• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.29 no.1
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• pp.39-55
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• 1993

Modal Analysis is the process of characterizing the dynamic properties of an elastic structure by identifying its modes of vibration. A mode of vibration is a global property of an elastic structure. That is, a mode has a specific natural frequency and damping factor which can be identified from response data at practically any point on a structure, and it has a characteristic mode shape which identifies the mode spatially over the entire structure. Modal testing is able to be performed on structural and mechanical structure in an effort to learn more about their elastic behavior. Once the dynamic properties of a structure are known its behavior can be predicted and therefore controlled or corrected. Resonant frequencies, damping factors and mode shape data can be used directly by a mechanical designer to pin point weak spots in a structure design, or this data can also be used to confirm or synthesize equations of motion for the elastic structure. These differential equations can be used to simulate structural response to know input forces and to examine the effects of pertubations in the distributed mass, stiffness and damping properties of the structure in more detail. In this paper the measurement of transfer functions in digital form, and the application of digital parameter identification techniques to identify modal parameters from the measured transfer function data are discussed. It is first shown that the transfer matrix, which is a complete dynamic model of an elastic plate structure can be written in terms of the structural modes of vibration. This special mathematical form allows one to identify the complete dynamics of the structure from a much reduced set of test data, and is the essence of the modal approach to identifying the dynamics of a structure. Finally, the application of transfer function models and identification techniques for obtaining modal parameters from the transfer function data are discussed. Characteristics on vibration response of elastic plate structure obtained from the dynamic analysis by Finite Element Method are compared with results of modal analysis.

• Journal of Korea Water Resources Association
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• v.37 no.12
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• pp.1009-1018
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• 2004

A systematic method using an optimal estimation algorithm is presented for simultaneous estimation of diffuse pollution distributed along a stream reach and model parameters for a stream water quality model. It was applied with the QVAL2E model to the South Han River for optimal estimation of kinetic constants and diffuse loads along the river. Initial calibration results for kinetic constants selected from a sensitivity analysis reveal that diffuse source inputs for nitrogen and phosphorus are essential to satisfy the system mass balance. Diffuse loads for total nitrogen and total phosphorus were estimated solving the expanded inverse problem. Comparison of kinetic constants estimated simultaneously with diffuse sources to those estimated without diffuse loads, suggests that diffuse sources must be included in the optimization not only for its own estimation but also for adequate estimation of the model parameters. Application of optimization method to river water quality modeling is discussed in terms of the sensitivity coefficient matrix structure.

• Carbon letters
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• v.19
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• pp.72-78
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• 2016

Spinnable pitches and carbon fibers were successfully prepared from petroleum or coal pyrolysis residues. After pyrolysis fuel oil (PFO), slurry oil, and coal tar were simply filtered to eliminate the solid impurities, the characteristics of the raw materials were evaluated by elemental analysis, ¹³C nuclear magnetic resonance spectrometer, matrix-assisted laser desorption/ionization time-of-flight mass spectrometer (MALDI-TOF-MS), and so on. Spinnable pitches were prepared for melt-spinning carbon fiber through a simple distillation under strong nitrogen flow, and further vacuum distillation to obtain a high softening point. Carbon fibers were produced from the above pitches by single-hole melt spinning and additional heat treatment, for oxidization and carbonization. Even though spinnable pitches and carbon fibers were processed under the same conditions, the melt-spinning and properties of the carbon fiber were different depending on the raw materials. A fine carbon fiber could not be prepared from slurry oil, and the different diameter carbon fibers were produced from the PFO and coal tar pitch. These results seem to be closely correlated with the initial characteristics of the raw materials, under this simple processing condition.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.5
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• pp.506-512
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• 2003

An output multiplexer of manifold type is widely used in a recent satellite transponder f3r its mass and volume reduction. For correct operation, the filter of such a multiplexer must be singly terminated. In this paper, a simple synthesis method of a 6-pole dual-mode singly terminated filter is described. From the transfer function of the filter, network parameters such as in/output terminations and coupling matrix are obtained with the aid of orthogonal projection and plane rotation. The rotation order, pivot, and rotation angle of the plane rotation process are given for easy filter synthesis. Two different-structure filters are taken into consideration and the network parameters of each filter have been obtained from the same transfer function. The method described in this paper can be applied to the other degree singly terminated filter.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.12
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• pp.1875-1882
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• 2013

Micro-array technology contributes numerous achievements such as ordering of gene network and integration of genomic. This technology is well established as means for investigating patterns of gene expression. DNA micro-arrays utilize Affymetric chips where a large quantity of DNA sequences may be synthesized. There are two general type of conventional DNA array spotter: contact and piezoelectric. The contact technology used spotting pin technology to make contact with the glass slide surface. This may caused damage or scratches to the surface matrix where protein will be contaminated and may not bind specifically. Piezoelectric technology available at this present time on the other hand requires the analyzer to print the result that can only be done within the laboratory despite of mass production. Therefore, in this paper, high-throughput technology is developed for providing greater consistency in feature spot without touching the glass slide surface.

