• Journal of Internet Computing and Services
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• v.21 no.5
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• pp.49-56
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• 2020

Detecting shadows in images and restoring or removing them was a very challenging task in computer vision. Traditional researches used color information, edges, and thresholds to detect shadows, but there were errors such as not considering the penumbra area of shadow or even detecting a black area that is not a shadow. Deep learning has been successful in various fields of computer vision, and research on applying deep learning has started in the field of shadow detection and removal. However, it was very difficult and time-consuming to collect data for network learning, and there were many limited conditions for shooting. In particular, it was more difficult to obtain shadow data from buildings and satellite images, which hindered the progress of the research. In this paper, we propose a method for generating shadow data from buildings and satellites using Unity3D. In the virtual Unity space, 3D objects existing in the real world were placed, and shadows were generated using lights effects to shoot. Through this, it is possible to get all three types of images (shadow-free, shadow image, shadow mask) necessary for shadow detection and removal when training deep learning networks. The method proposed in this paper contributes to helping the progress of the research by providing big data in the field of building or satellite shadow detection and removal research, which is difficult for learning deep learning networks due to the absence of data. And this can be a suboptimal method. We believe that we have contributed in that we can apply virtual data to test deep learning networks before applying real data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.11A
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• pp.979-986
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• 2005

In optical networks, traffic demands often demonstrate periodic nature for which time-overlapping property can be utilized in routing and wavelength assignment (RWA). A RWA problem for scheduled lightpath demands (SLDs) has been solved by combinatorial optimal solution (COS) and graph coloring, or heuristic sequential RWA (sRWA). Such methods are very complex and incurs large computational overhead. In this paper, we propose an efficient RWA algorithm to utilize the time disjoint property as well as space disjoint property through fast grouping of SLDs. The computer simulation shows that our proposed algorithm indeed achieves up to $54\%$ faster computation with similar number of wavelengths than the existing heuristic sRWA algorithm.

• Journal of the Korea Society of Computer and Information
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• v.16 no.8
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• pp.189-196
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• 2011

To develop a creative design concept, amount of idea thinking between team members is important. In the process of planning to proposal brainstorming helps clarification of problems and allows a creative solution. Here, idea generation is to express thinking into words, and greater amount of idea is more valued than to choose one fine idea at first. This paper studies actual processes of brainstorming, and we utilize network services upgraded in Web and multimedia techniques to develop idea with arrangement. We compare the amount of idea generation by groups and topics with Brainwriting and Braindrawing of Webstorming, without limitation of space and time. Then, we propose a creative idea thinking by analyzing the characteristics of design team members in various aspects. This result will contribute in improving national potential value and design competitiveness by the help of design and IT, on product research and marketing.

• Journal of the Korea Society of Computer and Information
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• v.11 no.5 s.43
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• pp.175-181
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• 2006

AMobile-supported spatial database systems have been introduced with development of mobile computing technology, they offer an advantage that we can access the data wherever we are. However, the studies on database system in traditional distributed environments must be reconsidered again, because of characteristics of mobile database system such as mobility and instability of wireless network. A new transaction model should be required for considering the characteristics, since especially a mobile computing environment is location-dependent, compared with the location transparency in a distributed computing environment. In other aspect, normally mobile host may be moving not in all space, but in some limited path. That is, a host is moving along the roads or the geographical features adjacent to the roads. The transaction processing should be considered not on the spatial coordinate but on the geographical features. In this paper, the feature based transaction processing model is proposed to process location-dependent transaction efficiently.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.6
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• pp.21-31
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• 2015

The Internet users want to get real-time services for various multi-media applications. Network traffic rate has been rapidly increased, and data amounts that the Internet has to carry have been exponentially increased. A packet is the basic unit in transferring data at the Internet, and packet classification is one of the most challenging functionalities that routers should perform at wire-speed. Among various known packet classification algorithms, area-based quad-trie (AQT) algorithm is one of the efficient algorithms which can lookup five header fields simultaneously. As a representative space decomposition algorithm, the AQT requires a small amount of memory in storing classification rules, but it does not provide high-speed classification performance. In this paper, we propose a new packet classification algorithm by applying a binary search for the codewords of the AQT to overcome the issue of the AQT. Throughout simulation, it is shown that the proposed algorithm provides a better performance than the AQT in the number of rule comparisons with each input packet.

