• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.3
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• pp.491-501
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• 2019

In side-channel analysis, which exploit physical leakage from a cryptographic device, deep learning based attack has been significantly interested in recent years. However, most of the state-of-the-art methods have been focused on classifying side-channel information in a profiled scenario where attackers can obtain label of training data. In this paper, we propose a new method based on deep learning to improve non-profiling side-channel attack such as Differential Power Analysis and Correlation Power Analysis. The proposed method is a signal preprocessing technique that reduces the noise in a trace by modifying Auto-Encoder framework to the context of side-channel analysis. Previous work on Denoising Auto-Encoder was trained through randomly added noise by an attacker. In this paper, the proposed model trains Auto-Encoder through the noise from real data using the noise-reduced-label. Also, the proposed method permits to perform non-profiled attack by training only a single neural network. We validate the performance of the noise reduction of the proposed method on real traces collected from ChipWhisperer board. We demonstrate that the proposed method outperforms classic preprocessing methods such as Principal Component Analysis and Linear Discriminant Analysis.

• 재활복지
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• v.18 no.4
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• pp.221-235
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• 2014

Recently, the frequency of stroke disease is increased due to the rapid aging population, and is contributed to the major occurrence factors of the posteriori acquired disability. This study is about an postural change device for the control of supine posture which is an assisted equipment using in daily rehabilitation process for overcoming the disability by the aftereffects of the stoke disease. In this paper, the existing domestic and Japan postural appliances is examined and its comparison and categorization is performed according to its functions and purposes. Here, in order to control the supine posture state, the design method for advanced multi functional system is proposed, which is devised to have an unified mattress control operations of combining the bedsore prevention tube with the supine posture tilting tube. And also, in addition of an smart function, it is designed to enable to perform an RF functions such as the monitoring of the present device state, the alteration of the basic position and the control of alternative floating and supine posture. This system control hardware consists of three main parts : the sensor detection part, the motor driving /control part, and the system control part for bluetooth communication. In results, we confirmed that the system designed by this research is possible to make it practical as an advanced smart postural change device combined by IoT technology in the application field of the recent IT technology.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.71-81
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• 2019

To extend the potential benefits of error, the current study examined factors that affect students' error perception in the classroom. An experimental design was used to measure relations of classroom goal structure, feedback, and social relationships on students' perception of error. A total of 316 fourth-, fifth-, and sixth-grade elementary students participated as part of their regular class curriculum. Self-reported questionnaires were administered to measure students' perception of errors and relationships with teacher and peers, and then students were manipulated by classroom goal structure and feedback. Multiple regression analysis results suggested that students' perception of learning from error was affected mostly by relationships with peers, followed by relationships with teacher and the type of feedback. Students' perception of risk taking for error was also affected by relationships with peers and teacher, followed by the classroom goal structure. However, classroom goal structure and feedback did not affect their perception of thinking about error to improve their learning as well as error strain. These results imply how the classroom climate should be structured to improve perception of errors to improve student's learning.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.231-242
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• 2019

The aim of this study was the relationship between smoking, alcohol drinking and vitamin D level among Korean adults using data from the '6th(2013-2014) Korean National Health and Nutrition Examination Survey'. The data used in this study were analyzed for 3,565 people who were over the age of 19 ages and checked vitamin D level and consumption frequencies of vitamin D rich foods among 15,568 respondents to the '6th(2013-2014) Korean National Health and Nutrition Examination Survey'. The subjects were divided into four groups: None group(non-smoking and non-alcohol drinking), smoking only group, alcohol drinking only group and both group (smoking and alcohol drinking). The mean serum vitamin D level of the subjects was $16.5{\pm}0.20ng/mL$ and 73.5% of vitamin D levels were insufficient and deficiency. The results from hierarchical multiple logistic regression showed that the Odds ratio for insufficient vitamin D due to smoking and alcohol drinking were significantly higher in the smoking only group 2.281(95% CI 1.080-4.817)times and both group 1.356(95% CI 1.010-1.922)times than none group. Our results showed the relationship between smoking, alcohol drinking and vitamin D level was significant in Korean adults. Future studies, such as a more systematic cohort study investigating the relationship between smoking, alcohol drinking and vitamin D level may be helpful in confirming the causal relationship between smoking, alcohol drinking and vitamin D level.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.126-136
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• 2018

The purpose of this study was to develop a severity-adjustment model for predicting mortality in acute stroke patients using machine learning. Using the Korean National Hospital Discharge In-depth Injury Survey from 2006 to 2015, the study population with disease code I60-I63 (KCD 7) were extracted for further analysis. Three tools were used for the severity-adjustment of comorbidity: the Charlson Comorbidity Index (CCI), the Elixhauser comorbidity index (ECI), and the Clinical Classification Software (CCS). The severity-adjustment models for mortality prediction in patients with acute stroke were developed using logistic regression, decision tree, neural network, and support vector machine methods. The most common comorbid disease in stroke patients were hypertension, uncomplicated (43.8%) in the ECI, and essential hypertension (43.9%) in the CCS. Among the CCI, ECI, and CCS, CCS had the highest AUC value. CCS was confirmed as the best severity correction tool. In addition, the AUC values for variables of CCS including main diagnosis, gender, age, hospitalization route, and existence of surgery were 0.808 for the logistic regression analysis, 0.785 for the decision tree, 0.809 for the neural network and 0.830 for the support vector machine. Therefore, the best predictive power was achieved by the support vector machine technique. The results of this study can be used in the establishment of health policy in the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.583-593
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• 2018

