143 research outputs found

    A Passivity-based Nonlinear Admittance Control with Application to Powered Upper-limb Control under Unknown Environmental Interactions

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    This paper presents an admittance controller based on the passivity theory for a powered upper-limb exoskeleton robot which is governed by the nonlinear equation of motion. Passivity allows us to include a human operator and environmental interaction in the control loop. The robot interacts with the human operator via F/T sensor and interacts with the environment mainly via end-effectors. Although the environmental interaction cannot be detected by any sensors (hence unknown), passivity allows us to have natural interaction. An analysis shows that the behavior of the actual system mimics that of a nominal model as the control gain goes to infinity, which implies that the proposed approach is an admittance controller. However, because the control gain cannot grow infinitely in practice, the performance limitation according to the achievable control gain is also analyzed. The result of this analysis indicates that the performance in the sense of infinite norm increases linearly with the control gain. In the experiments, the proposed properties were verified using 1 degree-of-freedom testbench, and an actual powered upper-limb exoskeleton was used to lift and maneuver the unknown payload.Comment: Accepted in IEEE/ASME Transactions on Mechatronics (T-MECH

    Effect of Bisphosphonates on Anodized and HeatĆ¢ Treated Titanium Surfaces: An Animal Experimental Study

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141247/1/jper1035.pd

    Prevalence of sarcopenia and sarcopenic obesity in Korean adults: The Korean Sarcopenic Obesity Study (KSOS)

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    *Context:* Sarcopenic obesity (SO), a combination of excess weight and reduced muscle mass and/or strength, is suggested to be associated with an increased risk of adverse health outcomes. 
*Objectives:* To examine the prevalence and characteristics of Sarcopenic and SO defined by using different indices such as Appendicular Skeletal muscle Mass (ASM)/height^2^ and Skeletal Muscle Index (SMI (%): skeletal muscle mass (kg)/weight (kg) × 100) for Korean adults. 
*Methods:* 591 participants were recruited from the Korean Sarcopenic Obesity Study (KSOS) which is an ongoing prospective observational cohort study. Analysis was conducted in 526 participants (328 women, 198 men) who had complete data on body composition using Dual X-ray absorptiometry and computed tomography. 
*Results:* The prevalence of sarcopenia and SO increases with aging. Using two or more standard deviations (SD) of ASM/height^2^ below reference values from young, healthy adults as a definition of sarcopenia, the prevalence of sarcopenia and SO was 6.3% and 1.3% in men and 4.1% and 1.7% in women over 60 years of age. However, using two or more SD of SMI, the prevalence of sarcopenia and SO was 5.1% and 5.1% respectively in men and 14.2% and 12.5% respectively in women. As defined by SMI, subjects with SO had 3 times the risk of metabolic syndrome (OR = 3.03, 95% confidence interval (CI) = 1.26-7.26) and subjects with non-sarcopenic obesity had approximately 2 times the risk of metabolic syndrome (OR = 1.89, 95% CI = 1.18-3.02) compared with normal subjects. 
*Conclusion:* Obese subjects with relative sarcopenia were associated with a greater likelihood for metabolic syndrome. As Koreans were more obese and aging, the prevalence of SO and its impact on health outcomes are estimated to be rapidly grow. Further research is requested to establish the definition, cause and consequences of SO.
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    Faunal Composition of Macro-moth in Rural Haitats, Compared to Semi-natural and Natural Habitats in the Southern Part of Korean Peninsula

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    Mokpo National University, KoreaPromoting Environmental Pesearch in Pan-Japan Sea Area : Young Researchers\u27 Network, Schedule: March 8-10,2006,Kanazawa Excel Hotel Tokyu, Japan, Organized by: Kanazawa University 21st-Century COE Program, Environmental Monitoring and Prediction of Long- & Short- Term Dynamics of Pan-Japan Sea Area ; IICRC(Ishikawa International Cooperation Research Centre), Sponsors : Japan Sea Research ; UNU-IAS(United Nations University Institute of Advanced Studies)+Ishikawa Prefecture Government ; City of Kanazaw

    Fatigue Prediction of the Discharge Pipe in Reciprocating Compressor

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    In this paper, a fatigue prediction of the line discharge tube for reciprocating compressor being installed in a refrigerator was studied. The tube usually gets plenty of the repeated loads caused by the start and stop motion of a reciprocating compressor. There are two representative methods to predict the fatigue stress. At first the stress-life can be applied to the problem which takes a lot of repeated stress within the elastic strain range. Second is the strain-life method which can be used when it comes to the problem of a small repeated stress in the plastic strain range. This paper presents the stress-life method how the design parameters of a discharge pipe relate to the fatigue prediction and analyzes the co-relation between them

