2,804 research outputs found

    Home Appreciation Participation Notes: A Solution to Housing Affordability and the Current Mortgage Crisis

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    This paper introduces Home Appreciation Participation Notes (HAPNs), an innovative new housing finance tool. Housing is a commodity providing two distinct utilities: shelter and investment. Traditionally, buyers have had to purchase both elements in tandom. HAPNs allow buyers to purchase these elements individually. Thus, buyers can focus on purchasing housing units that best fit their shelter needs, investing in housing appreciation to whatever extent is appropriate for the needs of their investment portfolio. HAPNs are different from previous financing tools in three key ways: there is no payment burden until ownership of the home is transferred, the risk of housing price declines is shifted to investors, and the final payoff is indexed to the appreciation rates of local housing prices. With these three features, HAPNs considerably improve the affordability of homeownership while reducing the risk of default and avoiding the moral hazard associated with shared appreciation instruments.

    Optimal Property Management Strategies

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    This paper examines the optimal operation strategies for income properties. Specifically, the rental rate and the operating expense should be set at levels to maximize the return on investment. The results suggest that for a given demand curve of a specific rental property, there exist optimal levels of the income ratio, the operating expense ratio, and the vacancy rate. With a Cobb-Douglas demand curve, we derived closed form solutions of these optimal ratios for a given income property. The relevant local comparative statics of these ratios also are derived. These comparative statics also provide insight into the optimal building size and optimal rehabilitation decisions. An empirical case study was conducted to demonstrate how the model can be applied in real life situations.Rental Property, Vacancy Rate; Operating Strategy, Profit Optimization

    The Chinese Housing Provident Fund

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    The Chinese government has embarked upon an effort to reduce the number of tenants living in publicly owned housing. This is a significant challenge for any government, but may be especially so for a country where private homeownership is a new option. Out of concern that many of its citizens could not afford to purchase their housing units, the Chinese government created the Housing Provident Fund. This program, which is similar to housing fund programs in other countries such as Thailand and Singapore, combines a 401(k)-like savings and retirement account with subsidized mortgage rates and price discounts to provide a mechanism through which an employee could save for, and eventually complete, a housing purchase.

    Effect of Environmental Factors on How Older Pedestrians Detect an Upcoming Step

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    The relationships between environmental features and older peopleā€™s ability to safely move around a complex pedestrian environment are, as yet, poorly understood. Specifically, the impact of light levels on trip hazard detection during walking has received relatively little attention. This study investigates the effect of illuminance on peopleā€™s ability to detect steps of different heights in a laboratory-based controlled environment. Sixteen young and 15 older participants walked along a 13.2 m walkway towards an either ascending or descending step at 200 lux or 4 lux light levels. Trial time, gaze behaviour and distance at which the step was first visually fixated (detection distance) were measured using an eye-tracker. It was found that both the trial time and detection distance of older participants were affected by light level whereas the fixation number and fixation duration of young participants were affected by step-height. Shorter detection distance, greater number of fixations and longer fixation duration were found among older participants as opposed to young participants. The results suggest that the processing efficiency for visual information on an upcoming step is slower among older people than among young people. This implies that the vulnerability of older pedestrians maybe be reduced if better lighting or a simplified visual environment is provided

    Infrastructureless pedestrian navigation to assess the response of Alzheimer's patients to visual cues

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    The aim of the study was to understand how patients with dementia were able to navigate in a domestic environment, and whether the presence of visual cues could assist in route finding. A simulated domestic environment was created in the Pedestrian Accessibility and Movement Environment Laboratory (PAMELA) comprising three different types of corridors and an open room with three doors. Three groups of subjects were studied: i) posterior cortical atrophy; ii) typical Alzheimerā€™s disease; iii) age- and gender matched controls. Foot-mounted inertial measurement units (IMUs) were used to measure accelerations in 3D. Data from the sensors was transmitted wirelessly to a laptop computer. Local accelerations were converted to global accelerations, and double integration was performed to calculate displacement; corrections for sensor drift were performed during this process

    Imaging the Disk around TW Hydrae with the Submillimeter Array

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    We present ~2"-4" aperture synthesis observations of the circumstellar disk surrounding the nearby young star TW Hya in the CO J = 2-1 and J = 3-2 lines and associated dust continuum obtained with the partially completed Submillimeter Array. The extent and peak flux of the 230 and 345 GHz dust emission follow closely the predictions of the irradiated accretion disk model of Calvet et al. The resolved molecular line emission extends to a radius of at least 200 AU, the full extent of the disk visible in scattered light, and shows a clear pattern of Keplerian rotation. Comparison of the images with two-dimensional Monte Carlo models constrains the disk inclination angle to 7Ā° Ā± 1Ā°. The CO emission is optically thick in both lines, and the kinetic temperature in the line formation region is ~20 K. Substantial CO depletion, by an order of magnitude or more from canonical dark cloud values, is required to explain the characteristics of the line emission

