• Title/Summary/Keyword: Joint Frequency Function

Search Result 95, Processing Time 0.026 seconds

A dynamic finite element method for the estimation of cable tension

  • Huang, Yonghui;Gan, Quan;Huang, Shiping;Wang, Ronghui
    • Structural Engineering and Mechanics
    • /
    • v.68 no.4
    • /
    • pp.399-408
    • /
    • 2018
  • Cable supported structures have been widely used in civil engineering. Cable tension estimation has great importance in cable supported structures' analysis, ranging from design to construction and from inspection to maintenance. Even though the Bernoulli-Euler beam element is commonly used in the traditional finite element method for calculation of frequency and cable tension estimation, many elements must be meshed to achieve accurate results, leading to expensive computation. To improve the accuracy and efficiency, a dynamic finite element method for estimation of cable tension is proposed. In this method, following the dynamic stiffness matrix method, frequency-dependent shape functions are adopted to derive the stiffness and mass matrices of an exact beam element that can be used for natural frequency calculation and cable tension estimation. An iterative algorithm is used for the exact beam element to determine both the exact natural frequencies and the cable tension. Illustrative examples show that, compared with the cable tension estimation method using the conventional beam element, the proposed method has a distinct advantage regarding the accuracy and the computational time.

Study on Prediction System Construction of Fire.Explosion Accident by NG & LPG among Domestic Gas Accidents (국내 가스 사고사례 중 NG 및 LPG의 가스 화재.폭발사고 예측시스템 구축에 관한 연구)

  • Ko Jae-Sun;Kim Hyo
    • Journal of the Korean Institute of Gas
    • /
    • v.10 no.1 s.30
    • /
    • pp.48-55
    • /
    • 2006
  • In order to establish the comprehensively, quantitatively predictable program to the fire and explosion accidents in the urban gas system, and to set up domestic criteria of societal risk, the collected urban gas accident data have been deeply analyzed. The Poisson probability distribution functions with t=5 for the database of the gas accidents in recent 11 year shows that 'careless work-explosion-pipeline' item has the lowest frequency, whereas 'joint loosening & erosion-release-pipeline' item has the highest frequency. And thus the proper counteractions must be carried out. The further works requires setting up successive database on the fire and explosion accidents systematically to obtain reliable analyses.

  • PDF

Dynamic Analysis Of Structures With Nonlinear Joints By Using Substructure Synthesis Method (부분구조 합성법을 이용한 비선형 결합부 구조물의 동적 해석)

  • 이신영;이장무
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.14 no.2
    • /
    • pp.324-330
    • /
    • 1990
  • In this study, in order to perform dynamic design of machine tools reasonably and effectively, a method was formulated to be applicable to the damped structures connected by joints having elasticity and damping by using substructure synthesis method. And a nonlinear solution method was proposed and it formulates the nonlinear parts by describing functions and uses the reducing transformation matrix by the substructure synthesis method. The results of frequency response analysis of a machine tool, where an NC lathe was partitioned by three parts of spindle, housing and bed-base part and the nonlinearity of bearing parts between spindle and housing was modelled, showed force dependency of the response.

Transported PDF Model for Turbulent Nonpremixed Flames (수송 확률밀도함수모델을 이용한 비예혼합 난류화염장 해석)

  • Lee, Jeong-Won;Seok, Joon-Ho;Kim, Yong-Mo
    • Journal of the Korean Society of Combustion
    • /
    • v.14 no.2
    • /
    • pp.32-41
    • /
    • 2009
  • The transported probability density function model combined with the consistent finite volume (FV) method has been applied to simulate the turbulent bluff-body reacting flows. To realistically account for the non-isotropic turbulence effects on the turbulent bluff-body reacting flows, the present PDF transport approach is based on the joint velocity- turbulent frequency-composition PDF formulation. The evolution of the fluctuating velocity of a particle is modeled by a simplified Langevin equation and the particle turbulence frequency is represented by the modified Jayesh - Pope model. Effects of molecular diffusion are represented by the interaction by exchange with the mean (IEM) mixing model. To validate this hybrid FV/PDF transport model, the numerical results are compared with experimental data for the turbulent bluff-body reacting flows.

