• PNF and Movement
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• v.22 no.1
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• pp.43-54
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• 2024

Purpose: Falls among persons older than 65 years are a significant concern due to their frequency and severity. This study aimed to develop a vest-type embedded artificial intelligence (AI) system capable of detecting and predicting falls in various scenarios. Methods: In this study, we established and developed a vest-type embedded AI system to judge and predict falls in various directions and situations. To train the AI, we collected data using acceleration and gyroscope values from a six-axis sensor attached to the seventh cervical and the second sacral vertebrae of the user, considering accurate motion analysis of the human body. The model was constructed using a neural network-based AI prediction algorithm to anticipate the direction of falls using the collected pedestrian data. Results: We focused on developing a lightweight and efficient fall prediction model for integration into an embedded AI algorithm system, ensuring real-time network optimization. Our results showed that the accuracy of fall occurrence and direction prediction using the trained fall prediction model was 89.0% and 78.8%, respectively. Furthermore, the fall occurrence and direction prediction accuracy of the model quantized for embedded porting was 87.0 % and 75.5 %, respectively. Conclusion: The developed fall detection and prediction system, designed as a vest-type with an embedded AI algorithm, offers the potential to provide real-time feedback to pedestrians in clinical settings and proactively prepare for accidents.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.2
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• pp.127-132
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• 2024

Recently, secondary batteries, commonly known as rechargeable batteries, find widespread applications across various industries. Particularly valued for their compact and lightweight characteristics, they play a crucial role in diverse portable electronic devices such as smartphones, laptops, and tablets, offering high energy density and efficient charge-discharge capabilities. Moreover, they serve as vital components in electric vehicles and contribute significantly to the field of renewable energy as part of Energy Storage Systems(ESS). However, despite advancements in this technology, issues such as reduced lifespan, cracking, damage, and even the risk of fire can arise due to excessive charging and discharging of secondary batteries. To address these challenges, Battery Management System(BMS) are employed to protect against overcharging and improve overall performance. Nevertheless, understanding the protective range settings of BMS using lithium-ion batteries, the most commonly used secondary batteries, and lead-acid batteries can be challenging. Therefore, this paper aims to utilize a battery charge-discharge tester and simulator to investigate the charging and discharging characteristics of lithium-ion batteries and lead-acid batteries, addressing the associated challenges of reduced lifespan, cracking, damage, and fire hazards in secondary batteries.

• Steel and Composite Structures
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• v.51 no.5
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• pp.509-527
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• 2024

Bonding carbon fiber-reinforced polymer (CFRP) laminates have been extensively employed in the restoration of steel constructions. In addition to the mechanical properties of the CFRP, the bond strength (P_U) between the CFRP and steel is often important in the eventual strengthened performance. Nonetheless, the bond behavior of the CFRP-steel (CS) interface is exceedingly complicated, with multiple failure causes, giving the P_U challenging to forecast, and the CFRP-enhanced steel structure is unsteady. In just this case, appropriate methods were established by hybridized Random Forests (RF) and support vector regression (SVR) approaches on assembled CS single-shear experiment data to foresee the P_U of CS, in which a recently established optimization algorithm named Aquila optimizer (AO) was used to tune the RF and SVR hyperparameters. In summary, the practical novelty of the article lies in its development of a reliable and efficient method for predicting bond strength at the CS interface, which has significant implications for structural rehabilitation, design optimization, risk mitigation, cost savings, and decision support in engineering practice. Moreover, the Fourier Amplitude Sensitivity Test was performed to depict each parameter's impact on the target. The order of parameter importance was t_c> L_c > E_A > t_A > E_c > b_c > f_c > f_A from largest to smallest by 0.9345 > 0.8562 > 0.79354 > 0.7289 > 0.6531 > 0.5718 > 0.4307 > 0.3657. In three training, testing, and all data phases, the superiority of AO - RF with respect to AO - SVR and MARS was obvious. In the training stage, the values of R² and VAF were slightly similar with a tiny superiority of AO - RF compared to AO - SVR with R² equal to 0.9977 and VAF equal to 99.772, but large differences with results of MARS.

