• The Journal of the Acoustical Society of Korea
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• v.42 no.1
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• pp.7-15
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• 2023

Recently, as interest in air quality in vehicles increases, the use of fine dust detection sensors for air quality measurement is becoming common. An axial-flow fan is inserted in the fine dust sensor installed in the air conditioning system in the vehicle to prevent dust from sinking directly on the sensor. When the sensor operates, the flow noise caused by the rotation of the axial-flow fan acts as a major noise source of the fine dust sensor. flow noise is recognized as one of the product competitiveness of fine dust sensors. In this study, the noise was gradually reduced at the same flow rate by improving the flow performance of the small axial flow fan. First, a virtual fan performance tester consisting of about 20 million grids was developed to analyze the aerodynamic performance of the target small axial-flow fan. In addition, the flow field was simulated by using compressible Large Eddy Simulation for direct computation of flow noise as well as high-accurate prediction of flow rate. The validity of numerical method are confirmed through the comparison of predicted results with experimental ones. After the effects of pitch angle on flow performance were analyzed using the verified numerical method, the pitch angle was determined to maximize the flow rate. It was found that the flow rate was increased by 8.1 % and noise was reduced by 0.8 dBA when the axial-flow fan with the optimum pitch angle was used.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.2
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• pp.157-162
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• 2023

Among the failures of photovoltaic power generation facilities, failures caused by surges account for 20% of the total failure rate, and energy emissions of tens to hundreds [A] during power generation and electrical damage to inverters and connection boards lead to electrical safety accidents. In particular, in the case of lightning, an abnormal voltage is induced in an electric circuit to destroy insulation, and the current flowing at this time causes a fire and acts as a factor that accelerates the deterioration of parts. Due to this action, the problem of electrical safety of solar power generation devices spreading from outside the city center to the inside of the city center such as houses, apartments, and government offices is emerging. Since lightning strikes cause both field-based and conducted electrical interference, this effect increases with increasing cable length or conductor loops. In addition, surge damages not only solar modules, inverters and monitoring devices, but also building facilities, which can eventually cause operational shutdown due to fire of the photovoltaic power generation system and consequent financial loss. Therefore, in this paper, a lightning protection system for solar power generation devices is studied for the purpose of reducing property damage and human casualties due to the increase in fire and electrical safety accidents caused by lightning strikes in photovoltaic power generation systems.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.2
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• pp.169-174
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• 2023

Currently, overall power usage is also increasing as power demand such as homes, offices, and factories increases. The increase in power use also raised interest in standby power as a change in awareness of energy saving appeared. Home and office devices are consuming power even in standby conditions. Accordingly, there is a growing need to reduce standby power, and it aims to have standby power of 1W or less. An intelligent outlet uses a near-field wireless network to connect to a home network and cut or reduce standby power of a lamp or appliance connected to an outlet. This research aims to develop a monitoring system and an intelligent outlet that can remotely monitor the amount of electricity used in a lighting lamp or a home appliance connected to an outlet using a short-range wireless network (Zigbee). Also, The intelligent outlet and monitoring system developed makes it possible for a user to easily cut off standby power by using a portable device. Intelligent outlets will not only reduce standby power but also be applicable to fire prevention systems. Devices that cut off standby power include intelligent outlets and standby power cutoff switches, so they will prevent short circuits and fires.

• Journal of Broadcast Engineering
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• v.28 no.2
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• pp.213-229
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• 2023

In this paper, we introduce a spatial sound rendering system that provides 6DoF spatial sound in real time in response to the movement of a listener located in a virtual environment. This system was implemented using MPEG-I AEP as a development environment for the CfP response of MPEG-I Immersive Audio and consists of an encoder and a renderer including a decoder. The encoder serves to offline encode metadata such as the spatial audio parameters of the virtual space scene included in EIF and the directivity information of the sound source provided in the SOFA file and deliver them to the bitstream. The renderer receives the transmitted bitstream and performs 6DoF spatial sound rendering in real time according to the position of the listener. The main spatial sound processing technologies applied to the rendering system include sound source effect and obstacle effect, and other ones for the system processing include Doppler effect, sound field effect and etc. The results of self-subjective evaluation of the developed system are introduced.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.4
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• pp.293-297
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• 2022

In 2022, Korea reported a total of 224 perfusionists, employing nurses or clinical laboratory technologists (also known as medical technologists) to provide hospital self-education or reliable education. In 2021, the total number of perfusionists in Japan was 2,100, mainly supported by clinical engineering technologists. During the same period, the number of perfusionists reported in the United States was 4,212, who had received training in the master's program, post-bachelor certificate program, and bachelor's program. Most personnel in the USA were graduates of healthcare sciences or life sciences. Perfusionists must be knowledgeable in heart anatomy, physiology, pharmacology, pathology, hemodynamics, laboratory analysis, and quality assurance, as well as techniques to operate the cardiopulmonary bypass machine (heart-lung bypass machine). These are jobs similarly handled by clinical laboratory technologists. The importance of perfusionists became more prominent during two major crises: the MERS-CoV and COVID-19 pandemic. Currently, perfusionists play a significant role in the rapidly expanding field of extracorporeal membrane oxygenation (ECMO) and extracorporeal circulation during cardiac surgery. Results of the current study indicate that hospitals offering cardiac surgery and infectious disease hospitalization need to be institutionalized to secure a certain number of qualified perfusionists. In the future, we look forward to establishing a perfusion technology association under the Korean Society for Clinical Laboratory Physiology to provide academic exchanges.

