• Title/Summary/Keyword: 정교한 접촉

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A Method of Robust Stabilization of the Plants Using DNP (DNP을 이용한 플랜트의 강인 안정화 기법)

  • Cho, Hyun-Seob
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.6
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    • pp.1574-1580
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    • 2008
  • In this paper, to bring under robust and accurate control of auto-equipment systems which disturbance, parameter alteration of system, uncertainty and so forth exist, neural network controller called dynamic neural processor(DNP) is designed In order to perform a elaborate task like as assembly, manufacturing and so forth of components, tracking control on the trajectory of power coming in contact with a target as well as tracking control on the movement course trajectory of end-effector is indispensable. Also, the learning architecture to compute inverse kinematic coordinates transformations in the Plants of auto-equipment systems is developed and the example that DNP can be used is explained. The architecture and learning algorithm of the proposed dynamic neural network, the DNP, are described and computer simulations are provided to demonstrate the effectiveness of the proposed learning method using the DNP.

Squeal Analysis of Disc Brake Using Analytical-FE Squeal Model (스퀼융합모델을 이용한 디스크 브레이크 스퀼 소음 연구)

  • Kang, Jaeyoung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.11
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    • pp.6406-6411
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    • 2014
  • This paper presents the analytical-FE (finite element) squeal model, which can provide the efficient simulation time and accuracy. The system geometry and the extraction of the vibration modes were constructed using the finite element method. Instead, the friction contact model was derived from theoretical contact kinematics of the rotating disc and the stationary pads. This modeling procedure was incorporated into the perturbed equations of motion based on the finite elements of the system. Throughout the analytical-FE squeal model, the accuracy of linear stability analysis and the simulation time of FE squeal analysis were improved. In addition, the sensitivity of contact stiffness on brake squeal and the mode-coupling mechanism were provided by the system parameter study.

Mechanics of Micro-Damage at Contact portion of Two Grains (두 입자의 접촉면에서의 손상역학 해석)

  • 정교철;김원영
    • The Journal of Engineering Geology
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    • v.4 no.2
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    • pp.231-243
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    • 1994
  • To better understand the fundamental problems of the true micro-damage in medium-grained granite under uniaxial compressive stress, micro-damage localization, initiation and propagation have been observed in a great detail in contact portion of two grains such as quartz and feldspar. For this purpose, new experimental system allowing us to observe the micro-damaging process continuously was developed. Earlier studies used the specimens of unloaded state and it is difficult to visualize stress-induced microcracks under unloading state. Thus, direct observation under loading state is very important for understanding the true micro-damage process. The results explain well the mechanism of micro-damage at two grains, and mechanics of the micro-damage is clarified well by Hertzian fracture mechanics.

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A Study of the Influence of Strain Gauge Location and Contact Conditions by Loading Platens on the Mechanical Behavior of Rock Specimens (암석공시체의 역학적 거동 해석에 미치는 변형율게이지 위치 및 단면구속 영향에 대한 연구)

  • 정교철
    • The Journal of Engineering Geology
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    • v.8 no.3
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    • pp.215-224
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    • 1998
  • In this study, total strain was measured by LVDTs and local strains on the surface of specimens were measured by strain gauges. And axi-symmetrically elastoplastic FEM analyses was carried out for cylindrical specimens. Considering the influence of the restraint induced by the loading platen, in the case of H/D=1, the strain distribution on the side of a specimen is obviously affected by the condition of platen contact. Furthermore, it is clear that the larger H/D ratio becomes, the smaller the influence to the strain distribution is. For the smooth contact condition, the strain on the side is not influenced by the stiffness of the specimen, the shape and the scale effect, the strain distribution coincides with the nominal total strain. Whereas, in the case of rough contact condition, the strain distribution is remarkably affected. It is made clear that strain responses of hard rock specimens may more sensitive than these of soft rock specimens as a results of interaction between loading platens and specimen and the uniaxial strength of specimens may strongly depends on this interaction and stress-strain relation is affected by the contact condition.

