• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제12권2호
• /
• pp.710-726
• /
• 2018

This paper presents an extended particle filter to increase the accuracy and decrease the computation load of vehicle tracking. Particle filter has been the subject of extensive interest in video-based tracking which is capable of solving nonlinear and non-Gaussian problems. However, there still exist problems such as preventing unnecessary particle consumption, reducing the computational burden, and increasing the accuracy. We aim to increase the accuracy without an increase in computation load. In proposed method, we calculate the direction angle of the target vehicle. The angular difference between the direction of the target vehicle and each particle of the particle filter is observed. Particles are filtered and weighted, based on their angular difference. Particles with angular difference greater than a threshold is eliminated and the remaining are stored with greater weights in order to increase their probability for state estimation. Threshold value is very critical for performance. Thus, instead of having a constant threshold value, proposed algorithm updates it online. The first advantage of our algorithm is that it prevents the system from failures caused by insufficient amount of particles. Second advantage is to reduce the risk of using unnecessary number of particles in tracking which causes computation load. Proposed algorithm is compared against camshift, direction-based particle filter and condensation algorithms. Results show that the proposed algorithm outperforms the other methods in terms of accuracy, tracking duration and particle consumption.

• 소음진동
• /
• 제11권1호
• /
• pp.147-155
• /
• 2001

This paper is concerned with the real-time automatic tuning of the multi-input multi-output positive position feedback controllers for smart structures by the genetic algorithms. The genetic algorithms have proven its effectiveness in searching optimal design parameters without falling into local minimums thus rendering globally optimal solutions. The previous real-time algorithm that tunes a single control parameter is extended to tune more parameters of the MIMO PPF controller. We employ the MIMO PPF controller since it can enhance the damping value of a target mode without affecting other modes if tuned properly. Hence, the traditional positive position feedback controller can be used in adaptive fashion in real time. The final form of the MIMO PPF controller results in the centralized control, thus it involves many parameters. The bounds of the control Parameters are estimated from the theoretical model to guarantee the stability. As in the previous research, the digital MIMO PPF control law is downloaded to the DSP chip and a main program, which runs genetic algorithms in real time, updates the parameters of the controller in real time. The experimental frequency response results show that the MIMO PPF controller tuned by GA gives better performance than the theoretically designed PPF. The time response also shows that the GA tuned MIMO PPF controller can suppress vibrations very well.

• 한국항해항만학회지
• /
• 제44권5호
• /
• pp.391-399
• /
• 2020

Every port is competing for attracting loyal customers from other ports to achieve more profits stably. This paper proposes a data-mining scheme to facilitate this process. For resolving the problem, the OD (Origination-Destination) data are gathered from the AIS (Automatic Identification System) data. The OD data are clustered according to the arrival dates and ports. The FP-growth algorithm is applied to mine the frequent patterns of ships arriving at ports. Maintaining a loyal customer list for port updates and accuracy is critical in establishing its usefulness. These lists are critical as they can be used to provide suggestions for new products and services to loyal customers. Finally, based on the frequent patterns of the ships and the mode of arrival times, a formula proposed in this paper to derive shipping companies' loyalty to ports was applied. The case of Kaohsiung port was shown as an example of our algorithm, and the OD data of ships in 2017-2018 were processed. Using the results of our algorithm, other rival ports, such as Shanghai or Busan, may attract customers no longer loyal to Kaohsiung ports in the last two years and attract them as new loyal customers.

• 융합신호처리학회논문지
• /
• 제1권1호
• /
• pp.74-81
• /
• 2000

기존의 전용선을 사용하는 화상 감시 시스템의 문제점을 해결하기 위해 인터넷을 이용한 3계층 웹기반 화상 감시 모델을 제안하고 시스템으로 구현하였다. 개발된 시스템은 3계층 웹기반 분산제어 모델을 채택함으로써 기존의 중앙 집중제어 방식의 시스템 안정성 문제를 해결하였고, 원격 웹브라우저에서 그룹으로 등록된 복수의 화상 감시 싸이트(Site)를 인터넷을 통해 원격제어 및 자동감시가 가능하다. 또한 자바 가상 기계(Java Virtual Machine) 코드와 가상 인스트루먼트(Virtual Instrument) 개념에 의한 운용 소프트웨어 설계로 다양한 종류의 컴퓨터와 OS에서도 운용이 가능하다. 또한 인터넷을 통한 네트워크 구성이므로 별도의 네트워크 구축비용이 들지 않으며, 웹서버를 사용한 운용 소프트웨어의 배포 및 보수 유지가 이루어지므로 소프트웨어 갱신 등에 따른 관리의 효율성을 크게 개선 할 수 있다.

