• Journal of KIISE:Computer Systems and Theory
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• v.37 no.4
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• pp.226-238
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• 2010

OpenSSL is an open-source library implementing SSL that is a secure communication protocol. However, the library has a severe vulnerability that its security information can be easily exposed to malicious software when the library is used in a form of shared library on Linux and UNIX operating systems. We propose a scheme to attack the vulnerability of the OpenSSL library. The scheme injects codes into a running client program to execute the following attacks on the vulnerability in a SSL handshake. First, when a client sends a server a list of cryptographic algorithms that the client is willing to support, our scheme replaces all algorithms in the list with a specific algorithm. Such a replacement causes the server to select the specific algorithm. Second, the scheme steals a key for data encryption and decryption when the key is generated. Then the key is sent to an outside attacker. After that, the outside attacker decrypts encrypted data that has been transmitted between the client and the server, using the specified algorithm and the key. To show that our scheme is realizable, we perform an experiment of collecting encrypted login data that an ftp client using the OpenSSL shared library sends its server and then decrypting the login data.

• Journal of Radiation Protection and Research
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• v.37 no.1
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• pp.10-15
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• 2012

Design and performance test results of a newly developed optically stimulated luminescence (OSL) measurement system are presented in this paper. Generally, different types of optical filters are used in OSL reader system to minimize the interference of the stimulation light in the OSL signal. For optically stimulation of $Al_2O_3:C$, we have arrived at an optimal combination of the filters, i.e., GG420 filter for filtering the stimulating light source, and a combined UG11 and BG39 filter at the detecting window (PMT). By using a high luminance blue LED (Luxeon V), sufficient luminous intensity could be obtained for optically stimulation. By using various control boards, the OSL reader device was successfully interfaced with a personal computer. A software was developed to deliver required commands to operate the OSL reader by using the LabView program (National Instruments, Inc.). In order to evaluate the reliability and the reproducibility of newly designed-OSL reader. Performance testing of the OSL reader was carried out for OSL efficiency, OSL decay curve and signal to noise ratio of the standard $Al_2O_3:C$ OSL material. It was found to be comparable with that of commercial Riso reader system.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.6
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• pp.681-689
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• 2019

Web usage pattern discovery is an advanced means by using web log data, and it's also a specific application of data mining technology in Web log data mining. In education Data Mining (DM) is the application of Data Mining techniques to educational data (such as Web logs of University, e-learning, adaptive hypermedia and intelligent tutoring systems, etc.), and so, its objective is to analyze these types of data in order to resolve educational research issues. In this paper, the Web log data of a university are used as the research object of data mining. With using the database OLAP technology the Web log data are preprocessed into the data format that can be used for data mining, and the processing results are stored into the MSSQL. At the same time the basic data statistics and analysis are completed based on the processed Web log records. In addition, we introduced the Apriori Algorithm of Web usage pattern mining and its implementation process, developed the Apriori Algorithm program in Python development environment, then gave the performance of the Apriori Algorithm and realized the mining of Web user access pattern. The results have important theoretical significance for the application of the patterns in the development of teaching systems. The next research is to explore the improvement of the Apriori Algorithm in the distributed computing environment.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.4
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• pp.253-262
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• 2006

In this paper, collision analysis is carried out between two FRP fishing boats. A computer simulation with finite element method is used to accomplish this objective. At first, a detailed geometric model of the boat is constructed using 3-D CAD program. The formation of a finite element from a geometric data of the boats is carried out using HYPERMESH that is the commercial software for mesh generation and post processing. Twelve collision configurations are established by combining two kinds of contact angle($90^{\circ},\;135^{\circ}$) and three different speed(5, 10, 15knot) for small and large boats. Collision analysis is accomplished using DYNA3D. Stress distribution and deformation shape are investigated for each collision condition. In general, $90^{\circ}$ collision angle generate larger stress than $135^{\circ}$ case and the collision for two moving boats showed larger maximum stress than the case that one is moving and the other is stationary. When analysis is carried out until 150ms contact parts of two boats are broken for 10 and 15knot collision speed, in which maximum stress is larger than ultimate strength of the material.

