• 제목/요약/키워드: technical aspect

검색결과 407건 처리시간 0.025초

Dynamic behaviour of thick plates resting on Winkler foundation with fourth order element

  • Ozdemir, Yaprak I.
    • Earthquakes and Structures
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    • 제16권3호
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    • pp.359-368
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    • 2019
  • This paper focuses on the study of dynamic analysis of thick plates resting on Winkler foundation. The governing equation is derived from Mindlin's theory. This study is a parametric analysis of the reflections of the thickness / span ratio, the aspect ratio and the boundary conditions on the earthquake excitations are studied. In the analysis, finite element method is used for spatial integration and the Newmark-${\beta}$ method is used for the time integration. While using finite element method, a new element is used. This element is 17-noded and it's formulation is derived from using higher order displacement shape functions. C++ program is used for the analyses. Graphs are presented to help engineers in the design of thick plates subjected to earthquake excitations. It is concluded that the 17-noded finite element is used in the earthquake analysis of thick plates. It is shown that the changes in the aspect ratio are more effective than the changes in the aspect ratio. The center displacements of the reinforced concrete thick clamped plates for b/a=1, and t/a=0.2, and for b/a=2, and t/a=0.2, reached their absolute maximum values of 0.00244 mm at 3.48 s, and of 0.00444 mm at 3.48 s, respectively.

다변수 함수를 이용한 형상 변화에 따른 리프팅 러그의 최적 설계에 관한 연구 (Lifting Lug by the Change of form Using Multivariate Functions: An Optimal Design Study)

  • 최경신;김지준;이지한;천광우
    • 한국기계가공학회지
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    • 제20권4호
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    • pp.31-38
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    • 2021
  • In this paper, we proposed an optimal design for determining the shape of a lifting lug freely by applying a multivariate function to the D-type lug, which is commonly used in shipyards. We derived the optimal aspect ratio of the lug through structural analysis and analyzed the safety and behavior of the lug aspect ratio. As a result, two types of final candidates, both lighter than the existing lug weight, were suitable for the ratio. They were found to have the greatest force at an angle of 45 degrees when a load of 100 tons was imposed. When the horizontal and vertical feature ratio of the lug was 1:3, it showed excellent results in terms of safety rates while maintaining weight reduction and functional aspects.

다발성 부분층 절개술을 이용한 늑연골 조각을 통한 이개재건 (Baseblock Sculpturing Using the Scoring Technique for the Reconstruction of Ear)

  • 이윤호;김현석
    • Archives of Plastic Surgery
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    • 제32권1호
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    • pp.60-66
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    • 2005
  • Total auricular reconstruction with autogenous tissue remains one of the greatest technical challenges for reconstructive plastic surgeons because of the ear's complex morphology with delicately convoluted cartilages and very thin skin. In a successfully created ear, a natural three-dimensional illusion visualized from the patient's profile, frontal, and posterior views is crucial. Accordingly ear framework should have adequate lateral aspect as well as suitable frontal aspect even before being lifted to this purpose. For this goal, rib cartilage should be harvested from three-dimensionally adequate area. It is the most essential point in framework fabrication that the baseblock should have semi-cup curvature via multiple parallel cuts made on its medial surface. Between January 1999 and May 2003, we performed 29 cases of total ear reconstruction with autogenous rib cartilage graft using this scoring technique and obtained satisfactory results, which showed more natural appearance visualized from the patient's profile, frontal, and posterior views.

Fabrication and properties of in-situ Al/AlB2 composite reinforced with high aspect ratio borides

  • Kayikci, Ramazan;Savas, Omer
    • Steel and Composite Structures
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    • 제19권3호
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    • pp.777-787
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    • 2015
  • Production and properties of metal matrix composites reinforced with an in-situ high aspect ratio $AlB_2$ flake have been investigated. Boron 2.2wt.% was dissolved in pure Al and Al-Cu alloy at $1300^{\circ}C$ by adding directly boron oxide which resulted in 4 vol.% reinforcing phase. The in-situ $AlB_2$ flake concentration was increased up to 30 vol.% in order to increase the tensile strength of the composites. Hardness, compressive strength and tensile strength of the composite were measured and compared with their matrix. Results showed that 30 vol.% $AlB_2/Al$ composite show a 193% increase in the compressive strength and a 322% increase in compressive yield strength. Results also showed that ductility of composites decreases with adding $AlB_2$ reinforcements.

On FEM modeling of piezoelectric actuators and sensors for thin-walled structures

  • Marinkovic, Dragan;Marinkovic, Zoran
    • Smart Structures and Systems
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    • 제9권5호
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    • pp.411-426
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    • 2012
  • Thin-walled adaptive structures render a large and important group of adaptive structures. Typical material system used for them is a composite laminate that includes piezoelectric material based sensors and actuators. The piezoelectric active elements are in the form of thin patches bonded onto or embedded into the structure. Among different types of patches, the paper considers those polarized in the thickness direction. The finite element method (FEM) imposed itself as an essential technical support for the needs of structural design. This paper gives a brief description of a developed shell type finite element for active/adaptive thin-walled structures and the element is, furthermore, used as a tool to consider the aspect of mesh distortion over the surface of actuators and sensors. The aspect is of significance for simulation of behavior of adaptive structures and implementation of control algorithms.

