• 제목/요약/키워드: Behaviour Quality

검색결과 162건 처리시간 0.038초

실물파괴실험에 의한 세그먼트 라이닝의 강섬유 보강 효과 평가 (Evaluation of steel fiber reinforcement effect in segment lining by full scale bending test)

  • 이규필;배규진;문도영;강태성;장수호
    • 한국터널지하공간학회 논문집
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    • 제15권3호
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    • pp.215-223
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    • 2013
  • 최근 유럽 및 일본에서는 강섬유 보강 콘크리트를 활용하여 철근을 생략하거나 최소화하기 위한 연구가 수행중에 있으며, 세그먼트 제작시 강섬유 보강 콘크리트 활용은 철근 생략 또는 최소화를 통한 경제성 향상은 물론 품질관리 향상효과가 있는 것으로 알려져 있다. 따라서 본 연구에서는 강섬유 보강효과 검토를 위하여 기존에 널리 활용되고 있는 철근만으로 보강된 세그먼트와 철근 및 강섬유로 보강된 세그먼트 실험체 제작 및 휨실험을 수행하였다. 실험결과 세그먼트 강섬유 보강은 콘크리트의 연성 증가효과로 인하여 균열제어는 물론 기존 세그먼트 보강재인 철근의 대체할 수 있는 보강재로 활용이 가능할 것으로 판단된다.

Nanodispersion-Strengthened Metallic Materials

  • Weissgaerber, Thomas;Sauer, Christa;Kieback, Bernd
    • 한국분말재료학회지
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    • 제9권6호
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    • pp.441-448
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    • 2002
  • Dispersions of non-soluble ceramic particles in a metallic matrix can enhance the strength and heat resistance of materials. With the advent of mechanical alloying it became possible to put the theoretical concept into practice by incorporating very fine particles in a flirty uniform distribution into often oxidation- and corrosion- resistant metal matrices. e.g. superalloys. The present paper will give an overview about the mechanical alloying technique as a dry, high energy ball milling process for producing composite metal powders with a fine controlled microstructure. The common way is milling of a mixture of metallic and nonmetallic powders (e.g. oxides. carbides, nitrides, borides) in a high energy ball mill. The heavy mechanical deformation during milling causes also fracture of the ceramic particles to be distributed homogeneously by further milling. The mechanisms of the process are described. To obtain a homogeneous distribution of nano-sized dispersoids in a more ductile matrix (e.g. aluminium-or copper based alloys) a reaction milling is suitable. Dispersoid can be formed in a solid state reaction by introducing materials that react with the matrix either during milling or during a subsequent heat treatment. The pre-conditions for obtaining high quality materials, which require a homogeneous distribution of small dis-persoids, are: milling behaviour of the ductile phase (Al, Cu) will be improved by the additives (e.g. graphite), homogeneous introduction of the additives into the granules is possible and the additive reacts with the matrix or an alloying element to form hard particles that are inert with respect to the matrix also at elevated temperatures. The mechanism of the in-situ formation of dispersoids is described using copper-based alloys as an example. A comparison between the in-situ formation of dispersoids (TiC) in the copper matrix and the milling of Cu-TiC mixtures is given with respect to the microstructure and properties, obtained.

Fishbein 모델을 이용한 패밀리 레스토랑의 호스트 호명제 서비스 타당성에 대한 연구 (A Study on the Validity of Host Call Service in the Family Restaurant using Fishbein Model)

