• Title/Summary/Keyword: penetration pattern

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A Study on the Application of Digital Signal Processing for Pattern Recognition of Microdefects (미소결함의 형상인식을 위한 디지털 신호처리 적용에 관한 연구)

  • 홍석주
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.9 no.1
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    • pp.119-127
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    • 2000
  • In this study the classified researches the artificial and natural flaws in welding parts are performed using the pattern recognition technology. For this purpose the signal pattern recognition package including the user defined function was developed and the total procedure including the digital signal processing feature extraction feature selection and classifi-er selection is teated by bulk,. Specially it is composed with and discussed using the statistical classifier such as the linear discriminant function the empirical Bayesian classifier. Also the pattern recognition technology is applied to classifica-tion problem of natural flaw(i.e multiple classification problem-crack lack of penetration lack of fusion porosity and slag inclusion the planar and volumetric flaw classification problem), According to this result it is possible to acquire the recognition rate of 83% above even through it is different a little according to domain extracting the feature and the classifier.

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Classification of Welding Defects in Austenitic Stainless Steel by Neural Pattern Recognition of Ultrasonic Signal (초음파신호의 신경망 형상인식법을 이용한 오스테나이트 스테인레스강의 용접부결함 분류에 관한 연구)

  • Lee, Gang-Yong;Kim, Jun-Seop
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.4
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    • pp.1309-1319
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    • 1996
  • The research for the classification of the natural defects in welding zone is performd using the neuro-pattern recognition technology. The signal pattern recognition package including the user's defined function is developed to perform the digital signal processing, feature extraction, feature selection and classifier selection, The neural network classifier and the statistical classifiers such as the linear discriminant function classifier and the empirical Bayesian calssifier are compared and discussed. The neuro-pattern recognition technique is applied to the classificaiton of such natural defects as root crack, incomplete penetration, lack of fusion, slag inclusion, porosity, etc. If appropriately learned, the neural network classifier is concluded to be better than the statistical classifiers in the classification of the natural welding defects.

Damage Effect on Glass Fibre Reinforced Plastics under Airflow by a Continuous Wave Laser (연속발진 레이저에 의한 공기 유동에 노출된 유리섬유 강화 플라스틱 손상효과)

  • Lee, Kwang Hyun;Shin, Wan-Soon;Kang, Eung-Cheol
    • Journal of the Korea Institute of Military Science and Technology
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    • v.18 no.3
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    • pp.293-299
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    • 2015
  • We analyzed the damage effect on Glass Fibre Reinforced Plastics(GFRP) under air flow by irradiation of continuous wave near-IR laser. Damage process and temporal temperature distribution were demonstrated and material characteristics were observed with laser intensity, surface flow speed and angle. Surface temperature on GFRP rapidly increased with laser intensity, and the damaged pattern was different with flow characteristics. In case of no flow, penetration on GFRP by burning and flame generation after laser irradiation was appeared at once. GFRP was penetrated by the heat generated from resin ignition. In case of laser irradiation under flow, a flame generated after burning extinguished at once by flow and penetration pattern on GFRP were differently shown with flow angle. From the results, we presented the damage process and its mechanism.

Underwater Localization using EM Wave Attenuation with Depth Information (전자기파의 감쇠패턴 및 깊이 정보 취득을 이용한 수중 위치추정 기법)

  • Kwak, Kyungmin;Park, Daegil;Chung, Wan Kyun;Kim, Jinhyun
    • The Journal of Korea Robotics Society
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    • v.11 no.3
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    • pp.156-162
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    • 2016
  • For the underwater localization, acoustic sensor systems are widely used due to greater penetration properties of acoustic signals in underwater environments. On the other hand, the good penetration property causes multipath and interference effects in structured environment too. To overcome this demerit, a localization method using the attenuation of electro-magnetic(EM) waves was proposed in several literatures, in which distance estimation and 2D-localization experiments show remarkable results. However, in 3D-localization application, the estimation difficulties increase due to the nonuniform (doughnut like) radiation pattern of an omni-directional antenna related to the depth direction. For solving this problem, we added a depth sensor for improving underwater 3D-localization with the EM wave method. A micro scale pressure sensor is located in the mobile node antenna, and the depth data from the pressure sensor is calibrated by the curve fitting algorithm. We adapted the depth(z) data to 3D EM wave pattern model for the error reduction of the localization. Finally, some experiments were executed for 3D localization with the fast calculation and less errors.

