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        검색결과 8

        1.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Smart farm is a breakthrough technology that can maximize crop productivity and economy through efficient utilization of space regardless of external environmental factors. This study was conducted to investigate the optimal growth and physiological conditions of Chinese matrimony vine (Lycium chinense) with LED light sources in a smart farm. The light source was composed of red+blue and red+blue+white mixed light using a LED system. In the red+blue mixed light, red and blue colored LEDs were mixed at ratios of 1:1, 2:1, 5:1, and 10:1, with duty ratios varied to 100%, 99%, and 97%. The experimental results showed that the photosynthetic rate according to the types of light sources did not show statistically significant differences. Meanwhile, the photosynthetic rate according to the mixed ratio of the red and the blue light was highest with the red light and blue LED ratio of 1:1 while the water use efficiency was highest with the red and blue LED ratio of 2:1. The photosynthetic rate according to duty ratio was highest with the duty ratio of 99% under the mixed light condition of red+blue+white whereas the water use efficiency was highest with the duty ratio of 97% under the mixed light of red+blue LED. The results indicate that the light source and light quality for the optimal growth of Lycium chinense in the smart farm using the LED system are the mixed light of red+blue (1:1) and the duty ratio of 97%.
        4,000원
        2.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the present study, we investigated the physiological effects of smartphone use at night when the display luminance and white balance were differently manipulated. Two levels of luminance and two types of white balance were combined to form four types of displays. Subjects were instructed to use smartphones between 23:00 to 01:00 twice a week for two weeks, and for each trial, subjects were given one of the four display types. Melatonin concentration in the saliva, body temperature and heart rate were measured before and after each experiment. The experimental result showed that the low luminance display supported melatonin secretion and thermoregulation compared to the high luminance display. With regard to the white balance, higher melatonin level was observed when using the display that filtered blue light. The low luminance display together with yellowish tint best supported restful sleep at night in terms of every physiological response. This study collectively demonstrates that bright and blue light emitted from smartphone displays adversely affect melatonin secretion, body temperature, and heart rate, and therefore, suggests the use of a display with low luminance or a display that filters blue light for a restful sleep at night.
        4,000원
        3.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to propose the use of a non-compliance rate for evaluation of the HACCP operational condition. We calculated the sectoral non-compliance rate from the HACCP prerequisite evaluation reports. This rate indicates vulnerability of the operational prerequisite conditions that must be improved to increase HACCP reliability for safe foods. The common weak point in the livestock products industry was storage and transportation management, and operating condition in butcher shops were worse than those for the other livestock businesses. In order to obtain better information on findings, evaluation items should be improved simply with one item for evaluation of one check point.
        3,000원
        4.
        2014.07 구독 인증기관·개인회원 무료
        Empirical studies provide evidence that many consumers prefer a flat-rate, even though their billing rate would be lower on a pay-per-use tariff. When it comes to tariff choices, some consumers thus seem to be subject to a cognitive error, a so-called “flat-rate bias”. Based on survey data, we analyse causes and strategies to enhance the occurrence and intensity of flat-rate biases within 2 studies. The results of study 1 (n=104) point out to five important drivers of flat-rate biases, namely the taximeter, insurance, overestimation, convenience and smart-shopping effect. Within study 2 (n=416), we subsequently evaluate the effectiveness of advertisements using the identified causes for a flat-rate bias as setting levers to increase consumers' tariff-specific willingness-to-pay. Our findings show that the most effective way to enhance the return on flat-rate bias would be to enhance communication of the fact that consumers can protect themselves from fluctuations in the billing amount through a flat rate (insurance effect) and that consumers must not worry about costs when using a flat rate (taximeter effect).
        6.
        1992.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This experiment was conducted over a 3-year period (1990-1992) to evaluate the production and quality of orchardgrass (Potomac)-red clover (Kenland) mixture when orchardgrass + red clover mixture was sown at seed rates of 20+0. 18+2, 16+4, 14+6 and 12+8 k
        4,000원
        7.
        2020.02 KCI 등재 서비스 종료(열람 제한)
        Seasonal changes in the CO2 fixation rate and water-use efficiency in the leaves of six evergreen and two deciduous broad-leaved tree species on Jeju Island, Korea, were measured using a portable photosynthesis analyzer, to identify which species are most efficient in taking up CO2 from the air. The CO2 fixation rate was high in the deciduous species in spring and summer and decreased in fall, whereas it was high in the evergreen species in summer and fall and decreased in winter. The rate remained high in the deciduous tree Prunus yedoensis from spring to fall (> 7.1 μmol CO2/m2/s) and in two evergreen trees, Castanopsis cuspidata var. sieboldii and Cinnamomum camphora, in summer and fall (7.0 9.9 μmol CO2/m2/s). Therefore, these tree species fix atmospheric CO2 effectively. The water-use efficiency was higher in evergreen species than in deciduous species regardless of the season. Exceptionally, it was high in the deciduous species Zelkova serrata in spring and summer (> 100 μmol CO2/mol H2O), suggesting that Z. serrata is a useful tree for dry conditions due to its tolerance of water stress. The regressions of the CO2 fixation rate versus the evaporation rate and stomatal conductance were linear and non-linear, respectively. This suggests that the stomatal activity of leaves plays an important part in CO2 fixation of plants. In conclusion, C. cuspidata var. sieboldii, C. camphora, and P. yedoensis should be planted along roads or in urban spaces for the greening of cities and mitigation of CO2 concentrations in the air.