• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.429-434
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• 2007

This study was conducted to estimate site productivity of Quercus acutissima and Quercus mongolica by four forest climatic zones. We used site environmental variables (28 geographical and pedological factors) and site index as a site productivity indicator from nation-wide 23,315 stands. Based on multiple regression analysis between site index and major environmental variables, the best-fit multivaliate models were made by each species and forest climatic zone. Most of site index prediction models by species were regressed with seven to eight factors, including altitude, relief, soil depth, and soil moisture etc. For those models, three evaluation statistics such as mean difference, standard deviation of difference, and standard error of difference were applied to the test data set for the validation of the results. According to the evaluation statistics, it was found that the models by climatic zones and species fitted well to the test data set with relatively low bias and variation. Also having above middle of site index range, total area of productive sites for the two Quercus spp. estimated by those models would be about 6% of total forest area. Northern temperate forest zone and central temperate forest zone had more productive area than southern temperate forest zone and warm temperate forest zone. As a result, it was concluded that the regressive prediction with site environmental variables by climatic zones and species had enough estimation capability of forest site productivity.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.584-590
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• 2018

The adults of Hermetia illucens collected in Korea were about the same size as those from their origin. The body part with the largest size variation was the antenna 2 followed by the head width and the abdomen width. It can be the baseline of selection of superior individuals for organic waste decomposition and compost production. In regards to the habitat, the adult Hermetia illucens were collected from 22 of the 51 localities. Although geographical characteristics such as coordinates and altitude may not affect the insects, the presence of organic matters could affect them. The distribution pattern of the insects may act as an indicator of natural recycling of organic wastes.

• Journal of Practical Agriculture & Fisheries Research
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• v.9 no.1
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• pp.13-25
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• 2007

The present study analyzed the spatial characteristics of S village according to the Feng-Shui theory(風水理論). People's life span is affected by several factors including hereditary constitution, dietary life and life habits but recently there is an opinion that longevity village in Korea are commonly located in areas at a proper altitude. The objective of the present study was to basic investigate the characteristics of S village from the viewpoint of Feng-Shui(風水). As for this study, it will be given help to a longevity village plan. For this purpose, we conducted field survey and map investigation of the natural geographic situation of S village focused on Ryong(龍, contiguous line of terrestrial stratum), Hull(穴, village location), Sa(砂, geographical feature of surrounding mountains), Su(水, water flow) and Hyang(向), which are Feng-Shui(風水) objects to be observed. According to the result of this research, S Village, which has mountains in the rear and a river in the front, was found to be in fine geographic situation equipped with Sashinsa(四神砂). According to the Feng-Shui theory(風水理論), the village was hang-ju-hyoung(行舟形), which means that people and properties flourish together. A shortcoming of the village was the absence of Ahnsan(案山) to block harmful winds blowing to the fore of the village. In addition, another shortcoming of the village in terms of Feng-Shui(風水) was the large variation of temperature because of its location surrounded by high mountains as if the village was situated inside a bowl. The Hyang(向) of village houses were arranged by the geographical feature and not by Feng-Shui(風水).

• Korean Journal of Environment and Ecology
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• v.28 no.5
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• pp.574-587
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• 2014

In this study, vertical distribution patterns of Quercus mongolica Fisch. ex Ledeb. and Q. serrata Murray in Korea were recognized and possibility of introgressive hybridization and gene flow between Q. mongolica and Q. serrata in Mt. Jiri was inferred by flavonoid analyses. The most critical factor on distribution patterns was the altitude in accordance with temperature condition. A zonal distribution was recognized: Quercus mongolica zone in the upper area and Q. serrata zone in the lower area. In Central Korea, the range of vertical distribution of Q. mongolica was above alt. 100m, almost everywhere, whereas that of Q. serrata was from alt. 0 m to alt. 500(-700) m, and the species is rare above that altitude. But in Southern Korea, Q. serrata is found up to above alt. 1,000 m, whereas frequency of Q. mongolica reduces as elevation in decline and the species is rare below alt. 300 m, even though pure stands being formed on higher mountain slope. Altitudinal distribution of the two species, however, overlaps, where the two species occur together. Thirty-seven individuals of Q. mongolica and Q. serrata in Mt. Jiri and other area were examined for leaf flavonoid constituents. Twenty-three flavonoid compounds were isolated and identified; they were glycosylated derivatives of the flavonols kaempferol, quercetin, isorhamnetin, myricetin, and four compounds among the flavonoid compounds were acylated. Kaempferol 3-O-glucoside, quercetin 3-O-glucoside, quercetin 3-O-galactoside and its acylated compounds were major constituents and present in all individuals. Quercus mongolica is distinguished from Q. serrata by the presence of quercetin 3-O-arabinosylglucoside and by high concentration of three acylated compounds, acylated kaempferol 3-O-glucoside, quercetin 3-O-glucoside, quercetin 3-O-galactoside, and by relatively low concentration or lacking of rhamnosyl flavonol compounds. There are intraspecific variations in flavonoid profiles for Q. mongolica and Q. serrata, the flavonoid profiles for individuals of two species in hybrid zone (sympatric zone) tend to be similar to each other, qualitatively and quantitatively. These findings strongly suggest that gene exchange or gene flow occurs through the introgressive hybridization between Q. mongolica and Q. serrata in Mt. Jiri. Therefore, Quercus crispula, occupying morphologically intermediate position between Q. mongolica and Q. serrata, is suspected of being a hybrid taxon of two putative parental species.