  • 서광규;안범준
    • 한국산학기술학회논문지
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    • 제7권4호
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    • pp.753-758
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    • 2006
  • 근래의 외국계 레스토랑의 국내 진출은 의식 서비스 품질의 중요성을 인식시켜주는 계기가 되었으며, 고객 만족은 그 어떤 무엇보다도 중요한 비즈니스 활동의 목적으로 여기게 되었다. 이러한 점을 감안하여, 본 연구에서는 한국에서 패밀리 레스토랑의 고객 만족을 위한 중요한 요소들을 규명하기 위하여, Fishbein의 행동모델을 이용하여 패밀리 레스토랑의 호스트 호명제 서비스 타당성을 검증하고자 하였다. 연구가설은 문헌연구를 통해 설정하였으며, 패밀리 레스토랑 고객을 대상으로 설문조사하여 실증연구를 수행하였다. 수집된 설문조사 자료는 SPSS를 이용하여 분석하였으며, 기술통계, t-test. F-test 및 회귀분석을 수행하였다. 분석결과 본 연구에서 설정한 4개의 가설이 모두 유의함을 확인하였다. 따라서 패밀리 레스토랑의 호스트 호명제 서비스는 고객 만족을 증대시키기 위하여 도입되어야 함을 유추할 수 있다. 결론적으로 패밀리 레스토랑의 호스트 호명제 서비스는 고객의 만족도를 향상시킬 수 있는 중요한 요소임을 입증하였고, 패밀리 레스토랑의 경쟁력을 강화하기 위해서는 차별화된 서비스를 지속적으로 개발하여야 한다.

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가구 탄소모니터링 시스템에 의한 탄소배출특성 - 세종시 첫마을을 대상으로 - (Households' Characteristics in Energy Consumption Data from Carbon Emission Monitoring System (CEMS) in Sejong City, Korea)

  • 임윤택;이상호
    • KIEAE Journal
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    • 제13권6호
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    • pp.55-65
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    • 2013
  • Korean Government has developed Sejong City as a new administration city. This city of future was planned and designed toward one of the most eco-friendly city on the basis of ICTs. To attain this object, a carbon emission monitoring system (CEMS) was designed and installed as a part of u-city service which provides various information anytime and anywhere to enrich the people's quality of life. In this paper, at first, the structure and functions of CEMS are introduced. This system is consist of 5 parts - data collection from user and linked public DBs, transforming data into meaningful information for the policy makers, system-user interfacing via statistical tables and graphs, and system maintenance. This system can be operated by the citizen participation through whole the process. With the help of GIS map and graphic interface, statistics of monitored data for both citizen and decision maker provided and after feed-back, they have affected on the behaviour of citizen's energy consumption and related policy as well. By the CEMS, energy consumption data of 124 agreed households were collected during 9 months in 2012. Electricity, gas and water consumption were remote-metered automatically by the system and analysed. This showed that more than 85% of CO2 emission is rely on electricity usage. Furthermore, number of family members and size of house influences on the emission of CO2 by each household together with the life-style of the occupants. Electricity and water consumption showed the seasonal factor while gas consumption represents the number of family members. Even this paper has limitations caused by 9 months of data collection, it shows the policy directions to reduce the emission of CO2 focusing on the house size and number of family members of each households. With the result of this research, life-style of the generation of dwellers should be investigated and the CO2 emission characteristics of other housing type as well for the data building for future policy making.

지중 송전관로 되메움용 순환골재의 현장실증시험을 통한 적용성 평가 (Assessment on Applicability of Recycled Aggregates for Backfill Materials of Underground Transmission Lines Based on Field Demonstration Tests)

  • 강성철;이강렬;안태봉
    • 한국건설순환자원학회논문집
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    • 제3권1호
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    • pp.72-83
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    • 2015
  • 지중 송전선은 전기저항에 의한 발열현상이 늘 있으며, 그 주변의 되메움재를 통하여 열을 방출하게 된다. 따라서, 송전관로의 설계에는 발생하는 열을 주변 지반이 효과적으로 외부에 전달하여, 열적 안정성을 확보하는 것이 매우 중요한 설계 요소가 된다. 본 연구에서는 지중 송전관로 되메움재용 순환골재의 현장 적용성을 향상시키기 위하여, 순환골재의 품질기준 및 시공기준을 제시하고, 현장 실증시험을 통하여 송전관로의 열안정성을 분석하였다. 현장 실증시험에서는 순환골재 두 종류와 현재 되메움재로 사용하고 있는 모래의 열적 거동을 비교하였다. 시험 결과, 순환골재는 시간경과와 관로에서의 이격거리에 따라 온도와 함수비 변화가 모래와 유사하게 나타났다. 따라서 순환골재는 지중 송전관로 되메움재로서 일반 모래를 대체하여 적용 가능할 것으로 판단된다.

