• Journal of the Korea Convergence Society
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• v.13 no.3
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• pp.191-196
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• 2022

Unlike an international combustion engine car, a battery-powered electric vehicle requires an additional heat source for its heating system. A high-voltage coolant heater has the advantages of high efficiency and a wide operating temperature range. In its development, the geometry design of the coolant flow path is essential. This paper presents the thermal flow simulations of a 7kW high-voltage heater with symmetric serpentine flow channels arranged parallelly. The heater performance was evaluated from the simulation results in terms of the pressure and temperature differences and the flow uniformity. The proposed design showed a greater flow resistance and similar heat exchanging capability than the existing parallel serpentine design. It has the advantage of a relatively wide low-temperature surface area, where the control circuit board susceptible to high temperatures can be located.

• Nuclear Engineering and Technology
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• v.54 no.7
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• pp.2444-2452
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• 2022

The field-programmable gate array (FPGA) is gaining popularity in industrial automation such as nuclear power plant instrumentation and control (I&C) systems due to the benefits of having non-existence of operating system, minimum software errors, and minimum common reason failures. Separate functions can be processed individually and in parallel on the same integrated circuit using FPGAs in comparison to the conventional microprocessor-based systems used in any plant operations. The use of FPGAs offers the potential to minimize complexity and the accompanying difficulty of securing regulatory approval, as well as provide superior protection against obsolescence. Wireless sensor networks (WSNs) are a new technology for acquiring and processing plant data wirelessly in which sensor nodes are configured for real-time signal processing, data acquisition, and monitoring. ZigBee (IEEE 802.15.4) is an open worldwide standard for minimum power, low-cost machine-to-machine (M2M), and internet of things (IoT) enabled wireless network communication. It is always a challenge to follow the specific topology when different Zigbee nodes are placed in a large network such as a plant. The research article focuses on the hardware chip design of different topological structures supported by ZigBee that can be used for monitoring and controlling the different operations of the plant and evaluates the performance in Vitex-5 FPGA hardware. The research work presents a strategy for configuring FPGA with ZigBee sensor nodes when communicating in a large area such as an industrial plant for real-time monitoring.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.394-402
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• 2021

Electronic voting systems have been widely used in many countries around the world since the mid-1990s. In recent years, studies have applied blockchain to existing electronic voting systems in order to provide reliability, fairness, and transparency for voters. This approach is highly useful as a technology that promotes decentralized citizen participation. However, the existing electronic voting systems using blockchain have not sufficiently considered anonymity. Lack of anonymity acts as an important constraint in cases of small- and medium-sized voting, which is often required in decentralized citizen participation. In this study, we propose a model that provides anonymity to a voting system using blockchain by applying the concept of the master node in Dash cryptocurrency. First, we define the differences in the requirements of the transfer and voting systems in blockchain. We propose a parallel and autonomous model and algorithm to provide anonymity in the blockchain-that is, a decentralized development environment. In addition, a discussion of security and the environment for the proposed model is described.

• Molecules and Cells
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• v.45 no.8
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• pp.537-549
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• 2022

Preproenkephalin (PPE) is a precursor molecule for multiple endogenous opioid peptides Leu-enkephalin (ENK) and Met-ENK, which are involved in a wide variety of modulatory functions in the nervous system. Despite the functional importance of ENK in the brain, the effect of brain-derived factor(s) on PPE expression is unknown. We report the dual effect of neural epidermal growth factor (EGF)-like-like 2 (NELL2) on PPE gene expression. In cultured NIH3T3 cells, transfection of NELL2 expression vectors induced an inhibition of PPE transcription intracellularly, in parallel with downregulation of protein kinase C signaling pathways and extracellular signal-regulated kinase. Interestingly, these phenomena were reversed when synthetic NELL2 was administered extracellularly. The in vivo disruption of NELL2 synthesis resulted in an increase in PPE mRNA level in the rat brain, suggesting that the inhibitory action of intracellular NELL2 predominates the activation effect of extracellular NELL2 on PPE gene expression in the brain. Biochemical and molecular studies with mutant NELL2 structures further demonstrated the critical role of EGF-like repeat domains in NELL2 for regulation of PPE transcription. These are the first results to reveal the spatio-specific role of NELL2 in the homeostatic regulation of PPE gene expression.

• Journal of Society of Preventive Korean Medicine
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• v.26 no.3
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• pp.17-28
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• 2022

Objectives : This study was conducted to prepare basic data for improving the system related to Extramural herbal dispensaries by analyzing the characteristic factors of Korean medicine clinics that affect the type of Extramural herbal dispensaries. Methods : This study utilized '2021 Korean Herbal Medicine Consumption Survey', with 1,817 final participants. We performed ANOVA to compare the characteristics of Korean medicine clinics according to the type of extramural herbal dispensary. Multinomial logistic regression analysis were conducted to analyze characteristics of Korean medicine clinics affecting the form of extramural dispensaries. Results : Among Korean medicine clinics, 71.22% of the institutions used only the intraherbal dispensaries, 11.12% of the institutions used the Extramural herbal dispensaries in parallel, and 17.67% of the institutions used only the Extramural herbal dispensaries. The characteristics of Korean medicine clinics that increased the probability of concurrently using extramural herbal dispensaries were institution area, bed presence or absence, number of regular workers, region, number of prescriptions for insurance herbal medicines, and number of prescriptions for uninsured herbal medicines. The characteristics of Korean medicine clinics, which increase the probability of using only extramural herbal dispensaries, were age, durations of clinical experience, specialist license, franchise, area, bed presence or absence, number of regular workers, number of prescriptions for uninsured herbal medicines, and price of treatment for diseases. Conclusion : The reason why Korean medicine clinics use extramural herbal dispensaries is the result of a combination of efficient use of clinic size and the preparation of uninsured herbal medicines.

