• Title/Summary/Keyword: Reconstruction analysis

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A Study on the Side Collision Accident Reconstruction Using 3-Dimensional Crash Analysis (3차원 충돌해석 정보를 이용한 측면 충돌 사고 재구성)

  • Jang, In-Sik;Kim, Il-Dong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.1
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    • pp.52-63
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    • 2008
  • The side collision reconstruction algorithm is developed using three dimensional car crash analysis. Medium size passenger car is modeled for finite element analysis. Total 24 side collision configurations, four different speed and six different angle, are set up for making side collision database. Deformation index and degree index are built up for each collision case. Deformation index is a kind of deformation estimate averaging displacement of side door of crashed car from finite element analysis result. Angle index is constructed measuring deformed angle of crashing car. There are two kinds of angle index, one is measured at driver's side and the other is measured at passenger's side. Also a collision analysis information in side of cars is used for giving a basis for scientific and practical reason in a reconstruction of the car accident. The analysis program, LS-DYNA3D is utilized for finite element analysis program for a collision analysis. Those database are used for side collision reconstruction. Side collision reconstruction algorithm is developed, and applied to find the collision conditions before the accident occurs. Three example collision cases are tried to check the effectiveness of the algorithm. Deformation index and angle index is extracted for the case from the analysis result. Deformation index is compared to the established database, and estimated collision speed and angle are introduced by interpolation function. Angle index is used to select a specific collision condition from the several available conditions. The collision condition found by reconstruction algorithm shows good match with original condition within 10% error for speed and angle. As a result, the calculation from the reconstruction of the situation is reproducing the situation well. The performance in this study can be used in many ways for practical field using deformation index and degree index. Other different collision situations may be set up for extending the scope of this study in the future.

Structural health monitoring data reconstruction of a concrete cable-stayed bridge based on wavelet multi-resolution analysis and support vector machine

  • Ye, X.W.;Su, Y.H.;Xi, P.S.;Liu, H.
    • Computers and Concrete
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    • v.20 no.5
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    • pp.555-562
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    • 2017
  • The accuracy and integrity of stress data acquired by bridge heath monitoring system is of significant importance for bridge safety assessment. However, the missing and abnormal data are inevitably existed in a realistic monitoring system. This paper presents a data reconstruction approach for bridge heath monitoring based on the wavelet multi-resolution analysis and support vector machine (SVM). The proposed method has been applied for data imputation based on the recorded data by the structural health monitoring (SHM) system instrumented on a prestressed concrete cable-stayed bridge. The effectiveness and accuracy of the proposed wavelet-based SVM prediction method is examined by comparing with the traditional autoregression moving average (ARMA) method and SVM prediction method without wavelet multi-resolution analysis in accordance with the prediction errors. The data reconstruction analysis based on 5-day and 1-day continuous stress history data with obvious preternatural signals is performed to examine the effect of sample size on the accuracy of data reconstruction. The results indicate that the proposed data reconstruction approach based on wavelet multi-resolution analysis and SVM is an effective tool for missing data imputation or preternatural signal replacement, which can serve as a solid foundation for the purpose of accurately evaluating the safety of bridge structures.

Design of Lazy Classifier based on Fuzzy k-Nearest Neighbors and Reconstruction Error (퍼지 k-Nearest Neighbors 와 Reconstruction Error 기반 Lazy Classifier 설계)

  • Roh, Seok-Beom;Ahn, Tae-Chon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.20 no.1
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    • pp.101-108
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    • 2010
  • In this paper, we proposed a new lazy classifier with fuzzy k-nearest neighbors approach and feature selection which is based on reconstruction error. Reconstruction error is the performance index for locally linear reconstruction. When a new query point is given, fuzzy k-nearest neighbors approach defines the local area where the local classifier is available and assigns the weighting values to the data patterns which are involved within the local area. After defining the local area and assigning the weighting value, the feature selection is carried out to reduce the dimension of the feature space. When some features are selected in terms of the reconstruction error, the local classifier which is a sort of polynomial is developed using weighted least square estimation. In addition, the experimental application covers a comparative analysis including several previously commonly encountered methods such as standard neural networks, support vector machine, linear discriminant analysis, and C4.5 trees.

