• Journal of Positioning, Navigation, and Timing
• /
• v.4 no.2
• /
• pp.79-85
• /
• 2015

Existing Differential GPS (DGPS) pseudorange correction (PRC) generation techniques based on a virtual reference station cannot effectively assign a weighting factor if the baseline distance between a user and a reference station is not long enough. In this study, a virtual reference station DGPS PRC generation technique was developed based on an enhanced inverse distance weighting method using an exponential function that can maximize a small baseline distance difference due to the dense arrangement of DGPS reference stations in South Korea, and its positioning performance was validated. For the performance verification, the performance of the model developed in this study (EIDW) was compared with those of typical inverse distance weighting (IDW), first- and second-order multiple linear regression analyses (Planar 1 and 2), the model of Abousalem (1996) (Ab_EXP), and the model of Kim (2013) (Kim_EXP). The model developed in the present study had a horizontal accuracy of 53 cm, and the positioning based on the second-order multiple linear regression analysis that showed the highest positioning accuracy among the existing models had a horizontal accuracy of 51 cm, indicating that they have similar levels of performance. Also, when positioning was performed using five reference stations, the horizontal accuracy of the developed model improved by 8 ~ 42% compared to those of the existing models. In particular, the bias was improved by up to 27 cm.

• Journal of Oral Medicine and Pain
• /
• v.24 no.4
• /
• pp.455-466
• /
• 1999

The purpose of this study was to investigate the magnitude of mandibular rotational torque movements in subjects with TMJ sounds, and to analyse correlation between quantitative characteristics of TMJ sounds and mandibular rotational torque movement. Twenty dental college students with TMJ clicking and twenty students without any TMD signs and symptoms were examined by mean of SonoPak and Rotate program of BioPAK system(Bioresearch Inc. MilWaukee, wisconsin, USA) in this study. Mandibular rotational torque movements were recorded and analysed during maximum mouth opening, protrusion, and lateral excursion in frontal and horizontal planes. The obtained results were as follows: 1. On maximum mouth opening, mandibular rotational angle and distance of clicking group were significantly greater than those of control group in frontal plane. (P<0.05). 2. During maximum mouth opening closing, maximum mandibular rotational angle and distance of clicking group were significantly greater than those of control group in frontal plane. (P<0.01). 3. On protrusion, mandibular rotational angle and distance of clickin group were significantly greater than those of control group in horizontal plane. (P<0.05). 4. On lateral excursion, there was no significant difference in mandibular rotational angle and distance between clicking group and control group in frontal and horizontal planes. 5. There were significant correlations between peak amplitude of TMJ sounds and maximum mandibular rotational distance during maximum mouth opening (r=-.481) and mandibular rotational distance on maximum mouth opening (r=-.455) in horizontal plane. 6. There were significant correlations between Above 300/(0-300)Hz ratio of TMJ sounds and mandibular rotational angle (r=-.499) and distance (r=-.457) on maximum mouth opening in frontal plane.

• Korean Journal of Applied Biomechanics
• /
• v.16 no.1
• /
• pp.139-149
• /
• 2006

This study is to analyze the kinematic variables of inward $1{\frac{1}{2}}$ somersault in platform diver. For the manner, 3 people form the national diving team in the year 2000were chosen as the subjects and two S-VHS video cameras set in 60frames/sec were used for recording their motions. Coordinated raw positions data through digitizing are smoothing by butter-worth's low-pass filterin method at a cut off frequency 6.0Hz. and the direct linear transformation(DLT) method was employed to obtain 3-D position coordinates. The conclusions were as follows. However, horizontal distance which is the change of the COG, form the point of the jump to the point of Event 3 where the player is out of the board range completely, Subject B showed 105.1cm and 71.1cm of the vertical distance which are shorter horizontal distance and higher vertical distance, thus, took a great advantage of the position to prepare for the entry. Therefore, if a player takes higher position by speeding up the vertical velocity at the moment of the jumping off the board, and stays in the air longer, the player can have more time to show his skill. Because of the use of the characteristics of the inward somersault, keeping the safe distance form the board is important but in order to higher the completeness, it is ideal to keep the horizontal distance little over 100cm. Also, the angles of shoulder and elbow from Event 1 to 4, depending on swing of the arms, motions in the air, getting ready for the entry, showed some difference individual by individual, according to the velocity of the thigh and shank showed much difference while getting ready and take-off, and it's because of the individual's different bending and straightening for horizontal and vertical distance.

