• International Journal of Fuzzy Logic and Intelligent Systems
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• 제9권3호
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• pp.232-237
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• 2009

Active safety vehicle devices are getting more attention recently. To prevent traffic accidents, the environment in front and even around the vehicle must be checked and monitored. In the present applications, mainly camera and radar based systems are used as sensing devices. Laser scanner, one of the sensing devices, has the advantage of obtaining accurate measurement of the distance and the geometric information about the objects in the field of view of the laser scanner. However, there is a problem that detecting object occluded by a foreground one is difficult. In this paper, criterions are proposed to manage this problem. Simulation is conducted by vehicle mounted the laser scanner and multiple-hypothesis algorithm tracks the candidate objects. We compare the running times as multi-hypothesis algorithm parameter varies.

• 한국산업정보학회논문지
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• 제27권3호
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• pp.11-20
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• 2022

현재 광고 분야 등에 널리 사용되고 있는 흑백 QR코드의 정보 저장 용량을 증가시키기 위해 칼라 QR코드에 대한 연구가 활발히 진행되고 있다. 그러나 칼라 QR코드는 프린팅 또는 스캐닝 과정에 의해 복재가 될 수 있으며, 이 과정에서 불충분한 조도에 의한 색상 왜곡과 잡음, 카메라의 낮은 해상도와 기하학적 변형의 가능성이 있다. 이러한 일련의 복합적인 과정들은 품질 저하와 인식률 저하를 초래한다. 이러한 문제점을 극복하기 위해 본 논문에서는 칼라 QR코드에 패턴 삽입을 고려하고, 이를 위한 효과적인 인식 방법을 제안한다. 또한, 제안한 방법을 통해 기존에 다루어진 대표적인 패턴을 도입하고, 인식률 측면에서 실험을 수행하여 그 결과를 비교 분석한다. 즉, 인식과정에 있어서 쉽게 초래되는 가우시안 잡음과 블러링, 기하학적 변형 등의 잡음을 고려하여 성능을 비교 분석한다. 다양한 실험을 통해 가우시안 잡음과 블러 측면에서 단순한 패턴의 칼라 QR코드가 우수한 성능을 보이는 것을 확인할 수 있다.

• 대한산업공학회지
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• 제28권1호
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• pp.1-13
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• 2002

We study a multi-component production/inventory system in which individual components are made to meet various demand types. We assume that the demands arrive according to a Poisson process, but there is a fixed probability that a demand requests a particular kit of different components. Each component is produced by a flow line with several stations. The production of each component is operated by the CONWIP control mechanism. To analyse this system, we propose an approximation method based on aggregation method. In application of the aggregation method, a product-form approximation technique as well as a matrix-geometric method is used. Comparisons with simulation show that the approximation method provides fairly good results.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2010-2014
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• 2005

Object detection and parameter estimation in point cloud data is a relevant subject to robotics, reverse engineering, computer vision, and sport mechanics. In this paper a software is presented for fully-automatic object detection and parameter estimation in unordered, incomplete and error-contaminated point cloud with a large number of data points. The software consists of three algorithmic modules each for object identification, point segmentation, and model fitting. The newly developed algorithms for orthogonal distance fitting (ODF) play a fundamental role in each of the three modules. The ODF algorithms estimate the model parameters by minimizing the square sum of the shortest distances between the model feature and the measurement points. Curvature analysis of the local quadric surfaces fitted to small patches of point cloud provides the necessary seed information for automatic model selection, point segmentation, and model fitting. The performance of the software on a variety of point cloud data will be demonstrated live.

• 한국통신학회논문지
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• 제34권5A호
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• pp.331-340
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• 2009

In this paper, we propose a new power loading algorithm for orthogonalized spatial multiplexing(OSM) systems over flat-fading multiple-input multiple-output (MIMO) channels. Compared to SVD-based transmission scheme, the OSM scheme exhibits a good system performance with lower complexity and feedback overhead. To further improve the performance in OSM systems with power loading, we introduce a geometric approach on the Euclidean distance between the constellation points in the effective channel. Using this approach, we show that the optimal power loading parameters in terms of the minimum distance can be obtained. Simulation results demonstrate that our algorithm provides a 5dB gain at a bit error rate (BER) of $10^{-4}$ over that of no power loading case with both QPSK and 16-QAM. Consequently, our power loading algorithm allows us to significantly improve the system performance with one additional feedback value.

