• Title/Summary/Keyword: Pattern Density

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Calculation of Critical Current Density Degradation in the HTS Magnet due to Mechanical Strain (고온초전도마그네트 내부의 스트레인에 의한 임계전류밀도 감소 계산)

  • Lee, In-Kyu;Nah, Wan-Soo
    • Proceedings of the KIEE Conference
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    • 1997.07a
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    • pp.260-263
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    • 1997
  • In this paper, we describe the mechanical strain effects on the critical current density of HTS (BSCCO) pancake-type-magnet. Firstly the strain of pancake coil is calculated in terms of coil length, which is also a function of angle, and then the critical current density degradation due to strain is calculated along the coil. We assumed that the critical current density degradation pattern is same with that of $Nb_{3}Sn$. We also modelled the effects of magnetic field on the critical curent degradation, and the results are compared with those with null magnetic field.

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Effect of Current Density and Solution pH on Properties of Electrodeposited Cu Thin Films from Sulfate Baths for FCCL Applications (Sulfate 용액을 이용하여 전기도금 한 FCCL용 Cu 필름의 특성에 미치는 전류밀도와 pH의 영향)

  • Shin, Dong-Yul;Park, Doek-Yong;Koo, Bon-Keup
    • Journal of the Korean institute of surface engineering
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    • v.42 no.4
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    • pp.145-151
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    • 2009
  • Nanocrystalline Cu thin films for FCCL were electrodeposited from sulfate baths to investigate systematically the influences of current density, solution pH on current efficiency, residual stress, surface morphology, and microstructure of thin Cu films. Current efficiencies were measured to be approximately 100%, irrespective of the applied current density and solution pH. But these influenced residual stress, surface morphology, XRD pattern, and grain size of electrodeposited Cu thin film. The residual stress decreased with decreasing the surface roughness, but increased with increasing the fcc(111) peak strength of XRD patterns.

Spatial Distribution Pattern of Beet Armyworm, Spodoptera exigua(Hubner), Larvae in the Welsh Onion Field (파 포장에서 파밤나방 유충의 공간분포)

  • 고현관;최재승;엄기백;최귀문;김정화
    • Korean journal of applied entomology
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    • v.32 no.2
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    • pp.134-138
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    • 1993
  • Larval densities and spatial distribution patterns of beet armyWorm, Spodoptera exigua, were studied in the welsh onion field located in Asan from June to November, 1991. During the period, there were two denslty-peaks;mid August and mid~late September. The larvae showed clumped distribution patterns. but the patterns changed into random as larval density decreased in Oct.ober. Each larval instar showed clumped pattern expect 6th instar surveyed on September 25, which distributed in a random pattern. The larval distribution pattern were also influenced by the host plants;clumped pattern on such host. as red pepper and welsh onion, versus random pattern on such hosts as chrysanthemum, peanut and soybean.

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Improvement of Test Method for t-ws Falult Detect (t-ws 고장 검출을 위한 테스트 방법의 개선)

  • 김철운;김영민;김태성
    • Electrical & Electronic Materials
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    • v.10 no.4
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    • pp.349-354
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    • 1997
  • This paper aims at studying the improvement of test method for t-weight sensitive fault (t-wsf) detect. The development of RAM fabrication technology results in not only the increase at device density on chips but also the decrease in line widths in VLSI. But, the chip size that was large and complex is shortened and simplified while the cost of chips remains at the present level, in many cases, even lowering. First of all, The testing patterns for RAM fault detect, which is apt to be complicated , need to be simplified. This new testing method made use of Local Lower Bound (L.L.B) which has the memory with the beginning pattern of 0(l) and the finishing pattern of 0(1). The proposed testing patterns can detect all of RAM faults which contain stuck-at faults, coupling faults. The number of operation is 6N at 1-weight sensitive fault, 9,5N at 2-weight sensitive fault, 7N at 3-weight sensitive fault, and 3N at 4-weight sensitive fault. This test techniques can reduce the number of test pattern in memory cells, saving much more time in test, This testing patterns can detect all static weight sensitive faults and pattern sensitive faults in RAM.

