• Title/Summary/Keyword: Synthetic method

Search Result 2,114, Processing Time 0.029 seconds

Condition monitoring and rating of bridge components in a rail or road network by using SHM systems within SRP

  • Aflatooni, Mehran;Chan, Tommy H.T;Thambiratnam, David P.
    • Structural Monitoring and Maintenance
    • /
    • v.2 no.3
    • /
    • pp.199-211
    • /
    • 2015
  • The safety and performance of bridges could be monitored and evaluated by Structural Health Monitoring (SHM) systems. These systems try to identify and locate the damages in a structure and estimate their severities. Current SHM systems are applied to a single bridge, and they have not been used to monitor the structural condition of a network of bridges. This paper propose a new method which will be used in Synthetic Rating Procedures (SRP) developed by the authors of this paper and utilizes SHM systems for monitoring and evaluating the condition of a network of bridges. Synthetic rating procedures are used to assess the condition of a network of bridges and identify their ratings. As an additional part of the SRP, the method proposed in this paper can continuously monitor the behaviour of a network of bridges and therefore it can assist to prevent the sudden collapses of bridges or the disruptions to their serviceability. The method could be an important part of a bridge management system (BMS) for managers and engineers who work on condition assessment of a network of bridges.

Quantitative Assessment of 3D Reconstruction Procedure Using Stereo Matching (스테레오 정합을 이용한 3차원 재구성 과정의 정량적 평가)

  • Woo, Dong-Min
    • Journal of IKEEE
    • /
    • v.17 no.1
    • /
    • pp.1-9
    • /
    • 2013
  • The quantitative evaluation of DEM(Digital Elevation Map) is very important to the assessment of the effectiveness for the applied 3D image analysis technique. This paper presents a new quantitative evaluation method of 3D reconstruction process by using synthetic images. The proposed method is based on the assumption that a preacquired DEM and ortho-image should be the pseudo ground truth. The proposed evaluation process begins by generating a pair of photo-realistic synthetic images of the terrain from any viewpoint in terms of application of the constructed ray tracing algorithm to the pseudo ground truth. By comparing the DEM obtained by a pair of photo-realistic synthetic images with the assumed pseudo ground truth, we can analyze the quantitative error in DEM and evaluate the effectiveness of the applied 3D analysis method. To verify the effectiveness of the proposed evaluation method, we carry out the quantitative and the qualitative experiments. For the quantitative experiment, we prove the accuracy of the photo-realistic synthetic image. Also, the proposed evaluation method is experimented on the 3D reconstruction with regards to the change of the matching window. Based on the fact that the experimental result agrees with the anticipation, we can qualitatively manifest the effectiveness of the proposed evaluation method.

Estimation of the Forest Stand Volumes from Forest Inventory Data Based on Synthetic Estimation Method: A Case of the Economic Forest in Gangwon-do, Republic of Korea

  • Seo, Hwan seok;Park, Jeong mook;Lee, Jung soo
    • Journal of Forest and Environmental Science
    • /
    • v.32 no.2
    • /
    • pp.140-148
    • /
    • 2016
  • This study aims to estimate the forest volumes of the economic forest in Gangwon Province of Republic of Korea (hereinafter referred to as Gangwon) through the synthetic estimation. To estimate the forest volume, Stratified systematic sampling method was used along with the forest type maps and the $5^{th}$ National Forest Inventory data. The synthetic estimation includes sample plots of the expanded areas as well as those of the target area, and the forest volume of economic forest in every city and county throughout Gangwon. Results show that the average forest volume calculated by synthetic estimation was $159.6m^3/ha$ in national economic forest and $129.6m^3/ha$ in private economic forest. The total forest volume of the national economic forest was approximately $59.45million\;m^3$, which was $20.18million\;m^3$ higher than that of the private economic forest. On the other hands, the standard error of the national economic forest was approximately ${\pm}2.21m^3/ha$, which was ${\pm}0.30m^3/ha$ lower than that of the private economic forest. The lowest standard errors was about ${\pm}3.12 m^3/ha$ in broad-leaved forest, followed by ${\pm}4.33m^3/ha$ of mixed forest, and ${\pm}5.78m^3/ha$ of coniferous forest.

