• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.15 no.4
• /
• pp.291-297
• /
• 2022

This Paper is about the study that design performance and reliability measurement circuits of the IPM which is an intelligent switching switch module included at an inverter circuits for driving of A.C. Servo motors in home appliance. IPM is a core device of motor driver and it's switching characteristics should be retained uniformly during the driving of a servo system. All of it's specification, the collector emitter switch on voltage Vce(on) spec. is very important. As the IPM are core part of inverters and producing from several brands and versions, for optimal performances of application systems a method and measurement & evaluation system to measure Vce(on) value, collector emitter switch on voltage, of the IPM IGBT switches with various brands are required. Especially, the proposed method can measure and evaluate Vce(on) values of IPM with load at mounting state on the motor driving circuits and proposed measurement & evaluation system can be important instrument systems for IPM user companies.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.26 no.7
• /
• pp.1040-1046
• /
• 2022

In this paper, we consider a system with massive user equipments (UEs) in a cell and assume path loss and Rayleigh fading channels between the base station (BS) and UEs. In addition, it is assumed that the system bandwidth consists of multiple identical frequency subchannels. Under such assumptions, we propose a channel state information (CSI) feedback scheme and a resource allocation scheme for non-orthogonal multiple access (NOMA) transmission in order to reduce the feedback overhead of CSI generated by massive UEs and to reduce the complexity of resource allocation. In particular, for the proposed schemes, we analyze the sum data rate achievable by massive UEs in a cell and the outage probability with which the UEs in a cell do not meet the target data rate. Through the simulation results, we show that the proposed schemes can provide the superior outage probability, although it degrades the average sum data rate.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.22 no.1
• /
• pp.171-179
• /
• 2022

This paper introduces a monitoring and tracking system for corona19 confirmed patients based on the collected data by installing a device that can manage the access list at the entrance to each building on the campus. The existing QR-based electronic access list can't measure the temperature of the person entering the building and it is inconvenient that members have to scan their QR codes with a smartphone. In addition, when the state manages information about confirmed patients and contacts on campus, it is not easy for members to quickly share and track information. These could lead to cases where a person is in close contact with an infected person developing another patient. Therefore, this paper introduces a device using face recognition library and a temperature sensor installed at the entrance of each building on the campus, enabling the administrator to monitor the access status and quickly track members of each building in real-time.

• International Journal of Internet, Broadcasting and Communication
• /
• v.14 no.3
• /
• pp.249-257
• /
• 2022

In recent years, if we order food by easily accessing the online market with our smartphone, we can receive the product in a fresh state at dawn the next day. Cold chain is an industry that can create high added value because it has both the characteristics of general logistics and sensitivity to temperature. Based on the electrical specifications derived from the reefer container capacity requirement investigation, we proved that power supply to up to 33 reefer containers can be made by using three additional auxiliary power supplies which are applied for freight trains in Korea. In this paper, we conducted a research on a design of power supply system for freight train reefer container based on simulation as a basic research necessary for low-temperature distribution and cold chain construction based on the reefer container railroad. Consequently, the simulation was conducted using the three-phase inverter diagram in PSIM and the SVPWM (3-harmonic injection method) control technique, and it was verified that the required power voltage was satisfied with 622V_dc, which is lower than the input voltage of general SPWM of 718V_dc. The details of this paper could be used as a foundational study for constructing cold chains based on a reefer container dedicated to freight trains in the future.

• The Korean Journal of Emergency Medical Services
• /
• v.26 no.2
• /
• pp.7-18
• /
• 2022

Purpose: This study aimed to develop a pre-hospital subarachnoid hemorrhage (SAH) prediction tool by analyzing the extant predictive factors of patients with non-traumatic SAH who visited the hospital through the 119 emergency medical services. Methods: We retrospectively reviewed pre-hospital care reports (PCRs) and electronic medical records (EMRs) of 103 patients with non-traumatic SAH who were transported to the emergency department of two national hospitals via the 119 emergency medical service from January 1, 2017 to December 31, 2020. Variables required to apply the Ottawa SAH Rule and EMERALD SAH Rule, which are early prediction tools for SAH, were extracted and applied. Results: The most common symptoms-which were found in 94.1% and 97.0% of all patients according to PCRs and EMRs, respectively-appeared in the following order: headache, altered state of consciousness, and nausea/vomiting. When the variables used for the EMERALD Rule, namely systolic blood pressure (SBP), diastolic blood pressure (DBP), and blood sugar test (BST), were applied, the sensitivities of EMR and PCRs were 99.9% and 92.2%, respectively. Conclusion: For the timely prediction of SAH at the pre-hospital phase, patient age and symptoms should be assessed, and SBP, DBP, and BST should be measured to transport the patient to an appropriate hospital.

