• Journal of Positioning, Navigation, and Timing
• /
• v.4 no.2
• /
• pp.67-72
• /
• 2015

Power grid techniques are distributed over general power systems ranging from power stations to power transmission, power distribution, and users. To monitor and control the elements and performance of a power system in real time in the extensive area of power generation, power transmission, wide-area monitoring (WAM) and control techniques are required (Sattinger et al. 2007). Also, to efficiently operate a power grid, integrated techniques of information and communication technology are required for the application of communication network and relevant equipment, computing, and system control software. WAM should make a precise power grid measurement of more than once per cycle by time synchronization using GPS. By collecting the measurement values of a power grid from substations located at faraway regions through remote communication, the current status of the entire power grid system can be examined. However, for GPS that is used in general national industries, unexpected dangerous situations have occurred due to its deterioration and jamming. Currently, the power grid is based on a synchronization system using GPS. Thus, interruption of the time synchronization system of the power system due to the failure or abnormal condition of GPS would have enormous effects on each field such as economy, security, and the lives of the public due to the destruction of the synchronization system of the national power grid. Developed countries have an emergency substitute system in preparation for this abnormal situation of GPS. Therefore, in Korea, a system that is used to prepare for the interruption of GPS reception should also be established on a long-term basis; but prior to this, it is required that an evaluation technique for the time synchronization performance of a GPS receiver using an atomic clock within the power grid. In this study, a monitoring system of time synchronization based on GPS at a power grid was implemented, and the results were presented.

• Journal of Advanced Navigation Technology
• /
• v.20 no.6
• /
• pp.604-611
• /
• 2016

Drone, which refers to unmanned aerial vehicles (UAV), industries are improving rapidly and exceeding existing level of remote controlled aircraft models. Also, they are applying automation and cloud network technology. Recently, the ability of drones can bring serious threats to public safety such as explosives and unmanned aircraft carrying hazardous materials. On the purpose of reducing these kinds of threats, it is necessary to detect these illegal drones, using acoustic feature extraction and classifying technology. In this paper, we introduce sound feature vector extraction method by harmonic feature extraction method (HLA). Feature vector extraction method based on HLA make it possible to distinguish drone sound, extracting features of sound data. In order to assess the performance of distinguishing sounds which exists in outdoor environment, we analyzed various sounds of things and real drones, and classified sounds of drone and others as simulation of each sound source.

• Journal of Navigation and Port Research
• /
• v.30 no.3 s.109
• /
• pp.189-195
• /
• 2006

Sea operation monitoring system is a system for the automatic ship operation that is used on the variety sea operations such as laying optical cables on the sea between the countries, laying cables on the seabed for a remote island, laying pipelines for the natural gas, and so forth. This system processes data which obtained through setting up environment and input from several sensors, and display GPS information with ENC data. And this system processes not only data of route file about sea operation, but also realtime information from PDA of client wirelessly connected with AP on wireless LAN. In addition, this system can improve efficiency of the operation as a result of enabling free movement within valid range. This paper design and implementation monitoring system from above appropriate to the embedded system, and improve competitive power of ship through prevention of a ship accident, to keep minimizing operation loads and support both the automatic ship operation and the safety voyage.

• Journal of Advanced Navigation Technology
• /
• v.2 no.2
• /
• pp.132-142
• /
• 1998

In optical scanning holography, 3-D holographic information of an object is generated by 2-D active optical scanning. The optical scanning beam can be a time-dependent Gaussian apodized Fresnel zone plate. In this technique, the holographic information manifests itself as an electrical signal which can be sent to an electron-beam-addressed spatial light modulator for coherent image reconstruction. This technique can be applied to 3-D optical remote sensing especially for identifying flying objects. In this paper, we first briefly review optical scanning holography and analyze the resolution achievable with the system. We then present mathematical expression of real and virtual image which are responsible for holographic image reconstruction by using Gaussian beam profile.

• Journal of Advanced Navigation Technology
• /
• v.20 no.1
• /
• pp.99-106
• /
• 2016

Wearable display market is a consistently growing field to handle a smart device with ease. Wearable display is an efficient device that can show the information to the user. In this paper, propose the scheme of a wearable display using LED and implement it including controlling remotely with BLE. Traditional outdoor LED display requires the dedicated controller and its software. Therefore, to control those LED display, it should implement a driver and its own way of communication. The proposed method is to ensure the independence and extensibility by separating driver module and communication module for controlling LED display. In addition, by adopting a short-range communication with Bluetooth 4.0 and a LED driver with low-power technology, it can be showed to control system configuration and display with a smart device.

