• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.85-90
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• 2017

Indoor location-based services have been developed based on the Internet of Things technologies which measure and analyze users who are moving in their daily lives. These various indoor positioning technologies require separate hardware and have several disadvantages, such as a communication protocol which becomes complicated. Based on the fact that a reduction in signal strength occurs according to the distance due to the physical characteristics of the transmitted signal, RSSI technology that uses the received signal strength of the wireless signal used in this paper measures the strength of the transmitted signal and the intensity of the attenuated received signal and then calculates the distance between a transmitter and a receiver, which requires no separate costs and makes to implement simple measurements. It was applied calculating the value for the average RSSI and the RSSI filtering feedback. Filtering is used to reduce the error of the RSSI values that are measured at long distance.It was confirmed that the RSSI values through the average filtering and the RSSI values measured by setting the coefficient value of the feedback filtering to 0.5 were ranged from -61 dBm to - 52.5 dBm, which shows irregular and high values decrease slightly as much as about -2 dBm to -6 dBm as compared to general measurements.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.3
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• pp.25-33
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• 2023

Purpose : Stabilization exercise and respiratory muscle training are used to train trunk muscles that affect postural control and respiratory function. However, there have been no studies that combine stabilization exercise and respiratory muscle training. The purpose of this study is to investigate effects of stabilization exercise with and without respiratory muscle training on respiratory function and postural sway. Methods : Fifteen healthy adults were recruited for this experiment. All the subjects performed stabilization exercise with and without respiratory muscle training. For stabilization exercise with respiratory muscle training, the subjects sat on a gym ball wearing a stretch sensor. The subjects inspire maximally as long as possible during lifting one foot off the ground, alternately for 30 seconds. The stretch sensor was placed on both anterior superior iliac spine (ASIS), and the stretch sensor was used to monitor inspiration. For stabilization exercise without respiratory muscle training, the subjects sat on a gym ball and lifted one foot off the ground, without respiratory muscle training. Kinovea program used to investigate postural sway tracking during exercise. The maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) were measured using a spirometer to investigate changes of respiratory muscle strength before and after exercise. A paired t-test was used to determine significant differences postural sway tracking, MIP, and MEP between stabilization exercise with and without respiratory muscle training. Results : There were significantly lower a distance of postural sway tracking during stabilization exercise with respiratory muscle training, compared with stabilization exercise without respiratory muscle training (p<.05). The MIP and MEP were significantly increased after stabilization exercise with respiratory muscle training compared with before stabilization exercise with respiratory muscle trianing (p<.05). Conclusion : The results of this study suggest that stabilization exercise with repiratory muscle training would be recommended to improve postural control and respiratory muscle strength.

• Korean Journal of Remote Sensing
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• v.34 no.6_2
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• pp.1299-1310
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• 2018

In this study, we analyzed distribution and movement trends using in-situ observations and particle tracking methods to understand the movement of the drift ice in the Arctic Ocean. The in-situ movement data of the drift ice in the Arctic Ocean used ITP (Ice-Tethered Profiler) provided by NOAA (National Oceanic and Atmospheric Administration) from 2009 to 2018, which was analyzed with the location and speed for each year. Particle tracking simulates the movement of the drift ice using daily current and wind data provided by HYCOM (Hybrid Coordinate Ocean Model) and ECMWF (European Centre for Medium-Range Weather Forecasts, 2009-2017). In order to simulate the movement of the drift ice throughout the Arctic Ocean, ITP data, a field observation data, were used as input to calculate the relationship between the current and wind and follow up the Lagrangian particle tracking. Particle tracking simulations were conducted with two experiments taking into account the effects of current and the combined effects of current and wind, most of which were reproduced in the same way as in-situ observations, given the effects of currents and winds. The movement of the drift ice in the Arctic Ocean was reproduced using a wind-imposed equation, which analyzed the movement of the drift ice in a particular year. In 2010, the Arctic Ocean Index (AOI) was a negative year, with particles clearly moving along the Beaufort Gyre, resulting in relatively large movements in Beaufort Sea. On the other hand, in 2017 AOI was a positive year, with most particles not affected by Gyre, resulting in relatively low speed and distance. Around the pole, the speed of the drift ice is lower in 2017 than 2010. From seasonal characteristics in 2010 and 2017, the movement of the drift ice increase in winter 2010 (0.22 m/s) and decrease to spring 2010 (0.16 m/s). In the case of 2017, the movement is increased in summer (0.22 m/s) and decreased to spring time (0.13 m/s). As a result, the particle tracking method will be appropriate to understand long-term drift ice movement trends by linking them with satellite data in place of limited field observations.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.1
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• pp.37-47
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• 2023

