• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.5
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• pp.472-478
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• 2003

In this paper, a near zero If mixer was designed in cascode structure by using two single-gate FETs. Since it is driven by the second order harmonic of LO signal, a sub-harmonic cascode FET mixer has good LO-RF port isolation characteristic. In order to solve DC offset of a homodyne system, near zero If is used instead of zero If and the mixer is driven by sub-harmonic of LO signal. As RF input power was -30 dBm and LO power was 6 dBm, the designed mixer had 6.7 dB conversion gain, 8.4 dB noise figure, 31.5 dB LO-RF port isolation, -1.9 dBm lIP3 and -2.8 dBm IIP2.

• Science of Emotion and Sensibility
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• v.9 no.spc3
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• pp.187-196
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• 2006

This study has showed verified results on 'Survey into Observer Preference for Table Decoration for Eating and Drinking'. It is a preliminary study to look into interrelation of preference to color tables, image adjectives, aesthetic value, by giving color changes in a certain regularity to each influential factor in functional table decoration. The result has demonstrated that, as for color image and preference,'observers prefers mid/low dark-toned brown which gives a feeling of 'high-quality, and like to eat', and orange tone with a fooling of 'warm and colorful'. In evaluating interrelation between preference and aesthetic value, the study has revealed that ordinary people take the influential factor of 'unity and Gestalt' seriously, while non-professionals preferred 'uniqueness'. Stimulant No. 7 is one of constituent factors of functional table decoration, eliciting significance of images on colors ant aesthetic value. This study also has practical problems about insufficiency or inadequateness in producing mood suitable to T P O, according to depending upon color changes in picking up stimulants, or other problems in selecting stimulants, according to time, seasons and generational parameter in which the inquiry is conducted, but it will serve as a stepping stone for developing new design using both qualitative and quantitative data in 려nctional table decoration.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.3
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• pp.125-132
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• 2007

We estimated the distribution of predator-prey interaction strengths for 12 species of herbivores (including amphipods, isopods, gastropods, and sea urchins) and made a regression model that may be applicable to other species. Laboratory experiments were used to determine per capita grazing rate (PCGR; g seaweeds/individual/day). Relationship between the biomass of individual grazers and fourth-root transformed PCGR was fitted to power curve ($y=0.2310x^{0.3290}$, r=0.8864). This finding supported that the grazing efficiency was not even as individual grazers increase in size (biomass). Therefore, the biomass-normalized PCGR was estimated and revealed that smaller size herbivores were more effective grazers. Grazing impact considering density of each taxon was calculated. The sea hare Aplysia kurodai had greatest grazing impact on the seaweed bed and the sea urchin Strongylocentrotus nudus and S. intermedius were ranked in descending order of the impact. The amount of seaweed grazed by the amphipod Elasmopus sp. (>4,000 $ind./m^2$) and Jassa falcata (>2,000 $ind./m^2$) were 3.435 and $1.697mg/m^2/day$ respectively. The combined grazing amount of herbivores was $5,045mg/m^2/day$ in the seaweed bed. Although sea hare and sea urchin had strong impacts on seaweeds, the effects of dense, smaller species could not be seen as negligible. Surprisingly, the calculated grazing potential of sea urchins with a mean density of 3 $ind./m^2$ exceeded the mean production of seaweed cultured in domestic coastal waters in Korea (ca., 5 ton/ha). Small crustaceans were also expected to consume up to 16% of the seaweed production if their densities were rising under weak predation conditions. Considering that the population density of herbivores are strongly controlled by fish, human interference like overfishing may have strong negative effects on persistence of seaweeds communities.