• Title/Summary/Keyword: Fatigue Evaluation

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Surface Electromyographic Characteristics of a Myofascial Trigger Point of the Temporalis Muscle: A Case Report (측두근의 근막동통 발통점의 표면 근전도 특성: 증례 보고)

  • Im, Yeong-Gwan;Baek, Hey-Sung;Lee, Guem-Sug;Kim, Byung-Gook
    • Journal of Oral Medicine and Pain
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    • v.38 no.3
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    • pp.261-266
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    • 2013
  • Myofascial pain is a condition associated with regional pain and muscle tenderness characterized by the presence of myofascial trigger points. In this case report, a subject complaining of nighttime bruxism was clinically assessed, and a latent trigger point of the anterior temporalis muscle was identified with manual palpation. A surface electromyographic (SEMG) exam of the anterior temporalis muscle harboring the latent trigger point demonstrated several SEMG features, including post-contraction irritability, delayed relaxation following contraction and accelerated muscle fatigue. It was concluded that a SEMG exam may detect abnormal masticatory muscle function and, therefore, assist in the evaluation of myogenous temporomandibular disorders.

Psychiatric Characteristics According to Tinnitus Severity (이명 심각도에 따른 정신의학적 특징)

  • Kim, Jae Hong;Kim, Jung Ho;Cho, Sung Il;Park, Sang Hag;Kim, Sang Hoon;Choo, Il Han;Kim, Seung Gon
    • Korean Journal of Biological Psychiatry
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    • v.22 no.1
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    • pp.7-13
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    • 2015
  • Objectives The purpose of this study was to examine the psychiatric characteristics of outpatients with tinnitus. Methods A total of 88 subjects were included in this study. According to Tinnitus Handicap Inventory (THI) scores, the subjects were classified into two group ; a mild tinnitus symptoms (mild-tinnitus) group and a severe tinnitus symptoms (severe-tinnitus) group. A questionnaire was used for an assessment of demographic characteristics, and the THI, the Visual Analogue Scale (VAS) about tinnitus, the Beck Depression Inventory (BDI), and the Beck Anxiety Inventory (BAI) are applied for evaluation of other clinical psychiatric characteristics. Results Higher THI scores were positively correlated with tinnitus course, the number of accompanying symptoms, and the VAS. BDI total scores, BDI factors, and BAI total scores were significantly higher in the severe-tinnitus group than in the mild-tinnitus group. Also suicidal ideation, interpersonal problems, sleep problems, occupational impairment, and fatigue were significantly higher in the severe-tinnitus group than in the mild-tinnitus group. Conclusions Tinnitus is a common disorder of hearing which is associated frequently with psychiatric problems. This study suggests that psychiatric interventions should be taken into consideration in the treatment of patients suffering from tinnitus.

Improvement in Thermomechanical Reliability of Power Conversion Modules Using SiC Power Semiconductors: A Comparison of SiC and Si via FEM Simulation

  • Kim, Cheolgyu;Oh, Chulmin;Choi, Yunhwa;Jang, Kyung-Oun;Kim, Taek-Soo
    • Journal of the Microelectronics and Packaging Society
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    • v.25 no.3
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    • pp.21-30
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    • 2018
  • Driven by the recent energy saving trend, conventional silicon based power conversion modules are being replaced by modules using silicon carbide. Previous papers have focused mainly on the electrical advantages of silicon carbide semiconductors that can be used to design switching devices with much lower losses than conventional silicon based devices. However, no systematic study of their thermomechanical reliability in power conversion modules using finite element method (FEM) simulation has been presented. In this paper, silicon and silicon carbide based power devices with three-phase switching were designed and compared from the viewpoint of thermomechanical reliability. The switching loss of power conversion module was measured by the switching loss evaluation system and measured switching loss data was used for the thermal FEM simulation. Temperature and stress/strain distributions were analyzed. Finally, a thermal fatigue simulation was conducted to analyze the creep phenomenon of the joining materials. It was shown that at the working frequency of 20 kHz, the maximum temperature and stress of the power conversion module with SiC chips were reduced by 56% and 47%, respectively, compared with Si chips. In addition, the creep equivalent strain of joining material in SiC chip was reduced by 53% after thermal cycle, compared with the joining material in Si chip.

