• Journal of Korean Neurosurgical Society
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• v.59 no.1
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• pp.6-10
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• 2016

Objective : The objectives of this study was to determine the incidence and outcomes of procedural rupture (PR) during coil embolization of unruptured intracranial aneurysm (UIA) and to explore potential risk factors. Methods : This retrospective study evaluated 1038 patients treated with coil embolization between January 2001 and May 2013 in a single tertiary medical institute. PR was defined as evidence of rupture during coil embolization or post procedural imaging. The patient's medical records were reviewed including procedure description, image findings and clinical outcomes. Results : Twelve of 1038 (1.1%) patients showed PR. Points and time of rupture were parent artery rupture during stent delivery (n=2), aneurysm rupture during filling stage (n=9) and unknown (n=1). Two parent artery rupture and one aneurysm neck rupture showed poor clinical outcomes [modified Rankin Scale (mRs) >2] Nine aneurysm dome rupture cases showed favorable outcomes ($mRS{\leq}2$). Location (anterior cerebral artery) of aneurysm was associated with high procedural rupture rate (p<0.05). Conclusion : The clinical course of a patientwith procedural aneurysm rupture during filling stage seemed benign. Parent artery and aneurysm neck rupture seemed relatively urgent, serious and life threatening. Although the permanent morbidity rate was low, clinicians should pay attention to prevent PR, especially when confronting the anterior cerebral artery aneurysm.

• Child Health Nursing Research
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• v.15 no.1
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• pp.24-33
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• 2009

Purpose: The purpose of this study was to explore the parent related factors that influence internet game addiction among elementary school students. Method: Data was collected through self-administered questionnaires and descriptive statistics, t-test, ANOVA, correlation and stepwise multiple regression were used to analyze the data. Data survey was conducted with 739 conveniently selected students who were in grades 4, 5, and 6 of elementary schools in Seoul or Gyung-gi province. Results: The addiction groups were classified as general user group (84.3%), potential risk group (10.0%) and high risk group (5.7%). There were significant internet game addiction differences by gender, grade, expense of internet cafe, religion, school record, place where child played, economic status, and duration and frequency of game play. The addiction was negatively correlated to parents' attachment, supervision, attitude to child nurturing, and expectations regarding school study. The most significant variables were both parents' attitude to child nurturing, and mother's supervision. These three variables explained 20.7% of internet game addiction in elementary school students. Conclusion: These findings are expected to make a contribution to the creation of ideal interventions at school, home, and counselling centers to prevent internet game addiction.

• International Journal of Industrial Entomology and Biomaterials
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• v.11 no.1
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• pp.75-78
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• 2005

Inheritance of cocoon and shell weight characters in silkworm crosses between sex-limited at larva stage lines, including three (NIG$_{1}$ $\times$ TV$_{3/2}$ ,NIG$_{1}$ $\times$ TBV$_{2/24}$ and NIG$_{1}$ $\times$ B$_{2/6}$ ) from Japanese type and three (NIG$_{2}$ $\times$ B$_{2/6}$ ,TV$_{3/2}$ $\times$ NIG$_{1}$ and NIG$_{2}$ $\times$ TBV$_{2/24}$ ) from Chinese type was studied at Regional Centre for Scientific­Applied Service - Vratza during the period of 2000 ­2002. Inheritance of tested characters in F I was deter­mined through genetic parameters, additiveness (a), dominance (d) and their ratio (d/a). Degree and frequency of transgressions in F$_{2}$ were calculated also. Over dominance (d/a(>) 1) with bigger contribution of the parent with higher value was determined at inheritance tested characters. Transgressions obtained at cocoon and shell weight characters were positive and varied in wide limits. The productivity of parent's lines had defined the variability of genetic parameters for degree and frequency of transgressions. Combination of positive transgressions at cocoon and shell weight characters in F2 hybrid populations from sex-limited at larva stage allow us to select individuals with high productive potential for further use in selection programs.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.2
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• pp.492-501
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• 1990

