• Korean Journal of Materials Research
• /
• v.20 no.5
• /
• pp.267-270
• /
• 2010

Sn doped $In_2O_3$ (ITO) and ITO/Cu/ITO (ICI) multilayer films were prepared on glass substrates with a reactive radio frequency (RF) magnetron sputter without intentional substrate heating, and then the influence of the Cu interlayer on the methanol gas sensitivity of the ICI films were considered. Although both ITO and ICI film sensors had the same thickness of 100 nm, the ICI sensors had a sandwich structure of ITO 50 nm/Cu 5 nm/ITO 45 nm. The ICI films showed a ten times higher carrier density than that of the pure ITO films. However, the Cu interlayer may also have caused the decrement of carrier mobility because the interfaces between the ITO and Cu interlayer acted as a barrier to carrier movement. Although the ICI films had two times a lower mobility than that of the pure ITO films, the ICI films had a higher conductivity of $3.6{\cdot}10^{-4}\;{\Omega}cm$ due to a higher carrier density. The changes in the sensitivity of the film sensors caused by methanol gas ranging from 50 to 500 ppm were measured at room temperature. The ICI sensors showed a higher gas sensitivity than that of the ITO single layer sensors. Finally, it can be concluded that the ICI film sensors have the potential to be used as improved methanol gas sensors.

• Korean Journal of Materials Research
• /
• v.9 no.2
• /
• pp.173-180
• /
• 1999

Thermally evaporated ZnTe films were investigated as a back contact material for CdS/CdTe solar cells. Two deposition methods, coevaporation and double-layer methods, were used for Cu doping in ZnTe films. ZnTe layers (0.2$\mu\textrm{m}$ thick) were deposited either on glass or on CdS/CdTe substrates without intentional heating of the substrates. Post-deposition annealing was performed at 200,300 and $400^{\circ}C$ for 3,6 and 9 minutes, respectively. Band gap of 2.2eV was measured for both undoped and doped films and a slight change in the shape of absorption spectra was observed in Cu-doped samples after annealing at $400^{\circ}C$. The resistivity of as-deposited ZnTe decreased from 10\ulcorner~10\ulcornerΩcm down to 10\ulcornerΩcm as Cu concentration increased from 0 to 14 at.%. There was not a noticeable change in less of annealing temperature up to $300^{\circ}C$ whereas films annealed at $400^{\circ}C$ revealed hexagonal (101) orientations as well. Some of Cu-doped ZnTe revealed x-ray diffraction (XRD) peaks related with Cu\ulcornerTe(x=1.75~2). Grain growth was observed from about 20nm in as-deposited films to 50nm after annealing at $400^{\circ}C$ by scanning electron microscopy (SEM). Cu distribution in ZnTe films was not uniform according to Auger electron spectroscopy (AES) measurements.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.23 no.6
• /
• pp.565-570
• /
• 2013

The mirror neuron regions which are distributed in cortical area handled a functionality of intention recognition on the basis of imitative learning of an observed action which is acquired from visual-information of a goal-directed action. In this paper an automated intention recognition system is proposed by applying computational model of mirror neuron system to the human-robot interaction system. The computational model of mirror neuron system is designed by using dynamic neural networks which have model input which includes sequential feature vector set from the behaviors from the target object and actor and produce results as a form of motor data which can be used to perform the corresponding intentional action through the imitative learning and estimation procedures of the proposed computational model. The intention recognition framework is designed by a system which has a model input from KINECT sensor and has a model output by calculating the corresponding motor data within a virtual robot simulation environment on the basis of intention-related scenario with the limited experimental space and specified target object.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.11
• /
• pp.5698-5706
• /
• 2013

This study presents research into the patterns that affect the understanding and acceptance of healthcare management systems as part of a healthcare information technology infrastructure targeted at university students. The participants were 623 university students in D city and K province. This study employed a descriptive and correlational cross-sectional survey and made use of the ubiquitous healthcare management services measurement scale. 48.5% of respondents had accessed healthcare-related information on the Internet. Among the independent variables of general characteristics related to perceived susceptibility was found to have adj $R^2$ of 11% while the other dependent factors reported much lower between 0.5 to 4.7%. Female respondents, medical-related majors, self-efficacy, and intention to use had significant positive effects while health beliefs and concern had a significant negative effect on the intentional acceptance of healthcare information technology systems.

• The Korean Journal of Applied Statistics
• /
• v.29 no.5
• /
• pp.907-920
• /
• 2016

This study suggests an outlier detection algorithm that uses quantile autoregressive model in time series data, eventually applying it to actual stock manipulation cases by comparing its performance to existing methods. Studies on outlier detection have traditionally been conducted mostly in general data and those in time series data are insufficient. They have also been limited to a parametric model, which is not convenient as it is complicated with an analysis that takes a long time. Thus, we suggest a new algorithm of outlier detection in time series data and through various simulations, compare it to existing algorithms. Especially, the outlier detection algorithm in time series data can be useful in finding stock manipulation. If stock price which had a certain pattern goes out of flow and generates an outlier, it can be due to intentional intervention and manipulation. We examined how fast the model can detect stock manipulations by applying it to actual stock manipulation cases.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.8 no.12
• /
• pp.4568-4587
• /
• 2014

