• Journal of radiological science and technology
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• v.26 no.3
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• pp.19-24
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• 2003

We carried out studies on development and characteristic of ultrasound brast training biopsy phantom. the major finding were of follow ; (1) C type TMM was shown good homogeneity, brightness and attenuation as like human soft tissue. (2) $TiO_2$ 4.10%w/v TMM was shown good homogeneous echo texture and propagated speed as like the human Tissue. (3) $TiO_2$ type TMM was appeared lower brightness and higher penetration rate than C type TMM. Therefor, Breast TM phantom and target material TMM will be useful $TiO_2$ 4.10 %w/v TMM and C 2.09 %w/v TMM.

• The Journal of the Korea Contents Association
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• v.13 no.9
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• pp.10-19
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• 2013

This Paper proposed the development of new magnetic sensor and recognition system to expendite pattern recognition of a handwriting character. Received character graphics should be performed the session and balancing and no extraction of end points, bend points and juntions separately. The Artifical intelligence algorithm is adapted to structure snalysis and recognition process by individual basic letter dictionary except for the handwriing character graphic dictionaryimproving error of recognition algorithm and enomous dictionary for generalization. In this Paper, recognition rate of the received character are compared with pre registered character at letter dictionary for performance test of magnetic ball sensor. As a result of unicode conversion and eomparison, the artificial intelligence study have recognition rate more than 95% at initial recognition rate of 70%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.1986-1992
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• 2009

A user often searches a data by inputting a variant such as the abbreviation or substring of a word, or a misspelled word. The simple approach to the searching for variants is to build a variants dictionary. However, it entails enormous cost and time and can not handle variants by misspelling. Approximate searching, searching by approximate string matching, is a good approach to the searching. A problem in the approach is that it cannot handle variants by abbreviations. This paper propose a method for searching various variants including abbreviations and misspelled words, by using the trie indexing. First, this paper shows a variant matching method with the calculation of path weighted-metric. In addition, it provides variant searching algorithm to reduce the search time.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1628-1631
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• 2010

본 연구에서는 최근 인기를 끌고 있는 스마트폰 중 하나인 Apple 사의 iPhone 3GS 용 차선이탈경보 애플리케이션 개발을 수행하였다. 국내외적으로 수행되고 있는 지능형 자동차 연구를 통해 개발된 다양한 안전주행 지원 기술들이 단계적으로 상용화되면서 자동차를 지능화시키고 있는 시점에서 고가의 안전주행 지원장치를 대체할 수 있는 플랫폼으로 스마트폰을 활용하고, 안전주행 지원기술을 애플리케이션으로 개발하여 사용자가 쉽고 저렴하고 편리하게 사용할 수 있는 제품을 개발하고자 하였다. Before-Market 에만 집중된 차선이탈경보장치 기능을 iPhone 에 적용하기 위해서 제한된 컴퓨팅 자원을 효율적으로 활용할 수 있는 차선인식알고리즘이 필요하고, 본 연구에서는 Hough Transform 기반의 알고리즘을 사용하였다. 이외에도 iPhone 이라는 플랫폼의 여러 가지 특징을 고려하여 애플리케이션을 개발하였다. 효율적인 영상처리를 위해 OpenCV 라이브러리를 사용하였고, 개발은 매킨토시 컴퓨터에서 개발 후 iPhone 에 탑재하여 확인하였다. 현재까지 개발된 애플리케이션의 기능에서 보완할 점은 차선인식률과 처리 속도를 향상 시키는 것이다. 2011 년 2 월까지 완제품을 개발하여 앱스토어에 등록하는 것을 목표로 하고 있으며, 향후 안드로이드용 애플리케이션도 개발할 계획이다.

• Knowledge Management Research
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• v.21 no.3
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• pp.177-195
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• 2020

The social consciousness on fake reviews has triggered researchers to suggest ways to cope with them by analyzing contents of fake reviews or finding ways to discover them by means of structural characteristics of them. This research tried to collect data from blog posts in Naver and detect habitual patterns users use unconsciously by variables extracted from blogs and blog posts by a machine learning model and wanted to use the technique in predicting fake reviews. Data analysis showed that there was a very high relationship between the number of all the posts registered in the blog of the writer of the related writing and the date when it was registered. And, it was found that, as model to detect advertising reviews, Random Forest is the most suitable. If a review is predicted to be an advertising one by the model suggested in this research, it is very likely that it is fake review, and that it violates the guidelines on investigation into markings and advertising regarding recommendation and guarantee in the Law of Marking and Advertising. The fact that, instead of using analysis of morphemes in contents of writings, this research adopts behavior analysis of the writer, and, based on such an approach, collects characteristic data of blogs and blog posts not by manual works, but by automated system, and discerns whether a certain writing is advertising or not is expected to have positive effects on improving efficiency and effectiveness in detecting fake reviews.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.348-351
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• 2009

