• Journal of Convergence for Information Technology
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• v.8 no.2
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• pp.77-82
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• 2018

Recently, as cloud services become popular with general users, users' information is freely transmitted and received among the information used in the cloud environment, so security problems related to user information disclosure are occurring. we propose a method to secure personal information of multiple users by making personal information stored in the cloud server and a key for accessing the shared information so that the privacy information of the multi users using the cloud service can be prevented in advance do. The first key used in the proposed scheme is a key for accessing the user 's personal information, and is used to operate the information related to the personal information in the form of a multi - layer. The second key is the key to accessing information that is open to other users than to personal information, and is necessary to associate with other users of the cloud. The proposed scheme is constructed to anonymize personal information with multiple hash chains to process multiple kinds of information used in the cloud environment. As a result of the performance evaluation, the proposed method works by allowing third parties to safely access and process the personal information of multiple users processed by the multi - type structure, resulting in a reduction of the personal information management cost by 13.4%. The efficiency of the proposed method is 19.5% higher than that of the existing method.

• Korean Journal of Optics and Photonics
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• v.19 no.1
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• pp.1-8
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• 2008

Shack-Hartmann sensors are widely employed as a wavefront measuring device in various applications. Adaptive optics is one of the major applications. Since an adaptive optics system should be operated in real-time, high-speed wavefront sensing is essential. In high-speed operation, integration time of an image detector is very short. In this case, noises such as readout noise and photon noise greatly influence the accuracy of wavefront sensing. Therefore a fast and noise-insensitive centroid finding algorithm is required for the real-time wavefront sensing. In this paper, the multi-resolution correlation method is proposed. By employing multi-resolution images, this method greatly reduces the computation time when compared to the fast Fourier transform (FFT) correlation method. The verification is performed through the computational simulation. In this paper, the center of mass method, correlation method and multi-resolution correlation method are employed to compare the measurement accuracy of the centroid finding algorithms. The accuracy of a Shack-Hartmann wavefront sensor using the proposed algorithm is proved to be comparable to that of the conventional correlation method.

• The Korean Journal of Applied Statistics
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• v.32 no.1
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• pp.83-97
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• 2019

As society develops, the dissemination of microdata has increased to respond to diverse analytical needs of users. Analysis of microdata for policy making, academic purposes, etc. is highly desirable in terms of value creation. However, the provision of microdata, whose usefulness is guaranteed, has a risk of exposure of personal information. Several methods have been considered to ensure the protection of personal information while ensuring the usefulness of the data. One of these methods has been studied to generate and utilize synthetic data. This paper aims to understand the synthetic data by exploring methodologies and precautions related to synthetic data. To this end, we first explain muptiple imputation, Bayesian predictive model, and Bayesian bootstrap, which are basic foundations for synthetic data. And then, we link these concepts to the construction of fully/partially synthetic data. To understand the creation of synthetic data, we review a real longitudinal synthetic data example which is based on sequential regression multivariate imputation.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.4 no.3
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• pp.217-224
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• 2011

This paper proposes DDPT(Dynamic Data Protection Technique) which solves the problem of private information exposure occurring in a dynamic database environment. The DDPT in this paper generates the MAG(Multi-Attribute Generalization) rules using multi-attributes generalization algorithm, and the EC(equivalence class) satisfying the k-anonymity according to the MAG rules. Whenever data is changed, it reconstructs the EC according to the MAC rules, and protects the identification exposure which is caused by the EC change. Also, it measures the information loss rates of the EC which satisfies the ${\ell}$-diversity. It keeps data accuracy by selecting the EC which is less than critical value and enhances private information protection.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.8
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• pp.1790-1795
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• 2004

In this paper, the new password system called SPS(Secure Password System) in order to enhance the security of the system as well as to improve the weakness of the password which is very easy to be disclosed by other people, improving the methods which is identifying the users' legality using the computer system in the multi-users computer. SPS is adopting several strong points such as Easy Embodiment, Low Cost, and most of the good points of the traditional password system. In addition, it makes an easy introduction from the traditional password system. Above SPS has the high stable security in the practical experiments about both the literal attack of the online intruders and the exposure of Clients' password.

• Environmental Analysis Health and Toxicology
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• v.23 no.3
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• pp.171-178
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• 2008

