• Communications of the Korean Mathematical Society
• /
• v.31 no.3
• /
• pp.507-518
• /
• 2016

The aim of this paper is to prove some strong convergence theorems for the modified Ishikawa iteration process involving a pair of a generalized asymptotically nonexpansive single-valued mapping and a quasi-nonexpansive multi-valued mapping in the framework of $\mathbb{R}$-trees under the gate condition.

• IE interfaces
• /
• v.9 no.3
• /
• pp.44-51
• /
• 1996

The purpose of this paper is to develop a modeling framework for analyzing the effect of price on the PCS (Personal Commununications Service) demand. To achieve this aim, a nonlinear regression model was derived to capture the income effect on the PCS demand and then was combined into an integrated Bass diffusion model. The model was then applied to the emerging PCS market in Korea and the market demands up to the year 2006 were estimated. The results were reviewed and evaluated in various aspects. Finally, the possibilities of model enhancement and model extensions were explored.

• Journal of the Economic Geographical Society of Korea
• /
• v.10 no.4
• /
• pp.355-376
• /
• 2007

The aim of this study is to examine the changes of approach methods of research framework in the history of Korean economic geography during the last fifty years($1956{\sim}2005$). The five factors that have influenced Korean economic geography are Korean geography, European, American, and Japanese geography, fundamental theories of economics and business administration, regional problems, and culture. The study of Korean economic geography can be divided into four periods: 'period of cradle of economic geography($1956{\sim}1962$)', 'period of establishment of economic geography(1963$\sim$later 1970s)', 'period of leap of economic geography(the former half of 1980s$\sim$the former half of 1990s)', and 'period of transition of economic geography (since later 1990s)'. And research framework of Korean economic geography has changed from the regional structure theory in 'period of leap' to the spatial system of economies and network theory in 'period of transition'. Spatial system of economies and network theory consists of spatial system of world economies, spatial system of national economies, spatial system of regional economies, spatial network of enterprise economies, and spatial network of information economies.

• The Journal of Advanced Prosthodontics
• /
• v.8 no.3
• /
• pp.181-186
• /
• 2016

PURPOSE. The opacity of zirconia is an esthetic disadvantage that hinders achieving natural and shade-matched restorations. The aim of this study was to evaluate the translucency of non-colored and colored framework zirconia and monolithic zirconia. MATERIALS AND METHODS. The three groups tested were: non-colored framework zirconia, colored framework zirconia with the A3 shade according to Vita Classic Scale, and monolithic zirconia (n=5). The specimens were fabricated in the dimensions of $15{\times}12{\times}0.5mm$. A spectrophotometer was used to measure the contrast ratio, which is indicative of translucency. Three measurements were made to obtain the contrast ratios of the materials over a white background ($L^*w$) and a black background ($L^*b$). The data were analyzed using the one-way analysis of variance and Tukey HSD tests. One specimen from each group was chosen for scanning electron microscope analysis. The determined areas of the SEM images were divided by the number of grains in order to calculate the mean grain size. RESULTS. Statistically significant differences were observed among all groups (P<.05). Non-colored zirconia had the highest translucency with a contrast ratio of 0.75, while monolithic zirconia had the lowest translucency with a contrast ratio of 0.8. The mean grain sizes of the non-colored, colored, and monolithic zirconia were 233, 256, and 361 nm, respectively. CONCLUSION. The translucency of the zirconia was affected by the coloring procedure and the grain size. Although monolithic zirconia may not be the best esthetic material for the anterior region, it may serve as an alternative in the posterior region for the bilayered zirconia restorations.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.8 no.2
• /
• pp.137-148
• /
• 2009

Recently, as technology for obtaining locational awareness and wireless telecommunications improve, technologies and services involving Telematics has grown rapidly. However, the services are currently available on certain terminals selected by the telematics service provider (TSP). This means in order to access services provided by other TSPs, it is necessary to purchase related terminals. To solve this problem, it is essential to achieve service interoperability between TSPs, or between TSPs and the contents provider (CP). Under this backdrop, the aim of this paper is to design and implement a telematics service framework for openning services in a heterogeneous network environment. Futhermore, the paper presents open telematics protocols required for communication in the telematics service framework, and develop technologies to deal with this in different network environments.

