• Title/Summary/Keyword: Stiffness Improvement

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Clinical and Radiographical Follow-up for Residual Displacement of Fracture Fragments after Interlocking Intramedullary Nailing in Humeral Shaft Fractures (상완골 간부 골절에서 교합성 골수강 내 금속정 고정 후 잔존한 골절편 전위에 대한 임상적, 방사선학적 추시)

  • Yum, Jae-Kwang;Lim, Dong-Ju;Jung, Eui-Yub;Sohn, Su-Een
    • Clinics in Shoulder and Elbow
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    • v.16 no.2
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    • pp.107-114
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    • 2013
  • Purpose: This study is designed to evaluate the clinical and radiographical results for the displacement of fracture fragments after interlocking intramedullary nailing in humeral shaft fractures. Materials and Methods: We retrospectively reviewed the results of 8 cases of humeral shaft fractures that have displacements of over 10 mm and under 20 mm after interlocking intramedullary nailing between July 2004 and August 2011. The mean age was 54.1 years (range, 43 to 70 years) and there were 3 male and 5 female patients. Radiographically, the time to bony union, change of displacement and angulation of the fracture site, and degree of improvement of these two factors were measured. Clinically, the range of motion of shoulder and elbow joints, postoperative pain and complications were evaluated. Results: All cases showed complete bony union in last follow-up. The mean time to bony union was 16.1 weeks. At the last follow-up, almost all cases had normal range of motion of shoulder and elbow joints. But, one case had stiffness of shoulder joint. Therefore, arthroscopic capsular release and manipulation was performed. One case had transient shoulder pain and the other case had transient elbow pain. In the two cases, pull-out of proximal interlocking screw were noted, but they finally had bony union. Conclusion: Although considerable displacement of fracture fragments after interlocking intramedullary nailing in humeral shaft fractures was present, we had excellent radiographical and clinical outcomes. Therefore, an additional procedure, such as open reduction or another fixation for the fracture site, was not necessary.

The Improvement of Incompatible Sliding Contact Problem Using Mesh Refinement And Its Application to Railway Skewed Culvert Problem (요소 세분화를 이용한 비적합 미끄러지는 접촉문제의 개선과 철도 사각암거 문제에의 적용)

  • Choi, Chan-Yong;Yeo, In-Ho;Chung, Keun-Young;Lee, Gye-Hee
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.30 no.5
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    • pp.435-444
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    • 2017
  • The vehicle-track structure dynamic interaction analysis problem can be treated as sliding contact problem, and it is assumed that vehicle run at a constant speed over a rail modeled as beam elements. Unfortunately, Salome-Meca can not satisfy the compatibility condition for the beam master elements, which are consist of the elements with higher order polynomial shape function, in sliding contact problem. In this study, it is suggested to use more finer beam master element mesh as the remedy for incompatibility in sliding contact problem, and the accuracy of the solution is secured. For this, the effect of beam element mesh refinement consisting runway is analysed through simple examples, and the applicability to the dynamic interaction analysis is evaluated. Finally, the dynamic interaction analysis of railway skewed culvert transition problem is carried out to evaluate the effect of supporting stiffness due to backfill pattern changes and track irregularity due to uneven subgrade settlement.

Study of 4 Cases with Changes of Unified Parkinson's Disease Rating Scale, Heart Rate Variability and Quality of Life in Parkinson's Disease Patients through Whole Body Gi-Hyeol Therapy (전신기혈요법 치료를 통해 Unified Parkinson's Disease Rating Scale, Heart Rate Variability 및 삶의 질이 변화된 파킨슨 환자 4례에 대한 증례보고)

