• 제목/요약/키워드: structural work

검색결과 2,861건 처리시간 0.032초

섬유시트로 보강된 T형 철근콘크리트보의 휨 강도 해석 (Flexural Strength Analysis of RC T-Beams Strengthened Using Fiber Sheets)

  • 박대효;이규철
    • 콘크리트학회논문집
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    • 제15권2호
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    • pp.234-245
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    • 2003
  • 대부분의 콘크리트 교량 구조물은 과도한 교통량과 구조물의 사용수명의 도래로 손상된다. 콘크리트의 손상은 철근의 부식과 콘크리트와 철근의 분리로 인하여 성능저하 촉진의 원인이 된다. 손상된 콘크리트 구조물의 빠른 복원은 콘크리트 구조 체계에서 콘크리트 성능저하의 심화를 막기 위하여 매우 중요하게 되었다. 최근 섬유시트는 고인장강도, 내구성, 부식저항성, 경량성, 제작편리성, 비용절감, 균열 제어, 두께 대비 고강도, 사용성 등의 많은 장점이 원인이 되어 손상된 콘크리트 구조물의 보강에 널리 사용되고 있다. 그러나 섬유시트 보강에 따른 공칭휨모멘트 성능을 예측하는 방법에 대한 해석과정의 결여로 구조물의 보강 과정에서 효과적인 인자의 결정이 어렵게 된다. 본 연구에서는 T형 철근콘크리트보의 보강을 위해 부재의 밑면에 부착된 섬유시트가 휨 강도에 미치게 되는 영향이 연구된다. 또한 밑면섬유시트의 박리 방지를 위해 감싸는 섬유시트의 옆면부분에 의한 부수적인 휨 보강 효과가 이론적으로 조사된다. 제안한 접근방법을 입증하기 위하여 해석 결과가 참고된 다른 실험연구의 결과와 비교된다. 예측된 결과와 실험결과는 잘 일치하였다.

석조유구(石造遺構)를 통한 한국(韓國) 고대건축(古代建築)에 관한 연구(硏究) -삼국시대와 통일신라시대를 중심으로- (A Study on the Ancient Architecture in view of the Stone Remains (focused on the 3 Kingdom Period and Unificated Shilla Period))

  • 천득염;박지민
    • 건축역사연구
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    • 제8권3호
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    • pp.23-38
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    • 1999
  • The purpose of this study is to analogize the appearance of Korean Ancient Architecture in view of the Stone Remains from 3 Kingdom Period to Unificated Shilla Period. But in these period, there is no building remains but some stupas and fine arts. Especially, there are many architectural appearance and revealing signature in these Historical Stone remains. Architectural elements which are analogized by stone remains what has value as historical materials by preservation of original form from 3 Kingdom Preiod to Unificated Shilla Period are as follows : 1) Platform, the representative characteristic of Korean traditional architecture, was frame structure and accumulate structure. And circular or square footing stood a same shape column on it is put on the platform. 2) In the case of column, there used entasis column and inclined column and circular chamfer technique was applied on the top side of it. Upper side of column, capital and head pentrating tie that small bearing block was put on the center of it was joined. And longitu야nal rest(長舌) supported a cross beam. Capital and small bearing block had no bottom heel, and heel side was curved and straight. Centered bracket structure was often used, and multi bracket structure is not used yet. Inward incline technique was used. 3) Inward opening pair door which had lintel, threshold, doorjamb was usually used, Fixing stone was used for structural safety, and circular handle and lock was used for decoration. Handrail was used on the edge of wooden floor for decorative effect and safety. 4) Square rafter and circular rafter were used in the same period and so did flying rafter. Double eaves and single eave were used in the same period but, single eave was usually used. In this period, square rafter was usually used. This would be studied more by comparing with Japanese wooden architecture. 5) Hipped roof was used and half-hipped roof was not used yet. In front of th hip, there are small sculpture called Jap-Sang(雜像), and windbell was hang on the end of the hip rafter. Concave roof tile, convex roof tile, round eaver tile, decorative tile at end of roof ridge were used. Lotus style was well used on the face of roof tile for decoration. From the results of this study, wooden architecture of Unificated Shilla period was simple compare to Koryo dynasty and Chosun dynasty but, it had some brilliant character. It was hard work that analogized the form of non-existent wood architecture of Ancient Korean period by restricted stone remains. But, in addition to the results of this study and research of old documentations, more study should be go on.

