• Journal of Communications and Networks
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• v.13 no.5
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• pp.525-535
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• 2011

In this paper, we study the contribution of network coding (NC) in improving the multicast capacity of random wireless ad hoc networks when nodes are endowed with multi-packet transmission (MPT) and multi-packet reception (MPR) capabilities. We show that a per session throughput capacity of ${\Theta}$(nT$^3$(n)) can be achieved as a tight bound when each session contains a constant number of sinks where n is the total number of nodes and T(n) is the transmission range. Surprisingly, an identical order capacity can be achieved when nodes have only MPR and MPT capabilities. This result proves that NC does not contribute to the order capacity of multicast traffic in wireless ad hoc networks when MPR and MPT are used in the network. The result is in sharp contrast to the general belief (conjecture) that NC improves the order capacity of multicast. Furthermore, if the communication range is selected to guarantee the connectivity in the network, i.e., ${\Omega}$($\sqrt{log\;n/n}$)=T(n) = O(log log n / log n), then the combination of MPR and MPT achieves a throughput capacity of ${\Theta}$(log$^{\frac{3}{2}}$ n/$\sqrt{n}$) which provides an order capacity gain of ${\Theta}$(log$^2$ n) compared to the point-to-point multicast capacity with the same number of destinations.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.5
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• pp.189-199
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• 2021

This study aimed to explore the factors affecting the innovation capacity of students at the National Economics University, Vietnam. Researchers used the innovation capacity model based on six factors, including personality traits, future orientation, creative skills, social interaction, content knowledge, and management skills. The empirical analysis used data from the survey of 303 students at National Economics University, Vietnam, with reliable tools (SPSS 26.0 software). The data were analyzed by testing the reliability of the scales, correlation analysis, and Pearson' Linear Correlation Coefficient, exploratory factor analysis, as well as regression model based on the survey data. The research results identified the following factors affecting innovation capacity of students: management skills, social interaction, and personality traits have the strongest impact on innovation capacity of students; content knowledge has the following strongest effects on innovation capacity of students; and finally the creative skills that affects on innovation capacity of students. There is also a positive relationship between all the factors and innovation capacity of students. The result can serve as useful reference sources for scholars who are interested in the innovation field. It also helps university's managers and policymakers build the appropriate environment to improve innovation capacity of students.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.6
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• pp.139-149
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• 2022

The article investigates the impact mechanism of absorption capacity (potential absorptive capacity - PAC and realized absorptive capacity - RAC) on the innovation efficiency of enterprises through the intermediate variable of dual innovation (exploratory innovation- INOR and exploitative innovation- INOI), based on the actual situation of Vietnam's small and medium enterprises (SMEs). A survey of Vietnam's SMEs was conducted from August 2020 to April 2021. The data was collected through interviews and questionnaires, and 146 valid questionnaires were received. The following results were acquired using SPSS 20.0 software to do correlation and regression analysis of data results.: The results show that the absorptive capacity of enterprises has a positive impact on innovation performance and dual innovation acts as a mediator in how absorptive capacity affects innovation performance. This study deepens the understanding of how absorptive capacity affects innovation performance and provides important new evidence for developing absorptive capacity and dual innovation in both theories and practice in Vietnam's SMEs. The study also proposes several solutions and recommendations to help Vietnam's small and medium enterprises improve their innovation capacity, competitiveness, and performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10A
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• pp.788-795
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• 2003

We analyze the performance of a truncated power controlled CDMA(code division multiple access) cellular systems with base station antenna arrays. Erlang capacity and the channel capacity which is a maximum date rate to maintain almost error free communication are analytically derived. The numerical results show there can be a substantial increase in Erlang capacity and in channel capacity by antenna arrays incorporating with the truncated power control scheme.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.455-462
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• 2003