Clinical Evaluation and The Diagnositic Significances of Disital Infrared Thermal Image(D.I.T.I.) on the Patients of Dam Hun(痰暈) (담훈(痰暈)환자의 임상적 고찰과 복부 적외선 체열촬영의 의의)

  • Park, Mee-Yeon;Choi, Hae-Yun;Kim, Jong-Dae;Song, Kwang-Kyu
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.20 no.2
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    • pp.488-493
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    • 2006
  • To make a objective diagnosis of Dam Hun(痰暈), we investigated the 63 patients with Dam Hun(痰暈) and 34 normal people as control group. we compared the thermal difference between Chon-jung(CV17 ) and Chung-wan(CV12 中脘), Chon-jung(CV17 ) and Gwan-won(CV4 關元) and we compared the thermal difference of Yang-mun(ST21 梁門), Chun_chu(ST25 天樞), Su-do(ST28 水道), too. All 63 patients had dizziness and GI trouble. They had the symptom - fatigue, nausea vomitting, head heaviness, indigestion, cold limbs, headache, heart burn, constipation, diarrhea, anorexia. And some had edema, numbness, insomnia, palpitation, facial flushing, dysuria, ringing. Considering the average temparature of Chon-jung(CV17 ), Chung-wan(CV12 中脘), Gwan-won(CV4 關元), Yang-mun(ST21 梁門), Chun-chu(ST25 天樞), Su-do(ST28 水道) between the patients group and the control group, the patients group were lower than the control group except for Chon-jung(CV17 ), Gwan-won(CV4 關元), but the statistical significance was not. Considering the thermal difference of Chon-jung(CV17 ) and Chung-wan(CV12 中脘), Gwan-won(CV4 關元), Yang-mun(ST21 梁門), Chun-chu(ST25 天樞), Su-do(ST28 氷道) between the patients group and the control group, the temparature deviation of Chon-jung(CV17 ) and Chung-wan(CV12 中脘), Chon-jung(CV17 ) and Yang-mun(ST21 梁門) was significant. We suggest that coldness of upper abdomen is significant in diagnosis of Dam Hun(痰暈).

Optimal Design of Blade Shape for 200-kW-Class Horizontal Axis Tidal Current Turbines (200kW급 수평축 조류발전 터빈 블레이드 형상 최적설계)

  • Seo, JiHye;Yi, Jin-Hak;Park, Jin-Soon;Lee, Kwang-Soo
    • Journal of Ocean Engineering and Technology
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    • v.29 no.5
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    • pp.366-372
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    • 2015
  • Ocean energy is one of the most promising renewable energy resources. In particular, South Korea is one of the countries where it is economically and technically feasible to develop tidal current power plants to use tidal current energy. In this study, based on the design code for HARP_Opt (Horizontal axis rotor performance optimizer) developed by NREL (National Renewable Energy Laboratory) in the United States, and applying the BEMT (Blade element momentum theory) and GA (Genetic algorithm), the optimal shape design and performance evaluation of the horizontal axis rotor for a 200-kW-class tidal current turbine were performed using different numbers of blades (two or three) and a pitch control method (variable pitch or fixed pitch). As a result, the VSFP (Variable Speed Fixed Pitch) turbine with three blades showed the best performance. However, the performances of four different cases did not show significant differences. Hence, it is necessary when selecting the final design to consider the structural integrity related to the fatigue, along with the economic feasibility of manufacturing the blades.

Thermal Stress Evaluation by Elastic-Creep Analysis during Start-up of Boiler Header (보일러 헤더 기동시의 탄성 크리프 해석에 의한 열응력 평가)

  • Shin, Kyu-In;Yoon, Kee-Bong
    • Journal of the Korean Society of Safety
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    • v.24 no.2
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    • pp.17-22
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    • 2009
  • Thermal stress and elastic creeping stress analysis was conducted by finite element method to simulate start-up process of a boiler header of 500MW standard fossil power plant. Start-up temperature and operating pressure history were simplified from the real field data and they were used for the thermal stress analysis. Two kinds of thermal stress analysis were considered. In the first case only temperature increase was considered and in the second case both of temperature and operating pressure histories were considered. In the first analysis peak stress was occurred during the temperature increase from the room temperature. Hence cracking or fracture may occur at the temperature far below the operating maximum temperature. In the results of the second analysis von Mises stress appeared to be higher after the second temperature increase. This is due to internal pressure increase not due to the thermal stress. When the stress components of radial(r), hoop($\theta$) and longitudinal(z) stress were investigated, compression hoop stress was occurred at inner surface of the stub tube when the temperature increased from room temperature to elevated temperature. Then it was changed to tension hoop stress and increased because of the operating pressure. It was expected that frequent start-up and shut-down operations could cause thermal fatigue damage and cracking at the stub tube hole in the header. Elastic-creeping analysis was also carried out to investigate the stress relaxation due to creep and stabilized stress after considerable elapsed time. The results could be used for assessing the creep damage and the residual life of the boiler header during the long-tenn service.

