• Advances in nano research
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• v.16 no.5
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• pp.509-519
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• 2024

In this study, the static analysis of carbon nanotube-reinforced composites (CNTRC) beams resting on a Winkler-Pasternak elastic foundation is presented. The developed theories account for higher-order variation of transverse shear strain through the depth of the beam and satisfy the stress-free boundary conditions on the top and bottom surfaces of the beam. To study the effect of carbon nanotubes distribution in functionally graded (FG-CNT), we introduce in the equation of CNT volume fraction a new exponent equation. The SWCNTs are assumed to be aligned and distributed in the polymeric matrix with different patterns of reinforcement. The rule of mixture is used to describe the material properties of the CNTRC beams. The governing equations were derived by employing Hamilton's principle. The models presented in this work are numerically provided to verify the accuracy of the present theory. The analytical solutions are presented, and the obtained results are compared with the existing solutions to verify the validity of the developed theories. Many parameters are investigated, such as the Pasternak shear modulus parameter, the Winkler modulus parameter, the volume fraction, and the order of the exponent in the volume fraction equation. New results obtained from bending and stresses are presented and discussed in detail. From the obtained results, it became clear the influence of the exponential CNTs distribution and Winkler-Pasternak model improved the mechanical properties of the CNTRC beams.

• Journal of The Korean Association For Science Education
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• v.30 no.1
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• pp.140-156
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• 2010

This study aimed to investigate how science teachers perceived major features of the 2007 revised science curriculum and implementing them in classes. The 2007 revised science curriculum included critical features such as creativity, open inquiry, science writing, discussion and STS. In terms of necessity, clarity and complexity of those features for curriculum implementation, teacher perceptions were examined. Particularly with regard to open inquiry assigned 6 class periods per semester as one of the critical features of 2007 revised science curriculum, we asked teachers how they would prepare and implement the technique in their teaching. In results of this study, science teachers agreed on the necessity and importance of those major features of the 2007 revised science curriculum, including creativity, open inquiry, science writing, discussion, and STS. However, they were not clear on how those would work in their classrooms and expected various impediments. Open inquiry was specifically perceived as most negative in its implementation with the mention of various complex reasons. Based on findings in this study, we proposed the 'Dual Action Research Model' for curriculum implementation. It tries to explain how curriculum is implemented in classrooms and diminish the gaps between curriculum developers and teacher users by means of leading teachers to understand the curriculum meaningfully and implement their teaching based on this understanding.

• Management & Information Systems Review
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• v.34 no.4
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• pp.31-66
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• 2015

The purpose of this research is to examine that internal virtue (i.e. virtue between organizational members) and external virtue (i.e. virtue between organizational members and external members) positively associate with job performance when considering organizational identification, positive work-related identity, affective commitment, emotional exhaustion, and collective self-esteem as mediators. Virtue in organization has received attention as critical attribute of positive organizational scholarship. Cameron(2003) defined the study of virtue as a study of the capacity, attributes, and reserve in organization that facilitates the expression of positive deviance among organization member. In addition, this study contributes to the qualitative investigation on how internal giving virtue (i.e. the employees' virtue for their organization), internal receiving virtue (i.e. virtue employees receive from their organization), external giving virtue (i.e. the organization's virtue for society), and external receiving virtue (i.e. virtue the organization receives from society), used as independent variables, influence job performance after creating research model for the four virtuous behaviors through qualitative research. Therefore, this research contributes to the creation of research model for virtuous behaviors within organizations and virtuous behaviors with external members through qualitative study and sheds light on how these variables influence job performance by virtue of qualitative research.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.3
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• pp.422-427
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• 2010

Korean Game industry, especially MMORPG(Massively Multiplayer Online Game) has been rapidly expanding in these days. But As game industry is growing, lots of online game security incidents have also been increasing and getting prevailing. One of the most critical security incidents is 'Game Bots', which are programs to play MMORPG instead of human players. If player let the game bots play for them, they can get a lot of benefic game elements (experience points, items, etc.) without any effort, and it is considered unfair to other players. Plenty of game companies try to prevent bots, but it does not work well. In this paper, we propose a behavior pattern model for detecting bots. We analyzed behaviors of human players as well as bots and identified six game features to build the model to differentiate game bots from human players. Based on these features, we made a Naive Bayesian classifier to reasoning the game bot or not. To evaluated our method, we used 10 game bot data and 6 human Player data. As a result, we classify Game bot and human player with 88% accuracy.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.43-52
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• 2018

