• Title/Summary/Keyword: roll technique

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A Study of Measuring Yield Rate and Error Rate in Steel Pipe Production using Decision Tree Technique (의사결정트리 기법을 이용한 스틸 파이프 생산 수율 및 불량률 측정에 관한 연구)

  • Kim, Woong-Kyung;Kim, Jong-Wan;Kim, Su-Yeon;Nam, In-Gil
    • Journal of Korea Society of Industrial Information Systems
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    • v.14 no.4
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    • pp.116-127
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    • 2009
  • This research aims to improve the efficiency of production by selecting production configuration with high yield rate and lower error rate based on production history of steel pipe. To achieve this, we identify the properties of various types of MTO(make-to-order) steel pipe products and determine properties affecting yield rate and error rate using decision tree technique. From experimental results, we find out that specification is critical to determine yield rate and error rate of ERW steel pipes with mostly small and medium caliber, and an external diameter range in case of roll benders or spiral steel pipes with mostly large caliber. This research classified and embodied the patterns of yield rate and error rate mathematically by product properties.

Study on Characteristics of the Forward Link Signal for the UHF RFID Reader (UHF 대역 RFID 리더의 순방향 링크 신호 특성에 관한 연구)

  • Kim, Do-Yun;Jang, Byung-Jun;Yoon, Hyun-Goo;Park, Jun-Seok;Yook, Jong-Gwan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.18 no.6 s.121
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    • pp.602-611
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    • 2007
  • In this paper, the forward link of UHF RFID system is modeled in accordance with the EPCglobal class 1 generation 2(EPCglobal C1G2) UHF Radio-Frequency Identity protocol specification at $860{\sim}960MHz$. Based on the constructed model, characteristics on the forward link signal for the EPCglobal C1G2 RFID reader are simulated with the help of a MATLAB softwarein order to extract the design parameters of a transmit digital filter which meets the Korean RFID regulations. Herein, the forward link model is consisted of PIE source coding, transmit digital filter, modulation, local oscillator, and antenna. From the simulation results, the ranges of three design parameters(roll-off factor, cutoff frequency, the number of tabs) for transmit digital filter are obtained with different modulation techniques and the Tari(type a reference interval) values. Finally, DSB/SSB-ASK modulation technique can not satisfy the EPCglobal C1G2 specification when Tari equals to $6.25{\mu}sec$ in a multiple-reader environment. Consequently this paper can provide a guideline for design parameters of a RFID reader as well as the basic scheme of analyzing frequency interference problems in RFID environments, including multiple-reader and dense-reader environments.

Development of a Probabilistic Approach to Predict Motion Characteristics of a Ship under Wind Loads (풍하중을 고려한 확률론적 운동특성 평가기법 개발에 관한 연구)

  • Sang-Eui Lee
    • Journal of Navigation and Port Research
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    • v.47 no.6
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    • pp.315-323
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    • 2023
  • Marine accidents due to loss of stability of small ships have continued to increase over the past decade. In particular, since sudden winds have been pointed out as main causes of most small ship accidents, safety measures have been established to prevent them. In this regard, to prevent accidents caused by sudden winds, a systematic analysis technique is required. The aim of the present study was to develop a probabilistic approach to estimate extreme value and evaluate effects of wind on motion characteristics of ships. The present study included studies of motion analysis, extraction of extreme values, and motion characteristics. A series analysis was conducted for three conditions: wave only, wave with uniform wind speed, and wave with the NPD wind model. Hysteresis filtering and Peak-Valley filtering techniques were applied to time-domain motion analysis results for extreme value extraction. Using extracted extreme values, the goodness of fit test was performed on four distribution functions to select the optimal distribution-function that best expressed extreme values. Motion characteristics of a fishing boat were evaluated for three periodic motion conditions (Heave, Roll, and Pitch) and results were compared. Numerical analysis was performed using a commercial solver, ANSYS-AQWA.

