Earticle

In this study, energy-efficient (EE) resource allocation in orthogonal frequency division multiplexing-based cognitive radio networks with imperfect spectrum sensing is investigated. We present a new EE model by considering the sensing errors. Optimizing such an EE expression saves valuable resources, such as battery life, by selectively allocating power to underutilized subcarriers, and also achieves EE gain compared with general EE expression. Given that the primary user’s interference tolerance can be defined as either the Peak Interference Power (PIP) constraint or Average Interference Power (AIP) constraint for all subchannels, we compare the EE performance for the two interference power constraints. Finally, we propose an optimal EE resource allocation scheme based on the quasiconcave relation between the EE and transmit power. Simulations show that the new EE design improves EE compared with the conventional EE design, and the EE is higher with AIP constraint than that with PIP constrain under certain interference power.

This study aims to design and develop smart game based on Unity3D engine that is a multi-platform game engine. The functions that Unity3D supports autonomously are very abundant. All game developments are possible such as shader, physics engine, network, terrain manipulation, audio, video, and animation, and it is enabled so that it is possible to revise, meeting demand of user according to the need. For the efficiency of game development process, this study aims to plan, design, and develop a smart game based on multi-platform game engine.

In this paper, we study the relay-based communication schemes for cooperative spectrum sharing among multiple primary users (PUs) and multiple secondary users (SUs) with incomplete information. Inspired by contract theory, we model the network as a labor market. In this market, PUs and SUs are regarded as employer and employee respectively. Each PU proposes certain contracts to attract the SUs, the contract include relay power and spectrum access time, each SU maximize its utility by selecting the most suitable contract. But PUs and SUs have conflicting objectives in contract content. To tackle this problem, we put forward to a centralized maximizing expectation utility scheme, which convert the optimal contract design into an optimization problem. After that, a approximate method for solving the optimization problem is proposed. Simulation results show that the losses of PUs’ total utilities caused by incomplete information and approximate algorithm are relatively small, especially when the number of SUs is very large.

This study suggests an effective and valid method of inducing emotions in Korean college students and teenagers. While 605 subjects were experiencing different types of emotions, multimodal emotional responses (physiological signals and facial, vocal, thermal and EEG signals) were acquired. Emotional response data were categorized by self-reports and partially by raters. This is the first Korean multimodal emotional database incomparable to databases in terms of its scale. For this reason, the developed database can be used for emotion research in the future.

The huge amount of data are being generated by rapid development of internet and social networks with the wide spread of smart devices. Many data has started to be produced more and more and become complex as the IoT, M2M is active. A lot of research has been progressed in business and government in order to create new business model using this. The application value of these big data is expanding in various fields. The demand of technique and professional manpower as a source of future competitive advantage is expected to jump. In case of Korea it has been estimated that there is a shortage of professional manpower and technology gap with the advanced counties. Therefore, we analyzed the characteristics and paradigm of the Big data business in this paper. We also analyzed applied technology for development model of Big data business through it. In particular, we divided the development model for Big data business step-by-step and analyzed consideration about this systematically. The companies and public institutions based on the analyzed result in this paper will provide advantages to production of big data systems.

Automated offline handwritten character recognition of Devanagari script is a growing area of research in the field of pattern recognition. A new approach for Devanagari handwritten character / digit recognition has been proposed in this paper. This approach employs Uniform Local Binary Pattern (ULBP) operator as the feature extraction method. This operator has great performance in research areas such as texture classification and object recognition, but it has not been used in Devanagari handwritten character/digit recognition problem. The proposed method extracts both local and global features. The proposed method have two steps, in the first step image is preprocessed to remove noise and to convert it to binary image and then resizing it to a fixed size of 48x48. In the second step, ULBP operator is applied to the image to extract global features then input image is divided into 9 blocks, ULBP operator is applied to each block to extract local features. Finally, global and local features are used to train Support Vector Machine(SVM). The proposed method has been tested on large set of handwritten character and numeral database and empirical results reveals that the proposed method yields very good accuracy (98.77%) . To establish the superiority of the proposed method, it has also been compared with the contemporary algorithms. The comparative analysis shows that the proposed method out performs the existing methods.

That was a common thing when Escrow Service of Money (ESM) providers handled by the institution that has a legal aspect (structural assurance) to operates their business activities. However, how if the bank-like service agency operates by the individual, performed online and does not have some guaranteeing assets? How they do warrant their customers that they will not violate the consumer trusts? In addition, did the customers trust them? In this paper appointed a case study of the Rekening Bersama (RekBer) phenomenon as Indonesian ESM. Where, most of them ran the bank-like business without forming a legal entity as a reliable guarantee. In spite of that, we found a unique behavioral pattern that either incorporated RekBer or individual RekBer has the same opportunity to being trusted by their trustors.

These days, most of the important features of advanced metering infrastructure or AMI have already been developed and many AMI devices have been tested in the field as well. However, some security issues still remain unsolved. This paper presents an overview of AMI entities, smart meter, DCU, and MDMS, and then proposes mutual authentication scheme and data exchange schemes between them. More importantly, DCU has not been considered in any authentication scheme until this paper now. The proposed scheme can be adapted easily to the field-testing of the AMI components for enhancing their security.