  • PDF

A review of test norm of Non-insulated AF Track Circuit (무절연 가청주파수(AF) 궤도회로 시험기준 고찰)

  • Chang, Seok-Gahk;Lee, Chang-Young;Kwon, Sung-Tae
    • Proceedings of the KSR Conference
    • /
    • 2007.05a
    • /
    • pp.1701-1706
    • /
    • 2007
  • Jointless AF(Audio Frequency) Track Circuit is more comfortable than exist joint track circuit. This electrical circuit's function is detection train on rail, and transmit information between wayside and vehicle. 'Korea Railroad Corporation' proposed for revision of the Korean railway standards(KRS SG 0038-06 R, 2006.5.16) "Non-insulated AF Track Circuit". This proposal equipment developed to extend use for station of National Railway exist line. According to test standards Korean railway safety law and its ordinances, which were committed to Korea Railroad Research Institute, the professional committee 'Railway facility sector II' have helded on January in 2007. In this investigation, the changed test norm will be review the difference of important function test standards of new version to conform effectivity and safety test procedure according to the KS A 1025.

  • PDF

Effects of Auricle Electric Stimulation on Pain, Gait and Balance in the Old Aged with Knee Joint Disease (외이전기자극이 슬관절질환 노인의 통증과 보행 및 균형에 미치는 영향)

  • Seo, Sam-Ki;Cho, Woon-Su;Lee, Jeong-Woo;Kim, Yong-Nam;Jung, Jin-Kyue;Hwang, Tae-Yeun
    • The Journal of Korean Physical Therapy
    • /
    • v.20 no.2
    • /
    • pp.11-17
    • /
    • 2008
  • Purpose: This study examined the application of electric stimulation to the auricle acupoint (frequency 2 Hz, stimulation level: noxious) with 30 elderly people over 65 years that received treatment in a rural hospital to determine the influence of pain, gait and balance in the aged with knee joint disease. Methods: The subjects were divided into three groups; the degenerative joint diseases (DJD) group (1 male, 9 females), the total knee replacement (TKR) group (1 male, 9 females) and the control group (1 male, 9 females). Auricualr electrical stimulation (AES) was applied with low frequency, high intensity transcutaneous electrical nerve stimulation for 10 seconds per each point. Results: 1. For the change of pain according to AES, there was interaction in the resting period (p<0.001) and gait (p<0.001) and pain of the DJD group and TKR group was decreased. 2. The range of motion (ROM) of the knee joint showed a significant difference in interaction for each group of elderly people (p<0.001) and the ROM for the DJD group and TKR group of elderly people was increased. 3. In the analysis of gait speed changes, there was a significant difference in interaction for each group of elderly people (p<0.001) and for gait speed in the DJD group and TKR group of elderly people. 4. It was found in the change of static balance that there was a significant difference in interaction for each group of elderly people (p<0.01) and balance capacity in the DJD group and TKR group of elderly people was increased. Conclusion: The aged with knee joint disease have pain, and a decreased function of gait and balance. AES was an excellent treatment for control of pain, and an excellent treatment to enhanced joint functions. AES was useful for improving gait and balance due to decreased pain.

