• 한국신뢰성학회지:신뢰성응용연구
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• 제13권1호
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• pp.11-18
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• 2013

For a reliability assessment of machinery parts, accurate performance test, environmental test, life test, etc. are required on the sample. In the performance test conditions of various machinery parts, some problems happen such as needs to rise temperature rapidly with large flow of oil having very low thermal conductivity and to measure very high torque or tiny torque, etc. This study brings out the method to apply heat to rise temperature for large flow of oil without chemical change in a performance test of oil cooler. To measure large scale of torque in a performance test of planetary gearbox of excavator, the method of torque measurement is proposed by replacing the large torque meter priced very expensive. To measure very small torque on lubricated friction, a methode of force balance type test mechanism is introduced for tests of piston assembly.

• 한국태양에너지학회 논문집
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• 제27권4호
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• pp.137-146
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• 2007

This study is about the passive cooling effects of three outdoor solar shading facilities as trees, pergola with wistaria vine and membrane shading structure, which are expected to provide cool spots in the summer. Field observations of measuring thermal environment of selected facilities is executed. Thermal environment measuring was categorized as short wave radiation, long wave radiation, net radiation, globe temperature, surface temperature measured by infrared camera. Heat transfer mechanism is analyzed with overall data from field measurement. Results from this study are as below; 1) Radiation balance measured on shaded surface under membrane shading structure was 17%($86W/m^2$) of the unshaded surface radiation balance($511W/m^2$). 2) Surface temperature comparison between vegetation and membrane of the shading structure is performed at 3 o'clock in the afternoon. Surface temperature of vegetation was same as air temperature and that of membrane was $5^{\circ}C$ higher than air temperature. Vegetation transpiration is considered as the causing factor which make those differences. 3) Results from this study could be used as fundamental data for reducing heat island phenomena and continuos research on this subject would be needed.

• PNF and Movement
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• 제5권1호
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• pp.29-35
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• 2007

Purpose : The purpose of this study was investigated to find the approach in the PNF and TC for frail elder Method : This is a literature study with books, articles, seminal note and books for PNF and TC international course. Result : Neural mechanisms contribute significantly to the gains that occur in the range of motion about a joint with stretching exercises. The participation in a stretch-training program decreases tonic reflex activity and increases flexibility and decreases in force production and muscle activation. Also the stretching-induced decreases may be due to a central nervous system inhibitory mechanism. PNF stretch techniques can increase ROM in older adults. These results may differ from those of studies performed with younger populations because of age-related physiologic changes. TC exercise improves balance control and muscle strength and were associated with reorganized lower extremity neuromuscular patterns. Conclusions : The stretch training program of the PNF and TC contribute to increase the balance and coordination for frail elder. Therefore, The frail elder prevent falling. Further study, The PNF and TC be introduced as the new therapeutic intervention for frail elder.

• 제어로봇시스템학회논문지
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• 제11권10호
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• pp.843-850
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• 2005

FBA(flux balance analysis) with Boolean rules for representing regulatory events has correctly predicted cellular behaviors, such as optimal flux distribution, maximal growth rate, metabolic by-product, and substrate concentration changes, with various environmental conditions. However, until now, since FBA has not taken into account a hierarchical regulatory network, it has limited the representation of the whole transcriptional regulation mechanism and interactions between specific regulatory proteins and genes. In this paper, in order to solve these problems, we describe the construction of hierarchical regulatory network with defined symbols and the introduction of a weight for representing interactions between symbols. Finally, the whole cellular behaviors with time were simulated through the linkage of a hierarchical regulatory network module and dynamic simulation module including FBA. The central metabolic network of E. coli was chosen as the basic model to identify our suggested modeling method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1705-1711
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• 1991

