• Title/Summary/Keyword: Natural Phenomena

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Deep Unsupervised Learning for Rain Streak Removal using Time-varying Rain Streak Scene (시간에 따라 변화하는 빗줄기 장면을 이용한 딥러닝 기반 비지도 학습 빗줄기 제거 기법)

  • Cho, Jaehoon;Jang, Hyunsung;Ha, Namkoo;Lee, Seungha;Park, Sungsoon;Sohn, Kwanghoon
    • Journal of Korea Multimedia Society
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    • v.22 no.1
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    • pp.1-9
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    • 2019
  • Single image rain removal is a typical inverse problem which decomposes the image into a background scene and a rain streak. Recent works have witnessed a substantial progress on the task due to the development of convolutional neural network (CNN). However, existing CNN-based approaches train the network with synthetically generated training examples. These data tend to make the network bias to the synthetic scenes. In this paper, we present an unsupervised framework for removing rain streaks from real-world rainy images. We focus on the natural phenomena that static rainy scenes capture a common background but different rain streak. From this observation, we train siamese network with the real rain image pairs, which outputs identical backgrounds from the pairs. To train our network, a real rainy dataset is constructed via web-crawling. We show that our unsupervised framework outperforms the recent CNN-based approaches, which are trained by supervised manner. Experimental results demonstrate that the effectiveness of our framework on both synthetic and real-world datasets, showing improved performance over previous approaches.

Review on the Roles of Laboratory Work in School (학교 실험활동의 역할에 대한 문헌 고찰)

  • Kim, Ja-Hyeon;Kim, Hyo-Nam;Yang, Il-Ho
    • Journal of Korean Elementary Science Education
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    • v.38 no.2
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    • pp.203-215
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    • 2019
  • The purpose of this study is to clarify the roles of laboratory work in school. Twenty-one literatures were identified about roles of laboratory work in school by applying criteria such as published in CI level journals or used as a reference over 100 times during 1960-2017. Twenty-one literatures were reviewed according to periods such as 1960-1989, 1990-2003, and 2004-2017, and identified the roles of laboratory work in school that commonly presented in more than two literature. Seven roles of laboratory work in school identified were as follows (a) learning scientific knowledge, (b) enhancing attitude toward science, (c) learning scientific inquiry methods, (d) acquiring skills to use specific laboratory instruments, (e) enhancing scientific attitude, (f) understanding the nature of science(NOS), and (g) providing opportunity to experience natural or scientific phenomena. The results of this study can be used to provide school teachers and students a clear meaning of the roles of laboratory work in school.

Research on the Perception of Pre-service Teachers on Effective Seasonal Constellation Experiment according to School Level (학교 급별에 효과적인 계절별 별자리 실험에 대한 예비교사의 인식 연구)

  • Han, Je-Jun
    • Journal of the Korean Society of Earth Science Education
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    • v.14 no.3
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    • pp.267-276
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    • 2021
  • The purpose of this study is to research seasonal constellation experiments and to find out what are effective seasonal constellation experiments according to school salary. we organized seasonal constellation experiments with 24 elementary preparatory teachers and asked them to what effective experiments are for each school class. As a result, constellation learning through direct experience activities through role play is the most effective in elementary school, and in middle and high schools, using the stellarium program to realistically observe and reason about seasonal changes in constellations was selected as an effective experiment. Pre-service teachers recognized that experiments in which direct experience and specific manipulation activities were emphasized in elementary school, and experiments in which observation of realistic natural phenomena and reasoning activities were emphasized were effective in middle and high schools.

Assessment of DVC measurement uncertainty on GFRPs with various fiber architectures

  • Bartulovic, Ante;Tomicevic, Zvonimir;Bubalo, Ante;Hild, Francois
    • Coupled systems mechanics
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    • v.11 no.1
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    • pp.15-32
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    • 2022
  • The comprehensive understanding of the fiber reinforced polymer behavior requires the use of advanced non-destructive testing methods due to its heterogeneous microstructure and anisotropic mechanical proprieties. In addition, the material response under load is strongly associated with manufacturing defects (e.g., voids, inclusions, fiber misalignment, debonds, improper cure and delamination). Such imperfections and microstructures induce various damage mechanisms arising at different scales before macrocracks are formed. The origin of damage phenomena can only be fully understood with the access to underlying microstructural features. This makes X-ray Computed Tomography an appropriate imaging tool to capture changes in the bulk of fibrous materials. Moreover, Digital Volume Correlation (DVC) can be used to measure kinematic fields induced by various loading histories. The correlation technique relies on image contrast induced by microstructures. Fibrous composites can be reinforced by different fiber architectures that may lead to poor natural contrast. Hence, a priori analyses need to be performed to assess the corresponding DVC measurement uncertainties. This study aimed to evaluate measurement resolutions of global and regularized DVC for glass fiber reinforced polymers with different fiber architectures. The measurement uncertainties were evaluated with respect to element size and regularization lengths. Even though FE-based DVC could not reach the recommended displacement uncertainty with low spatial resolution, regularized DVC enabled for the use of fine meshes when applying appropriate regularization.

