• Title/Summary/Keyword: Uncut

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A Study on Machining of Uncut Volume at the Boundary Region of Curved Surfaces (곡면 경계부 미절삭 체적의 잔삭 가공에 관한 연구)

  • Maeng, Hee-Young;Yim, Choong-Hyuk
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.19 no.2
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    • pp.251-259
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    • 2010
  • It is presented in this study a new efficient intelligent machining strategy, which can be used to remove the uncut volume at the boundary region of curved surfaces caused by cutter interference. The geometric form definitions and recognition of topological features of the surface triangulation mesh are used to generate cutter paths along successive and interconnected steepest pathways, that minimize the cusp height left after flat end milling. In order to machine the uncut volume gradually, the z-map cutter centers are adjusted to avoid cutter interference for the 6 kinds of avoidance types. And then, the generative subsequent paths are sequenced to determine the second step cutter paths for the next uncut volume. For the 2 kinds of test models with convex and concave surface region, the implemented software algorithm is evaluated by investigating the residual swelling of uncut volume for each machining step.

A Study on an Algorithm for Eliminating False Feature Points (의사 특징점 제거 알고리즘 관한 연구)

  • Jeong, Yang-Gwon;Choe, Jae-Ho
    • The Transactions of the Korea Information Processing Society
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    • v.3 no.4
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    • pp.899-907
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    • 1996
  • In this paper, we proposed an algorithm to eliminate false feature points to upgrade the system ability using the cross number method. By using the proposal algorithm, it was able to extract feature points exactly and increase the recognition rates.In the experiment, we used3 groups : the uncut-partially noised, and uncut completely noised fingerprint to verify our proposal. We then compared the results of the proposed system with those of another system in which false feature points were not eliminated. We have obtained good recognition rates of 97.7%, 97.7%, and95.0% in the cut, uncut-partially noised, and the uncut-completely noised fingerprints. However, the other system received the results of the cut 60%, the uncut-partially noised 35%, and the uncut-completely noised 50% respectively. As a result, we belive that the fingerprint may be recognized after adapting the proposal algorithm.

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Uncut Roux-en-Y Reconstruction after Laparoscopic Distal Gastrectomy Can Be a Favorable Method in Terms of Gastritis, Bile Reflux, and Gastric Residue

  • Park, Ji Yeon;Kim, Yong Jin
    • Journal of Gastric Cancer
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    • v.14 no.4
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    • pp.229-237
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    • 2014
  • Purpose: Laparoscopic distal gastrectomy (LDG) is a well-established procedure for the treatment of early gastric cancer. Several reconstruction methods can be adopted after LDG according to tumor characteristics and surgeon preference. This study aimed to compare the remnant gastric functions after different reconstructions. Materials and Methods: In total, 221 patients who underwent LDG between March 2005 and October 2013 were reviewed retrospectively. The patients were classified into four groups based on the reconstructive procedure: Billroth I (BI) anastomosis, Billroth II (BII) with Braun anastomosis, Roux-en-Y (RY) reconstruction, or uncut RY reconstruction. Patient demographics, surgical outcomes, and postoperative endoscopic findings were reviewed and compared among groups. Results: Endoscopic evaluations at $11.8{\pm}3.8$ months postoperatively showed less frequent gastritis and bile reflux in the remnant stomach in the RY group compared to the BI and BII groups. There was no significant difference in the gastric residue among the BI, BII, and RY groups. The incidence of gastritis and bile reflux in the uncut RY group was similar to that in the RY group, while residual gastric content in the uncut RY group was significantly smaller and less frequently observed than that in the RY group (5.8% versus 35.3%, P=0.010). Conclusions: RY and uncut RY reconstructions are equally superior to BI and BII with Braun anastomoses in terms of gastritis and bile reflux in the remnant stomach. Furthermore, uncut RY reconstruction showed improved stasis compared to conventional RY gastrojejunostomy. Uncut RY reconstruction can be a favorable reconstructive procedure after LDG.

