• The Journal of Economics, Marketing and Management
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• v.3 no.2
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• pp.1-8
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• 2015

In this paper, the effects of auditor change on audit quality in companies accepted in Tehran stock exchange placed review and we assessed the presence or absence of a significant correlation between them. to assess the quality of data auditing and tax distortions, falsification of accounting estimates, distortion of rules, distortion caused by mistakes in applying accounting policies and other distortions are used as the dependent variable Is. the sample group consisted of 56 companies as experimental group and a control group of 56 other companies a 4-year period, during the years 2011 to 2014 were studied. data needed for research discovery success ratio distortion before and after the change of auditor. To test the research hypotheses paired comparison method is used.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.1
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• pp.48.2-48.2
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• 2021

We have developed a frequentist approach for model selection which determines consistency of a cosmological model and the data using the distribution of likelihoods from the iterative smoothing method. Using this approach, we have shown how confidently we can distinguish different models without comparison with one another. In this current work, we compare our approach with conventional Bayesian approach based on estimation of Bayesian evidence using nested sampling for the purpose of model selection. We use simulated future Roman (formerly WFIRST)-like type Ia supernovae data in our analysis. We discuss limits of the Bayesian approach for model selection and display how our proposed frequentist approach, if implemented appropriately, can perform better in falsification of individual models.

• Journal of Information Technology Services
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• v.3 no.1
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• pp.101-115
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• 2004

The phrase "Ubiquitous Computing" has become popular ever since Mark Weiser used it in an article. It is to realize a computerized environment in which small computers are embedded and cooperate with each other. This environment will support many activities of our daily life. In a Ubiquitous Computing environment, various devices will be connected to the network from houses and buildings. Therefore it is necessary to ensure network security and to protect private data from tapping, falsification and the disguising of identity by others. This study reviews the Ubiquitous Computing technologies in detail and outlines the design concept of the Stream Cipher Algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.5
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• pp.2067-2080
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• 2016

Cooperative spectrum sensing (CSS) for vacant licensed bands is one of the key techniques in cognitive radio networks. Currently, sequential probability ratio test scheme (SPRT) is considered as a powerful soft decision approach to improve the sensing result for CSS. However, SPRT assumes all secondary users (SU) are honest, and thus offering opportunities for malicious SUs to launch the spectrum sensing data falsification attack (SSDF attack). To combat such misbehaved behaviors, recent efforts have been made to trust mechanism. In this paper, we argue that powering SPRT with traditional trust mechanism is not enough. Dynamic SSDF attackers can maintain high trust in an alternant process of submitting honest or false sensing data, resulting in difficultly detecting them. Noting that the trust value of dymamic SSDF attackers behave highly volatile, a novel trusted SPRT scheme (VSPRT) based on volatility decay analysis is proposed in this paper to mitigate the harmful effect of dynamic SSDF attackers in the process of the soft-decision data fusion, and thus improving the accuracy of the final sensing result. Simulation results show that the VSPRT scheme outperforms the conventional SPRT schemes.

• IEMEK Journal of Embedded Systems and Applications
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• v.12 no.4
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• pp.259-266
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• 2017

GPS was developed for military purposes. As a result, it is used as a military important means such as guided weapons and strategy / tactics. However, GPS depends on the communication infrastructure and is affected by interference signals. In this paper, we propose a secure micro - web page - based smart map that can enhance security without relying on communication infrastructure on the battlefield. The proposed system consists of general smartphone, security QR, central server and smart map. Only use the network when downloading the security key and SmartMap before the task starts. During operation, the smartphone transmits and receives data using a secure QR. The security QR inserts the security code to prevent forgery and falsification and confirms whether the data is authentic by checking whether the smart phone is forged or not. As a result of implementation, we solved communication security problem of existing technology by using location based service without relying on communication infrastructure.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.1
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• pp.1-17
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• 2014

