• Title/Summary/Keyword: physical shapes

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Proposal of the Stress Wave Concept and Its Applied Study as a Theory for the Dislocation Formation (전위생성에 대한 이론으로서의 응력파 개념에 대한 제안 및 적용 연구)

  • 서정현
    • Transactions of Materials Processing
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    • v.10 no.6
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    • pp.449-456
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    • 2001
  • The concept of stress wave was introduced through the quantized kinetic energy which is related to the potentional energy change of atom, molecular bond energy. Differentiated molecular bond energy $\varphi$() by the lst order displacement u becomes force F(F = d$\varphi$($u_i$)/du), if resversely stated, causing physically atomic displacement $u_i$. Such physical phenomena lead stress(force/area of applied force) can be expressed by wave equation of linearly quantized physical property. Through the stress wave concept, formation of dislocation, which could not explained easily from a theory of continuum mechanics, can be explained. Moreover, this linearly quantized stress wave equation with a stress concept for grains in a crystalline solid was applied to three typical metallic microstructures and a simple shape. The result appears to be a product from well treated equations of a quantized stress wave. From this result, it can be expected to answer the reason why the defect free and very fine diameters of long crystalline shapes exhibit ideal tensile strength of materials.

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A STUDY ON THE AERODYNAMIC SHAPE DESIGN WITH THE PARSEC FUNCTION (PARSEC 함수를 이용한 헤어포일의 공력 형상 설계 연구)

  • Lee, Jae-Hun;Jung, Kyung-Jin;Kwon, Jang-Hyuk;Ahn, Joong-Ki
    • 한국전산유체공학회:학술대회논문집
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    • 2007.10a
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    • pp.88-91
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    • 2007
  • In the shape design optimization of an airfoil, the shape function has been used to find the optimal airfoil shape for given conditions. The parameters determining the airfoil shape are used in the shape design optimization as design variables. However, they usually don't have physical meaning. The PARSEC (Parametric Shapes) function is a recently proposed shape function and its parameters have the physical meaning. In this study the usefulness of the PARSEC is tested for the RAE2822 airfoil in the transonic flow region to reduce the shock strength and the result is compared with Hicks-Henne function. The optimized airfoils reduce the shock strength and they show similar result.

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Nano Patterning on Graphite by Ion-Beam Sputtering

  • Yoon, Sun Mi;Kim, J.S.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.214-214
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    • 2013
  • Ion beam sputtering (IBS) by collision of energetic ions at surfaces is one of the representative methods for physical self-assembly. It is in spotlight as an easy tool to make nano structures in various sizes and shapes by controlling physical variablesWe investigate nano patterning on graphite. We found well-ordered nano ripple patterns after sputtering under the oblique angle and mean wavelengths of these ripples could be controlled as ion fluence increases from sub-10 nm to 80 nm. Each nano ripple is terminated by nano buds, which look like a cotton bud. We also examined the formation of various patterns on graphite by sputtering during swinging the sample at a constant angular velocity that have been never reported.

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ESTIMATION ALGORITHM FOR PHYSICAL PARAMETERS IN A SHALLOW ARCH

  • Gutman, Semion;Ha, Junhong;Shon, Sudeok
    • Journal of the Korean Mathematical Society
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    • v.58 no.3
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    • pp.723-740
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    • 2021
  • Design and maintenance of large span roof structures require an analysis of their static and dynamic behavior depending on the physical parameters defining the structures. Therefore, it is highly desirable to estimate the parameters from observations of the system. In this paper we study the parameter estimation problem for damped shallow arches. We discuss both symmetric and non-symmetric shapes and loads, and provide theoretical and numerical studies of the model behavior. Our study of the behavior of such structures shows that it is greatly affected by the existence of critical parameters. A small change in such parameters causes a significant change in the model behavior. The presence of the critical parameters makes it challenging to obtain good estimation. We overcome this difficulty by presenting the Parameter Estimation Algorithm that identifies the unknown parameters sequentially. It is shown numerically that the algorithm achieves a successful parameter estimation for models defined by arbitrary parameters, including the critical ones.

