• 한국건설관리학회논문집
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• 제25권4호
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• pp.3-14
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• 2024

OSC (Off-Site Construction) 생산방식은 기존의 건설 생산 방식과 달리 생산환경 및 기술에 따른 제약사항들이 다수 존재하기 때문에 이와 같은 제약사항을 고려한 설계안을 개발하고, 건축 생산 과정의 전반적인 효율을 고려한 최적의 설계 대안을 선정하는 것이 중요하다. 이에 건설업계에서는 OSC 프로젝트의 최적 설계안을 도출하기 위해 DfMA (Design for Manufacturing & Assembly)에 주목하고 있다. 싱가포르, 영국 등 OSC 선도국에서는 DfMA 적용의 필요성을 인정하여 OSC 산업 특성에 적합한 DfMA 가이드라인 및 적용 전략을 제시하였으며, 여러 연구자들이 건설업에 DfMA를 융합하는 연구를 진행 중에 있다. 하지만, 국내의 경우에는 DfMA의 산업 적용 및 산업 적용에 대한 필요성은 인식하고 있으나, DfMA의 개념을 실제 건설 프로젝트의 설계에 구현하는데 필요한 방법 및 도구가 부재하다. 이에 본 연구에서는 해외 건설분야 DfMA 개발 및 적용 현황을 분석하여 벤치마킹하고, 전문가 의견 수렴과정을 거쳐서 국내 OSC 산업 발전을 위한 DfMA 적용 및 도구 개발을 위한 전략 수립의 기본 방향을 제시하였다. 본 연구의 결과는 향후 국내 OSC 산업에 적합한 DfMA 도구 개발 및 DfMA 관련 정책 수립의 기초자료로 활용할 수 있을 것이다.

• 토지주택연구
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• 제14권2호
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• pp.97-107
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• 2023

본 연구는 자연 재해 및 사회 재난 발생으로 주거권의 보장을 위한 임시주거 시설의 수요가 증가하는 추세에 대비하여 이재민에게 신속하게 양질의 주택을 공급코자 수행되었다. 대량 생산 및 운반에 효율적인 계획 모델을 만들기에 적합한 DfMA 설계 방식, 즉 제조 및 조립 기반 모듈러주택 모델을 제시하였으며, 특징은 다음 세 가지이다. 첫째, 모듈러주택을 서비스 모듈과 기능 모듈로 구분하여 고정성과 변동성을 발전시켜 다양성을 만들도록 계획했다. 둘째, 제품과 같이 이동하여 편리한 위치에 놓고 사용할 수 있도록 계획하여 대지 여건 및 수요에 맞춰 융통성 있는 배치계획을 하는 시스템을 제안 했다. 이러한 계획은 동일한 주택을 대량 생산하여 국내외의 다양한 위치와 사업에 활용할 수 있다. 셋째, 생산효율성을 높일 수 있도록 생산의 자동화를 염두해 두고 건식 공법으로 공정을 단순화하고 최소화하는 방식으로 계획했다. 이러한 DfMA설계방식 적용으로 제작 및 시공기간 단축, 공사비 절감, 주택 품질 제고를 도모하여 건설 생산성을 향상시킬 수 있다.

• 한국BIM학회 논문집
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• 제12권1호
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• pp.10-22
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• 2022

Prefabricated bridges require strict management of tolerance during fabrication and assembly. In this paper, digital engineering models for prefabricated bridge components such as deck, girder, pier, abutment are suggested to support information delivery through the life-cycle of the bridge. Rule-based modeling is used to define geometry of the members considering variable dimensions due to fabrication and assembly error. DfMA(design for manufacturing and assembly) provides the rules for ease of fabrication and assembly. The digital engineering model consists of geometry, constraints and corresponding parameters for each phase. Alignment and control points are defined to manage tolerances of the prefabricated bridge during fabrication and assembly. Quality control by digital measurement of dimensions was also considered in the model definition. A pilot bridge was defined virtually to validate the suggested digital engineering models. The digital engineering models for DfMA showed excellent potential to realize prefabricated bridges.

