• Title/Summary/Keyword: 거리함수

Search Result 967, Processing Time 0.03 seconds

On the plane geometry using taxicab distance function (택시거리함수를 이용한 평면기하에 관한 연구)

  • Kwak, Kyung-Min;Baik, Seung-Min;Choi, Woo-Seok;Choi, Jun-Bum;Ko, Il-Seog;Kim, Byung-Hak
    • Communications of Mathematical Education
    • /
    • v.24 no.3
    • /
    • pp.659-689
    • /
    • 2010
  • Taxicab distance function is a practical distance notion which gives us information of real world pathway distance that really taxi can go through. As one of the non-Euclidean geometry, this study of an ideal city with all roads running horizontal or vertical, was introduced by the Russian Mathematician H. Minkowski and synthetically reported by the E. F. Kraus in 1986. After that, there were many reports and papers on this topic and still being researched. At this point of view, our research about taxicab geometry provides its differences from Euclidean plane geometry, and considers about several theorems on plane geometry using the taxicab distance function.

Applying distance metric learning for improvement of genre classification (장르 분류 성능 향상을 위한 거리함수 학습의 활용)

  • Jang, Dal-Won;Sin, Sa-Im;Lee, Jong-Seol;Jang, Se-Jin;Lim, Tae-Beom
    • Proceedings of the Korean Society of Broadcast Engineers Conference
    • /
    • 2013.11a
    • /
    • pp.36-37
    • /
    • 2013
  • 음악 장르 분류 분야에서는 다양한 특징을 모아서 사용하는 방법과 support vector machine (SVM) 분류기가 주로 사용되고 있다. 이 논문에서는 거리 함수 학습를 음악 장르 분류에 적용하여 성능 향상을 꾀한다. 여러 거리 함수 학습 방법 중 하나의 방법을 선택하고, 일반적으로 많이 사용되는 특징 셋을 활용하여 다양한 특징 셋에 대해서 적용하였을 때, 실제 성능 향상이 있는지를 알아본다. 세 종류의 특징 셋을 사용하여 실험한 결과 두 가지 특징이 같이 있는 특징 셋에 대해서만 성능 향상이 있었으며, SVM보다 높은 성능을 보이지 못 했다.

  • PDF

Local Obstacle Avoidance Method of Mobile Robot Using Virtual Distance Function (가상 거리 함수를 이용한 이동 로봇의 지역 장애물 회피 방법)

  • 임춘환;김성철;편석범
    • Journal of the Korean Institute of Telematics and Electronics T
    • /
    • v.35T no.3
    • /
    • pp.67-75
    • /
    • 1998
  • This paper presents a new robot motion planning method for moving obstacle avoidance. To consider the mobility of a moving obstacle, we define virtual distance function(VDF) between the robot and the obstacle. At each sampling time, we use the VDF to construct an artificial potential, considering the motion of obstacles. The robot moves according to the repulsive and attractive force vector induced by the artificial potential function. The proposed algorithm can be driven the robot to avoid moving obstacles in real time. Some simulation studies show the effectiveness of the proposed method.

  • PDF

A Range Dependent Structural HRTF Model for 3D Sound Generation in Virtual Environments (가상현실 환경에서의 3 차원 사운드 생성을 위한 거리 변화에 따른 구조적 머리전달함수 모델)

  • Lee, Young-Han;Lee, Gil-Ho;Kim, Hong-Kook
    • 한국HCI학회:학술대회논문집
    • /
    • 2006.02a
    • /
    • pp.632-637
    • /
    • 2006
  • 본 논문에서는 가상현실 환경에서 방위각, 고도, 거리 등의 위치 정보를 인지할 수 있는 3 차원 사운드를 생성하기 위한 구조적 머리전달함수(Head-Related Transfer Function, HRTF) 모델을 제안하고 이를 구현한다. 이를 위해 우선 기존에 연구된 방위각과 고도에 관한 head model 과 pinna model 을 근간으로 거리의 변화를 고려하도록 하는 HRTF 모델을 제안한다. 제안된 거리 변화에 따른 HRTF 모델은 거리 차이에 따른 음압의 변화 모델과 근거리에서 사람의 머리에 의해 생기는 shadowing 모델로 구성된다. 본 논문에서는 제안한 모델로 부터 mono 사운드를 방위각, 고도, 거리를 인지할 수 있는 stereo 사운드로 변환하여 생성하는 3 차원 사운드 생성기를 구현하였고, 일반인을 대상으로 거리에 대한 청취 실험을 통하여 제안한 모델의 성능을 측정하였다. 그리고 제안된 모델을 가상현실의 실감모델인 MP3 에 구현하여 그 효과를 입증하였다.

