المؤلفون: M. Wang, C. C. Wang, S. Sepasgozar, S. Zlatanova

المصدر: ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol X-4-W2-2022, Pp 273-280 (2022)

مصطلحات موضوعية: Technology, Engineering (General). Civil engineering (General), TA1-2040, Applied optics. Photonics, TA1501-1820

الوصف: Verticality check of prefabricated elements is an essential part of prefabrication construction. Currently, it is mostly carried out by manual methods, which is slow and inefficient. Previous studies have used laser scanning for the quality check but mainly focused on surface defects, flatness, and the dimension of construction elements. Very few studies used laser scanning to evaluate the installation quality of prefabricated elements. Those, who adopted the laser scanning method, compared the as-built with the initial design version of BIM. Such approach requires an accurate design version of BIM with tedious manual tasks relying on human skills that involve errors. This on-going study investigates a verticality check method based on laser scanning for assessing the quality of wall panel installations without relying on previous drawings or BIM. The proposed method enables practitioners to confirm the quality of the wall panel installation and its vertical deviations based on the processed point cloud data. The region growing segmentation and random sample consensus are used to process the acquired data for computing the deviations. This method is validated in a real high-rise prefabrication residential building. Our method took about 9 min/100 m2, versus the conventional method, which took 31 min/100 m2. The experiments indicate that the proposed method is significantly more time-efficient compared to the conventional manual method. The contribution of this study includes suggesting suitable parameters for measuring the vertical dimensions of prefabricated wall panels and deviations that can be replicated in high-rise prefabricated residential projects.

وصف الملف: electronic resource

العلاقة: https://www.isprs-ann-photogramm-remote-sens-spatial-inf-sci.net/X-4-W2-2022/273/2022/isprs-annals-X-4-W2-2022-273-2022.pdfTest; https://doaj.org/toc/2194-9042Test; https://doaj.org/toc/2194-9050Test

الوصول الحر: https://doaj.org/article/8bf37f17cc00444f85000fa25c19cb17Test

المؤلفون: H. Xu, C. C. Wang, X. Shen, S. Zlatanova

المصدر: ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol X-4-W3-2022, Pp 277-284 (2022)

مصطلحات موضوعية: Technology, Engineering (General). Civil engineering (General), TA1-2040, Applied optics. Photonics, TA1501-1820

الوصف: Present urbanization influences urban morphology by the increasing number of dense buildings and infrastructure, which effects climate change. Microclimate simulations including urban vegetation help in mitigating climate change. Most of existing microclimate simulations simplify trees and thereby may introduce some erroneous estimates. Tree models of high levels of detail (LOD) can provide a more accurate measure. Technology advances make it possible to reconstruct detailed tree models, which can be further used in microclimate simulations. However, the few studies presenting detailed tree models focus predominantly on the reconstruction process and omit the microclimate simulations. The objective of this study is to investigate high LOD tree models in microclimate simulation to estimate the potential gain in accuracy. This study focuses on voxel-based tree models and microclimate simulations using computer fluid dynamics software. A series of microclimate simulations are completed in two scenarios, which are single tree and a set of trees with buildings. Based on the simulation results, the advantages of detailed voxel tree models are demonstrated. Final discussion elaborates on the needed and preferred levels of detail for tree models.

وصف الملف: electronic resource

العلاقة: https://www.isprs-ann-photogramm-remote-sens-spatial-inf-sci.net/X-4-W3-2022/277/2022/isprs-annals-X-4-W3-2022-277-2022.pdfTest; https://doaj.org/toc/2194-9042Test; https://doaj.org/toc/2194-9050Test

الوصول الحر: https://doaj.org/article/ce2d18bd2b2a4fa685bd46dd556124dbTest

المؤلفون: W. S. Yu, M. H. Chang, H. L. Lee, Y. T. Lee, M. C. Tsai, C. C. Wang

المصدر: BMC Gastroenterology, Vol 22, Iss 1, Pp 1-4 (2022)

