• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 춘계학술대회
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• pp.307-309
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• 2012

노드의 위치인식은 M2M 무선센서네트워크에서의 위치에 기반을 둔 여러 응용들을 위해 매우 중요한 문제이다. 센서 네트워크에서의 위치인식은 거리 정보가 사용되느냐 그렇지 않느냐에 따라 range-free와 range-based 기법으로 분류될 수 있는데, 센서노드 특성상 제한된 하드웨어로 동작해야 한다는 점에서 range-free 위치인식 기법이 range-based 기법에 비해 효율적인 방법이라 할 수 있다. DV-Hop은 range-free 위치인식 기법 중 대표적인 것으로서 홉 수와 거리 간 추정을 사용한다. 본 논문에서는 홉 수와 거리 간 추정을 위해 홉 수보다 거리와의 상관도가 높은 홉 수 평균을 사용하여 DV-Hop 에 비해 정확도를 향상시킨 DV-ANHC 알고리즘을 제시한다.

• 한국의류학회지
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• 제22권5호
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• pp.607-616
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• 1998

The purpose of this study was to develope a practical color range for the fashion industry in Korea. 3623 color sample used by 109 brands from'93 spring/summer to'96 spring/summer were collected. Also, the application frequency and consumer responses of each collected colorwere analyzed in this study. To clarify the characterstics of color range used in the fashion industry, density of color was etermined by color clustering based on A: and consumer responses. The resultsof this study were as follow; 1. The result analyzed based on the Munsell System revealed that the distributions of hue were concentrated in R, YR, Y, and PB. The chroma was concenturated mostly in the low range and the value, on the contrary, showed relatively even distribution. 2. 458 representative colors were selected by color clustering based on the toEless than 1. 0. In addition, the frequency of color applications and consumer responses were also considered when selecting the colors frequently used in the fashion industry and finals, 1163 colors wereobtained. The color range of the representative colors showed similar color characteristics with the 3623 colors supplied by the fashion industry. As a results, this approach was proven to appropriate to develope a color range for a practical use. 3. In conclusion, around 1200 colors were suggested to organize the color range to reflect the characteristics of the fashion industry with an acceptable color differance for color planning and management.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.42.1-42
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• 2002

A model to predict population by sex, age and district over a long-range period is proposed based on fuzzy theories. First, a fuzzy model is described. Second, a method to estimate the social increase by sex and age in each district is proposed based on a fuzzy clustering method for dealing with long-range socioeconomic changes in population migration. By the proposed methods, it became possible to predict the population by sex, age and district over a long-range period. Third, the structure and characteristics of the three models of employment model, time distance model, and land use model constructed to predict various socioeconomic indicators, which are require...

• 전자공학회논문지B
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• 제32B권8호
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• pp.1074-1084
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• 1995

In this paper, we investigate edge extraction and segmentation of range images. We first discuss problems that arise in the conventional region-based segmentation methods and edge-based ones using principal curvatures, then we propose an edge-based algorithm. In the proposed algorithm, we extract edge contours by using the Gaussian filter and directional derivatives, and segment a range image based on extracted edge contours, Also we present the problem that arises in the conventional thresholding, then we propose a new threshold selection method. To solve the problem that local maxima of the first- and second- order derivatives gather near step edges, we first find closed roof edge contours, fill the step edge region, and finally thin edge boundaries. Computer simulations with several range images show that the proposed method yields better performance than the conventional one.

• ETRI Journal
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• 제29권5호
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• pp.691-693
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• 2007

Existing methods to process continuous range queries are not scalable. In particular, as the number of continuous range queries on a large number of moving objects becomes larger, their performance degrades significantly. We propose a novel query indexing method called the projected attribute bit (PAB)-based query index. We project a two-dimensional continuous range query on each axis to get two one-dimensional bit lists. Since the queries are transformed to bit lists and query evaluation is performed by bit operations, the storage cost of indexing and query evaluation time are reduced significantly. Through various experiments, we show that our method outperforms the containment-encoded squares-based indexing method, which is one of the most recently proposed methods.