It was known that the fracture incidences of offshore structure were mostly originated from the surface defects. Especially, in the case of the welded structures, since the welded region has some defects and incomplete beads which are apt to behave like the surface cracks, it has been necessary to evaluate the environmental effects on crack growth at HAZ for the design crack growth behaviour at multi-pall HAZ for SWS41 steel under free corrosion and cathodic protection(-0.9V vs Ag/Agcl) conditions. The results are summarized as follows ; (1) Crack growth rate of the as weld in air was faster than that of the parent and PWHT specimens over all .DELTA.K rang. (2) In free corrosion test, surface crack growth rate of the as welded was decreased in comparison with that of the parents. (3) In fatigue test under cathodic protection, cathodic electric potential(-0.9V vs Ag/Agcl) for the SWS41 steel parent was effective, while for the as welded ineffective. (4) There was a tendency that the exponent(m) of the Paris' equation was decreased in order of microhardness magnititude in air and under cathodic protection conditions and vise versa in free corrosion. (5) Fracture surface has dimples and ductile striations in air test, but transgranular cracks and brittle striations under cathodic protection test.

• Journal of the Society of Naval Architects of Korea
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• v.53 no.6
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• pp.456-464
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• 2016

To design the modified hull form with relatively unfavorable dimensions and constraints than the parent ship the stepwise design was applied. In each design step the resistance characteristics was estimated by numerical calculations using CFD programs as Wavis 1.4, Wavis 2.1 and Fluent 12.1. The wave profiles along hull surface by potential flow calculations were investigated to improve wave resistance by modifying the bow shapes. To improve the stern shapes with a point of viscous form resistance the pressure distributions on hull surface and the limiting streamlines are investigated by viscous flow calculations. The design objectives such as shortening the LBP, enlarging the propeller tip clearance, moving forward of the LCB location and increasing the displacement were applied by stepwise to develop the new hull form of DWT 75,000 product oil carrier. Finally a new hull form was developed without the resistance performance loss compared with the parent ship.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.325-330
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• 2004

Recently, the request for the high strength of material is more and more increased in the area of industrial environment and machinery. To accomplish the high strength of materials, carbonizing treatment, nitrifying treatment, shot-peening method are representatively applied, however, shot-peening method is generally used among the surface processes. Shot peening is a cold working process used to impact Compressive residual stressed in the exposed surface layers. Benefits due to shot peening are increase in resistance to fatigue, stress corrosion cracking, fretting, galling, erosion and closing of pores. In this study, the influence of shot peening on the corrosion was investigated on spring steel immersed in 3.5% NaCl. The immersion test as performed on the two kinds of specimens. Corrsion potential, polarization curve, residual stress and etc, were investigated from experiment results. From test result the effect of shot peening on the corrosion was evaluated. The important results of the experimental study on the effects of shot peened on the environment corrosion of spring steels are as follows; In case of corrosion potential, shot peened specimen shows more activated negative direction as compared with parent mental. Surface of specimen, which is treated with the shot peened is placed as more activated state against inner base metal. It can cause t도 anti-corrosion effect on the base metal.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.1
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• pp.159-165
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• 2005

Shot peening can be defined as the process of work hardening of the surface of components by means of propelled stream of spherical shot. Benefits due to shot peening are increase in resistance to fatigue, stress corrosion cracking, fretting, galling, erosion and closing of pores. In this study, the influence of shot peening on the corrosion was investigated on spring steel immersed in $3.5\%\;NaCl$. The immersion test was performed on the two kinds of specimens. Corrosion potential, polarization curve, residual stress and etc. were investigated from experimental results. From test results, the effect of shot peening on the corrosion was evaluated. The important results of the experimental study on the effects of shot peened spring steels on the environment corrosion are as follows; In case of corrosion potential, shot peened specimen shows more activated negative direction as compared with parent metal. Surface of specimen, which is treated with the shot peened, is placed as more activated state against inner base metal. It can cause the anti-corrosion effect on the base metal.