Livestock production is the second largest economic activity of Pakistan's rural population, more specifically; sixty-seven percent of Pakistan's total population that live in rural areas sources their income from livestock activities. As this subsector of agriculture within rural Pakistan is so critical to Pakistan's economy it is especially important to further develop the sector through the introduction of cost effective, efficient, and practical technologies. In an effort to improve such an important sector within the agriculture sector in Pakistan research has been carried out to better understand the capabilities and feasibility of leveraging Internet of Things based technologies, such as, microprocessors and microcontrollers within Pakistan's livestock production and management. The internet of Things can potentially allow for the scaling of small-scale rural livestock production to larger operations through cost effective and efficient livestock management through the application of IoT technologies. This paper discusses the architecture models of IoT based smart animal farms and delves into the pitfalls and advantages of applying IoT technologies in this sector. In this work we will explore the cheap sensors to monitor the internal activities of cattle farm with the aim of using these sensors as part of system to detect the important operations that need on the time response. This system should provide the feed and water as required, and control the temperature in sheds to protect the cattle being ill and on heat, and humidity level .internet connection used to connect these devices with smartphones or computers. In this paper we proposed the architecture model of IoT based smart animal farm.

• Journal of Gifted/Talented Education
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• v.21 no.4
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• pp.927-943
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• 2011

What are the critical factors in deciding future career to the gifted and talented students? The present study started with this question, and was to develop a career decision-making scale for scientifically gifted undergraduates. For this, literatures related to the scientifically gifted/talent and scientists' career decision-making were reviewed and examined in depth. Based on the review of the related literature, the developed scale of career decision-making was comprised of 26 items in 6 factors, such as individual aptitude & self-realization, economic aspect, work & leisure, familial influence, parents/teachers' recommendation, and experience of science activity during the school days. For the preliminary exploratory factor analysis, 153 undergraduate students who were majoring in natural sciences and engineer participated in the study. For the confirmatory factor analysis, 264 undergraduates who were awarded the presidential scholarships and 93 undergraduates who completed a university-affiliated gifted education center participated. The results of the study are as follows. The fit of measurement model was found to be $x^{2}$=645.157 (df=279, p=.00), TLI=.924, CFI= .935, RMSEA=.061, indicating most of fit indexes were acceptable. Cronbach's ${\alpha}$ in each sub-factor was quite high, .82 for individual aptitude & self-realization, .94 for economic aspect, .84 for work and leisure, .88 for familial influence, .79 for patents/ teachers' recommendation, and .79 for experience of science activity during the school days. The results of the study were discussed whether the developed scale could be used as a valid and reliable tool for measuring career decision-making factors of the scientifically gifted undergraduates in our country.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.6
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• pp.31-43
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• 2014

Confined and mechanically ventilated broiler house has been recently come into wide use to increase productivity and control rearing conditions. However, high dust concentration inside facility can threaten respiratory welfare of farmers and broilers. In Korea, there is no regulation in terms of air quality control inside agricultural facilities and sufficient data is not available. To cope with these, periodic monitoring of inhalable and respirable dust concentration were conducted according to season, broiler's activity and specific events such as shipment work for broilers in mechanically ventilated broiler house. Chamber experiment was also designed to analyze mechanism of dust generation from ground beds according to water contents and surrounding wind environment. Results showed that significant increase of inhalable (p=0.002) and respirable (p=0.03) dust were observed when activity of broilers was high according to entrance of the workers. Even shipment work for matured broilers, high level of dust were observed; inhalable dust was exceeded the threshold limit over maximum 303 % and respirable dust was over maximum 1,550 %, implying that acute respiratory symptoms could be manifested for the workers. From the chamber experiment, critical water contents for interrupting of dust generation were measured; about 45 % for inhalable dust and about 50 % for respirable dust. These results can be a trigger for designing plan of dust control however it still needs consideration of various environmental conditions, hygiene problems, etc.

