• Transactions on Electrical and Electronic Materials
• /
• v.18 no.2
• /
• pp.103-110
• /
• 2017

The number of applications of solar photovoltaic (PV) systems in power generation grids has increased in the last decade because of their ability to generate efficient and reliable power in a variety of low installation in domestic applications. Various PV converter topologies have therefore emerged, among which the modular multilevel converter (MMC) is very attractive due to its modularity and transformerless features. The modeling and control of the MMC has become an interesting issue due to the extremely large expansion of PV power plants at the residential scale and due to the power quality requirement of this application. This paper proposes a novel control method of MMC which is used to directly integrate the photovoltaic arrays with the power grid. Traditionally, a closed loop control has been used, although circulating current control and capacitors voltage balancing in each individual leg have remained unsolved problem. In this paper, the integration of model predictive control (MPC) and traditional closed loop control is proposed to control the MMC structure in a PV grid tied mode. Simulation results demonstrate the efficiency and effectiveness of the proposed control model.

• Journal of Life Science
• /
• v.18 no.7
• /
• pp.1011-1014
• /
• 2008

The ability or inability to taste phenylthiocarbamide (PTC) is a classic inherited trait that has been best-studied in human populations. Also, variation in PTC perception has been correlated with dietary preferences and thus may have important consequence for diet-related diseases in modem populations. The recent identification of the TAS2R38 gene (PTC gene) which is a member of TAS2R family of bitter taste receptor genes and three common polymorphisms in the gene is highly correlated with taste sensitivity to PTC. Balancing natural selection has acted to maintain high frequency of both alleles of the gene in human population. Future detailed studies of the relationships between molecular mechanisms and taste function may have therapeutic implications, such as helping patients to consume beneficial bitter-tasting compounds.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.05a
• /
• pp.615-620
• /
• 2005

Vibration in Engine module could be reduced by introducing a balance shaft module which has one or more unbalanced rotors. The unbalanced rotor is unbalanced in one direction that act as a opposite direction of the inertia force or moment triggered by engine component so that the largest order factor in vibration is efficiently decreased The ability of balance shaft to reduce the order element of engine component is investigated by a vehicle testing that is focused on comparing the vibration with balance shaft to that of without balance shaft. One of the commonly adapted balance shaft is tested by modal scheme for indemnifying the dynamic characteristics and an, the modal information is used for a clue to design the balance shaft module. The essential equation deriving the design parameters of unbalanced rotor is also presented for two cases, 3 in-ling and 4 in-ling cylinder model. Finally, the overall design process is explained with flow chart.

• Korean Journal of Applied Biomechanics
• /
• v.22 no.2
• /
• pp.173-181
• /
• 2012

The purpose of this study was to research on the movement of Fouette A La Second which was a type of turning movements on cheerleading. This research was conducted for helping cheerleaders to improve their overall skills. The three cheerleading national team members were participated in this research and the movements of Fouette A La Second were recorded with 6 digital motion master 60 video cameras, operating at a sampling frequency of 60 fields/sec. Six out of ten turning motion data were collected and analyzed with Kwon3D XP. The results were as follow: 1) The subject A's Releve motion was not executed precisely because of the COG's unstability. So she was required to improve the balancing ability. 2) The subject B could not execute the precise A La Second motion because of subject B's large hip angle. By tracing the projection of B's right toe on x-y plane, the subject made an elliptical orbit. Because B did not have a proper turning skills she needed to improve the muscle power and flexibility. She also needed to move quickly from Releve to Plie movement. 3) The subject C could not execute the Plie movement precisely, so she could not turn her body correctly around a certain spot. The subject C needed to decrease the knee angle at the Plie motion.

• Journal of Korean Physical Therapy Science
• /
• v.17 no.1_2
• /
• pp.33-39
• /
• 2010

Purpose: The purpose of this study was to analyze the effects of a balance training program using the TARGET Balance Trainer(TBT), which utilizes a visual target, on the balancing ability of normal, healthy individuals. Methods: Twelve healthy female students with an average of 20.7 years(SD=0.25), were participated in this study. They were randomly divided into two groups(6 subjects in each group); experimental group, control group. The experimental group underwent a 3-week training program using the TBT, while the control group trained using only a dynamic air cushion(DAC). Results: Compared to those who trained using only the DAC, participants who trained with the TBT had a smaller difference between the weights distributed(N) to their left and right foot while normal standing with their eyes open. The TBT group also showed a smaller discrepancy between the weights distributed(N) to their left and right sides while standing on one leg with their eyes open, and also with their eyes closed by eye band. Conclusions: TBT is effective to reduce the degree of weight shifting between left and right side in each group. This study is expected to provide a model for future clinical studies.

