| 1. |
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| 2. |
- Yang, Bin, et al.
(författare)
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Non-invasive (non-contact) measurements of human thermal physiology signals and thermal comfort/discomfort poses -A review
- 2020
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Ingår i: Energy and Buildings. - : ELSEVIER SCIENCE SA. - 0378-7788 .- 1872-6178. ; 224
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Forskningsöversikt (refereegranskat)abstract
- Heating, ventilation and air-conditioning (HVAC) systems have been adopted to create comfortable, healthy and safe indoor environments. In the control loop, the technical feature of the human demand-oriented supply can help operate HVAC effectively. Among many technical options, real time monitoring based on feedback signals from end users has been frequently reported as a critical technology to confirm optimizing building performance. Recent studies have incorporated human thermal physiology signals and thermal comfort/discomfort status as real-time feedback signals. A series of human subject experiments used to be conducted by primarily adopting subjective questionnaire surveys in a lab-setting study, which is limited in the application for reality. With the help of advanced technologies, physiological signals have been detected, measured and processed by using multiple technical formats, such as wearable sensors. Nevertheless, they mostly require physical contacts with the skin surface in spite of the small physical dimension and compatibility with other wearable accessories, such as goggles, and intelligent bracelets. Most recently, a low cost small infrared camera has been adopted for monitoring human facial images, which could detect the facial skin temperature and blood perfusion in a contact less way. Also, according to latest pilot studies, a conventional digital camera can generate infrared images with the help of new methods, such as the Euler video magnification technology. Human thermal comfort/discomfort poses can also be detected by video methods without contacting human bodies and be analyzed by the skeleton keypoints model. In this review, new sensing technologies were summarized, their cons and pros were discussed, and extended applications for the demand-oriented ventilation were also reviewed as potential development and applications.
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| 3. |
- Cheng, Xiaogang, et al.
(författare)
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A Contactless Measuring Method of Skin Temperature based on the Skin Sensitivity Index and Deep Learning
- 2019
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Ingår i: Applied Sciences. - Switzerland : MDPI. - 2076-3417 .- 1454-5101. ; 9:7
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Tidskriftsartikel (refereegranskat)abstract
- Featured Application The NISDL method proposed in this paper can be used for real time contactless measuring of human skin temperature, which reflects human body thermal comfort status and can be used for control HVAC devices. Abstract In human-centered intelligent building, real-time measurements of human thermal comfort play critical roles and supply feedback control signals for building heating, ventilation, and air conditioning (HVAC) systems. Due to the challenges of intra- and inter-individual differences and skin subtleness variations, there has not been any satisfactory solution for thermal comfort measurements until now. In this paper, a contactless measuring method based on a skin sensitivity index and deep learning (NISDL) was proposed to measure real-time skin temperature. A new evaluating index, named the skin sensitivity index (SSI), was defined to overcome individual differences and skin subtleness variations. To illustrate the effectiveness of SSI proposed, a two multi-layers deep learning framework (NISDL method I and II) was designed and the DenseNet201 was used for extracting features from skin images. The partly personal saturation temperature (NIPST) algorithm was use for algorithm comparisons. Another deep learning algorithm without SSI (DL) was also generated for algorithm comparisons. Finally, a total of 1.44 million image data was used for algorithm validation. The results show that 55.62% and 52.25% error values (NISDL method I, II) are scattered at (0 degrees C, 0.25 degrees C), and the same error intervals distribution of NIPST is 35.39%.
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| 4. |
- Li, Hanbing, et al.
