• Title/Summary/Keyword: Shape Value

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Combustion Chamber Shape Effects on Flame Temperatgure and KL Value in a Diesel Engine (디젤엔진에서 연소실 형상이 화영온도 및 KL치에 미치는 영향)

  • 이선봉;이태원;하종률
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.8
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    • pp.99-106
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    • 1999
  • The present study deals with the effect of combustion chamber shape on in-cylinder soot oxidation characteristics of a D.I . diesel engine. The analysed combustion chambers were a toroidal and a reentrant with a projection(Complex). The two-color method was used to measure in-cylinder flame temperature and KL value which is approximately proportional to the soot amount along the optical path. In addition, heat release rate was calculated from the in-cylinder pressure data. From these investigations , the soot oxidation of the reentrant and the complex which were strengthen squish flows went worse in late combustion period under heavy-load operation compared to that of the toroidal at retarded fuel injection timing . It might be the cause of the flame holding that squish lip depress the outflow of flame from the bowl to the entire combustion space.

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Effect of Shape and Flow Rate on T10 in Clearwell (정수지의 형상과 유입 유량이 T10에 미치는 영향 연구)

  • Shin, Eun-Her;Kim, Sung-Hoon;Park, Hee-Kyung;Ahn, Jae-Chan;Choi, Jae-Ho;Choi, Young-June
    • Journal of Korean Society of Water and Wastewater
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    • v.19 no.6
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    • pp.819-826
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    • 2005
  • To guarantee the disinfection ability in clearwell, a value of CT is considered where C[mg/l] is disinfectant residual at the exit of clearwell and T[min] means $T_{10}$, the contact time when 10% of tracer is out of clearwell after introducing the tracer at the inlet. To meet a CT value required, increasing the C value is not recommended because high C value can increase potential of producing disinfection by product like THMs. Increasing the hydraulic efficiency surrogated by $T_{10}$ is thus an option widely recommended. Right now, it is widely adopted estimating $T_{10}$ considering LW ratio only due to the suggestions of previous researches. The authors think however there are other factors to consider including shape, flow rate, configuration of inlet and outlet, and the existence of intra basin. This study is initiated to closely look at the effects of two factor on hydraulic efficiency. The factors are shape and inlet flow velocity, i.e., inflow. For that, computational fluid dynamics (CFD) model is developed and pilot test is also carried out. The results show that at a L/W ratio, disinfection ability is overestimated with larger length in shape and higher inlet flow velocity. This suggests that in determining $T_{10}$, the shapes of clearwell and inlet flow velocity should also be considered as well as L/W ratio.

A Study on the Immateriality in Contemporary Interior Space (현대 실내공간에서의 비물질적 특성에 관한 연구)

  • 신홍경;옥창수
    • Korean Institute of Interior Design Journal
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    • v.13 no.3
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    • pp.76-83
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    • 2004
  • Nowadays, our societies use digital technology in new architectural shape and space design to transcend three dimension limit so the boundary of the imagination world and actuality world has been collapsed. Traditional spatial value has been collapsed. Also indetermination and temporary assumption in time, fluidness and dematerialized, simultaneity and reiteration in image are relative with this circumstances. In architectural shape, media characteristics which secede from traditional characteristics of place tectonic value have occurred. Therefore, indifference and interests in shape, inter-permeation in interior and exterior space, homogeneous equivalence spatial extension have occurred. The purpose in this study examines dematerialized in contemporary space design and light materials and also investigates general and architectural background. The results of this study are as follows. First, circumstances of human have changed from physically limited boundary to unfixed, nonphysical, lightness and vague things. Second, casting off volume in shape and also dissembling exclusive and constructive Third, interior and exterior space by transparency intimates media possibility of information screen. Fourth, seek information and organic response, ambivalent transformation, accumulation of image and new mutual understanding system.

Shape Optimization in Laminated Composite Plates by Volume Control (최적 제어를 통한 복합적층판의 형상최적화)

  • 한석영;백춘호;박재용
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2003.10a
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    • pp.277-282
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    • 2003
  • The growth-strain method was applied to cutout optimization in laminated composite plates. Since the growth-strain method optimizes a shape by generating the bulk strain to make the distributed parameter uniform, the distributed parameter was chosen as Tsai-Hill value. In this study, of particular interest is to see whether the growth-strain method developed for shape optimization in isotropic media would work for laminated composite Plates. In volume control of the growth-strain method, it makes Tsai-Hill value at each element uniform in laminated composite plates under the predetermined volume. The shapes optimized by Tsai-Hill fracture index were compared with those of the initial shapes for the various load conditions and predetermined volumes of laminated composite plates. As a result, it was verified that volume control of the growth-strain method worked very well for cutout optimization in laminated composite plates.

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A Study on the Pressure and Velocity Distributions by POD Shape of Hydrofoil Vessel (쾌속여객선의 POD 형상에 따른 압력과 속도 분포에 관한 연구)

  • Lee, Chun-Ki;Lim, Tae-Woo;Moon, Seong-Bae
    • Journal of Fisheries and Marine Sciences Education
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    • v.26 no.4
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    • pp.831-837
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    • 2014
  • This paper focuses on the effects of the changes in the resistance characteristics caused by the changes of the POD shape installed in the Hydrofoil vessel, using the CFD(Computational Fluid Dynamics). We input the POD sections' basic shape as the origin of the x and y axis. Then as we cut the x-axis 0 to 2 cm, and the more we cut it, the total resistance value had increased. However, we have recognized the fact that as we cut the POD section, 3 to 5 cm, the resistance value had rather decreased. Furthermore we found out the result that as the cut partition was larger; the POD cross-section would decrease, resulting in the linear decrease of the viscous force.

