• Title/Summary/Keyword: normal curvature

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Fingernail Configuration

  • Jung, Jin Woo;Kim, Kwang Seog;Shin, Jun Ho;Kwon, Yu Jin;Hwang, Jae Ha;Lee, Sam Yong
    • Archives of Plastic Surgery
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    • v.42 no.6
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    • pp.753-760
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    • 2015
  • Background A number of conditions can alter a person's fingernail configuration. The ratio between fingernail width and length (W/L) is an important aesthetic criterion, and some underlying diseases can alter the size of the fingernail. Fingernail curvature can be altered by systemic disorders or disorders of the fingernail itself. Although the shape and curvature of the fingernail can provide diagnostic clues for various diseases, few studies have precisely characterized normal fingernail configuration. Methods We measured the W/L ratio of the fingernail, transverse fingernail curvature, hand length, hand breadth, and distal interphalangeal joint width in 300 volunteers with healthy fingernails. We also investigated whether age, sex, height, and handedness influenced the fingernail W/L ratio and transverse fingernail curvature. Results In women, fingernail W/L ratios were similar across all five fingers, and were lower than those in men. The highest value of transverse fingernail curvature was found in the thumb, followed by the index, middle, ring, and little fingers. Handedness and aging influenced transverse fingernail curvature, but not the fingernail W/L ratio. Fingernails were flatter on the dominant hand than on the non-dominant hand. The radius of transverse fingernail curvature increased with age, indicating that fingernails tended to flatten with age. Conclusions Our quantitative data on fingernail configuration can be used as a reference range for diagnosing various diseases and deformities of the fingernail, and for performing reconstructive or aesthetic fingernail surgery.

A Study on Cervical Curvature and Thermography in Some Neck Pain Patients (경항통 환자의 경추 만곡도와 체표열에 대한 연구)

  • Yang, Jae-Sun;Lee, Sang-Gyu;Lee, Chong-woo;Yeom, Seung-Ryong;Kwon, Young-Dal;Lee, Soo-Kyung;Song, Yong-Sun
    • Journal of Korean Medicine Rehabilitation
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    • v.15 no.2
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    • pp.105-105
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    • 2005
  • Objectives : The purpose of this study was to investigate the correlation between cervical spine curvature and thermography on neck pain patients. Methods : The cervical spine curvature was assessed on lateral view of plain radiograph by three measurements(Depth of cervical curve, Method of Jochumsen, Angle of cervical curve), then the neck pain patients were divided into straight curvature group(Straight group), normal curvature group(Control I), and no neck pain group(Control II) was selected by random sampling. I measured temperature of the both side Pungji(風池, G20), Kyonjong(肩井, G21), Chonjong(天宗, SI11) by thermography examination on Experimental group(Straight group) and control group(Control I, II), then analyzed the temperature statically with student's t-test, ANOVA. Results : The temperature of six point on Straigt group was lower than that of Control I, but had no significant difference(p>0.05). The temperature of six point on Straigt group was lower than that of Control II. The descent of temperature on Lt. Pungji(風池, G20), Lt. Kyonjong(肩井, G21), Rt. Chonjong(天宗, SI11) had significance(p<0.05). There is no corelation between onset period and mean temperature of six points. Conclusions : Thermography represnets the presence of neck pain, but has no correlation with straight of cervical curvature.

Shape Design Sensitivity Analysis using Isogeometric Approach (CAD 형상을 활용한 설계 민감도 해석)

  • Ha, Seung-Hyun;Cho, Seon-Ho
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.577-582
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    • 2007
  • A variational formulation for plane elasticity problems is derived based on an isogeometric approach. The isogeometric analysis is an emerging methodology such that the basis functions in analysis domain arc generated directly from NURBS (Non-Uniform Rational B-Splines) geometry. Thus. the solution space can be represented in terms of the same functions to represent the geometry. The coefficients of basis functions or the control variables play the role of degrees-of-freedom. Furthermore, due to h-. p-, and k-refinement schemes, the high order geometric features can be described exactly and easily without tedious re-meshing process. The isogeometric sensitivity analysis method enables us to analyze arbitrarily shaped structures without re-meshing. Also, it provides a precise construction method of finite element model to exactly represent geometry using B-spline base functions in CAD geometric modeling. To obtain precise shape sensitivity, the normal and curvature of boundary should be taken into account in the shape sensitivity expressions. However, in conventional finite element methods, the normal information is inaccurate and the curvature is generally missing due to the use of linear interpolation functions. A continuum-based adjoint sensitivity analysis method using the isogeometric approach is derived for the plane elasticity problems. The conventional shape optimization using the finite element method has some difficulties in the parameterization of boundary. In isogeometric analysis, however, the geometric properties arc already embedded in the B-spline shape functions and control points. The perturbation of control points in isogeometric analysis automatically results in shape changes. Using the conventional finite clement method, the inter-element continuity of the design space is not guaranteed so that the normal vector and curvature arc not accurate enough. On tile other hand, in isogeometric analysis, these values arc continuous over the whole design space so that accurate shape sensitivity can be obtained. Through numerical examples, the developed isogeometric sensitivity analysis method is verified to show excellent agreement with finite difference sensitivity.