A Study on the Design of Stage Costumes Required for Opera Ch′un Hyang Jeon

  • Lee, Seo-Hee
    • The International Journal of Costume Culture
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    • 제2권2호
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    • pp.119-126
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    • 1999
  • The cultural art would be the most competitive commercial value in the 21st century. This research is about the stage costumes of the opera 'Ch'un Hyang Jeon'which is designed and made to fit modern times and the purpose is to set the opera 'Ch'un Hyang Jeon'as groundwork for the future opera of Korea. To extend the stage costumes of the Korea opera : First, We have to inform the world about our traditional costumes and design them to express our culture. Second, Not only the costumes but also the technical aspect such as stage music, setting, and lighting and the artistic aspect should be balanced in development. Third, We need a good training system for future designers of the stage costumes.

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Business Intelligence를 지원하기 위한 Big Data 기반 Data Lake 플랫폼의 선행 연구 (A Leading Study of Data Lake Platform based on Big Data to support Business Intelligence)

  • 이상범
    • 한국컴퓨터정보학회:학술대회논문집
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    • 한국컴퓨터정보학회 2018년도 제57차 동계학술대회논문집 26권1호
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    • pp.31-34
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    • 2018
  • We live in the digital era, and the characteristics of our customers in the digital era are constantly changing. That's why understanding business requirements and converting them to technical requirements is essential, and you have to understand the data model behind the business layout. Moreover, BI(Business Intelligence) is at the crux of revolutionizing enterprise to minimize losses and maximize profits. In this paper, we have described a leading study about the situation of desk-top BI(software product & programming language) in aspect of front-end side and the Data Lake platform based on Big Data by data modeling in aspect of back-end side to support the business intelligence.

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비염 레이저 치료환자의 만족도 (Determinants of Patient Satisfaction -Allergic Rhinitis Patients Treated with Laser Therapy-)

  • 진기남;정우경;장승연
    • Journal of Preventive Medicine and Public Health
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    • 제30권2호
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    • pp.402-412
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    • 1997
  • The purpose of this study is to examine the factors influencing the allergic rhinitis patients' satisfaction with laser surgery. The data were collected by telephone interviews with 211 patients who visited I university hospital. The statistical methods used for the analysis were factor analysis, reliability test, and hierarchical multiple regression. We find that satisfaction level is a function of not only the surgery outcome but also the socio-psychological experience during treatment. With the improvement in nasal allergic condition, patients were more likely to be satisfied with medical services. And patients who had positive experience with physicians and facilities reported higher satisfaction level. While the surgery outcome explained 68% of the variation of satisfaction level, socio-psychological experience explained 23% of it. This result clearly shows that physicians need to pay attention to the socio-psychological aspect as well as the technical aspect of medical services.

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네팔 르왕지역의 지속적 유기농차 재배 방향 (Prospect of Sustainable Organic Tea Farming in Lwang, Kaski, Nepa)

  • 장광진;황대선;박철호;전운성;전상호;비노드
    • 현장농수산연구지
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    • 제12권1호
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    • pp.137-150
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    • 2010
  • 1. Lwang은 해발 1,200m 정도의 산악지역으로 일교차가 크고 햇볕의 양이 많은 지역으로 토양산도는 차재배에 이상적인 pH(H2O)가 평균 5.60이다. 2. pH(KCL) 4.26으로 이상적이다. 그러나 두 pH 차이가 1.34으로 심한 양분 부족 현상을 보이며 토양 EC가 0.05 mS/cm로 심각한 토양 수탈현상을 보이고 있다. 3. 토양의 산화환원전위(ORP)는 393mV로 아주 이상적인 토양을 보이고 있다. 토양산도와 함께 산화환원전위(ORP)는 좋은 유기농 차를 만드는데 큰 역할을 하고 있다. 4. 차는 연중 양분(養分)을 흡수하고 있는데, 측정 결과는 전 항목에서 심한 양분의 부족현상을 보여 향후 유기물의 투입이 요구되고 있다.

Optimum Allocation of Reactive Power in Real-Time Operation under Deregulated Electricity Market

  • Rajabzadeh, Mahdi;Golkar, Masoud A.
    • Journal of Electrical Engineering and Technology
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    • 제4권3호
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    • pp.337-345
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    • 2009
  • Deregulation in power industry has made the reactive power ancillary service management a critical task to power system operators from both technical and economic perspectives. Reactive power management in power systems is a complex combinatorial optimization problem involving nonlinear functions with multiple local minima and nonlinear constraints. This paper proposes a practical market-based reactive power ancillary service management scheme to tackle the challenge. In this paper a new model for voltage security and reactive power management is presented. The proposed model minimizes reactive support cost as an economic aspect and insures the voltage security as a technical constraint. For modeling validation study, two optimization algorithm, a genetic algorithm (GA) and particle swarm optimization (PSO) method are used to solve the problem of optimum allocation of reactive power in power systems under open market environment and the results are compared. As a case study, the IEEE-30 bus power system is used. Results show that the algorithm is well competent for optimal allocation of reactive power under practical constraints and price based conditions.