• Knowledge Management Research
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• v.25 no.1
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• pp.217-233
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• 2024

The demand for two-wheelers has increased in recent years, driven by the growing delivery culture, which has also led to a rise in the number of two-wheelers. Although two-wheelers are economically efficient in congested traffic conditions, reckless driving and ambiguous traffic laws for two-wheelers have turned two-wheeler accidents into a significant social issue. Given the high fatality rate associated with two-wheelers, the severity and risk of two-wheeler accidents are considerable. It is, therefore, crucial to thoroughly understand the characteristics of two-wheeler accidents by analyzing their attributes. In this study, the characteristics of two-wheeled vehicle accidents were categorized using the K-prototypes algorithm, based on data from two-wheeled vehicle accidents. As a result, the accidents were divided into four clusters according to their characteristics. Each cluster showed distinct traits in terms of the roads where accidents occurred, the major laws violated, the types of accidents, and the times of accident occurrences. By tailoring enforcement methods and regulations to the specific characteristics of each type of accident, we can reduce the incidence of accidents involving two-wheelers in metropolitan areas, thereby enhancing road safety. Furthermore, by applying machine learning techniques to urban transportation and safety, this study adds to the body of related literature.

• Progress in Medical Physics
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• v.34 no.4
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• pp.48-54
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• 2023

Purpose: In this study, the dosimetric characteristics of lung stereotactic body radiotherapy (SBRT) plans using the new Halcyon system were analyzed to assess its suitability. Methods: We compared the key dosimetric parameters calculated for the Halcyon SBRT plans with those of a conventional C-arm linear accelerator (LINAC) equipped with a high-definition multileaf collimator (HD-MLC)-Trilogy Tx. A total of 10 patients with non-small-cell lung cancer were selected, and all SBRT plans were generated using the RapidArc technique. Results: Trilogy Tx exhibited significant superiority over Halcyon in terms of target dose coverage (conformity index, homogeneity index, D_{0.1 cc}, and D_95%) and dose spillage (gradient). Trilogy Tx was more efficient than Halcyon in the lung SBRT beam delivery process in terms of the total number of monitor units, modulation factor, and beam-on time. However, it was feasible to achieve a dose distribution that met SBRT plan requirements using Halcyon, with no significant differences in satisfying organs at risk dose constraints between both plans. Conclusions: Results confirm that Halcyon is a viable alternative for performing lung SBRT in the absence of a LINAC equipped with HD-MLC. However, extra consideration should be taken in determining whether to use Halcyon when the planning target volume setting is enormous, as in the case of significant tumor motions.

• Structural Engineering and Mechanics
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• v.91 no.2
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• pp.211-225
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• 2024

Soft bending actuators have gained significant interest in robotic applications due to their compliance and lightweight nature. Their compliance allows for safer and more natural interactions with humans or other objects, reducing the risk of injury or damage. However, the nonlinear behaviour of soft actuators presents challenges in accurately predicting their bending motion and force exertion. In this research, a new comprehensive study has been conducted by employing a developed 3D finite element model (FEM) to investigate the effect of geometrical and material parameters on the bending behaviour of a soft pneumatic actuator reinforced with Kevlar fibres. A series of experiments are designed to validate the FE model, and the FE model investigates the improvement of actuator performance. The material used for fabricating the actuator is RTV-2 silicone rubber. In this study, the Cauchy stress was expanded for hyperelastic models and the best model to express the stress-strain behaviour based on ASTM D412 Type C tensile test for this material has been obtained. The results show that the greatest bending angle was achieved for the semi-elliptical actuator made of RTV2 material with a pitch of 1.5 mm and second layer thickness of 1 mm. In comparison, the maximum response force was obtained for the semi-elliptical actuator made of RTV2 material with a pitch of 6 mm and a second layer thickness of 2 mm. Additionally, this research opens up new possibilities for development of safer and more efficient robotic systems that can interact seamlessly with humans and their environment.

• Korean Journal of Agricultural Science
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• v.49 no.4
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• pp.749-760
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• 2022

Omics-driven synthetic biology is a multidisciplinary research field that creates new artificial life by employing genetic components, biological devices, and engineering technique based on genetic knowledge and technological expertise. It is also utilized to make valuable biomaterials with limited production via current organisms faster, more efficient, and in huge quantities. As the bioeconomic age begins, and the global synthetic biology market becomes more competitive, investment in research and development (R&D) and associated sectors has grown considerably. By overcoming the constraints of present biotechnologies through the merging of big data and artificial intelligence technologies, huge ripple effects are envisaged in the pharmaceutical, chemical, and energy industries. In agriculture, synthetic biology is being used to solve current agricultural problems and develop sustainable agricultural systems by increasing crop productivity, implementing low-carbon agriculture, and developing plant-based, high-value-added bio-materials such as vaccines for diagnosing and preventing livestock diseases. As international regulatory debates on synthetic biology are now underway, discussions should also take place in our country for the growth of bioindustries and the dissemination of research findings. Furthermore, the system must be improved to facilitate practical application and to enhance the risk evaluation technology and management system.

