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Residential building performance analysis at near extreme weather conditions in Hong Kong through a thermal-comfort-based strategy

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Building Simulation 2023年第1期16卷 13-25页

作者： K.F.Fong c.K.Lee kevin Ka-Lun Lau Edward Yan Yung Ng Division of Building Science and Technology College of EngineeringCity University of Hong KongHong KongChina Department of civil Engineering and Natural Resources Lulea University of TechnologySweden School of Architecture The Chinese University of Hong KongHong KongChina

The precise building performance assessment of residential housings in subtropical regions is usually more difficult than that for the commercial premises due to the much more complicated behavior of the occupants with regard to the change in indoor *** conventional use of a fixed schedule for window opening,clothing insulation and cooling equipment operation cannot reflect the real situation when the occupants respond to the change in thermal comfort,thus affecting the appropriateness of the assessment *** rectify the situation,a new modeling strategy in which the modification of the various operation schedules was based on the calculated thermal comfort(Tc),was developed in this *** this new Tc-based strategy,the realistic building performances under different cooling provision scenarios applied to a high-rise residential building under the near extreme weather conditions were investigated and *** was found that sole provision of ventilation fans could not meet the zone thermal comfort by over 68%of the time,and air-conditioning was *** optimal use of ventilation fans for cooling could only help reduce the total cooling energy demand by less than 12%at best which could only be realistically evaluated by adopting the present *** studies were conducted which revealed that some design factors could offer opportunities for reducing the total cooling energy under the near extreme weather conditions.

关键词： predicted mean vote thermal comfort ventilation potential building performance simulation residential housings

Behavioural and energetic consequences of competition among three overwintering swan(cygnus spp.)species

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Avian Research 2021年第4期12卷 707-721页

作者： kevin A.Wood Julia L.Newth Geoff M.Hilton Eileen c.Rees Wildfowl&Wetlands Trust SlimbridgeGloucestershire GL27BTUnited Kingdom centre for Ecology and conservation/Environment and Sustainabil-ity Institute College of Life and Environmental SciencesUniversity of ExeterExeter TR109EZUnited Kingdom Department of Zoology University of CambridgeDowning StreetCambridge CB23EJUnited Kingdom

Background:Winter numbers of the northwest European population of Bewick's Swans(cygnus columbianus bewickii)declined recently by c.40%.During the same period,numbers of two sympatric and ecologically-similar congeners,the Mute Swan(cygnus olor)and Whooper Swan(cygnus cygnus)showed increases or *** has been suggested that these opposing population trends could have a causal relationship,as Mute and Whooper Swans are larger and competitively dominant to Bewick's Swans in foraging *** so,effects of competition of Mute and Whooper Swans on Bewick's Swans should be detectable as measurable impacts on behaviour and ***:Here,we studied the diurnal behaviour and energetics of 1083 focal adults and first-winter juveniles("cygnets")of the three swan species on their winter grounds in eastern *** analysed video recordings to derive time-activity budgets and these,together with estimates of energy gain and expenditure,were analysed to determine whether individual Bewick's Swans altered the time spent on key behaviours when sharing feeding habitat with other swan species,and any consequences for their energy expenditure and net energy ***:All three swan species spent a small proportion of their total time(0.011)on aggressive interactions,and these were predominantly intraspecific(≥0.714).Mixed-effects models indicated that sharing feeding habitat with higher densities of Mute and Whooper Swans increased the likelihood of engaging in aggression for cygnet Bewick's Swans,but not for *** levels of interspecific competition decreased the time spent by Bewick's Swan cygnets on foraging,whilst adults showed the opposite *** among low densities of conspecifics(c.200 individuals/km^(2)),individual Bewick's Swans spent more time on vigilance in the presence of higher densities of Mute and Whooper Swans,whilst individuals within higher density Bewick's Swan flocks showed the opposite ***,we found no evide

关键词： Avian behaviour Energy expenditure Ethology Interference competition Interspecific interactions Time activity budgets Video observations

Preliminary studies on the stability of arsenolipids:Implications for sample handling and analysis

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Journal of Environmental Sciences 2016年第11期28卷 97-103页

作者： Muslim Khan kevin A.Francesconi Institute of chemistry-Analytical chemistry University of Graz

