• 해양환경안전학회지
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• 제26권3호
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• pp.286-296
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• 2020

Sandwich structures are general-purpose structures that can reduce the structural weight of composite ships. Core materials are essential for these structures, with polyvinyl chloride (PVC) foams being the most popular. These foam core materials are subjected to various tests in the development process, and must satisfy the performance requirements of several ISO and ASTM standards. Therefore, a procedure for evaluating the performance of foam core materials was proposed in this paper. In addition, prototypes were fabricated using a commercial PVC foam core product in accordance with the structural design of an 11 m fiber-reinforced plastic yacht. Then, a case study was conducted on the proposed evaluation procedure. The proposed procedure facilitates the understanding of the performance requirements and evaluation of core materials used in composite ships and is expected to be utilized in developing core materials for marine structures.

• 한국전기전자재료학회논문지
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• 제14권6호
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• pp.499-504
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• 2001

We evaluated the degree of texture through depth of the superconductor core of Bi-Sr-Ca-Cu-O(BSCCO) superconductor tape. The degree of texture was characterized by pole figure analysis indicating that the degree of texture varied significantly with depth of the superconductor core. It was observed that the degree of texture was higher near the interface than inside the superconductor core. Specifically, as getting near to the center from the sheath/core interface, the orientation of BSCCO became dispersed from normal direction(ND) which, in turn, resulted in the degradation of <001>-fiber texture. In addition, the <001> texture was non-uniform an, better texture was developed along rolling direction(RD), compared to transverse direction(TD). Microstructural investigation showed that grain alignment was locally degraded by the existence of second phases. I was observed that larger grain size and better texturing were developed near the relatively straight interface compared to those inside the superconducting core. Based on our study, the region near the interface is thought to carry significant current compared to that inside the core.

• 한국의류학회지
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• 제37권2호
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• pp.224-234
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• 2013

This study investigates the fabrication of core-sheath nanocomposite fibers by locating germanium (Ge) and silicon dioxide ($SiO_2$) nanoparticles selectively in the sheath layer by co-axial electrospinning. Co-axially spun fibers were prepared by electrospinning a pure PVA solution and Ge/$SiO_2$/PVA solution as the core and sheath layer, respectively. Core-sheath nanocomposite fibers were electrospun under a variety of conditions that include various feed rates for the core and sheath solutions, voltages, and concentric needle diameters, in order to find an optimum spinning condition. Ge/$SiO_2$ nanocomposite fibers were also prepared by uniaxial electrospinning to compare fiber morphology and nanoparticle distribution with core-sheath nanofibers. Using scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray analysis, it was demonstrated that the co-axial approach resulted in the presence of nanoparticles near the surface region of the fibers compared to the overall distribution obtained for uni-axial fibers. The co-axially electrospun Ge/$SiO_2$/PVA nanofiber webs have possible uses in high efficiency functional textiles in which the nanoparticles located in the sheath region provide enhanced functionality.

• 한국응급구조학회지
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• 제21권3호
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• pp.35-48
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• 2017

Purpose: The purpose of the study was to investigate the core competency of disaster management of 119 paramedics. Methods: A self-reported questionnaire was completed by 242 paramedics in C area from April 28 to May 12, 2017. The study instrument included general characteristics of the subjects (4 items), disaster experience, recognition, and preparedness (20 items), and importance and performance of disaster management core competency (24 items) by Likert 5-point scale. Data were analyzed using t-test, ANOVA, Pearson's correlation coefficient using IBM SPSS 24.0. Results: The seriousness of personal disaster was 4.02 points and the importance of disaster-related education was 4.28 points. The importance to core competency of disaster management was 4.39 points and the ability to perform core competency was 3.58 points. The seriousness of personal disaster and the importance of disaster-related education were positively correlated (r=.600, p=.000). The importance and ability to perform core competency were positively correlated (r=.389, p=.000). Conclusion: It is necessary to strengthen core competency of disaster management in paramedics who are the first defense line of disaster.

• 대한수학회지
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• 제39권5호
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• pp.745-764
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• 2002

In this paper we Study a time-optimal model of pursuit in which the players move on a plane with bounded velocities. This game is supposed to be a nonzero-sum group pursuit game. The main point of the work is to construct and compare cooperative and non-cooperative solutions in the game and make a conclusion about cooperation possibility in differential pursuit games. We consider all possible cooperations of the players in the game. For that purpose for every game $\Gamma(x_0,y_0,z_0)$ we construct the corresponding game in characteristic function form $\Gamma_v(x_0,y_0,z_0)$. We show that in this game there exists the nonempty core for any initial positions of the players. The core can take four various forms depending on initial positions of the players. We study how the core changes when the game is proceeding. For the original agreement (an imputation from the original core) to remain in force at each current instant t it is necessary for the core to be time-consistent. Nonemptiness of the core in any current subgame constructing along a cooperative trajectory and its time-consistency are shown. Finally, we discuss advantages and disadvantages of choosing this or that imputation from the core.

