• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12A
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• pp.966-974
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• 2011

In this paper, we propose an asset tracking system for applying a container port environment. If we attempt to apply this common locating system to a port environment for logistics automation, the system performance is degraded because there are many steel obstacles that cause interference in the RF communication and measurement. We divided readers into two types - fixed and mobile readers; hence, the location method operates in two steps for efficient wireless communication and precise measurement. In addition, the system estimates the location with trajectory information of assets when the small number of measurement is gathered. We implemented all the system components and installed these at a real port for evaluation. The success rate of communication and estimation is much better than that of the existing general locating system, and the location precision is substantially increased.

• Journal of Navigation and Port Research
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• v.26 no.3
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• pp.303-310
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• 2002

Nowadays, the combined land navigation system using GPS(Global Positioning System) and DR(Deduced Reckoning), etc. has been used. Although GPS is popular with the land navigation system, this is not useful for the kinematic positioning of the vehicles in the urban canyon because of its few satellites. Thus, this study deals with the kinematic positioning of the vehicles with the combined GPS/GLONASS(GLObal Navigation Satellite System) to compliment the drawbacks of GPS. So the kinematic positioning of the vehicles can be performed constantly by the combined GPS/GLONASS based on the high acquisition rate of data with the help of GLONASS despite of many obstacles and few satellites tracked in the test sites. Consequently, the combined GPS/GLONASS can be applicable to the control of traffic flow and the effective management of read system.

• Journal of Advanced Navigation Technology
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• v.19 no.2
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• pp.168-174
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• 2015

Wireless communication system for firefighters has an important role as the last communication method between the commander and the firefighters in disaster sites like fire. But the operation of Gyeongnam wireless communication system is installed, and maintained and controlled without criteria for the selection of a transmitting station and the analysis of propagation environment because of the lack of budget and the absence of professional personnel. To improve the performance of the radio station, this paper theoretically calculated free space loss of UHF 400 MHz band used by all firefighters in Gyeongnam and diffractions caused by single and multiple obstacles and computed the error after comparing the results of the actual measurement to those of simulation with FRAS operated by KFL. In the results, Deygout model was the most consistent with the actual measurement for 400MHz band in Kimhae site.

• Journal of the Institute of Convergence Signal Processing
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• v.21 no.3
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• pp.133-141
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• 2020

In this paper, the communication method of data information accepted by underwater drones and the implementation method to console display of data information were described, and the function of integrated monitoring system interface and the design and implementation of sonar interface were explained. The operation and posture of underwater drones can be controlled using a controller connected to the console, and the distance information between underwater drones and obstacles is obtained from sonar so that they can be visually displayed on the console screen along with camera images. The integrated monitoring navigation console is implemented to suit improvements, making it convenient and easy for workers to use. In addition, by upgrading integrated monitoring and control software functions, the company added user-specific project management functions and the output of reports for hull inspection to make them different and competitive from other underwater drones.

• The Journal of the Korea Contents Association
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• v.22 no.10
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• pp.535-545
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• 2022

The purpose of this study is to classify the various problems in surface road according to their severity and to propose a priority decision making process for road policy makers. For this purpose, the road problems reported by Cheok-cheok app were classified, and the EPDO was adopted and calculated as an index of their severity. To test applicability of the proposed process, some images of road problems reported by the app were classified and annotated, and the Deep Learning was used for machine learning of the curated images, and then the other images of road problems were used for verification. The detecting success rate of the road problems with high severity such as road kills, obstacles in a lane, road surface cracks was over 90%, which shows the applicability of the proposed process. It is expected that the proposed process will make the app possible to be used in the filed to make a priority decision making by classifying the level of severity of the reported road problems automatically.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.4
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• pp.677-686
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• 2023

In this paper, we study the design and implementation of a smart home outing care system that recognizes the user's purpose of going out and delivers useful information that can help when going out. RSS service data of the Korea Meteorological Administration can be transmitted in real time using ESP8266, and a system that can provide weather information to users after analyzing the data using Arduino MEGA is implemented. Using App Inventor, you can pack the necessary items without forgetting, and you can change the settings according to the desired weather and purpose. The position of the microphone was placed outside to increase awareness by 12%, and the sensitivity of the pressure sensor was set to a maximum of 210 kΩ. If there is an obstacle between the doors, the doors open automatically. An ultrasonic sensor was placed on the ceiling of the drawer to recognize an object within the range of 0.5cm to 10cm to check the existence of an object, and a camera was installed to research a security reinforcement system.

