• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2010.04a
• /
• pp.317-319
• /
• 2010

VRS는 현재 여러가지 토목공사에 이용되고 있으나 지하공사와 연계하는데는 아직 어려운 문제이다. 본 연구에서는 터널공사에 VRS를 통합하여 TBM 안내시스템을 TBM감시시스템으로 업데이트하도록 소프트웨어의 활용성을 높이고자 하였다. 여기서 개발된 TBM감시시스템은 설계경로와의 편차는 물론 여러가지 다른 측면들을 제공할 수 있을 것이다.

• 한국IT서비스학회:학술대회논문집
• /
• 2009.11a
• /
• pp.409-412
• /
• 2009

고객과 접하는 통화수단으로 VRS의 필요성이 대두되고 있다. 기존 ARS를 통해 서비스를 하고 있는 사업체의 경우 VRS는 또하나의 새로운 시스템 도입이라는 점과 기존 고객에게 접근하는데 있어서 큰 변화를 느끼지 않으면서 보다 쉽고, 편리하게 다가 갈 수 있어야 한다는 점에서 고민을 안겨준다. 본 논문에서는 기존 ARS 시스템을 이용하여 쉽게 VRS를 적용할 수 있는 방법을 제시하고, 향후 VRS의 발전방향을 제시한다.

• Radiation Oncology Journal
• /
• v.31 no.2
• /
• pp.81-87
• /
• 2013

Purpose: To describe chronic rectal mucosal damage after pelvic radiotherapy (RT) for cervical cancer and correlate these findings with clinical symptoms and radiation dose. Materials and Methods: Thirty-two patients who underwent pelvic RT were diagnosed with radiation-induced proctitis based on endoscopy findings. The median follow-up period was 35 months after external beam radiotherapy (EBRT) and intracavitary radiotherapy (ICR). The Vienna Rectoscopy Score (VRS) was used to describe the endoscopic findings and compared to the European Organization for Research and Treatment of Cancer (EORTC)/Radiation Therapy Oncology Group (RTOG) morbidity score and the dosimetric parameters of RT (the ratio of rectal dose calculated at the rectal point [RP] to the prescribed dose, biologically effective dose [BED] at the RP in the ICR and EBRT plans, ${\alpha}/{\beta}$ = 3). Results: Rectal symptoms were noted in 28 patients (rectal bleeding in 21 patients, bowel habit changes in 6, mucosal stools in 1), and 4 patients had no symptoms. Endoscopic findings included telangiectasia in 18 patients, congested mucosa in 20, ulceration in 5, and stricture in 1. The RP ratio, $BED_{ICR}$, $BED_{ICR+EBRT}$ was significantly associated with the VRS (RP ratio, median 76.5%; $BED_{ICR}$, median 37.1 $Gy_3$; $BED_{ICR+EBRT}$, median 102.5 $Gy_3$; p < 0.001). The VRS was significantly associated with the EORTC/RTOG score (p = 0.038). Conclusion: The most prevalent endoscopic findings of RT-induced proctitis were telangiectasia and congested mucosa. The VRS was significantly associated with the EORTC/RTOG score and RP radiation dose.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.29 no.3
• /
• pp.221-228
• /
• 2011

For service-area-widening and commercialization of DGNSS service, Ministry of Land, Transport and Maritime Affairs is developing a DGNSS service based on VRS using T-DMB. In this study, three PRC generation algorithms are developed for VRS DGNSS and their accuracies were evaluated. Three DGNSS correction generation algorithms are based on inverse distance weighting, 1st- and 2nd- multiple linear regression, and their positioning accuracies were compared in terms of the number of reference stations used for network composition and the algorithm type. As a result, the positioning accuracy of the case of using 16 sites is better than that of 6 sites. And the algorithm using the multiple linear regression showed the best performance. When the positioning accuracy of VRS DGNSS was compared with the traditional single-reference DGNSS, the improvement ratio was 20-23% and 20-36% for the horizontal and vertical directions, respectively.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.30 no.6_1
• /
• pp.575-581
• /
• 2012

In general, various modeling and estimation techniques have been proposed to extract the tropospheric and ionospheric delays from the GPS CORS. In this study, Kalman filter approach is adopted to estimate the tropospheric and ionospheric delays and the proper modeling for the state vector and the variance-covariance matrix for the process noises are performed. The coordinates of reference stations and the zenith wet delays are estimated with the assumption of random walk stochastic process. Also, the first-order Gauss-Markov stochastic process is applied to compute the ionospheric effects. For the evaluation of the proposed modeling technique, Kalman filter algorithm is implemented and the numerical test is performed with the CORS data. The results show that the atmospheric effects can be estimated successfully and, as a consequence, can be used for the generation of VRS data.

