• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.620-626
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• 2020

This research propose and simulate a solar power generation system monitoring system based on Modbus TCP communication using RaspberryPi, an IOT equipment, as a master and an inverter as a slave. In this model, various sensors are added to the RaspberryPi to add necessary information for monitoring solar power plants, and power generation prediction and monitoring information are transmitted to the smart phone through real-time power generation prediction. In addition, information that is continuously generated by the solar power plant is built on the server as big data, and a deep learning model for predicting power generation is trained and updated. As a result of the study, stable communication was possible based on Modbus TCP with the Raspberry Pi in the inverter, and real-time prediction was possible with the deep learning model learned in the Raspberry Pi. The server was able to train various deep learning models with big data, and it was confirmed that LSTM showed the best error with a learning error of 0.0069, a test error of 0.0075, and an RMSE of 0.0866. This model suggested that it is possible to implement a real-time monitoring system that is simpler, more convenient, and can predict the amount of power generation for inverters of various manufacturers.

• Smart Media Journal
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• v.10 no.1
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• pp.9-15
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• 2021

The eye tracking system designed in this paper is an eye-based computer input device designed to give an easy access for those who are uncomfortable with Lou Gehrig's or various muscle-related diseases. It is an eye-based-computer-using device for users whose potential demand alone amounts to 30,000. Combining the number of Lou Gehrig's patients in Korea estimated at around 1,700, and those who are unable to move their bodies due to various accidents or diseases. Because these eye input devices are intended for a small group of users, many types of commercial devices are available on the market. It is making them more expensive and difficult to use for these potential users, less accessible. For this reason, each individual's economic situation and individual experience with smart devices are slightly different. Therefore, making it difficult to access them in terms of cost or usability to use a commercial eye tracking system. Accordingly, attempts to improve accessibility to IT devices through low-cost but easy-to-use technologies are essential. Thus, this paper proposes a complementary superior performance eye tracking system that can be conveniently used by far more people and patients by improving the deficiencies of the existing system. Through voluntary VoCs(Voice of Customers) of users who have used different kinds of eye tracking systems that satisfies it through various usability tests, and we propose a reduced system that the amount of calculation to 1/15th, and eye-gaze tracking error rate to 0.5~1 degree under.

• Journal of the Korean Society of Radiology
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• v.15 no.4
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• pp.437-444
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• 2021

To evaluate the usefulness of Volume Axial Mode by comparing analyzing the exposure dose of the patients and the quality of each images from CT images obtained from high pitch mode using the local phantom or volume axial mode to determine the usefulness of he volume axial mode in diagnosing the head and cervical disease in adults. High Pitch Mode, Helical Mode, and Volume axial Mode as adult phantom were tested according to 70 kVp, 80 kVp, and 100 kVp tube voltages during an adult frontal CT scans. The equipment used was GE's Revolution (GE Healthcare, Wisconsin USA) model and iMED X-ray Phantom. The exposure dose of phantom was compared using the images obtained from each protocol, and the image quality was compared by calculating SNR and CNR by setting ROI on each image. When examined using Volume Axial Mode, the exposure dose of phantom was measured 17.12% lower than Helical Mode, 5.35% lower than High Pitch Mode, and both SNR and CNR were improved. Volume Axial Mode is a useful test that reduces investigation time without table movement using high speed rotary scanner, and in which exposure dose is reduced and image quality is improved by acquiring images in a short time of 0.28 seconds of phantom than using High Pitch Mode and Helical Mode. In addition, the fast testing time of Volume Axial Mode can be seen as the biggest advantage CT scans of emergency patients or patients with physical discomfort.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.8
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• pp.1103-1109
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• 2021

ECS is a control device so that the warship can perform the mission stably by controlling and monitoring the entire propulsion system. As the recent provisions of the warship, it's propelling system is complicated than past, as the demand performance and mission of the warships are diverse. In accordance with the complicated propulsion system configuration, the demand for automatic control function of the ECS is increasing for convenient and stable propulsion system control for convenient and stable. As a result, verification of ECS stability and reliability is required. In this paper, we develop an interlocking signal simulator for verifying ECS control logic and communication protocol for warship with CODLOG propulsion systems. The simulator developed was implemented to simulate a signal of gas turbine, propulsion motors, diesel generator and 11 kinds of auxiliary equipment. The reliability of ECS was verified through the ECS communication program and the I/O signal static test with the simulator.

• Journal of radiological science and technology
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• v.44 no.6
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• pp.671-677
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• 2021

Interest in the everyday hazards of radon has recently increased as such, this study attempted to examine the dangers of radon in spilled groundwater by comparing the radon concentrations of the drained groundwater and tap water used in recirculating systems in Incheon Subway restrooms. At five stations of Incheon Subway Line 1 and three stations of Line 2, drained groundwater is recirculated and used in restrooms for toilet flushing. Stations restroom tap water for hand washing that used as a control and the measured values of each were compared. With the cooperation of Incheon Transportation Corporation, samples of spilled groundwater and tap water were collected sealed to prevent contact with the air, and a DURRIDGE RAD7 was used as the experimental equipment. The collected samples were subjected to radial equilibration for approximately 3.5 h, at which the radon concentration reached its maximum, and then calculated as 10 measurements using the RAD7 underwater radon measurement mode. In all eight stations, the radon concentration in tap water was lower than the recommended amount. However, in an average of 7 out of the eight stations, the radon concentration in the effluent groundwater was 100 times higher than that in tap water. Since high radon concentrations in groundwater runoff can be harmful to humans, and there is no accurate standard for radon concentrations in domestic water, it is necessary to continuously monitor radon in water and prepare a guidance of recommended values.