(författare)
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Dual Function of PI(4,5)P2 in Insulin-Regulated Exocytic Trafficking of GLUT4 in Adipocytes
- 2020
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Ingår i: Journal of Molecular Biology. - : Elsevier BV. - 0022-2836 .- 1089-8638. ; 432:16, s. 4341-4357
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Tidskriftsartikel (refereegranskat)abstract
- Phosphoinositides are important signaling molecules involved in the regulation of vesicular trafficking. It has been implicated that phosphatidylinositol 4,5-bisphosphate [PI(4,5)P-2] is involved in insulin-regulated GLUT4 translocation in adipocytes. However, it remains unclear where and how PI(4,5)P-2 regulates discrete steps of GLUT4 vesicle translocation in adipocytes, especially on the exocytic arm of regulation. Here, we employed optogenetic tools to acutely control the PI(4,5)P-2 metabolism in living cells. By combination of TIRFM imaging, we were able to monitor the temporal-spatial-dependent PI(4,5)P-2 regulation on discrete steps of GLUT4 translocation in adipocytes. We found that the plasma membrane localized PI(4,5)P-2 is crucial for proper insulin signaling propagation and for insulin-stimulated GLUT4 vesicle translocation in 3T3-L1 adipocytes. Global depletion of PI(4,5)P-2 on the cell surface blunted insulin-stimulated Akt phosphorylation and abolished insulin effects in promotion of the docking and fusion of GLUT4 vesicle with the plasma membrane. Furthermore, by development of a novel optogenetic module to selectively modulate PI(4,5)P-2 levels on the GLUT4 vesicle docking site, we identified an important regulatory role of PI(4,5)P-2 in controlling of vesicle docking process. Local depletion of PI(4,5)P-2 at the vesicle docking site promoted GLUT4 vesicle undocking, diminished insulin-stimulated GLUT4 vesicle docking and fusion, but without perturbation of insulin signaling propagation in adipocytes. Our results provide strong evidence that cell surface PI(4,5)P-2 plays two distinct functions on regulation of the exocytic trafficking of GLUT4 in adipocytes. PI(4,5)P-2 not only regulates the proper activation of insulin signaling in general but also controls GLUT4 vesicle docking process at the vesicle-membrane contact sites.
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| 5. |
- Qian, Junpeng, et al.
(författare)
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Vision-Based Contactless Pose Estimation for Human Thermal Discomfort
- 2020
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Ingår i: Atmosphere. - : MDPI. - 2073-4433. ; 11:4
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Tidskriftsartikel (refereegranskat)abstract
- Real-time and effective human thermal discomfort detection plays a critical role in achieving energy efficient control of human centered intelligent buildings because estimation results can provide effective feedback signals to heating, ventilation and air conditioning (HVAC) systems. How to detect occupant thermal discomfort is a challenge. Unfortunately, contact or semi-contact perception methods are inconvenient in practical application. From the contactless perspective, a kind of vision-based contactless human discomfort pose estimation method was proposed in this paper. Firstly, human pose data were captured from a vision-based sensor, and corresponding human skeleton information was extracted. Five thermal discomfort-related human poses were analyzed, and corresponding algorithms were constructed. To verify the effectiveness of the algorithms, 16 subjects were invited for physiological experiments. The validation results show that the proposed algorithms can recognize the five human poses of thermal discomfort.
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| 6. |
- Cheng, Xiaogang, et al.
(författare)
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A pilot study of online non-invasive measuring technology based on video magnification to determine skin temperature
- 2017
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Ingår i: Building and Environment. - : Elsevier. - 0360-1323 .- 1873-684X. ; 121, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- Much attention was paid on human centered design strategies for environmental control systems of indoor built environments. The goal is to achieve thermally comfortable, healthy and safe working or living environments in energy efficient manners. Normally building Heating, Ventilation and Air Conditioning (HVAC) systems have fixed operating settings, which can't satisfy human thermal comfort requirements under transient and non-uniform indoor thermal environments. Therefore, human thermal physiology signal such as skin temperature, which can reflect human body thermal sensation, has to be measured over time. Several trials have been performed by minimizing measuring sensors such as i-Button and mounting measuring sensors into wearable devices such as glasses. Infrared thermography technology has also been tried to achieve non-invasive measurements. However, it would be much more convenient and feasible if normal computer camera could record images, which could be used to obtain human thermal physiology signals. In this study, skin temperature of hand back, which has a high density of blood vessels and is normally not covered by clothing, was measured by i-button sensors. Images recorded by normal camera were amplified to analyzing skin temperature variation, which are impossible to see with naked eyes. The agreement between i-button sensor measuring results and image magnification results demonstrated the possibility of non-invasive measuring technology by image magnification. Partly personalized saturation-temperature model (T = 96.5 × S + bi) can be used to predict skin temperatures for young East Asia females.
