• KIPS Transactions on Software and Data Engineering
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• v.3 no.1
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• pp.19-30
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• 2014

For the expansion of the Semantic Web, studies in converting the data stored in the relational database into the ontology are actively in process. Such studies mainly use an RDB to RDF mapping model, the model to map relational database components to RDF components. However, pre-proposed mapping models have got different expression modes and these damage the accessibility and reusability of the users. As a consequence, the necessity of the standardized mapping language was raised and the W3C suggested the R2RML as the standard mapping language for the RDB to RDF model. The R2RML has a characteristic that converts only the relational database schema data to RDF. For the same reasons above, the ontology about the relation data between table name and column name of the relational database cannot be added. In this paper, we propose an RDB to RDF mapping system considering semantic relations of RDB components in order to solve the above issue. The proposed system generates the mapping data by adding the RDFS attribute data into the schema data defined by the R2RML in the relational database. This mapping data converts the data stored in the relational database into RDF which includes the RDFS attribute data. In this paper, we implement the proposed system as a Java-based prototype, perform the experiment which converts the data stored in the relational database into RDF for the comparison evaluation purpose and compare the results against D2RQ, RDBToOnto and Morph. The proposed system expresses semantic relations which has richer converted ontology than any other studies and shows the best performance in data conversion time.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.1
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• pp.9-18
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• 2004

This paper presents an efficient image compression method for memory reduction in multimedia processor which can be simply implemented in hardware and provides high performance. The multimedia processor, which includes processing of high-resolution images and videos, requires large memories: they are external frame memories to store frames and internal line memories for implementing some linear filters. If we can reduce those memories by adopting a simple compression method in multimedia processor, it will strengthen its cost competitiveness. There exist many standards for efficiently compressing images and videos. However, those standards are too complex for our purpose and most of them are 2-D block-based methods, which do not support raster scanned input and output. In this paper, we propose a low-complexity compression method which has good performance, can be implemented with simple hardware logic, and supports raster scan. We have adopted 1${\times}$8 Hadamard transform for simple implementation in hardware and compression efficiency. After analyzing the coefficients, we applied an adaptive thresholding and quantization. We provide some simulation results to analyze its performance and compare with the existing methods. We also provide its hardware implementation results and discuss about cost reduction effects when applied in implementing a multimedia processor.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.6
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• pp.90-100
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• 2017

The purpose of this study is to detect and label the vehicles using the drone images as a way to overcome the limitation of the existing point and section detection system and vehicle gap estimation on Arterial road. In order to select the appropriate time zone, position, and altitude for the acquisition of the drone image data, the final image data was acquired by shooting under various conditions. The vehicle was detected by applying mixed Gaussian, image binarization and morphology among various image analysis techniques, and the vehicle was labeled by applying Kalman filter. As a result of the labeling rate analysis, it was confirmed that the vehicle labeling rate is 65% by detecting 185 out of 285 vehicles. The gap was calculated by pixel unitization, and the results were verified through comparison and analysis with Daum maps. As a result, the gap error was less than 5m and the mean error was 1.67m with the preceding vehicle and 1.1m with the following vehicle. The gaps estimated in this study can be used as the density of the urban roads and the criteria for judging the service level.

• The KIPS Transactions:PartB
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• v.10B no.3
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• pp.287-296
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• 2003

There has been much research focused on collaborative filtering technique in Recommender System. However, these studies have shown the First-Rater Problem and the Sparsity Problem. The main purpose of this Paper is to solve these Problems. In this Paper, we suggest the user's predicting preference method using Bayesian estimated value and the associative user clustering for the recalculation of preference. In addition to this method, to complement a shortcoming, which doesn't regard the attribution of item, we use Representative Attribute-Neighborhood method that is used for the prediction when we find the similar neighborhood through extracting the representative attribution, which most affect the preference. We improved the efficiency by using the associative user's clustering analysis in order to calculate the preference of specific item within the cluster item vector to the collaborative filtering algorithm. Besides, for the problem of the Sparsity and First-Rater, through using Association Rule Hypergraph Partitioning algorithm associative users are clustered according to the genre. New users are classified into one of these genres by Naive Bayes classifier. In addition, in order to get the similarity value between users belonged to the classified genre and new users, and this paper allows the different estimated value to item which user evaluated through Naive Bayes learning. As applying the preference granted the estimated value to Pearson correlation coefficient, it can make the higher accuracy because the errors that cause the missing value come less. We evaluate our method on a large collaborative filtering database of user rating and it significantly outperforms previous proposed method.

