• Korean Journal of Environment and Ecology
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• v.30 no.2
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• pp.146-154
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• 2016

In this study, understanding the habitats on spot-billed duck that wintering-breed in the korea, which using the GPS-Mobile based Telemtry (WT-200), I tried to take advantage as the basic data of the protection and management of the habitats of the waterbirds of Korea. Study area is Gyeonggi-do Bokhacheon, Chonmichon, Chungcheongnam-do Gokugyochon, Chungcheongbuk-do Byeongcheoncheon, Jeollabuk-do Mangyunggang, which Five rivers and Jeju Island reservoir, I have attached the tracking of the location(WT -200) to the twenty-five spot-billed ducks. among twenty five ducks, twelve ducks moved to overseas countries, the arrival site was China, North Korea, Russia. Moving average distance was 683km, the largest distance was 1,238km. The average northbound starting date was April 26. The average daily movement distance of thirteen ducks remaining in the domestic country is $1.0{\pm}0.89km$, maximum travel distance was 23.8km. The average daily movement distance of wintering prior to average going north dating is a 0.9km, is the largest 14.6km, the breeding season is an average 1.3km, maximum was 14.4km. Spot-billed duck used the rivers in domestic country most frequently, following was rice field, a filed, reservoir. It used the river most frequently during the wintering period, in the breeding season it used paddy paddies most frequently. While wintering, during the day and night's utilization rate was the highest in the river, but utilization rate was incleased on filed, paddy filed at night. During breeding season, daytime and night's utilization rate was the highest but, utilization rate was increased on river and utilization rate was decreased on river. In accordance with time change, spot-billed duck showed different tendency in paddy fields, and they utilized the filed adjacent to rivers mostly.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.4
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• pp.9-21
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• 2008

In this paper, we propose a GNSS-based RF receiver, A high precision localization architecture, and a high sensitivity localization architecture in order to solve the satellite navigation system's problem mentioned above. The GNSS-based RF receiver model should have the structure to simultaneously receive both the conventional GPS and navigation information data of future-usable Galileo. As a result, it is constructed as the multi-band which can receive at the same time Ll band (1575.42MHz) of GPS and El band (1575.42MHz), E5A band (1207.1MHz), and E4B band (1176.45MHz) of Galileo This high precision localization architecture proposes a delay lock loop with the structure of Early_early code, Early_late code, Prompt code, Late_early code, and Late_late code other than Early code, Prompt code, and Late code which a previous delay lock loop structure has. As we suggest the delay lock loop structure of 1/4chips spacing, we successfully deal with the synchronization problem with the C/A code derived from inaccuracy of the signal received from the satellite navigation system. The synchronization problem with the C/A code causes an acquisition delay time problem of the vehicle navigation system and leads to performance reduction of the receiver. In addition, as this high sensitivity localization architecture is designed as an asymmetry structure using 20 correlators, maximizes reception amplification factor, and minimizes noise, it improves a reception rate. Satellite navigation system repeatedly transmits the same C/A code 20 times. Consequently, we propose a structure which can use all of the same C/A code. Since this has an adaptive structure and can limit(offer) the number of the correlator according to the nearby environment, it can reduce unnecessary delay time of the system. With the use of this structure, we can lower the acquisition delay time and guarantee the continuity of tracking.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3A
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• pp.297-307
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• 2010

Recently, maintenance engineering and technology for civil and building structures have begun to draw big attention and actually the number of structures that need to be evaluate on structural safety due to deterioration and performance degradation of structures are rapidly increasing. When stiffness is decreased because of deterioration of structures and member cracks, dynamic characteristics of structures would be changed. And it is important that the damaged areas and extent of the damage are correctly evaluated by analyzing dynamic characteristics from the actual behavior of a structure. In general, typical measurement instruments used for structure monitoring are dynamic instruments. Existing dynamic instruments are not easy to obtain reliable data when the cable connecting measurement sensors and device is long, and have uneconomical for 1 to 1 connection process between each sensor and instrument. Therefore, a method without attaching sensors to measure vibration at a long range is required. The representative applicable non-contact methods to measure the vibration of structures are laser doppler effect, a method using GPS, and image processing technique. The method using laser doppler effect shows relatively high accuracy but uneconomical while the method using GPS requires expensive equipment, and has its signal's own error and limited speed of sampling rate. But the method using image signal is simple and economical, and is proper to get vibration of inaccessible structures and dynamic characteristics. Image signals of camera instead of sensors had been recently used by many researchers. But the existing method, which records a point of a target attached on a structure and then measures vibration using image processing technique, could have relatively the limited objects of measurement. Therefore, this study conducted shaking table test and field load test to verify the validity of the method that can measure multi-point displacement responses of structures using image processing technique.

