377 research outputs found

    Challenges facing housing affordability in Beijing in the Twenty-first century

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    Purpose &ndash; The purpose of this paper is analyse to what extent the high price had led to low levels of housing affordability in the period 2002-2006 in Beijing. Due to the importance of housing for local residents and the crucial position that real estate market in the Chinese economy is currently in, research into the housing affordability issues is now essential. It is important to consider the social circumstances that are predominantly related to both the standard of living and the national economy in Beijing.Design/methodology/approach &ndash; The housing price to income ratio (PIR) method and Housing Affordability Index (HAI) model are used to measure housing affordability in Beijing. Then, the reasons for the high housing prices in Beijing are discussed and government homeownership-oriented policies to help citizen on housing issues are examined. Finally, future proposals which can contribute to ease the housing affordability problem are recommended.Findings &ndash; The main findings in this research are that the PIR in the Beijing housing market (based on an average gross floor area of 60?m2) fluctuated between 6.69 and 9.12, respectively, between 2002 and 2006. Over the same period, the HAI was approximately 75 between 2002 and 2004, although decreasing sharply in 2005 (65.78) and 2006 (51.33). It appears that the Chinese government\u27s new housing provision policies may be able to ease this affordability problem, especially with regards to the economic housing scheme.Originality/value &ndash; China has experienced rapid growth in gross domestic product (GDP) with a substantial increase in house prices which have affected housing affordability for typical Beijing households. Since the housing reform in China commenced in 1998, Beijing residents, government officers and academics have been concerned about high housing prices in the city, which is considered beyond the buying capability of the ordinary residents. The results are designed to provide an insight into the level of housing affordability in Beijing and whether a trend exists.<br /

    Mismatched Training Data Enhancement for Automatic Recognition of Children’s Speech using DNN-HMM

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    The increasing profusion of commercial automatic speech recognition technology applications has been driven by big-data techniques, using high quality labelled speech datasets. Children's speech has greater time and frequency domain variability than typical adult speech, lacks good large scale training data, and presents difficulties relating to capture quality. Each of these factors reduces the performance of systems that automatically recognise children's speech. In this paper, children's speech recognition is investigated using a hybrid acoustic modelling approach based on deep neural networks and Gaussian mixture models with hidden Markov model back ends. We explore the incorporation of mismatched training data to achieve a better acoustic model and improve performance in the face of limited training data, as well as training data augmentation using noise. We also explore two arrangements for vocal tract length normalisation and a gender-based data selection technique suitable for training a children's speech recogniser

    Effects of distance from home to campus on undergraduate place attachment and university experience in China

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    First-year students in transition from hometown to campus are generally confronted by intellectual and social challenges as well as disruption and the formation of the place attachments associated with relocation. Understanding the variables affecting student place attachment helps address the widespread concern about student transition. Interactions between place attachment to hometown and campus, and the effects of endogenous and exogenous variables on place attachments, were analysed using covariance analysis, based on questionnaire data gathered at a Chinese university. Campus identity acts as a predictor for the other three dimensions of place attachment to hometown and campus: hometown identity, hometown dependence and campus dependence. Place attachment to campus exerts a direct effect on place attachment to hometown, while the latter indirectly impacts on the former through mediators including academic self-efficacy and peer relationships. Gender, household registration record and duration of dormitory stay were also identified as statistically significant predictors of student place attachment

    Investigation of skewing effects on the vibration reduction of three-phase switched reluctance motors

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    Switched reluctance motors (SRMs) are gaining in popularity because of their robustness, low cost, and excellent high-speed characteristics. However, they are known to cause vibration and noise primarily due to the radial pulsating force resulting from their double-saliency structure. This paper investigates the effect of skewing the stator and/or rotor on the vibration reduction of the three-phase SRMs by developing four 12/8-pole SRMs, including a conventional SRM, a skewed rotor-SRM (SR-SRM), a skewed stator-SRM (SS-SRM), and a skewed stator and rotor-SRM (SSR-SRM). The radial force distributed on the stator yoke under different skewing angles is extensively studied by the finite-element method and experimental tests on the four prototypes. The inductance and torque characteristics of the four motors are also compared, and a control strategy by modulating the turn-ON and turn-OFF angles for the SR-SRM and the SS-SRM are also presented. Furthermore, experimental results validate the numerical models and the effectiveness of the skewing in reducing the motor vibration. Test results also suggest that skewing the stator is more effective than skewing the rotor in the SRMs

    Investigation of Short Permanent Magnet and Stator Flux Bridge Effects on Cogging Torque Mitigation in FSPM Machines