• Journal of Korean Society of Disaster and Security
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• v.16 no.1
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• pp.1-11
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• 2023

The comprehensive natural disaster reduction plan, the highest plan in the disaster prevention field, was implemented by local governments. second plan is currently being formulated. In order to minimize human and property damage, structural and non-structural measures for each of the nine disaster types are established and implemented for 10 years. Structural measures are based on engineering and quantitative analysis, and the criteria for setting reduction measures are clear. Non-structural measures, however, currently lack the set criteria. the basic disaster and safety management law included the safety vulnerable class in 2018. Currently, the safety vulnerable class of the detailed establishment criteria of the comprehensive natural disaster reduction plan is being established, including children, the elderly, and the disabled. However, due to the lack of data securing and database construction by local governments, it is difficult to prepare a location map for establishing reduction measures for the safety vulnerable. Therefore, in this study, OPEN API data of the safety vulnerable class were collected and statistical information and GIS of SGIS information services were used. The distribution diagram of the safety vulnerable class in Samcheok, Gangwon-do, which is a sample area, and the distribution diagram of the safety vulnerable class in units of the output area (OA) in Geundeok-myeon were prepared.

• Journal of Internet of Things and Convergence
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• v.9 no.1
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• pp.33-39
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• 2023

As the number of people with chronic diseases increases due to an aging society, it is urgent to prevent and manage their diseases. Although biometric authentication methods and Telemedicine Systems have been introduced to solve these problems, it is difficult to solve the security problem of medical information and personal authentication. Since smart healthcare includes personal medical information of subjects, the security of personal information is the most important field. Therefore, in this paper, we tried to propose a Telemedicine System using a smart wearable device ECG in the form of a wristband and face personal authentication in a private blockchain environment. This system targets various medical personnel and patients with chronic diseases in all regions, and uses a private blockchain that can increase data integrity and transparency, ECG and face authentication that are difficult to forge and alter and have high personal identification to provide a system with high security and reliability. composed. Through this, it is intended to contribute to increasing the efficiency of chronic disease management by focusing on disease prevention and health management for patients with chronic diseases at home.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.6
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• pp.275-284
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• 2023

Virtual reality simulations are used for education and training in various fields, and are especially widely used in the medical field recently. The education/training simulator consists of tactile/force feedback generation and image/sound output hardware that provides a sense similar to a doctor's treatment of a real patient using real surgical tools, and software that produces realistic images and tactile feedback. Existing simulators are complicated and expensive because they have to use various types of hardware to simulate various surgical instruments used during surgery. In this paper, we propose a dental surgical simulation system using a force feedback device and a morphable haptic controller. Haptic hardware determines whether the surgical tool collides with the surgical site and provides a sense of resistance and vibration. In particular, haptic controllers that can be deformed, such as length changes and bending, can express various senses felt depending on the shape of various surgical tools. When the user manipulates the haptic feedback device, events such as movement of the haptic feedback device or button clicks are delivered to the simulation system, resulting in interaction between dental surgical tools and oral internal models, and thus haptic feedback is delivered to the haptic feedback device. Using these basic techniques, we provide a realistic training experience of impacted wisdom tooth extraction surgery, a representative dental surgery technique, in a virtual environment represented by sophisticated three-dimensional models.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.624-633
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• 2023

Purpose: It Vas intended to identify problems and derive improvement plans by grasping the current status of safety management of public institutions among construction Vork orders. Method: By comparing the disaster status of public institutions compared to the total construction Vork, the analysis Vas conducted based on the results of the evaluation of the level of safety activities of public institutions Vith a high disaster rate and the results of actual consulting. Result: As a result of comparing and analyzing the current status of safety management of public institutions, the current status and problems of safety management in public institutions Vith a high accident rate Vere similarly discovered. Safety management organizations, document management systems, safety management systems, and risk assessment activities are operated Vithout reflecting the size and characteristics of the organization, so improvement in the relevant field is needed. Conclusion: Safety-related professionals and organizations should be formed according to the size of construction orders, and responsibility and authority should be clearly assigned. Since risk assessment is conducted formally to prepare a safety and health ledger, it is necessary to derive risk factors to prevent safety accidents for the actual construction. It is expected that the level of safety activities can be improved if it is improved by reflecting the size and characteristics of public institutions.

• The Journal of the Acoustical Society of Korea
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• v.42 no.5
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• pp.429-440
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• 2023

This study explores recent research trends and potential applications of ultrasound optical imaging-based multimodal technology. Ultrasound imaging has been widely utilized in medical diagnostics due to its real-time capability and relative safety. However, the drawback of low resolution in ultrasound imaging has prompted active research on multimodal imaging techniques that combine ultrasound with other imaging modalities to enhance diagnostic accuracy. In particular, ultrasound optical imaging-based multimodal technology enables the utilization of each modality's advantages while compensating for their limitations, offering a means to improve the accuracy of the diagnosis. Various forms of multimodal imaging techniques have been proposed, including the fusion of optical coherence tomography, photoacoustic, fluorescence, fluorescence lifetime, and spectral technology with ultrasound. This study investigates recent research trends in ultrasound optical imaging-based multimodal technology, and its potential applications are demonstrated in the biomedical field. The ultrasound optical imaging-based multimodal technology provides insights into the progress of integrating ultrasound and optical technologies, laying the foundation for novel approaches to enhance diagnostic accuracy in the biomedical domain.