    STEP-UP: Enabling low-cost IMU sensors to predict the type of dementia during everyday stair climbing

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    Posterior Cortical Atrophy is a rare but significant form of dementia which affects peoplesā€™ visual ability before their memory. This is often misdiagnosed as an eyesight rather than brain sight problem. This paper aims to address the frequent, initial misdiagnosis of this disease as a vision problem through the use of an intelligent, cost-effective, wearable system, alongside diagnosis of the more typical Alzheimerā€™s Disease. We propose low-level features constructed from the IMU data gathered from 35 participants, while they performed a stair climbing and descending task in a real-world simulated environment. We demonstrate that with these features the machine learning models predict dementia with 87.02% accuracy. Furthermore, we investigate how system parameters, such as number of sensors, affect the prediction accuracy. This lays the groundwork for a simple clinical test to enable detection of dementia which can be carried out in the wild

    Infrared Luminosities and Dust Properties of z ~ 2 Dust-Obscured Galaxies

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    We present SHARC-II 350um imaging of twelve 24um-bright (F_24um > 0.8 mJy) Dust-Obscured Galaxies (DOGs) and CARMA 1mm imaging of a subset of 2 DOGs, all selected from the Bootes field of the NOAO Deep Wide-Field Survey. Detections of 4 DOGs at 350um imply IR luminosities which are consistent within a factor of 2 of expectations based on a warm dust spectral energy distribution (SED) scaled to the observed 24um flux density. The 350um upper limits for the 8 non-detected DOGs are consistent with both Mrk231 and M82 (warm dust SEDs), but exclude cold dust (Arp220) SEDs. The two DOGs targeted at 1mm were not detected in our CARMA observations, placing strong constraints on the dust temperature: T_dust > 35-60 K. Assuming these dust properties apply to the entire sample, we find dust masses of ~3x10^8 M_sun. In comparison to other dusty z ~ 2 galaxy populations such as sub-millimeter galaxies (SMGs) and other Spitzer-selected high-redshift sources, this sample of DOGs has higher IR luminosities (2x10^13 L_sun vs. 6x10^12 L_sun for the other galaxy populations), warmer dust temperatures (>35-60 K vs. ~30 K), and lower inferred dust masses (3x10^8 M_sun vs. 3x10^9 M_sun). Herschel and SCUBA-2 surveys should be able to detect hundreds of these power-law dominated DOGs. We use HST and Spitzer/IRAC data to estimate stellar masses of these sources and find that the stellar to gas mass ratio may be higher in our 24um-bright sample of DOGs than in SMGs and other Spitzer-selected sources. Although larger sample sizes are needed to provide a definitive conclusion, the data are consistent with an evolutionary trend in which the formation of massive galaxies at z~2 involves a sub-millimeter bright, cold-dust and star-formation dominated phase followed by a 24um-bright, warm-dust and AGN-dominated phase.Comment: 16 pages, 7 figures, 6 tables; accepted to the Ap

    Estimating measures of interaction on an additive scale for preventive exposures

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    Measures of interaction on an additive scale (relative excess risk due to interaction [RERI], attributable proportion [AP], synergy index [S]), were developed for risk factors rather than preventive factors. It has been suggested that preventive factors should be recoded to risk factors before calculating these measures. We aimed to show that these measures are problematic with preventive factors prior to recoding, and to clarify the recoding method to be used to circumvent these problems. Recoding of preventive factors should be done such that the stratum with the lowest risk becomes the reference category when both factors are considered jointly (rather than one at a time). We used data from a case-control study on the interaction between ACE inhibitors and the ACE gene on incident diabetes. Use of ACE inhibitors was a preventive factor and DD ACE genotype was a risk factor. Before recoding, the RERI, AP and S showed inconsistent results (RERIĀ =Ā 0.26 [95%CI: āˆ’0.30; 0.82], APĀ =Ā 0.30 [95%CI: āˆ’0.28; 0.88], SĀ =Ā 0.35 [95%CI: 0.02; 7.38]), with the first two measures suggesting positive interaction and the third negative interaction. After recoding the use of ACE inhibitors, they showed consistent results (RERIĀ =Ā āˆ’0.37 [95%CI: āˆ’1.23; 0.49], APĀ =Ā āˆ’0.29 [95%CI: āˆ’0.98; 0.40], SĀ =Ā 0.43 [95%CI: 0.07; 2.60]), all indicating negative interaction. Preventive factors should not be used to calculate measures of interaction on an additive scale without recoding
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