• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.6
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• pp.390-396
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• 2021

Lithium-ion batteries have been designed and used as battery packs with series and parallel combinations that are suitable for use. However, due to its internal electrochemical properties, producing the battery's condition at the same value is impossible for individual cells. In addition, the management of characteristic deviations between individual cells is essential for the safe and efficient use of batteries as aging progresses with the use of batteries. In this work, we propose a method to manage deviation properties and detect abnormal behavior in the configuration of a combined battery pack of these multiple battery cells. The proposed method can separate and detect probabilistic low-frequency information according to statistical information based on Z-score. The verification of the proposed algorithm was validated using experimental results from 10S3P battery packs, and the implemented algorithm based on Z-score was validated as a way to effectively manage multiple individual cell information.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.1
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• pp.1-8
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• 2022

Recently, photovoltaic (PV) systems have been gradually applied in eco-friendly vehicle applications to improve fuel economy. The relevant market is expected to continue to grow because the installation of large-capacity PV systems to other eco-friendly vehicles, such as electric buses and trains, is being considered. However, in a PV system, power imbalance between submodules and low power generation efficiency occur due to factors such as cell aging, contamination, and shading. To resolve this problem, various differential power processing (DPP) converters have been researched and developed. However, conventional DPP converters suffer from large volume and low efficiency. Therefore, to apply DPP converters to eco-friendly vehicles, increasing efficiency and reducing volume and price compared with existing DPP converters is necessary. In this paper, a novel DPP converter with an integrated transformer is proposed and analyzed. The proposed DPP converter uses a single magnetic component by integrating transformers and secondary sides of conventional DPP converters. Therefore, the proposed DPP converter shows high power density and high efficiency, and it is suitable for PV systems in eco-friendly vehicle applications.

• International journal of advanced smart convergence
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• v.11 no.4
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• pp.129-140
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• 2022

The purpose of this study to improve the shoulder wheel that is used frequently during shoulder circumduction exercise in a park, to link the shoulder wheel to a game application comprising various shoulder circumduction exercise and shoulder ROM exercise, and to enjoy the game during the exercises. A step motor was added to the shoulder wheel, and the rotating speed and rotating angle, and rotating direction can be controlled. The shoulder height, different for different people, can be controlled as well, so that any user can use this device. The developed application content includes the game elements, to enjoy the repetitive and boring exercise with fun and interest, and the control to adjust the degree of difficulty. This was to help users heighten their desire to rehabilitate by inducing active participation during repetitive shoulder rehabilitation exercise because the game vests users with intrinsic motivation and immersion. If the shoulder wheel and application contents proposed in this study are used, shoulder diseases can be prevented in advance by performing muscle strengthening exercises required in an aging society. This study is expected to contribute to the field of research related to serious games and rehabilitation.

• Journal of the Semiconductor & Display Technology
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• v.22 no.4
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• pp.87-92
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• 2023

As the elderly population increases, the number of patients with various joint diseases, including degenerative arthritis, is steadily increasing. CPM medical devices are needed to effectively treat degenerative arthritis that is common in the elderly population. Domestic CPM medical devices have limited functions and are highly dependent on imports for expensive imported medical devices. To solve this problem, we designed a ROM measurement function using a current sensor that is not present in existing composite joint CPM medical devices. The algorithm was designed using the fact that the force caused by joint stiffness greatly increases the current flowing through the DC motor. In addition, the need for digital healthcare in the medical field is gradually expanding as the proportion of chronically ill patients increases due to the spread of the non-face-to-face economy due to COVID-19 and the aging population. Therefore, this paper aims to improve the performance of CPM medical devices by allowing real-time confirmation of rehabilitation exercise information and operation range measurement results in accordance with digital healthcare trends through a Bluetooth application developed as an Android studio.