Daily Setup Uncertainties and Organ Motion Based on the Tomoimages in Prostatic Radiotherapy (전립선암 치료 시 Tomoimage에 기초한 Setup 오차에 관한 고찰)

  • Cho, Jeong-Hee;Lee, Sang-Kyu;Kim, Sei-Joon;Na, Soo-Kyung
    • The Journal of Korean Society for Radiation Therapy
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    • v.19 no.2
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    • pp.99-106
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    • 2007
  • Purpose: The patient's position and anatomy during the treatment course little bit varies to some extend due to setup uncertainties and organ motions. These factors could affected to not only the dose coverage of the gross tumor but over dosage of normal tissue. Setup uncertainties and organ motions can be minimized by precise patient positioning and rigid immobilization device but some anatomical site such as prostate, the internal organ motion due to physiological processes are challenge. In planning procedure, the clinical target volume is a little bit enlarged to create a planning target volume that accounts for setup uncertainties and organ motion as well. These uncertainties lead to differences between the calculated dose by treatment planning system and the actually delivered dose. The purpose of this study was to evaluate the differences of interfractional displacement of organ and GTV based on the tomoimages. Materials and Methods: Over the course of 3 months, 3 patients, those who has applied rectal balloon, treated for prostatic cancer patient's tomoimage were studied. During the treatment sessions 26 tomoimages per patient, Total 76 tomoimages were collected. Tomoimage had been taken everyday after initial setup with lead marker attached on the patient's skin center to comparing with C-T simulation images. Tomoimage was taken after rectal balloon inflated with 60 cc of air for prostate gland immobilization for daily treatment just before treatment and it was used routinely in each case. The intrarectal balloon was inserted to a depth of 6 cm from the anal verge. MVCT image was taken with 5 mm slice thickness after the intrarectal balloon in place and inflated. For this study, lead balls are used to guide the registration between the MVCT and CT simulation images. There are three image fusion methods in the tomotherapy, bone technique, bone/tissue technique, and full image technique. We used all this 3 methods to analysis the setup errors. Initially, image fusions were based on the visual alignment of lead ball, CT anatomy and CT simulation contours and then the radiation therapist registered the MVCT images with the CT simulation images based on the bone based, rectal balloon based and GTV based respectively and registered image was compared with each others. The average and standard deviation of each X, Y, Z and rotation from the initial planning center was calculated for each patient. The image fusions were based on the visual alignment of lead ball, CT anatomy and CT simulation contours. Results: There was a significant difference in the mean variations of the rectal balloon among the methods. Statistical results based on the bone fusion shows that maximum x-direction shift was 8 mm and 4.2 mm to the y-direction. It was statistically significant (P=<0.0001) in balloon based fusion, maximum X and Y shift was 6 mm, 16mm respectively. One patient's result was more than 16 mm shift and that was derived from the rectal expansions due to the bowl gas and stool. GTV based fusion results ranging from 2.7 to 6.6 mm to the x-direction and 4.3$\sim$7.8 mm to the y-direction respectively. We have checked rotational error in this study but there are no significant differences among fusion methods and the result was 0.37$\pm$0.36 in bone based fusion and 0.34$\pm$0.38 in GTV based fusion.

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Short Segment Screw Fixation without Fusion for Unstable Thoracolumbar and Lumbar Burst Fracture : A Prospective Study on Selective Consecutive Patients

