• Title/Summary/Keyword: Cutting Region

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Analysis of Cutting Characteristic of the Sapphire Wafer Using a Internal Laser Scribing Process for LED Chip (LED 칩 제조용 사파이어 웨이퍼 절단을 위한 내부 레이저 스크라이빙 가공 특성 분석)

  • Song, Ki-Hyeok;Cho, Yong-Kyu;Kim, Byung-Chan;Kang, Dong-Seong;Cho, Myeong-Woo;Kim, Jong-Su;Ryu, Byung-So
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.9
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    • pp.5748-5755
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    • 2015
  • Scribing is cutting process to determine production amount and characteristic of LED chip. So it is an important process for fabrication of LED chip. Mechanical process and conventional scribing process with laser source has several problems such as thermal deformation, decreasing of material strength and limitation of cutting region. To solve these problems, internal laser scribing process that generates void in wafer and derives self-crack has been researched. However, studies of sapphire wafer cutting by internal laser scribing process for fabrication of LED chip are still insufficient. In this paper, cutting parameters were determined to apply internal laser scribing process for sapphire wafer for fabrication of LED chip. Then, foundation of cutting condition was established to set up internal laser scribing system through investigation of cutting characteristics by several experiments.

Study on the Application of Patterns of Xuzhou Paper-cut in Cultural and Creative Product Design (쉬저우(徐州) 지엔즈(剪紙) 문양(紋樣)의 문화 창작물 제품 디자인 적용에 관한 연구)

  • Hao Pei Pei;Lee Jin Wook
    • Smart Media Journal
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    • v.12 no.11
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    • pp.211-221
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    • 2023
  • In the context of integration of culture and tourism, the effective application of folk art in cultural creative products is of great significance to the development of local cultural industry. Xuzhou paper-cutting is the only world-class intangible cultural heritage project in the northern Jiangsu region of China. Its high humanistic value and artistic characteristics are widely used in modern art design. The application of cultural and creative products relative to paper-cutting in Xuzhou mainly focuses on two-dimensional decorative and ornamental products, which is short of diversity in form and not practical. In addition, it doesn't meet the aesthetic needs of living of modern people, This article studies paper-cut works by Wang Guiying and proposes principles for the design of cultural and creative products relative to paper-cutting by analyzing the typical "goose" pattern in Wang's paper cutting handcrafts. By exploring the application value of Xuzhou paper-cutting in cultural and creative product design and demonstrating the feasibility of the design principles via visiting experts, this article hopes to provide some reference for the modern inheritance and innovative development of paper-cutting culture.

Development of Exit Burr Identification Algorithm on Multiple Feature Workpiece and Multiple Tool Path (복합형상 및 다중경로에 대한 Exit Burr 판별 알고리듬의 개발- 스플라인을 포함한 Exit Burr의 해석 -)

  • Kim, Ji-Hwan;Lee, Jang-Beom;Kim, Young-Jin
    • IE interfaces
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    • v.18 no.3
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    • pp.247-252
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    • 2005
  • In the automated production environment in the present days, the minimization of manual operation becomes a very important factor in increasing the efficiency of the production system. The exit burr produced through the milling operation on the edge of workpiece usually requires manual deburring process to enhance the level of precision of the resulting product. So far, researchers have developed various methods to understand the formation of exit burr in cutting process. One method to analytically identify the formation of exit burr was to use the geometrical information of CAD and CAM data used in automated machining. This method, in turn, generated the information resulting from the analysis such as burr type, cutting region, and exit angle. Up to now, the geometrical data were restricted to the single feature and single path. In this paper, a method to deal with the complicated geometric features such as line segment, arc, hole, and spline will be presented and validated using the field data. This method also deals with the complex workpiece shape which is a combination of multiple features. As for the cutting path, multiple tool path is analyzed in order to simulate the real cutting process. All this analysis is combined into a Windows based software and real data are used to validate the program in the conclusion.

