• The Journal of Korean Academy of Prosthodontics
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• v.28 no.2
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• pp.125-146
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• 1990

The relationale for recording mandibular movement is to accurately adjust an articulator. Techniques to record mandibular movement include radiographic interpretation, extraoral tracing, and intraoral recording materials. This study was performed to compare the concylar guidance inclination and Bennett shift(immediate & progressive side shift)obtained by using an electronic pantograph, pantograph and wax interocclusal records in Korean. Ten adults who have normal occlusion and are free of TMJ dysfunction were selected and clutches were constructed. At first Pantronic survey was performed three times by using an kinematic hinge axis according to manufacturer's direction. Next pantographic survey was performed three times and the articulator was adjusted with each pantographic recording. And then maxillary cast was attached to the articulator with pantographic as a face-bow and the mandibular cast was mounted to the articulator with centric relation record. Three protrusive, three left lateral and three right lateral wax interocclusal records were taken on the subjects and the articulator was adjusted with each interocclusal record. Protrusive condylar inclination, lateral condylar inclination, immediate side shift and progressive side shift obtained by using electronic pantograph, pantograph and wax interocclusal record were compared and analized. The results were as follows; 1. The average left and right protrusive and orbiting condylar inclination($33.7^{\circ},\;37.1^{\circ},\;40.6^{\circ},\;43.5^{\circ}$) record with Pantronic was significantly greater than that recorded with other methods. 2. The average left and right protrusive and orbiting condylar inclination($24.8^{\circ},\;27.0^{\circ},\;31.4^{\circ},\;32.4^{\circ}$)recorded with wax interocclusal record was less than that of other methods. 3. The average left and right immediate side shift(0.57mm,0.44mm)recorded with wax interocclusal record was greater than that of other methods and the average left rigtht immmediate side shift(0.30mm,0.41mm)recorded with Pantronic was significantly greater than that recorded with pantograph(0.11mm,0.20mm). 4. The average variance of wax interocclusal was signivicantly higher than that of other methods.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.6
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• pp.769-774
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• 2013

Turbine blades and disc, which are one of the most important rotating parts of a gas turbine engine, are required to have highly efficient performance in order to minimize the total life cycle costs. Owing to these requirements, these components are exposed to severe conditions such as extreme turbine inlet temperatures, high compression ratios, and high speeds. To evaluate the structural integrity of a turbine disc under these conditions, material modeling and finite element analysis techniques are essential; furthermore, shape optimization is necessary for determining the optimal solution. This study aims to generate 2D finite element models of an axisymmetry model and a sector one and to perform thermal-structural coupled-field analysis and contact analysis. Structurally vulnerable areas such as the disc bore and disc-blade interface region are analyzed by a parametric study. Finally, an improved design is provided based on the results, and the necessity of elaborate shape optimization is confirmed.

• Journal of Korea Water Resources Association
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• v.38 no.2
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• pp.97-110
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• 2005

This paper presents a procedure of evaluation of reservoir capacity for additional water storage for dam rehabilitation. One of the techniques on the extension of rainfall has been developed, and the daily stream flows were simulated by the NWS-PC long-term rainfall-runoff model with the input of the extended daily rainfall which was stochastically generated by the nonhomogeneous markov chain model. We peformed a reliability analysis to Guisan dam about the optimal capacity of dam rehabilitation by using performance criteria that Hashimoto et al. (1982) presented. We estimated that the most suitable water level is approximately 155EL.M. suggested that this method can use supplemental methods to estimate optimum dam scale.

• Journal of Korean Society for Geospatial Information Science
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• v.9 no.2 s.18
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• pp.47-54
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• 2001

The aim of this study is to represent the effective method for undertaking cadastral surveying works through analyzing and comparison of the surveying results both Total Station and GPS surveying techniques. in the value of coordinate of land parcels, the surveying results of using Total Station and Real Time Kinematic GPS surveying are compared and anayzed. As a results, each axis X and Y differences are ${\Delta}X=0.02m\;and\;{\Delta}Y=0.02$. Therefore the latter surveying method is available to use for production of numerical casdastral map at a large scale and for field surveying in farmland adjustment area. Furthermore travers surveying is not needed to be done when horizontal position of the boundary of a land parcel is determined by the method of RTK. It is recognized as a effective and efficient method in rapaid, accurate and economical aspects.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.4
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• pp.347-353
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• 2003

Lately, Digital Photogrammetry has been increasingly applied to various hightech industries and becomes one of more interesting focuses of study than ever. Thus, this study aims to develop a Road Horizontal Alignment Information System by means of digital photogrammetry. Data acquired from digital photographic techniques were processed using Delphi, an object oriented programming language to develop a computer aided program, that allows us to build the information on Road Horizontal Alignment(Beginning Point of Curve, Ending Point of Curve, Radius, Intersection Point). The developed program could maximize visualization for better analysis compared with traditional programs because it utilizes many image data. Comparing with data from traditional horizontal alignment extraction programs based on the principle of least square method, the data acquired by Horizontal Alignment Information and kinematic GPS showed out of the developed road information systems the improved accuracy of IP value up to about 2m in the direction of X, Y axes, where the accuracy of curve radius(R) becomes enhanced up to about 2.5 m.

