• Title/Summary/Keyword: Stability Limit

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Structural System Parameter Estimation using Strain Output Feedback (스트레인 출력 되먹임을 이용한 구조 시스템 계수 추정)

  • Ha, Jae-Hoon;Park, Youn-Sik;Park, Young-Jin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.124-127
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    • 2005
  • As computer capability and test skill become more and more advanced, finite element method and modal test are being widely applied in engineering design. In order to correlate and reconcile the inevitable discrepancies between the analytical and experimental models, many techniques have been developed. Among these methods, multiple-system methods are known as the effective tools in that they can supply the rich modal data available which are experimentally obtained. These abundant modal data can help structural system parameters estimated well. Multiple-system methods can be classified into the structural modification methods and feedback controller methods. The structural modification methods need the physical attachment of structures and their concept may limit the application of them. To overcome this drawback, the feedback controller methods are addressed which enable us to get more modal data without the structural change. Mode decoupling controller(MDC), one of them, is to use acceleration out)ut feedback to perturb an open-loop system. The output feedback controller generally cannot guarantee the stability of a closed-loop system. However, MDC can solve this problem under the certain constraints. So far, MDC utilizes accelerations as the sensor signals. In this research, strain sensors are going to be picked up to apply to the MDC. Strain output is recently used for structural system identification due to the drastically improved and miniaturized strain sensor. In this paper, we show that the MDC using strain output has differences compared with acceleration output in estimating the structural system parameters. The associated simulation is performed to demonstrate the above mentioned characteristics.

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Effects of Elastic Band Resistance Exercise Program on Body Functions and HbA1c of the Elderly with Type 2 Diabetes (탄력밴드 저항운동이 당뇨 노인의 신체 기능과 당화혈색소에 미치는 영향)

  • Park, Sang-Young;Kim, Chung-Sun;Nam, Seok-Hyun
    • The Journal of Korean Physical Therapy
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    • v.24 no.5
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    • pp.362-369
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    • 2012
  • Purpose: This study examined the effects of an elastic band resistance exercise program on the body functions and Glycosylated hemoglobin (HbA1c) of elderly people with type 2 diabetes. Methods: Twenty-seven elderly patients with type 2 diabetes were enrolled in this study (exercise group 14, control group 13). The subjects in the exercise group participated in the program for 60 minutes a day, three times a week, for 12 weeks. All the subject's body functions, HbA1c were measured to compare the following: before the intervention, at the completion of the 12 weeks intervention, and eight weeks after the intervention. Results: Compared to the control group, the exercise group showed significant improvements in the 12 week and follow-up measurement after the intervention in body function, such as the strength of the upper and lower limbs, agility and limit of stability. The body functions of the exercise group improved as the period of intervention progressed. On the other hand, the HbA1c level at each follow-up measurement was similar in the two groups. Conclusion: The 12 week elastic band exercise program is recommended as an effective intervention for improving the body functions of elderly people with type 2 diabetes. Nevertheless, a combined intervention of steady exercise, diet therapy and drug therapy will be needed for further active prevention and management of type 2 diabetes.

The Experimental Studu on the P-Δ Influence of Weak Beam Unbraced Frames (보항복형 비가새 골조의 PΔ 영향에 관한 실험적 연구)

  • Kim, Hee Dong;Park, Sang Chul;Lee, Myung Jae
    • Journal of Korean Society of Steel Construction
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    • v.13 no.4
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    • pp.363-372
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    • 2001
  • The objective of this study is to evaluate the $P-{\Delta}$ effect in the case of weak beam unbraced frames by experimental approach. To evaluate $P-{\Delta}$ effect, four specimens were tested under monotonic loading condition. The parameters of tests are the stiffness of column and the axial load ratio. The results show that the value of axial load affects frame stability because $P-{\Delta}$ effects promote the yielding of beam. The maximum lateral load increases in proportion to the increment of column stiffness and rotational stiffness of supports, The collapse mechanism of weak beam unbraced frames is stably formed in the condition of low axial load ratio. The $B_2$ factor of limit state design code does not properly consider the $P-{\Delta}$ effect in inelastic region.

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The research of 5.2 protocol performance and structure (V5.2 프로토콜의 성능 및 구조분석)

  • 이성우;이병란;이종영
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.05a
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    • pp.226-230
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    • 2003
  • In this thesis I analyzed that V5.2 protocol function is effective to fulfill all of the services that are provided at the existing local exchange. I analyzed this in five methods that refer to ETSI inside patronage. I experimented turnaround time by Start-up method and verified V5.2 protocol function when Start-up. Also I confirmed stability of system by the reconstruction-ability experiment related E1 switch over. I verified V5.2 protocol function through PSTN call process that uses a special service test and local call simulator. As a result of experiment, I confirmed the best method when simultaneous Start-up. V5.2 protocol function was excellent and It becomes switch over at 1/1000 seconds when E1 is out of service. V5.2 protocol function was effective to fulfill all of the special services that are provided at local exchange and its long call process ability was superior to KT standard with 4 fails in 20000 calls. Through the experiment, it was proved that V5.2 interface will become a significant element of communication network when after LE side expanse of v5 interface ID with TDX-100 exchanger and the AN occurrences OOS by message transmission limit and call disconnect when E1 switch over are improved.

