• Title/Summary/Keyword: continuation methods

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Detection of Broken Bars in Induction Motors Using a Neural Network

  • Moradian M.;Ebrahimi M.;Danesh M.;Bayat M.
    • Journal of Power Electronics
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    • v.6 no.3
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    • pp.245-252
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    • 2006
  • This paper presents a method based on neural networks to detect the broken rotor bars and end rings of squirrel cage induction motors. At first, detection methods are studied, and then traditional methods of fault detection and dynamic models of induction motors by using winding function model are introduced. In this method, all of the stator slots and rotor bars are considered, thus the performance of the motor in healthy situations or breakage in each part can be checked. The frequency spectrum of current signals is derived by using Fourier transformation and is analyzed in different conditions. In continuation, an analytical discussion and a simple algorithm are presented to detect the fault. This algorithm is based on neural networks. The neural network has been trained by using information of a 1.1 KW induction motor. This system has been tested with a different amount of load torque, and it is capable of working on-line and of recognizing all normal and ill conditions.

Comparative Studies of Methods for Continuation and Derivatives of Potential Fields (포텐셜장(場)의 상하향연속(上下向連續) 및 미분법(微分法)에 대(對)한 비교연구(比較硏究))

  • Kwon, Byung Doo
    • Economic and Environmental Geology
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    • v.14 no.2
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    • pp.93-102
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    • 1981
  • Studies of model potential fields continued upward and downward show differences depending on the method of continuation. Beginning with a magnetic field computed over a buried vertical cylinder, the field was continued to various levels by a method introduced by Henderson (Lagrangian interpolation) and by a spectral method (frequency domain analysis). Resultant fields show (1) no significant differences in upward continued values, (2) in downward continuation, accurate values are obtained with the spectral method over the central part of the anomaly, and (3) accurate values are obtained with Henderson's method on the flanks of the anomaly, while oscillations usually characterize the spectral method in this region. Essentially the same observations are made for derivative calculations. Field oscillations are empirically predicted at levels continued to approximately two-thirds of the depth of the source. Our spectral computer program output yields marked oscillations at one-half of the depth of the source. Henderson's method shows no oscillations at this depth and only minor oscillations at the top of the body (some negative values appear on the flanks of the anomaly). The Henderson output is a smooth field even if continued below the top of the body. These results suggest that the presence of oscillations cannot be used to identify the top of a buried source without careful consideration of the method used to continue the field. Use of the derivative to outline and isolate anomalies must similarly include consideration of the method of calculation.

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Useful MRI Features for Distinguishing Benign Peripheral Nerve Sheath Tumors and Myxoid Tumors in the Musculoskeletal System

  • Lee, Eunchae;Lee, Guen Young;Cho, Whan Sung;Lee, Joon Woo;Ahn, Joong Mo;Lee, Eugene;Kang, Heung Sik
    • Investigative Magnetic Resonance Imaging
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    • v.19 no.3
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    • pp.153-161
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    • 2015
  • Purpose: To identify the differential MRI findings between myxoid tumors and benign peripheral nerve sheath tumors (BPNSTs) in the musculoskeletal system. Materials and Methods: The study participants included a total of 35 consecutive patients who underwent MRI between September 2011 and December 2013. The patients were pathologically diagnosed with myxoid tumors (22 patients) or BPNSTs (13 patients). Evaluation was done by two radiologists, based on the following characteristics: size, margin, degree of signal intensity (SI) on T2-weighted images (T2WI), homogeneity of SI on T2WI, enhancement pattern, enhancement homogeneity, presence of cystic portion, internal fat component, presence of fat split sign, presence of target sign, presence of continuation with adjacent neurovascular bundle, and presence of surrounding halo. Results: Large size, high SI on T2WI, heterogeneous enhancement, and internal fat component were commonly observed in myxoid tumors, while homogenous enhancement, fat split sign, target sign were common in BPNSTs. The differences were statistically significant (P < 0.05). Other findings, such as margin, homogeneity of SI on T2WI, enhancement pattern (peripheral or solid), internal cystic portion, continuation with neurovascular bundle, and surrounding halo, did not show significant difference between myxoid tumors and BPNSTs (P > 0.05). Conclusion: In the differential diagnosis of myxoid tumors and BPNSTs involving the musculoskeletal system, several MRI findings such as degree of SI on T2WI, enhancement homogeneity, internal fat component, fat split sign, and target sign, may be helpful in establishing the diagnosis.

