• 제목/요약/키워드: control threshold

검색결과 1,141건 처리시간 0.031초

An Optimal Thresholding Method for the Voxel Coloring in the 3D Shape Reconstruction

  • Ye, Soo-Young;Kim, Hyo-Sung;Yi, Young-Youl;Nam, Ki-Gon
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.1695-1700
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    • 2005
  • In this paper, we propose an optimal thresholding method for the voxel coloring in the reconstruction of a 3D shape. Our purposed method is a new approach to resolve the trade-off error of the threshold value on determining the photo-consistency in the conventional method. Optimal thresholding value is decided to compare the surface voxel of photo-consistency with inside voxel on the optic ray of the center camera. As iterating the process of the voxels, the threshold value is approached to the optimal value for the individual surface voxel. And also, graph cut method is reduced to the surface noise on eliminating neighboring voxel. To verify the proposed algorithm, we simulated in the virtual and real environment. It is advantaged to speed up and accuracy of a 3D face reconstruction by applying the methods of optimal threshold and graph cut as compare with conventional algorithms.

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염화물 혼입 콘크리트 중의 철근부식 임계 염화물량 (Threshold Chloride Contents of Steel Corrosion in Concrete Containing Chloride)

  • 문한영;김성수;김홍삼;이승태;김은호
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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    • pp.395-398
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    • 2000
  • Recently, increasement of usage contents of sea sand in constructing concrete structures due to insufficiency of high quality river sand, led to many studies for steel corrosion and control methods on it in concrete. But, domestic studies for threshold chloride contents of steel corrosion are not so many as those of foreign states. In this study, the electrochemical test as half cell potential measurement and linear polarization method to estimate the corrosion of steel in contents mixed with several levels chloride contents was performed, thereby, pre-mixed chloride were compared with results measured quantitatively for steel corrosion. And, based on these data, a trial to determine threshold chloride contents of steel corrosion was made.

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ATM 네트워크에서 TCP 성능향상을 위한 평균 전송율 기반의 버퍼관리 알고리즘 (A Rate-Based Buffer Management Algorithm to Improve TCP Performance over ATM networks)

  • 김관웅;이창기
    • 한국통신학회논문지
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    • 제29권2B호
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    • pp.263-271
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    • 2004
  • 본 논문에서는 perVC-Queuing 기반의 버퍼관리알고리즘을 제안한다. 제안된 알고리즘은 서비스 율 측정과 동적 VC 임계치를 사용하여 GFR VC에 네트워크 자원을 공정하게 분배하고 모든 VC가 요구하는 MCR을 보장한다. 컴퓨터 시뮬레이션결과 제안된 알고리즘이 GFR 서비스 클래스가 요구하는 QoS를 보장하고 TCP의 성능을 향상하였다.

ATM 망용 우선순위제어 알고리즘의 개선에 관한 연구 (A Study on the Enhancement of Priority control Algorithm for ATM Network)

  • 정상국;진용옥
    • 전자공학회논문지A
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    • 제31A권2호
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    • pp.9-17
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    • 1994
  • This paper proposes Double queue threshold QLT(Queue Length Threshold) algorithm and Hysteresis effect QLT algorithm. as being DPS(Dynamic Priority Scheduling) techniques. in order to advance the processing of multiple class traffics. Also, the performance of the proposed algorithms is analyzed through computer simulations,and the priority scheduling is analyzed using a retrial queue with two types of calls. Our simulation results show that the performance of the proposed Double queue length threshold QLT algorithm is superior to that of the conventinal QLT algorithm for 2 or more classes delay sensitive traffics. Also we find that Hysteresis effecT QLT algorithm is better mechanism than that of the existing QLT for real time and non-real time traffics.

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Thiamine deficiency as one of the mechanisms for neurotoxicity induced by lead intoxication in rats.

