• ETRI Journal
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• v.36 no.4
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• pp.554-563
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• 2014

The burgeoning growth of real-time applications, such as interactive video and VoIP, places a heavy demand for a high data rate and guarantee of QoS from a network. This is being addressed by fourth generation networks such as Long-Term Evolution (LTE). But, the mobility of user equipment that needs to be handed over to a new evolved node base-station (eNB) while maintaining connectivity with high data rates poses a significant challenge that needs to be addressed. Handover (HO) normally takes place at cell borders, which normally suffers high interference. This inter-cell interference (ICI) can affect HO procedures, as well as reduce throughput. In this paper, soft frequency reuse (SFR) and multiple preparations (MP), so-called SFRAMP, are proposed to provide a seamless and fast handover with high throughput by keeping the ICI low. Simulation results using LTE-Sim show that the outage probability and delay are reduced by 24.4% and 11.9%, respectively, over the hard handover method - quite a significant result.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.1
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• pp.37-47
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• 2018

Dynamic simulation is critical for electrical ship studies as it obtains the necessary information to capture and characterize system performance over the range of system operations and dynamic events such as disturbances or contingencies. However, modeling and simulation of the interactive electrical and mechanical dynamics involves setting up and solving system equations in time-domain that is typically time consuming and computationally expensive. Accurate assessment of system dynamic behaviors of interest without excessive computational overhead has become a serious concern and challenge for practical application of electrical ship design, analysis, optimization and control. This paper aims to develop a systematic approach to classify the sophisticated dynamic phenomenon encountered in electrical ship modeling and simulation practices based on the design intention and the time scale of interest. Then a novel, comprehensive, coherent, and end-to-end mathematical modeling and simulation approach has been developed for the latest Medium Voltage Direct Current (MVDC) Shipboard Power System (SPS) with the objective to effectively and efficiently capture the system behavior for ship-wide system-level studies. The accuracy and computation efficiency of the proposed approach has been evaluated and validated within the time frame of interest in the cast studies. The significance and the potential application of the proposed modeling and simulation approach are also discussed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7508-7512
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• 2015

We propose a brain-machine interface(BMI) based human-robot interaction(HRI) platform which operates machines by interfacing intentions by capturing brain waves. Platform consists of capture, processing/mapping, and action parts. A noninvasive brain wave sensor, PC, and robot-avatar/LED/motor are selected as capture, processing/mapping, and action part(s), respectively. Various investigations to ensure the relations between intentions and brainwave sensing have been explored. Case studies-an interactive game, on-off controls of LED(s), and motor control(s) are presented to show the design and implementation process of new BMI based HRI platform.

• Archives of design research
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• v.17 no.1
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• pp.299-308
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• 2004

The methods of presenting information are more variable with advanced computer media technology. However, when we visualize information of database, it is more difficult to understand data meaning by complex date, which is not required by user. To compose new information, user needs to combine own his memory and new information presenting result. To be quickly explored new information and be exactly understood relationship of data structure, the data presenting of visualized information is more structured and presented with meaning form. It is possible to make information visualization system, which users can explore database by oneself, with supporting interaction to be able to control and combine relationship of three-dimensional scene graphic structure, presenting factors of animation and data structure of database. There are several diagrams, such as VR diagram, Form structure diagram and simulated diagram as the case study.

• Journal of Korea Multimedia Society
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• v.5 no.1
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• pp.94-104
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• 2002

This paper presents a new way of texture mapping on the Genus N object constructed over a single domain. The problem of 2D texture mapping is the discontinuity of texture domain at the virtual boundary on the object. Such phenomenon decreases smoothness of the object as well as looks unnatural. Especially it is necessary for the Genus N object of infinite coninuity to apply the seamless texture mapping. For seamless texture mapping, a multiperiodic function, which transforms a discontinuous function into a continuous function, is suggested. In some applications, however, the visual seams on the textured object provide more realistic appearance. Therefore, this research supports the interactive control from the discontinuity and the continuity across the boundary using the coefficient of the weight function.

