• Journal of Navigation and Port Research
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• v.37 no.4
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• pp.367-373
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• 2013

Wide area differential GNSS(WA-DGNSS) collects GPS measurements from the several reference stations and estimates 3-D satellite orbit error, satellite clock error, ionospheric delay. These correction messages are broadcasted to user, then user can have more accurate and reliable position estimates. The performance of WA-DGPS can be changed depending on the position of reference stations. To select proper reference stations, performance analysis with the change of reference stations is necessary. In this paper, changing the geographical location of reference stations, we carried out simulation based test and show the performance of WA-DGNSS in Korea.

• Journal of Korean Society of Water Science and Technology
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• v.26 no.6
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• pp.89-97
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• 2018

The purpose of this reaserch is to analyze the charateristics of water quality in space through the operation of ARA River in Artificial Rivers of the Brackish Water Zone. The spatial distribution measured water temperature and salt levels for the surface, middle and deep layers by dividing the four areas of Incheon, Sicheon, Gyeyang and Gimpo. Water temperature did not vary much by water depth and branch, and its purpose is to maintain stable water environment through correlation analysis and operation. To examine the temporal and spatial distribution patterns of the Arachon, we measured DO on the Incheon branch, Sicheon, Gyeyang and Gimpo branch twice a month, and on the surface, the temperature level, The water temperature did not vary much by depth and location, and the water temperature in January and March tended to rise from Incheon to Gimpo, with the average difference of 1.1 degrees during the same period. The salinity difference between Incheon and Gimpo sites was 3.3 psu deep and 5.4 psu deep. In particular, floodgates from July to September are found to be less than 10psu overall, which is considered to be a gas due to the effects of floods and the inflow of Gulpo Stream. D.O. is located in some areas due to summer rains. The hypoxic layer has been identified.Analysis of seasonal data shows that water temperature and DO are strongly correlated in autumn. It was found that the water temperature and salt levels in the fall showed a weak correlation.

• Journal of the Korean Geosynthetics Society
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• v.21 no.3
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• pp.21-27
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• 2022

For carbon neutrality, interest in R&D and infrastructure construction for hydrogen energy, an eco-friendly energy source, is growing worldwide. In particular, for hydrogen stations installed in downtown areas, underground hydrogen infrastructure are being considered to increase a safety distance from hydrogen tank explosions to adjacent structures. In order to design an appropriate location and depth of the underground hydrogen infrastructure, it is necessary to evaluate the impact of the explosion of the underground hydrogen infrastructure on adjacent structures. In this paper, a numerical model was developed to analyze the effect of the underground hydrogen infrastructure explosion on adjacent structures, and the over pressure of the hydrogen tank was evaluated using the equivalent TNT (Trinitrotoluene) model. In addition, parametric analysis was performed to estimate the stability of adjacent structures according to the construction conditions of the underground hydrogen infrastructure.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.3
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• pp.175-183
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• 2021

Purpose : Few studies have examined the relationship between elderly falls and quality of life (QOL) in a large general population. Furthermore, although many studies have investigated the relationships between socio-demographic factors and falls, relatively few studies have evaluated the associations of places and environments with QOL of fall. The purpose of the scheme was to identify the relationship between falls and QOL in a large sample of the elderly. Methods : This study used raw data from the 2013 Korean community health survey. A total of 228,781 people participated in the 2013 study among them 61.552 people were aged 65 or older. Authors also excluded 40 people whose QOL confirmation was unclear. Therefore, final analysis was conducted 61,512 senior citizens. The survey contained questions about the occurrence of falls, number of falls occurring per year, location of occurrence, and cause of falls. QOL was measured using the EQ-5D, an evaluation tool developed by the EuroQol group. Results : The results showed a statistically significantly lower QOL to little fear and full of fear as compared with no fear of falls (p<.05). The number of falls was statistically significantly lower in one, two, and three or more times, than in zero (i.e. no falls)(p<.05). In the falling environments, fall experience, but not related to lighting (p>.05), had a significant lower in QOL compared without the experience (p<.05). Conclusion : This study concluded that there is a strong connection between fall and QOL to the elderly, particularly regarding the number of occurrences, place, and environment. However, we found that an environment (e.g. the lack of lighting) might not affect QOL. It means that when the experts who make an effective tool or intervention may not need to consider indoor and outdoor darkness.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.1
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• pp.867-874
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• 2018

This study aims to develop a sort of expert system to simulate Internet of Things (IoT) service in architectural design alternatives and enhance the simulation performance using building information. The proposed protype system, named iotBIM, visualizes human behaviors and IoT services in a virtual place that is automatically generated from among design alternatives. We use commercial building information modeling (BIM) authoring tool for the development of iotBIM. The decision to develop iotBIM on the BIM platform was made because BIM tools already generate precise 3D models of design alternatives; iotBIM is plugged into the BIM tool as a simulation module. In the midst of the design process, architectural designers can activate iotBIM to investigate and establish IoT services that accord visually with design alternatives. The purpose of this study is to provide a theoretical and technological basis for the ultimate goal of this study.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.3
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• pp.80-96
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• 2024

This study conducted over two rounds Delphi survey targeting experts in the fields of roads, transportation, automobiles, intelligent transport systems(ITS), and communications to analyze the direction of change in road design, operation, and systems in the Lv.4/4+ autonomous driving era. To construct the Delphi survey items, a basic survey was conducted. The first and second Delphi surveys targeted experts in fields closely related to autonomous driving. The results of the survey revealed an expectation that in the future, transportation operations would change focus to shared autonomous vehicle(AV) and public transportation transfers, and there would be corresponding changes in the cross-sectional configuration. Exclusive lanes for AV are expected to be introduced commencing from highways and general national roads, and there was a consensus that they should be installed in the center of the road rather than on the sides and would use the same lane width as that of the existing road. In terms of facilities for AVs, it was found that it would be necessary to expand pedestrian-vehicle separation facilities, insert communication chips into facilities for location recognition, advance precision maps, and expand roadside communication facilities.