Structural and thermal analysis of electrochemically Li intercalated synthetic graphite (전기 화학적으로 리튬이 층간 삽입된 인조흑연의 구조와 열적 특성 분석)

  • Oh, Won-Chun
    • Analytical Science and Technology
    • /
    • v.14 no.3
    • /
    • pp.197-202
    • /
    • 2001
  • The characteristics of the electrochemically Li intercalated synthetic graphite were determined from the studies with XRD method, DSC and solid $^7Li-NMR$ spectrophotometric analysis. From the results of X-ray diffraction method, it was found that the compounds in the stage 1 structure were predominantly formed. The enthalpy and entropy changes of the compounds can be obtained from the differential scanning calorimetric analysis results. From these results, it was found that exothermic and endothermic reactions of lithium intercalated into synthetic graphite are related to thermal stability of lithium ion between carbon graphene layers. From the $^7Li-NMR$ data, scientific observation found that bands are shift toward higher frequencies with increasing lithium concentration because non-occupied electron shells of Li increased in charge carrier density. Line widths of the Li intercalated synthetic graphite compounds decreased slowly because of non-homogeneous local magnetic order and the random electron spin direction for substituted Li.

  • PDF

Genetic relationship between purebred and synthetic pigs for growth performance using single step method

  • Hong, Joon Ki;Cho, Kyu Ho;Kim, Young Sin;Chung, Hak Jae;Baek, Sun Young;Cho, Eun Seok;Sa, Soo Jin
    • Animal Bioscience
    • /
    • v.34 no.6
    • /
    • pp.967-974
    • /
    • 2021
  • Objective: The objective of this study was to estimate the genetic correlation (rpc) of growth performance between purebred (Duroc and Korean native) and synthetic (WooriHeukDon) pigs using a single-step method. Methods: Phenotypes of 15,902 pigs with genotyped data from 1,792 pigs from a nucleus farm were used for this study. We estimated the rpc of several performance traits between WooriHeukDon and purebred pigs: day of target weight (DAY), backfat thickness (BF), feed conversion rate (FCR), and residual feed intake (RFI). The variances and covariances of the studied traits were estimated by an animal multi-trait model that applied the Bayesian inference. Results: rpc within traits was lower than 0.1 for DAY and BF, but high for FCR and RFI; in particular, rpc for RFI between Duroc and WooriHeukDon pigs was nearly 1. Comparison between different traits revealed that RFI in Duroc pigs was associated with different traits in WooriHeukDon pigs. However, the most of rpc between different traits were estimated with low or with high standard deviation. Conclusion: The results indicated that there were substantial differences in rpc of traits in the synthetic WooriHeukDon pigs, which could be caused by these pigs having a more complex origin than other crossbred pigs. RFI was strongly correlated between Duroc and WooriHeukDon pigs, and these breeds might have similar single nucleotide polymorphism effects that control RFI. RFI is more essential for metabolism than other growth traits and these metabolic characteristics in purebred pigs, such as nutrient utilization, could significantly affect those in synthetic pigs. The findings of this study can be used to elucidate the genetic architecture of crossbred pigs and help develop new breeds with target traits.

Numerical Study on the Correction of Sea Effect in Magnetotelluric (MT) Data

  • Yang, Jun-Mo;Yoo, Hai-Soo
    • Journal of the Korean earth science society
    • /
    • v.30 no.5
    • /
    • pp.550-564
    • /
    • 2009
  • When magnetotelluric (MT) data are obtained in the vicinity of the coast, the surrounding seas make it difficult to interpret subsurface structure, especially the deep part of the subsurface. We introduce an iterative method to correct the sea effect, based on the previous topographic correction method that removes the distortion due to topographic changes in seafloor MT data. The method first corrects the sea effect in observed MT impedance, and then inverts corrected response in a model space without the sea. Due to mutual coupling between the sea and the subsurface structure, the correction and inversion steps are iterated until the changes in each result become negligible. The method is tested for 1- and 2-D structures using synthetic MT data produced by 3-D forward modeling including surrounding seas. In all cases, the method closely recovers the true structure assumed to generate synthetic responses after a few iterations.