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Geomechanical properties of synthesised clayey rocks in process of high-pressure compression and consolidation

  • Liu, Taogen;Li, Ling;Liu, Zaobao;Xie, Shouyi;Shao, Jianfu
    • Geomechanics and Engineering
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    • 제20권6호
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    • pp.537-546
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    • 2020
  • Oil and natural gas reserves have been recognised abundantly in clayey rich rock formations in deep costal reservoirs. It is necessary to understand the sedimentary history of those reservoir rocks to well explore these natural resources. This work designs a group of laboratory experiments to mimic the physical process of the sedimentary clay-rich rock formation. It presents characterisation results of the physical properties of the artificial clayey rocks synthesized from illite clay, quartz sand and brine water by high-pressure consolidation tests. Special focus is given on the effects of illite clay content and high-stress consolidation on the physical properties. Multi-step loaded consolidation experiments were carried out with stress up to 35 MPa on mixtures constituting of the illite clay, quartz sand and brine water with five initial illite clay contents (w=85%, 70%, 55%, 40% and 25%). Compressibility and void ratio were characterised throughout the physical compaction process of the mixtures constituting of five illite clay contents and their water permeability was measured as well. Results show that the applied stress induces a great reduction of clayey rock void ratio. Illite clay contents has a significant influence on the compressibility, void ratio and the permeability of the physically synthesized clayey rocks. There is a critical illite clay content w=70% that induces the minimum void ratio in the physically synthesised clayey rocks. The SEM study indicates, in the high-pressure synthesised clayey rocks with high illite clay contents, the illite clay minerals are located in layers and serve as the material matrix, and the quartz minerals fill in the inter-mineral pores or are embedded in the illite clay matrix. The arrangements of the minerals in microscale originate the structural anisotropy of the high-pressure synthesised clayey rock. The test findings can give an intuitive physical understanding of the deep-buried clayey rock basins in energy reservoirs.

교육서비스 품질이 관계관리에 미치는 영향: 서비스 유통 관점에서 (Effects of Education Service Quality on Relationship Management from the Service Distribution Perspective)

  • 조현진
    • 유통과학연구
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    • 제13권3호
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    • pp.41-49
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    • 2015
  • Purpose - Universities are placing a greater emphasis on relationship management as a source of competitive advantage due to increasingly competitive environments and social changes. The purpose of this study is to analyze the relationships among education service quality, relationship quality, and relationship performance from the perspective of service distribution. In other words, this study is focused on the role of education service quality with regard to relationship management. In this study, education service quality is divided into lecture, job assistance, student-faculty interaction, student-student interaction, facility welfare, and scholarship welfare quality components; relationship quality is composed of satisfaction and commitment; and relationship performance is divided into recommendation and defection intentions. Research design, data, and methodology - This study aims to identify how the various elements of education service quality affect satisfaction. Further, it aims to test the relationships among satisfaction, commitment, recommendation intentions, and defection intentions. Distribution and marketing students were randomly selected for the experiment. Out of the 380 administered questionnaires, a total of 361 respondents provided complete and usable data. The sample consisted of 232 males (64.3%) and 129 females (35.7%). The variables of the proposed model were measured through assessments that were measured on a 5-point Likert scale. Using Lisrel 8.7, a structural model was analyzed and the path coefficients were estimated. Results - The overall fit of the model was acceptable (χ2=1121.8 (df=603, P=0.00), GFI=0.967, NFI=0.974, CFI=0.981, RMR=0.021). The results generally supported the hypothesized relationships of the proposed model, except for Hypothesis 1. First, lecture, job assistance, student-faculty interaction, student-student interaction, and facility welfare quality were revealed to have positive effects on satisfaction. In particular, lecture and facility welfare quality had the strongest effects on satisfaction. However, scholarship welfare quality did not significantly affect satisfaction; this means that Hypothesis 3-2 was not supported. Second, satisfaction was positively related to commitment and recommendation intentions but it was negatively related to defection intentions. Third, commitment was positively related to recommendation intentions but it was negatively related to defection intentions. Conclusions - This study emphasizes the influence of education service quality on satisfaction in the long-term. In addition, this research has the following implications for university relationship management. First, the findings suggest that the various dimensions of education service quality have differing effects on satisfaction. In particular, lecture and facility welfare quality are found to be the most important factors in increasing the level of satisfaction. Therefore, university managers need to prioritize enhancing lecture quality and upgrading educational facilities. Second, satisfaction also improves through job assistance systems and opportunities for social interactions. Therefore, university managers should reinforce their job skills programs and should provide opportunities for social relationships to develop. Finally, it is important for university managers to take a relationship approach to maximizing relationship performance. Therefore, university managers should work to increase student recommendations and prevent their defections based on satisfaction and commitment.

