• Journal of Ecology and Environment
• /
• v.35 no.2
• /
• pp.141-147
• /
• 2012

The rapid urbanization in developing countries is accelerating both the depletion and fragmentation of urban green space, despite the known positive effects of green spaces on the environmental conditions in cities and the quality of life of residents. Consequently, there is a need for practical tools that can support the development of networks of urban green spaces. This article presents a study that used a GIS-based least cost path (LCP) analysis to identify the best alternative for developing an urban green space network in the coastal city of Jakarta, Indonesia, which was based on the evaluation of topography and land use characteristics. Pair-wise analysis was used to reduce the sensitivity in the LCP model. The results showed that the coastal wetlands in the northern part of Jakarta and the agricultural fields in the suburban areas of Jakarta play an important role in connecting the green space network. On the other hand, some green spaces in the central part of Jakarta could not be connected by the LCP model. The method used in this study can serve as a tool to support the identification of networks of potential urban green spaces. It can also provide useful information for sustainable urban landscape planning and management in urban ecosystems. However, the inclusion of socio-economic criteria would further improve the model.

• Journal of the Institute of Convergence Signal Processing
• /
• v.1 no.1
• /
• pp.32-41
• /
• 2000

In this paper, we proposed a method which predict the verb by using the neural network in order to enhance communication rate in augmentative communication system for Korean language disorders. Each word is represented by an information vector according to syntax and semantics, and is positioned at the state space by being partitioned into various regions different from a dictionary-like lexicon. Conceptual similarity is realized through position in state space. When a symbol was pressed, we could find the word for the symbol at the position in the state space. In order to prevent verb prediction's redundancy according to input units, we predicted the verb after separating class using the neural network. In the result we can enhance $20\% communication rate in the restricted space

• Journal of Digital Convergence
• /
• v.9 no.3
• /
• pp.11-19
• /
• 2011

The spread of computer and network gets various social and economic activities done quickly and efficiently. As a result, it makes a crime using network easy and increases the vulnerability of a social system. As there is a crime as a social being, we need to give careful consideration to the crime occurring in virtual space. Accordingly, the purpose of this paper is to investigate the regulatory need of the Criminal Procedure concerning the network security issues as the new legal and regulatory space that begins to be realized from the late of 20th century because of the extent of social threat. Above all, we addresses whether the amendment of existing legal regulations is necessary, based on the special characteristics of the virtual space.

• The KIPS Transactions:PartC
• /
• v.16C no.5
• /
• pp.597-604
• /
• 2009

An SMTP(Simple Mail Transfer Protocol) server was designed for delivering and storing user's email across a network. An SMTP server can be distributed as multiple servers for large service, huge users or massive emails. An SMTP server can be constructed by multiple servers with separating file system as email storing space, and each SMTP server can usually share each file system by using the NFS(Network File system). However the NFS is originally designed for sharing each file system across a network, and contains all attributes and features of regular file system. Using this NFS for email storing space of SMTP servers, it makes overhead due to unnecessary work of regular file system. In this paper, we propose a method to do directly operation with socket for reducing work overhead caused by the NFS. For doing directly operation with socket, this paper defines information based storing space structure and a protocol for storing emails. We performed experiments using Mailstone made by Netscape. The experimental results show the performance improvement of the proposed method compared to the existing method.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.4B
• /
• pp.397-402
• /
• 2004

In this paper, we have designed and simulated a new file transmission method. This method restricts memory copy and context switching happened in traditional file transmission. This method shows an improved performance than traditional method in network environment. When the UNIX/LINUX system that uses the existing file transfer technique transmits a packet to the remote system, a memory copy between the user and kernel space occurs over twice at least. Memory copy between the user and kernel space increase a file transmission time and the number of context switching. As a result, the existing file transfer technique has a problem of deteriorating the performance of file transmission. We propose a new algorithm for solving these problems. It doesn't perform memory copy between the user and kernel space. Hence, the number of memory copy and context switching is limited to the minimum. We have modified the network related source code of LINUX kernel 2.6.0 to analyzing the performance of proposed algorithm and implement new network system calls.

