• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.266-267
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• 2006

We present a systematic study of the heating and pre-sintering behavior of porous copper powder metal compacts. We employ a TE102 single mode microwave system to position the samples in the separated electric field (E) or magnetic field (H) anti-node of the cavity. We observe significant differences in the heating, pre-sintering, and microstructure evolution of the samples due to the individual fields. We note that sample history (whether heated first in the E-field or H-field) greatly effects a difference in heating trends and subsequent heating behavior and does not appear to be solely a thermal process.

• Nuclear Engineering and Technology
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• 제49권1호
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• pp.124-133
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• 2017

In-vessel retention by passive external reactor vessel cooling under severe accident conditions is a viable approach for retention of radioactive core melt within the reactor vessel. In this study, a new and versatile coating technique known as "cold spray" that can readily be applied to operating and advanced reactors was developed to form a microporous coating on the outer surface of a simulated reactor lower head. Quenching experiments were performed under simulated in-vessel retention by passive external reactor vessel cooling conditions using test vessels with and without cold spray coatings. Quantitative measurements show that for all angular locations on the vessel outer surface, the local critical heat flux (CHF) values for the coated vessel were consistently higher than the corresponding CHF values for the bare vessel. However, it was also observed for both coated and uncoated surfaces that the local rate of boiling and local CHF limit vary appreciably along the outer surface of the test vessel. Nonetheless, results of this intriguing study clearly show that the use of cold spray coatings could enhance the local CHF limit for downward-facing boiling by > 88%.

• 지적과 국토정보
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• 제46권2호
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• pp.197-209
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• 2016

The Marcellus Shale industry has impacted Pennsylvania since 2005 and has been a major driver of land use change ever since. The Pennsylvania state park system has been facing encroachment from this industry ever since the first Pennsylvania wellpad was drilled in 2008. Previous research conducted overviews the impacts associated with this industry in regards to environmental quality, but there is limited research associated with the social impacts. The conducted research overviews the Marcellus Shale industry in regards to encroachment on Pennsylvania state parks through a GIS analysis. The purpose of the research is to evaluate how the viewsheds (areas of vision from a given point) of Pennsylvania state park land has been impaired by the Marcellus Shale industry. The results of the research show how the landscape of state parks have change due to the Marcellus Shale industry, and also a focus will be placed on scenic vistas (areas that highlight spectacular views within state parks) of selected parks to see to what extent that pristine landscape has been altered. The results of the research will help provide an idea of landscape change utilizing a GIS analysis and hopefully help to guide future growth.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제22권1호
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• pp.47-82
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• 2019

Pennsylvania is one of the states that adopted the Common Core State Standards for Mathematics (CCSSM) and crafted its own standards (The PA Core State Standards). Pennsylvania teachers are required to have a clear understanding of the PA Core Standards. It is timely and appropriate to study Pennsylvania teachers' beliefs, as the standards have been adopted and implemented for several years since the revision of the PA Core Standards (2014). This study examined how eight western Pennsylvania elementary school teachers' beliefs about teaching and learning mathematics related to the SMP. To this end, I conducted an in-depth interview with each participating teacher. The in-depth interviews featured the teachers' overarching mathematical instructional goals and their productive beliefs. Furthermore, I linked these beliefs with the CCSSM Standards for Mathematical Practice (SMP).

• 천문학회지
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• 제29권spc1호
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• pp.43-43
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• 1996

• 대한지리학회:학술대회논문집
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• 대한지리학회 1999년도 춘계학술대회 요약집
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• pp.56-59
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• 1999

• Journal of Dental Anesthesia and Pain Medicine
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• 제19권5호
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• pp.261-270
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• 2019

Background: People with the Ehlers-Danlos Syndromes (EDS), a group of heritable disorders of connective tissue, often report experiencing dental procedure pain despite local anesthetic (LA) use. Clinicians have been uncertain how to interpret this apparent LA resistance, as comparison of EDS and non-EDS patient experience is limited to anecdotal evidence and small case series. The primary goal of this hypothesis-generating study was to investigate the recalled adequacy of pain prevention with LA administered during dental procedures in a large cohort of people with and without EDS. A secondary exploratory aim asked people with EDS to recall comparative LA experiences. Methods: We administered an online survey through various social media platforms to people with EDS and their friends without EDS, asking about past dental procedures, LA exposures, and the adequacy of procedure pain prevention. Among EDS respondents who both received LA and recalled the specific LA used, we compared agent-specific pain prevention for lidocaine, procaine, bupivacaine, mepivacaine, and articaine. Results: Among the 980 EDS respondents who had undergone a dental procedure LA, 88% (n = 860) recalled inadequate pain prevention. Among 249 non EDS respondents only 33% (n = 83) recalled inadequate pain prevention (P < 0.001 compared to EDS respondents). The agent with the highest EDS-respondent reported success rate was articaine (30%), followed by bupivacaine (25%), and mepivacaine (22%). Conclusions: EDS survey respondents reported nearly three times the rate of LA non-response compared to non-EDS respondents, suggesting that LAs were less effective in preventing their pain associated with routine office dental procedures.