• 한국CDE학회논문집
• /
• 제11권5호
• /
• pp.335-343
• /
• 2006

Design changes for an original surface model are frequently required in a manufacturing area: for example, when the physical parts are modified or when the parts are partially manufactured from analogous shapes. In this case, an efficient 3D model updating method by locally adding scan data for the modified area is highly desirable. For this purpose, this paper presents a new procedure to update an initial model that is composed of combinatorial triangular facets based on a set of locally added point data. The initial surface model is first created from the initial point set by Tight Cocone, which is a water-tight surface reconstructor; and then the point cloud data for the updates is locally added onto the initial model maintaining the same coordinate system. In order to update the initial model, the special region on the initial surface that needs to be updated is recognized through the detection of the overlapping area between the initial model and the boundary of the newly added point cloud. After that, the initial surface model is eventually updated to the final output by replacing the recognized region with the newly added point cloud. The proposed method has been implemented and tested with several examples. This algorithm will be practically useful to modify the surface model with physical part changes and free-form surface design.

• 정보처리학회논문지D
• /
• 제13D권5호
• /
• pp.641-650
• /
• 2006

XML은 자기 기술적인 특징이 있기 때문에 구조를 한정하기 위해서 DTD 또는 XML 스키마를 사용한다. XML 스키마가 아직 권고안에 불과하지만 DTD는 XML 언어가 아니고 표현에도 한계가 있기 때문에 XML 스키마의 사용이 보편화 될 것이다. XML 문서의 구조와 데이터는 XML 스키마의 잘못된 디자인, 어플리케이션의 새로운 요구 등의 여러 복합적인 이유로 변할 수가 있다. 이에 우리는 XML 스키마 진화(schema evolution)을 분석하여 w;ls화의 기능을 실현할 수 있는 최소한의 연산자들을 제안한다. 이러한 스키마 진화 연산자들은 XML스키마에 순응하는 XML 문서의 수가 많을 경우, XSE가 없다면 불가능한 XML 스키마와 XML 문서의 수정을 가능하게 한다. 더욱이 연산자들은 자동적으로 XML 스키마에 등록되어 있는 모든 XML 문서의 수정위치를 찾아주고 수정 후에도 XML 문서를 well-form 상태가 아닌 valid 상태를 유지시키는 기능을 포함하고 있다 이 논문은 XML 스키마를 체계적으로 수정하는 첫 번째 시도이며 XML의 수정에 필요한 대부분의 연산을 제공한다. 이 논문의 연구는 XML 문서의 구조뿐만 아니라 데이터까지 쉽고 정확하게 수정하는 것을 도와주기 때문에 XML 어플리케이션의 개발과 유지를 위해 꼭 필요한 작업이다.

• 한국항해항만학회지
• /
• 제40권5호
• /
• pp.241-247
• /
• 2016

The tracking filter plays a key role in the accurate estimation and prediction of maneuvering a vessel's position and velocity when attempting to enhance safety by avoiding collision. Therefore, in order to achieve accurate estimation and prediction, many oceangoing vessels are equipped with the Automatic Radar Plotting Aid (ARPA) system. However, the accuracy of prediction depends on the tracking filter's ability to reduce noise and maintain a stable transient response. The purpose of this paper is to derive the optimal values of the gain parameters used in tracking a High Dynamic Warship. The algorithm employs a ${\alpha}-{\beta}-{\gamma}$ filter to provide accurate estimates and updates of the state variables, that is, positions, velocity and acceleration of the high dynamic warship based on previously observed values. In this study, the filtering coefficients ${\alpha}$, ${\beta}$ and ${\gamma}$ are determined from set values of the damping parameter, ${\xi}$. Optimization of the damping parameter, ${\xi}$, is achieved experimentally by plotting the residual error against different values of the damping parameter to determine the least value of the damping parameter that results in the optimum smoothing coefficients leading to a reduction in the noise corruption effect. Further investigation of the performance of the filter indicates that optimal smoothing coefficients depend on the initial and average velocity of the target.