  • Mok, Seo-Hee;Lee, Ji-Won;Lee, Tae-Jong;Seo, Jung-Bok;Kim, Kyoung-Ah;Kim, Joe-Young;Park, Byung-Jun;Kim, Dong-Hee
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.35 no.2
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    • pp.71-80
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    • 2021
  • Parkinson's disease is one of the typical neurodegenerative disease and it is caused by the destruction of substantia nigra in brain leading to lack of dopamine secretion, and it presents 4 major motor symptoms such as tremor, bradykinesia, stiffness, postural instability. Furthermore, it causes many non-motor symptoms such as anosmia, REM sleep conduct disorder, orthostatic hypotension, dementia and autonomic ataxia such as lack of adjusting blood pressure, hyperhydrosis, constipation. Dopaminergic therapy is the most commonly used strategy, but long term treatment of levodopa induce various adverse effects. Thus, many people are focusing on new therapies other than established therapies, and there are many tries and approaches with paradigm shift. Our medical team was able to get 4 cases of PD patients who are hospitalized in our hospital, treated by Whole Body Gi-Hyeol Therapy consisting of acupuncture therapy, herbal therapy, and mental therapy, and their conditions improved in perspective of Unified Parkinson's Disease Rating Scale(UPDRS), Heart Rate Variability(HRV), and Quality of life. Among all 4 cases, UPDRS score and quality of life score is gotton better, and among 2 cases SDNN, RMS-SD, TP, LF, HF scores are finely increased. And PDQ-39 score which shows quality of life is also improved. However, in spite of these improvements and positive results, there were no meaningful improvement in a hurt from a fall which is important to the aged, muscular atrophy which causes bone fracture and SMI(Skeletal Muscle Mass Index) which is indicator of osteoporosis. Thus, supplementary treatment about Whole Body Gi-Hyeol Therapy such as more active nutrition intervention, safe and effective kinesitherapy is needed, and from now on continuous case reports and systematic clinical research which has control group must be carried out.

Effects of Task Training for Cognitive Activation of Stroke Patients on Upper Function and Activities of Daily Living (뇌졸중 환자의 인지활성화를 위한 과제 훈련이 상지기능 및 일상생활동작에 미치는 영향)

  • Kim, Yu-Jeong;Kang, Bo-Ra;Ahn, Si-Nae
    • Journal of Korean Society of Neurocognitive Rehabilitation
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    • v.10 no.2
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    • pp.27-34
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    • 2018
  • The purpose of this study is to investigate the effect of task training for cognitive activation of upper extremity on upper limb function and activities of daily living and to suggest intervention in rehabilitation treatment. From January to February of 2018, nine stroke patients were arbitrated 30 minutes a day, five days a week, for four weeks. For the experimental group, the therapist has induced the group using the linguistic guidance to patients, so they utilize the cognition strategy. The control group conducted active exercises in a range of motion using the instruments and passive exercises in a range of motion to reduce the stiffness of joints and upper limbs. As muscle strengthening exercises, the patients were assigned to work on the biceps muscle of arm, triceps muscle of arm, and deltoid according to the individual patient's muscular strength level. For the experimental group, the MBI was improved by ten points at maximum, and K-AMPS motor skills showed the improvements of 1.0 logit at maximum, and processing skills showed improvements of 0.6 logits at maximum. In MFT, the maximum improvement was by two points. For the control group, MBI was improved by five points at maximum, and 0.2 maximum improvements were shown in K-AMPS' motor skills and 0.3 maximum improvements in processing skills. MFT showed no change. The conclusion is that the challenges to enable training for stroke patients give a positive impact on upper limb function and activities of daily living.

Behavioral Characteristics and Safety Management Plan for Fill Dam During Water Level Fluctuation Using Numerical Analysis (수치해석을 이용한 수위변동시 필댐의 거동특성 및 안전관리방안)

  • Jung, Heedon;Kim, Yongseong;Lee, Moojae;Lee, Seungjoo;Tamang, Bibek;Heo, Joon;Ahn, Sungsoo
    • Journal of the Korean Geosynthetics Society
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    • v.20 no.1
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    • pp.45-55
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    • 2021
  • In this study, the behavioral characteristics of the fill dam were analyzed during water level fluctuations through a numerical analysis model, and the reservoir safety management plan was prepared. The variation in plastic deviatoric strain, horizontal displacement, stress path, pore water pressure, etc., due to elevation of water level in the upper and lower sides of shell and core were analyzed using numerical analysis software, viz. GTS NX and LIQCA. The analysis results manifest that as the water level in the dam body increases rapidly, the pore water pressure and displacement also increase quickly. It was found that the elevation of the water level causes an increase in pore water pressure in the dam body as well as an increase in the saturation of the dam body and decreased effective stress. It is considered that this type of dam behavior can be the cause of the reduction of strength and stiffness of the dam. Also, it is assumed that the accumulated plastic deviatoric strain due to the deformation of the dam body caused by water infiltration causes an increase in displacement. Based on these experimental results and the results of analyses of the existing reservoir safety diagnosis techniques, an improvement plan for dam safety diagnosis and evaluation criteria was proposed, and these results can be used as primary data while revising dam safety diagnosis guidelines.