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A Customer Segmentation Scheme Base on Big Data in a Bank (빅데이터를 활용한 은행권 고객 세분화 기법 연구)

  • Chang, Min-Suk;Kim, Hyoung Joong
    • Journal of Digital Contents Society
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    • v.19 no.1
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    • pp.85-91
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    • 2018
  • Most banks use only demographic information such as gender, age, occupation and address to segment customers, but they do not reflect financial behavior patterns of customers. In this study, we aim to solve the problems by using various big data in a bank and to develop customer segmentation method which can be widely used in many banks in the future. In this paper, we propose an approach of segmenting clustering blocks with bottom-up method. This method has an advantage that it can accurately reflect various financial needs of customers based on various transaction patterns, channel contact patterns, and existing demographic information. Based on this, we will develop various marketing models such as product recommendation, financial need rating calculation, and customer churn-out prediction based on this, and we will adapt this models for the marketing strategy of NH Bank.

Study on the Nonlinear Electromagnetic Acoustic Resonance Method for the Evaluation of Hidden Damage in a Metallic Material (금속 재료의 잠닉손상 평가를 위한 비선형 전자기음향공진 기법에 관한 연구)

  • Cho, Seung-Wan;Cho, Seung-Hyun;Park, Choon-Su;Seo, Dae-Cheol;Jhang, Kyung-Young
    • Journal of the Korean Society for Nondestructive Testing
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    • v.34 no.4
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    • pp.277-282
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    • 2014
  • Recently, much attention has been paid to nonlinear ultrasonic technology as a potential tool to assess hidden damages that cannot be detected by conventional ultrasonic testing. One nonlinear ultrasonic technique is measurement of the resonance frequency shift, which is based on the hysteresis of the material elasticity. Sophisticated measurement of resonance frequency is required, because the change in resonance frequency is usually quite small. In this investigation, the nonlinear electromagnetic acoustic resonance (NEMAR) method was employed. The NEMAR method uses noncontact electromagnetic acoustic transducers (EMATs) in order to minimize the effect of the transducer on the frequency response of the object. Aluminum plate specimens that underwent three point bending fatigue were tested with a shear wave EMAT. The hysteretic nonlinear parameter ${\alpha}$, a key indicator of damage, was calculated from the resonance frequency shift at several levels of input voltage. The hysteretic nonlinear parameter of a damaged sample was compared to that of an intact one, showing a difference in the values.

Framework for Measuring Dynamic Influence Index & Influence Factors using Social Data on Facebook (페이스북 소셜 데이터를 이용한 동적 영향 요인 및 영향력 측정 방법에 관한 프레임워크)

  • Koh, Seoung-hyun;You, Yen-yoo
    • Journal of Digital Convergence
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    • v.14 no.10
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    • pp.137-145
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    • 2016
  • The explosive growth of social networking services based on smart devices popularize these relationships and activities online in accordance with the far larger impact of this on the real life offline, the interest and importance for the online activity is increasing. In this study, factors affecting the SNS activity are defined by object, user, influence direction, influence distance and proposed a method to measure organic terms in effect between the SNS users. Influence Direction and Influence Strength (or Distance) are elaborated by using the existing influence measurement element such as structured data - the number of friends, the difference between the number of contacts - and the new influence measurement element such as unstructured data - gap between the former time and the latter time, preference and type of response behavior - that occur in social network service. In addition, the system for collecting and analysing data for measuring influence from social network service and the process model on the method for measuring influence is tested by using sample data on Facebook and explained the implementation probability.

A Comprehensive Representation Model for Spatial Relations among Regions and Physical Objects considering Property of Container and Gravity (Container 성질과 중력을 고려한 공간과 객체의 통합적 공간관계 표현 모델)