Molecular characterization and expression pattern of a novel Keratin-associated protein 11.1 gene in the Liaoning cashmere goat (Capra hircus)

  • Jin, Mei;Cao, Qian;Wang, Ruilong;Piao, Jun;Zhao, Fengqin;Piao, Jing'ai
    • Asian-Australasian Journal of Animal Sciences
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    • 제30권3호
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    • pp.328-337
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    • 2017
  • Objective: An experiment was conducted to determine the relationship between the KAP11.1 and the regulation wool fineness. Methods: In previous work, we constructed a skin cDNA library and isolated a full-length cDNA clone termed KAP11.1. On this basis, we conducted a series of bioinformatics analysis. Tissue distribution of KAP11.1 mRNA was performed using semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) analysis. The expression of KAP11.1 mRNA in primary and secondary hair follicles was performed using real-time PCR (real-time polymerase chain reaction) analysis. The expression location of KAP11.1 mRNA in primary and secondary hair follicles was performed using in situ hybridization. Results: Bioinformatics analysis showed that KAP11.1 gene encodes a putative 158 amino acid protein that exhibited a high content of cysteine, serine, threonine, and valine and has a pubertal mammary gland) structural domain. Secondary structure prediction revealed a high proportion of random coils (76.73%). Semi-quantitative RT-PCR showed that KAP11.1 gene was expressed in heart, skin, and liver, but not expressed in spleen, lung and kidney. Real time PCR results showed that the expression of KAP11.1 has a higher expression in catagen than in anagen in the primary hair follicles. However, in the secondary hair follicles, KAP11.1 has a significantly higher expression in anagen than in catagen. Moreover, KAP11.1 gene has a strong expression in inner root sheath, hair matrix, and a lower expression in hair bulb. Conclusion: We conclude that KAP11.1 gene may play an important role in regulating the fiber diameter.

중심 보로노이 조각화와 아이콘 및 레이블 배치 알고리즘을 이용한 도식화된 지도 생성 시스템 (A Schematic Map Generation System Using Centroidal Voronoi Tessellation and Icon-Label Replacement Algorithm)

  • 류동성;어윤;박동규
    • 한국멀티미디어학회논문지
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    • 제9권2호
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    • pp.139-150
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    • 2006
  • 도식화된 지도란 일반적인 지도가 가진 복잡한 지리 정보를 특정한 사용 목적에 따라 논리적으로 간략화시킨 다음 중요한 정보들은 부각시켜, 사용자가 인식하기 편하게 제작한 지도이다. 본 논문에서는 도로와 레이블 그리고 그 아이콘이 중요한 의미를 가지는 도식화된 지도를 제작하기 위한 알고리즘을 소개한다. 구조적인 지도의 생성을 위해서는 간략화 된 도로정보와 이에 따른 객체들의 배치 작업이 필요하다. 그러나 원본 지리정보의 복잡성으로 인하여 원본 도로 정보를 중심으로 객체들의 배치작업을 수행할 경우 객체들 간의 중첩이 발생하게 되어, 시각적으로 잘 정돈된 지도 생성이 어렵다. 논문에서 제안한 시스템은 이와 같이 상대적으로 복잡한 경로를 가진 구조적 지도를 효과적으로 시각화하기 위하여 다음과 같은 처리 절차를 수행한다. 1)DEC 기법을 사용하여 다각형으로 구성된 경로 곡선을 이루는 정점들 중에서 중요도가 떨어지는 정점들을 제거한다. 2) 중심 보로노이 조각화와 그리드 스내핑을 적용하여, 원본지도의 구조적 정보를 유지하면서 밀집도가 균일한 도로 정보를 생성한다. 3) 아이콘과 레이블이 서로 겹쳐지지 않도록 적절하게 배치하여 도식화된 지도를 완성한다. 그 결과 원본 지도의 밀집된 정점들을 균일한 간격으로 배치하였으며, 아이콘과 레이블을 배치할 수 있는 공간을 확보하였다. 이를 통해 아이콘과 레이블의 중첩을 최소화 할 수 있었으며, 복잡한 지도 정보로 부터 가독성이 높은 지도를 제작할 수 있었다.

