Re recognition method, the meaning of the formula for calculating memory retention 30

Re-recognition: Randomly mix the items that have been learned with the items that have not been learned and present them to the participant, and ask the participant to indicate what has been learned and what has not been learned.

Retention (number of pairs, number of mistakes) (number of items learned, number of items not learned) 100%.

Amount of Saved (Percentage of items that have been recognized correctly) (Percentage of items that have not been learned incorrectly).

These two formulas are only different in form, but the essence is the same.

The meaning of this formula is that if the subject recognizes n wrong items that he has not learned, then there are also n correct items that he has learned correctly and guessed correctly, so the percentage of correctly guessed items should be subtracted from the percentage of correct items to be the percentage of items that have been truly recognized.

Forgetting the amount is the same as retaining the amount? This statement is not very clear. If you have learned 10 items, recognize 7 and deny 3; 10 items were not studied, 6 were negative, and 4 were recognized. Using both formulas, it's 30%. You can do the math for yourself.

If the number of pairs is the same as the number of errors, the amount of hold should be zero. If you recognize the number of mistakes, you will guess the number of logs. The above is my own understanding (not in the book), welcome to communicate.

The amount of memory retention can be solved by the signal detection theory. Memory retention (number of correct, number of mistakes) (number of items learned, number of items not learned) 100, that is, (hit correct rejection) (false negative, false report) (learned items, unlearned items). The amount saved (the percentage of items that have been correctly recognized) (the percentage of items that have not been learned that have been mistakenly recognized), i.e. hit the items that have been studied and falsely reported the items that have not been studied.

We can assume that the number of learned items and the number of unlearned items are both 10, the number of hits is 6, the number of false reports is 5, and the calculated answers are all is, so we can see that there is no essential difference between the two formulas themselves, but only the difference in expression methods.

The landlord explained very well, but the example was wrong, 10 new projects but 6 were correct, and 4 were wrong, so as to get 30% of the retention.

Simple, then remember a bunch of useless knowledge, keep the quantity equal to the useful knowledge, forget the useless...

It seems that the first one is already very good, so I won't repeat it.

The volume of the square timber is the volume, the formula is the length times the width by the height, and the volume of the log has a calculation formula:

The diameter of the log refers to the diameter after the bark is removed.

1. The formula for calculating the volume of log wood with a length of less than 2m and more than 10m is as follows:

v 2, the ruler is longer than or equal to 2m but less than or equal to 14 log volume calculation formula:

v 3, the ruler is longer than or equal to 2m, but greater than 14 of the volume of raw wood calculation formula:

v = v volume, unit: m3

d Ruler length, unit: m

l Ruler diameter, unit:

4. The volume of the log wood with a diameter of 4-6 retains four decimal places, and the volume of the log with a diameter of more than 8 retains three decimal places and is rounded.

When calculating, you only need to bring the ruler length and ruler diameter into the formula to get the volume.

Another way is that you go online and search for a sawn timber volume calculator or a log wood volume calculator to calculate the volume of wood very conveniently.

Memory Interpretation: bai

du1) Be able to recall things that you have known.

2) Psychological. Finger.

A kind of reflection of what has been experienced, including recognition (recognition and memory of the current thing), recognitization (recognition of the reappearance of the object), and reproduction (recall of the impression in the mind).

Memory is the human brain's recognition, retention, reproduction or recognition of things experienced, and it is the basis for high-level mental activities such as thinking and imagining. Human memory is related to changes in the structure of the brain's hippocampus, the chemistry inside the brain.

Memory, as a basic mental process, is closely related to other mental activities. Memory is connected to people's mental activities and is the basic function of people's study, work and life. The process of transforming abstract disorder into figurative order is the key to memory.

round (quantity calculation, 2).

This means that the result of the quantity calculation formula is rounded to two decimal places"Quantity calculation formula"It should refer to a defined value in your ** or parameter 2 in the formula, which refers to rounding to 2 decimal places.

The round function is a rounding function.

The round function is a function that intercepts the precision of the number, the first parameter is the number source, that is, the number you need to determine the precision, which can refer to the cell or be a formula; The second parameter is precision, 0 means that there are no decimal places for integers, 1 means that 1 decimal place is retained, 2 means 2 decimal places, and so on. -1 can also be used, which means that it is accurate to ten digits, and the single digit after ten digits is 0 (such as round(,-1)=1230); -2 indicates that it is accurate to the hundreds, and the tens and single digits after the hundred digits are 0 (for example, round(,-2)=1200), and so on.

round is the number rounded to the specified number of digits, for example, your first parameter is the number calculated by the formula, if it is, take the last two decimal places of the whole number, and the result will be.

This is a formula that retains two decimal places after calculating quantities. The formula is directly entered into the formula in parentheses after round, but the data in the formula should be assigned to the corresponding cell, and 2 refers to rounding the 3rd decimal place of the value.

