• Title/Summary/Keyword: Shape Context

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Shape Based Framework for Recognition and Tracking of Texture-free Objects for Submerged Robots in Structured Underwater Environment (수중로봇을 위한 형태를 기반으로 하는 인공표식의 인식 및 추종 알고리즘)

  • Han, Kyung-Min;Choi, Hyun-Taek
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.48 no.6
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    • pp.91-98
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    • 2011
  • This paper proposes an efficient and accurate vision based recognition and tracking framework for texture free objects. We approached this problem with a two phased algorithm: detection phase and tracking phase. In the detection phase, the algorithm extracts shape context descriptors that used for classifying objects into predetermined interesting targets. Later on, the matching result is further refined by a minimization technique. In the tracking phase, we resorted to meanshift tracking algorithm based on Bhattacharyya coefficient measurement. In summary, the contributions of our methods for the underwater robot vision are four folds: 1) Our method can deal with camera motion and scale changes of objects in underwater environment; 2) It is inexpensive vision based recognition algorithm; 3) The advantage of shape based method compared to a distinct feature point based method (SIFT) in the underwater environment with possible turbidity variation; 4) We made a quantitative comparison of our method with a few other well-known methods. The result is quite promising for the map based underwater SLAM task which is the goal of our research.

A Critical Review on Behavioral Economics with a Focus on Prospect Theory and EBA Model (프로스펙트 이론과 속성별 제거모형을 중심으로 한 행동경제학에 대한 비판적 고찰)

  • Won, Jee-Sung
    • Journal of Distribution Science
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    • v.11 no.5
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    • pp.63-76
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    • 2013
  • Purpose - For the past several decades, behavioral economics or behavioral decision theory has undergone rapid development. This study provides a critical review of the development of behavioral economics with a focus on what are deemed to be core theories in the field. Starting from the utility function proposed by Daniel Bernoulli in the 18th century, the development history of utility functions until the emergence of the prospect theory is thoroughly reviewed. Some of the experimental results violating the traditionally assumed utility function and supporting the prospect theory value function are summarized. The most representative principles of rational choice are transitivity, independence from irrelevant alternatives (IIA), and regularity. The development of behavioral economics has been triggered by finding counter-examples to these principles. Some of the choice behaviors discussed in this study as counter-examples to the traditional theories of rational choice are the St. Petersburg paradox; the Allais paradox; gambling behavior; and the various context effects including the similarity effect, attraction effect, and the compromise effect. The Elimination-by-Aspects (EBA) model, which was proposed as an explanation for the similarity effect, is discussed in detail as well. Based on the literature review and further analysis, this study summarizes the relationship between the context effects, prospect theory, and EBA model. Research design, data, and methodology - This study provides an extensive literature review on several important theories in the field of behavioral decision theory and adds some critical comments to the theories and the relationships among them. This study first reviews the development of utility functions. Daniel Bernoulli introduced the concept of utility function to solve the St. Petersburg paradox. In the mid-20th century, Herbert Simon proposed the "satisficing" heuristic and presented a value function with a shape different from traditional utility functions. This study highlights the strengths and weaknesses of several utility functions proposed until the emergence of the prospect theory value function. Results - This study posits that prospect theory and EBA model are the two most important theories in the field of behavioral decision theory. They can explain various choice behaviors that traditional utility maximization analysis has been unable to. The application of these models to various fields is further increasing nowadays. This study explains how prospect theory and the EBA model can be used to explain the context effects. Conclusions - The traditional economic theory relies on a single variable called "utility" in explaining consumer choice. However, this study argues that, in investigating consumer choice, several other variables should also be considered. These are the similarity among alternatives, an alternative's prototypicality within the category, the dominance relationship between alternatives, and the reference point in evaluating alternatives. Due to the development of behavioral economics, we are now closer to a more complete understanding of consumer choice behavior than in the past when we had only a single tool called utility.

