• Title/Summary/Keyword: Control thresholds

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Change of Balance Ability in Subjects with Pain-Related Temporomandibular Disorders

  • Ja Young Kim;Sang Seok Yeo
    • The Journal of Korean Physical Therapy
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    • v.34 no.6
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    • pp.321-325
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    • 2022
  • Purpose: Temporomandibular disorder (TMD) is a condition defined as pain and dysfunction of temporomandibular joints and masticatory muscles. Abnormal interconnections between temporomandibular muscles and cervical spine structures can cause the changes of postural alignment and balance ability. The aim of this study was to investigate changes in static balance ability in subjects with painrelated TMD. Methods: This study conducted on 25 subjects with TMD and 25 control subjects with no TMD. Pressure pain thresholds (PPTs) of the masseter and temporalis muscles were measured using a pressure algometer. Static balance ability was assessed during one leg standing using an Inertial Measurement Unit (IMU) sensor. During balance task, the IMU sensors measured motion and transfer movement data for center of mass (COM) motion, ankle sway and hip sway. Results: PPTs of masseter and temporalis muscles were significantly lower in the TMD group than in the control group (p<0.05). One leg standing, hip sway, and COM sway results were significantly greater in the TMD group (p<0.05), but ankle sways were not different between group. Conclusion: We suggest pain-related TMD is positively related to reduced PPTs of masticatory muscles and to static balance ability. These results should be considered together with global body posture when evaluating or treating pain-related TMD.

Complexity Control Method of Chaos Dynamics in Recurrent Neural Networks

  • Sakai, Masao;Homma, Noriyasu;Abe, Kenichi
    • Transactions on Control, Automation and Systems Engineering
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    • v.4 no.2
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    • pp.124-129
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    • 2002
  • This paper demonstrates that the largest Lyapunov exponent λ of recurrent neural networks can be controlled efficiently by a stochastic gradient method. An essential core of the proposed method is a novel stochastic approximate formulation of the Lyapunov exponent λ as a function of the network parameters such as connection weights and thresholds of neural activation functions. By a gradient method, a direct calculation to minimize a square error (λ - λ$\^$obj/)$^2$, where λ$\^$obj/ is a desired exponent value, needs gradients collection through time which are given by a recursive calculation from past to present values. The collection is computationally expensive and causes unstable control of the exponent for networks with chaotic dynamics because of chaotic instability. The stochastic formulation derived in this paper gives us an approximation of the gradients collection in a fashion without the recursive calculation. This approximation can realize not only a faster calculation of the gradient, but also stable control for chaotic dynamics. Due to the non-recursive calculation. without respect to the time evolutions, the running times of this approximation grow only about as N$^2$ compared to as N$\^$5/T that is of the direct calculation method. It is also shown by simulation studies that the approximation is a robust formulation for the network size and that proposed method can control the chaos dynamics in recurrent neural networks efficiently.

Influence of stress and pure tone audiometry on noise-exposed dental laboratory technicians by dental instrument (치과기공 소음 노출이 치기공과 학생의 스트레스와 순음청력에 미치는 영향)

  • Yon, Jung-Min;Lee, Ju-Hee;Kim, Dae-Hyun;Lee, Og-Kyoung
    • Journal of Digital Convergence
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    • v.14 no.4
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    • pp.363-370
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    • 2016
  • Noise is unwanted sound that is the reason of the stress and hearing loss. The current study attempted to estimate whether the noise of dental laboratory affected stress and pure tone audiometry (PTA) of dental laboratory technicians (DLTs) using heart rate variability, air and bone conduction audiometry. The age, heights, and weights of DLTs were resembled control. Standard deviation of normal to normal interval such as stress resistance and normalized HF of DLTs were significantly decreased, but heart rates, normalized LF, and LF/HF ratio of DLTs were significantly increased compared with control. In air conduction audiometry of DLTs, significant increments of thresholds encountered in 125, 250, 500, 1000, 2000, 3000, 4000, and 6000 Hz in the right ears and 125, 250, 500, 1000, and 2000 Hz in the left ears. Thresholds of bone conduction audiometry in both ears were significantly increased in 250, 500, 1000, 2000, and 4000 Hz. The findings in this study provide that stress and hearing loss observed in noise-exposed DLTs at dental laboratory. Therefore, proper safety precautions should be carried out at dental laboratory.

A Study on the Taste of Burning Mouth Syndrome Patients (구강작열감증후군 환자의 미각에 관한 연구)

  • Ko, Myung-Yun;Jang, Yong-Seog;Heo, Jun-Young;Ahn, Yong-Woo
    • Journal of Oral Medicine and Pain
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    • v.31 no.4
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    • pp.275-281
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    • 2006
  • The purpose of this study was to investigate whether there were any changes in taste function with buring mouth syndrome(BMS). 133 subjects (31 males and 99 females) were included for the study and they were categorized into 2 groups BMS 33 persons, control 100 persons) and investigated in the Dept. of Oral Medicine, Pusan National University Hospital from April,2005 to February,2006. The electrical taste thresholds were measured using an electrogustometer of 4 different sites in oral cavity (tongue tip, tongue lateral, circumvallate papillar and soft palate). The results were as follows : 1. The electrical taste threshold in BMS group was very significantly low. 2. The electrical taste thresholds in male and female of BMS group were significantly lower each other than those of control group 3. The electrical taste threshold of BMS group according to single/multiple lesions and chronicity were not different. 4. After treatment, electrical taste threshold and NAS decreased more significantly.