Formula: the density of the sample ( = mass of the sample (mp) mass of the standard sand used (ms) density of the standard sand (ps));

The dry density of the specimen (d) = (mass of standard sand (ms) density of standard sand (ps)).

Note: —Moisture content of the sample, %.

1. According to the steps of digging the pit in the irrigation test, dig the test pit according to the size, weigh the quality of the sample, and determine the moisture content of the sample;

2. Fill the sand bottle with sand, close the valve, and weigh the total mass of the sand bottle, funnel and sand accurately, to 10g;

3. The density tester is placed upside down on the dug hole, and the valve is opened to inject sand into the test pit. It should not be shaken during the sand injection process. When the sand is filled with the test pit, close the valve, weigh the total mass of the sand bottle, funnel and residual sand accurately, accurate to 10g, and calculate the quality of the standard sand used to fill the test pit;

Select BAI

Sand filling bucket, calibrating the sand volume of the conical part of the tank sand tube, and calibrating the unit of sand in the sand filling cylinder.

plate quality, select the detection point, press the right substrate, fill the sand, calibrate the sand volume occupied by the gap between the substrate and the measuring point surface, record the data and clear it. Re-put the substrate on the measuring point, pit according to the substrate, ensure that the diameter of the pit is consistent with the substrate, the pit is deep to the surface of the next base layer and must not damage the surface of the lower layer, and the aggregate should be collected into a closed container at any time during the pit pit process, and care should not evaporate the water. A representative sample was taken to test the moisture content.

Clean the aggregates in the pit and collect them into containers and do not spill them. Place the sand filling cylinder, turn on the switch to fill the sand until the sand no longer flows out naturally, turn off the switch, remove the sand filling cylinder, measure the quality of the remaining sand in the cylinder and record it (in order to check whether the amount of sand in the test pit is accurate).

Calculate the wet density of the material in the planed foundation pit: p = (wet material mass mass of sand filling the test pit) * unit weight of sand.

Dry density = wet density (1 + water content).

Symbols are not easy to type, use words.

The relevant technical standards should include the operation and calculation of sand filling experiments.

Sand filling is only to calculate the volume of the sample, it is important to calculate the standard of the material.

Density. Expert. According to the regulations, when measuring the standard compactness, it must be ground into powder by the same kind of material, loaded into a container under the condition of the specified moisture content, and then tamped the standard sample with a weight hammer of the specified weight at the specified height and free fall for the specified number of times, and then dried and weighed as the standard weight, and compared with your sampling weight, the compaction index of sampling is obtained.

The amount of water used to measure the standard consistency of cement by the standard method is uncertain. When the constant water method is employed, the water consumption is determined. The amount of water used for mixing is accurate.

The water consumption of cement standard consistency is the consistency of cement slurry achieved under a certain water consumption and specific test, and this consistency and water consumption is the standard consistency of cement. Generally speaking, if the water consumption of cement standard consistency is small, the concrete unit water demand is less, the admixture is less, the strength is high, and the durability is better.

GBT1346-2001 Cement Standard Consistency Water Consumption Setting Time Stability Test Method This is the detection method of cement standard consistency water consumption, but it does not mention how many decimal places are accurate, and I have never seen it in other books.

If the calculation result is calculated, it should not be followed by a decimal point, and it should be accurate to the gram.

Leave one decimal place. When we measure the standard consistency of cement water, we weigh 500g of samples, and the accuracy of the water measuring device used is. When adjusting the amount of water, the habitual amount is taken as an integer, such as 124ml, the water requirement is 124ml, then the cement standard consistency water consumption of this cement (calculated as a percentage of cement mass) p=124 500x100%=.

Sometimes the amount is taken to the cement standard consistency of cement water consumption p= when measured with constant water volume: p (%) = s refers to the sinking depth (mm) For example, if the sinking is 28mm, then p = It seems that there is no explanation in the book, but in the large comparison of cement testing conducted across the country, keeping a single decimal place is the standard answer.

1. "Test Regulations for Cement and Cement Concrete in Highway Engineering" (JTG E30-2005).

a.The weight of the bar per meter (round bar) = the square of the diameter.

is the theoretical weight of the reinforcement of 10, and the diameter of 12 and below retains three decimal places;

Two decimal places are kept for diameters above 12; Rounding up to 6 when retained.

b.6 mm per meter weighs kilograms.

8 mm per meter weighs kilograms.

10 mm per meter weighs kilograms.

12 mm per meter weighs kilograms.

Weight calculation publicity: w*m*

For example, you buy 12 pieces of 20 and 6 meter rebar.

Weight per meter (kg) Diameter of rebar (mm) Diameter of rebar (mm) 6=

18=2kg

22=3kg