• Journal of KIISE:Computing Practices and Letters
• /
• v.11 no.1
• /
• pp.15-25
• /
• 2005

Embedded systems have a set of tasks to execute. These tasks can be implemented either on application specific hardware or as software running on a specific processor. The design of an embedded system involves the selection of hardware software resources, Partition of tasks into hardware and software, and performance evaluation. An accurate estimation of execution time for extreme cases (best and worst case) is important for hardware/software codesign. A tighter estimation of the execution time bound nay allow the use of a slower processor to execute the code and may help lower the system cost. In this paper, we consider an ARM-based embedded system and developed a tool to estimate the tight boundary of execution time of a task with loop bounds and any additional program path information. The tool we developed is based on an exiting timing analysis tool named 'Cinderella' which currently supports i960 and m68k architectures. We add a module to handle ARM ELF object file, which extracts control flow and debugging information, and a module to handle ARM instruction set so that the new tool can support ARM processor. We validate the tool by comparing the estimated bound of execution time with the run-time execution time measured by ARMulator for a selected bechmark programs.

• Journal of KIISE:Software and Applications
• /
• v.35 no.1
• /
• pp.22-32
• /
• 2008

To overcome the weakness of the image retrieval system using the existing Ontology and the distributed image based on the database having a simple structure, HERMES was suggested to ensure the self-control of various image suppliers and support the image retrieval based on semantic, the mentioned framework could not solve the problems which are not considered the deterioration in the capacity and scalability when many users connect to broker server simultaneously. In this paper the tables are written which in the case numerous users connect at the same time to the supply analogous level of services without the deterioration in the capacity installs Broker servers and then measures the performance time of each inner Broker Component through Monitoring System and saved and decides the ranking in saved data. As many Query performances are dispersed into several Servers User inputted from the users Interface with reference to Broker Ranking Table, Load Balancing system improving reliability in capacity is proposed. Through the experiment, the scheduling technique has proved that this schedule is faster than existing techniques.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2007.05a
• /
• pp.1342-1347
• /
• 2007

최근 수자원 분야에서 GIS의 활용은 유역의 수리, 수문분석을 위한 모형의 입력자료 생성 및 모의 결과를 가시화, 이에 따른 유역관리 시스템의 구축 등 폭넓게 활용되고 있다. 또한 국가지리정보시스템에 조사를 통해서 수치지형도 및 주제도를 구축, 구축된 자료의 표준화를 실시하고 있는 실정이다. 그러나 수자원 분야에서 GIS를 활용하기 위한 기술은 주로 선진국을 중심으로 발전하여 왔기 때문에 우리의 실정에 맞지 않아 활용측면에 있어 신뢰할 만한 결과를 얻지 못하고 있는 실정이다. 따라서 국내 상황을 고려하면서 수자원이라는 전문분야 적용에 적합한 GIS(HyGIS)를 개발하고 여기에 수리, 수문분석모형을 연계하여 국내 실무분야에 적용함에 있어 편의성과 실용성을 구비한 모형개발이 이루어져야 한다. 따라서 본 연구에서는 국내 소프트웨어 GeoMania(HyGIS)에 의한 GIS 정보처리의 자동화를 기반으로 하여 실무에서 활용도가 높은 수문모형인 HEC-HMS 및 HEC-1과 수리모형인 HEC-RAS를 연계 및 통합하기 위해서 HyGIS에서 DLL형태로 제공되도록 하였다. HyGIS에서는 수문학적 DEM 분석 및 공간정보 생성, 선형참조가 가능한 하천 네트워크 생성, 유역 시설물 관리 등의 기능을 제공하며 COM(Component Object Model)을 기반으로 개발된 시스템으로 다른 소스로부터 개발된 컴포넌트를 연계하여 시스템의 기능 확장을 손쉽게 수행할 수 있도록 하였을 뿐만 아니라 공간 DB는 GeoMania의 고유 DB인 GSS를 이용한다. HyGIS-HMS는 HyGIS를 통한 국내 유역의 지리정보를 활용하여 HEC-HMS 뿐만 아니라 HEC-1을 추가하여 사용자의 기호와 편의에 따라 모형을 선택할 수 있도록 하였으며 HEC-1의 결과를 가시화하기 위해서 챠트 기능을 추가하였으며 매개변수를 자동으로 산정할 수 있도록 시스템을 구축하였다. HyGIS-RAS는 국내 하천유역에 대해서 기구축 되어있는 하천관리지리정보시스템(RIMGIS)자료를 직접 활용하도록 구성되어있고 자료를 활용하여 제내지와 제외지를 통합하여 TIN분석을 실시하여 범람 홍수해석에 활용할 수 있도록 하였다. 하천수리해석의 기능을 보강하기 위해 역산조도계수 산정모형, 상류-사류 천이류 구간에 대한 부등류 해석모형, 범람 홍수류에 대한 홍수위 산정모형, 하천수리계산시의 불확실도 해석모형 등의 새로운 기능을 추가하여 제시하였다. 모든 입출력자료는 프로젝트 단위별로 운영되어 data의 관리가 손쉽도록 하였으며 결과를 DB에 저장하여 다른 모형에서도 적용할 수 있도록 하였다. 그리고 HyGIS-HMS 및 HyGIS-RAS 모형에서 강우-유출-하도 수리해석-범람해석 등이 일괄되게 하나의 시스템 내에서 구현될 수 있도록 하였다. 따라서 HyGIS와 통합된 수리, 수문모형은 국내 하천 및 유역에 적합한 시스템으로서 향후 HydroInformatics 구현을 염두에 둔 특화된 국내 수자원 분야 소프트웨어의 개발에 기본 토대를 제공할 것으로 판단된다.

