• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.25 no.4
• /
• pp.241-250
• /
• 1992

This study was covered the amount of food consumed per day as well as methods estimating the daily food consumption per fish of Agrammus agrammus in natural population to understand flow of food organisms among trophic levels in bio-community of the coastal waters, Shinsudo, Samchonpo. The estimating formulas were induced from the mathematical models that representing the diurnal fluctuation of the stomach fullness of the fish. The daily food consumption could be estimated by both feeding rates and gastric evacuation rates, but it was more reasonable method that based on gastric evacuation rates than feeding rates. The daily food consumption in wet weight per fish by gastric evacuation rates were 1.9856g/day, 3.4725g/day, 4.4418g/day, 5.8168g/day, and 7.2113g/day in the order of age groups from 0 to 4. The daily rations as percentage of body weight were $9.35\%,\;6.65\%,\;5.76\%,\;4.72\%\;and\;5.31\%$ in the order of ages. The daily food consumption was proportional to the body weight of fish, but the daily food consumption per specific body weight was reciprocal to the body weight. Annual food consumption in wet weight. per fish by gastric evacuation rates were 529.98g from the age of 0.25 to 1.0, 1,269.28g from the age of 1.0 to 2.0, 1,622.76g from the age of 2.0 to 3.0, 2,125.57g from the age of 3.0 to 4.0, 1,316.09g from the age of 4.0 to 4.5 The amount of food consumed per fish during 4.25 years, from the age of 0.25 to 4.5, was 6,863.68g in wet weight. the relationships between the daily food consumption(Dr) by gastric evacuation rates and the total length(L, cm) or the body weight(W, g) were as follows: $$Dr=0.036L^{1.702}$$ $$Dr=0.254W^{0.664}$$

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.4 no.3
• /
• pp.75-83
• /
• 1984

The probability of failure is used to analyze the reliability of three dimensional slope failure, instead of conventional factor of safety. The strength parameters are assumed to be normal variated and beta variated. These are interval estimated under the specified confidence level and maximum likelihood estimation. The pseudonormal and beta random variables are generated using the uniform probability transformation method according to central limit theorem and rejection method. By means of a Monte-Carlo Simulation, the probability of failure is defined as; $P_f=M/N$ N: Total number of trials M: Total number of failures Some of the conclusions derived. from the case study include; 1. Three dimensional factors of safety are generally much higher than 2-D factors of safety. However situations appear to exist where the 3-D factor of safety can be lower than the 2-D factor of safety. 2. The $F_3/F_2$ ratio appears to be quite sensitive to c and ${\phi}$ and to the shape of the 3-D shear surface and the slope but not to be to the unit weight of soil. 3. From the two models (normal, beta) considered for the distribution of the factor of safety, the beta distribution generally provides lager than normal distribution. 4. Results obtained using the beta and normal models are presented in a nomgraph relating slope height and slop angle to probability of failure.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.9
• /
• pp.1305-1310
• /
• 2010

In a practical design process, the method of extracting the design space information of the complex system for verifying, improving, and optimizing the design process by taking into account the design variables and their shape tolerance is very important. Finite element analysis has been successfully implemented and integrated with design of experiment such as D-Optimal array; thus, a response surface model and optimization tools have been obtained, and design variables can be optimized by using the model and these tools. Then, to guarantee the robustness of the design variables, a robust design should be additionally performed by taking into account the statistical variation of the shape tolerance of the optimized design variables. In this study, a new approach based on the use of the response surface model is proposed; in this approach, the standard normal distribution of the shape tolerance is considered. By adopting this approach, it is possible to simultaneously optimize variables and perform a robust design. This approach can serve as a means of efficiently modeling the trade-off among many conflicting goals in the applications of finite element analysis. A case study on the robust optimal design of disc brakes under thermal loadings was carried out to solve multiple objective functions and determine the constraints of the design variables, such as a thermal deformation and weight.

