• Title/Summary/Keyword: No.of Cut

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An Efficient No-Core Cut Pocketing CAM System for Wire-EDM

  • EL-Midany, Tawfik T.;Kohail, Ahmed M.;Tawfik, Hamdy
    • International Journal of CAD/CAM
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    • v.6 no.1
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    • pp.167-172
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    • 2006
  • Recently, wire-EDM became a necessity for many engineering applications, particularly in the dies making. No-Core cut process is helpful for operations in which falling slug can jam the machine or wire. In this paper a proposed CAM system (called NCPP) is introduced, to overcome the limitations of the existing CAM systems in the machining of No-Core cut. The proposed CAM system (NCPP) provides pocketing of No-core cut and optimal selection of the position of starting hole (wire threading point), to minimize toolpath length. It was written for data exchange between CAD-CAM-CNC machines. This data model will become part of the ISO (Data model for Computerized Numerical Controllers) international standard. The NCPP system has been implemented in Visual C++. Many examples are used to illustrate NCPP system. The results show that, NCPP saves the machining time by significant value. This value depends on the shape and complexity of the workpiece that is being cut.

Inapproximability of the Max-cut Problem with Negative Weights

  • Hong, Sung-Pil
    • Management Science and Financial Engineering
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    • v.14 no.1
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    • pp.87-90
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    • 2008
  • We show that when a max-cut problem is allowed native-weight edges, to decide if the problem has a cut of a positive weight is NP-hard. This implies that there is no polynomial time algorithm which guarantees a cut whose objective value is no less than $1/p(<I>)$ times the optimum for any polynomially computable polynomial p, where denotes the encoding length of an instance I.

A Study on the Ultraviolet(UV)-Cut Fiber (자외선 차단 직물에 환한 연구)

  • 최인려
    • The Research Journal of the Costume Culture
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    • v.11 no.6
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    • pp.967-971
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    • 2003
  • As the concerns over health increased in 1990's, research and development on the health material were also activated. The development of UV-cut textile became the hot issue, because the damage of W irradiation due to ozone depletion has become widely known. UV-cut effect is determined by the material, the color, the organization and the density of UV-cut fibers. UV-cut effect is very different according to the fibers. Polyester is known to have a better effect. Even in the same textile material, staple fiber has more effect than filament fiber. Different colors have different offsets. Although textiles have the same color, the effects can be different according to the depth of color. PET, PET/cotton blend, nylon and cotton fabrics were ultraviolet cutting finished with padding method using several absorbers. These UV-cut effect can be improved through the processing. Safety of UV-cut textile for the body must be considered future, Until now the figure of the UV-cut effects has been emphasized. There has been no experiment on the human body, although the textiles are directly on the human body. Futhermore there os no safety standard of UV-cut textiles. Therefore every effort will be made to set the standard UV-cut processing is established. The need of UV-cut products will be known to the consumers.

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Assessing the Adequacy of Superficial Temporal Artery Blood Flow in Korean Patients Undergoing STA-MCA Anastomosis

  • Jin Eun; Ik Seong Park
    • Journal of Korean Neurosurgical Society
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    • v.67 no.2
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    • pp.158-165
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    • 2024
  • Objective : Superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis is conducted for flow augmentation. In this study, we measured the STA cut flow of a Korean population and evaluated the relationship between STA cut flow and long-term patency of the bypass. Methods : A retrospective study was conducted. Intraoperative measurement of STA flow was conducted using a microvascular flow meter on patients who underwent STA-MCA. After cutting the distal end, the STA flow rate was measured with no resistance and recorded. After finishing anastomosis, STA flow was measured and recorded. The cut flow index was calculated by dividing post anastomosis flow by cut flow in intracranial atherosclerotic stenosis patients. Results : The median STA cut flow was 35.0 mL/min and the post anastomosis flow was 24.0 mL/min. The cut flow of STA decreased with aging (p=0.027) and increased with diameter (p=0.004). The cut flow showed no correlation with history of hypertension or diabetes mellitus (p=0.713 and p=0.786), but did correlate a positively with history of hyperlipidemia (p=0.004). There were no statistical differences in cut flow, STA diameter, and post anastomosis flow between the frontal and parietal branches (p=0.081, p=0.853, and p=0.990, respectively). Conclusion : The median STA cut flow of a Korean population was 35 mL/min. Upon reviewing previous articles, it appears that there are differences in the STA cut flow between Western and Asian patients.

A Study on the Usage of Clothing Stitches of Cut and sewn knit Garment Fabrication (컷 앤 쏘운 니트(cut and sewn knit) 의류제조의 스티치 사용 실태에 관한 연구)

  • Lee, Suyeon;Ha, Hee Jung
    • Human Ecology Research
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    • v.57 no.1
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    • pp.91-107
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    • 2019
  • The use of standardized stitches in globalized apparel markets is becoming increasingly important. However, many apparel vendors still use disunified stitches, such as Japanese and English. This study analyzes the usage of clothing stitches of cut and sewn knit garment fabrication of small companies. The results of the analysis of 464 worksheets of cut and sewn knit garments are as follows. First, of the 464 worksheets, only 4.31% are labeled as ISO 4915 No. Among the 1,399 stitches, only 3.15% were marked with the ISO 4915 No. Second, among 1,399 stitches, ISO 4915 No. 406 followed by 401 was the most frequently used. Third, in the case of the top, ISO 4915 No. 406 was used the most; in addition, ISO 4915 No. 401, 301 and 304 were also frequently used. Fourth, in the case of the bottoms, the stitch with the highest frequency was ISO 4915 No. 406 followed by ISO 4915 No. 103 and 401, respectively. Fifth, in the case of the top, ISO 4915 No. 406 was most commonly used in hemlines and sleeve edges; in addition, in the case of the bottoms, ISO 4915 No. 406 and 103 were most commonly used as hemlines. In conclusion, it is important to use international standard stitches, especially for the most frequently used stitches. By using the standard stitches, the communication errors between production departments can be reduced and information can be accurately delivered.

