• Journal of the Korean Society for Precision Engineering
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• v.21 no.3
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• pp.59-65
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• 2004

The paper presents a small unmanned probing ship that can be used for acquiring information on marine and coastal environments. For communication system, we adopt direct and indirect methods based on the wireless modem of a commercial cellular telephone. The former is a direct communication between the modems of the ship and the server, and the latter is an indirect communication via internet between the ship and the server. The system is equipped with a digital compass and a GPS for position estimation, and extended Kalman filter is used for Navigation. The performance of the ship is demonstrated with the results produced by sets of experiments.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.15-19
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• 2004

Domestic use, or embody program that transmit NMEA protocol using multi port as software and is using because there is no fee and product that develop NMEA protocol Multiplexer, import mounting for foreign climax present. These method is paid or there is problem that must make out special processing part in each application program. Also, each mountings that display NMEA protocol can cause double resources waste and damage etc. because manufacturing firm and platform are different. Can act separatively as single hardware module of reliable processing method and high efficiency to supplement this in this treatise, and because using design of optimized cue, heighten memory efficiency of module, and proposed NMEA protocol Multiplexer that can keep high trustability of Come on, deviation compass, echo sound, mountings of GPS and so on and real time communication that is main input sensor equipment about embodiment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.4
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• pp.1294-1300
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• 2010

In an environment where all nodes move, the sensor node receives anchor node's position information within communication radius and modifies the received anchor node's position information by one's traveled distance and direction in saving in one's memory, where if there at least 3, one's position is determined by performing localization through trilateration. The proposed localization mechanisms have been simulated in the Matlab. In an environment where certain distance is maintained and nodes move towards the same direction, the probability for the sensor node to meet at least 3 anchor nodes with absolute coordinates within 1 hub range is remote. Even if the sensor node has estimated its position with at least 3 beacon information, the angle ${\theta}$ error of accelerator and digital compass will continuously apply by the passage of time in enlarging the error tolerance and its estimated position not being relied. Dead reckoning technology is used as a supplementary position tracking navigation technology in places where GPS doesn't operate, where one's position can be estimated by knowing the distance and direction the node has traveled with acceleration sensor and digital compass. The localization algorithm to be explained is a localization technique that uses Dead reckoning where all nodes are loaded with omnidirectional antenna, and assumes that one's traveling distance and direction can be known with accelerator and digital compass. The simulation results show that our scheme performed better than other mechanisms (e.g. MCL, DV-distance).

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.1
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• pp.84-92
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• 1995

The methods by turning circle test and maneuvering indices have been used to study and evaluate the maneuverability of a ship. However recently many studies utilizing the GPS are made on the measurement of the turning circle and in the fishery and hydrographic survey. In this paper, the author carried out the turning circle test using the differential GPS and dumb card together, and compared the data measured by them and analyzed the accuracies of them to obtain the utility basic ones on the measurement of the turning circle by the DGPS. The main results area s follows : 1) To check the accuracies of the GPS, the circling experiments of 50m radius by the DGPS were made on the ground. The accuracies of turning circle measured by the DGPS were found to be very high as the errors of 1.5m. 2) the turning circle by the DGPS could be measured very accurately, by the seed, rudder angle, starboard and port respectively. 3) The turning circle measured by the dumb card was found to be measured accurately as much as the DGPS, when using large rudder angle, the turning circle was large, the turning circle by the dumb car could not be measured accurately on account of large error of bearing of compass. 4) The tactical diameters by the DGPS in case of the rudder angle 35。~5。, were found to be 2.6。15.0 times the Lpp of S.T HAELIM-3 at her slow speed 2.8~16.6 times her Lpp at her half speed, 3.1~17.4 times her Lpp at her full speed. The tactical diameter by the dumb card was found to be 2.4~9.5 times, 2.6~9.6 times, 3.2~12.2 times her Lpp respectively, in the above case and speed.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.3
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• pp.301-310
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• 2013

To suggest a standard concerning with the arrangement of bridge equipment, the authors conducted the video observations with 3CCD (charge coupled device) cameras installed on the ceil of the bridge for monitoring the working activities of two bridge teams (the skipper/mate1 and the skipper/mate2) in a Korean coastal large trawler(gross tonnage: 139) for five days from July 30th. 2010 and analyzed of the data. Work elements coded by the work activities were input on the sheet of work analysis by the time unit of 1 sec according to the time occurred. A single work element among the work activities for every 5 minutes was denoted as the number of occurrence. The frequency of equipment usage was limited only in the usage of the equipment. In the case of the navigation and the towing net two ranks were integrated and analyzed. On the other hand, in the case of the casting net and the hauling net, two processes were integrated to as one and then analyzed separately as two ranks. As the results, 15 elements of work was carried out between two bridge teams for the observation; lookout, radar, GPS plotter, fish finder, net monitor, fishing deck, RPM indicator, rudder angle indicator, compass card, for maneuver; steering, ship speed control, trawl winch operation and external communications, paper works and others. It was found that the work load of the skipper per 5 minutes accordance with the navigation, the casting net, the towing net and the hauling net are 20.5 times, 11.9 times, 38.0 times and 9.5 times respectively, the mates are 65.2 times, 66.5 times, 85.7 times and 59.1 times respectively. The radar was shown the highest frequency of the equipment usage and the next was the fish finder, the GPS plotter and the external communications in the case of the navigation. In the case of the towing net the frequency of usage was high the ranking as the radar, the net monitor, the fish finder, the GPS plotter, the steering system and the external communications. In the case of the integrated process both of the casting and hauling net the trawl winch was shown the highest frequency to the skipper and the next was the GPS plotter and the radar, and the steering system was shown the highest frequency to the mate and the next was the radar, the ship speed control system, the GPS plotter, the net monitor and the fish finder.

