• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.108-108
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• 2022

In this study, multispectral images of wheat according to soil water state were collected, compared, and analyzed to measure the physiological response of crops to environmental stress at the individual level. CMS-V multi-spectral camera(Silios Technologies) was used for image acquisition. The camera lens consists of eight spectral bands between 550nm and 830nm. Light Reflective information collected in each band sensor and stored in digital values, and it is converted into a reflectance for calculating the vegetation index and used. According to the camera manual, the NDVI(Normalized Difference vegetation index) value was calculated using 628 nm and 752 nm bands. Image measurement was conducted under natural light conditions, and reflectance standards(Labsphere) were captured with plants for reflectance calculation. The wheat variety used Gosomil, and the wheat grown in the field was transplanted into a pot after heading date and measured. Three treatments were performed so that the soil volumetric water content of the pot was 13~17%, 20~23%, and 25%, and the growth response of wheat according to each treatment was compared using the NDVI value. In the first measurement after port transplantation, the difference in NDVI value according to treatment was not significant, but in the subsequent measurement, the NDVI value of the treatment with a water content of 13 to 17% was lowest and was the highest at 20 to 23%. The NDVI values decreased compared to the first measurement in all treatment, and the decrease was the largest at 13-17% water content and the smallest at 20-23%. Although the difference in NDVI values could be confirmed, it would be difficult to directly relate it to the water stress of plants, and further research on the response of crops to environmental stress and the analysis of multi-spectral image will be needed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.4
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• pp.410-416
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• 2013

In this paper, we propose a chaotic correlation delay shift keying(CDSK) using digital retrodirective array antenna (RDA) for improving security and receive performance. Chaotic signals provide improved security due to non-periodic and non-predictable performance of chaotic signals. However, the receive performance of these chaotic signals is degraded due to self-interference and interference signals. Therefore, this paper, we analyze the receive BER performance of chaos communication system which has digital RDA based on CDSK modulation schemes for improving security without receive performance degradation. Simulation results show that the proposed system can get the same receiving performance compared to BPSK modulation schemes when array elements of RDA are 5.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.1
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• pp.24-30
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• 2014

A digital RDA(Retrodirective Antenna) system is a retransmit system that received signal without prior information turn back by estimated phase of the signal to received direction. The RDA can decrease consumption of power by increase of directivity because signal concentrates on received direction compare to omni-direction antenna which transmit power all direction. Generally, the RDA is known to show better performance than the single-antenna system in multi-path environment. However, the RDA occurs performance degradation in serious ISI channel. In this paper, to solve this problem, we propose retrodirective antenna combined with turbo equalizer combined which can compensate serious ISI channel, we increase the BER performance through proposed retrodirective antenna combined with turbo equalizer in serious ISI channel.

• Horticultural Science & Technology
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• v.17 no.2
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• pp.127-130
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• 1999

This study was attempted to develop the algorithm for recognizing fruits acquired from apple tree images with digital camera in sunlight. As the result of L*a*b* color transformation for reducing the effect of sunlight, a* and b* color index were effective to extract apple pixels in tree images and linear discrimination functions with color index a* b* were developed. To recognize fruits from apple pixels, those were classified into 4 patterns according to clustering condition and morphologically filtered. Test results showed that apple fruits unoccluded were exactly recognized, whereas apple fruits occluded with leaves and trunk were miscounted 2 apples on average.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.8
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• pp.623-628
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• 2013

The retrodirective array antenna system is operated faster than existing techniques of beamforming due to its less complexity. Therefore, it is effective for beam tracking in the environment of fast vehicle. On the other hand, it also has difficulty in estimating AOA according to multipath environment or multiuser signals. To improve the certainty of estimating AOA), this article proposes hybrid digital retrodirective array antenna systme combined with MUSIC algorithm. In this paper, the digital retrodirective array antenna system is designed according to the number of antenna array by using only one digital PLL which finds angle of delayed phase. And we evaluate the performance of the digital retrodirective array antenna for the high speed tracking application. Performance is studied by simulink when the speed of mobile is 300km/h and the distance between transmitter and receiver is 100m and then we have to confirm the performance of the system in multi path environment. As a result, the mean of AOA (Angle Of Arrival) error is $4.2^{\circ}$ when SNR is 10dB and it is $1.3^{\circ}$ when SNR is 20dB. Consequently, the digital RDA shows very good performance for high speed tracking due to the simple calculation and realization.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.3
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• pp.225-231
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• 2015

Improving current pasture productivity by precision management requires practical tools to collect site specific pasture biomass data. Recent developments in unmanned aerial vehicle (UAV) technology provide cost effective and real time applications for site specific data collection. For the mapping of herbage biomass (BM) on a hill pasture, we tested a UAV system with digital cameras (visible and near-infrared (NIR) camera). The field measurements were conducted on the grazing hill pasture at Hanwoo Improvement Office, Seosan City, Chungcheongnam-do Province, Korea on May 17 and June 27, 2014. Plant samples were obtained from 28 sites. A UAV system was used to obtain aerial photos from a height of approximately 50 m (approximately 30 cm spatial resolution). Normalized digital number (DN) values of Red and NIR channels were extracted from the aerial photos and a normalized differential vegetation index using DN ($NDVI_{dn}$) was calculated. The results show that the correlation coefficient between BM and $NDVI_{dn}$ was 0.88. For the precision management of hilly grazing pastures, UAV monitoring systems can be a quick and cost effective tool to obtain site-specific herbage BM data.