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Dependence of Sliding Friction Properties on the Angle of Laser Surface Texturing for a Grooved Crosshatch Pattern Under Grease Lubrication (그리스 윤활하에서 레이저 표면 텍스쳐링된 그루브 빗살무늬 패턴의 사잇각에 따른 미끄럼 마찰특성 평가)

  • Kong, Minseon;Chae, Younghun
    • Tribology and Lubricants
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    • v.38 no.6
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    • pp.261-266
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    • 2022
  • Notably, laser surface patterning facilitates tribological applications under lubricated sliding contacts. Consequently, a special pattern that can reduce the coefficient of friction under contact is considered necessary for improved machine efficiency. However, inappropriate pattern designs produce higher friction coefficients and cannot reduce friction. In this study, we use cast iron pins as specimens to investigate their friction and wear characteristics. Moreover, we experimentally investigate the correlation between the friction reduction effect and the design of groove crosshatch patterns fabricated with various angles and widths. We conduct a friction test using a pin-on-disc type tribometer under grease lubrication to study the friction reduction effect of the specimens, and we observe that the average coefficient of friction changes with the crosshatch angle and width. The experiment reveals that grooved crosshatch specimens with a crosshatch angle of 135°maximize friction reduction. The coefficient of friction of the groove specimens with a width of 120 ㎛ is lower than that of the specimens with a width of 200?. The friction reduction effect of the width of the groove is attributed to the density of the groove pattern. Thus, grooved crosshatch patterns can be designed to maximize friction reduction, and the friction property of a grooved crosshatch pattern is found to be related to its width and angle.

Evaluation of the Nutritional Value of Traditional Korean Noodles through Energy Density and Diversity (에너지 밀도 및 다양성 측면의 전통 면류의 영양적 가치 평가에 관한 연구)

  • Yang, YoonKyoung;Kim, SungOk;Kim, Juhyeon
    • The Korean Journal of Food And Nutrition
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    • v.27 no.4
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    • pp.732-741
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    • 2014
  • Korean foods have the strengths to addresssome of the health problems of modern man. To assess the properties of Korean noodles, daily value %, DVS, DDS and energy density were compared between many kinds of noodles from around the world. Using a variety of reference materials, a nutritional database of noodles was built for this study. For carbohydrate, lipid, vitamin A, vitamin K, vitamin C, niacin, zinc, and copper, the daily values % of western noodles were significantly higher. Also, the serving size of Korean noodles was significantly small. Comparing the average energy density of the noodles, they showed $1.87{\pm}0.93kcal/g$ (Korean noodles), $2.42{\pm}1.08kcal/g$ (western noodles) and $1.84{\pm}0.84kcal/g$ (other noodles). The dietary fiber, polyphenols, and flavonoids content of the noodles showed no significant difference. Neither DVS nor DDS showed a statistically significant difference. In the Korean noodles, the GMDFV pattern showed a diverse choice of food groups. Korean noodles show a lower energy density, and the small serving size to have favorable for the prevention of obesity. Thus, Korean noodles are an excellent choice in terms of diversity and energy density.

Studies on the Acoustical Characteristics of Violin Bridges and SDM Simulation (바이올린 브릿지의 음향적 특성 및 SDM 시뮬레이션에 관한 연구)

  • 정우양
    • Journal of the Korea Furniture Society
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    • v.12 no.1
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    • pp.47-55
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    • 2001
  • Violin bridge blank cut from maple wood with good quality has typical pattern of the radial direction in the side edge with minimal dispersion. This experimental study was designed and carried out to examine the effect of the physical and macroscopical characteristics on the compressive creep of violin bridge blank which had been imported from European manufacturer. This research arose from the idea that the maple solid wood with heterogeneous wood density and ray direction in the side edge would have uneven rheological property of violin bridge blank which is supposed to be pressed by the tension of strings. Experimentally, the compressive creep of bridge blank became smaller with the higher density of imported maple wood and showed clear density-dependence for the duration of load under the string tension of 5 kgf. Every bridge blank showed the behavior of primary creep stage(stress stabilization) having logarithmic regression creep curve with high correlation coefficient under the designed stress level. Even though the relationship between compressive creep and ray direction on the side edge of bridge was not so clear contrary to expectation, we could conclude that wood density and ray direction should be the quality decisive factors affecting the acoustical characteristics and performance of the bridge, the core member of violin-family bow instruments.

