• Title/Summary/Keyword: PGA scale

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Seismic performance of RC frames retrofitted with haunch technique

  • Akbar, Junaid;Ahmad, Naveed;Alam, Bashir;Ashraf, Muhammad
    • Structural Engineering and Mechanics
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    • v.67 no.1
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    • pp.1-8
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    • 2018
  • Shake table tests performed on five 1:3 reduced scale two story RC moment resisting frames having construction defects, have shown severe joint damageability in deficient RC frames, resulting in joint panels' cover spalling and core concrete crushing. Haunch retrofitting technique was adopted herein to upgrade the seismic resistance of the deficient RC frames. Additional four deficient RC frames were built and retrofitted with steel haunch; both axially stiffer and deformable with energy dissipation, fixed to the beam-column connections to reduce shear demand on joint panels. The as-built and retrofitted frames' seismic response parameters are calculated and compared to evaluate the viability of haunch retrofitting technique. The haunch retrofitting technique increased the lateral stiffness and strength of the structure, resulting in the increase of structure's overstrength. The retrofitting increased response modification factor R by 60% to 100%. Further, the input excitation PGA was correlated with the lateral roof displacement to derive structure response curve that have shown significant resistance of retrofitted models against input excitations. The technique can significantly enhance the seismic performance of deficient RC frames, particularly against the frequent and rare earthquake events, hence, promising for seismic risk mitigation.

Optimal Economic Load Dispatch using Parallel Genetic Algorithms in Large Scale Power Systems (병렬유전알고리즘을 응용한 대규모 전력계통의 최적 부하배분)

  • Kim, Tae-Kyun;Kim, Kyu-Ho;Yu, Seok-Ku
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.4
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    • pp.388-394
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    • 1999
  • This paper is concerned with an application of Parallel Genetic Algorithms(PGA) to optimal econmic load dispatch(ELD) in power systems. The ELD problem is to minimize the total generation fuel cost of power outputs for all generating units while satisfying load balancing constraints. Genetic Algorithms(GA) is a good candidate for effective parallelization because of their inherent principle of evolving in parallel a population of individuals. Each individual of a population evaluates the fitness function without data exchanges between individuals. In application of the parallel processing to GA, it is possible to use Single Instruction stream, Multiple Data stream(SIMD), a kind of parallel system. The architecture of SIMD system need not data communications between processors assigned. The proposed ELD problem with C code is implemented by SIMSCRIPT language for parallel processing which is a powerfrul, free-from and versatile computer simulation programming language. The proposed algorithms has been tested for 38 units system and has been compared with Sequential Quadratic programming(SQP).

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Seismic and collapse analysis of a UHV transmission tower-line system under cross-fault ground motions

  • Tian, Li;Bi, Wenzhe;Liu, Juncai;Dong, Xu;Xin, Aiqiang
    • Earthquakes and Structures
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    • v.19 no.6
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    • pp.445-457
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    • 2020
  • An ultra-high voltage (UHV) transmission system has the advantages of low circuitry loss, high bulk capacity and long-distance transmission capabilities over conventional transmission systems, but it is easier for this system to cross fault rupture zones and become damaged during earthquakes. This paper experimentally and numerically investigates the seismic responses and collapse failure of a UHV transmission tower-line system crossing a fault. A 1:25 reduced-scale model is constructed and tested by using shaking tables to evaluate the influence of the forward-directivity and fling-step effects on the responses of suspension-type towers. Furthermore, the collapse failure tests of the system under specific cross-fault scenarios are carried out. The corresponding finite element (FE) model is established in ABAQUS software and verified based on the Tian-Ma-Qu material model. The results reveal that the seismic responses of the transmission system under the cross-fault scenario are larger than those under the near-fault scenario, and the permanent ground displacements in the fling-step ground motions tend to magnify the seismic responses of the fault-crossing transmission system. The critical collapse peak ground acceleration (PGA), failure mode and weak position determined by the model experiment and numerical simulation are in relatively good agreement. The sequential failure of the members in Segments 4 and 5 leads to the collapse of the entire model, whereas other segments basically remain in the intact state.