• Journal of Animal Science and Technology
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• v.51 no.1
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• pp.1-8
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• 2009

We generated 57,598 expressed sequence tags (ESTs) from 3 cDNA libraries of Hanwooo (Korean Cattle), fat, loin, liver. Liver, intermuscular fat and longissimus dorsi tissues were obtained from a 24-month-old Hanwoo steer immediately after slaughter. cDNA library was constructed according to the oligocapped method. The EST data were clustered and assembled into unique sequences, 4,759 contigs and 7,587 singletons. To carry out functional analysis, Gene Ontology annotation and identification of significant leaf nodes were performed that were detected by searching significant p-values from $2^{nd}$ level GO terms to leaf nodes using Bonferroni correction. We found that 13, 26 and 8 significant leaf nodes are unique in the transcripts according to 3 GO categories, molecular function, biological process and cellular component. Also digital gene expression profiling using the Audic's test was performed and tissue specific genes were detected in the above 3 libraries.

• Journal of Embryo Transfer
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• v.25 no.3
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• pp.195-199
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• 2010

This studies were conducted to investigate the survival rate of frozen-thawed spermatozoa of Jindo Dog by monosaccharide and freezing rates. Experimental animals were prepared 12 males within 1~8 year's old and collected once in a couple of weeks by digital manuplation methods. Collected semen was diluted 1:1 with Tris-egg yolk extender and added 4, 6 or 8% of glycerol and none, 4 mM glucose or 4 mM fructose as cryoprotectant and was equilibrated for 2 hrs in $4^{\circ}C$. In monosaccharide groups, the freezing rate was 5 cm-5 min. above $LN_2$. The survival rates without monosaccharide were $50.7{\pm}19.0%$, $58.6{\pm}18.0%$, $40.0{\pm}10.0%$ in 4, 6 or 8% glycerol, respectively. In addition of glucose, the survival rates were $43.1{\pm}14.7%$, $38.1{\pm}16.5%$, $33.3{\pm}4.0%$ in 4, 6 or 8% glycerol, respectively and in fructose, were $47.9{\pm}21.1%$, $61.3{\pm}6.2%$, $34.3{\pm}12.6%$ in 4, 6 or 8% glycerol, respectively. There showed significantly different between glycerol groups and monosaccharides groups (p<0.05). The survival rates of freezing rate in 5 cm-5 min. group was $64.5{\pm}15.8%$, $51.9{\pm}27.6%$, $29.7{\pm}24.8%$ and in 10 cm-10 min. group was $62.5{\pm}20.3%$, $64.9{\pm}23.6%$, $34.5{\pm}27.4%$ in 4, 6 or 8% glycerol, respectively. There were significantly different between freezing rates (p<0.05). These results suggest that the addition of fructose with 6%-glycerol and slow freezing improve the survival of frozen-thawed sperm in Jindo Dog.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.1
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• pp.69-74
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• 2015

To analyze quantitatively environmental characteristics of cultivation area of citrus, Satsuma mandarin (Citrus unshiu Marc.), we made digital maps of environmental elements such as topography and climate. Elevation, degree of slope, and slope aspect were selected as elements of topological environment, and the annual mean air temperature, annual total precipitation, mean air temperature on January, extreme value of daily minimum air temperature, and the number of days below $-5^{\circ}C$ were selected as elements of climatic environments. The grid values of 8 environmental elements were extracted by shape of citrus farm area and analyzed distribution patterns. We can determine 3 agroclimatic criteria for growing Satsuma mandarin as over $14.5^{\circ}C$ of annual mean air temperature, over $-10.0^{\circ}C$ of extreme value of daily minimum air temperature, and less 5 days of below $-5^{\circ}C$ of daily minimum air temperature.

• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.4
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• pp.215-222
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• 2017

The potential change of the cultivation area of main citrus cultivars, satsuma mandarin (Citrus unshiu Marc.) and 'Shiranuhi' mandarin hybrid [(Citrus unshiu ${\times}$ C. sinensis) ${\times}$ C. reticulata] were determined with base year (1981 to 2010) to 2090. The meteorological data provided by the Korea Meteorological Administration (KMA), and the digital agricultural climate map of 30m-solution based on the Representative Concentration Pathways (RCP) 8.5 was used for projection of potential cultivation area. As a result, the potential suitable region of satsuma mandarin included almost Jeju region during base year. At the 2030s, the potential suitable region of satsuma mandarin increased and the cultivable region also increased focused on the coast region of Jeonnam province. From the 2060s, the suitable area spread out to mountain area of Jeju, Jeonnam, Gyeongnam, and the coast region of Kangwon, and the cultivable region expanded to the area of Gyeongbuk, Chungnam, and Jeonbuk. In the case of 'Shiranuhi' mandarin hybrid, the suitable region included only the partial coast area of Jeju, and cultivable area covered Jeju region and the partial southern coast of Jeonnam during the standard period. At the 2030s, the suitable region of 'Shiranuhi' included the current cultivation area of satsuma mandarin, and the cultivable region moved to northward by the partial southern coast region. At the 2090s, the slightly increased suitable region covered all Jeju regions, Jeonnam, Gyeongnam, and the coast area of Kangwon, and the cultivable region proceeded northward focusing on the coastline. In conclusion, the prediction of the potential land for citrus cultivation based on the RCP 8.5 showed that the suitable region of satsuma mandarin decreased, whereas that of cultivation of 'Shiranuhi' increased. Moreover, it was forecasted that citrus cultivation area would extend to Kangwon region at the end of the $21^{st}$ century.