• Title/Summary/Keyword: Length to width ratio

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Stress Intensity Factors of Combined Mode(Mode I/II) Crack in a Variable Thickness Plate (두께가 변화하는 부재 내의 혼합모드(모드 I/II) 균열의 응력확대계수)

  • 조명래;양원호;최용식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.8
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    • pp.1875-1882
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    • 1993
  • Variable thickness plates are commonly used as structural members in the majority of industrial sectors. Previous fracture mechanics researches on variable thickness plates were limited to mode I loading cases. In practice, however, cracks are usually located inclined to the loading direction. In this respect, combined mode(mode I/II) stress intensity factors $K_{I}$ and $K_{II}$ at the crack tip for a variable thickness plate were obtained by 3-dimensional finite element analysis. Variable thickness plates containing a slant edge crack were chosen. The parameters used in this study were dimensionless crack $length{\lambda}$, slant $angle{\alpha}$, thickness $ratio{\beta}$ and width ratio{\omega}$. Stress intensity factors were calculated by crack opening displacement(COD) and crack sliding displacement(CSD)method proposed by Ingraffea and Manu.

A Study of the Young Aged Women′s Bust (청년기 여성의 상반신 체형 연구)

  • 엄정옥;문명옥
    • Journal of the Korean Society of Costume
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    • v.50 no.5
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    • pp.117-130
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    • 2000
  • The purpose of this thesis is to offer basic data for clothing design which is intended to apply appropriate shape and capacity to clothes. The following are the analyzed results of an investigation which was conducted to characterize the upper half of the female body of 193 women whose ages are 18 to 25, taking part in this investigation. According to the results of analyzing young women's bust, I came to find a large individual difference of the wide varying factor numbers at the items of the side feature, the body stance, and the dart quantity. For the analysis of the female's upper body, 11 factors are used. The are as follows: Factor 1. width of the bust Factor 2. height of the bust and length of the arm Factor 3. side thickness of the bust and the upside type Factor 4. length of the bust on the front Factor 5. length of the bust on the back Factor 6. salient ratio of the breast Factor 7. width of the neck. the armhole, and measurement of the droop Factor 8. length of the shoulder Factor 9. flat ratio of the bust Factor 10. inclination of the shoulder factor 11. form of the back The shape of young women's upper bodies can be divided into four groups. The character ization of each group are as follows : Group 1 . 28.5% of the women who take part in this investigation belong to Group 1 These women have the shortest body, with a longer length of the front than the back and more thickness on the front than the back. Group 2. 21.1% of the women who take part in this investigation belong to this group. They show a longer length of the back and more thickness of the back than the front. In addition, this group is bent forward. Group 3. This group is the mast common type, showing the shortest and thickest character. 37.8% of the women who take part in this investigation have this bust character Group 4. 12.4% of the women belong to Group 4. They possess the highest and fattest character, skewing smaller necks, armholes, and waists than the other groups. This group also shows the drooping shoulders.

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Relationship between morphological characteristics and hand emotional quotient of hands (손의 형태학적 특성과 손감성지수와의 상관관계)

  • Jeong, Eun-Young;Ryu, Hee-Wook
    • Science of Emotion and Sensibility
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    • v.13 no.4
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    • pp.769-776
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    • 2010
  • The relationship between morphological characteristics and sensibility of hands for beautiful hands were investigated for college woman in early twenties. Hand Emotional Quotient (HEQ) which is classified as 10 grades was newly suggested as one of the sensibility evaluation methods for the beautiful hands and was applied to assess the qualitative and quantitative relationships between morphological characteristics and HEQ. The factors influenced on the HEQ were in order as width-length ratio of hands, finger length-hand length and finger width-hand length ratios. Otherwise the influences of hand length-nail length and finger length-nail length ratios on HEQ were insignificant. The longer length of hand, finger, and nail and the narrower width of hand and finger, the higher HEQ hands get. In conclusion, it is found that all morphologic characteristics of hands influenced on the sensitivity synthetically. The data constructed on the hand's sensibility is very useful for various beauty products and service areas related to hands.

