• Journal of the Institute of Convergence Signal Processing
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• v.22 no.1
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• pp.7-13
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• 2021

In recent years, the importance of environmental regulations is increasing in the shipping industry, and the demands of the industry for this are rapidly increasing. Accordingly, the demand of ship owners is increasing as the shaft generator is a technology that responds to environmental regulations that can be applied to ships the fastest. The shaft generator is a device that can increase the fuel consumption rate of the main propulsion engine by installing an electric motor in the main propulsion engine and using it variably according to the load environment. It operates by the power of the motor at low speeds, and when a sudden load is required, the main propulsion engine and motor operate together, enabling efficient operation. In this paper, the diesel engine and shaft generator of a tug boat are modeled using MATLAB Simulink, and the fuel consumption rate is verified through simulation.

• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.424-431
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• 2021

This study explores fire prevention measures for single-person households on the phenomenon of an increase in single-person households due to changes in the family structure due to low birthrate and aging population, full marriage, non-marriage, separation, bereavement, and returning to farming villages, and increased flexibility in the labor market. The factor that affects the fire of single-person households is the residential environment problem at the structural level. In terms of behavior, there is an increase in fire occurrence due to the rearing of companion animals. In order to prevent fires in single-person households, safety regulations without exceptions are needed to improve the residential environment at the structural level. At the behavioral level, it is necessary to expand the prevention and safety guidance of related organizations. In addition, as a measure to prevent fire caused by companion animals, manufacturers of electric ranges should develop safety devices to prevent fires caused by companion animals, such as an automatic power-off device or power supply using a timer. It can also be an important means to create and distribute promotional videos of measures necessary to safely raise companion animals, or to develop and distribute disaster preparedness programs implemented in virtual reality.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.1
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• pp.108-114
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• 2021

AVTE(Air Vehicle Test Equipment) is a device to check status of on-board aircraft equipment before and after flight for performing successful UAV(Unmanned Aerial Vehicle) missions. This paper describes software design and test sequence of the AVTE for enabling easy-manual check by the operator and convenient automatic check of on-board electric equipment respectively. The proposed AVTE inspects BIT(Built-In Test) results of on-board LRUs(Line Replacement Units) including avionics and sensor sub-system devices. Also, it monitors all the LRU status and check the normality of aircraft equipment by means of setting specific values of the LRUs and confirming the expected test results. The AVTE prints the test results as a form of report to easily check the normal conditions of the aircraft equipment and operates automatically without operator interaction, thus being thought to effectively reduce workload of the operator.

• Journal of the Korea Convergence Society
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• v.12 no.2
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• pp.29-34
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• 2021

In this paper, a cylindrical photonic crystal waveguide with a low-index core is first proposed. The core can be filled with air, liquid, or arbitrary dielectric materials. Exact analyses for the electromagnetic field characteristics of guided modes, by using appropriate Bessel functions and applying the boundary conditions, are performed to find out the guiding characteristics of the proposed waveguide. For verification and usage in design and manufacturing process, the computer-calculation of the waveguide transmission characteristics is also performed by applying the rigorous full-vectorial finite difference method. Providing variations of the effective area for the fundamental mode of the designed waveguide with different numbers of cladding layers, ranging from 2.6056 ㎛2 to 5.9673 ㎛2 over the operation wavelength, generally as the core refractive index n1 is higher, the mode area becomes smaller and the result leads to more optimistic effect for nonlinear device applications.

• Journal of Internet of Things and Convergence
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• v.8 no.5
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• pp.127-132
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• 2022

As the IoT technology is more developed, it is more important for the accuracy of IoT data. Since the IoT data supports a different formats and protocols, it is often happened that the IoT system is failed or the incorrect data is generated with the unreliable IoT devices(sensor, actuator). Because the abnormality of IoT device or the user situation is not detected correctly, this problem makes the user to be unsatisfied with the IoT system. This study proposes the decision methodology of IoT data consistency whether the IoT data is generated in normal range or not by using the mathematical functions('gradient descent function' and 'linear regression function'). It may be concluded that the gradient function method is suitable for the IoT data which the 'increasing velocity' is related with the next generated pattern(eg. sensor devices), the linear regression function method is suitable for the IoT data which the 'the difference from linear regression function' is related with the next generated pattern in case the data has a linear pattern(eg. water meter, electric meter).

