• 대한전기학회논문지
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• 제35권4호
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• pp.156-162
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• 1986

The last few years have seen a rapid development of so-called lattice algorithms for the fast solution of finite date algorithms. So far, most of the work on ladder form has been done for the prewindowed case. In this paper, the covariance lattice algorithm for instrumental variable recusions is presented. This algorithm can be used in various areas of adaptive signal processing, spectral estimation and system identification. The behavior of the proposed algorithm is illustrated by some simulation results for spectral estimation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1589-1592
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• 1997

Among the prerequisite abilities (perception of environment, path planning and position estimation) of an autonomous mobile robot, position estimation has been seldom studied by mobile robot researchers. In most cases, conventional positioin estimation has been performed by placing landmarks or giving the entrire environmental information in advance. Unlikely to the conventional ones, the study addresses a new method that the robot itself can select distinctive features in the environment and save them as landmarks without any a priori knowledge, which can maximize the autonomous behavior of the robot. First, an orjentaion probaility model is applied to construct a lcoal map of robot's surrounding. The feature of the object in the map is then extracted and the map is saved as landmark. Also, presented is the position estimation method that utilizes the correspondence between landmarks and current local map. In dong this, the uncertainty of the robot's current positioin is estimated in order to select the corresponding landmark stored in the previous steps. The usefulness of all these approaches are illustrated with the results porduced by a real robot equipped with ultrasonic sensors.

• 대한기계학회논문집
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• 제18권7호
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• pp.1632-1642
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• 1994

The Stewart Platform is a six-degree-of-freedom in-parallel-actuated manipiulator mechanism. The kinematic behavior of parallel mechanisms shows inverse characteristics as compared that of serial mechanisms; i.e, the inverse kinematic problem of Stewart Platform is straightforward, but no closed form solution of the forward kinematic problem has been previously presented. Thus it is difficult to calculate the 6 DOF displacement of the platform from the measured lengths of the six actuators in real time. Here, a real-time estimation algorithm which solves the Stewart Platform kinematic problem is proposed and tested through computer simulations and experiments. The proposed algorithm shows stable convergence characteristics, no estimation errors in steady state and good estimation performance with higher sampling rate. In experiments it is shown that the estimation result is the same as that of simulation even in the presence of measurement noise.

• 산업경영시스템학회지
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• 제30권4호
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• pp.164-169
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• 2007

The estimation of mortality characteristics of industrial property is an important adjunct to engineering valuation and depreciation estimation. Once the important of depreciation estimation is determined, it is desirable to understand the processes upon which these estimates are based. The Iowa type survivor curves are a set of generalized retirement dispersion models. These curves were based on analysis of actual retirement experience and represent typical retirement behavior patterns likely to be encountered. The retirement rate of Iowa type survivor curves on the semiconductor equipments in Korea industry was estimated by the life estimation process. In this paper, estimates of service lives based on directly observed data of the domestic semiconductor equipments are presented.

• Journal of the Korean Statistical Society
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• 제35권1호
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• pp.91-103
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• 2006

Yun (2005) introduced an estimator of the second order parameter characterizing the tail behavior of probability distributions and proved its consistency. In this paper we prove its asymptotic normality under a third order condition.

• Journal of the Korean Statistical Society
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• 제34권4호
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• pp.273-280
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• 2005

In this paper we introduce an estimator of the second order parameter characterizing the tail behavior of probability distributions and prove its consistency.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권2호
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• pp.800-816
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• 2018

In recent years, video surveillance research has been able to recognize various behaviors of pedestrians and analyze the overall situation of objects by combining image analysis technology and deep learning method. Human Activity Recognition (HAR), which is important issue in video surveillance research, is a field to detect abnormal behavior of pedestrians in CCTV environment. In order to recognize human behavior, it is necessary to detect the human in the image and to estimate the pose from the detected human. In this paper, we propose a novel approach for 2D Human Pose Estimation based on object detection using RGB-D information. By adding depth information to the RGB information that has some limitation in detecting object due to lack of topological information, we can improve the detecting accuracy. Subsequently, the rescaled region of the detected object is applied to ConVol.utional Pose Machines (CPM) which is a sequential prediction structure based on ConVol.utional Neural Network. We utilize CPM to generate belief maps to predict the positions of keypoint representing human body parts and to estimate human pose by detecting 14 key body points. From the experimental results, we can prove that the proposed method detects target objects robustly in occlusion. It is also possible to perform 2D human pose estimation by providing an accurately detected region as an input of the CPM. As for the future work, we will estimate the 3D human pose by mapping the 2D coordinate information on the body part onto the 3D space. Consequently, we can provide useful human behavior information in the research of HAR.

