• 한국안전학회지
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• 제35권3호
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• pp.105-115
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• 2020

This study compares the difference of fit factors (FF) and visual acuity according to masks and eyeglasses preferences for 54 participants. We the precautions and behaviors of discomfort when wearing masks of eyewear wearers. Contact lens discomfort and priority action of complaints was investigated Glasses fitting factors is Optical Center Height(OH), Vertex Distance(VD) and Pantoscopic Angle(PA). We measured those factors and expressed by the ratio of standard point and change point. Quantitative fit factor was measured by Portacount Pro+ 8038. Also, we selected to 6 exercises among 8 exercises OSHA QNFT (Quantitative Fit testing) protocol to measure the fit factors. The pass/ fail criterion of FF was set at 100. Visual acuity(VA) test chart is developed by Chunsuk Han was used, Descriptive statistics was performed. Descriptive statistics(SAS ver 9.2), it is used geometric means, Wilcoxon analysis(P=0.05) When wearing the mask preferentially, fit factor(FF) was high according to the step of glasses fitting parameter. on the other hand, when the glasses first choice, the visual acuity(VA) was high. there was no significant difference. In the case of fit factor (FF), mask first choice/ glasses first choice is OH (p=0.671/ p=0.332), VD (p=0.602/ p=0.571) and PA (p=0.549/ p=0.607). Visual acuity (VA), mask first choice/ glasses first choice is OH (p=0.753/ p=0.386), VD (p=0.815/ p=0.557) and PA (p=0.856/ p=0.562). The workers of workplace and office chose glasses but occupational health workers and students chose mask. In case of discomforts, it was suggested to remove the mask and tolerate discomforts. The main discomforts and usual action of lens were dryness, hyperemia, foreign body sensation, ophthalmodynia, decreased vision and glasses wearing. Therefore, it is necessary to develop a mask wearing method education program considering glasses fitting and develop a hybrid model that minimizes inconvenience when wearing glasses and a mask at the same time.

• Geomechanics and Engineering
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• 제15권5호
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• pp.1101-1111
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• 2018

This study aims to present accurate soil modeling and validation of a single roadside guardrail post as well as a single concrete pile installed near cut slopes or compacted sloping embankment. The conventional Winkler's elastic spring model and p-y curve approach for horizontal ground cannot directly be applied to sloping ground where ultimate soil resistance is significantly dependent on ground inclination. In this study, both grid-based 3-D FE model and particle-based SPH (smoothed particle hydrodynamics) model available in LS-DYNA have been adopted to predict the static behavior of a laterally loaded guardrail post. The SPH model has potential to eliminate any artificial soil stiffness due to the deterioration of the node-connected Lagrangian soil mesh. For this purpose, this study comprises two parts. Firstly, only 3-D FE modeling has been tested to show the numerical validity for a single concrete pile in sloping ground using Mohr-Coulomb material. However, this material option cannot be implemented for SPH elements. Nevertheless, Mohr-Coulomb model has been used since this material model requires six input soil data that can be obtained from the comparative papers in literatures. Secondly, this work is extended to compute the lateral resistance of a guardrail post located near the slope using the hybrid approach that combines Lagrange FE elements and SPH elements by the suitable node-merging option provided by LS-DYNA. For this analysis, the FHWA soil material developed for application to road-base soils has been used and also allows the application of SPH element.

• 한국해양공학회지
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• 제24권5호
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• pp.67-74
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• 2010

Chromate conversion coating is a coating technique used to passivate aluminum, zinc, cadmium, copper, silver, magnesium, tin, and their alloys to slow corrosion. The process uses various toxic chromium compounds, which may include hexavalent chromium. The industry is developing less toxic alternatives in order to comply with substance restriction legislation, such as RoHS. One alternative is to develop a Cr-free coating solution. In this study, eco-friendly, Cr-free solutions (urethane solution S-700, organic/inorganic solution with Si LRO-317) were used. Test specimens were dried in a drying oven at $190^{\circ}C$ for 3, 5, 7, and 9 minutes. Corrosion resistance was evaluated using a salt spray test for 72 hours. The results show that the optimum corrosion resistance was achieved at $190^{\circ}C$ for five minutes for EGI and three or five minutes for HDGI, respectively. The adhesive properties of the two types of coating solutions were superior regardless of drying time.

