• Title/Summary/Keyword: threshold methods

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The Effects of Joint Mobilization and TENS on Pain Threshold and Hormonal Changes in Patients with Chronic Low Back Pain (관절가동술과 TENS가 만성요통환자의 통증역치 및 호르몬 변화에 미치는 영향)

  • Lee, Seung-byung;Jeong, Seong-gwan;Lee, Ho-jun
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.26 no.1
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    • pp.65-72
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    • 2020
  • Background: The purpose of this research is to investigate the effects of joint mobilization and transcutaneous electrical nerve stimulation (TENS) on pain threshold and hormonal changes in patients with chronic LBP. Methods: 14 patients with chronic LBP were divided into the experimental group and the control group with 7 patients each, and both groups of patients were evaluated on pain duration, blood tests, and pressure pain threshold (PPT) on their first visit. On their second visit, joint mobilization was applied to the experimental group for 10 min and TENS to the control group for 20 min. Results: Pain threshold and duration of analgesia increased from after treatment in the experimental group. Serotonin and Cortisol decreased after treatment in the experimental group. Conclusion: Joint mobilization in patients with chronic LBP caused an increase in pain duration and pain thresholds and a decrease in serotonin, whereas there was little difference in cortisol.

Study on lowering the percolation threshold of carbon nanotube-filled conductive polypropylene composites

  • Park, Seung Bin;Lee, Moo Sung;Park, Min
    • Carbon letters
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    • v.15 no.2
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    • pp.117-124
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    • 2014
  • Conductive polymer composites (CPCs) consist of a polymeric matrix and a conductive filler, for example, carbon black, carbon fibers, graphite or carbon nanotubes (CNTs). The critical amount of the electrically conductive filler necessary to build up a continuous conductive network, and accordingly, to make the material conductive; is referred to as the percolation threshold. From technical and economical viewpoints, it is desirable to decrease the conductive-filler percolation-threshold as much as possible. In this study, we investigated the effect of polymer/conductive-filler interactions, as well as the processing and morphological development of low-percolation-threshold (${\Phi}c$) conductive-polymer composites. The aim of the study was to produce conductive composites containing less multi-walled CNTs (MWCNTs) than required for pure polypropylene (PP) through two approaches: one using various mixing methods and the other using immiscible polymer blends. Variants of the conductive PP composite filled with MWCNT was prepared by dry mixing, melt mixing, mechanofusion, and compression molding. The percolation threshold (${\Phi}c$) of the MWCNT-PP composites was most successfully lowered using the mechanofusion process than with any other mixing method (2-5 wt%). The mechanofusion process was found to enhance formation of a percolation network structure, and to ensure a more uniform state of dispersion in the CPCs. The immiscible-polymer blends were prepared by melt mixing (internal mixer) poly(vinylidene fluoride) (PVDF, PP/PVDF, volume ratio 1:1) filled with MWCNT.

Automatic Thresholding Selection for Image Segmentation Based on Genetic Algorithm (유전자알고리즘을 이용한 영상분할 문턱값의 자동선정에 관한 연구)

  • Lee, Byung-Ryong;Truong, Quoc Bao;Pham, Van Huy;Kim, Hyoung-Seok
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.6
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    • pp.587-595
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    • 2011
  • In this paper, we focus on the issue of automatic selection for multi-level threshold, and we greatly improve the efficiency of Otsu's method for image segmentation based on genetic algorithm. We have investigated and evaluated the performance of the Otsu and Valley-emphasis threshold methods. Based on this observation we propose a method for automatic threshold method that segments an image into more than two regions with high performance and processing in real-time. Our paper introduced new peak detection, combines with evolution algorithm using MAGA (Modified Adaptive Genetic Algorithm) and HCA (Hill Climbing Algorithm), to find the best threshold automatically, accurately, and quickly. The experimental results show that the proposed evolutionary algorithm achieves a satisfactory segmentation effect and that the processing time can be greatly reduced when the number of thresholds increases.