  • Kim, Hee-Yul;Kim, Hyeun-Sung;Kim, Seok-Won;Ju, Chang-Il;Lee, Sung-Myung;Park, Hyun-Jong
    • Journal of Korean Neurosurgical Society
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    • v.51 no.4
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    • pp.203-207
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    • 2012
  • Objective: The purpose of this prospective study was to evaluate the efficacy and safety of screw fixation without bone fusion for unstable thoracolumbar and lumbar burst fracture. Methods: Nine patients younger than 40 years underwent screw fixation without bone fusion, following postural reduction using a soft roll at the involved vertebra, in cases of burst fracture. Their motor power was intact in spite of severe canal compromise. The surgical procedure included postural reduction for 3 days and screw fixations at one level above, one level below and at the fractured level itself. The patients underwent removal of implants 12 months after the initial operation, due to possibility of implant failure. Imaging and clinical findings, including canal encroachment, vertebral height, clinical outcome, and complications were analyzed. Results: Prior to surgery, the mean pain score (visual analogue scale) was 8.2, which decreased to 2.2 at 12 months after screw fixation. None of the patients complained of worsening of pain during 6 months after implant removal. All patients were graded as having excellent or good outcomes at 6 months after implant removal. The proportion of canal compromise at the fractured level improved from 55% to 35% at 12 months after surgery. The mean preoperative vertebral height loss was 45.3%, which improved to 20.6% at 6 months after implant removal. There were no neurological deficits related to neural injury. The improved vertebral height and canal compromise were maintained at 6 months after implant removal. Conclusion: Short segment pedicle screw fixation, including fractured level itself, without bone fusion following postural reduction can be an effective and safe operative technique in the management of selected young patients suffering from unstable burst fracture.

Design of The Autopilot System of vessel using Fuzzy Algorithm (퍼지제어 알고리즘을 이용한 선박의 자율운항 시스템 설계)

  • 이민수;추연규;이광석;김현덕;박연식
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.10a
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    • pp.801-804
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    • 2003
  • The autopilot system of vessel is proposed to take service safety sorority, to elevate service efficiency, to decrease labor and to improve working environment. Ultimate purpose of it is to minimize the number of crew by guaranteeing economical efficiency of shipping service. Recently, the research is being achieving to compensate various nonlinear parameters of vessel and apply it is course keeping control, track keeping control, roll-rudder stabilization, dynamic ship positioning and automatic mooring control etc. using optimizing control technique. Relation between rudder angle controlled by steering machine of vessel and ship-heading angle, and load condition of ship are nonlinear, which affect various parameters of shipping service. The speed and direction of waves, velocity and quantity of wind, which also cause the non-linearity of it. Therefore the autopilot system of ship requires the robust control algorithm can overcome various non-linearity. On this paper, we design the autopilot system of ship, which overcome nonlinear parameters and disturbance of it using Fuzzy Algorithm, evaluate the proposed algorithm and its excellence through simulation

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An Approach to decide the location of a method using the logistic analysis (로지스틱 분석을 이용한 메소드 위치 결정 방법)

  • Jung Young A.;Park Young B,
    • The KIPS Transactions:PartD
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    • v.12D no.7 s.103
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    • pp.1017-1022
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    • 2005
  • There are many changes in the software requirements during the whole software life cycle. These changes require modification of the software, and it is important to keep software quality and stability while we are modifying the software. Refactoring is one of the technology to keep software quality and stability during the software modification; there are many researches related to automatic refactoring. In this paper, we propose three factors for Move Method which is one of the refactoring technique. We applied binomial logistic analysis to data which were extracted from sample program by each factor. The result of this process was very close to the result of manual analysis by program experts. Furthermore, we found that these factors have major roll to determine Position of a method, and these factors can be used as a basis of finding optimal position of a method.

Tension Control of a Winding Machine using Time-delay Estimation (시간 지연 추정 기법을 이용한 권취기의 장력 제어 알고리즘)

  • Heo, Jeong-Heon;You, Byungyong;Kim, Jinwook
    • Journal of Drive and Control
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    • v.15 no.3
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    • pp.21-28
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    • 2018
  • We propose a tension controller based on a time-delay estimation (TDE) technique for a winding machine. Firstly, we perform the necessary calculations to derive a mathematical model of the winding machine. In this sense, it is revealed that the roll radius of the winding machine is characteristically seen to be increasing or decreasing during the winding process. That being said, it is noted that the parameters of the winding machine are coupled and constantly changing during this process. Understandably then, it is noted that the model is shown to be nonlinear and time-varying. Secondly, we propose the way to apply the TDE based controller which is the so-called Time-delay Control (TDC). The TDC utilizes the time-delayed information intentionally to compensate the nonlinear and time-varying characteristics. As we have seen, the proposed controller consists of two parts: one is a TDE component, and the other is an error dynamics component which is defined by a user. In a computer simulation based on the Matlab/Simulink program, the proposed controller is compared with a conventional PID controller, which is widely used in the tension control of the winding machine. The proposed controller reduces the incidence of overshoot and steady-state error in the tension control, as compared to the conventional PID controller.