مصطلحات موضوعية: Umbilical varix rupture, Liver cirrhosis, Hemoperitoneum, Exploratory laparotomy, Hepatocellular carcinoma, Diseases of the digestive system. Gastroenterology, RC799-869

الوصف: Abstract Background Non-traumatic hemoperitoneum was a rare event with the risk of sudden death. Spontaneous rupture of hepatocellular carcinoma is the most intuitive diagnosis when hemoperitoneum occurs in cirrhotic patients who are not regularly followed up. However, other etiologies of hemoperitoneum, such as intra-abdominal varix rupture, should be kept in mind. Case presentation A 44-year-old man with alcoholic liver cirrhosis, Child–Pugh B was sent to our emergency department (ED) because of recurrent abdominal pain and hypovolemic shock. He had similar symptoms one month ago and was diagnosed as hepatocellular carcinoma (HCC) rupture with hemoperitoneum, therefore he underwent trans-arterial embolization (TAE). However, the follow-up magnetic resonance imaging (MRI) showed less possibility of hepatocellular carcinoma. Contrast enhanced abdominal computed tomography (CT) showed possible umbilical vein contrast agent extravasation. Exploratory laparotomy confirmed the diagnosis of rupture umbilical varix with hemoperitoneum. Conclusion Although umbilical varix rupture is a rare cause of hemoperitoneum, it should be kept in mind in cirrhotic patients with unexplained hemoperitoneum.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/1471-230XTest

الوصول الحر: https://doaj.org/article/dd070fada029492db221c17b86d58ab2Test

المؤلفون: C. C. Wang, S. Shirowzhan

المصدر: The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XLVIII-4-W5-2022, Pp 1-2 (2022)

مصطلحات موضوعية: Technology, Engineering (General). Civil engineering (General), TA1-2040, Applied optics. Photonics, TA1501-1820

وصف الملف: electronic resource

العلاقة: https://www.int-arch-photogramm-remote-sens-spatial-inf-sci.net/XLVIII-4-W5-2022/1/2022/isprs-archives-XLVIII-4-W5-2022-1-2022.pdfTest; https://doaj.org/toc/1682-1750Test; https://doaj.org/toc/2194-9034Test

الوصول الحر: https://doaj.org/article/b7d86c2e2e2d4ef4ba3b79b1afa07437Test

المؤلفون: S. Shirowzhan, C. C. Wang

المصدر: ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol X-4-W3-2022, Pp 1-1 (2022)

مصطلحات موضوعية: Technology, Engineering (General). Civil engineering (General), TA1-2040, Applied optics. Photonics, TA1501-1820

وصف الملف: electronic resource

العلاقة: https://www.isprs-ann-photogramm-remote-sens-spatial-inf-sci.net/X-4-W3-2022/1/2022/isprs-annals-X-4-W3-2022-1-2022.pdfTest; https://doaj.org/toc/2194-9042Test; https://doaj.org/toc/2194-9050Test

الوصول الحر: https://doaj.org/article/ead9802f53a3430b9f3730ae7a9b40c0Test

المؤلفون: Tao Gao, Ting Chen, C. C. Wang, Zhanwen Liu, Wei Lu, Y. H. Li

المصدر: IEEE Access, Vol 7, Pp 40746-40756 (2019)

مصطلحات موضوعية: Feature extraction, Weber law, feature learning, illumination variations, Electrical engineering. Electronics. Nuclear engineering, TK1-9971