Human health risk assessments concerning arsenic are now estimating exposure through food in addition to exposure through drinking water. Intrinsic to this assessment is sample handling and preparation that maintains the arsenic species in the form that they occur in foods. We investigated the stability of three arsenolipids（two arsenic fatty acids, As FA-362 and As FA-388, and one arsenic hydrocarbon As Hc-332）, common constituents of fish and algae, relevant to sample storage and transport, and to their preparation for quantitative measurements. The fate of the arsenolipids was followed by high performance liquid chromatography/electrospray triple quadruple mass spectrometry（HPLc/ESIMS） *** of the compounds dry as pure compounds or mixed in fish oil at up to 60？c did not result in significant changes to the compounds, although losses were observed by apparent adsorption onto the plastic walls of the polypropylene tubes. No losses occurred when the experiment was repeated with glass tubes. When the compounds were stored in ethanol for up to 15 days under acidic, neutral, or alkaline conditions（each at room temperature）, no significant decomposition was observed, although esterification of the fatty acids occurred at low p H. The compounds were also stable during a sample preparation step involving passage through a small silica column. The results indicate that these typical arsenolipids are stable when stored in glass at temperatures up to 60？c for at least 2 days, and that,consequently, samples of food or extracts thereof can be transported dry at ambient temperatures, i.e. without the need for cool conditions.

关键词： Arsenolipids Stability Mass spectrometry

Statin, aspirin and metformin use and risk of hepatocellular carcinoma related outcomes following liver transplantation: A retrospective study

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World Journal of Transplantation 2024年第3期14卷 120-131页

作者： William chung kevin Wong Noel Ravindranayagam Lauren Tang Josephine Grace Darren Wong Danny con Marie Sinclair Avik Majumdar Numan Kutaiba Samuel Hui Paul Gow Vijayaragavan Muralidharan Alexander Dobrovic Adam Testro Department of Gastroenterology Austin HealthHeidelberg 3084VictoriaAustralia Victorian Liver Transplant Unit Austin HealthHeidelberg 3084VictoriaAustralia Department of Radiology Austin HealthHeidelberg 3084VictoriaAustralia Department of Gastroenterology Monash HealthClayton 3168VictoriaAustralia Department of Surgery University of MelbourneAustin HealthHeidelberg 3048VictoriaAustralia Department of Surgery Beacon LaboratoryAustin PrecinctThe University of MelbourneAustin HospitalHeidelberg 3048VictoriaAustralia

BAcKGROUND Liver transplantation(LT)is a potentially curative therapy for patients with hepatocellular carcinoma(Hcc).Hcc-recurrence following LT is associated with reduced *** is increasing interest in chemoprophylaxis to improve Hcc-related outcomes *** To investigate whether there is any benefit for the use of drugs with proposed chemoprophylactic properties against Hcc,and patient outcomes following *** This was a retrospective study of adult patients who received Deceased Donor LT for Hcc from 2005-2022,from a single Australian *** use was defined as statin,aspirin or metformin therapy for≥29 days,within 24 months post-LT.A cox proportional-hazards model with time-dependent covariates was used for survival *** measures were the composite-endpoint of Hcc-recurrence and all-cause mortality,Hcc-recurrence and Hcc-related *** analysis was performed to account for immortality time bias and statin *** Three hundred and five patients were included in this study,with 253(82.95%)males with a median age of 58.90 *** of liver disease were 150(49.18%)hepatitis c,73(23.93%)hepatitis B(HBV)and 33(10.82%)non-alcoholic fatty liver disease(NAFLD).56(18.36%)took statins,51(16.72%)aspirin and 50(16.39%)*** a median follow-up time of 59.90 months,34(11.15%)developed Hcc-recurrence,48(15.74%)died,17(5.57%)from Hcc-related ***,aspirin or metformin use was not associated with statistically significant differences in the composite endpoint of Hcc-recurrence or all-cause mortality[hazard ratio(HR):1.16,95%cI:0.58-2.30;HR:1.21,95%cI:0.28-5.27;HR:0.61,95%cI:0.27-1.36],Hcc-recurrence(HR:0.52,95%cI:0.20-1.35;HR:0.51,95%cI:0.14-1.93;HR 1.00,95%cI:0.37-2.72),or Hcc-related mortality(HR:0.32,95%cI:0.033-3.09;HR:0.71,95%cI:0.14-3.73;HR:1.57,95%cI:0.61-4.04)*** dosing was not associated with statist-ically significant differences in Hcc-related ***

