• KIPS Transactions on Computer and Communication Systems
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• v.1 no.3
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• pp.219-228
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• 2012

As the wireless Internet become more widely accessible, variety of Internet services can be used without limitation of location. However, existing mobility management methods such as MIP and PMIP of IETF requires the load of heavy protocol stack on the mobile nodes or the addition of components such as LMA and MAG. In this paper, we proposed the location management technique in the PMIPv6 and Fast Handover technique. according to the moving pattern of the node, the location management technique proposed in order to adjust the paging area dynamically. The Fast Handover technique applied MIH technology and it reduced the handover signal processing time between heterogeneous network. The location management cost in the environment which the node moves in order to evaluate this and handover delay time was calculate. The proposal technique was efficiently more evaluated than PMIPv6 with the smallest 29% and maximum 83%.

• The Journal of the Korea Contents Association
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• v.3 no.2
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• pp.57-64
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• 2003

A Web Service is an URL addressable set of functionality that is exposed over a network to serve as a building Hock for creating distributed applications. SOAP is a protocol that Web Service consumers often use, when they request and response to a Web Service, and it is a lightweight, XML-based protocol over HTTP for exchange to information in decentralized, distributed environments. A Web Service is very useful forimplementing common functions in especially a large size business area, because it is invoked by a protocol like HTTP or SOAP that we easily use, and by an XML-based data format In this paper, we implement Web Services that process dip data by computers in enterprise accounts in order to enhance the transparency and productivity of enterprises. we analyse the structure of slip data, design dip database, implement stored procedures for manipulating data of slip database, and make thorn controlled by Web Services. The result of this paper will contribute to the standardization and activation of accounting process systems for e-business area.

• The Journal of Korean Institute of Information Technology
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• v.17 no.12
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• pp.125-134
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• 2019

As the limitations of the passive recognition domain, which is not guaranteed transparency of the operation process, AI technology has a vulnerability that depends on the data. Human error is inherent because raw data for artificial intelligence learning must be processed and inspected manually to secure data quality for the advancement of AI learning. In this study, we examine the necessity of learning data management before machine learning by analyzing inaccurate cases of AI learning data and cyber security attack method through the approach from cyber security perspective. In order to verify the learning data integrity, this paper presents the direction of data-preserving artificial intelligence system, a blockchain-based learning data environment model. The proposed method is expected to prevent the threats such as cyber attack and data corruption in providing and using data in the open network for data processing and raw data collection.

• Journal of KIISE
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• v.45 no.1
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• pp.53-60
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• 2018

This study describes a spatial web object retrieval system using Spark, an in - memory based distributed processing system. Development of social networks has created massive amounts of spatial web objects, and retrieval and analysis of data is difficult by using exist spatial web object retrieval systems. Recently, development of distributed processing systems supports the ability to analyze and retrieve large amounts of data quickly. Therefore, a method is promoted to search a large-capacity spatial web object by using the distributed processing system. Data is processed in block units, and one of these blocks is converted to RDD and processed in Spark. Regarding the discussed method, we propose a system in which each RDD consists of spatial web object index for the included data, dividing the entire spatial region into non-overlapping spatial regions, and allocating one divided region to one RDD. We propose a system that can efficiently use the distributed processing system by dividing space and increasing efficiency of searching the divided space. Additionally by comparing QP-tree with R-tree, we confirm that the proposed system is better for searching the spatial web objects; QP-tree builds index with both spatial and words information while R-tree build index only with spatial information.

• Journal of Convergence Society for SMB
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• v.6 no.4
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• pp.65-70
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• 2016

Smart city is an urban development vision to integrate multiple information and communication technology(ICT) and Internet of Things(IoT). The goal of building a smart city is to improve the quality of life by using urban informatics and technology to improve the efficiency of services and meet residents' needs. Many devices in today have been used on various industrial regions. These devices use Internet to transfer their informations. We call these situations as the IoT(Internet of Things). We studied various application examples of IoT in smart city industrial region. In this paper, we described two actual cases such as smart park system and smart bin.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2008.11a
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• pp.81-84
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• 2008

