• 제목/요약/키워드: Non-unique features

검색결과 75건 처리시간 0.03초

가공시간에 의한 복합특징형상의 가공순서 생성 (Machining Sequence Generation with Machining Times for Composite Features)

  • 서영훈;최후곤
    • 한국CDE학회논문집
    • /
    • 제6권4호
    • /
    • pp.244-253
    • /
    • 2001
  • For more complete process planning, machining sequence determination is critical to attain machining economics. Although many studies have been conducted in recent years, most of them suggests the non-unique machining sequences. When the tool approach directions(TAD) are considered fur a feature, both machining time and number of setups can be reduced. Then, the unique machining sequence can be extracted from alternate(non-unique) sequences by minimizing the idle time between operations within a sequence. This study develops an algorithm to generate the best machining sequence for composite prismatic features in a vertical milling operation. The algorithm contains five steps to produce an unique sequence: a precedence relation matrix(PRM) development, tool approach direction determination, machining time calculation, alternate machining sequence generation, and finally, best machining sequence generation with idle times. As a result, the study shows that the algorithm is effective for a given composite feature and can be applicable fur other prismatic parts.

  • PDF

비고유 특징을 갖는 의미정보를 이용한 지상 자율이동체 측위 기법 (Autonomous Ground Vehicle Localization Filter Design Using Landmarks with Non-Unique Features)

  • 김찬영;홍다니엘;나원상
    • 전기학회논문지
    • /
    • 제67권11호
    • /
    • pp.1486-1495
    • /
    • 2018
  • This paper investigates the autonomous ground vehicle (AGV) localization filter design problem under GNSS-denied environments. It is assumed that the given landmarks do not have unique features due to the lack of a prior knowledge on them. For such case, the AGV may have difficulties in distinguishing the position measurement of the detected landmark from those of other landmarks with the same feature, hence the conventional localization filters are not applicable. To resolve this technical issue, the localization filter design problem is formulated as a special form of the data association determining whether the detected feature is actually originated from which landmark. The measurement hypotheses generated by landmarks with the same feature are evaluated by the nearest neighbor data association scheme to reduce the computational burden. The position measurement corresponding to the landmark with the most probable hypothesis is used for localization filter. Through the experiments in real-driving condition, it is shown that the proposed method provides satisfactory localization performance in spite of using non-unique landmarks.

『동의보감』 심장도(心臟圖)의 묘사 특징과 그 기원에 대한 연구 (A Study on the Descriptive Features and Origin of the Heart Diagram in the Donguibogam(東醫寶鑑))

  • 조학준
    • 대한한의학원전학회지
    • /
    • 제36권1호
    • /
    • pp.17-32
    • /
    • 2023
  • Objectives : This paper investigates the background, meaning and origin of the descriptions of the Heart such as 'seven orifices', 'sanmao', 'saw-toothed four layered lines' that are unique to the diagram in the Donguibogam. Methods : First the Heart diagram of the Donguibogam was compared with other Zhangfu diagrams of the past. Materials related to unique features in the descriptions of the Heart in the Donguibogam were collected, against which descriptive features were analyzed. Results : Of the many unique features, the descriptive basis of the 'seven orifices' could be found in the Qixingban[七星板] as a physical entity reflecting basic anatomical knowledge. The 'sanmao', which is compared to the Santaixing[三台星], could be understood as a non-physical entity whose descriptive basis could be found in the Xinxuetu of the Xinching. It could be assumed that the 'saw-toothed four layered lines' are likened to the multi-layered petals or calyx of a lotus flower bud to describe the Pericardium, or to the multiple walls of a mountain fortress surrounding a palace to describe the Danzhong, which is the chest cavity. These features could be understood as results of spiritualism influence. Conclusions : It could be concluded that Heo Jun, in his attempt to describe the Heart in more detail than previous diagrams of the Zangfu, referenced popular texts and images based on anatomical knowledge of previous texts, added varied descriptions resulting in a new diagram with a completely different origin.