The current practice of estimating bearing capacity usually employs the conventional bearing capacity formula originally developed for strip footings under vertical central loading, In order account for the effect of footing shape and eccentricity and inclination of loads, correction factors are introduced in the formula, which are derived based on a number of small-scale model test observations. In this paper, comparison of several formulations of bearing capacity factors, as well as values of these factors, are presented. And the conventional bearing capacity equations are compared with some of other failure loci proposed for cohesive soil. Also, the bearing capacity of shallow foundation estimated by the conventional bearing capacity equations are compared with the experimental load test results.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.7
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• pp.363-370
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• 2003

This paper presents the analysis of the load transfer capacity and study of conductor size for variable contingencies in distribution systems. The operation capacity of feeders was changed to improve operation efficiency in KEPCO, considerations for contingencies are still based on the previous capacity. In order to cope with the changes such as operation capacity, it is necessary to study whether the present "contingency support criteria" is reasonable or not, also to confirm the whether the present criteria should be improved or not. We analyze the load transfer capacity and conductor size on a distribution system for contingency levels such as the substation-level, bank-level, feeder-level, and zone-level.one-level.

• Journal of the Korean Society of Industry Convergence
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• v.6 no.1
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• pp.11-15
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• 2003

There are various method for the LEV(Low Emission Vehicle) regulation, but 2-catalyst system using one catalyst near exhaust manifold and another catalyst underfloor, is the most popular. This system uses the proven catalyst technology and doesn't use energy. But it is difficult to determine capacity of the two catalysts. So an optimization method to determine the capacity has been proposed by other researcher. It uses the fact that emission decreases with capacity increasing, but the decreasing ratio slows down in high capacity range. It means that the emission and capacity of catalyst is exponentially decreasing relation. In this paper this method will be verified with various experiments. And this method was proven to be very useful to determine the capacity of two catalysts system.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.7
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• pp.81-90
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• 2009

Due to environmental issues, the development of low energy consumption products has become one of the main topics in the home appliance industry. The energy consumption of a refrigerator depends on the efficiency of its compressor as well as on the refrigerator cycle design, such as the capacity modulation. In this study, a dual capacity, i.e., two-step capacity modulation (TCM), reciprocating compressor is developed. In a TCM compressor, capacity modulation is achieved by changing the dead volume in the cylinder. Instead of a concentric sleeve, an eccentric sleeve, a key, and a spring are used to change the dead volume for the clockwise and counterclockwise rotation of a motor. When the compressor changes its operating mode from full capacity to partial capacity or in opposite direction, the key may collide with the eccentric sleeve. The structural reliability and mode change reliability were confirmed by analysis and experiment.

• Journal of the Korean Society of Safety
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• v.25 no.3
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• pp.83-90
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• 2010

In this study, it is conducted that the performance verification of the ambient load carrying capacity algorithm using long-term measurement systems of bridges. For this purpose, a steel-box type model bridge is fabricated and the public load carrying capacity of a steel-box model bridge is estimated by conducting the numerical analysis and load test. In addition, we compare the public load carrying capacity with the estimated result of a steel-box model bridge using the ambient load carrying capacity algorithm. By the assessment result, it is shown that the estimated ambient load carrying capacity is the difference of approximately 6.0 percentages as compared with the public load carrying capacity.

• International Journal of Knowledge Content Development & Technology
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• v.10 no.1
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• pp.35-45
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• 2020

This study is on capacity building and attitude to work of librarians in Edo State public libraries, Nigeria. Investigation was on the capacity building programs in the Edo State public libraries, the levels of librarians' awareness and participation in the programs, methods of building the capacity programs, influence on the librarians' attitudes to work and factors militating against the programs. Descriptive survey design was adopted for the study and the entire population of 23 librarians were used. Results indicate that the capacity building programs in the library include computer literacy skills, online public access catalogue (OPAC), Internet collection management and general trends in librarianship. The methods used in building the capacity programs in the library include conferences, workshops/seminars, on-the-job and internally organized courses. Respondents indicated very low level of participation in the programs and a negative influence of the programs on their attitudes to work. Various problems were identified as militating against the capacity building programs and solutions were suggested.