• Journal of the Korean Society for Nondestructive Testing
• /
• v.24 no.5
• /
• pp.494-498
• /
• 2004

Fire accidents often happen in large buildings because large buildings are equipped with heavy electrical wiring and piping. When fire is to be occurred in those buildings, it is very dangerous to People and building structures. Therefore, multi-point wireless temperature sensors for large buildings are necessary in order to detect fire in the early time and thus to minimize the loss. A wireless device was composed of the transmitter and receiver. The specification of this device was as follows: 915MHz of transmitted frequency, 4 channels, 9600bps of the transmitted speed, and 10mW of the transmitted power. We confirmed through experiment that the temperature was well sensed and fire location was determined by the 4 channel sensors of the developed sensor system.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.35 no.1
• /
• pp.18-24
• /
• 2015

Train positioning detection information is fundamental for high-speed railroad inspection, making it possible to simultaneously determine the status and evaluate the integrity of railroad equipment. This paper presents the results of measurements and an analysis of an inertial measurement unit (IMU) used as a positioning detection sensors. Acceleration and angular rate measurements from the IMU were analyzed in the amplitude and frequency domains, with a discussion on vibration and train motions. Using these results and GPS information, the positioning detection of a Korean tilting train express was performed from Naju station to Illo station on the Honam-line. The results of a synchronized analysis of sensor measurements and train motion can help in the design of a train location detection system and improve the positioning detection performance.

• Journal of Advanced Navigation Technology
• /
• v.19 no.6
• /
• pp.465-472
• /
• 2015

In order to improve the performance of TCAS it should improve the performance of the sensor, which transmits a variety of information. In this paper, To improve the performance of the existing radar sensors such as being used in behalf of the next generation air traffic control system, ads-b the applied. In addition, ADS-B in a high precision by using information from the correction GPS system, SBAS assume would be able to apply an improved location accuracy for TCAS and analyzed TCAS and ADS-B. Played the simulation results, TCAS equipment receives the help of these ADS-B can calculate a CPA to determine the position of the aircraft in advance, and it was confirmed that it is possible to reduce the unnecessary RA operation, also, the pilot reduction and the workload, it has advantages such as fuel consumption and time associated with the reduced operation unnecessary RA was confirmed.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.4
• /
• pp.759-764
• /
• 2011

This paper deals with the method of using the amended virtual force field technique to avoidance the front environment(wall, obstacles etc.) in navigating by using the environmental informations recognized by a ultrasonic-ring and pan/tilt CCD camera equipped on a mobile robot. we will give an explanation for the robot system architecture designed and implemented in this study and a short review of existing techniques, since there exist several recent thorough books and review paper on this paper. It is proposed the rusult from the experimental run based on a virtual force field(VFF) method to support the validity of the aforementioned architecture of mobile service robot for local navigation and obstacle avoidance for autonomous mobile robots. We will conclude by discussing some possible future extensions of the project. The results show that the proposed algorithm is apt to identify obstacles in an indoor environments to guide the robot to the goal location safely.

• Journal of the Korean Institute of Gas
• /
• v.4 no.1 s.9
• /
• pp.1-8
• /
• 2000

Third party damage is one of the causes intrimiting the safety of a buried pipelines and it is very important to detect third party damage on pipelines as soon as possible. The purpose of this study is whether third-party damage can be detected by accelerometer sensor and how far the third-party damage signal can propagate. And a pilot experiment was carried out in order to find third-party damage location. As a result, the detected signal's spectum is high frequency at short distances, as the distance is far, the signals in high frequency range are attenuated and those in low frequency range remain. It was also proved that third-party damage within 5.3km distance can be detected by monitoring vibration signals.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.38 no.1
• /
• pp.49-56
• /
• 2014

In this study, the generation efficiency of the limited area of a concentrator solar cell was increased by using a solar concentrator and a tracking device. Heat generated by the solar cell was collected using a thermal absorber for supplying hot water or heating. Thus, the concentrator solar cell system provided electricity and heat simultaneously. Tracking of the sun by detecting the sun's position, repositioning of heating device towards the east after sunset, and shutting down of system after sunset were successfully implemented using an illuminance sensor (CdS) and Simulink, a commercial software package. We performed parametric analysis of the velocity, fin installation, and entrance location with respect to the operating temperature of the concentrator solar cell. A heat transfer simulation model was developed for comparing the actual temperature profiles of the concentrator solar cell and thermal absorber, and good agreement was found between the results of the simulations and the experiments.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.11 no.5
• /
• pp.80-85
• /
• 1997

