• Title/Summary/Keyword: Time Pattern

Search Result 7,033, Processing Time 0.044 seconds

Ultrasonic Pattern Recognition of Welding Defects Using the Chaotic Feature Extraction (카오스 특징 추출에 의한 용접 결함의 초음파 형상 인식)

  • Lee, Won;Yoon, In-Sik;Lee, Byung-Chae
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.15 no.6
    • /
    • pp.167-174
    • /
    • 1998
  • The ultrasonic test is recognized for its significance as a non-destructive testing method to detect volume defects such as porosity and incomplete penetration which reduce strength in the weld zone. This paper illustrates the defect detection in the weld zone of ferritic carbon steel using ultrasonic wave and the evaluation of pattern recognition by chaotic feature extraction using time series signal of detected defects as data. Shown in the time series data were that the time delay was 4 and the embedding dimension was 6 which indicate the geometric dimension of the subject system and the extent of information correlation. Based on fractal dimension and lyapunov exponent in quantitative chaotic feature extraction, feature value of 2.15, 0.47 is presented for porosity and 2.24, 0.51 for incomplete penetration The precision rate of the pattern recognition is enhanced with these values on the total waveform of defect signal in the weld zone. Therefore, we think that the ultrasonic pattern recognition method of weld zone defects of ferritic carbon steel by ultrasonic-chaotic feature extraction proposed in this paper can boost precision rate further than the existing method applying only partial waveform.

  • PDF

Study on the Rapid Manufacturing for Investment Casting (쾌속조형기를 이용한 정밀주조물의 쾌속제작에 관한 연구)

  • 주영철;김태완
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.3 no.2
    • /
    • pp.136-140
    • /
    • 2002
  • The investment casting process is used frequently to manufacture precise and complex shape metal parts. The previous wax pattern manufacturing process takes long time and high costs because the process is performed by hands. In order to improve the wax manufacturing process, a new process is developed to manufacture the wax pattern by using a rapid prototyping system. A CastForm pattern is made by a Selective laser Sintering type RP with CastForm powder. The CastForm pattern is dipped in the melted wax liquid, and the melted wax penetrates into the pores of the CastForm pattern. Wax pattern is obtained after cooling the CastForm pattern slowly. A stainless steel part has been manufactured by the suggested process. By obtaining the suggested process the manufacturing time and costs are reduced largely and the accuracy is improved.

  • PDF

The Pattern Recognition System Using the Fractal Dimension of Chaos Theory

  • Shon, Young-Woo
    • International Journal of Fuzzy Logic and Intelligent Systems
    • /
    • v.15 no.2
    • /
    • pp.121-125
    • /
    • 2015
  • In this paper, we propose a method that extracts features from character patterns using the fractal dimension of chaos theory. The input character pattern image is converted into time-series data. Then, using the modified Henon system suggested in this paper, it determines the last features of the character pattern image after calculating the box-counting dimension, natural measure, information bit, and information (fractal) dimension. Finally, character pattern recognition is performed by statistically finding each information bit that shows the minimum difference compared with a normalized character pattern database.

Tree-based Navigation Pattern Analysis

  • Choi, Hyun-Jip
    • Communications for Statistical Applications and Methods
    • /
    • v.8 no.1
    • /
    • pp.271-279
    • /
    • 2001
  • Sequential pattern discovery is one of main interests in web usage mining. the technique of sequential pattern discovery attempts to find inter-session patterns such that the presence of a set of items is followed by another item in a time-ordered set of server sessions. In this paper, a tree-based sequential pattern finding method is proposed in order to discover navigation patterns in server sessions. At each learning process, the suggested method learns about the navigation patterns per server session and summarized into the modified Rymon's tree.

  • PDF

A study on the railway signal system for high density traffic (열차의 고밀도운전을 위한 신호보안 시스템에 관한 연구)

  • 강규현;김희식
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1997.10a
    • /
    • pp.163-166
    • /
    • 1997
  • In order to shorten head-way time on existing railway lines without any change of signal block length between stations, it is a realistic optional way to change the control method of train signal, i.e. to modernize the cab signal using transponder. A new signalling system of operation pattern control technique is suggested as new model to increase the railway traffic efficiency. Through the computer simulation of this model, the train head-way time by the fixed signalling system and the new pattern control system is analyzed.

