• Title/Summary/Keyword: Shape prior

Search Result 303, Processing Time 0.026 seconds

Three Dimensional Shape Estimation by Shading Analysis of Endoscopic Image (음영분석에 의한 내시경 영상의 3차원 형체 추정에 관한 연구)

  • Lee, Tae-Su;Cha, Eun-Jong;Yun, Se-Jin
    • Journal of Biomedical Engineering Research
    • /
    • v.16 no.4
    • /
    • pp.499-506
    • /
    • 1995
  • A new numerical method estimated three dimensional shape of the internal surface of the stomach by analyzing the shading data of endoscopic image. First analyzed was the inherent instrumentational characteristics of the endoscope system, followed by the analysis of the stomach surface properties, both of which affected the imaging properties. We employed these prior informations to implement the iterative algorithm of shading analysis based on Hom's variational approach. The present algorithm was validated by performing simulation on a $256{\times}320$ image data chosen from original $512{\times}512$ image of the stomach surface model. The best 3-dimensional estimation of the surface was achieved with the Lagrangian multiplier, of 0.3, when the algorithm best converged showing minimal estimation error.

  • PDF

Effect of Design Factors on the Performance of Stratified Thermal Storage Tank (성층축열조의 성능에 대한 설계인자의 영향)

  • Chung Jae Dong;Park Joohyuk;Cho Sung-Hwan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.16 no.11
    • /
    • pp.1077-1083
    • /
    • 2004
  • This study is to systematically analyze the effect of various kinds of design factors on the performance of stratified thermal storage tank. Taguchi method, known as a very reasonable tool in the parametric study, is employed in the present work. Three dimensional unsteady numerical experiment is conducted for 4 design parameters of stratified thermal storage tank: inlet Reynolds number, Froude number, diffuser size d with 3 levels (Re=400, 800, 1200, Fr=0.5, 1.0, 2.0 and d=150 mm, 200mm, 300 mm) and diffuser shape with 2 levels. Orthogonal array $L_{18}(2{\times}3^7)$ is adopted for the analysis of variance. The result gives quantitative estimation of the various design parameters affecting the performance and helps to select the main factors for the optimum design of stratified thermal storage tank. Reynolds number is found to be the most dominant parameter and the diffuser shape plays significant role on the performance of stratified thermal storage tank. Based on this finding, the prior questions on the contribution of the diffuser shape proposed by the authors become clear. The optimum condition for the performance is a set of d=300mm, Re=800, and radial regulated plate diffuser. Conformation test shows the repeatability in the analysis and $1.3\%$ difference between the estimated thermocline thickness and that of numerical result.

The comparison between Pleuronichthys cornutus and Pleuronichthys japonicus for the activation of fishery marine tourism (수산관광 활성화를 위한 도다리와 흘림도다리의 비교)

  • Shin, Lim-Soo
    • Journal of Digital Convergence
    • /
    • v.19 no.8
    • /
    • pp.43-48
    • /
    • 2021
  • There are prior studies that describe in detail the classification and shape of 26 species of Korean flounder, but it is difficult to make them out and they are used interchangeably or misused. It is intended to present the taxonomic standards of Pleuronichthys cornutus and Pleuronichthys japonicus and use them as tourism education materials using aquatic resources. Morphological comparison was made through counting and measurement. The two fish species were generally flattened in an oval shape with a low body height and a wide body width, and the anal fin developed and sized similar to the dorsal fin, and the caudal fin was widely spread out. Among the hyoid bones, in three parts of the coccyx, the main part, the ischial part, and the cardinal process, there were differences in the degree of curvature, the open angle, and the shape of the ischial part and the lateral process, which corresponded to the representative classification characteristics. In addition, it will be expected that it will serve as a basis as a fishery and marine education material for marine tourism that classifies and categorizes the characteristics as a genus of flounder and categorizes the characteristics, and reduces misuse of scientific names and names in the future.