  • Cheong, Jae-Hoon;Ryu, Jae-Ryeon;Kim, Hye-Chung;Lee, Sang-Derk;Ko, Kwang-Ho
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1995년도 제3회 추계심포지움
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    • pp.137-146
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    • 1995
  • In this study, it was tested whether lead intoxication could change thiamine content and the thiamine related biochemical factor such as activity of transketolase in the brain, and whether the changes of the myelin composition :s well as the seizure threshold induced by lead intoxication in rats be related to these changes of thiamine status and thiamine related biochemical factors. In addition, it was also tested whether administration of excessive thiamine can reverse the toxic manifestation of lead in lead intoxicated animals. Five groups of Wistar rats were prepared: 1)Control group, 2)lead treated group, 3)thiamine treated group, 4)lead plus thiamine treated group and 5)thiamine deficiency group. Each group of animals was divided into three subgroups based on ages: 3, 7 and 10 weeks of age subgroups. Lead concentration, thiamine content, the activity of transketolase and myelin composition in brain areas and threshold of electric shock seizure were tested in each group. Lead concentrations in all brain regions of lead treated group were higher than those of control group, and those of lead plus thiamine treated group were significantly lower than those of lead treated group. Thiamine contents in the brain regions of lead treated group were significantly lower than those of control group, and those of lead plus thiamine treated group were recovered back to those of control group. Activities of transketolase of lead treated group were significantly lower than those of control group, while those of lead plus thiamine treated group were recovered back to those of control group. The cases of which was observed with the concomitant changes of thiamine content and transketolase activity in myelin content or constituent of all the brain regions tested were total amount of myelin protein in the cerebellum of 3 week old rats, and phospholipid in the cerebellum of 3 week old rats and the telencephalon of 16 week old rats. Thresholds of the electroshock seizure of lead-treated group and thiamine-deficient group in 3, 7 week old rats were significantly lower than those of control group, while those of the lead plus thiamine-treated group were similar to those of control group. Changes of the electroshock seizure threshold induced by lead intoxication were observed in 3 week and 7 week old animals with the concomitant decrement of thiamine content in all the brain regions tested. These observations were reversed by the supplementation with thiamine to those animals. However, the changes of seizure threshold induced by lead intoxication corelated with the changes of thiamine contents as well as. transketolase due to lead intoxication. The changes of myelin phospholipid as one of myelin composition and those of myelin Protein content only in the cerebellum of 3 week old rats correlated with the changes of the seizure threshold as well as thiamine content due to lead intoxication. The results from the present study may indicate that neurotoxicity of lead in rats may be mediated at least in part through the changes of thiamine status. Such changes of thiamine status may induce the changes of myelin composition such as myelin phospholipid and those of myelin protein content especially in the cerebellum of 3 week old rats which may eventually affect the threshold of seizure.

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TENS와 SSP가 전류지각역치 및 통증역치에 미치는 효과 (The Effect of Current Perception Threshold and Pain Threshold through Transcutaneous Electrical Nerve Stimulation and Silver Spike Point Therapy)

  • 윤미정;이완희
    • The Journal of Korean Physical Therapy
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    • 제23권2호
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    • pp.53-59
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    • 2011
  • Purpose: This study was designed to compare the effects of transcutaneous electrical nerve stimulation (TENS) and silver spike point (SSP) therapy on current perception threshold (CPT) and mechanical pain threshold (MPT). Methods: Forty-five healthy adult male and female subjects were studied. Fourteen of them were males and twenty-one were females. Subject were randomly assigned to receive; (1) TENS (80/120 Hz alternating frequency), (2) SSP (3 Hz), or (3) no treatment (control group). Electric stimulation was applied over LI4 and LI11 on acupuncture points of the left forearm for 30 minutes. CPT and MPT were recorded before and after electrical stimulation. The data were analyzed using linear mixed models, with group treated as a between subject factor and time a within-subject factor. Results: At 30 minutes after cessation of electrical stimulation the CPT of C fibers and A${\delta}$fibers was reduced in the TENS group that of C fibers was reduced in the SSP group (p<0.05). After cessation of electrical stimulation, the MPT of C fibers and A${\delta}$fibers increased in the TENS group, and that of A${\delta}$fibers increased in the SSP group (p<0.05). Conclusion: After TENS and SSP stimulation, MPT of C fibers and A${\delta}$fibers were selectively increased. In particular, the TENS group showed increases in both C and A${\delta}$fibers, while the SSP group showed increases only in A${\delta}$fibers.

급성 및 아급성 천막상 허혈성 뇌졸중에서 발생하는 말초신경 흥분성 변화 (Altered Peripheral Nerve Excitability Properties in Acute and Subacute Supratentorial Ischemic Stroke)

  • 서정화;지기환;정은주;김상진;김응규;팽성화;배종석
    • Annals of Clinical Neurophysiology
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    • 제14권2호
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    • pp.64-71
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    • 2012
  • Background: It is generally accepted that upper motor neuron (UMN) lesion can alter lower motor neuron (LMN) function by the plasticity of neural circuit. However there have been only few researches regarding the axonal excitability of LMN after UMN injury especially during the acute stage. The aim of this study was to investigate the nerve excitability properties of the LMNs following an acute to subacute supratentorial corticospinal tract lesion. Methods: An automated nerve excitability test (NET) using the threshold tracking technique was utilized to measure multiple excitability indices in median motor axons of 15 stroke patients and 20 controls. Testing of both paretic and non-paretic side was repeated twice, during the acute stage and subacute stage. The protocols calculated the strength-duration time constant from the duration-charge curve, parameters of threshold electrotonus (TE), the current-threshold relationship from sequential sub-threshold current, and the recovery cycle from sequential supra-threshold stimulation. Results: On the paretic side, compared with the control group, significant decline of superexcitablity and increase in the relative refractory period were observed during the subacute stage of stroke. Additionally, despite the absence of statistical significance, a mildly collapsing in ('fanning in') of the TE was found. Conclusions: Our results suggest that supratentorial brain lesions can affect peripheral axonal excitability even during the early stage. The NET pattern probably suggests background membrane depolarization of LMNs. These features could be associated with trans-synaptic regulation of UMNs to LMNs as one of the "neural plasticity" mechanisms in acute brain injury.