• Bulletin of the Korean Chemical Society
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• 제11권2호
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• pp.154-156
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• 1990

The alternating copolymers of dihydropyran(DP)-maleic anhydride(MA), dihydrofuran(DF)-MA and DF-vinylene carbonate(VC) were prepared by free radical copolymerization of DP or DF with MA or VC. The reactivity ratios for poly(DF-VC) were found to be less than unity (0.05, 0.04) and its alternating sequences were obtained by feeding an equimolar amount of the comonomers at the onset of copolymerizations. The copolymers were hydrolyzed to give poly(TP-CE), poly(TF-CE) and poly(TF-HE), whose cytotoxicities against normal and tumor cells (3LL, B16) were measured in vitro.

• Smart Structures and Systems
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• 제30권1호
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• pp.35-47
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• 2022

Data-driven engineering is crucial for information delivery between design, fabrication, assembly, and maintenance of prefabricated structures. Design for manufacturing and assembly (DfMA) is a critical methodology for prefabricated bridge structures. In this study, a novel concept of digital engineering model that combined existing knowledge of DfMA with object-oriented parametric modeling technologies was developed. Three-dimensional (3D) geometry models and their data models for each phase of a construction project were defined for information delivery. Digital design models were used for conceptual design, including aesthetic consideration and possible variation during fabrication and assembly. The seismic performance of a bridge pier was evaluated by linking the design parameters to the calculated moment-curvature curves. Control parameters were selected to consider the tolerance control and revision of the digital models. Digitalized fabrication of the prefabricated members was realized using the digital fabrication model with G-code for a concrete printer or a robot. The fabrication error was evaluated and the design digital models were updated. The revised fabrication models were used in the preassembly simulation to guarantee constructability. For the maintenance of the bridge, the as-built information was defined for the prefabricated bridge piers. The results of this process revealed that data-driven information delivery is crucial for lifecycle management of prefabricated bridge piers.

• Journal of Ginseng Research
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• 제22권2호
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• pp.73-81
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• 1998

In order to stabilize the price of fresh ginseng by extension of seasonal variation and marketing structure, and to reduce the cost of production by works of intensive and short term, studies were carried out. As fresh ginseng of 4 years old by the MA (modified atmosphere storage) and CA (controlled atmosphere storage) was stored for 12 week at 4$^{\circ}C$, samples were collected after every 1, 2, 3, 4, 6, 8, 12 weeks for processing red ginseng. Chemical characteristics on ginseng steamed red for the quality evaluation are summarized as follows. The composition of free sugar was consisted of fructose, glucose, sucrose, and maltose in fresh ginseng. And small change was revealed in free sugar composition during the storage period. Glucose and sucrose were largely increased in both treatments of MA (modified atmosphere storage) and CA (controlled atmosphere storage) after 4 week, wherein maltose was decreased. Fifteen different amino acids were identified, and total amount of histamine and arginine were over 40%. Phenylalanine was slightly decreased. As the volatile components in control red ginseng, six different ones including triisopropyl benzene were detected. B-1 ($CO_2$ : $O_2$ : N2=6 : 4.90, DF-100) of CA and E-1 (CPP, DF-100) of MA did not shown triisopropyl benzene as the volatile components. And ${\gamma}$-muurolene, guaiaene, and beta-patchoulene were reduced, but the other components showed the trend of increase.

• 정신신체의학
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• 제14권2호
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• pp.102-107
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• 2006