الوصف: Illumination-insensitive image representation is a great challenge in the computer vision field. Illumination variations considerably obstruct the effectiveness of image feature extraction. In this paper, we present a novel and generalized learning framework for illumination-insensitive image representation, which can learn the discriminative features through maximizing the inter-difference and minimizing intra-difference of the images with boosting. Particularly, we enhance the discriminative capacity of illumination-insensitive image representation in three aspects. First, we learn a subset of different synergistic Weber excitation patterns (SWEP) to generate the dominant SWEP (DSWEP) and DSWEP codebook for exploring optimal illumination-insensitive patterns. Second, a compact DSWEP (C-DSWEP) is learned with a boosted set of weight to generate C-DSWEP codebook. Discriminative learning is aimed at robustness and compactness. Third, the discriminative histogram learning model is established for encoding CDSEP to further improve the discriminative ability and reduce redundancy. The extensive experiments on CMUPIE, FERET, Yale B, Yale B ext., LFW, and PhoTex databases have highlighted the superiority and the robustness of our method compared with some other state-of-the-art methods.

وصف الملف: electronic resource

العلاقة: https://ieeexplore.ieee.org/document/8674724Test/; https://doaj.org/toc/2169-3536Test

الوصول الحر: https://doaj.org/article/95a809ede7db4c8788ee64bdd25dfe25Test

المؤلفون: Y. S. Yeh, C. C. Luo, B. H. Huang, C. C. Wang, S. X. Hung

المصدر: AIP Advances, Vol 10, Iss 4, Pp 045325-045325-9 (2020)

مصطلحات موضوعية: Physics, QC1-999

الوصف: The harmonic operation in a terahertz gyrotron traveling-wave amplifier (gyro-TWA) permits a reduced magnetic field, whereas a harmonic multiplying gyro-TWA enables magnetic field reduction and frequency multiplication. This study comparatively analyzes the 400-GHz fourth-harmonic gyro-TWAs and fourth-harmonic multiplying gyro-TWAs with axis-encircling electron beams. This property of the gyro-TWAs with axis-encircling electron beams enables us avoid the appearance of the majority of the competing modes. According to the simulation results obtained using multi-mode codes, the attenuating severs suppress the remaining competing modes. In the case of a harmonic gyro-TWA containing a sever section, the copper-section start-oscillation length is significantly influenced by a decrease in the sever-section radius when compared with an increase in the sever-section length. Furthermore, a stable fourth-harmonic TE41-mode gyro-TWA containing sever sections is proposed. We propose fourth-harmonic TE41-mode multiplying gyro-TWAs, where the drive stages operate in the fundamental-harmonic TE11 mode to reduce the frequency of the drive wave. We subsequently develop a stable fourth-harmonic multiplying gyro-TWA with sever sections in the drive and amplified stages to avoid the competing modes and enhance the output power. The stable high-gain fourth-harmonic gyro-TWA can yield a peak output power of 2.7 kW at 400.6 GHz with a saturated gain of 75 dB and a bandwidth of 0.7 GHz for a 75-kV and 2-A electron beam with an axial velocity spread of 3%. Furthermore, a peak output power of 1.7 kW can be obtained by the fourth-harmonic multiplying gyro-TWA at 400.4 GHz with a saturated gain of 57 dB and a bandwidth of 0.4 GHz. Subsequently, we calculate the power and gain scaling for the harmonic gyro-TWA and harmonic multiplying gyro-TWA.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2158-3226Test

الوصول الحر: https://doaj.org/article/346373791ec84704aa8f7475d20d9e63Test

المؤلفون: X. D. Jiang, X. Zhao, Y. M. Chou, Q. S. Liu, A. P. Roberts, J. B. Ren, X. M. Sun, J. H. Li, X. Tang, X. Y. Zhao, C. C. Wang

المصدر: Geochemistry, Geophysics, Geosystems, Vol 21, Iss 3, Pp n/a-n/a (2020)

مصطلحات موضوعية: manganese nodule, magnetofossil, manganese‐oxidizing bacteria, biomineralization, rock magnetism, Geophysics. Cosmic physics, QC801-809, Geology, QE1-996.5

