• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.4
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• pp.388-397
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• 1985

Forage productivity and sequential changes in forage quality of four rye and two triticale varieties were studied. All the observed characteristics were similar among rye or triticale varieties, but they were different between rye and triticale varieties. Early growth of rye was better compared to triticale varieties, but at heading stage yield in dry weight, digestible dry matter and percent dry matter of triticale were higher compared to rye varieties. Heading stage of rye was earlier than that of triticale by 11 - 14 days. Triticale had longer and broader leaf blades and a higher leaf blade/total dry weight ratio compared to rye. Protein content decreased as plant growth advanced and it was higher in rye before heading, but it was similar after heading compared to triticale. Cellulose and lignin contents of rye increased through 20 days after heading. However, in triticale cellulose increased until heading stage and it levelled off, but lignin content increased rapidly after heading. Among the crude fibers, only acid detergent fibers(ADF) was negatively correlated with in vitro dry matter digestibility(IVDMD) in both rye and triticale. IVDMD of rye decreased rapidly after heading, but it was maintained as high as heading stage up to 15 days after heading in triticale. Protein content and IVDMD in leaf blades were higher than those of culm + leaf sheath, hemicellulose was similar, and cellulose, lignin, and ADF in leaf blades were lower compared to culm + leaf sheath. In the early and middle part of April rye was superior to triticale as a soiling crop because of a better plant growth of rye under the low temperature conditions, but in the later part of April and early part of May triticale was superior to rye because of a rapid decreased in IVDMD of rye after heading and a late maturing characteristics of triticale. Planting both rye and triticale could prolong the utilization period of the soiling crops and increase in yield with better quality compared to a single crop of rye or triticale.

• Korean Journal of Environmental Biology
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• v.40 no.2
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• pp.187-198
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• 2022

In this study, Telenomus remus Nixon (Hymenoptera: Scelionidae) was first reported as a natural enemy of the fall armyworm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) egg collected from corn fields in Korea, and its biological characteristics was studied. Based on morphological and molecular analysis, the parasitoid emerged from S. frugiperda eggs was identified as T. remus. We found that T. remus can attack the eggs of S. frugiperda, Spodoptera litra and Spodoptera exigua under a laboratory condition. The longevity of T. remus female adult was longer than that of male adult. The egg-to-adult period of T. remus was not affected by the host age and sex. T. remus female adult laid at least 1-3 eggs a day to a maximum of 37 or more eggs, and the most oviposited on the 3^rd to 4^th day after emergence. The host preference for oviposition of T. remus adult was high in the order of S. litura>S. exigua>S. frugiperda. T. remus preferred to parasitize 1- and 2-day-old host egg rather than 3-day-old host egg. When compared to the sex ratio of T. remus progeny, the rate of female progeny was higher at the initiation time of oviposition, while the proportion of male progeny increased significantly with female adult age, especially after 8-day-old adult. This information may be useful for improving T. remus mass rearing system and developing a biological control program to control S. frugiperda.

• Korean Journal of Ecology and Environment
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• v.55 no.1
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• pp.35-48
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• 2022

Fish assemblage of total 325 of Korean peninsula estuaries were surveyed to analyze the characteristics of community structure and diversity by sea areas for three years from 2016 to 2018. The scale (stream width) of Korean estuaries were various (14~3,356 m), and 68.9% of all estuaries showed salinity of less than 2 psu. Total 149 species classified into 52 families of fish were identified, and the dominant and sub-dominant species were Tribolodon hakonensis (relative abundance, RA, 12.5%) and Mugil cephalus (RA, 9.5%), respectively. The estuary of the Korean Peninsula had different physical and chemical habitat environments depending on the sea area, and accordingly, fish community structure also showed statistically significant differences (PERMANOVA, Pseudo-F=26.69, P=0.001). In addition, the NMDS (nonmetric multidimensional scaling) results showed the patterns that indicating fish community difference by sea areas, even though low community similarity within sea area (SIMPER, 21.79~26.39%). The estuaries of east sea areas were distinguished from the others in the aspects of which, the higher importance of migratory fishes and endangered species, and that of brackish species were characterized at south sea estuaries. However, the estuaries of west sea showed higher importance of species that have a relation with freshwater (primary freshwater species, exotic species), which is the result that associating with the lower salinity of west sea estuaries because of the high ratio of closed estuaries(78.2%). The SIMPER analysis, scoring the contribution rates of species to community similarity, also showed results corresponding to the tendency of different fish community structures according to each sea area. So far, In Korea, most studies on fish communities in estuaries have been conducted in a single estuary unit, which made it difficult to understand the characteristics of estuaries at the national level, which are prerequisite for policy establishment. In present study, we are providing fish community structure characteristics of Korean estuaries in a national scale, including diversity index, habitat salinity ranges of major species, distribution of migratory species. We are expecting that our results could be utilized as baseline information for establishing management policies or further study of Korean estuaries.