• Journal of Veterinary Clinics
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• v.30 no.6
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• pp.482-485
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• 2013

This case report describes the increment of regulatory T cells in thyroid carcinoma of a mixed breed dog compared with normal dogs. A mixed breed dog was referred for a submandibular mass and hyperthermia. Right cervical mass was detected during the physical examination and radiography identified right cervical mass suspected thyroid gland. Accurate location and size of mass was confirmed using computed tomography and 3D reconstructed images. After confirmation of mass, surgical resection was performed and evaluation of regulatory T cells in blood of this patient was performed using flow cytometric assay. The percentage of regulatory T cells was 38.28% of all CD4 (+)/CD25 (+) T cells. This result was higher than median percentage of regulatory T cells of healthy 8 beagles ($7.66{\pm}1.65%$ (p<0.01) of all CD4 (+)/CD25 (+) T cells). And masses were confirmed as giant cell thyroid carcinoma based on histopathologic examination. After surgical resection of cervical mass was performed, the owner didn't want chemotherapy. Seven days later, cervical mass came out again. And CBC showed severe leukocytosis (WBC $47.6{\times}10^3/{\mu}L$) and non-regenerative anemia (PCV 21%). Suspected pulmonic metastasis regions became more severe. Finally the dog died of severe anemia and respiratory disorder.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.9
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• pp.778-786
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• 2012

Sensors that are used on wireless sensor networks can be divided into two types: directional sensors, such as PIR, image, and electromagnetic sensors; and non-directional sensors, such as seismic, acoustic and magnetic sensors. In order to guarantee the line-of-sight of a directional sensor, the installation location of the sensor must be higher than ground level. Among non-directional sensors, seismic sensors should be installed on the ground in order to ensure the maximal performance. As a result, seismic sensors may have network connectivity problems due to communication failure. In this paper, we propose a 3D node deployment method to maximize the coverage and the network connectivity considering the sensor-specific properties. The proposed method is for non-directional sensors to be placed on the ground, while the directional sensor is installed above the ground, using trees or poles, to maximize the coverage. As a result, through the topology that the detection data from non-directional sensors are transmitted to the directional sensor, we can maximize the network connectivity. Simulation results show that our strategy improves sensor coverage and network connectivity.

• Spatial Information Research
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• v.16 no.3
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• pp.279-290
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• 2008

Landslide, one of the serious natural disasters, has Incurred a large loss of human and material resources. Recently, many forecasting or alarm systems based on various kinds of measuring equipment have been developed to reduce the damage of landslide. However, only a few of these equipments are guaranteed to evaluate the safety of whole side of land slope with their accessibility to the slope. In this study, we performed some experiments to evaluate the applicability of a terrestrial LiDAR as a surveying tool to measure the displacement of a land slope surface far a slope collapsing protection system. In the experiments, we had applied a slope stability method to a land slope and then forced to this slope with a load increasing step by step. In each step, we measured the slope surface with both a total station and a terrestrial LiDAR simultaneously. As the result of Slope Fracturing analysis using all targets, the LiDAR system showed that three was 1cm RMSE on X-axis, irregularity errors on Y-axis and few errors on Z-axis compare with Total Station. As the result of Slope Fracturing analysis using continuous targets, the pattern of Slope Fracturing was different according to the location of continuous targets and we could detect a continuous change which couldn't be found using Total station. The accuracy of the LiDAR data was evaluated to be comparable to that of the total station data. We found that a LiDAR system was appropriate to measuring the behaviour of land slope. The LiDAR data can cover the whole surface of the land slope, whereas the total station data are available on a small number of targets. Moreover, we extracted more detail information about the behavior of land slope such as the volume and profile changes using the LiDAR data.

• Imaging Science in Dentistry
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• v.51 no.2
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• pp.117-127
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• 2021

Purpose: The aim of this study was to evaluate the volumetric characteristics of mucous retention cysts(MRCs) in the maxillary sinus and to analyze potential associations of MRCs with dentoalveolar pathologies. Materials and Methods: Cone-beam computed tomography (CBCT) scans exhibiting bilateral maxillary sinuses that were acquired from January 2016 to February 2019 were initially screened. A total of 227 scans(454 sinuses) that fulfilled the inclusion criteria were included. The presence, location, and volumetric characteristics of the diagnosed MRCs were evaluated on CBCT images using the 3D-Slicer software platform. The presence of MRCs was correlated with potential influencing factors including age, sex, and dentoalveolar pathology. For MRCs located on the sinus floor, factors with a potential impact on the volume, surface, and diameter were analyzed. Results: An MRC was present in 130 (28.6%) of the 454 sinuses. Most MRCs were located on the sinus walls and floor. The mean MRC volume, surface, and diameter were 551.21±1368.04 mm³, 228.09±437.56 mm², and 9.63±5.40 mm, respectively. Significantly more sinuses with associated endodontically treated teeth/periapical lesions were diagnosed with an MRC located on the sinus floor. For MRCs located on the sinus floor, endodontic status exhibited a significant association with increased volume, surface, and diameter. Conclusion: Periapical lesions might be a contributing factor associated with the presence and volume of MRCs located on the sinus floor. The 3D-Slicer software platform was found to be a useful tool for clinicians to analyze the size of MRCs before surgical interventions such as sinus floor elevation procedures.