• Structural Engineering and Mechanics
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• v.15 no.2
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• pp.199-223
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• 2003

The formulation of a non-linear shear deformable shell element is presented for the solution of stability problems of stiffened plates and shells. The formulation of the geometrical stiffness presented here is exactly defined on the midsurface and is efficient for analyzing stability problems of thick plates and shells by incorporating bending moment and transverse shear resultant force. As a result of the explicit integration of the tangent stiffness matrix, this formulation is computationally very efficient in incremental nonlinear analysis. The element is free of both membrane and shear locking behaviour by using the assumed strain method such that the element performs very well in the thin shells. By using six degrees of freedom per node, the present element can model stiffened plate and shell structures. The formulation includes large displacement effects and elasto-plastic material behaviour. The material is assumed to be isotropic and elasto-plastic obeying Von Mises's yield condition and its associated flow rules. The results showed good agreement with references and computational efficiency.

• Structural Engineering and Mechanics
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• v.41 no.6
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• pp.735-750
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• 2012

This paper presents a comparison between two different procedures to deal with the geometric nonlinear analysis of space trusses, considering its structural stability aspects. The first nonlinear formulation, called positional, uses nodal positions rather than nodal displacements to describe the finite elements kinematics. The strains are computed directly from the proposed position concept, using a Cartesian coordinate system fixed in space. The second formulation, called corotational, is based on the explicit separation between rigid body motion and deformed motion. The numerical examples demonstrate the performances and the convergence of the responses for both analyzed formulations. Two numerical examples were compared, including a lattice beam with postcritical behavior. Despite the two completely different approaches to deal with the geometrical nonlinear problem, the results present good agreement.

• Earthquakes and Structures
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• v.3 no.3_4
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• pp.271-295
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• 2012

This paper presents the solution scheme of using the continuous formulation of 1-D linear member for the dynamic analysis of structures consisting of axially loaded members. The context describes specific applications of such scheme to the verification of experimental data obtained from field test of bridges carried out by a microwave interferometer system and velocimeters. Attention is focused on analysis outlines that may be applicable to in-situ assessment for cable-stayed bridges. The derivation of the dynamic stiffness matrix of a prismatic member with distributed properties is briefly reviewed. A back calculation formula using frequencies of two arbitrary modes of vibration is next proposed to compute the tension force in cables. Derivation of the proposed formula is based on the formulation of an axially loaded flexural member. The applications of the formulation and the proposed formula are illustrated with a series of realistic examples.

• Structural Engineering and Mechanics
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• v.70 no.4
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• pp.445-455
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• 2019

Since the days of yore, plate's flexural analysis and formulation were dependent on the assumed coordinate system. In uncovering the coordinates-independent flexural interpretation, in this study, the plate bending analysis has been interpreted in terms of the tensor's components of curvatures and bending moments, in accordance with the continuum mechanics. The paper herein presents the theoretical formulations and conceptual perspectives of the Hydrostatic Method of Analysis (HM) that combines the continuum mechanics with the elasticity theory; the graphical statics and analysis; the theory of thin isotropic and orthotropic plates.

• Structural Engineering and Mechanics
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• v.83 no.2
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• pp.273-282
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• 2022

In this paper, we propose a new concept for error estimation in finite element solutions, which we call mode-based error estimation. The proposed error estimation predicts a posteriori error calculated by the difference between the direct finite element (FE) approximation and the recovered FE approximation. The mode-based FE formulation for the recently developed self-updated finite element is employed to calculate the recovered solution. The formulation is constructed by searching for optimal bending directions for each element, and deep learning is adopted to help find the optimal bending directions. Through various numerical examples using four-node quadrilateral finite elements, we demonstrate the improved predictive capability of the proposed error estimator compared with other competitive methods.