• Journal of the Korean Data and Information Science Society
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• v.22 no.4
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• pp.671-678
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• 2011

Data mining searches for interesting relationships among items in a given database. The methods of data mining are decision tree, association rules, clustering, neural network and so on. The decision tree approach is most useful in classification problems and to divide the search space into rectangular regions. Decision tree algorithms are used extensively for data mining in many domains such as retail target marketing, customer classification, etc. When create decision tree model, complicated model by standard of model creation and number of input variable is produced. Specially, there is difficulty in model creation and analysis in case of there are a lot of numbers of input variable. In this study, we study on decision tree using intervening variable. We apply to actuality data to suggest method that remove unnecessary input variable for created model and search the efficiency.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.3
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• pp.700-712
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• 2011

Due to recently advanced electrical devices, human can access computer network regardless of working location or time restriction. However, currently widely used mouse, joystick, and trackball input system are not easy to carry and they bound user hands exclusively within working space. Those make user inconvenient in Ubiquitous environments.. In this paper, we propose multiple dimension human motion detection system based on wireless sensor networks. It is a portable input device and provides easy installation process and unbinds user hands during input processing stages. Our implemented system is comprised of three components. One is input unit that senses user motions and transmits collected data to receiver. Second is receiver that conveys the received data to application, which runs on server computer. Third is application that performs command operations according to received data. Experiments shows that proposed system accurately detect the characteristics of user arm motions and fully support corresponding input requests.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.9
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• pp.1666-1673
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• 2017

Republic of Korea is divided into South Korea and North Korea, creating military conflicts and social conflicts. North Korea is conducting cyberattacks against South Korea and has hacked South Korea's defense network. In the world of cyberspace, the boundaries of the borders are becoming obscured, and cyberattacks and cyberterrorism for cyberwarfare operate with digital computing connected to points, time and space. Agenda and manual are needed for national cybersecurity. Also, it is necessary to study national cybersecurity laws and policies that can create and implement nationalcyber security policy. This paper investigates cyberterrorism situation in North and South Korean confrontation situation and damage to cyberwarfare in the world. We also study cybersecurity activities and cyberwarfare response agendas, manuals and new technologies at home and abroad. And propose national cybersecurity policy and propose policies so that '(tentative) The National Cybersecurity Law' is established. This study will be used as basic data of national cybersecurity law and policy.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.9C
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• pp.871-879
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• 2009

The performance variations of a spatio temporal smart antenna which is equipped at the basestation of CDMA cellular communication network due to the parametric change of multipath fading environment are studied in this paper. The smart antenna of interest employs space diversity based adaptive array structure in conjunction with rake receiver that has fingers the number of which is the same as that of multipath links. The beamforming is achieved via LMS(Least Mean Square) algorithm in which a reference signal is generated using decision directed formula. It has been shown by computer simulation that the performance of our smart antenna of interest depends significantly upon not only the degree of desired signal's DOA(Direction of Arrival)spread but the number of fingers of the rake receiver. The relative insensitivity of the smart antenna's performance on desired signal's delay spread has also been observed. Computer simulation has shown that the increase of the number of fingers brings in a nonlinear enhancement of the performance of our smart antenna. The renewal of weight vector in the beamforming procedure is taken place at post PN despread stage.

• Convergence Security Journal
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• v.8 no.4
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• pp.73-80
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• 2008

In this paper, we developed a WMS (Warehouse Management System) Simulator. There is no Simulator that supports optimized design for Warehouse, consider goods which storage in warehouse and using RFID and USN based on cable wireless network. Also, there is no tool for monitoring which decides delivery time with information about temperature, humidity and illumination, after goods are stocked into warehouse. In this paper, WMS Simulator Implements function of drawing a blueprint. The Simulator that can analyze moving information of Palette with RFID tags and the change about temperature, humidity and illumination is developed in this paper. Inventory accuracy, space equipment practical use, and decreasing of picking time, faulty storage and product loss by product processing ability elevation are expected by designing the way of operating of warehouse for most suitable use of system in physical distribution through these treatise.