• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1557-1564
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• 2020

In this paper, 3D model-based interactive gamma ray shielding package (MIGSHIELD) is developed in virtual reality platform for windows operating system. In MIGSHIELD, the computational methodology is based on point kernel algorithm (PK), several key parameters of PK are obtained using new technique and new methods. MIGSHIELD has interactive capability with virtual world. The main features made in the MIGSHIELD are (i) handling of physical information from virtual world, (ii) handling of arbitrary shapes radioactive source, (iii) calculating the mean free path of gamma ray, (iv) providing interactive function between PK and virtual world, (v) making better use of PK for virtual simulation, (vi) plug and play. The developed package will be of immense use for calculations involving radiation dose assessment in nuclear safety and contributing to fast radiation simulation for virtual nuclear facilities.

• Smart Media Journal
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• v.13 no.4
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• pp.94-103
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• 2024

The eyeball input system is a text input system designed based on 'eye tracking technology' and 'virtual keyboard character-input technology'. The current virtual keyboard structure used is a rectangular QWERTY array optimized for a multi-input method that simultaneously utilizes all 10 fingers on both hands. However, since 'eye-tracking technology' is a single-input method that relies solely on eye movement, requiring only one focal point for input, problems arise when used in conjunction with a rectangular virtual keyboard structure designed for multi-input method. To solve this problem, first of all, previous studies on the shape, type, and movement of muscles connected to the eyeball were investigated. Through the investigation, it was identified that the principle of eye movement occurs in a circle rather than in a straight line. This study, therefore, proposes a new key arrangement wherein the keys are arranged in a circular structure suitable for rotational motion rather than the key arrangement of the current virtual keyboard which is arranged in a rectangular structure and optimized for both-hand input. In addition, compared to the existing rectangular key arrangement, a performance verification experiment was conducted on the circular key arrangement, and through the experiment, it was confirmed that the circular arrangement would be a good replacement for the rectangular arrangement for the virtual keyboard.

• Journal of Distribution Science
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• v.18 no.2
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• pp.5-15
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• 2020

Purpose : Today's retailers are integrating new VR technology into their new marketing strategies. Thus, this research aims to understand the role of virtual experiences in the circumstance of sales channels. Research design, data and methodology : Our model hypothesizes that five key factors determine the consumer experience of VR in the virtual retailing context: smartness, vividness, interactivity, playfulness, escape. Information access and flow are mediating variables that connect key drivers and VR satisfaction. Information access and flow then give influence to satisfaction towards VR. Satisfaction serves as a mediator that determines changes in consumer's dual intention: intention to revisit VR and intention to visit the real site. Results : According to the test results, every path except the relationship between information access and satisfaction of VR is accepted as expected at the significance level of 0.05. Conclusions : This research emphasizes the potential importance of VR and continue VR marketing research as an advent research area. Through the dual-path model, this study found that the primary function of VR is information access and flow experience. This result shows that most VR users value emotional benefits rather than rational benefits provided by VR. Finally, the satisfaction of VR can stimulate both the intention to use the VR and the intention to visit real mall.

• Journal of Microbiology and Biotechnology
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• v.32 no.4
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• pp.504-513
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• 2022

Chitin deacetylase (CDA) inhibitors were developed as novel antifungal agents because CDA participates in critical fungal physiological and metabolic processes and increases virulence in soil-borne fungal pathogens. However, few CDA inhibitors have been reported. In this study, 150 candidate CDA inhibitors were selected from the commercial Chemdiv compound library through structure-based virtual screening. The top-ranked 25 compounds were further evaluated for biological activity. The compound J075-4187 had an IC50 of 4.24 ± 0.16 µM for AnCDA. Molecular docking calculations predicted that compound J075-4187 binds to the amino acid residues, including active sites (H101, D48). Furthermore, compound J075-4187 inhibited food spoilage fungi and plant pathogenic fungi, with minimum inhibitory concentration (MIC) at 260 ㎍/ml and minimum fungicidal concentration (MFC) at 520 ㎍/ml. Therefore, compound J075-4187 is a good candidate for use in developing antifungal agents for fungi control.

