• Structural Engineering and Mechanics
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• v.21 no.2
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• pp.151-168
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• 2005

In this paper an energy method is presented for the linear buckling analysis of first order shear deformable plates. The displacement fields are defined in terms of the shape functions, which correspond to a set of predefined points and are composed of significantly high order polynomials. The locations of these points are found by mapping the geometry using the naturalized coordinates and bilinear shape functions. In order to evaluate the method, fully clamped and simply supported rectangular plates subjected to uniform uniaxial compressive loading on two opposite edges of the plate are investigated thoroughly and the results are compared with the exact solution given in the monograph of Timoshenko and Gere (1961). The method is extended to the analysis of perforated plates, wherein the negative stiffness computed over the opening area from in-plane and out-of-plane deformation modes is superimposed to the stiffness of the full plate. Numerical results are then favorably compared with those obtained by finite element methods. Other cases such as; rectangular plates with eccentrically located openings of different shapes are studied and reported in this paper with regards to the effect of aspect ratio, hole size, and hole position on the buckling. For a square plate with a large circular opening at the center, diameter being 80 percent of the length, the present method yields buckling coefficient 12.5 percent higher than the one from the FEM.

• Journal of Forest and Environmental Science
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• v.34 no.1
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• pp.87-94
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• 2018

This study proposes a strategy for the creation and management of urban forests in Paju Heyri art village. Urban forest composition attributes (4 categories and 16 items) were extracted and the questionnaire was asked to the level and the current level for tourists, local residents and workers in Paju Heyri art village. And the priority order for the creation of urban forests was derived through the difference between the present level (performance) and the required level (importance) and the requirements analysis procedure. In this study, the priorities of each item of urban forest formation attributes were determined. The t-test alone had limitations, so we calculated the Borich needs which were not covered by the existing Importance - Performance Analysis (IPA). We used the Locus for Focus Model, which is a method for visually confirming the difference between the current level and the required value for the required level in the 4-quadrant coordinate plane. The results of this study show that the seven priorities can be used as a useful tool for the formulation of urban forests and operational strategies and can be a basic research for the activation of urban forests in the future.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.6B
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• pp.559-568
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• 2002

In this paper, we studied on combining the control of transmission fates and power for the real system where a finite set of transmission rates are used. In [1], the combined control of transmission rates and power was first researched, and suggested the Selective Power Control (SPC) algorithm. However, it can't guarantee the minimum rate to each user and results in frequent changes of rate due to oscillation of the SIR (Signal to Interference Ratio) values. As a main purpose of this paper, we derive a formulation model and propose a distributed iteration algorithm to solve these problems. To evaluate the performance of the proposed algorithm, we carried out numerical analysis and computational experiments. The results indicate that the proposed algorithm achieves better throughput than conventional one by keeping the low average transmission power.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.261-265
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• 2004

This paper proposes a fuzzy dual method for analyzing long-term transmission system expansion planning problem considering ambiguities of the power system using fuzzy lineal programming. Transmission expansion planning problem can be formulated integer programming or linear programming with minimization total cost subject to reliability (load balance). A long-term expansion planning problem of a grid is very complex, which have uncertainties fur budget, reliability criteria and construction time. Too much computation time is asked for actual system. Fuzzy set theory can be used efficiently in order to consider ambiguity of the investment budget (economics) for constructing the new transmission lines and the delivery marginal rate (reliability criteria) of the system in this paper. This paper presents formulation of fuzzy dual method as first step for developing a fuzzy Ford-Fulkerson algorithm in future and demonstrates sample study. In application study, firstly, a case study using fuzzy integer programming with branch and bound method is presented for practical system. Secondly, the other case study with crisp Ford Fulkerson is presented.