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| 7. |
- Cheng, Xiaogang, et al.
(författare)
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A total bounded variation approach to low visibility estimation on expressways
- 2018
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Ingår i: Sensors. - : MDPI. - 1424-8220. ; 18:2
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Tidskriftsartikel (refereegranskat)abstract
- Low visibility on expressways caused by heavy fog and haze is a main reason for traffic accidents. Real-time estimation of atmospheric visibility is an effective way to reduce traffic accident rates. With the development of computer technology, estimating atmospheric visibility via computer vision becomes a research focus. However, the estimation accuracy should be enhanced since fog and haze are complex and time-varying. In this paper, a total bounded variation (TBV) approach to estimate low visibility (less than 300 m) is introduced. Surveillance images of fog and haze are processed as blurred images (pseudo-blurred images), while the surveillance images at selected road points on sunny days are handled as clear images, when considering fog and haze as noise superimposed on the clear images. By combining image spectrum and TBV, the features of foggy and hazy images can be extracted. The extraction results are compared with features of images on sunny days. Firstly, the low visibility surveillance images can be filtered out according to spectrum features of foggy and hazy images. For foggy and hazy images with visibility less than 300 m, the high-frequency coefficient ratio of Fourier (discrete cosine) transform is less than 20%, while the low-frequency coefficient ratio is between 100% and 120%. Secondly, the relationship between TBV and real visibility is established based on machine learning and piecewise stationary time series analysis. The established piecewise function can be used for visibility estimation. Finally, the visibility estimation approach proposed is validated based on real surveillance video data. The validation results are compared with the results of image contrast model. Besides, the big video data are collected from the Tongqi expressway, Jiangsu, China. A total of 1,782,000 frames were used and the relative errors of the approach proposed are less than 10%.
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| 8. |
- Cheng, Xiaogang, et al.
(författare)
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A variational approach to atmospheric visibility estimation in the weather of fog and haze
- 2018
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Ingår i: Sustainable cities and society. - : Elsevier. - 2210-6707. ; 39, s. 215-224
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Tidskriftsartikel (refereegranskat)abstract
- Real-time atmospheric visibility estimation in foggy and hazy weather plays a crucial role in ensuring traffic safety. Overcoming the inherent drawbacks with traditional optical estimation methods, like limited sampling volume and high cost, vision-based approaches have received much more attention in recent research on atmospheric visibility estimation. Based on the classical Koschmieder's formula, atmospheric visibility estimation is carried out by extracting an inherent extinction coefficient. In this paper we present a variational framework to handle the nature of time-varying extinction coefficient and develop a novel algorithm of extracting the extinction coefficient through a piecewise functional fitting of observed luminance curves. The developed algorithm is validated and evaluated with a big database of road traffic video from Tongqi expressway (in China). The test results are very encouraging and show that the proposed algorithm could achieve an estimation error rate of 10%. More significantly, it is the first time that the effectiveness of Koschmieder's formula in atmospheric visibility estimation was validated with a big dataset, which contains more than two million luminance curves extracted from real-world traffic video surveillance data.
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| 9. |
- Cheng, Xiaogang, et al.
(författare)
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NIDL: A pilot study of contactless measurement of skin temperature for intelligent building
- 2019
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Ingår i: Energy and Buildings. - : Elsevier. - 0378-7788 .- 1872-6178. ; 198, s. 340-352
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Tidskriftsartikel (refereegranskat)abstract
- Human thermal comfort measurement plays a critical role in giving feedback signals for building energy efficiency. A contactless measuring method based on subtleness magnification and deep learning (NIDL) was designed to achieve a comfortable, energy efficient built environment. The method relies on skin feature data, e.g., subtle motion and texture variation, and a 315-layer deep neural network for constructing the relationship between skin features and skin temperature. A physiological experiment was conducted for collecting feature data (1.44 million) and algorithm validation. The contactless measurement algorithm based on a partly-personalized saturation temperature model (NIPST) was used for algorithm performance comparisons. The results show that the mean error and median error of the NIDL are 0.476 °C and 0.343°C which is equivalent to accuracy improvements of 39.07 % and 38.76 %, respectively.