• Journal of KIISE:Information Networking
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• v.32 no.6
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• pp.659-667
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• 2005

A Mobile Ad Hoc Network(MANET) is a multi hop wireless network with no prepared base stations or centralized administrations, where flocks of peer systems gather and compose a network. Each node operates as a normal end system in public networks. In addition to it, a MANET node is required to work as a router to forward traffic from a source or intermediate node to others. Each node operates as a normal end system in public networks, and further a MANET node work as a router to forward traffic from a source or intermediate node to the next node via routing path. Applications of MANET are extensively wide, such as battle field or any unwired place; however, these are exposed to critical problems related to network management, node's capability, and security because of frequent and dynamic changes in network topology, absence of centralized controls, restricted usage on network resources, and vulnerability oi mobile nodes which results from the special MANET's character, shared wireless media. These problems induce MANET to be weak from security attacks from eavesdropping to DoS. To guarantee secure authentication is the main part of security service In MANET because networks without secure authentication are exposed to exterior attacks. In this paper, a multistage authentication strategy based on CGSR is proposed to guarantee that only genuine and veritable nodes participate in communications. The proposed authentication model is composed of key manager, cluster head and common nodes. The cluster head is elected from secure nodes, and key manager is elected from cluster heads. The cluster head will verify other common nodes within its cluster range in MANET. Especially, ID of each node is used on communication, which allows digital signature and blocks non repudiation. For performance evaluation, attacks against node authentication are analyzed. Based on security parameters, strategies to resolve these attacks are drawn up.

• Journal of vocational education research
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• v.29 no.3
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• pp.23-40
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• 2010

Career guidance refers to services intended to assist students to make educational and occupational choices and to manage their careers. Young students, specially enrolled in vocational high schools, need programs to help them make transitions to the working world and to re-engage with further learning, and career guidance needs to be part of such programs. Teachers assume the critical roles in planning and organizing the career guidance programs in vocational high schools. The program includes career information provision, assessment and self-assessment tools, career counseling, work search, etc. In this study, we developed a research model based upon TRA(theory of reasoned action) developed by Ajzen and Fishbein to investigate the factors influencing the intention to provide career guidance services to students in vocational high schools. Based on 155 survey responses from vocational high school teachers, we show that attitude and subjective norm motivate teachers to provide career guidance services, and that attitude toward career guidance is directly influenced by self-efficacy for career guidance and burden from extra work. It was also confirmed that facilitating condition is the antecedent of self-efficacy. But contrary to our expectation, self-efficacy for career guidance has no significant effect on the intention for providing career guidance services at 5% significance level. In light of these findings, implications for theory and practice are discussed.

• Management & Information Systems Review
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• v.36 no.1
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• pp.115-141
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• 2017

This study is to find the key factors of the Internet of Things for development in public sector. In previous studies, it is said that Internet of Things can work digital system without human operation and gives a lot of outputs(information) users. Generally, people are a subject of operating digital system in traditional way, while people are an object on the internet of things. In other words, it is possible to work digital system with only networking from things to things. After all, it is reported that these advantages of the Internet of Things make possible to reduce social costs significantly in public sector. However, despite the strengths of the Internet of Things, there is a specific user acceptance of the technology factor for the Internet of Things rarely. It means that developing of the Internet of Things only focuses on the final purpose. If the focus on development meet this purpose, the user is ignored for the specific reason that using a technique. As a result of this, many users gradually decrease the continuous using of the Internet of Things. Thus, in this study, we need to find what critical factors should reflect to the Internet of Things in public sector. To find this result, there is no choice to use Technology Acceptance Model(TAM). Many researchers have proved that Technology Acceptance Model is valid through the four process in model introduction, confirmation, expansion and refinement from 1986 to 2003. The results of this study showed that the result explanatory power of Internet of Things in public sector is the most important factor affecting only perceived social usefulness and ease of use. Finally, it can be seen that the user has a positive attitude toward use, which has a positive effect on the intention to use continuously. The implications of this study are summarized as follows: When the public Internet of Things service is provided, it means that the user can easily understand the result, and when the person and the object communicate the result to each other, they should be able to communicate with each other. This means that a lot of user effort is needed to understand the outcome of the public Internet of Things being provided.