• Journal of Ecology and Environment
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• v.42 no.3
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• pp.111-119
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• 2018

Background: Juniperus chinensis L. populations are distributed locally on several areas including coastal cliffs which are difficult to access in the central eastern Korea. Wild populations inhabit relatively barren environments such as rocky areas and cliffs, which are very sensitive to even minor environmental disturbances including artificial interventions and natural disturbances, and thus demonstrate great fluctuations in the population size and density. This study aims to analyze the genetic diversity, differentiation, and genetic structure of each population in order to provide useful data required to establish a substantial conservation strategy of J. chinensis. Results: The genetic diversity of J. chinensis at the population level (P = 78.7%, h = 0.282, S.I. = 0.420) was somewhat higher compared with those measured in the same genus, Juniperus. The genetic differentiation degree among nine populations established naturally in central eastern Korea was 11.50% and that among sub-populations within the same area was 5.52%. On the other hand, genetic variation of individuals within the populations was 82.93%. But frequency of the main allele was different among loci. In particular, fixation of allele frequency and occurrence of rare allele in the highly isolated population suggest a likelihood that genetic drift would occur in populations of this plant. As the result of analysis on the genetic structure of nine populations, nearby populations and isolated populations tended to form separate clusters from each other as the hypothetical number of clusters (K) increase. Conclusions: This result implies that if the population size of J. chinensis is reduced due to environmental change and artificial and/or natural disturbances in the future, it could affect negatively on the genetic diversity of the plant species. In order to maintain and conserve genetic diversity of J. chinensis, ecological network, which can help genetic exchange among the local populations, should be prepared, and conservation strategies in situ as well as ex situ are also required with continuous monitoring.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.4
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• pp.505-513
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• 2000

This study suggests new antenna design for polarization diversity. For dual polarization, two port feeding lines are printed on two separate layers and cross-shaped aperture is located on ground between the substrates. For reducing back radiation, a reflector is attached around $\lambda$/4 behind feeding substrates. For wide bandwidth we use a perturbed patch with saw tooth shaped. This perturbation effect causes reduction of antenna size and also reduction of array size. With the antenna proposed here, $1\times4$ array dual polarization antenna for polarization diversity of PCS base station is built. One single element has as large as 10.3%, 11.3% bandwidths at each port, V.S.W.R less than 1.3 and the isolation is less than -40 dB, also array antenna has 13.2% 12.7% band bandwidth, V.S.W.R less than 1.3 the isolation below -36dB and the XPD of 10 dB.

• Animal Bioscience
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• v.36 no.10
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• pp.1508-1516
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• 2023

Objective: To carry out a comprehensive production planning of the existing Rongchang pig population from both environmental and genetic aspects, and to establish a closed population with stable genetic diversity and strict pathogen control, it is necessary to fully understand the genetic background of the population. Methods: We genotyped 54 specific pathogen free (SPF) Rongchang pigs using the Zhongxin-1 Porcine Breeding Array PLUS, calculated their genetic diversity parameters and constructed their families. In addition, we also counted the runs of homozygosity (ROH) of each individual and calculated the value of inbreeding coefficient based on ROH for each individual. Results: Firstly, the results of genetic diversity analysis showed that the effective population size (N_e) of this population was 3.2, proportion of polymorphic markers (P_N) was 0.515, desired heterozygosity (H_e) and observed heterozygosity (H_o) were 0.315 and 0.335. H_o was higher than H_e, indicating that the heterozygosity of all the selected loci was high. Secondly, combining the results of genomic relatedness analysis and cluster analysis, it was found that the existing Rongchang pig population could be divided into four families. Finally, we also counted the ROH of each individual and calculated the inbreeding coefficient value accordingly, whose mean value was 0.09. Conclusion: Due to the limitation of population size and other factors, the genetic diversity of this Rongchang pig population is low. The results of this study can provide basic data to support the development of Rongchang pig breeding program, the establishment of SPF Rongchang pig closed herd and its experimental utilization.

• Korean Journal of Environment and Ecology
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• v.28 no.3
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• pp.293-301
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• 2014

15 artificial ponds in Seoul have been examined to find out the characteristics of Odonata community according to age and size of pond. We found 6 Families 36 Species of Odonata community, and Libellulidae was the most frequent and 19 Species were observed among Libellulidae. Considering relative importance with frequency of appearance and density, Ischnura asiatica and Orthetrum albistylum was the most frequent. Also, 16 Species including Lestes temporaris, Sympetrum parvulum, and Anax nigrofasciatus were relatively rare. The result of dominant species tells that Ischnura asiatica in 1 ~ 3 year old ponds, Pantala flavescens-Orthetrum albistylum-Crocothemis servilia mariannae in order of mention in 4 ~ 6 year old ponds, Platycnemis phyllopoda-Ischnura asiatica in order of mention in 10 or more year old ponds are the dominant species. Species diversity index regarding age of pond has been researched, and species diversity index in 10 year old pond was higher than that of in 1 ~ 3 year old pond. Having done the analysis of variance for types of spawn, there are many species Endophytic egg-layers and pasting in mud or sand in 10 year old artificial ponds. The wider ponds get, the higher species diversity index gets. And, we suggest that desirable size for making artificial ponds to increase the species diversity index of Odonata is $100{\sim}300m^2$.