• Journal of the Korea Society of Computer and Information
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• v.14 no.11
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• pp.61-71
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• 2009

Vehicle license plate is the only way to check the registrated information of a vehicle. Many works have been devoted to the vision system of recognizing the license plate, which has been widely used to control an illegal parking. However, it is difficult to correctly segment characters on the license plate since an illumination is affected by a weather change and a neighboring obstacles. This paper proposes a robust method of segmenting the character of the license plate on irregular illumination condition. The proposed method enhance the contrast of license plate images using the Chi-Square probability density function. For segmenting characters on the license plate, binary images with the high quality are gained by applying the adaptive threshold. Preprocessing and labeling algorithm are used to eliminate noises existing during the whole segmentation process. Finally, profiling method is applied to segment characters on license plate from binary images.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.5
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• pp.747-754
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• 2023

Energy-efficient routing protocol is an important task in a wireless sensor network that is used for monitoring and control by wirelessly collecting information obtained from sensor nodes deployed in various environments. Various routing techniques have been studied for this, but it is also necessary to consider WSN environments with specific situations and conditions. In particular, due to topographical characteristics or specific obstacles, a hole where sensor nodes are not deployed may exist in most WSN environments, which may result in inefficient routing or routing failures. In this case, the geographical routing-based hall bypass routing method using GPS functions will form the most efficient path, but sensors with GPS functions have the disadvantage of being expensive and consuming energy. Therefore, we would like to find the boundary node of the hole in a WSN environment with holes through minimal sensor function and propose hole bypass routing through boundary line formation.

• Journal of the Health Care and Life Science
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• v.9 no.2
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• pp.297-302
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• 2021

As the price of LiDAR developed for autonomous driving has dropped dramatically, LiDAR has begun to be applied in various fields. Typical examples are vacuum cleaner robots, autonomous delivery robots, and autonomous obstacle avoidance drones. LiDAR is becoming the only means of figuring out the location of an object in real time while compensating for the weakness that 2D or 3D cameras are vulnerable to lighting. In this paper, we propose a method to monitor the movement of a patient by installing a 2D lidar in a hospital room. When a patient who needs intensive monitoring due to psychologically unstable, suicidal intention, or psychotic findings is alone in the ward, 2D LiDAR monitors the patient's movement and sends an appropriate alarm to the management room to effectively monitor the patient. devised a way to do it.

• Korean Journal of Construction Engineering and Management
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• v.17 no.3
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• pp.143-155
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• 2016

Recently, the interest on applying AVM(Around View Monitoring) systems in construction equipments have been increasing due to the demand for better control, work efficiency and safety. Most of the existing AVM systems have been developed focusing on the application in automobiles and only several AVM systems have been developed for construction equipments. However, the original technology of AVM remained the same as in the automobiles that failed to consider the main properties of construction equipments and suggest appropriate range of AVM display (Top-view). Therefore, the purpose of this study is to suggest a pilot type of AVM system for construction equipment. Accordingly, literature review, deduction of main consideration factors, selection of sensors, system design, algorithm development of a pilot type of AVM system for construction equipment have been conducted. A laboratory experiment has also been conducted for the deduction of further improvements. As a result, a minimum image refresh rate of 20 fps has been achieved that clearly reflects the actual situation of the equipment and also, the actual motions of Boom, Arm, Bucket have been displayed appropriately on the AVM system based on the angle data collected by sensors. However, the experiment results have also shown that the following tasks still remain for future work: 1)Improvement of AVM image interpolation, 2)Development of calibration module for variety construction equipment.