• Asia pacific journal of information systems
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• v.10 no.2
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• pp.71-95
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• 2000

Despite repeated exhortation about the importance of social and human dimensions of systems development, socio-organizational issues continue to be neglected and ignored in the current information systems practice. A review of the human information processing literature suggests that the reasons for this continuing lack of attention to social issues may be found in the limitations of human cognition and information processing capacities. Bostrom and Heinen(1978) and Kumar and Bjorn-Anderson(1990) also suggest that the inadequate attention to social problems and issues by the analyst could originate from the analysts limited problem perception. This research explores how the representation forms of information systems(IS) methodology used in understanding and modeling the problem situation affect such systems development problem perception. Typically, a system development methodology prescribes the use of system models(i.e., system representations) to understand, analyze, evaluate, and design the information system. Given the size and complexity of information systems, and the abstraction and simplification underlying the modeling process, system representations usually depict only a limited set of aspects of the system. Thus, a methodology whose representations are limited to technical aspects will tend to limit the analyst's perspective to a technical one only(Kumar & Welke, 1990). Following the same line of argument, in contrast, it is the conjecture of this study that a methodology which specifies both social and technical aspects of IS development will help the analyst develop a more comprehensive view of the IS problem domain. Based on the above concept, a theoretical model was first developed which explained the systems analysts cognitive process. Drawing on this model, a research model was developed hypothesizing the impacts of representation forms on problem identification. The model was tested using a laboratory experiment with 70 individual subjects. A special computer software was developed with a hypermedia authoring tool to conduct the experiments in order to avoid experimenter biases and to maintain consistency in administrating repeated experiments. The program, designed to replace the experimenter, consisted of functions such as presenting the subjects with problem material, asking the subjects questions, and saving the typed answers of the subjects. The results indicate that representation forms strongly influence problem identification. It was found that the use of the socio-technical representation form led to the findings of more social problems than the use of technical representation form. The results imply significant effects of representation forms on problem findings and also suggest that the use of adequate representation forms may help overcome dysfunctional effects of our limited information processing capacity.

• Journal of Radiation Protection and Research
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• v.40 no.1
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• pp.46-54
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• 2015

The thermoluminescence (TL) and optically stimulated luminescence (OSL) are commonly used to measure and record the expose of individuals to ionization radiation. Design and performance test results of a newly developed TL and OSL measurement system are presented in this paper. For this purpose, the temperature of the TL material can be controlled precisely in the range of $1{\sim}1.5^{\circ}C$ by using high-frequency (35 kHz) heating system. This high-frequency power supply was made of transformer with ferrite core. For optical stimulation, we have completed an optimal combination of the filters with the arrangement of GG420 filter for filtering the stimulating light source and a UG11 filter at the detecting window (PMT). By using a high luminance blue LED (Luxeon V), sufficient luminous intensity could be obtained for optical stimulation. By using various control boards, the TL/OSL reader device was successfully interfaced with a personal computer. A software based on LabView program (National Instruments, Inc.) was also developed to control the TL/OSL reader system. In this study, a multi-functional TL/OSL dosimeter was developed and the performance testing of the system was carried out to confirm its reliability and reproducibility.

• Korean Journal of Social Welfare
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• v.57 no.4
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• pp.343-370
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• 2005

This study is to find out factors that protect social workers in a medical setting from burnout. It is differentiated from the existing studies, which focused on factors or process causing burnout. The participants of the study were ten social workers, who have been working in a medical setting for at least seven years and were recognized as competent social workers by at least five other colleagues. The data were collected through intensive interviews. The contents of the interviews were analyzed by using Nvivo2, a computer software program for use qualitative study analysis. The result of this study categorized coping strategies that kept the social workers from burnout. Among such factors were their own admissions of having professional competency, feeling worthwhile and sense of accomplishment, having a firm belief system and value about their profession, teamwork, and their overall disposition. Additionally, they said that the support by their agency and the recognition and support by family contributed to their overall coping ability. Through this study, it was found that the social workers in medical setting were reducing risk factors related to burnout and overcoming them with various protective factors. These protective factors reflected the unique characteristics that social workers encounter in a medical setting. It was remarkable that 'developing and managing their professional competency' was emphasized most as a protective factor.

• Journal of Gifted/Talented Education
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• v.10 no.2
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• pp.87-108
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• 2000

