• 대한수학회지
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• 제46권4호
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• pp.813-826
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• 2009

In this paper, we generalize the notions of preserving and strongly preserving maps to arbitrary set based topological categories. Further, we obtain characterizations of each of these concepts as well as interprete analogues and generalizations of theorems of Gerlits at al [20] in the categories of filter and local filter convergence spaces.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권11호
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• pp.2893-2912
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• 2013

The design of geometrically invariant watermarking is one of the most challenging work in digital image watermarking research area. To achieve the robustness to geometrical attacks, the inherent characteristic of an image is usually used. In this paper, a geometrically invariant image watermarking scheme using connected objects and gravity center is proposed. First, the gray-scale image is converted into the binary one, and the connected objects according to the connectedness of binary image are obtained, then the coordinates of these connected objects are mapped to the gray-scale image, and the gravity centers of those bigger objects are chosen as the feature points for watermark embedding. After that, the line between each gravity center and the center of the whole image is rotated an angle to form a sector, and finally the same version of watermark is embedded into these sectors. Because the image connectedness is topologically invariant to geometrical attacks such as scaling and rotation, and the gravity center of the connected object as feature points is very stable, the watermark synchronization is realized successfully under the geometrical distortion. The proposed scheme can extract the watermark information without using the original image or template. The simulation results show the proposed scheme has a good invisibility for watermarking application, and stronger robustness than previous feature-based watermarking schemes against geometrical attacks such as rotation, scaling and cropping, and can also resist common image processing operations including JPEG compression, adding noise, median filtering, and histogram equalization, etc.

• International Journal of Internet, Broadcasting and Communication
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• 제16권4호
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• pp.442-459
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• 2024

Currently, many industrial fields are pursuing research and development toward a hyper-connected society. However, as we become a hyper-connected society that perceives virtual reality as if it were reality, accurate classification of data to recognize objects, emotions and facial expressions must be accompanied. In other words, only when data meaning objects, emotions, and facial expressions are accurately classified will reliability of cognition and recognition be obtained not only in the physical world but also in a hyper-connected society. In addition, errors in perception and recognition of objects, emotions, and facial expressions can be reduced through big data analysis, and it will be protected from secondary incidents and damages. Therefore, in this study, we try to find out whether the classification of data is well done in the stage where AI with automatic cognition ability recognizes and recognizes objects, emotions, and facial expressions, and whether the data classified according to characteristics is a reliable classification result. In the experiment, when classifying data using a decision tree, we plan to conduct a study to find out whether the classification criteria of the data affect the classification criteria according to the degree of correlation between variables.

• 융합보안논문지
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• 제15권5호
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• pp.53-59
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• 2015

정보통신기술의 급진적인 발달로 인해 우리 주위의 모든 사물들이 인터넷으로 연결되어 서로 정보를 주고받으며 각각의 사물들이 제공하던 것 이상의 새로운 가치를 제공하는 사물인터넷(IoT) 시대를 맞이하고 있다. 사물인터넷 환경에서는 기존과 다르게 인터넷에 연결되는 사물의 수가 급격히 증가하기 때문에 그만큼 보안 위협도 많아지게 될 것이다. 또한 셀 수 없이 많은 사물들을 어떻게 보호하고 관리할 것인지에 대해 새롭게 생각해 볼 필요가 있다. 본 논문에서는 기존의 보안 관제의 역할과 절차에 대해 살펴본다. 아울러 IoT 환경에서의 보안 관제의 방향에 대해 소개한다.

• 한국컴퓨터정보학회논문지
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• 제16권3호
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• pp.189-201
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• 2011

본 논문에서는 대표적인 학습 객체 메타데이터 형식들을 통합하여 상호운용성을 제공하면서 대학 강좌를 위한 학습 객체의 메타데이터를 기술할 때 사용되는 개념과 개념들 간의 의미적 관계를 정의하는 온톨로지를 설계한다. 그리고 서로 다른 형식을 이용해 학습 객체의 메타데이터를 기술하는 여러 지역 저장소에 대해 효율적인 학습 객체 검색이 가능하도록 계층적으로 구조화된 이러닝 시스템을 구성하고 추론에 기반한 질의 처리 기법을 제안한다. 본 논문에서 제안한 계층적으로 구조화된 이러닝 시스템에서 학습 객체 온톨로지를 이용한 질의 처리 기법을 적용하면 사용자 질의에 직접적으로 관련이 있는 학습 객체와 함께 의미적 연관성이 추론된 학습 객체도 검색되어 보다 정확하고 만족도 높은 검색 서비스를 제공할 수 있다.

