• Physical Therapy Korea
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• v.19 no.4
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• pp.55-60
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• 2012

The trochanteric prominence angle test (TPAT) has been used to measure the femoral anteversion angle between the tibial crest and the vertical line. However, the exact anatomical reference of the tibial crest has not yet been identified in the literature. Thus, the purposes of this research were twofold: first, to compare the femoral anteversion angle measured at three different anatomical references of the tibial crest (the proximal tibial crest, the proximal third of tibial crest, and the proximal half of tibial crest) and, second, to determine inter-and intra-rater reliabilities of the femoral anteversion angle measured at these three different anatomical references of the tibial crest during the TPAT. We recruited 14 healthy subjects, and a total of 28 legs were examined. The TPAT was measured using a digital inclinometer. A 1-way repeated-measure analysis of variance was used to compare the femoral anteversion angle measured at three different anatomical references of the tibial crest, and intraclass correlation coefficients (ICCs) were calculated to determine reliability. The femoral anteversion angle measured at the proximal tibial crest was significantly higher than that at the proximal third of the tibial crest and the proximal half of the tibial crest. The inter-and intra-rater reliabilities of femoral anteversion angle were measured at three anatomic references of the tibial crest were all found to be high during the TPAT (ICC=.9 0~.98). In conclusion, clinicians should recognize that the different degrees of the femoral anteversion angle could be measured when different anatomical references of the tibial crest were used, and that reliabilities were high when an exact anatomical reference of the tibial crest was used during the TPAT.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.5 no.2
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• pp.73-84
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• 2007

This study aims to examine changes from differences in the lumbar scoliosis angle and iliac crest height due to abnormal and habitual posture shown in unilateral weight load at standing posture and suggest data for preventing and treating lumbago. The subjects of this study are 16 lumbago patients between twenties and forties with chronic lumbago over six months, but without neurological symptoms. As a result of photographing front and back with three conditions such as weight load on both sides and left or right unilateral weight load posture in order to examine changes of lumbar scoliosis and iliac crest according to changes of posture at unilateral weight load, while scoliosis angle and iliac crest height by habitual unilateral support were increased, those by opposite support were decreased. In conclusion, it was found that habitual unilateral weight load may cause continuous distortion of spinal angle and change of iliac crest height and these may be a factor of lumbago. Therefore, if habitual unilateral weight load state is kept continuously, distortion of lumbar angle and iliac crest height may be greater and common efforts to change habitual unilateral weight load are needed.

• Journal of Korean Neurosurgical Society
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• v.66 no.6
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• pp.703-715
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• 2023

Objective : This retrospective study investigated the factors that affect cage obliquity angle despite orthogonal maneuvers performed during oblique lateral interbody fusion (OLIF) and assessed the relationship between cage obliquity angle and radiological outcomes post-surgery. Methods : Twenty-nine males who underwent L4-L5 OLIF for lumbar degenerative disease between 2019 and 2021 with a followup duration greater than 12 months were analyzed. Radiological parameters were measured including psoas muscle volume, total psoas area index (total psoas muscle area [cm²]/height squared [m²]), distance from the iliac artery to the origin of the psoas muscle (DIAPM), angle between the origin of the psoas muscle and the center of the vertebral disc (APCVD), iliac crest height, disc height, lumbar flexibility (lumbar flexion angle minus extension angle), cage location ratio, cage-induced segmental lumbar lordosis (LL) (postoperative index level segmental LL minus used cage angle), foraminal height changes, fusion grade. Results : DIAPM, APCVD, iliac crest height, postoperative index level segmental LL, and cage-induced segmental LL were significantly correlated with OLIF cage obliquity angle. However, other radiological parameters did not correlate with cage obliquity. Based on multiple regression analysis, the predictive equation for the OLIF cage obliquity angle was 13.062-0.318×DIAPM+0.325×1APCVD+0.174×iliac crest height. The greater the cage obliquity, the smaller the segmental LL compared to the cage angle used. Conclusion : At the L4-L5 level, OLIF cage obliquity was affected by DIAPM, APCVD, and iliac crest height, and as the cage obliquity angle increases, LL agnle achievable by the used cage could not be obtained.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.2
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• pp.274-282
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• 2007

Statement of problem: Main consideration was given to the stresses at the site of implant entry into the cortical bone at the alveolar crest. As a suspectible factor affecting the occurrence of stress concentrations, the contact angle between the implant and the alveolar crest bone was addressed. Purpose: The purpose of this study is to evaluate angles between the alveolar crest bone and the implant effect on the implant crestal area induced stresses using a finite element method. Material and methods: Cylindrically shaped, standard size ITI implants entering into alveolar crest with four different contact angles of 0, 15, 30, and 45 deg. with the long axis of the implant were axisymmetrically modelled. Alterations of stresses around the implants were computed and compared at the cervical cortical bone. Results and conclusion: The results demonstrated that regardless of the difference of the implant/alveolar crest bone contact angles, stress concentration occurred at the cervical bone and the angle differences led to insignificant variations in stress level.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2006.03a
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• pp.351-357
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• 2006

In this study, quantitative sensitivity analysis on rockfill material influencing the dam crest displacement of Concrete-Faced Rockfill Dam(CFRD) subjected to earthquake loading was carried out. The purpose of this study is to indicate the most important input parameter and to show the quantitative variation of displacement at the crest of CFR type dam during earthquake loading with this input parameter. From the sensitivity analysis, it was found that the crest displacement of CFR type dam subjected to dynamic loading was absolutely affected by the shear modulus of rockfill material and the effect of friction angle of it was negligible. This relative difference of sensitivity was more outstanding in case of crest settlement than in case of crest horizontal displacement. Also, it was found that the extent of effect of shear modulus on the displacement at the crest of CFRD due to dynamic loading decreased as maximum amplitude of input acceleration increased.