The black cutworm, Agrotis ipsilon (Hufnagel), is an important crop pest worldwide that feeds more than 80 plant species including cabbage, potato, maize, wheat and bean, and this moth is a typical pest attacking underground parts of crops. It has been known in farm booklets that the larvae of A. ipsilon overwinter in the soil in Korea, but no definitive data exist yet. This study was conducted to evaluate that the specific appearance time of A. ipsilon observed actually in the field could be explained when we assumed that this pest overwinters in a form of larvae or pupae. Degree day-based phenology models were applied for tracking forward or backward to find the predicted developmental stage which developed at a specific stage found in the field. As a result of the analysis, it was confirmed that an initial population could be established in a group that does not overwinter as larvae or pupae in Korea. In other words, the appearance of adults in early March to April could not be explained by the presence of domestic overwintering populations. Populations that overwinter as larvae or pupae in Korea were able to emerge as adults in June to July at the earliest. Therefore, the group of adults appearing in early spring is highly likely to be a population that migrated from outside Korea. Taken together, it was estimated that the colony of A. ipsilon in Korea would be formed by a mixture of a migrant population through long-distance migration and a overwintering population.

• Korean Journal of Environment and Ecology
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• v.28 no.6
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• pp.642-649
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• 2014

Mallard (Anas platyrhynchos) is the abundant winter visitor in South Korea. Mallard migrates long distances between Russian Siberia and Korea. This species prefers a rice paddy area as their winter habitat. We captured birds using cannon-net, and attached the GPS-Mobile phone based Telemetry(WT-200) on Seven Mallards in the winter of 2011~2013. We were monitored wintering home-range and movement distance. We analyzed the tracking location data using ArcGIS 9.0 and calculated Kernel Density Estimation (KDE) and Minimum Convex Polygon (MCP). The average home-range in the wintering ground by MCP was $118.8km^2$(SD=70.1, n=7)and the maximum home-rang was $221.8km^2$ and the minimum was $27.7km^2$. Extents of home-range by KDE were $60.0km^2$(KDE 90%), $23.0km^2$(KDE 70%) and $11.6km^2$(KDE 50%). Mallard moved an average of 19.4 km from start site(attach to WT-200 site), maximum moved was 33.2 km and minimum moved was 9.4 km. The average distance of 0.8 km between GPS fixed point(range 0.2~1.6 km), maximum moved was 19.7 km. Mallard moved a very short distance in wintering season and showed a very high water-dependent trends in wintering site.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.2
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• pp.229-236
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• 2016

In this paper, we suggest new technology that can draw characters at a long distance by tracking a hand and analysing the trajectories of hand positions. It's difficult to recognize the shape of a character without discriminating effective strokes from all drawing strokes. We detect end points from input trajectories of a syllable with camera system and localize strokes by using detected end points. Then we classify the patterns of the extracted strokes into eight classes and finally into two categories of stroke that is part of syllable and not. We only draw the strokes that are parts of syllable and can display a character. We can get 88.3% in classification accuracy of stroke patterns and 91.1% in stroke type classification.

• Korean Security Journal
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• no.21
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• pp.155-175
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• 2009

RFID that provide automatic identification by reading a tag attached to material through radio frequency without direct touch has some specification, such as rapid identification, long distance identification and penetration, so it is being used for distribution, transportation and safety by using the frequency of 125KHz, 134KHz, 13.56MHz, 433.92MHz, 900MHz, and 2.45GHz. Also it is one of main part of Ubiquitous that means connecting to net-work any time and any place they want. RFID is expected to be new growth industry worldwide, so Korean government think it as prospective field and promote research project and exhibition business program to linked with industry effectively. RFID could be used for access control of person and vehicle according to section and for personal certify with password. RFID can provide more confident security than magnetic card, so it could be used to prevent forgery of register card, passport and the others. Active RFID could be used for protecting operation service using it's long distance date transmission by application with positioning system. And RFID's identification and tracking function can provide effective visitor management through visitor's register, personal identification, position check and can control visitor's movement in the secure area without their approval. Also RFID can make possible of the efficient management and prevention of loss of carrying equipments and others. RFID could be applied to copying machine to manager and control it's user, copying quantity and It could provide some function such as observation of copy content, access control of user. RFID tag adhered to small storage device prevent carrying out of item using the position tracking function and control carrying-in and carrying-out of material efficiently. magnetic card and smart card have been doing good job in identification and control of person, but RFID can do above functions. RFID is very useful device but we should consider the prevention of privacy during its application.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.1
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• pp.7-14
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• 2013