자유곡면으로 이루어진 3차원 곡면의 고속 가공시스템

  • 이희관;김준형;양균의
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.782-787
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    • 1997
  • This paper proposes methods for pencil machining and uncut area machining. Based on Z-map represented by triangular facets, self-intersection-free offset surface is generated with K-offset method in case of ball mill and flat mill Pencil machining can elliminate overload area before main machining rough, semi-finish and finish cutting,preventing fluctuations of cutting forces in concave regions form causing bad machining condition. Low productivity is caused by uncut area which has excessive or irreguar finishing allowance. Uncut area machining has the finishing allowance keep uniformly on part surface. This paper deals with two types of uncaut area, machining detection of excessive area and user-defined area.

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Multi-stage NC Milling of Uncut Volume caused by Gouging Interference at the Machining of Curved Surfaces (곡면가공시 공구간섭에 따른 미절삭체적의 다단계 NC가공)

  • 맹희영;차지경
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.10a
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    • pp.439-444
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    • 2004
  • A new efficient intelligent machining strategy named the Steepest Directed Tree method is presented in this study, which makes surface model discrete with triangulation meshes and the cutter paths track along the tree directions. In order to formulate these algorithms practically, it is deduced the multi-stage machining approach of uncut volume caused by cutter gouging in the course of milling using flat end mill. It is systematized the checking process the cutter interference by grouping the 6 kinds of gouging types, which yields the environment of connectivity data lists including CL-data, and then the multi-stage machining strategy, that minimizes uncut area by continuously sequencing the generative subsequent CL-paths, is shamed to determine the second tool path for the next uncut area and to compose the operating multi-stage cutting processes. The completed machining system of curved surfaces is evaluated by testing the practical machining experiments which have various kinds of shape conditions.

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Roux Stasis Syndrome in Conventional Roux-en-Y Gastrojejunostomy and Uncut Roux-en-Y Gastrojejunostomy after Subtotal Gastrectomy (위아전절제술 후 Roux-en-Y 위공장 재건술식과 Uncut Roux-en-Y 재건술식에서의 Roux Stasis Syndrome)

  • Noh Seung-Moo;Bae Jin-Sun;Jeong Hyun-Yong;Cho June-Sik;Shin Kyung-Sook;Song Kyu-Sang
    • Journal of Gastric Cancer
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    • v.1 no.1
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    • pp.38-43
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    • 2001
  • Purpose: Roux stasis syndrome is the main complication of a Roux-en-Y gastrojejunostomy. The aim of this study was to compare the occurrence rate of Roux stasis syndrome with the passing of time in a conventional Roux-en-Y gastrojejunostomy and in an uncut Roux-en-Y gastrojejunostomy. Materials and Methods: 50 patients (31 men and 19 women) had a conventional Roux-en-Y reconstruction and 53 patients (35 men and 18 women) had an uncut Roux-en-Y reconstruction. The Roux stasis syndrome was defined by clinical criteria only. The criteria included one of the four following conditions at the time of follow-up: chronic upper abdominal pain, postprandial fullness, persistent nausea, and intermittent vomiting that are worsened by eating. Follow-up after surgery was done in all patients at $7\∼12,\;13\~18,\;19\~24,\;25\~30$, and $31\∼36$ months. Results: According to the criteria, the Roux stasis syndrome occurred in 40.0$\%$ of the patients at 7$\∼$12 months, 33.3$\%$ at $13\∼19$ months, $35.3\%$ at $19\∼24$ months, $32.0\%$ at $25\~30$ months, and $33.3\%$ at $31\∼36$ months after a conventional Roux-en-Y operation. The syndrome occurred in $22.6\%$ of the patients at $7\∼12$ months, $15.2\%$ at $13\∼18$ months, $17.1\%$ at $19\∼24$ months, $19.2\%$ at $25\∼30$ months, and $20\%$ at $31\∼36$ months after an uncut Roux-en-Y reconstruction. Conclusion: In terms of occurrence pattern, only a little variance existed one year after both procedures. Comparing the Roux stasis syndrome in both procedures, the uncut Roux operation had better results than the conventional Roux operation.