• Journal of agriculture & life science
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• v.50 no.2
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• pp.125-138
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• 2016

To assess the industrial possibility of mixed-extracts containing Hovenia dulcis Thunberg and 12 different botanical ingredients, a protective effect was confirmed in the chronic ethanol-induced the liver, brain, and blood injury in mouse. Blood glucose levels of the normal control group(NG) and ethanol administration group(EG) were respectively 119.43mg/dL and 305.25mg/dL, and the mixed-extracts administration group(100, 200mg/kg body weight + 25% ethanol 5g/kg body weight respectively; ME100 & ME200) were decreased to 272.76mg/dL and 234.60mg/dL. Blood ethanol contents were decreased in ME100 and ME200(3.85mg/dL, 3.08mg/dL) compared to EG(4.08mg/dL), and blood acetaldehyde contents were also decreased in ME(15.76mg/dL, 15.16mg/dL) compared to EG(18.72mg/dL). The contents of hepatotoxic indicators such as glutamine pyruvic transaminase(GPT) and glutamic oxaloacetic transaminase (GOT), nephrotoxic indicators such as blood urea nitrogen(BUN), and creatine(CRE), and total cholestero(TCHO), and triglyceride(TG) in mouse blood serum were significantly decreased in the ME compared to EG. The acetylcholinesterase(AChE) activity of ME(109.00% and 108.47%, respectively) in mouse brain tissues was decreased in ME compared to EG(116.10%). Finally, ME was remarkable in vivo antioxidant activities in the mouse liver and brain tissues by superoxide dismutase(SOD), oxidized glutathione(GSH)/total GSH ratio and the malondialdehyde (MDA) assay. Therefore, the mixed-extracts was considered to be effective a high value food with protective effect against chronic ethanol traetment-induced cytotoxicity in liver and brain tissues.

• Korean Journal of Remote Sensing
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• v.39 no.2
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• pp.207-221
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• 2023

This study suggests deep neural network models for estimating air temperature with Level 1B (L1B) datasets of GEO-KOMPSAT-2A (GK-2A). The temperature at 1.5 m above the ground impact not only daily life but also weather warnings such as cold and heat waves. There are many studies to assume the air temperature from the land surface temperature (LST) retrieved from satellites because the air temperature has a strong relationship with the LST. However, an algorithm of the LST, Level 2 output of GK-2A, works only clear sky pixels. To overcome the cloud effects, we apply a deep neural network (DNN) model to assume the air temperature with L1B calibrated for radiometric and geometrics from raw satellite data and compare the model with a linear regression model between LST and air temperature. The root mean square errors (RMSE) of the air temperature for model outputs are used to evaluate the model. The number of 95 in-situ air temperature data was 2,496,634 and the ratio of datasets paired with LST and L1B show 42.1% and 98.4%. The training years are 2020 and 2021 and 2022 is used to validate. The DNN model is designed with an input layer taking 16 channels and four hidden fully connected layers to assume an air temperature. As a result of the model using 16 bands of L1B, the DNN with RMSE 2.22℃ showed great performance than the baseline model with RMSE 3.55℃ on clear sky conditions and the total RMSE including overcast samples was 3.33℃. It is suggested that the DNN is able to overcome cloud effects. However, it showed different characteristics in seasonal and hourly analysis and needed to append solar information as inputs to make a general DNN model because the summer and winter seasons showed a low coefficient of determinations with high standard deviations.

