• Geomechanics and Engineering
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• 제12권6호
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• pp.965-981
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• 2017

Stability of vertical escarpments has been the subject of discussion for long time. However, available literature provides scarce knowledge about the effect of the formation of undercut and surface cracks on the stability of a vertical escarpment. The present study deals with a systematic analysis of the effect of surface cracks and undercut on slope stability using finite element based lower bound limit analysis. In the present analysis, the non-dimensional stability factor (${\gamma}H/c$) is used to inspect the degrading effect of undercut and cracks developed at different offset distances from the edge of the vertical escarpment. Failure patterns are also studied in detail to understand the extent and the type of failure zone which may generate during the state of collapse.

• 제어로봇시스템학회논문지
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• 제20권3호
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• pp.289-297
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• 2014

This article surveys the control theoretic study on time delay systems. Since time delay systems are infinite dimensional, there are not analytic but numerical solutions on almost analysis and synthesis problems, which implies that there are a tremendous number of approximated solutions. To show how to find such solutions, several results are summarized in terms of two different axes: 1) theoretic tools like integral inequality associated with the derivative of delay terms, Jensen inequality, lower bound lemma for reciprocal convexity, and Wirtinger-based inequality and 2) various candidates for Laypunov-Krasovskii functionals.

• 한국동물학회지
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• 제3권1호
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• pp.19-23
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• 1960

A method for determination of thyroid secretion rate in rabbit by means of radioactive iodine presented. After injection of radioactive iodine, in vivo determination so f radioactivity in thyroid gland were made during a 19 day-experimental period. In the same period blood samples were drawn and analyzed for protein-bound iodine (PBI) and for protein-bound radioactive iodine(PBI181). A rate constant for secretion of thyroid hormone was calculated from the disappearance rate of radioactive iodine in thyroid gland. The secretion rate of radioactive hormone iodine was calculated by multiplying this rate constant by the amount of radioactive iodine present in thyroid gland. Assuming that the specific radioactiveness of the circulating thyroid hormone and of the hormone just secreted were identical , thyroid secretion rate was calculated by the equation. {{{{ { Secreted hormone-iodine , gamma /hr} over { Secreted hormone-I^131, % dose/hr }= { PBI, ${\gamma}$/ml.Serum} over { PBI^131 , % dose/ml . Serum } }} The method presented consisted of measurements for series of independent criteria on thyroid function, and the resulting thyroid secretion rate was calculated by combination of those.

• Archives of Pharmacal Research
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• 제21권3호
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• pp.231-235
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• 1998

A sensitive enzyme immunoassay for serum TSH has been developed utilizing the tight binding between biotin and avidin, and three layered protein polystyrene beads as solid phase. To increase binding capacity of TSH and sensitivity of the assay, the polystyrene beads were coated sequentially with mouse immunoglobulin as first layer, rabbit antimouse immunoglobulin as second layer and monoclonal anti-TSH as third layer. A serum sample was incubated simultaneously with a monoclonal anti-TSH immobilized polystyrene beads and a second monoclonal anti-TSH covalently attached to biotin. After washing, the antibody bound serum TSH-anti-TSH-biotin complex is reacted with horseradish peroxidase (HRP)-labeled avidin. Following second wash, the bound HRP activity was measured calorimetrically. Reproducible results were obtained within 4 hours for serum TSH in the range between $0{\mu}\textrm{IU}$ml and ${50}{\mu}\textrm{IU}$ml with detection limit of $0.1{\mu}\textrm{IU}$ per test.

• Elastomers and Composites
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• 제52권1호
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• pp.17-21
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• 2017

The optimum mixing conditions of silica and silane containing rubber composites were evaluated by investigating the properties of rubber composites prepared with a silica composition of 10, 20, 40, 60, and 80 g, respectively. The crosslinking rate decreased with increasing silica content, with he promoters being adsorbed on the silica surface with in the rubber composite. As a result, the increase in crosslinking time resulted in the destruction of the silica structure. The increase of the bound rubber content due to the destruction of the silica structure inhibited the chain motion of the polymer molecules and reduced the cohesion of the silica itself. Finally, the increase of silica content showed the increase of hardness, tensile strength, and storage modulus of rubber composites.

• 산업경영시스템학회지
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• 제19권37호
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• pp.241-249
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• 1996

In this paper, a 0-1 integer programming model for solving vertical partitioning problem minimizing the number of disk accesses is formulated and a branch-and-bound method is used to solve the binary vertical partitioning problem. In relational databases, the number of disk accesses depends on the amount of data transferred from disk to main memory for processing the transactions. Vertical partitioning of the relation can often result in a decrease in the number of disk accesses, since not all attributes in a tuple are required by each transactions. The algorithm is illustrated with numerical examples and is shown to be computationally efficient. Numerical experiments reveal that the proposed method is more effective in reducing access costs than the existing algorithms.

• 한국수학사학회지
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• 제27권5호
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• pp.329-345
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• 2014

CAGD(Computer Aided Geometric Design) is a branch of applied mathematics concerned with algorithms for the design of smooth curves and surfaces and for their efficient mathematical representation. The representation is used for the computation of the curves and surfaces, as well as geometrical quantities of importance such as curvatures, intersection curves between two surfaces and offset surfaces. The $B\acute{e}zier$ curves, B-spline, rational $B\acute{e}zier$ curves and NURBS(Non-Uniform Rational B-Spline) are basically and widely used in CAGD. The definitions and properties of these curves are presented in this paper. And a brief history of study on the bound for derivative of rational curves in CAGD is also presented.

• 생약학회지
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• 제25권2호
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• pp.140-143
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• 1994

During the serial attempts to identify the chemical and biological characteristics of Ailanthi Cortex Radicis, the root bark of Ailanthus altissima (Simaroubaceae), we find out the serious toxic effect on kidney by chloroform fraction of the methanolic extract of the herb drug. The toxicities were revealed as the increase of urea nitrogen amount in blood and lactate dehydrogenase and ${\gamma}-glutamyltransferase$ activities in urine and the decrease of the concentration of glutathione and both of protein bound and non-protein bound -SH in kidney tissue.

• 한국정밀공학회지
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• 제5권4호
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• pp.24-31
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• 1988

The Upper Bound Solution has been used to investigate the effect of the various parameters on the floating-plug tube-drawing precess. A kinematically admissible velocity field considering the change of the tube thickness is proposed for the deformation process. Taking into account the position of the plug in the deforming region, shear energy at entrance and exit, friction energy on contact area, homogeneous energy are calculated. The theoretical values in proposed velocity field are good agreement with experimental values, It is investigated that the tube thickness in the deforming region is changed slightly toward minimization of deforming energy and then the drawing stress in lower than the crawing stress in the velocity field that the tube thickness is uniform.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1995년도 춘계학술대회논문집
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• pp.124-130
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• 1995

An upper-bound elemental stream function technique(UBST) is proposed for solivng forging and backward extrusion problems that are geometrically complex or need a forming simulation . And in the forging problems, this study investigates that layer of elements effects dissipation of total energy and load. The element system of UBSTuses the curve fitting property of FEM and the fluid incompressiblity of the stream function . The foumulated optimal design problems with constraints ae solved by the flixible toerance method. In the closed-die forging and backward extrusion, the result of layer of element by this study produces a lower upper-bound solution than that fo UBET and conventional layer of element . And the main advantage of UBST program is that a computer code, once written , can be used for a large variety problems by simply changing the input data.