• 제목/요약/키워드: Calculation algorithms

검색결과 467건 처리시간 0.032초

셀 기반 모델링을 이용한 경사계산 알고리즘 개발 (Developing of Slope Calculation Algorithm using Cell-based Modeling)

  • 안상현;강용석;신영철
    • 한국지리정보학회지
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    • 제8권3호
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    • pp.121-128
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    • 2005
  • 산불은 지형인자 중 경사에 의하여 대형화되는 경향이 강하다. 이러한 경사는 보통 GIS를 이용하여 분석하게 되는데 어떠한 분석 방법을 사용하는가에 따라 결과가 다르게 나타난다. 따라서 산불확대위험 분석에 합당한 경사 분석 방법을 선택하는 것이 중요하다. 본 연구에서는 셀기반 모델링을 이용하여 기존에 DEM 자료를 이용하여 경사를 계산하는 방법들을 검토하고, 산불확대위험 분석에 적합한 경사계산 알고리즘을 개발하고자 하였다. 그 결과 산불이 상향사면을 따라 급속하게 번지는 특성을 이용하여 산불확대위험 분석에 가장 적합한 경사계산 알고리즘으로 maximum uphill slope 알고리즘을 개발하였다.

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18세기 조선산학서의 대수 영역에 나타난 서양수학 표현 및 계산법 연구 (A Study of the Representation and Algorithms of Western Mathematics Reflected on the Algebra Domains of Chosun-Sanhak in the 18th Century)

  • 최은아
    • 한국학교수학회논문집
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    • 제23권1호
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    • pp.25-44
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    • 2020
  • 본 연구의 목적은 서양수학이 본격적으로 유입된 18세기 조선의 사회문화적 배경 하에 저슬된 조선 산학서의 대수 영역에서 서양수학의 표현과 계산법을 반영한 내용을 살펴보고, 서양식 계산법과 전통적 계산법의 공존 관계 또는 대체 양상을 분석하는 것이다. 이를 위해 18세기 산학문헌인 <구수략>, <고사신서>, <고사십이집>, <주해수용>을 중심으로 하여 <구일집>, <산학입문> 등 총 9종의 산학문헌을 분석하였다. 분석 결과, 산대 조작을 기반으로 하는 전통적인 사칙계산법이 과도기적 표현을 거쳐 유럽 수학의 필산으로 발달해가는 과정과 서양의 비례 개념과 비례식을 형식화하여 명시적으로 다루는 18세기 산학서의 공통적 변화를 확인하였다. 또한 연립일차방정식 해법의 계산식의 수학적 표현이 점진적으로 형식화되는 과정을 관찰하였다. 제곱근 계산법이 전통적인 개방술에서 증승개방법의 적용으로, 다시 유럽 산술이 반영된 제곱근을 구하는 필산으로 변화해가고 있음을 확인하였다. 이상의 18세기 조선산학 사례들은 수학의 진화적 속성과 사회문화적 속성을 이해할 수 있는 의미 있는 자료라고 할 수 있다.

고정 소수점 연산을 이용한 DVDR 서보의 강인 제어 알고리즘 해석 (Analysis of Robust Control Algorithms for DVDR Servo using Fixed-Point Arithmetic)

  • 박창범;김홍록;서일홍
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.259-259
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    • 2000
  • In the recent, the size of hardware is smaller and the structure is simpler, without reducing the performance of the digital controller. Accordingly, the fixed-point arithmetic is very important in the digital controller. This paper presents simulation to apply the robust control algorithms to DVDR servo controller using the floating-point and fixed-point arithmetic from the matlab. Also, it analyses and compares the performance of control algorithms in the each of point calculation and presents a method for improvement of drop in the performance, quantization error and overflow/underflow from using the fixed-point arithmetic

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운전시격의 계산 알고리즘에 관한 연구 (A Study on Minimum Headway Calculation)

  • 이종우;정의진;황종규;정철범
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2000년도 춘계학술대회 논문집
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    • pp.308-315
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    • 2000
  • Headway calculation is a important mean to evaluate railway system performance. A accurate headway calculation can be needed to headway reducing being achieved line capacity increasing by regulating signals spacing without any line construction. This paper introduced the theories and algorithms of calculating headways on wayside, multi step, one step braking and moving block signalling systems and showed some results of headways.

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화물 선적 최적화를 위한 LiDar 센서 기반 비규격 화물 체적산출 방법 연구 (A Study on the Method of Non-Standard Cargo Volume Calculation Based on LiDar Sensor for Cargo Loading Optimization)

  • 전영준;김예슬;안선규;정석찬
    • 한국멀티미디어학회논문지
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    • 제25권4호
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    • pp.559-567
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    • 2022
  • The optimal shipping location is determined by measuring the volume and weights of cargo shipped to non-standard cargo carriers. Currently, workers manually measure cargo volume, but automate it to improve work inefficiency. In this paper, we proposed the method of a real-time volume calculation using LiDar sensor for automating cargo measurement of non-standard cargo. For this purpose, we utilized the statistical techniques for data preprocessing and volume calculation, also used Voxel Grid filter to light weighted of data which are appropriate in real-time calculation. We implemented the function of Normal vectors and Triangle Mesh to generate surfaces and Alpha Shapes algorithms to process 3D modeling.

