• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.2089-2094
• /
• 2010

The importance of broadband wireless communication implemented at subway tunnels is growing up. At 18GHz wireless video transmission system, the transmitter requires a digital modulation method. At subway tunnel, A 18GHz's influence of the multi-pass padding is strong. OFDM digital modulation that is strong for multi-pass padding is recommended. In this paper, Suitable to a subway wireless video transmission OFDM receiver is designed. OFDM receiver system has 6dB gaion because uses diversity of space diversity and MRC(Maximum Ratio Combining) diversity. The transmitter system use C&ITechnologies's transmitter board. IF frequency of receiver is 480MHz. OFDM modulation parameter is as follow, The bandwidth is 8MHz, The numuber of carrier if 2,000, The modulation methode is QAM16, The guard interval is 1/32.

• The Journal of Asian Finance, Economics and Business
• /
• v.8 no.2
• /
• pp.943-952
• /
• 2021

The purpose of this study is to evaluate the effect of COVID-19 on corporate governance attributes and firm performance association. This research used a sample of 188 non-financial firms from the Malaysian market for the years 2019-2020. We found that the COVID-19 has affected all firm characteristics including firm performance, governance structure, dividend, liquidity, and leverage level, yet, the difference between prior and post COVID-19 pandemic is not significant. Also, the investigation revealed that board size exerts a significant positive impact on firm performance. After splitting the sample based on year, however, we found that board size does not matter in the uncertain time of the current crisis, while board diversity appeared to be significantly enhancing firm performance in the crisis time compared to the prior year where it has an inverse association with firm performance in both indicators. Board meetings and audit committee meetings seemed to have a significant negative influence on firm performance pre and post-COVID-19. This study contributes to the limited literature by providing the first empirical evidence on the impact of Coronavirus on the firm performance and corporate governance association.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.20 no.2
• /
• pp.37-43
• /
• 2010

The wild silkworm, Antheraea mylitta Drury (Lepidoptera: Saturniidae) is a polyphagous silk producing insect that feeds on Terminalia arjuna, T. tomentosa and Shorea robusta and is distributed in the forest belts in different states of India. Phenotypically distinct populations of the A. mylitta are called "eco-race" or "ecotypes". Genetic improvement of this wild silkworm has not progressed much due to lack of adequate information on the factors that control the expression of most of the economically important traits. Considering the amazing technological advances taking place in molecular biology, it is envisaged that it is now possible to take greater control on these intractable traits if a combination of genetic, molecular and bioinformatics tools are used. Linkage disequilibrium (LD) mapping is one such approach that has extensively been used in both animal and plant system to identify quantitative trait loci (QTLs) for a number of economically important traits. LD mapping has a number of advantages over conventional biparental linkage mapping. Therefore, LD mapping is considered more efficient for gene discovery to meet the challenge of connecting sequence diversity with heritable phenotypic differences. However, care must be taken to avoid detection of spurious associations which may occur due to population structure and variety interrelationships. In this review, we discuss how LD mapping is suitable for the dissection of complex traits in wild silkworms (Antheraea mylitta).

• Journal of the Korean Society for Library and Information Science
• /
• v.58 no.2
• /
• pp.81-100
• /
• 2024

This study analyzed the national diversity of journal editors and authors, focusing on international journals in library and information science, and quantified it through Simpson's Diversity Index. In addition, LIS journals were clustered according to diversity indicators and their characteristics were analyzed, and it was also confirmed whether nationality diversity of editorial members could induce nationality diversity of authors. As a result of the analysis, first, the diversity index of the editors of the LIS (Library & Information Science) international journal was found to be 0.64, which is less than the diversity of the authors, which is 0.76. It was confirmed that as the diversity of nationalities among editorial committee members increases, it is possible to attract authors of various nationalities (r = .79). Second, journals in the IS (Information Science) field showed a high index before or after 0.8 for both editorial members and author contributing countries, but those in the LS (Library Science) field showed relatively low scores, especially among the editorial members, with a very low index of 0.48. Third, the United States has the highest share of both authors and editors, and in particular, it has been confirmed that the LS field has an overwhelming share of 53.39% of editors. On the other hand, in Asian countries, including Korea, the ratio of contributions as editors compared to contributions as authors was found to be lower than in the United States and European countries.

• The Journal of Asian Finance, Economics and Business
• /
• v.8 no.4
• /
• pp.369-379
• /
• 2021

This paper investigated the relationship between corporate governance mechanisms and firm performance in Vietnam. Based on a dataset of 101 HOSE-listed manufacturing firms, the results showed that CEOs' knowledge capability, gender diversity, and board size are positively associated with firm performance, whereas firm age is negatively associated. These findings suggested that firms should consider enlarging the boardrooms, but to a certain extent to avoid an inverse-U-shaped decline of performance; furthermore, firms should promote women executives' presence in a boardroom for it brings greater cultural-diversity benefits and inhibits information asymmetry. Contrary, the aging process impedes firms' growth. It depreciates their values in terms of total assets, so managers must review their assets' net value after each working year to avoid such a hardship. However, the thesis constrains itself since it did not treat the TMTs' knowledge capability equally as the CEOs' and completely excluded their treatment. Besides, it did not regard the effect of external governance mechanisms such as the supply-demand relationship, customer behavior, market imperfections, and market concentration due to data unavailability. Based on the main findings, several suggestions are set forth for firms and managers to enhance performance and minimize a poor governance mechanism's adverse consequence.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.5A
• /
• pp.696-701
• /
• 2000