Authentication of videos and images based on the content is becoming an important problem in information security. Unfortunately, previous studies lack the consideration of Kerckhoffs's principle in order to achieve this (i.e., a cryptosystem should be secure even if everything about the system, except the key, is public knowledge). In this paper, a solution to the problem of finding a relationship between a frame's index and its content is proposed based on the creative utilization of a robust manifold feature. The proposed solution is based on a novel semi-fragile watermarking scheme for H.264/AVC video content authentication. At first, the input I-frame is partitioned for feature extraction and watermark embedding. This is followed by the temporal feature extraction using the Isometric Mapping algorithm. The frame index is included in the feature to produce the temporal watermark. In order to improve security, the spatial watermark will be encrypted together with the temporal watermark. Finally, the resultant watermark is embedded into the Discrete Cosine Transform coefficients in the diagonal positions. At the receiver side, after watermark extraction and decryption, temporal tampering is detected through a mismatch between the frame index extracted from the temporal watermark and the observed frame index. Next, the feature is regenerate through temporal feature regeneration, and compared with the extracted feature. It is judged through the comparison whether the extracted temporal watermark is similar to that of the original watermarked video. Additionally, for spatial authentication, the tampered areas are located via the comparison between extracted and regenerated spatial features. Experimental results show that the proposed method is sensitive to intentional malicious attacks and modifications, whereas it is robust to legitimate manipulations, such as certain level of lossy compression, channel noise, Gaussian filtering and brightness adjustment. Through a comparison between the extracted frame index and the current frame index, the temporal tempering is identified. With the proposed scheme, a solution to the Kerckhoffs's principle problem is specified.

• Journal of the Korean Society for Library and Information Science
• /
• v.33 no.2
• /
• pp.119-139
• /
• 1999

It Is the purpose of this research to analyse users' understanding how keyword and boolean search work in SELIS(SEoul Women's University Library and Information System) OPAC. Results of analyses of the subject, SELIS OPAC system processing, are: comprehension percentage of keyword extraction is $67(22.48\%)$ out of total 298 persons, no comprehension is $231(77.52\%)$ understanding of boolean OR In keyword search appears $115(22.48\%)$ out of 297, no understanding does $182(77.52\%)$ : comprehension of boolean AND is $98(33.11\%)$ out of 296, no understanding appears $198(66.89\%)$ understanding of using boolean and symbols is $109(36.49\%)$ out of 285, no understanding is $181(63.51\%)$ which Is lower percentage generally. And in SELIS OPAC system, in Intentional analyses to see any difference in understanding of keyword search between experience of keyword search or no, It shows no difference in interrelation $5\%$ level of significance, but In boolean search it does in interrelation $5\%$ level of significance.

• Journal of KIISE:Software and Applications
• /
• v.35 no.2
• /
• pp.59-69
• /
• 2008

Automatic obfuscation is known to be the most viable method for preventing reverse engineering intentional1y making code more difficult to understand for security purposes. In this paper, we study and implement an obfuscation method for protecting MS Visual C++ programs against attack on the intellectual property in software like reverse engineering attack. That is, the paper describes the implementation of a code obfuscator, a tool which converts a Visual C++ source program into an equivalent one that is much harder to understand. We have used ANTLR parser generator for handling Visual C++ sources, and implemented some obfuscating transformations such as 'Remove comments', 'Scramble identifiers', 'Split variables', 'Fold array', 'Insert class', 'Extend loop condition', 'Add redundant operands', and 'Insert dead code'. We have also evaluated the performance and effectiveness of the obfuscator in terms of potency, resilience, and cost. When the obfuscated source code has been compared with the original source code, it has enough effectiveness for software protection though it incurs some run-time overheads.

• Journal of the Korean institute of surface engineering
• /
• v.53 no.3
• /
• pp.104-108
• /
• 2020

ZnO single layer films (100 nm thick) and Au intermediated ZnO films (ZnO/Au/ZnO; ZAZ) were deposited on the glass substrate by RF and DC magnetron sputtering at room temperature and then the influence of the Au interlayer on the electrical and optical properties of the films were investigated. ZnO thin films show the visible transmittance of 90.3 % and sheet resistance of 63.2×10⁸ Ω/□. In ZAZ films, as Au interlayer thickness increased from 6 to 10 nm, the sheet resistance decreased from 58.3×10⁸ to 48.6 Ω/□, and the visible transmittance decreased from 84.2 to 73.9 %. From the observed results, it can be concluded that the intermediate Au thin film enhances the opto-electrical performance of ZnO films without intentional substrate heating.

• International Journal of Human Ecology
• /
• v.12 no.2
• /
• pp.133-146
• /
• 2011

This study evaluates common activity and quality of life in Swedish cohousing units to examine whether Swedish cohousing functions properly or not. A questionnaire survey was fulfilled during the autumn of 2010 in G$\ddot{o}$teborg Sweden. The subjects of study were 12 of 44 cohousing units in Sweden that included 4 of the +40 cohousing and 8 of the mixed-age cohousing. A total of 242 of 353 distributed questionnaires were collected (68.6%) and analyzed by SPSS statistical program. The findings are as follow: 1) General characteristics of the respondents are that they are mostly healthy, evenly aged from age 50s to 70s and highly educated with significant proportions of academics and civil workers. There are more females than males and more singles than cohabitants. 2) The most frequent and preferred common activity is a common meal followed by a coffee meeting. A common dinner, the 'hub of living together' is held almost every day or at least a few times a week. A common meal is considered one of the most important activities because of practical and social advantages in that residents can save time and cooking costs as well as engage in social contact. Referring to evaluation of frequency and content of common activity, more than a half of the respondents prefer the current situation. 3) All of the variables (except health conditions and education level) affect participation in common activity with statistical significance. 4) Most of the respondents indicate a high level of life satisfaction and are willing to recommend others move to cohousing. They agree that there is more mutual support among residents in cohousing units than in a conventional community. In conclusion, Swedish cohousing units function successfully as they have pursued intentional community ideology and most of the residents are proud of their current living situations.