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New Ruthenium Complexes for Semiconductor Device Using Atomic Layer Deposition

  • Jung, Eun Ae;Han, Jeong Hwan;Park, Bo Keun;Jeon, Dong Ju;Kim, Chang Gyoun;Chung, Taek-Mo
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.363-363
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    • 2014
  • Ruthenium (Ru) has attractive material properties due to its promising characteristics such as a low resistivity ($7.1{\mu}{\Omega}{\cdot}cm$ in the bulk), a high work function of 4.7 eV, and feasibility for the dry etch process. These properties make Ru films appropriate for various applications in the state-of-art semiconductor device technologies. Thus, it has been widely investigated as an electrode for capacitor in the dynamic random access memory (DRAM), a metal gate for metal-oxide semiconductor field effect transistor (MOSFET), and a seed layer for Cu metallization. Due to the continuous shrinkage of microelectronic devices, better deposition processes for Ru thin films are critically required with excellent step coverages in high aspect ratio (AR) structures. In these respects, atomic layer deposition (ALD) is a viable solution for preparing Ru thin films because it enables atomic-scale control of the film thickness with excellent conformality. A recent investigation reported that the nucleation of ALD-Ru film was enhanced considerably by using a zero-valent metallorganic precursor, compared to the utilization of precursors with higher metal valences. In this study, we will present our research results on the synthesis and characterization of novel ruthenium complexes. The ruthenium compounds were easy synthesized by the reaction of ruthenium halide with appropriate organic ligands in protic solvent, and characterized by NMR, elemental analysis and thermogravimetric analysis. The molecular structures of the complexes were studied by single crystal diffraction. ALD of Ru film was demonstrated using the new Ru metallorganic precursor and O2 as the Ru source and reactant, respectively, at the deposition temperatures of $300-350^{\circ}C$. Self-limited reaction behavior was observed as increasing Ru precursor and O2 pulse time, suggesting that newly developed Ru precursor is applicable for ALD process. Detailed discussions on the chemical and structural properties of Ru thin films as well as its growth behavior using new Ru precursor will be also presented.

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지하옹벽 무지주 거푸집 개발 및 경제성 분석에 관한 연구 (A Study on the Development of a Non-supporting Form for Basement Wall and the Analysis on Its Economical Efficiency)

  • 김재엽;이상우;손영진;김광희
    • 한국건축시공학회지
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    • 제9권6호
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    • pp.161-168
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    • 2009
  • 건축공사에서 지하공사는 주공정으로 전체공기와 공사비에서 큰 부분을 차지하고 있으며, 특히 도심지의 경우 해마다 규모가 증가하고 있다. 현재 현장에서 시공하는 지하옹벽은 많은 기능 인력이 필요하고, 공사기간 측면에서도 불리한 유로폼+솔져시스템에 의하여 공사가 진행되고 있다. 따라서 본 연구에서는 토목공사 현장에서 일부 사용되고 있는 무지주 거푸집을 기초로하여 건축공사에 적용 가능한 무지주 거푸집을 개발하였다. 또한 거푸집의 크기를 가정하여 건축공사 현장에서 가장 많이 사용되는 유로폼+솔져시스템과 경제성 측면에서 비교.분석하였다. 연구 결과, 합성 무지주 거푸집은 유로폼+솔져시스템에 비해 공사비가 약 9%높게 나타났으며, 비합성 무지주 거푸집은 약 9%낮게 나타났다. 하지만 합성 무지주 거푸집의 경우 구조체공사에서 콘크리트와 철근의 물량이 현저히 감소하여, 기존옹벽 시공가격 보다 약 35% 경제적 원가절감 효과를 볼 수 있다.