• Journal of Korean Society of Forest Science
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• v.90 no.4
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• pp.558-564
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• 2001

For the study of morphological variation in winter buds of Q. variabilis $B_L$. natural populations in Korea, 16 populations were selected through the country in consideration of latitude, longitude, altitude, and geographical characters. Thirty trees were randomly selected from each population and 30 terminal and 30 lateral buds were sampled below 1/3 crown length of each tree. Four morphological characters including length and width of terminal and lateral buds were measured. 1. Length and width of terminal and lateral buds were in the ranges 6.9~11.3cm, 3.0~3.7cm, 6.1~8.9cm, and 2.5~3.1cm, respectively. The coefficient of variation were in about 20% in all the characters investigated. 2. All the characters were significantly different among populations as well as among individuals within populations. The degree of contribution of variance among individuals within populations was higher than that among populations. 3. Length of terminal bud showed positive correlation with length and width of lateral bud; and width of lateral bud with width of terminal bud and length of lateral bud. Also, positive correlations were observed between longitude and width of terminal bud, between latitude and length of terminal and lateral bud. 4. Cluster analysis using complete linkage method for winter bud characters showed two groups to Euclidean distance 3.4. They were group I of population 8 and group II of populations 1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 13, 14, 15, and 16. However, group II was divided into two at Euclidean distance 1.5 that are a group including populations 1, 2, 7, 9, and 11(groupII-1) and the other group including populations 3, 4, 5, 6, 10, 12, 13, 14, 15, and 16(groupII-2).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.5
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• pp.379-386
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• 1990

Varietal difference of protein content in forty eight Korean recommended rice cultivars and environmental Variation in protein content of milled rice harvested at six sites of the middle and/or southern plain and four locations of mid-mountainous and/or alpine area in 1989 were investigated. Also, the composition of amino acid in milled rice was compared among three rice varieties: a high-protein japonica rice, Nongbaek, a high-protein Tongil-type rice, Yongjubyeo, and a low-protein japonica rice, Hwaseongbyeo. Korean recommended rice varieties showed 7.93% of average protein content with varietal variation from 5.5% to 10.2% for milled rice harvested in 1988, and 9.17% of mean protein content with the variation from 6.3% to 12.0% for milled rice harvested in 1989. Tongil-type rice was about 1% higher in protein content of milled rice than japonica. The low-protein japonica rice, Hwaseongbyeo exhibited lower content of essential amino acids per g of rice flour sample than the high-protein japoinica, Nongbaek and/or Tongil-type rice, Yongjubyeo, but the relative content of essential amino acids per 16.8g of nitrogen in milled rice of the former was not so different with those of the latters. Among amino acids the content of glutamic acid was highest and among essential amino acids the content of leucine was highest while methionine was lowest. The protein content of milled rice was negatively correlated with days from seeding to heading, K/Mg ratio, alkali digestion value(l-7) and amylose content, but it was positively correlated with translucency and magnesium content of milled rice. The protein content of milled rice harvested in the southern plain paddy field was about 1% higher compared with those harvested in the Middle plain. Also, the protein content of milled rice harvested in the southern mid-mountainous and alpine area was about 0.8% higher compared with those harvested in the resemble altitude area of the middle-northern part of Korea. The contribution of environmental variation to total in plain area was about 28.1% while that in mid-mountainous and alpine area was about 56.4%.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.9
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• pp.708-713
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• 2013

KARI is developing a solar-electric powered HALE UAV(EAV-3). For demonstrating the technology, EAV-2H, a down-scaled version of EAV-3, is developed and after EAV-2H's initial flight test, the directional stability and control need to be improved. Thus, the vertical tail and rudder of EAV-2H are redesigned with Advanced Aircraft Analysis(AAA). Size of the rudder is increased from mean chord ratio of rudder to vertical tail, $C_r/C_v(%)=30$ to $C_r/C_v(%)=60$ and size of the vertical tail is reduced 15%. As a result, the directional control to side wind($v_1$) is improved to sideslip angle, ${\beta}(deg)=25^{\circ}$ and $v_1(m/sec)=3.54$. Also, variation of airplane side force coefficient with sideslip angle ($C_{y_{\beta}}$) and variation of airplane side force coefficient with dimensionless rate of change of yaw rate ($C_{y_r}$) are reduced 15% and 22%, respectively to minimize the effect of side wind. The empennage design of EAV-2H is verified with flight tests and applied to design of KARI's solar-electric-powered EAV-3.