• Asia pacific journal of information systems
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• v.24 no.3
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• pp.299-323
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• 2014

The reason location based service is drawing attention recently is because smart phones are being supplied increasingly. Smart phone, basically equipped with GPS that can identify location information, has the advantage that it can provide contents and services suitable for the user by identifying user location accurately. Offering such diverse advantages, location based services are increasingly used. In addition, for use of location based services, release of user's personal information and location data is essentially required. Regarding personal information and location data, in addition to IT companies, general companies also are conducting various profitable businesses and sales activities based on personal information, and in particular, personal location data, comprehending high value of use among personal information, are drawing high attentions. Increase in demand of personal information is raising the risk of personal information infringement, and infringements of personal location data also are increasing in frequency and degree. Therefore, infringements of personal information should be minimized through user's action and efforts to reinforce security along with Act on the Protection of Personal Information and Act on the Protection of Location Information. This study aimed to improve the importance of personal information privacy by empirically analyzing the effect of perceived values on the intention to strengthen location information security and continuously use location information for users who received location-based services (LBS) in mobile environments with the privacy calculation model of benefits and risks as a theoretical background. This study regarded situation-based provision, the benefit which users perceived while using location-based services, and the risk related to personal location information, a risk which occurs while using services, as independent variables and investigated the perceived values of the two variables. It also examined whether there were efforts to reduce risks related to personal location information according to the values of location- based services, which consumers perceived through the intention to strengthen security. Furthermore, it presented a study model which intended to investigate the effect of perceived values and intention of strengthening security on the continuous use of location-based services. A survey was conducted for three hundred ten users who had received location-based services via their smartphones to verify study hypotheses. Three hundred four questionnaires except problematic ones were collected. The hypotheses were verified, using a statistical method and a logical basis was presented. An empirical analysis was made on the data collected through the survey with SPSS 12.0 and SmartPLS 2.0 to verify respondents' demographic characteristics, an exploratory factor analysis and the appropriateness of the study model. As a result, it was shown that the users who had received location-based services were significantly influenced by the perceived value of their benefits, but risk related to location information did not have an effect on consumers' perceived values. Even though users perceived the risk related to personal location information while using services, it was viewed that users' perceived value had nothing to do with the use of location-based services. However, it was shown that users significantly responded to the intention of strengthening security in relation to location information risks and tended to use services continuously, strengthening positive efforts for security when their perceived values were high.

• Korean Journal of Environment and Ecology
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• v.30 no.3
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• pp.328-334
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• 2016

This study identified the habitat use pattern and migration distance of spot-billed ducks during winter that occur for breed and wintering. The study was carried out using GPS-mobile phone based Telemetry (WT-300) to provide the research results as basic data for protection and management of the habitats of water birds in Korea. The tracking devices (WT-300) were attached to a total of twenty spot-billed ducks collected from the rivers and reservoirs in Gyeonggi-do Anseongcheon, Chungcheongnam-do Seocheongun, Jeollabuk-do Mangyunggang, Dongjingang, and Jeollanam-do Haenamgun. It was found that spot-billed ducks used rivers most frequently as their habitats (47.3%), followed by rice fields, ocean, inland wetlands, and tidal flats. While spot-billed ducks used rice fields at night time and ocean, inland wetlands, and tidal flatss at day time, they used rivers regardless of time. Change rate of habitat use pattern was highest between 6:00am and 8:00am and between 16:00pm and 18:00pm. The average daily migration distance was $0.75{\pm}0.27km$/2hours and accumulated migration distance was 8.95km. Spot-billed ducks covered the longest migration distance between 6:00am and 8:00am and between 16:00pm and 18:00pm; the distance they moved during the periods from 6:00am to 8:00am and from 16:00pm to 18:00pm was 2km but during the rest of the time, it was less than 1km for equivalent durations. The time when spot-billed ducks covered the longest migration distance also corresponds to the time when they showed the greatest change rate of habitat use pattern.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.6_1
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• pp.447-454
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• 2013

The geolocation accuracy of SAR satellite imagery is affected by orbit and sensor information and external variables such as DEM accuracy and atmospheric delay. To predict geolocation accuracy of KOMPSAT-5 and KOMPSAT-6, this paper uses TerraSAR-X imagery which has similar spec. Simulation data for sensitivity analysis are generated using range equation and doppler equation with several key error sources. As a result of simulation analysis, the effect of sensor information error is larger than orbit information error. Especially, onboard electronic delay needs to be monitored periodically because this error affects geolocation accuracy of slant range direction by 30m. Additionally, DEM accuracy causes geolocation error by 20~30m in mountainous area and atmospheric delay can occur by 5m in response to atmospheric condition and incidence angle.