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Noise reduction method using mean curvature diffusion (평균곡률 확산을 이용한 잡음감소 기법)

  • Ye Chul-Soo;Chung Hun-Suk;Kim Seong-Jong;Hyun Deuk-Chang
    • 한국컴퓨터산업교육학회:학술대회논문집
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    • 2003.11a
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    • pp.87-94
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    • 2003
  • Anisotropic diffusion is a selective smoothing technique that promotes smoothing within a region instead of smoothing across boundaries. In anisotropic diffusion, the rate of smoothing is controlled by the local value of the diffusion coefficient chosen to be a function of the local image gradient magnitude. El-Fallah and Gary E. Ford represented the image as a surface and proved that setting the inhomogeneous diffusion coefficient equal to the inverse of the magnitude of the surface normal results in surface evolving speed that is proportional to the mean curvature of the image surface. This model has the advantage of having the mean curvature diffusion (MCD) render invariant magnitude, thereby preserving structure and locality. In this paper, the proposed MCD model efficiently reduces diffusion coefficient at the thin edges using the smoothness of the surface.

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TIME ANALYTICITY FOR THE HEAT EQUATION UNDER BAKRY-ÉMERY RICCI CURVATURE CONDITION

  • Ling Wu
    • Bulletin of the Korean Mathematical Society
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    • v.60 no.6
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    • pp.1673-1685
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    • 2023
  • Inspired by Hongjie Dong and Qi S. Zhang's article [3], we find that the analyticity in time for a smooth solution of the heat equation with exponential quadratic growth in the space variable can be extended to any complete noncompact Riemannian manifolds with Bakry-Émery Ricci curvature bounded below and the potential function being of at most quadratic growth. Therefore, our result holds on all gradient Ricci solitons. As a corollary, we give a necessary and sufficient condition on the solvability of the backward heat equation in a class of functions with the similar growth condition. In addition, we also consider the solution in certain Lp spaces with p ∈ [2, +∞) and prove its analyticity with respect to time.

SEMI-INVARIANT SUBMANIFOLDS OF CODIMENSION 3 IN A COMPLEX SPACE FORM WITH 𝜉-PARALLEL STRUCTURE JACOBI OPERATOR

  • U-Hang KI;Hyunjung SONG
    • East Asian mathematical journal
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    • v.40 no.1
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    • pp.1-23
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    • 2024
  • Let M be a semi-invariant submanifold of codimension 3 with almost contact metric structure (𝜙, 𝜉, 𝜂, g) in a complex space form Mn+1(c). We denote by A, K and L the second fundamental forms with respect to the unit normal vector C, D and E respectively, where C is the distinguished normal vector, and by R𝜉 = R(𝜉, ·)𝜉 the structure Jacobi operator. Suppose that the third fundamental form t satisfies dt(X, Y) = 2𝜃g(𝜙X, Y) for a scalar 𝜃(≠ 2c) and any vector fields X and Y , and at the same time R𝜉K = KR𝜉 and ∇𝜙𝜉𝜉R𝜉 = 0. In this paper, we prove that if it satisfies ∇𝜉R𝜉 = 0 on M, then M is a real hypersurface of type (A) in Mn(c) provided that the scalar curvature $\bar{r}$ of M holds $\bar{r}-2(n-1)c{\leq}0$.

A STUDY OF WORKING EFFICIENCY AND FILE DEFORMATION OF GT ROTARY FILE IN CURVED CANALS (GT rotary file을 이용한 만곡 근관형성시 작업 효율 및 file 변형 발생에 관한 연구)