On-line fault detection and diagnosis has an increasing interest in a chemical process industry, especially for a process control and automation. The chemical process needs an intelligent operation-aided workstation which can do such tasks as process monitoring, fault detection, fault diagnosis and action guidance in semiautomatic mode. These tasks can increase the performance of a process operation and give merits in economics, safety and reliability. Aiming these tasks, series of researches have been done in our lab. Main results from these researches are building appropriate knowledge representation models and a diagnosis mechanism for fault detection and diagnosis in a chemical process. The knowledge representation schemes developed in our previous research, the symptom tree model and the fault-consequence digraph, showed the effectiveness and the usefulness in a real-time application, of the process diagnosis, especially in large and complex plants. However in our previous approach, the diagnosis speed is its demerit in spite of its merits of high resolution, mainly due to using two knowledge models complementarily. In our current study, new knowledge representation scheme is developed which integrates the previous two knowledge models, the symptom tree and the fault-consequence digraph, into one. This new model is constructed using a material balance, energy balance, momentum balance and equipment constraints. Controller related constraints are included in this new model, which possesses merits of the two previous models. This new integrated model will be tested and verified by the real-time application in a BTX process or a crude unit process. The reliability and flexibility will be greatly enhanced compared to the previous model in spite of the low diagnosis speed. Nexpert Object for the expert system shell and SUN4 workstation for the hardware platform are used. TCP/IP for a communication protocol and interfacing to a dynamic simulator, SPEEDUP, for a dynamic data generation are being studied.

• 한국운동역학회지
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• 제15권1호
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• pp.45-61
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• 2005

Stance is defined as any state in which the total mass of the body is supported by the feet. In order to maintain stance, the sum of gravito-inertial forces acting on the body must be registered by equal and opposite forces at the region of contact between the organism and the support surface. Balance is controlled by applying forces to the surface of support so as to maintain the body's center of mass vertically above the feet. for a muIti-segment organism, there can be a variety of ways in which balance can be controlled, since movements of different body segments can have similar effects on the control of balance. In general, the organism tends to have a body configuration that is aligned with gravito-inertial force when there are no external forces acting on it. If any segments of the body are not aligned with gravito-inertial force vector, a torque on that segment would tend to move the body's center of mass. The maintenance of postural stability is accomplished in humans by a complex neural control system. This requires organizing integrating and acting upon visual, vestibular, and somatosensory input, providing orientation information to the postural control system. The information necessary to control and coordinate movement is provided by the visual sense of eye position with respect to the surrounding surface layout, the vestibular sense of head orientation in the gravito-inertial space, and the somatic sense of body segment position relative to one another and to the support surface. In this study, perception and action capability was examined from various points of view. The underlying assumption of the study was that the change of postural configuration could be effected by organism, environment and task goal.

• 대한치과의사협회지
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• 제53권9호
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• pp.602-609
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• 2015

The aim of this document is to evaluate the effect of bite balance on physical fitness and motor capacity to determine the importance of the occlusal stability as a possible action mechanism of occlusal appliance including mouthguards on physical performances. We all remember that day when the prominent athlete was in the news wearing a mouthguard to improve human athletic performance. I once had investigated the determinants of athletic performance in all sorts of sports. Most of the studies had overinterpretation of results and lack of evidence to support the information. However, I discovered great expectations for new possibility in this field and settled for a more academic approach to this intriguing subject. The followings are some examples of the subject 1. Archers who wore occlusal appliances to increase the vertical dimension of occlusion by 2~3mm increased their ability to focus and to maintain good sense of balance. Their accuracy rate has been improved. The appliance was made of acrylic resin (a type of plastic). 2. Canoe players who wore occlusal appliances to increase the vertical dimension of occlusion by 5mm surpassed longtime competitor and won the race with 10 seconds gap. 3. A cycle rider who wore an occlusal appliance to treat his malocclusion surpassed his old record from 10.8 seconds to 10.3 seconds. His muscle reflexes (anaerobic exercise) and endurance (aerobic exercise) has been enhanced. 4. Occlusal appliances had a good effect on athletic performance in most sports such as swimming, diving, and weightlifting. As for the clenching on dentition, people clench their teeth when they push their physical and mental limits during sports activities. Clenching can be induced by physical exertion when maximum muscle strength is retained and this is similarly found in different types of exercises. In addition, restraint of respiratory function is observed. Therefore, creating a occlusal balance with occlusal appliance or mouthguard promoted a favorable influence when an athlete clenches.