  • PDF

A Study on the Rule for Creation of the Pattern Language of Christopher Alexander (크리스토퍼 알렉산더의 패턴언어 생성규칙에 관한 연구)

  • Jung, Sung-Wook;Kim, Moon-Duck
    • Korean Institute of Interior Design Journal
    • /
    • v.26 no.1
    • /
    • pp.75-82
    • /
    • 2017
  • This study reviews the process of creating the patterns through the Christopher Alexander's books to discover the fundamental rules for creation of the pattern language. The essential ideas of 11 rules describing the characteristics of the pattern language are organized by keyword depending on the characteristics of each rule. Then, this study analyzes which keyword was applied importantly and how it had been developed chronologically in the Alexander's books. As a result, 5 keywords - reflection of cultural difference, reflection of human desires, solving the repeated problem, function suitable for principal purpose, and network structure - are applied to his early books in which the pattern language was theoretically developed, the pattern of traditional society was discovered and the network structure was developed. Another 5 keywords - user participation method, new problem solving, structure preserving transformation, post-mechanization method, and central invariant structure - are applied to the books in his mid-term after completion of the pattern theory which discover new pattern for contemporary society and apply the pattern language to time and space. In his later books which organize the theory of pattern language and suggest the direction for using the pattern language, 5 keywords - wholeness, post-mechanization method, user participation method, new problem solving, and structure preserving transformation - are applied. Users may use the pattern language more precisely if he/she considers the keywords of the early period in searching the patterns of existing environment, the keywords of the intermediate period in searching the patterns of new environment or in regard to time and space, and the keywords of the later period in considering direction of the application of the pattern language.

An Intrusion Detection System Using Pattern Classification (패턴 분류를 이용한 침입탐지 시스템 모델)

  • 윤은준;김현성;부기동
    • Proceedings of the Korea Society of Information Technology Applications Conference
    • /
    • 2002.11a
    • /
    • pp.59-65
    • /
    • 2002
  • Recently, lots of researchers work focused on the intrusion detection system. Pattern matching technique is commonly used to detect the intrusion in the system, However, the method requires a lot of time to match between systems rule and inputted packet data. This paper proposes a new intrusion detection system based on the pattern matching technique. Proposed system reduces the required time for pattern matching by using classified system rule. The classified rule is implemented with a general tree for efficient pattern matching. Thereby, proposed system could perform network intrusion detection efficiently.

  • PDF

Mobile Web User Interface Patterns for Screen Usage and User Input (화면 활용과 사용자 입력을 위한 모바일 웹 사용자 인터페이스 패턴)

  • Choi, Jong Myung;Lee, Young Ho;Cho, Yong Yun
    • Journal of Korea Society of Digital Industry and Information Management
    • /
    • v.8 no.1
    • /
    • pp.183-190
    • /
    • 2012
  • Mobile web applications are different from desktop web applications because of their small screen size and small user input devices. Therefore user interface designers have spent their effort and time to re-design the user interface of mobile web applications to meet these differences. In this paper, we introduce five user interface patterns for mobile web applications to reduce their effort and time. Two of them are for utilizing small screen size efficiently, and they are space overloading pattern and data filtering pattern. These patterns enable designers to reduce screen usage. The other three patterns - data suggestion pattern, input reuse pattern, and incremental data input pattern - are for helping users' data input on mobile devices. These three patterns enable users to reduce direct data input. Our work will help user interface designers develop mobile web interface to utilize screen space efficiently and get data with less errors and less efforts from users.

A study on the thickness distribution and pattern deformation of films in vacuum-assisted thermoforming (열진공성형에서 발생하는 필름의 두께 분포와 패턴 변형에 관한 연구)

  • Seong, Gyeom-Son;Lee, Ho-Sang
    • Design & Manufacturing
    • /
    • v.12 no.2
    • /
    • pp.5-10
    • /
    • 2018
  • Vacuum-assisted thermoforming is one of the critical steps for successful application of film insert molding(FIM) to parts of complex shape. In this study, the simulations and experiments of thermoforming processes were performed to investigate the effects of process conditions on thickness distribution and printed pattern deformation of films in vacuum-assisted thermoforming. The film thickness uniformity increased with decreasing film heating time, whereas it increased with increasing vacuum delay time. After thermoforming of films with uniform pattern space of 5mm, the maximum space was 9.432mm. Based on the simulation, a modified pattern was calculated to obtain uniform spaces after thermoforming. In the experiments for film with the modified pattern, the maximum space appeared 5.837mm. In, addition. the predicted patterns were in good agreement with the experimental results.

Comparison of CAE Flow Analysis and Practical Molding on Elastomer Injection Molding (엘라스토머 사출성형시 CAE 유동해석과 실제 성형품의 비교)

  • Han S.R.;Kim J.H.;Jeon S.G.;Lee G.H.;Jeong Y.D.
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2006.05a
    • /
    • pp.375-376
    • /
    • 2006
  • Thermoplastic elastomer(TPE) can be molded by conventional injection molding. Therefore TPE injection molding could be analyzed by commercial flow analysis software. However there are a little of gaps on CAE simulation results and practical molding. In this study, the properties of TPE were measured and applied to CAE simulation for comparing the simulation flow pattern and real flow pattern. The pattern that was controlled by injection time was match. The pattern that was controlled by injection stroke and rate was not match.

  • PDF