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Rapid and Efficient Detection of 16SrI Group Areca Palm Yellow Leaf Phytoplasma in China by Loop-Mediated Isothermal Amplification

  • Yu, Shao-shuai;Che, Hai-yan;Wang, Sheng-jie;Lin, Cai-li;Lin, Ming-xing;Song, Wei-wei;Tang, Qing-hua;Yan, Wei;Qin, Wei-quan
    • The Plant Pathology Journal
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    • v.36 no.5
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    • pp.459-467
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    • 2020
  • Areca palm yellow leaf (AYL) disease caused by the 16SrI group phytoplasma is a serious threat to the development of the Areca palm industry in China. The 16S rRNA gene sequence was utilized to establish a rapid and efficient detection system efficient for the 16SrI-B subgroup AYL phytoplasma in China by loop-mediated isothermal amplification (LAMP). The results showed that two sets of LAMP detection primers, 16SrDNA-2 and 16SrDNA-3, were efficient for 16SrI-B subgroup AYL phytoplasma in China, with positive results appearing under reaction conditions of 64℃ for 40 min. The lowest detection limit for the two LAMP detection assays was the same at 200 ag/μl, namely approximately 53 copies/μl of the target fragments. Phytoplasma was detected in all AYL disease samples from Baoting, Tunchang, and Wanning counties in Hainan province using the two sets of LAMP primers 16SrDNA-2 and 16SrDNA-3, whereas no phytoplasma was detected in the negative control. The LAMP method established in this study with comparatively high sensitivity and stability, provides reliable results that could be visually detected, making it suitable for application and research in rapid diagnosis of AYL disease, detection of seedlings with the pathogen and breeding of disease-resistant Areca palm varieties.

Validation of a Selective Method for Simultaneous Determination of Doxifluridine and 5-Fluorouracil in Dog Plasma by LC-MS/MS (LC/MS/MS를 이용한 비글견의 혈장 중 Doxifluridine 및 5-Fluorouracil의 동시 분석법 Validation)

  • Kim, Ghee-Hwan;Kim, Won;Kim, Jin-Sung;Jin, Qingri;Kang, Won-Ku;Lee, Jong-Hwa;Ha, Jung-Heun;Jeong, Eun-Ju
    • Journal of Pharmaceutical Investigation
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    • v.37 no.3
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    • pp.179-186
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    • 2007
  • A simple, sensitive and selective liquid chromatographic/tandem mass spectrometric method (LC-MS/MS) was developed and validated for doxifluridine and 5-fluorouracil (5-FU) quantification in dog heparinized plasma. Sample preparation was based on liquid-liquid extraction using a mixture of isopropanol/ethyl acetate (1/9 v/v) to extract doxifluridine, 5-FU and 5-chlorouracil (5-CU, an internal standard) from plasma. Chromatography was performed on a C-18 analytical column and the retention times were 2.7, 1.5 and 1.7 min for doxifluridine, 5-FU and 5-CU, respectively with shorter analysis time within 5 min than previously reported methods. The ionization was optimized using ESI negative mode and selectivity was achieved by tandem mass spectrometric analysis by multiple reaction monitoring (MRM) using the transformations of m/z 244.8>107.6, 129.0>42.0 and 144.9>42.1 for doxifluridine, 5-FU and 5-CU, respectively. The achieved low limit of quantification was 20.0 ng/mL and the assay exhibited linear range of 20-2000 ng/mL ($R^2>0.99957$ for doxifluridine and $R^2>0.99857$ for 5-FU), using $100{\mu}L$ of plasma. Accuracy and precision of quality control samples for both doxifluridine and 5-FU met KFDA and FDA Guidance criteria of 15% for accuracy with coefficients of variation less than 15%. This method demonstrated adequate sensitivity, specificity, accuracy, precision and stability to support the simultaneous analysis of doxifluridine and 5-FU in dog plasma samples in pharmacokinetic and bioequivalence studies.

Detection of the Fungicide Iprovalicarb Residues Using a Surface Plasmon Resonance Biosensor (표면플라즈몬공명 바이오센서를 이용한 살균제 Iprovalicarb 잔류물의 검출)

  • Kim, Woon-Ho;Cho, Han-Keun;Kyung, Kee-Sung;Kim, Gi-Young
    • Journal of Biosystems Engineering
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    • v.34 no.1
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    • pp.50-56
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    • 2009
  • Surface plasmon resonance (SPR) biosensor has been used to detect many biochemical reactions, because this label-free sensor has high sensitivity and rapid response. The reactions are monitored by refractive index changes of the SPR biosensor. Iprovalicarb is protective, curative, and eradicative systemic fungicide introduced by Bayer AG in 1999. It has potential far control of downy mildew infesting onion, cucumber, grape and melon, late blight infesting tomato and potato, and anthracnose infesting watermelon and pepper. It is strictly limited to the maximum residue limit. In this study, the applicability of a portable SPR biosensor (Spreeta, Texas instrument, TX, USA) to detect the iprovalicarb residue was examined. The sensor chip was adopted to detect the reaction of iprovalicarb to immobilized iprovalicarb-antibody. The binding of the iprovalicarb onto the biosensor surface was measured by change of the refractive index (RI). Characteristics of the sensor chip including specificity, sensitivity, stability, and reusability were analyzed. In calibration test for seven levels of iprovalicarb concentration (0.32 to 5,000 mg/L) with three replications, a Sigmoidal model with Hill function was obtained between relative RI value and the iprovalicarb concentration with R-square of 0.998. It took 30 minutes to complete a set of detecting assay with the SPR biosensor.

