• Korean Journal of Agricultural Science
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• v.39 no.4
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• pp.545-553
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• 2012

In Asia, including Japan and Korea, rice paddies occupy the largest cultivated area in agricultural land. Rice paddies provide the habitats for many organisms including endemic species, sustaining high biodiversity. Insect natural enemies inhabiting rice paddies have an important function for rice production as agents of 'ecosystem services' because they play a major role in suppressing rice pests. The diversity and abundance of natural enemies can be a good index reflecting the 'healthiness' of agro-ecosystem services in rice paddies. The present study investigates whether insect natural enemies could be good biological indicators for general arthropod biodiversity and agricultural practice. First, the concept of ideal bio-indicators was summarized. The strategy to explore and select such bio-indicators was then proposed. Lastly, field survey was made to evaluate the abundance and biodiversity of natural enemies in Japanese rice paddies where chemical inputs, i.e., insecticide use, were different. The results showed that reduction of chemical inputs led to an increase in species richness or diversity of natural enemies including parasitoids and predators. Then, the data were analyzed to examine suitable indicator species to assess environmental soundness of agricultural practice and biodiversity in rice paddies. The density of several species of natural enemies did respond both to pesticide use and to general arthropod biodiversity. The analyses thus have indicated that natural enemies can be suitable as bio-indicators. Usefulness of indicator species in rice paddies is discussed in the context of ecologically sound agriculture.

• The Journal of the Acoustical Society of Korea
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• v.25 no.8
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• pp.362-369
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• 2006

In this paper, we improve a Physical modeling of sanio gayageum and synthesize sounds by right-hand playing styles. Parameters of loop filter are estimated from decay region of recorded sound. That results in improved accuracy and reduction of computational costs. Body is implemented to a resonator which has characteristics of main resonances extracted from impulse response. Residual signal with main resonances removed is used as excitation signal of proposed model. Amok alter is approximated to frequency response of amok and is implemented to the 15th order all-role digital filter. Beating (by middle and index finger) among the right-hand playing styles is represented by feedforward comb filter. Parameters of this filter are extracted from recorded sound. The synthesized sounds using improved physical model of sanjo gayageum. plucking and beating, are pretty similar to original sounds.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.951-955
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• 2007

Recently, drywall's demand is increasing by interest about spread of remodeling house and separated wall structure. This research evaluated panel's SRI and found out panel properties using material of small size. Conclusion of this research is as following. First, we confirmed the effectiveness of small-scale material. Measuring results appeared equally about 400 ${\sim}$ 500 Hz that is fc frequency. Second,, it is no big difference in SRI that use CRC or magnesium board that is used for protection of panel surface. Third, it is compared SRI by used junction to make wall that become disjointing assembly. By the result, sealed wall secures resemblant SRI performance almost with normal wall. Therefore, using joint materials and sealing junction became wall that is detached with high SRI.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.115-119
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• 2011

Instead of very expensive sound record and professional measurement microphones the low cost Surface Mounted Device (SMD) microphones are proposed for practical barrier ANC system. FRF of the microphones and theirs sensitivity to the wind interferences are evaluated in semi anechoic chamber. The improvement of feedforward algorithm noise reduction index was evaluated based on measured coherence function between tested SMD and reference microphone. Test was performed at various wind speed from 1 m/s to 5 m/s.

• Journal of the Korean Dietetic Association
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• v.4 no.2
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• pp.200-211
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• 1998

Most of college women are interested in their appearances, and those whose body weights are normal or even underweight try to lose weight. Many methods for weight control diets practiced by college women are unsound and irrational so that some side-effects should be watched out. The present study was aimed to investigate methods of diets, food habits, behaviors, and side effects of weight control and to suggest sound weight loss schemes for college women. The subjects were 353 college women living in Taegu and Kyung Buk area, comprising 178 women who have tried weight control diets and 175 women who have not tried diets. The items included in questionnaires were food habits, food behavoirs, food frequency, physical activity status, 24-hour daily activity record, height, weight, etc., and the survey was conducted in September 1997. There was no difference in body mass index between college women who have tried diets(20.1$\pm$2.26) and women who have not tried diets(19.3$\pm$1.58), and 24.2% of those who have tried diets had body mass index under 19. The leading reason for diets was to make better fitting for costumes(67%). While women who have tried diets also tried to exercise more, they tended to overeat than women who have not tried diets. Mean of food habit scores(9.33 vs 9.32) which corresponded to "poor" habit and food frequencies were not different with or without experiences of diets. This indicated that diets were not related to actual changes of food habits and food intakes. Diet methods used frequently by college women were relying on special diet foods(25.4%), fasting(24.9%) and exercise(22.6%). Trying both exercise and diet was practiced by only 5.1% of the subjects who have tried diets. The duration time of diets was mostly in the range of 1 week to 1 month, and the longer diet period was, the more weight loss was. The frequent side effects due to diets were anemia(41.8%) and enervation(23.7%). Activity coefficients were lower in those who have tried diets(1.38$\pm$0.13) than those who have not tried diets(1.41$\pm$0.19). Women who have tried diets spent more time on reading newspapers and magazines and on watching TV. This study indicates that college women who have tried diets practiced irrational diets for weight reduction and experienced undesirable side-effects. Therefore scientific and systematic weight reduction programs accompanying balanced diets and proper exercise with behavior changes should be developed.