• Journal of radiological science and technology
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• v.30 no.2
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• pp.121-127
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• 2007

The purpose of this study was to examine the indirect estimation of the lumbar intervertebral disc size by two anthropometric methods(Colombini's method and Turk and Celan's method), in order to compare these indirect methods with the direct analysis by computed tomography(CT). The wrist, elbow, knee and ankle joint(right side) diameters were measured in 52 normal volunteers and intervertebral disc sizes were measured in 50 normal subjects by CT. Then the intervertebral disc sizes were calculated using two anthropometric formula. The data were analysed with ANOVA to differentiation between indirect and direct estimation of the lumbar intervertebral disc sizes. This study shows that male subjects have significantly larger L4-5 and L5-S1 intervertebral disc sizes than female subjects. In addition, disc sizes calculated by Colombini's formula were significantly larger than Turk & Celan's formula but there was no significant differences in the compared Turk & Celan's estimation with CT values. The indirect estimation of the intervertebral disc size by Turk & Celan's formula can be considered as a clinically useful method. However, further study should be conducted to compare anthropometric values according to age.

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1857-1863
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• 2013

Most of biomaterials come in direct contact with the body, making standardized methods of evaluation and validation of biocompatibility an important aspect to biomaterial development. However, biomaterial validation guidelines have not been fully established, until now. This study was to compare the in vitro behavior of osteoblasts cultured on nanomaterial $TiO_2$ surfaces to osteoblast behavior on culture plates. Comparisons were also made to cells grown in conditioned media (CM) that creates an environment similar to the in vivo environment. Comparisons were made between the different growth conditions for osteoblast adhesion, proliferation, differentiation, and functionality. We found that the in vivo-like system of growing cells in concentrated CM provided a good validation method for biomaterial development and in vivo implant therapy. The $TiO_2$ materials were biocompatible, showing similar behavior to that observed in vivo. This study provided valuable information that would aid in the creation of guidelines into standardization and evaluation of biocompatibility in $TiO_2$ biomaterials.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.891-895
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• 1996

Performance and efficiency of hybrid (hydraulic-mechanical) pick-up device of deep sea manganese nodules collector are very sensitive to altitude and altitude of pick-up head relative to undulating seafloor. For this reason, motion control of pick-up head relative to the changing deep sea topography and other disturbances is of particular importance in design of pick-up device. The concept of design axiom is applied to a pick-up device of hybrid type. Kinematic analysis conducted in absolute Cartesian coordinates gives position, velocity, and acceleration of the hydraulic cylinders which enable the pick-up head to keep the preset optimal distance from seafloor. Inverse dynamic analysis provides the driving forces of hydraulic cylinders and the reaction forces at each joint. Design sensitivity analysis is performed in order to investigate the effects of possible design variables on the change of the maximum strokes of hydraulic cylinders. The direct differentiation method is used to obtain the design sensitivity coefficients.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.3
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• pp.68-74
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• 1998

Performance and efficiency of deep seabed collector is a primary factor for feasibility of commercial deep ocean mining. The efficiency of manganese nodules collector depends on vehicle mobility relative to undulating seafloor and is attributed pickup head to keep altitude and elevation of it against seafloor. For this reason, motion control of pickup head relative to the changing deep-sea topography and other disturbances is of particular importance in design of pickup device. The concept of design axiom is applied to a pickup device of hybrid type in order to evaluate the concept design. Kinematic analysis conducted in absolute Cartesian coordinates gives position, velocity, and acceleration of the hydraulic cylinders which enable the pickup head to keep the preset optimal distance from seafloor. Inverse dynamic analysis provides the driving forces of hydraulic cylinders and the reaction forces at each joint. Design sensitivity analysis is performed in order to investigate the effects of possible design variables on the change of the maximum strokes of hydraulic cylinders. The direct differentiation method is used to obtain the design sensitivity coefficients.

• Journal of Korean Medical classics
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• v.28 no.2
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• pp.61-66
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• 2015

Objectives : Through the analyze of formative factor of time sense and the vital movement temporal rhythm in Huang Di Nei Jing(黃帝內經). Methods : We find out the principle and methods of Chronomedicine and Health Preserving in Huang Di Nei Jing(黃帝內經), and this finding will direct the life nurturing for later generations. We find that time sense had been established in Huang Di Nei Jing(黃帝內經), which had yin-yang and five elements characteristic. Results : There have temporal rhythm of functions of zang-fu viscera, meridian and collateral, qi and blood. Based on the theory of correspondence between human body and natural environment, established principle of health maintenance about based on yin and yang, temporal rhythm of visceral qi. Conclusions : Established health maintenance methods based on time such as adjusting-spirit according to time, regular daily life, dietary regimen according to time, needling and moxibustion according to time. These methods will guide syndrome differentiation and therapeutic method and Medication which based on suitable time.

