• Smart Structures and Systems
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• v.31 no.3
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• pp.301-309
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• 2023

Tilt is a key indicator of structural safety. Real-time monitoring of tilt responses helps to evaluate structural condition, enable cost-effective maintenance, and enhance lifetime resilience. This paper presents a prototype wireless sensing system for structural tilt measurement. Long range (LoRa) technology is adopted by the sensing system to offer long-range wireless communication with low power consumption. The sensor integrates a gyroscope and an accelerometer as the sensing module. Although tilt can be estimated from the gyroscope or the accelerometer measurements, these estimates suffer from either drift issue or high noise. To address this challenging issue and obtain more reliable tilt results, two sensor fusion algorithms, the complementary filter and the Kalman filter, are investigated to fully exploit the advantages of both gyroscope and accelerometer measurements. Numerical simulation is carried out to validate and compare the sensor fusion algorithms. Laboratory experiment is conducted on a simply supported beam under moving vehicle load to further investigate the performance of the proposed wireless tilt sensing system.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.4
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• pp.1-12
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• 2011

There has been the increasing concern with the safety of seven major urban infrastructure such as road, electricity, water supply, sewerage and so on due to urban expansion and new town development. However, high technology development for the common duct which can be an alternative for the safety issue has not been completed due to the law of the national security area. Existing management method of the common duct by people could not respond to the urgent accidents adequately and immediately since it is impossible for us to get access to that in case of fire or gas leak. This study suggests to the method of installing monitoring devices and processing CCTV images with a water supply in a TestLab(a variety of the USN(Ubiquitous Sensor Network) equipment was tested in the TestLab in KICT). The suggested management method of common duct facilities make it possible to do real-time monitoring and prompt access and response to an accident inside the common duct.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.603-611
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• 2020

Potholes on the road directly affect drivers' safety, satisfaction, and vehicle damage. Thus, real-time detection and response are required. Increasing frequency of patrols allows for potholes to be detected and responded to quickly, but this takes much manpower, money, and time. In addition, potholes have different occurrence characteristics depending on the rain conditions, so it is necessary to consider the optimal frequency from an economic and road-service perspective. Therefore, a quantitative analysis was done on the effects of rainfall on the occurrence characteristics of potholes. Information on the persistence, impact of rainfall intensity, and weather information was collected over a long period. Based on the results, a risk-based, optimized, and changeable road-patrol strategy is presented. The analysis results show that the probability of pothole occurrence increases by 2.4 times in rainy weather. Furthermore, the impact continues for 3 days even after the rain stops. The probability of pothole occurrence increases by 0.46% per 1 mm of rainfall, and the occurrence characteristics react sensitively to even a small amount of rain of around 1 mm. It was concluded that road patrol is required at least once every three days for an effect-free period, while twice a day is needed for the "sphere of influence" period to achieve a 95% reliability level.ys for effect-free period, while twice a day for sphere of influence period to satisfy 95% reliability level.

• Journal of Cadastre & Land InformatiX
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• v.51 no.1
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• pp.53-65
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• 2021

C-ITS(Cooperative Intelligent Transport System) that pursues traffic safety and convenience uses various sensors to generate traffic information. Therefore, it is necessary to improve the sensor-related technology to increase the efficiency and reliability of the traffic information. Recently, the role of CCTV in collecting video information has become more important due to advances in AI(Artificial Intelligence) technology. In this study, we propose to identify and track dynamic objects(vehicles, people, etc.) in CCTV images, and to analyze and provide information about them in various environments. To this end, we conducted identification and tracking of dynamic objects using the Yolov4 and Deepsort algorithms, establishment of real-time multi-user support servers based on Kafka, defining transformation matrices between images and spatial coordinate systems, and map-based dynamic object visualization. In addition, a positional consistency evaluation was performed to confirm its usefulness. Through the proposed scheme, we confirmed that CCTVs can serve as important sensors to provide relevant information by analyzing road conditions in real time in terms of road infrastructure beyond a simple monitoring role.

• The Journal of Bigdata
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• v.7 no.1
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• pp.15-27
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• 2022

In the past five years, the fatality rate of single-vehicle accidents has been 4.7 times higher than that of all accidents, so it is necessary to establish a system that can detect and respond to single-vehicle accidents immediately. The IoT(Internet of Thing)-based real-time traffic accident recognition system proposed in this study is as following. By attaching an IoT sensor which detects the impact and vehicle ingress to the guardrail, when an impact occurs to the guardrail, the image of the accident site is analyzed through artificial intelligence technology and transmitted to a rescue organization to perform quick rescue operations to damage minimization. An IoT sensor module that recognizes vehicles entering the monitoring area and detects the impact of a guardrail and an AI-based object detection module based on vehicle image data learning were implemented. In addition, a monitoring and operation module that imanages sensor information and image data in integrate was also implemented. For the validation of the system, it was confirmed that the target values were all met by measuring the shock detection transmission speed, the object detection accuracy of vehicles and people, and the sensor failure detection accuracy. In the future, we plan to apply it to actual roads to verify the validity using real data and to commercialize it. This system will contribute to improving road safety.