• Journal of Broadcast Engineering
• /
• v.15 no.4
• /
• pp.474-486
• /
• 2010

In this paper, we propose a new method for detection moving object contour using spatial and temporal edge. In general, contour pixels of the moving object are likely present around pixels with high gradient value along the time axis and the spatial axis. Therefore, we can detect the contour of the moving objects by finding pixels which have high gradient value in the time axis and spatial axis. In this paper, we introduce a new computation method, termed as temporal edge, to compute an gradient value along the time axis for any pixel on an image. The temporal edge can be computed using two input gray images at time t and t-2 using the Sobel operator. Temporal edge is utilized to detect a candidate region of the moving object contour and then the detected candidate region is used to extract spatial edge information. The final contour of the moving object is detected using the combination of these two edge information, which are temporal edge and spatial edge, and then the post processing such as a morphological operation and a background edge removing procedure are applied to remove noise regions. The complexity of the proposed method is very low because it dose not use any background scene and high complex operation, therefore it can be applied to real-time applications. Experimental results show that the proposed method outperforms the conventional contour extraction methods in term of processing effort and a ghost effect which is occurred in the case of entropy method.

• Geophysics and Geophysical Exploration
• /
• v.23 no.2
• /
• pp.97-114
• /
• 2020

Recently, many studies have been actively conducted on the application of machine learning in all branches of science and engineering. Studies applying machine learning are also rapidly increasing in all sectors of seismic exploration, including interpretation, processing, and acquisition. Among them, fault detection is a critical technology in seismic interpretation and also the most suitable area for applying machine learning. In this study, we introduced various machine learning techniques, described techniques suitable for fault detection, and discussed the reasons for their suitability. We collected papers published in renowned international journals and abstracts presented at international conferences, summarized the current status of the research by year and field, and intensively analyzed studies on fault detection using machine learning. Based on the type of input data and machine learning model, fault detection techniques were divided into seismic attribute-, image-, and raw data-based technologies; their pros and cons were also discussed.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.1 no.1
• /
• pp.41-51
• /
• 2002

As Advanced Traveler Information System(ATIS) is the kernel of the Intelligent Transportation System, it is very important how to manage data from traffic information collectors on a road and have at borough grip of the travel time's change quickly and exactly for doing its part. Link travel time can be obtained by two method. One is measured by area detection systems and the other is estimated by point detection systems. Measured travel time by area detection systems has the limitation for real time information because it Is calculated by the probe which has already passed through the link. Estimated travel time by point detection systems is calculated by the data on the same time of each. section, this is, it use the characteristic of the various cars of each section to estimate travel time. For this reason, it has the difference with real travel time. In this study, Artificial Neural Networks is used for estimating link travel time concerned about the relationship with vehicle detector data and link travel time. The method of estimating link travel time are classified according to the kind of input data and the Absolute value of error between the estimated and the real are distributed within 5$\~$15minute over 90 percent with the result of testing the method using the vehicle detector data and AVI data of Namsan Tunnel $\#$1. It also reduces Time lag of the information offered time and draws late delay generation and dissolution.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.6
• /
• pp.107-116
• /
• 2015