    Chlorine Dioxide Gas Retain Postharvest Quality and Shelf Life of Tomato During Modified Atmosphere Packaging Storage

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    While surface sterilization can minimize the postharvest loss of fruits and vegetables, it depends on concentration, treatment duration, storage condition, and crops. This study was conducted to investigate the consequences of chlorine dioxide (ClO2) gas on post-harvest quality and shelf life of tomato fruits during the modified atmosphere packaging storage. Tomato fruits of light red maturity stage were harvested at Gangwon province in the Republic of Korea. Fruits were dipped in fungal suspension and, afterward, some of them were sterilized with NaOCl, while others were sterilized with ClO2 gas. On the final storage day, the 5 ppm ClO2 gas 12 hours treated tomato fruits showed the least carbon dioxide and ethylene, and the utmost oxygen concentration. The least fresh weight loss, prolonged shelf life and the most suppressed fungal incidence were obtained by the 5 ppm ClO2 gas 12 hours treatment. As compared to other treatments, the 5 ppm ClO2 gas 12 hours treatment yielded higher firmness, titratable acidity and vitamin C, and lower soluble solids. Therefore, the 5 ppm ClO2 gas 12 hours treatment may be useful to prevent fungal incidence as well as to retain the postharvest quality and increase the shelf life of tomato fruits

    Pig-to-Nonhuman Primate (NHP) Naked Islet Xenotransplantation

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    Islet transplantation is an established therapy for selected type 1 diabetes (T1D) patients with severe hypoglycemic unawareness and glycemic liability despite of insulin treatment. However, the donor organ is limited. Porcine islets are the best alternative source to overcome this limitation, and pig-to-nonhuman primate (NHP) naked islet xenotransplantation studies are being performed worldwide. Several studies including our own have presented successful proof-of-concept results based on immunosuppression regimen including the anti-CD154 monoclonal antibody. Particularly, long-term control of diabetes by adult porcine islet transplantation has been demonstrated in five consecutive monkeys, and the longest survival was ~1000 days after transplantation. Currently, pig-to-NHP islet xenotransplantation based on clinically applicable immunosuppression regimen is being pursued. In this chapter, we will describe all the procedures of pig-to-NHP naked islet xenotransplantation: (1) the porcine islet isolation from designated pathogen-free (DPF) miniature pigs, (2) diabetes induction in monkeys, (3) transplantation procedure via the portal vein, (4) immune monitoring comprising humoral and cellular immunity after porcine islet transplantation, and finally (5) liver biopsy and subsequent immunohistochemical procedure in detail

    Endoscopist Specialty Is Associated with High-Quality Endoscopy in Korea

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    Purpose: The present study was aimed to determine whether endoscopist specialty is associated with high-quality endoscopy. Materials and Methods: We prospectively collected endoscopy quality related data based on the Endoscopy Quality Rating Scale (EQRS) of 277 endoscopy units in a hospital setting from the National Cancer Screening Program of Korea in 2009. Gastroenterology medical professors (n=154) from university hospitals visited each endoscopy unit and graded the unit according to the EQRS. The scores from the EQRS were analyzed and compared in relation to endoscopy training during residency and endoscopy subspecialist certification. Results: After excluding data from 3 endoscopy units, EQRS data from 274 endoscopy units were analyzed: 263 esophagogastroduodenoscopy (EGD) screening units and 90 colonoscopy screening units. There were no significant differences in the scores of EQRS with respect to endoscopy training during residency (p=no significance), except for scores of EGDs for "Facility and Equipment" (p=0.030). However, EQRS scores were significantly higher in the endoscopy units where endoscopy subspecialists performed the endoscopies than those where Endoscopy Subspecialists did not perform the endoscopies (p<0.05, except p=0.08 for the "Process" criteria of EGD). Conclusion: Endoscopist specialty is an important determinant of high-quality endoscopy in Korea.This study was supported by a Grant-in-Aid for Cancer Research and Control from the National Cancer Center of Korea (#0960400-1)

    Complete Atrioventricular Block Secondary to Bortezomib Use in Multiple Myeloma

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    Bortezomib is an inhibitor of 26S proteasome, which is an effective treatment for multiple myeloma. The common adverse effects of bortezomib are asthenic conditions, gastrointestinal disturbances, and peripheral neuropathy. Here we describe a patient with dyspnea and general weakness because of complete atrioventricular block while receiving bortezomib. We immediately stopped bortezomib, and after inserting a permanent VDD pacemaker, the patients' symptoms disappeared
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