• Title/Summary/Keyword: Linear Models

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Analysis of the Bearing Capacity of Drilled Shafts Compared with Driven Piles (항타말뚝과 비교한 현장타설말뚝의 지지력분석)

  • Lee, Seong-Jun;Jeong, Sang-Seom;Kim, Su-Il
    • Geotechnical Engineering
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    • v.13 no.5
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    • pp.75-88
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    • 1997
  • In this study an iterative procedure for the analysis of drilled shafts was proposed on the basis of the load transfer mechanism. Special attention was given to the estimation of bearing capacity of drilled shafts which was compared with driven piles, and then with the results of pile load test. The load displacement at the pile head was calculated by load than sfer curves (t -z curves, q-z curves) by using Vljayvergiya, Castelli and hi -linear models. Bab ed on the analytical results, it is found that the behavior of drilled shafts is different from that of driven piles the smaller the skin friction mobilized at the pile-boil interface, the smaller the development of the bearing capacity. Hence the greater pile head movement is required to mobilize the same mainitride of bearing capacity. This trend is more noticeable in sand than in clay. It is also found that as the length-todiameter ratios increase, the dirtference of ultimate bearing capacity between drilled shafts and driven piles is becoming lass ger in sand, but it is minor in clay.

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The non-linear FEM analysis of different connection lengths of internal connection abutment (내측 연결형 임플란트 지대주의 체결부 길이 변화에 따른 비선형 유한요소법적 응력분석)

  • Lee, Yong-Sang;Kang, Kyoung-Tak;Han, Dong-Hoo
    • The Journal of Korean Academy of Prosthodontics
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    • v.54 no.2
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    • pp.110-119
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    • 2016
  • Purpose: This study is aimed to assess changes of stress distribution dependent on different connection lengths and placement of the fixture top relative to the ridge crest. Materials and methods: The internal-conical connection implant which has a hexagonal anti-rotation index was used for FEM analysis on stress distribution in accordance with connection length of fixture-abutment. Different connection lengths of 2.5 mm, 3.5 mm, and 4.5 mm were designed respectively with the top of the fixture flush with residual ridge crest level, or 2 mm above. Therefore, a total of 6 models were made for the FEM analysis. The load was 170 N and 30-degree tilted. Results: In all cases, the maximum von Mises stress was located adjacent to the top portion of the fixture and ridge crest in the bone. The longer the connection length was, the lower the maximum von Mises stress was in the fixture, abutment, screw and bone. The reduction rate of the maximum von Mises stress depending on increased connection length was greater in the case of the fixture top at 2 mm above the ridge crest versus flush with the ridge crest. Conclusion: It was found that the longer the connection length, the lower the maximum von Mises stress appears. Furthermore, it will help prevent mechanical or biological complications of implants.

Genomic partitioning of growth traits using a high-density single nucleotide polymorphism array in Hanwoo (Korean cattle)

  • Park, Mi Na;Seo, Dongwon;Chung, Ki-Yong;Lee, Soo-Hyun;Chung, Yoon-Ji;Lee, Hyo-Jun;Lee, Jun-Heon;Park, Byoungho;Choi, Tae-Jeong;Lee, Seung-Hwan
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.10
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    • pp.1558-1565
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    • 2020
  • Objective: The objective of this study was to characterize the number of loci affecting growth traits and the distribution of single nucleotide polymorphism (SNP) effects on growth traits, and to understand the genetic architecture for growth traits in Hanwoo (Korean cattle) using genome-wide association study (GWAS), genomic partitioning, and hierarchical Bayesian mixture models. Methods: GWAS: A single-marker regression-based mixed model was used to test the association between SNPs and causal variants. A genotype relationship matrix was fitted as a random effect in this linear mixed model to correct the genetic structure of a sire family. Genomic restricted maximum likelihood and BayesR: A priori information included setting the fixed additive genetic variance to a pre-specified value; the first mixture component was set to zero, the second to 0.0001×σ2g, the third 0.001×σ2g, and the fourth to 0.01×σ2g. BayesR fixed a priori information was not more than 1% of the genetic variance for each of the SNPs affecting the mixed distribution. Results: The GWAS revealed common genomic regions of 2 Mb on bovine chromosome 14 (BTA14) and 3 had a moderate effect that may contain causal variants for body weight at 6, 12, 18, and 24 months. This genomic region explained approximately 10% of the variance against total additive genetic variance and body weight heritability at 12, 18, and 24 months. BayesR identified the exact genomic region containing causal SNPs on BTA14, 3, and 22. However, the genetic variance explained by each chromosome or SNP was estimated to be very small compared to the total additive genetic variance. Causal SNPs for growth trait on BTA14 explained only 0.04% to 0.5% of the genetic variance Conclusion: Segregating mutations have a moderate effect on BTA14, 3, and 19; many other loci with small effects on growth traits at different ages were also identified.

