• 정보처리학회논문지B
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• 제17B권5호
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• pp.375-380
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• 2010

객체 윤곽을 추출하는 대부분의 기존 방법들은 단일객체의 윤곽검출에 대해 연구하였다. 그러나, 실 세계에서는 복수객체가 일반적이다. 본 논문에서 제안한 복수객체 윤곽추출 알고리즘은 2 단계로 구성된다. 첫 번째 단계는 외적 및 내적을 사용하여 초기에 복수객체를 포함한 윤곽을 고속으로 분리하고 연결하여 각각이 윤곽이 단일 개체만을 포함하는 방법을 제안한다. 두 번째 단계는 각각의 윤곽에 포함된 단일 객체의 윤곽을 추출하는 개선된 능동윤곽모델 알고리즘을 설명한다. 여러 실험영상에 대한 실험결과는 다른 방법과 비교하여 속도가 빠르며 정확하게 윤곽을 추출한다.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제12권10호
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• pp.299-308
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• 2023

다양한 서비스가 등장으로 인해 스펙트럼 부족 문제가 가속하됨에 따라, 면허 대역에서 통신하던 사용자들을 비면허 대역에서 통신하는 NR-U(New Radio-Unlicensed)가 등장하였다. 하지만 NR-U 네트워크 사용자로 인해 동일한 비면허 대역에서 통신하는 Wi-Fi 네트워크 사용자의 성능이 감소하게 된다. 본 논문에서는 NR-U 네트워크 사용자와 WiFi 네트워크 사용자가 공존해있는 비면허 대역의 처리량과 비면허 대역의 사용에 대한 공평성을 동시에 최대화하는 것을 목표로 한다. 먼저 비면허 대역에서 전송률 분할 다중 접속 기술을 활용한 NR-U 네트워크의 합-전송 속도 (Sum of Rate)를 최대화하기 위해 강화 학습의 몬테 카를로 정책 하강법(Monte Carlo Policy Gradient)을 활용한 최적의 전력 할당 기법을 제안하였다. 그 뒤, 동일한 비면허 대역에서 NR-U 네트워크와 WiFi 네트워크의 공존을 위해 시스템 처리량과 공정성을 동시에 최대화할 수 있는 게임 이론의 순차적 라이파 협상 해법(Sequential Raiffa Bargaining Solution)을 활용한 채널 점유 시간 분할 알고리즘을 제안하였다. 시뮬레이션 결과에서 동일한 전력 할당 기법을 사용하였을 때, 본 논문에서 제안한 전송률 분할 다중 접속 기술이 기존의 다중 접속 기술들보다 더 빠른 합-전송속도를 보임을 확인하였다. 또한 비면허 대역 네트워크의 전송량과 공평성을 비교해본 결과 본 논문의 순차적 라이파 협상 해법을 활용한 채널 점유 시간 분할 알고리즘이 타 알고리즘보다 처리량과 공정성을 동시에 만족함을 입증하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권6호
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• pp.2160-2179
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• 2015

In many Radio Frequency Identification (RFID) applications, the reader recognizes the tags within its scope repeatedly. For these applications, some algorithms such as the adaptive query splitting algorithm (AQS) and the novel semi-blocking AQS (SBA) were proposed. In these algorithms, a staying tag retransmits its ID to the reader to be identified, even though the ID of the tag is stored in the reader's memory. When the length of tag ID is long, the reader consumes a long time to identify the staying tags. To overcome this deficiency, we propose a slot allocated blocking anti-collision algorithm (SABA). In SABA, the reader assigns a unique slot to each tag in its range by using a slot allocation mechanism. Based on the allocated slot, each staying tag only replies a short data to the reader in the identification process. As a result, the amount of data transmitted by the staying tags is reduced greatly and the identification rate of the reader is improved effectively. The identification rate and the data amount transmitted by tags of SABA are analyzed theoretically and verified by various simulations. The simulation and analysis results show that the performance of SABA is superior to the existing algorithms significantly.

• Communications for Statistical Applications and Methods
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• 제9권3호
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• pp.809-824
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• 2002

we propose two methods which separate the variable selection step and the split-point selection step. We call these two algorithms as CHITES method and F&CHITES method. They adapted some of the best characteristics of CART, CHAID, and QUEST. In the first step the variable, which is most significant to predict the target class values, is selected. In the second step, the exhaustive search method is applied to find the splitting point based on the selected variable in the first step. We compared the proposed methods, CART, and QUEST in terms of variable selection bias and power, error rates, and training times. The proposed methods are not only unbiased in the null case, but also powerful for selecting correct variables in non-null cases.