  • PDF

The effect of pilates exercises on isokinetic muscular strength and balance in lower limb's for young aged women (필라테스 운동이 젊은 여성의 등속성 하지 근력과 밸런스에 미치는 영향)

  • Lee, Na-Ri;Yun, Sin-Jung;Choi, Kwang-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.17 no.11
    • /
    • pp.691-700
    • /
    • 2016
  • This study was performed to provide data for developing a more effective and practical pilates exercise program for young women. To meet this purpose, 20 young women were assigned to both groups. The experiment was conducted according to the experimental procedure. Ten subjects in the pilates exercise group performed exercise for 60 minutes everyday at a frequency of 3 days per week for 8 weeks. The subjects in both groups were measured for their physical composition, isokinetic muscular strength in legs, and body balance before and after the experiment. After 8 weeks, the pilates exercise group's body composition showed significantly increased muscular amount (p <.01). There was a statistical increase in knee joint muscle function. For the right knee joint and left knee joint, right knee joint extensor muscle's maximum muscular strength and total work significantly increased under conditions of $60^{\circ}/sec$ (p<.05). Under conditions of $180^{\circ}/sec$, there were statistically significant increases in left knee joint flexor muscle's maximum muscular strength (p<.05). For balance, balance of both legs and right leg showed statistically increases (p<.05).

Effects of Manual Lymphatic Drainage and High Frequency Diathermy on Pain, Volume, Function of Upper Extremity and Quality of Life in Breast Cancer Patients with Axillary Web Syndrome : a Study of Five Case Reports (겨드랑이막증후군을 가진 유방암 환자들의 도수림프배출법과 고주파 투열치료가 통증, 부피, 기능 및 삶의 질에 미치는 효과 : 사례군 연구)

  • Ahn, Soo-Yeon;Shin, Won-Seob
    • Journal of The Korean Society of Integrative Medicine
    • /
    • v.9 no.4
    • /
    • pp.19-28
    • /
    • 2021
  • Purpose : The purpose of this study was to apply manual lymphatic drainage (MLD) and high-frequency diathermy (HFD) to patients with axillary web syndrome (AWS), one of the side effects of breast cancer surgery, and to treat upper extremity pain, volume, function of the upper extremity, (joint range of motion; ROM, disabilities of the arm, shoulder and hand; DASH) and quality of life before and after treatment. It is to determine the effect of treatment by checking the level change. Methods : This study is a case series. A total of 5 patients diagnosed with AWS after breast cancer surgery voluntarily participated in this study. The intervention program consisted of stretching, MLD and HFD. It was conducted 3 times a week for 30 minutes for 4 weeks. In order to compare the effects of pain (numeric pain rating scale; NPRS), volume, upper limb function (ROM, DASH) and quality of life (the European organization for research and treatment of cancer quality of life questionnaire-breast, EORTC QLQ-BR23) evaluations were compared before and after 4 weeks of intervention. All measured variables were analyzed and expressed as mean, standard deviation and percentage. Results : The shoulder NPRS level of the subjects in all case groups decreased, the volume decreased and the shoulder flexion, abduction ROM increased. It showed improvement in DASH and quality of life, QLQ-BR23. Conclusion : After breast cancer surgery, we confirmed the possibility that MLD and HFD treatments could be effective in improving pain, decreasing volume, increasing upper extremity function, and quality of life for patients who have difficulties with AWS. The possibility has been confirmed, and additional research is needed by increasing the number of participants in the experiment in the future.

Development of Elbow Joint X-ray Examination Aid for Medical Imaging Diagnosis (의료영상 진단을 위한 팔꿉관절 X-선 검사 보조기구 개발)

  • Hyeong-Gyun Kim
    • Journal of the Korean Society of Radiology
    • /
    • v.18 no.2
    • /
    • pp.127-133
    • /
    • 2024
  • The elbow joint is made up of three different bones. X-rays or other radiological exams are commonly used to diagnose elbow injuries or disorders caused by physical activity and external forces. Previous research on the elbow joint reported a new examination method that meets the imaging evaluation criteria in the tilt position by Z-axis elevation of the forearm. Therefore, this study aims to design an optimized instrument and develop an aid applicable to other upper extremity exams. After completing the 2D drawing and 3D modeling design, the final design divided into four parts was fabricated with a 3D printer using ABS plastic and assembled. The developed examination aid consists of a four-stage Z-axis elevation tilt angle function (0°, 5°, 10°, and 15°) and can rotate and fixate 360° in 1-degree increments. It was designed to withstand a maximum equivalent stress of 56.107 Pa and a displacement of 1.6548e-5 mm through structural analysis to address loading issues caused by cumulative frequency of use and physical utilization. In addition to X-ray exams of the elbow joint, the developed aid can be used for shoulder function tests by rotating the humerus and also be applied to MRI and CT exams as it is made of non-metallic materials. It will contribute to the accuracy and efficiency of medical imaging diagnosis through clinical applications of various devices and medical imaging exams in the future.