• Computational Structural Engineering
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• v.11 no.1
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• pp.161-170
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• 1998

A general formulation of the long cylinder tolerance design for the joint structure is here presented. The aim of this paper is to calculate the tolerance of joint by defining tolerance as a kind of uncertainty and to obtain the robustness of the joint structure. It is formulated on the bases of the minimum sensitivity theorem. The objective function is the tolerance sensitivity for the Von-Mises stress. It also took into full account the stress, displacement and weight constraints. PLBA(Pshenichny-Lim-Belegundu-Arora) algorithm is used to solve the constrained nonlinear optimization problem. The finite element analysis is performed with CST(Constant-Strain-Triangle) axisymmetric element. Sensitivities for design variables are calculated by the direct differentiation method. The numerical result is presented for the cylindrical structure where the joint tolerance is treated as random variables.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.7
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• pp.90-99
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• 1996

In the area of assembly process of micro-chips and electronic parts on the printed circuit board, surface mounting device(SMD) is used as a fundamental tool. Generally speaking, the motion of the SMD is based on the ball screw system operated by any type of actuators. The ball screw system is a mechanical transformed which converts the mechanical rotational motion to the translational one. Also, this system could be considered as an efficient motion device against mechanical backlash and friction. Therefore a dynamic modeling and state sensitivity analysis of the ball screw system in SMD have to be done in the initial design stage. In this paper, a simple mathematical dynamic model for this system and the sensit- ivity analysis are mentioned. Especially, the bond graph approach is used for graphical modeling of the dynamic system before analysis stage. And the direct differentiation method is used for the state sensit- ivity analysis of the system. Finally, some trends for the state variables with respect to the design variables could be suggested for the better design and faster operating based on the results of dynamic and state sensitivity.

• Korean Journal of Poultry Science
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• v.20 no.4
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• pp.177-188
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• 1993

This study was performed to find out the reasonable sexing methods In the chicken, obtain the basic information for the mechanisms related to chicken sexual differentiation and identify the genes which known to involved in chicken sex differentiation. The chromosome analysis of chicken embryonic fibroblast was a simple method to determine sex of chicken by means of Z and W chromosome identification. The bands of female chicken genomic DNA digested with Xho Ⅰ and Eco RI restriction endonuclease showed to be useful in direct sex determination and these repetitive sequences of Xho Ⅰ and Eco RI families were proposed to be very homologous in their sequences by colony hybridization analysis. Seven of 150 random primers were selected to amplify the W chromosome-specific band by using arbitrary primed PCR and three of them were useful to identify the sex of chicken. To identify the sex differentiation genes in the chicken, PCR for the amplification of ZFY and SRY sequences was performed. ZFY and SRY sequences were amplified successfully in the chicken genome, implying that chicken genome might have the sex-related conserved sequences similar to mammalian ones. The PCR products of ZFY amplification were the same in both sexes, suggesting that these sequences may be located on autosome or Z chromosome. The profile of PCR amplification for SRY sequences showed variation between sexes, but this result was not enough to specify whether the SRY gene in chicken is on the autosome or sex chromosome.

• Journal of the Society of Naval Architects of Korea
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• v.35 no.3
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• pp.54-61
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• 1998

This paper presents a prediction method of natural frequencies of vertical hull girder vibration based on design sensitivity analysis in case of design modification and the variation of loading condition. The resented method premises the vibration analysis by the transfer matrix method. Governing sensitivity equation is derived from the direct differentiation of state vector and transfer matrix to parameters and its transfer over all the hull girder elements. Derivatives of natural frequencies and mode shapes are determined by two trial calculation of the governing equation. Using the derivatives, the changes of natural frequencies and mode shapes can be predicted when mass and stiffness parameter's are changed. As results, it is possible to optimize ship structure as well as to avoid troublesome calculation in hull girder vibration analysis rationally and efficiently. To verify the accuracy and efficiency of the resented method numerical results obtained by both the sensitivity analysis and the ordinary reanalysis far a real ore/bulk carrier in case of the change of mass and stiffness parameters are compared.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.2
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• pp.153-163
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• 2010

In this paper a frequency response analysis using Krylov subspace-based model reduction and its design sensitivity analysis with respect to design variables are presented. Since the frequency response and its design sensitivity information are necessary for a gradient-based optimization, problems of high computational cost and resource may occur in the case that frequency response of a large sized finite element model is involved in the optimization iterations. In the suggested method model order reduction of finite element models are used to calculate both frequency response and frequency response sensitivity, therefore one can maximize the speed of numerical computation for the frequency response and its design sensitivity. As numerical examples, a semi-monocoque shell and an array-type $4{\times}4$ MEMS resonator are adopted to show the accuracy and efficiency of the suggested approach in calculating the FRF and its design sensitivity. The frequency response sensitivity through the model reduction shows a great time reduction in numerical computation and a good agreement with that from the initial full finite element model.