• Journal of Electrical Engineering and Technology
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• v.11 no.6
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• pp.1556-1570
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• 2016

In the process of virtual inertia control (VIC), the frequency regulation capability of the directly-driven wind turbine with permanent-magnet synchronous generator (D-PMSG) on wind farm is related to its rotor kinetic energy and capacity margin. This paper proposes the method for assessing the D-PMSG frequency regulation capability and defining its coefficient according to the operating state of wind power generators. In addition, the calculating method of parameters in VIC is also discussed according to the principles of primary frequency regulation and inertia response of synchronous generators. Then, by introducing the capability coefficient into the proportion-differential virtual inertia control (PD-VIC) for power coordination, a coordinated virtual inertia control (C-VIC) strategy is developed, with the consideration of the difference in frequency regulation capability between wind power generators. The proposed control method can not only give full play to the frequency regulation capability of wind power generators, decrease the movements of the pitch angle control system but also bring some self-coordination capability to different wind power generators thus to avoid a secondary drop in system frequency. The simulations and experiments prove the proposed method to be effective and practicable.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.1
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• pp.5-15
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• 2015

Electronic transactions have been increasing with the development of the high-speed Internet and wireless communication. However, in recent years financial corporations and mobile carriers were attacked by hackers. And large numbers of privacy information have been leaked. In particular, in the case of credit card information can be misused in the online transaction, and the damage of this given to cardholder. To prevent these problems, it has been proposed to use a virtual card number instead of the actual card number. But it has security vulnerability and requires additional security infrastructure. In this paper, we analyzed the proposed virtual card number schemes. and we propose a new virtual credit card number scheme. In the newly proposed scheme, cardholder generates a key pair (public key/private key) and pre-register public key to the issuer. then, cardholder can pay no additional security infrastructure while still efficiently satisfy the security requirements.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.7
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• pp.2325-2349
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• 2014

Network virtualization technology plays a key role in cloud computing, which serves as an effective approach for provisioning a flexible and highly adaptable shared substrate network to satisfy the demands of various applications or services. Recently, the problem of mapping a virtual network (VN) onto a substrate network has been addressed by various algorithms. However, these algorithms are typically efficient for unicast service-oriented virtual networks, and generally not applicable to multicast service-oriented virtual networks (MVNs). Furthermore, the survivable MVN mapping (SMVNM) problem that considers the survivability of MVN has not been studied and is also the focus of this work. In this research, we discuss SMVNM problem under regional failures in the substrate network and propose an efficient algorithm for solving this problem. We first propose a framework and formulate the SMVNM problem with the objective of minimizing mapping cost by using mixed integer linear programming. Then we design an efficient heuristic to solve this problem and introduce several optimizations to achieve the better mapping solutions. We validate and evaluate our framework and algorithms by conducting extensive simulations on different realistic networks under various scenarios, and by comparing with existing approaches. Our simulation experiments and results show that our approach outperforms existing solutions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.8
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• pp.3841-3861
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• 2017

Virtualized small cell network is a promising architecture which can realize efficient utilization of the network resource. However, conventional full duplex self-backhauls lead to residual self-interference, which limits the network performance. To handle this issue, this paper proposes a virtual resource allocation, in which the residual self-interference is fully exploited by employing a physical-layer network coding (PNC) aided self-backhaul scheme. We formulate the features of PNC as time slot and information rate constraints, and based on that, the virtual resource allocation is formulated as a mixed combinatorial optimization problem. To solve the problem efficiently, it is decomposed into two sub problems, and a two-phase iteration algorithm is developed accordingly. In the algorithm, the first sub problem is approximated and transferred into a convex problem by utilizing the upper bound of the PNC rate constraint. On the basis of that, the convexity of the second sub problem is also proved. Simulation results show the advantages of the proposed scheme over conventional solution in both the profits of self-backhauls and utility of the network resource.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.12
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• pp.4950-4966
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• 2015

Cloud providers now face the problem of estimating the amount of computing resources required to satisfy a future workload. In this paper, a virtual machine provisioning (VMP) mechanism is designed to adapt workload fluctuation. The arrival rate of forthcoming jobs is predicted for acquiring the proper service rate by adopting an exponential smoothing (ES) method. The proper service rate is estimated to guarantee the service level agreement (SLA) constraints by using a diffusion approximation statistical model. The VMP problem is formulated as a facility location problem. Furthermore, it is characterized as the maximization of submodular function subject to the matroid constraints. A greedy-based VMP algorithm is designed to obtain the optimal virtual machine provision pattern. Simulation results illustrate that the proposed mechanism could increase the average profit efficiently without incurring significant quality of service (QoS) violations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.4
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• pp.1864-1876
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• 2016

Card-Not-Present (CNP) transactions taking place remotely over the Internet are becoming more prevalent. Cardholder authentication should be provided to prevent the CNP fraud resulting from the theft of stored credit card numbers. To address the security problems associated with CNP transactions, the use of a virtual card number derived from the transaction details for the payment has been proposed, instead of the real card number. Since all of the virtual card number schemes proposed so far are based on a password shared between the cardholder and card issuer, transaction disputes due to the malicious behavior of one of the parties involved in the transaction cannot be resolved. In this paper, a new virtual card number scheme is proposed, which is associated with the cardholder's public key for signature verification. It provides strong cardholder authentication and non-repudiation of the transaction without deploying a public-key infrastructure, so that the transaction dispute can be easily resolved. The proposed scheme is analyzed in terms of its security and usability, and compared with the previously proposed schemes.