• Journal of Korean Society for Geospatial Information Science
• /
• v.18 no.4
• /
• pp.87-92
• /
• 2010

With recent localized heavy rain, the collapsing accident of the cut slopes occur repeatedly every year. The maintenance of the cut slopes is very crucial as the collapsing of cut slopes causes various calamities such as human causalities and sweeping away of the roads. By looking at the study of current situation of the cut slopes, designed for maintenance of cut slopes, the locations of the damaged districts are hard to figure out as they are represented through distance mark and longitude and latitude. In this paper has used NDGPS methods and VRS service through GPS signal corrections that are received by DGPS standard department to correctly analyze the exact location and the shape of the slope. The result of this analysis shows that both methods produce similar shape of the slope. Therefore, these two methods, NDGPS methods and VRS service, can be applied to other analysis of cut slopes in different areas.

• Journal of The Korean Society of Integrative Medicine
• /
• v.7 no.1
• /
• pp.1-8
• /
• 2019

Purpose : The purpose of this study was to examine the correlation between static and dynamic balance according to the virtual reality-based squat and conventional squat exercise. Methods : Twenty four participants were randomly assigned to the virtual reality-based squat (VRS) group (n=12) or conventional squat (CS) group (n=12). The static balance (C90 area, C90 angle, trace length, sway average velocity) and dynamic balance (forward, rearward, leftward, rightward) were measured using a force plate by BT4. The VRS group used the virtual reality system during 4 weeks, while the CS group underwent classical squat training. Independent t-test was used to test the homogeneity of the general characteristics of the subjects. The collected data was analyzed using the paired t-test for static and dynamic balance comparisons before and after exercise in both groups and Pearson's test for the correlation between static and dynamic balance according to the measured time. The significance level was set to 0.05. Results : There was no significant correlation between group and static and dynamic balance related variables (p>.05). There was a significant correlation between measurement time and static and dynamic balance related variables (p<.05). According to the measurement time, the static balance parameter C90 area in the VRS group after exercise was significantly decreased (p<.05). The values of forward, leftward and rightward in the VRS group were significantly increased after exercise (p<.05). Conclusion : It is suggested that 20 normal healthy adult men and women who have normal balance ability can improve their ability to control their posture by improving the balance ability when applying virtual reality-based squat exercise.

• Journal of the Society of Disaster Information
• /
• v.12 no.2
• /
• pp.122-129
• /
• 2016

In this study, a dual structured pipe for a preventive monitoring on a accident damage, a smartphone app program for a survey and a construction data collection and a server program for a real-time monitoring were developed. A pilot system was installed in the test field to analyze effects of a system developed in this study. The data for a damage prevention was detected by the attached sensors on the pipe. Exclusion was tested by the pressure sensors to be installed at regular intervals. The app and server programs was enabled to the real-time data collection and real-time monitoring linked by VRS survey equipments and a smartphone.

• Journal of Digital Convergence
• /
• v.11 no.5
• /
• pp.119-133
• /
• 2013

This study aims to provide power generating plants with eco-efficiency information. To implement the purposes, of study, both DEA(Data, Envelopment Analysis) model and interview were incorporated in terms of methodologies. To analyze the managerial efficiency, total labor cost and number of employees were considered as input factors. CO2, NOx, and water also were considered as input factors to analyze eco-efficiency. Both annual total power product and annual total revenue were used as output factors. CRS(Constant Return to Scale) and VRS(Variable Return to) model were facilitated in this analysis. According to the findings, most of the power plants were evaluated as 'Efficient'' taking into consideration of average value, both 0.928 from CCR model and 0.969 from VRS model. 7 DMUs including DMU3 and DMU12 are efficient out of 35 DMUs relatively, other DMUs are inefficient. For results of inefficient output factors distribution, it was found that inefficiency for NOx was marked relatively higher than CO2. In order to improve the eco-efficiency in the power plants in the long term, the target amount of Co2 as well as NOx reduction needs to be properly proposed in consideration of particularity of power plants. In the long run, renewable energy, alternative fuels should be adapted to reduce the eco-inefficient.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.29 no.2
• /
• pp.201-208
• /
• 2011

With the increase in the number of smartphone users, precise 3D positional information is required by various applications. The positioning accuracy using civilian single-frequency pseudoranges is at the level of 10 m or so, but most applications these days are asking for a sub-meter level Therefore, instead of an absolute positioning technique, the VRS-based differential approach is applied along with the correction of the double-differenced (DD) residual errors using FKP (Flachen-Korrektur-Parameter). The VRS (Virual Reference Station) is located close to the rover, and the measurements are generated by correcting the geometrical distance to those of the master reference station. Since the unmodeled errors are generally proportional to the length of the baselines, the correction parameters are estimated by fitting a plane to the DD pseudorange errors of the CORS network. The DD positioning accuracy using 24 hours of C/A code measurements provides the RMS errors of 37 cm, 28 cm for latitudinal and longitudinal direction, respectively, and 76 cm for height. The accuracy of the horizontal components is within ${\pm}0.5m$ for about 90% of total epochs, and in particular the biases are significantly decreased to the level of 2-3 cm due to the network-based error modeling. Consequently, it is possible to consistently achieve a sub-meter level accuracy from the single-frequency pseudoranges using the VRS and double-differenced error modeling.