• Journal of the Korean GEO-environmental Society
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• v.23 no.1
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• pp.39-49
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• 2022

Expandable steel pipe piles are installed by inserting expansion equipment to increase the cross-sectional area of steel pipes, which can improve the pile performance compared to micro-piles. In this paper, a hydraulic expansion device was developed to expand steel pipe piles in practice. A series of laboratory and field tests were conducted to verify the performance of the developed expansion device to expand steel pipes. The expansion capability and expandable range was evaluated by measuring the strain and expansion time at the maximum pressure of the hydraulic expansion device. The thinner steel pipe, the larger strain but longer expansion time required in the test. For example, the 4.0-mm-thick steel pipe showed strain reduction by 30% and a decrease in the required expansion time by 40% compared to the 2.9-mm-thick steel pipe. In addition, in-situ expansion tests were performed to verify the expandability of steel pipes under the ground, and the exhumed specimen showed clear expanded sections. The structural integrity was determined by comparing the material performance the original and expanded specimens.

• Journal of Appropriate Technology
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• v.6 no.2
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• pp.126-135
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• 2020

Recently, with the development of the 4th Industrial Revolution era and the popularization of technologies the maker movement is spreading worldwide in various ways for education, entrepreneurship, and solving social problems. This paper introduces a case of establishing and operating a maker space in Tanzania, East Africa, one of the developing countries. iTEC Tech-shop was established in the first half of 2018 at the Nelson Mandela African Institution of Science and Technology (NM-AIST) in Arusha, Tanzania by Innovative Technology and Energy Center (iTEC), and has been operating for nearly two years. With the allocation of empty warehouse space from NM-AIST, physical facilities were established through the purchase and installation of equipment and hand tools. Based on the advice from Idea Factory of Seoul National University and Fab-Lab Seoul, iTEC Tech-shop operational system were established. Through a total of 7 technical workshops, iTEC Tech-shop provided training courses for about 180 local personnel. In addition, the smart Techshop test-bed project was promoted in order to improve the operation level along with securing sustainability of the Techshop. The case of the iTEC Tech-shop could be a useful case for institutions or organizations promoting the maker movement to developing countries.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.561-568
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• 2021

In this study, in order to observe the change in the amount of Tire and Road Wear Particles and the ratio of tire components in it according to the tire wear resistance performance, carried out the evaluation by varying the vulcanization reaction design of the tire tread rubber. In addition, in order to improve the reliability of the evaluation of Tire and Road Wear Particles, the evaluation was performed indoor laboratory test equipment that simulates the condition on real driving to exclude various environmental influences including minerals, driver's habits, road surface, weather, tire structure and pattern designs. After the evaluation in closed space, it is estimated that the amount of collected Tire and Road Wear Particles is 84% compared to 100% of the tire and road wear loss weight, of which 96.4~97.7% was around the road and 2.3~3.6% was in the air. As a result of analy sis of the collected Tire and Road Wear particles, the tire component existed 63~75% in the Tire and Road Wear Particles depending on the wear resistance performance of the tire.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.1
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• pp.67-75
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• 2022

When acquiring a product having an OS, it is very important to identify the exact kernel version of the OS. This is because the product's administrator needs to keep checking whether a new vulnerability is found in the kernel version. Also, if there is an acquisition requirement for exclusion or inclusion of a specific kernel version, the kernel identification becomes critical to the acquisition decision. In the case of the Linux kernel used in various equipment, sometimes it becomes difficult to pinpoint the device's exact version. The reason is that many manufacturers often modify the kernel to produce their own firmware optimized for their device. Furthermore, if a kernel patch is applied to the modified kernel, it will be very different from its base kernel. Therefore, it is hard to identify the Linux kernel accurately by simple methods such as a specific file existence test. In this paper, we propose a static method to classify a specific kernel version by analyzing function names stored in the symbol table. In an experiment with 100 Linux devices, we correctly identified the Linux kernel version with 99% accuracy.

• Journal of Korea Entertainment Industry Association
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• v.15 no.7
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• pp.87-96
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• 2021

The purpose of this study is to analyze the problems of the Physical Activity Promotion System(PAPS) implemented in elementary, middle, and high schools in Korea and to prepare improvement measures. The data of the study was obtained through in-depth interviews, related papers, and press releases. The research participants of this study were 5 incumbent physical education teachers who directly instruct and measure PAPS at school and 5 college students who directly experienced PAPS. The results of the study are as follows. First, the problems that occurred in the educational environment of PAPS were students' indifference, teachers' passive guidance, and decreased physical education hours replaced by PAPS measurement days. Second, the problems occurring in the measurement environment of PAPS were errors due to measurement equipment, deviations due to different measurement locations, and differences in grades according to measurement items. Third, the problems that occur in the measurement process of PAPS are the lack of measurement personnel, the expedient physical fitness measurement, and the non-standardized measurement method. In order to improve these problems and successfully apply PAPS, the following improvement measures should be attempted. Details on this are as follows. First, teachers should inspire students' interest and interest in PAPS. Second, it is necessary to secure the reliability of the measurement result value of PAPS. Third, it is necessary to systematically supplement the school education system for PAPS measurement.