• Journal of Astronomy and Space Sciences
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• v.27 no.2
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• pp.97-106
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• 2010

To prepare for a Korean lunar orbiter mission, a precise lunar orbit propagator; Yonsei precise lunar orbit propagator (YSPLOP) is developed. In the propagator, accelerations due to the Moon's non-spherical gravity, the point masses of the Earth, Moon, Sun, Mars, Jupiter and also, solar radiation pressures can be included. The developed propagator's performance is validated and propagation errors between YSPOLP and STK/Astrogator are found to have about maximum 4-m, in along-track direction during 30 days (Earth's time) of propagation. Also, it is found that the lifetime of a lunar polar orbiter is strongly affected by the different degrees and orders of the lunar gravity model, by a third body's gravitational attractions (especially the Earth), and by the different orbital inclinations. The reliable lifetime of circular lunar polar orbiter at about 100 km altitude is estimated to have about 160 days (Earth's time). However, to estimate the reasonable lifetime of circular lunar polar orbiter at about 100 km altitude, it is strongly recommended to consider at least $50\;{\times}\;50$ degrees and orders of the lunar gravity field. The results provided in this paper are expected to make further progress in the design fields of Korea's lunar orbiter missions.

• Journal of Environmental Science International
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• v.22 no.9
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• pp.1141-1152
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• 2013

Insect fauna were surveyed in 2011 at Ungok wetland, Obeygol, located in Gochang, Jeonbuk, Korea. In total, 149 species belonging to 11 orders and 57 families were surveyed. Among them, Lepidopterans composed 23.5% (35 species) of the total insect numbers surveyed, comprising the most abundant group, and followed by Coleoptera, Hemiptera, and Odonata with a composition of 22.1% (33 species), 17.4% (26 species), and 10.1% (15 species), respectively. Bothrogonia japonica Ishihara was the most dominant species, and followed by Gastrophysa atrocyanea Motschulsky and Celastrina argiolus (Linnaeus). Phytophagous insects accounted for 60 percent of the total species. Dominance index was the highest in spring by 0.21. Diversity, richness, and evenness indices were the highest in summer by 4.07, 11.84 and 0.96, respectively. In the study area, the legally-protect species were grouped into five groups; 9 export-restricted species, 17 endemic species, 28 indicator species, 1 climate-sensitive biological indicator and 3 southern characteristic species. Additionally, twenty forest insect pest species were surveyed, belonging to 5 orders and 15 families. Therefore, it is required to conduct long-term monitoring and appropriate management based on the ecological characteristic of the habitats to continuously conserve and maintain of wetland.

• Journal of Advanced Marine Engineering and Technology
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• v.10 no.2
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• pp.146-155
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• 1986

Until recently, the calculation of torsional vibration for the marine diesel engine shafting has been performed only for vibratory stresses of resonant points and vibratory stresses for other engine speeds are determined by the estimation. With the advent of energy-saving engines which have a long stroke and a small number of cylinders, the first major critical torsional vibration of the propulsion shaft appears ordinarily near the MCR speed of engine and the flank of its vibratory stress exceeds now and then the limit stress defined by the rules of Classification Society. In order to know the above condition in the design stage of propulsion shafting, it is necessary to calculate the forced torsional vibration with the damping of propulsion shafting for all orders and to synthesize its calculated results according to their phase angles. In this study, the forced torsional vibrations with the damping of propulsion shafting are calculated for several orders by mechanical impedance method, and their results are synthesized. A computer program for above calculations are developed and some test-runs of the developed program are performed for propulsion shaftings of actual ships. The results of calculations are compared with measured values and also with those of the modal analysis method. They show fairly good agreements and the developed program is checked up on its reliability.

