physical properties and microstructure of new coumarin 4 doped $SiO_2$-PDMS ORMOSILs, synthesized by one-step (OS, acid-catalysis) and two-step (TS, acid-base catalysis) routes of sol-gel method with varying pH (0.6 to 7) and dye content $(5\;{times}\;10^{-4}\;to\;5{\times}\;10^{-2}\;mole)$, are reported. BET, UV-visible spectroscopy and SEM were used for characterizations. The increase in acid or base concentration increased the size of pores and aggregated silica particles. The samples with pH ≤ 2.5 were transparent and attributed to the small size of pores (~20 Å) and silica particles. The samples with pH > 2.5 were translucent or opaque due to non-uniform pore system formed by voids and large aggregated silica particles. The surface area was found a key factor controlling the interactions between the gel matrix and the dye. The OS samples with the highest dye concentration exhibited the minimal values of pore size, surface area and silica particle size, resulting in the concentration-quenching phenomenon.

• Polymer(Korea)
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• v.26 no.6
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• pp.803-811
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• 2002

In this study the wear behavior of ultra high molecular polyethylene (UHMWPE) filled with kaolin particles by different methods was investigated. UHMWPE/kaolin composites were prepared by two different methods: polymerization-filling and powder mixing. Particularly in a powder mixing method. Particle dispersion and wear property according to powder mining method were examined. It was found from wear test that filling of inorganic filler into UHMWPE by polymerization filling was more effective way than by powder mixing method in improving Wear resistance of UHMWPE. It was also confirmed that abrasive wear was dominant wear mechanism and particle dispersion in the composite as well as interface property was an important factor in controlling the wear behavior of the resulting composites.

• Journal of Welding and Joining
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• v.12 no.1
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• pp.102-115
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• 1994

This paper is to evaluate the fatigue strength of lap joints of materials applied to LNG carrier cargo containment of GAZ-TRANSPORT(GT) type, which was welded by manual and automatic TIG welding process. The thicknesses of lapped members were 1.5mm/1.5mm or 1.5mm/0.7mm in Invar to Invar joint, and 1.5mm/8.0mm in Invar to stainless steel joint, respectively. These lap joints were mainly applied to the membrance fabrication of GT-LNG carrier. Fatigue tests of Invar/Inar lap joints were conducted under the stress ratio R=0 at room temperature. The effect of mean stress and cumulative fatigue damage on the allowable stress of Invar lap joint was evaluated on the basis of test results. Fatigue test was also conducted on Inver/Stainless steel lap joints welded by automatic TIG process without filler metals. The fatigue test of the joint was carried out under the same conditions as those of Invar/invar lap joints. The fatigue strength of the joint welded without filler metal was comparable to those welded with filler metal quoted from reference. The fatigue strength of Invar/stainless steel lap joint was only dependent on the lap throat thickness, and not on the welding process. Based on test results, the applicability of TIG welding process without filler metal in Invar/stainless steel lap joint was reviewed by controlling welding variables to assure the valid throat thickness of lap joints.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.272-273
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• 2013

Some living thingsuse micro- or nano- structures for living in nature. Scientists and engineers made efforts to mimic them, and they succeeded in making new types of applications. They used 'Namib desert beetle' to self-filling device by moisture harvesting and 'lotus leaf' to self-cleaning device by water repelling. 'Namib desert beetle' and lotus leaf have micro-patterns on their surface, which consists of hydrophobic or hydrophilic materials [1]. Moreover, micro-patterns on the surface make self-filling or self-cleaning property enhanced because of the surface roughness. Surface roughness enhances wettability [2]. Micro-pattern is a significant factor to make the surface be functional, so we want to make new types of functional surface by micro-patterning. In this work,we make several functional micro-patterns (radial, line, and dot arrays) using maskless lithography and analyze the characteristics of each micro-pattern. In order to analyze and understand surface characteristics, micro-patterns with varying sizes are investigated. All experiments are proceeded on mr-DWL5 photo resists coated on silicon wafers in same condition. All the experiments have demonstrated good performances about hydrophobic or hydrophilic property corresponding to their material and structural combinations. In radial micro-pattern, although the surface is flat, water drops on hydrophilic radial pattern can be convergent to a middle point and water drops on hydrophobic radial pattern can be divergent from the middle point. In line array micro-pattern, water drops can roll off along only one direction in parallel with the line arrays. Such phenomena might be mainly caused by the local change of surface roughness. From these results, controlling the movement and direction of water drops is made feasible without introducing a slope, which can potentially be used for new types of applications.

