• Geomechanics and Engineering
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• v.19 no.3
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• pp.229-240
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• 2019

The physical models are useful to understand the soil behaviour. Hence, these tools allow validating analytical theories and numerical data. This paper addresses the design, construction and implementation of a physical model able to simulate the soil liquefaction under different cyclic actions. The model was instrumented with a piezoelectric actuator and a set of transducers to measure the porewater pressures, displacements and accelerations of the system. The soil liquefaction was assessed in three different grain size particles of a natural sand by applying a sinusoidal signal, which incorporated three amplitudes and the fundamental frequencies of three different earthquakes occurred in Colombia. In addition, such frequencies were scaled in a micro shaking table device for 1, 50 and 80 g. Tests allowed identifying the liquefaction susceptibility at various frequency and displacement amplitude combinations. Experimental evidence validated that the liquefaction susceptibility is higher in the fine-grained sands than coarse-grained sands, and showed that the acceleration of the actuator controls the phenomena trigging in the model instead of the displacement amplitude.

• Biomedical Science Letters
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• v.23 no.3
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• pp.155-160
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• 2017

Biomedical laboratory is full of risks. Risk could be biological, chemical, radioactive, mechanical, physical, fire and electrical. All possible risks need to be identified, evaluated and controlled. A risk management system must be in place to prevent accident or loss of lives and to improve overall workplace safety and productivity. Safety in laboratory is a combination of appropriate risk management system, engineering controls and technical facilities, administrative controls and safety procedures and practices. Laboratory safety culture must be developed so that exposure to hazards for laboratory personnel, community and environment will be minimized or eliminated. In this review, importance of safety in a biomedical laboratory and risk management will be discussed.

• Proceedings of the Ginseng society Conference
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• 1993.09a
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• pp.164-170
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• 1993

Panax ginseng has been reported to protect animals or to help them recover from physical, chemical, or biological stress. The antistress effects of ginseng were evaluated through the measurement of adrenal ascorbic acid, rectal temperature, and plasma level of glucose. lipids and corticosterone. During the treadmill experiments of the antifatigue study, the groups of rats receiving P. ginseng or P. quinquefolius extracts were consistently found to leave fewer fecal boli on the wheel compared with controls. This phenomenon may be due to the reported antistress effects of ginseng. Another possibility could be that the Panax species examined produced anticholinergic effects which in turn inhibited the production of fecal boli. After an anticholinergic study. employing physostigmine and atropine as controls, anticholinergic effect was found not essential for the decrease of fecal boli number left on the wheels during antifatigue studies. The results were consistent with the antistress activity reported previously. Even though the active constituents responsible for the antistress effects of ginseng remained to be determined, the fecal boli counts for stressed rats can be employed as a new protocol for evaluating the antistress effects of ginseng.

• Physical Therapy Korea
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• v.22 no.4
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• pp.71-78
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• 2015

Previous studies have investigated stepping over obstacles in treadmill walking training (TWT-OS) and treadmill walking training (TWT) alone for walking capacity not considering real physical activity. As such, we investigated the effects of TWT-OS on physical activity and changes in different levels of physical activity based on community ambulation in stroke patients. Thirty subjects were randomly assigned to either the experimental group or the control group, with 15 and 15 subjects, respectively. However, one subject from the control group was excluded because of inadequate treatment sessions. All subjects underwent routine physical therapy in the form of treadmill walking. The subjects in the experimental group underwent simultaneous training in obstacle-stepping while walking on the treadmill for 30 min/day, five times/week, for four weeks. Subjects were given a three-axis accelerometer to wear at the hip on a belt for one-week pre- and post-training physical activity. Step counts for seven days, average daily step counts, and the average of minutes spent in sedentary, light, and above moderate activity were chosen as outcome measures of physical activity. No significant differences between the groups were found in terms of step counts for seven days, average daily activity, or daily activity spent at sedentary levels after four-week interventions. However, the average daily activity spent at light levels (-42.60 min vs. -6.71 min) was significantly lower in the experimental group than in the controls. Conversely, average daily activity spent at above moderate levels was higher (19.86 min vs. 11.07 min) (p<.05) after adjusting for each baseline value. Significant pre- and post-training differences were found in all variables of the experimental group (p<.05). Thus, TWT-OS could improve physical levels above moderate activity as a community-oriented task more than simple repetitive waking on a treadmill, and it could provide an opportunity for patients ambulatory after stroke to participate in the community again.

• The Journal of Korean Physical Therapy
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• v.26 no.3
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• pp.182-190
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• 2014

Purpose: This study aimed to determine the effects of open kinetic chain exercise (OKCE) and closed kinetic chain exercise (CKCE) using knee reposition sensing on balance, strength, and knee joint reposition sense (JPS) in chronic stroke patients. Methods: Twenty-nine hemiplegic patients participated in this study. Participants were randomly divided into 3 groups, CKCE, OKCE, and controls, with 9, 10, and 10 participants, respectively. The CKCE group completed CKCE using knee reposition sensing, whereas the OKCE group completed OKCE using knee reposition sensing. The control group completed conventional physical therapy. Results: Significant differences between the CKCE and OKCE groups were apparent for all outcomes except the functional reaching test. The CKCE group displayed significant improvements in knee JPS versus the OKCE and control groups (p<0.01). The OKCE group displayed significant improvements in knee extensor muscle strength versus the CKCE and control groups (p<0.05). The CKCE and OKCE groups displayed significantly improvements in static balance versus the control group (p<0.05). Conclusion: CKCE and OKCE improved balance, strength, and knee JPS. Additionally, CKCE might provide a more useful intervention benefit than OKCE for increasing knee JPS, a weight-bearing task. OKCE was sufficient to improve the knee extensor muscle strength.