• Fisheries and Aquatic Sciences
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• v.27 no.5
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• pp.306-313
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• 2024

The genus Chirostoma is endemic from the Mesa Central of Mexico. It is conformed of 18 species and six subspecies. Five species are in some category of risk, because of this, Chirostoma jordani is an excellent model species to implement biotechnologies like gametes cryopreservation. Aim of present study was to evaluate fertilizing capacity of cryopreserved C. jordani sperm, as alternative to conservation and assisted reproduction in this specie and genus. Males and females were collected from wild Atlangatepec dam stock, Tlaxcala State, Mexico. Seminal quality was evaluated in fresh and cryopreserved semen with three cryoprotective agents (CPAs): 10% dimethyl sulfoxide (DMSO), 10% methanol (MeOH), 14% ethylene glycol (EG) and it was determined its post-thaw fertilizing capacity. Sperm motility percentage decreased during cryopreservation process (p < 0.05). There were not significant differences in post-thaw motility percentage between EG (53.5 ± 1.9%) and MeOH (53.3 ± 1.3%), but DMSO (50.3 ± 0.5%) was significantly different (p < 0.05). Results showed that 0.2 μL fresh semen were enough to fertilize 100% oocytes (n = 60). 10 μL DMSO and 5 μL MeOH and EG cryopreserved semen were necessary to fertilize oocytes 100% (n = 60) (p < 0.05). Cryopreservation and fertilization protocol for C. jordani sperm was efficient and it could be used for its assisted reproduction.

• Journal of Venture Innovation
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• v.1 no.1
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• pp.83-98
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• 2018

This paper makes a theoretical approach to the differences between transaction tax and capital gains tax when the financial instruments are traded and imposed taxes in K-OTC market, a newly emerging off-board market. Since it is difficult to reduce risk to the level which investors would like to pursue - depending on the taxation methods of portfolio-composed financial instruments - when it comes to forming a synthetic bond to hedge risk, this paper also seeks for effective taxation methods to make this applicable. First of all, to thoroughly review the taxation balance of synthetic bonds, this paper analyzed the effects of the transaction tax and capital gains tax imposed upon synthetic bonds according to the changes in final stock price and strike price in K-OTC market, and analyzed after-tax profit differences among them depending on whether income tax deduction took place or not. As a result of the research upon the tax gap in transaction tax and capital gains tax according to the changes of final stock prices, it was shown that imposing transaction tax is more likely to be effective for some level of risk hedging with replicating portfolio considering taxation policies and financial markets, since the effect of the transaction tax has a much lower tax gap than that of capital gains tax. In addition, in relation to whether income tax deduction was permitted or not, it was proved that the effect of the transaction tax and the capital gains tax vary depending on the variation in the strike price. Above all, it was shown that if the strike price is lower than the stock price, the transaction tax will be less affected by the existence of income tax deduction than the capital gains tax, while both will be equally affected by the existence of income tax deduction if the strike price is higher than the stock price. Further study would be to demonstrate the validation of this in the K-OTC market with actual financial instruments and, also, to seek for a more systematic hedging method by using a ratio analysis approach to the calculation of the option transaction tax

• Clinical and Experimental Pediatrics
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• v.46 no.6
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• pp.561-565
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• 2003

Purpose : Urinary tract infection(UTI) is the most common bacterial infectious disease that may induce severe renal injury unless early diagnosis and appropriate treatment are performed. If recurrent UTI is prevented, renal injury can be also reduced. Therefore, we studied the risk factors of recurrent UTI in children. Methods : We performed a retrospective study of 168 children(58 girls and 110 boys) who were treated for UTI in the Department of Pediatrics, Korea University Medical Center, during 2000-2001. Among 168 children, 93 children were followed up for more than six months. For the detection of recurrence of UTI, we performed monthly routine urine cultures and physical examinations. Results : The total rate of recurrence was 32.3%. The recurrent rate in boys and girls were 37.1% and 17.4%, respectively(P<0.05). The most common causative bacteria in the first onset and in recurrence were Escherichia coli. There was a significant difference in the onset age of UTI between boys with recurrence($4.8{\pm}1.0months$) and without recurrence($16.5{\pm}3.8months$)(P<0.01). In 77% of cases, urinary tract infection recurred within six months of the first infection. The time of the first recurrence after UTI was $3.7{\pm}0.6months$ in boys and $14{\pm}8.2months$ in girls(P<0.01). The number of recurrences showed a significant difference between the group under the age of one year($0.69{\pm}0.8/year$) and those above the age of one year($0.16{\pm}0.4/year$)(P<0.05). There was no difference in the recurrent rate between those with structural abnormality and those with normal anatomy. Conclusion : Monthly routine urine cultures are efficient in detecting recurrent UTI in children. Because the male sex and young age especially less than one year of age are risk factors for increased recurrence rate of UTI, these children should be followed-up with urine cultures.