• 한국해양공학회지
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• 제24권5호
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• pp.60-66
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• 2010

Zinc has a number of characteristics that make it well suited for use as a coating to protecting iron and steel products from corrosion. Its excellent corrosion resistance in most environments accounts for its successful use as a protective coating on a variety of products and in many exposure conditions. The excellent field performance of zinc coatings results from their ability to form dense, adherent films that corrode at a rate that ranges from 1% to 10% of the corrosion rate of ferrous materials, depending on the environment. Recently, EU RoHS and EU ELV prohibited the use of materials that adversely affect the environment, such as Pb, Hg, Cd, and $Cr^{+6}$. In this study, environmentally-friendly, Cr-free solutions (epoxy solution, acrylic solution, and urethane solution S-700) and organic/inorganic solution with Si; LRO-317) were used to evaluate the corrosion resistance of zinc-coated steel subjected to a saltwater spray for 72 hours. The coating of urethane solution (S-700) was best among the three kinds of solution with heat treatment during five minutes at $190^{\circ}F$. Test specimens with S-700 and LRO-317 coating were heat treated in a drying oven at 170, 180, 190, 200, and $210^{\circ}C$ for five minutes. The results show that the optimum corrosion resistance was $190^{\circ}C$ in EGI and $170^{\circ}C$ in HDGI, respectively.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2009년도 학술대회
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• pp.512-515
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• 2009

본 논문에서는 디지로그 북 (Digilog Book) 저작 환경에서 레이아웃 기반 다감각 콘텐츠 저작 도구를 제안한다. 저작 과정에 사용자는 마우스나 펜 타입 장치를 통해 종이책 위에 반복적으로 가상 영역을 생성하고, 해당 영역에 증강될 콘텐츠의 위치, 사이즈, 파일 선택, 이벤트 처리 등의 속성을 지정한다. 저작이 완료되면 시스템은 기존에 인쇄된 페이지 번호를 인식하고, 해당 페이지에 생성된 영역과 속성 정보를 포함하는 레이아웃을 생성한다. 페이지 레이아웃은 증강현실 환경에서 렌더링 하기 적합한 씬 그래프 (Scene Graph) 형태로 표현 되고 XML 형태로 저장된다. 디지로그 북 뷰어는 저장된 레이아웃을 로딩하고 저작된 속성을 분석하여 해당 페이지에 영역별로 증강 및 기능을 실행한다. 제안된 저작 도구를 통해 사용자는 혼합 인터페이스를 통해 디지로그 북 환경에서 관심영역에 시각, 청각적인 다감각 콘텐츠를 손쉽게 저작할 수 있다. 증강현실 환경에서 사용자가 레이아웃을 보다 쉽게 생성하기 위하여 영역 템플릿을 제공한다. 또한, 제안된 저작 도구는 페이지 인식부와 페이지 추적부를 독립적으로 구성함에 따라 단일 마커만으로 다수 페이지 저작이 가능하다. 실험 결과, 제안된 저작도구는 증강현실 환경에서 적절한 수행시간을 나타냄을 보였다. 제안된 저작 도구는 교육, 출판 업계 등 여러 응용분야에서 널리 활용될 수 있을 것이다.

• 대한기계학회논문집 C: 기술과 교육
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• 제1권1호
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• pp.69-73
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• 2013

역삼투막을 이용한 해수담수화 공정에서 발생되는 농축수의 최소방류 및 회수율 극대화를 위한 공정으로 전기투석을 이용한 농축수의 이차 농축기술 연구를 수행하였다. 실험방법은 정전압운전 방식을 채용하였으며, 농축/탈염조의 용량비율, 전압별 변화 및 전해질을 농축수로 활용시 등에 대한 검토를 수행하였다. 사용한 막은 다가이온막을 채용하였으며, 전력효율을 최소화하며, 농축수의 농도를 극대화 및 탈염수의 농도를 최소화할 수 있는 조건 도출을 목표로 삼았다. 실험결과 농축/탈염조의 비율은 1대 5의 비율이, 전압의 경우 12V로 전해질의 경우 농축수를 이용시에도 효율에는 큰 차이가 발생하지 않았다. 이와 같은 실험조건에서 도출된 최적조건으로는 탈염수의 총용존고형물 농도가 5.32g/l, 이차 농축수의 염도는 17.07%이며 전력량은 탈염수 톤당 16.74kWh로 나타났다.

• 한국지역지리학회지
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• 제13권1호
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• pp.82-103
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• 2007

신자유주의는 국가 개입을 통해 작동하는 경로의존적, 혼종적, 모순적 프로젝트로 이해된다. 신자유주의 하에서 실제 국가의 개입은 그 힘이 약화되었다기보다는 전략이 변화했다고 할 수 있으며, 이는 특히 도시공간의 재구성을 위한 신자유주의적 정책들에서 잘 나타난다. 이러한 점에서 이 논문은 발전국가로 특징지워지는 한국에서 신자유주의의 도입과정과 이에 따른 도시정책의 특성 변화를 고찰하고자 한다. 이를 위해 이 논문은 우선 1960년대 이후 국가주도적, 수출지향적 경제개발을 주도한 발전국가 및 그 공간정책의 특성을 살펴보고, 1980년대 후반 이후 신자유주의의 전개과정을 두 단계, 즉 1980년대 후반에서 1997년 경제위기 이전(1단계)과 그 이후 현재까지(2단계)로 구분하여 고찰하고자 한다. 특히 이러한 신자유주의화 과정은 기존 발전주의와 상호 중첩적, 혼종적으로 결합되어 있으며, 이러한 성향은 공간정책의 변화과정에 반영되고 있다고 주장한다. 끝으로 국가와 시장 간 결합(즉 발전주의적 신자유주의)은 다양한 유형으로 전개될 수 있지만, 국가의 발전 전망과 공간정책은 산업(자본)중심이 아니라 복지(인간)중심이어야 한다는 점이 강조된다.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.28-31
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• 2002

