• Title/Summary/Keyword: leveling

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Development of Ultral Clean Machining Technology with Electrolytic Polishing Process

  • Lee, Eun-Sang;Park, Jeong--Woo;Moon, Young-Hun
    • International Journal of Precision Engineering and Manufacturing
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    • v.2 no.1
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    • pp.18-25
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    • 2001
  • Electrolytic polishing is the anodic dissolution process in the transpassive state. It removes non-metallic inclusion and improves mechanical and corrosion resistance of stainless steel. If there is a Bailby layer, it will be removed and the true structure of the surface will be restored. Electrolytic polishing is normally used to remove a very thin layer of material from the surface of metal object. A new electrolyte composed of phosphoric, sulfuric and distilled water has been developed in this study. Two current density, high & low current density regions, have been applied in this study. In this study, In the region of high current density, there is no plateau region but excellent electrolytic polishing effect can be accomplished in short machining time because material removel process and leveling process occur simultaneously. In the low current density region, there can be found plateau region. The material removal process and leveling process occur successively. The aim of this work is to determine electrolytic polishing for stainless steel in terms of high & low current density and workpiece surface roughness.

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Effect of Low Temperature Plasma Pretreatment on the Color Depth of Wool Fabrics (양모직물의 염착농도에 미치는 저온플라즈마 처리의 영향)

  • 배소영;이문철
    • Textile Coloration and Finishing
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    • v.4 no.2
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    • pp.76-83
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    • 1992
  • Wool tropical and nylon taffeta were treated with low temperature plasma of $O_2$, $N_2$, NH$_3$, CF$_4$ and CH$_4$ for the intervals of 10 to 300 sec, and then dyed with leveling and milling type acid dyes in presence or absence of buffer solution. From the color depth of dyed fabrics, effect of plasma gases, treated time, dyeing time and temperature on dyeing property was studied. The results of the experiment can be summarized as follows: 1) The plasma treatments except methane gas increased the color depth of dyed wool fabrics, but not that of dyed nylon fabrics regardless of the plasma gases used. 2) The color depth of wool fabrics dyed in the dye bath without buffer solution was increased by the low temperature plasma, especially increased much more by CF$_4$ plasma treatment. It is found that with the identification of F- ion in the residual dye bath the hydrogen fluoride gas was adsorbed on wool fabrics in the plasma treatment. 3) The color depth of wool fabrics was increased with the time of $O_2$ and CF$_4$ plasma treatments. 4) In both cases of the leveling and milling type acid dyes, the rate of dyeing was increased in the low temperature plasma treatments, and it is found that the leveling type acid dye increased the color depth at relatively low temperature below 4$0^{\circ}C$, compared with the milling type acid dye.

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Development of Standarized Staffing Indices in School Foodservice System (학교급식시스템 유형별 표준 조리인력 산정모델 개발)

  • 이보숙
    • Journal of Nutrition and Health
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    • v.31 no.3
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    • pp.354-362
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    • 1998
  • The purposes of this study were to develop standardized indices of staffing needs in each school, foodservice system through work sampling methodology . Conventional school foodservices were classified into 5 groups depending on size of meals served. Commissary school foodservices were also classified into 5 groups by cluster analysis using number of meals served, number of satellite schools, and time for transportation of food. Work measurement through work sampling methodology was conducted in 15 conventional and 21 commissary foodservices during 3 consecutive days from September to October in 1995. Statistical data analysis was completed using the SAS programs for descriptive analysis, cluster analysis, and simple linear regression. The results were as follows : Average points of leveling factors of conventional and commissary foodservices were 1.066 and 1.061 , respectively. Mean labor hours per work force was 328 minutes and 366 minutes in conventional and commissary foodservice , respectively. Standardized work time was calculated using leveling factor, ILO allowance rate (175) , and observational work time. The model for standardized indices of staffing needs was developed based on simple linear regression in each school foodservice system. In conventional school foodservice systems(for 100-1,900 meals per day) standardized staffing needs=3.2497 +0.005267$\times$number of meals served (F=273.1, R-square 0.9750, p<0.001). In commissary school foodservice systems (for 200-1,600 meals per day ) Standardized staffing needs=3.393384 +0.0063$\times$number of meals served (F=30.78, R-square 0.6580, p<0.001).