Preventive diagnosis technique of power transforms is very important for highly reliable operation of power systems, and especially that of online transformer is needed in view of economy. Acoustic methods for partial discharge points have been studied abroad since 1960's in earnest. Electric-ultrasonic locating method by which partial discharges are found through detecting the electric and ultrasonic signal generated in partial discharge and ultrasonic-ultrasonic locating method by which partial discharges are found through detecting two ultrasonic signal with two ultrasonic sensor have been researched in our country. By using this ultrasonic-ultrasonic locating method, it was proposed of graphical determination technique of partial discharge points one dimension, two dimension, three dimension. But in locating partial discharges, they have assumed that the number of signal origin is one. So in this study we suggests a method of locating and knowing the number of signal origins when there are several origins by using ultrasonic-ultrasonic method.

• Smart Structures and Systems
• /
• v.8 no.1
• /
• pp.119-137
• /
• 2011

A bio-inspired two-mode structural health monitoring (SHM) system based on the Na$\ddot{i}$ve Bayes (NB) classification method is discussed in this paper. To implement the molecular biology based Deoxyribonucleic acid (DNA) array concept in structural health monitoring, which has been demonstrated to be superior in disease detection, two types of array expression data have been proposed for the development of the SHM algorithm. For the micro-vibration mode, a two-tier auto-regression with exogenous (AR-ARX) process is used to extract the expression array from the recorded structural time history while an ARX process is applied for the analysis of the earthquake mode. The health condition of the structure is then determined using the NB classification method. In addition, the union concept in probability is used to improve the accuracy of the system. To verify the performance and reliability of the SHM algorithm, a downscaled eight-storey steel building located at the shaking table of the National Center for Research on Earthquake Engineering (NCREE) was used as the benchmark structure. The structural response from different damage levels and locations was collected and incorporated in the database to aid the structural health monitoring process. Preliminary verification has demonstrated that the structure health condition can be precisely detected by the proposed algorithm. To implement the developed SHM system in a practical application, a SHM prototype consisting of the input sensing module, the transmission module, and the SHM platform was developed. The vibration data were first measured by the deployed sensor, and subsequently the SHM mode corresponding to the desired excitation is chosen automatically to quickly evaluate the health condition of the structure. Test results from the ambient vibration and shaking table test showed that the condition and location of the benchmark structure damage can be successfully detected by the proposed SHM prototype system, and the information is instantaneously transmitted to a remote server to facilitate real-time monitoring. Implementing the bio-inspired two-mode SHM practically has been successfully demonstrated.

• The Journal of the Korea Contents Association
• /
• v.9 no.11
• /
• pp.80-89
• /
• 2009

The importance of personalized services has been attracted in smart home environments according to the development of ubiquitous computering. In this paper, we proposed the smart home personalized service system based on context information using the speech recognition. The proposed service consists of an OSGi framework based service mobile manager, service manager, voice recognition manager, and location manager. Also, this study defines the smart home space and configures the commands of units, sensor information, and user information that are largely used in the defined space as context information. In particular, this service identifies users who exist in the same space that shows a difficulty in the identification using RFID through the training model and pattern matching in voice recognition and supports the personalized service of smart home applications. In the results of the experiment, it was verified that the OSGi based automated and personalized service can be achieved through verifying users in the same space.

• Journal of Advanced Navigation Technology
• /
• v.22 no.1
• /
• pp.43-47
• /
• 2018

In recent years, bicycle craze has been blowing in Korea, and bicycle has become a means of transportation near. In addition, there is a lot of interest in the Internet of things, and recently there is a lot of interest in the Internet of things. However, despite the development of the bicycle market, the bicycle cradle does not have such a development, and it still has a drawback in that it requires a separate lock for the lock. In this regard, I would like to find some problems and solve them. In this paper, we have implemented a system that can control the location and use of the bicycle cradle in real time by communicating with the app and Arduino so that it can help the collection and retrieval of the bicycle which is the problem of the current bicycle cradle. n addition, we propose a method to establish a shared economic system based on Internet of things by providing shared services with acquaintances and others, and to improve user convenience by providing real - time services.