• 제어로봇시스템학회논문지
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• 제10권1호
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• pp.66-72
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• 2004

To assess tunnel safety, cracks in tunnel lining are measured by inspectors, who observe cracks with their naked eyes and record them. But manual inspection is slow, and measured crack data is subjective. Therefore, this study proposes inspection system fur measuring cracks in tunnel lining and providing objective crack data to be used in safety assessment. The system consists of On-vehicle system and Laboratory system. On-Vehicle system acquires image data with line CCD camera on scanning along the tunnel lining. Laboratory system extracts crack information from the acquired image using image processing. Measured crack information is crack thickness, length and orientation. To improve accuracy of crack recognition, the geometric properties and patterns of cracks in concrete structure were applied to image processing. The proposed system was verified with experiments in both laboratory environment and field environment such as subway tunnel.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1997년도 춘계학술대회 학술발표 논문집
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• pp.228-233
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• 1997

An efficient corner matching algorithm is developed to minimize the amount of calculation. To reduce the amount of calculation, all available information from a corner detector is used to make model. This information has uncertainties due to discretization noise and geometric distortion, and this is represented by fuzzy rule base which can represent and handle the uncertainties. Form fuzzy inference procedure, a matched segment list is extracted, and resulted segment list is used to calculate the transformation between object of model and scene. To reduce the false hypotheses, a vote and re-vote method is developed. Also an auto tuning scheme of the fuzzy rule base is developed to find out the uncertainties of features from recognized results automatically. To show the effectiveness of the developed algorithm, experiments are conducted for images of real electronic components.

• 한국컴퓨터정보학회논문지
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• 제10권1호
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• pp.35-44
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• 2005

서로 다른 기하학적 모델링 시스템을 사용하는 곡선 및 곡면의 자료 교환에서, 시스템이 지원하는 B-spline 곡선 및 곡면의 최대 차수에 제한이 있을 때, 주어진 허용 오차 범위 내에서 낮은 차수로의 차수 감소가 필요하다 본 논문에서는 근사 변환의 한 방법인 B-spline 곡선의 차수 감소 방법을 적용한 실험적 결과를 제공한다. B-spline 곡선의 근사변환에서 기존의 $B\acute{e}zier$ 곡선의 차수감소 방법들을 차수 감소 과정에 적용하고. 그 방법들을 비교 분석한다 knot 제거 알고리즘도 자료 감소를 위하여 차수 감소과정에 적용한다

• 한국컴퓨터정보학회논문지
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• 제8권1호
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• pp.7-12
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• 2003

시스템이 지원하는 곡선 및 곡면의 최대 차수에 제한이 있을 때, 낮은 차수로의 차수 감소가 필요하다. 본 논문에서는 근사 변환의 한 방법으로써 NURBS 곡선의 차수 감소 방법을 소개한다. 이 방법은 기존 Eck의 B$\'{e}$zier 차수 감소 방법과 자료 감소를 위해 knot 제거 알고리즘이 적용된다. 제시하는 방법은 안정적일 뿐만 아니라 수학적으로도 단순하므로 이해와 구현이 용이하다.

• 한국산업정보학회논문지
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• 제12권4호
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• pp.107-118
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• 2007

A single-server queueing model with infinite buffer and batch arrival of customers is considered. In contrast to the standard batch arrival when a whole batch arrives into the system at one epoch, we assume that the customers of an accepted batch arrive one-by one in exponentially distributed times. Service time is exponentially distributed. Flow of batches is the stationary Poisson arrival process. Batch size distribution is geometric. The number of batches, which can be admitted into the system simultaneously, is subject of control. Analysis of the joint distribution of the number batches and customers in the system and sojourn time distribution is implemented by means of the matrix technique and method of catastrophes. Effect of control on the main performance measures of the system is demonstrated numerically.