A Study on Design Identity of Fashion House - Focused on Saint Laurent House - (패션 하우스의 디자인 정체성 연구 - 생 로랑 하우스를 중심으로 -)

  • Hwang, Hyerim;Park, Eun Kyung
    • Journal of the Korean Society of Costume
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    • v.65 no.2
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    • pp.105-124
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    • 2015
  • This research was started to study how the design identity of an overseas fashion house was formed, changed and connected. For the purpose of the study, Saint Laurent House was selected as the subject of the study, because it began as a couture house and launched the $pr\hat{e}t-\grave{a}-porter$ for the first time among the designer brands, and also contributed to the development of modern women's fashion. Literature survey on related books and papers was performed to study the Saint Laurent House. Then, fashion collection photos of the house from 1962 SS to 2014 SS were collected to analyze and compare the features of the designs. The photos were collected from related books, fashion magazines and internet sites. The results are as follows: The features of Yves Saint Laurent's early designs were contemporarily sensational with their couture tradition. His representative designs including Le Smoking, Pea Coat, Loose Fit Blouse, Safari Look, Jumpsuit, Ethnic Look and Art Look became the signature looks of the Saint Laurent House. His designs expressed the liberation of sex, multi-cultural sensitivity and the fusion of art and fashion. His successor, chief designer Tom Ford designed with strong sensitivity of his own. He dealt with Yves Saint Laurent's design themes and signature looks in sensual as well as trendy and sophisticated way. Stefano Pilati showed the Parisienne chic and elegance. He re-made the legacies of Yves Saint Laurent with his own design style using new materials or cutting technique. Hedi Slimane reinterpreted the signature looks of the house with his rock' n roll mood for young, modern women while reflecting the spirit of Yves Saint Laurent's early stage. In conclusion, the design identity of Saint Laurent House is not just a fixed one. By the subsequent chief designers, the signature items and design spirit of Yves Saint Laurent have been succeeded, reintroduced or changed to be trendy and to reflect the designers' design sensitivity. All of these make and maintain the design identity of the fashion house.

Modified Fisher method for unilateral cleft lip-report of cases

  • Kim, Hui Young;Park, Joonhyoung;Chang, Ming-Chih;Song, In Seok;Seo, Byoung Moo
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.39
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    • pp.12.1-12.5
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    • 2017
  • Background: Rehabilitation of normal function and form is essential in cleft lip repair. In 2005, Dr. David M. Fisher introduced an innovative method, named "an anatomical subunit approximation technique" in unilateral cleft lip repair. According to this method, circumferential incision along the columella on cleft side of the medial flap is continued to the planned top of the Cupid's bow in straight manner, which runs parallel to the unaffected philtral ridge. Usually, small inlet incision is needed to lengthen the medial flap. On lateral flap, small triangle just above the cutaneous roll is used to prevent unesthetic shortening of upper lip. This allows better continuity of the Cupid's bow and ideal distribution of tension. Case presentation: As a modification to original method, orbicularis oris muscle overlapping suture is applied to make the elevated philtral ridge. Concomitant primary rhinoplasty also results in good esthetic outcome with symmetric nostrils and correction of alar web. As satisfactory results were obtained in three incomplete and one complete unilateral cleft lip patients, indicating Fisher's method can be useful in cleft lip surgery with functional and esthetic outcome. Conclusions: Clinically applied Fisher's method in unilateral cleft lip patients proved the effectiveness in improving the esthetic results with good symmetry. This method also applied with primary rhinoplasty.