• The Korean Journal of Ecology
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• 제16권2호
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• pp.155-157
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• 1993

The life-cycle and seasonal abundance of Anaulaciulus koreanus koreanus was studied at Hwang-dong, Chonbuk Province, Korea from October 1990 to February 1992. The egg hatches in spring and the pupoid stage is passed through within the egg shell. The juvenile develops as far as stadium IX by the third year following the birth. Pairing and oviposition take place in the fourth year spring when females are at stadium XI. They seem to live one or two years more after egg-laying. Anamorphosis was observed in this species. Abundance of A. koreanus koreSanus increases from April to May when there appears thefirst peak. It fals gradualy thereafter and the species spends summer months underground from July to September. The second peak appears in October and the activity decreases again in November getting ready to overwinter. The first peak arises from a large number of individuals of 2 and 3 year old overwintered plus newly hatched spring juveniles, and the second from 1 to 3 years old wanderings. Inactivity observed in the species during summer and winter seasons appears to be a temporal due to the extreme temperatures.

• 생태와환경
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• 제40권2호
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• pp.346-351
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• 2007

Change of carabid beelte (Coleoptera, Carabidae) diversity and population structures in Woopo Wetlands (Changneung-Gun, Gyeungsangnam-Do, S. Korea) were investigated after flooding events. During the investigation period, 11 species belonging to five genera were identified. Dolichus halensis halensis(Schaller), Chlaenius (Ch.) pallipes Gebler, Ch. (Ilaenchus) naeviger Morawitz, and Pheropsophus (Stenaptinus) jessoensis Morawitz were the predominant species in Woopo Wetlands. Floods occurred twice, August and September in 2004. After the flooding events, species diversity decreased and species assemblage structures changed dramatically. Changes of the diversity and species assemblage structures were more evident in August then in September, because water level was much higher and inundation period was longer than September. A non-linear patterning algorithm of the Self-Organizing Map (SOM) was applied to discover the relationship between flooding events and carabid beetles community dynamics. Although abundance of the majority species decreased after the flooding events, that of the predominant species increased. Further detailed studies on species distribution and emigration patterns will likely bring a new insight in understanding of the adaptation mechanism of carabid beetles in wetlands.

• 농촌지도와개발
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• 제9권2호
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• pp.185-197
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• 2002

The supporting system for agricultural workforce and education strategy has been changing both domestically and worldwide range term. To change the fundamental directions, much more needs to be learned about the process of structural adjustment regarding the dynamics of the agricultural and rural sectors. A rural development doctrine must pay more attention to the ongoing problems of population imbalance and the dissolution of the countryside. The focus should be young people prefer to live in cities because there are more opportunities, services, and great personal fulfillment. This paper was described the effective fostering directions of young agricultural workforce and educational program to prepare future and young farmer for teaching careers in agriculture, food, farm management, and marketing. To achieve these goals, the specific approaches are 1) establish the strong partnership between related organizations of agricultural business, 2) strengthen the management and marketing education of products, 3) create the various in-farming or out-fanning incomes including green tourism, 4) enhance the aggressive marketing strategies by Internet, Telephone, and TV etc, 5) make the association among the same items for the effective research and risk management.

• 한국환경과학회지
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• 제26권4호
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• pp.447-456
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• 2017

Chemical properties of aerosols were investigated by analyzing the inorganic water-soluble content in $PM_{2.5}$ collected in the downtown area of Jeju City in Jeju Island. Due to an increase in both the number of visiting tourists and the size of local population, the number of cars in this area is increasing, causing an increase in $PM_{2.5}$. Eight $PM_{2.5}$-bound major inorganic ions were analyzed during the summer and winter periods. The water-soluble inorganic component represents a significant fraction of $PM_{2.5}$. In particular, secondary inorganic aerosols contribute 36.2% and 47.5% of $PM_{2.5}$ mass in summer and winter, respectively. Nitrate concentrations increase for $[NH_4{^+}]/[SO_4{^{2-}}]$>1.5, and excess ammonium, which is necessary for ammonium nitrate formation, is linearly correlated with nitrate. These results are clearly observed during the winter because conditions are more conducive to the formation of ammonium nitrate. A significant negative correlation between Nitrogen Oxidation Ratio (NOR) and temperature was observed. The obtained results can be useful for a better understanding of the aerosol dynamics in the downtown area in Jeju City.

• 대한기계학회논문집A
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• 제33권10호
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• pp.1029-1037
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• 2009

Recently, the technologies of mobile robots have been growing rapidly in the fields such as cleaning robot, explosive ordnance disposal robot, patrol robot, etc. However, the researches about the autonomous underwater robots have not been done so much, and they still remain at the low level of technology. This paper describes a model of 3-joint (4 links) fish robot type. Then we calculate the dynamic motion equation of this fish robot and use Singular Value Decomposition (SVD) method to reduce the divergence of fish robot's motion when it operates in the underwater environment. And also, we analysis response characteristic of fish robot according to the parameters of input torque function and compare characteristic of fish robot with 3 joint and fish robot with 2 joint. Next, fish robot's maximum velocity is optimized by using the combination of Hill Climbing Algorithm (HCA) and Genetic Algorithm (GA). HCA is used to generate the good initial population for GA and then use GA is used to find the optimal parameters set that give maximum propulsion power in order to make fish robot swim at the fastest velocity.

