• Title/Summary/Keyword: unevenness

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A Study on Revising the Program for Enhancing Rural Living Environment in Korea (현행 농어촌 정주권개발사업의 문제점과 개선방안)

  • Joh, Young-Kug
    • Journal of Agricultural Extension & Community Development
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    • v.12 no.2
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    • pp.197-217
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    • 2005
  • Since 1990, the Korean Ministry of Agriculture and Forestry(MAF) has implemented the program for enhancing rural living environment (Jungjookunkaebal program) to stabilize rural population and community. The program has focused on providing rural areas with various social infrastructure facilities. But, because the program has been done without appropriate consideration on rural settlement system and the unevenness of rurality, people has discredit its necessity and efficacy. This paper discussed desirable strategies and tools to overcome criticism on the program.

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A study on the Hand and the Sensibility Image of Preferred Underwear Textiles

  • Kim, Hee-Sook;Na, Mi-Hee;Cho, Shin-Hyun
    • International Journal of Human Ecology
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    • v.8 no.1
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    • pp.27-37
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    • 2007
  • The purpose of this study is to investigate the preference of the hand and the sensibility image of underwear textiles according to seasons. According to a recent survey of 109 college students, using a 7 scale evaluation to the preference of the hand and the sensibility image among 13 summer and 10 winter underwear textiles. The data was analyzed through mean, SD, factor analysis, t-test, Person correlation analysis and regression analysis using SPSS Win 11.0. The summer underwear textiles were classified according to six tactile factors: stiffness/surface unevenness, weight, elasticity, moistness, extension, and warm-cool and 3 sensibility image factors: elegant individual, modern, and sporty-casual. The winter textiles were classified according to six tactile factors: stiffness/surface unevenness, elasticity, warm-cool, drapability, moistness and flexibility and divided into 2 sensibility images: modern elegant and sporty-casual. Factors expressing hand and sensibility image according to season showed significant difference. In the summer, weight, in the winter, drapability and flexibility showed significant difference at the hand factor evaluation. The hand factors: weight, warm-cool and modern sensibility image factors effect the preference of summer underwear textile, also the hand factors-elasticity, stiffness/surface unevenness and the sensibility image factor-easy-sport-casual-effect the preference of winter textiles. Therefore, the thin, light, and cool textiles which are also gorgeous and sporty-casual are preferred for summer underwear textiles while soft, simple and comfortable textiles are preferred for winter textiles.

Effects of Molding Condition on Surface Unevenness of GMT-Sheet Moldings (GMT-Sheet 성형품의 표면요철에 미치는 성형조건의 영향)

  • Kim, Hyoung-Seok;Kim, Jin-Woo;Kim, Yong-Jae;Lee, Dong-Gi
    • Composites Research
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    • v.23 no.5
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    • pp.30-38
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    • 2010
  • Observing of GMT-Sheet in molding conditions, we have investigated unexpected phenomenons of moldings surface. In microscope investigation, we observe that there exist deficiencies on the surface of GMT-Sheet moldings, such as the spherulite, fiber projection, crack, fiber exposure, micro-weldline, pinhole and winding. They are caused to arise unevenness and phenomenons influence polish on surface. Especially, the major cause of the unevenness, effected to surface roughness, is a shrinking of matrix in the process of holding pressure and cooling temperature. The higher holding pressure load in a molding process and the lower demolding temperature in an annealing experiment, the better GMT-Sheet moldings improved its appearance.

Effect of Opening Roller Speed, Drums Speed Difference and Suction Air Pressure on Properties of Open-End Friction Spun Polyester and Acrylic Yarns

  • Vishnoi Prashant;Ishtiaque S. M.;Das A.
    • Fibers and Polymers
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    • v.6 no.3
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    • pp.250-258
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    • 2005
  • The present paper is concerned with the influence of opening roller speed, drum speed difference and suction air pressure on properties of polyester and acrylic open-end friction spun yams. The results shows that the opening roller speed and the suction air pressure have considerable influence on the characteristics of polyester and acrylic open-end friction spun yams. In case of polyester yams the unevenness, imperfection and hairiness decreases and the yam tenacity increases with the increase in opening roller speed and suction air pressure. However for acrylic yams the unevenness and imperfections decreases and tenacity increases with the increase in opening roller speed and suction air pressure.

Roughness Mobilization Characteristics of Artificial Triangular Asperities (인공 삼각 돌출부의 거칠기 발현특성)

  • Hong, Eun-Soo;Choi, Sung-Oong;Lee, In-Mo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.760-767
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    • 2006
  • Underestimation of rock joint shear strength comes from an inadequate consideration of roughness mobilization behavior, which is changed by asperity size as well applied normal load. In this study, we performed rock joint shear tests, and studied the roughness mobilization characteristics related with the scale of normal stress and asperities. Test specimens with artificial triangular asperities were manufactured. The specimens consisted of 3 types, and each type represented unevenness, waviness and total roughness(superposition of unevenness and waviness). The experimental results show that the roughness mobilization characteristics are varied by the scale of normal stress and asperities. Furthermore, the investigation shows that the rate of geometrical component and mechanical component in the total roughness is also varied by the scale of normal stress and asperities. These results suggest that we should consider the roughness mobilization characteristics for the roughness quantification and the shear strength modelling.