수백여 종의 개별물질이 불완전 연소 혹은 유기물의 열분해로 인해 발생되는 다환방향족 탄화수소(PAHs)는 환경에서 중요한 오염원이 되고 있다. 본 연구는 다양한 바이오마커를 이용하여 수서생태계에 벤조피렌(benzo[a]pyrene)과 같은 다환방향족 탄화수소의 영향을 분석하였고, 이에 대한 통합적 결과 모델을 도출하였다. 즉, 잉어(Cyprinus carpio)를 이용하여 여러 농도의 벤조피렌(3, 12, $34{\mu}g/L$, 측정농도 기준)에 10일간 노출시킨 다음, DNA single-strand break, ethoxyresorufin-O-deethylase (EROD), acetylcholine esterase (AChE)와 vitellogenin (VTG)의 농도를 측정하였다. 벤조피렌은 잉어의 DNA 손상을 유도하였고, 낮은 농도에서 EROD와 VTC의 유의적인 활성을 보였으나, 신경전달물질과 관련이 깊은 AChE 효소활성에는 영향을 미치지 않았다. 이 결과를 star plot를 이용하여 통합 및 분석하였으며, 노출농도에 따른 통합 반응지수(integrated biomarker response value: IBR)로 나타내었다. 이런 다양한 바이오마커의 결과들은 벤조피렌에 대한 어류의 영향과 수생태 모니터링 자료로 이용 가능할 것으로 여겨지며, 통합반응지수는 생태위해성평가에서 유용한 도구로 쓰일 가치가 있는 것으로 평가된다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.2
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• pp.213-219
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• 2012

Recently, we are simultaneously exposed by various electromagnetic sources due to an increase of mobile communication services. However, EMF(Electric, Magnetic and Electromagnetic Field) study has been performed mainly about only single frequency. The objective of this paper is to develop an multiple-frequency exposure system for in vitro experiment. The exposure unit for in vitro experiments was designed by radial transmission line type to get broadband characteristics to generate signals of CDMA at 836.5 MHz and WCDMA at 1950 MHz frequency simultaneously. The modulated signals were delivered to the conical antenna through amplifier, digital attenuator and RF combiner. SAR values were obtained by the averaged values of 3 measured values at 9 points in petri dish using the fiber optic temperature probe. The measured return loss was under -15 dB. For 1 W input power, the mean value and standard deviation of SAR were $0.105{\pm}0.019$ for the CDMA frequency and $0.262{\pm}0.055$ for the WCDMA frequency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1714-1720
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• 2012

The purpose of the study was to evaluation of the radiation dose reduction and the possibility of the maintainability of the adequate image quality using various automatic exposure control (AEC) systems in multi-detector computed tomography (MDCT). We used three AEC systems for the study: General Electric Healthcare (Auto-mA 3D), Philips Medical systems (DoseRight) and Siemens Medical Solutions (Care Dose 4D). The general scanning protocol was created for the each examination with the same scanning parameters as many as possible. In the various AEC systems, the evaluation of reduced-dose was evaluated by comparing to fixed mAs with using human phantom. The image quality of the phantom was evaluated with measuring the image noise (standard deviation) by insert regions of interests. Finally, when we applied to AEC for three manufacturers, the radiation dose reduction decreased each 35.3% in the Auto-mA 3D, 58.2% in the DoseRight, and 48.6% in the Care Dose 4D. And, there was not statistical significant difference among the image quality in the Strong/Weak of the Care Dose 4D(P=.269). This applies to variety of the AEC systems which will be very useful to reduce the dose and to maintain the high quality.

• Korean Journal of Remote Sensing
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• v.21 no.4
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• pp.303-316
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• 2005

Strong radar returns were observed in oyster sea farms, and coherent interferometric pairs were successfully constructed. Tide height in coastal area is possible to be measured by using interferometric phase and intensity of SAR data. This SAR application technique for measuring the tide height in the near coastal zone can be further improved when applied to double bounce dominant areas. In this paper, we investigate the characteristics of polarimetric signature in the oyster farm structures. Laboratory experiments were carried out using Ku-band according to the target scale. Radar returns from vertical poles are stronger than those from horizontal Pole by 10.5 dB. Single bounce components were as strong as double bounce components and more sensitive to antenna look direction. Double bounce components show quasi-linear relation with the height of vertical poles, which implies double bounce is more useful to determine water level than total power. A L-band NASA/IPL airborne SAR (AIRSAR) image was classified into single-, double-bounce, and volume scattering components. It is observed that oyster farms are not always characterized by double bounced scattering. Double bounce is a main scattering mechanism in oyster farms standing above seawater, while single bounce is stronger than double bounce when bottom tidal flats are exposed to air. Ratios of the normalized single to double bounce components in the former and latter cases were 0.46 and 5.62, respectively. It is necessary to use double bounce dominant sea farms for tide height measurement by DInSAR technique.

• Journal of the Korea Society of Computer and Information
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• v.25 no.3
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• pp.235-241
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• 2020

Many studies have tried to explain the privacy paradox but reported conflicting results; Some of them found connection between privacy concerns and information disclosure, while others did not. This study examines the role of interaction privacy controls (mainly friend lists and privacy settings) as a moderating variable that has the potential to affect the relationship in the SNS context. The reason for this is that most users use interactive privacy controls to create their own social environment before conducting SNS activities, so the relationship between privacy concerns and information disclosure may vary depending on the degree of use of interactive privacy controls. The study collected data using survey method, analyzed the moderating effect of use of interaction privacy controls using hierarchical multiple regression analysis, and as a result, found that effect. Therefore, the degree of use of interactive privacy controls may be an important contingent variable that needs to be considered in a study examining the privacy paradox in SNS context.