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Friction Characteristics of W100×L25 Micro Ellipse Type Pattern (W100×L25 마이크로 타원형 딤플패턴의 마찰특성)

  • Choi, Won-Sik;Kwon, Soon-Hong;Chung, Sung-Won;Kwon, Soon-Goo;Park, Jong-Min;Kim, Jong-Sun;Park, Dae-Young;Chae, Young-Hoon
    • Tribology and Lubricants
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    • v.28 no.3
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    • pp.136-141
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    • 2012
  • In this paper, we investigated the friction characteristics of $W100^{\circ}{\o}L25m$ ellipse type surface pattern, on bearing steel. These characteristics are researched by utilizing a pin-on-disk wear test machine, under various velocities and other conditions. The reduction of friction is a necessary requirement for the improved efficiency of industrial parts. As the speed increases, there is a decrease in the effect of the dimple of friction characteristic in low velocity, with substantially little change to density. Conversely, as the load increases, the test direction of ellipse type dimple pattern, resulting in a difference in the texture of these two components. At a dimple density of 7.5% the friction characteristic is easily demonstrated, with a consistent change in both speed and load.

Analysis of the operation effciency with the application of fabirc design CAD system (직물설계 CAD System활용에 따른 작업성 분석)

  • Kim, Hee-Sam;Kim, Mi Sun;Lee, Young Hee
    • Journal of the Korean Society of Industry Convergence
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    • v.8 no.1
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    • pp.11-17
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    • 2005
  • This study was performed to analysis the operation process when fabric pattern design was done by the use of CAD system compared with the manual work in order to determine the operation efficiency with the application of fabric design CAD system. The results of the study were as follows: 1. since 160,000 colors were supported by CAD system, color proposed by consumer was able to match exactly according to the its design. However, exact color matching was not possible by manual work. 2. Woven state of back of pattern design could be identified simultaneously with face of it for CAD system, while face and back of the fabrics should be designed separatedly in case of manual work. 3. Since the combination of warp and filling yarn was compatible with the fabric density in one repeat unit in CAD system, exact size of pattern design to be woven was able to expressed. 4. Only simple graphical expression by manual work was seen, while with the CAD system, texture and shade effect as well as graphical expression could be expressed and so fault could be reduced in advance with the simulation of actual feeling of fabrics in the screen. In conclusion, when CAD system will be introduced to the textile industry, operation time of designing pattern can be reduced. Since the operation is easy and simple, a beginner can operate CAD system easily. Thus, production and wage costs can be saved and this can be related directly with the improvement of productivity which is the main purpose of introducing CAD system.

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Fault Diagnosis Method for Automatic Machine Using Artificial Neutral Network Based on DWT Power Spectral Density (인공신경망을 이용한 DWT 전력스펙트럼 밀도 기반 자동화 기계 고장 진단 기법)

  • Kang, Kyung-Won
    • Journal of the Institute of Convergence Signal Processing
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    • v.20 no.2
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    • pp.78-83
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    • 2019
  • Sounds based machine fault diagnosis recovers all the studies that aim to detect automatically abnormal sound on machines using the acoustic emission by these machines. Conventional methods that use mathematical models have been found inaccurate because of the complexity of the industry machinery systems and the obvious existence of nonlinear factors such as noises. Therefore, any fault diagnosis issue can be treated as a pattern recognition problem. We propose here an automatic fault diagnosis method of hand drills using discrete wavelet transform(DWT) and pattern recognition techniques such as artificial neural networks(ANN). We first conduct a filtering analysis based on DWT. The power spectral density(PSD) is performed on the wavelet subband except for the highest and lowest low frequency subband. The PSD of the wavelet coefficients are extracted as our features for classifier based on ANN the pattern recognition part. The results show that the proposed method can be effectively used not only to detect defects but also to various automatic diagnosis system based on sound.