• Journal of Oral Medicine and Pain
• /
• v.21 no.1
• /
• pp.55-65
• /
• 1996

This study was performed to investigate the effects of head posture and occlusal splint on the vertical dimension in mandibular rest position and swallowing. Thirty health dental students ware selected lot this study and BioEGNⓡ(Bioresearch Inc., USA) was used for measuring interocclusal distance during rest - swallowing - rest - tapping movement. This swallowing movements were observed in both normal head posture(NHP) and forward head posture (FHP). Thickness of occlusal splint was about 2mm at posterior molar area and even tooth contact were achieved on light biting. The four mandibular positions at which interocclusal distance measured were swallowing position, after swallowing position in which interocclusal distance was maximum, rest position follows swallowing, and tapping position after rest. Changes of distance in each position were measured for three mandibular planes, that is, sagittal, frontal, and horizontal plane, respectively. The results obtained were as follows : 1. In normal head posture, the mandible was raised 1.03mm without splint, and 0.77mm with splint on swallowing, and there was no significant difference between the two. In horizontal plane, however, mandible was displaced more anteriorly in both swallowing position and tapping position with splint. 2. In forward head posture, the mandible was less raised with splint on swallowing, but features in horizontal plane were almost same as those in normal head posture. 3. In natural dentition, significant difference between NHP and FHP were observed in horizontal plane trajectory for swallowing and tapping position. But the difference for same positions were observed in frontal trajectory with splint. 4. Total amount of mandibular movement of two groups classified with sagittal interocclusal distance of swallowing position generally showed significant difference between the higher and the lower height group in head posture without splint. 5. Correlationship among total amount of mandibular movement for three mandibular planes were observed between sagittal plane and horizontal plane, and between sagittal plane and frontal plane in head posture without splint.

• Journal of Korean Ophthalmic Optics Society
• /
• v.6 no.2
• /
• pp.155-160
• /
• 2001

To investigate the subjective refractive error with Von Graefe test. Maddox Rod test and polarizing lens test of Horizontal Heterophoria Measurement at distance on normal 109 subjects aged from 18 to 30 years old. The results were as follows: 1. Using Von Graefe Horizontal Heterophoria Measurement, they were measured 15% for orthophoria, 65% for exophoria and 20% for esophoria at distance. 2. Using Maddox Rod Horizontal Heterophoria Measurement, they were measured 14% for orthophoria, 57% for exophoria and 29% for esophoria at distance. 3. Using polarizing lens test of Horizontal Heterophoria Measurement, they were measured 15% for orthophoria, 72% for exophoria and 13% for esophoria at distance. 4. Each test average were $1.32{\Delta}BI$ for Von Graefe test, $0.88{\Delta}BI$ for Maddox Rod test and $1.76{\Delta}BI$ for polarizing lens test. 5. Patient's preference distribution were 44% for Von Graefe test, 28% for Maddox Rod test and 28% for polarizing lens test.

• Physical Therapy Korea
• /
• v.23 no.3
• /
• pp.68-75
• /
• 2016

Background: Shoulder horizontal adduction (HA) is performed in many activities of daily living. The limited range of motion (LROM) of HA is affected by the tightness of the posterior deltoid, infraspinatus, teres major, and posterior capsule of glenohumeral joint. The LROM of shoulder HA contributes to excessive scapular abduction. Objects: The aim of this study is to compare the scapular abduction distance and three-dimensional displacement of the scapula during shoulder horizontal adduction between subjects with and without the LROM of shoulder HA. Methods: 24 subjects (12 people in LROM group and 12 people in normal ROM group) participated. Subjects with less than $115^{\circ}$ of HA ROM were included in LROM group. Shoulder HA was performed 3 times for measuring scapular abduction distance and three-dimensional displacement of the scapula. Tape measure was used for measuring scapular abduction distance. Scapular abduction distance was normalized by dividing the scapular size. Polhemus Liberty was used for measuring the three-dimensional displacement of the scapula. Results: Normalized scapular abduction distance was significantly greater in LROM group than normal ROM group (p<.001). Three-dimensional displacement of the scapula during shoulder HA was greater in LROM group than normal ROM group (p<.05). Conclusion: LROM group had a greater scapular abduction and three-dimensional displacement of the scapula during shoulder HA compared to normal ROM group.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2004.05b
• /
• pp.474-478
• /
• 2004

Based on the recent laboratory experiments (Kim et al. 2004), comparisons of caisson sliding distance are made between the computations and experiments. The time history model of wave force, which is proposed by Tanimoto et al. (1996), is modified in the standing wave part of horizontal and uplift wave forces because of the overestimation of the time history model. The comparison between experimental and computational sliding distance has showed that the caisson tilting increases the resistant force to the horizontal sliding. Therefore, a titling resistant force, which is caused by caisson tilting, is introduced into computation of sliding distance.