Influence of Clearance in Half-piecing of Sheet Metal (금속판재의 하프피어싱 공정에서의 틈새 영향 연구)

  • Yeon, S.M.;Lee, S.K.;Chung, W.J.;Kim, J.H.
    • Transactions of Materials Processing
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    • v.22 no.8
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    • pp.437-441
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    • 2013
  • Recently, the engraving of letters or a pattern on a product surface has received more attention especially in trying to satisfy the customer requirements. Half-piecing is a protrusion forming process that pierces only 40~50% of the material thickness. In the current study, the half-piercing technique for making clear letters by protruding sheet material was selected and studied. The influence of clearance and penetration depth was investigated by measuring the camber and extruded length of a protrusion after experiments. In addition, a numerical analysis was performed for the same working conditions and compared with experimental results. It is shown that, as the clearance increases, the camber of a protrusion increases rapidly and the extruded length decreases slightly. The deformation pattern around the cutting edge during half-piercing changes from an extrusion mode to a shearing mode as the clearance changes from minus to plus values. It is also confirmed that the experimental results show a good agreement with the numerical analyses.

Diesel Spray Developement from VCO nozzles for High Pressure Direct-Injection (VCO노즐에서 고압으로 분사되는 디젤분무의 특성)

  • 강진석;배충식
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.3
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    • pp.28-36
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    • 2000
  • Spray characteristics of diesel fuel injection is one of the most important factors in diesel combustion and pollutant emissions especially in HSDI (High Speed Direct Injection) diesel engines where the interval between the onset of combustion and the evaporation of atomized fuel is relatively short, An investigation into various spray characteristics from different holes of VCO(Valve Covered Orifice) nozzles was performed and its results were compared to standard sac nozzle. The global characteristics of spray, including spray angle, spray tip penetration, and spray pattern were measured from the spray images which were frozen by an instantaneous photography with a spark light source. For better understanding of spray behavior, SMD of the fuel sprays from multi hole nozzles were measured with back light imaging while the sprays from the other holes are covered by a purpose-built nozzle cap. The investigation manifestly reveals the different spray patterns at the beginning of injection produced by VCO nozzles can be identified as three distinct types with their own macroscopic and microscopic characteristics, while macroscopic non-uniformity disappears at 0.9∼1.0ms from the start of injection.

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A Study on Street Types and Application Patterns in High-Rise Apartment Housing - The Case Study of Prizewinners in the Design Competitions since the 1990s - (고층 아파트 단지의 동선 유형 및 적용 패턴에 관한 연구 - '90년대 이후 공영 아파트 설계 경기 당선안을 중심으로 -)

  • Kim, Hyung-Jin;Kim, Young-Suk;Park, Chan-Kyu
    • Journal of the Korean housing association
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    • v.19 no.6
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    • pp.33-44
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    • 2008
  • The street system in multi-family housing is an important design element to control the circulation of vehicles and pedestrians, and to form the spatial organization of the projects. In particular, in the case of high-rise apartments, the street patterns have an influence on the safety, amenity, and convenience of facilities. Until now, however, the design of street patterns in most high-rise multi-family housing projects has diminished the quality of residential environments because priority of design consideration has primarily been given to planning road ways and parking areas. Nevertheless, the design competitions introduced for the first time in the 1980s have played a significant role in developing fresh ideas and concepts in housing design. Because street patterns have been respectably modified as a result of the generalizing of design competitions, it is important to review the ideas that have been proposed in competitions over the recent past. In this context, this study classified the types of street patterns and analyzed their design characteristics for the proposals of housing design competitions since the 1990s. As a result of this analysis, the road patterns are classified into 4 types: 1) serial type, 2) isolated type, 3) mixed type, and 4) not a road pattern due to the system of connection. In addition, these were further divided into 8 types: 1) loop, 2) ring, 3) penetration, 4) tree, 5) direct entry, 6) ring and penetration, 7) loop and penetration, 8) not a road pattern due to appearance and the collector.

