• Title/Summary/Keyword: Uneven

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A springback analysis of LCD TV bottom chassis (LCD TV BOTTOM CHASSIS 스프링백 해석)

  • Lee, Sung-Geun;Jung, Jin-Oh;Kim, Seung-Kyu;Chung, Wan-Jin
    • Design & Manufacturing
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    • v.6 no.1
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    • pp.63-66
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    • 2012
  • In the manufacturing of a LCD TV bottom chassis, the distortion after forming should be suppressed below pre-defined amount to avoid contact with electric components. Finite element analysis procedure of forming and springback of a LCD TV bottom chassis is developed to investigate the distortion behaviour. It is shown that after the first forming large distortion occur due to uneven metal flow induced by various embossings. In the second forming, distortion is decreased by introducing bead that absorbs the excessive metal flow. It is proved that analysis method could describe these behaviour effectively. The developed analysis method can be used to find the proper location and shape of bead more quickly and effectively.

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A Study on the Fabric Drape Evaluation Using a 3D Scanning System Based on Depth Camera with Elevating Device

  • Kim, Jongjun
    • Journal of Fashion Business
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    • v.19 no.6
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    • pp.28-41
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    • 2015
  • Properties of textile fabrics influence the appearance, aesthetics, and performance of garment. Drape and related properties of fabrics affect profoundly the static and dynamic appearance during wearer's movement. The three dimensional shape of the folded structure often deforms with time or with subtle vibration around the fabric specimen during the drape measurement. Due to the uneven and complex nature of fabrics, the overall shape of the fabric specimen on the drape tester often becomes unstable. There is a need to understand the fundamental mechanisms of how draping may generate pleasing forms. Two drape test methods, conventional Cusick drape test, and in-built drape tester, based on a depth camera, are compared. Fabric specimens including cotton, linen, silk, wool, polyester, and rayon are investigated for the fabric drape and other physical/mechanical parameters. Drape coefficient values of fabric specimens are compared based on the final drape images, together with the intermediate 3D drape images of the specimens during elevation process of the drape tester equipped with a stepper motor system. The correlation coefficient between the data based on the two methods is reasonably high. Another advantage from the depth camera system is that it allows further analysis of three-dimensional information regarding the fabric drape shape, including the shape of nodes or crest and trough.

Mechanical Characteristic of Backsulgi Added with Rich Sources of Phospholipid (인지방질 함유식품 첨가에 따른 백설기의 물성적 특성)

  • 이경아;김경자
    • Korean journal of food and cookery science
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    • v.18 no.4
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    • pp.381-389
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    • 2002
  • The purpose of this study was to select an ingredient acting as a natural emulsifier to retard the retrogradation of rice cake by the measurement of mechanical characteristics of the cakes. For the purpose, Backsulgi, the most basic type of rice cake, was prepared by adding various ingredients having high contents of lecithin such as raw soybean powder, parched soybean powder, soybean oil, egg yolk powder, and the measurements and observations on the chromaticity, swelling power, pore ratio and cross-section were made. In addition, changes in the textural characteristics of Backsulgi samples were determined while storing them at the temperatures of 4$^{\circ}C$ and 20$^{\circ}C$ for 0, 1, 2 and 3 days. The results of the study were as follows: 1. In terms of chromaticity, the Backsulgi samples added with egg yolk powder, raw soybean flour and parched soybean flour were higher in yellowness(b) than the controls. 2. Both swelling power and pore ratio of Backsulgies added with raw soybean flour were higher than those of controls. 3. A cross-sectional observation using an electron microscope indicated that rice flour particles of controls had uneven pores and were conglomerated in a large lump while Backsulgi samples of raw soybean flour or roasted soybean flour had large and even pores and showed loosened bonding to be transformed into a sponge shape. 4. In hardness, Backsulgi samples added with raw soybean flour had less changes in hardness than that of controls, indicating that the effect of retarding retrogradation was higher when the storage time got longer.

Development of Performance Evaluation and Control System of Multi-Air Conditioner (멀티에어컨의 성능평가 및 제어시스템 개발에 대한 연구)

  • Lee H.W.;Ko K.W.;Gwon Yeong-Cheol;Lee J.H.;Lee Y.J.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1107-1114
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    • 2005
  • The running condition of multi-system air conditioner is prone to vary largely as it is designed for individual conditioning in each space of middle and small sized buildings. This leads to overcooling in case of partial load run, while the lack of capacity happens in case of full load run. Besides these, there exist such problems as instabilities due to the uneven refrigerant distribution caused by fluctuation of load and the change in piping line. Based upon the basic study on the function characteristics found in parts needed for maximized system working design in order to troubleshoot, the system functioning pattern should be identified through the different tests with various operating circumstances and the analysis models should be developed. With this ground, the control logic has to be made to have a control over capacity and make possible the efficient distribution of refrigerant.

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Photographical observation of mulberry fruits (Morus sp.) during ripening

  • Ju, Wan-Teak;Kweon, HaeYong;Kim, Hyun-Bok;Jo, You-Young;Kim, Yong-Soon;Koo, Bonwoo
    • International Journal of Industrial Entomology and Biomaterials
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    • v.41 no.1
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    • pp.11-14
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    • 2020
  • This work was preliminary report on the shape of mulberry fruits and mulberry flowers. The shape of mulberry was varied with mulberry cultivars as bended oval shape (Daeshim), oval shape (Gwasang No. 2), oval-cylindrical shape (Sagyeppong), uneven heart shape (Suwonppong), and roundish shape (Cheonggangsang). The style of female flowers was also varied with cultivars as no style (Palchung), short style (Gwasang No. 2), cone style (Susungppong), and rectangular style (Daedangsang). This observation suggested that the shape and flower of mulberries are different among mulberry cultivars. It needs to further systematic study to know the shape and flower of mulberry cultivars and to elucidate the relationship between the morphological characters and mulberry cultivars.

