• Journal of Intelligence and Information Systems
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• v.13 no.2
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• pp.69-80
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• 2007

The preferences of customers change over time. However, existing collaborative filtering (CF) systems are static, since they only incorporate information regarding whether a customer buys a product during a certain period and do not make use of the purchase sequences of customers. Therefore, the quality of the recommendations of the typical CF could be improved through the use of information on such sequences. In this study, we propose a new methodology for enhancing the quality of CF recommendation that uses customer purchase sequences. The proposed methodology is applied to a large department store in Korea and compared to existing CF techniques. Various experiments using real-world data demonstrate that the proposed methodology provides higher quality recommendations than do typical CF techniques with better performance.

• Journal of Intelligence and Information Systems
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• v.13 no.4
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• pp.45-63
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• 2007

Recently as ubiquitous environment comes to the fore, information density is raised and enterprise is being able to capture and utilize customer-related information at the same time when the customer purchases a product. In this environment, a need for the recommender systems which can deliver proper information to the customer at the right time and right situation is highly increased. Therefore, the research on recommender systems continued actively in a variety of fields. Until now, most of recommender systems deal with item recommendation. However, in the market in ubiquitous environment where the same item can be purchased at several stores, it is highly desirable to recommend store to the customer based on his/her contextual situation and preference such as store location, store atmosphere, product quality and price, etc. In this line of research, we proposed the store recommender system using customer's contextual situation and preference in the market in ubiquitous environment. This system is based on collaborative filtering and Apriori algorithms. It will be able to provide customer-centric service to the customer, enhance shopping experiences and contribute in revitalizing market in the long term.

• Journal of Intelligence and Information Systems
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• v.13 no.4
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• pp.65-78
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• 2007

This paper proposes a new method of weighted template matching for machine-printed numeral recognition. The proposed weighted template matching, which emphasizes the feature of a pattern using adaptive Hamming distance on local feature areas, improves the recognition rate while template matching processes an input image as one global feature. Template matching is vulnerable to random noises that generate ragged outlines of a pattern when it is binarized. This paper offers a method of chain code trimming in order to remove ragged outlines. The method corrects specific chain codes within the chain codes of the inner and the outer contour of a pattern. The experiment compares confusion matrices of both the template matching and the proposed weighted template matching with chain code trimming. The result shows that the proposed method improves fairly the recognition rate of the machine-printed numerals.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.6
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• pp.1129-1135
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• 2007

Human face detection technique plays an important role in computer vision area. It has lots of applications such as face recognition, video surveillance, human computer interface, face image database management, and querying image databases. In this paper, a fast face detection approach using Principal Component Analysis (PCA) and Support Vector Machines (SVM) is proposed based on the previous study on face detection technique. In the proposed detection system, firstly it filter the face potential area using statistical feature which is generated by analyzing the local histogram distribution the detection process is speeded up by eliminating most of the non-face area in this step. In the next step, PCA feature vectors are generated, and then detect whether there are faces present in the test image using SVM classifier. Finally, store the detection results and output the results on the test image. The test images in this paper are from CMU face database. The face and non-face samples are selected from the MIT data set. The experimental results indicate the proposed method has good performance for face detection.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.3
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• pp.452-460
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• 2008

ALE-complient RFID middleware system receives EPC code data from reader devices and converts the data into URN format data internally. After filtering and grouping, the system sends the resulting URN code to application and(or) users. Meanwhile, not only the types of EPC code are very diverse, but also another new kinds of EPC code can be emerged in the future. Therefore, a method to process all kinds of EPC code effectively is required by RFID middleware. In this paper, a method to process various kinds of EPC code acquired from RFID reader devices in ALE-complient RFID middleware is proposed. Especially, we propose an approach using ontology technology to process not only existing EPC code but also newly defined code in the future. That is, we build an ontology of conversion rules for each EPC data type to effectively convert EPC data into URL format data. In this case, we can easily extend RFID middleware to process a new EPC code data by adding a conversion rule ontology for the code.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.3
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• pp.461-468
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• 2008

RFID technology is one of the core technologies for ubiquitous computing, and many research activities have been going on in this research area currently. Related with these researches, mobile RFID network services using mobile devices having a built-in RFID reader and mobile networks have been launched in Korea, for the first time in the world. In this paper, we propose a method to coulect ALE middleware suggested by EPCglobal and existing mobile RFID network services. Especially, a RFID code conversion method is proposed to process mobile RFID code systems within ALE middleware systems. Using the proposed method, application developers and(or) content business industries can acquire the information they want, which is filtered and refined in real-time or periodically, from mobile RFID users. So, they can Provide customized services to users by using the user preference information. In this war, the ALE middleware system can be easily extended to process mobile RFID code effectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.9
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• pp.1554-1563
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• 2008

As the interests on RFID technologies increase, a lot of research activities on RFID middleware systems to handle the data acquired by RFID readers are going on actively. Meanwhile, even though various kinds of RFID middleware methodologies and related techniques have been proposed, the common data type which is dealt with in those systems is an EPC code, mainly. Also, there are few researches of the implementation of collecting the stream data queued from RFID readers endlessly and without blocking, classifying the data into some groups according to usage, and sending the resulting data to specific applications. In this paper, we propose the method of data handling in RFID middleware to efficiently process an EPC event stream data using detail filtering, checking of data modification, creation of data set to transfer, data grouping, and various kinds of RFID data format transform. Our method is based on a de facto international standard interface defined in the ALE middleware specification by EPCglobal, and application and service users can directly set various kinds of conditions to handle the stream data.