Synthetic method and insecticidal activity of ricinine (Ricinine의 합성법 및 살충활성)

  • Kwon, Oh-Kyung;Lim, Soo-Kil;Choi, Dal-Soon;Kyung, Suk-Hun
    • The Korean Journal of Pesticide Science
    • /
    • v.2 no.1
    • /
    • pp.18-23
    • /
    • 1998
  • In order to obtain leading compound for the development of new pesticide through the organic synthesis of natural products, the synthesis of ricinine, an active compound of Ricinus communis, was established and biological activities of synthetic compounds against insects were examined. The synthetic scheme of ricinine was composed of four steps by the spontaneous condensation of the cyanoacetyl chloride. A modified synthetic process was also estabilshed to enhance the synthetic yield by simple cyclization of ethoxymethylene malononitrile. In the bioassay results of synthetic ricinine and intermediates on four insects, the mortality of ricinine on brown planthopper (BPH, Nilaparvata lugens) and pea weevil(PW, Bruchus rufimanus) was 80% and 75% at the concentration of 1,000 ${\mu}g/ml$ respectively. Chloronorricinine and chlororicinic acid having chloride group in molecular structure gave 60% mortality on two-spotted mite (TSSM, Tetranychus urticae) at the concentration of 500 ${\mu}g/ml$. The mortality of compounds on house mosquito (HM, Culex pipens pallens) was meager at 10 ${\mu}g/ml$ level.

  • PDF

Bistatic Synthetic Aperture Radar Imaging Using a Monostatic Equivalent Model (모노스태틱 등가 모델을 활용한 바이스태틱 SAR 영상 형성에 관한 연구)

  • Ryu, Bo-Hyun;Kang, Byung-Soo;Lee, Myung-Jun;Kim, Kyung-Tae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.29 no.9
    • /
    • pp.693-700
    • /
    • 2018
  • In this paper, we propose a method to generate SAR(synthetic aperture radar) images for bistatic radar. The bistatic SAR can overcome several limitations of monostatic SAR, because the former can be applied to a variety of scenarios, compared to the latter. However, no study has been conducted on bistatic SAR imaging so far. In this paper, we propose a method to generate bistatic SAR images using the monostatic equivalent model and conventional monostatic SAR imaging algorithms. Simulations using airborne SAR in the bistatic geometry validated the efficacy of the proposed method.

Evolution of the synthetic aperture imaging method in medical ultrasound system (초음파진단기 합성구경영상법의 진화)

  • Bae, MooHo
    • The Journal of the Acoustical Society of Korea
    • /
    • v.41 no.5
    • /
    • pp.534-544
    • /
    • 2022
  • Medical ultrasound system has been widely used to visualize the lesion for diagnostics in most medical service site including hospitals and clinics thanks to its advantages such as real time operation, ease of use, safety. Among many signal processing blocks of the system, one of the most important part that governs the image quality is the beamformer, and technologies for this part has been continuously developed in long time. The synthetic aperture imaging method, that is one of the major technologies of beamforming, was introduced to maximize utilizing the information delivered from the patient's body through the probe, and contributed to breakthrough of the image quality since it was introduced in around 1990's, and evolved continuously in decades. This paper reviews and surveys the process of development of this technology and expects future evolution.

ISAR Imaging of Airplane-like Targets by Matrix Pencil Method (Matrix Pencil 방법에 의한 비행기 모형의 ISAR 영상화)

  • 유지희;권경일;이용희
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.12 no.2
    • /
    • pp.299-307
    • /
    • 2001
  • This paper presents a experimental study of Inverse Synthetic Aperture Radar(ISAR) imaging using Matrix Pencil(MP) method. A series of measurement for two types of target model was done in a Compact Range(CR)facility. The first target is a set of distributed slim cylinders to get a ISAR image of point-like scatterers. The second is UAV model representing a complex real target. The results show that ISAR images by MP method are better than by conventional FFT method under the realistic measurement conditions.

  • PDF