Cooperative spectrum sensing (CSS) is considered as a powerful approach to improve the utilization of scarce radio spectrum resources. However, most of CSS schemes assume all secondary users (SU) are honest, and thus offering opportunities for malicious SUs to launch the spectrum sensing data falsification attack (SSDF attack). To combat such misbehaved behaviors, recent efforts have been made to trust schemes. In this paper, we argue that powering CSS with traditional trust schemes is not enough. The rational SSDF attack is found in this paper. Unlike the simple SSDF attack, rational SSDF attackers send out false sensing data on a small number of interested primary users (PUs) rather than all PUs. In this case, rational SSDF attackers can keep up high trustworthiness, resulting in difficultly detecting malicious SUs in the traditional trust schemes. Meanwhile, a defense scheme using a novel trust approach is proposed to counter rational SSDF attack. Simulation results show that this scheme can successfully reduce the power of rational SSDF, and thus ensure the performance of CSS.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.2
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• pp.305-314
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• 2017

Recently, user authentication through biometric traits such as fingerprint and iris raise more and more attention especially in mobile commerce and fin-tech fields. In particular, commercialized authentication methods using fingerprint recognition are widely utilized mainly because customers are more adopted and used to fingerprint recognition applications. In the meantime, the security issues caused by fingerprint falsification bring lots of attention. In this paper, we propose a new method to improve the performance of fake fingerprint detection using CNN(Convolutional Neural Network). It is common practice to increase the amount of learning data by using affine transformation or horizontal reflection to improve the detection rate in CNN characteristics that are influenced by learning data. However, in this paper we propose an effective data augmentation method based on the database difficulty level. The experimental results confirm the validity of proposed method.

• Journal of KIISE
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• v.41 no.11
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• pp.982-991
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• 2014

The integrity assurance of recorded video by car black boxes are necessary as the car black box is becoming more popular. In this paper, we propose a video data integrity assurance scheme reflecting the features of car black box. The proposed method can detect any kind of deletion, insertion, modification of frames by cyclic chaining using inter block relation. And, it provides the integrity assurance function consistently even in cases of file overwriting because of no more free space in storage, partial file data lost. And non-repudiation is supported. Experimental results with a car black box embedded system with A8 application processor show that our method has a feasible computational overhead to process full HD resolution video at 30 frames per second in a real time.

• Journal of the Korea Convergence Society
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• v.8 no.4
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• pp.19-24
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• 2017

The growing number of electronic financial transactions (e-banking) has entailed the rapid increase in security threats such as extortion and falsification of financial transaction data. Against such background, rigid security and countermeasures to hedge against such problems have risen as urgent tasks. Thus, this study aims to implement an improved case model by applying the Fraud Detection System (hereinafter, FDS) in a financial corporation 'A' using big data technique (e.g. the function to collect/store various types of typical/atypical financial transaction event data in real time regarding the external intrusion, outflow of internal data, and fraud financial transactions). As a result, There was reduction effect in terms of previous scenario detection target by minimizing false alarm via advanced scenario analysis. And further suggest the future direction of the enhanced FDS.

• Journal of Industrial Convergence
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• v.20 no.3
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• pp.41-46
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• 2022

This paper proposes a consumer-tailored solution to prevent the forgery and falsification of data by incorporating blockchain technology in the online and offline distribution of agricultural produce. The solution provides customized services to consumers based on an analysis of the data generated from the sales, distribution, and consumption of quality of the produce. It can also ensure the safety and credibility of the produce, and allow producers to identify consumption intent and the flow of distribution. Producers will be able to determine the flow of produce based on the data collected and thus tailor promotional efforts. This is expected to be the fourth industrial revolution in the agricultural produce distribution sector. Utilizing blockchain and big data technology to create integrated record management systems that combine multiple solutions will shape future technology trends. In addition, if eco-friendly certification is acknowledged as a valuable service and can be incorporated into the distribution process, this solution could become a one-stop distribution solution for agricultural produce.