Effect of tuberculosis treatment on leptin levels, weight gain, and percentage body fat in Indonesian children

  • Mexitalia, Maria;Dewi, Yesi Oktavia;Pramono, Adriyan;Anam, Mohammad Syarofil
    • Clinical and Experimental Pediatrics
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    • v.60 no.4
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    • pp.118-123
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    • 2017
  • Purpose: Tuberculosis (TB) remains a problem in the community. TB patients usually experience malnutrition, which is characterized by both decreased body weight (BW) and body fat percentage (BFP). Leptin, an important regulator of BW, also plays an important role in cellular immunity, which is integral to defense against Mycobacterium tuberculosis infection. We analyzed the effect of an anti-TB treatment regimen on the leptin level, BW, and BFP of children with TB. Methods: The design of this study was a group interrupted time series. The subjects were children with probable TB according to clinical criteria based on an Indonesian scoring system adopted from the Consensus of Expert Panel. BW; BFP; energy intake; fat and protein intake; and leptin levels before, 2 months after (intensive phase), and 6 months after (continuation phase) anti-TB treatment, were measured. About 40 children, aged 5-14 years, participated in this study. Results: The BW, BFP and leptin level increased from before treatment to after completion of the intensive phase and still showed an increased during the continuation phase: BW 18.65 kg, 19.75 kg, and 20.85 kg; BFP 18.3%, 19.5%, and 20.2%; and leptin level 1.9 mg/dL, 3.07 mg/dL, and 3.4 mg/dL, respectively (P<0.01). Conclusion: Leptin level, BW, and BFP increased throughout the course of anti-TB treatment, compared with pretreatment values. Further research is needed to compare the results with data for healthy children.

Disulfiram Implantation for the Treatment of Alcoholism: Clinical Experiences from the Plastic Surgeon's Point of View

  • Sezgin, Billur;Sibar, Serhat;Bulam, Hakan;Findikcioglu, Kemal;Tuncer, Serhan;Dogan, Bilge
    • Archives of Plastic Surgery
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    • v.41 no.5
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    • pp.571-575
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    • 2014
  • Background Disulfiram implantation is a widely used treatment alternative for alcohol abuse, yet reports on the surgical aspect of disulfiram implantation with respect to patient and drug-related treatment efficacy and wound complications are very limited. We present our clinical experiences with disulfiram implantation and discuss the surgical outcomes obtained with different anatomical planes for implantation. Methods Medical records of all patients referred to our clinic from the psychiatry department between 2007 and 2013 for disulfiram implantation were retrospectively analyzed. Implantation was carried out using 10 sterile Disulfiram tablets (WZF Polfa S.A.), each tablet containing 100 mg of disulfiram. The procedure was carried out by implanting the tablets randomly in either a subcutaneous or an intramuscular plane. The location and the plane of implantation and the complications were recorded for each patient and compared to determine the differences in the outcomes. Results A total of 32 implantation procedures were evaluated for this study. Twenty-five implants were placed in the intramuscular plane (78.2%), while seven implants were placed subcutaneously (21.8%). Exposure was encountered in three of the seven subcutaneous implants (42.9%), while no exposure was seen with the intramuscular implants. Incomplete absorption of the tablets was encountered in one patient with a previous subcutaneous implant who presented 1 year later for re-implantation as part of the continuation of therapy. Conclusions To overcome the issue of treatment continuation in the case of disulfiram therapy, which may be ceased due to frequently encountered wound complications, we believe that implantation in the subscapular intramuscular plane allows both uneventful healing and an out-of-reach implant location.

Effect of Direct Breastfeeding Program for Premature Infants in Neonatal Intensive Care Unit (신생아집중치료실 미숙아를 위한 직접모유수유 프로그램의 효과: 비동등성 대조군 전후 설계)

  • Kang, Ji Hyun;Son, Hyunmi;Byun, Shin Yun;Han, Gyumin
    • Journal of Korean Academy of Nursing
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    • v.51 no.1
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    • pp.119-132
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    • 2021
  • Purpose: This study aimed to identify the effects of a direct breastfeeding program for premature infants in neonatal intensive care units (NICUs). Methods: This quasi-experimental study was conducted during August 2016 to April 2017. Sixty mothers of premature infants were assigned to the experimental (n = 31) or control groups (n = 29). The program was comprised of breastfeeding education and direct breastfeeding support. The experimental and control groups were provided with education and counseling on breastfeeding at the time of admission and discharge. In the experimental group, the mothers initiated oral feeding with direct breastfeeding and engaged in breastfeeding at least seven times during the NICU stay. The collected data were analyzed by the χ2-test and repeated measures ANOVA using an SPSS program. Results: The experimental group showed a higher direct breastfeeding practice rate (χ2 = 19.29, p < .001), breastfeeding continuation rate (χ2 = 3.76, p < .001), and self-efficacy (F = 25.37, p < .001) than the control group except for maternal attachment. Conclusion: The direct breastfeeding program in the NICU has significant effects on the practice and continuation rate of breastfeeding and breastfeeding self-efficacy. Therefore, this program can be applied in the NICU settings where direct breastfeeding is limited.