Empirical Study on the Mode Choice Behavior of Travelers by Express Bus and Express Train (특급(特急)과 고속(高速)버스 이용자(利用者)의 수단선정행태(手段選定行態)에 관한 경험적(經驗的) 연구(研究))

  • Kim, Kyung Whan
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.3 no.2
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    • pp.119-126
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    • 1983
  • The purposes of this study are to analyze/model the mode choice behavior of the regional traveler by express bus/express train and to offer useful source in deciding the public transportation policy. The data analyzed were trips of both modes from March, 1980 to November, 1981, between Seoul and other nineteen cities; the data were grouped as five groups according to the change of service variables. Service variables were travel time(unit: minute), cost(:won), average allocation time(:won), service hour(:hour), and dummy variables by mode. As model Logit Model with linear or log utility function were postulated. As the result of this study, some reseanable models were constructed at Model Type I(eq. 2. of this paper) based on the above data except the dummy. It was judged that the parameters calibrated by Group III and Group IV data in table 4, were optimal. Among the parameters, the parameter of travel cost was most reliable. There was a tendency preferring express bus to train in October and November. With the constructed model and Pivot-Point Method. the demand change of express train caused by the service variables' change could be forecasted over 99%.

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Genome-wide association study reveals genetic loci and candidate genes for average daily gain in Duroc pigs

  • Quan, Jianping;Ding, Rongrong;Wang, Xingwang;Yang, Ming;Yang, Yang;Zheng, Enqin;Gu, Ting;Cai, Gengyuan;Wu, Zhenfang;Liu, Dewu;Yang, Jie
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.4
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    • pp.480-488
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    • 2018
  • Objective: Average daily gain (ADG) is an important target trait of pig breeding programs. We aimed to identify single nucleotide polymorphisms (SNPs) and genomic regions that are associated with ADG in the Duroc pig population. Methods: We performed a genome-wide association study involving 390 Duroc boars and by using the PorcineSNP60K Beadchip and two linear models. Results: After quality control, we detected 3,5971 SNPs, which included seven SNPs that are significantly associated with the ADG of pigs. We identified six quantitative trait loci (QTL) regions for ADG. These QTLs included four previously reported QTLs on Sus scrofa chromosome (SSC) 1, SSC5, SSC9, and SSC13, as well as two novel QTLs on SSC6 and SSC16. In addition, we selected six candidate genes (general transcription factor 3C polypeptide 5, high mobility group AT-hook 2, nicotinamide phosphoribosyltransferase, oligodendrocyte transcription factor 1, pleckstrin homology and RhoGEF domain containing G4B, and ENSSSCG00000031548) associated with ADG on the basis of their physiological roles and positional information. These candidate genes are involved in skeletal muscle cell differentiation, diet-induced obesity, and nervous system development. Conclusion: This study contributes to the identification of the casual mutation that underlies QTLs associated with ADG and to future pig breeding programs based on marker-assisted selection. Further studies are needed to elucidate the role of the identified candidate genes in the physiological processes involved in ADG regulation.

Presurgical Naso-Alveolar Molding Appliance for Unilateral Cleft Lip and Palate (편측성 순구개열 신생아 환자의 술전 비치조 정형장치)

  • Baek, Seung-Hak;Yang, Won-Sik;Kim, Sukwha
    • The korean journal of orthodontics
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    • v.28 no.6 s.71
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    • pp.905-914
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    • 1998
  • The goals of this study were to present presurgical naso-alveolar molding (PNAM) appliance in unilateral cleft lip and palate treatment and to evaluate the effects of PNAM appliance on alveolar molding. Samples were consisted of 4 unilateral cleft lip and palate infants (3 males and 1 female, mean age=23.2 days after birth) who were treated with PNAM appliances in Department of Orthodontics, Seoul National University Dental Hospital. Average alveolar cleft gap between the greater and lesser segment was 8.27mm and average duration of alveolar molding treatment was 9.7 weeks. These patients' models were obtained at initial visit (T1) and alter successful alveolar molding (T2). Seven linear and five angular variables were measured by using photometry and digital caliper. All statistical analyses were performed by SPSS win ver. 7.5 program. Paired t-test was used to compare the mean values. 1. The posterior part of alveolar segments are the stable structures during alveolar molding treatment period in infants. 2. Forward growth of the greater segment may be hindered by the action of alveolar molding. 3. The closure of cleft gap during alveolar molding were usually due to inward and backward bending of the anterior part of the greater segment and outward bending of the whole lesser segment.

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A study on the relationship between jaw size and tooth size (치아크키와 악골크기의 상관관계에 관한 연구)

  • Ahn, Hyo-Beom;Nahm, Dong-Seok
    • The korean journal of orthodontics
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    • v.33 no.3 s.98
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    • pp.157-167
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    • 2003
  • The purpose of this study was to find whether there is a correlation between tooth size and jaw size. Dental stone models and cephalometric radiographic films of 87 untreated individuals were evaluated. Repeated measurements of the maximum mesiodistal width of the teeth were taken by means of a digital vernier caliper. Linear measurements of jaw size were assessed by means of a digitizer and Visual C++ program. All measurements were taken separately according to the subject's gender. To determine the relationship between jaw and tooth size, the Pearson correlation was used. The results were as follows: 1. Male and female subjects showed a statistical difference in regard to tooth size and jaw size 2. In contrast to the results of the male subjects, there were no statistically significant correlations between maxillary size and maxillary teeth size in female subjects 3. In male subjects, the two maxillary sizes of PTM vert-ANS vert (FH plane) and PTM vert-A yen (palatal plane) were significantly correlated with themaxillary teeth size. Especially, the size of the upper central incisor showed significant correlation with all maxillary sizes. 4. In both male and female subjects, mandibular size B vert- Point J vert (mandibular plane) showed significant correlation with mandibular teeth size. As gleaned kom the results of this study, the relationship between jaw size and tooth size was fair or little in natural occurring good occlusion.