최근 센서네트워크와 같은 에너지 제한 환경을 위한 경량화 부호화 기술의 필요성이 대두됨에 따라 분산 소스 부호화 기술(Distributed Source Coding)의 응용기술로 비디오 부호화 복잡도의 대부분을 차지하는 움직임 예측/보상과정을 부호화기가 아닌 복호화기에서 수행하는 분산 비디오 부호화 기술(Distributed Video Coding)에 대한 연구가 활발히 이루어져 왔다. 이에 가장 대표적인 기술인 Wyner-Ziv 코딩 기술은 채널 코드를 이용하여 원본 프레임과 이에 대한 복호화기의 예측영상인 보조정보 사이의 잡음을 제거하여 영상을 복원한다. 일반적으로 보조정보는 원본영상에 유사한 키 프레임간의 프레임 보간을 통하여 생성되며 채널 코드는 Shannon limit에 근접한 성능을 보이는 Turbo 코드나 LDPC 코드가 사용된다. 이와 같은 채널 코드의 복호화는 채널 잡음 모델에 기반하여 수행되어지며 Wyner-Ziv 코딩 기술에서는 이 채널 잡음 모델을 '상관 잡음 모델' (Correlation Noise Modeling)이라 하고 일반적으로 Laplacian이나 Gaussian으로 모델화 한다. 하지만 복호화기에는 원본 영상에 대한 정보가 없기 때문에 정확한 상관 잡음 모델을 알 수 없으며 잡음 모델에 대한 예측의 부정확성은 잡음 제거를 위한 패리티 비트의 증가를 야기해 부호화 기술의 압축 성능 저하를 가져온다. 이에 본 논문은 원본 프레임과 보조정보 사이의 잡음을 정확하게 예측하여 잡음을 정정할 수 있는 향상된 상관 잡음 모델을 제안한다. 제안 방법은 잘못된 잡음 예측에 의해 Laplacian 계수가 너무 커지는 것을 방지하면서 영상내의 잡음의 유무에 별다른 영향을 받지 않는 새로운 문턱값을 사용한다. 다양한 영상에 대한 제안 방법의 실험 결과는 평균적으로 약 0.35dB에 해당하는 율-왜곡 성능 향상을 보여주었다.

• Convergence Security Journal
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• v.8 no.4
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• pp.105-113
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• 2008

Mobile computing environment is known to be quite difficult to provide user with a stable Quality of Service (QoS) due to vehicle mobility nature. In order to protect the inherent characteristics of wireless network such as low bandwidth and high transmission delay along with the vehicle's mobility, many works are conducted to apply caching and prefetching methods. This paper presents a novel prefetching technique which is based on owner's profile. It is the scheme with the vehicle velocity, the visit frequency and resident time of specific region for vehicle owner's past given period, and the user profile which has owner's personal inclination about a certain place. The proposed scheme shown relatively superior performance in terms of the utilization ratio of prefetched information and the failure ratio of information retrieval than the previous methods.

• Journal of Digital Policy
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• v.2 no.3
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• pp.1-7
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• 2023

In this paper, I proposes a method for performing single image super resolution by separating texture-spatial domains and then classifying features based on detailed information. In CNN (Convolutional Neural Network) based super resolution, the complex procedures and generation of redundant feature information in feature estimation process for enhancing details can lead to quality degradation in super resolution. The proposed method reduced procedural complexity and minimizes generation of redundant feature information by splitting input image into two channels: texture and spatial. In texture channel, a feature refinement process with step-wise skip connections is applied for detail restoration, while in spatial channel, a method is introduced to preserve the structural features of the image. Experimental results using proposed method demonstrate improved performance in terms of PSNR and SSIM evaluations compared to existing super resolution methods, confirmed the enhancement in quality.

• Convergence Security Journal
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• v.24 no.1
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• pp.21-26
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• 2024

The security model in the previous network environment has a vulnerability in which resource access control for trusted users is not properly achieved using the Perimeter model based on trust. The Zero Trust is an absolute principle to assume that the users and devices accessing internal data have nothing to trust. Applying the Zero Trust principle is very successful in reducing the attack surface of an organization, and by using the Zero Trust, it is possible to minimize damage when an attack occurs by limiting the intrusion to one small area through segmentation. ZTNA is a major technology that enables organizations to implement Zero Trust security, and similar to Software Defined Boundary (SDP), ZTNA hides most of its infrastructure and services, establishing one-to-one encrypted connections between devices and the resources they need. In this study, we review the functions and requirements that become the principles of the ZTNA architecture, and also study the security requirements and additional considerations according to the construction and operation of the ZTNA solution.

• Journal of the Society of Disaster Information
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• v.8 no.1
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• pp.1-9
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• 2012

Informatization of society through the computer and the Internet, because large amounts of information production and exchange and new way of communicating is born. Passive way past the one-sided information flows actively interact to evolve in a manner of information producers and information consumers distinction and personal relationships that enhance the online Social Networking Service (SNS) has developed into the social structure of. Thus, the spread of information work closely with the social network structure spark social conflict may act as a factor, and systems and the environment, personal and cultural adaptation of speed to keep up with the rapid development of science and technology as the inability conflict and confusion should lead to even. This paper the characteristics of the information society, with a look at the evolution of social risk factors as the wavelength of information about this look at the role of private security sought to evaluate. Information Society in time and space by shrinking the area of human life that has brought the convenience and simplicity, whereas the non-performance due to the nature of anonymous raises many social side-effects are. This made the preparation of national regulatory measures, but for the protection of personal protection devices in the private sector has not yet been discussed. Way of life and property of the purchaser to protect an individual's private security will have to charge it.