• 대학교육
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• s.134
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• pp.87-91
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• 2005

• 열병합발전
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• s.57
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• pp.4-10
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• 2007

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.1
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• pp.57-63
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• 2007

The systematic method to construct equivalent static load from a given dynamic load is proposed in the present study. Previously reported works to construct equivalent static load were based on ad hoc methods. Due to improper selection of loading position, they may results in unreliable structural design. The present study proposes the employment of primary degrees of freedom for imposing the equivalent static loads. The degrees of freedom are selected by two-level condensation scheme with reliability and efficiency. In several numerical examples, the efficiency and reliability of the proposed scheme is verified by comparison displacement for equivalent static loading and dynamic loading at the critical time.

• Journal of Plant Biotechnology
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• v.31 no.4
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• pp.295-300
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• 2004

This article was conducted to induce the transgenic hairy roots and determine the effect of culture conditions on optimum growth of hairy roots by Agrobacterium rhizogenes strain, 15834 in Lycium chinense Miller. Hairy roots of L. chinense Miller. were induced from leaf segments by co-cultivation with A. rhizogenes. When the hairy roots were cultured in various MS medium strength and sucrose concentrations, the highest growth of hairy roots was observed in half-strength MS media supplemented with 3% sucrose, respectively. In air lift bioreactor cultures, the liquid medium contained with 1/2 MS and 3% sucrose was also the best for optimum growth of hairy roots.

• Korean Journal of Environmental Agriculture
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• v.30 no.1
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• pp.68-75
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• 2011

BACKGROUND: To assess and prevent the environmental impacts and risks by veterinary pharmaceuticals, Guidance on Estimating Soil Persistence and Degradation Kinetics from Environmental Fate Studies on Veterinary Pharmaceuticals for Environmental Risk Assessment was proposed. METHODS AND RESULTS: Proposed guidance was coined by VICH, EU guideline, OECD guideline and soil dissipation studies for the purpose of international harmonizing. Guidance was also modified from pesticide soil persistence testing guidelines of US, EU, and Korea, with practical approaches adopting in-use test guideline for Korea. CONCLUSION(S): Proposed guidance are consisted of three parts; Laboratory Soil Experiment, Field Soil Dissipation Study, and Estimation of $DT_{50}/DT_{90}$. Proposed guidance is to be available for the requirement for registration of veterinary pharmaceuticals with fit for purpose in Korea.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.11
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• pp.1361-1370
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• 2012

A shape optimization is proposed to obtain the desired final shape of forming and forging products in the manufacturing process. The final shape of a forming product depends on the shape parameters of the initial blank shape. The final shape of a forging product depends on the shape parameters of the billet shape. Shape optimization can be used to determine the shape of the blank and billet to obtain the appropriate final forming and forging products. The equivalent static loads method for non linear static response structural optimization (ESLSO) is used to perform metal forming and forging optimization since nonlinear dynamic analysis is required. Stress equivalent static loads (stress ESLs) are newly defined using a virtual model by redefining the value of the material properties. The examples in this paper show that optimization using the stress ESLs is quite useful and the final shapes of a forming and forging products are identical to the desired shapes.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.6
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• pp.619-627
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• 2014

An optimization method is proposed for the simultaneous design of structural and control systems using the equivalent static loads. In the past researches, the control parameters of such feedback gains are obtained to improve some performance in the steady-state. However, the actuators which have position and velocity feedback gains should be designed to exhibit a good performance in the time domain. In other words, the system analysis should be conducted for the transient-state in dynamic manner. In this research, a new equivalent static loads method is presented to treat the control variables as the design variables. The equivalent static loads (ESLs) set is defined as a static load set which generates the same displacement field as that from dynamic loads at a certain time. The calculated sets of ESLs are applied as multiple loading conditions in the optimization process. Several examples are solved to validate the proposed method.

• Journal of Sericultural and Entomological Science
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• v.16 no.1
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• pp.57-65
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• 1974

This study has been carried out to investigate the effect of protein components of a diet on the increasing of larval body weight and diet efficiency, as well as the amylase activity of larval digestive juices during the 5th instar. Defending on the amounts of soybean meal as a protein source, the six different kind of artificial diets containing mulberry leaf powder fed to the larvae. The results obtained may be summarized as follows： 1. As the protein components of the diet were increased, the amount of increased larval body weight was also increased. 2. As the protein components of the diet were increased, both the cocoon weight and cocoon layer weight were also increased. 3. As the protein components of the diet were increased, both the amount of diet digested and coefficient of digestibility were also increased. 4. As the protein components of the diet were increased, the diet efficiency of larvae were also increased. 5. But the experimenters could not observe any correlation between the increase of protein components of a diet and the amylase activity of the digestive juices.

• Journal of the Korean Vacuum Society
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• v.13 no.2
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• pp.65-71
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• 2004

ESR spectrum change has been investigated for the PECVD deposited a-C : H films exposed in the atmosphere. Though depending on the deposition conditions, it was observed that generally ESR signal height decreased and linewidth increased as the exposure time increased. The spin density decreased down to 40-80% depending on samples. The decrease of spin density of the a-C : H films in the air was attributed to permeation of moisture into the films and subsequent migration and redistribution of hydrogens. And the ESR signal height increased again and the linewidth decreased when the a-C : H samples were placed again in the vacuum, which was attributed to oxygens extracted from the samples. Consequently, the ESR spectrum change for the a-C : H films exposed in the air was regarded to be associated with the decrease of spin density as well as the permeation of oxygens into films.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.3
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• pp.115-120
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• 1974

Secondary amines are known as one of the precursors of nitrosamines which are potent carcinogenic compounds of man and animals. Nitrosamines are formed when both secondary amines and nitrite are present. The nitrites are occurred naturally in vegetables, fruits and many others, and frequently used in fish product as a color fixative or a preservative. In this paper, to know the formation of nitrosamines in fish meat, the changes of dimethylamine (DMA) content during the heat treatment such as drying, roasting and fish cake processing are discussed. The results showed that generally DMA increased considerably during heat processing. During drying, DMA in cuttle fish increased 16 times higher, while in Alaska pollack doubled than the fresh. In the roasted mackerel, the DMA content appeared 6 times higher than the fresh, while 9 times higher in canning. In fish cake from yellow corvenia, DMA increased 4 times higher than the fresh. On the contrary diethylamine and diphenylamine were not found in this experiment.