The Impact of Salesperson Look-Brand Personality Congruence on Brand Affect: The Moderating Role of Social Anxiety

  • Lee, Heekyung;Yi, Youjae
    • Asia Marketing Journal
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    • v.20 no.3
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    • pp.17-38
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    • 2018
  • Branded service encounters, in which various aspects of frontline employees are strategically aligned with the firm's brand positioning, can be achieved along several dimensions such as employee appearance, manner, and personality. While previous research has mainly focused on behavioral traits of employees, this research examines the employee's physical appearance in association with the brand personality trait across two studies. Study 1 shows that salesperson look-brand personality congruence enhances brand affect by inducing positive affect. Specifically, a brand-congruent look of a salesperson increases positive affect among customers by confirming their prior expectations about what a salesperson of a certain brand should look like as a brand representative. Study 2 reveals that the positive impact of salesperson look-brand personality congruence on brand affect is significant only for customers with high social anxiety whereas this effect disappears for those with low social anxiety. These findings extend previous research on branded service encounters by showing why and when frontline employees' physical appearance shapes customers' affective responses toward the brand.

Simulation of Woody Leaf Netted Venation Based on Optimization Technique (최적화기법에 의한 나뭇잎 그물맥 시뮬레이션)

  • Chen, Lei;Li, Weizheng;Jang, Gang Won;Baek, Tae Hyun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.4
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    • pp.323-329
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    • 2013
  • This study attempts to simulate the structure of a woody leaf netted venation system by using topology optimization techniques. Based on finite element method (FEM) analysis of an incompressible fluid, a topology optimal design is applied to those woody leaf netted venation models. To solve the transverse shear locking problem of a thin plate caused by the Mindlin-Reissner plate model where a leaf netted venation is assumed to be a thin plate, a P1-nonconforming element and selective reduced integration are employed. Topology optimal design is applied to multiple physical domains. Combined with the Darcy-Stokes flow problems and extended to the optimal design of fluid channels, the multiple physical models of the flow system are analyzed and venation patterns of leafs are simulated. The calculated optimal shapes are compared with the natural shapes of woody leaf venation patterns. This interdisciplinary approach may improve our understanding of the leaf venation system.

Evaluation of the physical properties of organic fillers made from agricultural byproducts (농업부산물로 제조된 유기충전제의 물리적 특성 평가)

  • Lee, Ji-Young;Lim, Gi-Baek;Kim, Young-Hoon;Lee, Se-Ran;Kim, Man-Young;Kim, Chul-Hwan;Kim, Sun-Young;Kim, Jun-Sik
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.45 no.4
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    • pp.34-41
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    • 2013
  • In this study, we investigated the physical properties of powders made from agricultural byproducts, including rice straw, peanut husks, and garlic stems, to manufacture a new organic filler used for making paperboard. These materials were collected individually, and then we measured their chemical compositions. The byproducts were ground with a laboratory grinder and fractionated with 60-, 100-, and 200-mesh sieves to make many grades of organic fillers. After the grinding and fractionation, the yield, mean particle size, and particle size distribution of each grade were measured. Particle shapes were also investigated using a scanning electron microscope. The organic filler made from rice straw had the highest yield of the largest particle size group and higher contents of cellulose and hemicellulose than those made from peanut husks and garlic stems. The rice straw also showed more regular particle shapes and a lower aspect ratio than the other agricultural byproducts.