关键词： Liver transplantation Hepatocellular carcinoma Transplant oncology Statins HMG-co-A reductase Aspirin Metformin Mammalian target of rapamycin

Experimental study on modification of water-based filtercake to improve the bonding strength at the wellbore cement-formation interface

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Petroleum Research 2023年第4期8卷 531-540页

作者： kevin Nsolloh Lichinga Department of Engineering Development Tanzania Industrial Research and Development Organization(TIRDO)PO Box 23235Dar es SalaamTanzania Department of Petroleum Engineering Faculty of Earth Resources for Oil Well Cement Research and TestingNo.388Lumo RoadHongshan DistrictWuhanChina University of GeosciencesWuhan430074PR China

The objective of this experimental study is to improve the cementing bond quality of sandstone oil-gas well along the wellbore cement-formation interface(WcFI),so as to ensure long-term zonal isolation throughout the lifecycle of the well by using NsO solution as filtercake modifier which was developed in the *** to designed experimental method and API RP 10,the effectiveness of filtercake modifier(NSO)on the bonding strength at the WcFI was assessed by using designed simulated wellbore as sandstone *** experimental results indicated that the samples which were treated with NsO solution had higher bond strength over untreated *** strength generally increased with curing period as for treated samples,0.198,0.374,0.433 and 0.473 MPa for 3,7,15,and 30 days respectively while for the untreated samples the bond strength were 0.050,0.070,0.81 and 0.100 MPa for the same *** water-based filtercake modification techniques had significantly enhanced the bonding strength of WcFI by increasing rates above 296%.Improvement of bond strength to the treated sample was due to filtercake modification as a result of formation of cementitious material as revealed in FTIR spectral such as calcium-Silicate-Hydrate(c-S-H)and other geopolymers like calcium-Aluminium-Silicate-Hydrate(c-A-S-H)and Sodium-Aluminium-Silicate-Hydrate(N-A-S-H)along the interface which filled the existed pores hence reducing porosity hence high strength of *** low transmittance value for the NsO treated samples revealed that there were more cementitious materials existing at the WcFI which led to improvement of bonding strength as compared to the untreated *** lower/poor bond strength for the untreated samples is due to existence of untreated,thick water-based filtercake films at WcFI,which prevented the complete hydration process between rock grains and cement slurry components to make chemical binder of cement slurry material and formation.2022 The Authors.P

关键词： Geopolymer Bond strength Water-based mud Wellbore cement-formation interface NSO

Three-dimensional light structure of an upland Quercus stand post-tornado disturbance

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Journal of Forestry Research 2020年第1期31卷 141-153页

作者： kevin G.Willson Lauren E.cox Justin L.Hart Daniel c.Dey Department of Geography University of AlabamaTuscaloosaAL 35487USA Department of Environmental Science Policyand ManagementUniversity of CaliforniaBerkeleyCA 94720USA Northern Research Station USDA Forest ServiceColumbiaMO 65211USA

Light is the most common limiting factor in forest plant communities,influencing species composition,stand structure,and stand productivity in closed canopy *** vertical light structure is relatively simple under a closed canopy because most light is captured by overstory ***,wind disturbance events create canopy openings from local to landscape scales that increase understory light intensity and vertical light structural *** studied the effects of an EF-1 tornado on horizontal and vertical(***-dimensional)light structure within a Quercus stand to determine how light structure changed with increasing disturbance *** used a two-tiered method to collect photosynthetic photon flux density at 4.67 m and 1.37 m above the forest floor to construct three-dimensional light structure across a canopy disturbance severity gradient to see if light intensity varied with increasing tornado *** indicate that increased canopy disturbance closer to the tornado track increased light penetration and light structure heterogeneity at lower forest *** light intensity correlated with increased sapling density that was more randomly distributed across the plot and had shifted light capture higher in the stand *** penetration through the overstory was most strongly correlated with decreased stem density in the two most important tree species(based on relative dominance and relative density)in the stand,Quercus alba L.(r=-0.31)and Ostrya virginiana(Mill.)***(r=-0.27,pcated that understory light penetration was most affected by these two *** managers are increasingly interested in patterning silvicultural entries on natural disturbances,they must understand residual stand and light structures that occur after natural disturbance *** providing spatial light data that quantifies light structure post-disturbance,managers can use these results to improve planning required for long-term man

关键词： Photosynthetic photon flux density Midstory Blowdown Heterogeneity

How does covid-19 affect global equity markets?

