• Title/Summary/Keyword: artificial fit

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A Development of Optimal Design Model for Initial Blank Shape Using Artificial Neural Network in Rectangular Case Forming with Large Aspect Ratio (세장비가 큰 사각케이스 성형 공정에서의 인공신경망을 적용한 초기 블랭크 형상 최적설계 모델 개발)

  • Kwak, M.J.;Park, J.W.;Park, K.T.;Kang, B.S.
    • Transactions of Materials Processing
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    • v.29 no.5
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    • pp.272-281
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    • 2020
  • As the thickness of mobile communication devices is getting thinner, the size of the internal parts is also getting smaller. Among them, the battery case requires a high-level deep drawing technique because it has a rectangular shape with a large aspect ratio. In this study, the initial blank shape was optimized to minimize earing in a multi-stage deep drawing process using an artificial neural network(ANN). There has been no reported case of applying artificial neural network technology to the initial blank optimal design for a square case with large aspect ratio. The training data for ANN were obtained though simulation, and the model reliability was verified by performing comparative study with regression model using random sample test and goodness-of-fit test. Finally, the optimal design of the initial blank shape was performed through the verified ANN model.

Development of Flash Volume Prediction Model for Independent Suspension Parts for Large Commercial Vehicles (대형 상용차용 독립 현가부품 플래쉬 부피 예측 모델 개발)

  • J. W. Park
    • Transactions of Materials Processing
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    • v.32 no.6
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    • pp.352-359
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    • 2023
  • Recently, independent suspension systems have been applied not only to passenger cars but also to large commercial vehicles. Therefore, the need for research to domestically produce such independent suspensions for large commercial vehicles is gradually increasing. In this paper, we conducted research on the manufacturing technology of the relay lever, which are integral components of independent suspension systems for large commercial vehicles. Our goal was to reduce the flash volume generated during the forging process. The shape variables of the initial billet were adjusted to find proper forming conditions that could minimize flash volume while performing product forming smoothly. Shape variables were set as input variables and the flash volume was set as an output variable, and simulations were carried out to analytically predict the volume of the flash area for each variable condition. Based on the data obtained through numerical simulations, a regression model and an artificial neural network model were used to develop a prediction model that can easily predict the flash volume for variable conditions. For the corresponding prediction model, a goodness of-fit test was performed to confirm a high level of fit. By comparing and analyzing the two prediction models, the high level of fit of the ANN model was confirmed.

Improvement Plan for Artificial Ground Landscaping of Underground Parking Lot in Apartment Complex (공동주택단지 인공지반 식재환경 개선방안)

  • Kang, Myung Soo;Moon, Seog Gi;Kim, Nam Jung
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.17 no.5
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    • pp.51-64
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    • 2014
  • Most planting grounds have converted to the artificial ground of the upper part of underground parking lot in apartment complex recently by increasing utilization of underground parking area. This study has examined the composition of each ground and planting status. The study presents problems of planting plans in artificial ground landscaping in apartment complex. This study has conducted reference and field research. It has researched green space planning, planting characteristics and measures condition of soil depth in 3 regions surveyed. The results are listed below. First, hybrid ground has the highest percentage and natural soils has the lowest percentage in the composition of green space in apartment complex. Artificial green space is composed of a number of small-scale grounds. Second, The study has found that planting characteristics don't reflect soil properties. On the other hand, planting deep rooting big arbors has a high proportion in artificial Ground. Third, the study has figured out 98% of fit in minimum soil depth for growth. Fourth, planters and landscaping stones are constructed in case of small green space. On the other hand, mounding is constructed in case of large green space. However in case of mounding types it has low fit, so it needs to improve this problem.

Development of Intelligent Monitoring System for Welding Process Faults Detection in Auto Body Assembly (자동차 차체 제조 공정에서 용접 공정 오류 검출을 위한 지능형 모니터링 시스템 개발)

  • Kim, Tae-Hyung;Yu, Ji-Young;Rhee, Se-Hun;Park, Young-Whan
    • Journal of Welding and Joining
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    • v.28 no.4
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    • pp.81-86
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    • 2010
  • In resistance spot welding, regardless of the optimal condition, bad weld quality was still produced due to complicated manufacturing processes such as electrode wear, misalignment between the electrode and workpiece, poor part fit-up, and etc.. Therefore, the goal of this study was to measure the process signal which contains weld quality information, and to develop the process fault monitoring system. Welding force signal obtained through variety experimental conditions was analyzed and divided into three categories: good, shunt, and poor fit-up group. And then a monitoring algorithm made up of an artificial neural network that could estimate the process fault of each different category based on pattern was developed.

A Dynamic Processor Allocation Strategy for Mesh-Connected Multicomputers

  • Kim, Geunmo;Hyunsoo Yoon
    • Journal of Electrical Engineering and information Science
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    • v.1 no.1
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    • pp.129-139
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    • 1996
  • The processor allocation problem in mesh multicamputers is to recognize and locate a free submesh that can accommodate a request for a submesh of a specified size. An efficient submesh allocation strategy is required for achieving high performance on mesh multicomputers. In this paper, we propose a new best-fit submesh allocation strategy for mesh multicomputers. The proposed strategy maintains and uses a free submesh list to get global information for free submeshes. For an allocation request the proposed strategy tries to allocate a best-fit submesh which causes the least amount of potential processor fragmentation so as to preserve the large free submeshes as many as possible for later requests. For this purpose, we introduce a novel function for quantifying the degree of potential fragmentation of submeshes. The proposed strategy has the complete submesh recognition capability. Extensive simulation is carried out t compare the proposed strategy with the previous strategies and experimental results indicate that the proposed strategy exhibits the best performance along with about 10% to 30% average improvement over the best previous strategy.