• Korean Journal of Remote Sensing
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• v.31 no.3
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• pp.215-226
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• 2015

Normally, aero photography using UAV uses about 430 MHz bandwidth radio frequency (RF) modem and navigates and remotely controls through the connection between UAV and ground control system. When using the exhausting method, it has communication range of 1-2 km with frequent cross line and since wireless communication sends information using radio wave as a carrier, it has 10 mW of signal strength limitation which gave restraints on life my distance communication. The purpose of research is to use communication technologies such as long-term evolution (LTE) of smart camera, Bluetooth, Wi-Fi and other communication modules and cameras that can transfer data to design and develop automatic shooting system that acquires images to UAV at the necessary locations. We conclude that the android based UAV filming and communication module system can not only film images with just one smart camera but also connects UAV system and ground control system together and also able to obtain real-time 3D location information and 3D position information using UAV system, GPS, a gyroscope, an accelerometer, and magnetic measuring sensor which will allow us to use real-time position of the UAV and correction work through aerial triangulation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.5
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• pp.527-534
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• 2011

This paper describes an analysis of topographical changes to the Eulsuk-Island at the Nakdong River Estuary using a long-term dataset of high resolution aerial images from 1983 to 2007. Ground control surveying was performed at some feature points using GPS(Global Positioning System) to accomplish AT(Aerial Triangulation) for past aerial images. Even if some still existing feature points appeared on old aerial images were used as GCPs(Ground Control Points) for past aerial images in AT, its accuracy reached at 1m level. Since then, a quantitative analysis of topographical changes was conducted on digital orthophotos produced by a series of aerial images taken by different years. The change volume of total area, construction, vegetation, buildings and roads could be extracted per each period in study area. The total area decreased from 1983 to 1992, but it has not almost changed since 1992. According to the continuous development, the area of vegetation has steadily decreased, while that of buildings and roads has generally increased. The result of this study can provide us with invaluable base data for further topographical change monitoring in Eulsuk-Island and Nakdong River estuary caused by continuous development in this area.

• The Journal of the Korea Contents Association
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• v.13 no.5
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• pp.48-57
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• 2013

Smartphones provide users with environment for communication and sharing information and at the same time play an important role of mobile technology and mobile art development. Smartphone technology-related researches are being accelerated especially with the advent of mobile Augmented Reality(AR) age, but the studies on user participation that is essential for AR content industry were insufficient. In that regard, the assistance from mobile art area that has already developed these characteristics is essential. Thus, this article is to classify mobile art that has not been studied a lot domestically into feature phone usage and smartphone usage and to analyze each example case with the three most used methods. The usage of feature phones which use the sound and images of mobile devices can be divided into three: installation and performing methods, single channel video art method and five senses communication method. On the other hand, the usage of smartphones that use sensors, cameras, GPS and AR can be divided into location-based AR, marker-based AR and markerless AR. Also, as a result of examining mobile AR content utilization technology by industries, combined methods are utilized; tourism and game-related industries use location-based AR, education and medicine-related industries use marker-based AR, and shopping-related industries use markerless AR. The development of AR content industry is expected to be accelerated with mobile art that makes use of combined technology method and constant communication method through active participation of users. The future development direction of mobile AR industry is predicted to have minimized HMD, integration of hologram technology and artificial intelligence and make the most of big data and social network so that we could overcome the technological limitation of AR.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.513-522
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• 2017

Rapid urbanization is being portrayed around the world au causing difficulty to manage public hygiene and maintain public order. Common problems often detected in urban areas including traffic congestion and the deterioration of the ecological environment are also being exacerbated. Despite all the effort being made by the government and local governments to manage urban facilities, urban residents are subjected to various levels of difficulty, due to the number of facilities to be managed exceeding the number of management personnel and the lack of an adequate management system. The aim of this study is to propose a management method using smart phones to improve the maintenance efficiency of urban facilities. First, the one-stop maintenance of urban facilities, including facilities information management, maintenance management and history management, is made possible by using smart phones to collect and transfer pictures and the locations of the urban facilities. Second, maintenance management is based on the location and picture information of the subject, not the location of the smart phones, which enables a prompt understanding of and actions to be taken for the facility. This method is especially effective as the smart phone application sends the facility status information directly to the maintenance personnel. Third, all of the information and figures relating to the facilities is managed using a database, resulting in the easy utilization of the history management and data. Fourth, all of the urban residents have access to this information via smart phone applications and, therefore, expanding the role of the facility maintenance personnel is made possible without any additional investment in infrastructure. Lastly, the location-based information enables the management of roads, trees and trails.