Voltage and Frequency Tuning Methodology for Near-Threshold Manycore Computing using Critical Path Delay Variation

  • Li, Chang-Lin;Kim, Hyun Joong;Heo, Seo Weon;Han, Tae Hee
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.15 no.6
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    • pp.678-684
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    • 2015
  • Near-threshold computing (NTC) is now regarded as a promising candidate for innovative power reduction, which cannot be achieved with conventional super-threshold computing (STC). However, performance degradation and vulnerability to process variation in the NTC regime are the primary concerns. In this paper, we propose a voltage- and frequency-tuning methodology for mitigating the process-variation-induced problems in NTC-based manycore architectures. To implement the proposed methodology, we build up multiple-voltage multiple-frequency (MVMF) islands and apply a voltage-frequency tuning algorithm based on the critical-path monitoring technique to reduce the effects of process variation and maximize energy efficiency in the post-silicon stage. Experimental results show that the proposed methodology reduces overall power consumption by 8.2-20.0%, compared to existing methods in variation-sensitive NTC environments.

The Clinical Effects of Heating-Conduction Acupuncture Therapy(tentatively called) for Anterior Talofibular Ligament Injury Induced by Acute Ankle Sprain (전열침(가칭)이 급성 족관절 염좌로 인한 전거비 인대 손상에 미치는 임상적 효과)

  • An, Soon-Sun;Jang, Hyo-Kil;Heo, Dong-Seok
    • Journal of Korean Medicine Rehabilitation
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    • v.19 no.4
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    • pp.127-134
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    • 2009
  • Objectives : The purpose of this study is to investigate the clinical effects of heating-conduction acupuncture therapy on anterior talofibular ligament injury induced by acute ankle sprain. Methods : From October 31, 2008 to July 21, 2009, the 11 outpatients who had admitted to department of oriental rehabilitation medicine, Dae-Jeon oriental medicine hospital, Dae-Jeon university with acute ankle sprain were performed heating-conduction acupuncture therapy on anterior talofibular ligament injury. To evaluate the efficiency of heating-conduction acupuncture therapy, pain threshold with Pressure algometer and visual analogue scale(VAS) were applied before treatment and after 1st, 2nd treatment. Results : 1. The pain threshold score and the VAS score showed statistical significant improvement after 1st treatment. 2. The pain threshold score and the VAS score showed improvement but had no statistical significance after 2nd treatment. 3. The difference between left and right were not statistical significant in pain threshold score and VAS score. Conclusions : Heating-conduction acupuncture therapy has clinical effects of pain reduction on patient with anterior talofibular ligament injury induced by acute ankle sprain.

Effects of Multi-site and Single-site Functional Massage and Stretching on Pain, Tenderness Threshold and Grip Strength in Patients with Lateral Epicondylalgia (가쪽위관절융기 통증 환자에서 복합 부위와 단일 부위에 기능적 마사지와 스트레칭을 적용할 때 통증, 압통 역치와 악력에 미치는 영향)

  • Min-keun Jung;Jae-guk Jeon;Eui-joo Shin
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.29 no.3
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    • pp.13-22
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    • 2023
  • Background: The purpose of this study was to investigate the effects of functional massage and stretching, applied to the elbow and shoulder joints, on pain, tenderness threshold, and grip strength. Methods: A total of 29 individuals were assigned to a single site (n=15) or multiple sites (n=14). Pain measured through the visual analogue scale (VAS), tenderness threshold (TTH), and grip strength (GI) were measured before and four weeks after the intervention. Results: After four weeks of treatment, visual analogue scale significantly decreased in both groups (p<.05), and the tenderness threshold and grip strength significantly increased in both groups (p<.05). There was also a significant difference between the two groups (p<.05). Conclusion: The reduction of visual analogue scale and the increase in the tenderness threshold and grip strength were more significant in the multi-site treatment group than in the single-site treatment group.

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JPEG Image Quantization Method with Variable Thresholds (가변 임계값을 갖는 JPEG 영상의 양자화 방법)

  • O, Ha-Ryeong;Yun, Seok-Hyeon;Seong, Yeong-Rak
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.11
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    • pp.3150-3156
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    • 1999
  • In this paper, VTQM(Variable Threshold Quantization Method) is proposed, which enhances PSNR by composing the advantages of round-off and truncation quantization methods. From vast experiments, PSNR's of JPEG images with the method are compared with that of standard JPEG methods. At the boundary which affects the compression ratio, VTQM quantizes with a new threshold to reduce the length of compressed data; otherwise, VTQM employs the round-off quantization method to preserve the original image information. As a result, VTQM reduces bit rate while preserving the image quanity. The experimental results show that VTQM enhances PSNR by 0.2-0.3dB., 0.4-0.5dB, with the same bit rate than those of the traditional truncation and round-off quantization methods, respectively.