Nutritional Status Indicators Affecting the Tolerability of Postoperative Chemotherapy After Total Gastrectomy in Patients With Gastric Cancer

  • Toyota, Kazuhiro;Mori, Masayuki;Hirahara, Satoshi;Yoshioka, Shoko;Kubota, Haruna;Yano, Raita;Kobayashi, Hironori;Hashimoto, Yasushi;Sakashita, Yoshihiro;Yokoyama, Yujiro;Murakami, Yoshiaki;Miyamoto, Katsunari
    • Journal of Gastric Cancer
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    • v.22 no.1
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    • pp.56-66
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    • 2022
  • Purpose: Nutritional problems after gastrectomy affect continuation of postoperative chemotherapy. There have been no studies limited to total gastrectomy, which is particularly prone to nutritional problems. In this study, we aimed to investigate the factors that predict the continuation of postoperative chemotherapy. Materials and Methods: We included 101 patients who underwent curative total gastrectomy and postoperative chemotherapy at Hiroshima Memorial Hospital. The effects of 37 factors, including perioperative inflammatory, nutritional, and tumor status, on the persistence of postoperative chemotherapy were analyzed. Results: In univariate analysis of preoperative factors, age, carbohydrate antigen 19-9, platelet-to-neutrophil ratio, Onodera's prognostic nutritional index (PNI), controlling nutritional status score, and nutritional risk screening (NRS-2002) score were significantly associated with the duration of postoperative chemotherapy. In multivariate analysis of preoperative factors, age (≥74 years) was an independent factor for a shorter duration of postoperative chemotherapy (hazard ratio [HR], 5.24; 95% confidence interval [CI], 2.19-12.96; P<0.01). In univariate analysis of factors before postoperative chemotherapy, intraoperative blood loss, perioperative weight loss rate, postoperative performance status, PNI, albumin-to-bilirubin index, and NRS-2002 score were significantly associated with the duration of postoperative chemotherapy. In multivariate analysis of factors before postoperative therapy, age (≥74 years) (HR, 5.75; 95% CI, 1.90-19.49; P<0.01) and PNI (<39) (HR, 3.29; 95% CI, 1.26-8.56; P=0.02) were independent factors for a shorter duration of postoperative chemotherapy. Conclusions: Age and PNI are useful predictors of postoperative chemotherapy intolerance after total gastrectomy and may determine the treatment strategy and timing of chemotherapy initiation.

Image Contour Extraction Method base on Gestalt Theory (형태 이론에 기반한 이미지 윤곽선 추출 방법)

  • Ha, Chu-Ja;Kim, Cheol-Won
    • Journal of Advanced Navigation Technology
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    • v.13 no.2
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    • pp.257-261
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    • 2009
  • This paper propose a new method using Gestalt theory to extract image contour. The proposed method use Gestalt theory based on proximity, similarity and continuation for grouping objects from image segmentation. It use downward feedback and perception to materialize one visual level in image from heterogeneity visual levels in image. The experimental result show that the proposed method achieves better performance than other methods.

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The role of softening in the numerical analysis of R.C. framed structures

  • Bontempi, Franco;Malerba, Pier Giorgio
    • Structural Engineering and Mechanics
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    • v.5 no.6
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    • pp.785-801
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    • 1997
  • Reinforced Concrete beams with tension and compression softening material constitutive laws are studied. Energy-based and non-local regularisation techniques are presented and applied to a R.C. element. The element characteristics (sectional tangent stiffness matrix, element tangent stiffness matrix restoring forces) are directly derived from their symbolic expressions through numerical integration. In this way the same spatial grid allows us to obtain a non-local strain estimate and also to sample the contributions to the element stiffness matrix. Three examples show the spurious behaviors due to the strain localization and the stabilization effects given by the regularisation techniques, both in the case of tension and compression softening. The possibility to overestimate the ultimate load level when the non-local strain measure is applied to a non softening material is shown.

How to Improve Field Practices for Technical Highschools -By Analyzing the Requests by People-in-charge of Industries- (산업체 담당자의 요구 분석에 터한 공업계 고등학교 현장실습 개선 방안)

  • Woo, Yeoun-Jay;Lee, Chang-Hoon;Kim, Ki-Soo
    • 대한공업교육학회지
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    • v.30 no.2
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    • pp.12-22
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    • 2005
  • This study analyzes the requests by the people-in-charge in industries and presents methods to improve field practice systems for technical highschools. Requests from 43 industries in Korea were analyzed. The results about improvement methods for field practices are as follows: First of all, the study suggests the same educational curriculums and number of courses for the 10th grade (National Manditory and Basic Curriculum) and the 11th grade (Elective Program) both in general technical highschools and in "2+1 system" technical highschools. The school offers a dual program: completion and continuation curriculums. In the 12th grade, students choose their careers. Students can participate in field practice as a completion education. In other words, the same curriculums are operated in 10th and 11th grades for students who want to go to college and to get jobs. The different curriculum is arranged for the 12th grade. This system can allow flexibility in curriculum operation for students who want to change their careers or who drop in the middle of filed practice. Students who come back to schools in the middle of field practice are asked to complete technical courses and evaluated like in general technical highschools.