• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.18 no.2
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• pp.129-142
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• 2014

We propose a variational segmentation model based on statistical information of intensities in an image. The model consists of both a local region-based energy and a global region-based energy in order to handle misclassification which happens in a typical statistical variational model with an assumption that an image is a mixture of two Gaussian distributions. We find local ambiguous regions where misclassification might happen due to a small difference between two Gaussian distributions. Based on statistical information restricted to the local ambiguous regions, we design a local region-based energy in order to reduce the misclassification. We suggest an algorithm to avoid the difficulty of the Euler-Lagrange equations of the proposed variational model.

• International Journal of Internet, Broadcasting and Communication
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• v.7 no.2
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• pp.56-64
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• 2015

The personal image information compiled through closed-circuit television (CCTV) will be open to the internet with the technology such as Long-Tail, Mash-Up, Collective Intelligence, Tagging, Open Application Programming Interface (Open-API), Syndication, Podcasting and Asynchronous JavaScript and XML (AJAX). The movie User Created Contents (UCC) connected to the internet with the skill of web 2.0 has the effects of abuse and threat without precedent. The purpose of this research is to develop the institutional and technological method to reduce these effects. As a result of this research, in terms of technology this paper suggests Privacy Zone Masking, IP Filtering, Intrusion-detection System (IDS), Secure Sockets Layer (SSL), public key infrastructure (PKI), Hash and PDF Socket. While in terms of management this paper suggests Privacy Commons and Privacy Zone. Based on CCTV-UCC linked to the above network, the research regarding personal image information security is expected to aid in realizing insight and practical personal image information as a specific device in the following research.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.1
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• pp.115-123
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• 2001

This study describes the combustion characteristics under various condition of air excess ratio and ignition timing in a 2-valve gasoline optically accessible engine with swirl control valve(SCV). It adapted three different types of SCA(open ration 72.5%, 78%, 89%) to strengthen a swirl flow. Pressure data were acquired using pressure sensor to investigate the effect of swirl flow on combustion, and from these pressure data, IMEP(indicated mean effective pressure) and MFB(mass fraction burnt)were calculated to explain burn rate and flame speed. From acquired flame images, inspected the flame propagation direction, flame area, and flame centroid, Flame propagation direction was shown different tendency between with/without SCV, and flame area with SCV was faster and larger than that of conventional engine. Finally, the representative flame image at each crank angle were acquired by PDF method to verify flame growth process. It is found that strengthened swirl flow is more beneficial for faster and stable combustion.

• Journal of the Korean Society for Library and Information Science
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• v.32 no.2
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• pp.295-307
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• 1998

This article is an overview of the digital library project, indicating what roles Koreas diverse digital collections may play. Our digital library prototype has simple architecture, consisting of digital repositories, filters, indexing and searching, and clients. Digital repositories include various types of materials and databases. The role of filters is to recognize a format of a document collection and mark the structural components of each of its documents. We are using a database management system (ORACLE and ConText) supporting user-defined functions and access methods that allows us to easily incorporate new object analysis, structuring, and indexing technology into a repository. Clients can be considered browsers or viewers designed for different document data types, such as image, audio, video, SGML, PDF, and KORMARC. The combination of navigational tools supports a variety of approaches to identifying collections and browsing or searching for individual items. The search interface was implemented using HTML forms and the World Wide Web's CGI mechanism.

• Journal of the Korean Society for Library and Information Science
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• v.40 no.3
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• pp.391-413
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• 2006

This study analyzed the procedures and contents of digitalization of sinological resources owned by major sinological resource institutes in Korea. It investigated the united organizations that use such sinological resources It also assessed governmental policies and future Plans for digitalization of sinological resources. Finally, it proposed steps and conditions necessary for successful digitalization of sinological resources. (1) The level of digitalization of library management, searching, and usage system of national library, university library, and research library that has been applied since 1980s has already been highly advanced. The amount of sinological resources collected is significant and its substance value is very high. The digitalized resources are already distributed on internet partially. However, the level of digitalization of sinological resources still lacks some aspects and requires further effort. (2) The data base for digitalized sinological resources already available can be grouped into bibliographic information, contents and annotation, and full text. and it includes both domestic and foreign resources. The quantities of resources are as described in the body (3) The types of digital sinological resources include antient books. archives, micro, and book blocks. (4) The encoding DB methods of digital sinological resources include text. image, PDF. and etc. (5) The united organizations of sinological resources enable us to avoid duplicated investigation and enhance service efficiency. Here are some factors to consider in order to accomplish ideal digitalization of sinological resources. (1) First of all, it is necessary to organize a control center for digitalization procedures of old materials, and allow it a certain degree of authority to develop and Proceed a comprehensive Plan. (2) Both short- and long-term plans need to be developed in order to analyze various aspects of digitalization process. and their steps need to be taken gradually (3) It is necessary to train experts for old materials and let them construct and manage DB.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.2
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• pp.47-62
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• 2016

