• 대한의용생체공학회:의공학회지
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• 제38권1호
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• pp.32-42
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• 2017

The aim of this study was to evaluate driving performance of Healthy and disabled groups (with or without driver's license) to control steering wheel by using steering assistive devices in the driving simulator. The persons with partial loss of use of all four limbs have problems in operation of the motor vehicle because of functional loss to operate steering wheel. Therefore, if steering assistive devices for grasping the steering wheel are used to control the vehicle on the road in persons with disabilities, the disabled persons can improve mobility in their community life by driving a motor vehicle safely. Ten healthy subjects (with or w/o driver's license) and ten subjects with physical disabilities (with or w/o driver's license) were involved in this study to evaluate driving performance to operate steering wheel by using four types of steering assistive devices (Single-pin, V-grip, Palm-grip, Tri-pin) in driving simulator. STISim Drive 3 software was used to test the steering performance in four scenarios: straight road at low and high speed of vehicle (40 km/h and 80 km/h), curved road at low and high speed of vehicle (40 km/h and 80 km/h). This study used two-way ANOVA in order to compare the effects of two factors (type of steering assistive device and subject group) in the three dependent variables of driving performance (the lateral position of vehicle, standard deviation of lateral position representing the variation of the left and right movement of the vehicle and the number of line crossing). The mean values of the three dependent variables (lateral position, standard deviation of lateral position, the number of line crossing) of steering performance were statistically significantly smaller for the healthy or disabled groups with driver's license than the other groups without driver's license on the curved road at high speed of vehicle compared to low speed of vehicle.

• Imaging Science in Dentistry
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• 제37권1호
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• pp.15-18
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• 2007

Purpose : Disc and condylar position were observed on MRIs of temporomandibular joint disorder patients and condylar position agreement between MRI and tranascranal radiography was evaluated. Materials and Methods MRI and transcranial radiographs of both TM joints from 67 patients with temporemandibular disorder were used. On MRI, the position and shape of disc and condylar position as anterior, middle, posterior was evaluated at medial, center, and lateral views. On transcranial radiographs, condylar position was evaluated using the shortest distance from condyle to fossa in anterior, superior, and posterior directions. Results. 1. On MRI, 96 joints (71.6%) of 134 had anterior disc dispalcement with reduction and 38 joints (28.4%) without reduction. 2. Fourteen (14.6%) of 96 reducible joints showed anterior condylar position, 19 (19.8%) showed central position, 63 joints (65.6%) showed posterior position. Two joints (5.3%) of 38 non-reducible joints showed anterior condylar position, while 9 (23.7%) showed central position, and 27 (71.1%)-posterior position. 3. In 85 joints (63.4%) of 134, the transcranial condylar position agreed with that of the central MRI view, 10 joints (7.5%) with that of medial, 16 joints (11.9%) with that of lateral, and 23 joints (17.2%) disagreed with that of MRI. Conclusion : On MRT, most oi the reducible and non-reducible joints showed posterior condylar position. Transcranial radiographs taken with machine designed for TMJ had better agreement of condylar position with that of MRI. Extremely narrow joint spaces or very posterior condylar positions observed on transcranial radiographs had a little more than fifty percent agreement with those of MRIs.

• Geomechanics and Engineering
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• 제8권4호
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• pp.523-540
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• 2015

Based on limit equilibrium principles, this study presents a theoretical derivation of a new analytical formulation for estimating magnitude and lateral earth pressure distribution on a retaining wall subjected to seismic loads. The proposed solution accounts for failure wedge inclination, unit weight and friction angle of backfill soil, wall roughness, and horizontal and vertical seismic ground accelerations. The current analysis predicts a nonlinear lateral earth pressure variation along the wall with and without seismic loads. A parametric study is conducted to examine the influence of various parameters on lateral earth pressure distribution. Findings reveal that lateral earth pressure increases with the increase of horizontal ground acceleration while it decreases with the increase of vertical ground acceleration. Compared to classical theory, the position of resultant lateral earth force is located at a higher distance from wall base which in turn has a direct impact on wall stability and economy. A numerical example is presented to illustrate the computations of lateral earth pressure distribution based on the suggested analytical method.

• 대한간호학회지
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• 제33권4호
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• pp.488-494
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• 2003

Purpose. To examine the effects of body position and time after feeding on gastric residuals in low birth weight infants(LBW). Methods. A repeated measures design was conducted. Twenty LBW infants being fed via indwelling nasogastric tubes were randomly assigned to one of 5 different position orderings. In each position, gastric residuals were measured at 30, 60, 90, 120, 150, and 180 minutes after feeding. Results. In comparisons of gastric residuals with position and time, the main effects of position and time were statistically significant (F=5.038, p=0.001; F=429.763, p < 0.001, respectively), but the interaction between position and time was found not to be significant. In pairwise comparisons, the gastric residuals were more reduced in the right anterior oblique and prone positions compared with the left lateral position (p < 0.05) and the differences across time periods were significant (p < 0.001). Conclusions. The body position after feeding has a significant affect on gastric residuals over time in LBW infants. The right anterior oblique or prone position is recommended rather than left lateral position after feeding. Knowledge of the proper position and the pattern of gastric emptying over time after feeding may lead to the development of evidence-based nursing care.