• The Journal of Korean Academy of Prosthodontics
• /
• v.22 no.1
• /
• pp.72-78
• /
• 1984

The notion that the axis of the shaft of the articulator must coincide the patient's mandibular transverse axis tells us the importance of locating the axis precisely. When using kinematic axis to transfer a cast to an articulator, the anatomic asymmetry of the contralateral points will result in certain distortion when the axis transferred to an articulator where the mechanical axis produces symmetry. In this study, after locating the true hinge axis point with Denar hinge axis locator, the discrepancies between true hinge axis point and arbitrary hinge axis point that was 13mm anterior from the posterior margin of center of trangus to the outer canthus of eye were measured. And the discrepancies between left and right true hinge axis point in the superoinferior and anteroposterior directions were measured. For this study, 20 dental students who have no missing teeth and no difficulties of mandibular movement were selected. Upper and lower cast of subjects were mounted on Denar Mark II articulator uisng Denar Slidematic face-bow and centric relation record for the measurement of discrepancies between left and right true hinge axis points. The results obtained as follows. 1. The mean distance from the arbitrary hinge axis point to the true hinge axis point was as follows. Right: horizontal distance; 1.99mm, vertical distance; 2.12mm, linear distance; 3.36 mm. Left: horizontal distance; 1.39mm, vertical distance; 2.06mm, linear distance; 2.09mm. Total: horizontal distance; 1.69mm, vertical distance; 2.09mm linear distance; 3.06 mm. 2. The 87.5% of true hinge axis points were within 5mm of the arbitrary hinge axis point. 3. The mean discrepancies between the right and left hinge axis point were 2.92mm in superoinferior direction and 4.74mm in anteroposterior direction. 4. When transferring the axis to the articulator, anatomic asymmetry between right: and left axis point produces in dislocation of cast on the articulator, and undesirable shift in esthetic tooth position will be resulted.

• Journal of the Korean Society of Safety
• /
• v.24 no.2
• /
• pp.83-88
• /
• 2009

The objective of this paper was to evaluate the effectiveness of horizontal, vertical, asymmetric and coupling multipliers for manual material handling. Lifting tasks with 5 different horizontal distances ($30{\sim}70cm$) for 6 vertical distances(ankle, knee, waist, elbow, shoulder and head height) were experimented. The muscle activity and muscle exertion level during asymmetric load handling(without trunk flexion) was experimented. Lifting tasks with and without handle tote box for three postures(straight, bending, right angle posture) were experimented. The degrading tendency did not appeared almost in $60{\sim}70cm$ interval's horizontal distance. As a result of ANOVA, MVC paid attention to horizontal and vertical distance but cross effect was insignificant(p<0.01). The change of the MVC according to the horizontal, vertical distance appeared similar from of RWL. The results of normalized MVC measurement were decreased about 16%, 24%, 34% respectively as the asymmetry angle was $30^{\circ}$, $60^{\circ}$, $90^{\circ}$. RMS EMG values of right erector spinae muscles were decreased as the work posture went to $90^{\circ}$ and those of left erector spinae muscles were increased until the asymmetry angle was $40^{\circ}$ but decreased continually over $40^{\circ}$. 7 subjects, activities of left and right latissimus dorsi muscles were maintained constantly, while for remainer, those were irregular. MVC reduced maximum 23% by type of handle. MVC was highest in straight posture, but was lowest in right angle posture. As a result of ANOVA, MVC paid attention to posture, coupling(p<0.01). To all handle types, biceps brachii activity was increased in right angle posture, but reduced in straight posture. Based on the results of this study, it is suggested that the NIOSH guideline should not be directly applied to Korean without reasonable reexamination. In addition, we need to afterward study through an age classification.

• The Journal of Korean Academy of Prosthodontics
• /
• v.24 no.1
• /
• pp.17-26
• /
• 1986

The purpose of this study was to investigate true hinge axis location with different times (8:00-9:00 A.M.,2:00-3:00 P.M.) and with experienced and inexperienced groups. 25 subjects, 23-27 years of age , with functionally acceptable occlusion, and no clinical signs of temporomandibular joint dysfunction were participated in this study. In this study arbitrary hinge axis point was located 13 mm anterior to the posterior margin of the tragus on a line from the center of the tragus to the outer canthus of the eye and then the true hinge axis point was located with T.M.J. hinge axis locator. The discrepancies of distance and the direction between true hinge axis point and arbitrary hinge axis point were studied according to times and two groups. The results obtained were as follows : 1. The mean distance from arbitrary hinge axis point to the true hinge axis point on the right and left sides was as follows : Experienced group: linear distance: $1.228{\pm}3.145mm$, vertical distance: $-1.128{\pm}2.515mm$, horizontal distance: $-0.484{\pm}1.806mm$. Inexperience group: linear distance: $1.628{\pm}3.158mm$, vertical distance: $-1.169{\pm}2.090mm$, horizontal distance: $-1.133{\pm}2.367mm$. Horizontal distance between experienced and inexperienced groups was significant statistically. (P<0.1) 2. True hinge axis points located within 5 mm of arbitrary hinge axis point were 86.7% in the experienced group and 84% in the inexperienced group. 3. For experienced operator A with time, the mean distance from arbitrary hinge axis point to true hinge axis point was as follows: Horizontal distance: AM: $-0.613{\pm}1.966mm$, PM: $-0.860{\pm}2.156mm$. Vertical distance: AM: $-0.886{\pm}2.518mm$, PM : $-1.226{\pm}2.660mm$. True hinge axis points had tendency to be located posterior-inferiorly to tragus-canthus line in the afternoon than in the morning, but there was not significant statistically. (P>0.1)