Experimental Study of Braking Friction and Wear Characteristics of Disk Brake (디스크 브레이크의 제동마찰 및 마멸특성에 관한 실험적 연구)

  • Kim Chung-Kyun;Lee Boung-Kwan;Kim Han-Goo
    • Tribology and Lubricants
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    • v.22 no.3
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    • pp.149-154
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    • 2006
  • This paper presents the braking friction and wears on the rubbing surfaces of a friction pad-disk brake. In this study, four friction disk specimens are sampled from unused and used disks in which are taken from the disk brake system when the friction induced vibration and noise problems have been occurred during a braking period at a running period of 10,000 km, 20,000 km, and 30,000 km in random. The experimental results indicate that the tribological characteristics of an unused disk brake shows equal and stable as a friction coefficient and temperature distributions during a braking friction/wear test period including a total friction mode from the start to running periods. But the used disk brake shows unstable and uneven friction modes between an outside and inside rubbing surfaces of a disk brake in terms of a friction coefficient and wears. This may lead to a friction induced friction vibration and noise problems of a used disk brake.

Wear Characteristics of Automotive Disc Brakes: Effect of Gray Cast Iron Microstructures (자동차 브레이크용 디스크의 미세조직에 따른 편마모 특성에 관한 연구)

  • Lee, Jae-Young;Kim, Seong-Jin;Han, Chang-Joo;Jang, Ho
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2002.05a
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    • pp.235-239
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    • 2002
  • The objective of the experiment is to investigate the effect of microstructures of gray cast iron oil wear characteristics of automotive disc brakes. Six different gray cast iron rotors were manufactured by changing carbon equivalent and cooling rate. The change of DTV (disc thickness variation) before and after wear tests was measured to examine the wear properties according to the microstructures of gray iron discs since the DTV generation is caused by the circumferential uneven wear. Experimental results showed that the morphology of graphite flake and hardness in gray cast iron were crucially associated with the change of DTV. In particular, the DTV changes of rotor decrease when the length and area fraction of graphite flake in brake rotors increase and hardness of brake discs reduces.

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Effect of Power Mode of Plasma Anodization on the Properties of formed Oxide Films on AZ91D Magnesium Alloy

  • Lee, Sung-Hyung;Yashiro, Hitoshi;Kure-Chu, Song-Zhu
    • Korean Journal of Materials Research
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    • v.28 no.10
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    • pp.544-550
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    • 2018
  • The passivation of AZ91D Mg alloys by plasma anodization requires deliberate choice of process parameters due to the presence of large amounts of structural defects. We study the dependence of pore formation, surface roughness and corrosion resistance on voltage by comparing the direct current (DC) mode and the pulse wave (pulse) mode in which anodization is performed. In the DC plasma anodization mode, the thickness of the electrolytic oxide film of the AZ91D alloy is uneven. In the pulse mode, the thickness is relatively uniform and the formed thin film has a three-layer structure. The pulse mode creates less roughness, uniform thickness and improved corrosion resistance. Thus, the change of power mode from DC to pulse at 150 V decreases the surface roughness (Ra) from $0.9{\mu}m$ to $0.1{\mu}m$ and increases the corrosion resistance in rating number (RN) from 5 to 9.5. Our study shows that an optimal oxide film can be obtained with a pulse voltage of 150 V, which produces an excellent coating on the AZ91D casting alloy.

The effect of particle size on the determinability of maize composition in reflection mode.

  • MVaradi, Maria;Turza, Sandor
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1129-1129
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    • 2001
  • Maize, in Hungary, is the fodder-plant grown in the biggest quantity. It is not only used as a fodder but other products such as iso-sugar are made from it, too. The quality of the fodder and the produce is largely dependent on the composition of the supplied maize to the processing site. The examination of quality parameters besides conventional methods are investigated and measured by NIR spectroscopy on a routine basis. The investigated parameters are the following: water, total protein, starch and oil content. The accuracy and precision of determining these parameters we, apart from the wet chemical methods, influenced by sample preparation to a great extent. One of the main features of this is the sample particle size and its distribution across the sample. The uneven distribution of particle size negatively influences the measurement accuracy, decreases model robustness and prediction ability. With these in mind the aim of our experiment was to investigate the effect of particle size on the accuracy of maize composition determination using reflection measurement setup. In addition, we tested different spectrum transformations, which are suitable for canceling this effect. In our experiment 47 samples were analyzed with three different mesh sizes (1.5mm, 1.8mm and 2mm). The results of our findings are presented here.

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A Comparative Analysis of Demonstratives: based on Korean, English, Spanish and Russian text (지시사 대조연구)

  • 김명자;채숙희;조은영
    • Korean Journal of Cognitive Science
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    • v.15 no.1
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    • pp.13-24
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    • 2004
  • This paper deals with the anaphoric usage of demonstratives when they refer to what are already mentioned in the context. We examine syntactic, semantic and pragmatic factors that contribute to the choice of demonstratives. As for anaphoric usage, English and Spanish show the even distribution between proximal and distal demonstratives with the meaning of their deictic counterparts. Korean and Russian, however, show the uneven distribution of the more prevalent form (unmarked on) and the lesser one (market one). This study aims at a typological explanation for the anaphoric usage of demonstratives through comparison and contrast with such factors as the distance to the antecedent, cognitive status, psychological distance and the center of attention.

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