• Journal of the Korea Society of Computer and Information
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• v.19 no.2
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• pp.125-132
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• 2014

In this paper, we present marker-less fingertip and brush tracking system with inexpensive web camera. Parallel computation using CUDA is applied to the tracking system. This tracking system can run on inexpensive environment such as a laptop or a desktop and support for real-time application. We also present realistic water-based sign pen drawing model and implementation. The realistic drawing application with our inexpensive real-time fingertip and brush tracking system shows us the art class of the future. The realistic drawing application, along with our inexpensive real-time fingertip and brush tracking system, would be utilized in test-bed for the future high-technology education environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.2B
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• pp.279-288
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• 2004

Rapidly emerging P2P(Peer to Peer) applications generate very bursty traffic, which gives a lot of burden to network, and the amount of such traffic is increasing rapidly. Thus it is becoming more important to understand the characteristics of such traffic and reflect it when we design and analyze the network. To do that we measured the traffic in a campus network and present flow statistics and traffic models of the measured traffic, and compare them with those of the web traffic. The results indicate that P2P traffic is much burstier than web traffic and as a result it negatively affects network performance. We modeled P2P traffic using self-similar traffic model to predict packet delay and loss occurred in network which are very important to evaluate network performance. We also predict queue length distribution and loss probability in SSQ(Single Sewer Queue). To assess accuracy of traffic model, we compare the SSQ statistics of traffic models with that of the traffic trace. The results show that self-similar traffic models we use can predict P2P traffic behavior in network precisely. It is expected that the traffic models we derived can be used when we design network capacity and predict network performance and QoS of the P2P applications.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.2
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• pp.53-59
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• 2010

Android that was made by Google and Open Handset Alliance is the open source software toolkit for mobile phone. In a few years, Android will be used by millions of Android mobile phones and other mobile devices, and become the main platform of application developers. In this paper, we develop an application contents Booky based on Google Android flatform by using Webview merits and Google search engine. The features of the developed content are as follows. First, a mobile-based Web browser which has an advanced screen resolution and can support more faster viewer than normal web browser as it reduces the amount of data transmission. Second, efficient E-book search and reading functionality. In the performance evaluation, we show the results of simulation using AVD(Android Virture Device).

• Convergence Security Journal
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• v.24 no.1
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• pp.35-42
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• 2024

Multi-tenancy architecture plays a crucial role in cloud-based services and applications, and data isolation within such environments has emerged as a significant security challenge. This paper investigates various data isolation methods including schema-based isolation, logical isolation, and physical isolation, and compares their respective advantages and disadvantages. It evaluates the practical application and effectiveness of these data isolation methods, proposing security considerations and selection criteria for data isolation in the development of multi-tenant websites. This paper offers important guidance for developers, architects, and system administrators aiming to enhance data security in multi-tenancy environments. It suggests a foundational framework for the design and implementation of efficient and secure multi-tenant websites. Additionally, it provides insights into how the choice of data isolation methods impacts system performance, scalability, maintenance ease, and overall security, exploring ways to improve the security and stability of multi-tenant systems.

• Journal of the Korean Data and Information Science Society
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• v.26 no.5
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• pp.1035-1045
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• 2015

Recent studies in Big Data Analysis are showing promising results, utilizing the main memory for rapid data processing. In-memory computing technology can be highly advantageous when used with high-performing servers having tens of gigabytes of RAM with multi-core processors. The constraint in network in these infrastructure can be lessen by combining in-memory technology with distributed parallel processing. This paper discusses the research in the aforementioned concept applying to a test taxi hailing application without disregard to its underlying RDBMS structure. The application of IMDG technology in the application's backend API without restructuring the database schema yields 6 to 9 times increase in performance in data processing and throughput. Specifically, the change in throughput is very small even with increase in data load processing.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06c
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• pp.462-465
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• 2011

웹 애플리케이션의 사용이 늘어남에 따라 자바스크립트 프로그램의 성능을 높이는 것이 중요한 문제가 되었다. 자바스크립 프로그램에 대해 별칭 분석을 수행하면 더 많은 최적화가 가능해지지만, 자비스크립트가 가지는 동적인 특성으로 인해 분석 방법을 고안하는 데 어려움이 있었다. 본 논문에서는 자바스크립트의 주요한 동적 특성을 온전하게 다루는 별칭 분석 알고리즘을 최초로 제안한다. 제안한 방법은 별칭 그래프를 생성하여 프로그램 내의 별칭 관계를 완전하게 찾아내며, 또한 실행시킬 코드가 동적으로 추가될 때마다 이전에 이루어졌던 최적화가 유효한지 검사한다. 별칭 분석 결과를 이용하여 V8 자바스크립트 엔진에서 추가적으로 최적화를 수행한 결과, 유의미한 수행 시간 감소를 확인할 수 있었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.1186-1188
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• 2013