• Analytical Science and Technology
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• v.22 no.4
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• pp.285-292
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• 2009

It has been observed that, after long term storage, some ammunitions are misfired by tamping (combustionstopping) due to aging of the chemicals loaded in the ammunitions. Used in ammunitions are percussion powder which provides the initial energy, igniter which ignites the percussion powder, and a delay system that delays the combustion for a period of time. The percussion powder is loaded first, followed by the igniter and then the delay system, and the ammunitions explode by the energy being transferred in the same order. Tamping occurs by combustion-stopping of the igniter or insufficient energy transfer from the igniter to the delay system or the combustion-stopping of the delay system, which are suspected to be caused by low purity of the components, inappropriate mixing ratio, size distribution of particulate components, type of the binder, blending method, hydrolysis by the humidity penetrated during the long term storage, and chemical changes of the components by high temperature. Goal of this study is to find the causes of the combustion-stopping of the igniter and the delay system of the ammunitions after long term storage. In this study, a method was developed for testing of the combustion-stopping, and the size distributions of the particulate components were analyzed with field-flow fractionation (FFF), and then the mechanism of chemical change during long term storage was investigated by thermal analysis (differential scanning calorimetry), XRD (X-ray diffractometry), and XPS (X-ray photoelectron spectroscopy). For the ignition system, M (metal)-O (oxygen) and M-OH peaks were observed at the oxygen's 1s position in the XPS spectrum. It was also found by XRD that $Fe_3O_4$ was produced. Thus it can be concluded that the combustion-stopping is caused by reduction in energy due to oxidation of the igniter.

• Korean Journal of Poultry Science
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• v.50 no.2
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• pp.91-99
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• 2023

This study aimed to develop a high-productivity breed of Korean native Samgye chicken. We evaluated the production performance of six Korean native chicken combinations (KNC-SCYC, SCYD, SDYC, SDYD, SYYC, SYYD) and GSP-Hanhyup Korean native chickens, with Baeksemi chickens used as a control group. The performance test was conducted from hatching to 7 weeks of age on 756 chickens, and we measured survival rate, body weight, shank length, feed utility, and carcass yield. The overall survival rate was nearly 100% for all strains. However, body weight showed significant differences between strains at all ages (P<0.01), with Baeksemi weighing 863.8±76.9 g, GSP-Hanhyup weighing 804.7±72.5 g, and KNC-combinations weighing 543.0±61.8 g at 5 weeks of age. The duration needed to reach 850 g was estimated to be 34.5 days for Baeksemi, 37.5 days for GSP-Hanhyup, and 45.8-48.8 days for KNC-combinations. Carcass yield percentage was highest for KNC-SYYD combination at 63.3%, followed by Baeksemi at 60.4%, and GSP-Hanhyup at 56.1%. Shank length at 850 g body weight was 7.6 cm for KNC-SYYD combination, 7.8 cm for Baeksemi, and 8.0 cm for GSP-Hanhyup. The feed conversion ratio at 850 g body weight was 1.81 for Baeksemi, 2.17 for GSP-Hanhyup, and 2.27 for KNC-SCYC combination. Our results suggest that the KNC-SYYD combination and GSP-Hanhyup breed have the potential to be used in Samgye production due to their moderate growth performance, higher carcass yield, and shorter shank length, despite their lower growth productivity and feed efficiency when compared to Baeksemi.