• Korean Journal of Agricultural Science
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• v.42 no.1
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• pp.63-71
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• 2015

Path planning is an essential part for traveling and mowing of autonomous lawn mower tractors. Objectives of the paper were to analyze operation patterns by a skilled farmer, to extract and optimize waypoints, and to demonstrate generation of formatted planned path for autonomous lawn mower tractors. A 27-HP mower tractor was operated by a skilled farmer on grass fields. To measure tractor travel and operation characteristics, an RTK-GPS antenna with a 6-cm RMS error, an inertia motion sensing unit, a gyro compass, a wheel angle sensor, and a mower on/off sensor were mounted on the mower tractor, and all the data were collected at a 10-Hz rate. All the sensor data were transferred through a software program to show the status immediately on the notebook. Planned path was generated using the program parameter settings, mileage and time calculations, and the travel path was plotted using developed software. Based on the human operation patterns, path planning algorithm was suggested for autonomous mower tractor. Finally path generation was demonstrated in a formatted file and graphic display. After optimizing the path planning, a decrease in distance about 13% and saving of the working time about 30% was achieved. Field test data showed some overlap, especially in the turning areas. Results of the study would be useful to implement an autonomous mower tractor, but further research needs to improve the performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5564-5569
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• 2011

In this paper we introduced Augmented Reality (AR) on Android platform for ubiquitous learning (u-learning). Android is breaking new ground for mobile computing and open technologies. Android is versatile as it is not limited only to mobile phones, but it can be installed on various devices. Android gives developers the opportunity to leverage their development skills, while also building an exciting and active community. Augmented Reality (AR) is going to be the future of most apps; all it takes is a decent processor, a camera, a compass and a GPS, all of which are becoming increasingly common on smart phones. Through AR we can have educational tools that provide individuals with total flexibility to receive, send, and review training and detailed product information through an increasingly ubiquitous web-enabled communication device. In this paper, we proposed Augmented Reality for Species Identification using Android Smartphone with augmented reality in species determination. This study is appropriate in the field of Biology. This is useful in outdoor experimental activities of the students. Like for example while they are visiting the zoo, botanical garden and etc.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.251-256
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• 2006

In the work package 'Integrated Positioning' of the research project NAVIO (Pedestrian Navigation Systems in Combined Indoor/Outdoor Environements) we are dealing with the navigation and guidance of visitors of our University. Thereby start points are public transport stops in the surroundings of the Vienna University of Technology and the user of the system should be guided to certain office rooms or persons. For the position determination of the user different location sensors are employed, i.e., for outdoor positioning GPS and dead reckoning sensors such as a digital compass and gyro for heading determination and accelerometers for the determination of the travelled distance as well as a barometric pressure sensor for altitude determination and for indoor areas location determination using WiFi fingerprinting. All sensors and positioning methods are combined and integrated using a Kalman filter approach. Then an optimal estimate of the current location of the user is obtained using the filter. To perform an adequate weighting of the sensors in the stochastic filter model, the sensor characteristics and their performance was investigated in several tests. The tests were performed in different environments either with free satellite visibility or in urban canyons as well as inside of buildings. The tests have shown that it is possible to determine the user's location continuously with the required precision and that the selected sensors provide a good performance and high reliability. Selected tests results and our approach will be presented in the paper.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.45 no.3
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• pp.165-176
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• 2009

The process of berthing/deberthing operations for entering/leaving vessels in Busan northern harbor was analyzed and evaluated by using an integrated VTS(vessel traffic service) system installed in the ship training center of Pukyong National University, Busan, Korea. The integrated VTS system used in this study was consisted of ARPA radar, ECDIS(electronic chart display and information system), backup(recording) system, CCTV(closed-circuit television) camera system, gyro-compass, differential GPS receiver, anemometer, AIS(automatic identification system), VHF(very high frequency) communication system, etc. The network of these systems was designed to communicate with each other automatically and to exchange the critical information about the course, speed, position and intended routes of other traffic vessels in the navigational channel and Busan northern harbor. To evaluate quantitatively the overall dynamic situation such as maneuvering motions for target vessel and its tugboats while in transit to and from the berth structure inside a harbor, all traffic information in Busan northern harbor was automatically acquired, displayed, evaluated and recorded. The results obtained in this study suggest that the real-time tracking information of traffic vessels acquired by using an integrated VTS system can be used as a useful reference data in evaluating and analyzing exactly the dynamic situation such as the collision between ship and berth structure, in the process of berthing/deberthing operations for entering/leaving vessels in the confined waters and harbor.