Presently, there are many different technologies used for position detection. However, as signal-receiving devices operating in different locations must detect the precise position of objects located at long distances, it is essential to know the precise time at which an object's or a user's terminal device sends a signal. For this purpose, the existing time of arrival (ToA) technology is not sufficiently reliable, and the existing time difference of arrival (TDoA) technology is more suitable. If a TDoA-based electric surveillance system and other tracking devices fail to achieve precise time-synchronization between devices with separation distance operation, it is impossible to obtain correct TDoA values from the signals sent by the signal-receiving devices; this failure to obtain the correct values directly affects the location estimation error. For this reason, the technology for achieving precise time synchronization between signal-receiving devices in separation distance operation, among the technologies previously mentioned, is a core technology for detecting TDoA-based locations. In this paper, the accuracy of the proposed time synchronization and the measurement error in the TDoA-based location detection technology is evaluated. The TDoA-based location measurement error is significantly improved when using the proposed method for time-synchronization error reduction.

• KEPCO Journal on Electric Power and Energy
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• v.4 no.2
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• pp.115-123
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• 2018

Various types of robots running on power transmission lines have been developed for the purpose of line patrol monitoring. They usually have complex mechanism to run and avoid obstacles on the power line, but nevertheless did not show satisfactory performance for going over the obstacles. Moreover, they were so heavy that they could not be easily installed on the lines. To compensate these problems, flying robots have been developed and recently, multi-copter drones with flight stability have been used in the electric power industry. The drones could be remotely controlled by human operators to monitor power distribution lines. In the case of transmission line patrol, however, transmission towers are huge and their spans are very long, and thus, it is very difficult for the pilot to control the patrol drones with the naked eye from a long distance away. This means that the risk of a drone crash onto electric power facilities always resides. In addition, there exists another danger of electromagnetic interference with the drones on autopilot waypoint tracking under ultra-high voltage environments. This paper presents a patrol monitoring plan of autopilot drones for power transmission lines and its field tests. First, the magnetic field effect on an autopilot patrol drone is investigated. Then, how to build the flight path to avoid the magnetic interference is proposed and our autopilot drone system is introduced. Finally, the effectiveness of the proposed patrol plan is confirmed through its field test results in the 154 kV, 345 kV and 765 kV transmission lines in Chungcheongnam-do.

• Korean Institute of Interior Design Journal
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• v.23 no.6
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• pp.115-124
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• 2014

This study has carried out scanning tests in order to figure out the features of scanning search by sex of space users, with the result of which the validity of data has been estimated. In this research, the scanning patterns were set up for verifying the typology of scanning paths and then the reason for determining scanning paths and the validity of estimation method were reviewed. Since the observation features depends on sex, the analysis of visual activities for acquiring any information in a space will reveal the intention and purpose of space users. The findings by analyzing the features of scanning pattern by sex which were found at the determination of scanning patterns can be defined as the followings. First, for estimating the process of space-information search, the movement distance at each point of continuative-observation data from the angle of eye-movement has been extracted, on the ground of which the fixation and movement of eye have been defined for the establishment of scanning-cut characteristics. Second, the scanning times were estimated for the extraction of effective observation data that would be used for comparative analysis, which showed that men had more data (3,398.2/64.4%) than women (2,998.2/55.6%). This enables the acknowledgment that the scanning cut of men was relatively less, which indicates that men will acquire more information on space than women in the process of observing any space. Third, men's scanning times (58.0 times/2.02 seconds) were less than those of women (71.9 times/1.39 seconds) while the scanning time of the former was longer than that of the latter, which shows the feature that it takes longer for men than women in scanning while the scanning times of the former is less than those of the latter. Fourth, the observation features can be determined that the combination of this result with the predominance character by sex for a general viewpoint to be employed indicates that while men employ mixed-scanning for observation activities to acquire space-information spending for longer time, women, by concentrated-scanning, focus on a single point for shorter time or stay at one location for a considerably long time for space-information acquirement.