• Structural Engineering and Mechanics
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• v.57 no.1
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• pp.127-140
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• 2016

In this paper, a new first shear deformation plate theory based on neutral surface position is developed for the static and the free vibration analysis of functionally graded plates (FGPs). Moreover, the number of unknowns of this theory is the least one comparing with the traditional first-order and the other higher order shear deformation theories. The neutral surface position for a functionally graded plate which its material properties vary in the thickness direction is determined. The mechanical properties of the plate are assumed to vary continuously in the thickness direction by a simple power-law distribution in terms of the volume fractions of the constituents. Based on the present shear deformation plate theory and the neutral surface concept, the governing equations are derived from the principle of Hamilton. There is no stretching-bending coupling effect in the neutral surface based formulation. Numerical illustrations concern flexural and dynamic behavior of FG plates with Metal-Ceramic composition. Parametric studies are performed for varying ceramic volume fraction, length to thickness ratios. The accuracy of the present solutions is verified by comparing the obtained results with the existing solutions.

• Wind and Structures
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• v.37 no.1
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• pp.57-78
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• 2023

In this study, a generalized three-degree-of-freedom (3-DoF) analytical model is formulated to predict linear aerodynamic instabilities of a prism under quasi-steady (QS) conditions. The prism is assumed to possess a generic cross-section exposed to turbulent wind flow. The 3-DoFs encompass two orthogonal horizontal directions and rotation about the prism body axis. Inertial coupling is considered to account for the non-coincidence of the mass center and the rotation center. The aerodynamic force coefficients-drag, lift, and moment-depend on the Reynolds number based on relative flow velocity, angle of attack, and the angle between the wind and the cable. Aerodynamic forces are linearized with respect to the static equilibrium configuration and mean wind velocity. Routh-Hurwitz and Liénard and Chipart criteria are used in the eigenvalue problem, yielding an analytical solution for instabilities in galloping and static divergence types. Additionally, the minimum structural damping and stiffness required to prevent these instabilities are numerically determined. The proposed 3-DoF instability model is subsequently applied to a conductor with ice accretion and a full-scale dry inclined cable. In comparison to existing models, the developed model demonstrates superior prediction accuracy for unstable regions compared with results in wind tunnel tests.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.2
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• pp.231-238
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• 2015

An experiment was conducted to increase the quality of rice bran by fermentation using Bacillus amyloliquefaciens and humic substances and its utilization as a feed ingredient for broiler chickens. The experiment was carried out in two steps. First, the fermentation process was done using a completely randomized design in factorial with 16 treatments: i) Dosage of B.amyloliquefaciens ($2.10^8cfu/g$), 10 and 20 g/kg; ii) Graded levels of humic substances, 0, 100, 200, and 400 ppm; iii) Length of fermentation, three and five days. The results showed that the fermentation significantly (p<0.05) reduced crude fiber content. The recommended conditions for fermentation of rice bran: 20 g/kg dosage of inoculums B. amyloliquefaciens, 100 ppm level of humic substances and three days fermentation period. The second step was a feeding trial to evaluate the fermented rice bran (FRB) as a feed ingredient for broiler chickens. Three hundred and seventy-five one-day-old broiler chicks were randomly assigned into five treatment diets. Arrangement of the diets as follows: 0%, 5%, 10%, 15%, and 20% level of FRB and the diets formulation based on equal amounts of energy and protein. The results showed that 15% inclusion of FRB in the diet provided the best bodyweight gain and feed conversion ratio (FCR) values. In conclusion, the nutrient content of rice bran improved after fermentation and the utilization of FRB as a feed ingredient for broiler chickens could be included up to 15% of the broiler diet.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.15 no.1
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• pp.127-139
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• 2002

This study was carried out to prove the therapeutic effects of BNJB on the catract. The objects of this study were CXSD mice that spontaneously eye rupture occurred from three weeks after birth and eventually generate cataract within 12 weeks. We applied eyewash made from BNJB to eyes of CXSD mice twice in a day till all the eyes of the negative control showed up the symptoms of a cataract and recorded the increasing patterns of cataractous eyes. To explained the therapeutic effects of the BNJB, We carried out the ex vivo experiment which cultivating eyeballs were offered oxidative stress condition by $0.03{\%}$ $H_2O_2$ during three days. Total co-enzyme was extracted from the cultured eyeballs and used to measure activities of catalase, superoxide dismutase, glutathion S-transferase and content of GSH. The results were obtained as follows: 1. When we treated the catalin to CXSD mouse as a positive control, it represented the delaying effect for cataract generation for 2-3 days compare with negative control. But it seems that it doesn't appropriate as a therapeutic, or delaying agent. 2. In the experimental BNJB group, Cataract formation rate was dramatically reduced by BNJB. This rate was much lower than positive group and means our new formulation for the therapy of cataract has a good potential. 3. In the analysis of individual medicines of BNJB, Mok-Jeok-Cho, Hwang-Lyun and Ha-Go-Cho didn't have a major effect of BNJB. 4. The cataract formation rate was repressed by Bing-Pyun and Jin- Joo-Boon about $40{\%}$ and $50{\%}$, respectively. We can presume that the anti-cataract effect of BNJB was caused by these two medicines. 5. When we surveyed the anti-oxidant activities of BNJB, enzyme activities of GSH, SOD, and Catalase increased about $10{\%},\30{\%}$, and 2.5 folds, respectively.

