• Title/Summary/Keyword: Shape Space

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Tongue Image Segmentation via Thresholding and Gray Projection

  • Liu, Weixia;Hu, Jinmei;Li, Zuoyong;Zhang, Zuchang;Ma, Zhongli;Zhang, Daoqiang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.2
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    • pp.945-961
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    • 2019
  • Tongue diagnosis is one of the most important diagnostic methods in Traditional Chinese Medicine (TCM). Tongue image segmentation aims to extract the image object (i.e., tongue body), which plays a key role in the process of manufacturing an automated tongue diagnosis system. It is still challenging, because there exists the personal diversity in tongue appearances such as size, shape, and color. This paper proposes an innovative segmentation method that uses image thresholding, gray projection and active contour model (ACM). Specifically, an initial object region is first extracted by performing image thresholding in HSI (i.e., Hue Saturation Intensity) color space, and subsequent morphological operations. Then, a gray projection technique is used to determine the upper bound of the tongue body root for refining the initial object region. Finally, the contour of the refined object region is smoothed by ACM. Experimental results on a dataset composed of 100 color tongue images showed that the proposed method obtained more accurate segmentation results than other available state-of-the-art methods.

A study on Visual Expression to express Sound Characteristics of Public Places

  • Park, Dong-Cheol
    • International Journal of Internet, Broadcasting and Communication
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    • v.13 no.4
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    • pp.11-21
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    • 2021
  • The causes of noise generation according to the classification of indoor spaces are very diverse. Individual happiness is infringed by this noise. In this paper, We tried to visualize the spatial sound characteristics of public places using sound color to express them so that anyone can sympathize. The noise inside a conference room of a medical device company was measured for 100 minutes, and the frequency band was divided into three different types of existing sound pressure expression units. Because the size of the noise is expressed differently depending on the situation, There are cases where there is a difference of opinion between the measurer and the researcher. This noise measurement experiment was conducted, and the sound color was applied to classify it on a log scale considering auditory characteristics. As a result of comparing this with the result expression for different loudness expression units, A specific table in different units yielded almost similar results. In addition, the sound source section for 100 minutes was divided into three analysis sections, the analysis sections were different, and the size of the energy ratio for each analysis section was divided in the form of an envelope. The characteristics of the low-frequency region of the space have a high energy ratio, and the decrease in the energy ratio according to the increase in frequency is constant and regular. You can see that conversations are possible.

A Study on Frank Gehry's Architectural Changes After the Art Gallery of Ontario (온타리오 미술관 이후 프랭크 게리의 건축적 변화 연구)

  • Lee, Jae-In
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.2
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    • pp.95-106
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    • 2018
  • This study aimed at revaluating Frank Gehry's freeform constructions. To this end, the study analyzed the way the space composition and circulation system of general constructions are connected with newly extended parts in the Art Gallery of Ontario and, based on this, comparatively analyzed freeform constructions before and after the art gallery, finding out what changes were made in the exterior and interior spaces of freeform constructions built after the art gallery. The results of the study are as follows. First, starting from extending the Art Gallery of Ontario, Gehry came to use glass instead of metal as main material of freeform constructions. In order to create the circulation connecting the existing building and the extended mass, Gehry applied continuing circulation for the first time to the gallery. Third, in addition to design motives, such as the woodblock print depicting a carp by Hiroshige, still life depicting a glass bottle by Morandi and the crease of the shawl in Vermeer's paintings, which Gehry applied to freeform constructions, the design motif which was recently acquired from Pyrenees rock was added. Fourth, the trend of mall construction appeared before and after the Art Gallery of Ontario. Finally, Gary used the shape of fish as a design motif for his work at an important turning point in his Freeform Architecture.

Calculation Method for Nominal Area of Rock Core Specimen During Direct Shear Test (암석코어시편의 절리면 직접전단시험을 위한 겉보기 면적 계산방법)

  • Kang, Hoon;Park, Jung-Wook;Park, Chan;Oh, Tae-Min;Cho, Jung-Woo
    • Tunnel and Underground Space
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    • v.30 no.6
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    • pp.551-558
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    • 2020
  • This note presents the calculation of nominal area for rock core specimen under direct shear testing condition. The initial nominal area was assumed as ellipsoid, and the equations for calculating the nominal area are derived. The normalized shear displacement and normalized nominal area have an identical relationship regardless of the ellipsoid shape. New testing constants and the generalized method were suggested to calculate the decrease of the nominal area. The method was applied to calculate the direct shear testing data and the changes of result were discussed.