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| 10. |
- de Boer, Wietse, et al.
(författare)
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Pathogen suppression by microbial volatile organic compounds in soils
- 2019
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Ingår i: FEMS Microbiology Ecology. - : Oxford University Press (OUP). - 1574-6941. ; 95:8
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Forskningsöversikt (refereegranskat)abstract
- There is increasing evidence that microbial volatile organic compounds (mVOCs) play an important role in interactions between microbes in soils. In this minireview, we zoom in on the possible role of mVOCs in the suppression of plant-pathogenic soil fungi. In particular, we have screened the literature to see what the actual evidence is that mVOCs in soil atmospheres can contribute to pathogen suppression. Furthermore, we discuss biotic and abiotic factors that influence the production of suppressive mVOCs in soils. Since microbes producing mVOCs in soils are part of microbial communities, community ecological aspects such as diversity and assembly play an important role in the composition of produced mVOC blends. These aspects have not received much attention so far. In addition, the fluctuating abiotic conditions in soils, such as changing moisture contents, influence mVOC production and activity. The biotic and abiotic complexity of the soil environment hampers the extrapolation of the production and suppressing activity of mVOCs by microbial isolates on artificial growth media. Yet, several pathogen suppressive mVOCs produced by pure cultures do also occur in soil atmospheres. Therefore, an integration of lab and field studies on the production of mVOCs is needed to understand and predict the composition and dynamics of mVOCs in soil atmospheres. This knowledge, together with the knowledge of the chemistry and physical behaviour of mVOCs in soils, forms the basis for the development of sustainable management strategies to enhance the natural control of soil-borne pathogens with mVOCs. Possibilities for the mVOC-based control of soil-borne pathogens are discussed.
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| 11. |
- Deng, Min, et al.
(författare)
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Genome-wide association analyses in Han Chinese identify two new susceptibility loci for amyotrophic lateral sclerosis
- 2013
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Ingår i: Nature Genetics. - : Nature Publishing Group. - 1061-4036 .- 1546-1718. ; 45:6, s. 697-
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Tidskriftsartikel (refereegranskat)abstract
- To identify susceptibility genes for amyotrophic lateral sclerosis (ALS), we conducted a genome-wide association study (GWAS) in 506 individuals with sporadic ALS and 1,859 controls of Han Chinese ancestry. Ninety top SNPs suggested by the current GWAS and 6 SNPs identified by previous GWAS were analyzed in an independent cohort of 706 individuals with ALS and 1,777 controls of Han Chinese ancestry. We discovered two new susceptibility loci for ALS at 1q32 (CAMK1G, rs6703183, P-combined = 2.92 x 10(-8), odds ratio (OR) = 1.31) and 22p11 (CABIN1 and SUSD2, rs8141797, P-combined = 2.35 x 10(-9), OR = 1.52). These two loci explain 12.48% of the overall variance in disease risk in the Han Chinese population. We found no association evidence for the previously reported loci in the Han Chinese population, suggesting genetic heterogeneity of disease susceptibility for ALS between ancestry groups. Our study identifies two new susceptibility loci and suggests new pathogenic mechanisms of ALS.
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| 12. |
- He, Ting, et al.
(författare)
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Poly(vinylidene fluoride) (PVDF) membrane fabrication with an ionic liquid via non-solvent thermally induced phase separation (N-TIPs)
- 2022
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Ingår i: Applied water science. - : Springer. - 2190-5487 .- 2190-5495. ; 12:3
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate was the first time successfully utilized as single solvent in preparing the PVDF membrane with a good performance by N-TIPs method. The effects of quenching temperature and hydrophilic additive content on the morphology, permeability, and strength of the membranes were studied. All the prepared PVDF membranes were proved to be a pure β phase by FTIR and XRD, possessing a narrow pore size distribution. By adjusting quenching temperature and additive content, membranes with a flux of 383.2 L/m2 h and concentrated pore diameter of 26 nm obtained.