• Journal of Yeungnam Medical Science
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• v.40 no.4
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• pp.328-334
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• 2023

An aging population and changes in dietary habits have increased the incidence of diabetes, resulting in complications such as diabetic foot ulcers (DFUs). DFUs can lead to serious disabilities, substantial reductions in patient quality of life, and high financial costs for society. By understanding the etiology and pathophysiology of DFUs, their occurrence can be prevented and managed more effectively. The pathophysiology of DFUs involves metabolic dysfunction, diabetic immunopathy, diabetic neuropathy, and angiopathy. The processes by which hyperglycemia causes peripheral nerve damage are related to adenosine triphosphate deficiency, the polyol pathway, oxidative stress, protein kinase C activity, and proinflammatory processes. In the context of hyperglycemia, the suppression of endothelial nitric oxide production leads to microcirculation atherosclerosis, heightened inflammation, and abnormal intimal growth. Diabetic neuropathy involves sensory, motor, and autonomic neuropathies. The interaction between these neuropathies forms a callus that leads to subcutaneous hemorrhage and skin ulcers. Hyperglycemia causes peripheral vascular changes that result in endothelial cell dysfunction and decreased vasodilator secretion, leading to ischemia. The interplay among these four preceding pathophysiological factors fosters the development and progression of infections in individuals with diabetes. Charcot neuroarthropathy is a chronic and progressive degenerative arthropathy characterized by heightened blood flow, increased calcium dissolution, and repeated minor trauma to insensate joints. Directly and comprehensively addressing the pathogenesis of DFUs could pave the way for the development of innovative treatment approaches with the potential to avoid the most serious complications, including major amputations.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.3
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• pp.299-305
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• 2019

This study was initiated to solve the difficulties of aged and female workers in agriculture society due to aging and demise of young people. In the case of the conventional elevated lift, the risk of exposure to uneven road or work environment, not the difficulty of professional qualification and operation, and the risk of exposure to the uneven road or working environment, were also studied based on previous researches so that women could easily and efficiently perform productive agriculture. First, the simulation was carried out through the prediction model of traction performance using the object of agricultural forklift, and the soil of the Kimhae city in Gyeongnam (34.125kPa, internal friction angle 35.294deg, external friction angle 13.620deg, Adhesion force 5.750 kPa, average cone index 0-15 cm cl, 1001.8 kPa). In the case of the forklift for simulation, the driving force and the kinetic resistance prediction modeling of the agricultural electric forklift are modeled. Based on this model, the motor control drive adopts the 1232E model, which is a drive dedicated to AC motor, and divides the two drivers into master and slave And the model for the simulation was designed to control motor drive, hydraulic drive, and various outputs on the main PCB. The simulation model is undergoing continuous simulation, modification and supplementation. Based on this research, we will continue research for development of safer and more efficient agricultural electric forklift.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.4
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• pp.464-476
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• 2019

Objectives: This study aimed to assess the exposure levels of tollbooth workers to diesel particulate matter using black carbon (BC) and to find the correlations among variables associated with BC using the motor vehicle management act regulated by the Ministry of Land, Infrastructure and Transport. Methods: This study was performed over 14 days at a university in Seoul. BC levels were monitored using an aethalometer and were conducted around the breathing zones of the workers. There were three sampling locations: inside the tollbooth (front gate and rear gate) and an office as a control group. T-test, correlation, and multiple linear regression analysis were performed using SPSS. Results: The geometric mean (GM) of BC_30min concentrations in the exposure group was 2.44 ㎍/㎥, approximately 1.4 times higher than the control group (1.75 ㎍/㎥). The GM of BC_30min concentrations was 2.75 ㎍/㎥ during the heavy traffic time (9-10 am) and 2.30 ㎍/㎥ during non-heavy traffic times (p<0.001). The multiple linear regression analysis shows that the number of all types of vehicles and PM_2.5 concentrations in the atmosphere were factors increasing the GM of BC(ln(BC_30min)) concentrations (adjusted R²=0.42, p<0.001). The workers were constantly exposed to low concentrations (GM of BC_30min=2.44 ㎍/㎥), but they were exposed to peak concentrations instantly (BC_10sec=3545.04 ㎍/㎥). When the GM of BC_30min concentrations was momentarily represented as high, it was identified that a vehicle mainly using diesel fuel or an aging vehicle had passed. Conclusions: A ventilation system should be installed in the closed tollbooth or aging vehicles should be controlled so as not to pass tollbooths.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.5 no.1
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• pp.17-25
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• 2011