• 대한산업공학회지
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• 제30권2호
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• pp.159-164
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• 2004

Lot-streaming is the process of splitting a job (lot) into a number of smaller sublots and then scheduling these sublots in order to accelerate the completion of jobs in a multi-stage production system. Anew genetic algorithm (NGA) is proposed for an-job, m-machine, equal-size sublot lot-streaming flow shop scheduling problem with delivery windows in which the objective is to minimize the mean weighted absolute deviation of job completion times from due dates. The performance of NGA is compared with that of an adjacent pairwise interchange (API) method and the results of computational experiments show that NGA works well for this type of problem.

• Journal of Information Processing Systems
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• 제7권3호
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• pp.519-530
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• 2011

A Snake is an active contour for representing object contours. Traditional snake algorithms are often used to represent the contour of a single object. However, if there is more than one object in the image, the snake model must be adaptive to determine the corresponding contour of each object. Also, the previous initialized snake contours risk getting the wrong results when tracking multiple objects in successive frames due to the weak topology changes. To overcome this problem, in this paper, we present a new snake method for efficiently tracking contours of multiple objects. Our proposed algorithm can provide a straightforward approach for snake contour rapid splitting and connection, which usually cannot be gracefully handled by traditional snakes. Experimental results of various test sequence images with multiple objects have shown good performance, which proves that the proposed method is both effective and accurate.

• Journal of information and communication convergence engineering
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• 제13권3호
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• pp.215-219
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• 2015

Cells in a culture process transform with time and produce many overlapping cells in their vicinity. We are interested in a separation algorithm for images of overlapping cells taken using a fluorescence optical microscope system during a cell culture process. In this study, all cells are assumed to have an ellipse-like shape. For an ellipse fitting-based method, an improved least squares method is used by decomposing the design matrix into quadratic and linear parts for the separation of overlapping cells. Through various experiments, the improved least squares method (numerically stable direct least squares fitting [NSDLSF]) is compared with the conventional least squares method (direct least squares fitting [DLSF]). The results reveal that NSDLSF has a successful separation ratio with an average accuracy of 95% for two overlapping cells, an average accuracy of 91% for three overlapping cells, and about 82% accuracy for four overlapping cells.

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2004년도 춘계학술대회
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• pp.39-50
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• 2004

The decision tree approach is most useful in classification problems and to divide the search space into rectangular regions. Decision tree algorithms are used extensively for data mining in many domains such as retail target marketing, fraud dection, data reduction and variable screening, category merging, etc. CHAID(Chi-square Automatic Interaction Detector) uses the chi-squired statistic to determine splitting and is an exploratory method used to study the relationship between a dependent variable and a series of predictor variables. In this paper we propose CHAID algorithm by cube-based proportional sampling and explore CHAID algorithm in view of accuracy and speed by the number of variables.

• Journal of the Korean Data and Information Science Society
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• 제15권4호
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• pp.803-816
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• 2004

The decision tree approach is most useful in classification problems and to divide the search space into rectangular regions. Decision tree algorithms are used extensively for data mining in many domains such as retail target marketing, fraud dection, data reduction and variable screening, category merging, etc. CHAID uses the chi-squired statistic to determine splitting and is an exploratory method used to study the relationship between a dependent variable and a series of predictor variables. In this paper we propose CHAID algorithm by cube-based proportional sampling and explore CHAID algorithm in view of accuracy and speed by the number of variables.

• Structural Engineering and Mechanics
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• 제3권2호
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• pp.185-192
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• 1995

A numerical algorithm for plane stress and shell elasto-plasticity is presented in this paper. The proposed strain decomposition (SD) algorithm is an elastic predictor/plastic corrector algorithm, and in the context of operator splitting, is a return mapping algorithm. However, it differs significantly from other return mapping algorithms in that only the necessary response functions are used without invoking their gradients, and the stress increment is updated only at the end of the time step. This makes the proposed SD algorithm more suitable for materials with complex yield surfaces and will guard against error accumulation during the time step. Comparative analyses of structural systems using the proposed strain decomposition (SD) algorithm and the iterative radial return (IRR) algorithm are presented. The results demonstrate the accuracy and usefulness of the proposed algorithm.