1. A circuit substrate comprising:
a base including a plurality of resin layers; and
conductive layers disposed on a lower and an upper surfaces of the base;
wherein the resin layers include first resin layers including a filler, and a second resin layer interposed between the first resin layers and having no filler or a filler whose amount is smaller than an amount of the filler in the first resin layer and 1 volume % or less,
wherein the first resin layer includes a base material and a resin portion, the base material is made of fibers, the resin portion includes a filler, and the resin portion of the first resin layer is interposed between the base material and the second resin layer, and
wherein the second resin layer includes a first concave portion and a first convex portion on an upper surface thereof and a second concave portion and a second convex portion on a lower surface thereof, the first concave portion corresponds to the second convex portion, and the first convex portion corresponds to the second concave portion.
2. The circuit substrate according to claim 1, wherein
the first and the second resin layers includes the same resin material.
3. The circuit substrate according to claim 1, wherein
a thickness of the second resin layer is smaller than that of the first resin layer.
4. The circuit substrate according to claim 1, wherein
the first resin layer formed on the upper surface of the second resin layer includes a resin portion and a base material including a protruding portion and a dent portion on a lower surface of the base material,
the first concave portion corresponds to the protruding portion, and
the first convex portion corresponds to the dent portion.
5. A structure comprising:
the circuit substrate according to claim 1, and
an electronic component electrically connected to the circuit substrate.
6. A circuit substrate comprising:
a base including a plurality of resin layers; and
conductive layers disposed on a lower and an upper surfaces of the base;
wherein the resin layers include first resin layers including a filler, and a second resin layer interposed between the first resin layers and having no filler or a filler whose amount is smaller than an amount of the filler in the first resin layer and 1 volume % or less,
wherein the first resin layer includes a base material and a resin portion, the base material is made of fibers, the resin portion includes a filler, and the resin portion of the first resin layer is interposed between the base material and the second resin layer, and
wherein the second resin layer is wavy.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method comprising:
receiving a request to communicate with a remote computer identified by a destination address;
comparing the destination address of the remote computer to a list of known safe destination addresses stored on a computing device;
updating a first persistence value associated with the destination address if the destination address does not match an entry in the list of known safe destinations, the first persistence value being indicative of the regularity at which the computing device communicates with the remote computer identified by the destination address;
comparing the updated first persistence value to a predetermined threshold value; and
generating an alert on the computing device if the updated first persistence value is greater than the threshold value.
2. The method of claim 1, wherein the first persistence value is equal to a number of time periods during which the computing device connected to the destination address over a total number of time periods.
3. The method of claim 2, further comprising retrieving a first time value, the first time value defining the length of a first observation window corresponding to a period of time over which the first persistence value is to be determined.
4. The method of claim 3, further comprising retrieving a second time value, the second time value defining the length of a first tracking window corresponding to a period of time during which connection to the destination address is monitored, wherein the first observation window includes a plurality of first tracking windows.
5. The method of claim 4, further comprising determining a total number of first tracking windows based on the first time value and the second time value.
6. The method of claim 5, wherein the first persistence value is defined as the ratio of (i) a first numerator value equal to the number of first tracking windows during which the destination address was connected to at least once and (ii) a first denominator value equal to the total number of first tracking windows of the first observation window.
7. The method of claim 6, wherein updating the first persistence value comprises increasing the first numerator value by one if the destination address has not previously been connected to during the current first tracking window.
8. The method of claim 7, further comprising retrieving a third time value, the third time value defining the length of a second observation window corresponding to a period of time over which a second persistence value is to be determined.
9. The method of claim 8, further comprising retrieving a fourth time value, the fourth time value defining the length of a second tracking window corresponding to a period of time during which connection to the destination address is monitored, wherein the second observation window includes a plurality of second tracking windows.
10. The method of claim 9, wherein the second persistence value is the ratio of (i) a second numerator value equal to the number of second tracking windows during which the destination address was connected to at least once and (ii) a second denominator value equal to the total number of second tracking windows of the second observation window.
11. The method of claim 1, wherein comparing the updated persistence value comprises comparing the updated persistence value to a predetermined threshold value in the range of 0.5 and 0.7.
12. The method of claim 1, wherein comparing the updated persistence value comprises comparing the updated persistence value to a predetermined threshold value of about 0.6.
13. The method of claim 1, wherein generating an alert comprises displaying the destination address to a user of the computing device.
14. The method of claim 13, further comprising adding the destination address to the list of known safe destination addresses in response to the user identifying the destination address as a safe destination address.
15. The method of claim 1, wherein generating an alert comprises stopping connection to the remote computer by the computing device.
16. A non transitory machine readable storage medium comprising a plurality of instructions, that in response to being executed, result in a computing device:
comparing a destination address identifying a remote computer to a list of known safe destination addresses stored on the computing device;
determining a length of a first time period and a length of a second time period, the first time period including a plurality of the second time periods,
updating a persistence value associated with the destination address if the destination address does not match an entry in the list of known safe destinations, the persistence value being equal to a ratio of the number of second time periods during which the computing device connected to the destination address at least once over the total number of second time periods of the first time period; and
generating an alert if the updated persistence value is greater than a threshold value.
17. The non transitory machine readable storage of claim 16, wherein updating the persistence value comprises increasing the numerator of the ratio by one if the destination address has not previously been connected to during the current second time period.
18. The non transitory machine readable storage of claim 16, further adding the destination address to the list of known safe destination addresses in response to the user identifying the destination address as a safe destination address.
19. The non transitory machine readable storage of claim 16, wherein generating an alert comprises generating an alert if the updated persistence value is greater than about 0.6.
20. A computing device comprising:
a processor; and
a memory device having stored therein a plurality of instructions, which when executed by the processor, cause the processor to:
compare a destination address of a remote computer to a list of known safe destination addresses stored on the computing device;
update a persistence value associated with the destination address if the destination address does not match an entry in the list of known safe destinations, the persistence value being indicative of the regularity at which the computing device communicates with the remote computer identified by the destination address; and
generate an alert if the updated persistence value is greater than a predetermined threshold value.