Effect of Pretreatment and Holding Solution on Vase Life and Quality of Cut Flowers of Aster koraiensis Nakai (벌개미취 절화의 품질향상과 수명연장을 위한 전·후처리제의 효과)

  • Lee, Poong Ok;Hwang, Sun Ae;Choi, Mok Pli;Kim, Young A;Lee, Jong Suk
    • FLOWER RESEARCH JOURNAL
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    • v.19 no.1
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    • pp.42-48
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    • 2011
  • This experiment was conducted to improve postharvest quality and extended vase life of Korean native Aster koraiensis Nakai for use as cut flowers. Aster koraiensis Nakai cut flowers were treated with various pretreatment and holding solution. Postharvest pretreatment with 3% sucrose + $200mg{\cdot}L^{-1}$ HQC + $50mg{\cdot}L^{-1}\;AgNO_3$ + $50mg{\cdot}L^{-1}$ BA and 3% sucrose + $200mg{\cdot}L^{-1}$ HQC + $50mg{\cdot}L^{-1}\;AgNO_3$ + $150mg{\cdot}L^{-1}$ citric acid for 16 hours extended vase life of cut Aster koraiensis Nakai flowers by 1.4 times as compared with the control (distilled water). Holding solution of 3% sucrose + $200mg{\cdot}L^{-1}$ HQC + $50mg{\cdot}L^{-1}\;AgNO_3$ + $50mg{\cdot}L^{-1}$ BA and 3% sucrose + $200mg{\cdot}L^{-1}$ HQC + $50mg{\cdot}L^{-1}\;AgNO_3$ + $150mg{\cdot}L^{-1}\;GA_3$ extended vase life of cut Aster koraiensis Nakai flowers by1.6 and 1.7 times as compared with control (distilled water). Aster koraiensis Nakai.flowers held in this preservative solution increased fresh weight and were maintained positive water balance for a long vase period. It was suggested that the vase life of cut Aster koraiensis Nakai flowers was closely related to fresh weight and water balance of the cut flower.

Seasonal Phosphorus Dynamics in a Forest Stream Water Following Different Harvests

  • Park, Byung Bae
    • Journal of Korean Society of Forest Science
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    • v.97 no.2
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    • pp.181-186
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    • 2008
  • Even small changes in phosphorus concentrations in stream water could cause eutrophication because of very low level of phosphorus concentrations in natural waters. I investigated the impact of strip cut and clear cut on phosphorus concentrations in stream water at the Hubbard Brook Experimental Forest and investigated stream water phosphorus concentrations as a function of flow rate and season (as well as cutting history). Mean phosphate concentrations in the control (undisturbed forest) increased $1.9{\mu}g\;L^{-1}\;to\;2.6{\mu}g\;L^{-1}$, while strip cut treatment increased phosphate concentrations in stream water $2.2{\mu}g\;L^{-1}\;to\;3.7{\mu}g\;L^{-1}$ during the same period. There was no significant effect of clear cut treatment on phosphate concentrations in stream water. No relationships were found between discharge rate and phosphate concentrations, but the magnitude of fluctuation were increased during two decades in undisturbed forest: $1-5{\mu}g\;L^{-1}$ from 1963 to 1975 and $1-12{\mu}g\;L^{-1}$ from 1983 to 1995. Based on this study, forest harvests with buffer zone will not make a problem by imported phosphate to cause eutrophication in natural water.

A Study on Current State in Stitches and Seams Usage for Building Smart Sewing Systems: Focused on Sewing Specification of Cut and Sewn Knit (스마트 봉제 시스템 구축을 위한 스티치 및 솔기 사용 현황에 관한 고찰: 컷 앤 쏘운 니트 의류 봉제사양서를 중심으로)

  • Lee, Suyeon;Ha, Hee Jung
    • Human Ecology Research
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    • v.58 no.3
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    • pp.357-374
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    • 2020
  • This study suggests the use of standardized sewing terms for the construction of smart sewing systems. This study analyzed the use of stitches (ISO 4915) and seams (ISO 4916) for cut and sewn knit garment which are the basic elements of sewing on an ISO basis. The results of the analysis of sewing specifications of cut and sewn knit garments are as follows. First, the use of stitches and seams were analyzed. As a result, both stitches and seams were used as non-standard terms. Second, among 3,263 stitches, ISO 4915 No. 406 followed by 401, 504, 605 were the most frequently used; however, ISO 4915 No. 514 was anticipated the most because the ISO 4915 No. 514 used for joining was not recorded in the sewing specification. Finally, the use of stitch for each seam was analyzed. The most common stitch used for ISO 4916 No. 6.02.07 was ISO 4915 No. 406. In addition, when it was sewing ISO 4916 No. 4.04.01, ISO 4915 No. 504 was used in step 1, and ISO 4915 No. 406, 602, and 605 were used in step 2. It is important to use the international standard sewing terms for the production site based on the results. In addition, the construction of smart sewing systems and the work of international standardization through industry-university cooperation are important for securing global competitiveness. Therefore, the use of international standard terminology and practical training should be conducted with a focus on stitching and seams with high frequency of use.