• Journal of Korean Society of Coastal and Ocean Engineers
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• v.8 no.1
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• pp.28-36
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• 1996

The influence of vertical eddy viscosity to the nonlinear interaction of tidal current and wind-induced current is examined using a point model. A zero-equation turbulence model is derived by simplifying the q$^2$-q$^2$1 turbulence model under the assumption that the generation of turbulence kinetic energy is balanced with its dissipation and is further modified to include the depth of frictional influence properly The zero-equation turbulence model is derived and the possibility of resonance in the presence of Coriolis effect is suggested. The amplitudes of tidal currents remain the same regardless of the applied wind stress, but the over-tide component is generated due to the nonlinear interaction of tidal current and wind-induced current. Significant changes in the vertical profile of wind-induced currents can occur according to tide-induced background turbulence. The turbulence model can give rise to misleading results when applied to the wind-driven circulation in the tide-dominated sea such as Yellow Sea unless the tide-induced background turbulence is adequately included in the parameterization of vertical eddy viscosity.

• Archives of design research
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• v.17 no.1
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• pp.253-264
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• 2004

The final goal of this research is development of graphic design evaluation methodology in elevation of a usability at the mobile internet services and of measurement model which can forecast user needs in interface design, and systemize evaluation basis. For this, we systemize core contents of GUI design evaluation methodology and embodied UI design support system that supports prototype layout and evaluation process directly. The sight language that can inform flow of controled information by the quick and implicated method so that user may complete task in a short time without overload of recognition in limited display environment of Small Screen device it must improve objectivity in the reflection of UI design with image. Thus evaluation methodology that can evaluate usability of mobile internet systematically is important and specially, graphic design evaluation model which can forecast user's design need and trend is meaningful because of special quality that can reflect sensitive aspect of user in interface design. Mobile internet GUI was done by the result of this design evaluation, and I hope this result can be utilized for the GUI development of Ubiquitous environment for the future research.

• Archives of design research
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• v.17 no.3
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• pp.263-272
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• 2004

As the evolution of information and communication technologies alters the communication environment at an alarming rate, the avatar has presented itself as one of new means of communication in recent years. The Internet avatar has increasingly placed as an important profit making source of the digital contents. However, studies on how users make decision for choosing the avatar are very seldom. The aim of this study is to understand user's behaviors in the decision making process for selecting the most appropriate avatar among various choices. It also aims to identify major factors and elements for developing an avatar depending on the users purposes. A set of decision-making models, accordingly purpose model and cognitive model, as well as prototype of each model have been developed. Finally, it suggested practical guidelines for designing the avatar in conjunction with purposes of use.

• Journal of KIISE:Databases
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• v.36 no.3
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• pp.189-197
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• 2009

Top-k queries are important to many wireless sensor applications. Conventional Top-k query processing algorithms install a filter at each sensor node and suppress unnecessary sensor updates. However, they have some drawbacks that the sensor nodes consume energy extremely to probe sensor reading or update filters. Especially, it becomes worse, when the variation ratio of top-k result is higher. In this paper, we propose a novel Top-k query processing algorithm for energy-efficiency. First, each sensor determines its priority as the order of data gathering. Next, sensor nodes that have higher priority transmit their sensor readings to the base station until gathering k sensor readings. In order to show the superiority of our query processing algorithm, we simulate the performance with the existing query processing algorithms. As a result, our experimental results show that the network lifetime of our method is prolonged largely over the existing method.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.5
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• pp.628-638
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• 1999

In this paper, we presents a method of retrieving 24 bpp RGB images based on color-spatial features. For each image, it is subdivided into regions by using similarity of color after converting RGB color space to CIE L*u*v* color space that is perceptually uniform. Our segmentation algorithm constrains the size of region because a small region is discardable and a large region is difficult to extract spatial feature. For each region, averaging color and center of region are extracted to construct color-spatial features. During the image retrieval process, the color and spatial features of query are compared with those of the database images using our similarity measure to determine the set of candidate images to be retrieved. We implement a content-based color image retrieval system using the proposed method. The system is able to retrieve images by user graphic or example image query. Experimental results show that Recall/Precision is 0.80/0.84.