• Journal of Environmental Science International
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• v.11 no.4
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• pp.271-279
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• 2002

The purpose of this study is to focus on the townscape of Daegu based on the urban characteristics of the landscape cognition and images captured by citizens. The analysis was performed by the data obtained from questionnaires and interviews. This study methods were deals the cognition characteristics, landmark landscape, visual preference landscape, image and satisfaction. The results are summarized as follows: 1. The orders of cognition landscapes were estimated Apple＞ Weather＞ Texture＞ Mt.Palgong＞ Daegu Tower＞ Pretty Girl＞ Mt. Apsan＞ Dalsung Park＞ Conservative＞ Dongsung Road, etc. That is constructed Nonphysical elements(62.0%) and Physical elements(38.0%) 2. The orders of representative landscape(Landmark) in city were estimated Mt.Palgong＞ Daegu Tower＞ Gat Rock＞ Mt.Apsan＞ Dalsung Park, etc. As a whole middle and old people(over 30gen) preferenced as a history landscape or natural landscape, but youth people(10-20gen) preferenced as visible and interesting artifical places. 3. While the positive attitudes for the image of city were traditional(3.30), intimacy(3.58), and rest(2.90), the negative attitudes were unnewly(2.34), closing(2.37) and narrow(2.40). Also total satisfaction for that was estimated 5.51. 4. Psychological factors, related to the satisfaction of the image of city were composed of four factors, individuality character, pleasure character, amenity character, formation character. And the presumption formula of satisfaction was: Satisfaction = 5.477 ＋ 0.752(Individuality) ＋ 0.470(Pleasure) ＋ 0.413(Amenity) ＋ 0.241(Formation).

• The Journal of the Acoustical Society of Korea
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• v.16 no.1
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• pp.100-103
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• 1997

In this paper, we analyze the time delayed effect of speech feature. Here, the time delayed effect means that the current feature vector of speech is under the influence of the previous feature vectors. In this paper, we use a set of LPC driven cepstal coefficients and evaluate the time delayed effect of cepstrum with the performance of the speech recognition system. For the experiments, we used the speech database consisting of 22 words which uttered by 50 male speakers. The speech database uttered by 25 male speakers was used for training, and the other set was used for testing. The experimental results show that the time delayed effect is large in the lower orders of feature vector but small in the higher orders.

• Korean Institute of Interior Design Journal
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• v.24 no.5
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• pp.136-143
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• 2015

At this present, the world is in the era of digital and culture.Tourist resources through cultural infrastructure have been a crucial factor of a country's competitiveness. A Museum is tourism resource facility like one of core cultural infrastructures which provides experiential culture, history and tradition. The field of a planning and a design for a museum should be recognized like professional design industry.n Korea, the government has various laws and systems to support the design promotion policy but it is not sufficient. If you plan to extend the scope of the maintenance of law and institutions As today 'Exhibition Industry Development Act, which is responsible for maintenance, including a permanent exhibition area in the exhibition industry facilities will be efficient alternative. And also, it would like to analyze states of the orders in the exhibition design industry for past five years (2010 ~ 2014) and show the problems and alternatives. Exhibition business-related orders investigation into the recent five years to analyze and suggest improvements. In the delivery method it was found three types of goods, the services, the delivery method through the analysis of the enforcement order to the Corporation and that are mixed.If these alternatives has been reviewed and used for basic data to promote professional companies and designers for museums, it must be expected to be well worth a careful study.

• East Asian Journal of Business Economics (EAJBE)
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• v.9 no.3
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• pp.83-100
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• 2021

Purpose - The purpose of this study is to comprehensively understand the recent status of domestic e-commerce market and provide useful information for the revitalization of domestic on-line economy. This study looks over the association between type of e-commerce and demographic variables for each purchase ordering and sales order business. The demographics under consideration is administrative district, occupation and business organization type and type of e-commerce is B2B, B2C and B2G to deal with. Research design, data, and methodology - From January 2017 to December 2017, about 14000 samples are extracted from all businesses with experience in purchasing or selling products or services through e-commerce. The association between the two categorical variables considered by using two major statistical techniques such as chi-square test and correspondence analysis can be quantitatively and visually detected. Result - This study shows the association between the type of e-commerce with the administrative district and the occupation is completely different, but B2B and B2C are identical for organization type, with respect to both purchase and sales orders. Conclusion - The association between the type of e-commerce with the administrative district and the occupation is completely different, but B2B and B2C are identical for organization type, with respect to both purchase and sales orders.