Sensitivity analysis of mass ratio effect on settlement and seismic response of shallow foundation using numerical simulation

  • Kil-Wan Ko;Jeong-Gon Ha;Jinsun Lee;Gye-Chun Cho
    • Geomechanics and Engineering
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    • v.34 no.6
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    • pp.649-664
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    • 2023
  • Structural inertial interaction is a representative the effect of dynamic soil-foundation-structure interaction (SFSI), which leads to a relative displacement between soil and foundation, period lengthening, and damping increasing phenomena. However, for a system with a significantly heavy foundation, the dynamic inertia of the foundation influences and interacts with the structural seismic response. The structure-to-foundation mass ratio (MR) quantifies the distribution of mass between the structure and foundation for a structure on a shallow foundation. Although both systems exhibit the same vertical factor of safety (FSv), the MR and corresponding seismic responses attributed to the structure and foundation masses may differ. This study explored the influence of MR on the permanent deformation and seismic response of soil-foundation-structure system considering SFSI via numerical simulations. Given that numerous dimensionless parameters of SFSI described its influence on the structural seismic response, the parameters, except for MR and FSv, were fixed for the sensitivity analysis. The results demonstrated that the foundation inertia of heavier foundations induced more settlement due to sliding behavior of heavily-loaded systems. Moreover, the structural inertia of heavier structures evidently exhibited foundation rocking behavior, which results in a more elongated natural period of the structure for lightly-loaded systems.

Effect of Singing - Focusing on the Love Changbu Taryeong

  • Kyung Ja Ko;Cho Hyun-yong
    • CELLMED
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    • v.14 no.2
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    • pp.3.1-3.2
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    • 2024
  • The purpose of this study is to consider the health and well-being of singing, an expression activity of language. There are also many studies in which singing activities have a positive effect on individual quality of life and social activities. Therefore, this study attempted to suggest that more effective singing is being performed by increasing empathy through various expressions of onomatopoeia and mimic words. Love Changbu Taryeong (愛倡夫打令) is Korea's traditional representative Gyeonggi folk song. It is a cheerful and lyrical folk song based on the five scale of Sol-ra-do-re-mi. It sings not only human joy, sorrow, and pleasure, but also natural phenomena and scenes. It is an exciting rhythm based mainly on the Gutgeori jangdan (rhythmic pattern, 12/8) but it is a rhythm that you can feel the sadness in it. In particular, various onomatopoeia and mimic words appear in this song, making you think about the fun of singing and the origin of the language. Therefore, this study attempted to examine that more effective singing is becoming more effective by increasing empathy through various expressions of onomatopoeia and mimic words. You can watch our singing activities on YouTube.(https://youtu.be/IhnBqWiK-3w?si=AAMi2BVes9mPShnr)

Analysis of forced convection in the HTTU experiment using numerical codes

  • M.C. Potgieter;C.G. du Toit
    • Nuclear Engineering and Technology
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    • v.56 no.3
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    • pp.959-965
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    • 2024
  • The High Temperature Test Unit (HTTU) was an experimental set-up to conduct separate and integral effects tests of the Pebble Bed Modular Reactor (PBMR) core. The annular core consisted of a randomly packed bed of uniform spheres. Natural convection tests using both nitrogen and helium, and forced convection tests using nitrogen, were conducted. The maximum material temperature achieved during forced convection testing was 1200 ℃. This paper presents the numerical analysis of the flow and temperature distribution for a forced convection test using 3D CFD as well as a 1D systems-CFD computer code. Several modelling approaches are possible, ranging from a fully explicit to a semi-implicit method that relies on correlations of their associated phenomena. For the comparison between codes, the analysis was performed using a porous media approach, where the conduction and radiative heat transfer were lumped together as an effective thermal conductivity and the convective heat transfer was correlated between the solid and gas phases. The results from both codes were validated against the experimental measurements. Favourable results were obtained, in particular by the systems-CFD code with minimal computational and time requirements.

The Alterations of the Lymphocyte Subsets and the Natural Killer Cell Activity in the Pregnant Mouse (수태중인 생쥐에 있어서 림프구아형 및 자연살해세포 활성도의 변화)