• 한국인터넷방송통신학회논문지
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• 제23권4호
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• pp.107-113
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• 2023

본 논문은 인공지능 기술을 활용하여 영상에서 흡연 행위를 검출하는 방법을 제안한다. 흡연은 정적 현상이 아니라 행위에 해당하기 때문에 객체 탐지 기술에 행위를 탐지할 수 있는 자세 추정 기술을 접목하였다. 이미지에서 흡연자를 검출하기 위하여 흡연자 검출 학습 모델을 개발하였으며, 영상에서 흡연행위를 검출하기 위하여 흡연행위의 특성을 자세 추정 기술에 적용하였다. 객체 탐지를 위하여 YOLOv8을 사용하였으며, 자세 추정을 위하여 OpenPose를 이용하였다. 또한, 영상에 흡연자 및 비흡연자가 포함되어 있는 경우 사람들만 분리하는 방법도 적용하였다. 제안된 방법은 파이선으로 Google Colab NVIDEA Tesla T4 GPU를 사용구현 하였고, 테스트 결과 주어진 영상에서 흡연 행위를 완벽하게 검출함을 알 수 있었다.

• Nuclear Engineering and Technology
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• 제52권4호
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• pp.846-855
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• 2020

A loose part monitoring system is used to detect unexpected loose parts in a reactor coolant system in a nuclear power plant. It is still necessary to develop a new methodology for the localization and mass estimation of loose parts owing to the high estimation error of conventional methods. In addition, model-based diagnostics recently emphasized the importance of a model describing the behavior of a mechanical system or component. The purpose of this study is to propose a new localization and mass-estimation method based on finite element analysis (FEA) and optimization technique. First, an FEA model to simulate the propagation behavior of the bending wave generated by a metal sphere impact is validated by performing an impact test and a corresponding FEA and optimization for a downsized steam-generator structure. Second, a novel methodology based on FEA and optimization technique was proposed to estimate the impact location and mass of a loose part at the same time. The usefulness of the methodology was then validated through a series of FEAs and some blind tests. A new feature vector, the cross-correlation function, was also proposed to predict the impact location and mass of a loose part, and its usefulness was then validated. It is expected that the proposed methodology can be utilized in model-based diagnostics for the estimation of impact parameters such as the mass, velocity, and impact location of a loose part. In addition, the FEA-based model can be used to optimize the sensor position to improve the collected data quality in the site of nuclear power plants.

• 지능정보연구
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• 제12권4호
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• pp.1-14
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• 2006

본 연구는 상품추천을 위해 필요한 고객 선호도 추정모형(Customer Preference Estimation Model)을 제안하고, 이러한 선호도 추정결과에 따른 선호도 정보를 이용하여 궁극적으로 상품추천의 성과를 제고시키기 위한 방법을 제시하였다. 즉, 제품에 대한 고객 선호 영향요인들과 고객 선호도와의 관계를 모형화 함으로써 고객 선호도를 보다 더 정확히 추정할 수 있는 새로운 선호도 추정모형을 제안하였다. 이 제안모형은 선호도 영향요인들의 상대적인 가중치를 선호도 최적화 학습을 통해 도출함으로써, 보다 정확한 선호도 측정을 가능하게 해 준다. 한편, 이 모형의 타당성을 검증하기 위해서 본 연구에서는 가상서점 고객들을 대상으로 고객 선호도 정보를 수집한 후, 본 제안모형을 적용했을 때의 협업 필터링의 추천성과와 사전가중치 부여방식인 기존 선호도 계산식을 이용했을 경우의 추천성과를 비교 분석하였다. 이에 대한 실증분석 결과는 본 연구에서 제안한 선호도 추정모형을 적용했을 때의 협업 필터링의 성과가 기존 선호도 계산방식을 적용했을 때의 협업 필터링의 성과보다 더 우수한 것으로 나타났다.