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| 13. |
- Miehe, Georg, et al.
(författare)
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The Kobresia pygmaea ecosystem of the Tibetan highlands – Origin, functioning and degradation of the world's largest pastoral alpine ecosystem: Kobresia pastures of Tibet
- 2019
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697. ; 648, s. 754-771
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Tidskriftsartikel (refereegranskat)abstract
- With 450,000 km2 Kobresia (syn. Carex) pygmaea dominated pastures in the eastern Tibetan highlands are the world's largest pastoral alpine ecosystem forming a durable turf cover at 3000–6000 m a.s.l. Kobresia's resilience and competitiveness is based on dwarf habit, predominantly below-ground allocation of photo assimilates, mixture of seed production and clonal growth, and high genetic diversity. Kobresia growth is co-limited by livestock-mediated nutrient withdrawal and, in the drier parts of the plateau, low rainfall during the short and cold growing season. Overstocking has caused pasture degradation and soil deterioration over most parts of the Tibetan highlands and is the basis for this man-made ecosystem. Natural autocyclic processes of turf destruction and soil erosion are initiated through polygonal turf cover cracking, and accelerated by soil-dwelling endemic small mammals in the absence of predators. The major consequences of vegetation cover deterioration include the release of large amounts of C, earlier diurnal formation of clouds, and decreased surface temperatures. These effects decrease the recovery potential of Kobresia pastures and make them more vulnerable to anthropogenic pressure and climate change. Traditional migratory rangeland management was sustainable over millennia, and possibly still offers the best strategy to conserve and possibly increase C stocks in the Kobresia turf.
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| 14. |
- Wen, Xiaogang, et al.
(författare)
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Dendritic nanostructures of silver : Facile synthesis, structural characterizations, and sensing applications
- 2006
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 22:10, s. 4836-4842
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Tidskriftsartikel (refereegranskat)abstract
- Silver nanodendrites are synthesized by a simple surfactant-free method using a suspension of zinc microparticles as a heterogeneous reducing agent. Structural characterizations suggest the preferential growth along <100> and <111> directions by oriented attachment of silver nanocrystals in the diffusion limit, leading to the formation of silver nanodendrites 20−30 nm in stem and branch diameter and 5−50 μm in length. Surface-enhanced Raman scattering studies show that the silver nanodentrites give an intensive and enhanced Raman scattering when pyridine was used as a probing molecule. We have also demonstrated that the silver nanodendrites increase the sensitivity of an electrochemical glucose biosensor by as much as 1−2 orders of magnitude.
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| 15. |
- Wilson, Stephanie J., et al.
(författare)
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Global subterranean estuaries modify groundwater nutrient loading to the ocean
- 2024
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Ingår i: Limnology And Oceanography Letters. - 2378-2242.
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Tidskriftsartikel (refereegranskat)abstract
- Terrestrial groundwater travels through subterranean estuaries before reaching the sea. Groundwater-derived nutrients drive coastal water quality, primary production, and eutrophication. We determined how dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), and dissolved organic nitrogen (DON) are transformed within subterranean estuaries and estimated submarine groundwater discharge (SGD) nutrient loads compiling > 10,000 groundwater samples from 216 sites worldwide. Nutrients exhibited complex, nonconservative behavior in subterranean estuaries. Fresh groundwater DIN and DIP are usually produced, and DON is consumed during transport. Median total SGD (saline and fresh) fluxes globally were 5.4, 2.6, and 0.18 Tmol yr−1 for DIN, DON, and DIP, respectively. Despite large natural variability, total SGD fluxes likely exceed global riverine nutrient export. Fresh SGD is a small source of new nutrients, but saline SGD is an important source of mostly recycled nutrients. Nutrients exported via SGD via subterranean estuaries are critical to coastal biogeochemistry and a significant nutrient source to the oceans.