  • PDF

Behavioral Analysis of Re-scaled Width Function by Interaction between Overland and Stream network (지면과 하천망의 상호작용에 따른 재조정된 폭 함수의 거동해석)

  • Kim, Joo-Cheol;Kim, Jeong-Kon;Lee, Sang-Jin
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2011.05a
    • /
    • pp.296-296
    • /
    • 2011
  • 유역의 폭 함수는 출구를 기준으로 동일한 거리에 위치한 link의 개수로 정의된다. 하천망을 구성하는 기본 성분 중의 하나인 link는 동일한 유역의 경우 유사한 평균길이와 직접배수면적을 갖는 것으로 알려져 있다. 이는 폭 함수가 흐름방향 축을 따라 정의되는 지점별 배수면적의 기여도와 동일함을 의미하는 것으로 유역의 형태학적 특성에 따라 조직되는 초기유량분포함수로 해석할 수 있다. 따라서 DEM을 기반으로 원점으로부터 동일한 거리에 위치한 pixel의 수를 계량할 경우 비교적 쉽게 유역의 폭 함수를 유도할 수 있게 된다. 또한 물 입자의 동적특성에 따라 폭 함수의 흐름방향 축을 시간 축으로 재조정할 경우 대상 유역에 대한 수문학적 응답함수로의 변환이 가능해 진다. 본 연구에서는 보청천 시험유역의 탄부수위표 지점을 출구로 하여 DEM으로부터 폭 함수를 작성하고 지면과 하천유속의 차에 따른 운동학적 확산효과만을 고려하여 재조정된 폭 함수를 다음 그림과 같이 유도하여 보았다. Figs 1, 2에서 주목되는 사항은 왜곡도의 반전으로 부왜도의 형태를 갖던 폭 함수가 정왜도의 형태를 갖는 수문학적 응답함수(순간단위도)로 변환되어 가는 과정을 시각적으로 확인할 수 있다. 이는 Mod-Clark 방법에 따른 준분포형 순간단위도의 유도과정과 유사한 것으로 이에 따라 선형저수지의 저류효과는 지면과 하천유속의 차에 따른 운동학적 확산효과와 동일한 거동을 보일 수 있음이 추론된다.

  • PDF

Production Characteristics and Efficiency of Korean Railroad Industry using a Distance Function (거리함수를 이용한 한국 철도산업의 생산특성 및 효율성 분석)

  • Kim, Seong-Ho
    • Journal of Korean Society of Transportation
    • /
    • v.24 no.5 s.91
    • /
    • pp.45-56
    • /
    • 2006
  • In order to construct an information pool on the production characteristics and efficiency of Korean railroad industry, various alternative approaches have to be applied. In this paper we present an empirical application of the distance function to measure the technical efficiency and the production characteristics of Korean railroad industry, The distance function firstly introduced by Shephard (1953) provides the advantage that it does not need information about prices, so it can accommodate the multiple output nature of the railway only using the quantifies as data. This is of great relevance in the context of the public sector such as railroad industry where there are often distinct control mechanisms on input prices. Also the distance function allows us to obtain a measure of technical efficiency as well as a measure of production characteristics. From annual data on Korean railroad industry during 1964-2004, multiple output distance function is estimated using quadratic programming model. The resulting technical efficiency estimates has tended to be improved over the period $1980{\sim}2004$. The indirect Morishima elasticities of substitution indicate that the substitutabilities for labor are relatively very low or impossible. The average scale elasticity is 2.7 which means that increasing the scale by 1per cent will result in an output increase by 2.7 percent. This result indicates that economies of scale are present in the Korean railroad industry.