• Korean Journal of Community Nutrition
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• v.14 no.6
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• pp.817-830
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• 2009

The purpose of this study was to analysis the sanitary management performance based on HACCP system for school foodservice. This study was carried out from September 2008 until December 2008 and is targeted towards schools' dietitians that work at schools with school foodservice. The regional distribution of this research is as follows; 377 schools in Seoul, 648 schools in Gyeonggido, 160 schools in Kangwondo, 438 schools in Choongchungdo equaling 1,623 schools in total. When school foodservices were put through sanitation management achievement level analysis applied by the HACCP system, results displayed that management of temperature (3.96 points), time (4.08 points), and cross-contamination (4.07 points) were all below the average achievement level. HACCP system's achievement level based on the TQM showed that areas for strategy development, leadership, information and analysis had low achievement levels. Achievement levels for CCP are quality check, delivery/distribution process, sterilization/cleansing of food's contact surface. As a result of multiple regression analysis of the factors that influenced sanitation management achievement level of school foodservice HACCP system; sanitary job standard showed 35.6% and CCP achievement levels showed 26.8% explanatory rate. In particular, Kangwondo's number of foodservice provided to per cook was small. Also, the better the processing management was assessed, the higher the sanitary job standard achievement level became resulting to a explanatory rate of 39.5%. Elementary schools showed a higher explanatory rate of 37.0% than middle and high schools. CCP achievement levels in middle and high schools with self-operated foodservice had a 28.0% variable explanatory rate, which was the highest. The better the drainage system, leadership and assessments turned out to be, the higher the CCP achievement levels became. In summary, to revitalize HACCP system that is based on the TQM, it is considered that proper database of HACCP system for school foodservice's sanitation management be constructed and more emphasis should be put on strategy development to improve customers' satisfactory level. In addition, improvements in achievement levels of time, temperature, and cross-contamination for sanitary job standard and CCP achievement level are essential.

• Journal of Korean society of Dental Hygiene
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• v.18 no.4
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• pp.477-488
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• 2018

Objectives: The purpose of this study was to investigate career competency, tasks, and job satisfaction of public servants, public institutions, and researchers. Methods: The survey was conducted about career competency, job satisfaction, and satisfaction on work life. Next, they interviewed on the characteristics of each job by two or three dimensions. The following conclusions were obtained from July to August 2017. Results: Career competencies were GPA with 3.87, 818 points of TOEIC score, and ITQ certification. Public servants required the information on literacy skills for employment and job performance, while civil servants need more than one year of clinical experience in the dental hospital. The non-commissioned officer needed a written test and fitness training. The health insurance review and assessment center required more than one year of experience from general hospital or medical institutions. Researchers required a research career, language skill, and professors required research and teaching experiences with clinical experience more than three years. The main job tasks were as follows; for public servants, they were official document processing and community projects. For the civilian workers and military/noncommissioned officers, they were medical assistant and administrative works. The employees of the health insurance review and assessment service are examining the medical expenses and the medical examination, the researchers are experimenting, researching and writing articles, and the teaching staff are lecturing and conducting individual research. Conclusions: The results of job satisfaction survey showed that occupational satisfaction was the highest in civil servants, researchers, and teaching professions. Job security was the highest in health workers and health inspectors' evaluation centers, and time vacancy was the highest in civilian workers and military/noncommissioned officers. If you want to work in such an institution, you should prepare elements that match your basic literacy and job specific characteristics. And we should try to increase the satisfaction of work even after work.