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A study on the fitness measurement of artificial femur through medical image processing (의료영상처리를 이용한 인공고관절 정합도 측정 방법에 관한 연구)

  • 김용호;김중규
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.1071-1074
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    • 1999
  • In this paper, we studied a computer based three dimensional implantation system of artificial hip joint. The system can be utilized for doctors to select a suitable artificial femur which is best-fit for the patient and to find out the optimal implanting position as well. We proposed a new numerical index to measure the fitness between the artificial hip joint and the patient's femur. The proposed fitness index accounts for the variance of the distance between the outer contours of artificial hip joint and the femur in addition to the conventional area comparison. A few simulation are run to show results of fitness measurement and compared to the conventional method.

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The Comparison of Sphere Fitting Methods for Estimating the Center of Rotation on a Human Joint (인체관절의 회전중심 추정을 위한 구적합법의 비교)

  • Kim, Jin-Uk
    • Korean Journal of Applied Biomechanics
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    • v.23 no.1
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    • pp.53-62
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    • 2013
  • The methods of fitting a circle to measured data, geometric fit and algebraic fit, have been studied profoundly in various areas of science. However, they have not been applied exactly to a biomechanics discipline for locating the center of rotation of a human joint. The purpose of this study was to generalize the methods to fitting spheres to the points in 3-dimension, and to estimate the center of rotation of a hip joint by three of geometric fit methods(Levenberg-Marquardt, Landau, and Sp$\ddot{a}$th) and four of algebraic fit methods(Delogne-K${\aa}$sa, Pratt, Taubin, and Hyper). 1000 times of simulation experiments for flexion/extension and ad/abduction at an artificial hip joint with four levels of range of motion(10, 15, 30, and $60^{\circ}$) and three levels of angular velocity(30, 60, and $90^{\circ}$/s) were executed to analyze the responses of the estimated center of rotation. The results showed that the Sp$\ddot{a}$th estimate was very sensitive to the marker near the center of rotation. The bias of Delogne-K${\aa}$sa estimate existed in an even larger range of motion. The Levenberg-Marquardt algorithm of geometric fit and the Pratt of algebraic fit showed the best results. The combination of two methods, using the Pratt's estimate as initial values of the Levenberg-Marquardt algorithm, could be a candidate of more valid estimator.

Application of neural networks and an adapted wavelet packet for generating artificial ground motion

  • Asadi, A.;Fadavi, M.;Bagheri, A.;Ghodrati Amiri, G.
    • Structural Engineering and Mechanics
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    • v.37 no.6
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    • pp.575-592
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    • 2011
  • For seismic resistant design of critical structures, a dynamic analysis, either response spectrum or time history is frequently required. Owing to the lack of recorded data and the randomness of earthquake ground motion that may be experienced by structure in the future, usually it is difficult to obtain recorded data which fit the requirements (site type, epicenteral distance, etc.) well. Therefore, the artificial seismic records are widely used in seismic designs, verification of seismic capacity and seismic assessment of structures. The purpose of this paper is to develop a numerical method using Artificial Neural Network (ANN) and wavelet packet transform in best basis method which is presented for the decomposition of artificial earthquake records consistent with any arbitrarily specified target response spectra requirements. The ground motion has been modeled as a non-stationary process using wavelet packet. This study shows that the procedure using ANN-based models and wavelet packets in best-basis method are applicable to generate artificial earthquakes compatible with any response spectra. Several numerical examples are given to verify the developed model.

Comparison of the fit of cast gold crowns fabricated from the digital and the conventional impression techniques

  • Yun, Mi-Jung;Jeon, Young-Chan;Jeong, Chang-Mo;Huh, Jung-Bo
    • The Journal of Advanced Prosthodontics
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    • v.9 no.1
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    • pp.1-13
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    • 2017
  • PURPOSE. The purpose of this study was to compare the fit of cast gold crowns fabricated from the conventional and the digital impression technique. MATERIALS AND METHODS. Artificial tooth in a master model and abutment teeth in ten patients were restored with cast gold crowns fabricated from the digital and the conventional impression technique. The forty silicone replicas were cut in three sections; each section was evaluated in nine points. The measurement was carried out by using a measuring microscope and I-Soultion. Data from the silicone replica were analyzed and all tests were performed with ${\alpha}$-level of 0.05. RESULTS. 1. The average gaps of cast gold crowns fabricated from the digital impression technique were larger than those of the conventional impression technique significantly. 2. In marginal and internal axial gap of cast gold crowns, no statistical differences were found between the two impression techniques. 3. The internal occlusal gaps of cast gold crowns fabricated from the digital impression technique were larger than those of the conventional impression technique significantly. CONCLUSION. Both prostheses presented clinically acceptable results with comparing the fit. The prostheses fabricated from the digital impression technique showed more gaps, in respect of occlusal surface.

An Adaptive Recommendation System for Personalized Stock Trading Advice Using Artificial Neural Networks

  • Kaensar, Chayaporn;Chalidabhongse, Thanarat
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.931-934
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    • 2005
  • This paper describes an adaptive recommendation system that provides real-time personalized trading advice to the investors based on their profiles and trading information environment. A proposed system integrates Stochastic technical analysis and artificial neural network that incorporates an adaptive user modeling. The user model is constructed and updated based on initial user profile and recorded user interactions with the system. The information presented to each individual user is also tailor-made to fit the user's behavior and preference. A system prototype was implemented in JAVA. Experiments used to evaluate the system's performance were done on both human subjects and synthetic users. The results show our proposed system is able to rapidly learn to provide appropriate advice to different types of users.

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