• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.193-200
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• 2004

In this study, the impact load on bridge by vessel collision in consideration of fender system is evaluated by numerical method. The bow of object vessel(DWT5000) is standardized, and modeled by shell elements. The main body of objective vessel is modeled by beam elements that present mass distribution and stiffness of vessel. The buoyancy effect of vessel is considered as linear spring. The two types of fender systems, such as steel and rubber are analyzed in this study. In steel fender system, the steel plates that absorb collision energy by its collapse are modeled by shell element with stiffener. The steel is material modeled elastic-plastic material. In the rubber fender system, the rubber material is modeled hyper-elastic material and the main body of fender is modeled by solid elements. The global impact responses of vessel and fender system are evaluated by explicit dynamic scheme. The results show that the magnitude of vessel collision force are depended on the material behavior of fender system. Also the values of collision load are conservative compare to the those of design codes.

• The Korean Journal of Ecology
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• v.8 no.1
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• pp.7-14
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• 1985

Biomass, carbon, nitrogen and phosphorus standing crops of bethic community were estimated at the trophic levels in the intertidal zone of Kum river estuary. Annual mean biomass of zoobenthos was 130.5g/$m^2$, body fraction 26.7g/$m^2$ and shell fraction 103.8 g/$m^3$. Biomass estimated as ash-free dry weight was total 28.9g/$m^2$, body fraction 20.2g/$m^2$ and shell fraction 8.7g/$m^2$ Carbon standing crops of zoobenthos were 15.9gC/$m^2$, in which organic carbon content was 7.0gC/$m^2$ and carbonate carbon was 8.9gC/$m^2$. Production efficiency by carbon standing crops from sediment to herbivores and carnivores and 10.6% and 16.0% in phosphorus, respectively. Annual primary production of benthic algae was crudely estimated to 329g.dw/$m^2$/yr by using the biomass and turn-over rate of benthic algae.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1026-1030
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• 2007

A linear compressor used in a refrigerator has higher energy efficiency than a reciprocating compressor. But its vibration level is still severe than others. The vibration level of linear compressor at the frequency of 60Hz is dominant since it is the exciting frequency of a motor. Experimental approach to reduce the vibration needs much effort and long period. In this paper, simulation tool to predict the vibration of the shell of the linear compressor was developed. The piston, body and shell are assumed to be rigid, while the loop pipe is flexible. The results by the developed tool showed good agreements with those by experiments.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.871-876
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• 2001

One-touch fittings are important components that can make a quick and tight connection between pneumatic pipe systems. In this study, the stress analyses with various working pressures on these one-touch fittings are carried out using finite element method. Material properties, to use the stress analyses, are measured by the universal tester and digital Vickers hardness tester. The stress analyses on the circular shell spring forced by various pressures(100, 150, 200, 250kpa) and on the main body due to the fluid-structural interaction are investigated. Results show that the stresses of one-touch fitting are concentrated to supported part of main body and the soundness of a circular shell spring with maximum pressure 250kpa was confirmed.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.18-30
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• 2006

In this paper is studied a theoretical approach to predict structural performances and weight reduction rates of a car-body with shell type sections in case that its materials have to be substituted. For the material substitution design of a car-body, bending, axial and twisting deformations are considered under constant stiffness and strength conditions, which utilize some new indices derived from a structural performance point of view. The developed indices to measure the weight reduction by the material substitution give good guidelines on conceptual design of car-bodies.

• Proceedings of the Korean Ceranic Society Conference
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• 2000.04a
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• pp.25.2-25.2
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• 2000

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.6
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• pp.933-938
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• 2007

An experiment was conducted to study the laying performance, shell quality, bone mineralization, hatchability of eggs and performance of progeny (weight at day one and 14 d of age, P content in day old chick, leg score and survivability of chicks) of synthetic broiler breeders fed different levels of non-phytate phosphorus (NPP). Six levels of NPP (1.2, 1.8, 2.4, 3.0, 3.6 and 4.2 g/kg diet) at a constant calcium (Ca) level (30 g/kg) in a maize-soya-deoiled rice bran based diet were tested. Levels of dicalcium phosphate, shell grit and deoiled rice bran were adjusted to achieve the desired levels of NPP and Ca. Each level of NPP was fed with a weighed quantity of feed (160 g/b/d) to 40 female broiler breeders from 25 to 40 weeks of age housed in individual cages. Each bird was considered as a replicate. Egg production, feed/egg mass, body weight, egg weight, shell weight, shell thickness, egg specific gravity, serum Ca content and tibia breaking strength were not influenced (p>0.05) by the variation in dietary NPP levels tested. Increasing the dietary levels of NPP did not influence the hatchability of eggs, phosphorus (P) contents both in egg yolk and day old chick, chick body weight at day one and 14 d of age, leg score and survivability of chicks up to 14 d of age. Maximum response ($p{\leq}0.01$) in shell breaking strength, tibia ash and serum inorganic P contents were observed at NPP levels of 2.09, 2.25 and 3.50 g per kg diet, respectively. The retention of Ca increased, while the P retention decreased ($p{\leq}0.01$) with increasing dietary levels of NPP. Though maximum responses in shell breaking strength, bone ash and serum inorganic P were observed at NPP higher than 1.2 g/kg diet, the broiler breeder performance in terms of egg production, shell quality, hatchability of eggs and progeny performance and their survivability was not influenced by dietary NPP concentrations. It is concluded that synthetic broiler breeders maintained in cages do not require more than 1.2 g NPP/kg diet with a daily intake of 192 mg NPP/b/d during 24 to 40 weeks of age.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.8
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• pp.1164-1170
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• 2008