연구목적 : 본 연구는 메스암페타민 의존자의 우울감 정도를 알아보고, 이들의 우울감이 메스암페타민 사용행태와 관련이 있는지 알아보기 위해 실시되었다. 방법: 메스암페타민 의존자 43명과 대조군 40명을 대상으로 메스암페타민 사용행태를 조사하였고, Beck 우울척도(Beck Depression Inventory, BDI)를 이용하여 우울감에 대해 알아보았다. 결과: 메스암페타민 군의 평균 BDI 점수는$14.1{\pm}7.7$점으로 대조군의 $7.3{\pm}5.7$점에 비해 유의하게 높았다(t=4.04, df=65, p<0.001). 의미있는 우울감을 호소하는 이의 비율도 대조군(경도-중등도 : 22.6%, 중등도-중증 : 3.2%)에 비해 메스암페타민 의존자(경도-중등도 : 38.9% : 중등도-중증 : 27.8%)에서 더욱 컸다(p=0.001). 성별, 연령, 음주량과 흡연량을 보정한 후에도 메스암페타민 의존자에서 우울감을 호소하는 이가 더 많았다. (OR=300.7, p=0.012). 메스암페타민 의존자의 BDI점수는 메스암페타민 단약기간과 유의한 음의 상관관계를 보였지만(r=-0.35, n=36, p=0.042), 메스암페타민 사용 용량이나 사용 기간과는 유의한 상관관계를 보이지 않았다(r=-0.08, n=36, p=0.677 ; r=-0.08, n=36, p=0.658). 결론: 메스암페타민 의존자는 대조군에 비해 우울감이 심하며 의미있는 우울감을 보고하는 경우도 더 흔하였다. 메스암페타민 의존자의 우울감은 메스암페타민 사용 정도와는 관련이 없었으나, 장기간의 단약을 통해 감소할 가능성이 시사되었다.

• International Journal of Railway
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• 제1권2호
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• pp.31-36
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• 2008

$DF_{21}$ diesel locomotive was designed to satisfy the requirement of Kunming Meter track and the 2Co self-guided radial bogie was used to suit the complex curve track. There are totally 12 locomotives was served on the track. The first two locomotives were devotion running on the track since April 2003, the wheel tread splling was occurred on the middle wheel set of the two locomotives after running nearly 150 thousands km on the track of the two locomotives at August 2004. The dynamic analysis was carried out to find the reason. The wheel set longitudinal vibration resonance phenomenon was existed on the locomotive dynamic performance, and this was caused by the too big longitudinal stiffness of the journal box bar on the middle wheel set. Wheel set longitudinal vibration resonance maybe an important reason of lead to wheel tread spalling. The corresponding mend methods were put forward from the point of view of wheel set longitudinal vibration resonance. All the wheel tread of the 12 locomotives on the middle wheel set were in good condition and not occurred the wheel tread spalling after the mend till December 2007 after 350 thousands km were finished. The mechanism of the wheel tread splling and corresponding mend method was discussed in detail in this paper.

• 한국BIM학회 논문집
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• 제13권4호
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• pp.36-44
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• 2023

Recently in Korea, efforts are underway to enhance smart construction by implementing Building Information Modeling (BIM) comprehensively across all sectors of the construction industry. This study focused on the adoption of BIM for prefab bridges currently executed in the industry and It examined the process of creating a BIM-based prefab bridge model that can support production. Additionally, it explored how prefab products made by manufacturers can be integrated with road alignments using BIM technology and how the DfMA (Design for Manufacturing and Assembly) approach, which supports production based on designed information, can be adopted. The process of creating the prefab bridge model aims to shorten production time, reduce costs, and enhance quality by leveraging digital information related to design and manufacturing within the BIM framework

• 한국보건간호학회지
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• 제26권2호
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• pp.303-313
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• 2012

Purpose: This study was conducted to examine the correlation between social support, loneliness, sleep quality, and perceived health status among community-dwelling older adults. Methods: Older adults who lived in urban and rural local communities were taken into account. Among them, 396 people participated in this study. Path analysis was conducted in order to verify the study model and its verification. SPSS WIN 18.0 and AMOS17.0 were used for analysis of collected data. Results: The results showed that social support had a significant effect on perceived health status (${\beta}$=.17, p= .003) and loneliness (${\beta}$=-.56, p<.001), while loneliness had a significant effect on perceived health status (${\beta}$=-.12, p=.045) and sleep quality (${\beta}$=.20, p<.001). In addition, the results also indicated that sleep quality had a significant influence on perceived health status (${\beta}$=-.16, p <.001). According to results derived from the model, Chi-square=.359, df=1 NC=.359, CFI=1.0, NFI=0.98, RMSEA=.000; thus, the model was shown to be significant. Conclusion: For maintenance of the health of the aged, social support, loneliness, and sleep quality should be secured; in order to realize this, an effort should be made toward health promotion while providing the aged with more social attention.