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Comparison of the Cross-Sectional Area of Longus Colli and Muscle Activity of Sternocleidomastoid in Subjects With Forward Head Posture on the Two Craniocervical Flexion Methods

  • Son, Min-chan;Hwang, Ui-jae;Jung, Sung-hoon;Ahn, Sun-hee;Kim, Hyun-a;Kwon, Oh-yun
    • Physical Therapy Korea
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    • v.25 no.2
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    • pp.62-70
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    • 2018
  • Background: The craniocervical flexion (CCF) exercise is one of the effective exercise in correcting forward head posture (FHP). However, some people with FHP achieve CCF with compensatory movements, for example, low cervical flexion using superficial neck flexors such as the sternocleidomastoid (SCM) muscle. No study has yet investigated whether a dual­pres ure biofeedback unit (D-PBU) method to prevent low cervical flexion would be helpful in performing pure CCF movement. Objects: The purpose of this study was to compare the effects of the CCF using D-PBU method and the traditional CCF method on the cross-sectional area (CSA) of the longus colli muscle (LCM) and the activity of SCM muscle in subjects with FHP. Methods: Twenty­four FHP subjects (male: 16, female: 8) were recruited for this study. All subjects performed CCF using two different methods: the traditional CCF method and the CCF using D-PBU method. The CSA of the LCM was measured via ultrasound, and surface electromyography was used to measure SCM muscle activity. Results: The change in CSA of the LCM was significantly larger during the CCF using D-PBU method ($1.28{\pm}.09$) compared with the traditional CCF method ($1.19{\pm}.08$) (p<.05). The SCM muscle activity using the CCF using D-PBU method ($2.01{\pm}1.97$ %MVIC) was significantly lower than when using the traditional CCF method ($2.79{\pm}2.32$ %MVIC) (p<.05). Conclusion: The CCF using D-PBU method can be recommended for increasing LCM activation and decreasing SCM muscle activity during CCF movement in subjects with FHP.

Characteristics of Accommodative Lags Determined by Objective and Subjective Methods and Their Correlation (타각적 및 자각적으로 결정된 조절래그의 특성과 상관관계)

  • Yu, Dong-Sik;Kwak, Ho-Weon;Roh, Byeong-Ho;Son, Jeong-Sik
    • Journal of Korean Ophthalmic Optics Society
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    • v.20 no.3
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    • pp.333-339
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    • 2015
  • Purpose: The aim of this study was to evaluate clinical characteristics of subjective accommodative lags determined by fused cross-cylinder (subjective method), and an open-field autorefractor (objective method) under uncorrected and corrected conditions. Methods: Thirty three healthy subjects (26 males and 7 females aged $23.73{\pm}1.35$ years from 22 to 27 years) participated. Four methods were used to determine accommodative lag: (1) a subjective method with the fused cross-cylinder (FCC) under +2.00 D fogging lenses condition, (2) an objective method with the autorefractor under uncorrected condition (3) a corrected method (effective accommodative lag) using equations presented by Gwiazda et al. in objective methods, and (4) a corrected method using equations presented by Mutti et al. in objective methods. Results: The mean accommodative lags were 0.72 D for subjective method, 0.82 D for uncorrected objective method, 0.88 D for corrected method with Gwiazda's equations, and 0.78 D for corrected method with Mutti's equations. There were significant differences between the objective accommodative lags, but no significant differences between the objective and subjective accommodative lags. The effective accommodative lags showed significant correlations between phorias and refractive errors. The effective accommodative lag by Mutti's equations had a high correlation with uncorrected accommodative lags (r=0.99, p<0.001). Conclusions: The objective accommodative lag correlated with phorias and refractive errors. Especially, The effective accommodative lag using Mutti's equations may be considered for clinical availability and qualitative evaluation associated with symptoms.

Simplified HPLC Method for the Determination of Pseudoephedrine Hydrochloride from Allegra D Tablet