Le Corbusier is an architect known for his use of mostly white color during the Purism period. On the other hand, he actually utilized polychromy in his works while the principles behind his use of polychromy is not well defined. Through the analysis of the Pessac project, where he deliberately utilized polychromy in the exterior of housing, this study examined not only the principles behind his utilization of colors, but also the fact that this project was a laboratory to set up his architectural language and develop the method of how to employ polychromy. An analysis of this project found that he changed spaces and categorized objects using polychromy based on the white color. He also chose and used colors based on the psychophysiological experience that is related to emotions and habits. To compensate for the problems arising from the architectural space and form in the site, he used various techniques, such as camouflage, optical illusion, 'gift box' technique, and dismantlement method of volume. Therefore, polychromy is used as a method to emphasize his architectural language.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.309-311
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• 2014

Despite increasing demands for big data application based on the analysis of scattered unstructured data, few relevant studies have been reported. Accordingly, the present study suggests a technique enabling a sentence-based semantic analysis by extracting objects from collected web information and automatically analyzing the relationships between such objects with collective intelligence and language processing technology. To be specific, collected information is stored in DBMS in a structured form, and then morpheme and feature information is analyzed. Obtained morphemes are classified into objects of interest, marginal objects and objects of non-interest. Then, with an inter-object attribute recognition technique, the relationships between objects are analyzed in terms of the degree, scope and nature of such relationships. As a result, the analysis of relevance between the information was based on certain keywords and used an inter-object relationship extraction technique that can determine positivity and negativity. Also, the present study suggested a method to design a system fit for real-time large-capacity processing and applicable to high value-added services.

• Clean Technology
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• v.25 no.3
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• pp.189-197
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• 2019

In this study an optimization of the preparation conditions of activated carbon with a ternary metal ion material to treat $H_2S$, which is classified as a representative odor substance, was carried out. For a metal ion material for enhancing the adsorption performance of hydrogen sulfide, performance enhancement was confirmed by combining Li and Fe or a ternary combination (K, Li, Fe) based on KI, which is a substance promoting hydrogen sulfide adsorption performance. Also, it was determined by XRD analysis that the reaction of each active substance with $H_2S$ was because of binding. The adsorption performance increased more than 3 times with heat treatment of the adsorbent with nitrogen compared with heat treatment with air. The maximum adsorption constant ($q_m$) value of the optimum adsorbent was 97.07, which is 6 times higher than that of the existing K-based impregnated activated carbon. It was confirmed that the objective adsorption amount ($0.3g\;g^{-1}$) was secured by an equilibrium between the mass transfer rate and adsorption rate. From the results, it was confirmed that the performance improvement was noticeable even when activated carbon with a reagent grade activated carbon particle size was modified. It was confirmed that the adsorption performance exists at high relative humidity levels of 60 and 100%, and the optimized preparation can be applied to a wet process such as a scrubber downstream.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.406-412
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• 2019

In this paper, we propose two algorithms for classifying services with similar delay characteristics into three classes and allocating radio resources according to priority in LTE-A system where H2H and M2M services coexist. The first is to allocate resources from the higher priority class to the lower priority class, and each class gives priority to H2H over M2M, and the other is to give priority to H2H regardless of delay characteristics except for the class with the highest priority. The RA success probability was analyzed according to the access rate(${\alpha}$) of M2M devices in each class. In comparison with the conventional systems, it was improved from 0.5 to 0.52 for ${\alpha}_{2M}=0.05$ in two classes. In the three classes, the success probability was slightly increased from 0.5 to 0.57 for ${\alpha}_{2M}={\alpha}_{3M}=1$ and from 0.5 to 0.58 for ${\alpha}_{2M}=0.5$ and ${\alpha}_{3M}=0.1$. Although 6 services are considered in the proposed scheme, the RA success probability is almost similar to the previous scheme because the average arrival rate of H2H of each class is set to the same.

• Ecology and Resilient Infrastructure
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• v.6 no.2
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• pp.89-100
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• 2019

We've reviewed existing studies on the interactions among vegetation, hydrology, and geomorphology in the stream corridors, adding one more factor of vegetation in the traditional area of hydro-geomorphology. Understanding of the interactions among those three factors is important not only academically but also practically since it is related intimately to the restoration of river corridor as well as management itself. Studies of this area started from field investigations in the latter part of the 20th century and focused on the flume experiments and then computer modelling in the 1990s and 2000s. Now, it has turned again to the field investigations of specific phenomena of the vegetative-hydrologic-geomorphologic interactions in detailed micro scales. Relevant studies in Korea, however, seem to be uncommon and far behind the international status quo in spite that practically important issues related directly to this topic have been emerged. In this study, we propose, based on the extensive literature review and authors' own knowledge and experiences, a conceptual diagram expressing the interactions among vegetation, flow (water), sediment, and geomorphology. Existing relevant studies in Korea since the 1990s are classified according to the categorization in the proposed diagrams and then briefly reviewed. Finally, considering the practical issues of riparian vegetation that have emerged recently in Korea, we propose areas of investigation needed in near future such as, among others, long-term and systematic field investigations and monitoring at multiple river corridors having different attributes on vegetative-hydrologic-geomorphologic interactions, including vegetative dynamics for succession.