4,761 research outputs found
Bill of Sale from James Lock to Joel Coney, December 1831
No full textBill of sale signed by James Lock detailing the sale of an enslaved girl named Jane to Joel Coney. The document is dated December 13, 1831.https://knowledge.e.southern.edu/fullercollection/1003/thumbnail.jp
LOSCO A Ship Lock Scheduling Model
No full textA ship lock scheduling model called LOSCO was developed in order to decrease passage times at locks with two parallel chambers. Three locks were chosen to model, as they are some of the busiest locks of the Netherlands. The Krammersluizen, the Sluizen Hansweert and the Kreekraksluizen. Passage times are not collected at the locks, therefore the model was compared to SIVAK. SIVAK is the standard model for research on locks at Rijkswaterstaat. To schedule vessels in locks three types of choices can be made. Every vessel needs to be assigned to a chamber, the initiation time of locking should be decided and the order of sailing in a chamber should bedefined. By optimising these choices, passage times can be decreased. Optimising is however not straightforward, as the problem is an instance of the job shop scheduling problem. No exact algorithm has been found to solve these problems in a practical amount of time. Therefore the challange is to find a balance in solution quality and the speed of the model when creating a lock scheduling model. In this thesis, four ideas to improve the lock scheduling model by Verstichel were researched. The first idea is to change the resolution of the timesteps. The gain in performance was however not found to weight up against the loss in solution quality for resolution to be useful. The second idea is to drop the first come, first serve constraint that Verstichel created. This idea was also not found to be effective. The third idea is to divide the scheduling problem up into chunks. This is called cut separation. Chunks of around 25 vessels were found to be effective. The fourth and last idea is that of a maximum waiting time. The maximum waiting time makes the performance of the model better and also makes the scheduling model fairer. Data from the year 2016 was used to schedule all lockings. The LOSCO model is effective for reducing the average assage time per vessel with about 3.9 ± 0.12 SE minutes for the Krammersluizen and 2.0 ± 0.14 SE minutes for the Sluizen Hansweert compared to the SIVAK model. At the Kreekraksluizen, the model could not find a solution, as the Kreekraksluizen are a lot busier than the other locks that were tested. At the Kreekraksluizen on average every 7.8 minutes a vessel arrives, whereas at the Krammersluizen and the Sluizen Hansweert respectively every 14.0 and 13.0 minutes a vessel arrives throughout the year. The LOSCO model is only better than SIVAK if the lock is relatively quiet. At the busiest time of the day, typically in the afternoon, SIVAK performs better. The models perform equal at inter arrival times of around 8to 10 minutes. Optimisation on economical value of the vessels was found to be less effective than optimisation on time. Optimisation on time was also found to be fairer. The LOSCO model is a step ahead towards a practical lock scheduling model. In order to achieve a fully practical model, some simplifications need to be expanded. It is recommended to first improve the model before it is applied in practice, as the model is able to outperform SIVAK in some cases, but not in the busiest cases. After this some extra features can be implemented, such as the model dealing with vessel delays and locks with 3 chambers
Capital Gains Taxes and Asset Prices: Capitalization or Lock-In?
No full textThis paper examines the impact on asset prices from a reduction in the long-term capital gains tax rate using an equilibrium approach that considers both demand and supply responses. We demonstrate that the equilibrium impact of capital gains taxes reflects both the capitalization effect (i.e., capital gains taxes decrease demand) and the lock-in effect (i.e., capital gains taxes decrease supply). Depending on time periods and stock characteristics, either effect may dominate. Using the Taxpayer Relief Act of 1997 as our event, we find evidence supporting a dominant capitalization effect in the week following news that sharply increased the probability of a reduction in the capital gains tax rate and a dominant lock-in effect in the week after the rate reduction became effective. Nondividend paying stocks (whose shareholders only face capital gains taxes) experience higher average returns during the week the capitalization effect dominates and stocks with large embedded capital gains and high tax sensitive investor ownership exhibit lower average returns during the week the lock-in effect dominates. We also find that the tax cut increases the trading volume during the week immediately before and after the tax cut becomes effective and in stocks with large embedded capital gains and high tax sensitive ownership during the dominant lock-in week.
Avoiding Carbon Lock-In: Policy Options for Advancing Structural Change
No full textA major obstacle for the transformation to a low-carbon economy is the risk of a carbon lock-in: fossil fuel-based ('dirty') technologies dominate the market although their carbon-free ('clean') alternatives are dynamically more efficient. We study the interaction of learning-by-doing spillovers and the substitution elasticity between the clean and the dirty sector in an intertemporal general equilibrium model. We find that the substitution possibilities between the two sectors have an ambivalent effect: although a high substitution elasticity requires less aggressive mitigation policies than a low one, it creates a greater lock-in in the absence of regulation. The optimal policy response consists of a permanent carbon tax as well as a learning subsidy for clean technologies. A single policy instrument can also avoid high welfare losses, but a more stringent mitigation target can only be achieved at painful costs. We demonstrate that the policy implication of [Acemoglu et al. 2012] is limited in scope. Our numerical results also highlight that infrastructure provision is crucial to facilitate the low-carbon transformation.structural change, low-carbon economy, carbon lock-in, mitigation policies, learning-by-doing
Employment-Based Health Insurance and Job Mobility: Is There Evidence ofJob-Lock?
No full textThis paper assesses the impact of employer-provided health insurance on job mobility by exploring the extent to which workers are 'locked' into their jobs because preexisting conditions exclusions make it expensive for individuals with medical problems to relinquish their current health insurance. I estimate the degree of job-lock by comparing the difference in the turnover rates of those with high and low medical expenses for those with and without employer-provided health insurance. Using data from the 1987 National Medical Expenditure Survey, I estimate that job-lock reduces the voluntary turnover rate of those with employer-provided health insurance by 25 percent, from 16 percent to 12 percent per year.
Nut Lock.
No full textPatent for a nut lock with a locking plate that can be used for multiple nuts, "particularly those used in securing the joints of railroad rails, frogs, switches, and crossings" (lines 10-12), with illustrations
Maritime flight trials of the Southampton University laser sintered aircraft – Project Albatross
No full textAs part of the ongoing development of small unmanned air systems by the University of Southampton, an all laser sintered aircraft has been test flown from the Royal Navy's ice patrol ship HMS Protector to assist with navigating through the Antarctic. These flights were carried out with pre-planned autopilot control with oversight from Andrew Lock, acting as the pilot embarked on HMS Protector. This is the first time the Royal Navy has used unmanned aerial vehicles in this part of the world. In this paper, we set out the trial reports and lessons learnt from this series of test flights
Lock.
No full textPatent for a permutation lock with illustrations. The combination on the lock can be changed an infinite number of times by the user
Receipt from James Lock & Co. to Robert Goelet
No full texthttps://digitalcommons.salve.edu/goelet-personal-expenses/1263/thumbnail.jp
The "Lock Step Parade" at the American Prison Congress
No full textA b/w photograph of attendees at the American Prison Congress of 1933 forming a "lock step parade" The congress was held in Atlantic City, New Jersey in 1933
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