• Korean Journal of Environmental Biology
• /
• v.19 no.1
• /
• pp.79-86
• /
• 2001

The apicomplexan parasite, Perkinsus sp., has been reported as a causative pathogen responsible for the mass mortality of the Manila clams, Ruditapes philippinarum in European countries as well as in Korea. Prevalence, infection intensity, histopathologic features and zoosporulation of Perkinsus found in the Manila clams distributed along the coast of Cheju Island were investigated in this study. Clams were collected from nine different beaches along the Cheju Island from May to July in 2000. Ray's Fluid Thioglycollate Medium (RFTM) and Choi's NaOH lysis methods were applied in the diagnosis and quantification of the Perkinsus infection. Prevalence, percentage infection of the parasite examined was 100% in Pyosun, 70% in Sungsan, 63% in Kumneong, 33% in Jongdalri, 21% in Iho, 17% in Moslpo, and 14% in Seogwipo. No Perkinsus was found in the clams collected from Kimnyong and Yongmeo-ri. Infection intensity as a number of Perkinsus cells per gram tissue wet weight (twwt), was 98,430 cells/g twwt in Pyosun, 78,553 cells/g twwt in Sungsan, 18,980 cells/g twwt in Kumneong, 4,290 cells/g twwt in Jongdalri, 1,527 cells/g twwt in Iho, 1,069 cells/g twwt in Moslpo, and 853 cells/g twwt in Seogwipo. Histological preparation of the infected tissues revealed trophozoites of Perkinsus sp., ranged from 5 to 10 ${\mu}{\textrm}{m}$, in diameter mostly distributed in the digestive gland and the gill filaments. Zoospores were discharged from the hypnospore via discharging tube about 2 days after incubated in filtered and aerated seawater. In general, the prevalence and infection intensity of Perkinsus in Cheju Island were much lower than that reported from the western and southern coast of Korea.

• International Journal of Highway Engineering
• /
• v.10 no.4
• /
• pp.103-116
• /
• 2008

In this study, in-situ testing method, Dynamic Cone Penetration Test(DCPT) was presented to establish a new compaction control criteria with using mechanical property like elastic modulus instead of unit weight for field compaction control. Soil chamber tests and in-situ tests were carried out to confirm DCPT tests can predict the designed elastic modulus after field compaction, and correlation analysis among the DCPT, CBR and resilient modulus of sub grade were performed. Also, DCPT test spacing criteria in the construction site was proposed from the literature review. In the result of laboratory tests, Livneh's equation was the best in correlation between PR of DCPT and CBR, George and Pradesh's equation was the best in the predicted resilient modulus. In the resilient modulus using FWD, Gudishala's equation estimates little larger than predicted resilient modulus and Chen's equation estimates little smaller. And KICT's equation estimates the modulus smaller than predicted resilient modulus. But using the results of laboratory resilient modulus tests considering the deviatoric and confining stress from the moving vehicle, the KICT's equation was the best. In the results of In-situ DCPT tests, the variation of PR can occur according to size distribution of penetrate points. So DCPT test spacing was proposed to reduce the difference of PR. Also it was shows that average PR was different according to subgrade materials although the subgrade was satisfied the degree of compaction. Especially large sized materials show smaller PR, and it is also found that field water contents have influence a lot of degree of compaction but a little on the average PR of the DCPT tests.

• The Journal of Engineering Geology
• /
• v.25 no.2
• /
• pp.189-199
• /
• 2015

Our country's leading granite weathered soil of the ground slope failures that occur in cutting slope most cases, it does not require in-depth to the shear strength most of the surface layer is affected by weathering (1~2 m) at a shallow depth close to the ground, it is important to identify the reliability. Based on the result obtained in actual field investigation, the field slope type was classified by each type of wedge slope, Infinite slope, finite slope -I and finite slope -II, and the slope stability was examined respectively. In addition, using the numerical analysis results, the relationship between the slope inclination angle and safety factor was analyzed and it tried to offer basic data to which the stability in the field slope was able to be estimated by analyzing the safety factor change of the slope according to the slope type. In this study, classified into four types of natural slope, safety factor estimation method by slope types is proposed through the numerical analysis. However, some limit exists in generalizing in this research because it does not test various case studies. Therefore, the case study of a wide range of various sypes to assess the safety of various types slope can be made, accommodate a wide range of field conditions reasonable risk evaluation criteria may be derived.