• Journal of KIISE:Databases
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• v.31 no.6
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• pp.664-674
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• 2004

The trajectory preservation property that stores only one trajectory in a leaf node is the most important feature of an index structure, such as the TB-tree for retrieving object's moving paths in the spatio-temporal space. It performs well in trajectory-related queries such as navigational queries and combined queries. But, the MBR of non-leaf nodes in the TB-tree have large amounts of dead space because trajectory preservation is achieved at the sacrifice of the spatial locality of trajectories. As dead space increases, the overlap between nodes also increases, and, thus, the classical range query cost increases. We present a new split policy and entry relocation policies, which have no deterioration of the performance for trajectory-related queries, for improving the performance of range queries. To maximally reduce the dead space of a non-leaf node's MBR, the Maximal Area Reduction (MAR) policy is used as a split policy for non-leaf nodes. The entry relocation policy induces entries in non-leaf nodes to exchange each other for the purpose of reducing dead spaces in these nodes. We propose two algorithms for the entry relocation policy, and evaluate the performance studies of new algorithms comparing to the TB-tree under a varying set of spatio-temporal queries.

• The KIPS Transactions:PartD
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• v.18D no.4
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• pp.275-286
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• 2011

The purpose of this study is to find the beneficial plan for business success by the advantage of social media service in the business organization. There is few research for applying social media on a variety of fields in business organization although many companies are trying to find the way for its application. Hence, this study identifies the possibility for the utilization of social media services, and it also finds the plan for their effective application. The social relationship is created by increasing communications between users of social media service. The research model is established on the basis of the hypothesis that the social relationship affects knowledge share, pursuit of ego, social participation, amusement. To maximize the impact of results, the research was conducted on the basis of the target on two groups including the business men and non-business men who use social media services. As results of the research, the business men tend to appeal their impression based on sharing knowledge with anonymous people. Also, it is necessary to make a social participation to a management participation, and to utilize the social media in the organization by including amusement to its function. This research is expected to have significant implication to companies which wants to apply social media services in the future.

• The KIPS Transactions:PartA
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• v.8A no.4
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• pp.319-330
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• 2001

In virtual memory system, when a process attempts to access a page that is not resident in memory, the system generates and handles a page fault that causes unpredictable delay. So virtual memory system is not appropriate for the real-time system, because it can increase the deadline miss ratio of real-time task. In multimedia system, virtual memory system may degrade the QoS(quality of service) of multimedia application. Furthermore, in general-purpose operating system, whenever a new task is dynamically loaded, virtual memory system suffers from extensive page fault that cause transient overloading state. In this paper, we present efficient overloading control mechanism called RBPFH (Rate-Based Page Fault Handling). A significant feature of the RBPFH algorithm is page fault dispersion that keeps page fault ratio from exceeding available bound by monitoring current system resources. Furthermore, whenever the amount of available system resource is changed, the RBPFH algorithm dynamically adjusts the page fault handling rate. The RBPFH algorithm is implemented in the Linux operating system and its performance measured. The results demonstrate RBPFH\`s superior performance in supporting multimedia applications. Experiment result shows that RBPFH could achieve 10%∼20% reduction in deadline miss ratio and 50%∼60% reduction in average delay.

• The KIPS Transactions:PartC
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• v.18C no.4
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• pp.265-278
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• 2011

The objective of this paper is to analyze and characterize end-to-end packet statistics after modeling and simulation of WiFi (IEEE 802.11g) and WiMAX (IEEE 802.16e) of a virtual wireless network using OPNET Modeler Wireless Suite. Wireless internal and external network simulators such as Remcom's Wireless InSite Real Time (RT) module, WinProp: W-LAN/Fixed WiMAX/Mobile WiMAX, and SMI system, are designed to consider data transfer rate based on wireless propagation signal strength. However, we approached our research in a different perspective without support for characteristic of these wireless network simulators. That is, we will discuss the purpose of a visual analysis for these packets, how to receive each point packets (e.g., wireless user, base station or access point, and http server) through end-to-end virtual network modeling based on integrated wired and wireless network without wireless propagation signal strength. Measuring packet statistics is important in QoS metric analysis among wireless network performance metrics. Clear packet statistics is an especially essential metric in guaranteeing QoS for WiMAX users. We have found some interesting results through modeling and simulation for virtual wireless network using OPNET Modeler Wireless Suite. We are also able to analyze multi-view efficiency through experiment/observation result.