• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.4
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• pp.45-54
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• 2004

In this paper, a view point tracking system has been realized for outdoor augmented reality including broad area monitoring. Since the surroundings of the moving view point are changing, it is necessary to track the position and observation moment of the view point system for consistency between real and virtual images. For this reason, the GPS(Global Positioning System) is applied to the realized system for tracking the information on position and direction of the moving system. In addition, an optical position tracking system that is able to track view point in a limited area is used, because the local tracking system has to trace the image variation, seen to the observer in a moving vehicle, at a particular position and time. It was found that the realized outdoor augmented reality system, which combined the virtual information tracked in real time with the real image, can be very practical in various application area.

• Atmosphere
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• v.19 no.2
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• pp.213-226
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• 2009

In order to investigate the characteristics of Changma over the Korean peninsula, KEOP-2007 IOP (Intensive Observing Period) was conducted from 15 June 2007 to 15 July 2007. KEOP-2007 IOP is high spatial and temporal radiosonde observations (RAOB) which consisted of three special stations (Munsan, Haenam, and Ieodo) from National Institute of Meteorological Research, five operational stations (Sokcho, Baengnyeongdo, Pohang, Heuksando, and Gosan) from Korea Meteorological Administration (KMA), and two operational stations (Osan and Gwangju) from Korean Air Force (KAF) using four different types of radiosonde sensors. The error statistics of the sensor of radiosonde were investigated using quality control check. The minimum and maximum error frequency appears at the sensor of RS92-SGP and RS1524L respectively. The error frequency of DFM-06 tends to increase below 200 hPa but RS80-15L and RS1524L show vice versa. Especially, the error frequency of RS1524L tends to increase rapidly over 200 hPa. Systematic biases of radiosonde show warm biases in case of temperature and dry biases in case of relative humidity compared with ECMWF (European Center for Medium-Range Weather Forecast) analysis data and precipitable water vapor from GPS. The maximum and minimum values of systematic bias appear at the sensor of DFM-06 and RS92-SGP in case of temperature and RS80-15L and DFM-06 in case of relative humidity. The systematic warm and dry biases at all sensors tend to increase during daytime than nighttime because air temperature around sensor increases from the solar heating during daytime. Systematic biases of radiosonde are affected by the sensor type and the height of the sun but random errors are more correlated with the moisture conditions at each observation station.

• Korean Journal of Environmental Biology
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• v.38 no.3
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• pp.424-432
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• 2020

The present study aimed to analyze the metaproteome of the microbial community comprising harmful algal bloom (HAB) in the Daechung reservoir, Korea. HAB samples located at GPS coordinates of 36°29'N latitude and 127°28'E longitude were harvested in October 2013. Microscopic observation of the HAB samples revealed red signals that were presumably caused by the autofluorescence of chlorophyll and phycocyanin in viable cyanobacteria. Metaproteomic analysis was performed by a gelbased shotgun proteomic method. Protein identification was conducted through a two-step analysis including a forward search strategy (FSS) (random search with the National Center for Biotechnology Information (NCBI), Cyanobase, and Phytozome), and a subsequent reverse search strategy (RSS) (additional Cyanobase search with a decoy database). The total number of proteins identified by the two-step analysis (FSS and RSS) was 1.8-fold higher than that by one-step analysis (FSS only). A total of 194 proteins were assigned to 12 cyanobacterial species (99 mol%) and one green algae species (1 mol%). Among the species identified, the toxic microcystin-producing Microcystis aeruginosa NIES-843 (62.3%) species was the most dominant. The largest functional category was proteins belonging to the energy category (39%), followed by metabolism (15%), and translation (12%). This study will be a good reference for monitoring ecological variations at the meta-protein level of aquatic microalgae for understanding HAB.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.8
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• pp.1080-1088
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• 2018

General methods of controlling a drone are divided into manual control and automatic control, which means a drone moves along the route. In case of manual control, a man should be able to figure out the location and status of a drone and have a controller to control it remotely. When people control a drone, they collect information about the location and position of a drone with the eyes and have its internal information such as the battery voltage and atmospheric pressure delivered through telemetry. They make a decision about the movement of a drone based on the gathered information and control it with a radio device. The automatic control method of a drone finding its route itself is not much different from manual control by man. The information about the position of a drone is collected with the gyro and accelerator sensor, and the internal information is delivered to the CPU digitally. The location information of a drone is collected with GPS, atmospheric pressure sensors, camera sensors, and ultrasound sensors. This paper presents an investigation into drone control by a remote computer. Instead of using the automatic control function of a drone, this approach involves a computer observing a drone, determining its movement based on the observation results, and controlling it with a radio device. The computer with a Depth camera collects information, makes a decision, and controls a drone in a similar way to human beings, which makes it applicable to various fields. Its usability is enhanced further since it can control common commercial drones instead of specially manufactured drones for swarm flight. It can also be used to prevent drones clashing each other, control access to a drone, and control drones with no permit.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.5
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• pp.106-121
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• 2008

In this paper, we proposed and designed the protocol for energy efficiency and the center of data aiming at the design of a Multi Location Awareness System that recognizes a shadow site in parking and tunnel, which stands on the basis of CSS(Chirp Spread Spectrum) method using ISM Band of IEEE 802.15.4a that aware close location with wireless RF only. As a result of the protocol measurement, it displays the observation errors of less than 15cm, the data error rate of less than 5%, and can implement the Multi Location Awareness System with maximum length of life for 13.5 days using battery of 3V(1500 mAh).

