• 한국영어학회지:영어학
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• 제1권4호
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• pp.587-608
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• 2001

When teaching English in elementary schools was introduced in Korea in 1997, the theoretical basis was the critical period hypothesis (CPH). The object of this study was to test whether the Korean situation satisfies the conditions for the CPH such as the amount of English input and needs. As a test for this, English input and needs were compared in Korea, the U.S.A. and Singapore. The items for English input were on a continuum of primary to secondary sources and the items for English needs were on a continuum of immediate to future needs. The 0-5 scale was used. The result showed that the total means of English input were 4.87, 4.62, and 1.05 for children in the U.S.A., Singapore and Korea respectively. The total means of English needs were 4.32, 3.81, and 1.52 for children in the U.S.A., Singapore and Korea respectively. These figures show that Korean children's levels of both input and needs were from “almost none” to “little,” while those of children in the U.S.A. and Singapore were from “much” to “very much.” This shows that teaching English in Korea presently is far from meeting the conditions that are expected by the CPH. As an alternative to explain what happens cognitively to Korean children, this paper suggests the automatization and proceduralization processes.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2003년도 하계학술연구발표회 및 한.일 공동심포지엄
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• pp.260-261
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• 2003

It is recognized that the magnetization reverses with a sequence of discrete and jerky jumps, known as the Barkhausen effect. Recently, interest in the Barkhausen effect has grown as it is a good example of dynamical critical behavior, evidenced by experimental observation of a power law distribution of the Barkhausen jump size. So far, most experimental studies have been carried out on bulk samples using a classical inductive technique, which is difficult to apply to thin film samples mainly due to the ]ow signal intensity. For this reason, very few experiments have been done on two-dimensional ferromagnetic thin films. In this talk, we report a direct domain observation of Barkhausen avalanche at criticality in Co and MnAs thin films investigated by means of a magnetooptical microscope magnetometer (MOMM), capable of time-resolved domain observation with an image grabbing rate of 30 frames/s in real time. In Fig. 1, we demonstrate a series of six representative domain-evolution patterns of 25-nm Co film observed successively by means of the MOMM, where one can directly witness Barkhausen avalanche.

• 한국병원경영학회지
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• 제22권1호
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• pp.21-39
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• 2017

Purpose : This study was intended to investigate the structural relationship among empowerment, self-efficacy, job motivation, autonomy, critical thinking, job-satisfaction, burnout, and self-achievement. In addition, we tested the moderating effect of the career period on the influence of empowerment. Methodology : The structural equation model was used to test the causal relationship between factors, and t-test, ANOVA, descriptive statistics are applied to analyze the research data. Findings : The result of this study shows that the structural model that is the empowerment encourages the self-efficacy, job motivation, autonomy, and critical thinking, also these factors affect the self-achievement through both the job-satisfaction and burnout is acceptable according to the goodness of fitness indices. In addition, we show that the career period moderates the influence of empowerment on the self-efficacy, job-motivation, and autonomy, but not critical thinking. Usually, the shorter the career period is the higher the influence of empowerment is. This moderating effect means that to give proper empowerment to lower position nurses encourage them, and prevent from burnout. Therefore, they feel job-satisfaction and finally self-achievement. Practical Implications : The empowerment helps the nurse to activate self-efficacy, job motivation, autonomy, critical thinking. Hence, these factors decrease burn-out but increase job satisfaction. Finally a sense of self-perfection increase.

• 한국안전학회지
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• 제12권4호
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• pp.114-121
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• 1997

Helical anchors are foundation structure that designed to resist uplift loads are installed by applying in load to shaft while rotating it into the ground. These can be a cost effective means of proving tension anchorage for foundation where soil conditions permit their installation because of ease of installation. At present time, tapered helical anchors are commonly used to carry uplift loads. The uplift capacity includes the following factors : the height of overburden above the top helix, the resistant along a cylinder, the weight of the soil in the cylinder and suction force. In order to make clear behavior characteristics of helical anchors with pullout, model tests were conducted with respect to various embedment depth, space of helix, shape of helix. Based on the experimental study, the following conclusions are drawn. 1) The uplift capacity of multi helical anchors increase with embedment ratio of anchors The increase is smooth after critical uplift capacity. 2) Critical breakout factors and critical embedment ratio of multi helical anchor exist 7∼8, 4∼6 respectively. 3) Variation of uplift capacity with helix spaces show down after S/D=5. 4) Critical breakout factors of helical anchor in the laboratory test are similar to Das's theory.

• Structural Engineering and Mechanics
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• 제13권5호
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• pp.543-556
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• 2002

A dynamic elastic local buckling analysis is presented for a pile subjected to an axial impact load. The pile is assumed to be geometrically perfect. The interactions between the pile and the surrounding soil are taken into account. The interactions include the normal pressure and skin friction on the surface of the pile due to the resistance of the soil. The analysis also includes the influence of the propagation of stress waves through the length of the pile to the distance at which buckling is initiated and the mass of the pile. A perturbation technique is used to determine the critical buckling length and the associated critical time. As a special case, the explicit expression for the buckling length of a pile is obtained without considering soil resistance and compared with the one obtained for a column by means of an alternative method. Numerical results obtained show good agreement with the experimental results. The effects of the normal pressure and the skin friction due to the surrounding soil, self-weight, stiffness and geometric dimension of the cross section on the critical buckling length are discussed. The sudden change of buckling modes is further considered to show the 'snap-through' phenomenon occurring as a result of stress wave propagation.

