• The Journal of the Korea Contents Association
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• v.17 no.6
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• pp.527-539
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• 2017

This case study examines the experiences of an African American student's successful second language acquisition in Korea. There is an increasing number of multicultural families in Korea; but few research on African American students' second language learning. In the past, some American researchers have analyzed African American students as academic underachievers for learning and there is a scarcity of research on African American students' successfully acquiring a second language. With this qualitative research design, the researchers interviewed, and observed an African American girl named Mary. The researchers also interviewed Mary's mother, teacher, and peers about Mary's Korean language development. The results of this study revealed Mary's determined efforts to become a fluent Korean speaker with support from family, community and friends. Mary underwent unique social and systematic supports for her language development. This paper concludes with the educational implication for multicultural language learners in Korea and the possibility to diminish the common stereotypes of African Americans as underachievers.

• Journal of Satellite, Information and Communications
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• v.6 no.1
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• pp.75-79
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• 2011

Wireless devices can communicate between each other without existing infrastructure in mobile Ad-hod network. Ad hoc networks can be used under difficult conditions, where it is difficult to construct infrastructures, such as shadowing areas, disaster areas, war area, and so on. In order to support to considerable and various wireless services, more spectrum resources are needed. However, efficient utilization of the frequency resource is difficult because of spectrum scarcity and the conventional frequency regulation. Ad-hoc networks employing cognitive radio (CR) system that guarantee high spectrum utilization provide effective way to increase the network capacity. In this paper, we simulate and compare the performance of conventional single and cooperative spectrum sensing with CR system using ad-hoc networks in additive white Gaussian noise (AWGN) and Rayleigh channel model. And we demonstrate performance improvement by analyzing the system performance.

• Journal of the Korea Fashion and Costume Design Association
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• v.13 no.4
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• pp.15-28
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• 2011

This study will focus on research and analysis covering the period of time since the creation of the People's Republic of China to current day China, with an emphasis on 20-something year-old women living in Shanghai. In conducting this research, historical evidence of fashion was derived from books, photographs, and Internet resources pertaining to the specific periods of interest. Furthermore, each set of data has been organized in approximately decade-long segments that best reflect the transformation of Chinese fashion from 1949 to 2000. As a result of the countrywide emphasis placed on revitalization of the newly created Chinese state during the period of 1949 to 1965, detail to fashion was largely ignored, in preference to the successful upstart of a working economic foundation. This neglect of fashion is evident by the scarcity of new and daring styles during this period. The following the period of 1966 to 1977 ushered in a cultural revolution that was aptly demonstrated in the changing fashion tastes. When compared with the previous period, the blandness of clothing, authorized by the Chinese government clearly reflected the rules and regulations strictly enforced by a government mandate of conformity and obedience. These orthodox changes were so drastic, that women wearing these clothes could hardly be differentiated from men in the same style wear. After Mao Ze Dong's death in 1976 and the end of the sternest period of the Chinese Revolution, a new era of Chinese culture and fashion was made possible by a more lax and tolerant government. During the later palt of the seventies through the eighties, this new governmental policy fostered more openness and self-expression, both of which led to a newfound interest in expressing one's desires and personality through the clothes he or she chose to wear.

• Journal of Korean Library and Information Science Society
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• v.37 no.1
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• pp.193-219
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• 2006

This study analyzes 47 articles dealing with refugees in library and information science field. The subjects of these articles are such various as the cases of refugee service in libraries and information centers, the library service guidance for refugees, information resources of refugees and forced migration study, and information need and Information seeking behavior of refugees. However, the research of this area has such limitations and weakness as the small scale of articles about refugees, the scarcity of professional researchers, the deficient studies concentrating refugees directly, and the unprepared research methods. Tn particular, there was no article about refugee which was produced by the library and information science field in South Korea. Urgently needed is the research of information needs and information seeking behavior of North Korean refugees considering the recent influx of North Korean refugee into South Korea.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.364-369
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• 2009

Today, as various access technologies appear, for example WiMax, WiBro, the demand for spectrum is increasing rapidly. Spectrums are a national resource with scarcity value so that we need to a]locate them effectively for the national economy and industry. Accordingly, In the paper, we proposed several factors and new model for estimating spectrum requirements of a next generation mobile network with multimedia data services. These are self-similarity characteristics of data traffic, engineered capacity considering QoS, structure of FA increase, asymmetry of data traffic between uplink and downlink, handoff traffic, and uneven traffic pattern among base stations. It can applied mobile WiMax or other wireless broadband systems in general.

• Ocean and Polar Research
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• v.26 no.4
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• pp.559-565
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• 2004

Total magnetic field measurements were performed to study paleomagnetism of three seamounts (OSM7, OSM8-1, and OSM8-2) to the northwest of the Marshall Islands in the western Pacific. The study area is located at the Ogasawara Fracture Zone which is a boundary between the Pigafetta and East Mariana basins. The magnetic parameters and paleopoles of three seamounts were derived from inversion of the measured magnetic field. The goodness-of-fit ratio of OSM7 is too low to be included to the estimation of parameters. The complex magnetic anomalies of center, scarcity of flank rift zones and steep slope at OSM7 suggest that the multiple intrusions of magma converge into the center of volcanic edifice. Inclination calculated from the magnetic anomalies of OSM8-1 and OSM8-2 is $-41.2^{\circ}$, and the paleolatitude calculated from the inclination is $23.6^{\circ}S$. The corresponding paleopoles for OSM8-1 and OSM8-2 are $(24^{\circ}42'W,\;48^{\circ}54'N)\;and\;(18^{\circ}18'W,\;48^{\circ}30'N)$, respectively. In comparison with the apparent polar wander path (APWP) of the Pacific plate, the paleopoles are close to 129-Ma pole. The paleopoles and paleolatitudes of OSM8-1 and OSM8-2 suggest that they were formed at similar time and location. The seamounts have drifted northward about $41^{\circ}$ from the paleolatitude to present latitude of seamounts.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.1
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• pp.30-34
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• 1998