Analyses of Shear and Frictional Characteristics in Drilling Process (드릴링 공정의 전단 및 마찰 특성 해석)

  • Kim, Sun-Il;Choi, Won-Sik;Son, Jae-Hwan;Jang, Eun-Suk;Lee, Young-Moon
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.6
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    • pp.22-27
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    • 2012
  • Drilling process is usually the most efficient and economical method of making a hole in a solid body. However, there have been no analytical method to assess drilling process based on the shear and frictional characteristics. In this paper, procedures for analyzing shear and frictional processes of drilling have been established by adopting an equivalent turning system to drilling. A series of drilling experiments were carried out with varying feed, velocity and drill shape factors. Using the results of the experiments, the cutting characteristics including shear in the primary shear zone and friction in the chip-tool contact region of drilling process have been analyzed. The specific cutting energy tends to decrease exponentially with increase of feed rate. In drilling process 35-40% of the total energy is consumed in the friction process. This is greater than that of turning process in cutting of the same work material.

A Case Study on the Stability Analysis of a Cutting Slope Composed of Weathered Granite and Soil (화강풍화암 및 풍화토층 지역 깍기 비탈면의 안정성 검토 사례 연구)

  • Han, Kong-Chang;Ryu, Dong-Woo;Cheon, Dae-Sung;Hong, Eun-Soo
    • Tunnel and Underground Space
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    • v.18 no.4
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    • pp.289-299
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    • 2008
  • Based on the case study on the causes for the failure of cutting slope composed of weathered rock and soil, the factors influencing the design of a cutting slope have been examined, This type of rock and soil is widely distributed on the region whose parent rock is granite. To analyze the stability of the cutting slope, the following series of progress has been conducted: (1) ground characterization by geological survey and ground investigation, (2) the safety factor examination by limit equilibrium analysis and numerical analysis and (3) the comparison and analysis of rainfall and failure history. As a result, the main factors to cause the failure is determined to be the decrease of shear strength in the upper parts whose ground condition is weakened during localized heavy rain. Moreover, the analysis indicates the failure is also closely related to the groundwater inflow path. On the base of this investigation, a reinforcement method is proposed to ensure the stability of the cutting slope.

Method for measuring 3-axis cutting force of a pick cutter using the single-axis load cell array (1축 로드셀 배열을 사용한 픽 커터의 3축 절삭력 측정방법)

  • Kang, Hoon;Jang, Jin-Seok;Park, Jin-Young;Cho, Jung-Woo;Jung, Myeong-Sik;Lee, Jae-Wook
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.9
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    • pp.749-755
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    • 2016
  • A new method for measuring the 3-axis cutting forces of a pick cutter by substituting costly 3-D load cells is proposed in this paper. The proposed cutting force measurement method is capable of estimating the 3-axis cutting forces through mechanical constraints using four single-axis compressive load cells and shoulder bolts. The feasibility of the proposed method was verified by finite element analysis, and the accuracy of the force measurement of the developed force measurement device was investigated by conducting linear rock cutting tests. The tests showed that the new cutting force measurement method is able to measure 3-axis cutting forces with a relative error of approximately 6%. These results imply that the new method could be a suitable alternative to conventional 3-D load cells. In addition, it will allow a significant reduction of approximately 20-30% in the costs required for measuring the cutting force when compared to conventional 3-D load cells.

Yield and Species Composition of Binary Mixtures of Kura Clover with Kentucky Bluegrass, Orchardgrass, or Smooth Bromegrass

  • Kim, B.W.;Albrecht, K.A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.7
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    • pp.995-1002
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    • 2008
  • Kura clover (Trifolium ambiguum M. Bieb.) is a rhizomatous perennial legume that has potential as a forage crop in the North-Central USA because of its excellent persistence under environmental extremes. Little information is available about defoliation effects on productivity of mixtures of kura clover with grasses typically grown in this region. Two field trials were conducted to evaluate the effects of defoliation management on yield and species composition of binary mixtures of 'Rhizo' kura clover with 'Comet' orchardgrass (Dactylis glomerata L.), 'Badger' smooth bromegrass (Bromus inermis Leyss.), 'Park' Kentucky bluegrass (Poa pratensis L.), and solo-seeded kura clover near Arlington, WI. Three harvest schedules (three, four, or five times annually) and two cutting heights (4 or 10 cm) were imposed. Infrequent defoliation and lower cutting height produced significantly greater total forage yield, 6.6, 5.8, and 5.2 Mg/ha in 3-, 4-, and 5-harvest systems, respectively; and 6.5 and 5.2 Mg/ha for the 4- and 10-cm cutting height, respectively. Averaged over 3 yr and two environments, mixtures had higher forage productions than solo kura clover (6.3, 5.7, and 6.0 Mg/ha for the Kentucky bluegrass, orchardgrass, and smooth bromegrass mixtures, respectively; compared to 5.2 Mg/ha for solo kura clover). The proportion of kura clover in mixtures increased from yr 1 to yr 2 and was constant from yr 2 to yr 3 (34, 58, and 57%, respectively). We conclude that kura clover has excellent potential as a long-term component of grass-legume mixtures regardless of the cutting height, harvest frequency or grass species, even though the proportion of kura clover in harvested forage was significantly greater with less frequent harvest and shorter cutting height of all mixtures.