Performance Improvement of an Energy Efficient Cluster Management Based on Autonomous Learning (자율학습기반의 에너지 효율적인 클러스터 관리에서의 성능 개선)

  • Cho, Sungchul;Chung, Kyusik
    • KIPS Transactions on Computer and Communication Systems
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    • v.4 no.11
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    • pp.369-382
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    • 2015
  • Energy aware server clusters aim to reduce power consumption at maximum while keeping QoS(quality of service) compared to energy non-aware server clusters. They adjust the power mode of each server in a fixed or variable time interval to activate only the minimum number of servers needed to handle current user requests. Previous studies on energy aware server cluster put efforts to reduce power consumption or heat dissipation, but they do not consider energy efficiency well. In this paper, we propose an energy efficient cluster management method to improve not only performance per watt but also QoS of the existing server power mode control method based on autonomous learning. Our proposed method is to adjust server power mode based on a hybrid approach of autonomous learning method with multi level thresholds and power consumption prediction method. Autonomous learning method with multi level thresholds is applied under normal load situation whereas power consumption prediction method is applied under abnormal load situation. The decision on whether current load is normal or abnormal depends on the ratio of the number of current user requests over the average number of user requests during recent past few minutes. Also, a dynamic shutdown method is additionally applied to shorten the time delay to make servers off. We performed experiments with a cluster of 16 servers using three different kinds of load patterns. The multi-threshold based learning method with prediction and dynamic shutdown shows the best result in terms of normalized QoS and performance per watt (valid responses). For banking load pattern, real load pattern, and virtual load pattern, the numbers of good response per watt in the proposed method increase by 1.66%, 2.9% and 3.84%, respectively, whereas QoS in the proposed method increase by 0.45%, 1.33% and 8.82%, respectively, compared to those in the existing autonomous learning method with single level threshold.

Effects of Hetero-segmental Electro-acupuncture on Formalin Induced Pain in the Rat (거자법(巨刺法)에 의한 전침자극(電鍼刺戟)이 흰쥐의 formalin 유도(誘導) 통증(痛症)에 미치는 영향(影響))

  • Park, Sang-Kyun;Kim, Jae-Hyo;Kim, Min-Sun;Park, Byung-Rim;Sohn, In-Chul;Kim, Kyung-Sik
    • Journal of Acupuncture Research
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    • v.17 no.2
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    • pp.231-246
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    • 2000
  • Acupuncture has been used for treatment of numerous diseases, especially for pain control in the oriental culture. However, the mechanism of pain control by acupuncture was not clear so far. The present study was examined that the effects of electro-acupuncture (EA) applied to the acu-point of extra-segmental area on modulation of formalin induced pain in Sprague - Dawley rats. In order to apply EA to acu-points in the plantar area of right fore paws, a pair of teflon - coated stainless steel wires were implanted in HT 7 (shin-mun) and PC 7 (dae-neong) 5 days before behavioral test. A behavioral test was performed by means of video camera after injection of 5% formalin ($50{\mu}l$) into the lateral plantar region of left hind paw. EA was delivered by a constant current stimulator at 4~5 mA, 2 ms, and 10 Hz for 30 min. The electromyographic activities were recorded in the biceps femoris muscle under chloral hydrate anesthesia. Test stimuli with 1~9mA were applied to the sural nerve territory including the medial portion of the 4th toe and the lateral portion of the 5th toe. Behavioral responses including favoring, flinching and bitting were occured in the biphasic pattern, such as the lst phase (0~5 min) and the 2nd phase (20~45 min) after formalin injection. However, EA (4~5 mA, 2 ms, 10 Hz) significantly inhibited Che behavioral responses. EMG activities of flexor reflex had a latency of 100~300 ms and thresholds of test stimuli for EMG were 4~5 mA in normal rats. Injection of formalin decreased threshold of test stimuli and increased EMG activities for 2hrs after injection. However, EA significantly inhibited EMG activities of flexor reflex increased by formalin and recovered EMG evoked thresholds. These results suggest that contralateral extra-segmental EA inhibits the first and second phases of formalin induced pain but their mechanism be needed to examine additionally.

