• Journal of the Korean Data and Information Science Society
• /
• v.17 no.3
• /
• pp.983-990
• /
• 2006

In this paper, we study an asymmetric power fractionally integrated GARCH model and find a region on which the process is stationary ergodic and has long memory property.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.39 no.6
• /
• pp.19-25
• /
• 2002

A regular virtual topology requires little processing time for routing purposes which may be a desirable property for high-speed networks. Asymmetric bilayered ShuffleNet, proposed by us as a virtual topology, can be more efficient to be used to design a wide-area optical network compared to ShuffleNet. In this paper, asymmetric bilayered ShuffleNet is imbedded on a given physical topology with the objective of minimizing the total message delay.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.7
• /
• pp.3231-3244
• /
• 2016

As processor design has been transiting from homogeneous multicore processor to heterogeneous multicore processor, traditional Amdahl's law cannot meet the new challenges for asymmetric multicore system. In order to further investigate the impact factors related to the Overhead of Data Preparation (ODP) for Asymmetric multicore systems, we evaluate an asymmetric multicore system built with CPU-GPU by measuring the overheads of memory transfer, computing kernel, cache missing and synchronization. This paper demonstrates that decreasing the overhead of data preparation is a promising approach to improve the whole performance of heterogeneous system.

• The Journal of Information Systems
• /
• v.15 no.4
• /
• pp.211-224
• /
• 2006

This study investigates the application of data mining techniques such as artificial neural networks, rough sets, and induction teaming to the intrusion detection systems. To maximize the effectiveness of data mining for intrusion detection systems, we introduced the asymmetric costs with false positive errors and false negative errors. And we present a method for intrusion detection systems to utilize the asymmetric costs of errors in data mining. The results of our empirical experiment show our intrusion detection model provides high accuracy in intrusion detection. In addition the approach using the asymmetric costs of errors in rough sets and neural networks is effective according to the change of threshold value. We found the threshold has most important role of intrusion detection model for decreasing the costs, which result from false negative errors.

• Korean Management Science Review
• /
• v.33 no.4
• /
• pp.65-75
• /
• 2016

We study limit pricing in a price-based duopoly market under asymmetric information on the demand state. An incumbent, who is a monopolist in the initial period, has complete information on the size of a market, while a potential entrant only knows it partially. After observing the sales price of the incumbent in the first period, the entrant decides whether to enter a duopoly market and the sales price if she chooses to. We present a separating perfect Bayesian equilibrium, which indicates that limit pricing can deter the entry of a potential entrant under price competition when there is information asymmetry about the demand state.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.12
• /
• pp.5361-5374
• /
• 2016

Combining channel coding and network coding in a physical layer in a fading channel, generalized joint channel-network coding (G-JCNC) is proved to highly perform in a two-way relay channel (TWRC). However, most relevant discussions are restricted to symmetric networks. This paper investigates the G-JCNC protocols in an asymmetric TWRC (A-TWRC). A newly designed encoder used by source nodes that is dedicated to correlate codewords with different orders is presented. Moreover, the capability of a simple common non-binary decoder at a relay node is verified. The effects of a power match under various numbers of iteration and code lengths are also analyzed. The simulation results give the optimum power match ratio and demonstrate that the designed scheme based on G-JCNC in an A-TWRC has excellent bit error rate performance under an appropriate power match ratio.

• The Journal of Fisheries Business Administration
• /
• v.51 no.4
• /
• pp.69-83
• /
• 2020

The purpose of this paper is to empirically investigate whether asymmetric price transmission exists in the distribution stage of farmed olive flounder market. For the analysis, time series data were used for the producer prices of Jeju and Wando, and the wholesale prices of Incheon, Hanam and Busan. Through the Granger causality test, the causal relationship from the producer price to the wholesale price was derived and the asymmetric price transmission was analyzed using the autoregressive distributed lag model (ARDL). As a result of the analysis, it was found that there is a phenomenon of 'positive asymmetric price transmission' from the producer price to the wholesale price. This result can be one evidence that excess profits are received in the intermediate distribution stage, and can be said to be a result showing the incompleteness and inefficiency of the distribution structure of the farmed olive flounder. In the future, it is required to establish an information-sharing system in all stages of production, distribution, and consumption that can create a competitive environment for distribution participants and resolve information asymmetry. Also, it is necessary to review the distribution center specializing in live fish from the viewpoint of the establishment of new distribution channels and sales diversification strategy under the rapidly changing fisheries environment.

• Journal of the Korea Society of Computer and Information
• /
• v.25 no.11
• /
• pp.89-95
• /
• 2020

In this paper, we present Beamforming (BF) Training (BFT) for asymmetric links in IEEE 802.11ay. IEEE 802.11ay introduced BFT for asymmetric links that aims to increase the BFT success probability for Station (STA) with insufficient link budget to communicate with an Access Point (AP). BFT for asymmetric links utilizes directional BFT allocation to avoid the usage of quasi-omni pattern at the AP side, and thus to increase STA's BFT success rate. However, there are no publicly available simulation tools supporting IEEE 802.11ay. For these reasons, we present in this paper an implementation of BFT for asymmetric links in ns-3 with its novel techniques such as Training RX (TRN-R) subfield and BFT allocation. We then evaluate by simulation the performance of BFT for asymmetric links.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.11a
• /
• pp.1218-1223
• /
• 2007

In this study, we experimentally investigate the equivalent ring theory for a slightly asymmetric ring. The slightly asymmetric ring has mode pair and frequency pair due to the small asymmetry and this mode pair generates beat in vibration and sound. In this paper, a slightly asymmetric ring is modeled as the equivalent ring, i.e., the assemblage of a symmetric ring and imperfect point masses. The equivalent ring has the same mode pair condition as that of the original asymmetric ring. Effect of the additional mass attachment is investigated by the equivalent ring theory and the result is compared with those of the measurement and the finite element analysis. It is confirmed that the original ring and the equivalent ring show the same change in frequency and mode under the various additional imperfection mass conditions. The equivalent ring theory explains how the asymmetric elements influence the mode characteristics and provides useful information to tune the beat property.

• Journal of Power Electronics
• /
• v.18 no.6
• /
• pp.1683-1696
• /
• 2018

Under the conventional control strategy, the asymmetry of arm impedances may result in the poor operating performance of modular multilevel converters (MMCs). For example, fundamental frequency oscillation and double frequency components may occur in the dc and ac sides, respectively; and submodule (SM) capacitor voltages among the arms may not be balanced. This study presents an enhanced control strategy to deal with these problems. A mathematical model of an MMC with asymmetric arm impedance is first established. The causes for the above phenomena are analyzed on the basis of the model. Subsequently, an enhanced current control with five integrated proportional integral resonant regulators is designed to protect the ac and dc terminal behavior of converters from asymmetric arm impedances. Furthermore, an enhanced capacitor voltage control is designed to balance the capacitor voltage among the arms with high efficiency and to decouple the ac side control, dc side control, and capacitor voltage balance control among the arms. The accuracy of the theoretical analysis and the effectiveness of the proposed enhanced control strategy are verified through simulation and experimental results.