• Korean Journal of Veterinary Research
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• v.50 no.2
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• pp.93-103
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• 2010

This study investigated the potential effects of amitraz on the pre- and postnatal development, behavior, and reproductive performance of offspring of parent rats given amitraz during pre-mating, gestation, and lactation. The test chemical was administered via the drinking water containing 0, 40, 120, and 360 ppm to male rats from 2 weeks before mating to the end of 14-day mating period and to females from 2 weeks before mating, throughout mating, gestation and lactation up to weaning. Based on fluid consumption, the male rats received an average of $0,\;5.7{\pm}1.33,\;13.2{\pm}2.08,$ and $35.8{\pm}3.42$ mg/kg/day amitraz, and the female rats received an average of $0,8.7{\pm}4.42,\;20.1{\pm}9.60,\;and\;47.6{\pm}22.38$ mg/kg/day amitraz, respectively. At 360 ppm, an increase in the incidence of abnormal clinical signs, a suppression in the body weight gain, a decrease in the food consumption and litter size, an increase in the post-implantation loss, and a decrease in the seminal vesicle weight were observed in the parent animals. In addition, a suppression in the body weight gain, a decrease in the grip strength, a delay in the negative geotaxis, an increase in the pre- and post-implantation loss, and a decrease in the number of live embryos were observed in the offspring. At 120 ppm, suppressed body weight gain and reduced food consumption were observed in the parent rats. Suppressed body weight gain and decreased grip strength were also observed in the offspring. There were no signs of either reproductive or developmental toxicity at 40 ppm. Under these experimental conditions, the no-observed-adverse-effect level of amitraz for parent rats and their offspring was estimated to be 40 ppm in rats.

• Journal of Korean Home Economics Education Association
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• v.32 no.1
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• pp.167-184
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• 2020

The purpose of this study was to examine the effects of storytelling lessons using picture books on the resilience of adolescents and the parent-child relationships in the family unit of home economics subject in middle school. For this purpose, I selected picture books of five themes on family type, family relationship, family conflict, sexual violence, domestic violence, and family loss, and developed a teaching-learning process plan for 'Family class with picture book' using storytelling elements and techniques. The teaching-learning plan was applied to 194 middle school students in technology·home economics classes, and the learning effet was evaluated by comparing pre- and post-tests. As a result, the resilience level perceived by adolescents increased significantly after class, but no significant effect was found on self-expansion, which is a sub-factor of sociality. In the parent-child relationship of adolescents, the effect of instruction was shown in all areas, and the affectional bonds felt in the relationship with mother than with father showed higher increase. In the family unit of home economics, storytelling lesson through picture book seems to have a positive influence on the adolescents in their relationship with the family by bringing up the potential power in them to stand against the adversities they may face.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.5
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• pp.896-903
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• 2002

The susceptibility of SCC for the weldment and PWHT specimens of HT-60 steel was evaluated using a slow strain rate method under applied potential by means of the potentiostat in synthetic seawater. In case of the parent, anodic polarization voltage was inappropriate in elongating the time to failure(TTF). -0.8V corresponding to cathodic protection range is most effective in improving the SCC resistance against corrosive environment. In case of the weldment, the values of reduction of area(ROA) and TTF at -0.68V corresponding to cathodic polarization value were 45.2% and 715,809sec which were the largest and longest life among other applied potentials. Those were vise versa at -1.1V. In case of the PWHT specimens, TTF and ROA at -0.68V was longest and largest like the weldment. Besides, PWHT is effective in prolonging the time to failure of the welded off-shore structure due to softening of effect. Regardless of the weldment and PWHT specimen, as corrosion rate gets higher, TTF becomes shorter and deformation behaviour for the weldment and PWHT specimen at -1.1V was shown to be irregular. Finally, it was found that specimens showed brittle fracture at -1.1V, but more ductile fracture accompanying the micro-cracks at applied potential of -0.68V.