• Plant Biotechnology Reports
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• v.3 no.3
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• pp.243-250
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• 2009

In the present study, a simple one medium formulation protocol for callus culture, somatic embryogenesis and in vitro production of ${\beta}-carboline$ alkaloids and diosgenin in Tribulus terrestris L. was developed. Extensive callus induction and proliferation was obtained in leaf explant on Murashige and Skoog (MS) medium supplemented with $5.0{\mu}M$ 6 benzyl adenine (BA) and $2.5{\mu}M$ ${\alpha}-naphthaleneacetic$ acid (NAA). The embryogenic callus was maintained on subculture to fresh parental medium at 4-week intervals over a period of 28 months. The frequency of embryo formation was at a maximum ($18.1{\pm}0.9$ per g of callus) on MS medium containing $5.0{\mu}M$ BA and $2.5{\mu}M$ NAA together with $75mg\;1^{-1}$ casein hydrolysate. Globular embryo developed into torpedo stage embryo under the influence of starvation. The accumulation of ${\beta}-carboline$ alkaloids (harmaline and harmine) and steroidal saponin (diosgenin) in non-embryogenic and embryogenic callus culture derived from leaf explant was compared with root, leaf, stem, and fruit of the mother plant. The embryogenic callus accumulated equivalent amounts of harmaline ($66.4{\pm}0.5{\mu}g/g$ dry weight), harmine ($82.7{\pm}0.6{\mu}g/g$ dry weight), and diosgenin ($170.7{\pm}1.0{\mu}g/g$ dry weight) to that of the fruit of T. terrestris. The embryogenic callus culture of this species might offer a potential source for production of important pharmaceuticals.

• Journal of Ginseng Research
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• v.22 no.4
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• pp.223-228
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• 1998

As part of a study on the ability of fungicides to control disappearing root rot of ginseng (Panax quinquvdius) caused by Cylindruarpn destmtans, 15 fungicides were screened for toxicity to the fungus in vitro. Highly toxic fungicides were Benlate (benomyl), Thiram (thiram), and Orbit (propiconazole). EC5O values (mg a.i./L) were less than 1 and EC95 values were less than 10. Crown (carbathiin and thiabendazole), ASC-66835 (fluazinam), and UBI-2584 (tebuconazole) were moderately toxic, with EC5O values in the range 1-10 and EC95 values in the range 32-45. Weakly toxic fungicides (EC5O in the range 20-80, EC95 in the range 35-140) included UBI-2643 (thiabendazole), UBI-2565 (cyproconazole), and Vitaflo-280 (carbathiin and thiram). Anvil (hexaconazole), Vitaflo-250 (carbathiin), UBI-2383 (triadimenol), Daconil (chlorothalonil), CGA-173506 (fludioxonil), and CGA-169374 (difeno- conazole) were considered nontoxic to C. destmtan (EC5O 1.29->600, EC95>500). Relations between proportional inhibition of growth and concentration of fungicide were linear on arithmetic plots (Benlate, UBI-2643, UBI-2565, Vitaflo-280) or logarithmic plots (all other fungicides). Based on toxicity in vitro and formulation, it is recommended that Benlate, Orbit, and ASC-66835 be tested as soil drenches, and Benlate, Thiram, UBI-2584, and Crown be tested as seed treatments for controlling disappearing root rot.