• International Journal of Computer Science & Network Security
• /
• v.23 no.2
• /
• pp.1-12
• /
• 2023

The article examines the axiological psycho-philosophical understanding of the phenomenon of money and its value role in modern society. The traditional and virtual context of the representation of the money phenomenon is considered.Following the ideas of G. Simmel, the authors consider money not only as a purely economic, but also a psycho-philosophical, cultural and social phenomenon. Money appears as a result of cultural development of the world and gradually forms a monetary culture as a space of economic and social interaction of people. Under the influence of the monetary culture of one or another historical period, the character of a person's economic activity, values and life orientations are formed. Modern money culture is often called financial civilization. Peculiarities of modern monetary culture are studied, its main features and problems are determined in the article. The problem of the peculiarities of the constructive and destructive attitude of the individual towards money is identified; a psycho-philosophical and cultural-identification typology of people is described, which is based on clinical observations and interpreted through the prism of psychoanalytic theory. The concept of money is highlighted from the standpoint of a social-psychological approach. The theoretical foundations of money's influence on the decision-making process and human behavior are also revealed.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2000.02a
• /
• pp.173-173
• /
• 2000

Multilayered films (MLF) consisting of transition metals and semiconductors have drawn a great deal of interest because of their unique properties and potential technological applications. Fe/Si MLF are a particular topic of research due to their interesting antiferromagnetic coupling behavior. although a number of experimental works have been done to understand the mechanism of the interlayer coupling in this system, the results are controversial and it is not yet well understood how the formation of an iron silicide in the spacer layers affects the coupling. The interpretation of the coupling data had been hampered by the lack of knowledge about the intermixed iron silicide layer which has been variously hypothesized to be a metallic compound in the B2 structure or a semiconductor in the more complex B20 structure. It is well known that both magneto-optical (MO0 and optical properties of a metal depend strongly on their electronic structure that is also correlated with the atomic and chemical ordering. In order to understand the structure and physical properties of the interfacial regions, Fe/Si multilayers with very thin sublayers were investigated by the MO and optical spectroscopies. The Fe/si MLF were prepared by rf-sputtering onto glass substrates at room temperature with a totall thickness of about 100nm. The thicknesses of Fe and Si sublayers were varied from 0.3 to 0.8 nm. In order to understand the fully intermixed state, the MLF were also annealed at various temperatures. The structure and magnetic properties of Fe/Si MLF were investigated by x-ray diffraction and vibrating sample magnertometer, respectively. The MO and optical properties were measured at toom temperature in the 1.0-4.7 eV energy range. The results were analyzed in connection with the MO and optical properties of bulk and thin-film silicides with various structures and stoichiometries.

• Journal of the Institute of Convergence Signal Processing
• /
• v.23 no.4
• /
• pp.185-193
• /
• 2022

This paper proposes an adaptive sliding mode control with radial basis function neural network(RBFNN) scheme to enhance the performance of position and attitude tracking control of quadrotor UAV. The RBFNN is utilized on the approximation of nonlinear function in the UAV dynmic model and the weights of the RBFNN are adjusted online according to adaptive law from the Lyapunov stability analysis to ensure the state hitting the sliding surface and sliding along it. In order to compensate the network approximation error and eliminate the existing chattering problems, the sliding mode control term is adjusted by adaptive laws, which can enhance the robust performance of the system. The simulation results of the proposed control method confirm the effectiveness of the proposed controller which applied for a nonlinear quadrotor UAV is presented. Form the results, it's shown that the developed control system is achieved satisfactory control performance and robustness.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.22 no.1
• /
• pp.115-125
• /
• 2023

This paper relates to the development of CCTV camera posture calibration algorithm that can simultaneously collect traffic information such as traffic volume and speed in the state of view of the CCTV camera set for traffic monitoring. The developed autonomous posture calibration algorithm uses vehicle recognition and tracking techniques to identify the road, and automatically determines the angle of view for the operator's traffic surveillance and traffic information collection. To verify the performance of the proposed algorithm, a CCTV installed on site was used, and the results of the angle of view automatically calculated by the autonomous posture calibration algorithm for the angle of view set for traffic surveillance and traffic information collection were compared.

• The Journal of the Acoustical Society of Korea
• /
• v.41 no.6
• /
• pp.669-679
• /
• 2022

Lithium-ion battery has been used for lots of electronic devices. With the popularization of batteries, researchers have focused on batteries' electrochemical performances by environmental conditions, such as temperature, vibration, shock and charging state. Meanwhile, due to very serious global warming, car companies have started using lithium-ion batteries even in cars, replacing internal combustion engines. However, batteries have been developed based on non-moving systems which is totally different from vehicles. In the line of the differences, researchers have tried to reveal relationship between variables from dynamic systems and batteries. In this review, we discuss the comprehensive effect of vibration and shock on batteries. We firstly summarize vibration profiles and effect of normal vibration on batteries. We also sum up effect of shock and penetration on batteries and introduce how ultrasound influences on batteries. Lastly, outlook for the battery design as well as dynamic design of EVs are discussed.