Electronic Toll Collection (ETC) System makes the telecommunication possible between the Beacon and the On Board Unit(OBU) for automatic toll collection. In this paper, the propagation path of microwave is modelled and the induced voltage of receiving antenna is analyzed numerically according to multi-path fading effect. In our modelling, we consider frequency, weather condition, polarization and antenna radiation pattern. Also, we suggest the diversity technique in order to reduce the fading effect. In the resuts, the fading effect is reduced significantly in case of the vertical polarization at the rain condition. In general the circular polarization is the most desirable in this application. The antenna which has the high directivity, is also desirable. Using the space and frequency diversity technique at the Beacon, the fading effect is reduced effectively. These results are compared with our experimental data.

• Journal of Christian Education in Korea
• /
• v.73
• /
• pp.21-37
• /
• 2023

Several tensions are visible in contemporary Dutch society, including those around refugees and sexual diversity, and the place of (strict) religion in society has changed. From both a theoretical and empirical perspective, we examine what this means for Christian education in general and for teachers in conservative Protestant schools in particular when it comes to citizenship education. It is concluded that the role of the school board and management is important in supporting teachers and promoting a shared vision within the school. In thinking about Christian citizenship education, a focus on Christian attitudes instead of morals has become more important, as it is in religious education.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.10 no.1
• /
• pp.51-59
• /
• 2005

Genetic diversity within and between populations of Antheraea mylitta Drury was studied using thirty individuals from three ecoraces using 12 ISSR and 10 RAPD primers. Rally, Daba and Modal ecoraces were collected from Chattisgarh, Jharkhand and Orissa states of India respectively. The ISSR and RAPD primers generated $94.7\%$ and $95.6\%$ polymorphism among the 30 individuals. The cluster analysis grouped these individuals according to their ecorace. The intra-ecoracial heterozygosity estimated with ISSR markers were $0.123{\pm}0.18,\;0.169{\pm}0.17\;and\;0.214{\pm}0.17$ respectively for Modal, Raily and Daba ecoraces. Like wise, with RAPD markers the intraecoracial heterozygosity was $0.17{\pm}0.22$ in Modal, $0.229{\pm}0.17$ in Raily and $0.23{\pm}0.19$ in Daba ecoraces. However, the significantly low genetic differentiation (GST) (0.182 for ISSR and 0.161 for RAPD) and the high gene flow (Nm) (2.249 for ISSR and 2.60 for RAPD markers) among the ecoraces revealed that the amount of genetic diversity present among the ecoraces is not significant enough to make drastic genetic drifts among these ecoraces in the near future.

• International Journal of Aeronautical and Space Sciences
• /
• v.16 no.3
• /
• pp.445-450
• /
• 2015

Generally, Low Earth Orbit (LEO) satellites are used to collect image or video from earth's surface. The collected data are stored on-board and/or transmitted to the main ground station directly or via polar ground station using terrestrial line. Today, an intersatellite link between a LEO and a GEO satellite allows transmission of the collected data to the main ground station through the GEO satellite. In this study, an approach for a continuous communication starting from LEO through GEO to ground station is proposed by determining the optimum ground station locations. In doing so, diverse ground stations help to determine the GEO orbit as well. Cross-correlation of the long term daily rainfall averages are multiplied with the logarithmic correlation of the sites to calculate the joint correlation of the diverse ground station locations. The minimum values of this joint correlation yield the optimum locations of the ground stations for Q/V-band communication and satellite control operations. Results for several case studies are listed.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.1044-1053
• /
• 2010

Transmitting correct train control information is important in a train control system which demands safety. The train control information includes the maximum speed of trains, position of preceding trains, incline of tracks and curve sections etc. A radio frequency-communication based train control system is influenced by the noise and interference because the train control information is transmitted by wireless between a on-board system and wayside system. The radio frequency-communication based train control system is a mobile communication system due to moving trains. The inter symbol interference(ISI) occurs by the multipath fading in the mobile ommunication system. As signal-to-noise ratio(SNR) is decreased by the ISI, the train control information is not received correctly. In case of tunnel section, numerous reflected waves exist. Therefore, the power density of receiver is decreased by difference among the received times, magnitudes, phases through the multipath. So, the train suddenly is stopped by the fail-safe operation in the train control system on account of decreasing the power density of receiver. In this paper, a line of sight model-(Additive White Gaussian noise(AWGN) channel), rayleigh and rician fading model are presented. Probability density functions which are related to the SNR are derived from the models. The fading phenomenon severely occurs as a result of analyzing the probability density functions. So, the space diversity method is used in order to reduce the fading effect and it is demonstrated by using Matlab program.