A Study on the Optimal Blank Shape of the Axisymmetric Deep Drawing Process (축대칭 ?드로잉 공정의 최적 블랭크 형상에 관한 연구)

  • 천석규;한철호
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1998.03a
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    • pp.237-241
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    • 1998
  • This study is concerned with the optimum blank design which is able to minimize earing phenomena. A new analytic method is proposed to determine the optimum blank shape only using the tension test and standard deep drawing tests. Introducing a dimensionless parameter related to the earing and using a Fourier analysis, the optimum blank shape can be obtained by R-value and the tested results. The theoretical results by the proposed method are good agreement with the experimental results through several deep drawing tests using steel as working materials.

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A Study on the Lightweight Design of a Cross Beam for Railway Passenger Coach (철도객차용 크로스 빔의 경량화 설계에 관한 연구)

  • Jang, Deuk-Yul;Jeon, Hyung-Yong
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.16 no.5
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    • pp.126-133
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    • 2017
  • This report investigates the stress distribution according to the location and shape change of the circular hole for the lightweight design of the cross beam of a railway passenger car and studies the lightweight design. To design a lightweight cross beam with a circular hole, we selected the non-circular crossbeam as a basic model, examined the stress distribution and displacement by position and determined the location, shape, size and quantity of the hole for light weight. We analyzed the effects of the position and shape of the hole on the maximum equivalent stress and displacement. The influencing factors were set as the design parameters, and the stress value was examined according to the variation of each variable. By considering the stress value according to the change of each variable and selecting the design parameter with the narrowest scattering value of the stress at each position of the hollow cross beam with various hole positions and shapes, we studied a cross beam with a circle hole under identical load condition to have an equal stress distribution to that of a non-circular cross beam.

A Comparison of Chinese Women's Lower Body Features in Shanghai and Hong Kong

  • Cha, Sujoung
    • Journal of Fashion Business
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    • v.17 no.6
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    • pp.141-157
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    • 2013
  • In this study, we analyzed the figure type and lower-body size of Shanghai and Hong Kong adult women in their early twenties using the data obtained from 3D whole body scanners. We also provided concrete information related to women's lower bodies, in terms of crotch width, crotch length, inseam, outseam, slope of waist, etc., among women in Shanghai and Hong Kong. The result may be useful to the Chinese apparel industry when designing trouser pants for adult women. According to the results of the factor analysis for categorizing the body shape of the lower half, 5 factors were obtained: obesity of the lower half factor, height of the lower half factor, length from waist to the crotch factor, factor related to legs, and shape of the abdomen factor. After performing a cluster analysis according to the factor analysis, three clusters were set: Cluster 1 was represented as the lower half growth type, which has a high value in height of the lower half factor and grows in the abdomen part. Cluster 2 was represented as thin legs type, which has a low value in most part compared to the length of leg bones and factors about legs that have high value. Cluster 3 was represented as the obesity type having a high value in the obesity of the lower half factor. Overall, thin legs type achieved a high rate in Shanghai adult women and obesity type received a high rate in adult women living in Hong Kong.

A note on Hvorslev's shape factor for a flush bottom piezometer in uniform soil

  • Silvestri, Vincenzo;Bravo-Jonard, Christian;Abou-Samra, Ghassan
    • Geomechanics and Engineering
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    • v.3 no.2
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    • pp.109-116
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    • 2011
  • This note presents an analytical solution for the determination of the shape factor of a flush bottom piezometer in a uniform, isotropic, and incompressible deep soil deposit. The deduced shape factor is compared to published values obtained by approximate methods. Depending on the selected value, the difference may reach 11%.

Shape Description and Retrieval Using Included-Angular Ternary Pattern

  • Xu, Guoqing;Xiao, Ke;Li, Chen
    • Journal of Information Processing Systems
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    • v.15 no.4
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    • pp.737-747
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    • 2019
  • Shape description is an important and fundamental issue in content-based image retrieval (CBIR), and a number of shape description methods have been reported in the literature. For shape description, both global information and local contour variations play important roles. In this paper a new included-angular ternary pattern (IATP) based shape descriptor is proposed for shape image retrieval. For each point on the shape contour, IATP is derived from its neighbor points, and IATP has good properties for shape description. IATP is intrinsically invariant to rotation, translation and scaling. To enhance the description capability, multiscale IATP histogram is presented to describe both local and global information of shape. Then multiscale IATP histogram is combined with included-angular histogram for efficient shape retrieval. In the matching stage, cosine distance is used to measure shape features' similarity. Image retrieval experiments are conducted on the standard MPEG-7 shape database and Swedish leaf database. And the shape image retrieval performance of the proposed method is compared with other shape descriptors using the standard evaluation method. The experimental results of shape retrieval indicate that the proposed method reaches higher precision at the same recall value compared with other description method.