• 보건교육건강증진학회지
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• 제10권2호
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• pp.86-99
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• 1993

본 연구의 목적은 한국청소년들의 건강행동실태를 파악하기 위한 것이다. 본 연구의 의의는 미국에서 행해지고 있는 청소년의 건강유지 및 증진과 아울러 성인병이나 조기사망에 대한 역학적인 접근방식을 한국청소년을 대상으로 하여 응용하는 데 있다. 이 연구에 사용된 연구도구는 미국의 Centers for Disease Control에서 청소년의 건강행동을 역학적으로 연구하기 위해 개발한 Youth Risk Behavior Survey를 한국 사회환경의 요구도에 맞게 수정한 것이다. 본 연구는 한국인 청소년들의 건강행동을 조사하기 위한 타당성있는 연구도구를 개발하기 위해 4개의 단계로 구성되어 있다. 두번의 focus group discussion과 pilot test, 그리고 실제조사로 이루어져 있다. 서울지역의 중.고등학생을 대표할 표본추출은 cluster sampling을 사용하였다. Cluster는 본 연구에서 구분한 서울의 지리적인 구역들, 즉 북부, 남부, 그리고 산업지역을 포함했고, 남자학교, 여자학교, 남녀공학학교를 포함했다. 총38개 중.고교 학생 4,747명이 조사되었다. 약 52.4%의 응답자가 심각하게 자살을 생각해본 적이 있다고 답했다. 그리고 23.6%가 설문조사전 30일 중에 담배를 피운 적이 있다고 응답했으며 49.7%는 설문조사전 30일중에 술을 마신 적이 있다고 답했다. 약 29%가 설문조사전 30일 중에 싸움에 가담한 적이 있다고 응답했다. 본 연구에서 조사된 건강관련행동 (건강위험행동 포함)들은 성, 연령, 성적, 사회경제적 위치, 학교 종류, 그리고 서울의 지리적인 구역에 따라 다양하게 나타났다. 남학생이 여학생보다 더 간강위험행동을 나타내었다. 건강위험행동은 나이가 증가함에 따라 증가했다. 사회경제적 위치가 낮다고 응답한 학생들과 학급에서 성적이 하위라고 응답한 학생들의 경우 건강위험행동은 더 많이 나타났다.

• 국제학술발표논문집
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• The 8th International Conference on Construction Engineering and Project Management
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• pp.188-197
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• 2020

Due to hazardous working environments at complex, unstructured, and dynamic construction sites, workers frequently face potential safety and health risks throughout the construction process. In this regard, addressing safety challenges remains one of the top priorities. Construction workers' ability to identify and assess risks is acquired through training, which is one of the primary key factors to determine their safety and wellbeing in hazardous working environments. As such, safety managers constantly focus on the effectiveness of the training materials provided to the workers. However, the construction workers are considerably at greater risk of injuries and fatalities compared to the workers in other industries. In this regard, further studies are required to build up a body of knowledge on the conventional safety training approaches as well as their evaluation techniques in order to boost up the adoption by the practitioners in a widespread manner. This paper provides a systematic review of the current safety training approaches and the various techniques for measuring their effectiveness. The attributes of the current safety training methods for construction workers and their evaluation techniques are identified and analyzed. Results indicated that: 1) immersive environment-based training methods are effective than the traditional safety training methods; 2) this effectiveness can be empirically supported by evaluation strategies, but the current techniques are subjective, intrusive, and error-prone. This research offers fresh opportunities to investigate the training strategies by objectively monitoring the physiological responses of construction crews. The results of this study can be used by researchers and practitioners to identify and determine optimal safety training programs that could potentially become ubiquitous in the construction industry.

• 대순사상과 동아시아종교
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• 제2권1호
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• pp.163-166
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• 2022