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A SHEAR BOND STRENGTH OF RESIN CEMENT BONDED TO HUMAN UNCUT ENAMEL, CUT ENAMEL, AND DENTIN IN VITRO

  • Lee Jong-Yeop
    • The Journal of Korean Academy of Prosthodontics
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    • v.41 no.3
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    • pp.319-324
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    • 2003
  • Statement of problem. Adhesives in dentistry playa major role in the success of restorative treatments. In the treatment of all ceramic restoration it is needed to find the adequate bond strength between enamel and dentin. Purpose. The purpose of this study was to evaluate shear bond strength of resin cement bonded to extracted human uncut enamel, cut enamel, and dentin in vitro. Material and methods. Ten freshly extracted anterior teeth without any previous restorative treatments were chosen. The extracted teeth were embedded in PMMA cold acrylic in the shape of a cylinder, 25 mm in diameter by 25 mm in height. The bonding system used was as follow: Uni-Etch (32% phosphoric acid), One-Step adhesive, Duolink resin cement. The specimens were acid etched and rinsed with water. Two layers of One-Step adhesive were coated with a disposable brush on the uncut enamel. VIP curing light at $500mV/cm^2$ was used to cure the adhesive. For cut enamel shear bond test, the specimen used for uncut enamel was further reduced approximately $0.3{\sim}0.5mm$ using a laminate preparation diamond bur (0.3 mm in depth). The specimens were subsequently treated with 320-grit SiC paper followed by 600-grit SiC paper and cleaned with distilled water. The bonding procedure on the cut enamel was same as uncut enamel bonding procedure. For dentin bonding test, the specimen used for cut enamel was further reduced approximately $0.5mm{\sim}1.0mm$ using a laminate preparation diamond bur (0.5 mm in depth of diamond cutting). The amount of reduction was evaluated with the silicone mold. The specimens were subsequently treated with 320-grit SiC paper followed by 600-grit silicon carbon paper and cleaned in distilled water. The bonding procedure on the dentin was same as uncut enamel bonding procedure. All samples were mounted and secured on the Ultradent shear bond test sample holder, and Ultradent restricted shear bond testing device was used with Universal Instron machine until fracture. Analysis of variance (ANOVA) test was performed comparing the result at P<0.05. Multiple comparison (Tukey) was used to compare each groups. Result. The result showed that the mean value in shear bond strength of resin cement bonded to uncut enamel, cut enamel and dentin were 27.04 Mpa, 30.25 Mpa and 26.39 Mpa with respect. Conclusion. Within the limitation of this study, the mean value of the shear bond strength of cut enamel was higher than those of uncut enamel or dentin. However there existed no statistical differences between three different human dentition substrates due to increased adhesive characteristics.

Effects of Canopy Removal on Cellulose Decomposition and Nitrogen Mineralization in Quercus rubra Stands (임관 제거가 루브라참나무림의 셀룰로오스 분해와 질소 무기화에 미치는 영향)

  • Kim, Choonsig
    • The Korean Journal of Ecology
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    • v.18 no.2
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    • pp.219-230
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    • 1995
  • Although many studies of nutrient cycling in forest ecosystems have reported that clearcutting creates increased organic matter decomposition and nitrogen (N) mineralization in soils, little is known about the change of these factors following various levels of canopy removal. A series of experimental plots with four levels of canopy cover, i.e., clearcut, 25%, 75%, and uncut, was established in northern red oak (Quercus rubra L.) stands in northern Lover Michigan, U.S.A. I examined decomposition of cellulose filter papers and N mineralization using an in situ soil incubation technique in the top 15cm of mineral soil during the second growing season (1992, May-October) following stand manipulation. Mass loss from cellulose filter papers was more rapid in the canopy removal treatments than in the uncut treatment. similarly, net N mineralization was significantly greater in the canopy removal treatments than in the uncut treatment. There was no significant difference in net N mineralization rates among the three levels of canopy removal. Net N mineralization for the growing season was 58 kg/ha for the clearcut, 54 kg/ha for the 25% canopy cover, 51 kg/ha for the 75% canopy cover, and 22 kg/ha for the uncut treatment. These results indicated that even only small amounts of canopy removal (leaving 75% canopy cover) let to substantial increases of cellulose decomposition and the amount of available soil nitrogen.

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