석회석 광산에서 발생한 대규모 암반사면의 붕괴원인 분석에 관한 연구 (A Study on the Failure Cause of Large Scale Rock Slope in Limestone Quarries)

  • 이상은;김학성;장윤호
    • 터널과지하공간
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    • 제24권4호
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    • pp.255-274
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    • 2014
  • 본 연구는 강원도 강릉시 소재의 ${\bigcirc}{\bigcirc}$ 석회석 광산에서 2012년 8월 23일 오후 7시경 붕괴된 대규모 암반사면을 대상으로 한다. 붕괴 이전에 사면의 높이는 약 200 m이고 평균경사는 $45^{\circ}$로 형성되어 있다. 사면 붕괴 후 추정된 붕괴량은 $1,500,000m^3$ 정도이다. 사면 붕괴의 원인을 분석하기 위하여 시추, 물리탐사, 지표지질조사, 선구조분석, 공내영상촬영, 입체사진영상촬영, 실내시험 및 현장시험, 년도별 채광현황 및 강우량 분석등의 현장 및 지반조사를 실시하였다. 사면의 안정성을 파악하기 위하여 SMR, 평사투영법, 한계평형법, 연속체 및 불연속체 해석을 수행하였다. 이 결과들로부터 사면붕괴의 원인은 지형, 강우, 암종 및 암질, 불연속면, 석회암 공동이나 단층의 지질구조적 특성 등 여러 요인들이 복합적으로 작용하여 사면활동이 발생한 것으로 추정되지만, 석회암 공동을 고려하지 않을 경우 사면 붕괴는 발생하지 않는 것으로 분석되었다. 석회암 공동을 고려한 연속체 해석에서 사면 안전율이 0.66으로 나타났다. 따라서 대규모 사면붕괴의 근본적인 원인은 단층대를 따라 발달하고 있는 석회암 공동의 영향에 기인하는 것으로 판단된다.

식물 미토콘드리아에 대한 Superoxide독성의 생화학적 측면 (Biochemical Aspect of Superoxide Toxicity to Plant Mitochondria)

  • 정진;인만진
    • Applied Biological Chemistry
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    • 제32권1호
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    • pp.23-29
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    • 1989
  • soybean hypocotyl에서 분리한 미토콘드리아로부터 submitochondrial particles와 matrix 단백질 추출액을 준비하고 전기분해법으로 제조한 superoxide를 처리하여 malate dehydrogenase 및 cytochrome C oxidase의 불활성화와 mitochondrial membrane의 과산화를 각각 조사하였다. 막에 결합되어 있는 cytochrome C oxidase나 수용액상태의 malate dehydrogenas는 모두 $O^{-}_{2}$에 대해 매우 민감하게 불활성화되었다. 즉 dismutation 반응이 빠르게 진행되어 실질적으로 효소의 불활성화에 기여하게 될 농도는 대단히 낮을 것으로 추정되는 $O^{-}_{2}$의 명목상 처리농도 1.4mM 전후에서 두 효소는 그 활성을 완전히 상실하였다. 한편 malondialdehyde의 생성을 지표로 하여 측정된 membrane 과산화는 인지질로서만 이루어진 liposome의 경우보다는 다소 낮은 수준이었으나 무시할 수는 없는 정도였다. mitochondrial membrane의 과산화가 상대적으로 억제된 것은 막에 결합되어 있는 항산화제 및 단백질들에 의한 $O^{-}_{2}$소거효과에 기인하였으리라 해석된다. 식물 미토콘드리아의 대표적인 대사과정인 TCA cycle과 호흡전자전달반응의 성분효소들인 malate dehydrogenase와 cytochrome C oxidase가 불활성화되었고 membrane이 과산화 되었다는 사실은, 식물의 냉해와 광피해 발현기작에서 공히공통적인 화학적 인자로 인정되는 $O^{-}_{2}$의 과잉생성 및 축적이 그것의 주 생성처인 미토콘드리아의 생화학적 기능과 구조에 미칠수 있는 파괴적 효과를 적절히 지시하는 것이다.

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