• Journal of Environmental Impact Assessment
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• v.31 no.5
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• pp.334-342
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• 2022

The stringent air environment conservation act forced to build an indoor dome for coal storage. However, it causes some problems due to accumulation of fly ash and harmful substances inside. To solve this problem, this study analyzed the pattern of internal airflow and the amount of ventilation for an indoor coal yard. Overall, the airflow inside the indoor coal yard tended to move to the southwest facing the mountain. In addition, sea-breeze was blowing from the northern louver window facing the sea, where airflow was flowing in. The total flow rate flowing into the indoor coal yard was 918,691 m³/h, and the number of natural ventilation per hour was 0.6 times. Therefore, it is proposed to install a forced ventilation device at the location where internal air flow is concentrated.

• Journal of the Korea Institute of Building Construction
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• v.21 no.3
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• pp.189-194
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• 2021

LIBS has been attracting attention as an analytical method capable of real-time measurement without sample preparation. In this study, a Lab. scale LIBS device was fabricated to examine the applicability and reproducibility of LIBS in the analysis of chloride contents in mortar. The existing analysis method and LIBS analysis were performed simultaneously on the mortar test specimen with the chloride content adjusted. Compared to the chloride content condition of the mortar, the XRF and Potentiometric Titration results also showed a similar trend. As a result of LIBS analysis, chlorine ions were detected at a wavelength of 837.59 nm according to the chloride content condition. In order to improve the precision in various concentration ranges, the LIBS signal amplification of about 50 times through the electric field enhancement was implemented. Through the verification of the aqueous solution-based reproducibility, a high correlation between the LIBS signal strength and the Cl concentration was confirmed, and the possibility of applying LIBS to the durability diagnosis of concrete damage by chloride was confirmed.

• Resources Recycling
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• v.31 no.3
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• pp.27-39
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• 2022

The global demand for lithium-ion batteries (LIBs) has been continuously increasing since the 1990s along with the growth of the portable electronic device market. Of late, the rapid growth of the electric vehicle market has further accelerated the demand for LIBs. The demand for the LIBs is expected to surpass the supply of lithium from natural resources in the near future, posing a risk to the global lithium supply chain. Moreover, the continuous accumulation of end-of-life LIBs is expected to cause serious environmental problems. To solve these problems, recycling the spent LIBs must be viewed as a critical technological challenge that must be urgently addressed. In this study, recycling LIBs using pyrometallurgical processes and post-processes for efficient lithium recovery are briefly reviewed along with the major accomplishments in the field and current challenges.

• Applied Chemistry for Engineering
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• v.33 no.4
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• pp.343-351
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• 2022

Lithium-ion batteries (LIBs) are considered promising energy storage devices with good performance such as high energy density, slow self-discharge rate, high rate charge capacity, and long battery life. However, the application of these LIBs in the high-energy density electric vehicle and large device industries poses a major safety problem. In order to solve this problem, developing a material having high thermal stability and intrinsic safety is the ultimate solution for improving the stability and electrochemical performance of LIBs. This review introduced a surface modification technology of a separator to overcome the stability problem of a commercial separator, and summarized and summarized the research trends using the modified separator for a lithium-ion battery. Based on this, the future prospects for the separator development by surface modification were discussed.

• Journal of the Society of Disaster Information
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• v.18 no.4
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• pp.699-705
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• 2022

Purpose: Sequence control is widely used by being applied to manufacturing, distribution, construction, and automation in the medical industry. With the development of the fourth industry, artificial intelligence convergence technology in the control field is becoming an important factor in the industry. In particular, it is required to evaluate the safety and innovation of facilities where microprocessors and artificial intelligence are fused to existing systems and develop reliable equipment, so it is intended to develop equipment for educational purposes and drive the development of the field. Method: The self-developed all-in-one artificial intelligence controller module is a device that combines artificial intelligence capabilities with existing sequence and PLC control circuits. As the performance evaluation items of this equipment, the recognition ability of motion, voice, text, color, etc. and the stability and reliability of the circuit were evaluated. Conclusion: After designing the sequence and PLC circuit, the performance evaluation items of the integrated integrated artificial intelligence controller module were all satisfied, and there was no problem in the safety and reliability of the circuit.