In compliance with digital device growth, the proliferation of high-tech computers, the availability of high quality and inexpensive video cameras, the demands for automated video analysis is increasing, especially in field of intelligent monitor system, video compression and robot vision. That is why object tracking of computer vision comes into the spotlight. Tracking is the process of locating a moving object over time using a camera. The consideration of object's scale, rotation and shape deformation is the most important thing in robust object tracking. In this paper, we propose a robust object tracking scheme using Random Forest. Specifically, an object detection scheme based on region covariance and ZNCC(zeros mean normalized cross correlation) is adopted for estimating accurate object location. Next, the detected region will be divided into five regions for random forest-based learning. The five regions are verified by random forest. The verified regions are put into the model pool. Finally, the input model is updated for the object location correction when the region does not contain the object. The experiments shows that the proposed method produces better accurate performance with respect to object location than the existing methods.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.26 no.3
• /
• pp.563-572
• /
• 2016

Recently, a plenty of credit card payment protocols have been proposed in Korea. Several features of proposed protocols include: using passwords for user authentication in stead of official certificate for authenticity, and no need to download additional security module via ActiveX into user's devices. In this paper, we suggest two new credit card payment protocols that use both SSL(Security Socket Layer) as a standardized secure transaction protocol and password authentication to perform online shopping and payment. The first one is for the case where online shopping mall is different from PG(Payment Gateway) and can be compared to PayPal-based payment methods, and the second one is for the case where online shopping mall is the same as PG and thus can be compared to Amazon-like methods. Two proposed protocols do not require users to perform any pre-registration process which is separate from an underlying shopping process, instead users can perform both shopping and payment into a single process in a convenient way. Also, users are asked to input a distinct payment password, which increases the level of security in the payment protocols. We believe that two proposed protocols can help readers to better understand the recent payment protocols that are suggested by various vendors, and to analyze the security of their payment protocols.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.1 s.45
• /
• pp.177-188
• /
• 2007

A star schema consists of a central fact table, which is surrounded by one or more dimension tables. Each row in the fact table contains a multi-part primary key(or a composite foreign key) along with one or more columns containing various facts about the data stored in the row. Each of the composit foreign key components is related to a dimensional table. The combination of keys in the fact table creates a composite foreign key that is unique to the fact table record. The composite foreign key, however, is rarely unique to the fact table retold in real-world applications, particularly in financial applications. In order to make the composite foreign key be the determinant in real-world application, some precalculation might be performed in the SQL relational database, and cached in the OLAP database. However, there are many drawbacks to this approach. In some cases, this approach might give users the wrong results. In this paper, an approach to fact table modeling and related MDX query composing, which can be used in real-world applications without performing any precalculation and gives users the correct results, is proposed.

• Journal of the Korea Computer Graphics Society
• /
• v.17 no.3
• /
• pp.1-7
• /
• 2011

Recently, various researches have been proposed to accelerate GPU-based volume ray-casting. However, those researches may cause several problems such as bottleneck of data transmission between CPU and GPU, requirement of additional video memory for hierarchical structure and increase of processing time whenever opacity transfer function changes. In this paper, we propose an efficient GPU-based empty space skipping technique to solve these problems. We store maximum density in a brick of volume dataset on a vertex element. Then we delete vertices regarded as transparent one by opacity transfer function in geometry shader. Remaining vertices are used to generate bounding boxes of non-transparent area that helps the ray to traverse efficiently. Although these vertices are independent on viewing condition they need to be reproduced when opacity transfer function changes. Our technique provides fast generation of opaque vertices for interactive processing since the generation stage of the opaque vertices is running in GPU pipeline. The rendering results of our algorithm are identical to the that of general GPU ray-casting, but the performance can be up to more than 10 times faster.