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Financial Innovation 2022年第1期8卷 624-642页

作者： Eddie c.M.Hui Ka Kwan kevin chan ZN744 Department of Building and Real EstateThe Hong Kong Polytechnic UniversityHung HomHong KongChina

This study applies OLS,panel regression and Granger causality test to investigate the impact of the coronavirus disease 2019(covid-19)outbreak on the global equity markets during the early stage of the *** find that the covid-19 outbreak has a significant negative impact on the overall equity index return of the eight economies even at 0.1%significance ***,the pandemic has a more significant impact on the European countries than on the East Asian *** results have three main ***,policy makers should react fast to mitigate the impact of a ***,investors should be aware of an outbreak of disease or other risks and adjust their investments ***,the covid-19 outbreak results in a shift of power from the west to the east.

关键词： covid-19 confirmed cases Panel regression Equity index

An unsupervised learning approach to study synchroneity of past events in the South china Sea

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Frontiers of Earth Science 2019年第3期13卷 628-640页

作者： kevin c. Tse Hon-chim chiu Man-Yin Tsang Yiliang Li Edmund Y. Lam Department of Earth Sciences The University of Hong KongPokfulamHong KongChina Department of Geography and centre for Geo-computation Studies Hong Kong Baptist UniversityKowloon TongHong KongChina Department of Earth Sciences University of TorontoCanada Department of Electrical and Electronic Engineering The University of Hong KongPokfulamHong KongChina

Unsupervised machine learning methods were applied on multivariate geophysical and geochemical datasets of ocean floor sediment cores collected from the South china Sea. The well-preserved and continuous core samples comprising high resolution cenozoic sediment records enable scientists to carry out paleoenvironment studies in detail. Bayesian age-depth chronological models constructed from biostratigraphic control points for the drilling sites are applied on cluster boundaries generated from two popular unsupervised learning methods: K-means and random forest. The unsupervised learning methods experimented have produced compact and unambiguous clusters from the datasets, indicating that previously unknown data patterns can be revealed when all variables from the datasets are taken into account simultaneously. A study of synchroneity of past events represented by the cluster boundaries across geographically separated ocean drilling sites is achieved through converting the fixed depths of cluster boundaries into chronological ranges represented by Gaussian density plots which are then compared with known past events in the region. A Gaussian density peak at around 7.2 Ma has been identified from results of all three sites and it is suggested to coincide with the initiation of the East Asian monsoon. contrary to traditional statistical approach, a priori assumptions are not required for unsupervised learning, and the clustering results serve as a novel data-driven proxy for studying the complex and dynamic processes of the paleoenvironment surrounding the ocean sediment. This work serves as a pioneering approach to extract valuable information of regional events and opens up a systematic and objective way to study the vast global ocean sediment datasets.

关键词： machine learning ocean sediments unsupervised classification

Unsupervised learning on scientific ocean drilling datasets from the South china Sea

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Frontiers of Earth Science 2019年第1期13卷 180-190页

作者： kevin c.TSE Hon-chim cHIU Man-Yin TSANG Yiliang LI Edmund Y.LAM Department of Earth Sciences The University of Hong KongPokfulamHong KongChina Department of Geography and centre for Geo-computation Studies Hong Kong Baptist UniversityKowloon TongHong KongChina Department of Earth Sciences University of TorontoTorontoON M5S 2M8Canada Department of Electrical and Electronic Engineering The University of Hong KongPokfulamHong KongChina

Unsupervised learning methods were applied to explore data patterns in multivariate geophysical datasets collected from ocean floor sediment core samples coming from scientific ocean drilling in the South china *** to studies on similar datasets,but using supervised learning methods which are designed to make predictions based on sample training data,unsupervised learning methods require no a priori information and focus only on the input *** this study,popular unsupervised learning methods including K-means,self-organizing maps,hierarchical clustering and random forest were coupled with different distance metrics to form exploratory data *** resulting data clusters were externally validated with lithologic units and geologic time scales assigned to the datasets by conventional methods. compact and connected data clusters displayed varying degrees of correspondence with existing classification by lithologic units and geologic time scales.K-means and self-organizing maps were observed to perform better with lithologic units while random forest corresponded best with geologic time *** study sets a pioneering example of how unsupervised machine learning methods can be used as an automatic processing tool for the increasingly high volume of scientific ocean drilling data.

关键词： machine learning unsupervised learning ODP IODP clustering