On the Development of Lofts for Doubly Curved Sheet Metal Components

  • Prasad, K.S.R.K.;Selvaraj, P.;Ayachit, Praveen V.;Nagamani, B.V.
    • International Journal of CAD/CAM
    • /
    • 제6권1호
    • /
    • pp.199-211
    • /
    • 2006
  • Practical automated flat pattern generation with inbuilt production features for doubly curved sheet metal components (SMCs) is addressed here utilizing a new and unique Point Transformation Algorithm (PTA). This is the third in the series of papers on practical Flat Pattern Development (FPD) [8] and Production Loft Generation Systems (PLGS) [9] complementing the pioneering work [6,7]. In the first two publications, automated loft generation programs have addressed sheet metal components having a Principal Flat Surface (PFS) only. The flat pattern development of 3-D components that do not have the flat surface(termed as Non-PFS components) having complex features of double curvature in addition to cutouts and nibbled holes typical of aircraft components were so far not addressed due to lack of relevant published algorithms. This paper traces the evolution of developments and provides the record of fully illustrated, automated loft generation scheme for aircraft SMCs including the Non-PFS components which underwent validation through production tests by sponsors. Details of some of the unique features of the system like simplified surface model generation, termed as topological model and powerful algorithms deployed with potential for CAD/CAM applications are included.

Computer Analysis of Non-vaulted Nef Unique System

  • Hong, Seong-Woo
    • Architectural research
    • /
    • 제2권1호
    • /
    • pp.1-6
    • /
    • 2000
  • Ever since Viollet-le-Due began to examine Gothic structural elements using his method of geometrical analysis in the nineteenth century, art and architectural historians and a few engineers have periodically attempted to ascertain the structural advantages of the various characteristic features of Gothic architecture. In none of these studies, however, has the way forces work within the lightweight and spacious masonry Gothic buildings been precisely interpreted. The approach taken by art and architectural historians has therefore tended to be primarily descriptive and to be based on intuitive assumptions. This study intend to analyze the Gothic non-vaulted nef unique(aisleless) structures of Lower Languedoc which has never been scientifically tested, and to provide as comprehensive an explanation as possible of the way in which these non-vaulted buildings work. In order to achieve this goal, this paper Is to examine, by means of finite element analysis. the links between the width of non-vaulted aisleless structures, the configuration of the arches, diaphragm arch, and the buttress. Finite element analysis with a computer provides a more accurate analysis than the methods of analysis that have been heretofore applied to Gothic structures, as well as permits us to visualize the global stress behavior of the structure. Combined with traditional methods of studying historical buildings, therefore, finite element analysis inevitably give us a broader understanding of the processes involved in the design and construction of medieval buildings.

  • PDF

Fibromyalgia diagnostic model derived from combination of American College of Rheumatology 1990 and 2011 criteria

  • Ghavidel-Parsa, Banafsheh;Bidari, Ali;Hajiabbasi, Asghar;Shenavar, Irandokht;Ghalehbaghi, Babak;Sanaei, Omid
    • The Korean Journal of Pain
    • /
    • 제32권2호
    • /
    • pp.120-128
    • /
    • 2019
  • Background: We aimed to explore the American College of Rheumatology (ACR) 1990 and 2011 fibromyalgia (FM) classification criteria's items and the components of Fibromyalgia Impact Questionnaire (FIQ) to identify features best discriminating FM features. Finally, we developed a combined FM diagnostic (C-FM) model using the FM's key features. Methods: The means and frequency on tender points (TPs), ACR 2011 components and FIQ items were calculated in the FM and non-FM (osteoarthritis [OA] and non-OA) patients. Then, two-step multiple logistic regression analysis was performed to order these variables according to their maximal statistical contribution in predicting group membership. Partial correlations assessed their unique contribution, and two-group discriminant analysis provided a classification table. Using receiver operator characteristic analyses, we determined the sensitivity and specificity of the final model. Results: A total of 172 patients with FM, 75 with OA and 21 with periarthritis or regional pain syndromes were enrolled. Two steps multiple logistic regression analysis identified 8 key features of FM which accounted for 64.8% of variance associated with FM group membership: lateral epicondyle TP with variance percentages (36.9%), neck pain (14.5%), fatigue (4.7%), insomnia (3%), upper back pain (2.2%), shoulder pain (1.5%), gluteal TP (1.2%), and FIQ fatigue (0.9%). The C-FM model demonstrated a 91.4% correct classification rate, 91.9% for sensitivity and 91.7% for specificity. Conclusions: The C-FM model can accurately detect FM patients among other pain disorders. Re-inclusion of TPs along with saving of FM main symptoms in the C-FM model is a unique feature of this model.

