• The Journal of Asian Finance, Economics and Business
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• v.8 no.1
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• pp.791-801
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• 2021

This study aims to test whether and to what extend national culture affects the readiness of business-to-consumer (B2C) e-commerce across the world. We regress two sets of data at national level: (1) the ratings of two main dimensions of Hofstede's national culture framework, uncertainty avoidance and individualism, and (2) UTCTAD B2C e-commerce index value. A sample of 83 countries was tested in this study. Several control variables at national level are included in our regression model. We find that these two cultural dimensions have an effect on the readiness of B2C e-commerce in various ways. We find that countries with high individualism score have high index value of B2C e-commerce development. We discuss the implications of these findings for B2C e-commerce developing strategies. We then call for designing relative policies with full consideration on national culture to promote the development of B2C e-commerce. In addition, we identify the limitations of the study and propose recommendations for future research. This study is the first one to use UNCTAD data on B2C e-commerce to explore the relationships between two dimensions of Hofstede's national culture and the readiness of B2C e-commerce and adds to the knowledge of literature in this research field.

• Korean Journal of Environmental Agriculture
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• v.29 no.4
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• pp.427-433
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• 2010

Aquatic invertebrates are the major important fauna to sustain the paddy ecosystem as predators of the lower trophic level and prey for birds in food-web dynamics as well. The nationwide distribution of scavenger beetles (Hydrophilidae) that is the top predator in an aquatic insect in the paddy field was investigated. A total of 15 scavenger beetles were recognized. Enochrus simulans (98.6%) and Laccobius bedeli (87.7%) showed a high frequency of occurrence on a nationwide scale. The majority of scavenger beetles were higher frequency of occurrence in mountainous regions(33.7%) than in open field regions(5.0%). On the other hand, E. uniformis, Coelostoma stultum and Berosus japonicus showed a low occurrence frequency. Hydrochara affinis, Sternolophus rufipes, Amphiops mater, B. elongatulus, B. signaticollis punctipennis, B. lewisius and H. libera showed regional specific distribution aspect. Therefore, these species can be used as biological index to research the biotic changes in paddy ecology according to an agro-environmental changes including climatic change in the future.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.1
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• pp.131-145
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• 2013

The purposes of this research are : to analyze biotop type and carry out conservation value assessment in study areas, Daegu Science Park national industrial complex; to supply basic data for the landscape ecological planning; and to improve the application of assessment model with the development of Biotop Value Assessment Tool (B-VAT). The result is as follows. First of all, the field survey showed 434 species of flora and 220 species of insecta. According to the result of biotop type analysis in the biotop classification system with field survey, 13 biotope groups and 63 biotope types were classified. In the map of biotop type classification, readjusted farmland biotop(FA) was prevalent and forest biotop(E) was shown to the southeast side of the site. Next, according to the first assessment with B-VAT, total 19 biotop types including natural river(BA) with abundant plants had I grade and total 16 biotop types such as vegetable garden adjacent to river(BC) had V grade. In terms of the second assessment, we analyzed total 30 areas, total 82 areas, respectively, which had special meaning for the conservation of species and biotop(1a, 1b) and which had meaning for the conservation of species and biotop(2a, 2b, 2c). This research will be a basic data, which can solve the damage problem systematically and control it landscape-friendly with biotop classification and assessment which we developed. In particular, we expect that biotop value assessment tool(B-VAT) with GIS will be a great contribution to popularity compared with the value model by complicated algorism such as adding-matrix, weight and equal distribution. In addition, this will save the time and improve the accuracy for hand-counting.

• Investigative Magnetic Resonance Imaging
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• v.24 no.3
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• pp.95-122
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• 2020

In this article, we evaluated the performance of radiofrequency (RF) coils in terms of the signal-to-noise ratio (S/N) and homogeneity of magnetic resonance images when used for ultrahigh-frequency (UHF) 7T magnetic resonance imaging (MRI). High-quality MRI can be obtained when these two basic requirements are met. However, because of the dielectric effect, 7T magnetic resonance imaging still produces essentially a non-uniform magnetic flux (|B₁|) density distribution. In general, heterogeneous and homogeneous RF coils may be designed using electromagnetic (EM) modeling. Heterogeneous coils, which are surface coils, are used in consideration of scalability in the |B₁| region with a high S/N as multichannel loop coils rather than selecting a single loop. Loop coils are considered state of the art for their simplicity yet effective |B₁|-field distribution and intensity. In addition, combining multiple loop coils allows phase arrays (PA). PA coils have gained great interest for use in receiving signals because of parallel imaging (PI) techniques, such as sensitivity encoding (SENSE) and generalized autocalibrating partial parallel acquisition (GRAPPA), which drastically reduce the acquisition time. With the introduction of a parallel transmit coil (pTx) system, a form of transceiver loop arrays has also been proposed. In this article, we discussed the applications and proposed designs of loop coils. RF homogeneous coils for volume imaging include Alderman-Grant resonators, birdcage coils, saddle coils, traveling wave coils, transmission line arrays, composite right-/left-handed arrays, and fusion coils. In this article, we also discussed the basic operation, design, and applications of these coils.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.8
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• pp.1064-1072
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• 1998

The evaporation of sludge particles in a sludge dryer has been numerically investigated with commercial CFX4.1 code. Gas flow field, gas temperature field, sludge particle trajectories, and the moisture content variation of sludge particles are calculated fort various influencing factors, i. e., gas swirl velocity, initial particle distribution, gas temperature. Evaporation of sludge particles increases with gas swirl velocity, several supplying positions, and gas temperature, respectively due to increased residence time, increased contacting surface area, and increased temperature difference between gas and particle.