Smart monitoring analysis system for tunnels in heterogeneous rock mass

  • Kim, Chang-Yong;Hong, Sung-Wan;Bae, Gyu-Jin;Kim, Kwang-Yeom;Schubert, Wulf
    • 한국지구물리탐사학회:학술대회논문집
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    • 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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    • pp.255-261
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    • 2003
  • Tunnelling in poor and heterogeneous ground is a difficult task. Even with a good geological investigation, uncertainties with respect to the local rock mass structure will remain. Especially for such conditions, a reliable short-term prediction of the conditions ahead and outside the tunnel profile are of paramount importance for the choice of appropriate excavation and support methods. The information contained in the absolute displacement monitoring data allows a comprehensive evaluation of the displacements and the determination of the behaviour and influence of an anisotropic rock mass. Case histories and with numerical simulations show, that changes in the displacement vector orientation can indicate changing rock mass conditions ahead of the tunnel face (Schubert & Budil 1995, Steindorfer & Schubert 1997). Further research has been conducted to quantify the influence of weak zones on stresses and displacements (Grossauer 2001). Sellner (2000) developed software, which allows predicting displacements (GeoFit$\circledR$). The function parameters describe the time and advance dependent deformation of a tunnel. Routinely applying this method at each measuring section allows determining trends of those parameters. It shows, that the trends of parameter sets indicate changes in the stiffness of the rock mass outside the tunnel in a similar way, as the displacement vector orientation does. Three-dimensional Finite Element simulations of different weakness zone properties, thicknesses, and orientations relative to the tunnel axis were carried out and the function parameters evaluated from the results. The results are compared to monitoring results from alpine tunnels in heterogeneous rock. The good qualitative correlation between trends observed on site and numerical results gives hope that by a routine determination of the function parameters during excavation the prediction of rock mass conditions ahead of the tunnel face can be improved. Implementing the rules developed from experience and simulations into the monitoring data evaluation program allows to automatically issuing information on the expected rock mass quality ahead of the tunnel.

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Analytical and higher order finite element hybrid approach for an efficient simulation of ultrasonic guided waves I: 2D-analysis

  • Vivar-Perez, Juan M.;Duczek, Sascha;Gabbert, Ulrich
    • Smart Structures and Systems
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    • 제13권4호
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    • pp.587-614
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    • 2014
  • In recent years the interest in online monitoring of lightweight structures with ultrasonic guided waves is steadily growing. Especially the aircraft industry is a driving force in the development of structural health monitoring (SHM) systems. In order to optimally design SHM systems powerful and efficient numerical simulation tools to predict the behaviour of ultrasonic elastic waves in thin-walled structures are required. It has been shown that in real industrial applications, such as airplane wings or fuselages, conventional linear and quadratic pure displacement finite elements commonly used to model ultrasonic elastic waves quickly reach their limits. The required mesh density, to obtain good quality solutions, results in enormous computational costs when solving the wave propagation problem in the time domain. To resolve this problem different possibilities are available. Analytical methods and higher order finite element method approaches (HO-FEM), like p-FEM, spectral elements, spectral analysis and isogeometric analysis, are among them. Although analytical approaches offer fast and accurate results, they are limited to rather simple geometries. On the other hand, the application of higher order finite element schemes is a computationally demanding task. The drawbacks of both methods can be circumvented if regions of complex geometry are modelled using a HO-FEM approach while the response of the remaining structure is computed utilizing an analytical approach. The objective of the paper is to present an efficient method to couple different HO-FEM schemes with an analytical description of an undisturbed region. Using this hybrid formulation the numerical effort can be drastically reduced. The functionality of the proposed scheme is demonstrated by studying the propagation of ultrasonic guided waves in plates, excited by a piezoelectric patch actuator. The actuator is modelled utilizing higher order coupled field finite elements, whereas the homogenous, isotropic plate is described analytically. The results of this "semi-analytical" approach highlight the opportunities to reduce the numerical effort if closed-form solutions are partially available.