• Korean Journal of Applied Biomechanics
• /
• v.30 no.1
• /
• pp.83-91
• /
• 2020

Objective: The study aimed to develop a functional performance index that evaluates the functional performance of Parkinson's patients, i.e., to integrate biomechanical measurements of walking, balance, muscle strength and tremor, and to use multiple linear regression with stepwise methods to identify the most suitable predictors for the progression of disease. Method: A total of 60 subjects were tested for sub-variables of four factors: walking, balance, isometric strength and hand tremors. Potential independet variables were extracted through correlation analysis of the sub-variables and dependent variables, Hoehn & Yahr scale. And then, a stepwise multiple regression analysis using the potential independent variables was performed to identify predictor of Hoehn & Yahr scale. Results: First, the results of the study showed that physical composition and gait had a relatively more correlated with the progression of the disease, compared to balance and hand tremor. Second, Parkinson's functional performance is characterized by dynamic pattern of walking, such as foot clearance and turning angle (TA) of walking, and a high-explained regression model is completed. Conclusion: The study emphasized the importance of walking variables and body composition in minor pathological features compared to Parkinson's patient's balancing ability and hand tremor. Specifically, it revealed that dynamic walking patterns functionally characterize patients. The results are worth considering when assessing functional performance related to the progression of the disease at the site.

• The Journal of Korean Physical Therapy
• /
• v.22 no.3
• /
• pp.23-30
• /
• 2010

Purpose: The purpose of this study was to determine whether a balance training program could improve the balancing ability of elderly patients with type II diabetes mellitus. If yes, the results could lead to development of a method to prevent falls in elderly patients with type II diabetes mellitus (DM). Methods: Subjects were 28 elderly patients with type II DM. Subjects were divided into a control and an experimental group with 14 patients in each group. The experimental group had a balance training program consisting of balance training and lower extremity muscle strengthening exercises. The exercise group met twice a week for 8 weeks. All subjects were evaluated using a force plate for the amount of postural sway. To determine the degree of diabetes, we measured Hemoglobin A1c. Results: Balance in the experimental group (p<0.05) increased significantly compared to the control group. Conclusion: The results suggest that a balance training program should be recommended for improving balance and preventing falls in elderly type II DM patients.

• Transactions on Electrical and Electronic Materials
• /
• v.15 no.3
• /
• pp.144-148
• /
• 2014

The purpose of this research is to utilizing the Tetrax$^{(R)}$ balance measuring instrument in order to analyze the postural balance of males and females in their 30 s diagnosed with chronic lower back pain who have followed a 12-week rehabilitation exercise program. The research also examines the effects on any change in back pain level. In terms of the variables in this research, postural balance (left/right, front/back, postural balance) and pain level change (0~100 mm) were measured. Pre-/post-experimental differences were assessed using the paired-t test. In addition, to identify any gender gap, we set the preliminary scores as a covariate and ran the Analysis of Covariance. Statistical significance (a) herein was set at 0.05. As a result of this research experiment, the left/right, front/back, and overall postural balance were found to increase in both the male and female cases, but with no statistical significance or gender gap. However, both males and females showed a significant decrease in their back pain levels. These findings demonstrate the necessity of continuing clinical research based on the Tetrax$^{(R)}$ equipment for scientific evaluation of the effects of rehabilitation exercises on chronic lower back pain patients and their balancing ability.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.19 no.4
• /
• pp.1088-1091
• /
• 2005

This study was designed to research whether Dinamika can yield a suitable diagnosis for Activity of Autonomic Nene System on stroke. The testing of Dinamika was carried out at Oriental Medical Centar of Dong-Eui University with the participation of 27 patients. The results of Dinamika examinations shows as follows : Group A(the rising of a parasympathetic nerve system) is 0 persons. And Group B(the balancing autonomic none system) is 4 persons. Group C(the rising of a sympathetic nerve system) is 23 persons. There are 7 persons that it is difference of more than $20\%$ between B1 (the control ability of autonomic nerve system) and B2(the potential energy to control autonomic nerve system), 11 person that B1 and B2 are less than $10\%$, 1 person that B1 and B2 are balanced about $60\%$, 8 person that it is balanced domain from $10\%\;to\; 60\%$ between B1 and B2. According to this study on activity of autonomic nerve system using Dinamika on Stroke, these results suggest that 27 patients evidence the problem of autonomic none systems.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.2
• /
• pp.522-541
• /
• 2016

Network virtualization provides an effective way to overcome the Internet ossification problem. As one of the main challenges in network virtualization, virtual network embedding refers to mapping multiple virtual networks onto a shared substrate network. However, existing heuristic embedding algorithms evaluate the embedding potential of the nodes simply by the product of different resource attributes, which would result in an unbalanced embedding. Furthermore, ignoring the hops of substrate paths that the virtual links would be mapped onto may restrict the ability of the substrate network to accept additional virtual network requests, and lead to low utilization rate of resource. In this paper, we introduce and extend five node attributes that quantify the embedding potential of the nodes from both the local and global views, and adopt the technique for order preference by similarity ideal solution (TOPSIS) to rank the nodes, aiming at balancing different node attributes to increase the utilization rate of resource. Moreover, we propose a novel two-stage virtual network embedding algorithm, which maps the virtual nodes onto the substrate nodes according to the node ranks, and adopts a shortest path-based algorithm to map the virtual links. Simulation results show that the new algorithm significantly increases the long-term average revenue, the long-term revenue to cost ratio and the acceptance ratio.