• Journal of the Korean Society of Radiology
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• v.13 no.1
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• pp.141-146
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• 2019

Radiation sources used in the field of industrial non-destructive pose a risk of exposure due to ageing equipment and operator carelessness. Thus, the need for a safety management system to trace the location of the source is being added. In this study, Monte Carlo Simulation was performed to analyse the angle dependence of the unit-cell comprising the line-array dosimeter for tracking the location of radiation sources. As a result, the margin of error for the top 10% of each slope was 5.90% at $0^{\circ}$, 8.08% at $30^{\circ}$, and 20.90% at $60^{\circ}$. The ratio of the total absorbed dose was 83.77% at $30^{\circ}$ and 53.36% at $60^{\circ}$ based on $0^{\circ}$(100%) and showed a tendency to decrease with increasing slope. For all gradients, the maximum number was shown at $30^{\circ}$ No. 9 pixels, and for No. 10, there was a tendency to drop 7.24 percent. This study has shown a large amount of angle dependence, and it is estimated that the proper distance between the source and line-array dosimeters should be maintained at a distance of not less than 1 cm to reduce them.

• Journal of The Korean Society of Emergency Medicine
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• v.29 no.5
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• pp.449-454
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• 2018

Objective: The SAFARI score was introduced to assess the risk of convulsive seizure during admission for aneurysmal subarachnoid hemorrhage in 2017. This study was conducted to determine whether the SAFARI score derived from the afore-mentioned study could be applied to patients with aneurysmal subarachnoid hemorrhage in Korea. Methods: We conducted a retrospective study of patients who were diagnosed with aneurysmal subarachnoid hemorrhage from March 2013 to October 2017. Patients' age, sex, blood pressure, pulse rate, body temperature, Glasgow-Coma Scale, Hunt-Hess scale, modified Fisher grade, size of ruptured aneurysm, surgery type, transfusion, and SAFARI score were compared between the seizure and non-seizure groups. The area under the receiver operator characteristic curves was calculated to evaluate the predictive ability for seizure during admission. Logistic regression analysis was used to analyze predictive factors for seizure during admission. Results: A total of 220 patients were included. Ninety-seven (44.1%) were male and 123 (55.9%) were female. The mean age of the patients was 65.8 years old (range, 56-75). The area under the curve of the SAFARI score for predicting seizure was 0.813. The SAFARI score was the only significant predictor of seizure during admission, while other factors were not statistically significant upon logistic regression analysis. Conclusion: The SAFARI score could be used for predicting seizure during admission in patients with aneurysmal subarachnoid hemorrhage.

• Journal of the Korea Institute of Building Construction
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• v.21 no.5
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• pp.445-457
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• 2021

In previous studies, it was confirmed that through the in-situ production of precast concrete members, costs could be reduced by 14.5-39.4% compared to in-plant production. In particular, it was confirmed that the factory owner did not make a contract if it did not earn more than 20% of the production cost. If precast concrete members are produced in-situ under the same conditions, the quality equivalent to that of factory production can be secured. As it is advantageous in terms of cost and quality, precast concrete members must be produced in-situ. However, it is difficult to produce all quantities in-situ due to time and various other constraints. This is because in-situ production is avoided due to anticipated risks during the project management process. However, if the risk factors are analyzed before performing in-situ production of precast concrete members, it will increase the opportunity for in-situ production. Therefore, this study develops a checklist for evaluating the risk of in-situ production of precast concrete members. By applying the checklist to one case site, it was verified that risk factors can be evaluated easily and quickly. As a result, it was analyzed that sites with a high building coverage ratio are classified as high-risk sites because it is difficult to secure usable area for production and storage. The developed checklist efficiently evaluates the risk factors of in-site production, and makes it possible for the operator to determine the risk factors, which can change frequently during project execution, and respond according to the situation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.320-323
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• 2014

Today is going with the advancement of intelligent transportation systems and traffic environment and helping to provide safe and convenient service through a mobile device work with the popularization of the vehicle black box. The traffic flow by a variety of causes is constantly changing, it is often unable to prepare the driver, depending on external factors can not be controlled by the power of the public, leading to a major accident. The system needs to pass the real-time weather data in the inter-operator to prevent this. The proposed detection algorithm weather information delivered real-time weather information for this paper. The weather condition is detected by using the contrast between the histogram of the motion of the wiper and the clear day algorithm. In general, the wiper is worked in extreme weather conditions that will have a value different contrast due to rain or snow. Situation was considered clear, snowy conditions, such as using it on a rainy situation. First, designated as ROI (Region Of Interest) of the minimum area that can be detected in order to reduce the amount of calculation for the wiper, the wiper, which was detected through the operation of the threshold Thresholding the brightness of the vehicle wiper. In addition, we distinguish the value of each meteorological situation by using contrast. Results was obtained to 80% for the snow conditions, a rainy situation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.6
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• pp.77-83
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• 2020

The heat treatment facility is in a situation where the scope of application of the remote IOT system is expanding due to the harsh environment caused by high heat and long working hours among the root industries. In this heat treatment process environment, the IOT middleware is required to play a pivotal role in interpreting, managing and controlling data information of IoT devices (sensors, etc.). Until now, the system controlled by the heat treatment remotely was operated with the command of the operator's batch system without overall monitoring of the site situation. However, for the safety and precise control of the heat treatment facility, it is necessary to control various sensors and recognize the surrounding work environment. As a solution to this, the heat treatment safety support system presented in this paper proposes a support system that can detect the access of the work manpower to the heat treatment furnace through thermal image detection and operate safely when ordering work from a remote location. In addition, an OPEN CV-based deterioration analysis system using DNN deep learning network was constructed for faster and more accurate recognition than general fixed hot spot monitoring-based thermal image analysis. Through this, we would like to propose a system that can be used universally in the heat treatment environment and support the safety management specialized in the heat treatment industry.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.766-773
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• 2021