• BMB Reports
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• v.31 no.3
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• pp.233-239
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• 1998

A GABA synthesizing enzyme, glutamate decarboxylase, has been purified from bovine brain by several chromatographic procedures. The preparation appeared homogeneous on SDS-PAGE. The enzyme is a homodimeric protein with a molecular mass of 120 kDa. The activation of glutamate decarboxylase by ginesenosides from Panax ginseng C.A. Meyer has been studied. Preincubation of the enzyme with total ginsenoside, $Rb_2$ and Rc ginsenosides, increased glutamate decarboxylase activities in a dose-dependent manner. There was a reproducible decrease in $K_m$, in addition to a increase in $V_{max}$, in response to increasing concentrations of the Rc ginsenoside fraction. Upon addition of the ginsenoside to the enzyme, a decrease in flurorescence intensity was discernible, together with an increase in emission anisotropy. Judging from the anisotropy values, the ginsenoside is rapidly trapped by the protein matrix. Total ginsenoside was administered to rats and the rat brains were removed for the measurement of the changes of GABA shunt regulating enzyme activities. Among the GABA shunt regulating enzymes, only the glutamate decarboxylase activities were increased after ginsenoside treatment. Therefore, it is suggested that the ginsenosides may elevate the GABA level in brain by activation of glutamate decarboxylase and the enzymatic activation might be due to the conformational change induced by binding of ginsenoside to the enzyme.

• Composites Research
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• v.15 no.2
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• pp.11-17
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• 2002

The piezoelectric thin film sensor can be used to interpret variations in structural and material properties, e.g. for structural integrity monitoring and assessment. To illustrate one of this potential benefit, PVDF (polyvinylidene fluoride) film sensors are used for monitoring impact damage in Gr/Ep composite panels. Both PVDF film sensors and strain gages are attached to the surface of Gr/Ep specimens. A series of impact tests at various impact energy by changing impact mass the height are performed on the instrumented drop weight impact tester. The sensor responses are carefully examined to predict the onset of impact damage such as indentation, matrix cracking, and delamination, etc. Test results show that the particular waveforms of sensor signals implying the damage initiation and development are detected above the damage initiation impact energy. As expected, the PVDF film sensor is found to be more sensitive to impact damage initiation event than the strain gage.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.6
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• pp.1967-1974
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• 1991

When the functional electrical stimulation is employed to recover mobility to the plegic, it is very important to understand functions of the selected muscles. I have investigated how a muscle acts to accelerate the body segments, since the body segements are connected by joints so that contraction of a muscle not only rotates the segments to which it is attached but also causes other segments to rotate by creation a reaction force at every joint, which is called the inertial coupling. I found that a single-joint muscle always acts to accelerate the spanned joint in the same direction as the joint torque produced by the muscle. However, a double-joint muscle can act to accelerate the spanned joint in the opposite direction to the joint torque produced by the muscle depending on (1) the body position, (2) the body-segmental parameters, and (3) the type of the movement. Investigating the condition number of the inertia matrix of the body-segmental model gave us some insights into how controllable the body-segmental system is for different values of the factors mentioned above. The results suggested that the upright position is the most undesirable position to independently control the three segments(trunk, thigh and shank) and that the controllability is the most sensitive to variation of the shank length and the trunk mass, which implies that accuracy is required particularly when we estimate these two body-segmental parameters before the paralyzed muscles are innervated by using electrical stimulation.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.912-918
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• 2008

This study was conducted to identify the differences in proteomic characteristics of 'Agakong', recombinant inbred line, and its parental genotypes 'Eunhakong' (Glycine max) and 'KLG10084' (G. soja). The isoflavone content of 'Agakong' was 3 times higher than that of its parental lines. A combined high-throughput proteomic approach was employed to determine the expression profile and identity of proteins using 2-dimensional gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry. The overall distribution patterns of proteins are quite similar, but lots of protein spot intensities varied among the genotypes. A total of 41 proteins, representing significant difference in the quantities of protein among the lines, were successfully identified. Among them, more than 50% of the proteins identified were subunits of glycinin and $\beta$-conglycinin, 2 major storage proteins. This study showed that the proteomic analysis could help to define specific changes in protein level and composition, which can occur in the generation of new soybean varieties.

• Korean Journal of Food Science and Technology
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• v.43 no.1
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• pp.12-16
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• 2011

This study was conducted to identify the differences in proteomic characteristics between Ca-enriched king oyster mushrooms and general king oyster mushrooms. A combined high-throughput proteomic approach was employed to determine the expression profiles and identity of proteins using 2-dimensional gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry. The overall distribution patterns of the proteins were quite similar, but many of the protein spot intensities varied. A total of 10 proteins, representing a significant difference in the quantities of protein betweenthe two types of mushrooms, were successfully identified. Among these proteins, eight kinds were increased in the Ca-enriched king oyster mushrooms and two kinds were decreased. This study showed that proteomic analysis can help define specific changes in protein level and composition, which can occur in mushrooms where Ca content may or may not be enriched.