Characteristics of Flexuarl-Shear Behavior of Beam Using Demonstrated CFRP Rod (국내 시범 생산 CFRP rod를 적용한 보 부재의 휨-전단 특성)

  • Choi, So-Yoeng;Kim, Il-Sun;Choi, Myoung-Sung;Yang, Eun-Ik
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.26 no.5
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    • pp.86-94
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    • 2022
  • Replacement of FRP rod as steel reinforcement has been attracted significantly to prevent the degradation of the concrete structure due to corrosion. So, the technology development to extend the structure's service life by improving FRP properties has been proceeded worldwide. Accordingly, it is necessary to develop Korea's CFRP rod and CFRP grid, including the manufacturing techniques to improve the properties of high-strength and high-stiffness. Moreover, the research should be conducted to evaluate the structural behavior of the beams using the CFRP rod or grid. This study investigates the flexural and shear behavior of reinforced concrete beam using demonstrated CFRP rod as reinforcement according to the reinforcement ratio and shear span to depth ratio. From the results, when the reinforcement ratio is out of a specific range, it is seemed that the effect on performance improvement of the beam using CFRP rod is cancelled or not significant. Meanwhile, when the CFRP rod was used as reinforcement, the possibility of shear failure occurred, even steel stirrups were installed in the beam with CFRP rod as tensile reinforcement according to the Korean Design Standard. Therefore, when the CFRP rod is used as tensile reinforcement in a beam, it should be prepared that a specific limitation of reinforcement ratio and an investigation against shear failure. Also, the ductility of the beam using the CFRP rod is determined by the deformation energy evaluation method. So, the ductility should be investigated by applying the deformation energy evaluation method that reflects the structural behavior of the beam.

Further Improvement of Direct Solution-based FETI Algorithm (직접해법 기반의 FETI 알고리즘의 개선)

  • Kang, Seung-Hoon;Gong, DuHyun;Shin, SangJoon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.35 no.5
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    • pp.249-257
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    • 2022
  • This paper presents an improved computational framework for the direct-solution-based finite element tearing and interconnecting (FETI) algorithm. The FETI-local algorithm is further improved herein, and localized Lagrange multipliers are used to define the interface among its subdomains. Selective inverse entry computation, using a property of the Boolean matrix, is employed for the computation of the subdomain interface stiffness and load, in which the original FETI-local algorithm requires a full matrix inverse computation of a high computational cost. In the global interface computation step, the original serial computation is replaced by a parallel multi-frontal method. The performance of the improved FETI-local algorithm was evaluated using a numerical example with 64 million degrees of freedom (DOFs). The computational time was reduced by up to 97.8% compared to that of the original algorithm. In addition, further stable and improved scalability was obtained in terms of a speed-up indicator. Furthermore, a performance comparison was conducted to evaluate the differences between the proposed algorithm and commercial software ANSYS using a large-scale computation with 432 million DOFs. Although ANSYS is superior in terms of computational time, the proposed algorithm has an advantage in terms of the speed-up increase per processor increase.

Compressional and Shear Wave Properties of Cement Grout Including Carbon Fiber (탄소섬유를 포함한 시멘트 그라우트의 압축파 및 전단파 특성)

  • Choi, Hyojun;Cho, Wanjei;Yune, Chanyoung
    • Journal of the Korean GEO-environmental Society
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    • v.22 no.12
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    • pp.15-24
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    • 2021
  • In Korea, which is mostly mountainous, the proportion of tunnel and underground space development are increasing. Although the ground is reinforced by applying the ground improvement method during underground space development, accidents still occur frequently in Korea. In the grouting method, a representative ground reinforcement method, the effect was judged by comparing the total amount of injection material with the amount of injection material used during the actual grouting construction. However, it is difficult to determine whether the ground reinforcement is properly performed during construction or within the target ground. In order to solve this problem, it is necessary to study a new method for quality control during or after construction by measuring electrical resistivity after performing grouting by mixing carbon fiber, which is a conductive material, and microcement, which is a grout material. In this study, as a basic study, a cement specimen mix ed with 0%, 3%, 5%, 7% of carbon fiber was prepared to evaluate the performance of the grout material mixed with carbon fiber, which is a conductive material. The prepared specimens were wet curing for 3 days, 7 days, and 28 days under 99% humidity, and then compression wave velocity and shear wave velocity were measured. As a result of the compression wave velocity and shear wave velocity measurement, it showed a tendency to increase with the increase in the compounding ratio of carbon fibers and the number of days of age, and it was confirmed that the elastic modulus and shear modulus, which are the stiffness of the material, also increased.