Mechanical properties and failure mechanism of gravelly soils in large scale direct shear test using DEM

  • Tu, Yiliang;Wang, Xingchi;Lan, Yuzhou;Wang, Junbao;Liao, Qian
    • Geomechanics and Engineering
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    • v.30 no.1
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    • pp.27-44
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    • 2022
  • Gravelly soil is a kind of special geotechnical material, which is widely used in the subgrade engineering of railway, highway and airport. Its mechanical properties are very complex, and will greatly influence the stability of subgrade engineering. To investigate the mechanical properties and failure mechanism of gravelly soils, this paper introduced and verified a new discrete element method (DEM) of gravelly soils in large scale direct shear test, which considers the actual shape and broken characteristics of gravels. Then, the stress and strain characteristics, particle interaction, particle contact force, crack development and energy conversion in gravelly soils during the shear process were analyzed using this method. Moreover, the effects of gravel content (GC) on the mechanical properties and failure characteristics were discussed. The results reveal that as GC increases, the shear stress becomes more fluctuating, the peak shear stress increases, the volumetric strain tends to dilate, the average particle contact force increases, the cumulative number of cracks increases, and the shear failure plane becomes coarser. Higher GC will change the friction angle with a trend of "stability", "increase", and "stability". Differently, it affects the cohesion with a law of "increase", "stability" and "increase".

Multiepoch Optical Images of IRC+10216 Tell about the Central Star and the Adjacent Environment

  • Kim, Hyosun;Lee, Ho-Gyu;Ohyama, Youichi;Kim, Ji Hoon;Scicluna, Peter;Chu, You-Hua;Mauron, Nicolas;Ueta, Toshiya
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.2
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    • pp.36.1-37
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    • 2021
  • Six images of IRC+10216 taken by the Hubble Space Telescope at three epochs in 2001, 2011, and 2016 are compared in the rest frame of the central carbon star. An accurate astrometry has been achieved with the help of Gaia Data Release 2. The positions of the carbon star in the individual epochs are determined using its known proper motion, defining the rest frame of the star. In 2016, a local brightness peak with compact and red nature is detected at the stellar position. A comparison of the color maps between 2016 and 2011 epochs reveals that the reddest spot moved along with the star, suggesting a possibility of its being the dusty material surrounding the carbon star. Relatively red, ambient region is distributed in an Ω shape and well corresponds to the dusty disk previously suggested based on near-infrared polarization observations. In a larger scale, differential proper motion of multiple ring-like pattern in the rest frame of the star is used to derive the average expansion velocity of transverse wind components, resulting in ~12.5 km s-1 (d/123 pc), where d is the distance to IRC+10216. Three dimensional geometry is implied from its comparison with the line-of-sight wind velocity determined from half-widths of submillimeter emission line profiles of abundant molecules. Uneven temporal variations in brightness for different searchlight beams and anisotropic distribution of extended halo are revisited in the context of the stellar light illumination through a porous envelope with postulated longer-term variations for a period of 10 years.

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Cosmology with Type Ia Supernova gravitational lensing

  • Asorey, Jacobo
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.52.2-52.2
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    • 2019
  • In the last decades, the use of type Ia supernovae (SN) as standard candles has allowed us to understand the geometry of the Universe as they help to measure the expansion rate of the Universe, especially in combination with other cosmological probes such as the study of cosmic microwave background radiation anisotropies or the study of the imprint of baryonic acoustic oscillations on the galaxy clustering. Cosmological parameter constraints obtained with type Ia SN are mainly affected by intrinsic systematic errors. But there are other systematic effects related with the correlation of the observed brightness of Supernova and the large-scale structure of the Universe such as the effect of peculiar velocities and gravitational lensing. The former is relevant for SN at low redshifts while the latter starts being relevant for SN at higher redshifts. Gravitational lensing depends on how much matter is along the trajectory of each SN light beam. In order to account for this effect, we consider a statistical approach by defining the probability distribution (PDF) that a given supernova brightness is magnified by a given amount, for a particular redshift. We will show that different theoretical approaches to define the matter density along the light trajectory hugely affect the shape and width of the PDF. This may have catastrophic effects on cosmology fits using Supernova lensing as planned for surveys such as the Dark Energy Survey or future surveys such the Large Synoptic Survey Telescope.