• Journal of Advanced Navigation Technology
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• v.27 no.4
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• pp.356-364
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• 2023

Sophisticated Air Navigation System has contributed to enhancing the capacity of airspace capacity, leading to an efficient airspace environment. However, it has acted as a factor increasing the probability of collision. When an aircraft fails to maintain vertical separation and instead exhibits lateral positional errors, it does not necessarily lead to a collision. However, as the lateral positional accuracy increases, the randomness of aircraft positions decrease, resulting in an elevated probability of collisions. Consequently, The International Civil Aviation Organization has introduced Strategic Lateral Offset Procedures(SLOP), intentionally deviating aircraft from the centerline of airways. Likewise, South Korea also operates Offset procedure. The Y579 was operated using the Offset before its conversion to a dual airway and the analysis of the Offset track revealed that it was being operated similarly to a unidirectional dual airway. This paper develops a safety assessment methodology applicable to unidirectional dual airways, and applies it to perform a safety assessment of the Y579 Offset procedure.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.3
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• pp.958-979
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• 2023

Due to laws, regulations, privacy, etc., between 70-90 percent of providers do not share medical data, forming a "data island". It is essential to collaborate across multiple institutions without sharing patient data. Most existing methods adopt distributed learning and centralized federal architecture to solve this problem, but there are problems of resource heterogeneity and data heterogeneity in the practical application process. This paper proposes a collaborative deep learning modelling method based on the blockchain network. The training process uses encryption parameters to replace the original remote source data transmission to protect privacy. Hyperledger Fabric blockchain is adopted to realize that the parties are not restricted by the third-party authoritative verification end. To a certain extent, the distrust and single point of failure caused by the centralized system are avoided. The aggregation algorithm uses the FedProx algorithm to solve the problem of device heterogeneity and data heterogeneity. The experiments show that the maximum improvement of segmentation accuracy in the collaborative training mode proposed in this paper is 11.179% compared to local training. In the sequential training mode, the average accuracy improvement is greater than 7%. In the parallel training mode, the average accuracy improvement is greater than 8%. The experimental results show that the model proposed in this paper can solve the current problem of centralized modelling of multicenter data. In particular, it provides ideas to solve privacy protection and break "data silos", and protects all data.

• Journal of the Institute of Convergence Signal Processing
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• v.23 no.4
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• pp.234-240
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• 2022

This paper proposes a customized AI exercise recommendation service for balancing the relative amount of exercise according to the working environment by each occupation. WISDM database is collected by using acceleration and gyro sensors, and is a dataset that classifies physical activities into 18 categories. Our system recommends a adaptive exercise using the analyzed activity type after classifying 18 physical activities into 3 physical activities types such as whole body, upper body and lower body. 1 Dimensional convolutional neural network is used for classifying a physical activity in this paper. Proposed model is composed of a convolution blocks in which 1D convolution layers with a various sized kernel are connected in parallel. Convolution blocks can extract a detailed local features of input pattern effectively that can be extracted from deep neural network models, as applying multi 1D convolution layers to input pattern. To evaluate performance of the proposed neural network model, as a result of comparing the previous recurrent neural network, our method showed a remarkable 98.4% accuracy.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.2
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• pp.361-366
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• 2023

Apache Hadoop, a representative framework for distributed processing of big data, has the advantage of increasing cluster size up to thousands of nodes to improve parallel distributed processing performance. However, reducing the size of the cluster is limited to the extent of permanently decommissioning nodes with defects or degraded performance, so there are limitations to operate multiple nodes flexibly in small clusters. In this paper, we discuss the problems that occur when removing nodes from the Hadoop cluster and propose a dynamic down-scaling technique to manage the distributed cluster more flexibly. To do this, we design and implement a modified Hadoop system and interfaces to support dynamic down-scaling of the cluster which supports temporary pause of a node and reconnection of it when necessary, rather than decommissioning the node when removing a node from the Hadoop cluster. We have verified that effective downsizing can be performed without performance degradation based on experimental results.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.2
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• pp.221-230
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• 2023

Purpose : This study was performed to evaluate the effects of virtual reality combined robot assist gait training (VRG) on improvement of balance and respiratory function in chronic stroke patients. Methods : A single-blind, randomized controlled trial (RCT) was conducted with 35 chronic stroke patients. They were randomly allocated 2 groups; VRG group (n=18) and conservative treatment group (CG; n=17). The VRG group received 30 minutes robot assisted gait training combined virtual reality training, robot assisted gait training was conducted in parallel using a virtual reality device (2 sessions of 15 minutes in a 3D-recorded walking environment and 15 minutes in a downtown walking environment). In the conservative treatment group, neurodevelopmental therapy and exercise therapy were performed according to the function of stroke patients. Each group performed 30 minutes a day 3 times a week for 8 weeks. The primary outcome balance and respiratory function were measured by a balance measurement system (BioRescue, Marseille, France), Berg balance scale, functional reach test for balance, Spirometry (Cosmed Micro Quark, Cosmed, Italy) for respiratory function Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV₁), and maximum expiratory volume (PEF) were measured according to the protocol. The measurement were performed before and after the 8 weeks intervention period. Results : Both groups demonstrated significant improvement of outcome in balance and respiratory function during intervention period. VRG revealed significant differences in balance and respiratory function as compared to the CG groups (p<.05). Our results showed that VRG was more effective on balance and respiratory function in patients with chronic stroke. Conclusion : Our findings indicate that VRG can improve balance and respiratory function, highlight the benefits of VRG. This study will be able to be used as an intervention data for recovering balance and respiratory function in chronic stroke patients.