In this study, the effects of propolis and vitamin C (L-ascorbic acid) supplementation in diets were investigated on feed intake (FI), body weight (BW), body weight gain (BWG), feed conversion rate (FCR) and digestibility and on egg production and qualities (weight, mortality, shell thickness) in laying hens exposed to heat stress. A total of 150 Hyline White Leghorn, aged 42 weeks, hens was divided into five groups of 30 hens. Chicks were randomly divided into 1 positive control, 1 control and 3 treatment groups. The chicks were kept in cages in temperature-controlled rooms at $22^{\circ}C$ for 24 h/d (positive control, Thermoneutral, TN group) or $34^{\circ}C$ for 9 h/d from 08.00-17.00 h followed by $22^{\circ}C$ for 15 h (control, heat stress, HS group) and fed a basal diet or basal diet supplemented with vitamin C (250 mg/kg of L- ascorbic acid/kg of diet) or two levels of propolis (2 and 5 g of ethanol extracted propolis/kg of diet). Increased FI (p<0.05) and improvement in FCR (p<0.05), hen day egg (p<0.05) and egg weight (p<0.05) were found in Vitamin C and propolis-supplemented laying hens reared under heat stress conditions. Mortality rate was higher in the control group than TN, vitamin C and propolis groups (p<0.05). Digestibility of dry matter, organic matter, crude protein and ether extract improved with increasing of both dietary vitamin C and propolis (p<0.05). Vitamin C or propolis supplementation did not affect either the percentage shape index, yolk index or haugh unit and albumen index (p>0.05). However, the egg shell thickness and egg shell weight appeared to be increased in Vitamin C and propolis groups in comparison to HS group birds (p<0.05). In conclusion, dietary supplementation of laying hens with anti-oxidants (vitamin C and propolis) can attenuate heat stress-induced oxidative damage. These positive effects were evidenced by increased growth performance and digestibility, improvement of egg shell thickness and egg weight in comparison to non-supplemented birds. Moreover, supplementation with propolis (5 g/kg diet) was the most efficient treatment.

• Fisheries and Aquatic Sciences
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• v.18 no.2
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• pp.159-164
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• 2015

A feeding experiment was conducted to determine the effect of dietary distillers dried grain (DDG) on the growth and body composition of juvenile abalone, Haliotis discus hannai. Three diets were formulated to contain 0% (DDG0), 30% DDG (DDG1) replacing wheat flour and 30% DDG (DDG2) replacing fish meal and wheat flour. A commercial feed (CF) was also compared with experimental diets. Three replicate groups of abalone averaging $0.6{\pm}0.01g$ were fed one of the four diets for 14 weeks. The highest survival rate was observed in the abalone fed the DDG2 diet, which was higher than that of abalone fed the DDG0 diet. Weight gain, shell length, shell width and soft body weight of the abalone were not affected by dietary DDG and CF diet (P > 0.05). Proximate and amino acid composition of the soft whole body were not affected by dietary DDG and CF diet (P > 0.05). The result of this experiment suggests that DDG is a good ingredient to replace fish meal and wheat flour in the diet and could be used up to 30% in the diet without negative effects on the growth performance of juvenile abalone Haliotis discus hannai.

• Structural Monitoring and Maintenance
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• v.5 no.2
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• pp.297-311
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• 2018

Plate and shell structure is widely applied in engineering, i.e. building roofs, aircraft wings, ship platforms, and satellite solar arrays. Its vibration problem has become increasingly prominent due to the tendency of lightening, upsizing and flexibility. As a new smart material with great actuating force and toughness, macro-fiber composite (MFC) is composed of piezoelectric fiber and epoxy resin basal body, which can be directly pasted onto the surface of plate and shell and is suitable for vibration control. This paper deduces the actuation equation of MFC coupled plate in different boundary conditions, an equivalent finite element modeling method is proposed which uses MFC actuating force as the applied excitation, and on this basis the active control simulation and experiment of MFC over plate and shell structure vibration are accomplished. The results indicate that MFC is able to implement effective control over plate and shell structure vibration in multi-band range. The comparison between experiment and simulation proves that the actuation equation deduced herein, effective and practicable, can be applied into the simulation calculation of MFC vibration control over plate and shell structure.