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    Flux-switching permanent magnet (FSPM) machines are gaining in popularity due to their robustness, wide speed range, high torque, and high power density. However, their strong cogging torque can lead to vibration and noise due to the double-saliency structure. This paper investigates the effects of the short permanent magnet (PM) and stator flux bridge (FB) on the cogging torque reduction of three-phase 12/10-pole FSPM machines. Four different FSPM machines, including an inner-inner topology, an inner-outer topology, an outer-inner topology, and an outer-outer topology, are developed and analyzed with both short PM and stator FB. The configurations are obtained by placing the FB at inner/outer stator lamination and reducing the PM towards inner/outer directions. The cogging torque, average output torque, and PM utilization ratio of different topologies are extensively studied and compared by the finite element method (FEM). Finally, prototype machines are manufactured and tested. The experimental results have validated the numerical models and the effectiveness of the developed machine in reducing the cogging torque. The results also suggest that the outer-inner topology is more effective to reduce the cogging torque, which not only reduces the utilization of the PM materials, but also mitigates the cogging torque at only slight cost of torque performance

    Associations between polygenic risk, negative symptoms, and functional connectome topology during a working memory task in early-onset schizophrenia

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    Working memory (WM) deficit in schizophrenia is thought to arise from a widespread neural inefficiency. However, we do not know if this deficit results from the illness-related genetic risk and influence the symptom burden in various domains, especially in patients who have an early onset illness. We used graph theory to examine the topology of the functional connectome in 99 subjects (27 early-onset schizophrenia (EOS), 24 asymptomatic siblings, and 48 healthy subjects) during an n-back task, and calculated their polygenic risk score (PRS) for susceptibility to schizophrenia. Linear regression analysis was used to test associations of the PRS, clinical symptoms, altered connectomic properties, and WM accuracy in EOS. Indices of small-worldness and segregation were elevated in EOS during the WM task compared with the other two groups; these connectomic aberrations correlated with increased PRS and negative symptoms. In patients with higher polygenic risk, WM performance was lower only when both the connectomic aberrations and the burden of negative symptoms were higher. Negative symptoms had a stronger moderating role in this relationship. Our findings suggest that the aberrant connectomic topology is a feature of WM task performance in schizophrenia; this relates to higher polygenic risk score as well as higher burden of negative symptoms. The deleterious effects of polygenic risk on cognition are played out via its effects on the functional connectome, as well as negative symptoms

    A study on influential factors of occupant window-opening behavior in an office building in China

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    Occupants often perform many types of behavior in buildings to adjust the indoor thermal environment. In these types, opening/closing the windows, often regarded as window-opening behavior, is more commonly observed because of its convenience. It not only improves indoor air quality to satisfy occupants' requirement for indoor thermal comfort but also influences building energy consumption. To learn more about potential factors having effects on occupants' window-opening behavior, a field study was carried out in an office building within a university in Beijing. Window state (open/closed) for a total of 5 windows in 5 offices on the second floor in 285 days (9.5 months) were recorded daily. Potential factors, categorized as environmental and non-environmental ones, were subsequently identified with their impact on window-opening behavior through logistic regression and Pearson correlation approaches. The analytical results show that occupants' window-opening behavior is more strongly correlated to environmental factors, such as indoor and outdoor air temperatures, wind speed, relative humidity, outdoor PM2.5 concentrations, solar radiation, sunshine hours, in which air temperatures dominate the influence. While the non-environmental factors, i.e. seasonal change, time of day and personal preference, also affects the patterns of window-opening probability. This paper provides solid field data on occupant window opening behavior in China, with high resolutions and demonstrates the way in analyzing and predicting the probability of window-opening behavior. Its discussion into the potential impact factors shall be useful for further investigation of the relationship between building energy consumption and window-opening behavior

    Simultaneous Extraction and Identification of Phenolic Compounds in Anoectochilus roxburghii Using Microwave-Assisted Extraction Combined with UPLC-Q-TOF-MS/MS and Their Antioxidant Activities

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    This study used MAE and RSM to extract phenolic compounds from Anoectochilus roxburghii, and the optimum conditions defined by the model to give an optimum yield of 1.31%. The antioxidant activity in vitro showed when the concentration of phenolic compounds was reached 1 mg mL-1, the clearance rates were 82.58% for DPPH and 97.62% for ABTS+. In vivo antioxidant experiments used D-galactose to build oxidative damage in healthy Kunming mice. The result showed that the extractions of A. roxburghii can improve the antioxidant ability and the medium and low dose groups had better ability to scavenge free radicals. The UPLC-Q-TOF-MS/MS was developed to identify 21 kinds of phenolic compounds by molecular mass, ms/ms fragmentation, as well as retention time. The result showed that the phenolic compounds of A. roxburghii had significant potential as a natural antioxidant to promote health and to reduce the risk of disease
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