• Journal of IKEEE
• /
• v.26 no.4
• /
• pp.681-685
• /
• 2022

Including the COVID-19 crisis, humanity is constantly exposed to viral infections, and efforts are being made to prevent the spread of infection by quickly isolating infected people and tracing contacts. Passive epidemiological investigations that confirm contact with an infected person through contact have limitations in terms of accuracy and speed, so automatic tracking methods using various digital technologies are being proposed. This paper verify contact by utilizing Bluetooth Low Energy (BLE) technology and present an algorithm that identifies close contact through analysis and correction of RSSI (Received Signal Strength Indicator) values. Also, propose a system that can prevent the spread of viruses in a centralized server structure.

• Journal of Cadastre & Land InformatiX
• /
• v.51 no.1
• /
• pp.53-65
• /
• 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 the Acoustical Society of Korea
• /
• v.20 no.4
• /
• pp.22-28
• /
• 2001

This paper describes the implementation of a robust speaker position location system using the voice signal received by microphone array. To be robust to the reverberation which is the major factor of the performance degradation, low-frequency phase restoration algorithm which eliminates the influence of reverberations using the low-frequency information of the CPSP function is proposed. The implemented real-time system consists of a general purpose DSP (TMS320C31 of Texas instruments), analog part which contains amplifiers and filters, and digital part which is composed of the external memory and 12-bit A/D converter. In the real conference room environment, the implemented system that was constructed by the proposed algorithms showed better performance than the conventional system. The error of the TDOA estimation reduced more than 15 samples.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.3
• /
• pp.258-263
• /
• 2010

Sound localization algorithm usually adapts three step process: sampling sound signals, estimating time difference of arrival between microphones, estimate location of sound source. To apply this process in indoor environment, sound localization algorithm must be strong enough against reverberant and noisy condition. Additionally, calculation efficiency must be considered in implementing real-time sound localization system. To implement real-time robust sound localization system we adapt four low cost condenser microphones which reduce the cost and total calculation load. And to get TDOA(Time Differences of Arrival) of microphones we adapt GCC-PHAT(Generalized Cross Correlation-Phase Transform) which is robust algorithm to the reverberant and noise environment. The position of sound source was calculated by using iterative least square algorithm which produce highly accurate position data.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2012.05a
• /
• pp.419-419
• /
• 2012

현재 농업용 저수지에 대한 설계홍수량 유입 시 방류량을 산정하는 데 있어, 홍수기시 운영 초기수위는 상시 만수위를 제한수위로 하고 있다. 비록 제한수위를 상시만수위로 하는 시나리오는 저수지 설계시의 안전을 고려하는 측면에서 유효하다고 할 수 있으나, 실제 농업용 저수지의 홍수조절에 따른 방류량으로 인한 하류하천에 대한 영향을 평가하기에는 미흡한 부분이 있다. 결국 설계홍수량의 유입에 따른 저수지 홍수추적 결과 산정된 방류량은 제한수위를 상시만수위보다 낮은 수위에서 조절하여 모의 운영된 저수지의 방류량에 비해 과다 추정되기도 한다. 따라서 저수지 운영방식에 따라 홍수 유입 시 과다 추정되는 방류량으로 인한 하류하천에 대한 영향 부담은 커질 수밖에 없다. 또한 현재 토지이용변화에 따른 농업용수 수요량의 감소로 인해 홍수조절용량을 과거보다 더 확보할 수 있으므로 홍수 유입 시 제한수위를 조절하여 저수지 방류량으로 인한 하류하천에 대한 영향을 줄일 수 있다. 따라서 본 연구에서는 제한수위 조절에 따른 저수지 홍수추적을 모의하고, 산정된 방류량으로 인한 하류하천에 대한 영향을 검토해 보았다. 저수지 상류 유역의 홍수량 산정은 HEC-HMS 모형을 이용하였으며, 저수지 홍수추적에는 저수지 모의 운영프로그램의 대표적인 모형이라 할 수 있는 HEC-5 모형을 이용하였다. 또한 HEC-RAS 모형을 통해 저수지 방류량으로 인한 하류하천에 대한 수위변화를 모의하였다. 농업용 저수지 제한수위 검토를 위한 용수 수요량에 따른 저수지 수위의 결정을 위해 수리시설물 모의조작시스템(HOMWARS) 모형을 활용하였다. 대상 유역은 황룡강유역으로 선정하였으며, 황룡강유역 내 저수지별 제한수위 설정에 따른 하류하천에 대한 영향 평가를 수행하였다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.9
• /
• pp.49-55
• /
• 2019