• Asian-Australasian Journal of Animal Sciences
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• 제1권2호
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• pp.81-88
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• 1988

Experiments were conducted with chicks and pigs to determine whether the sparing effects of cobalt (Co) or nickel (Ni) on zinc (Zn) nutrition were due to an improved Zn availability. They included a Zn balance study with New Hampshire X Leghorn cross chicks, a $^{65}Zn$ absorption study with Ancona chicks and a $^{65}Zn$ balance study with pigs. The basal diet was a corn-soybean type diet high in calcium. In the Zn balance study with New Hampshire X Leghorn cross chicks, Zn retention percentages for basal, + 54 ppm Ni or + 54 ppm Co were 39.4, 40.4 and 48.3, respectively. In the $^{65}Zn$ absorption study with chicks, adding these levels of Ni or Co to the basal diet increased $^{65}Zn$ absorption from 12.8% to 14.0% and 15.1%, respectively. Supplemental Ni and Co increased the proportion of body $^{65}Zn$ found in liver and bone. With the pig experiment, $^{65}Zn$ retention percentages for basal, +54 ppm Co and + 60 ppm Zn groups were 20.0, 26.7 and 12.2, respectively; while Zn retention values (mg) in the body were 29.5, 45.1 and 60.5, respectively. In addition, supplemental Co increased $^{65}Zn$ concentration in the blood, liver, kidney and duodenum. These studies showed that supplementation of the basal diet with Co resulted in increased absorption of dietary Zn in chicks and pigs. The effect of Ni in chicks was less than that of Co. The ability of supplemental Co and to a lesser extent of Ni to improve weight gain as well as reduce other Zn-deficient signs in both species fed a practical corn-soybean type diet high in in calcium can be explained, at least in part by an associated increase in Zn absorption. The possible mechanism involved in these effects are discussed.

• Ocean and Polar Research
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• 제38권1호
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• pp.81-88
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• 2016

In many fish species, including Nile tilapia (Oreochromis niloticus), gonadal development occurs at the expense of stored energy and nutrients. Therefore, reproductive systems are inhibited by limited food supply. It has been well established that reproductive function is highly sensitive to both metabolic status and energy balance. Nothing is known about the possible mediated connection between energy balance and reproduction. Kisspeptin, a neuropeptide product of the Kiss gene has emerged as an essential gatekeeper of reproduction and may be possibly be linked to energy balance and reproduction in non-mammalians. Thus, in this study, the effect of fasting (10 days) on the expression of kisspeptin and the gonadotropin-releasing hormone (GnRH) gene were assessed in Nile tilapia (male and female) using qRT-PCR. In addition, plasma levels of estradiol-$17{\beta}$ ($E_2$) and 11-ketotestosterone (11-KT) in adult tilapia were measured by ELISA. In male tilapia, fasting reduced Kiss2 and GnRH I mRNA expression in the brain and 11-KT level in comparison with the fed tilapia (p < 0.05). In females, however, there were no significant differences in GnRH I mRNA expression and $E_2$ between fish subjected to fasting and those fed (p > 0.05). These data indicate the impact of nutritional states on kisspeptin as a potential regulatory mechanism for the control of reproduction in male Nile tilapia.

• 대한의용생체공학회:의공학회지
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• 제18권2호
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• pp.157-166
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• 1997

Postural balancing in human is known to be maintained by the complex mechanism coupled with cerebellum, equilibrium organ of ear, proprioception and other various organs. We developed a Computerized Balance Evaluation and Training system(COBET system) to evaluate postural control and to rehabilitate geriatrics and disabled patient. In addition, 55 normal adult were tested to investigate the influencing factors on balancing posture. For the analysis of static postural sway, areas of the moving center of pressure were calculated under 8 different positions of subjects. And subjects were also asked to follow the visual targets on monitor for the evaluation of the dynamic postural sway. In comparison of the first and the second sets of tests, there was test-retest reliability($\textit{p}$< 0.05). The controllability of the static pmtwn sway was decreased as the ages of subjects increase. When the ages of subject are over 60, the controllability was significantly decrease4 The dynamic postural sway was significantly greater in the age groups of 7th and 8th decade than the younger groups. It is concluded that COBET system is a reliable system in the evaluation of postural sway. The COBET system is considered to be a valuable training modality for the disabled patients as well as the elderly.