• 한국농공학회지
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• 제44권1호
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• pp.57-68
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• 2002

In the irrigation facilities, the irrigation system is connected systematically, and thus, it agrees to the object-oriented concept. Since it is necessary to go through comparative evaluations and to devise several alternatives plans in designing the irrigation system, it will be very efficient to use the objects that contain the design data. In this study, the object-oriented methodology has been proposed to define the objects, which will be used in the design system of irrigation facility. Furthermore, as for the essential elements of the objects, concept of element objects is formulated. By employing this concept, appropriate element objects have been derided for the irrigation facility. Necessary data model for realization of the objects is examined and selected. And then, required elements for applying the selected data model to the irrigation facility will be proposed

• 제어로봇시스템학회논문지
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• 제15권11호
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• pp.1115-1121
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• 2009

For HRI (Human-Robot Interaction) in daily life, robots need to recognize non-rigid objects such as clothes and blankets. However, the recognition of non-rigid objects is challenging because of the variation of the shapes according to the places and laying manners. In this paper, the cognition of non-rigid object based on a cognitive system is presented. The characteristics of non-rigid objects are analysed in the view of HRI and referred to design a framework for the cognition of them. We adopt a linguistic cognitive system for describing all of the events happened to robots. When an event related to the non-rigid objects is occurred, the cognitive system describes the event into a sentential form and stores it at a sentential memory, and depicts the objects with a spatial model for being used as references. The cognitive system parses each sentence syntactically and semantically, in which the nouns meaning objects are connected to their models. For answering the questions of humans, sentences are retrieved by searching temporal information in the sentential memory and by spatial reasoning in a schematic imagery. Experiments show the feasibility of the cognitive system for cognizing non-rigid objects in HRI.

• 한국CDE학회논문집
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• 제2권4호
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• pp.267-275
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• 1997

A ship-block cutting module is being developed as part of a computational system for a ship design. The module supports product-information to other modules in design process and displays ship-blocks in cutting-operation. Welding-information is essential to process-planning and scheduling. In the module, ship-blocks are modeled by Plate-Objects and then divided into several cutting pieces. The module automatically creates Welding-Objects containing welding-information in the process. Since the module is connected to WWW(World Wide Web), users in various platforms can access the models simultaneously In addition, users can check manufacturing constraints by inspecting a virtual model.

• 디지털산업정보학회논문지
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• 제13권1호
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• pp.49-57
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• 2017

IoT can be connected through a single network not only objects which can be connected to existing internet but also objects which has communication capability. This IoT environment will be a huge change to the existing communication paradigm. However, the big security problem must be solved in order to develop further IoT. Security mechanisms reflecting these characteristics should be applied because devices participating in the IoT have low processing ability and low power. In addition, devices which perform abnormal behaviors between objects should be also detected. Therefore, in this paper, we proposed D-IDS technique for efficient detection of malicious attack nodes between devices participating in the IoT. The proposed technique performs the central detection and distribution detection to improve the performance of attack detection. The central detection monitors the entire network traffic at the boundary router using SVM technique and detects abnormal behavior. And the distribution detection combines RSSI value and reliability of node and detects Sybil attack node. The performance of attack detection against malicious nodes is improved through the attack detection process. The superiority of the proposed technique can be verified by experiments.

• 한국산학기술학회논문지
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• 제8권6호
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• pp.1480-1490
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• 2007

본 논문에서는 WINDOWS CE .NET 기반의 PDA를 이용한 원격제어시스템을 구현하였다. 서버 시스템의 운영체제는 WINDOWS CE .NET을 사용하여 사용자에게 쉬운 사용 환경을 제공하며, 운영체제 이미지에 개발한 디바이스 드라이버를 추가하여 하드웨어 장치를 제어한다. 임베디드 서버는 PC 클라이언트와 PC 클라이언트, PC 클라이언트와 PDA 클라이언트, PDA 클라이언트와 PDA 클라이언트간의 메시지 통신을 지원한다. 본 논문은 원격제어시스템을 구현하는데 있어서 에뮬레이터를 사용하지 않고 실제 PDA와 임베디드 보드로 시스템을 구현하였다. 제안된 시스템은 임베디드 보드를 서버로 사용하고 PDA를 클라이언트로 사용하여 무선 인터넷이 제공되는 환경이라면 어느 곳에서나 원격으로 대상물을 제어할 수 있다.