• Journal of Digital Contents Society
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• v.19 no.9
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• pp.1653-1662
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• 2018

Inspired by the increasing popularity of cosmetic-related mobile application as a tool for instant beautification, the present study examined colors of virtual makeup templates and makeup looks. A survey study was performed by thirty-six respondents to determine the top three desirable virtual makeup templates among nineteen templates. The templates of 'Bella', 'Hilary' and 'Cara' were then analyzed by makeup specialists and color experts for the evaluation of their makeup design and colors. Each color feature of three makeup templates were also evaluated through statistical analysis of ANOVA on the measure of $L^*a^*b^*$ crossed with five types of face elements on three types of virtual makeup images. Overall results indicate that Korean female users in their 20s and 30s preferred a similar makeup concept appeared in makeup template and key worlds. They also preferred a pale skin tone with higher lightness and a slightly higher saturated lip color as an emphasis than other features.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1167-1172
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• 2017

Desktop computers, which were the main means of Internet use and information activity, were pushed out by smart devices that emphasized mobility and simplicity. The recent information production and consumption activities are performed through smart devices, but there is no input device for smart devices that can fully replace traditional input devices such as full-size PC compatible keyboards. Because of the small size of the virtual keyboard that uses the touch screen of the smart device, typographical error occurs at a high rate. In this paper, we propose a variable virtual keyboard that minimizes the typographical errors of the conventional virtual keyboards. The proposed method minimizes the user 's input error by adjusting the size of each key of the virtual keyboard based on accumulated dataset of position and pressure of the user' s input error even though there is no difference in the key position arrangement of the conventional virtual keyboards.

• Smart Media Journal
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• v.13 no.4
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• pp.76-85
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• 2024

In this paper, we propose a system that improves the data integrity of IoT(Internet of Things) devices in the virtual environment by combining Hyperledger Indy and MQTT(Message Queuing Telemetry Transport). The system complements the limitations of the centralized system by realizing a DPKI(Decentralized Public Key Infrastructure) structure that utilizes a distributed network in publish-subscribe(pub/sub) pattern communication. Digital signature technology was applied to ensure the data integrity of IoT devices and communication scenarios between the four core components of the client, IoT device, broker, and blockchain, as well as a topic structure using a decentralized identifier to ensure safety in the virtual environment. We present a systematic method for transparent data exchange. To prove the performance of the proposed system, this paper conducted experiments on four scenarios and evaluated communication performance in a virtual environment. The experimental results confirmed that the proposed system provides a reliable IoT data communication structure in a virtual environment.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.5
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• pp.1175-1186
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• 2015

Financial fraud has been increasing along with credit card usage. Magnetic stripe cards have vulnerabilities in that credit card information is exposed in plaintext and cardholder verification is untrustworthy. So they have been replaced by a smart card scheme to provide enhanced security. Furthermore, the FinTech that combines the IT with Financial product is being prevalent. For that reason, many mobile device based payment schemes have been proposed for card present transaction. In this paper, we propose a virtual credit card number payment scheme based on public key system for efficient authentication in card present transaction. Our proposed scheme is able to authenticate efficiently in card present transaction by pre-registering virtual credit card number based on cardholder's public key without PKI. And we compare and analyze our proposed scheme with EMV.

• Journal of Internet Computing and Services
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• v.14 no.3
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• pp.15-21
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• 2013

Due to the widespread propagation of mobile platforms such as smartphones and tablets, financial and e-commercial transactions based on these mobile platforms are growing rapidly. Unlike PCs, almost all mobile platforms do not provide physical keyboards or mice but provide virtual keypads using touchscreens. For this reason, an attacker attempts to obtain the coordinates of touches on the virtual keypad in order to get actual key values. To tackle this vulnerability, financial applications for mobile platforms use secure keypads, which change position of each key displayed on the virtual keypad. However, these secure keypads cannot protect users' private information more securely than the virtual keypads because each key has only 2 or 3 positions and moreover its probability distribution is not uniform. In this paper, we analyze secure keypads used by the most financial mobile applications, point out the limitation of the previous research, and then propose a more general and accurate attack method on the secure keypads.