• International Journal of Industrial Entomology and Biomaterials
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• 제31권2호
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• pp.35-39
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• 2015

The developmental responses of insects to temperature are important considerations in gaining a better understanding of their ecology and life histories. Temperature-dependent phenology models permit examination of the effects of temperature on the geographical distributions, population dynamics, and management of insects. Measurements of insect developmental and survival responses to temperature pose practical challenges that depend on the chosen modality, variability among individuals, and high mortality rates near the lower and upper threshold temperatures. Different temperature levels can significantly affect larval development of Eurema hecabe. The development of E. hecabe reared on leaves of Lespedeza cuneata was investigated at three temperature regimes (20, 25, and 30℃), a relative humidity of 60%, and a light:dark photoperiod of 14:10 h. The developmental time from larva to adult was 34.3, 20.6, and 17.9 d at temperatures of 20, 25, and 30℃, respectively. Pupal rate was 47.6%, 47.6%, and 61.9% at temperatures of 20, 25, and 30℃, respectively. The developmental threshold temperature estimated from larva to pupae was 8.1℃ with 381.7 degree-days. There is an increasing need for a standardized manual for rearing this butterfly species based on adequate knowledge of its ecology.

• Asian review of World Histories
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• 제2권2호
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• pp.197-216
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• 2014

This paper examines A. G. Frank's views about 15th-19th Korea (Joseon Dynasty) in his Reorient. A. G. Frank recognized that Korea might have played a great role in the international relations of East Asia, but he did not write systematically about it and he did not treat Korea as an independent player in the history of East Asia. I think the greatest limitation to his re-interpretation of East Asia is in that he depends too much on China's and Japan's perspective. In order to overcome Frank's shortcomings regarding the history of Korea, first I examine what Frank recognized about the Joseon dynasty between 1400 and 1800. Next I compare Joseon's development to that of China and Japan between 1400 and 1800. Frank compared Europe and East Asia (mainly China and Japan) from three aspects of quantities (population, production, productivity, and trade), qualities (science and technology), and mechanism (economic and financial institutions). With this research we insist that Joseon should not be dismissed in 15th-19th East Asia. The reasons are as follows. First, Joseon between 1400 and 1800 had developed economically as much as China and Japan. Second, Joseon had played a great role in connecting China and Japan and had a positive influence on the development of Japan. So we need to reappraise Reorient's view about East Asia. Only when role of Joseon can be correctly estimated, the dynamics and diversity of East Asia can be properly understood.

• Asian-Australasian Journal of Animal Sciences
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• 제13권9호
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• pp.1219-1227
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• 2000

Rumination behavior, in vivo digestibility of cell wall constituents, particle size reduction in the rumen, and retention time in the digestive tract of sheep were examined using rice and oat straw as roughage sources. The in sacco digestibility, rumen fermentation, and microbial population and internal adenosine 5-triphosphate (ATP) content were also determined under feeding conditions of high-roughage and high-concentrate diets. Chewing number and time in rumination behavior were higher with rice straw than with oat straw, while the in sacco and in vivo DMD of rice straw were consistently lower than those of oat straw. Rice straw also showed higher frequency of thinner and longer particles in the rumen contents and lower retention time in the whole digestive tract as compared to those of oat straw. Rice straw was more effective to maintain the ruminal pH than oat straw, being reflected in higher internal ATP content of large-type protozoa on the high- concentrate diet. Changes in the ruminal microflora by shifting from the low- to the high- concentrate diet were also different between rice and oat straw.

• Ocean and Polar Research
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• 제31권3호
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• pp.265-276
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• 2009

Acartia hongi is the most dominant and widespread planktonic copepod in Gyeonggi Bay, Yellow sea. Ingestion rates and selectivity of A. hongi on phytoplankton and planktonic ciliates were determined in the laboratory. Ingestion rates of A. hongi on planktonic ciliates and phytoplankton increased in proportion to prey concentration increase. When A. hongi was fed with various mixture combinations of planktonic ciliates and phytoplankton, their ingestion rate on ciliates tended to increase as the percentage of ciliates in prey biomass increased. Clearance rate of A. hongi on planktonic ciliates was higher than for phytoplankton in all experiments without regard to relative percent of ciliate biomass. This trend suggests that A. hongi was preferentially preying on planktonic ciliates. Under mixed prey availability, it is likely that selective feeding and higher clearance rate of planktonic ciliates by A. hongi is related to the higher nutritional value of ciliates compared to phytoplankton. Therefore, our results suggest that selective ciliate feeding by A. hongi will positively benefit its growth and abundance, and as a result negatively impact the population dynamics of planktonic ciliates in Gyeonggi Bay.

• Journal of Microbiology and Biotechnology
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• 제12권5호
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• pp.801-806
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• 2002

A multiplex competitive polymerase chain reaction (PCR) method was developed for the rapid identification and quantification of Leuconostoc mesnteroides and Lactobacillus plantarum populations which are the key microorganisms in kimchi fermentation. The strain-specific primers were designed to selectively amplify the target genes encoding 165 rRNA of L. plantarum and dextransucrase of L. mesenteroides. There was a linear relationship between the band intensity of PCR products and the number of colony forming units of each model organism. The PCR quantification method was compared with a traditional plate-counting method f3r the enumeration of the two lactic acid bacteria in a mixed suspension culture and also applied to a real food system, namely, watery kimchi. The population dynamics of the two model organisms in the mixed culture were reliably predictable by the competitive PCR analysis.