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| 16. |
- Wu, Hongwei, et al.
(författare)
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Crystal Multi-Conformational Control Through Deformable Carbon-Sulfur Bond for Singlet-Triplet Emissive Tuning
- 2019
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Ingår i: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773. ; 58:13, s. 4328-4333
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Tidskriftsartikel (refereegranskat)abstract
- Crystal-state luminophores have been of great interest in optoelectronics for years, whereas the excited state regulation at the crystal level is still restricted by the lack of control ways. We report that the singlet-triplet emissive property can be profoundly regulated by crystal conformational distortions. Employing fluoro-substituted tetrakis(arylthio)benzene luminophores as prototype, we found that couples of molecular conformations formed during different crystallizations. The deformable carbon-sulphur bond essentially drove the distortion of the molecular conformation and varied the stacking mode, together with diverse non-covalent interactions, leading to the proportional adjustment of the fluorescence and phosphorescence bands. This intrinsic strategy was further applied for solid-state multicolor emissive conversion and mechanoluminescence, probably offering new insights for design of smart crystal luminescent materials.
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| 17. |
- Yang, Bin, et al.
(författare)
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Computer Vision Technology for Monitoring of Indoor and Outdoor Environments and HVAC Equipment : A Review
- 2023
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Ingår i: Sensors. - : MDPI. - 1424-8220. ; 23:13
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Forskningsöversikt (refereegranskat)abstract
- Artificial intelligence technologies such as computer vision (CV), machine learning, Internet of Things (IoT), and robotics have advanced rapidly in recent years. The new technologies provide non-contact measurements in three areas: indoor environmental monitoring, outdoor environ-mental monitoring, and equipment monitoring. This paper summarizes the specific applications of non-contact measurement based on infrared images and visible images in the areas of personnel skin temperature, position posture, the urban physical environment, building construction safety, and equipment operation status. At the same time, the challenges and opportunities associated with the application of CV technology are anticipated.
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| 18. |
- Yang, Bin, et al.
(författare)
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Real-time and contactless measurements of thermal discomfort based on human poses for energy efficient control of buildings
- 2019
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Ingår i: Building and Environment. - : Elsevier. - 0360-1323 .- 1873-684X. ; 162
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Tidskriftsartikel (refereegranskat)abstract
- Individual thermal discomfort perception gives important feedback signals for energy efficient control of building heating, ventilation and air conditioning systems. However, there is few effective method to measure thermal discomfort status of occupants in a real-time and contactless way. A novel method based on contactless measurements of human thermal discomfort status was presented. Images of occupant poses, which are related to thermoregulation mechanisms, were captured by a digital camera and the corresponding 2D coordinates were obtained. These poses were converted into skeletal configurations. An algorithm was developed to recognize different poses related to thermal discomfort, such as hugging oneself or wiping sweat off the brow. The algorithm could recognize twelve thermal discomfort related human poses. These poses were derived from a questionnaire survey of 369 human subjects. Some other human subjects participated in the validation experiments of the proposed method. All twelve thermal discomfort related poses can be recognized effectively.
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| 19. |
- Zhang, Xiaogang, 1970, et al.
(författare)
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Corrosion induced stress field and cracking time of reinforced concrete with initial defects: Analytical modeling and experimental investigation
- 2017
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Ingår i: Corrosion Science. - : Elsevier BV. - 0010-938X. ; 120, s. 158-170
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents an analytical model for calculation of corrosion induced stress field and cracking time of concrete cover with initial defects in a reinforced concrete. In the proposed model, two types of initial defects in concrete cover (surface and middle defect) were considered. Experiments were also performed to validate the effectiveness and accuracy of the proposed model. Based on the model analysis, it was found out that initial defects have significant influence on the stress distribution, the corrosion induced expansion pressure in concrete cover, the critical mass of corrosion products, and the cracking time of concrete cover.
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| 20. |
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