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A Study on Remaining Efficiency of Thermal Straightening after Block Lifting

  • Ha, Yunsok;Yi, Myungsu
    • Journal of Advanced Research in Ocean Engineering
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    • v.1 no.3
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    • pp.148-156
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    • 2015
  • Deck plates of ships or offshore structures would make out-of-plane distortion for their thin thickness. These distortions are usually straightened by thermal straightening such as flame heating method. After thermal straightening, the blocks are lifted and moved by cranes to assemble it at dry-dock stage. After this lifting process, out-of-plane deformation again happens frequently. And then, they continuously cause quality and accuracy problems in the final dry-dock process. So, it takes more time for repair and correction working. According to preceding research, the lifting process by cranes would offset the effect on thermal straightening. The target of this study is to develop a methodology analyzing the remaining efficiency of thermal straightening after block lifting. The development was based on the assumption of yield state at straightening region. Therefore the remaining efficiency was obtained by different stiffness slope while lifting & relieving. The efficiency formula was designed using inherent strain, and we made a table of zero-efficiency by cooling speed and class rule's steels. As a result, if the stress orthogonal to straightened line is calculated during lifting analysis by FEA, the efficiency can be obtained linearly to the values in the table. Finally, even optimized carling position can be designed by considering the regional data from series project and welding region on deck.

A Vehicle Tracking Algorithm Focused on the Initialization of Vehicle Detection-and Distance Estimation (초기 차량 검출 및 거리 추정을 중심으로 한 차량 추적 알고리즘)

  • 이철헌;설성욱;김효성;남기곤;주재흠
    • Journal of KIISE:Software and Applications
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    • v.31 no.11
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    • pp.1496-1504
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    • 2004
  • In this paper, we propose an algorithm for initializing a target vehicle detection, tracking the vehicle and estimating the distance from it on the stereo images acquired from a forward-looking stereo camera mounted on a road driving vehicle. The process of vehicle detection extracts road region using lane recognition and searches vehicle feature from road region. The distance of tracking vehicle is estimated by TSS correlogram matching from stereo Images. Through the simulation, this paper shows that the proposed method segments, matches and tracks vehicles robustly from image sequences obtained by moving stereo camera.

PGA Implementation Technique for Stripmap SAR Signal Processing (Stripmap SAR 신호처리를 위한 PGA 적용 기법)

  • Yoon, Sang-Ho;Koh, Bo-Yeon;Kong, Young-Kyun;Shin, Hee-Sub
    • Korean Journal of Remote Sensing
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    • v.27 no.2
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    • pp.151-161
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    • 2011
  • PGA(Phase Gradient Autofocus) is a representative autofocus technique to improve the SAR(Synthetic Aperture Radar) image quality. PGA can estimate high order phase errors and have good robustness in noisy environments. However, PGA is not suitable to apply to the stripmap mode data directly because it is based on the spotlight mode operation. In this paper, the PGA implementation technique for stripmap mode data and the method of ROI(Region of Interest) selection that affects severely on PGA performance have been proposed. The proposed technique was verified by the point target simulation first, and was applied to the real SAR signal data acquired by the flight test. Finally, the significant improvements in focusing quality were shown in the processed SAR images using the proposed method.

Estimation and Validation of Collection 6 Moderate Resolution Imaging Spectroradiometer Aerosol Products for East Asia

  • Lee, Kwon-Ho
    • Asian Journal of Atmospheric Environment
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    • v.12 no.3
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    • pp.193-203
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    • 2018
  • The operational aerosol retrieval algorithm for the Moderate Resolution Imaging Spectroradiometer (MODIS) measurements was recently updated and named collection 6 (C6). The C6 MODIS aerosol algorithm, a substantially improved version of the collection 5 (C5) algorithm, uses an enhanced aerosol optical thickness(AOT) retrieval process consisting of new surface reflection and aerosol models. This study reports on the estimation and validation of the two latest versions, the C5 and C6 MODIS aerosol products over the East Asian region covering $20^{\circ}N$ to $56^{\circ}N$ and $80^{\circ}E$ to $150^{\circ}E$. This study also presents a comparative validation of the two versions(C5 and C6) of algorithms with different methods(Dark Target(DT) and Deep Blue (DB) retrieval methods) from the Terra and Aqua platforms to make use of the Aerosol Robotic Network (AERONET) sites for the years 2000-2016. Over the study region, the spatially averaged annual mean AOT retrieved from C6 AOT is about 0.035 (5%) less than the C5 counterparts. The linear correlations between MODIS and AERONET AOT are R = 0.89 (slope = 0.86) for C5 and R = 0.95 (slope = 1.00) for C6. Moreover, the magnitude of the mean error in C6 AOT-the difference between MODIS AOT and AERONET AOT-is 40% less than that in C5 AOT.

Effect of pre-miRNA-1658 gene polymorphism on chicken growth and carcass traits

  • Shi, Jianzhou;Sun, Guirong
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.4
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    • pp.455-461
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    • 2017
  • Objective: Polymorphisms occurring in the precursor region of microRNAs (miRNAs) affect the target gene and alter the biogenesis of miRNAs, resulting in phenotypic variation. The purpose of the study was to investigate the genetic effects of rs16681031 (C>G) mutation in the precursor region of gga-miR-1658 on the economic traits of the Gushi-Anka chicken F2 resource population. Methods: To explore the effect of miR-1658 polymorphisms on chicken economic traits, the SNP was genotyped by MassArray matrix-assisted laser desorption/ionization-time of flight mass spectrometry. The association between the SNP and chicken body size, growth and carcass traits was determined by linear mixed models. Results: The SNP was not only significantly associated with body weight at the age of 6, 8, 10, 12 weeks, respectively, but also with the breadth of the chicken chest, body slanting length and pelvic breadth at 4 weeks, chest depth at 8 weeks of age, and body slanting length at 12 weeks (p<0.05), respectively. Conclusion: Our data serve as a useful resource for further analysis of miRNA function, and represent a molecular genetic basis for poultry breeding.