A Study on E-business Possibility through the Characteristic Analysis of Smart Phone Market in South Asia : Focusing on Vietnam

  • Kim, Dong-Hwa;Sung, Seo-Dae
    • East Asian Journal of Business Economics (EAJBE)
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    • v.5 no.3
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    • pp.33-40
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    • 2017
  • Purpose - This paper suggests approaching methods for a way of strategies for traditional market extend and new ebusiness, market development, and plan of new product in the future and develop a way of method for cooperation through analysis on the smart phone market trend in different culture, effectively. Research design, data, methodology - As research design, data, and methodology, this paper suggests new idea and approaches from comparing characteristics analysis of smart phone market in different culture in AEC. This paper takes data to analysis from ITU, World Bank, AEC, and IMF. These organizer's data can be trusted as official society in the world. This paper can prove market and the characteristics of society through the corresponding results. Results - This paper can suggest the novel idea on market development and the big possibility depend on ACE country and can describe the possibility on new market because of low smart phone market penetration and low digital market penetration. Conclusions - This paper concludes to develop e-business, culture friendly ship, linking with education, development of appropriate technology depend on country, and should develop new strategy for market extend to low penetration.

Research on the penetration depth of low-energy electron beam in the PMMA-resist film using Monte Carlo numerical analysis (Monte Carlo 수치해석법을 이용한 PMMA resist에서의 저 에너지 전자빔 투과 깊이에 관한 연구)

  • Ahn, Seung-Joon;Ahn, Seong-Joon;Kim, Ho-Seob
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.4
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    • pp.743-747
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    • 2007
  • There has been steady effect for the development of the electron-beam lithography technologies for the circuit patterning of the future semiconductor devices. In this study, we have performed a Monte-Carlo simulation whore $1{\times}10^4$ electrons with various kinetic energies (100eV, 300eV, 500eV, 700eV, and 1000eV) were shot into polymethyl methacrylate(PMMA) resist of 100-nm thickness. The penetration depth of each electron beam in the resist layer were analyzed using Gaussian analysis method.

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The Effect of Neck Strengthening Exercise Using Proprioceptive Neuromuscular Facilitation on Swallow ability of Patient with Dysphagia: A Single Case Study (고유수용성신경근촉진법을 이용한 목근육 강화운동이 삼킴 장애환자에게 미치는 영향: 단일사례연구)

  • Lee, Soon-Hyun;Won, Young-Sick
    • PNF and Movement
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    • v.13 no.3
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    • pp.163-168
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    • 2015
  • Purpose: The current study seeks to identify the effect of neck muscle strengthening exercise using proprioceptive neuromuscular facilitation (PNF) on the swallowing ability of patients diagnosed with dysphagia due to stroke. Methods: As a single case study, the current research conducted neck muscle strengthening exercise using PNF on the patient with dysphagia for 40 minutes, four times per week for a six-week period. At the same time, typical rehabilitation therapy for dysphagia was provided. This type of therapy included food-swallowing and the relation of the muscles surrounding the neck. The functional dysphagia scale and the penetration-aspiration scale were used to assess swallowing ability. Results: After the therapy, the functional dysphagia scale and the penetration-aspiration scale decreased by 18 points and 3 points, respectively, which proves the effectiveness of this type of therapy for dysphagia. Conclusion: The results of the current study indicate that neck muscle strengthening exercise using PNF reduces penetration-aspiration in patients with dysphagia, and that PNF can be clinically utilized to improve the swallowing ability of dysphagic patients.