• Journal of the Korean Society for Railway
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• v.18 no.6
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• pp.619-629
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• 2015

The train conflict resolution problem refers to an adjustment of the train operation schedule in order to minimize the delay propagation when a train conflict is predicted or when a train conflict occurs. Previous train studies of train conflict resolutions are limited in terms of the size of the problems to be solved due to exponential increases in the variables. In this paper, we propose a train conflict resolution model using a time-space network to solve the train conflict situation in the operational phase. The proposed model adjusts the size of the problem by giving only the dwell tolerance in the time-space network only for stops at the station after a train conflict. In addition, the proposed model can solve large problems using a path flow variable. The study presents a train delay propagation analysis and experimental results of train conflict resolution assessments as well using the proposed model.

• Journal of the Korea Society of Computer and Information
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• v.26 no.5
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• pp.9-16
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• 2021

In this paper, we propose a building exploration drone that can be used for a digital twin-based building control system. The existing building control system using a fixed position sensor box has a problem that a management blind spot occurs. And because people patrol themselves, it takes a lot of human resources. In this paper, a drone equipped with a temperature and humidity sensor and a gas leak detection sensor is used to search the internal path of the building centering on the control blind spot. It also aims to solve the problem of the building control system by transmitting information in real time along with the video. In addition, it has a stable hovering function using an optical floor sensor and can be applied to an existing digital twin-based building control system. The results of this study are believed to be of great help in improving the quality of digital twin control systems using drones.

• The Journal of Society for e-Business Studies
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• v.23 no.4
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• pp.137-152
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• 2018

It is a measure to overcome limitations that occur in the activity of detecting and blocking abnormal information leakage activity by collecting the activity log generated by the security solution to detect the leakage of existing financial information and analyzing it by pattern analysis. First, it monitors real-time execution programs in PC that are used as information leakage path (read from the outside, save to the outside, transfer to the outside, etc.) in the PC. Second, it determines whether it is a normal controlled exception control circumvention by interacting with the related security control process at the time the program is executed. Finally, we propose a risk management model that can control the risk of financial information leakage through the process procedure created on the basis of scenario.

• Journal of IKEEE
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• v.22 no.4
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• pp.896-900
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• 2018

Traditionally, Linear Shift Feedback Register (LFSR) has been widely employed to implement Cyclic Redundant Check (CRC) codes for a serial input. Since many applications including network and storage systems demand as high throughput as ever, various efforts have been made to implement CRC hardware to support parallel inputs. Among various parallel schemes, the look-ahead scheme is one of the most widely used schemes due to its short critical path. However, it is very cumbersome to design HDL codes for parallel CRC codes since the look-ahead scheme is inevitable to consider how register and input values move in the next cycles. Thus, this paper proposes a novel CRC hardware generator, which automatically produces HDL codes given a CRC polynomial and parallel factor. The experimental results verify the applicability to use the proposed generator by analyzing the synthesis results from the generated HDL code.

• Journal of Convergence for Information Technology
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• v.9 no.8
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• pp.35-44
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• 2019

The purpose of this study is to find out quantitative vulnerability assessment about COTS(Commercial Off The Shelf) O/S based I&C System. This paper analyzed vulnerability's lifecycle and it's impact. this paper is to develop a quantitative assessment of overall cyber security risks and vulnerabilities I&C System by studying the vulnerability analysis and prediction method. The probabilistic vulnerability assessment method proposed in this study suggests a modeling method that enables setting priority of patches, threshold setting of vulnerable size, and attack path in a commercial OS-based measurement control system that is difficult to patch an immediate vulnerability.

• Journal of the Korea Society of Computer and Information
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• v.27 no.7
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• pp.75-82
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• 2022

There are various exhibition halls, shopping malls, theme parks around us and analysis of interest in exhibits or contents is mainly done through questionnaires. These questionnaires are mainly depend on the subjective memory of the person being investigated, resulting in incorrect statistical results. Therefore, it is possible to identify an exhibition space with low interest by tracking the movement and counting the number of visitors. Based on this, it can be used as quantitative data for exhibits that need replacement. In this paper, we use deep learning-based artificial intelligence algorithms to recognize visitors, assign IDs to the recognized visitors, and continuously track them to identify the movement path. When visitors pass the counting line, the system is designed to count the number and transmit data to the server for integrated management.