  • 신주희;백승호;배광식;임성삼;윤수한;김병현
    • Restorative Dentistry and Endodontics
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    • v.26 no.5
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    • pp.418-435
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    • 2001
  • Root canal preparation process is of utmost importance in successful treatment of root canal. Also, one of the most important purpose of the root canal preparation is to enlarge the root canal three dimensionally without changing the curvature of the root canal However as the curvature of the root canal increases, there are many difficulties involved in formation of optimum root canal. Therefore in order to solve the above mentioned problems, new developments in methods of root canal preparation and equipments for such purposes were made. Recently, vigorous studies about newly introduced engine-driven nickel-ti-tanium rotary file are conducted. As shown in research results to dates, it is well established that the use of nickel-titanium file is better suited for curved root canal than stainless steel file in maintaining the curvature or root canal and reducing the deformation of root canal. However it is also acknowledged that there are a few discrepancies in research results according to protocol, due to failure to remove variables in experiments. In addition, although it is recommended by the manufacturer that the GT rotary file should maintain a low rotational speed of 150~350rpm and 'light pressure' as light as not to break the lead of a pencil, academic studies about the vertical force which is not yet standardized are not sufficiently explored. Therefore, this research devised and utilized a special research equipment to standardize the appropriate range of vertical force for GT rotary file through experiments by breaking of the lead of a pencil as expressed by the manufacturer and to accurately measure factors involved through repeating and recreating the environment of root canal preparation. Forming nine experimental groups by varying the vertical forces (150g. 220g, 300g) and rpm (150rpm, 250rpm, 350rpm), the effects of changing vertical forces and rpm on working efficiency were measured in terms of time expended in root canal preparation by crown-down method using a transparent resin block with 35 degree curvature and GT rotary file (z-test). The following research using this special research equipment that involved nine experimental groups and varying the vertical force for root canal preparation from 300g which is within the normal vertical force range to 700g and 1000g which fall outside the normal rpm range. The results were as follows : 1. Analysis of the experiment results revealed that the time spent in root canal preparation decreased as the vertical forces and rpm increased (p<0.05). Also, the effects of rpm were greater than those of the vertical forces within the normal vertical force range ($\beta$-weight test). 2. Observation of the deformation of GT rotary file revealed that deformation increases in a direct correlation with the vertical force increase and in a reverse correlation with the rpm decrease. In the case of the vertical forces close to the normal range, the probability of GT rotary file deformation were quite different depending on the rpm changes. In the case of greater vertical forces, the occurrences of deformation of the file were more frequent regardless of the rpm changes. 3. Deformation and breakage of file were also commonly observed in the expended time measurement experiments and GT rotary file deformation experiments in which low speed rpm (150rpm) was used and at the curved portion of the resin block.

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The Relationship Between Neck Pain and Physical Factors in Female Office Workers (사무직 여성 근로자의 경부 통증과 물리적 요인의 상관성 연구)

  • Nam, Ki-Bong;Jo, Yoong-Ki;Rew, Jae-Hwan;Kim, Sung-Su
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.4 no.1
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    • pp.53-63
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    • 2009
  • Objectives : The purpose of this study was to investigate the relation between neck pain and physical factors in female office workers. Methods : Neck pain group of 31 female subjects complained of neck and arm discomfort. Normal group of 20 female subjects had no complaints or minimal discomfort. Cervical curvature and muscle tone were assessed by whole spine x-ray, meridian-electromyography(MEMG), craniovertebral angle. Neck pain was evaluated by Neck Disability Index(NDI) and Visual Analog Scale(VAS). Results : The NDI score and contraction power of upper trapezius by MEMG had a relationship significantly. However, there was no relationship between NDI and cervical curvature. Conclusions : The results suggest that neck pain is related to muscle tone rather than physical stress and cervical curvature.

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Detection of ST-T Episode Based on the Global Curvature of Isoelectric Level in ECG (ECG 신호의 global curvature를 이용한 ST-T 에피소드 검출)

  • Kang, Dong-Won;Jun, Dae-Gun;Lee, Kyoung-Joung;Yoon, Hyung-Ro
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.50 no.4
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    • pp.201-207
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    • 2001
  • This paper describes an automated detection algorithm of ST-T episodes using global curvature which can connect the isoelectric level in ECG and can eliminate not only the slope of ST segment, but also difference of the baseline and global curve. This above method of baseline correction is very faster than the classical baseline correction methods. The optimal values of parameters for baseline correction were found as the value having the highest detection rate of ST episode. The features as input of backpropagation Neural Network were extracted from the whole ST segment. The European ST-T database was used as training and test data. Finally, ST elevation, ST depression and normal ST were classified. The average ST episode sensitivity and predictivity were 85.42%, 80.29%, respectively. This result shows the high speed and reliability in ST episode detection. In conclusion, the proposed method showed the possibility in various applications for the Holter system.

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Effects of Three Week 3D Pilates Breathing Exercise on Spinal Curvature, Trunk Imbalance and Alignment of Healthy Adults

  • Kim, Seongyeol
    • Journal of International Academy of Physical Therapy Research
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    • v.10 no.2
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    • pp.1797-1802
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    • 2019
  • Background: Breathing is the essential step of Pilates exercise and can be used to activate core muscles. Although the effects of breathing exercise on pain, breathing muscles, and cervical posture have been extensively studied, little is known about the impact of Pilates breathing on spinal posture and alignment. Purpose: To determine the effect of 3D-Pilates breathing exercise on spinal curvature and alignment of healthy adults during corrected to normal alignment. Design: One group pre-post test design Methods: Eighteen participants were given a 3D-pilates breathing exercise twice a week (20 minutes per session) for three weeks and warmed up for 10 minutes before each exercise session. To examine spinal curvature and alignment of each subject, this study used radiation free rasterstereography (Formetric III, Germany). Paired t-test and Wilcoxon signed rank test were performed to determine the difference between pre and post exercise. Results: There were statistically significant differences in height (p<.001), kyphosis angle (p<.05), trunk imbalance (p<.05), kyphotic apex (p<.01), cervical fleche (p<.05), pelvic tilt (p<.01), and lateral deviation (p<.05) between before and after 3D Pilates breathing exercise. However, there was no significant difference in lordosis angle. Conclusions: The study results indicated that three week 3D-pilates breathing exercise program could be presented as an effective rehabilitation method for improving spinal curvature and alignment.