• Geomechanics and Engineering
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• v.13 no.4
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• pp.701-714
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• 2017

The effect of nearby cohesionless sloping ground on the uplift capacity of horizontal strip plate anchor embedded in sand deposit with horizontal ground surface has been studied numerically. The numerical analysis has been carried out by using the lower bound theorem of limit analysis with finite elements and linear optimization. The results have been presented in the form of non-dimensional uplift capacity factor of anchor plate by changing its distance from the slope crest for different slope angles, embedment ratios and angles of soil internal friction. It has been found that the decrease in horizontal distance between the edge of the anchor plate and the slope crest causes a continuous decrease in uplift capacity of anchor plate. The optimum distance is that distance between slope crest and anchor plate below which uplift capacity of an anchor plate has been found to decrease with a decrease in normalized crest distance from the anchor plate in presence of nearby sloping ground. The normalized optimum distance between the slope crest and the anchor plate has been found to increase with an increase in slope angle, embedment ratio and soil internal friction angle.

• The korean journal of orthodontics
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• v.48 no.6
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• pp.349-356
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• 2018

Objective: This study was performed to investigate the alveolar bone of lower incisors in skeletal Class III adults of different vertical facial patterns and to compare it with that of Class I adults using cone-beam computed tomography (CBCT) images. Methods: CBCT images of 90 skeletal Class III and 29 Class I patients were evaluated. Class III subjects were divided by mandibular plane angle: high (SN-MP > $38.0^{\circ}$), normal ($30.0^{\circ}$ < SN-MP < $37.0^{\circ}$), and low (SN-MP < $28.0^{\circ}$) groups. Buccolingual alveolar bone thickness was measured using CBCT images of mandibular incisors at alveolar crest and 3, 6, and 9 mm apical levels. Linear mixed model, Bonferroni post-hoc test, and Pearson correlation analysis were used for statistical significance. Results: Buccolingual alveolar bone in Class III high, normal and low angle subjects was not significantly different at alveolar crest and 3 mm apical level while lingual bone was thicker at 6 and 9 mm apical levels than on buccal side. Class III high angle group had thinner alveolar bone at all levels except at buccal alveolar crest and 9 mm apical level on lingual side compared to the Class I group. Class III high angle group showed thinner alveolar bone than the Class III normal or low angle groups in most regions. Mandibular plane angle showed negative correlations with mandibular anterior alveolar bone thickness. Conclusions: Skeletal Class III subjects with high mandibular plane angles showed thinner mandibular alveolar bone in most areas compared to normal or low angle subjects. Mandibular plane angle was negatively correlated with buccolingual alveolar bone thickness.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.2
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• pp.154-163
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• 2009

Incident wave angles are conventionally estimated by the directional spectrum analysis of wave data collected from in-situ sensors. The in-situ measurements are limited in monitoring incident wave angles in the wide surf zone, since the techniques are typically expensive, labor-intensive, and point-measuring. In this study, estimation of incident wave angles using wave crest features captured in digital video imagery is proposed to observe incident wave directions over the surf zone. Line signatures of wave crests having high image pixel intensities are extracted by moving an interrogation window to identify high intensity pixels in sequential video images. Wave angles are computed by taking the first derivative of the extracted crest signatures, i.e. local slope of the crest signatures in the two-dimensional physical plane. Compared to the wave angle estimates obtained by the directional spectrum analysis, video-based wave angle estimates show good agreements in general.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.312-315
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• 2002

This paper summarizes the results of a numerical study conducted to analyze the effect of selected process parameters on material flow and thread profile in thread rolling of large diameter blanks. Based on the previous work where a plane strain mode was found to provide a reasonable approximation of the thread rolling process, the effect of varying thread form, friction factor, flow stress, and blank diameter on effective strain and thread height was analyzed using the finite element code DEFORM. This study show that effective strain for flank angle, that blank diameter had important effect on the as-rolled thread while flow stress, friction factor, and crest round of dies had significant impact on effective strain at the thread root and crest and load of thread rolling. While the rate of strain harding was found to have an effect on the crest profile, the results indicate that it is the primary factor responsible for seam formation in rolled threads.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.553-556
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• 2008

A Magneto Plasma Sail(MPS) produces propulsive force by the interaction between the solar wind and an artificial magnetic field inflated by injecting plasma. Using a 2D hybrid PIC code, we evaluate the inflation of magnetic field when Argon(Ar) plasma with different ${\beta}_{in}$ including the value less than one is injected into the dipolar magnetic field generated by a superconducting coil. It is found that the magnetic field can be inflated by injecting plasma within an angle of $30^{\circ}$ in the polar direction and the magnetic field decays in the polar direction according to $B{\propto}r^{-2.4}$ after the plasma(${\beta}_{in}$=0.1) is injected.