• 대한공간정보학회지
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• 제8권1호
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• pp.43-49
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• 2000

본 논문에서는 지리 정보 시스템을 인터넷에서 연동함으로써 사용자에게 다양한 지리적 정보를 좀 더 이해하기 쉬운 형태로 웹을 통하여 제공해 주고, 또한 공간 데이타에 대한 효율적인 검색을 위한 수단을 제공하기 위해 인터넷 지리 정보시스템인 IGIS(Internet Geographic Information System)을 설계 및 구현한다. IGIS는 네트워크 상의 전송 시간을 줄이면서 모든 지리 특성을 표현할 수 있도록 웹과의 연동을 위해 CGI를 이용한 벡터 지도를 전송하는 방식을 채택한다. IGIS 사용자는 인터넷을 통하여 대화식으로 지리 정보를 검색하고, 출력된 주변지도를 확대i축소 또는 이동하며 원하는 상세한 결과를 얻을 수 있다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 추계종합학술대회
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• pp.87-90
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• 2007

오늘날의 모든 통신은 IP(Internet Protocol)을 기반으로 통합 및 연계되어 발전하고 있으며, IP를 통하여 사용자에게 '언제, 어디서나, 끊김 없는 서비스'를 제공할 수 있게 하기 위하여 많은 연구들이 이루어지고 있다. IETF에서는 IPv6를 사용하여 이동성을 제공하는 MIPv6를 제안하였으나 이동노드가 네트워크를 이동할 때 마다 HA(Home Agent)와 CN(Correspondent Node)에게 BU(Binding Update) 메시지를 보냄으로써 많은 Overhead와 전송지연이 발생한다. 이에 현재 MAP(Mobility Anchor Pointer)를 사용하여 CN에게 아무런 영향을 끼치지 않으면서 이동노드가 매번 핸드오버마다 발생하는 HA와 CN에게의 BU를 통한 지연과 Overhead를 줄일 수 있는 HMIPv6를 개발하였다. HMIPv6는 이동노드가 MAP 내부에서 핸드오버시, 같은 RCoA(Regional Care of Address)를 가지고 있음으로 BU를 HA와 CN에게 전달하지 않고 MAP가 직접 처리하여 MAP 내부에서의 이동에 관하여 전송지연과 Overhead 문제를 해결하였지만, MAP와 MAP간의 Macro 핸드오버를 효율적으로 수행하지 못한다. 본 논문은 HMIPv6환경에서 MAP간의 Macro 핸드오버시, 이동노드의 위치정보를 이용한 핸드오버를 사용함으로써 효율을 높일 수 있는 방안을 제시한다.

• 한국공간정보시스템학회 논문지
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• 제11권4호
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• pp.56-64
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• 2009

최근 웹 2.0 기술의 활용이 증가하면서 RIA (Rich Internet Application) 기술에 대한 중요성도 증가하고 있다. RIA는 인터넷 서비스가 가능한 데스크탑 및 모바일 기기에서 다양한 정보를 제공할 수 있는 장점이 있다. 본 논문에서는 RIA 기술 중에서 플래시를 사용하여 공간 데이터를 모바일 환경에서 서비스하는 방법을 제안한다. 공간 데이터 서버는 사용자가 요구한 공간 데이터를 RIA 기술 중 하나인 플래시 기반의 웹 어플리케이션에 포함하여 제공하는 방법을 사용한다. 본 논문에서 제안하는 방법은 클라이언트에서 렌더링 및 사용자 인터페이스 처리를 담당하는 특징을 가진다. 또한, 서버로부터 웹 어플리케이션을 다운로드 받으면 추가로 공간 데이터 서버에 접속 없이도 클라이언트 자체에서 공간 데이터의 패닝, 확대/축소 등의 처리가 가능하므로 무선 언터넷 환경을 사용하는 모바일 장치에서 효과적이다. 그리고, 풀랫폼에 독립적으로 동작되어 모바일 환경에서도 데스크탑 환경과 동일하게 활용할 수 있는 장점이 있다. 본 논문에서 제안하는 공간 데이터 서버의 성능을 평가하기 위하여 WMS(Web Map Server)와 비교 분석한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권12호
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• pp.5963-5980
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• 2017

Image scrambling is an important technology in information hiding, where the Arnold transformation is widely used. Several researchers have proposed the application of $H{\acute{e}}non$ map in square image scrambling, and certain improved technologies require scrambling many times to achieve a good effect without resisting chosen-plaintext attack although it can be directly applied to non-square images. This paper presents a non-square image scrambling algorithm, which can resist chosen-plaintext attack based on a chaotic two-dimensional Sine Logistic modulation map and $H{\acute{e}}non$ map (2D-SLHM). Theoretical analysis and experimental results show that the proposed algorithm has advantages in terms of key space, efficiency, scrambling degree, ability of anti-attack and robustness to noise interference.