  • 신주옥;고기석;최임순
    • Biomedical Science Letters
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    • v.2 no.2
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    • pp.211-222
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    • 1996
  • The conceptus which are resulted by mating between two genetically non-identical partners can be considered to be an allograft to the mother science which is not rejected by the mother's immunological attack. The present studies have been, therefore, attempted in order to elucidate the mechanism by which protection of the fete-placental allograft, between the C3H/HeJ female mouse and DBA/2 male mouse occurred. For this purpose, firstly systemic immunity was investigated by measuring T and B lymphocytes subsets. Natural killer cell activity in maternal splenic tissue and by observing the effects of pregnancy serums, progesterone and hCG on immune systems. Secondly, local immunity also investigated by measuring T lymphocytes subsets, natural killer cell activity in lymph nodes draining the uterus. The subsets of Thy-1.2$^+$ cells and L 3T4$^+$ cells decreased slightly while the subsets of Ly2$^+$ cell increased significantly compared with those of the control group beyond the mid-gestational stage. The subsets of B cell gradually in-creased from the mid-gestational stage untill delivery. The natural killer cell activity in the maternal splenic tissue significantly increased during the period of 5th to 8th day of gestation. The natural killer cell activity was significantly suppressed by the pregnancy serums and non-pregnant serums compared with those of serum-free group. The treatment of hCG significantly suppressed natural killer cell activity in the dose dependent manner (1 unit/ml-1000 unit/ml) while pro-gesterone increased the natural killer cell activity at phamarcological dose only. In the lymph nodes draining the uterus, the subsets of Thy-1.2$^+$ cells significantly increased during the period of implantation and L3T4$^+$ cell subsets slightly increased during the mid-gestational stage. The subsets of Ly2$^+$ cell increased significantly during the mid-gestational stage, but decreasing slightly be-fore delivery. The natural killer cell activity was significantly elevated after the implantation period in the lymph nodes draining the uterus. The natural killer cell activity of the lymph nodes draining the uterus was higher than those of splenic tissue during the same periods of gestation. It is therefore, concluded that during the pregnancy, the phenomena which the fete-placental allograft has not been rejected and rather protected from the maternal immunological attack might be due to local immune suppression in fete-maternal interface tissues rather than systemic immune suppression. And the subsets of Thy-1.2$^+$ cells and L3T4$^+$ cells mainly contribute to accepting allograft in early stage of pregnancy, while the subsets of Ly2$^+$ cell and the subsets of B cell increased significantly compared with those of the control group beyond the mid-gestational stage, so their role in systemic immunity and local immunity gradually increased from the mid-gestational stage until delivery.

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Apoptotic Effect of Rubia cordifolia Dichloromethane Extracts on Human Acute Jurkat T Cells (천초근 dichloromethane 추출물의 Jurkat T 세포에서 세포사멸 효과)

  • Kim, Ji-Hye;Lee, Jong-Hwan;Kim, Young-Ho;Kim, Kwang-Hyeon
    • Journal of Life Science
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    • v.19 no.2
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    • pp.163-168
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    • 2009
  • To understand cytotoxic activity of Rubia cordifolia L. (Rubiaceae), which has been used as a traditional oriental medicine, the mechanism underlying cytotoxic effect of its extract on human acute Jurkat T cells was investigated. The methanol extract of roots (3 kg) of R. codifolia was evaporated, dissolved in water, and then extracted by dichloromethane. The substances in the chloroform extract showing the most cytotoxic activity were further purified by a series of preparative HPLC. The extracted active substance (65 mg) was designated as CCH1. When Jurkat T cells were treated with CCH1 at concentration ranging from 0.5 to 2.0 ${\mu}g$/ml, apoptotic phenomena of cells companying several subsequent biochemical reactions such as mitochondria cytochrome c release, activation of casapase-8, -9, and caspase- 3, degradation of PARP and DNA fragmentation occurred via mitochondria-dependent pathway. However, abrogation of apoptosis was observed in an ectopic expression of Bcl-xL, which is a suppressor for mitochondrial cytochrome c release. These results demonstrate that the cytotoxicity of CCH1 against Jurkat T cells is attributable to apoptosis mediated by mitochodria-dependent death-signaling regulated by Bcl-xL. In addition, the CCH1 is more potent to leukemia Jurkat T cell than to human peripheral blood monocyte cells (PBMC).

Studies on the Adsorption of Coloring Food Additives (식품(食品) 착색제(着色劑)의 흡착(吸着)에 관(關)한 연구(硏究))

  • Park, Hong-Koo
    • Applied Biological Chemistry
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    • v.30 no.3
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    • pp.201-209
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    • 1987
  • Solutions of food colorants were tested with insoluble drugs (kaolin, active carbon, talc, natural aluminum silicate) for their adsorption phenomena in purified water, gastric and intestinal fluid test solutions, respectively. The adsorption isotherms of kaolin with Red 2 in purified water, and active carbon with Red 2, 3, 40 in the three media, with Yellow 4 in purified water, gastric fluid, with Yellow 5 in intestinal fluid and natural aluminum silicate with Red 3 in purified water, intestinal fluid, with Yellow 4, 5 in purified water followed the Freundlich equation, and those of talc with Red 2, 3, Yellow 5 in the three media, with Red 40 in purified water, gastric fluid, with Yellow 4 in intestinal fluid fitted the Langmuir equation. With decrease of the alcohol content of aqueous solutions, the adsorption of coloring food additives is increased, but it decreased in high temperature. Also the activation energy of adsorption of coloring food additives by active carbon was determined.

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