• 한국콘텐츠학회논문지
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• 제12권4호
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• pp.367-372
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• 2012

본 연구는 체질량지수에 따른 관전압(kVp)과 관전류량(mAs)의 변화에서 선량과 화질의 연관성을 알아보고자 하였다. 실험대상군은 A군(100 kVp, 240 mAs, N=20), B군(120 kVp, 240 mAs, N=20), C군(100 kVp, 270 mAs, N=20), D군(120 kVp, 270 mAs, N=20)으로 나누어 관전류량의 변화에 관계된 화질을 평가하였다. 실험대상군에 대한 화질평가는 4점 척도를 사용하여 very good 4점, good 3점, fair 2점, poor 1점 등급으로 나누어 평가하였고, 피폭선량은 DLP(dose length product)를 이용하여 평가하였다. 결론적으로 100 kVp에서는 5.6 $mGy{\cdot}cm$, 120 kVp에서는 11 $mGy{\cdot}cm$, 정도 낮은 선량을 보였고 통계적으로 유의한 차이를 보였다(p<0.05). 하지만 화질평가에서도 통계적으로 유의한 차이가 없었으며 진단적 가치가 동등한 영상을 획득하였다(p>0.05). 따라서 CT 관상동맥조영술 검사에서는 사전에 체질량지수(body mass index)을 고려하여 검사조건을 적절하게 선택하는 것이 환자의 피폭선량을 줄이면서 최적의 화질을 획득할 수 있을 것이라 사료된다.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제27권2호
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• pp.135-163
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• 2013

본 연구는 수학 학습 관련 긍정적 심리체험 검사지인 PPE-M을 사용하여 측정한 고등학생들의 긍정심리를 집단별로 비교하는데 그 목적이 있다. 본 연구의 목적을 위하여 측정된 자료를 t검증을 통하여 영재학생과 일반학생들 사이의 차이를 살펴보았으며, 또한 학년 및 성별 변인에 따른 차이도 분석하였다. 그리고 계열 변인에 따른 차이를 살펴보기 위해서 일원변량분석(One-way ANOVA)을 실시하였다. 그 결과, PPE-M의 총점에 대하여 영재학생과 일반학생들 간의 유의미한 차이가 있었고, 통찰 정직 뿌듯함 성취감의 4가지 요소를 제외한 나머지 19개의 요소 및 5개의 영역에서도 두 집단 간의 유의미한 차이가 나타났다. 그러나 학년 간의 유의미한 차이는 없었으며, 일반계학생들의 성별에 대한 비교에서는 판단력, 통찰, 정직, 신중함, 배려, 감사와 행복, 몰입, 우월감, 성취감, 쾌감, 뿌듯함, 자기효능감의 12개의 요소를 제외한 나머지 11개의 요소에서는 유의미한 차이가 있었다. 계열에 따른 비교에서는 정직을 제외한 22개의 요소에서 유의미한 차이가 나타났다.

• 산업진흥연구
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• 제6권4호
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• pp.11-21
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• 2021

본 연구는 콘텐츠 산업 대표 기업인 CJ E&M를 대상으로 기업 성장성 요인을 분석하고자 하였다. 먼저 CJ E&M 성장 동력을 분석하고자 마이클 포터의 다이아몬드 모델을 활용하여 핵심요인을 검토하였으며, 이후 4P 모델을 기준하여 향후 기업 성장을 도모할 수 있는 방향을 제시하고자 하였다. 연구결과, 기업 성장요인으로는 생산조건 측면에 다양한 장르에 기준한 미디어 콘텐츠와 스타급 인재 영입을 제시할 수 있으며, 수요조건 측면에서는 중국시장 수요조건을 충족 시켜왔다. 또한 관련 산업 측면에 K-Culture를 겨냥한 한류 산업을 뽑을 수 있으며 경영 여건 즉 전략, 구조, 경쟁 측면에 '투 트랙 전략인 글로벌·글로컬 전략, 미디어 커머스 전략이 유효하였다. 향후 발전 방향을 제시해 보면, 계열사 협업체계에 기초한 다양한 제품, 가격 측면에서 넷플릭스를 벤치마킹한 티빙을 제시하고자 하며, 유통경로 측면에서는 OTT 플랫폼의 글로벌 확장과 촉진 측면에서는 틱톡 플랫폼을 활용한 챌린지 마케팅을 활성화 시켜나갈 필요성이 있다.