유비쿼터스 사회를 실현하는 핵심기술인 u-GIS 공간정보 기술은 데이터 스트림 처리 시스템(Data Stream Management System)과 지리정보 시스템(Geography Information System)이 결합된 플랫폼인 u-GIS DSMS를 요구한다. u-GIS DSMS는 GeoSeonsor에서 수집되는 센서 테이터와 GIS의 공간정보 데이터를 결합하여 처리하는 공간영역질의가 다수 요구된다. 이런 공간영역질의들은 특정 지역에 밀집하게 등록되는 경향이 있으며, 유사한 프리디킷을 가질 가능성이 높다. 이러한 특징은 공간영역질의가 특정 지역에 밀집되면 다수의 비슷한 연산들이 반복적으로 처리하기 때문에 시스템 성능이 저하 될 것이다. 이를 해결하기 위해 영역질의 색인기법 연구가 활발히 진행되고 있다. 그러나 기존의 VCR-Index와 CQI-Index 기법은 질의영역을 셀 구조나 가상구조로 분할하여 처리하기 때문에 자원 및 연산을 공유 할 수 없어 질의 처리 속도가 현저히 저하되기 때문에 대량의 공간영역질의 처리에는 부적합하다. 그래서 본 논문에서는 공간영역질의의 효율적인 연산 공유를 위한 질의영역 밀집도 기반의 그룹화 기법을 제안한다. 이 기법은 질의영역의 밀집도를 이용하여 공간영역질의들을 그룹화 후 색인을 구성한다. 색인된 영역들의 데이터는 단일 큐로 구성 후 질의들의 프리디킷을 분석하여 자원 및 연산 공유기법을 통해 기존의 기법보다 처리 속도 향상 및 메모리 사용을 감소시켰다.

• Journal of Internet Computing and Services
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• v.17 no.6
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• pp.25-31
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• 2016

Recently, with greatly improving the wireless communication technology, new services are created using smart sensors, i.e., machine-to-machine (M2M) and Internet of Things (IoT). In this paper, we propose a novel IoT device (IoTD) personalization method that adopt Small-cell Access Points (SAPs) to control IoTDs using user equipments (UEs), e.g., smart phones and tablet PC, from service users. First, we introduce a system architecture that consists of UE, IoTD, and SAP and propose the IoTD personalization method with two procedures, i.e., IoTD profile registration procedure and IoTD control procedure. Finally, through simulations, we evaluated the system performance of the proposed scheme and it is shown that the proposed scheme outperforms the conventional scheme in terms of the packet delay, packet loss probability, and normalized throughput.

• Journal of KIISE:Databases
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• v.35 no.6
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• pp.459-468
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• 2008

A data stream which is a massive unbounded sequence of data elements continuously generated at a rapid rate. Many recent research activities for emerging applications often need to deal with the data stream. Such applications can be web click monitoring, sensor data processing, network traffic analysis. telephone records and multi-media data. For this. data processing over a data stream are not performed on the stored data but performed the newly updated data with pre-registered queries, and then return a result immediately or periodically. Recently, many studies are focused on dealing with a data stream more than a stored data set. Especially. there are many researches to optimize continuous queries in order to perform them efficiently. This paper proposes a query optimization algorithm to manage continuous query which has multiple join operators(Multi-way join) over data streams. It is called by an Extended Greedy query optimization based on a greedy algorithm. It defines a join cost by a required operation to compute a join and an operation to process a result and then stores all information for computing join cost and join cost in the statistics catalog. To overcome a weak point of greedy algorithm which has poor performance, the algorithm selects the set of operators with a small lay, instead of operator with the smallest cost. The set is influenced the accuracy and execution time of the algorithm and can be controlled adaptively by two user-defined values. Experiment results illustrate the performance of the EGA algorithm in various stream environments.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.4
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• pp.258-266
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• 2011

AR(Augmented Reality) technology is now easily shown around us with respect to its applicable areas' being spreaded into various shapes since the usage is simply generalized and many-sided. Currently existing camera vision based AR used marker based methods rather than using real world's informations. For the marker based AR technology, there are limitations on applicable areas and its environmental properties that a user could immerse into the usage of application program. In this paper, we proposed a novel AR method which users could recognize objects from the real world's data and the related 3-dimensional contents are also displayed. Those are done using image processing skills and a smart mobile embedded camera for terminal based AR implementations without any markers. Object recognition is done from the comparison of pre-registered and referenced images. In this process, we tried to minimize the amount of computations of similarity measurements for improving working speed by considering features of smart mobile devices. Additionally, the proposed method is designed to perform reciprocal interactions through touch events using smart mobile devices after the 3-dimensional contents are displayed on the screen. Since then, a user is able to acquire object related informations through a web browser with respect to the user's choice. With the system described in this paper, we analyzed and compared a degree of object recognition, working speed, recognition error for functional differences to the existing AR technologies. The experimental results are presented and verified in smart mobile environments to be considered as an alternate and appropriate AR technology.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.3
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• pp.301-307
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• 2010

Actuation using a shape memory alloy (SMA) is considered to be an important technology that will play a leading role in market for next-generation medical devices because an SMA actuator can accurately imitate skillful and delicate hand movements. However, SMA actuators have not been successfully used because of problems in control design caused by the nonlinear hysteresis effect of SMA, which leads to inaccuracies in control systems. In order to overcome the effect, the authors invented a SMA actuator, which could actively and rapidly cool down and heat up, by combining a SMA catheter and a TE module using the Peltier effect. In order to evaluate the TE characteristics of our TE module system, the changes in the temperature with 1) incremental increases in a continuous electric current and 2) the appearance of a discontinuous constant or reverse current are discussed in this paper.