Evaluation of Vertical Vibration Performance of Tridimensional Hybrid Isolation System for Traffic Loads (교통하중에 대한 3차원 하이브리드 면진시스템의 수직 진동성능 평가)

  • Yonghun Lee;Sang-Hyun Lee;Moo-Won Hur
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.28 no.1
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    • pp.70-81
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    • 2024
  • In this study, Tridimensional Hybrid Isolation System(THIS) was proposed as a vibration isolator for traffic loads, combining vertical and horizontal isolation systems. Its efficacy in improving serviceability for vertical vibration was analytically evaluated. Firstly, for the analysis, the major vibration modes of the existing apartment were identified through eigenvalue analysis for the system and pulse response analysis for the bedroom slab using commercial structural analysis software. Subsequently, a 16-story model with horizontal, vertical and rotational degrees of freedom for each slab was numerically organized to represent the achieved modes. The dynamic analysis for the measured acceleration from an adjacent ground to high-speed railway was performed by state-space equations with the stiffness and damping ratio of THIS as variables. The result indicated that as the vertical period ratio increased, the threshold period ratio where the slab response started to be suppressed varied. Specifically, when the period ratio is greater than or equal to 5, the acceleration levels of all slabs decreased to approximately 70% or less compared to the non-isolated condition. On the other hand, it was ascertained that the influence of damping ratios on the response control of THIS is inconsequential in the analysis. Finally, the improvement in vertical vibration performance of THIS was evaluated according to design guidelines for floor vibration of AIJ, SCI and AISC. It was confirmed that, after the application of THIS, the residential performance criteria were met, whereas the non-isolated structure failed to satisfy them.

A Study on the Investigation into Dental Hygienists' Awareness of Health Impairment Factors by Occupational Diseases (치과위생사의 직업병에 의한 건강장애요인 인식도 조사)

  • Yoon, Mi-Sook;Song, Gui-Sook;Ko, Mi-Hee
    • Journal of dental hygiene science
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    • v.3 no.2
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    • pp.59-66
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    • 2003
  • As a basic research material to make more efficient healthcare and health promotion for dental hygienists, this study intends to determine which factors may affect their awareness of occupational diseases. For this sake, this study attempted to investigate into a variety of literatures and data, and applied a questionnaire survey to 160 dental hygienists for about 5 months(from June to October 2003), who were all employed in domestic dental clinics or offices. As a result of analysis, this study can be concluded as follows: (1) The result of analyzing how dental hygienists recognized their occupational diseases showed that 'stiffness in muscle, neck or shoulder due to intensive use of specific physical regions' and 'stress resulting from the attributes of each task' reached the highest awareness(90.6%) of all, which was followed by 'lower eyesight due to detailed or even sophisticated tasks for many hours(65%)' and 'symptoms of ruptured disk due to standing tasks as dental hygienists do for many hours(62.5%).' (2) The result of analyzing how dental hygienists recognize their occupational diseases showed that their awareness averaged 7.28 points out of 14 points, which implies that their awareness of occupational diseases is not very high. Meanwhile, the result of examining how they recognize detrimental or harmful properties of given materials against human body showed that a majority of total respondents(74.4%) regarded given materials as detrimental to human body. (3) The result of examining how dental hygienists recognize their occupational diseases showed that a majority of total respondents(91.9%) identified their own occupational diseases. Many of total respondents(41.9%) pointed out that environmental improvement around workshop in each clinic or office should be foremost prerequisite to health and welfare for dental hygienists. Next, 34.4% of total respondents pointed out the necessity to perform in-house health diagnosis and examination on a regular basis, and 13.1% of total respondents thought it necessary to carry on healthcare education into harmful properties in the aspect of dental materiology, respectively.

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