To compare response of feeding concentrate mixtere and wheat straw (Group I) with either urea molasses liquid diet (UMLD) as sole ration (group II) or UMLD (similar to protein equivalent of concentrate mixture) plus wheat straw (group III) on intake and utilisation of nutrients and overall performance, twelve crossbred adult male cattle (Holstein Friesian ${\times}$ Hariana) aged about 2.5 years and weighing 342 kg were randomly allotted into three equal groups following completely randomised design and fed respective diets for a period of 60 days. Thereafter, a metabolism trial of seven days duration was conducted to assess nutrient utilisation and nitrogen balance. Animals fed UMLD as sole ration consumed significantly (p < 0.01) less amount of most of the nutrients as compared to other two groups, except crude protein, intake of which was higher in this group but it was comparable between II and III and III and I. On the other hand, digestibilities of nutrients were higher (p < 0.01) in group II, though it was comparable between other two groups, except ADF, the digestibility of which was lower in group II. Inspite of positive nitrogen balance in all the three groups, being significantly (p < 0.01) higher in group I, animals of group II and III lost their body weight especially to the utmost extent in group II, although the amount of energy (TDN) intake were similar statistically. Results indicate that during a scarcity period and economic compulsions, feeding of UMLD can be practised to replace only concentrate mixture from the maintenance ration of adult crossbred cattle for shorter duration as roughage part seems to be essential for the normal functioning of the rumen microbes and overall performance of the animals.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.2
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• pp.37-47
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• 2017

In this study, we analyzed the variability of irrigation water amounts based on the combination of various crops and soil textures using the Irrigation Water Management Model (IWMM). IWMM evaluates the degree of agricultural drought using the Soil Moisture Deficit Index (SMDI). When crops are damaged by the water scarcity under the drought condition indicating that the SMDI values are in negative (SMDI<0), IWMM irrigates appropriate water amounts that can shift the negative SMDI values to "0" to crop fields. To test the IWMM model, we selected the Bandong-ri (BDR) and Jucheon (JC) sites in Gangwon-do and Jeollabuk-do provinces. We derived the soil hydraulic properties using the near-surface data assimilation scheme form the Time Domain Reflectrometry (TDR)-based soil moisture measurements. The daily root zone soil moisture dynamics (R: 0.792/0.588 and RMSE: 0.013/0.018 for BDR/JC) estimated by the derived soil parameters were matched well with the TDR-based measurements for validation. During the long-term (2001~2015) period, IWMM irrigated the minimum water amounts to crop fields, while there were no irrigation events during the rainy days. Also, Sandy Loam (SL) and Silt (Si) soils require more irrigation water amounts than others, while the irrigation water were higher in the order of radish, wheat, soybean, and potato, respectively. Thus, the IWMM model can provide efficient irrigation water amounts to crop fields and be useful for regions at where limited water resources are available.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.5661-5668
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• 2012

In the era of water scarcity, saving toilet water is one of the most effective ways to save water. In this study, two-phase flow for the development of highly-efficient toilet has been analysed with VOF(Volume Of Fluid) method. Since the whole model requires extensive computing time, part of the whole model has also been adopted to reduce the analysis time. Four different rim models were considered for flow distribution analysis and sizes of rim holes were found to become more important rather than locations or numbers of rim holes in achieving flow distribution effectively. In addition, velocity and pressure of two-phase flow due to siphon phenomenon have been studied through the analysis of whole model. Therefore, this study provides a variety of fundamental data for the development of highly-efficient toilet.

• Geomechanics and Engineering
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• v.4 no.4
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• pp.281-294
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• 2012

Filtration using granular media such as quarried sand, anthracite and granular activated carbon is a well-known technique used in both water and wastewater treatment. A relatively new pre-filtration method called pebble matrix filtration (PMF) technology has been proved effective in treating high turbidity water during heavy rain periods that occur in many parts of the world. Sand and pebbles are the principal filter media used in PMF laboratory and pilot field trials conducted in the UK, Papua New Guinea and Serbia. However during first full-scale trials at a water treatment plant in Sri Lanka in 2008, problems were encountered in sourcing the required uniform size and shape of pebbles due to cost, scarcity and Government regulations on pebble dredging. As an alternative to pebbles, hand-made clay pebbles (balls) were fired in a kiln and their performance evaluated for the sustainability of the PMF system. These clay balls within a filter bed are subjected to stresses due to self-weight and overburden, therefore, it is important that clay balls should be able to withstand these stresses in water saturated conditions. In this paper, experimentally determined physical properties including compression failure load (Uniaxial Compressive Strength) and tensile strength at failure (theoretical) of hand-made clay balls are described. Hand-made clay balls fired between the kiln temperatures of $875^{\circ}C$ to $960^{\circ}C$ gave failure loads of between 3.0 kN and 7.1 kN. In another test when clay balls were fired to $1250^{\circ}C$ the failure load was 35.0 kN compared to natural Scottish cobbles with an average failure load of 29.5 kN. The uniaxial compressive strength of clay balls obtained by experiment has been presented in terms of the tensile yield stress of clay balls. Based on the effective stress principle in soil mechanics, a method for the estimation of maximum theoretical load on clay balls used as filter media is proposed and compared with experimental failure loads.