• The Korean Journal of Emergency Medical Services
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• v.23 no.3
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• pp.97-110
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• 2019

Purpose: This study aimed to investigate the role of life stress in the relation between health behaviors and bioethics awareness among paramedic students. Methods: This study recruited 238 paramedic students in F and R areas as participants. Multiple regression analysis was performed using Baron and Kenny's three-step procedure. Results: In the first stage, health behaviors had a significant effect on life stress (β=-.202, p<.01). In the second stage, health behaviors had a significant effect on bioethics awareness (β=.240, p<.001). In the third stage, life stress had a significant influence on bioethics awareness (β=-.167, p<.01). In the fourth stage, the regression coefficient of the third stage (β=.137) was less than that of the second stage (β=.159). In addition, when controlling for life stress, health behavior was shown to affect bioethics awareness (β=.206, p<.01). The mediating effect of life stress was found to be significant in the relation between health behavior and bioethics awareness (Z=2.04, p<.05). Conclusion: As health behavior is a factor that affects bioethics awareness through the mediation of living stress, universities should prepare training programs to improve the health behavior and reduce the life stress among students.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.252-255
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• 2008

The purpose of construction project management is to achieve planned quality by adequate cost and schedule of the project, thus the effective time management is a critical factor to actualize the object. But the traditional time management by using milestone has several limitations which are not sufficiently considered mutual relation and variated from the task. On this wise, applying the concept and principles of lean construction to the project will be the best way not only reduce waste and variation, but also improve the productivity and ability to overcome limitation as mentioned above. Thus the study, Last Planner System, specially focuses on constraint analysis which is used in lookahead planning system. The results of this research will provide the constraints classification that is able to improve work reliable and percent plan complete when time planning by controlling constraints of project.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.E
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• pp.9-17
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• 1998

Oxides of nitrogen play important roles in atmospheric chemistry. Soil has been recognized as a major natural source of NO, and its emission depends on soil parameters such as soil nitrogen availability, soil moisture and temperature. It is necessary to understand effects of these controlling parameters on soil NO emission. In order to understand soil moisture effects on NO emission, variations of NO concentration and existence of its equilibrium concentration were observed from ammonium fertilized Japanese upland soil prepared for different soil moisture conditions. The closed chamber technique was employed for this study. The significant increases in NO with soil moisture were found. Maximum was occurred at sample ID4 (55% of water-filled pore space (WFPS)), but it decreased as soil moisture increased. No significant NO concentration was emitted from soil sample without fertilizer, but there was significant NO in fertilized soil samples. The magnitudes of NO from soil increased with time and reached at steady state within ten minutes approximately. These results suggest that nitrogen input from fertilizer takes charge in the first step of sharp increase in NO emission, and then soil moisture becomes important factor to control NO emission from the soils. NO concentrations from soil were compared to those one-day after the experiment. Results from the comparison analysis suggest that the soil NO flux might have been stimulated by soil disturbances like mixing, and this is much more effective in dry soils rather than in wet soils. It was found that much less NO came out from soils after a day; suggesting that most of NO was released from the soils within a day after fertilizer application during our experiment. The length of NO releasing time span may depend on the amounts of fertilizer applied, soil moisture condition, and other soil physical parameters.