Quantitative Application of TM Data in Shallow Geological Structure Reconstruction

  • Yang, Liu;Liqun, Zou;Mingxin, Liu
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.1313-1315
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    • 2003
  • This paper is dedicated to studying the quantitative analysis method with remote-sensing data in shallow geological structure reconstruction by the example of TM data in western China. A new method of computing attitude of geological contacts from remote-sensing data is developed and assessed. We generate several geological profiles with remotely derived measurements to constrain the shallow geological structure reconstruction in three dimensions.

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Tomographic Reconstruction of Two-Phase Flows

  • Ko, Han-Seo;Kim, Yong-Jae
    • Journal of Mechanical Science and Technology
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    • v.17 no.4
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    • pp.571-580
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    • 2003
  • Tomography has been investigated to observe bubble behaviors in two-phase flows. A bubbly flow and an annular flow have been reconstructed by tomography methods such as an algebraic reconstruction technique (ART) and a multiplicative algebraic reconstruction technique (MART) . Computer synthesized phantom fields have been used to calculate asymmetric density distributions for limited cases of 3, 5, and 7 projection angles. As a result of comparison of two tomography methods, the MART method has shown a significant improvement in the reconstruction accuracy for analysis of the two-phase flows.

Development of an Automobile Black Box for Reconstruction Analysis of Collision Accidents (충돌사고 재구성 해석을 위한 차량 블랙박스의 개발)

  • 이원희;한인환
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.2
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    • pp.205-214
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    • 2004
  • This paper presents design concepts, specifications and performances of a newly developed Black Box, the reconstruction analysis tool with the records, and results of validation tests. The Black Box can detect crash accidents automatically, and record the vehicle's motion and driver's maneuvers during a pre-defined time period before and after the accident. The items of the Black Box included the acceleration, yaw-rate, vehicle speed, engine RPM, braking application, steering and several digital inputs for recording driver's maneuvers. To detect the accident-related-crash, it is important to understand characteristics of the crash signal, which are much different from those of normal driving. Therefore, analytical considerations should be taken in designing pre-filtering circuits and selecting appropriate parameters for identifying crash accidents. And, it is necessary to select proper combination of motion sensors and design proper pre-filtering circuits in order to describe the vehicle's motion. The analysis algorithms were developed and implemented which can perform accurate detection of crash accidents, simulating pre-crash trajectories, and calculating parameters for reconstruction analysis of crash accidents. The developed Black Box was installed on passenger cars and several types of validation tests were conducted. Through the tests, the accuracy of the recorded data and usefulness of the analysis tool for reconstruction have been validated.

Cost Analysis for Assessment of Reconstruction Projects (재건축사업의 진단평가를 위한 비용분석)

  • Kwon Dong-Chan;Lee Chan-Sik
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • autumn
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    • pp.477-480
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    • 2003
  • The objective procedure and criterion needs to efficiently perform the safety assessment and improve reliability for results of the cost analysis. There are many studies about cost analysis of safety assessment, but the these studies have problems such as non-quantification of criterions and methods. The purpose of this study to suggest the procedure and criterion for successful cost analysis and quantify cost factors. First, in the cost analysis of the housing reconstruction that is presented this study, determinate the life-cycle and the discount rate, then estimate reconstruction cost and remodeling cost. Finally, compare the annual equivalent LCC of two costs for decision malting to reconstruction or remodeling.