• Korean Journal of Plant Taxonomy
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• v.52 no.1
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• pp.64-70
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• 2022

The genus Gueldenstaedtia Fisch. is small genus of Fabaceae that includes four species worldwide. Among these, G. monophylla Fisch and G. verna (Georgi) Boriss. are currently recognized as occurring in Mongolia. Here, we present our findings on G. verna from our recent field surveys in eastern Mongolia in 2020. Gueldenstaedtia monophylla is mostly distributed in the western region, whereas G. verna occurs in eastern Mongolia. The regional conservation status of both species was assessed as near threatened based on criterion B in the country. We provided descriptions, grid distribution maps, taxonomic notes and photographic illustrations of the two species based on our newly collected samples.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.12
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• pp.79-84
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• 2007

This paper presents an improved field uniformity in a reverberation chamber, that can be alternatively used for the analysis and the measurement of electromagnetic interference and immunity, with a designed CRD(Cubical Residue Diffuser) that have various dimensions. The Schroeder type CRD is designed for $1\sim3$ GHz band and the FDTD(Finite Difference Time Domain) method is used to analyze the field characteristics. At 2 GHz, the standard deviation of test volume in the reverberation chamber is the smallest and has a good field distribution with a CRD of $40\sim80%$ dimension of one side of the reverberation chamber. The Electric field uniformity gets worse when the dimension of a CRD is either below 40 % or above 80 % of the side wall. The result shows that the standard deviation of the test volume in the reverberation chamber with a CRD of 44 % dimension is improved by 1 dB compared with that of the reverberation chamber with a CRD of 100 % dimension.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.4
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• pp.291-298
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• 2015

In this study, the reverberation time of apartment living room was measured and distribution of the reverberation time was analyzed. In addition, sound field characteristics of mock-up test room similar with living room and timber structured bedroom was investigated with addition of furniture and sound absorption material. Average reverberation time of unfurnished apartment unit was 1.11 s, and reverberation time in 630 Hz~2000 Hz bands were longer than 1.2 s. It was found that from the field measurement results, reverberation time characteristic of furnished apartment living room was uniform in most of frequency bands. Averaged reverberation time of furnished living room was 0.48 s and the reverberation time of bedroom was 0.44 s. Standardized sound pressure level correction values were calculated from the average reverberation time of furnished and unfurnished apartment units. The correction value of unfurnished living room was −3.4 dB and that of furnished living room was 0.2 dB. Measured reverberation time of furnished and unfurnished apartment units indicated that reference reverberation time; 0.5 s, in KS and ISO standards is reasonable also in Korean residential environment.

• Wind and Structures
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• v.19 no.4
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• pp.421-441
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• 2014

With the assistance of typhoon field data at aerial elevation level observed by meteorological satellites and wind velocity and direction records nearby the ground gathered in Guangzhou Weather Station between 1985 and 2001, some key wind field parameters under typhoon climate in Guangzhou region were calibrated based on Monte-Carlo stochastic algorithm and Meng's typhoon numerical model. By using Peak Over Threshold method (POT) and Generalized Pareto Distribution (GPD), Wind field characteristics during typhoons for various return periods in several typical engineering fields were predicted, showing that some distribution rules in relation to gradient height of atmosphere boundary layer, power-law component of wind profile, gust factor and extreme wind velocity at 1-3s time interval are obviously different from corresponding items in Chinese wind load Codes. In order to evaluate the influence of typhoon field parameters on long-span flexible bridges, 1:100 reduced-scale wind field of type B terrain was reillustrated under typhoon and normal conditions utilizing passive turbulence generators in TJ-3 wind tunnel, and wind-induced performance tests of aero-elastic model of long-span Guangzhou Xinguang arch bridge were carried out as well. Furthermore, aerodynamic admittance function about lattice cross section in mid-span arch lib under the condition of higher turbulence intensity of typhoon field was identified via using high-frequency force-measured balance. Based on identified aerodynamic admittance expressions, Wind-induced stochastic vibration of Xinguang arch bridge under typhoon and normal climates was calculated and compared, considering structural geometrical non-linearity, stochastic wind attack angle effects, etc. Thus, the aerodynamic response characteristics under typhoon and normal conditions can be illustrated and checked, which are of satisfactory response results for different oncoming wind velocities with resemblance to those wind tunnel testing data under the two types of climate modes.

• Publications of The Korean Astronomical Society
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• v.4 no.1
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• pp.31-52
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• 1989

The rotational properties of late-type main sequence stars in the solar neighborhood have been investigated. So rotation periods and stellar radii are determined for 104 field stars, 8 Ursa Major Group stars, and 20 Hyades cluster stars. Most of the rotation periods are derived using the Noyes et al. (1984)'s relation between chromospheric activity and rotation period. Stellar radii are calculated by the Stefan law for the nearby stars within 25 pc from the sun. Rotational velocities at equator are determined by the above rotation periods and stellar radii. Their distribution along the (B-V) color shows an upper boundary and an abrupt drop for the stars in the range of 0.4<(B-V)<0.8, as found from the apparent rotational velocity data. Furthermore, it is apparent that there is an lower boundary of rotational velocity. The inclination of rotation axis to line-of-sight is obtained by comparing the rotational velocity at equator with the apparent rotational velocity given by the analysis of the line profiles. For the field stars, it is found that the inclination has no correlation with the galactic lattitude and follows random distribution.