• 융합정보논문지
• /
• 제8권1호
• /
• pp.139-145
• /
• 2018

랜섬웨어란 악성코드의 일종이다. 랜섬웨어에 감염된 컴퓨터는 시스템 접근이 제한된다. 이를 해제하기 위해서는 악성 코드 제작자에게 대가를 제공해야 한다. 최근 최대 규모의 랜섬웨어 공격이 발생함에 따라 인터넷 보안 환경에 대한 우려가 점점 커지고 있다. 랜섬웨어에 대한 종류와 사이버테러 피해를 막기 위한 대응 방안을 알아본다. 강력한 감염성을 가지며 최근에도 끊임없이 공격해오는 랜섬웨어는 대표적으로 Locky, Petya, Cerber, Samam, Jigsaw가 있고, 점점 공격패턴이 진화중이며 요구 결제 금액 또한 증가하고 있다. 현재로써 랜섬웨어 방어는 100% 특효약이 있는 것이 아니다. 하지만 자동업데이트, 백신설치, 주기적 백업을 통해 랜섬웨어에 대응 할 수 있다. 본 연구에서는 네트워크와 시스템에 도달하지 못하도록 다층적인 접근 방법을 제시하여, 기업과 개인 사용자들의 랜섬웨어 예방 방법을 제시하였다.

• 대한조선학회논문집
• /
• 제50권6호
• /
• pp.458-465
• /
• 2013

Ship design engineering refers to the development and design of shipbuilding architectures in a drawing which reflects all relevant manufacturing processes. This paper provides analysis methods for model-information interfaces between hull structure design and outfitting design, and a technical application for manufacturing phases reflecting the pipe support pad and angle item automatically. The existing information procedure of pipe support pad and angle system processes information using drawing without model specification. Outfitting design team directly distributes drawings to the shop floor then manual-based marking and installation work are conducted refer to the distributed drawings. As a result, this process has become time consuming and causes problems in the productivity and quality improvement due to the rework caused by omitted or incorrect marking. The pipe support pad and angle marking is a method that automatically updates model information to hull structure design using sets of data that analyse the generated model in outfitting design processes. Therefore, this approach provides an efficient solution through design references without manual activities such as a reflection of hull structure design, cutting process, numerical control work, and dimension measurement and marking. The conversion of a method from the existing procedure based on manual marking to the reflective and automatic approach would have enabled to proceed installation work without manual activities for the measurement. Therefore, this research study proposes an efficient approach using pre-data analysis of model information interfaces between design and manufacturing phases to improve productivity during construction for shipbuilding.

• 정보과학회 컴퓨팅의 실제 논문지
• /
• 제22권9호
• /
• pp.419-425
• /
• 2016

내비게이션 시스템에서 지도 데이터를 최신 정보로 유지하는 것은 중요한 일이다. 그러나 수작업을 통한 갱신은 비용이 많이 소요될 뿐만 아니라 갱신되는 정보를 즉각적으로 반영하기 힘들다. 본 논문에서는 GPS 데이터를 이용하여 자동으로 도로를 생성해주는 시스템에서 가장 중요한 문제 중 하나인 중심 도로를 추출하는 기법에 관하여 살펴보고자 한다. 중심도로를 추출하기 위해서는 클러스터링 시킨 궤적이 필요하지만, 실제 궤적은 클러스터링 되어있지 않다. 이 문제를 해결하기 위하여 본 논문에서는 최대 중첩구간 탐색과 궤적 클러스터링 과정을 통하여 효과적으로 궤적에 대해 클러스터링 하는 기법을 제안한다. 마지막으로 클러스터링 시킨 궤적에 대하여 가상달리기 기법을 적용하여 중심도로를 추출하였다. 실험 데이터로는 실제 대용량의 강남구, 성남시, 서울시 전체를 지나다니는 택시 GPS 데이터를 수집하여 실험을 하였고, 실험 결과 제안기법이 실제 중심 도로를 추출하는데 안정적이고 효율적인 것을 보였다.