• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.173-173
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• 2004

현재 건설 현장에서는 유압 굴삭기를 이용하여 굴삭 작업뿐 아니라 비교적 가벼운 물체의 크레인 작업도 병행하고 있다 그러나 국내의 경우 유압 굴삭기를 사용한 크레인 작업은 법으로 못하게 하도록 규제되어 있다. 그럼에도 불구하고 작업 현장에서는 필요에 의해 불법으로 작업을 하고 있으며 이로 인한 사고가 증가하고 있고, 그 비율이 전체 굴삭기 작업 재해의 약 38％에 이르고 있다.(중략)

• The korean journal of orthodontics
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• v.36 no.1 s.114
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• pp.30-44
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• 2006

This study was performed to investigate the location of the ideal bracket positioning plane in lingual orthodontics using the three-dimensional finite element method. Displacement of the anterior teeth were evaluated according to the vertical and the angular movements of the bracket positioning plane. To achieve the ideal movement of anterior teeth in the lingual central plane, the location of the force application point and the amount of the moment applied to the four incisors were evaluated. As the bracket positioning plane was moved parallel toward the incisal edge, uncontrolled tipping and extrusion of the maxillary and the mandibular incisors were increased. But lingual tipping of the crown was decreased in the maxillary and the mandibular canines. As the bracket positioning plane was inclined toward the incisal edge, lingual tipping was increased in the 6 anterior teeth and extrusion of incisors and intrusion of the canine was also increased. As the retraction hook of the canine bracket was elongated, lingual tipping and extrusion of the central incisor and mesial movement and extrusion of the lateral incisor were increased. In the canine, mesial and labial movements of the crown were increased. When the moment was applied to the 4 incisors of the maxillary and the mandibular arch in the lingual central plane, 280 gf-mm in the maxillary central incisor, 500 gf-mm in the maxillary lateral incisor, 170 gf-mm in the mandibular central incisor and 370 gf-mm in the mandibular lateral incisor produced bodily movement of the individual tooth.

• The korean journal of orthodontics
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• v.45 no.1
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• pp.20-28
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• 2015

Objective: The purpose of this study was to observe stress distribution and displacement patterns of the entire maxillary arch with regard to distalizing force vectors applied from interdental miniscrews. Methods: A standard three-dimensional finite element model was constructed to simulate the maxillary teeth, periodontal ligament, and alveolar process. The displacement of each tooth was calculated on x, y, and z axes, and the von Mises stress distribution was visualized using color-coded scales. Results: A single distalizing force at the archwire level induced lingual inclination of the anterior segment, and slight intrusive distal tipping of the posterior segment. In contrast, force at the high level of the retraction hook resulted in lingual root movement of the anterior segment, and extrusive distal translation of the posterior segment. As the force application point was located posteriorly along the archwire, the likelihood of extrusive lingual inclination of the anterior segment increased, and the vertical component of the force led to intrusion and buccal tipping of the posterior segment. Rotation of the occlusal plane was dependent on the relationship between the line of force and the possible center of resistance of the entire arch. Conclusions: Displacement of the entire arch may be dictated by a direct relationship between the center of resistance of the whole arch and the line of action generated between the miniscrews and force application points at the archwire, which makes the total arch movement highly predictable.

• Journal of Korean Biological Nursing Science
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• v.20 no.3
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• pp.159-168
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• 2018

Purpose: This study aimed to explore nursing students' experiences of observing surgeries in the operating room. Methods: The data were collected through written scripts of nursing students who participated in the operating room practice. Data were analyzed via qualitative content analysis. Results: Five themes emerged from the data: 'preparing with the thrilled hearts toward unknown area', 'drawing back in front of the mirror of realities', 'becoming an audience at a lifesaving orchestra', 'reaching a tipping point of knowing', and 'redrawing the trajectory of dream to be a nurse'. Conclusion: This study will prove helpful in describing their needs for systemic and emotional support. Findings indicated that major contributions of surgical observations to nursing students are more integrated understandings of nursing and the determinations of their career preferences.

• Journal of Biosystems Engineering
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• v.15 no.4
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• pp.298-309
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• 1990

A mathematical model was developed to simulate sideways overturning of agricultural tractor-trailer systems. Sideways overturn of a tractor-trailer system was described by oscillatory motions of the tractor with respect to the first and second tipping axes, and of the trailer with respect to the drawbar hitch point when either the tractor or trailer rides over an obstacle on slopes. By a computer simulation, critical slope angles of the ground on which the tractor-trailer system is likely to sideways overturn were evaluated under the given operational conditions. Validity of the proposed mathematical model was proved by comparing the results of computer simulation and experiment with a model tractor-trailer system. A close agreement was observed between the two results.