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Tibial Plateau Leveling Osteotomy Combined with Tibial Tuberosity Transposition in a Dog with Medial Patellar Luxation and Cranial Cruciate Ligament Rupture

  • Kim, Ji-hye;Park, Jiyoung;Jeong, Seong Mok;Lee, Haebeom
    • Journal of Veterinary Clinics
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    • v.34 no.5
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    • pp.366-369
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    • 2017
  • A 30 kg, 6-year-old spayed female Samoyed dog was referred with a history of intermittent weight-bearing lameness in her right hindlimb for 3 weeks. The patient hadsurgery to correct a medial patellar luxation in the same limb 3 years prior. Based on the physical examination and radiographic findings, MPL and CCLR of the right hindlimb were diagnosed. Pre-surgical arthroscopy examination was performed, revealing a complete rupture of the cranial cruciate ligament, medial caudal meniscal tears and fibrotic cartilagechanges on the trochlear groove. An arthroscopy-assisted partial meniscectomy was used to repair themedial caudal meniscus. To correct the tibial plateau angle and medial patellar luxation, a tibial plateau leveling osteotomy (TPLO) was performed. A tibial tuberosity transposition (TTT) was performed to realignthe quadriceps mechanism with the trochlear block recession followed by soft tissue reconstruction. The post-surgical recovery was uneventful, and the patient was weight-bearing with normal ambulation on the repaired limb. There were no complications, and the implants were well positioned at the last follow-up. The clinical outcome of the caseindicates that combining TPLO with TTTis a good surgical option for treatingconcurrent CCLR and MPL.

A Study on the Adjustment of Precise Leveling Nets by the Method of Dynamic Least Squares (동적최소(動的最小)제곱법(法)에 의한 정밀수준강(精密水準綱)의 조정(調整))

  • Lee, Kye Hak;Jang, Ji Won;Kang, Hee Bog;Sung, Soo Lyeon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.8 no.2
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    • pp.177-184
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    • 1988
  • The method of least squares has been applied to the static data, but it was not applications for the processing of observed values accompaning real-time variation. In this paper, having been considered all observations to be the function of time, leveling nets were analized dynamically by introducing the concept of time to conventional method of least squares. As a results, the method of dynamic least squares was well applicable to the adjustment of leveling nets.

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The Development of Level Net Information System (수준망(水準網) 정보(情報)시스템의 개발(開發))

  • Lee, Suck Chan;Cho, Kyu Jon;Lee, Chang Kyung;Choi, Byoung Gil
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.11 no.2
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    • pp.39-49
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    • 1991
  • An information system to manage leveling data efficiently is presented. The system is consisted of input, adjustment, and query/answer module. The input module manipulating leveling data is based on the chain structure. The adjustment module adjusts the abservations by least squares method, and tests outlier by Baarda's data snooping method. The query/answer module serves user with the height and location of bench marks. In this system, the efficiency of works was increased as a result of removing the boring routine by applying the characteristics of leveling data. If necessary, for the special purpose, the system is expanded easily by appending some pertinent unit modules.

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9f-leveling: An Efficient Wear-leveling Scheme for Flash Memory (K-평준화: 플래시 메모리의 효율적인 소거 횟수 평준화 기법)

  • Kim Do Yun;Yoo Hyun-Seok;Park Sung-Hwan;Park Won-Joo;Park Sangwon
    • Proceedings of the Korean Information Science Society Conference
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    • 2005.07a
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    • pp.787-789
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    • 2005
  • 최근 이동성이 중요한 요소로 차지하는 기기들이 등장하면서 플래시 메모리가 각광을 받고 있다. 플래시 메모리의 소형화, 대용량화, 저전력화, 비휘발성, 고속화 그리고 충격에 강한 장점으로 인하여 많은 응용에서 디스크를 대체할 것으로 예상된다. 하지만 이런 플래시 메모리는 데이터를 기록하기 전에 해당 블록이 미리 소거가 되어야 하는 제약 조건을 가지고 있으며 각 블록들의 최대 소거 횟수가 제한되어 있다는 한계가 있다. 이때 소거 연산이 특정 블록에 집중되어 특정 블록의 수명이 단축되는 문제점을 해결하기 위하여 블록에 대한 소거 횟수 평준화 기법(wear-leveling)이 필요하다. 기존에 제안된 소거 횟수 평준화 기법은 각 블록의 소거 횟수를 유지해야하는 비용이 필요로 하거나 플래시 메모리가 대용량일 경우에는 블록 영역을 이동시키는데 비용이 발생하는 문제가 있다. 본 논문에서는 플래시 메모리의 소거 횟수 평준화를 위하여 해당 블록의 소거 횟수에 대한 정보의 유지의 부담을 줄이고 플래시 메모리의 대용량화 및 디스크 대체 시에 효율적인 소거 횟수 평준화 기법을 제안하고, 실험을 통하여 성능의 우수함을 보인다.