• 대한기계학회논문집
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• 제10권2호
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• pp.198-207
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• 1986

본 연구에서는 Fig.1과 같이 시편 부위에 균일응력분포가 작용하도록 M.Arcan 등에 의해 제시된 비대칭형상의 시편고정물에 층간균열을 가진 시편을 부착한 다음 하중각도를 바꾸어가며 모우드 II뿐 아니라 혼합모우드 및 모우드 I까지도 실험 할 수 있는 실험장치를 사용하여 균열면에서의 섬유방향이 〔0/0〕이고 초기균열길이비가 0.4, 0.5, 0.6인 시편의 모우드I, 혼합모우드 및 모우드II 층간파괴인 성치들을 실험 적으로 구해 혼합모우드 파괴결정조건식들에 적용시켜 보았다. 또한 균열면에서의 섬유방향이 〔0/0〕, 〔0/30〕, 〔0/45〕및 〔0/60〕인 경우의 층간파괴인성치와 이때 의 파괴현상에 대해 관찰하였다.

• 한국가스학회지
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• 제24권1호
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• pp.56-65
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• 2020

일반적으로 화재는 다양한 원인으로 발생하며 무작위로 보이기에 화재의 발생을 예측한다는 것은 매우 도전적인 문제이다. 하지만 모든 화재가 아닌 큰 피해를 주는 초대형 화재사고의 예측이 가능하다면, 선제적 대응을 통한 손실 최소화를 기대할 수 있다. 본 연구에서는 국가 전체를 대상으로 초대형 화재사고를 예측하기 위해 기계학습 기법인 k-평균 클러스터링을 이용하여 화재사고를 분류하고, 이를 인위적인 설정이 강한 비전문가 기준, 전문가 기준 분류 결과와 비교하여 예측에 적절한 분류 기준을 제안하였다. 비교 결과 기계학습을 이용한 분류가 일정한 피해규모와 비율로 분류되어, 예측에 적절한 분류 기준이라 판단하였다. 또한 초대형 화재사고의 주기성을 분석한 결과 일정한 패턴을 보였지만 높은 편차를 보였다. 따라서 단순 예측기법이 아닌 고급 예측기법을 사용하였을 때 초대형 화재사고의 발생 예측이 가능하다고 판단되었다.

• Geomechanics and Engineering
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• 제31권1호
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• pp.87-97
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• 2022

The excessive settlement and deformation of disintegrated carbonaceous mudstone (DCM) embankments under dynamic loading have long been problems for engineers and technicians. In this work, the characteristics and mechanism of the plastic deformation of DCM under different degrees of compaction, water contents and confining pressures were studied by static triaxial, dynamic triaxial and scanning electron microscopy testing. The research results show that the axial stress increases with increasing confining pressure and degree of compaction and decreases with increasing water content when DCM failure. The axial strain at failure of the DCM decreases with increasing confining pressure and degree of compaction and increases with increasing water content. Under cyclic dynamic stress, the change in the axial stress level of the DCM can be divided into four stages: the stable stage, transition stage, safety reserve stage and unstable stage, respectively. The effects of compaction, water content and confining pressure on the critical axial stress level which means shakedown of the DCM are similar. However, an increase in confining pressure reduces the effects of compaction and water content on the critical axial stress level. The main deformation of DCM is fatigue cracking. Based on the allowable critical axial stress, a method for embankment deformation control was proposed. This method can determine the degree of compaction and fill range of the embankment fill material according to the equilibrium moisture content of the DCM embankment.

• 대한장애인치과학회지
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• 제3권2호
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• pp.80-86
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• 2007

A critical pathway (CP) defines the optimal care process, sequencing and timing of intervention by multi-disciplinary health care teams for a particular diagnosis and procedure. It plays an important role as a cost-effective health care delivery system and a tool for quality control of medical and dental services by means of standardizing medical practices. The aim of this study is to investigate the satisfaction of patients and medical/dental staff after implementation of a critical pathway for dental treatment of disabled children under general anesthesia and its cost effectiveness. Ten patients who underwent dental treatment under general anesthesia were included in the CP group between August and December 2006. The pre-CP group included 20 patients who underwent the same procedure from February 2003. The satisfaction of parent of child patient and medical staff members were compared between two groups. The parents' satisfaction was significantly improved after the implementation of CP and medical/dental staff members were highly satisfied with the usefulness of the critical pathway. In conclusion, the critical pathway for the dental treatment of disabled treatment under general anesthesia can highly improve the satisfaction of parents and medical/ dental staff members.

• 한국간호교육학회지
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• 제19권4호
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• pp.606-616
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• 2013

Purpose: The purpose of this study was to investigate the effect of critical thinking disposition on emotional regulation, perceived stress and communication competence of students in nursing. Methods: A total of 362 students were recruited from two nursing colleges in C and S city. Data were collected by means of self reported questionnaires from December 1 to 15, 2012 and analyzed using descriptive statistics, t-test, ANOVA, Pearson correlation coefficients and multiple regression with SPSS 18.0. Results: A positive correlation was found between critical thinking disposition and seeking support emotional regulation, active emotional regulation and communication competence. A negative correlation was found between critical thinking disposition and perceived stress. Critical thinking disposition was the strongest predictor of seeking support emotional regulation, active emotional regulation, perceived stress and communication competence. Conclusion: The results of this study suggest that to enhance positive emotional regulation and communication competence and to reduce stress for nursing students, it is necessary to develop a teaching program and curriculum for increasing critical thinking disposition.