• Journal of KIISE:Information Networking
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• v.37 no.5
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• pp.403-408
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• 2010

The sensor nodes can be installed in the environment in which the temperature change is considerable, such as desert, urban, and data center. Particularly, because the output power becomes less than the targeted power if a temperature is increasing, link quality is degraded and packet losses are occurred. In order to compensate the temperature changes, existing schemes detect the change of the link quality between nodes and control transmission power through a series of feedback process. However, these approaches can cause heavy overhead by additional control packets. In this paper, we propose the T2PC(Temperature-aware Transmission Power Control) to keep up the link quality despite temperature variation. At each node, T2PC compensates the attenuated link quality by controlling the transmission power based on the local temperature measurement. In addition, the packet reception ratio can be improved with less control packets than ones required in existing transmission power control methods based on the feedback control.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.4
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• pp.143-150
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• 2013

The School Curriculum amend in 2007 mandates the contents from which students can learn the principles and concepts of computer science. Computer Science is one of the most rapidly changing subjects, and the Informatics textbook should accurately explain the basic principles and concepts based on the latest technology. However, we found that the middle school textbooks in circulation lack accuracy and consistency in describing CPU. This paper attempted to discover the root-cause of the fallacy and suggest timely and appropriate explanation based on the historical and technical analysis. According to our study, it is appropriate to state that CPU is composed of datapath and control unit. The Datapath performs operations on data and holds data temporarily, and it is composed of the hardware components such as memory, register, ALU and adder. The Control unit decides the operation types of datapath elements, main memory and I/O devices. Nevertheless, considering the technological literacy of middle school students, we suggest the terms, 'arithmetic part' and 'control part' instead of datapath and control unit.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.11
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• pp.483-488
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• 2013

Users can access their data anywhere, at any time by using outsourced storage. But they cannot know how service provider manage the data. Even user cannot know when data damaged. To solve these problems, the outsourced storage auditing schemes has been proposed. Most proposed schemes are based on Homomorphic Verifiable Tags. But it has computational efficiency limitation because data used to exponent. In this paper, we propose a novel approach to outsourced storage auditing scheme using coefficient matrix. In the proposed scheme, data used to auditing by coefficient matrix form. Auditing procedures are proceed as solving the linear simultaneous equation. The auditor can audit easily by solving the equation using solution vector. The auditor can audit the n size data using sqrt(n) size data through out proposed scheme.

• Journal of Internet Computing and Services
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• v.15 no.2
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• pp.59-71
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• 2014

This study applied customer perspective to find out ways how to protect customers' privacy by themselves. It does so by examining the factors which affect customer privacy protection behaviors. Based on the Privacy Act, this study developed the construct of Privacy Rights awareness and finds the law's effect on privacy awareness and behavioral change. The study finds that there exists a significant difference in privacy protection behavior according to privacy rights awareness. Independent variables are as follows: Five variables (Perceived vulnerability, Perceived severity, Perceived response effectiveness, Perceived barriers, Privacy Rights awareness) were tested as critical variables influencing Behavioral Intention in PMT model. Privacy awareness had a moderating effect on the relationship between perceived severity and privacy protection behavior. This study would contribute on theoretical expansion of Protection Motivation Theory and also provide practical implications for effective ways to promote behavioral changes.

• Journal of Gifted/Talented Education
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• v.20 no.3
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• pp.681-701
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• 2010

This study examined the perception of gifted teachers toward 'conception of creativity personality education,' 'methodology of creativity personality education,' and 'support of creativity personality education' in the future gifted education. As a result, gifted teachers conceptualized creativity personality education as education to foster creative social capitals(social + moral leaders), which showed movement from gifted education focused on cognitive development into future-developmental orientation. Gifted teachers mentioned education to foster social sensitivity, creativity, and leadership as methodology of creativity personality education. More specifically, they recommended inductive curriculum in learning and teaching in order to encourage domain-specific giftedness. As pointing not to separate creativity personality education for gifted from a formal education but to deploy with conjunction with it, gifted teachers mentioned the social recognition for creativity personality education and the development of teacher's professionalism and educational programs.