  • Park, Moon-Hee;Shin, In-Chul
    • Biomolecules & Therapeutics
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    • v.15 no.2
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    • pp.123-126
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    • 2007
  • A sensitive, simple and highly selective liquid chromatography method of determination for extraction of pseudoephedrine hydrochloride from Allegra D tablet was developed. The chief benefit of the present method is the minimal sample preparation, as the procedure is only filtering through pore syringe filter. Two drugs (pseudoephedrine hydrochloride, fexofenadine) were separated on a C$_{18}$ column and analyzed by high performance liquid chromatography (HPLC). The method had a chromatographic run time of 8.0 min. 1 ml of pseudoephedrine hydrochloride solution (1 mg/ml) was filtered through 0.22 um pore syringe filter. 50 ul of filtering solution was injected to HPLC pump and we knew the retention time (1.85 min) of separating of pseudoephedrine hydrochloride using UV detector at 280 nm. We used C$_{18}$ column (4.6 mm${\times}$250 mm), mobile phase solution (<0.05 mol/L NaH$_2$PO$_4$, 2 ml/L H$_3$PO$_4$>/CH$_3$CN / sodium dodesyl sulfate = 60 ml / 40 ml / 1 g). We separated psedoephedrine hydrochloride at run time of 1.85 min from Allegra D tablet solution (1 mg/ml) filtered through 0.22 um pore syringe filter using UV detector at 280 nm. Flow rate was set at 1.0 ml/min and the column temperature was set at 40$^{\circ}C$. Psedoephedrine hydrochloride solution (1 mg/ml) separated from Allegra D tablet was filtered through 0.22 um pore syringe filter and injected 50 ul. We confirmed the peak of psedoephedrine hydrochloride at same retention time and the separating solution was freeze-dried. In conclusion, A simple isocratic reverse-phase HPLC method has been developed that provides excellent separation of pseudoephedrine from Allegra D tablet.

Comparison between Alginate Method and 3D Whole Body Scanning in Measuring Body Surface Area (알지네이트를 이용한 체표면적 측정방법과 삼차원 스캐닝에 의한 체표면적 측정방법의 비교)

  • Lee Joo-Young;Choi Jeong-Wha
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.11
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    • pp.1507-1519
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    • 2005
  • The purpose of this study was to compare two methods of measuring body surface area (BSA). The BSA of Korean adults was measured using both three-dimensional (3D) scanning and an alginate method. Two males (one overweight and one lean) and one overweight female participated as subjects. The results were as follows: First, the 3D scanned BSA of all three subjects was smaller than the BSA measured using the alginate method by as much as $6-14\%$. The difference in methods was greater in the overweight participants than in the lean subject. Second, the results comparing the BSA obtained using these two methods and the BSA estimated by 10 previously developed formulas, showed that the 3D scanned BSA was the smallest among the 12 BSAs. Third, in comparing the regional differences between these two methods, the regional BSA of the lean subject (male 2) did not show any significant difference, but the overweight subjects (male 1, female 1) showed a significant difference. Forth, the biggest difference in regional BSA obtained through these two methods was in the hand, for all three subjects. The 3D scanned hand surface area was smaller than the hand surface area measured by the alginate method by as much as $24-34\%$. Fifth, in the percentage of regional BSA, there was no significant difference in these two methods. The reasons for the underestimation in the 3D scanning might be because: 1) the 3D scanner can not recognize the folding and shading of body parts, such as the finger, toe, ear, armpit, crotch and breast, 2) 3D patching and smoothing processes depend on researchers. However, the 3D scanning method is applicable to the estimation of the entire BSA, if the surface area of the hands is known, and the participant is not overweight.

A Method for Generation of Contour lines and 3D Modeling using Depth Sensor (깊이 센서를 이용한 등고선 레이어 생성 및 모델링 방법)

  • Jung, Hunjo;Lee, Dongeun
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.12 no.1
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    • pp.27-33
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    • 2016
  • In this study we propose a method for 3D landform reconstruction and object modeling method by generating contour lines on the map using a depth sensor which abstracts characteristics of geological layers from the depth map. Unlike the common visual camera, the depth-sensor is not affected by the intensity of illumination, and therefore a more robust contour and object can be extracted. The algorithm suggested in this paper first abstracts the characteristics of each geological layer from the depth map image and rearranges it into the proper order, then creates contour lines using the Bezier curve. Using the created contour lines, 3D images are reconstructed through rendering by mapping RGB images of the visual camera. Experimental results show that the proposed method using depth sensor can reconstruct contour map and 3D modeling in real-time. The generation of the contours with depth data is more efficient and economical in terms of the quality and accuracy.

Generation of 2-D Parametric Surfaces with Highly Irregular Boundaries

  • Sarkar, Subhajit;Dey, Partha Pratim
    • International Journal of CAD/CAM
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    • v.8 no.1
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    • pp.11-20
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    • 2009
  • The conventional methods of boundary-conformed 2D surfaces generation usually yield some problems. This paper deals with two boundary-conformed 2D surface generation methods, one conventional approach, the linear Coons method, and a new method, boundary-conformed interpolation. In this new method, unidirectional 2D surface has been generated using some of the geometric properties of the given boundary curves. A method of simultaneous displacement of the interpolated curves from the opposite boundaries has been adopted. The geometric properties considered for displacements include weighted combination of angle bisector and linear displacement vectors at all the data-points of the two opposite generating curves. The algorithm has one adjustable parameter that controls the characteristics of transformation of one set of curves from its parents. This unidirectional process has been extended to bi-directional parameterization by superimposing two sets of unidirectional curves generated from both boundary pairs. Case studies show that this algorithm gives reasonably smooth transformation of the boundaries. This algorithm is more robust than the linear Coons method and capable of resolving the 2D boundary-conformed parameterization problems.