Hybrid machine learning with mode shape assessment for damage identification of plates

  • Pei Yi Siow;Zhi Chao Ong;Shin Yee Khoo;Kok-Sing Lim;Bee Teng Chew
    • Smart Structures and Systems
    • /
    • v.31 no.5
    • /
    • pp.485-500
    • /
    • 2023
  • Machine learning-based structural health monitoring (ML-based SHM) methods are researched extensively in the recent decade due to the availability of advanced information and sensing technology. ML methods are well-known for their pattern recognition capability for complex problems. However, the main obstacle of ML-based SHM is that it often requires pre-collected historical data for model training. In most actual scenarios, damage presence can be detected using the unsupervised learning method through anomaly detection, but to further identify the damage types would require prior knowledge or historical events as references. This creates the cold-start problem, especially for new and unobserved structures. Modal-based methods identify damages based on the changes in the structural global properties but often require dense measurements for accurate results. Therefore, a two-stage hybrid modal-machine learning damage detection scheme is proposed. The first stage detects damage presence using Principal Component Analysis-Frequency Response Function (PCA-FRF) in an unsupervised manner, whereas the second stage further identifies the damage. To solve the cold-start problem, mode shape assessment using the first mode is initiated when no trained model is available yet in the second stage. The damage identified by the modal-based method would be stored for future training. This work highlights the performance of the scheme in alleviating the cold-start issue as it transitions through different phases, starting from zero damage sample available. Results showed that single and multiple damages can be identified at an acceptable accuracy level even when training samples are limited.

A Combined Hough Transform based Edge Detection and Region Growing Method for Region Extraction (영역 추출을 위한 Hough 변환 기반 에지 검출과 영역 확장을 통합한 방법)

  • N.T.B., Nguyen;Kim, Yong-Kwon;Chung, Chin-Wan;Lee, Seok-Lyong;Kim, Deok-Hwan
    • Journal of KIISE:Databases
    • /
    • v.36 no.4
    • /
    • pp.263-279
    • /
    • 2009
  • Shape features in a content-based image retrieval (CBIR) system are divided into two classes: contour-based and region-based. Contour-based shape features are simple but they are not as efficient as region-based shape features. Most systems using the region-based shape feature have to extract the region firs t. The prior works on region-based systems still have shortcomings. They are complex to implement, particularly with respect to region extraction, and do not sufficiently use the spatial relationship between regions in the distance model In this paper, a region extraction method that is the combination of an edge-based method and a region growing method is proposed to accurately extract regions inside an object. Edges inside an object are accurately detected based on the Canny edge detector and the Hough transform. And the modified Integrated Region Matching (IRM) scheme which includes the adjacency relationship of regions is also proposed. It is used to compute the distance between images for the similarity search using shape features. The experimental results show the effectiveness of our region extraction method as well as the modified IRM. In comparison with other works, it is shown that the new region extraction method outperforms others.

Diversity and origin of bottle gourd, Lagenaria

  • Yuasa, Hiroshi
    • Proceedings of the Plant Resources Society of Korea Conference
    • /
    • 2002.11a
    • /
    • pp.96-97
    • /
    • 2002
  • Bottle gourd, Lagenaria siceraria, is one of the oldest cultivated plants. To bigin with, its fruit was used as a complete liquid bottle or container. It was a very widespread cultivated plant in prehistoric times, for example (there) is a report from Peru as early as between 13,000 B.C and 11,000 B.C. The dug-out finds in Japan proved to be about 95,000 years old according to the /sup 14/C analysis. The bottle grourd was the most important plant before the invention of pottery in many areas of Asia, New Guinea, Polynesia, America, and Africa. I would like to suggest that there should be "The Bottle Gourd Age" prior to the Pottery Age. Bottle gourds are also used for various purposes such as food, masks, pipes, musical instruments, medicine, symbols, artistic products and also as penis-sheaths of men's attire. Their purposes number more than 220 including 70 varienties of containers or bottles. I consider that its utilization should be called a culture, as it were, "The gourd culture." The shape and the size of the fruit of bottle gourd have a larger variety than those of any other plant. As for the size, it is reported that they range from those that are shorter than 3cm to those that are ovoid and longer than 60cm in diameter. With regard to the shape of its fruit, the bottle gourd can be classified into 7 groups and even more than 30 races, considering the difference of the size. The seeds are so variable without two horn-like projections, with smooth surface or longitudinalines, white or brown, with smooth corky margin. Generally, it seems that there is no correlation between seem shape and fruit shape. My study shows that the seeds of gourd. My study shows that the seeds of gourd in Asia are so simple in shape and in color except for the size. But the seeds of those in Africa are various and seem to be beyond the confines. Explaining the great diversity of the seeds of those in Africa therefore, they appear to have no correlation among the types of fruit of the bottle gourd with African origin. It might be supposed that another 4 wild Lagenaria spp. distribute only in Africa. The intraspecies hybrid is confirmed between the bottle gourd, Lagenaria siceraria, and wild L. spehaerica. And Fl hybrid is sterile: it has no fertility. However, even though the shapes of the fruit and the seeds are different, they can cross with each other. Moreover, their hybrids grow up to be extremely vigorous and have normal fertility. Fruit shapes of Fl plants are similar to those of their parents, if they have the same character. Whereas, the fruit shape often became different from each other when the cross occurs between those with different fruit shapes. It is shown that dumbbell shapes, HYOTAN in Japanese, is recessive while its bitterness is dominant. Thus the character of F2 hybrids Is segregative. I'll give further particulars of the heredity of the groud in my lecture.