Optimal Reserve Allocation to Maximize Kinetic Energy in a Wind Power Plant

  • Yoon, Gihwan;Lee, Hyewon;Lee, Jinsik;Yoon, Gi-Gab;Park, Jong Keun;Kang, Yong Cheol
    • Journal of Electrical Engineering and Technology
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    • v.10 no.5
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    • pp.1950-1957
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    • 2015
  • Modern wind generators (WGs) are forced or encouraged to participate in frequency control in the form of inertial and/or primary control to improve the frequency stability of power systems. To participate in primary control, WGs should perform deloaded operation that maintains reserve power using speed and/or pitch-angle control. This paper proposes an optimization formulation that allocates the required reserve to WGs to maximize the kinetic energy (KE) stored in a wind power plant (WPP). The proposed optimization formulation considers the rotor speed margin of each WG to the maximum speed limit, which is different from each other because of the wake effects in a WPP. As a result, the proposed formulation allows a WG with a lower rotor speed to retain more KE in the WPP. The performance of the proposed formulation was investigated in a 100-MW WPP consisting of 20 units of 5-MW permanent magnet synchronous generators using an EMTP-RV simulator. The results show that the proposed formulation retains the maximum amount of KE with the same reserve and successfully increases the frequency nadir in a power system by releasing the stored KE in a WPP in the case of a disturbance.

Mitigation of Ammonia Dispersion with Mesh Barrier under Various Atmospheric Stability Conditions

  • Gerdroodbary, M. Barzegar;Mokhtari, Mojtaba;Bishehsari, Shervin;Fallah, Keivan
    • Asian Journal of Atmospheric Environment
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    • v.10 no.3
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    • pp.125-136
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    • 2016
  • In this study, the effects of the mesh barrier on the free dispersion of ammonia were numerically investigated under different atmospheric conditions. This study presents the detail and flow feature of the dispersion of ammonia through the mesh barrier on various free stream conditions to decline and limit the toxic danger of the ammonia. It is assumed that the dispersion of the ammonia occurred through the leakage in the pipeline. Parametric studies were conducted on the performance of the mesh barrier by using the Reynolds-averaged Navier-Stokes equations with realizable k-${\varepsilon}$ turbulence model. Numerical simulations of ammonia dispersion in the presence of mesh barrier revealed significant results in a fully turbulent free stream condition. The results clearly show that the flow behavior was found to be a direct result of mesh size and ammonia dispersion is highly influenced by these changes in flow patterns in downstream. In fact, the flow regime becomes laminar as flow passes through mesh barrier. According to the results, the mesh barrier decreased the maximum concentration of the ammonia gas and limited the risk zone (more than 500 ppm) lower than 2 m height. Furthermore, a significant reduction occurs in the slope of the upper boundary of $NH_3$ risk zone distribution at downstream when a mesh barrier is presented. Thus, this device highly restricts the leak distribution of ammonia in the industrial plan.

The Effects of visuo-perceptual biofeedback training on dynamic postural balance in stroke patients (시지각적 되먹임 훈련이 뇌졸중 환자의 동적자세 균형에 미치는 영향)

  • Lee, Geon-Cheol;Yoon, Jung-Gyu
    • Journal of Korean Physical Therapy Science
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    • v.9 no.2
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    • pp.17-26
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    • 2002
  • This study is aimed to compare the effect of visuo-perceptual biofeedback sitting balance training and conventional sitting balance training using Balance Master on stroke patients with that of program in order to analyze the effect it has on dynamic postural balance. The subjects are twenty-four stroke patients who are receiving physical therapy in Ilsan Paik Hospital and can maintain sitting posture by themselves. These patients were divided to control group and experimental group randomly. In order to compare to control and experimental group before and after the balance training, they were tested with Mann-Whitney U test and in order to compared the changes before and after the balance training, they were tested with Wilcoxon signed-ranks test. The results are as follows: we measured the ability of dynamic posture balance control with limit of stability(LOS) test and rhythmic weight shift test. There was an increasing improvement in the ability of dynamic posture balance control of the experimental group that had visuo-perceptual biofeedback sitting balance control training using the Balance Master(p<0.05, p<0.01). According to the results from above, compared to conventional sitting balance training programs, visuo-perceptual biofeedback sitting balance control training using the Balance Master is considered to be a more valuable therapy in balance control improvement and physical function improvement. It is considered that if the weak points are made up, the training with Balance Master will give help to stroke patients and to patients with balance control disabilities and will further more contribute to successful rehabilitation therapy.

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