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CORA Based Leveling Osteotomy with Tibial Tuberosity Transposition for Cranial Cruciate Ligament Rupture with Concurrent Medial Patellar Luxation in Two Small Breed Dogs

  • Shin, Seo-Hyun;Kang, Jin-Su;Lee, Dong-bin;Lee, Hae-Beom;Kim, Nam-Soo;Heo, Su-Young
    • Journal of Veterinary Clinics
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    • v.36 no.5
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    • pp.285-288
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    • 2019
  • A 5-year-old 6 kg male mongrel (case 1) and a 7-year-old 4.3 kg male yorkshire terrier (case 2) were presented to Chonbuk animal medical center (CAMC). Both animals had non-weight bearing hind limb lameness. Case 1 had complete rupture of cranial cruciate ligament with grade 3 medial patellar luxation. Case 2 had complete cranial cruciate ligament rupture with grade 4 medial patellar luxation. During surgery, in both cases, trochlear block recession was performed followed by CORA based leveling osteotomy (CBLO) and tibial tuberosity transposition (TTT). General soft tissue reconstructions for medial patellar luxation including medial releasing and lateral imbrication were also performed. Postoperatively, both animals demonstrated excellent recovery and regained normal weight bearing of the affected hind limb without any recognizable complication. CBLO followed by TTT can be a curative surgical option without complications in cases of cranial cruciate ligament rupture with high-grade medial patellar luxation in small breed dogs.

Parametric Study on Straightness of Steel Wire in Roller Leveling Process Using Numerical Analysis (수치해석을 이용한 선재 롤러교정공정 주요인자의 직진도 영향 분석)

  • Bang, J.H.;Song, J.H.;Lee, M.G.;Lee, H.J.;Sung, D.Y.;Bae, G.H.
    • Transactions of Materials Processing
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    • v.31 no.5
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    • pp.296-301
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    • 2022
  • In this study, influence of the process parameters of the roller leveling process on the straightness of the steel wire was analyzed using numerical analysis. To construct the numerical analysis model, cross-sectional and longitudinal element sizes, which affect the prediction accuracy of longitudinal stress caused by bending deformation of the steel wire, were optimized, and mass scaling that satisfies prediction accuracy while reducing computational time was confirmed. By using the constructed numerical analysis model, the influence of various process parameters such as input direction of the steel wire, initial diameter of the steel wire, back tension and intermesh on the straightness was confirmed. The simulation result shows that the 3rd and 4th roller of vertical straightener had a significant influence on vertical shape of the steel wire.

ROOT SURFACE CHANCES DURING THE INITIAL LEVELING AND ALIGNMENT PHASE IN ORTHODONTICS: A SCANNING ELECTRON MICROSCOPIC STUDY (교정적 치아초기배열단계시 발생하는 치근 변화에 관한 주사전자현미경적 연구)

  • Choi, Jung-Yoon;Chung, Kyu-Rhim
    • The korean journal of orthodontics
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    • v.28 no.4 s.69
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    • pp.591-600
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    • 1998
  • The purpose of this study was to investigate the root resolution and repair pattern of human teeth according to the force magnitude, direction and duration during the initial leveling and alignment phase. 40gms to 500gms of force applied to the 37 experimental teeth with duration of 3 weeks to 7 months. Then, the experimental teeth were extracted. 13 control teeth were extracted without treatment. The results are as follows: 1. $59.5\%$ of 37 teeth exhibited root resorption. The initial resorption site was visible at the apex within 3 weeks with 100 gms samples, and the initial repair site was visible at the apex within 3 months with 400 gms samples. 2. Number of resorbed teeth increased with the duration of the force. 3. The depth of the resorption increased with the magnitude of the force. 4. The areas of resorbed root corresponded with the loading pattern. 5. The areas of resorbed root were highly correlated with the magnitude of the force. The result of this study suggest that root resorption could occur during the initial leveling and alignment phase, These initial injuries are all small and insignificant. It is the extensive type of apical root resolution that must be regarded as deleterious to the function and stability of the tooth moved. During the initial leveling and alignment phase lighter force of the interrupted type and short treatment period would be favorable with regard to avoidance of root resorption and repair of resorbed root surface.

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