• International Journal of Highway Engineering
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• v.10 no.3
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• pp.19-31
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• 2008

Video image processing systems(VIPS) offer numerous benefits to transportation models and applications, due to their ability to monitor traffic in real time. VIPS based on wide-area detection, i.e., multi-lane surveillance algorithm provide traffic parameters with single camera such as flow and velocity, as well as occupancy and density. However, most current commercial VIPS utilize a tripwire detection algorithm that examines image intensity changes in the detection regions to indicate vehicle presence and passage, i.e., they do not identify individual vehicles as unique targets. If VIPS are developed to track individual vehicles and thus trace vehicle trajectories, many existing transportation models will benefit from more detailed information of individual vehicles. Furthermore, additional information obtained from the vehicle trajectories will improve incident detection by identifying lane change maneuvers and acceleration/deceleration patterns. The objective of this research was to relate traffic safety to VIPS tracking and this paper has developed a computer vision system of monitoring individual vehicle trajectories based on image processing, and offer the detailed information, for example, volumes, speed, and occupancy rate as well as traffic information via tripwire image detectors. Also the developed system has been verified by comparing with commercial VIP detectors.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.921-929
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• 2008

도로절토사면을 지속적으로 관리함에도 불구하고 집중호우 시 도로절토사면 붕괴로 인한 피해가 속출하고 있다. 이러한 절토사면 붕괴에 의한 피해를 최소화 하기위해 각종 신공법들이 개발, 도입되고 있으며 IT와 접목된 상시계측시스템도 많은 현장에 적용되고 있다. 국토해양부 각 지방국토관리청 산하 국도관리사무소에서 관리중인 절토사면 중 현재 상시계측시스템을 운용하고 있는 현장은 총 93개소이며 이들 현장들에 문제가 발생할 시 즉각적으로 경보시스템이 작동하여 붕괴에 의한 피해를 최소한으로 줄일 수 있다. 또한 시스템 작동에 차질이 없도록 정기적인 현장 점검이 이루어지고 있으며 2008년 3월경에 한국건설기술연구원, 한국시설안전공단, (주)GMG에서 합동현장조사를 실시하였다. 이 현장조사 결과를 토대로 전국국도 상시계측시스템의 현황 및 특성, 상시계측시스템의 문제점 및 개선방향에 대하여 분석하였다. 이에 본 연구에서는 전국 국도 사면 중 상시계측 시스템이 설치된 현장에 대하여 암종별, 규모별, 지역별로 분석을 실시하였으며 특히 상시계측시스템이 설치된 현장 중 붕괴발생현장 및 붕괴위험 현장에 대하여 붕괴특성분석, 유지관리 사례분석 등을 실시하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.319-321
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• 2005

최근 효율적인 교통 흐름 제어 및 교통정보 서비스 제공을 위한 ITS(Intelligent Transport System)에 대표적인 서비스로는 수집된 정보를 바탕으로 도로의 소통정보를 모니터링하고 이용자들에게 웹이나 지역에 설치된 VMS를 통해 정보를 제공하는 것이라 할 수 있다. 그러나 이러한 서비스를 위한 GIS가 OpenGIS와 같은 표준화 단체에서 제안하고 있는 구조를 따르지 않고 있으며, 지리정보의 표현도 검증 없이 자체적으로 GIS정보를 이용함으로 인해 서비스의 성능과 품질 저하는 물론 정보통합의 어려움을 가지고 있다. 본 논문에서는 OpenGIS에서 공간정보 표현에 권고되고 있는 GML을 기반으로 도로망에 구축되어진 각종 교통정보 기기로부터 ITS로 수집된 실시간 교통정보를 이용하여 데이터베이스를 구축하고, 이를 반영하여 모바일 기기 또는 웹서비스를 통해 교통상황을 모니터링 할 수 있는 시스템을 제안하고자 한다. 제안된 시스템은 GML을 기반으로 한 지리정보 DB와 각종 교통정보 기기로부터 수집된 실시간 교통정보의 통합을 통해 모바일 기기나 웹을 통해 공통적으로 서비스를 제공할 수 있는 Client/server 시스템에 주안점을 두고 설계하였다. 본 연구에서 설계된 시스템은 전용 공간데이터를 구축하지 않고, 표준화된 공간정보인 GML을 이용한 변환 메커니즘을 통하여 서비스를 제공함으로써 비용과 시간을 절약할 수 있으며, 이 기종의 시스템에 서비스가 가능하도록 하였다.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.1
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• pp.63-68
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• 2004

In this paper, we propose a method about the extraction of vehicle and tracking trajectory for moving vehicle tracking system in road. This system applied to the monitoring system of the traffic flow for ATMS(advanced traffic management system) of ITS(intelligent transport system). Also, this system can solve the problem of maintenance of loop sensor. And we detected vehicle using differential image analysis. Because of the road environment changes by real time. Therefore, the method to use background image is not suitable. And we used Kalman filter and innovation value and variable search area for vehicle tracking system. Previous method using fixed search area is sensitive to the moving trajectory and the speed of vehicle. Simulation results show that proposed method increases the possibility of traffic measurement more than fixed area traffic measurement system.

• Smart Structures and Systems
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• v.15 no.3
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• pp.769-785
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• 2015

Although timber structures have been extensively used in underground temporary supporting system, their actual performance is poorly understood, resulting in potentially conservative and over-engineered design. In this paper, a novel wireless sensor technology, SmartPlank, is introduced to monitor the field performance of timber structures during underground construction. It consists of a wooden beam equipped with a streamlined wireless sensor node, two thin foil strain gauges and two temperature sensors, which enables to measure the strain and temperature at two sides of the beam, and to transmit this information in real-time over an IPv6 (6LowPan) multi-hop wireless mesh network and Internet. Four SmartPlanks were deployed at the London Underground's Tottenham Court Road (TCR) station redevelopment site during the Stair 14 excavation, together with seven relay nodes and a gateway. The monitoring started from August 2013, and will last for one and a half years until the Central Line possession in 2015. This paper reports both the short-term and long-term performances of the monitored timber structures. The grouting effect on the short-term performance of timber structures is highlighted; the grout injection process creates a large downward pressure on the top surface of the SmartPlank. The short and long term earth pressures applied to the monitored structures are estimated from the measured strains, and the estimated values are compared to the design loads.