• Journal of Information Processing Systems
• /
• v.3 no.2
• /
• pp.43-53
• /
• 2007

The use of agent paradigm in today's applications is hampered by the security concerns of agents and hosts alike. The agents require the presence of a secure and trusted execution environment; while hosts aim at preventing the execution of potentially malicious code. In general, hosts support the migration of agents through the provision of an agent server and managing the activities of arriving agents on the host. Numerous studies have been conducted to address the security concerns present in the mobile agent paradigm with a strong focus on the theoretical aspect of the problem. Various proposals in Intrusion Detection Systems aim at securing hosts in traditional client-server execution environments. The use of such proposals to address the security of agent hosts is not desirable since migrating agents typically execute on hosts as a separate thread of the agent server process. Agent servers are open to the execution of virtually any migrating agent; thus the intent or tasks of such agents cannot be known a priori. It is also conceivable that migrating agents may wish to hide their intentions from agent servers. In light of these observations, this work attempts to bridge the gap from theory to practice by analyzing the security mechanisms available in Aglet. We lay the foundation for implementation of application specific protocols dotted with access control, secured communication and ability to detect tampering of agent data. As agents exists in a distributed environment, our proposal also introduces a novel security framework to address the security concerns of hosts through collaboration and pattern matching even in the presence of differing views of the system. The introduced framework has been implemented on the Aglet platform and evaluated in terms of accuracy, false positive, and false negative rates along with its performance strain on the system.

• Journal of Educational Research in Mathematics
• /
• v.22 no.4
• /
• pp.535-555
• /
• 2012

The aim of this study is to analyze how the context problems by prospective teachers are solved. In order to achieve this aim, this study examined the conceptual nature of context based on previous studies. I developed context problems about linear programming with reference to the results of the examination about the natural characterization of context. These problems were given to 44 prospective teachers and qualitative methods were used to analyze the data obtained from the written solutions by the participants. This study also developed the framework descriptors for this analysis in the light of the Mathematics Scoring Rubric from Illinois Department of Education(2005). The data was analyzed and interpreted in terms of this framework and the specific characteristics shown in the process of problem solving by the teachers were categorized into four types as a result.

• School Mathematics
• /
• v.19 no.3
• /
• pp.461-480
• /
• 2017

The aim of this study was to analyze characteristics of teachers' knowledge about correlation with data presented in $2{\times}2$ tables. In order to achieve the aim, this study conducted didactical analysis about two-way tables through examining previous researches and developed a questionnaire with reference to the results of the analysis. The questionnaire was given to 53 middle and high school teachers and qualitative methods were used to analyze the data obtained from the written responses by the participants. This study also elaborated the framework descriptors for interpreting the teachers' responses in the light of the didactical analysis and the data was elucidated in terms of this framework. The specific features of teachers' knowledge about correlation with data presented in $2{\times}2$ tables were categorized into three types as a result. This study raised several implications for teachers' professional development for effective mathematics instruction about correlation and related concepts dealt with in probability and statistics.

• International Area Studies Review
• /
• v.12 no.3
• /
• pp.89-109
• /
• 2008

Using hybrid channel affords the benefits of achieving control through the direct channel and achieving flexibility through the indirect channel. However, using a hybrid channel also poses special challenges to a manufacturer, including the problem of managing multiple channel members with disparate goals and priorities. The purpose of this study is to enhance our understanding on the management of hybrid channel. We study marketing channels for fashion apparel to examine governance challenges and solutions of a hybrid channel. We have two objectives to fulfill that purpose. First, we aim to tie two largely separate research streams of salesforce management and marketing channel management together by examining both intrafrim governance and interfirm governance issues under one conceptual framework. Second, we aim to lay a ground work for rigorous further research on this topic by tying two major theoretical approaches of governance together under one conceptual framework. Our predictions were tested with data from the survey of apparel manufacturers and retailers. The analysis results support the predictions moderately.

• Journal of Science and Technology Studies
• /
• v.19 no.2
• /
• pp.41-83
• /
• 2019

Recently, the establishment of the Special Act on National Research and Development(tentatively named) has been discussed with the aim of providing a legal basis for the comprehensive management of national research and development programs, which have thus far been independently implemented by government ministries. This paper analyzes the legislative process of the Framework Act on Science and Technology(hereafter, the "Framework Act") introduced for a similar purpose in 2001. By examining who had proposed various versions of the legislation prior to the enactment of the Framework Act, and which draft bill was derived ultimately through controversies, this paper will present the following two arguments: First, the obsession with a single regulation that can be applicable to all national research and development programs may lead to unintended consequences, given that the history of national research and development programs, each of which has been implemented by different government ministries, is quite long. Second, the Framework Act has an impact to date while it consistently internalizes the very unique orientations, as the concepts of "national competitiveness" and "national innovation system" postulate, even though it failed to establish an integrated rule. The case of the Framework Act will be a window through which one can glimpse how the present debate on the enactment of the Special Act on National Research and Development shall proceed, and further, reflect on the issues that were overlooked.