Lifestyle Behaviors and Early Diagnosis Practices of Cancer Patients

  • Yilmaz, Medine;Sanli, Deniz;Ucgun, Mujde;Kaya, Nur Sahin;Tokem, Yasemin
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권5호
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    • pp.3269-3274
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    • 2013
  • Background: The aim was to determine the lifestyle behaviors and the practices for early diagnosis of cancer of cancer patients. Materials and Methods: A descriptive cross-sectional design was used for this study. The sample consisted of 222 patients with a diagnosis of cancer (non-random sample method). Ethical permission was obtained of the Non-interventional Research Ethics Committee of our Institution. Values of p<0.05 were accepted as statistically significant. Results: It was observed that 54.4% of the patients had never performed breast self-examination, 60.8% had never had a mammography, and 71.2% had never had a Pap smear. Sixty-six point two percent of patients had never had screening for colon cancer within the past ten years. GIS cancers were higher in smokers and ex-smokers (p=0.005), in drinkers and in ex-drinkers (p=0.000). The breast cancer rate was higher in obese people (p=0.019). Conclusions: The results of this study provide information on the healthy lifestyle behavior of cancer patients before their diagnosis, and their use of early diagnosis practices. The important aspect of this study is to extend cancer patients' period of life after the diagnosis and treatment process, to make them conscious of risky lifestyle and nutritional behavior so that they can maintain a high quality of life, and to start initiatives in this direction that would ensure changes in behavior.

현대패션쇼의 대중문화적 특성(제1보) -1990년대 중반이후 기성복컬렉션을 중심으로- (The Characteristics of the Popular Culture Contemporary Fashion Shows -Focus on Pret-a-Porter collections after the mid of 1990s-)

  • 장안화;박민여
    • 복식
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    • 제54권4호
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    • pp.1-14
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    • 2004
  • This study suggests the popular culture theory as a basic framework to find out the characteristics of contemporary fashion show meeting the popular culture, and describes that the show is the popular culture of this generation. The culture is the way of our life unifying the world at common area of human being. The popular culture is to subdivide it into the public culture that shares aesthetic taste, and to borrow each other and develop it mutually because of the collapse of dichotomous boundary with high quality culture, and to represent the people’s thought and behaviour expanding their areas. The author has examined the characteristics of popular culture of modern fashion show by four collections, that is, commercialism, mass media, political relationship and interaction, etc: Firstly, at the commercialism, the fashion show combines it with other genre organically to do mass production and sales and produces cultural consumption goods supplying a lot of sight-seeing. Secondly, at the mass media, the image of contemporary fashion show has been spread out with mass media such as fashion magazines, cable TV and Internet beyond time and space to produce advertisement effects and makes new fashion and bring democratic culture. Thirdly, at political relationship, the fashion in its peak can make a big stream of wealth, so that it plays important roles under governmental regulations in this era and governments make efforts to support and develop it. Lastly, at interaction, the fashion show shares media functions to let users participate in the program and to exchange information as a feedback to influence each other.

유도침투량의 정량화를 위한 해석모형과 수치모형의 분석 (Analysis of Analytical Models and Numerical Model for Evaluating Induced Infiltration Rate)

  • 이도훈;이은태
    • 한국수자원학회논문집
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    • 제32권3호
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    • pp.301-310
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    • 1999
  • 본 연구에서는 하천-대수층 계에서 수치모형과 두 종류의 해석모형을 적용하여 유도침투량 곡선을 유도하여 비교하였으며, 투수계수의 이방성비 및 지하수 유입 방향이 유도침투량 산정에 미치는 영향을 평가하였다. 유도침투량 곡선은 단순한 그래프 형태로 표시되며, 유도침투량, 양수량, 하천과 우물사이의 거리, 유동 지하수 유입량 등의 4가지 인자만을 포함하기 때문에 유도침투량의 결정에 유용하게 적용될 수 있다. 검토된 조건 아래에서 Wilson 해석모형과 FEWA 수치모형의 유도침투량 곡선은 근사적으로 일치하였으며, 투수게수의 이방성비는 유도침투량에 큰 영향을 미치는 인자로 평가되었다. 본 연구에서 적용된 방법과 도출된 결과들은 유도침투 현상을 이해하는데 도움이 되며, 양수우물의 계획 및 설계, 용수공급 우물의 수질관리에 필요한 유도침투량과 양수량의 최적 결정에 적용될 수 있다.

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