Functional Status in Turkish Women with Gynecological Cancer

  • Akkuzu, Gulcihan;Talas, Melek Serpil;Ortac, Firat
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.5
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    • pp.2045-2049
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    • 2014
  • Background: Functional status is the ability to perform daily activities. Little is known about quality of life and health status of gynaecological cancer patients. The present study therefore aimed to evaluate the functional status of women receiving treatment for gynecological oncological disease while not hospitalised. Materials and Methods: This descriptive study covered 42 patients monitored by the Gynecological Oncology Unit in 2011. Data were collected using the Functional Living Index-Cancer and analysed with the chi square test, independent samples t-test, Mann-Whitney U test, one-way ANOVA test and the Kruskal-Wallis H test. Results: Of the 42 cases, 66.7% had been diagnosed within the previous year and 90.5% were undergoing chemotherapy. The most severe symptoms experienced were pain (35.7%), fatigue-weakness (40.5%) and nausea and vomiting (56.5%). Daily activities where the most difficulty was experienced were housework (28.6%), average pace walking (31.0%), carrying more than 5 kg (28.6%). The mean Functional Living Index score was quite high ($103.5{\pm}24.1$). FLIC-C scale scores did not vary with the educational status, diagnosis duration, and family history of cancer (p>0.05). Conclusions: Evaluation of the functional status of gynecological cancer patients and how they cope with problems should indicate to healthcare professionals what help can be given to maintain quality of life.

A Study on the Strength Evaluation and Defect Detection Capability of Adhesive Joint with CNTs (CNT를 첨가한 접착조인트의 결함탐지능 및 강도 평가에 관한 연구)

  • Kim, Tae-Hyeong;Kim, Cheol-Hwan;Choi, Jin-Ho
    • Composites Research
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    • v.31 no.4
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    • pp.151-155
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    • 2018
  • Mechanical joint and adhesive joint are two typical joining methods for structures. The adhesive joints distribute the load over a larger area than mechanical joints and have excellent fatigue properties. However, the strength of adhesive joint greatly depends on the environmental conditions and the skill of the operator. Therefore, there is a need for techniques to evaluate the quality of the adhesive joints. The electric resistance method is a very promising technique for detecting defects by measuring the electrical resistance of an adhesive joint in which CNTs are dispersed in an adhesive. In this study, Aluminium-Aluminium adhesive single lap joint specimens were fabricated by using the adhesive dispersing CNTs using a sonicator and a 3-roll mill, and the static strengths and defect detection capabilities of the joints using the electrical resistance method were evaluated according to the CNTs content.

Physiological and Psychological Effects of an Interior Falling Waterscape Facility on University Students (실내 계류형 수경시설이 대학생의 생리·심리에 미치는 영향)

  • Park, Sun-Nam;Jo, Hyun-Ju
    • Journal of the Korean Institute of Landscape Architecture
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    • v.44 no.5
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    • pp.38-46
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    • 2016
  • The purpose of this study was to quantitatively examine the physiological and psychological effects of a waterscape facility in an interior landscape space. Data were collected as participants under stress relaxed in either an interior space with greenery(Type G) or an interior space with a waterscape facility(Type W). The participants relaxing in the Type W space showed significantly decreased systolic and diastolic blood pressures, and an impression evaluation by the SD method indicated that their impressions were expressed in more positive terms, such as 'vigor', 'dynamism', 'pleasantness', and 'vitality'; when compared to participants relaxing in the Type G space. A POMS analysis showed waterscape elements influenced participants' psychological mood states by decreasing tension and fatigue, but increasing vitality. Introduction of waterscape facilities into interior landscape spaces could therefore provide stressed individuals with health benefits, including decreased blood pressure and positively changed psychological mood states.

Crack Initiation Life Analysis in Notched Pipe Under Cyclic Bending Loads (굽힘피로 하중을 받는 배관의 피로균열 발생수명 예측)

  • Gwak, Sang-Rok;Lee, Jun-Seong;Kim, Yeong-Jin;Park, Yun-Won
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.10
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    • pp.1528-1534
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    • 2001
  • In order to improve Leak-Be(ore-Break methodology, more precisely the crack growth evaluation, a round robin analysis was proposed by the CEA Saclay. The aim of this analysis was to evaluate the crack initiation life, penetration life and shape of through wall crack under cyclic bending loads. The proposed round robin analysis is composed of three main topic; fatigue crack initiation, crack propagation and crack penetration. This paper deals with the first topic, crack initiation in a notched pipe under four point bending. Both elastic-plastic finite element analysis and Neuber's rule were used to estimate the crack initiation life and the finite element models were verified by mesh-refinement, stress distribution and global deflection. In elastic-plastic finite element analysis, crack initiation life was determined by strain amplitude at the notch tip and strain-life curve of the material. In the analytical method, Neuber's rule with the consideration of load history and mean stress effect, was used for the life estimation. The effect of notch tip radius, strain range, cyclic hardening rule were examined in this study. When these results were compared with the experimental ones, the global deformation was a good agreement but the crack initiation cycle was higher than the experimental result.