• Journal of Communications and Networks
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• v.15 no.1
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• pp.71-76
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• 2013

A new class of quantum low-density parity-check (LDPC) codes whose parity-check matrices are dual-containing matrices constructed based on lines of Euclidean geometries (EGs) is presented. The parity-check matrices of our quantum codes contain one and only one 4-cycle in every two rows and have better distance properties. However, the classical parity-check matrix constructed from EGs does not satisfy the condition of dual-containing. In some parameter conditions, parts of the rows in the matrix maybe have not any nonzero element in common. Notably, we propose four families of fascinating structure according to changes in all the parameters, and the parity-check matrices are adopted to satisfy the requirement of dual-containing. Series of matrix properties are proved. Construction methods of the parity-check matrices with dual-containing property are given. The simulation results show that the quantum LDPC codes constructed by this method perform very well over the depolarizing channel when decoded with iterative decoding based on the sum-product algorithm. Also, the quantum codes constructed in this paper outperform other quantum codes based on EGs.

• Asia pacific journal of information systems
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• v.8 no.1
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• pp.125-144
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• 1998

This article describes the use of Internet as a means of operating the class which is business simulation game. The aims of investigation are to summarize the characteristics of distance learning using information technology, to find proper operating procedures for the internet class focusing on small group formation, to check the major factors affecting the teaching effectiveness, and to suggest the business simulation game as a proper distance learning class using internet.

• International Journal of Fluid Machinery and Systems
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• v.1 no.1
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• pp.140-147
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• 2008

An experiment setup was introduced to study dynamic behaviour of different types of check valves and the effects of air entrainment on the check valve performance under pressure transient condition. The experiment results show that the check valves with low inertia, assisted by springs or small traveling distance/angle gave better performance under pressure transient condition than check valves without these features. Air entrainment was found to affect both wave speed and reverse velocity. With the increase of the initial air void fraction in pipeline, the experiment results show that the wave speed was reduced, the reverse velocity was increased. The first peak pressure increased initially and then decreased with the increase of the initial air void fraction, the pressure surge periods were increased proportionally with air void fraction due to the greatly reduced wave speed. The study can be applied to help choosing suitable check valves for a particular pumping system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.10
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• pp.852-857
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• 2013

In this paper we propose a design algorithm for nonbinary LDPC (low-density parity-check) codes with low error-floors. The proposed algorithm determines the nonbinary values of the nonzero entries in the parity-check matrix in order to maximize the binary minimum distance of the designed nonbinary LDPC codes. We verify the performance of the designed nonbinary LDPC codes in the error-floor region by Monte Carlo simulation and importance sampling over BPSK (binary phase-shift keying) modulation.

• Knowledge Management Research
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• v.18 no.3
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• pp.163-178
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• 2017

Recent advances in technology are evolving to enable individuals to perform various activities necessary for their lives, without being constrained by physical, temporal, and spatial constraints. The online services and experiences that originated from solving the discomfort in the actual offline space have created the newness that can only be experienced in the digital world and furthermore uniquely new experiences in actual space as well. While many previous studies have suggested several interpretations of unique individual behaviors in virtual environments, a recent research approaches virtuality as an interesting perspective of the change of thinking style. Virtuality is defined as how far apart we are from everyday reality, and if the individual faces a situation far from reality, the psychological distance of the individual becomes distant and ultimately leads to the thinking style of high construal level. Otherwise, it is said to have a relatively low construal level of thinking style. In this study, I try to confirm the virtual distance as the role of psychological distance in new virtual contexts. Simultaneously considering temporal distance, which are most used in psychological distance, and virtual distance based on virtuality, this study tries to find whether the effect of virtual distance on product attitude is the same as that of temporal distance and check the relationship between virtual distance and temporal distance in the context of consumers' product evaluations depending on product information type.