Periondontal Disease Detection in Dental Radiography by ROI segment (관심영역을 이용한 치과용 방사선 영상에서의 자연치아 주위 미세변화 검출에 관한 연구)

  • 안용학;이정헌;채옥삼
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.6
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    • pp.73-80
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    • 2004
  • In this paper, we propose a medical image processing method for detection of periodontal disease. The proposed method is the method of an automatic image alignment and detection of minute changes, to overcome defects in the conventional subtraction radiography by digital image processing technique, that is necessary for getting subtraction image and ROI(Region of Interest) focused on a selection method using the structured features in target images. And the method services accuracy, consistency and objective information or data to results. In result, easily and visually we can identify minute differences in the affected parts whether they have problems or not, and using application system.

Estimation of Under-5 Child Mortality Rates in 52 Low-migration Countries

  • Sapkota, Nirmal;Gautam, Nirmal;Lim, Apiradee;Ueranantasun, Attachai
    • Child Health Nursing Research
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    • v.26 no.4
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    • pp.463-469
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    • 2020
  • Reduction of the under-5 mortality rate is a target of the Sustainable Development Goals. Therefore, this study aimed to estimate under-5 child mortality rates in 52 low-migration countries using population data. The study utilized population data from the US Census Bureau from 1990 to 2015. The method involved first estimating mortality rates for countries with negligible net migration and then applying these rates to countries with matching mortality profiles, where it is reasonable to assume that migration is negligible for children under the age of 5 years. The highest child mortality was concentrated in the African region, followed by Asia and the Western region. However, steady progress in child mortality trends was concentrated in low-income countries. This simple method demonstrated that child mortality has significantly improved in high-income countries, followed by middle- and low-income countries. To reduce the under-5 mortality rates even further in these 52 countries, there is a need to accelerate equitable plans and policies related to child health to promote children's longevity and survival.

Nuclear star formation in galaxies due to non-axisymmetric bulges

  • Kim, Eunbin;Kim, Sungsoo S.;Lee, Gwang-Ho;Lee, Myung Gyoon;de Grijs, Richard;Choi, Yun-Young
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.2
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    • pp.61.2-61.2
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    • 2014
  • A non-axisymmetric mass distribution of galactic structures including bulge (or bar) causes gas inflow from the disk to the nuclear region, including intense star formation within few hundred parsecs of galactic central. In order to investigate the relation between the ellipticity of the bulge and the presence of a nuclear starburst, we use a volume-limited sample of galaxies with Mr < -19.5 mag at 0.02 < z < 0.05 from the Sloan Digital Sky Survey Data Release 7. Total sample is 3252 spiral galaxies, which include nuclear starburst galaxies. We find that the occurrence of nuclear starbursts has a moderate correlation with bulge ellipticity of intermediate-type spiral galaxies (morphology classes Sab-Sb) in low galaxy number density environments and isolated regions where the distance between the target galaxies and the closest galaxies is relatively far. In high galaxy number density environments and interacting regions, close encounters and mergers between galaxies can cause gas inflow to the nuclear region even without the presence of non-axisymmetric bulges.

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Bone loss Detection in Dental Digital X-ray Image by Structure Analysis (구조적 분석을 이용한 치과용 디지털 X-ray 영상에서의 골조직 변화 검출에 관한 연구)

  • Ahn, Yong-Hak;Chae, Ok-Sam
    • The KIPS Transactions:PartB
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    • v.11B no.3
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    • pp.275-280
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    • 2004
  • In this paper, we propose automatic subtraction radiography algorithms to overcome conventional subtraction radiography's defects by applying image processing technique. In order to reach these goals, this paper suggests the image alignment method that is necessary for getting subtraction image and ROI(Region Of Interest) focused on a selection method using the structure characteristics in target images. Therefore, we use these methods because they give accurary, consistency and objective information or data to results. According to the results, easily and visually we can identify fine difference int the affected parts wether they have problems or not.

Evaluation and Direction of the New Town Development in Korea (우리나라 신도시 개발의 평가 및 발전방향)

  • Kim, Dong-Yoon
    • Journal of The Korean Digital Architecture Interior Association
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    • v.13 no.2
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    • pp.5-16
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    • 2013
  • With regard to the new town developments which have supplied lots of houses in a short period of time in Korea this study aims to evaluation and finding out problems of the developments finally to suggest the direction. A new town's competitiveness model set in the previous paper takes a role of research frame to recognize the problems and to show the direction. The model explains that new town's competitiveness is composed of 4 factors; Self-sufficiency, Innovativenss, Identity and Sustainability. Problems of the developments are as follows; incongruity of spatial structure especially in the capital region, deficiency of self-sufficiency resulted from single-use development, restriction on mixed development by a number of regulations in capital region, low business value, grand scale of land compensation, house oriented planning guidance, unfair share of infrastructure fee, and physical structure depending mainly on fossil energy. Based on this recognition this study conclusively suggests corresponding direction such as role performance as a means of urban growth management, promotion of quality of life by accumulating social capital, introduction of socially sustainable management program for the new towns, discovery and creation of town's value, reexamination of self-sufficiency's meaning or target, selective deregulation of metropolitan development, institutional strategy for cost reduction, changeover from house index to urban function oriented index, and pursuit of low-carbon green town.