• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.7
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• pp.612-622
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• 2013

In this paper, we propose a coding packet group-based ARQ scheme (rNC) for file delivery in wireless networks. rNC assumes multiple network coding points between the source and the destination. Each network coding point gathers and codes a group of packets according to the queue polling system. A queue polling system makes a few or several packets available for coding in a queue while polling the other queues in the system. Thus, we assuem a queue polling system at each network coding point. We call this group of packets as coded packet group. Each coding point acknowledges the reception of every code packet group to its previous coding point for reliable delivery. Thus, the intermediate coding points including the source can release its buffer before the packet is delivered to the destination. To guarantee the ultimate file delivery to the destination, the destination sends acknowledgement to the sender. We evaluate our proposed scheme using ns-2 and compare the performance with CodeCast. The results show that rNC works better than CodeCast in terms of packet delivery ratio and control overhead in unreliable wireless networks.

• Journal of Korean Society of Forest Science
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• v.104 no.1
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• pp.14-25
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• 2015

This study was carried out to classify forest communities and to aggregate forest cover types for the complex and diversified natural forest areas of Guryongsan, Sobaeksan, Baekhwasan, Sokrisan, and Baekhaksan in the middle part of Baekdudaegan. The vegetation data were collected by point-centered quarter sampling method. One thousand one hundred fourteen sample points were subjected to cluster analysis to classify 27 forest communities, which were aggregated into 7 representative forest cover types on the basis of community similarity from composition of canopy species. They were Quercus mongolica forest cover type, mixed mesophytic forest cover type, Q. variabilis forest cover type, Pinus densiflora forest cover type, the others deciduous forest cover type, Q. serrata forest cover type, and subalpine forest cover type. The Q. mongolica forest cover type was most widely distributed in the study areas. It was assumed that abundance of Q. mongolica might be negatively associated with species diversity. Mixed mesophytic forest cover type and the others deciduous forest cover type were commonly distributed in the areas of valley, on the other hand, Q. mongolica cover type and P. densiflora cover type tended to be distributed in the areas of ridge.

• Korean Journal of Environment and Ecology
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• v.31 no.2
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• pp.188-201
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• 2017

Based on a total of 272 vegetation data collected by the ZM school phytosociological study method, the composition and structural characteristics of the forest vegetation in the Sogwang-ri forest genetic resource reservoir located in Uljin-gun, Gyeongsangbuk-do were compared using the table comparison method and the TWINSPAN method, And their ecological characteristics were analyzed. The types of forest vegetation were classified into 7 types, and it was divided into two major groups, 'Slope and Ridge type', which characterized by Quercus mongolica, Pinus densiflora for. erecta, Lespedeza bicolor etc. and 'valley and concave slope', which characterized by Cornus controversa, Fraxinus mandshurica, Morus bombycis, Hydrangea serrata for. acuminata etc. The hierarchy of the vegetation unit was 2 community groups, 4 communities, and 6 subcommunities. The structural characteristics such as the total percent cover, species importance value, species diversity of the constituent species per unit area($/100m^2$) of each type of forest vegetation were also identified. In order to understand the spatial distribution of forest vegetation, 1/5,000 large-scale physiognomic vegetation map was created by the uppermost dominant species. The composition and structural characteristics of Geumgang pine(P. densiflora for. erecta) forest, which is a core community of protected area by natural and anthropogenic influences, appear as a subtype of Quercus mongolica forest, which is a potential natural vegetation, Appropriate maintenance measures seemed urgently needed.

• Journal of Mushroom
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• v.6 no.3_4
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• pp.121-125
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• 2008

A first, we made white strain 'S line' adaptable to elevated temperature after collected brown strains were characterized with culture characterization on temperature and their monokaryons isolated at the high temperature were crossed with white strain. These S line monokaryons were crossed again with other monokaryons derived from a commercial white. As a result of successive crossing, finally a new variety 'Baengno' was developed. The optimum temperature of mycelial growth was $25^{\circ}C$ but it needed to adjust to $18{\sim}20^{\circ}C$ when incubated at the bottle cultivation. It brought incubation period shortening as 21 days saved 2~3 days when compared with other white varieties. The optimum temperatures of fruiting body initiation and development were almost same to others like as $14^{\circ}C$ and $7^{\circ}C$, respectively. Fruiting body of 'Baengno' was pure white even developed from crossing with brown strains. 'Baengno' was a good variety with high quality and high productivity characterized as quite even budding habit, long stipes and hemi-spherical pilei. This variety needed more air ventilation and had to be adjusted its cultivation environment for the good cultivation.

• Korean Journal of Plant Resources
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• v.28 no.1
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• pp.79-92
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• 2015

This study was conducted during two separate periods, from April to December 2008 and from April to November 2013, to identify the folk plants growing in Jeollanam-do which are used daily. A total of 1,200 questionnaires were distributed to 120 residents living in 14 counties and cities. From the results of the survey, 172 taxa of folk plants (77 families, 153 genera, 154 species, 2 subspecies, 14 varieties, and 2 forma) were identified. By regions, the city of Suncheon yielded 82 taxa, followed by 67 taxa from Gurye county, 65 taxa from Hampyeong county, 64 taxa from Jangseong county, 62 taxa from city of Naju, and 61 taxa from Jangheung county. Uses of the identified folk plants were: as edibles (117 taxa), for medicinal purposes (66 taxa), tea (15 taxa), for starch (6 taxa) for vegetable fat and oil (3 taxa), for nectar (2 taxa), for sap (2 taxa), for spice (2 taxa), for aroma (1 taxa), for fiber (1 taxa), and others (14 taxa). Thus, edible and medicinal uses of the plants appeared higher than other uses. The consistency of the local names of plants with the standard botanical nomenclature was 23.2% (40 taxa), while the proportion of local plant names analogous to the standard names was 18.6% (32 taxa). The consistency of the local plant names with the same plants in different cities and counties was 28.5% (49 taxa) and the proportion of local plant names analogous to each other in this category was 25.6% (44 taxa). Therefore, 54% of the folk plants growing in Jeollanam-do are known by location specific names. The usage types of the local folk plants were mostly collected through verbal communications.