• 한국항해항만학회지
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• 제32권9호
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• pp.723-727
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• 2008

Sensing performances of evanescent field absorption (EFA) hetero-core fiber sensor has been presented based on EFA by changing the length and the core diameter of the single mode fiber. Experimental results have demonstrated a good feature in their relationship between the length and the core diameter of the single mode fiber. The sensor consists of 2 fiber optics which have the same cladding diameter of $125{\mu}m$ However one fiber optic used is single mode and has varying core diameter ranging from 3.3 to $5.6{\mu}m$. The other fiber is multimode type and has a thicker fixed core diameter of $62.5{\mu}m$. The 2 fiber optics are thermally spliced together. Experiments conducted to measure the resonance wavelength were carried out over a range of refractive index, to find the optimum sensing length Experiments show that core diameter of the single mode fiber and sensing length offects the linearity and sensitivity.

• 대한정형도수물리치료학회지
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• 제25권2호
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• pp.47-56
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• 2019

Background: The purpose of this study was compare and analyze the Cobb's angle, core muscle strengthening in adolescents with idiopathic scoliosis and provide scientific basis for effectively treating idiopathic scoliosis in the future. Methods: The subjects of this study were 20 members of adolescent girls. Measurement tools were comprised Cobb's angle test, core muscle strengthening test. After 8 weeks of program, both groups had the same measurements as before program start. Results: The results of the study are as follows. First, the experimental group was decreased statistically significantly in Cobb's angle than the control group. Second, Both groups were increased statistically significantly in core muscle strengthening. The experimental group was increased statistically significantly direction in front, back l than the control group. Conclusion: Sling exercise with core exercise was effective in the decrease of Cobb's angle and core muscle strength than general scoliosis exercise in adolescents with idiopathic scoliosis.

• 대한전자공학회논문지SD
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• 제46권10호
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• pp.46-52
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• 2009

현재 개발되고 있는 Shader 프로세서는 처리 성능을 높이기 위하여 Multi-Core, Multi-Thread를 채택하고 있다. 또한 Shader 프로세서에서 각 수행 단계별 마다 IP를 따로 구현하지 않고 하나의 Core IP를 다양한 목적으로 사용할 수 있도록 설계하고 있다. 본 논문에서는 이러한 목적에 맞게 Shader-Core를 이용하여 연산이 가능하고, Multi-Core, Multi-Thread 기반에서 픽셀의 병렬처리가 가능하도록 고안된 Vector 기반의 Rasterization알고리즘을 제안한다. 이를 통하여 동일 조건의 기존 알고리즘에 비하여 약 2%의 연산량을 가지면서 각 픽셀이 독립적으로 연산이 가능하도록 하였다.

• 성인간호학회지
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• 제26권1호
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• pp.11-21
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• 2014

Purpose: This study was conducted to describe core competencies and identify factors affecting core competencies among infection control nurses (ICN). Methods: Infection control nurses from hospital with more than 200 beds comprised the sample. Questionnaires were sent to the sample via e-mail. One hundred and three questionnaires were returned. Data were analyzed with descriptive statistics and stepwise multiple regression via SPSS/WIN 21.0. Results: The core competency level of healthcare workers area was the highest that of the education and research was the lowest. There were significant differences in core competencies related to demographics such as age, clinical carrier, infection control carrier, position, academic degree, infection control specialist license, hospital location, and hospital type. The explained variances for the core competency were 38.3% and the contributing factors to core competencies were infection control carrier and infection control specialist license. Conclusion: It showed various levels of core competencies depending on infection control nurses' demographics and hospital traits, therefore consistent management efforts for the licensing and career path of infection control would be required.

• 부모자녀건강학회지
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• 제16권1호
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• pp.37-44
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• 2013

Purpose: The purpose of this study is to analyze the effectiveness of maternity nursing education-knowledge, skills and attitude among the third year students who have completed maternity nursing, practice at the college, clinical practice and core skill practicum. Methods: This is the descriptive research to verify the effectiveness of simulation-based practice education for core skill of maternity nursing. Third year nursing students who have completed maternity nursing related theories and practice have been selected as population. Total of 202 surveys have been used for analysis. Data analysis is done by using SPSS/WIN 18.0. Results: Self-confidence of core skill in maternity nursing is experimental group 4.52 and control group 4.37 score (p<.05). Performance competence in childbirth care is experimental group 4.53 and control group 4.35 score (p<.05). The students who have maternity nursing related clinical practice and core skill practicum experience show high core skill evaluation score. Conclusion: Therefore, it is recommended that current maternity nursing core skill curriculum should be reviewed and improved, and the students should be provided variety of simulation techniques to gain essential knowledge and core nursing skills.