This paper presents a marker image evaluation method based on analysis of object distribution in images and classification of images with repetitive patterns for effective marker-based augmented reality (AR) system development. We measure the variance of feature point coordinates to distinguish marker images that are vulnerable to occlusion, since object distribution affects object tracking performance according to partial occlusion in the images. Moreover, we propose a method to classify images suitable for object recognition and tracking based on the fact that the distributions of descriptor vectors among general images and repetitive-pattern images are significantly different. Comprehensive experiments for marker images confirm that the proposed marker image evaluation method distinguishes images vulnerable to occlusion and repetitive-pattern images very well. Furthermore, we suggest that scale-invariant feature transform (SIFT) is superior to speeded up robust features (SURF) in terms of object tracking in marker images. The proposed method provides users with suitability information for various images, and it helps AR systems to be realized more effectively.

• Journal of Advanced Navigation Technology
• /
• v.27 no.5
• /
• pp.568-573
• /
• 2023

Range resolution is the ability to distinguish different targets placed in same angular direction but at different distances from the radar. Normally, Range resolution requirement is defined as the width of transmitting pulse. The width of transmitting pulse does not mean the ability to distinguish two different targets. Range resolution performance to detect and track targets separately depends on the signal processing and tracking algorithm not only the width of transmitting pulse. This paper analyzes the processing steps in algorithms to affect the range resolution performance and verifies the results by roof-lab ground test using beacon signal. As a result, to track targets with the same angular position separately, it is desirable to have larger range difference than plot-track association test gate.

• Journal of Digital Convergence
• /
• v.11 no.2
• /
• pp.249-256
• /
• 2013

Recent days, the global warming problem due to excessive use of fossil fuels has been the world wide issue so that Korea government and developed countries make an alternative plan for eco-friendly and transportations by utilizing bicycles for health promotion. Existing Public Bicycle Rental Service Systems provide simple service such as bicycle rental management and tracking the location. However there is no user-side service for the information of the measure of carbon reduction, or use of bicycles. The proposed system in this paper provides users' health information, environmental information, personal information, counseling services and the measures of carbon reduction. The new system has been developed to carry out reducing carbon and growing green in terms of using bicycles by adopting Web 2.0 technology.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.14 no.2
• /
• pp.299-305
• /
• 1994

An experimental test section was placed in Pangyo-Guri Expressway to monitor the performance of CRCP(Continuously Reinforced Concrete Pavement). So far early-age behaviors of the test section have been monitored for about two years. The purposes of this paper are to analyze the early-age behavior and temperature pattern of the test section and to compare the results with those of similar test sections placed in Houston. As results of this study, following findings were obtained. The results of Pangyo-Guri test section were generally better than those of Houston test sections in terms of the early-age crack patterns. Type II cement was more effective than type I cement in controlling the early-age cracking. Afternoon placement was more effective than morning construction in controlling the early-age cracking in summer season.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.24 no.2
• /
• pp.205-211
• /
• 2024

The purpose of this study is to implement an agent that intelligently performs tracking and movement through reinforcement learning using the Unity and ML-Agents. In this study, we conducted an experiment to compare the learning performance between training one agent in a single learning simulation environment and parallel training of several agents simultaneously in a multi-learning simulation environment. From the experimental results, we could be confirmed that the parallel training method is about 4.9 times faster than the single training method in terms of learning speed, and more stable and effective learning occurs in terms of learning stability.