• Korean journal of applied entomology
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• v.62 no.3
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• pp.183-191
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• 2023

After examining the temperature change in berry sawdust during the fermentation period and the developmental characteristics of Protaetia brevitarsis larvae according to the fermentation period, it was found that the fermentation speed was faster than with oak sawdust and a fermentation period of 50-70 days was the most suitable for larval growth. During the fermentation period, the temperature change in sawdust was quickly fermented as berry sawdust passed a high temperature of more than 60℃ in the early stages of fermentation compared to fermentation speed of oak sawdust, and stabilized within 60 days. In individual breeding, the total growth period of P. brevitarsis larvae by fermentation period was the longest at 104.8 days after fermentation for 30 days, which was a significant difference. There was no difference in the growth period between 50 and 90 days of fermentation. Oak sawdust tended to be the same as berry sawdust, but the larval development period was approximately 30 days. The developmental period by larval stage differed greatly between berries and oak sawdust. The weight of larvae according to the fermentation period of sawdust was the lowest after 90 days of fermentation, with a long fermentation period for both berry and oak sawdust, and there was no difference in the 30-70 days fermentation periods. The survival rate was more than 95% in individual breeding, and there was no difference among the fermentation periods. However, in group breeding, the survival rate was lower than that of individual breeding and was lowest at 90 days of fermentation. In group breeding, the ratio of larvae weighing ≥ 2.5 g, which is the standard for shipment, was 85% after 30-70 days of fermentation of berry sawdust, but was lower at 70% after 90 days of fermentation, which was a significant difference. The survival rate with oak sawdust showed the same trend, which was approximately 10% lower than that with sawdust. In addition, the larvae from the berry sawdust weighed > 2.5 g in 40-60 days, while it took 75-105 days with oak-fermented sawdust.

• Korean Journal of Remote Sensing
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• v.39 no.5_1
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• pp.655-667
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• 2023

Algal bloom outbreaks are frequently reported around the world, and serious water pollution problems arise every year in Korea. It is necessary to protect the aquatic ecosystem through continuous management and rapid response. Many studies using satellite images are being conducted to estimate the concentration of chlorophyll-a (Chl-a), an indicator of algal bloom occurrence. However, machine learning models have recently been used because it is difficult to accurately calculate Chl-a due to the spectral characteristics and atmospheric correction errors that change depending on the water system. It is necessary to consider the factors affecting algal bloom as well as the satellite spectral index. Therefore, this study constructed a dataset by considering water quality, hydrological and meteorological factors, and sentinel-2 images in combination. Representative ensemble models random forest and extreme gradient boosting (XGBoost) were used to predict the concentration of Chl-a in eight weirs located on the Nakdong river over the past five years. R-squared score (R²), root mean square errors (RMSE), and mean absolute errors (MAE) were used as model evaluation indicators, and it was confirmed that R² of XGBoost was 0.80, RMSE was 6.612, and MAE was 4.457. Shapley additive expansion analysis showed that water quality factors, suspended solids, biochemical oxygen demand, dissolved oxygen, and the band ratio using red edge bands were of high importance in both models. Various input data were confirmed to help improve model performance, and it seems that it can be applied to domestic and international algal bloom detection.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.3
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• pp.134-146
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• 2023

Phytophthora root rot (PRR) is a major soybean disease caused by an oomycete, Phytophthora sojae. PRR can be severe in poorly drained fields or wet soils. The disease management primarily relies on resistance genes called Rps (resistance to P. sojae). This study aimed to identify resistance loci associated with resistance to P. sojae isolate 40468 in Daepung × CheonAl recombinant inbred line (RIL) population. CheonAl is resistant to the isolate, while Daepung is generally susceptible. We genotyped the parents and RIL population via high-throughput single nucleotide polymorphism genotyping and constructed a set of genetic maps. The presence or absence of resistance to P. sojae was evaluated via hypocotyl inoculation technique, and phenotypic distribution fit to a ratio of 1:1 (R:S) (χ² = 0.57, p = 0.75), indicating single gene mediated inheritance. Single-marker association and the linkage analysis identified a highly significant genomic region of 55.9~56.4 megabase pairs on chromosome 18 that explained ~98% of phenotypic variance. Many previous studies have reported several Rps genes in this region, and also it contains nine genes that are annotated to code leucine-rich repeat or serine/threonine kinase within the approximate 500 kilobase pairs interval based on the reference genome database. CheonAl is the first domestic soybean genotype characterized for resistance against P. sojae isolate 40468. Therefore, CheonAl could be a valuable genetic source for breeding resistance to P. sojae.