• Nuclear Engineering and Technology
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• v.53 no.7
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• pp.2195-2206
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• 2021

In order to mitigate the damage caused by accidents in nuclear power plants (NPPs), evacuation strategies are usually managed on the basis of off-site effects such as the diffusion of radioactive materials and evacuee traffic simulations. However, the interactive behavior between evacuees and the accident environment has a significant effect on the consequential gap. Agent-based modeling (ABM) is a method that can control and observe such interactions by establishing agents (i.e., the evacuees) and patches (i.e., the accident environments). In this paper, a radiological emergency evacuation model is constructed to realistically check the effectiveness of an evacuation strategy using NetLogo, an ABM toolbox. Geographic layers such as radiation sources, roads, buildings, and shelters were downloaded from an official geographic information system (GIS) of Korea, and were modified into respective patches. The dispersion model adopted from the puff equation was also modified to fit the patches on the geographic layer. The evacuees were defined as vehicle agents and a traffic model was implemented by combining the shortest path search (determined by an A ^* algorithm) and a traffic flow model incorporated in the Nagel-Schreckenberg cellular automata model. To evaluate the radiological harm to the evacuees due to the spread of radioactive materials, a simple exposure model was established to calculate the overlap fraction between the agents and the dispersion patches. This paper aims to demonstrate that the potential of ABM can handle disaster evacuation strategies more realistically than previous approaches.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.1
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• pp.39-45
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• 2019

We propose an active color model based method for tracking motions of multiple human using a networked multiple-camera system in IoT space as a human-robot coexistent system. An IoT space is a space where many intelligent devices, such as computers and sensors(color CCD cameras for example), are distributed. Human beings can be a part of IoT space as well. One of the main goals of IoT space is to assist humans and to do different services for them. In order to be capable of doing that, IoT space must be able to do different human related tasks. One of them is to identify and track multiple objects seamlessly. In the environment where many camera modules are distributed on network, it is important to identify object in order to track it, because different cameras may be needed as object moves throughout the space and IoT space should determine the appropriate one. This paper describes appearance based unknown object tracking with the distributed vision system in IoT space. First, we discuss how object color information is obtained and how the color appearance based model is constructed from this data. Then, we discuss the global color model based on the local color information. The process of learning within global model and the experimental results are also presented.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.781-784
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• 2009

IPTV, which is convergence of Communication and Broadcasting, has improved quickly recently. This service can provide high quality and various services to their customers, such as choosing channels freely, VOD and many kinds of Interactive service. As the technology of IPTV rapid development, more and more people worry about its disadvantages during the spread and apply, for instance, the illegal application, illegal copy, access authority abuse and the danger of the IPTV contents. This paper will provide the solution to solve these problems, through the Public Key Certificate of PKI(Public Key Infrastructure) and the Attribute Certificate of PMI(Privilege Management Infrastructure).

• The Journal of Asian Finance, Economics and Business
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• v.8 no.4
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• pp.517-527
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• 2021

While the two principles of lean manufacturing and time-driven activity-based costing (TDABC) have been established out of multiple incentives and do not follow the same particular targets, there is substantial commonality between them. In these conditions, the supply management of a multi-product system needs a rigorous production model to minimize costs. In this sense, this paper proposes an interactive model with the consideration of optimizing product-mix decisions using both lean development tools and TDABC. This paper proposes a qualitative approach using the case study of the Iraqi state company for battery production. The suggested model decreased manufacturing time and costs, along with some substantial reduction in idle production capacity by 26 percent in 2019, based on the findings of the case study. On the other hand, the proposed model gives two side advantages: an efficient division of costs on goods due to the use of time spent as a cost factor for products and cost savings due to the introduction of the lean manufacturing approach that reduces all additional costs and increases product-mix decisions. Furthermore, the analytical data gathered here suggests that the incorporation of lean management concepts and TDABC has a strong and important influence on product-mix decisions.

• International Journal of Computer Science & Network Security
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• v.21 no.5
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• pp.222-230
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• 2021

The article reviews the issue of formation of information culture of social work bachelors in the process of their professional training. The main internal / external factors that determine the need for the information culture formation of social workers-to-be have been identified. To determine the levels of information culture formed in bachelors of social work criteria and their indicators have been substantiated. The model of information culture formation in BSW has been developed and implemented in Ukrainian universities under the following pedagogic conditions: organized informational environment; interconnection between general and professionally-directed courses; curriculum includes course directed on IC formation. The model contained interconnected components: aim - to achieve higher level of information culture formed; specific principles; content, interactive methods and forms of organization of educational process, methods of control and correction; components of information culture. The implemented mastered learning procedure has contributed to the leveling up of information culture formed in social work bachelors.