• 대한공업교육학회지
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• 제35권2호
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• pp.140-158
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• 2010

과학기술교육의 수월성을 높이기 위해 기술과 담당 교사들의 역할이 매우 긴요하다는 인식 아래 이 연구는 내재적, 외재적 요인이 광주, 전라남도 소재 중 고등학교 기술과 담당 교사의 직무만족과 교직몰입에 미치는 영향을 분석하였다. 수집된 자료를 SPSS 통계 프로그랩을 통해 유의도 수준 p<.05 혹은 그 이상에서 다중회귀분석하였다. 교사들의 교직만족도는 M = 3.91, 교직몰입도는 M=3.69 이었다. 그들의 교직 만족에 대한 5개의 내재적 요인-성취, 일 자체, 책무성, 인정, 성장 가능성 등과 5개 외재적 요인-직업안정, 직무환경, 보수, 감독기술, 인간관계 등의 통합적 영향력은 R=.717, $R^2$=.515로 나타났으며 모두 유의하였다. 위 10개 요인들의 통합적 작용은 교사의 직무만족의 변화량에 대하여 51.5% ($R^2$=.515)의 설명력을 가지고 있었다. 이들 중, 보수가 가장 중요했고 다음이 성취였다. 이들의 통합이 교사들의 교직몰입에 미치는 영향을 분석한 결과, R=.785, $R^2$ =.616은 유의하였다. 통합은 교직몰입의 변화량에 대하여 61.6% ($R^2$=.616)의 설명력을 가지고 있었다. 요인별 중요성에서는 성취가 가장 높았고 책무성은 다음이었다. 10개 요인의 복합 투입량을 높이면 교사들의 교직만족과 교직몰입은 높아질 수 있다. 특히 보수와 성취도를 높여주는 것이 교직만족도 향상에, 그리고 성취와 책무성을 높이는 것은 교직몰입에 상대적으로 더 효과적이다. 본 연구는 광주와 전남의 중 고등학교 기술과 담당 교사들을 대상으로 했기 때문에 연구결과를 전국적으로 혹은 타 분야 담당 교사들에게 일반화하는 데는 한계가 있다.

• 대한수학회지
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• 제35권2호
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• pp.331-340
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• 1998

We define the spherical non-commutative torus $L_{\omega}$/ as the crossed product obtained by an iteration of l crossed products by actions of, the first action on C( $S^{2n＋l}$). Assume the fibres are isomorphic to the tensor product of a completely irrational non-commutative torus $A_{p}$ with a matrix algebra $M_{m}$ ( ) (m > 1). We prove that $L_{\omega}$/ $M_{p}$ (C) is not isomorphic to C(Prim( $L_{\omega}$/)) $A_{p}$ $M_{mp}$ (C), and that the tensor product of $L_{\omega}$/ with a UHF-algebra $M_{p{\infty}}$ of type $p^{\infty}$ is isomorphic to C(Prim( $L_{\omega}$/)) $A_{p}$ $M_{m}$ (C) $M_{p{\infty}}$ if and only if the set of prime factors of m is a subset of the set of prime factors of p. Furthermore, it is shown that the tensor product of $L_{\omega}$/, with the C＊-algebra K(H) of compact operators on a separable Hilbert space H is not isomorphic to C(Prim( $L_{\omega}$/)) $A_{p}$ $M_{m}$ (C) K(H) if Prim( $L_{\omega}$/) is homeomorphic to $L^{k}$ (n)$\times$ $T^{l'}$ for k and l' non-negative integers (k > 1), where $L^{k}$ (n) is the lens space.$T^{l'}$ for k and l' non-negative integers (k > 1), where $L^{k}$ (n) is the lens space.e.