• The Journal of Korean Physical Therapy
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• v.20 no.3
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• pp.1-7
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• 2008

Purpose: Implicit motor learning is the capacity to acquire skill through physical practice without conscious awareness of what elements of performance improved. This study investigated whether subacute stroke patients can implicitly learn a perceptual-motor task. Methods: We recruited 12 patients with subacute stroke and 12 age-matched controls. All participants performed a perceptual-motor task that involved pressing a button corresponding with colored circles (blue, green, yellow, red) on a computer screen. The task consists of 7 blocks composed of 10 repetitions for a repeating 12-element sequence (total 120 responses). Results: Both groups demonstrated significant improvement in acquisition performance. Reaction times deceased in both groups at similar rate within the sequential block trials (2-5 blocks), and reaction times increased at a similar rate when the task paradigm was transferred from the sequential block trial to the random block trial (5-6-7 blocks). Conclusion: The results of this study suggest that patients with sub-actue stroke can implicitly learn a perceptual motor skill. Although explicit instructions should be used to focus the learner's attention rather than provide information about the task, the application of implicit motor learning strategies in the rehabilitation setting may be beneficial.

• Physical Therapy Rehabilitation Science
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• v.2 no.2
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• pp.87-91
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• 2013

Objective: The present study was aimed at determining the effect of physical training on glutamate transporter activity in a middle cerebral artery occlusion (MCAO)-induced ischemia injury rat model. Design: Randomized controlled trial. Methods: In this study, we randomly divided them into three groups. Group I included non-occlusion sham controls (n=10), Group II included non-physical training after MCAO (n=10), and Group III included rats that were subjected to physical training after MCAO (n=10). Rats in the physical training group underwent treadmill training, which began at 24 h after MCAO and continued for 14 consecutive days. The training intensity was gradually increased from 5 m/min on the first day to 12 m/min on day 3, and it was maintained until day 14. Focal cerebral ischemia was examined in adult male Sprague-Dawley rats by using the MCAO model. We determined the functional outcomes for each rat on days 1, 7, and 14. Glutamate transporter-1 (GLT-1) activity in the cortex of rats from all three groups was examined at the end of the experiment. Results: Out result show that MCAO rats exhibited severe neurological deficits on the 1 day, and there was no statistically significant in each groups. We observed that the functional outcomes were improved at days 7 and 14 after middle cerebral artery occlusion, and GLT-1 activity was increased in the physical training group (p<0.05). Conclusions: These results indicated that physical training after focal cerebral ischemia exerts neuroprotective effects against ischemic brain injury by improving motor performance and increasing the levels of GLT-1 activity.

• Journal of Nutrition and Health
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• v.26 no.3
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• pp.299-312
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• 1993

Anthropometry, computed tomography(CT) at the umbilical level, nutrient intake, blood pressure, serum levels of lipids and lipoproteins and response of glucose, c-peptide, insulin, and free fatty acid(FFA) during oral glucose tolerance test(OGTT) were estimated on 11 normal-weight controls and 35 overweight and obese middle-agd men. The areas of total abdominal, subcutaneous and visceral were determined by CT scanning technique. Total abdominal fat area correlated the most significantly with the levels of serum lipids, lipoproteins and insulin among several obese indices. Compared with normal-weight controls, overweight and obese men with abdominal fat lower than 29000$\textrm{mm}^2$ showed an increase in waist-hip ratio, areas of total abdominal(35%), visceral and subcutaneous fat and C-peptide response area during OGTT, though age, percent ideal body weight, body mass index, % body fat, and all biochemical indices except C-peptide response area were not different between two groups. Overweight and obese men with abdominal fat greater than 29000$\textrm{mm}^2$ showed a higher values in total abdominal fat(85%), serum levels of triglyceride, total-and LDL-cholesterol, the ratio of LDL-to HDL-cholesterol, and response areas of FFA, insulin and C-peptide during OGTT than normal-weight controls. Overweight and obese men with great abdominal fat showed an increase in alcohol ingestion and percent calorie intake per total energy expenditure, compared with normal-weight controls. Our results indicate that obesity and a certain level of total abdominal fat accumulation is required to observe abnormal levels of serum lipids, lipoproteins and insulin in Korean middle-aged men. In addition, increased alcohol and calorie intake and decreased physical activity could partly explain total abdominal fat accumulation in men.