최근 소셜 네트워크의 등장과 기술의 발달로 인해 빅 데이터가 등장하였다. 특히, 소셜 네트워크나 웹 데이터 등과 같은 빅 데이터를 이용하는 애플리케이션이 많아지고 있다. 이러한 그래프 데이터는 크기가 매우 방대하여 인-메모리 기법을 통해 연산하기 어렵다. 최근 대용량 그래프 상에서 효율적인 최단 경로 탐색을 위해 부분 최단 경로를 저장하는 인덱스 테이블을 활용한 기법이 제안되었으나, 인덱스 참조율을 고려하지 않아 비효율적이다. 본 논문에서는 인덱스 참조율이 높은 노드의 차수를 이용한 k-차수 인덱스 테이블을 이용한 효율적인 최단 경로 탐색 기법을 제안한다. 실험을 통하여 제안하는 기법이 거리 기반 인덱스를 이용한 기존의 기법에 비해 약 12% 정도 성능이 향상됨을 보였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.254-256
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• 2014

In this paper, using the Android App to remote database monitoring system is proposed. Existing remote database monitoring scheme CS(Client / Server) based. Conventional CS based systems are space constraints and a plurality of administrator to access the database at that degrade performance disadvantages. The advantage of the proposed system first, because the web -based interface allows the application program, and also the ease of maintenance, through a web browser, if you have Internet access anytime, anywhere environment without restrictions of time and space monitoring. Second, the proposed system because the App -based technology due to an increase in connection session and query execution does not affect the performance of your database. Third, if there is a problem with the remote database through which social networks immediately notify the administrator of the smartphone in real time so that the administrator can identify the problem.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.157-163
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• 2016

This paper presents Finger Keyboard which detects the user's key types on a keyboard drawn on the paper using a video camera. The Finger Keyboard software was written in standard C/C++ language and thus easy to port to other computing environments. We installed a popular USB-type web camera on a Windows PC and implemented the Finger Keyboard as a Windows application which detects key typing and then injects the key code into the message queue of the Windows operating system. Also we implemented the Finger Keyboard on the Raspberry Pi 2 embedded computer with a dedicated camera and connected it to the Android device as an external keyboard through the Bluetooth. The result of experiments showed that the average ratio of recognition success is around 80% at the typing speed of 120 characters per minute.

• The Journal of Korean Institute of Next Generation Computing
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• v.14 no.6
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• pp.30-43
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• 2018

Many studies have been carried out to retrieve images using colors, shapes, and textures which are characteristic of images. In addition, there is also progress in research related to the disease images of the crop. In this paper, to be a help to identify the disease occurred in crops grown in the agricultural field, we propose a similarity-based crop disease search system using the diseases image of horticulture crops. The proposed system improves the similarity retrieval performance compared to existing ones through the combination descriptor without using a single descriptor and applied the weight based calculation method to provide users with highly readable similarity search results. In this paper, a total of 13 Descriptors were used in combination. We used to retrieval of disease of six crops using a combination Descriptor, and a combination Descriptor with the highest average accuracy for each crop was selected as a combination Descriptor for the crop. The retrieved result were expressed as a percentage using the calculation method based on the ratio of disease names, and calculation method based on the weight. The calculation method based on the ratio of disease name has a problem in that number of images used in the query image and similarity search was output in a first order. To solve this problem, we used a calculation method based on weight. We applied the test image of each disease name to each of the two calculation methods to measure the classification performance of the retrieval results. We compared averages of retrieval performance for two calculation method for each crop. In cases of red pepper and apple, the performance of the calculation method based on the ratio of disease names was about 11.89% on average higher than that of the calculation method based on weight, respectively. In cases of chrysanthemum, strawberry, pear, and grape, the performance of the calculation method based on the weight was about 20.34% on average higher than that of the calculation method based on the ratio of disease names, respectively. In addition, the system proposed in this paper, UI/UX was configured conveniently via the feedback of actual users. Each system screen has a title and a description of the screen at the top, and was configured to display a user to conveniently view the information on the disease. The information of the disease searched based on the calculation method proposed above displays images and disease names of similar diseases. The system's environment is implemented for use with a web browser based on a pc environment and a web browser based on a mobile device environment.