• Journal of Ginseng Research
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• v.42 no.4
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• pp.485-495
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• 2018

Background: The geographical origin of Panax ginseng Meyer, a valuable medicinal plant, is important to both ginseng producers and consumers in the context of economic profit and human health benefits. We, therefore, aimed to discriminate between the cultivation regions of ginseng using the stable isotope ratios of C, N, O, and S, which are abundant bioelements in living organisms. Methods: Six Korean ginseng cultivars (3-yr-old roots) were collected from five different regions in Korea. The C, N, O, and S stable isotope ratios in ginseng roots were measured by isotope ratio mass spectrometry, and then these isotope ratio profiles were statistically analyzed using chemometrics. Results: The various isotope ratios found in P. ginseng roots were significantly influenced by region, cultivar, and the interactions between these two factors ($p{\leq}0.001$). The variation in ${\delta}^{15}N$ and ${\delta}^{13}C$ in ginseng roots was significant for discriminating between different ginseng cultivation regions, and ${\delta}^{18}O$ and ${\delta}^{34}S$ were also affected by both altitude and proximity to coastal areas. Chemometric model results tested in this study provided discrimination between the majority of different cultivation regions. Based on the external validation, this chemometric model also showed good model performance ($R^2=0.853$ and $Q^2=0.738$). Conclusion: Our case study elucidates the variation of C, N, O, and S stable isotope ratios in ginseng root depending on cultivation region. Hence, the analysis of stable isotope ratios is a suitable tool for discrimination between the regional origins of ginseng samples from Korea, with potential application to other countries.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.5
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• pp.578-585
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• 1996

This experiment was carried out to obtain the basic informations on yield performance and physicochemical quality properties of North Korean rices at southern high altitude area, Unbong and southeren plain area, Iksan. North Korean cultivars showed significant difference in number of spikelets per panicle, percentage of ripened grain and yield between two locations, but not significant in number of panicle per hill and l000-grain weight. The highest contribution to grain yield was the percentage of ripened grain and l000-grain weight at Iksan and Unbong, respectively, The protein, amylose content, alkali digestion value and Mg/K ratio showed larger variation in varieties than that in the locations cultivated. Mg and K revealed highly significant variations in locations, varieties and variety $\times$ location (V$\times$L) interaction. The amylogram characteristics such as initial pasting temperature, peak, breakdown, setback and consistency viscosities showed highly significant variation in locations, varieties and V$\times$L interaction. The physical characteristics of cooked rice such as adhesiveness, gumniness and chewiness also showed highly significant variations in locations, varieties and V$\times$L interaction.

• Korean Journal of Breeding Science
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• v.42 no.1
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• pp.40-49
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• 2010

This study was conducted to examine genetic variation on leaf characteristics of Zelkova serrata populations. Leaf samples were obtained from eighteen populations and fourteen leaf characteristics such as leaf blade length, leaf width, leaf area and etc. were measured. In all leaf characteristics, there were significant differences among populations and among individuals within population. Most variance of leaf characteristics was contributed to among individuals within population except for length from leaf base to maximum width (x3) and the ratio of x3 to leaf blade length (x10). The relatively high variations of leaf characteristics were found at Gurye, Jungeup and Gyungju populations while Youngwol, Cheongsong, Youngchun populations showed the lower variation. There was high correlation among leaf characteristics related to leaf size, but not among the variables of ratio between leaf characteristics. Length from leaf base to maximum width(x3) and the ratio of x3 to x10 showed significant positive correlation with latitude and altitude of populations, which reflect the differences of mean annual temperature among populations. Mean annual rainfall of populations showed negative correlation with leaf blade length, leaf width, length from apex to first serration and leaf area. Four principal components (PC) were deduced from principal component analysis, which explain the 88.5% of total variance of leaf characteristics. Leaf area, length from leaf base to maximum width, serration number and petiole length showed the highest contribution to PC1, PC2, PC3, PC4, respectively. According to cluster analysis, the populations of Z. serrata were divided into two groups, which reflect the difference of mean annual temperature between groups. Within group, however, specific tendency of clustering was not observed among populattions.