Clinical Study on the Case of Charcot-Marie-Tooth Disease Treated with Korean Medicine: A Case Report (Charcot-Marie-Tooth Disease 환자에 대한 한방치료 1례)

  • Kim, Yu Ri;Kim, Dae Hun;Kim, Kun Hyung;Yang, Gi Young;Kim, Jae Kyu;Lee, Byung Ryul
    • Journal of Acupuncture Research
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    • v.31 no.4
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    • pp.173-183
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    • 2014
  • Objectives : The purpose of this study is to report the effect of Korean Medicine treatment on a patient with Charcot-Marie-Tooth disease. Methods : A 60-year-old woman who was diagnosed as Charcot-Marie-Tooth disease was admitted with both lower and upper limbs weakness, difficulty in walking, palm pain and neck pain. The patient was treated with acupuncture, electroacupuncture, herbal medicine, cupping therapy and physical treatment from 2th September 2013 to 14th November 2013. Improvement of the patient's symptoms was evaluated by numeric rating scale(NRS), visual analog scale(VAS), SF-36 bodily pain and patient global assessment(PGA). Results : After treatment, pain Intensity evaluated by VAS was significantly decreased(from 7.2 to 2). Increased SF-36 bodily pain score(from 10 to 67.5) showed that patient's quality of life has been improved. Conclusions : These results suggest that Korean medicine treatment may be effective in reducing the symptoms of Charcot-Marie-Tooth disease.

Effectiveness and Safety of Korean Medicine for Trigeminal Neuralgia: A Case Report

  • Bae, Ji Min;Kim, Dae Hun;Lee, Byung Ryul;Yang, Gi Young
    • Journal of Acupuncture Research
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    • v.34 no.1
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    • pp.59-66
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    • 2017
  • Objectives : This study aims to report the effectiveness and safety of Korean medicine with thread embedding acupuncture in the treatment of trigeminal neuralgia (TN). Methods : A 73-year-old man who had suffered from severe facial pain for one year and who had had a healthy tooth extracted due to the pain is reported. He could not eat or sleep due to the severe pain. Acupuncture, thread embedding acupuncture, cupping, herbal steam, and herbal medicines were used for the treatment. Numeric Rating Scale (NRS) and adverse events were checked daily, and other outcomes (Baseline Evaluation, Visual Analogue Scale [VAS], Short Form Health Survey 36-Bodily Pain [SF-36 BP], and Patient Global Assessment [PGA]) were measured at hospital admission and discharge. During the follow-up examinations, his pain was evaluated roughly, without using any formal measurements, on the basis of a global assessment. Results : All measured parameters, including pain, quality of life, and patient satisfaction were noted to have improved at the time of discharge compared to admission: VAS from 10 to 1.5, NRS from 7-8 to 1-2, and SF-36 BP from 0 to 22.5, and the patient's global assessment was somewhat improved. He did not take any analgesics after discharge and noted only mild adverse events, like pain where the acupuncture and thread embedding acupuncture needles were inserted. His pain relief was maintained for 6 months. Conclusion : Korean medicine with thread embedding acupuncture might be a safe and effective treatment for TN. In the future, larger sample sizes and high quality randomized clinical trials are warranted to confirm its efficacy and safety.

Golf participation after rotator cuff repair: functional outcomes, rate of return and factors associated with return to play

  • Thomas R Williamson;Patrick G Robinson;Iain R Murray;Andrew D Murray;Julie M McBirnie;C Michael Robinson;Deborah J MacDonald;Nicholas D Clement
    • Clinics in Shoulder and Elbow
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    • v.26 no.2
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    • pp.109-116
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    • 2023
  • Background: Golf is a popular sport involving overhead activity and engagement of the rotator cuff (RC). This study aimed to determine to what level golfers were able to return to golf following RC repair, the barriers to them returning to golf and factors associated with their failure to return to golf. Methods: Patients preoperatively identifying as golfers undergoing RC repair at the study centre from 2012 to 2020 were retrospectively followed up with to assess their golf-playing status, performance and frequency of play and functional and quality of life (QoL) outcomes. Results: Forty-seven golfers (40 men [85.1%] and 7 women [14.9%]) with a mean age of 56.8 years met the inclusion criteria, and 80.1% were followed up with at a mean of 27.1 months postoperatively. Twenty-nine patients (76.3%) had returned to golf with a mean handicap change of +1.0 (P=0.291). Golf frequency decreased from a mean of 1.8 rounds per week preinjury to 1.5 rounds per week postoperatively (P=0.052). The EuroQol 5-dimension 5-level (EQ-5D-5L) index and visual analog scale (EQ-VAS) score were significantly greater in those returning to golf (P=0.024 and P=0.002), although functional outcome measures were not significantly different. The primary barriers to return were ipsilateral shoulder dysfunction (78%) and loss of the habit of play (22%). Conclusions: Golfers were likely (76%) to return to golf following RC repair, including mostly to their premorbid performance level with little residual symptomatology. Return to golf was associated with a greater QoL. Persistent subjective shoulder dysfunction (78%) was the most common barrier to returning to golf.