  • Park, Jong-Hee;Lim, Young-Jae
    • Journal of KIISE:Software and Applications
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    • v.37 no.3
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    • pp.194-204
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    • 2010
  • A space, real or virtual, comprises regions as its parts and physical objects residing in them. A coherent and sophisticated representaion scheme for their spatial relations premises the precision and plausibility in its associated agents' inferencing on the spatial relations and the development of events occurring in such a space. The existing spatial models are not suitable for a comprehensive representation of the general spatial relations in that they have limited expressive powers based on the dichotomy between the large and small scales, or support only a small set of topological relations. The representaion model we propose has the following distinctive chracteristics: firstly, our model provides a comprehensive representation scheme to accommodate large and small scale spaces in an integrated fashion; secondly, our model greatly elaborated the spatial relations among the small-scale objects based on their contact relations and the compositional relations among their respective components objects beyond the basic topological relations like disjoint and touch; thirdly, our model further diversifies the types of supported relations by adding the container property besides the soildness together with considering the gravity direction. The resulting integrated spatial knowledge representation scheme considering the gravity allows the diverse spatial relations in the real world to be simulated in a precise manner in relation to the associated spatial events and provides an expression measure for the agents in such a cyber-world to capture the spatial knowledge to be used for recognizing the situations in the spatial aspects.

Engineering Geological Implications of Fault Zone in Deep Drill Cores: Microtextural Characterization of Pseudotachylite and Seismic Activity (시추코어 단층대에서의 지질공학적 의미: 슈도타킬라이트의 미세조직의 특징과 지진활동)

  • Choo, Chang-Oh;Jeong, Gyo-Cheol
    • The Journal of Engineering Geology
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    • v.27 no.4
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    • pp.489-500
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    • 2017
  • It is not rare that pseudotachylite, dark colored rock with glassy texture, is recognizable in deep core samples drilled up to 900 m from the surface. Pseudotachylite with widths varying few to 20 cm is sharply contacted or interlayered with the host rocks composed of Jurassic granite and Precambrian amphibolite gneiss, showing moderately ductile deformation or slight folding. Pseudotachylite occurring at varying depths in the deep drill core are slightly different in texture and thickness. There is evidence of fault gouge at shallower depths, although brittle deformation is pervasive in most drill cores and pseudotachylite is identified at random depth intervals. Under scanning electron microscope (SEM), it is evident that the surface of pseudotachylite is characterized by a smooth, glassy matrix even at micrometer scale and there is little residual fragments in the glass matrix except microcrystals of quartz with embayed shape. Such textural evidence strongly supports the idea that the pseudotachylite was generated through the friction melting related to strong seismic events. Based on X-ray diffraction (XRD) quantitative analysis, it consists of primary minerals such as quartz, feldspars, biotite, amphibole and secondary minerals including clay minerals, calcite and glassy materials. Such mineralogical features of fractured materials including pseudotachylite indicate that the fractured zone might form at low temperatures possibly below $300^{\circ}C$, which implies that the seismic activity related to the formation of pseudotachylite took place at shallow depths, possibly at most 10 km. Identification and characterization of pseudotachylite provide insight into a better understanding of the paleoseismic activity of deep grounds and fundamental information on the stability of candidate disposal sites for high-level radioactive waste.

A COMPARISON STUDY ON THE COMMUNICATIVE INTENT OF CHILDREN WITH REACTIVE ATTACHMENT DISORDER AND DEVELOPMENTAL LANGUAGE DISORDER (반응성 애착장애아와 발달성 언어장애아의 의사소통 의도 비교 연구)

  • Lee, Kyung-Sook;Lee, Ho-Boon;Shin, Cheong-Hyoun;Noh, Kyung-Sun;Im, Yun-Hwa
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.8 no.2
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    • pp.207-216
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    • 1997
  • This study was conducted to investigate the communicative intent between Reactive Attachment Disorder(RAD) and Developmental Language Disorder(DLD). The subject of this study were 20 27-51 monthold children(10 RAD Children, 10 DLD children) functioning at similar stage of language development. The communicative intent was investigated vertical and horizontal dimension. Rating of vertical communicative intent was based on the assessment scales devised by Wetherby and Prutting(1984). Horizontal dimension was measured by the assessment guidelines of Wetherby and Prizant(1989). All the data were rated by two rators independantly. 1) In communicative intent, vertical development level of DLD children was more sophiscated than that of RAD children. 2) DLD children expressed more horizontal communicative intent than RAD children. The percentage of the three major categories(behavioral regulation, social interaction, and joint attention) of communicative intent in DLD children was lined up social interaction>joint attention>behavioral regulation. On the contrary, RAD children displayed in order of behavioral regulation>social interaction>joint attention. In addition, DLD children showed diversely as compared with RAD children.

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