• Journal of Korea Multimedia Society
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• v.14 no.3
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• pp.348-355
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• 2011

In this paper, we propose an automatic prostate segmentation method from dynamic magnetic resonance (MR) images. Our method detects contrast-enhanced images among the dynamic MR images using an average intensity analysis. Then, the candidate regions of prostate are detected by the B-spline non-rigid registration and subtraction between the pre-contrast and contrast-enhanced MR images. Finally, the prostate is segmented by performing a dilation operation outward, and sequential shape propagation inward. Our method was validated by ten data sets and the results were compared with the manually segmented results. The average volumetric overlap error was 6.8%, and average absolute volumetric measurement error was 2.5%. Our method could be used for the computer-aided prostate diagnosis, which requires an accurate prostate segmentation.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.4
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• pp.67-75
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• 2009

Multi-layered video coding that provides scalability across the visual content has emerged for easily adaptive service over current heterogeneous network. However, the network is still error prone environment so that video service may suffer packet loss or erroneous decoding of the video. Especially distortion caused by the burst error may propagate to several pictures until intra refreshing, which will raise a terrific degradation of picture quality. To overcome the problem at terminal independently, we propose a new error concealment algorithm for the multi-layered video coding. The proposed method uses the similarity of between layers in the multi-layered video coding and POCS (Projections Onto Convex Sets) which is a powerful error concealment tool, but heavily dependent on initial values. To find adequate initial value which can reduce iteration times as well as achieve high performance, we took consideration into both features of layered approach coding and the correlation in neighbor blocks. The simulation results show that the proposed concealment method works well.

• Korean Journal of Construction Engineering and Management
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• v.24 no.6
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• pp.66-73
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• 2023

The construction industry suffers losses due to failures in demand forecasting due to price fluctuations in construction raw materials, increased user costs due to project cost changes, and lack of forecasting system. Accordingly, it is necessary to improve the accuracy of construction raw material price forecasting. This study aims to predict the price of construction raw materials and verify applicability through the improvement of the Data Refactor technique. In order to improve the accuracy of price prediction of construction raw materials, the existing data refactor classification of low and high frequency and ARIMAX utilization method was improved to frequency-oriented and ARIMA method utilization, so that short-term (3 months in the future) six items such as construction raw materials lumber and cement were improved. ), mid-term (6 months in the future), and long-term (12 months in the future) price forecasts. As a result of the analysis, the predicted value based on the improved Data Refactor technique reduced the error and expanded the variability. Therefore, it is expected that the budget can be managed effectively by predicting the price of construction raw materials more accurately through the Data Refactor technique proposed in this study.

• The KIPS Transactions:PartD
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• v.14D no.1 s.111
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• pp.35-44
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• 2007

Recently, an increasing in quantity of multimedia data have brought a new problem that expected data should be retrieved fast and exactly. The adequate representation for the multimedia data is the key element for efficient retrieval. For this reason, MPEG-7 standard was established for description of multimedia data. In this paper, we propose a new approach to metadata production. The user can decompose a given content into units and easily annotate each unit by adding basic Information such as time, place, etc. as well as classification information such as event, relationship, etc. according to the MPEG-7 standard. The objective is to build automatically a pure semantic description; the nodes are the events and the links are the graphs which describe the relationships among the events. Finally, we have implemented an annotation tool(SMAT) for semantic description based on proposed technique and assess some of the experiment results. In conclusion, we ran say that the proposod annotation tool is characterized by two important proprieties : reusability and extendibility.