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The Analysis of Voice after Vertical Partial Laryngectomy with Mucosal Flap and Fat Graft Reconstruction (수직후두부분절제술 및 점막 피판과 지방 이식을 통한 성대 재건술 후의 음성분석)

  • Chu, Hyung-Ro;Choi, In-Ja;Kim, Jin-Hwan;Ahn, Hwoe-Young;Rho, Young-Soo
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.18 no.2
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    • pp.134-137
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    • 2007
  • Background and Objectives: The goals of laryngeal reconstruction have been prevention of aspiration, production of a functional voice, and maintenance of an adequate airway for decannulation. It is generally believed that the reconstruction of the glottic region after vertical partial laryngectomy (VPL) can improve laryngeal function. The objective of this study is to evaluate of voice function after VPL with mucosal flap and fat graft reconstruction. Materials and Methods: From 1994 to 2006, 13 patients, who had been treated with VPL with mucosal flap and fat graft reconstruction. The voice characteristics, acoustic, aerodynamic parameter were measured in 13 patients after vertical partial laryngectomy with mucosal flap and fat graft reconstruction. Acoustic analysis was carried out using Computerized Speech Lab (CSL) and aerodynamic analysis were carried out using Aerophon II,3 months and 12 months after surgery. Results: The GRBAS scale, jitter, shimmer, NHR were improved as time goes on after surgery. But, maximum phonation time was shortened after surgery and there is no significant differences between before and after surgery in mean flow rate. Conclusion: The voice function of the mucosal flap and fat graft reconstruction after VPL were satisfactory. This can be an excellent reconstruction method after vertical partial laryngectomy.

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An Analysis on the Actual Condition and the Influential Factors in Reconstruction Projects for Deteriorated Apartment Housing (노후아파트의 재건축 추진 영향요인 분석 -대구광역시 사례를 중심으로-)

  • 장석하;현택수;최무현
    • Journal of the Korean housing association
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    • v.10 no.1
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    • pp.145-154
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    • 1999
  • In this study, various factors affect on the reconstruction of the deteriorated apartment housing complex in the Taegu-City were analyzed. The conclusions obtained in this research were summarized as follows; 1) In case of 4 to 5 storied apartment buildings, those were main objects for reconstruction. The number of the buildings and households consisting apartment complex and the total building area and the ground area were appeared as major factors. Those factors were highly correlated with the consensus of reconstruction. 2) As a maximun area of reconstruction was limited, higher existing consensus capacity and its ratio affect negatively on reconstruction of deteriorated apartments. 3) The main motivation for reconstruction is disadvantages among the members of reconstruction association were main obstacles to reconstruct the deteriorated apartment buildings. Therefore, a resoanble alternatives for reconstruction plans and administrative managements were needed.

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A Scientometric Analysis of 20 Years of Research on Breast Reconstruction Surgery: A Guide for Research Design and Journal Selection

  • Moghimi, Mehrdad;Fathi, Mehdi;Marashi, Ali;Kamani, Freshteh;Habibi, Gholamreza;Hirbod-Mobarakeh, Armin;Ghaemi, Marjan;Hosseinian-Sarajehlou, Mahdi
    • Archives of Plastic Surgery
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    • v.40 no.2
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    • pp.109-115
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    • 2013
  • Background Breast reconstruction refers to the rebuilding of a woman's breast using autologous tissue or prosthetic material to form a natural-looking breast. It is increasingly offered to women undergoing mastectomy for breast cancer. However, there is no systematic analysis available for the expanding area of research on breast reconstruction. Methods A bibliometric method was used to obtain a view of the scientific production about breast reconstruction by data extracted from the Institute for Scientific Information (ISI). Specific parameters were retrieved from the ISI. Articles about breast reconstruction were analyzed to obtain a view of the topic's structure, history, and document relationships using HistCite software. Trends in the most influential publications and authors were analyzed. Results The number of articles was constantly increasing. Most highly cited articles described the methods of flap construction in the surgery. Other highly cited articles discussed the psychological or emotional aspects of breast reconstruction, skin sparing mastectomy, and breast reconstruction in the irradiated breast. Conclusions This was the first breast reconstruction scientometric analysis, representing the characteristics of papers and the trends of scientific production. A constant increase in the number of breast reconstruction papers and also the increasing number of citations shows that there is an increasing interest in this area of medical science. It seems that most of the research in this field is focused on the technical aspects of surgery.