Immediate Effects of Pulsed Magnetic Field in Subjects with Upper Trapezius Trigger Point

  • Kang, Sun-Young;Park, Joo-Hee;Song, Ja-Eik;Jeon, Hye-Seon;Lee, Hyun Sook
    • The Journal of Korean Physical Therapy
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    • 제26권6호
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    • pp.379-385
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    • 2014
  • Purpose: This study was to determine the immediate effects of pulsed magnetic field (PMF) in subjects with upper trapezius (UT) trigger point (TrP). Methods: Fifteen subjects with UT TrP were recruited for the study's PMF group (pain threshold=$2.29kg/cm^2$), and 15 age-, weight-, and gender-matched subjects with UT TrP were recruited for control group (pain threshold=$2.25kg/cm^2$). Pressure algometer was used to measure pressure pain threshold on UT TrP and, cervical range of motion (ROM) inclinometer was used to measure cervical ROM. Surface electromyography was used to record UT, lower trapezius, and serratus anterior muscle activity and relative ratio during scapular plane abduction between pre- and post-treatment. Results: The PMF effectively improved pain threshold and concurrently increased ROM (rotation to the painful side, lateral flexion to the nonpainful side). In addition, the PMF may effectively deactivate UT activity during abduction and the muscle activity ratio between UT and serratus anterior. Conclusion: These findings provided empirical evidence that PMF can be an effective treatment method to reduce pain threshold, to increase cervical ROM, and deactivate UT activity in individuals with TrP.

Phonation Threshold Flow and Phonation Threshold Pressure in Patients with Adductor Spasmodic Dysphonia

  • Choi, Seong-Hee;Jiang, Jack J.;Yun, Bo-Ram;Lee, Ji-Yeoun;Lim, Sung-Eun;Choi, Hong-Shik
    • 말소리와 음성과학
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    • 제2권3호
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    • pp.157-164
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    • 2010
  • This study investigated the characteristics of two aerodynamic indices, PTP (Phonation threshold pressure) and PTF (Phonation threshold flow) in patients with ADSD (adductor spasmodic dysphonia) and to see if two new aerodynamic indices can differentiate between normal and ADSD group. Additionally, PTP and PTF values were compared in terms of overall severity of ADSD in the patient group. The severity of ADSD was rated on a 7-point rating scale by two experienced speech language pathologists. The Kay Elemetrics Phonatory Aerodynamic System (PAS) (Kay Elemetrics Corp., Lincoln Park, NJ) was used to collect PTP and PTF measurements from 16 female normal subjects, 31 female patients with ADSD. Significantly lower PTF values (P< 0.05) were observed in ADSD when compared to those of normal control. Also, significantly lower PTF values in severe ADSD patients (P<.001). However, PTP could not distinguish patients with ADSD from control groups (P=0.119) and among the ADSD groups according to the severity (P=0.177). Consequently, PTF was more sensitive than PTP which might differentiate between normal speakers and ADSD and among different levels of severity within ADSD, suggesting that PTF could be a useful diagnostic parameter to measure the aerodynamic function of ADSD and provide the neurolaryngeal dysfunction in patients with ADSD.

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Effects of mechanical intervention on cutaneous sensory change and pressure pain threshold in the same spinal segment of myofascial pain

  • Kim, Do Hyung;Lee, Su-Hyun;Lee, Byoung Hee
    • Physical Therapy Rehabilitation Science
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    • 제8권1호
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    • pp.15-21
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    • 2019
  • Objective: The purpose of this study was to identify whether cutaneous sensory (CS) changes induced by mechanical intervention (MI) increases the trigger point threshold of the same spinal segment as well as to investigate the relationship between the amounts of change in CS pressure pain thresholds (PPT). Design: Randomized controlled trial. Methods: Thirty-nine persons with myofacial pain (MFP) were recruited in this experiment. The subjects consisted of 20 men and 19 women (age 20-39). MI was applied on the subjects using the Graston technique for 5 minutes to induce CS changes. The CS changes were measured with sensory tests by using the Von Frey Filament, and PPT changes were estimated by using the pressure threshold meter. For the observation of sensory and PPT changes with time, the test was conducted for 15 minutes including a pre, post, and after intervention session. Results: CS threshold increased significantly when MI was applied (p<0.001). On the same spinal segment, changes in the right infraspinatus PPT was observed (p<0.001) but the PPT changes in other muscles were not significantly different. Furthermore, the control group CS and PPT were not significantly different. In addition, regression analysis showed that the CS changes have a larger impact on PPT in the same spinal segment (p<0.001). Conclusions: CS changes induced by MI make to change PPT on the same spinal segment. In other words, it is possible to identify PPT changes following CS changes except for the muscle which belongs to a different spinal segment. Therefore, application of MI is necessary for the CS changes in the same spinal segment. Furthermore, it can be useful in the clinical fields as a method of providing pain control and increasing the PPT.