A fundamental study of J-integral using the method of caustics for polycarbonate (Caustics 방법에 의한 Polycarbonate의 J-적분값 결정에 관한 기초적 연구)

  • 이억섭;박기용
    • Journal of the korean Society of Automotive Engineers
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    • v.12 no.1
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    • pp.26-32
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    • 1990
  • This study investigated a method for the determination of the J-integral for a tough glassy polymer such as polycarbonate plates by using the method of caustics. Comparing the values of J-integral determined by a numerical analysis and by the method of caustics, the method of caustics was found to be an effective experimental technique for the determination of the J-integral. The ratio between two J-integrals determined by the method of caustics and by finite element method converged into 1 within the limit of low load. However, it was noticed that the greater the plastic zone at the crack tip was, the lower the J-integral obtained by the reflect method of caustics. This difference may be deduced from the damage at the crack tip such as craze appeared in the polycarbonate plate. It was confirmed that the ratio of longitudinal diameter( $D_{l}$ ) to transverse diameter ( $D_{t}$) of caustics generally converged into 1 at the low load. The transition of the state of stress at the vicinity of a crack tip from plane strain to plane stress was deduced by noticing that the longitudinal diameter( $D_{l}$ ) grew faster than the transverse diameter( $D_{t}$) of caustics within the higher load range.

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An Evaluation Method for Scientists and Engineers in Project - oriented R&D Organizations (Project를 위주로 하는 연구개발(硏究開發) 기관에 있어서 과학자(科學者), 기술자(技術者)의 평가방법(評價方法))

  • Park, Sun-Dal
    • Journal of Korean Institute of Industrial Engineers
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    • v.1 no.1
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    • pp.57-65
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    • 1975
  • A perfect evaluation for scientists and engineers is impossible unless the R&D process is fully explored. But the study in this area is being intencified, and consequently progress is being made. In this paper an evaluation method for scientists and engineers in project-oriented R&D organizations is developed. That is, a method that the evaluation for the job performance directly influences personnel management such as promotion, and the evaluation for their potential, characteristics influences indirectly. Further systematization of evaluation process, which is no less importatant than evaluation itself, is attempted.

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Transient heat transfer of unidirectional (1D) and multidirectional (2D/3D) functionally graded panels

  • Samarjeet Kumar;Vishesh Ranjan Kar
    • Steel and Composite Structures
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    • v.49 no.5
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    • pp.587-602
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    • 2023
  • This article presents the numerical modelling of transient heat transfer in highly heterogeneous composite materials where the thermal conductivity, specific heat and density are assumed to be directional-dependent. This article uses a coupled finite element-finite difference scheme to perform the transient heat transfer analysis of unidirectional (1D) and multidirectional (2D/3D) functionally graded composite panels. Here, 1D/2D/3D functionally graded structures are subjected to nonuniform heat source and inhomogeneous boundary conditions. Here, the multidirectional functionally graded materials are modelled by varying material properties in individual or in-combination of spatial directions. Here, fully spatial-dependent material properties are evaluated using Voigt's micromechanics scheme via multivariable power-law functions. The weak form is obtained through the Galerkin method and solved further via the element-space and time-step discretisation through the 2D-isoparametric finite element and the implicit backward finite difference schemes, respectively. The present model is verified by comparing it with the previously reported results and the commercially available finite element tool. The numerous illustrations confirm the significance of boundary conditions and material heterogeneity on the transient temperature responses of 1D/2D/3D functionally graded panels.

Method of Shape Error Measurement for the Optimal Blank Design of Shapes with 3D Contour Lines (목표윤곽선이 3 차원 곡선인 형상의 최적블랭크 설계를 위한 형상오차 측정법)

  • Shim, H.B.
    • Transactions of Materials Processing
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    • v.24 no.1
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    • pp.28-36
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    • 2015
  • After a short review of the iterative optimal blank method, a new method of measuring the shape error for stamped parts with 3D contour lines, which is an essential component of the optimal blank design, is proposed. When the contour line of the target shape does not exist in a plane, but exists in 3D space, especially when the shape of the target contour line is very complicated as in the real automotive parts, then the measurement of the shape error is critical. In the current study, a method of shape error measurement based on the minimum distance is suggested as an evolution of the radius vector method. With the proposed method, the optimal blank shapes of real automotive parts were found and compared to the results of the radius vector method. From the current investigation the new method is found to resolve the issues with the radius vector method.