A Fast Background Subtraction Method Robust to High Traffic and Rapid Illumination Changes (많은 통행량과 조명 변화에 강인한 빠른 배경 모델링 방법)

  • Lee, Gwang-Gook;Kim, Jae-Jun;Kim, Whoi-Yul
    • Journal of Korea Multimedia Society
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    • v.13 no.3
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    • pp.417-429
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    • 2010
  • Though background subtraction has been widely studied for last decades, it is still a poorly solved problem especially when it meets real environments. In this paper, we first address some common problems for background subtraction that occur in real environments and then those problems are resolved by improving an existing GMM-based background modeling method. First, to achieve low computations, fixed point operations are used. Because background model usually does not require high precision of variables, we can reduce the computation time while maintaining its accuracy by adopting fixed point operations rather than floating point operations. Secondly, to avoid erroneous backgrounds that are induced by high pedestrian traffic, static levels of pixels are examined using shot-time statistics of pixel history. By using a lower learning rate for non-static pixels, we can preserve valid backgrounds even for busy scenes where foregrounds dominate. Finally, to adapt rapid illumination changes, we estimated the intensity change between two consecutive frames as a linear transform and compensated learned background models according to the estimated transform. By applying the fixed point operation to existing GMM-based method, it was able to reduce the computation time to about 30% of the original processing time. Also, experiments on a real video with high pedestrian traffic showed that our proposed method improves the previous background modeling methods by 20% in detection rate and 5~10% in false alarm rate.

The Scattering and Absorption Effects of Fluorescence Spectroscopy in a Real Time Optical Biopsy (실시간 광학적 생검에서 형광분광법의 산란과 흡수에 대한 영향)

  • Han, Seunghee;Muller, Markus G.;Kang, Seunghee;Kang, Haejin
    • Progress in Medical Physics
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    • v.12 no.1
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    • pp.79-94
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    • 2001
  • The fluorescence emanating from a biological tissue contains information about scattering, absorption and the intrinsic fluorescence (fluorescence only due to fluorophores). Becaue fluorescence spectra of biological tissue are often significantly affected by the presence of tissue absorbers and scatterers, the measured tissue fluorescence cannot be interpreted as a linear combination of intrinsic fluorescence spectra of different tissue biochemical. We conducted experiments to examine the influence of scattering and absorption on the experimentally measured fluorescence of a turbid medium such as biological tissue. Therefore, we acquired fluorescence and reflectance spectra of tissue phantoms with a wide range of scatterer and absorber concentrations. By applying a photon migration model, which uses the scattering and absorption information contained in reflectance spectra to remove their distortion also present in fluorescence spectra, we extract the intrinsic fluorescence of these tissue models. We achieved excellent agreement between modeled and actual intrinsic fluorescence spectra. The motivation for this research is that intrinsic fluorescence spectra are expected to change with progression of disease in human tissue, due to changes in the tissue biochemical composition. It is not possible to distinguish the two tissue types by using only the measured fluorescence, however clear separation can be achieved with the intrinsic fluorescence in real time optical biopsy.

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Shaking Table Test of a 1/10 Scale Isolated Fifteen-story Flat Plate Apartment Building (면진층을 가지는 1/10 축소된 15층 무량판 아파트건물의 진동대 실험)

  • Chun, Young-Soo
    • Land and Housing Review
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    • v.2 no.3
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    • pp.287-297
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    • 2011
  • This paper presents the results of performance verification tests of the isolated flat plate apartment building with the laminated rubber bearings. The shaking table test is carried out in CABR(China Academy of Building Research) with two 1/10 scale isolation and non-isolation models under 4 excitation waves. The shaking table test is proceeding from x axis, y axis and x+y axis with different amplitude of acceleration values. The results show that, to non-isolated model, the natural vibration period is remarkably decreased and entered non-linear condition after moderate earthquake. Its accelerations become lager with increasing storey number and completely collapsed under large earthquake. The inter-storey shifts largely exceed the limit values of regulated displacement angles. But to isolated model, the natural vibration period of isolated modal is almost the same in all conditions and still in its elastic condition. The earthquake loading is greatly reduced and the accelerations of superstructure are greatly reduced. The inter-storey drifts are very small and can be neglected. The isolated model is in translational state and can be seen as a rigid whole. The displacements of isolation layer are in the allowable range. This experiment demonstrates that the seismic isolation is very effective to mitigate the influence of earthquake on structures and it is possible to increase the serviceability due to decrease the floor acceleration. facilities from their good states that is superior to non-isolated structure.