• 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 Periodontal and Implant Science
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• v.27 no.1
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• pp.111-116
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• 1997

The oral cavity is easily accessible for direct exposure of a malignant disease. 1 percent of the oral malignant tumors are of metastatic origin and approximately 10 percent to 25 percent of the 1 percent fraction originate from the lungs. A case of metastatic lung carcinoma to the gingiva in a 88-year-old male is reported. He complained of pain and swelling between right maxillary 1st premolar and 2nd molar. Although surgical excision of the lesion has been done, the gingival lesion developed as a quickly growing mass and recurred 2 weeks after surgical excision. The gingival mass was histopathologically diagnosed as an undifferentiated carcinoma. Epithelial layer was continuous without ulceration and it seems that the cancer cells are originated from primary tumor. Infiltrated cancer cells were pleomorphic and dyskeratotic. The cells had 2 or more nuclei, not showing squamous or glandular differentiation. Immunohistochemical study revealed the cells originated from the epithelial cells. The prognosis is poor, because prognosis depends on surgical elimination of the primary tumor.

• Animal cells and systems
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• v.16 no.6
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• pp.498-505
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• 2012

This study uses the mitochondrial DNA control region to identify the genetic diversity and population structure of the marbled soles (Pleuronectes yokohamae) that inhabit Jinhae Bay and Yokji Island in the nearby sea and the adjacent waters of Namhae, Hansan Island, and Jaran Bay. Direct sequencing of the PCR products revealed 379 bp sequences with 83 variable nucleotide sites, defining a total of 91 haplotypes. The haplotype diversity was high, ranging from $0.917{\pm}0.031$ to $0.983{\pm}0.008$, and nucleotide diversity ranged from $0.015{\pm}0.008$ to $0.024{\pm}0.012$. In addition, 48 haplotypes (52.7%) were unique. Pairwise $F_{ST}$ values were very low, with the maximum value occurring between PYH (Hansan Island) and PJI (Jinhae Bay) ($F_{ST}$ = 0.011). Therefore, no significant genetic differentiation was evident between any pair of sampling localities.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.2
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• pp.105-113
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• 1999

This paper resents a prediction method of natural frequencies of coupled horizontal and torsional vibration of hull girder based on design sensitivity analysis in case of the changes of system parameters. The sensitivity analysis is formulated applying the direct differentiation method and transfer matrix method. In the analysis, warping, shear deformation due to torsion and the continuity condition at the connected part of open and closed hull section are considered. Using the presented method. The affection for natural frequencies by the change of system parameters, especially cargo and added mass and their centers, is numerically investigated for a real large container carrier.

• 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.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.11 s.242
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• pp.1527-1533
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• 2005

Three methods for design sensitivity analysis such as finite difference method(FDM), direct differentiation method(DDM) and adjoint variable method(AVM) are well known. FDM and DDM for design sensitivity analysis cost too much when the number of design variables is too large. An AVM is required to compute adjoint variables from the simultaneous linear system equation, the so-called adjoint equation. Because the adjoint equation is independent of the number of design variables, an AVM is efficient for when number of design variables is too large. In this study, AVM has been extended to the eigenproblem of damped systems whose eigenvlaues and eigenvectors are complex numbers. Moreover, this method is implemented into a commercial finite element analysis program by means of the semi-analytical method to show applicability of the developed method into practical structural problems. The proposed_method is compared with FDM and verified its accuracy for analytical and practical cases.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.1038-1043
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• 2003

There are many industrial applications including thin-body structures such as fins. For the numerical modeling of radiation of sound from thin bodies, the conventional boundary element method (BEM) using the Helmholtz integral equation fails to yield a reliable solution. Therefore, many researchers have tried to solve the thin-body acoustic problems. In the area of the design sensitivity analysis (DSA) and optimization methods, however, there has been just a few study reported. Especially fur the thin-body acoustics, however, no further study in the DSA and optimization fields has been reported. In this research, the normal derivative integral equation is adopted as an analysis formulation in the thin-body acoustics, and then used for the sizing DSA and optimization. Since the gradient-based method is used for the optimization, it is important to have accurate gradients (design sensitivities) of the objective function and constraints with respect to the design variables. The DSA formulations are derived through chain-ruled derivatives using the finite element method (FEM) and BEM by using the direct differentiation and continuum variation concepts. The proposed approaches are implemented and validated using a numerical example.

• Tuberculosis and Respiratory Diseases
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• v.40 no.4
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• pp.345-352
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• 1993

The role of magnetic resonance(MR) imaging in the evaluation of thoracic disease has been limited Nontheless, MR has inherent properties of better contrast resolution than CT allowing tissue-specific diagnosis. MR has capability of direct imaging in sagittal, coronal, and oblique planes which provide better anatomic information than axial images of CT such as lesions in the pulmonary apex, aorticopulmonary window, peridiaphragmatic region, and subcarinal region. MR is sensitive to blood flow making it an ideal imaging modality for the evaluation of cardiovascular system of the thorax without the need for intravenous contrast media. Technical developments and better control of motion artifacts have resulted in improved image quality, and clinical applications of MR imaging in thoracic diseases have been expanded. Although MR imaging is considered as a problem-solving tool in patients with equivocal CT findings, MR should be used as the primary imaging modality in the following situations: 1) Evaluation of the cardiovascular abnormalities of the thorax 2) Evaluation of the superior sulcus tumors 3) Evaluation of the chest wall invasion or mediastinal invasion by tumor 4) Evaluation of the posterior mediastinal mass, especially neurogenic tumor 5) Differentiation of fibrosis and residual or recurrent tumor, especially in lymphoma 6) Evaluation of brachial plexopathy With technical developments and fast scan capabilities, clinical indications for MR imaging in thorax will increase in the area of pulmonary parenchymal and pulmonary vascular imaging.