• Korean Journal of Biological Psychiatry
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• v.9 no.2
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• pp.140-151
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• 2002

Object and Method:Minor physical anomalies(MPAs) are frequently seen in patients with schizophrenia. MPAs are considered to arise from the anomalous development of ectoderm-originated tissues in the developing fetus. Since the central nervous system originates from ectoderm, MPAs can be regarded as externally observable and objective indicators of the aberrant development which might have taken place in the central nervous system. To investigate whether MPAs are more frequent in schizophrenic patients, the frequencies of MPAs were compared between schizophrenic patients and normal controls. Total 245 schizophrenic patients diagnosed with DSM-IV(male : 158, female : 87), and 418 normal control subjects(male : 216, female : 202) were included in this study. The MPAs were measured using the modified Waldrop scale with fifteen items in six bodily regions; head, eye, ear, mouth, hand, and foot. Result:The total scores of Waldrop scale were $4.40{\pm}1.93$($mean{\pm}standard$ deviation) in patients and $3.43{\pm}1.68$ in controls for females, and for males, $4.58{\pm}1.75$ in patients and $4.28{\pm}1.59$ in controls. For females, the excess of MPAs in schizophrenic patients was statistically significant(t-test : p<0.001). For males, schizophrenic patients also showed more MPAs than normal controls, but this tendency did not reach statistical significance (t-test : p=0.094). When the modified Waldrop total scores excluding head circumference were compared, the total scores in schizophrenic patients were significantly higher for both male and female subjects(t-test : male p<0.001, female p=0.001). The individual anomaly items included in Waldrop scale were also investigated. The items of epicanthus, hypertelorism, malformed ears, syndactylia were significantly more frequent in schizophrenic patients. In contrast, the items of adherent ear lobes, asymmetric ears, furrowed tongue, curved fifth finger, single palmar crease and big gap between toes did not show any differences in frequency between schizophrenic patients and normal controls. Since a lot of statistical analyses showed different results between male and female subjects, it seems to be necessary to consider gender as an important controlling variable for the analysis, however only the item of head circumference showed statistically significant gender-related difference according to log-linear analysis. Conclusion:With a relatively large sample size, the frequencies of MPAs enlisted in Waldrop scale were compared between schizophrenic patients and normal controls in this study. MPAs were more frequently seen in schizophrenic patients and, especially, several specific items in the Waldrop scale showed prominent excess in schizophrenic patients. Although definite conclusions cannot be drawn due to the inherent limitation of the study using Waldrop scale, these results seem to support the possibility that aberrant neurodevelopmental process might be involved in the pathogenesis of schizophrenia in some of the patients.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.47-47
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• 2010

Over the past 20 years, constant progress in noise and vibration (NVH) engineering has enabled to constantly advance quality and comfort of operation and use of really any products - from automobiles to aircraft, to all kinds of industrial vehicles and machines - to the extend that for many products, supreme NVH performance has becomes part of its brand image in the market. At the same time, the product innovation agenda in the automotive, aircraft and really many other industries, has been extended very much in recent years by meeting ever more strict environmental regulations. Like in the automotive industry, the drive towards meeting emission and CO2 targets leads to very much accelerated adoption of new powertrain concepts (downsizing of ICE, hybrid-electrical...), and to new vehicle architectures and the application of new materials to reduce weight, which bring new challenges for not only maintaining but further improving NVH performance. This drives for innovation in NVH engineering, so as to succeed in meeting a product brand performance for NVH, while as the same time satisfying eco-constraints. Product innovation has also become increasingly dependent on the adoption of electronics and software, which drives for new solutions for NVH engineering that can be applied for NVH performance optimization of mechatronic products. Finally, relentless pressure to shorten time to market while maintaining overall product quality and reliability, mandates that the practice and solutions for NVH engineering can be optimally applied in all phases of product development. The presentation will first review the afore trends for product and process innovation, and discuss the challenges they represent for NVH engineering. Next, the presentation discusses new solutions for NVH engineering of products, so as to meet target brand values, while at the same time meeting ever more strict eco constraints, and this within a context of increasing adoption of electronics and controls to drive product innovation. NVH being very much defined by system level performance, these solutions implement the approach of "Model Based System Engineering" to increase the impact of system level analysis for NVH in all phases of product development: - At the Concept Phase, to be able to do business case analysis of new product concepts; to arrive at an optimized and robust product architecture (e.g. to hybrid powertrain lay-out, to optimize fuel economy); to enable target cascading, to subsystem and component level. - In Development Phase, to increase realism and productivity of simulation, so as to frontload virtual validation of components and subsystems and to further reduce reliance on physical testing. - During the final System Testing Phase, to enable subsystem testing by a combination of physical testing and simulation: using simulation models to simulate the final integration context when testing a subsystem, enabling to frontload subsystem testing before final system integration is possible. - To interconnect Mechanical, Electronical and Controls engineering, in all phases of development, by supporting model driven controls engineering (MIL, SIL, HIL). Finally, the presentation reviews examples of how LMS is implementing such new applications for NVH engineering with lead customers in Europe, Asia and US, with demonstrated benefits both in terms of shortening development cycles, and/or enabling a simulation based approach to reduce reliance on physical testing.