• 간호행정학회지
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• 제4권1호
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• pp.5-17
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• 1998

The Purpose of this study is to find out differences among the leader's traits on the hierarchy of Nurse managers in Nurse system of the hospital. In this study 152 managers over head nurse working in 6 University hospitals and 5 general hospitals were selected and the questionary paper answered by them was collected from 1st to 30th in September in 1997. The measuring instrument used in this study is the one integrated and classified by Stogdill (1981), which nurse professor and 2 students of the master's course translated and modified with myself. And its validity was verified through making a test on 130 nurses. The measuring instrument used in this study is made up of 4 items about physical characteristics, 3 items about social background, 4 items about intelligence and ability, 17 items about personaity, 6 items about task-related characteristics, 9 items about social characteristics and 8 items about general background in the triats of leader. And this instrument is made to be marked using five point Likert type. It's reliability is Cronbach's Alpha =.93. The data for study were analyzed through SPSS/PC+ The result of this study are as follows: 1. The order in importantly perceptible degree of the leader's traits showed like these: the intelligence and ability (M=4.683), the task-related characteristics (M=4.605), the personality (M=4.39), the social characteristics (M=4.327), the social back-ground (M=4.056), the physical characteristics (M=3.601). 2. The order in degree to percept the importance of 44 detailed items of the leader's traits showed like these: the judgement and decisiveness (M=4.967), the sense of responsibility (M=4.904), the activity and energy (M=4.796), the self-confidence (M=4.776), the creativity (M=4.748), the intelligence (M=4.743), the responsibility in the pursuit of objectives (M=4.743), the enthusiasm (M=4.717), the objectivity (M=4.704), the moral sense and ethical conduct (M=4.704), the ability to enlist cooperation (M=4.694), the strength of conviction (M =4.678), the enterprise (M=4.691), the administrative ability (M=4.678) and the cooperativeness (M=4.638) 3. As the result of analyzing the leader's trait differences on the hierarchy of nurse managers in six factors of the leader's traits, the social background showed the meaningful differences(F=4.983, P=0.008). 4. As the result of analyzing the leader's traits defferences made from the upper first to 15th rank among the detailed items of the leader's trait factors on the heirarchy of nurse managers, the meaningful defferences appeared in the following items: the objectivity(F=3.413, P=0.033), the creativity (F=3.550, P=0.031), the sense of responsibility(F=3.345, P=0.049), and the administrative ability (F=3.363, P=0.037). 5. As the result of analyzing the leader's trait factors in general background, only the social background of 6 leader's trait factors showed the meaningful differences according to the working place (F=4.057, P=0.008). The study shows that we should consider the above leader's trait factors in selecting nurse managers and that we should develop the educational program for hierarchy of nurse managers urgently.

• 산업기술연구
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• 제24권A호
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• pp.139-155
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• 2004

A room and pillar mining method has been adopting at the Jeungsun limestone mine. To check stability of pillar with multiple and irregular openings, the size, shape and spacing of rib pillar were first designed using some empirical suggestions. The Finite Difference Method(FDM)was used to analyze the pillar stability. Twelve different cases with the variation of K(horizontal/vertical stress)values, different height and different spacing of pillar were used in this study. Finally Mohr-Coulomb criterion was adopted to calculate the safety factors. Horizontal and vertical displacement, maximum and minimum principal stresses, range of plastic zone and safety factors were calculated at each case. As a result of analysis, the size of one block is 160m long, 70m wide, 40m high with 20m wide rib pillar and 20m square column pillar. The overall recovery at this case can be estimated about 40%.

• 한국대기환경학회지
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• 제26권5호
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• pp.507-516
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• 2010