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Surface Extraction from Multi-material CT Data

  • Fujimori, Tomoyuki;Suzuki, Hiromasa
    • International Journal of CAD/CAM
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    • v.6 no.1
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    • pp.81-87
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    • 2006
  • This paper describes a method for extracting surfaces from multi-material CT (Computed Tomography) data. Most contouring methods such as Marching Cubes algorithm assume that CT data are composed of only two materials. Some extended methods such as [3, 6] can extract surfaces from the multi-material (non-manifold) implicit representation. However, these methods are not directly applicable to CT data that are composed of three or more materials. There are two major problems that arise from fundamentals of CT. The first problem is that we have to use n(n-1)/2 threshold values for CT data contains n materials and select appropriately one threshold value for each boundary area. The second is that we cannot reconstruct only from CT data in which area three or more materials are adjacent each other. In this paper, we propose a method to solve the problems by using image analysis and demonstrate the effectiveness of the method with application examples construct polygon models from CT data of machine parts.

Multilevel Threshold Selection Method Based on Gaussian-Type Finite Mixture Distributions (가우시안형 유한 혼합 분포에 기반한 다중 임계값 결정법)

  • Seo, Suk-T.;Lee, In-K.;Jeong, Hye-C.;Kwon, Soon-H.
    • Journal of the Korean Institute of Intelligent Systems
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    • v.17 no.6
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    • pp.725-730
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    • 2007
  • Gray-level histogram-based threshold selection methods such as Otsu's method, Huang and Wang's method, and etc. have been widely used for the threshold selection in image processing. They are simple and effective, but take too much time to determine the optimal multilevel threshold values as the number of thresholds are increased. In this paper, we measure correlation between gray-levels by using the Gaussian function and define a Gaussian-type finite mixture distribution which is combination of the Gaussian distribution function with the gray-level histogram, and propose a fast and effective threshold selection method using it. We show the effectiveness of the proposed through experimental results applied it to three images and the efficiency though comparison of the computational complexity of the proposed with that of Otsu's method.

The Comparative Study on the Effect of Trigger Point Treatment, Self-Exercise Treatment, Trigger Point - Self-Exercise Cooperative Treatment for Neck Pain Caused by Traffic Accidents (교통사고 후 경항통 발생환자 중 Trigger Point 치료군, 자가운동 치료군, Trigger Point 및 자가운동 병행 치료군 비교연구)

  • Lee, Hyun-Jae;Park, Jung-Oh;Oh, Min-Seok
    • Journal of Korean Medicine Rehabilitation
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    • v.24 no.2
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    • pp.131-140
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    • 2014
  • Objectives This study was aimed at comparing clinical effectiveness among trigger point treatment, Self-exercise treatment, trigger point - self-exercise cooperative treatment for neck pain caused by traffic accidents. Methods 63 patients with neck pain by traffic accidents were divided into 3 groups. Different types of treatments were carried out for each groups ; group A with trigger point, group B with self-exercise, group C with trigger point and self-exercise cooperative treatment. 3 groups were also treated with general acupuncture and herb-medicine treatment. Pain threshold, visual analogue scale (VAS), and neck disability index (NDI) were checked on a daily basis. SPSS ver. 18.0 for Windows was used for analysis of data. The effectiveness of treatment of each groups were verified by using paired test and one-way repeated-measures ANOVA test, and the comparison of VAS, NDI and pain threshold were demonstrated by independent samples t-test. Results 3 groups all showed significant difference in pain threshold, VAS and NDI after 8 days later. Group C showed more improvement in pain threshold, VAS and NDI than shown in group A and B. In the first period (from pre-treatment to 4th day treatment) group C showed significant difference in NDI and pain threshold but not in VAS as compared to group A and B. In the second period (from 4th treatment to 8th day treatment), Group C showed significant difference in pain threshold, VAS and NDI as compared to group A and B. Conclusions Trigger point - self-exercise cooperative treatment is proved to be more helpful to improve the unstability and reduce neck pain than trigger point treatment or self-exercise treatment only, therefore eventually leading to better satisfaction for patients with neck pain.