受験番号：32IPE035

問１．
[Claim 1]
A cardiothoracic ratio calculation device that calculates acardiothoracic ratio on the basis of a chest X-ray image, thecardiothoracic ratio calculation device comprising:a measurement position estimation unit that estimates a lung rightend position, a lung left end position, a heart right end position, anda heart left end position in the chest X-ray image; anda cardiothoracic ratio calculation unit that calculates thecardiothoracic ratio on the basis of the estimated lung right end
position, lung left end position, heart right end position, and heart
left end position, wherein
the measurement position estimation unit divides the chest X-ray
image into a plurality of horizontal areas, detects, for each of thehorizontal areas, a lung right end candidate and a lung left end candidateon the basis of a pixel value, detects a heart right end candidate anda heart left end candidate on the basis of a differential value of thepixel value in a horizontal direction,
extracts a specific horizontal area on the basis of a distance
between a lung midpoint defined by the lung right end candidate and thelung left end candidate and a heart midpoint defined by the heart rightend candidate and the heart left end candidate or on the basis of a ratioof the distance to a lung width defined by the lung right end candidate
and the lung left end candidate, and estimates a lung right end candidate,a lung left end candidate, a heart right end candidate, and a heart left
end candidate in the extracted horizontal area to be the lung right end
position, the lung left end position, the heart right end position, andthe heart left end position, respectively.
[Claim 2]
The cardiothoracic ratio calculation device according to claim
1, wherein
when the pixel value increases as X-ray transmittance increases,
the measurement position estimation unit detects,
as the lung right end candidate, a position with the lowest pixelvalue in an area within a predetermined range from a right end of eachof the horizontal areas, andas the lung left end candidate, a position with the lowest pixel
value in an area within a predetermined range from a left end of eachof the horizontal areas.
[Claim 3]
The cardiothoracic ratio calculation device according to claim
1 or 2, wherein
the measurement position estimation unit detects,
as the heart right end candidate, a position where thedifferential value is largest in a negative direction between the lungright end candidate and the lung left end candidate in each of thehorizontal areas, andas the heart left end candidate, a position where the differential
value is largest in a positive direction between the lung right end
candidate and the lung left end candidate in each of the horizontal areas.
問２．
Conventionally, a technique called a blockchain is known. This
technique is a mechanism to synchronize the same record between many
nodes on the network, and is called so because, when a new record isadded to an existing record, a block as a recording unit is added one
after another in a chain while contents (hash) of the immediately
preceding block are inherited. In general, the term of blockchain may
refer to a structure of a database in which blocks are connected in achain, but may be used in a broad sense including a mechanism for operating
as a P2P network and a mechanism for transaction approval, and thedefinition of the term is not clear at this time. Therefore, in thisspecification, in order to prevent confusion between the two meanings,
the former used in the narrow sense is referred to as "blockchain", andthe latter used in the broad sense is referred to as "blockchaintechnology".
The blockchain technology has many advantages such as zero
downtime, tamper resistance, and low cost, and thus is beginning toattract attention not only as a virtual currency including Bitcoin andits derivative currencies, but also as a method for managing information

on various assets as transactions. For example, Non-Patent Document
1 describes that a blockchain that can play an important role inestablishing reliability is used for proof of existence and proof ofidentity of various documents.
The blockchain technology mainly has a public node method anda private node method.

The public node method is a method in which anyone

can participate as a node on the network. On the other hand, the private
node method is a method in which only those who are authorized canparticipate as nodes on the network.
問３．
<At the time of occurrence of flashback>In the burner 100, when the flashback R penetrates from the burnerelement 15, as shown in FIG. 3(B), the heat-expandable member 22
thermally expands toward the inner peripheral side due to the heat of
the flashback R, to form a heat-expandable member 222 in which the opening
22H is closed.
As a result, the opening 22H of the heat-expandable member 222(22) is closed, which prevents the heat of the flashback R and theultraviolet ray L emitted by the flame F generated by the burner element
15 from arriving at the flame detection sensor 23.
In this embodiment, a control unit (not shown) is configured todetermine that the burner 100 is burning normally, for example, when
the flame detection sensor 23 detects the ultraviolet ray L, anddetermines that a flashback or misfire has occurred when the amount of
the ultraviolet ray L detected by the flame detection sensor 23 is equal
to or less than a set threshold value (including zero).
As a result, when the burner 100 misfires and does not emit theultraviolet ray L, when the heat-expandable member 22 thermally expands
and the flame detection sensor 23 does not detect the ultraviolet rayL, as shown in FIG. 3(B), and when the amount of the detected ultraviolet
ray L is equal to or less than the threshold value, it is determinedthat a misfire or flashback has occurred in the burner 100.