• The Korean Journal of Pesticide Science
• /
• v.7 no.4
• /
• pp.271-279
• /
• 2003

To investigate the toxicological effects of technical of IAP-3006, we performed subchronic oral toxicity study in Sprague-Dawley (SD) rats. In the subchronic dietary study, rats of both sexes were fed diets containing technical of IAP-3006 at concentrations of 0, 1000, 10,000, or 15,000 ppm for 90 days. No clinical signs and mortality were observed in animals treated with technical of IAP-3006 throughout the experimental period. There were also no significant changes in body weights, feed consumption, and any gross or histopathological lesions. Although there were statistically significant differences between the control and treated groups in some relative and absolute organ weights, and hematological and biochemical analyses, the data were in biologically normal ranges and did not show a dose-dependent manner. From these results, it is suggested that subchronic oral toxicity NOEL of technical of IAP-3006 in rats may be over 15,000 ppm.

• The Korean Journal of Community Living Science
• /
• v.15 no.1
• /
• pp.91-104
• /
• 2004

This study was designed to investigate and evaluate the dietary intake of 30 housewives, aged 35 to 59. The subjects kept daily diet records lot a period of one year. Their mean daily nutrient intakes met or exceeded the RDA (recommended dietary allowance) for all categories except energy, calcium, iron, vitamin A, and vitamin B$_2$. Mean daily calorie intakes were 81.2% of the RDA. The subjects received about 19% of their energy from fat and 15% from protein. Nutrient adequacy ratios (NAR) were 0.60 for calcium, 0.62 for iron, 0.71 for vitamin A, and 0.76 for vitamin B$_2$. The mean adequacy ratio (MAR) was 0.79. Subjects received various nutrients from rice, pork, eggs, and Kimchi. Rice was a major contribute. to many subjects' nutrient intake due to the high amount of consumption. Pork, rice, and vegetable oil greatly contributed to fat intakes while eggs, pork, and beef supplied a high level of cholesterol compared to other foods. Kimchi, anchovies, and milk were the major contributors of calcium, while rice, pork, and Kimchi were the major contributors of iron. These results indicate that the major nutritional problem of middle-aged housewives is an overall inadequate intake of energy, calcium, and iron.

• Korean Journal of Food Science and Technology
• /
• v.43 no.4
• /
• pp.453-457
• /
• 2011

The effect of the amount of water added during fermentation on the quality of takju (rice beer) was investigated. Takju was made by adding water 2-fold (A), 4-fold (B), 5-fold (C), and 6-fold (D), respectively, of the rice weight (w/w). Although the amount of takju increased in proportion to the amount of water added before fermentation, the amounts of B, C, and D were 1.17-1.19 times larger than the amount in A, and the total acidities of B, C, and D were 1.34, 1.40 and 1.46 times higher than those in A after adjusting alcohol content to 6%(v/v). Moreover, the sensory preferences for B, C, and D were higher overall than those for A, which was suggested to be due to the amount of sweet, sour, and bitter tastes as well as body in A. Different types of takju could be made by changing the amount of water added before fermentation.

• Korean Journal of Microbiology
• /
• v.50 no.4
• /
• pp.302-307
• /
• 2014

Many rhizobacteria can promote plant growth through various direct or indirect mechanisms, and their production of phytohormones such as indole-3-acetic acid (IAA) may have pronounced effects on growth and development of plants. Rhizobacterial strain isolated from rhizosphere of foxtail (Setaria viridis), Acinetobacter sp. SW5 produced 118.1 mg/L of IAA and 4.5 mg/L of gibberellin ($GA_3$) in brain heart broth medium at 2 and 1 day of incubation, respectively. In a pot test the lengths of stem and root and fresh weight of the germinated tomato seedlings treated with Acinetobacter sp. SW5 significantly increased by 26.3, 33.3, and 105.3%, respectively compared to those of the uninoculated control in 12 weeks of cultivation. When the root exudate secreted from tomato seedlings was analyzed by HPLC, 3.75 ng mg tomato $root^{-1}$ of tryptophan which is an IAA precursor was detected. Acinetobacter sp. SW5 could produce $4.06{\mu}M$ of IAA from root exudate from 8 tomato seedlings. Together with the capability of growth of Acinetobacter sp. SW5 in the tomato root exudates, this IAA secreted by bacteria might contribute to enhance the growth of tomato plants.