• Journal of The Korean Astronomical Society
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• v.52 no.3
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• pp.57-69
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• 2019

We present an analysis of the chemical abundances and kinematics of six low-mass dwarf stars, previously claimed to be candidate hypervelocity stars (HVSs). We obtained moderate-resolution (R ~ 6000) spectra of these stars to estimate the abundances of several chemical elements (Mg, Si, Ca, Ti, Cr, Fe, and Ni), and derived their space velocities and orbital parameters using proper motions from the Gaia Data Release 2. All six stars are shown to be bound to the Milky Way, and in fact are not even considered high-velocity stars with respect to the Galactic rest frame. Nevertheless, we attempt to characterize their parent Galactic stellar components by simultaneously comparing their element abundance patterns and orbital parameters with those expected from various Galactic stellar components. We find that two of our program stars are typical disk stars. For four stars, even though their kinematic probabilistic membership assignment suggests membership in the Galactic disk, based on their distinct orbital properties and chemical characteristics, we cannot rule out exotic origins as follows. Two stars may be runaway stars from the Galactic disk. One star has possibly been accreted from a disrupted dwarf galaxy or dynamically heated from a birthplace in the Galactic bulge. The last object may be either a runaway disk star or has been dynamically heated. Spectroscopic follow-up observations with higher resolution for these curious objects will provide a better understanding of their origin.

• Journal of People, Plants, and Environment
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• v.24 no.4
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• pp.441-450
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• 2021

Background and objective: The purpose of study is to analyze the three-dimensional (3D) structure by creating a 3D model for green spaces in a park using unmanned aerial vehicle (UAV) images. Methods: After producing a digital surface model (DSM) and a digital terrain model (DTM) using UAV images taken in Mureung Park in Chuncheon-si, we generated a digital tree height model (DHM). In addition, we used the mean shift algorithm to test the classification accuracy, and obtain accurate tree height and volume measures through field survey. Results: Most of the tree species planted in Mureung Park were Pinus koraiensis, followed by Pinus densiflora, and Zelkova serrata, and most of the shrubs planted were Rhododendron yedoense, followed by Buxus microphylla, and Spiraea prunifolia. The average height of trees measured at the site was 7.8 m, and the average height estimated by the model was 7.5 m, showing a difference of about 0.3 m. As a result of the t-test, there was no significant difference between height values of the field survey data and the model. The estimated green coverage and volume of the study site using the UAV were 5,019 m² and 14,897 m³, respectively, and the green coverage and volume measured through the field survey were 6,339 m² and 17,167 m³. It was analyzed that the green coverage showed a difference of about 21% and the volume showed a difference of about 13%. Conclusion: The UAV equipped with RTK (Real-Time Kinematic) and GNSS (Global Navigation Satellite System) modules used in this study could collect information on tree height, green coverage, and volume with relatively high accuracy within a short period of time. This could serve as an alternative to overcome the limitations of time and cost in previous field surveys using remote sensing techniques.

• Clinics in Shoulder and Elbow
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• v.25 no.4
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• pp.265-273
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• 2022

Background: Massive rotator cuff tears (MRCTs) with subscapularis (SSC) tears cause severe shoulder dysfunction. In the present study, the influence of SSC tears on three-dimensional (3D) shoulder kinematics during scapular plane abduction in patients with MRCTs was examined. Methods: This study included 15 patients who were divided into two groups: supraspinatus (SSP) and infraspinatus (ISP) tears with SSC tear (torn SSC group: 10 shoulders) or without SSC tear (intact SSC group: 5 shoulders). Single-plane fluoroscopic images during scapular plane elevation and computed tomography (CT)-derived 3D bone models were matched to the fluoroscopic images using two-dimensional (2D)/3D registration techniques. Changes in 3D kinematic results were compared. Results: The humeral head center at the beginning of arm elevation was significantly higher in the torn SSC group than in the intact SSC group (1.8±3.4 mm vs. -1.1±1.6 mm, p<0.05). In the torn SSC group, the center of the humeral head migrated superiorly, then significantly downward at 60° arm elevation (p<0.05). In the intact SSC group, significant difference was not observed in the superior-inferior translation of the humeral head between the elevation angles. Conclusions: In cases of MRCTs with a torn SSC, the center of the humeral head showed a superior translation at the initial phase of scapular plane abduction followed by inferior translation. These findings indicate the SSC muscle plays an important role in determining the dynamic stability of the glenohumeral joint in a superior-inferior direction in patients with MRCTs.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.3
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• pp.215-228
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• 2023

The State Space Representation (SSR) method provides individual corrections for each Global Navigation Satellite System (GNSS) error components. This method can lead to less bandwidth for transmission and allows selective use of each correction. Precise Point Positioning (PPP) - Real-Time Kinematic (RTK) is one of the carrier-based precise positioning techniques using SSR correction. This technique enables high-precision positioning with a fast convergence time by providing atmospheric correction as well as satellite orbit and clock correction. Currently, the positioning service that supports PPP-RTK technology is the Quazi-Zenith Satellite System Centimeter Level Augmentation System (QZSS CLAS) in Japan. A system that provides correction for each GNSS error component, such as QZSS CLAS, requires monitoring of each error component to provide reliable correction and integrity information to the user. In this study, we conducted an analysis of the performance of residual error bounding for each error component. To assess this performance, we utilized the correction and quality indicators provided by QZSS CLAS. Performance analyses included the range domain, dispersive part, non-dispersive part, and satellite orbit/clock part. The residual root mean square (RMS) of CLAS correction for the range domain approximated 0.0369 m, and the residual RMS for both dispersive and non-dispersive components is around 0.0363 m. It has also been confirmed that the residual errors are properly bounded by the integrity parameters. However, the satellite orbit and clock part have a larger residual of about 0.6508 m, and it was confirmed that this residual was not bounded by the integrity parameters. Users who rely solely on satellite orbit and clock correction, particularly maritime users, thus should exercise caution when utilizing QZSS CLAS.