Unsupervised Clustering of Multivariate Time Series Microarray Experiments based on Incremental Non-Gaussian Analysis

  • Ng, Kam Swee;Yang, Hyung-Jeong;Kim, Soo-Hyung;Kim, Sun-Hee;Anh, Nguyen Thi Ngoc
    • International Journal of Contents
    • /
    • 제8권1호
    • /
    • pp.23-29
    • /
    • 2012
  • Multiple expression levels of genes obtained using time series microarray experiments have been exploited effectively to enhance understanding of a wide range of biological phenomena. However, the unique nature of microarray data is usually in the form of large matrices of expression genes with high dimensions. Among the huge number of genes presented in microarrays, only a small number of genes are expected to be effective for performing a certain task. Hence, discounting the majority of unaffected genes is the crucial goal of gene selection to improve accuracy for disease diagnosis. In this paper, a non-Gaussian weight matrix obtained from an incremental model is proposed to extract useful features of multivariate time series microarrays. The proposed method can automatically identify a small number of significant features via discovering hidden variables from a huge number of features. An unsupervised hierarchical clustering representative is then taken to evaluate the effectiveness of the proposed methodology. The proposed method achieves promising results based on predictive accuracy of clustering compared to existing methods of analysis. Furthermore, the proposed method offers a robust approach with low memory and computation costs.

An Effective Stopping Rule for Software Reliability Testing

  • Yoon, Bok-Sik
    • International Journal of Reliability and Applications
    • /
    • 제3권2호
    • /
    • pp.81-90
    • /
    • 2002
  • The importance of the reliability of software is growing more and more as more complicated digital computer systems are used for real-time control applications. To provide more reliable software, the testing period should be long enough, but not unnecessarily too long. In this study, we suggest a simple but effective stopping rule which can provide just proper amount of testing time. We take unique features of software into consideration and adopt non-homogeneous Poisson process model and Bayesian approach. A numerical example is given to demonstrate the validity of our stopping rule.

  • PDF

Examining Portraits in Digital Fashion Art Non-Fungible Tokens (NFTs) through Baudrillard's Simulation

  • Yoon Kyung Lee
    • 한국의류학회지
    • /
    • 제47권5호
    • /
    • pp.929-942
    • /
    • 2023
  • Web 3.0 enables people and machines to connect, evolve, share, and use knowledge on an unprecedented scale and in new ways, drastically improving our Internet experience. The metaverse is a collective, virtual shared space supporting all digital activities. Prompted by the rapid growth of digital art and digital fashion, this theoretical analysis explores using Jean Baudrillard's simulation concept to create unique digital art non-fungible tokens (NFTs), allowing them to express and communicate ideas like real-world art. Specifically, this study analyzes 120 digital fashion portraits of humans and animals and classifies them under three types of simulacra covering four stages of Baudrillard's simulation process. The result shows that NFT fashion artworks reflect the core features of a digital reality by connecting and transcending the boundaries of cultures, genders, and nationalities. However, in the final simulation stage (the fourth step), the simulacrum can only coexist in the virtual world as a hyperreal object (the Type III of simulacrum): an object more real than reality.

Distinct Features of Brain-Resident Macrophages: Microglia and Non-Parenchymal Brain Macrophages

  • Lee, Eunju;Eo, Jun-Cheol;Lee, Changjun;Yu, Je-Wook
    • Molecules and Cells
    • /
    • 제44권5호
    • /
    • pp.281-291
    • /
    • 2021
  • Tissue-resident macrophages play an important role in maintaining tissue homeostasis and innate immune defense against invading microbial pathogens. Brain-resident macrophages can be classified into microglia in the brain parenchyma and non-parenchymal brain macrophages, also known as central nervous system-associated or border-associated macrophages, in the brain-circulation interface. Microglia and non-parenchymal brain macrophages, including meningeal, perivascular, and choroid plexus macrophages, are mostly produced during embryonic development, and maintained their population by self-renewal. Microglia have gained much attention for their dual roles in the maintenance of brain homeostasis and the induction of neuroinflammation. In particular, diverse phenotypes of microglia have been increasingly identified under pathological conditions. Single-cell phenotypic analysis revealed that microglia are highly heterogenous and plastic, thus it is difficult to define the status of microglia as M1/M2 or resting/activated state due to complex nature of microglia. Meanwhile, physiological function of non-parenchymal brain macrophages remain to be fully demonstrated. In this review, we have summarized the origin and signatures of brain-resident macrophages and discussed the unique features of microglia, particularly, their phenotypic polarization, diversity of subtypes, and inflammasome responses related to neurodegenerative diseases.