• Journal of the Korean Wood Science and Technology
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• v.31 no.2
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• pp.31-37
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• 2003

Among the nondestructive evaluation (NDE) methods for wood defect detection, ultrasonic wave has been considered as competitive technique in terms of economics and workability. Until now, researches on application of NDE methods for wood have focused mainly on standing tree and logs. Recently, some attempts have been conducted with NDE technique, for evaluation of wooden structural members. However, wooden structural members are different from others (standing tree or log) in various aspects. Expecially when some parts or whole member are covered with other materials, they can't be evaluated appropriately on general NDE methods. For the purpose of development of proper NDE technique for the wooden structural members, the ultrasonic wave transmission process investigated on artificial defect in wood. First, various types of transmission process were assumed, and then the transmission times were predicted respectively. Predicted times were compared with the measured time of ultrasonic wave and then a suitable type of transmission process is determined. In case of the ultrasonic wave doesn't transmit directly due to defect, it is reflected once only at the opposite surface of member, and the path is accord with the line of shortest length.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.3
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• pp.1-17
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• 2022

Accurate analysis of the causes of metro rail traffic congestion provides a means of addressing issues arising from metro rail traffic congestion in metropolitan areas. Currently, congestion analysis based on counting, weight detection, CCTVs, and mobile Wi-Fi is limited by poor accuracies or because studies have been restricted to single routes and trains. In this study, a train congestion analysis model was used that includes the transfer and multi-path behavior of metro passengers and train operation plans for metropolitan urban railroads. Analysis accuracy was improved by considering traffic patterns in which passengers must wait for next trains due to overcrowding. The model updates train crowding levels every 10 minutes, provides information to potential passengers, and thus, is expected to increase the social benefits provided by the Seoul metropolitan subway

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.2
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• pp.142-154
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• 2023

The canine tooth is important both functionally and aesthetically, being positioned between the anterior and posterior teeth. The upper canine has the longest eruption path, forming in the deepest part of the maxillary bone and often experiencing eruption disorders, leading to significant aesthetic and functional issues. Early detection and management of canine impaction are crucial in pediatric dentistry, which focuses on tooth growth and eruption. The prevalence of maxillary canine impaction ranges from 1.1% to 3.0%. In Western populations, palatal impaction is twice as common as labial impaction, while some Korean studies report more labial impaction. Maxillary canine impaction occurs more frequently in women and is associated with various factors such as structural obstacles, pathological conditions in surrounding tissues, developmental abnormalities, and genetic factors. Labial displaced canines are linked to narrow maxillary intercanine width, total dental crowding, and skeletal Class III malocclusion. Maxillary palatal displaced canine impaction is more prevalent in patients with familial agenesis of lateral incisors or conical supernumerary lateral incisors. Understanding these factors aids in early diagnosis and appropriate intervention for canine tooth impaction, ensuring optimal oral health and aesthetics.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.4
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• pp.601-608
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• 2023

Mobile robots are widely used in industries because mobile robots perform tasks in various environments. In order to carry out tasks, determining the precise location of the robot in real-time is important due to the need for path generation and obstacle detection. In particular, when mobile robots autonomously navigate in indoor environments and carry out assigned tasks within pre-determined areas, highly precise positioning performance is required. However, mobile robots frequently experience data missing in wireless communication environments. The robots need to rely on predictive techniques to autonomously determine the mobile robot positions and continue performing mobile robot tasks. In this paper, we propose an extended Kalman filter-based algorithm to enhance the accuracy of mobile robot localization and address the issue of data missing. Trilateration algorithm relies on measurements taken at that moment, resulting in inaccurate localization performance. In contrast, the proposed algorithm uses residual values of predicted measurements in data missing environments, making precise mobile robot position estimation. We conducted simulations in terms of data missing to verify the superior performance of the proposed algorithm.