• Geophysics and Geophysical Exploration
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• v.19 no.4
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• pp.228-235
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• 2016

We investigated pre- and post- seismic total electron content (TEC) anomalies in ionosphere caused by recent large-scale earthquakes around the globe and additionally examined whether the similar phenomena are detected in connection with the earthquakes around the Korean Penisula. TEC anomalies associated with the large-scale earthquakes showed the similar results to previous studies. In addition, we newly found the similar TEC changes from the recent 2016 Ecuador earthquake (M7.8). However, the post-seismic TEC changes would be falsely interpreted as the pre-seismic TEC changes dependent on the post-processing of TEC observation. We also investigated the possibility of TEC responses from the recent domestic earthquakes including 2016 Gyeongju earthquake but could not find any anomalous TEC changes. This is probably because the domestic earthquakes release significantly smaller acoustic wave energy than that of large-scale earthquakes occurring in plate boundaries.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.3
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• pp.429-435
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• 2019

The drifters of the Global Drifter Program were deployed in the northern East Sea for two years from March 2015 to compare and validate currents estimated from sea-level measurements with the SARAL/AltiKa altimetry satellite mission, specially designed to accurately measure sea level in the near-coastal area. The collocated (less than 20 km apart) directly measured current from GPS locations every 30 minutes and the currents normal to the satellite tracks show a similar correlation in the area shallower than 200 m depth as the open ocean and it makes it possible to investigate the time variations of the current along the coast in the northern East sea, where direct observations of current are scarce. The Liman Current along the Siberian coast is found to be southward all year round, but the North Korean Cold Current flows southward only in the summer. The North Korean Cold Current south of the Musudan cape mostly flows to the south, but the current direction depends on the presence of an eddy around the coast of Musudan cape.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.8
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• pp.549-557
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• 2019

In this paper, we focus on the real-time detection method of a seismic ionospheric disturbance using Global Navigation Satellite System (GNSS) signal. First, the monitor for the detection of the seismic ionospheric disturbance is studied based on the estimated ionospheric delay using the GNSS signals. And then, the threshold for the automatic detection is computed. Moreover, to discriminate the seismic ionospheric disturbance against the other ionospheric anomalies due to other error sources such as cycle slips, the signatures of the ionospheric perturbation caused by the seismic wave is investigated. Based on the observation, the detection strategy is proposed. Using GPS observations collected from the 47 permanent stations in South Korea and Japan, the proposed real-time detection method is evaluated.

• Journal of Korean Society of Forest Science
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• v.108 no.3
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• pp.382-391
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• 2019

This study was conducted to verify whether smartphone hiking apps, which generate social network data including location information, are useful tools for analyzing the use characteristics of a forest recreation area. For this purpose, the study identified the functions and service characteristics of smartphone hiking apps. Also, the use characteristics of the area of Daegwallyoung were analyzed, compared with the results of the field survey, and the applicability of hiking apps was reviewed. As a result, the service types of hiking apps were analyzed in terms of three categories: "information offering," "hiking record," and "information sharing." This study focused on an app that is one of the "hiking record" types with the greatest number of users. Analysis of the data from hiking apps and a field survey in the Daegwallyoung area showed that both hiking apps and the field survey can be used to identify the movement patterns, but hiking apps based on a global positioning system (GPS) are more efficient and objective tools for understanding the use patterns in a forest recreation area, as well as for extracting user-generated photos. Second, although it is advantageous to analyze the patterns objectively through the walking-speed data generated, field surveys and observation are needed as complements for understanding the types of activities in each space. The hiking apps are based on cellphone use and are specific to "hiking" use, so user bias can limit the usefulness of the data. It is significant that this research shows the applicability of hiking apps for analyzing the use patterns of forest recreation areas through the location-based social network data of app users who record their hiking information voluntarily.

• Korean Journal of Environment and Ecology
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• v.34 no.1
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• pp.9-17
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• 2020

Domestic cats (Felis catus) introduced to insular environments can be invasive predators that often threaten endemic species and cause biodiversity loss or local extinction on the island. This study was conducted from March to July 2018 to understand the population size, home range, and spatial use of cats introduced to Mara Islet (N 33° 07', E 126° 16') in Jeju Special Governing Province, the Republic of Korea. Observation records based on their natural marks revealed that there were 20 adult cats on Mara Islet. A capture-recapture method also estimated 20 adult individuals (95% confidence interval: 20-24 individuals). According to our telemetry study on ten adults deployed with GPS-based telemetry units, the home range size was 12.05±6.99 ha (95% KDE: kernel density estimation), and the core habitat size was 1.60±0.77 ha (50% KDE). There were no significant differences in the home range and core habitat sizes by sex. The home range of domestic cats overlapped with the human residential area, where they might secure easy foods. Five of ten tracked cats were active at potential breeding colonies for the Crested Murrlet (Synthliboramphus wumizusume), and six approached potential breeding areas of the Styan's Grasshopper Warbler (Locustella pleskei), suggesting the predation risk of the two endangered species by cats. This study provides novel information on the population size and home range of introduced cats on Mara Islet which is an important stopover site of migratory birds as well as a breeding habitat of the two endangered avian species. Reducing the potential negative impacts of the introduced cats on migratory birds and the endangered species on Mara Islet requires monitoring of the predation rate of birds by cats, the population trends of cats and endangered breeding birds as well as the effective cat population control and management.