Development of a Multiobjective Optimization Algorithm Using Data Distribution Characteristics (데이터 분포특성을 이용한 다목적함수 최적화 알고리즘 개발)

  • Hwang, In-Jin;Park, Gyung-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.34 no.12
    • /
    • pp.1793-1803
    • /
    • 2010
  • The weighting method and goal programming require weighting factors or target values to obtain a Pareto optimal solution. However, it is difficult to define these parameters, and a Pareto solution is not guaranteed when the choice of the parameters is incorrect. Recently, the Mahalanobis Taguchi System (MTS) has been introduced to minimize the Mahalanobis distance (MD). However, the MTS method cannot obtain a Pareto optimal solution. We propose a function called the skewed Mahalanobis distance (SMD) to obtain a Pareto optimal solution while retaining the advantages of the MD. The SMD is a new distance scale that multiplies the skewed value of a design point by the MD. The weighting factors are automatically reflected when the SMD is calculated. The SMD always gives a unique Pareto optimal solution. To verify the efficiency of the SMD, we present two numerical examples and show that the SMD can obtain a unique Pareto optimal solution without any additional information.

Pattern Spectrum Component Function and Warning Traffic Sign Recognition (패턴 스펙트럼 성분 함수와 주의 교통 표지 인식)

  • 김회진;장강의;최태영
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.22 no.3
    • /
    • pp.401-409
    • /
    • 1997
  • In this paper, a pattern spectrum component function is introduced for an oriented shape analysis and its properties are discussed. It can represent directional information of shape more precisely than the conventional oriented pattern spectrum. An adaptive distance function between two pattern spectrum component functions is presented to recognize different shapes in noise. As a practical application, the pattern spectrum component function is applied to warning traffic sign recognitions utilizing the adaptive distance functions. Favorable results are obtained compared to the oriented pattern spectrum.

  • PDF

A Method of Reducing the Processing Cost of Similarity Queries in Databases (데이터베이스에서 유사도 질의 처리 비용 감소 방법)

  • Kim, Sunkyung;Park, Ji Su;Shon, Jin Gon
    • KIPS Transactions on Software and Data Engineering
    • /
    • v.11 no.4
    • /
    • pp.157-162
    • /
    • 2022
  • Today, most data is stored in a database (DB). In the DB environment, the users requests the DB to find the data they wants. Similarity Query has predicate that explained by a similarity. However, in the process of processing the similarity query, it is difficult to use an index that can reduce the range of processed records, so the cost of calculating the similarity for all records in the table is high each time. To solve this problem, this paper defines a lightweight similarity function. The lightweight similarity function has lower data filtering accuracy than the similarity function, but consumes less cost than the similarity function. We present a method for reducing similarity query processing cost by using the lightweight similarity function features. Then, Chebyshev distance is presented as a lightweight similarity function to the Euclidean distance function, and the processing cost of a query using the existing similarity function and a query using the lightweight similarity function is compared. And through experiments, it is confirmed that the similarity query processing cost is reduced when Chebyshev distance is applied as a lightweight similarity function for Euclidean similarity.

A new Implementation of Perceptual LPC Cepstrum and its Application to Speech Recognition (인지 LPC cepstrum의 새로운 구현 및 음성인식에의 적용)

  • Kim, Jin-Young;Choi, Seong-Ho
    • The Journal of the Acoustical Society of Korea
    • /
    • v.15 no.5
    • /
    • pp.61-64
    • /
    • 1996
  • To improve the performance of a recognition system, namely the recognition rate, we propose a hew implementation of perceptual distance using LPC cepstrum(perceptual cepstrum, PLC). The PLC is caculated by convolution of a usual LPC cepstrum and a perceptual lifter(PL). To caculate PL, we define a new weighting function in the linear frequency domain considering the frequency scale(Bark-scale) characteristics. The PL is the inverse Fourier transform of the exponents of the weighting function. We verified our method through the speech recognition experiments. The performance of PLC was compared with that of the rasied sine liftering method.

  • PDF