INPUT ARTICLE: Article: Natural fillings, such as ones made of duck or goose feathers, provide great insulation and warmth. They also let moisture escape, creating a soft, breathable duvet.  Types of natural fillings include goose and duck feathers, silk, and wool. Hypoallergenic down duvets are available if you have allergies but still want the down quality. Down- and feather-filled duvets tend to be the most expensive option. If you're allergic to feathers, synthetic fillings are a great choice. They're cheaper than natural fillings and are super lightweight. They're usually made of either hollowfibre or microfibre. Synthetic duvets can be washed much more often than natural fillings. Finding out what the duvet’s fill power is will tell you about its insulation. The higher the fill power, the fluffier and warmer the feathers. Fill powers may range from 450 to 900, with 700 being very plump. Down-filled duvets are made of the tiniest and fluffiest feathers and provide great insulation. If you live in a cold climate or want to stay super warm at night, a duvet filled with down is your best option. Feather-filled duvets contain larger feathers than down and are heavier. They're less expensive than down-filled duvets and still provide great warmth. You can also buy a duvet that has a combination of both down and feather filling. Silk is a great option for a filling because it’s hypoallergenic, lightweight, and durable. The silk prevents you from becoming too hot or cold while asleep, and it even protects your duvet from dust mites. As a natural filling, wool is very breathable. It’s an ideal choice if you want a duvet that insulates you while also evaporating moisture. Plus, wool is even fire resistant, making your night’s sleep even safer. The two options for synthetic fillings are microfibre or hollowfibre. Hollowfibre has hollow strands that are more wire-like than microfibre, but they’re also more durable and trap warmth well. Microfibre is the synthetic version of down, and it’s much lighter than feather-filled duvets.

SUMMARY: Choose a natural filling for great insulation. Opt for a synthetic filling for an affordable, lightweight option. Look for the duvet's fill power when buying a feather filling. Select a down-filled duvet for the best level of warmth. Decide on a feather-filled duvet for a more cost-efficient option. Pick a duvet filled with silk if you have allergies but want a natural filling. Buy a wool-filled duvet to help with temperature regulation. Decide on a hollowfibre or microfibre filling for a non-allergenic duvet.


INPUT ARTICLE: Article: The period is the timeframe in which your stock price varies. This can be daily, monthly, or even yearly. However, daily periods are most commonly used. The number of periods, n, represents how many periods you will be measuring within your calculation. If you are calculating daily periods, a common number of periods is 21, the average number of trading days in a month. A smaller value would not give you very good results. In fact, the larger the value, the smoother your result becomes. You can also use 63 periods to represent the number of trading days in three months or 252 periods to represent the average number of trading days in a year. The prices you will use to calculate volatility are the closing prices of the stock at the ends of your chosen periods. For example, for daily periods these would be the closing price on that day. Market data can be found, and in some cases downloaded, from market-tracking websites like Yahoo! Finance and MarketWatch. The return of a stock in a given period can be defined as the natural log, ln, of the closing price of a stock at the end of the period divided by the closing price of the stock at the end of the previous period. In equation form, this is: Rn=ln(Cn/(C(n-1)), where Rn is the return of a given stock over the period, ln is the natural log function, Cn is the closing price at the end of the period, and C(n-1) is the closing price at the end of the last period.  On many calculators, the natural log key is simply "ln" and must be pressed after the rest of the equation has already been calculated. For example, to find the returns when the price closed on one day at $11 and had closed at $10 the day before, you would set up your equation as Rn=ln($11/$10). This would simplify to Rn=ln(1.1). Pressing the ln key to solve gives a result of about 0.0953. The natural log is used to convert the numerical change in value of the stock over the period to an approximation of the percent change between days.

SUMMARY: Determine a period in which to measure returns. Choose a number of periods. Locate closing price information. Calculate returns.


INPUT ARTICLE: Article: As with the method for sewing by hand, the first thing to do is to clean up the hole or rip by trimming away any loose or dangling threads. Take care as you do this and try to be as precise as possible. Threading the needle on a sewing machine can be a bit tricky as they use two sources of thread, one from the bobbin and one from the spool. The first thing to do is wind the bobbin so that it is wrapped with thread. Once the spool and bobbin are in place on the top of your machine, unravel a few inches of thread towards the far left side of the spool and wrap it around the nubbin on the left hand side of your machine.  Then pull this thread to the bobbin, thread it through the small hole, and wrap it around the bobbin a few times to secure it. Fix the bobbin in place by pushing it to the right and then gentle press down on your peddle to wind the thread from the spool to the bobbin until you have as much thread as you need on the bobbin. Cut the thread to separate the spool and bobbin, then remove the bobbin and switch off your machine.

SUMMARY:
Cut away the loose threads. Wind the bobbin on the sewing machine.