Stationary combustion sources such as coal-fired power plants, waste incinerators, industrial manufacturing, etc. are recognized as major sources of mercury emissions. Due to rapid economic growth, zinc production in Korea has increased significantly during the last 30 years. Total zinc production in Korea exceeded 739,000 tons in 2008, and Korea is currently the third largest zinc producing country in the world. Previous studies have revealed that zinc smelting has become one of the largest single sectors of total mercury emissions in the World. However, studies on this sector are very limited, and a large gap in the knowledge regarding emissions from this sector needs to be bridged. In this paper, Hg emission measurements were performed to develop emission factors from zinc smelting process. Stack sampling and analysis were carried out utilizing the Ontario Hydro method and US EPA method 101A. Preliminary data showed that $Hg^0$ concentrations in the flue gas ranged from 4.56 to $9.90\;{\mu}g/m^3$ with an average of $6.40\;{\mu}g/m^3$, Hg(p) concentrations ranged from 0.03 to $0.09\;{\mu}g/m^3$ with an average of $0.04\;{\mu}g/m^3$, and RGM concentrations ranged from 0.23 to $1.17\;{\mu}g/m^3$ with an average of $6.40\;{\mu}g/m^3$. To date, emission factors of 7.5~8.0 g/ton for Europe, North America and Australia, and of 20 or 25 g/ton for Africa, Asia and South America are widely accepted by researchers. In this study, Hg emission factors were estimated using the data measured at the commercial facilities as emissions per ton of zinc product. Emission factors for mercury from zinc smelting pross ranged from 4.32 to 12.96 mg/ton with an average of 8.31 mg/ton. The emission factors that we obtained in this study are relatively low, considering Hg contents in the zinc ores and control technology in use. However, as these values are estimated by limited data of single measurement of each, the emission factor and total emission amount must be updated in future.

• 한국산업보건학회지
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• 제27권4호
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• pp.313-323
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• 2017

Objectives: This study aimed to assess exposure to black carbon(BC) among forklift operators and to identify environmental and occupational factors influencing their BC exposure. Methods: We studied a total of 23 forklift operators from six workplaces manufacturing paper boxes. A daily BC exposure assessment was conducted during working hours from January to April 2017. A micro-aethalometer was used to monitor daily BC exposure, and information on work activities was also obtained through a time-activity diary(TAD) and interviews. BC exposure records were classified into four categories influencing BC exposure level: working environment, workplace, forklift operation, and job characteristics. Analysis of variance(ANOVA) was used to compare average BC exposure levels among the four categories and the relationships between potential factors and BC exposure were analyzed using a multiple linear regression model. Results: The operators' daily exposure was $12.9{\mu}g/m^3$(N=9,148, $GM=7.5{\mu}g/m^3$) with a range: $0.001-811.4{\mu}g/m^3$. The operators were exposed to significantly higher levels when they operate a forklift in a room ${\leq}20,000m^3$($AM=12.3{\mu}g/m^3$), in indoor workplaces($AM=16.3{\mu}g/m^3$), when they operate a forklift manufactured before 2006 ($AM=13.2{\mu}g/m^3$), a forklift with a loading limit of four-tons($AM=27.1{\mu}g/m^3$), with a roll and bale type clamp($AM=17.1{\mu}g/m^3$), and with no particulate filter($AM=15.7{\mu}g/m^3$). Conclusions: Occupational factors including temperature, smoking, season, daytime, room volume($m^3$), location of operating, and manufacturing era and model of forklift influenced the BC exposure of forklift operators. The results of this study can be used to minimize the BC exposure of forklift operators.

• Journal of Korean Neurosurgical Society
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• 제58권3호
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• pp.192-196
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• 2015

Objective : The aim of this study is to investigate good prognostic factors for an acute occlusion of a major cerebral artery using mechanical thrombectomy. Methods : Between January 2013 to December 2014, 37 consecutive patients with acute occlusion of a major cerebral artery treated by mechanical thrombectomy with stent retrievers were conducted. We analyzed clinical and angiographic factors retrospectively. The collateral flow and the result of recanalization were sorted by grading systems. Outcome was assessed by National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) at 90 days. We compared the various parameters between good and poor angiographic and clinical results. Results : Twenty seven patients demonstrated good recanalization [Thrombolysis in Cerebral Infarction (TICI) 2b or 3] after thrombectomy. At the 90-day follow up, 19 patients had good (mRS, 0-2), 14 had moderate (3-4) and four had poor outcomes (5-6). The mRS of older patients (${\geq}75years$) were poor than younger patients. Early recanalization, high Thrombolysis in Myocardial Infarction risk score, and low baseline NIHSS were closely related to 90-day mRS, whereas high TICI was related to both mRS and the decrease in the NIHSS. Conclusion : NIHSS decreased markedly only when recanalization was successful. A good mRS was related to low initial NIHSS, good collateral, and early successful recanalization.