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The study of combustion characteristics and emissions with the variation of design factor on slit gas burner (슬릿버너에서 형상변화가 연소특성 및 배기배출물에 미치는 영향)

  • Kim, Tae-Woo;Cho, Seung-Wan;Chang, Young-June;Jeon, Chung-Hwan
    • 한국연소학회:학술대회논문집
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    • 2005.10a
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    • pp.314-319
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    • 2005
  • In this study, the combustion characteristics were investigated with the variation of design factors on multiple slit gas burner. The design factors consist of slit height, width, spacing, and inner length. The combustion characteristics were made analysis of the CO emission and NOx emission by using CO analyzer and NOx analyzer. The lower perimeter to area and the narrow spacing extends the lift-flame limit. The CO emission increases with the increasing perimeter to area ratio at the same condition. The NOx emission is found to be less significant with the port perimeter to area ratio. The flame interference might highly depend on the spacing and port perimeter to area ratio, and it also affects the burner performance.

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Optimization of a 3-D Thermally Asymmetric Rectangular Fin

  • Gang, Hyeong-Seok
    • Journal of Mechanical Science and Technology
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    • v.15 no.11
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    • pp.1541-1547
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    • 2001
  • The non-dimensional fin length for optimum heat loss from a thermally asymmetric rectangular fin is represented as a function of the ratio of the bottom surface Biot number to the top surface Biot number, fin tip surface Biot number and the non-dimensional fin width. Optimum heat loss is taken as 98% of the maximum heat loss. For this analysis, three dimensional separation of variables method is used. Also, the relation between the ratio of the bottom surface Biot number to the top surface Biot number and the ratio of the right surface Biot number to the left surface Biot number is presented.

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The Effect of Welding Parameters on the Weld Shape in Pulsed GTA Welding of a STS304L Stainless Steel Capsule (STS304L 캡슐의 펄스형 GTA 용접에서 용접변수들이 용접부 형상에 미치는 영향)

  • Lee, Hyoung-Keun;Han, Hyon-Soo;Son, Kwang-Jae
    • Journal of Welding and Joining
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    • v.25 no.5
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    • pp.64-71
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    • 2007
  • The aim of this paper is to investigate the effects of welding parameters on the weld shape in seal-welding of STS304L capsule for manufacturing a radioisotope source which is widely used in nondestructive testing of metal structures using gamma ray. Pulsed gas tungsten arc (Pulsed GTA) welding is performed for thin cross sectional area of the capsule. Seven welding parameters including current waveform parameters and arc length etc. are selected as main process parameters using design of experiment. The weld shape such as bead width, penetration depth, weld area, aspect ratio and area rate is investigated to assess the effects of welding parameters. As results, the combination of pulse duty/welding speed largely affects on bead width, penetration depth, area and aspect ratio. Finally, it is concluded that the key parameters are the combination of pulse duty/welding speed, base current and arc length, and their optimal conditions are 50%/1.77mm/s, 6.4A and 1 mm.

Seed Pelletizing of Salvia splendens and Calendula officinalis for the Greening and Re-vegetating (녹화와 식생조성을 위한 샐비어와 금잔화 종자의 펠렛처리)

  • Kim, Seung-Hyun;Lee, Byoung-Ryong;Choi, Byoung-Kon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.10 no.5
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    • pp.67-75
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    • 2007
  • The purpose of this study was to pelletize to calendula and salvia seeds with peat moss as basic material for the efficient greening and vegetating of slopes and damaged areas. Also the pelletizing was compressed by spherical types that mixed basic fertilizer of N.;300 mg/l, P.;200 mg/l, K.;400 mg/g and plant growth regulator of A and NAA each 300PPM. Soil and soil surface seeding methods were researched to find the growing state of germination percent, germination date, germination force, length of leaf, number of leaf, width of leaf, length of plant, and etc. Comparing with controlled pelletizing, peat moss and +GA pelletizing treatments resulted in higher from two to three times as following growing states : length of leaves, number of leaves, width of leaves, length of plants, length of roots, fresh weights, and ratio of germination. Especially the two treatments above showed four more times effects than the +NNA treatment. Also their germinating date germinating force were earlier and stronger. The surface seeding method was superior to soil seeding.