• Journal of Korean Library and Information Science Society
• /
• v.37 no.1
• /
• pp.29-53
• /
• 2006

The continuous accumulation of printed materials prompts rethinking of library space problem and systematic preservation of library collection. To respond to this challenge, this study provides actionable models for the National Repository library and the Cooperative Repository Network. The development of the models is based on the analysis of overseas best practices as well as data derived from current state of public library cooperative network administered by the National Library of Korea. This study also offers a range of strategies for the operation of repository library system.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.5 no.2
• /
• pp.287-312
• /
• 2011

Internet chat programs and instant messaging services are becoming increasingly popular among Internet users. One of the crucial issues with Internet chat is how to manage the corresponding pairs of questions and answers in a sequence of conversations. Although many novel methodologies have been introduced to cope with this problem, most are poor in managing interruptions, organizing turn-taking, and conveying comprehension. The Internet environment is recently evolving into a 3D environment, but the problems with managing chat dialogues with the standard 2D text-based chat have remained. Therefore, we propose a more realistic communication model for chat agents in 3D virtual space in this paper. First, we propose a new method to measure the capacity of communication between chat agents and a novel visualization method to depict the hierarchical structure of chat dialogues. In addition, we are concerned with communication networks for virtual people (avatars) living in virtual worlds. In this paper we consider a microscopic aspect of a social network in a relatively short period of time. Our experiments show that our model is highly effective in a virtual chat environment, and the communication network based on our model greatly facilitates investigation of a very large and complicated communication network.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.45 no.9
• /
• pp.794-806
• /
• 2017

It is essential to protect the national space assets and space environment safely as a space development country from the continuously increasing space debris. And Active Debris Removal(ADR) is the most active way to solve this problem. In this paper, we studied the Artificial Neural Network(ANN) for a stable recognition model of vision-based space debris tracking system. We obtained the simulated image of the space environment by the KARICAT which is the ground-based space debris clearing satellite testbed developed by the Korea Aerospace Research Institute, and created the vector which encodes structure and color-based features of each object after image segmentation by depth discontinuity. The Feature Vector consists of 3D surface area, principle vector of point cloud, 2D shape and color information. We designed artificial neural network model based on the separated Feature Vector. In order to improve the performance of the artificial neural network, the model is divided according to the categories of the input feature vectors, and the ensemble technique is applied to each model. As a result, we confirmed the performance improvement of recognition model by ensemble technique.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.6 no.3
• /
• pp.487-492
• /
• 2002

In this paper, we proposed a control method of an unknown nonlinear system using a dynamical neural network. The proposed method is composed of neural network of state space model type, performs for a unknown nonlinear system, identification with using the dynamical neural network, and then a nonlinear adaptive controller is designed with these identified informations. In order to verify the effectiveness of the proposed method, we simulated one-link manipulator. The simulation results showed the effectiveness of using the dynamical neural network in the adaptive control of one-link manipulator.

• Journal of Communications and Networks
• /
• v.17 no.2
• /
• pp.100-109
• /
• 2015

Mobile phone carriers face challenges from three synergistic dimensions: Wireless, social, and mobile. Despite significant advances that have been made about social networks and human mobility, respectively, our knowledge about the interplay between two layers remains largely limited, partly due to the difficulty in obtaining large-scale datasets that could offer at the same time social and mobile information across a substantial population over an extended period of time. In this paper, we take advantage of a massive, longitudinal mobile phone dataset that consists of human mobility and social network information simultaneously, allowing us to explore the impact of human mobility patterns on the underlying social network. We find that human mobility plays an important role in shaping both local and global structural properties of social network. In contrast to the lack of scale in social networks and human movements, we discovered a characteristic distance in physical space between 10 and 20 km that impacts both local clustering and modular structure in social network. We also find a surprising distinction in trajectory overlap that segments social ties into two categories. Our results are of fundamental relevance to quantitative studies of human behavior, and could serve as the basis of anchoring potential theoretical models of human behavior and building and developing new applications using social and mobile technologies.