This study analyzes the factors influencing self-esteem of the gifted children. The factors are divided into the environmental ones and innate ones. The purposes of this study is presented as follows. 1) To analyze the environmental factors influencing self-esteem of the gifted children (1) whether the education period affects self-esteem of the gifted children? (2) what influences do the manners of parental child-rearing behavior make? (3) what influences do peer relationships make on self-esteem of the gifted children? 2) To analyze the innate factors influencing self-esteem of the gifted children (1) does the gender make a difference to self-esteem of the gifted children? (2) does the level of intelligence make a difference to self-esteem of the gifted children? (3) what influences does the locus of control make on the self-esteem of the gifted children? To solve these questions 120 gifted children were selected, who were taking a special education program at C Korea Academy of Gifted Education located at Yangjae-dong Seocho-gu. They were 1st to 3rd grades at elementary school. We used Hare Self-Esteem Scale developed by Bruce R. Hare in 1985, the Index of Peer Relations developed by Hudson in 1986, and Nowicki & Strickland Locus of Control Scale developed by Nowicki and Strickland in 1973. At the other hand the nursing behaviors of 120 mothers of the gifted, were also investigated, based on the Korean Maternal Behavior Inventory, developed by Sungyeon Park in 1989 with some modifications. For statistical analysis we adopted SPSS, a computer software, and calaulated the coefficient of internal appropriateness and the frequencies and percentages of general aspects of the cases. We analysed the factors influencing the self-esteem of the gifted children by way of Pearson's product moment correlation coefficient, t-test, ANOVA, and multiple regression analysis and Duncan for ex-post-facto approval. The results of this study can be summarized as follows. 1) Influences of the environmental factors on the self-esteem of the gifted children: (1) The duration of education period had a significant effect on the self-esteem; the longer the duration were, the higher self-esteem they possessed. (2) Of parental child-rearing behaviors, active involvement had positive influence on the self-esteem; on the contrary, authoritarian control and overprotection had negative influences on the self-esteem. (3) An acceptable peer relationship had a positive influence on the self-esteem of the gifted children. 2) Influences of individual innate characteristics on the self-esteem of the gifted children: (1) The gender made no difference on the self-esteem of the gifted. (2) The intelligence did not have a statistically significant effect on the self-esteem of the gifted. (3) When the locus of control was external, the self-esteem of the gifted tended to be low.

• Journal of The Korean Association of Information Education
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• v.23 no.5
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• pp.469-480
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• 2019

One of the goals of the new 2015 revised curriculum is to cultivate the creativity of students who will live in the era of the Fourth Industrial Revolution to create new things through diverse ideas and challenges based on basic learning skills. Accordingly, in order to solve the given problems rationally, the convergence problem solving ability that can process and utilize various areas of knowledge and information is becoming important. Therefore, in this study, we designed the integrative education using a 3D printer based on Tinkercad modeling and applied it to the class to investigate the effect on the improvement of computing thinking ability of elementary school students. To verify the contents of the study, two classes of 25 sixth-grade elementary school students were divided into an experimental group and a controlled group. For the experimental group, 12 classes of convergence education programs using a 3D printer were applied for about three months, and the same amount of general curriculum was conducted for the control group. After that, the t-tests were carried out using the pre-post test to measure the effectiveness of the computational thinking ability. After the application of the program, the experimental group showed statistically significant improvement in computational thinking ability, but the controlled group showed no statistically significant difference. The results show that convergence education using the Tinkercad modeling-based 3D printer has a positive effect on the improvement of computing thinking ability of elementary school students.

• Structural Engineering and Mechanics
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• v.50 no.5
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• pp.589-603
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• 2014

Expressions for determining the value of the impact force as reported in the literature and incorporated into code provisions are essentially quasi-static forces for emulating deflection. Quasi-static forces are not to be confused with contact force which is generated in the vicinity of the point of contact between the impactor and target, and contact force is responsible for damage featuring perforation and denting. The distinction between the two types of forces in the context of impact actions is not widely understood and few guidelines have been developed for their estimation. The value of the contact force can be many times higher than that of the quasi-static force and lasts for a matter of a few milli-seconds whereas the deflection of the target can evolve over a much longer time span. The stiffer the impactor the shorter the period of time to deliver the impulsive action onto the target and consequently the higher the peak value of the contact force. This phenomenon is not taken into account by any contemporary codified method of modelling impact actions which are mostly based on the considerations of momentum and energy principles. Computer software such as LS-DYNA has the capability of predicting contact force but the dynamic stiffness parameters of the impactor material which is required for input into the program has not been documented for debris materials. The alternative, direct, approach for an accurate evaluation of the damage potential of an impact scenario is by physical experimentation. However, it can be difficult to extrapolate observations from laboratory testings to behaviour in real scenarios when the underlying principles have not been established. Contact force is also difficult to measure. Thus, the amount of useful information that can be retrieved from isolated impact experiments to guide design and to quantify risk is very limited. In this paper, practical methods for estimating the amount of contact force that can be generated by the impact of a fallen debris object are introduced along with the governing principles. An experimental-calibration procedure forming part of the assessment procedure has also been verified.