• Journal of Advanced Navigation Technology
• /
• v.17 no.2
• /
• pp.240-246
• /
• 2013

Airtouch technology to integrate the system in the way of information delivery devices, touch screen DID this study is to develop new ways of information delivery systems. Airtouch technology to design and implement a system that can be utilized to view the college campus announcements, education, information, and employment information, and store the remote operation and sharing content, the development of cloud services to sync content via smart technology implementation fusion DID systemto develop. Packs USB interface kinek because you may be used in connection with the information appliances, and low-cost product by leveraging the Kinect sensor, Airtouch technology implementation. Types of input devices paper Airtouch technology systems, the user's hand gestures alone can interact with information appliances, smart fusion system developed by DID by tracking the user's hand movements to manipulate the mouse pointer, and information through the user's hand gestures to command the unit so that you can make. Airtouch technology smart fusion DID system technology utilizing a ripple effect on other industries, such as the online education industry, advertising, information industry increases. Also, replace the existing interface device with the versatility of a wide range of technologies, usability is an infinite expansion.

• Journal of Advanced Navigation Technology
• /
• v.21 no.2
• /
• pp.179-186
• /
• 2017

This paper is concerned with an interrogator capable of constructing a interrogation scenario for acquiring active airspace to the intruding aircraft into the surveillance area of the MLAT system. In the MLAT system, the interrogator is an important device used to carry out the interrogation towards the aircraft within the surveillance airspace in the appropriate surveillance scenario. Unlike a conventional SSR's interrogation methods that interrogate for airplanes flying within a certain range, the MLAT system requires a interrogation system that can actively interrogate from remote to near range, or according to operational scenarios, for aircraft intruding into the surveillance range. The interrogator implemented in this paper can be used for interrogating and monitoring aircraft within each surveillance airspace using whisper-shout algorithm according to varying output power based on the actual operation distance.

• Journal of Advanced Navigation Technology
• /
• v.24 no.2
• /
• pp.67-72
• /
• 2020

Satellite communication is not used by many people like mobile communication, but it is a necessary technology for public service and communication services, such as providing the Internet in military, disaster, remote education and medical services, island areas, and infrastructure vulnerable areas. However, on ships and aircraft, mobile communications requiring base stations are either unavailable or restricted in their use. In this paper, we used a Raspberry Pi board as the terminal device to communicate network through satellite modem and PPP protocol, and implemented two-way data link using the text message of the modem to connect to the Thuraya geo-stationary orbit network. In addition, I/O devices were connected to the controller of the terminal equipment to design and implement an IoT device system for ships that can remotely access the system under control and control I/Os and transmit measured data through various sensors.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• v.2
• /
• pp.21-26
• /
• 2006

A contract for shipbuilding is usually a complicated process and involves a statement of rights, and obligations and responsibilities to which each party agrees vis-a vis the other. Most countries are now well settled with regard to liability of a manufacturer in tort for physical injury and on the other hand, for pure economic loss to remote owners of chattels. Where there is a breach of either contractual warranty or an implied warranty, there may be admiralty jurisdiction, depending once again on the situs of the event and its relationship to traditional maritime activity. First of all, this thesis deals with the contents of contract under English Law. Secondly, this thesis analyse ' s the liability of shipbuilders in Products Liability under English, United States, German and korean Law comparisons. In conclusion, the author gives some suggestions as countermeasures to Products Liability for the shipbuilders in Korea.

• Journal of Institute of Control, Robotics and Systems
• /
• v.19 no.7
• /
• pp.605-613
• /
• 2013

This research proposes a vibration pattern algorithm to implement the haptic joystick to control a mobile robot at the remote site without watching the navigation environment. When the user cannot watch the navigation environment of the mobile robot, the user may rely on the haptic joystick solely to avoid obstacles and to guide the mobile robot to the target. To generate vibration patterns, there is a vibration motor at the bottom of the joystick which is held by the user to control the motion direction of the mobile robot remotely. When the mobile robot approaches to an obstacle, a pattern of vibration is generated by the motor, and by feeling the vibration pattern which is determined by the relative position of the mobile robot to the obstacle, the user can move the joystick to avoid the collision to the obstacle for the mobile robot. To generate the vibration patterns to convey the relative location of the obstacle near the mobile robot to the user, Fuzzy interferences have been utilized. To measure the distance and location of the obstacle near the mobile robot, ultrasonic sensors with the ring structure have been adopted and they are attached at the front and back sides of the mobile robot. The precise location of the obstacle is obtained by fusing the multiple data from ultrasonic sensors. Effectiveness of the proposed algorithm has been verified through the real experiments and the results are demonstrated.