A Study on Shear Resistance Effect along Marginal Region of Sliding Mass using 3D Slope Stability Analysis (3차원 사면안정해석을 이용한 활동지괴 가장자리부의 전단저항에 관한 연구)

  • Seo Yong-Seok;Ohta Hidemasa;Chae Byung-Gon;Yoon Woon-Sang
    • The Journal of Engineering Geology
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    • v.14 no.4 s.41
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    • pp.451-460
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    • 2004
  • The strength of sliding plane is usually assigned on the whole sliding plane with same value in 2D limit equilibrium slope stability method. However, the potential sliding plane is divided into two or three parts which have different sliding resistances. According to the calculation results of 3D slope stability analyses using 4 types of slope cutting models, marginal sliding resistance could affect the safety of slope significantly. In this calculation two kinds of the sliding plane strengths were applied differently to the parts of bottom and margin of the model slope. The effect of marginal resistance was calculated quantitatively. In case of lower sliding resistance of the bottom, the safety factor becomes low in a margin cutting model. However, in case of higher sliding resistance of the bottom, the safety factor decreased slightly in a lower part cutting model and increased in a upper margin cutting model.

A Study on Reinforcing Effect of Multi-Bar Spring Nailing (다철근 스프링 네일링 공법의 보강효과 검토에 관한 연구)

  • Lee, Choong-Ho;Jung, Young-Jin;Kim, Dong-Sik;Chae, Young-Su
    • Journal of the Society of Disaster Information
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    • v.3 no.2
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    • pp.147-169
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    • 2007
  • This study investigates the reinforcing effects of the Multi-bar Spring nails with respect to the conventional Soil-nails in artificial slopes. Based on wide experience related to design and construction, soil nails have been widely applied to reinforce slope in the world. Multi-bar spring nails are one of the improved soil nailing methods. These method maximizes bending, shearing, pull-out resistance for those multi-nails, not unit nail, that are inserted in the borehole using special spacer at regular intervals. In addition, because cutting plane is confined effect resulting from a pressured plate at the end of the nails with compression spring equipment, slope stability is secured using MS-nailing method. Analyzing bending, pull-out, shearing condition of MS-nail, it was examined throughly elastic region, load transfer capacity, reinforcing effect on cutting plate of MS-nails. In addition, Pilot and laboratory tests, numerical analysis were carried out to verify the superiority of MS-nailing method. In case, MS nailing method is applied to reinforce artificial slope, it was analyzed that bending, pull-out, shearing resistance was increased more than existing nailing method was applied. In this study, it was shown that surface failure was more or less prevented using MS-nailing method, confining effect on cutting plane using spring stuck to flexible equipment.

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Design and Test of Elliptical Vibration Assisted Cutting Tool Post for Ultra-precision Machines (초정밀가공기용 타원 진동절삭 공구대의 설계 및 성능실험)

  • 이대희;김호상;김의중;오창진
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.261-264
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    • 2004
  • This paper presents the design and test of elliptical vibration assisted cutting tool post. It is actuated by two piezoelectric actuators which are connected to the moving part through the elastic hinge with its role of imposing the preliminary pressures. These two actuators are located at right angles so that the resulting tool tip moves like a two-dimensional ellipse. Also, the tool post is activated within the region of linear actuation in order to overcome the distorted elliptical motion. For the precise measurement of the displacement of the tool tip, three-dimensional experimental apparatus was designed and the strokes of the tool post in major and minor axes were measured. The results show that the tool post can produce the variety of vibration locus from a circle with a radius of 5 ${\mu}{\textrm}{m}$ to an ellipse with a major axis, a =10 ${\mu}{\textrm}{m}$, and a minor axis, b =2.5 ${\mu}{\textrm}{m}$

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