Chemicals, such as ammunition, are disposable items that cannot be reused because of their operational characteristics. The reliability of the test process and test results are important factors in evaluating the performance of guns and ammunition. The pressure after firing is a crucial value in an acceptance test of guns and ammunition performance; hence, accurate measurements are required. The pressure in the artillery is measured using the copper crusher gauge. The compression amount of copper is converted into a pressure by either a length-pressure conversion table or conversion formula. Therefore, the exact measurement of the squeeze of the copper crusher is related directly to the correct estimate of the pressure. Currently, the pressure is measured manually by the operator, which always includes some human error. In this study, the cause of the measurement error was analyzed, and the automatic measuring system for copper crusher deformation was developed to minimize the error elements. A copper crusher could be measured using the probe sensor and CCD camera, and the Jig for stable positioning was also designed. A designated SW was also developed for the system operating and measurement-analysis. This measuring system through this study may be used for an ammunition stockpile reliability test and gun/ammunition acceptance test.

• Journal of the Korean Society of Systems Engineering
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• v.17 no.1
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• pp.85-96
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• 2021

Radioactive mixed waste (RMW) means waste mixed with radioactive substances and hazardous substances. In Korea, there are definitions and disposal restrictions on RMW in the Nuclear Safety Management Act, but it is difficult to apply because the contents are insufficient, so this paper proposed applicable management standards. The main RMW generated from nuclear power plants is waste oil, waste asbestos, PCB, and waste fluorescent liquid, and their radiation characteristics are mostly at very low levels and some are estimated at low levels. In addition to nuclear power plants, RMW also occurs in research institutes, industries, and hospitals. The acceptance criteria of all disposal facilities in the world basically prohibit disposal of RMW unless the hazardous substances of RMW are removed or mitigated below the standard value. Cases in Korea, the United States, Japan and Europe were reviewed to propose the RMW management standards in Korea. With reference to the results of the above review, this paper clearly defined RMW and proposed detailed management standards for the separation, storage, treatment and disposal of hazardous substances by applying the Waste Control Act. It also mentioned legislation of management standards, regulatory methods, and acceptance criteria of disposal facility operator.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.591-598
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• 2021

One of the requirements of metro trains is to stop with precision to ensure that the train can stop precisely at the designated location on the platform. If this is not satisfied, interference with the screen door occurs, causing inconvenience to passengers and delays in operation. In the case of an automatic operated train, the current position is determined by the current speed information of the train, and control is performed by issuing an acceleration/deceleration command. Therefore, accurate control becomes impossible if the error of the speed information is large. In metro railroads, a Precision Stop Marker (PSM) is used to correct the position error, so that the error of stop control can be reduced by correcting the position error at a specific point. On the other hand, because the PSM itself has only position information, it does not compensate for the speed error. This paper proposes a method for performing in-place stop control by estimating the speed with the PSM progress information. The speed can be estimated when the train is operated at a constant deceleration speed, and the target deceleration can be obtained to perform stop control. The feasibility and excellence of the proposed method are shown through a numerical simulation.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.6
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• pp.1201-1208
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• 2020

A mass of seawater with similar properties in the ocean is called a water mass, and the front is a sea area where two masses of different properties meet. The gradient algorithm is a method of extracting where the sea water temperature pixel changes rapidly assuming that the slope is large, and the place with the large slope is assumed to be a front. This method is able to process large amounts of satellite data at once. Therefore, in this study, we tried to find the front lines in the sea area around the Korean Peninsula by using a gradient algorithm. The study data used gridded sea surface temperature satellite data. The resolution was 1/4°, and the monthly average data from January 1993 to December 2018 were used. There were major five fronts representatively, China Coastal Front, South Sea Coastal Front, Kuroshio Front/ Kuroshio Extension Front, Subpolar Front and the Subarctic Front. As a result of comparing the distribution of front by season, more types of front were distributed in winter and spring than in summer and autumn, and the distribution range was wider.

• Journal of the Korea Society for Simulation
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• v.30 no.2
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• pp.11-22
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• 2021

Sonobuoy is widely used as a very important sensor in combat management system using P-3 patrol aircraft due to its advantages of rapid searching into wide exploration range. It is necessary to verify the performance of developed sonobuoy system using various maritime test data in order to be successfully applied in combat management system. But it is difficult to acquire various real maritime data because it needs much time and effort. Therefore we have developed in this paper a synthetic signal generator and a simulator that they can verify the performance of sonobuoy system and evaluate its operational effectiveness without conducting maritime test. We have synthesized target signals based on the characteristics of underwater sound sources, and then developed the synthesized signal generator which consider to sound propagation etc. like as underwater environment. And in the simulator development we use a HMI technique to enhance the convenience of operator, and design to verify the performance of sonobuoy system. The developed signal generator and simulator can be used as useful tools to evaluate the operational effectiveness such as optimal deployment of sonobuoy in combat management system using P-3 patrol aircraft.