• 한국통신학회논문지
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• 제39C권8호
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• pp.643-650
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• 2014

최근 센서 네트워크와 같이 근거리 무선 통신 시스템에 대한 연구가 활발히 진행되면서 다양한 환경에서의 무선통신 관련 연구를 수행하고 있다. 본 논문에서는 수신 신호 세기를 이용한 선박용 실내 위치 추정 알고리즘을 분석하고 각 상황에 맞는 위치 추정 알고리즘을 제안한다. 무선 네트워크로부터 수신한 신호 세기를 이용하는 위치 추정 방식은 거리 추정 후 최소 제곱법을 이용하여 추정하는 Range based 방법이 있으며 네트워크를 구성하는 고정 노드와의 특성을 이용하여 위치를 추정하는 Range free 방식이 있다. 위치 추정 기법을 적용할 수 있는 해군 함정의 모델을 기반으로 효과적인 위치 추정 알고리즘을 시뮬레이션을 통해 분석하였다.

• 방송공학회논문지
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• 제14권4호
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• pp.428-437
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• 2009

A high dynamic range (HDR) image can represent real world scenes that have a wide range of luminance intensity. However, compared with the range of real world luminance, conventional display devices have a low dynamic range (LDR). To display HDR images onto conventional displayable devices such as monitors and printers, we propose the logarithmic based global reproduction algorithm that considers the features of the image using reproduction parameters. Based on the characteristics of the image, we first modify the input luminance values for reproducing perceptually tuned images and then obtain the displayable output values directly. The experimental results show that the proposed algorithm achieves good subjective results while preserving details of the image; furthermore, the proposed algorithm has a fast, simple and practical structure for implementation.

• Macromolecular Research
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• 제16권4호
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• pp.320-328
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• 2008

We established a thermodynamic framework of group contribution method based on modified double lattice (MDL) model. The proposed model included the long-range interaction contribution caused by the Coulomb electrostatic forces, the middle-range interaction contribution from the indirect effects of the charge interactions and the short-range interaction from modified double lattice model. The group contribution method explained the combinatorial energy contribution responsible for the revised Flory-Huggins entropy of mixing, the van der Waals energy contribution from dispersion, the polar force, and the specific energy contribution from hydrogen bonding. We showed the solvent activities of various polymer solution systems in comparison with theoretical predictions based on experimental data. The proposed model gave a very good agreement with the experimental data.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2010년도 추계학술발표대회
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• pp.829-832
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• 2010

Wireless Sensor Networks have been proposed for several location-dependent applications. For such systems, the cost and limitations of the hardware on sensing nodes prevent the use of range-based localization schemes that depend on absolute point to point distance estimates. Because coarse accuracy is sufficient for most sensor network applications, solutions in range-free localization are being pursued as a cost-effective alternative to more expensive range-based approaches. In this paper, we proposed a modified DV-Hop (range-free localization) algorithm which reduces node's location error and cumulated distance error by minimizing localization error. Simulation results have verified the high estimation accuracy with our approach which outperforms the classical DV-Hop.

• 한국통신학회논문지
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• 제38C권2호
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• pp.155-164
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• 2013

종래 측위 기법들의 큰 추정 오차, 고비용, 제한된 서비스 범위 등의 문제점들을 극복하기 위해, 가시광 통신과 애드혹 무선 네트워크 인프라를 사용하여 정확하고 편리한 두 가지 하이브리드 측위 설계 기법들을 제안한다. 한가지 방법은 저속의 광 센싱, 좁은 범위의 가시광 수신, 장거리 측위 등의 서비스를 위한 비캐리어 가시광 통신기반의 하이브리드 측위 기법이며, 또 다른 방식은 고속 광 센싱, 넓은 범위의 가시광 수신, 중거리 측위 등의 서비스를 위한 4 MHz 캐리어를 사용하는 가시광 통신 기반의 하이브리드 측위 기법이다. 이 논문에서는 장애물이 있는 실내 환경에서 목표물과 관측자사이 7731.4cm 장거리와 2368cm 중거리 범위일 때, 각각 두 가지 기법으로 하이브리드 측위 시스템들이 구현되어 측위가 수행되고, 제안 시스템이 검증과 분석된다.