• Korean Journal of Optics and Photonics
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• v.14 no.3
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• pp.255-259
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• 2003

In this paper, we propose an improved image encryption and decryption method using a virtual image and a joint transform correlator (JTC). The encrypted image is obtained by the Fourier transform of the product of a virtual-phase image and a random-phase image, and a Fourier transform of the decrypting key generated by the proposed phase assignment rule is used as the Fourier decrypting key. Based on the solution, the original image is reconstructed using JTC in the frequency-domain. The proposed method using a virtual image, which does not contain any information from the original image, prevents the possibility of counterfeiting by unauthorized people. And also the auto-correlation terms, which are the drawback of a JTC system, contribute to reconstructing the original image rather than to disturbing its identification. But because phase-only encryptions are sensitive to noise and scratches, phase errors can be generated in fabricating the encrypted image or the Fourier decrypting key so the errors that are responsible for degradation of the quality of the reconstructed image are analyzed and the solution is demonstrated. Computer simulations show the solution, and the proposed method is very useful for JTC architecture.

• Journal of the Korea Society of Computer and Information
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• v.21 no.5
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• pp.99-109
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• 2016

Creative performance has been regarded as the key to the success of an organization in recent years, and is considered essential for the survival of an organization. Organizations must find and develop creative solutions to deal with a variety of business issues. How can organizations become more creative? To develop creativity, organizations must make it easier to connect the knowledge and perspectives of its various members, who may be scattered around the world, by developing a virtual team. Drawing from the transactive memory systems (TMS), which include expertise location, credibility, and coordination, this study investigates how the positive affect of team members influences the development of creative performance during virtual collaboration where face-to-face team activities are limited. The proposed structured model was empirically tested with cross-sectional data from 322 individuals. Results indicated that the positive affect of team members was found to moderate the relationship between TMS and creativity. Through this study, we expect to provide an understanding of the mechanisms involved in developing creativity among team members in a virtual work environment.

• Proceedings of the Korea Society for Simulation Conference
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• 1998.03a
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• pp.101-105
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• 1998

A large system predictor, which can perform prediction of sales trend in a huge number of distribution centers, is presented using neural predictive model. There are 20,000 number of distribution centers, and each distribution center need to forecast future demand in order to establish a reasonable inventory policy. Therefore, the number of forecasting models corresponds to the number of distribution centers, which is not possible to estimate that kind of huge number of accurate models in ERP (Enterprise Resource Planning)module. Multilayer neural net as universal approximation is employed for fitting the prediction model. In order to improve prediction accuracy, a sequential simulation procedure is performed to get appropriate network structure and also to improve forecasting accuracy. The proposed simulation procedure includes neural structure identification and virtual predictive model generation. The predictive model generation consists of generating virtual signals and estimating predictive model. The virtual predictive model plays a key role in tuning the real model by absorbing the real model errors. The complement approach, based on real and virtual model, could forecast the future demands of various distribution centers.

• International Journal of CAD/CAM
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• v.2 no.1
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• pp.39-44
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• 2002

This paper presents a structure and architecture of an integrated simulation method (ISM) to meet the requirements of virtual factory engineering (VFE). Combining CAD, VR and discrete event simulation techniques, the ISM provides static and dynamic simulation functions for implementation of VFE throughout the lifecycle. The static simulation can be used to evaluate the factory layout. The dynamic simulation enables us to evaluate ergonomics of factory, process performance of production system, feasibility of production plan and operation of factory, and to train operators safely, which cover the whole VFE lifecycle. The principles of the key techniques of VFE, including virtual factory data management system (VFDMS), static and dynamic simulation, are also discussed. To demonstrate and validate the ISM, a case study has been carried out in an assembly factory.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.208-210
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• 2019

Creating a virtual reality ecosystem is more important than anything else for virtual reality, which has recently been drawing attention as a sector of the fourth industrial revolution. Virtual reality ecosystem consists of content (C), device (D), platform (P), and network (N). While content is key among these, virtual reality depends on input and output devices, so device utilization is very important. Recently, hands-on devices are being developed for realistic experiences. This study presents examples of contents development using VirZOOM, an experienced device, to reduce immersion and motion sickness of VR contents. We look forward to further promoting the development of virtual reality content in the future through this study.