Filmless full-PACS in korea has rapidly been growing, since government had supported collaborative PACS project between industry and university hospital in late of 1995. At the same time, a small company had started PACS business, while the Korea PACS society was being formed. In the beginning, PACS societies had focused on developing peripheral solutions such as DICOM gateway for image acquisition, x-ray film digitizer, and viewing software for research or management of personal image data, while Samsung Medical Center had started installing an imported partial PACS system which had recently upgraded with a new system. In similar time frame, a few hospitals had started developing and installing domestic large scale full-PACS system. Several years later, many hospitals have installed full-PACS system with national policy of reimbursement for PACS exams in November 1999. It is believed that Korea is the first country that adopted PACS reimbursement for filmless full-PACS as a national policy. Both experiences of full-PACS installation and national policy generated tremendous intellectual and technological expertise about PACS at all levels, clinical, hospital management, education, and industrial sectors. There are currently three types of PACS system which includes domestic, imported, and hybrid PACS system with imported solution for core system and domestic solution for peripheral system. There are more than 20 domestic PACS companies and they have now enough experiences so that they are capable of installing a truly full-PACS system for large-scale teaching hospitals. PACS societies in Korea understand how to design, implement, install, manage, sustain, and provide good services for large-scale full-PACS. PACS society has also strength for the highest integration technology of the Hospital Information. However, further understanding and timely implementation of continuously evolving international standard and integrated healthcare enterprise concepts may be necessary for international leading of PACS technologies for the future.

• 대한기계학회논문집 C: 기술과 교육
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• 제2권1호
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• pp.9-13
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• 2014

현재 소비자들이 자동차를 선택하는 여러 이유 중에서, NVH 성능이 아주 중요한 역할을 하고 있다. 근래 하이브리드 및 전기자동차들은 전통적인 차량의 주요 소음원 이었던 엔진의 소음이 거의 발생되지 않아 자동차 실내의 소음에 대한 관심은 더욱 커지고 있다. 해외 참고문헌에 의하면 자동차 휠의 높은 Lateral Dynamic Stiffness(LDS)가 운전 중 발생되는 Structure Bone Noise(SBN)를 저감시키는 것으로 기술되어 있다. 하지만 유효한 기준 및 시험적 결과가 미비하여, 본 연구에서는 LDS가 서로 다른 휠에 동일 타이어를 부착하여 실내소음을 시험 측정하였다. 그 결과 휠의 LDS에 따라 실내소음이 변화되는 것을 확인하였다. 이는 휠의 최적설계로 실내소음의 저감이 가능할수 있다.

• 대한간호학회지
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• 제29권3호
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• pp.467-484
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• 1999

The main objectives of this study were to investigate the concept of family function from the perspective of the contemporary Korean family, and to construct model of change of family function with chronic illness. The hybrid model approach was applied in which three phases(theoretical phase, empirical phase, and analytic phase) of concept development were explored for family functioning. The study was conducted from 1997 to 1998. In empirical phase, two groups of purposive samples were drawn : normal family group composed of six families without ill family member, and ill family group composed of seven families of which wives have rheumatoid arthritis. Only families with child(or children) in primary or secondary schools were included in the study. The results were as follows : In theoretical phase, six dimensions of family concept were emerged : affective, structural, control, cognitive, financial, and reproductive dimension. In order to analyse the Korean normal family function in middle class with middle-aged women, financial and reproductive dimension were not included. In empirical phase, five dimensions(affective, structural, control, cognitive, and external relationship) were found from the normal family data. External relationship dimension is very important factor as a resource of the support, especially when their parents or siblings had no help or support to them. In the affective dimension, Korean family emphasized harmony and balance rather than affective expression between couples and between parents and children. They also showed common goals of the families to solve their problems to control the family members. The priority of the goals was getting into the higher education of their children or helping their unhealthy parents or family members. Six dimensions (affective, structural, control, cognitive, external relationship, and financial) of family functions were emerged from the ill family data. From the analysis of ill family data, types of restructuring house chore after wives illness were developed : (a) negociated, (b) accomodated, and (c) isolated, enduring types. Although the dimensions of family functioning identified in this study are similar to the conceptualizations that exist in the western literature, there were distinct differences in the nature of major themes and subconcepts under these family function dimensions.