Effect of Particle Shape and Size of Calcium Carbonate on Physical Properties of Paper (탄성칼슘에 성상이 종이물성에 미치는 영향)

  • 한영림;서영범
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.29 no.1
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    • pp.7-12
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    • 1997
  • This study was intended to investigate the proper shape and size of calcium carbonate for the improvement of paper properties and its end use performance. We loaded calcium carbonate of various shapes and size in the handsheet and measured their physical and optical properties. Results obtained from the study are summarized as follows : 1. Due to different particle shapes and sizes, precipitated calcium carbonate (PCC) contributed greater to bulk improvement than ground calcium carbonate (GCC). Scalenohedral form of PCC produced the bulkiest sheet, GCC made the sheet bulkier as average particle size increases. 2. Tensile strength increased as average particle size was increasing. GCC kept tensile strength more effectively than PCC. The effect of particle size on tensile strength was much more pronounced as filler addition level was increasing. 3. Over the average particle size of 6.99$\mu$m, GCC gave much higher burst strength and internal bond than PCC did. In the filler levels of 20% and 30%, GCC by using bigger size fillers showed 50~100% improvement in some cases than PCC at the same filler content. 4. Tear strength increased as average particle size was increasing. At the filler level of 30%, PCC decreased tear greatly. 5. Over the average particle size of 13.56$\mu$m, GCC kept bending stiffness greater than PCC. Due to its shape, Scalenohedral form of PCC showed higher stiffness than others at the same particle size. 6. Cubic and acicular form of PCC improved light scattering coefficient very effectively. Light scattering coefficient of GCC decreased as average particle size increased. 7. Both of particle shape and size of filler were important factor in developing optical properties and bending stiffness. Particle size was the only important factor in developing other strength properties

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The Physical Characteristics of Elderly Women Resulting from activity Amoumt (노년층여성(老年層女性)의 활동량(活動量)에 따른 신체적(身體的) 특성(特性))

  • Hahm, Ock Sang
    • Journal of the Korean Society of Clothing and Textiles
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    • v.17 no.4
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    • pp.587-601
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    • 1993
  • In the order to grasp their physical characteristics stemming from activity amount, this paper has divided elderly women into the following group ; those with high activity in the past, those with low activity in the present, those with high activity in the present and those with low activity in the present. The analyses of the body measurements and the pie chart, and the classification of back shapes by taking photographs have led to the following results. 1. The items of depth and girth among the body measurements were significant in the past and the present activity. Those with high activity in the past had smaller sizes in depth and girth than those with low activity. 2. From the pie chart, it was shown that those with high activity in the past had smaller sizes in every index as well as in girth than those with low activity in the past. Both those with low activity in the present and those with medium activity in the present had somewhat large sizes in waist girth, bust girth, hip girth and abdominal girth and in the indices of these items. 3. The classification of back shapes by taking photograpes has shown that those with high activity in the past had the less bent body type-42 percent of Type A and 6.5 percent of Type D. Among those with medium activity in the present, Type A was most outstanding and Type C and Type D were less, This fact shows that those with medium activity in the present keep the most normal body type. This proves that the medium activity of elderly women is desirable for keeping the normal body type.

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A Comparison Study on the Body Types of Korean Women and Korean Women Residing in Japan -Focusing on Women in Their Twenties- (한국 여성과 일본 거주 한인 여성의 체형 비교 -20대를 중심으로-)

  • Seok, Hye-Jung;Lee, Jong-Sook;Im, Soon
    • Journal of the Korea Fashion and Costume Design Association
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    • v.13 no.2
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    • pp.1-11
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    • 2011
  • As a result of comparison analysis on body types of Korean women in their twenties and Korean women residing in Japan, the following results had been found. 1. The comparison of 49 items in physical measurements between the Korean women in their 20's and Korean women residing in Japan resulted in the differences in 33 items. 2. The comparison of the factor analysis results for physical measurements did not reveal big differences. 3. The comparison of the physical shapes according to the grouping resulted in three types each for both groups, with different features for individual types. Women residing in Korea were classified into tall and normal body, normal height with obese body, and short and thin body. Women residing in Japan showed different characteristics with tall and obese body, short and thin body and normal height with obese body. As a result of this study, identical ethnic group was found to take on different body types resulting from sociocultural differences and difference in eating habits if their place of residence differs for a long time.

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