الوصف: Abstract Abyssal manganese nodules have been explored widely for their economic potential and paleoenvironmental significance. Debate about whether biogenic or physical‐chemical processes are responsible for their formation remains because of difficulties in quantifying ancient microbiological contributions. To address this question, we investigated microbial fossils in manganese nodules from the western Pacific Ocean by integrating scanning electron microscope, transmission electron microscope, and synchrotron transmission X‐ray microscope observations. Our results suggest that the nodules host abundant fossil biogenic magnetite and manganese‐oxidizing bacteria. These organisms engage in redox reactions or live in environments with redox gradients. By combining magnetic properties and observations of fossil biogenic magnetite morphology, we estimate magnetofossil abundances and further assess fossil biogenic manganese oxide in nodules. Our results imply that manganese nodule formation appears to be dominated by biomineralization with an additional terrestrial contribution. Extensive biomineralization in ultralow‐productivity oceanic environments suggests that manganese nodule formation is an important aspect of biogeochemical cycling in abyssal seafloor environments.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/1525-2027Test

الوصول الحر: https://doaj.org/article/26372aafd58f499eb6f261575dc46da8Test

المؤلفون: C. C. Wang, M. H. Wang, J. Wu

المصدر: IEEE Photonics Journal, Vol 7, Iss 2, Pp 1-10 (2015)

مصطلحات موضوعية: Applied optics. Photonics, TA1501-1820, Optics. Light, QC350-467

الوصف: A heavily germanium-doped (Ge-doped) silica fiber with a four-layer refractive index profile is proposed to obtain all normal flat dispersion property. The waveguide dispersion in the fiber can be modified by adjusting the fiber parameters, including the refractive indices and the core radiuses. As a result, the flat normal dispersion in the fiber can be obtained in the wavelength range of 1540-2600 nm, where the values of the dispersion slope are between -0.0058 and 0.03 ps/nm2/km. Furthermore, the numerical results show that the flat-top supercontinuum spectrum ranging from 1000 to 2600 nm can be generated by launching pump pulses at the wavelength of 1550 nm in the heavily Ge-doped fiber with a four-layer refractive index profile.

وصف الملف: electronic resource

العلاقة: https://ieeexplore.ieee.org/document/7062072Test/; https://doaj.org/toc/1943-0655Test

الوصول الحر: https://doaj.org/article/a1626eba08b4405193e44daf68851e37Test

المؤلفون: C. C. Wang, J. Y. Tan, L. H. Liu

المصدر: AIP Advances, Vol 7, Iss 3, Pp 035115-035115-14 (2017)

مصطلحات موضوعية: Physics, QC1-999

الوصف: The temperature and pressure-dependent dielectric functions of liquids are of great importance to the thermal radiation transfer and the diagnosis and control of fuel combustion. In this work, we apply the state-of-the-art ab initio molecular dynamics (AIMD) method to calculate the infrared dielectric functions of liquid methanol at 183–573 K and 0.1–160 MPa in the spectral range 10−4000 cm−1, and study the temperature and pressure effects on the dielectric functions. The AIMD approach is validated by the Infrared Variable Angle Spectroscopic Ellipsometry (IR-VASE) experimental measurements at 298 K and 0.1 MPa, and the proposed IR-VASE method is verified by comparison with paper data of distilled water. The results of the AIMD approach agrees well with the experimental values of IR-VASE. The experimental and theoretical analyses indicate that the temperature and pressure exert a noticeable influence on the infrared dielectric functions of liquid methanol. As temperature increases, the average molecular dipole moment decreases. The amplitudes of dominant absorption peaks reduce to almost one half as temperature increases from 183 to 333 K at 0.1 MPa and from 273 to 573 K at 160 MPa. The absorption peaks below 1500 cm–1 show a redshift, while those centered around 3200 cm–1 show a blueshift. Moreover, larger average dipole moments are observed as pressure increases. The amplitudes of dominant absorption peaks increase to almost two times as pressure increases from 1 to 160 MPa at 373 K.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2158-3226Test

الوصول الحر: https://doaj.org/article/3b98df1eceae4c44ae15f2d9e6227ae0Test