This paper aims to find the optimal control gain for enhancing the convenience of electric walking frames and design a control algorithm. With the recent advances in medical technology, there has been a rapid increase in the aging population and a variety of mobile walking frames have been developed for improvement of the quality of life. However, the manual walking frames of such mobile aids don't have any electric motor which helps facilitate elderly users' walking and thus are not efficient enough for the old people of weak strength to use especially when moving on uneven surfaces such as slopes or thresholds. The types of electric walking frames have been developed to overcome such inefficiency. Electric walking frames require users' control operations for motor driving unlike manual frames. Therefore, when they are not properly handled, it causes considerable inconvenience to their users. The present study compared the electric walking frames with manual ones in terms of operational convenience and attempted to improve the user convenience of walking frames varying the control value for user convenience based on certain standards. This paper presented a haptic sensor designed to recognize the will to walk and measure the degree of convenience and proposed a control algorithm for improvement of convenience. For user convenience, this paper evaluated the relative convenience of walking frames in view of changing differences between the center of vehicle (COV) and the center of position (COP). With the employment of an electric walking frame and a new measuring method, all the processes were experimentally tested and validated.

• 재활복지
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• v.18 no.4
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• pp.221-235
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• 2014

Recently, the frequency of stroke disease is increased due to the rapid aging population, and is contributed to the major occurrence factors of the posteriori acquired disability. This study is about an postural change device for the control of supine posture which is an assisted equipment using in daily rehabilitation process for overcoming the disability by the aftereffects of the stoke disease. In this paper, the existing domestic and Japan postural appliances is examined and its comparison and categorization is performed according to its functions and purposes. Here, in order to control the supine posture state, the design method for advanced multi functional system is proposed, which is devised to have an unified mattress control operations of combining the bedsore prevention tube with the supine posture tilting tube. And also, in addition of an smart function, it is designed to enable to perform an RF functions such as the monitoring of the present device state, the alteration of the basic position and the control of alternative floating and supine posture. This system control hardware consists of three main parts : the sensor detection part, the motor driving /control part, and the system control part for bluetooth communication. In results, we confirmed that the system designed by this research is possible to make it practical as an advanced smart postural change device combined by IoT technology in the application field of the recent IT technology.

• Journal of the Korean Applied Science and Technology
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• v.40 no.2
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• pp.290-300
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• 2023

This study was understood the risk mechanism of falls in the elderly and reviewed previous research data to see if the principle of Pilates rehabilitation exercise could have a positive effect on balance ability and postural stabilization in the elderly, and the purpose of this study is to present literature-based data on the fall prevention effect of rehabilitation Pilates exercise. First, the rehabilitation Pilates exercise makes it available for strengthening the center of the body to stabilize the spine and pelvis and stimulates the nerve root, thereby having an effect on the balance and the joint stabilization. Second, a proprioceptive sensory impairment and a musculoskeletal degenerative disease due to aging increase the loss of balance ability and the instability in posture maintenance, thereby coming to raise the risk of a fall damage caused by the difficulty in performing motor functions and by the gait disturbance. Third, the rehabilitation Pilates exercise leads to improving the core muscle strength in older adults, resulting in being capable of expecting the betterment in the balance and the reaction time motor function. And there is a positive impact on the improvement in body imbalance and on the stability in movement involved in the fall prevention, resulting in being able to suggest the possibility of likely contributing to a reduction in a fall risk rate. In conclusion, the rehabilitation Pilates as the elderly exercise program showed effects on the improvement in the body's muscular strength, on the upgrade in a sense of balance, and on the stabilization of core. Thus, it was considered to diminish the risk factors for a fall damage caused by musculoskeletal degeneration and to be capable of preventing a serious disorder of activity due to a chronic senile disease.