• Journal of the Korean Society of Safety
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• v.28 no.4
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• pp.91-96
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• 2013

Forklift truck is one of the dangerous machines which causes the fatal accidents most frequently. The causes of fatalities by forklift from 2008 to 2011 were analyzed. Crushing the operator when tipping over or falling off a truck were the major causes of death in this study. The purpose of this study is to show measures from the engineering point of view to prevent the forklift truck accidents. In order for that, the domestic requirement for forklift safety was compared with those of foreign and international standards. The manufacturers' opinion was also collected regarding to improve the forklift safety. Several measures were suggested in order to prevent fatalities caused by forklift.

• Proceedings of the Safety Management and Science Conference
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• 2013.04a
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• pp.41-52
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• 2013

Forklift truck is one of the dangerous machines which causes the fatal accidents most frequently. The causes of fatalities by forklift from 2008 to 2011 were analyzed. Crushing the operator when tipping over or falling off a truck were the major causes of death in this study. The purpose of this study is to show measures from the engineering point of view to prevent the forklift truck accidents. In order for that, the domestic requirement for forklift safety was compared with those of foreign and international standards. The manufacturers' opinion was also collected regarding to improve the forklift safety. Several measures were suggested in order to prevent fatalities caused by forklift.

• Electronics and Telecommunications Trends
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• v.27 no.6
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• pp.182-196
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• 2012

본고에서는 미래인터넷 환경으로서 사람 사물 공간 간의 새로운 관계망으로서의 만물지능통신 기반 초연결 네트워크(All Things on Ambient Network: ATAN)에 주목한다. ATAN은 네트워크를 구성하는 행위 주체로서 인간과 인간의 소통에서 인간과 사물, 사물과 사물, 공간과 공간으로 확장되어 데이터, 정보 그리고 행동을 초연결하는 시스템의 총체로 본다. 본고에서는 ATAN이 포스트 스마트 사회 인프라로 이행하는 기여 지점에서 인간과 비인간의 의사소통 티핑 포인트(tipping point)로서의 ATAN 싱귤래리티(singularity) 개념이 존재함을 제안한다. 이러한 전제하에서 ATAN 싱귤래리티의 발생 구도를 설정하고, 웹의 과거 현재 미래 고찰을 통해 ATAN 패러다임으로 전개되는 과정을 고찰한다. 또한 주요국의 미래인터넷 전략 분석을 통하여 ATAN으로의 공통 지향성을 추출한다. 이러한 작업을 통해 우리나라의 미래 네트워크의 전략적 콘셉트로서 ATAN 국가전략기조를 제시한다. 마지막으로 첨단 네트워크 기술이 사회변형을 촉진하고 사회가 기술을 인간 중심으로 수용하는 건강한 기술사회 복합체(technology-social complex)를 지향할 것을 강조하였다.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.5
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• pp.129-137
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• 2015

The objective of this study was to test the non-point source pollution (NPS) control by the vegetated ridge and silt fence through field monitoring. The experiment plots were established with three sizes which are 5 m width by 22 m length with 8 %, 3 % slope and 15m width by 15 m length with 6 % slope. Flumes with the floating type stage gages were installed at the outlet of each plot to monitor the runoff. For a rainfall monitoring, tipping bucket rain gage was installed within the experiment site. Water quality samples were monitored during the heavy rainfall occurred. The amount of rainfall from 4 monitored events ranged from 27.6 mm to 130 mm. The runoff reduction rate could vary depending on slope, soil, crop growth condition, rainfall amount, rainfall intensity, antecedent moisture condition, and many other factors. The runoff from vegetated ridge and silt fence treatment plots was 24.05 % and -8.28 % lower than that from control plot, respectively. The monitoring results showed that the average pollution loads reduced by vegetated ridge compared to control were BOD 36.62~53.60 %, SS 40.41~73.71 %, COD 39.34~56.41 %, DOC 49.08~53.67 %, TN 26.74~67.23 %, and TP 52.72~91.80 %; by silt fence compared to control were SS 41.73 %, COD 1.93 %, and TN 2.38 %. The paired t-test result indicated that the vegetated ridge and silt fence were statistically significant effect in SS load reduction, with a 5 % significant level. Monitored results indicated that vegetated ridge and silt fence were both effective to reduce the pollutant from the field surface runoff.

• Review of KIISC
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• v.20 no.4
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• pp.42-51
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• 2010

Government legislates a private sector preparedness act related to disasters such as natural, technological, and social ones. According to the law, it announces new standard for private sector preparedness. This paper illustrates a mitigation action plan based on the standard in terms of a cyber disaster. This plan includes organization, policy, assessment, impact analysis, strategy, plan, action, evaluation, and feedback. It will also help for business to mitigate a cyber disaster. Private sector accreditation and certification preparedness program which introduces on the law is the realization that enterprise disaster management will be expected as a great tipping-point.