An integrated database(DB) system was developed to manage the marine geological data and geophysical data acquired from around the Korean peninsula from 2009 to 2013. Geological data such as size analysis data, columnar section images, X-ray images, heavy metal data, and organic carbon data of sediment samples, were collected in the form of text files, excel files, PDF files and image files. Geophysical data such as seismic data, magnetic data, and gravity data were gathered in the form of SEG-Y binary files, image files and text files. We collected scientific data from research projects funded by the Ministry of Oceans and Fisheries, data produced by domestic marine organizations, and public data provided by foreign organizations. All the collected data were validated manually and stored in the archive DB according to data processing procedures. A geographic information system was developed to manage the spatial information and provide data effectively using the map interface. Geographic information system(GIS) software was used to import the position data from text files, manipulate spatial data, and produce shape files. A GIS DB was set up using the Oracle database system and ArcGIS spatial data engine. A client/server GIS application was developed to support data search, data provision, and visualization of scientific data. It provided complex search functions and on-the-fly visualization using ChartFX and specially developed programs. The system is currently being maintained and newly collected data is added to the DB system every year.

• Journal of Korean Society of Archives and Records Management
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• v.2 no.1
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• pp.119-131
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• 2002

The study designs and implements a KORMARC/EAD integrated system for the Myongji Digital Library Collections. The purpose of this paper is to design the metadata to Myongji Korean History Collections to provide digital information of high quality to clients, and to develop and implement a model for managing digital library collections. In order to test the model and the quality of the derived metadata, we built a metadata management system, which is connected to the existing KORMARC system. The system consists of two modules- a retrieval and an input module. While in the retrieve mode, one can retrieve KORMARC records of books and archival items, with links to modified EAD files for archival items or to image files for books, in the input mode, one can type two types of data such as a catalog data and an inventory data. Finally, we evaluated the proposed system via mail questionnaires, and propose three suggestions to make this system a much more comprehensive and effective system.

• The Korean Journal of Nuclear Medicine
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• v.38 no.6
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• pp.486-491
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• 2004

Purpose: factor analysis and independent component analysis (ICA) has been used for handling dynamic image sequences. Theoretical advantages of a newly suggested ICA method, ensemble ICA, leaded us to consider applying this method to the analysis of dynamic myocardial $H_2^{15}O$ PET data. In this study, we quantified patients' blood flow using the ensemble ICA method. Materials and Methods: Twenty subjects underwent $H_2^{15}O$ PET scans using ECAT EXACT 47 scanner and myocardial perfusion SPECT using Vertex scanner. After transmission scanning, dynamic emission scans were initiated simultaneously with the injection of $555{\sim}740$ MBq $H_2^{15}O$. Hidden independent components can be extracted from the observed mixed data (PET image) by means of ICA algorithms. Ensemble learning is a variational Bayesian method that provides an analytical approximation to the parameter posterior using a tractable distribution. Variational approximation forms a lower bound on the ensemble likelihood and the maximization of the lower bound is achieved through minimizing the Kullback-Leibler divergence between the true posterior and the variational posterior. In this study, posterior pdf was approximated by a rectified Gaussian distribution to incorporate non-negativity constraint, which is suitable to dynamic images in nuclear medicine. Blood flow was measured in 9 regions - apex, four areas in mid wall, and four areas in base wall. Myocardial perfusion SPECT score and angiography results were compared with the regional blood flow. Results: Major cardiac components were separated successfully by the ensemble ICA method and blood flow could be estimated in 15 among 20 patients. Mean myocardial blood flow was $1.2{\pm}0.40$ ml/min/g in rest, $1.85{\pm}1.12$ ml/min/g in stress state. Blood flow values obtained by an operator in two different occasion were highly correlated (r=0.99). In myocardium component image, the image contrast between left ventricle and myocardium was 1:2.7 in average. Perfusion reserve was significantly different between the regions with and without stenosis detected by the coronary angiography (P<0.01). In 66 segment with stenosis confirmed by angiography, the segments with reversible perfusion decrease in perfusion SPECT showed lower perfusion reserve values in $H_2^{15}O$ PET. Conclusions: Myocardial blood flow could be estimated using an ICA method with ensemble learning. We suggest that the ensemble ICA incorporating non-negative constraint is a feasible method to handle dynamic image sequence obtained by the nuclear medicine techniques.