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A Study on the Threadline Instability on the Belt-type Texturing Process (벨트형 가연공정에서의 사도불안정에 관한 연구)

  • 이민수;김승진;박경순
    • Textile Coloration and Finishing
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    • v.16 no.1
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    • pp.5-9
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    • 2004
  • This research surveys the threadline instability on the belt texturing machine according to the 1st heater temperature, draw ratio and velocity ratio. the threadline instability to the time, which is called surging phenomena, is analysed with variations of draw ratio and velocity ratio. In addiction, the surging phenomena is investigated with the variation of the untwisting tension and false twist mechanism on the belt texturing machine. The breaking strain, modulus and yam unevenness of the DTY along the yarn length are measured and analysed with the surging phenomena which is due to untwisting tension variation on the threadline according to the draw ratio, 1st heater temperature and velocity ratio.

A Study on Control System for Balancing a Boom of Self-Propelled Boom Sprayer (수도작용 붐 방제기의 수평제어장치 개발에 관한 연구)

  • 정창주;노현권;최영수;장영창
    • Journal of Biosystems Engineering
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    • v.22 no.2
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    • pp.151-162
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    • 1997
  • Chemical application is one of the most important field operation in rice production. Rolling of a boom due to local unevenness and softness in fields causes a local under/over-application of spray. In this study, the vertical movement of boom tips due to unevenness of ground in paddy fields was investigated, and an active pendulum suspension control system was designed and tested for compensating the movement and balancing the boom to the ground. The results for testing the performance of the control system showed that the system could balance the boom both in flat and inclined fields. The active pendulum control system developed in this study could be properly used for improving spraying performance of a boom sprayer.

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Impact of Fiber Projection from GMT-Sheet Moldings on Surface Unevenness (GMT-Sheet 성형품의 표면요철에 미치는 섬유돌출의 영향)

  • Kim, Hyoung-Seok;Kim, Jin-Woo;Kim, Yong-Jae;Lee, Dong-Gi
    • Composites Research
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    • v.24 no.6
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    • pp.31-36
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    • 2011
  • According to the evaluation on GMT-sheet by molding conditions, fiber projection on the moldings surface was investigated. Fiber projection is one of the major defects on moldings surface due to matrix shrinkage. That is, fiber projection happens from different shrinkage of matrix and glass fiber. Height of fiber projection from moldings surface becomes smaller when molding pressure is higher during holding pressure and cooling process. Height of fiber projection is dominantly affected by molding pressure. With consideration of molding pressure, the formation of surface unevenness and change in fiber projection height was elucidated. In addition, coating layer is effective to suppress surface defects, and there is no fiber projection or crack in case that coating is applied. Coating layer improves surface roughness up to the level of the polypropylene which is a single material.

Effects of Molding Condition on Surface Unevenness of GFRP Composites in Compression Molding (GFRP 복합재료의 압축성형에서 표면요철에 미치는 성형조건의 영향)

  • Kim, Hyoung-Seok;Kim, Jin-Woo;Kim, Yong-Jae;Lee, Dong-Gi
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.11
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    • pp.1649-1657
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    • 2010
  • We have investigated the unexpected phenomena on the surface of molded GFRP composites. The major cause of the unevenness, as a result of which the surface becomes rough, is a shrinking of the matrix in the process of holding pressure and cooling temperature. The higher holding pressure load in a molding process and the lower demolding temperature in an annealing experiment, the better GFRP composites moldings improved its appearance. In addition, by taking the holding pressure and demolding temperature into consideration, we evaluate the process that causes the surface unevenness and the variation in the fiber projection height.

Real-Time Water Wave Simulation with Surface Advection based on Mass Conservancy

  • Kim, Dong-Young;Yoo, Kwan-Hee
    • International Journal of Contents
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    • v.4 no.2
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    • pp.7-12
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    • 2008
  • In this paper, we present a real-time physical simulation model of water surfaces with a novel method to represent the water mass flow in full three dimensions. In a physical simulation model, the state of the water surfaces is represented by a set of physical values, including height, velocity, and the gradient. The evolution of the velocity field in previous works is handled by a velocity solver based on the Navier-Stokes equations, which occurs as a result of the unevenness of the velocity propagation. In this paper, we integrate the principle of the mass conservation in a fluid of equilateral density to upgrade the height field from the unevenness, which in mathematical terms can be represented by the divergence operator. Thus the model generates waves induced by horizontal velocity, offering a simulation that puts forces added in all direction into account when calculating the values for height and velocity for the next frame. Other effects such as reflection off the boundaries, and interactions with floating objects are involved in our method. The implementation of our method demonstrates to run with fast speed scalable to real-time rates even for large simulation domains. Therefore, our model is appropriate for a real-time and large scale water surface simulation into which the animator wishes to visualize the global fluid flow as a main emphasis.