• 대한정형도수물리치료학회지
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• 제15권1호
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• pp.58-63
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• 2009

Purpose: The purpose of this study is to figure out that the scapular stability exercise on unstable position can effect on the pain relief of the patient with lateral epicondylitis. Methods: The subject was 35 year old male, diagnosed as lateral epicondylitis. This patient was controled to do scapular stability exercise with crawling position on unstable surface, changing elbow movement from flexion to extension for 4 weeks, 5 times a week, 20 times in total. We used VAS to find the degree of pain and Cozen's test, Mill's test and Resisted middle finger test were determined for the measurement of epicondylitis changed. Results: The following is the result of this study. 1. Pain on lateral epicondylitis was relived from VAS 7 to VAS 0. 2. There were improvements that the results of tests for epicondylitis, Cozen's test, Mill's test and Resisted middle finger test, changed positive into negative signs. Conclusion: The result of this study indicates that the application scapular stability exercise on the unstable surface to the patient with lateral epicondylitis can relief the pain degree on the lateral epicondylitis and be used as one of lateral epicondylitis treatments.

• 국제물리치료학회지
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• 제3권2호
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• pp.464-468
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• 2012

The objective of this study is to provide basic information on coupled motions in thoracic spine during lateral bending from a neutral position for football and baseball players as well as for general university students. In the experiment, a total of 30 subjects participated(football players: 10, baseball players: 10, general students: 10). All subjects were in their 20's. The subjects sat on a chair with lumbar support in a neutral position and bent to the right. As a result, for baseball players, coupled motions were observed in the opposite direction of the lateral bending in all parts of thoracic spine. For both football players and general students, coupled motions were observed in the same direction. These results confirmed that unilateral movements like baseball could affect coupled motions.

• 한국산업융합학회 논문집
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• 제26권2_2호
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• pp.359-370
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• 2023

For a vehicle to follow a reference path accurately, its position must be estimated accurately and reliably. In this paper, we propose a lateral control algorithm for autonomous navigation of a vehicle via USAT(Ultrasonic Satellite System), which is an absolute position measurement system using an ultrasonic wave and INS(Inertial Navigation System) integration. In order to estimate the vehicle's parameters, a J-turn test is used. And the autonomous navigation performances of proposed lateral control algorithm and validity of proposed lateral control algorithm are verified and evaluated by simulation and experiments.

• Imaging Science in Dentistry
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• 제47권3호
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• pp.181-187
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• 2017

Purpose: The purpose of this study was to measure the buccal bone thickness and angulation of the maxillary incisors and to analyze the correlation between these parameters and the root position in the alveolar bone using cone-beam computed tomography (CBCT). Materials and Methods: CBCT images of 398 maxillary central and lateral incisors from 199 patients were retrospectively reviewed. The root position in the alveolar bone was classified as buccal, middle, or palatal, and the buccal type was further classified into subtypes I, II, and III. In addition, the buccolingual inclination of the tooth and buccal bone thickness were evaluated. Results: A majority of the maxillary incisors were positioned more buccally within the alveolar bone, and only 2 lateral incisors(0.5%) were positioned more palatally. The angulation of buccal subtype III was the greatest and that of the middle type was the lowest. Most of the maxillary incisors exhibited a thin facial bone wall, and the lateral incisors had a significantly thinner buccal bone than the central incisors. The buccal bone of buccal subtypes II and III was significantly thinner than that of buccal subtype I. Conclusion: A majority of the maxillary incisor roots were positioned close to the buccal cortical plate and had a thin buccal bone wall. Significant relationships were observed between the root position in the alveolar bone, the angulation of the tooth in the alveolar bone, and buccal bone thickness. CBCT analyses of the buccal bone and sagittal root position are recommended for the selection of the appropriate treatment approach.

• 제어로봇시스템학회논문지
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• 제13권9호
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• pp.875-882
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• 2007

In order for a vehicle to follow a predetermined trajectory accurately, its position must be estimated accurately and reliably. In this thesis, we propose trajectory tracking control methods for unmanned vehicle and a positioning system using ultrasonic wave. The positioning problem is an important part of control problem for unmanned navigation of a vehicle. Dead Reckoning is widely used for positioning of vehicle. However this method has problems because it accumulates estimation errors. We propose a new method to increase the accuracy of position estimation using the Ultrasonic Satellite System (USAT). It is shown that we will be able to estimate the position of vehicle precisely, in which errors are not accumulated. And proposed trajectory tracking control methods include both a new path planning method and a lateral control method for vehicle. The experimental results show that the proposed methods enables exact vehicle trajectory tracking even under various environmental factors.

• 드라이브 ㆍ 컨트롤
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• 제17권4호
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• pp.72-79
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• 2020

To ensure the safety of Advanced Driver Assistance Systems (ADAS) or autonomous vehicles, it is important to recognize the vehicle position, and specifically, the increased accuracy of the lateral position of the vehicle is required. In recent years, the quality of GPS signals has improved a lot and the price has decreased significantly, but extreme urban environments such as tunnels still pose a critical challenge. In this study, we proposed stable and precise lane recognition and tracking methods to solve these two issues via fusion of AVM images and vehicle sensor data using an extended Kalman filter. In addition, the vehicle's lateral position recognition and the abnormal state of RTK GPS were determined using this approach. The proposed method was validated via actual vehicle experiments in urban areas reporting multipath and signal disconnections.