• Journal of Korea Trade
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• v.25 no.4
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• pp.60-87
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• 2021

Purpose - This study examines the role of e-commerce resulting from technological innovation as a new approach toward internationalization. We study the relationship between e-commerce export and country distance, measured in CAGE distance, which has hindered traditional internationalization. As a control variable, entrepreneurship was introduced to check the moderating effect on the relationship between country distance and e-commerce export. Design/methodology - Based on empirical analysis, e-commerce exports from the Republic of Korea to 96 countries were used as dependent variables. First, hierarchical regression analysis was conducted to test the hypothesis about each country's distance, measured by CAGE distance, and each dimension of CAGE, on e-commerce exports. Next, the hypothesis was tested through the interaction term to examine the moderating effect of entrepreneurship. Findings - The analysis showed that the hypothesis, which postulated e-commerce exports as affected negatively by the country's distance, was supported but not that all CAGE dimensions affected it. Specifically, geographical distance and economic distance have negative effects, but cultural distance and administrative distance did not affect e-commerce exports. Thus, in contrast to the expectation that distance restrictions in e-commerce would not exist, this study confirmed that distance still matters to internationalization and that entrepreneurship can mitigate the adverse effects. Originality/value - Through these results, when export firms try to enter new markets and start internationalization through e-commerce, the entrepreneurship of the importing country should be considered.

• ETRI Journal
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• v.29 no.3
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• pp.381-389
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• 2007

In this paper we propose a graph-theoretic method based on linear congruence for constructing low-density parity check (LDPC) codes. In this method, we design a connection graph with three kinds of special paths to ensure that the Tanner graph of the parity check matrix mapped from the connection graph is without short cycles. The new construction method results in a class of (3, ${\rho}$)-regular quasi-cyclic LDPC codes with a girth of 12. Based on the structure of the parity check matrix, the lower bound on the minimum distance of the codes is found. The simulation studies of several proposed LDPC codes demonstrate powerful bit-error-rate performance with iterative decoding in additive white Gaussian noise channels.

• Corrosion Science and Technology
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• v.9 no.6
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• pp.239-246
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• 2010

When galvanized steel strip is produced through a continuous hot-dip galvanizing process, the thickness of the adhered zinc film is controlled by impinging a thin plane nitrogen gas jet. The thickness of the zinc film is generally affected by impinging pressure distribution, its gradient and shearing stress at the steel strip. These factors are influenced by static pressure of gas spraying at air knife nozzle, a nozzle-to-strip distance and strip and a geometric shape of the air knife, as well. At industries, galvanized steel strip is produced by changing static pressure of gas and a distance between the air knife nozzle and strip based on experimental values but remaining a geometric shape of nozzle. Splashing and check-mark strain can generally occur when a distance between the air knife nozzle and strip is too short, while ability of zinc removal can lower due to pressure loss of impinging jet when a distance between the air knife nozzle and strip is too long. In present study, buckling of the jet and change of static pressure are observed by analyzing flow characteristics of the impinging jet. The distance from the nozzle exit to the strip varies from 6 mm to 16 mm by an increment of 2 mm. Moreover, final coating thickness with change of a distance between the air knife nozzle and strip is compared with each case. An ability of zinc removal with the various distances is predicted by numerically calculating the final coating thickness.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.1
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• pp.57-62
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• 2004

We have proposed an efficient method of word separation in a handwritten legal amount on bank check based on the spatial gaps between the connected components. The previous gap measures all suffer from the inherent problem of underestimation or overestimation that causes a deterioration in separation performance. In order to alleviate such burden, we have developed a modified version of each distance measure. Also, 4 class clustering based method of integrating three different types of distance measures has been proposed to compensate effectively the errors in each measure, whereby further improvement in performance of word separation is expected. Through a series of word separation experiments, we found that the modified distance measures show a better performance with over 2 - 3% of the word separation rate than their corresponding original distance measures. In addition, the proposed combining method based on 4-class clustering achieved further improvement by effectively reducing the errors common to two of three distance measures as well as the individual errors.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.04a
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• pp.422-425
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• 2004

Many believe that electronic distance teaming education transform higher education, saving money and improving learning qualify So, the open University, which teaches around 280,000 students at a distance, is examining the adaption of its distance teaching methods for the internet. But, there are only one type of distance learning education of one way direction. To understand all of a student which selected some of e teaming course, teacher must check that how many student to understand and what is the difficult problems. Without checking this condition, It will be a very difficult and boring distance learning course. In this paper, we introduce of intelligent learning contents of full duplex direction that teach understanding student and not understanding student. The computer simulation results confirms that full duplex e learning system has been proven to be much more efficient than one way direction which not considering about understanding problems.