• Proceedings of the Materials Research Society of Korea Conference
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• 1992.05a
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• pp.128-128
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• 1992

• Korean Journal of Environmental Agriculture
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• v.15 no.1
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• pp.116-127
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• 1996

Recent development in Japan on jumbo formulation of pesticides for paddy application by hand throw was reviewed. In addition, the diffusion of liquid formulations in water was examined to establish the research strategy for the jumbo formulation. Research on jumbo formulation in Japan has been focused on gas-generating formulations and self-emulsifiable formulations. Although continuous efforts to minimize the problem of pesticide deposit on the treated site have been made for the gas-generating formulations, much work is still needed to establish a generally acceptable formulation method and to commercialize a herbicide formulation. The self-emulsifiable jumbo formulations have recently been investigated. These formulations could simply be processed and showed relatively high biological efficacy. The emulsifiable concentrate was more diffusible than the suspension concentrate in water. The diffusion of the emulsifiable concentrate was not greatly disturbed by floating obstacles. And the diffusion rate was high when the specific grabity was lower than one.

• Korean Journal of Pharmacognosy
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• v.44 no.4
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• pp.362-367
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• 2013

Ojeok-san has been commonly used to treat low back pain disease. We performed the experiments on simultaneous analysis of 11 compounds and antioxidant effects of Ojeok-san. A HPLC method was established for simultaneous analysis of 11 compounds. The detection wavelengths were set at 230, 254, 280, 320, and 330 nm. The detected 11 compounds from Ojeok-san water extract showed good linearity($r^2{\geq}0.9997$). Limit of detection(LOD) and limit of quantification(LOQ) were 0.04-0.87 ${\mu}g/mL$ and 0.13-2.63 ${\mu}g/mL$, respectively. The antioxidant effects of Ojeok-san water extract were investigated by DPPH and ABTS assays. Ojeok-san water extract significantly increased the DPPH and ABTS radical scavenging effects in a dose-dependent manner. The $RC_{50}$ value of Ojeok-san on DPPH radical was 284.71 ${\mu}g/mL$ and that of ABTS radical was 96.16 ${\mu}g/mL$.

• CELLMED
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• v.10 no.2
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• pp.16.1-16.8
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• 2020

Standardization of drug deals with confirmation of drug identity and determination of drug quality and purity. Unani herbal formulations are used in traditional medicine for the treatment of various diseases. Cancer is a disease which causes abnormal, uncontrolled growth of body tissue or cells, which tend to proliferate in an uncontrolled way. Spread of cancer from site of origin to other organs of the body is called metastasis. It is a hyper proliferative disorder involving, transformation, dysregulation of apoptosis, invasion and angiogenesis. The present study aimed to standardize a classical Unani formulation (CUF) described as anticancer properties. The CUF has been used for anti-cancerous activity (Dāfi'-i-saraṭān) in human population by Unani physicians for centuries. The standardization parameters carried out for classical Unani formulation are pharmacognostical studies, physicochemical parameters, high-performance thin layer chromatography (HPTLC), microbial load, aflatoxins, and heavy metals revealing specific identities and to evaluate Pharmacopoeial standards. Experiment and the data obtained established the Pharmacopoeial standards for this formulation for identification and quality control purpose. The CUF has been successfully standardized and standard operating procedures (SOPs) for its preparation has been laid down which may serve as a standard reference in future. The standardization data of this formulation may be used as a standard guideline for preparation of the formulation in future.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.5
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• pp.662-668
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• 2010

We evaluated the physiological effects of formulations added with black garlic extract on skin care. Black garlic was made by spontaneous fermentation for 40 days at $60{\sim}70^{\circ}C$ and 85~95% RH without any additives. When black garlic extract was added to formulation, the tyrosinase activity was decreased significantly (p<0.05, p<0.01, p<0.001). Base formulation inhibited slightly elastase activity (<5%), while black garlic formulation had about 8-fold higher elastase inhibitory activity (p<0.01). It was observed that formulations, with or without black garlic extract, decreased thiobarbituric acid reactive substances (TBARS) and hydrogen peroxide which were increased by UVB irradiation, although there were no significant differences of these contents between black garlic formulation and base formulation. In conclusion, black garlic formulation had high inhibitory activities for tyrosinase and elastase, suggesting that black garlic may have beneficial properties as a material for cosmeceuticals.