Comparative Anatomy of Diffuse-Porous Woods Grown in Korea(II) -Characteristics by Habit and Phenology- (한국산(韓國産) 산공재(散孔材)의 해부학적(解剖學的) 특성(特性)에 관한 비교연구(比較硏究)(II) -Habit과 Phenology에 따른 특성(特性)-)

  • Chung, Youn-Jib;Lee, Phil-Woo
    • Journal of the Korean Wood Science and Technology
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    • v.24 no.1
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    • pp.1-10
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    • 1996
  • The frequency distribution diagrams of Korean diffuse-porous woods, 36 families, 75 genera, 145 species, 215 specimens in relation to habit and phenology were analyzed. As the habit character changes from shrub to tree, such quantitative features as vessel frequency, percentage of solitary vessels, length/diameter(L/D) ratio of vessel element decreased but tangential vessel diameter, fiber length/vessel element length(F/V) ratio increased. Qualitative features such as helical vessel wall thickening, diffuse distribution of longitudinal parenchyma, heterogeneous ray composition decreased, while alternate intervessel pits, libriform wood fiber, simple perforations increase. As the phenology character changes from evergreen to deciduous species, such quantitative features as percentage of solitary vessels, vessel element length and L/D ratio decreased but tangential vessel diameter, F/V ratio increased. Diffuse distribution of longitudinal parenchyma, heterogeneous ray composition, and crystals in qualitative features decreased, while alternate intervessel pits, libriform wood fiber, simple perforation of vessel element, ray width and ray height increased.

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Flexural Fracture Behavior of Reinforced Concrete Beam Based on Fracture Mechanics Approach (파괴역학에 근거한 철근콘크리트 보의 휨 파괴거동)

  • 어석홍;최덕진;홍기호;김희성
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.10a
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    • pp.149-154
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    • 2002
  • An analytical fracture mechanics approach was used to investigate the fracture behavior of reinforced concrete beams. By use of this approach based on fracture mechanics concepts, the crack width and length as well as the strength and cracking stability of reinforced concrete beams were investigated. The results obtained from the analytical studies were also discussed in terms of the minimum reinforcement ratio and crack width specified in design code provisions. The analytical approach based on fracture mechanics concepts are very useful to predict the fracture behavior of reinforced concrete beams.

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The Study on Flame Structure and NOx Emissions by Swirl Numbers and Fuel-Air Mixing Length in a Dump Combustor Gas Turbine (모형 가스터빈 연소기에서의 스월수와 혼합길이에 따른 화염구조와 NOx배출에 관한 실험적 연구)

  • Choi, Do-Wook;Kim, Gyu-Bo;Jeon, Chung-Hwan;Song, Ju-Hun;Chang, Young-June
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.33 no.11
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    • pp.849-857
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    • 2009
  • The experimental study was performed to investigate the effects of partial premixing, varying the equivalence ratio, mixing degree, swirl intensity, mixing length on the characteristics of flame structure and NOx emission. Experiments were conducted in a dump combustor at 1 bar using methane as fuel. Inlet air temperature was 570K. OH chemiluminescence images were acquired with an ICCD camera. As a result of the experimental investigation of characteristics of flame and NOx emission in partial premixed combustor, we can conclude the results as below. With the increase of swirl number, The flame length decreases and the flame width increases and it helps flame stabilization. It means that lean flammability limit is extended. With the increase of mixing of fuel-air length ratio, Flame goes to be stabilized and NOx emission and $OH^{\ast}$ intensity decrease. Through the comparison of preceding results, It is possible that the exhausted NOx emission from a gas turbine combustor will be able to predict through the $OH^{\ast}$ intensity.