A Comparative Study of the Handicaps in and Satisfaction with the Ordinary Life before and after the Plastic Operation for Artificial Joint Replacement-Centering around Those Who suffer from Joint Diseases (인공관절 전치환 성형 수술 전후의 일상활동 장애정도 및 삶의 만족도 비교연구 - 관절 질환 환자를 중심으로 -)

  • Kang, Shin-Hwa
    • Journal of muscle and joint health
    • /
    • v.3 no.1
    • /
    • pp.37-49
    • /
    • 1996
  • The joint diseases threaten modern people's healthy life. They bring about a long pain, an anasarca, loss of joint function or even deformation and rigidity of joint, limiting people's ordinary activities much. The chronic joint patients may be subject to some hypochondria caused by anxiety for their life, social isolation, financial problem and physical disability. Therefore, this population should continue to be duely taken care of by medical personnels. In particular, nurses should adequately help these people to recover and improve their health through suitable adaptations. With such basic conceptions in mind, this study was aimed at reviewing these patients' conditions in their ordinary life before and after a plastic operation for artificial joint replacement as well as their satisfaction with their life. For this purpose, those patients who underwent some plastic operations for artificial joint replacement at university hospitals in Seoul from January 2, 1993 to June 30, 1995 were selected as the population of this study. Among them, 87 people were randomly sampled to answer a questionnaire designed specially. For the surveying tools, Jette's (1980) scale was applied to address the sample people's inconveniences experienced and supports received in their ordinary life, while the scale of Wood, Wylie & Sheafer was used to measure their satisfaction with their life. The collected data were analyzed for percentiles, means, SD, t-test and Pearson's correlations. The results of survey can be summarized as follows ; As a result of t-test the frequencies of other people's support before and after the plastic operation, it was disclosed that those who underwent the operation were supported less frequently. In addition, as a result of t-testing their satisfaction with life before and after the operation, it was found that the operation increased their satisfaction with life significantly. Meanwhile, as a result of t-test inconveniences, frequencies of supports and life satisfaction before and after the plastic operation for artificial knee replacement, it was disclosed that only the inconveniences were significantly reduced after the operation. In contrast, the t-test the variables before and after the plastic operation for artificial hip replacement, it was found that only the frequencies of other people's supports were significant reduced after the operation. Furthermore, the differences 6 months, one year and two years after the plastic operation for artificial joint replacement were t-tested on the variables. As a result, it was disclosed that people's inconvenience, frequencies of supports and life satisfaction were not improved 6 months after the operation but their frequencies of supports decreased significantly one year after, while their inconveniences and life satisfaction were significantly improved two years after. As a result of analyzing the variables with Pearson's correlations, inconveniences and frequency of supports were negatively correlated significantly with the life satisfaction. In conclusion, the plastic operation for artificial joint replacement significantly improved people's living inconveniences, reduced their frequency of other people's support and enhanced their satisfaction with life. To break don the plastic operation for artificial knee replacement improved patients' inconveniences, while the plastic operation for artificial hip replacement not only improved patients' inconveniences but reduced the frequencies of other people's support also. Finally, the finding that the plastic operation for artificial joint replacement brought about the improvement two years after suggests that this period is needed for the patients to adapt themselves to the post-operation conditions.

  • PDF