  • PDF

Analytic Estimation of Interrupting capability on contact system in MCCB (배선용 차단기(MCCB) 차단성능 평가해석 기법)

  • Choi, Y.K.;Chong, J.K.;Kim, I.Y.;Park, I.H.;Hwang, G.C.;Lee, K.S.
    • Proceedings of the KIEE Conference
    • /
    • 2002.07b
    • /
    • pp.628-632
    • /
    • 2002
  • Low voltage circuit breakers which interrupt rapidly and raise the reliability of power supply are widly used in power distribution systems. In the paper, it was investigated how much Interrupting capability was improved by correcting the shape of the contact system in molded case circuit breaker(below MCCB), especially arc runner. Prior to the interrupting testing, it was necessary for the optimum design to analyze electromagnetic forces on the contact system, generated by current and flux density. This paper presents both our compuational analysis and test results on contact system in MCCB

  • PDF

Growth of Bi2O3 doped ZnO nanostructures fabricated by thermal evaporation method

  • Kim, Gyeong-Beom;Kim, Seon-Hong;Jeong, Yeong-Hun;Lee, Yeong-Jin;Baek, Jong-Hu
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2009.11a
    • /
    • pp.243-243
    • /
    • 2009
  • Bi2O3 doped ZnO nanostructures structure were successfully synthesized by a thermal evaporatiion process and their structural characteristics were investigated. It is demonstrated that the growth condition such as the areal density, pretreatment of the substrates and growth temperature have great influence on the morphology and the alignment of the nanorods arrays. The density of Bi2O3 doped ZnO nanostructures is controlled by the gold (Au) nanoparticle density deposited on the silicon substrates. Relatively homogenous size and shape were observed by introducing gold(Au) seed-layer as nucleation centers on the substrates prior to the VLS reaction. The samples were characterized by X-ray diffraction, scanning electron microscopy.

  • PDF

Transient Heat Transfer for the Evaporators of Capillary Pumped Loop at Intial Startup (초기시동 시의 모세펌핑 루프 증발기에 대한 과도열전달 해석)

  • Park, Byung-Kyu;Kim, Geun-Oh;Kim, Moo-Geun
    • Proceedings of the KSME Conference
    • /
    • 2001.06d
    • /
    • pp.252-259
    • /
    • 2001
  • It is derived for the temperature profile in a cylindrical and planar shape capillary pumped loop evaporators subject to a uniform heat flux prior to the initiation of boiling using the finite difference method. The results of the analysis allow for the determination of applied power levels for which nucleation is likely to occur only within the vapor grooves of the evaporator while maintaining subcooling in the liquid core, thereby increasing the likelihood of a successful startup. Also, limits are found for which additional increases in the applied heat flux do not increase the temperature difference between the vapor grooves and the wick-liquid core interface. Several advantages of larger diameter evaporators observed experimentally in startup are explained and quantified by the model. This analysis is appropriate for standard capillary pumped loop evaporators during a fully-flooded startup as well as starter pump designs and loop heat pipes.

  • PDF

Theoretical Design of Ion Optics for Effective Ion Detection in Single Particle Mass Spectrometer (단일 입자 질량분석기의 효과적인 이온검출을 위한 이온계의 이론적인 설계)

  • Cho Sung-Woo;Lee Dong-Geun
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.30 no.7 s.250
    • /
    • pp.638-645
    • /
    • 2006
  • Recently, we reported that significant ion loss occurred prior to its detection in the conventional single particles mass spectrometry and more seriously the loss is ion-kinetic-energy-dependent. These lead to significant error in the measured chemical composition of nanoparticles. Here we attempted to design a novel ion optics that is capable of 100% detection of ions generated from single nanoparticle. Using a commercial software SIMION, we simulated the trajectories of ions launched at different speeds inside the previous single particle mass spectrometer We tested how affect changes in shape of repelling plate, adding Einzel lens, substitution of tube electrode between extraction and acceleration grids. As a results, we could find a best design by assembling the trials in the present condition.