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Evaluation of Gustatory Function in Patients with Sleep Disordered Breathing

  • Ahn, Jong-Mo;Bae, Kook-Jin;Yoon, Chang-Lyuk;Ryu, Ji-Won
    • Journal of Oral Medicine and Pain
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    • v.39 no.1
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    • pp.10-14
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    • 2014
  • Purpose: The aim of this study is to evaluate the difference between gustatory functions in a sleep disordered breathing (SDB) group and a control group. The pathogenesis of SDB has not been fully understood. Though the precise contributions of neuromuscular and anatomical factors on SDB pathogenesis are still debated, we hypothesized that the gustatory dysfunction could be predisposed to SDB. Methods: All patients were diagnosed as SDB by polysomnography (PSG). On the basis of PSG results, patients were divided into 3 groups: snoring, mixed, and obstructive sleep apnea (OSA). The control group comprised healthy volunteers who were the same age as those of the SDB group and whose breathing was verified as normal using a portable sleep monitor device. The patient group and the control group were evaluated for gustatory functions with an electrogustometry (EGM). The electrical taste thresholds were measured in the anterior, midlateral, and posterior sides of the tongue and soft palatal regions, both sides. To find out the difference in EGM scores, statistical analysis was performed using the Kruskal-wallis and Mann-Whitney U test with 95% confidence interval and p<0.05 significance level. Results: The patients with SDB had higher EGM scores than the control group at all spots tested, except for the right midlateral of the tongue, and there was a statistical significance in the comparison between the control group and the divided SDB groups, respectively. Among the divided SDB groups, the snoring group had the most significant differences in the number of the measured spots, but there was no difference among the snoring, mixed, and OSA groups. Conclusions: These results may suggest that neurologic alterations with sleep disordered breathing could be associated with gustatory dysfunction. In the future, further systemic studies will be needed to confirm this study.

One-Step-Ahead Control of Waveform and Detection Threshold for Optimal Target Tracking in Clutter (클러터 환경에서 최적의 표적 추적을 위한 파형 파라미터와 검출문턱 값의 One-Step-Ahead 제어)

  • Shin Han-Seop;Hong Sun-Mog
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.43 no.1 s.307
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    • pp.31-38
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    • 2006
  • In this paper, we consider one-step-ahead control of waveform parameters (pulse amplitudes and lengths, and FM sweep rate) as well as detection thresholds for optimal range and range-rate tracking in clutter. The optimal control of the combined parameter set minimizes a tracking performance index under a set of parameter constraints. The performance index includes the probability of track loss and a function of estimation error covariances. The track loss probability and the error covariance are predicted using a hybrid conditional average algorithm The effect of the false alarms and clutter interference is taken into account in the prediction. Tracking performance of the one-step-ahead control is presented for several examples and compared with a control strategy heuristically derived from a finite horizon optimization.

Performance improvement of ER switch congestion control algorithm for ABR service in ATM network (ATM망에서 ABR 서비스를 위한 ER 스위치 폭주 제어 알고리즘의 성능 개선)

  • 김운하;박성곤;조용환
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.9
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    • pp.1890-1906
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    • 1997
  • A new ER feedback switch control algorithm, called EMRCA(Explicit Max-min Rate Control Algorithm), to control the ABR services traffic in the ATM networks, is proposed in this thesis. This scheme was interpreted the ACR variation residing on between a transient state and a stable state using the two thresholds that is the $TH_{high}$ and $TH_{low}$ in the queue to detect switch nodes congestion, and decreased the difference of minimum and maximum ACR all active connection to enhance the line bandwidth utilization. The proiposed scheme used a minimum and maximum rate of all active connections to select the connection whose the congestion rate inveoked, and uses a congestion detection mechanixm to prevent some potential cogestion by regulating selected contection.s The EMRCA scheme showed ACR variation more stable that the EPRCA scheme, also reduced buffer size of the switch, and achieved higher link utilization than the EPRCA scheme.

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Allopregnanolone suppresses mechanical allodynia and internalization of neurokinin-1 receptors at the spinal dorsal horn in a rat postoperative pain model

  • Fujita, Masahide;Fukuda, Taeko;Sato, Yasuhiro;Takasusuki, Toshifumi;Tanaka, Makoto
    • The Korean Journal of Pain
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    • v.31 no.1
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    • pp.10-15
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    • 2018
  • Background: To identify a new strategy for postoperative pain management, we investigated the analgesic effects of allopregnanolone (Allo) in an incisional pain model, and also assessed its effects on the activities of the primary afferent fibers at the dorsal horn. Methods: In experiment 1, 45 rats were assigned to Control, Allo small-dose (0.16 mg/kg), and Allo large-dose (1.6 mg/kg) groups (n = 15 in each). The weight bearing and mechanical withdrawal thresholds of the hind limb were measured before and at 2, 24, 48, and 168 h after Brennan's surgery. In experiment 2, 16 rats were assigned to Control and Allo (0.16 mg/kg) groups (n = 8 in each). The degree of spontaneous pain was measured using the grimace scale after the surgery. Activities of the primary afferent fibers in the spinal cord (L6) were evaluated using immunohistochemical staining. Results: In experiment 1, the withdrawal threshold of the Allo small-dose group was significantly higher than that of the Control group at 2 h after surgery. Intergroup differences in weight bearing were not significant. In experiment 2, intergroup differences in the grimace scale scores were not significant. Substance P release in the Allo (0.16 mg/kg) group was significantly lower than that in the Control group. Conclusions: Systemic administration of Allo inhibited mechanical allodynia and activities of the primary afferent fibers at the dorsal horn in a rat postoperative pain model. Allo was proposed as a candidate for postoperative pain management.