예측 모델 제어기 설계에서의 예측 시간의 최적화 및 예측 샘플링 시간의 최적화에 대한 연구 (A Study of Optimization of Integral Time and Sampling Time on Predictive Model Controller)

  • 왕현민;우광준;허경무
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 학술대회 논문집 정보 및 제어부문
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    • pp.421-424
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    • 2008
  • The real time modeling of dynamic system on adaptive control system is very important for flying control system(FCS). Using traditional method, it is required much calculation load for integral/differential at control system. Therefore, It is very important theme of study in these days to find algorithms for integration/differential at FCS. These algorithms for integral/differential influence strongly stability/reliability to control flying object. In this paper, we present optimal predictive sampling time for reduce calculation load at FCS and optimal predictive time on general cost function by applying adaptive control method.

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Automatic Determination of Constraint Parameter for Improving Homography Matrix Calculation in RANSAC Algorithm

  • Chandra, Devy;Lee, Kee-Sung;Jo, Geun-Sik
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2014년도 춘계학술발표대회
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    • pp.830-833
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    • 2014
  • This paper proposes dynamic constraint parameter to filter out degenerate configurations (i.e. set of collinear or adjacent features) in RANSAC algorithm. We define five different groups of image based on the feature distribution pattern. We apply the same linear and distance constraints for every image, but we use different constraint parameter for every group, which will affect the filtering result. An evaluation is done by comparing the proposed dynamic CS-RANSAC algorithm with the classic RANSAC and regular CS-RANSAC algorithms in the calculation of a homography matrix. The experimental results show that dynamic CS-RANSAC algorithm provides the lowest error rate compared to the other two algorithms.

국내 원자력발전소 지진 PSA의 CDF 과평가 방지를 위한 비희귀사건 모델링 방법 연구 (A Simple Approach to Calculate CDF with Non-rare Events in Seismic PSA Model of Korean Nuclear Power Plants)

  • 임학규
    • 한국안전학회지
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    • 제36권5호
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    • pp.86-91
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    • 2021
  • Calculating the scrutable core damage frequency (CDF) of nuclear power plants is an important component of the seismic probabilistic safety assessment (SPSA). In this work, a simple approach is developed to calculate CDF from minimal cut sets (MCSs) with non-rare events. When conventional calculation methods based on rare event approximations are employed, the CDF of industry SPSA models is significantly overestimated by non-rare events in the MCSs. Recently, quantification algorithms using binary decision diagrams (BDDs) have been introduced to prevent CDF overestimation in the SPSA. However, BDD structures are generated from a small part of whole MCSs due to limited computational memory, and they cannot be reviewed due to their complicated logic structure. This study suggests a simple approach for scrutinizing the CDF calculation based on whole MCSs in the SPSA system analysis model. The proposed approach compares the new results to outputs from existing algorithms, which helps in avoiding CDF overestimation.

Collaborative Filtering Algorithm Based on User-Item Attribute Preference

  • Ji, JiaQi;Chung, Yeongjee
    • Journal of information and communication convergence engineering
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    • 제17권2호
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    • pp.135-141
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    • 2019
  • Collaborative filtering algorithms often encounter data sparsity issues. To overcome this issue, auxiliary information of relevant items is analyzed and an item attribute matrix is derived. In this study, we combine the user-item attribute preference with the traditional similarity calculation method to develop an improved similarity calculation approach and use weights to control the importance of these two elements. A collaborative filtering algorithm based on user-item attribute preference is proposed. The experimental results show that the performance of the recommender system is the most optimal when the weight of traditional similarity is equal to that of user-item attribute preference similarity. Although the rating-matrix is sparse, better recommendation results can be obtained by adding a suitable proportion of user-item attribute preference similarity. Moreover, the mean absolute error of the proposed approach is less than that of two traditional collaborative filtering algorithms.

Research on Keyword-Overlap Similarity Algorithm Optimization in Short English Text Based on Lexical Chunk Theory

  • Na Li;Cheng Li;Honglie Zhang
    • Journal of Information Processing Systems
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    • 제19권5호
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    • pp.631-640
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    • 2023
  • Short-text similarity calculation is one of the hot issues in natural language processing research. The conventional keyword-overlap similarity algorithms merely consider the lexical item information and neglect the effect of the word order. And some of its optimized algorithms combine the word order, but the weights are hard to be determined. In the paper, viewing the keyword-overlap similarity algorithm, the short English text similarity algorithm based on lexical chunk theory (LC-SETSA) is proposed, which introduces the lexical chunk theory existing in cognitive psychology category into the short English text similarity calculation for the first time. The lexical chunks are applied to segment short English texts, and the segmentation results demonstrate the semantic connotation and the fixed word order of the lexical chunks, and then the overlap similarity of the lexical chunks is calculated accordingly. Finally, the comparative experiments are carried out, and the experimental results prove that the proposed algorithm of the paper is feasible, stable, and effective to a large extent.