Earthquake Simulation Tests of A 1:5 Scale Gravity Load Designed 3-Story Reinforced Concrete Frame (중력하중 설계된 1:5 축소 3층 철근콘크리트 골조의 지진모의실험)

  • 이한선;우성우
    • Magazine of the Korea Concrete Institute
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    • v.10 no.6
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    • pp.241-252
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    • 1998
  • The objective of the research stated herein is to observe the actual responses of a low-rise nonseismic moment-resisting reinforced concrete frame subjected to varied levels of earthquake ground motions. First, the reduction scale for the model was determined as 1 : 5 considering the capacity of the shaking table to be used and the model was manufactured according to the similitude law. This model was, then, subjected to the shaking table motions simulating Taft N21E component earthquake ground motions, whose peak ground accelations (PGAs) were modified to 0.12g, 0.2g, 0.3g, and 0.4g. The lateral accelerations and displacements at each story and local deformations at the critical reginos of the structure were measured. The base shear was measured by using self-made load cells. Before and after each earthquake simulation test, free vibration tests were performed to find the change in the natural period and damping ratio of the model. The test data on the global and local behaviors are interpreted. The model showed the linear elastic behavior under the Taft N21E motion with the PGA if 0.12g, which represents the design earthquake in Korea. The maximum base shear was 1.8tf, approximately 4.7 times the design base shear. The model revealed fairly good resistance to the higher level of earthquake simulation tests. The main components of its resistance to the high level of earthquakes appeared to be 1) the high overstrength, 2) the elongation of the fundamental period, and 3) the minor energy dissipation by inelastic deformations. The drifts of the model under these tests were approximately within the allowable limit.

Shaking Table Test for Seismic Performance Evaluation of Non-Seismic Designed Wall-Type Apartment (내진설계 되지 않은 공동주택의 진동대 실험에 의한 내진성능 평가)

  • Chung, Lan;Lee, Joung-Woo;Park, Tae-Won
    • Journal of the Korea Concrete Institute
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    • v.18 no.6 s.96
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    • pp.721-728
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    • 2006
  • Earthquakes are reported thai building structures have been colossal damaged, but before 1988 designed structures which were not applicate seismic design code have no seismic performance. Especially, for the apartment structures were indicated that it have no resist wall element of earthquake before 1988 designed structures. We have to evaluate for seismic performance this structures, therefore it will be retrofitted for seismic index sufficient structures. We performed seismic performance evaluation for model structures by MIDAS which is general structure analysis software. In this study, it was performed shaking table test to evaluate model structure which is reinforcement concrete and 5 floors for seismic performance index. We made specimens by similar's law and tested shaking table test. In the shaking table test it is not performed prototype model test because of space and equipment condition. So we had made scale-down model for 1/5 by similar's law. That's why it needs for the evaluation of performance. However, it is not possible to do an experiment of prototype owing to the shortage of space and the limit of an experimental instrument in the shaking table test. Then, modeling and reducing the part of prototype do the experiment. In this experiment a shaking table test is done and seismic performance of model structures is evaluated by using similitude laws for scale down specimen. As a result it is proved that non-seismic design structures need to retrofit since seismic performance shows life safe grade in 0.12g of an earthquake.

A Case Report of Complex Korean Medicine Treatment Including Modified Gamiguibi-tang in a Paraneoplastic Cerebellar Degeneration Patient with Dysarthria and Weakness of Distal Extremity (구음장애와 사지원위부 무력감을 호소하는 신생물딸림소뇌변성 환자에 대한 가미귀비탕가감방을 포함한 한의복합치료 1례)

  • Ji-hyeon Kang;Seo-hyun Kim;Chae-eun Kim;Hee-ju Won;Kyungmin Baek
    • The Journal of Internal Korean Medicine
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    • v.45 no.3
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    • pp.497-507
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    • 2024
  • Objectives: This study investigated the treatment response to Korean medicine of a paraneoplastic cerebellar degeneration (PCD) patient with dysarthria and weakness of distal extremity. Case presentation: A 53-year-old female diagnosed with PCD complained of dysarthria and weakness of distal extremity. During 32-day hospitalization, she was treated with Korean medicine, namely, herbal medicine (modified Gamiguibi-tang), acupuncture (15 minutes twice a day at CV23, HT7, LI4, LR3, ST36, SP6, GB20, TE17, PC6, GV20, Ex-HN1, GV24 etc.), moxibustion, and cupping, combined with Western medicine (prednisolone, azathioprine) and physical therapy. Post-treatment, the patient global assessment (PGA) score of dysarthria fell from 100 to 60; grasp power rose from 15 kg to 19 kg and 13 kg to 17 kg in the right and left hands, respectively; and the 5-level EQ-5D version (EQ-5D-5L), EQ visual analogue scale (EQ-VAS), and Beck depression inventory (BDI-II) scores changed from 10 to 8, 0 to 80, and 34 to 7 respectively. Follow-up visits continued for about a month after discharge, improvement in symptoms maintained, and there were no significant side effects. Conclusions: Given the lack of standard treatment for PCD, Korean medicine can be tried clinically for the treatment of PCD patients with dysarthria and weakness of distal extremity. However, further studies with control groups are needed.