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Magnet Location Estimation Technology in 3D Using MI Sensors (MI센서를 이용한 3차원상 자석 위치 추정 기술)

  • Ju Hyeok Jo;Hwa Young Kim
    • Journal of Sensor Science and Technology
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    • v.32 no.4
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    • pp.232-237
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    • 2023
  • This paper presents a system for estimating the position of a magnet using a magnetic sensor. An algorithm is presented to analyze the waveform and output voltage values of the magnetic field generated at each position when the magnet moves and to estimate the position of the magnet based on the analyzed data. Here, the magnet is sufficiently small to be inserted into a blood vessel and has a micro-magnetic field of hundreds of nanoteslas owing to the small size and shape of the guide wire. In this study, a highly sensitive magneto-impedance (MI) sensor was used to detect these micro-magnetic fields. Nine MI sensors were arranged in a 3×3 configuration to detect a magnetic field that changes according to the position of the magnet through the MI sensor, and the voltage value output was polynomially regressed to specify a position value for each voltage value. The accuracy was confirmed by comparing the actual position value with the estimated position value by expanding it from a 1D straight line to a 3D space. Additionally, we could estimate the position of the magnet within a 3% error.

Transverse Wind Velocity Recorded in Spiral-Shell Pattern

  • Hyosun Kim
    • Journal of The Korean Astronomical Society
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    • v.56 no.2
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    • pp.149-157
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    • 2023
  • The propagation speed of a circumstellar pattern revealed in the plane of the sky is often assumed to represent the expansion speed of the wind matter ejected from a post-main-sequence star at the center. We point out that the often-adopted isotropic wind assumption and the binary hypothesis as the underlying origin for the circumstellar pattern in the shape of multilayered shells are, however, mutually incompatible. We revisit the hydrodynamic models for spiral-shell patterns induced by the orbital motion of a hypothesized binary, of which one star is losing mass at a high rate. The distributions of transverse wind velocities as a function of position angle in the plane of the sky are explored along viewing directions. The variation of the transverse wind velocity is as large as half the average wind velocity over the entire three dimensional domain in the simulated models investigated in this work. The directional dependence of the wind velocity is indicative of the overall morphology of the circumstellar material, implying that kinematic information is an important ingredient in modeling the snapshot monitoring (often in the optical and near-infrared) or the spectral imaging observations for molecular line emissions.

A Study on Detecting Changes in Injection Molding Process through Similarity Analysis of Mold Vibration Signal Patterns (금형 기반 진동 신호 패턴의 유사도 분석을 통한 사출성형공정 변화 감지에 대한 연구)

  • Jong-Sun Kim
    • Design & Manufacturing
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    • v.17 no.3
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    • pp.34-40
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    • 2023
  • In this study, real-time collection of mold vibration signals during injection molding processes was achieved through IoT devices installed on the mold surface. To analyze changes in the collected vibration signals, injection molding was performed under six different process conditions. Analysis of the mold vibration signals according to process conditions revealed distinct trends and patterns. Based on this result, cosine similarity was applied to compare pattern changes in the mold vibration signals. The similarity in time and acceleration vector space between the collected data was analyzed. The results showed that under identical conditions for all six process settings, the cosine similarity remained around 0.92±0.07. However, when different process conditions were applied, the cosine similarity decreased to the range of 0.47±0.07. Based on these results, a cosine similarity threshold of 0.60~0.70 was established. When applied to the analysis of mold vibration signals, it was possible to determine whether the molding process was stable or whether variations had occurred due to changes in process conditions. This establishes the potential use of cosine similarity based on mold vibration signals in future applications for real-time monitoring of molding process changes and anomaly detection.