• The Research Journal of the Costume Culture
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• v.31 no.5
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• pp.586-606
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• 2023

This study initiated research aligned with the body positivity movement, aiming to explore size diversity for groups facing relative size discrimination due to their deviation from average body types. Using KS adult women's apparel dimensions as a reference, jackets were developed for women in their 20s to 30s who belong to the small petite-size (S[P]) category, which is characterized by a height under 155cm (petite) and a bust-circumference from 72cm to less than 82cm (small). Using 3D virtual-fitting, we conducted experiment-pattern production and refinement and subsequent real-fitting evaluations by participants to objectively validate aesthetics and comfort. The study's findings are as follows: First, utilizing a 3D virtual-fitting program by identifying 'creases' and 'garment pressure points' in the jacket appearance, experiment patterns were refined and real jackets were produced. This approach addressed challenges in recruiting participants with specific body types and allowed for efficient research in terms of cost and time. Second, through real-fitting evaluations, basic-fit and slim-fit jackets labeled as <79-88-150> were developed for the S(P) size. we presented 'size spec' and 'ease allowance' for jackets by waist fit. Both fits received positive evaluations with approximately 53.5cm sleeve length, and 11.7cm shoulder length. The ease allowances for the basic-fit jacket were approximately 9.2cm at the bust circumference, 12.8cm at the waist circumference, and 6cm at the hip circumference. Similarly, the slim-fit jacket exhibited ease allowances of about 4.8cm at the bust circumference, 4cm at the waist circumference, and 4cm at the hip circumference, receiving positive evaluations for aesthetics and comfort.

• Journal of Environmental Impact Assessment
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• v.23 no.3
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• pp.208-219
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• 2014

This work aims to establish the landscape ecological countermeasures to improve the sustainability of urban mountain forest and to enrich the biodiversity in twenty mountains of the Seoul Metropolitan City. Landscape ecological analysis was conducted based upon various criteria, such as area and elevation of mountains, flora, naturalized plants, vegetation, forest types, mountain trails, and public facilities. Various measures were suggested for the better maintenances of floristic diversity, introduced plants, vegetation and forest types of urban mountain forests. Sustainable recommendations for land use adminstration were developed for the preparations of a climate change-adapted urban mountain forests, as well as rational managements of ecosystem, walking trails, and public facilities within mountain forest. Rich and diverse natural vegetation as well as high floristic diversity were reported at mountains with higher elevations, larger area size, and rich landscape diversity. Mountains with low elevation, small size with easy public access, however, might require an urgent action to decrease the burdens by anthropogenic disturbances and urban development.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.10C
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• pp.999-1006
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• 2005

The difference threshold test (DTT) declares erasures whenever the difference between the largest and second largest energy detector outputs does not exceed a given threshold. we show that the DTT outperforms the ratio threshold test (RTT) for finite modulation size and diversity order in the detection of M-FSK signals. The asymptotic performance for infinite modulation size and diversity order is then investigated. It is shown that the minimum signal-to-noise ratio required to achieve error-free communication for the DTT is the same as that for the RTT.

• Journal of Industrial Technology
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• v.36
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• pp.89-92
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• 2016

In this paper, we propose an efficient anonymity algorithm for personal information protections in big data systems. Firstly, we briefly introduce fundamental algorithms of k-anonymity, l-diversity, t-closeness. And then we propose an anonymity algorithm using controlling the size of anonymity groups as well as exchanging the data tuple between anonymity groups. Finally, we demonstrate an example on which proposed algorithm applied. The proposed scheme gave an efficient and simple algorithms for the processing of a big amount of data.

• ALGAE
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• v.33 no.2
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• pp.167-180
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• 2018

Benthic diatoms are ubiquitous in tidal flats and play major roles in maintaining coastal ecosystems. Spatio-temporal variations in diatom diversity have not been well-studied, mainly because of difficulties in morphological identification and the lack of appropriate genetic tools. To overcome these problems, we used the gene encoding the ribulose bisphosphate carboxylase large-subunit (rbcL) as a molecular marker, and sequenced these genes with the aid of the MiSeq platform. In this manner, we explored the genetic diversity of benthic diatoms in tidal flats of Guenso Bay on the west coast of Korea; differences in the spatial distributions of benthic diatoms were evident. The diatom communities were dominated by Nitzschia, Navicula, and Amphora; their relative distributions were affected by the sand proportion, grain size, and air exposure time. Our results suggest that meta-barcoding of the rbcL gene and next-generation sequencing can be used to explore the diversity of benthic diatoms.

• Journal of Ecology and Environment
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• v.36 no.3
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• pp.205-210
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• 2013

Cicuta virosa L. (Apiaceae) is a perennial emergent plant designated as an endangered species in South Korea. According to the former records, only four natural habitats remain in South Korea. A former study suggested that three of four populations (Pyeongchang: PC, Hoengseong: HS, Gunsan: GS) would be classified as different ecotypes based on their different morphological characteristics and life cycle under different environmental conditions. To evaluate this suggestion, we estimated genetic diversity in each population and distance among three populations by random amplification of polymorphic DNA. Seven random primers generated a total of 61 different banding positions, 36 (59%) of them were polymorphic. Nei's gene diversity and the Shannon diversity index increased in the order of PC < HS < GS, which is the same order of population size. In the two-dimensional (2D) plot of first two principal components in principal component analysis with the presence of 61 loci, individuals could be grouped as three populations easily (proportion of variance = 0.6125). Nei's genetic distance for the three populations showed the same tendency with the geographical distance within three populations. And it is also similar to the result of discriminant analysis with the morphological or life-cycle factors from the previous study. From the results, we concluded that three different populations of C. virosa should be classified as ecotypes based on not only morphology and phenology but genetic differences in terms of diversity and distance as well.