• The Korean Journal of Mycology
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• v.48 no.2
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• pp.125-133
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• 2020

A new oak mushroom cultivar 'Hwadam' was bred from monokaryotic strains of 'GMLE36062' and 'LE15401'. The optimum temperature for mycelial growth of 'Hwadam' on potato dextrose agar was 25℃. The cultivation period of 'Hwadam' lasted for 129 days until the first harvest of the fruiting bodies, including 35 days for spawn run, 84 days for browning, and 10 days for development of fruiting bodies. The fruiting bodies of 'Hwadam' had a hemispherical, brighter pileus and thicker stipe than the control cultivar (Sanjo 701ho). The three-cycle yield of 'Hwadam' was 554 g, which was higher than that of control cultivar (405 g). In addition, 'Hwadam' contained 79.4 mg/g of beta-glucan and 0.93 mg GAEs/g of phenolic compounds, which was similar to that of the control cultivar but higher than that of 'L808' and 'Chujae 2ho'.

• Geophysics and Geophysical Exploration
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• v.18 no.4
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• pp.171-180
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• 2015

Electrical resistivity of 23 core samples from Ulleung Island at dry or saturated condition has been measured along with dry density and effective porosity, and the relations between the properties has also been discussed. Upper and lower bounds of electrical resistivity at room temperature can be provided by the dry- and saturated-resistivity, respectively. Injecting nitrogen gas to the pore space at the very end of drying process can prevent humid air from getting into the pore space, so that measurement of dry-resistivity can be less affected by humidity in the air. Dry density and porosity have very close correlation; the ratio between increase of porosity and the decrease of density showed distinct relation to the rock types, such that basaltic rocks showed higher ratio while trachytic rocks showed lower. Saturated resistivity showed close correlation to density and effective porosity of the rock sample, while dry resistivity didn't.

• Journal of Korea Water Resources Association
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• v.39 no.5 s.166
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• pp.395-403
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• 2006

This study suggests the use of a simple method, called the unit concentration response function(UCRF) for predicting travel time and dispersion of pollutants with the minimum information of study area instead of numerical models which are widely used In the Previous studies. However, the numerical models require time-consuming, tedious effort, and many data sets. So we derive the UCRF using some components such as travel time, peak concentration, and passage time of pollutant etc. We use the regression equation for the estimations of components which were developed from the investigations of many river basins in USA. This study used the regression equaiton for the UCRF to the accident of Dichloromethane leak into the Nakdong River occurred on June 30, 1994 and applied the UCRF for the predictions of travel time and dispersion. The predictions were compared with the results by QUAL2E model. The results by the regression equaiton and QUAL2E model had a good agreement between observed and simulated concentrations. Therefore, the regression equation for the UCRF which can simply estimate travel time and concentration of pollutants showed its applicability for the ungaged basin.

• Food Science and Preservation
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• v.23 no.7
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• pp.1004-1011
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• 2016

Flavonoids, non-nutrient secondary metabolites of plants, are widely distributed in commonly consumed agro-food resources. Flavonoids include aglycones, and their glycosides are reported to have potential health-promoting compounds. The aim of this study was to investigate flavonoid glycosides in the fruit and leaves of Zizyphus jujuba var. inermis (Bunge) Rehder (jujube). A total of six flavonoids (five flavonols and one chalcone) were identified in jujube fruit and leaves by using ultra-performance liquid chromatography-diode array detector-quadrupole time of flight mass spectrometry along with chemical library and an internal standard. In positive ion mode, six flavonoids were linked to the C- and O-glycosides which were conjugated with sugar moieties based on kaempferol, quercetin, and phloretin aglycones. Total flavonoid contents of leaves (8,356.5 mg/100 g dry weight (DW)) was approximately 900-fold higher than that of fruit (fresh fruit, 13.6 mg/100 g dry DW; sun-dried fruits, 9.2 mg/100 g dry DW). Quercetin 3-O-rutinoside (rutin) and quercetin 3-O-robinobioside were the predominant flavonols in fruit and leaves of jujube. In particular, rutin had the highest content (6,735.2 mg/100 g DW) in leaves, and rutin is a widely reported bioactive compound. Phloretin 3',5'-di-C-glucoside (chalcone type) was detected only in leaves. The leaves of jujube contain a high content of flavonoids and the results of this study indicate that jujube leaves may be a source of bioactive flavonoids.

• Korean Journal of Plant Resources
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• v.25 no.1
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• pp.48-62
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• 2012

This study was carried out to classify the folk plants in inland of northern region of Gangwon-do. According to the survey results from 35 places of 9 counties and cities from April to October, 2010, the folk plants in inland of northern region of Gangwon-do consisted of a total 261 taxa; 73 families, 185 genera, 225 species, 2 subspecies, 30 varieties, and 4 form. Among the investigated 261 taxa, 3 Korean endemic, 11 rare plants and 9 naturalized plants were also included. The use by usage of 261 taxa was: 378 times; Edible, 53 times; Medicinal, 8 times; Dye, 7 times; Ornamental, 6 times; Fuel, 5 times; Spice, 3 times; Aroma, 2 times; Nectar, 41 times; Others, respectively, so the edible use is the highest. The most useful part was the leaf, followed by whole plant and root. The consistency comparison between the scientific name and the local name were the highest in the 20's and the lowest in 80's.