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An Experimental Study on Heat Transfer Characteristics and Pressure Drop in Micro Plated Heat Exchangers with S-shape of Microchannel (S 형상의 마이크로 채널을 가진 마이크로 판형 열교환기의 열전달 특성 및 압력강하에 관한 실험적 연구)

  • Seo, Jang-Won;Kim, Yoon-Ho;Moon, Chung-Eun;Lee, Kyu-Jung
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.1876-1881
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    • 2007
  • The micro plated heat exchangers were designed to transfer more heat/volume or mass than previous heat exchangers within the context of the design constraints specified. The increase of the surface-to-volume ratio results in an increase of the interfacial area. This enhances considerably the performance of a heat exchanger. This can be an important component in a wide range of applications fuel cell, aerospace, automotive, electronic system and home heating, etc). In this study, the performance evaluation of micro plated heat exchangers under the counter flows with straight and S-shaped channel are carried out. The pressure drop as well as inlet and outlet fluid temperature were measured at steady state under various operating conditions and the total heat transfer rate were also calculated.

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Investigation and Numerical Analysis of Node Connectors in Free-Form Spatial Structures

  • Hwang, Kyung-Ju;Park, Don-U;Park, Sun-Woo;Knippers, Jan
    • Journal of Korean Association for Spatial Structures
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    • v.7 no.3 s.25
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    • pp.87-95
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    • 2007
  • The recent completions of free-form spatial structures provide us a very attractive form. To realize such an extraordinary shape, it is absolutely necessary that the connector systems have to be investigated the characteristics of the systems and analyzed with a practicable method. In this context, this research consists of not only literature research but also numerical analysis with selected connector systems, which was adopted in real free-form spatial structures. For numerical analysis, especially, finite element analysis (FEA) is performed with a various test parameter using a commercial program ANSYS. Consequently, the general characteristics of node connectors the moment-rotation-curves are presented by considering a large deformation effect as well as a multi-linear material properties.

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Bayesian Estimators Using Record Statistics of Exponentiated Inverse Weibull Distribution

  • Kim, Yong-Ku;Seo, Jung-In;Kang, Suk-Bok
    • Communications for Statistical Applications and Methods
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    • v.19 no.3
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    • pp.479-493
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    • 2012
  • The inverse Weibull distribution(IWD) is a complementary Weibull distribution and plays an important role in many application areas. In this paper, we develop a Bayesian estimator in the context of record statistics values from the exponentiated inverse Weibull distribution(EIWD). We obtained Bayesian estimators through the squared error loss function (quadratic loss) and LINEX loss function. This is done with respect to the conjugate priors for shape and scale parameters. The results may be of interest especially when only record values are stored.

Synthesis of complex nanoparticles using bioceramic silica (바이오 세라믹 실리카를 이용한 복합 나노입자 구조체의 합성)

  • Yoon, Seokyoung;Lee, Jung Heon
    • Ceramist
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    • v.21 no.3
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    • pp.283-292
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    • 2018
  • Here, we introduce various type of inorganic nanostructure synthesized with functional nanoparticles and silica. From two decades ago, functional inorganic nanoparticles have been synthesized and highlighted, now we moved to next level of wet-chemical synthesis. By integrating functional nanoparticles with silica, we were able to synthesize multi-functional nanostructure, which expand the applications of nanoparticles to catalyst, drug carrier, sensors. In this context, silica has been spotlighted due to its versatility. Silica has highly biocompatible, relatively transparent and stable under harsh conditions. Thus it can be used as good supporter to synthesize complex multi-functional nanostructure when mixed with other functional nanoparticles. A various shape of complex nanostructures have been synthesized including core-shell type, yolk-shell type and janus type etc. In this paper, we have described the purposes of synthesizing silica noncomplex and various case studies for biomedical applications and self-assembly.