• The KIPS Transactions:PartD
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• v.11D no.1
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• pp.203-210
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• 2004

A new research of geographic information system has been focused on an open architecture, interoperability and extensibility in their design. In order to process huge data, multidimensional data and heterogeneous geographic format data, these research move away from monolithic system to open structure system managing application layer and user interface layer. Nowadays, many developers have used CORBA middleware for the OGIS systems. However, CORBA middleware has some problems that support only a point-to-point communication and takes a long time to transfer sever data to client. Thus, in this paper, we propose a method on modifying a point-to-point communication and implement the efficient communication method. The proposed method that transfer data from sever to client in one connection support a group communication and reduce a transfer time delay.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.726-730
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• 2009

The proliferation of the web and digital photography has drastically increased multimedia data and has resulted in the need of the high quality internet service based on the moving picture like user generated contents(UGC). The keyword-based search on large scale images and video collections is too expensive and requires much manual intervention. Therefore the web search engine may provide the content-based retrieval on the multimedia data for search accuracy and customer satisfaction. In this paper, we propose a novel distributed index structure based on multiple length signature files according to data distribution. In addition, we describe how our scalable index technique can be used to find the nearest neighbors in the cluster environments.

• The Journal of Bigdata
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• v.2 no.2
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• pp.1-7
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• 2017

Intelligent transportation system (ITS) has been introduced to maximize the efficiency of operation and utilization of the urban traffic facilities and promote the safety and convenience of the users. With the expansion of ITS, various traffic big data such as road traffic situation, traffic volume, public transportation operation status, management situation, and public traffic use status have been increased exponentially. In this paper, we derive structural characteristics of urban traffic according to the vehicle flow by using big data network analysis. DSRC (Dedicated Short Range Communications) data is used to construct the traffic network. The results can help to understand the complex urban traffic characteristics more easily and provide basic research data for urban transportation plan such as road congestion resolution plan, road expansion plan, and bus line/interval plan in a city.

• Spatial Information Research
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• v.11 no.1
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• pp.61-72
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• 2003

LBS has attracted considerable attention with the spread of high performance mobile devices and the expansion of mobile business. Our study starts from the recognition of the problems associated with the current mobile Sales Force Automation(SFA) which is one of the application domain of LBS: they lack the capabilities such as an efficient sharing of information. This paper presents a technical framework in which the location information on the move and the mobile P2P service are utilized for the realization of truly mobile SF A platforms. Major contributions of our study include feasible prototyping of gCRM middleware via which the location-based services on the move are enabled, and a agent module involving the P2P service for mobile clients.

• 한국공간정보시스템학회:학술대회논문집
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• 2003.11a
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• pp.147-152
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• 2003

TPR-tree는 이동체의 위치 데이터에 대해 현재 및 미래 위치 질의를 지원하기 위하여 시간 함수 기반의 경계사각형(Sounding Rectangle)으로 이동체를 색인한다. 경계사각형의 각 축은 가장 빠른 속도로 이동하는 이동체의 속도 값을 이용하여 시간에 따라 확장한다. 경계사각형 영역의 확장으로 중복(overlap)이 심화되고 사장영역(dead space)이 커지는 문제가 있다. 따라서 시간이 지날수록 영역질의 시 성능이 떨어진다. 이 논문에서는 시간이 지남에 따라 발생하는 노드간의 심한 중복과 사장영역을 줄이기 위해 중복이 심한 두 개의 단말노드를 강제 합병하고 재분할하는 강제 합병 정책과 이동체의 삭제가 발생한 노드의 모든 이동체들을 강제적으로 재삽입하는 삭제노드 강제 재삽입 정책과 삭제가 발생한 노드와 중복되는 노드들의 이동체들을 강제적으로 재삽입하는 중복 노드 강제 재삽입 정책을 이용한다. 강제 합병 정책과 삭제 노드 강제 재삽입 정책, 그리고 중복 노드 강제 재삽입은 TPR-tree의 구조를 점진적으로 재구성하기 때문에 이동체의 현재 분포를 고려하여 색인 구조를 동적으로 개선하는 장점을 가진다.

• The KIPS Transactions:PartD
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• v.9D no.4
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• pp.579-586
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• 2002

This paper propose an efficient algorithm for mining association rules in the large main memory systems. To do this, the paper attempts firstly to extend the conventional algorithms such as DHP and Partition in order to be compatible to the large main memory systems and proposes secondly an algorithm to improve Partition algorithm by applying the techniques of the hash table and the bit map. The proposed algorithm is compared to the extended DHP within the experimental environments and the results show up to 65% performance improvement in comparison to the expanded DHP.