• International Journal of Internet, Broadcasting and Communication
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• 제9권1호
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• pp.9-17
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• 2017

This paper describes a process of developing commercial real time image recognition system with company. In this paper we will make a system that is combining an empirical kernel map method and conjugate least squares support vector machine in order to represent images in a low-dimensional subspace for real time image recognition. In the traditional approach calculating these eigenspace models, known as traditional PCA method, model must capture all the images needed to build the internal representation. Updating of the existing eigenspace is only possible when all the images must be kept in order to update the eigenspace, requiring a lot of storage capability. Proposed method allows discarding the acquired images immediately after the update. By experimental results we can show that empirical kernel map has similar accuracy compare to traditional batch way eigenspace method and more efficient in memory requirement than traditional one. This experimental result shows that proposed model is suitable for commercial real time image recognition system.

• 수산해양교육연구
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• 제19권1호
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• pp.29-38
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• 2007

Recent Internet Service Environment has been moved to provide geographic information based on location as well as existent various information. In this paper, we develop an integrated software connecting GIS information to Internet. In the other hand, in GIS S/W, it is important that rapid output of Digital Map and effective trnasmission of specified Digital Map about moving area. To achieve the purpose, we propose a reduced digital format to diminish original digital maps. Also, we develop a GIS-based software engine with functions connecting location information to URL as well as map viewer and map handling. Futhermore, our developed GIS S/W is based Module in LBS application using GPS sensor.

• 사물인터넷융복합논문지
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• 제1권1호
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• pp.11-19
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• 2015

The mobile and ubiquitous environment is experiencing a rapid development of information and communications technology as it provides an ever increasing flow of information. Particularly, GIS is now widely applied in daily life due to its high accuracy and functionality. GIS information is utilized through the tiling method, which divides and manages large-scale map information. The tiling method manages map information and additional information to allow overlay, so as to facilitate quick access to tiled data. Unlike past studies, this paper proposes a new architecture and algorithms for tile searching and indexing management to optimize map information and additional information for GIS mobile applications. Since this involves the processing of large-scale information and continuous information changes, information is clustered for rapid processing. In addition, data size is minimized to overcome the constrained performance associated with mobile devices. Our system has been implemented in actual services, leading to a twofold increase in performance in terms of processing speed and mobile bandwidth.

• 인터넷정보학회논문지
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• 제20권1호
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• pp.125-133
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• 2019

Company A should maintain myriad conversion tools for the purpose of making a geometric compilation of navigation maps. Company A is already using complex compilation tools, which are tailored to geographical areas and various GPS models. However, due to frequent requirement and personnel changes, there is an endless challenge for perfect tool configuration and multiple map consolidation. To solve this problem, Company A launched a process automation project using Graphviz, which is an open source workflow graph visualization software. Before implementation, they had to document their current map compilation processes and then match it with the applicable conversion tool. For effective representation of process controls, a new graphical process notation is designed, i.e. Y Block diagram. The authors will compare Y Block diagram with other process notations and explain why Y Block diagram is more useful for tool based business processes such as digital map generation processes.

• International Journal of Internet, Broadcasting and Communication
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• 제13권4호
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• pp.39-47
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• 2021

Lempel-Ziv coding is one of the most famous source coding schemes. The output of this source coding is usually a non-uniform code, which requires additional source coding, such as arithmetic coding, to reduce a redundancy. However, this additional source code increases complexity and decoding latency. Thus, this paper proposes the optimal maximum a-posteriori (MAP) receiver for non-uniform source non-orthogonal multiple access (NOMA) with symmetric superposition coding (SSC). First, we derive an analytical expression of the bit-error rate (BER) for non-uniform source NOMA with SSC. Then, Monte Carlo simulations demonstrate that the BER of the optimal MAP receiver for the non-uniform source improves slightly, compared to that of the conventional receiver for the uniform source. Moreover, we also show that the BER of an approximate analytical expression is in a good agreement with the BER of Monte Carlo simulation. As a result, the proposed optimal MAP receiver for non-uniform source could be a promising scheme for NOMA with SSC, to reduce complexity and decoding latency due to additional source coding.

• International Journal of Internet, Broadcasting and Communication
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• 제13권4호
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• pp.48-54
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• 2021

In most existing researches on non-orthogonal multiple access (NOMA) with symmetric superposition coding (SSC), uniform sources have been usually considered. For the first part in this two-part paper, for the strongest channel gain user, we showed that the bit-error rate (BER) for the optimal maximum a-posteriori (MAP) receiver for the non-uniform source improves slightly, compared to that of the conventional receiver for the uniform sources. We demonstrate that in communication scenarios of the non-uniform source NOMA schemes, for the weakest channel gain user, the BER performance of the optimal MAP receiver for a non-uniform source improves greatly, compared to that of the conventional receiver for uniform sources. We first derive an analytical expression of the BER for non-uniform source NOMA with SSC. Then, simulations demonstrate that the BER of the optimal MAP receiver for the non-uniform source improves, compared with that of the conventional maximum likelihood (ML) receiver for the uniform sources. In result, the proposed optimal MAP receiver for the non-uniform source could be a promising scheme for SSC NOMA, with improved BER performances.