A Fast Motion Estimation Algorithm for MPEG-4 Shape Coding (MPEG-4의 형상 정보 부호화에 사용되는 움직임 추정부의 고속 알고리즘)

  • 유동훈;장성균;나종범
    • Proceedings of the IEEK Conference
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    • 2000.09a
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    • pp.421-424
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    • 2000
  • 본 논문에서는 MPEG-4 의 형상 정보 부호화에 사용되는 움직임 추정부의 고속 알고리즘을 제안한다. 형상정보 부호기에서 사용되는 움직임 추정부는 기존의 텍스처 기반의 움직임 추정부와는 다른 특성을 가지는데 형상 정보 추정기에서 사용되는 움직임 추정부는 CAE(Context-based Arithmetic Encoding)에서 사용될 컨텍스트를 만들기 위해 수행된다는 점과 움직임 벡터의 공간적 상관성, 그리고 형상정보가 이진성을 가진다는 점이 그것이다. 이러한 세가지 특성을 사용한 제안된 알고리즘은 움직임 추정부의 수행 속도를 비약적으로 향상시킨다. 실험 결과에 의하면 계산량은 최악의 경우에도 10% 이하로 떨어지는 것을 볼 수 있다. 따라서 본 논문에서 제안한 알고리즘은 실시간 소프트웨어의 구현에 적합한 알고리즘이라고 할 수 있다.

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Supply Chain Management from the Strategic Perspective through the Theory of Constraints (TOC 이론을 기반으로 한 전략적 관점에서의 공급사슬관리)

  • 간형식;김기주;황재훈
    • Journal of Korea Society of Industrial Information Systems
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    • v.7 no.3
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    • pp.95-106
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    • 2002
  • As the information technology including Internet not only opened the cyber world but also has evolved as a platform that enables a new generation of businesses and remolds the shape of thinking and the rules of supply chain management (SCM). By using the Theory of Constraints, which seems simple but robust to review the traditional SCM context, the paper proposes a conceptual framework to handle the SCM issues. From the strategic perspective, this paper focuses on three policy constraints: supplier-manufacturer oriented constraints, manufacturer-distributor oriented constraints, and supply chain oriented constraints. To optimize the throughput and sustain the competitiveness of supply chain members in the dynamic business environment, the companies should utilize the potential competency of information technology and consistently perform the activities of removing and/or reinforcing the constraints.

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Free and Forced Vibration Analyses of HDD Spindle Systems Supported by Hydrodynamic Bearings (유체 동압 베어링 지지 HDD 스핀들 계의 자유 및 강제 진동 해석)

  • 임승철
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.13 no.11
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    • pp.852-859
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    • 2003
  • In order to meet the growing demands for higher storage density as well as lower noise level, the spindles in hard disk drives are to be supported by hydrodynamic bearings in place of conventional ball-type ones. However, the existing models are inappropriate to apply to accurate prediction of vibration characteristics because the HDD spindle tends to take quite a complex shape to secure its performance and cost-effectiveness. In this context, this paper treats analysis of free and forced vibrations of such-designed HDD spindles based on more sophisticated models and validations via experiments. Remarkably, to this end all the components in the system are modeled as elastic adopting the finite element method.

Automated Modification of Irregular Shape of Building Edges Extracted from High Spatial Resolution Satellite Imagery Using Road Direction Information (고해상도 위성영상에서 추출된 건물경계의 도로방향정보 기반 선형보정)

  • Lee Jong-Yeol
    • Proceedings of the KSRS Conference
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    • 2006.03a
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    • pp.173-177
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    • 2006
  • 고해상도의 위성영상이 수집됨에 따라 이에서 지형지물을 자동 추출하려는 분야가 점차 중요해지고 있다. 지형지물을 수작업을 거치지 않고 추출하는 방법의 연구 중에서는 지형지물의 경계추출을 기반으로 하는 방법이 많이 이용된다. 그러나 일반적으로 추출된 지형지물 경계의 선형이 왜곡된 형태를 갖으며, 지형지물의 실제 경계의 형태와는 다소 차이가 있는 결과를 보인다. 이 연구에서는 선형이 굴곡이 있는 지형지물 중 건축물의 경계를 인접한 도로 정보를 이용하여 실제의 경계 형태에 가깝게 보정하는 방법을 검토하였다. context 정보로서 이것을 이용한다면 블록 내의 건축물의 경계를 보다 규칙적으로 정비할 수 있을 것이다. 이 연구에서는 이러한 전제를 가지고 도로로 분할된 블록 내 건축물 경계를 도로의 방향을 기반으로 보정하는 방법을 제안하였다.

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