• Journal of Environmental Science International
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• v.27 no.11
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• pp.1007-1021
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• 2018

Community dynamics of benthic macroinvertebrates and biological evaluation of water quality were investigated at Gigyecheon of Pohang and Gyeongju, Korea. The survey was carried out at 8 sites from May to October, 2017. As a result, total of 104 species under 54 families, 15 orders, 8 classes in 4 phyla with 5,052 individuals were revealed. The number of species was the most abundantly identified in aquatic insects, 76 species under 34 families, 6 orders. Among them, the order Odonata was the most abundant taxon as 21 species(20.2%). The most abundant individuals were collected in the phylum Mollusca as 1,453 individuals(28.8%). Various species appeared dominantly at each site by season, and the most dominant species was Caridina denticulata denticulata belonging to the class Malacostraca with 0.08 of dominance index. According to the results of community structure analyses, the diversity and richness indices were the highest at site II, the evenness index was the highest at site I, and the dominance index was the highest at site IV. The number of species and individuals of gathering collectors were the highest among functional feeding groups. Those of sprawlers were the highest among habitat orientation groups. The ESB showed a tendency to change according to season and site, and it was the highest in May at most surveyed sites. The KSI was also somewhat fluctuated according to season and site. From these indices, average biological water quality was evaluated as class II.

• Korean Journal of Environment and Ecology
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• v.25 no.6
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• pp.836-845
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• 2011

This study aims feeding habit of the Korean water deer(Hydropotes inermis argyropus) using a visual analysis of rumen contents of 44 individuals. The samples were collected from Cheorwon(Gangwon province) and the eastern part of Jeonnam province. Based on the analysis, a total of 15 orders, 18 families and 13 species were identified. Among them, Solanceae(53.8%) and Graminease(30.3%) showed the highest proportions. Plants of 13 orders, 15 families and 10 species were found and forbs(70.21%) and Solanceae(54.9%) were most preferred in Cheorwon. Eight orders, 7 families and 4 species were found in the Eastern parts of Jeonnam province, and Gramineae(78.6%) and woody plants(14.70%) was most preferred. Among four seasons, Gramineae in spring(80.6%) and autumn(68.8%), Leguminosae(75.9%) in summer, and Solanceae(85.4%) in winter were the highest proportions.

• Korean Journal of Microbiology
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• v.47 no.3
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• pp.209-217
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• 2011

Archaeal communities were investigated using 454 pyrosequencing technology based on 16S rRNA gene in 11 samples collected from six different full-scale anaerobic digesters. Observed operational taxonomic units (OTUs) estimated from the archaeal 16S rRNA gene sequences were 13-55 OTUs (3% cutoff) which was corresponded to 29-89% of Chao1 richness estimates. In the anaerobic digesters there were archaeal sequences within the orders Thermoproteales, Thermoplasmatales, Desulfurococcales as well as within the orders Methanomicrobiales, Methanobacteriales, Methanococcales, Methanosarcinales, and Methanocellales, which are known to produce methane. Among these orders, Methanococcales known to produce methane using hydrogen was the predominant taxon and constituted 51.8-99.7% of total sequences. All samples showed a very similar community structure (Pearson correlation coefficient=0.99) except for one sample based on a heat map analysis. In addition, canonical correspondence analysis correlating archaeal communities to the environmental variables demonstrated that digester temperature and total solids removal rate were the two important explanatory variables. Overall results suggested that environmental and operational variables of anaerobic digester are important factors determining archaeal diversity and community structure.