• Journal of the Korea Society of Computer and Information
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• v.24 no.10
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• pp.65-70
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• 2019

In recently, ship trajectory data consisting of ship position, speed, course, and so on can be obtained from the Automatic Identification System device with which all ships should be equipped. These data are gathered more than 2GB every day at a crowed sea port and used for analysis of ship traffic statistic and patterns. In this study, we propose a method to process ship trajectory data efficiently with distributed computing resources using MapReduce algorithm. In data preprocessing phase, ship dynamic and static data are integrated into target dataset and filtered out ship trajectory that is not of interest. In mapping phase, we convert ship's position to Geohash code, and assign Geohash and ship MMSI to key and value. In reducing phase, key-value pairs are sorted according to the same key value and counted the ship traffic number in a grid cell. To evaluate the proposed method, we implemented it and compared it with IALA waterway risk assessment program(IWRAP) in their performance. The data processing performance improve 1 to 4 times that of the existing ship trajectory analysis program.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.203-208
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• 2019

Digital watermarking was developed to protect copyright by discouraging the illegal copying of digital content. On the other hand, recently, watermarking has also been used to verify the integrity of digital content, such as medical images, and detect illegal manipulation or distortion locations. Watermarking should be tenacious so as to protect copyright from illegal copying and should remain firm to the content through a range of attacks, such as distortion or filtering. At the same time, however, it should be removed easily even in a slight transformation of the material to verify the integrity. Therefore, this paper proposes a watermarking technique that easily checks and verifies the deformation or manipulation of digital images. In the proposed method, the entire image was examined in $16{\times}16$ blocks to check for deformation of the image. When deformation was detected, further inspection proceeded in $4{\times}4$ blocks and the location where deformation occurred was identified.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.633-633
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• 2015

재해의 발생 빈도 증가와 불규칙성, 대형화 추세에 따른 SOC 시설물 피해가 증가함에 따라 유관 기관의 재난/재해 정보 수집은 지속적으로 이루어지고 있다. 그러나 각 기관별로 자료가 분산 관리됨에 따라 선제적 재해대응 체계는 갖추어지지 못하고 있는 실정이다. 이에, 예방적 유지관리체계 구현을 위한 분산정보 공유형 재해대응 인벤토리를 구축하고자 한다. 본 인벤토리는 3차원 공간정보를 기반으로 분산 관리되고 있는 재난/재해 관련 정보를 수집하고 이렇게 수집된 데이터들의 통합적 관리를 위해 데이터 표준화를 거쳐 선제적 재해 대응의 원천 데이터로 활용될 수 있다. 본 연구에서는 인벤토리 관리/연계 모듈의 설계 방안을 마련하고자 국내외 인벤토리 관련 시스템 현황조사를 진행하고 관리 및 연계 대상 데이터의 항목을 선정하고 내용을 분류하였다. 또한, 시스템 요구사항을 수집하고 정의하고 관리/연계 모듈의 세부기능 정의를 하였다. 뿐만아니라, 프로토타입 개발을 위해 서비스 제공 형태와 데이터 제공 방식을 결정하였다. 본 연구에서 개발하고 있는 프로토타입은 Web Service 기반의 REST 방식으로 데이터를 제공할 것이며, 3차원 공간 정보를 기반으로 하고 있다. 본 연구에서는 프로토타입 개발을 위해 기본 주재도를 제작하고 연구 지역의 시설물 정보를 구축하였다. 분산정보 공유형 재해대응 인벤토리 시스템은 분산 관리되고 있는 재난/재해 정보들을 자료 송/수신 모듈을 통하여 수집하고 데이터 필터링 모듈에서 수집된 자료의 표준화와 품질측정을 진행하여 데이터의 신뢰도를 향상 시킬 것이다. 또한, 데이터 관리 모듈을 이용하여 공간정보 데이터를 검증하고 최적화 관리를 할 수 있도록 하며, 시스템 관리 모듈에서 유관기관에서 유입되는 자료들을 관리하고자 한다. 이렇게 구축된 인벤토리 시스템은 선제적 재해대응 의사결정의 원천 데이터를 제공하고 SOC 시설물의 유지관리에 활용될 수 있을 것으로 판단된다.