受験番号：32IPE002

Q1
1. A cardiothoracic ratio calculation device for calculating a cardiothoracic ratio based on a chest
X-ray image, comprising:a measurement location estimation unit for estimating a rightmost lung location, a leftmost lunglocation, a rightmost heart location, and a leftmost heart location in the chest X-ray image; anda cardiothoracic ratio calculation unit for calculating a cardiothoracic ratio based on theestimated rightmost lung location, leftmost lung location, rightmost heart location, and leftmost
heart location,
wherein the measurement location estimation unit divides the chest X-ray image into a pluralityof horizontal regions and, for each horizontal region, detects a rightmost lung candidate and aleftmost lung candidate based on pixel values as well as a rightmost heart candidate and a leftmost
heart candidate based on a horizontal differential value of the pixel values, andwherein the measurement location estimation unit further extracts a specific horizontal region
based on a distance between a lung midpoint defined by the rightmost lung candidate and theleftmost lung candidate and a heart midpoint defined by the rightmost heart candidate and theleftmost heart candidate, or based on a ratio of this distance to a lung width defined by therightmost lung candidate and the leftmost lung candidate, and estimates the rightmost lungcandidate, the leftmost lung candidate, the rightmost heart candidate, and the leftmost heartcandidate in the extracted horizontal region as the rightmost lung location, the leftmost lunglocation, the rightmost heart location, and the leftmost heart location.
2. The cardiothoracic ratio calculation device according to Claim 1, wherein
the measurement location estimation unit detects
a location with the lowest pixel value in an area within a predetermined range from a rightmostedge of the horizontal area as the rightmost lung candidate, anda location with the lowest pixel value in an area within a predetermined range from a leftmostedge of the horizontal area as the leftmost lung candidate,assuming the higher an X-ray transmittance, the higher the pixel value.
3. The cardiothoracic ratio calculation device according to Claim 1 or 2, wherein
the measurement location estimation unit
detects a location with the largest differential value in negative direction between the rightmost
lung candidate and the leftmost lung candidate in the horizontal area as a rightmost heartcandidate, anddetects a location with the largest differential value in positive direction between the rightmost
lung candidate and the leftmost lung candidate in the horizontal area as the leftmost heartcandidate.

Q2
There is a conventionally known technology called blockchain. This technology is a mechanism
for synchronizing identical records among a multitude of nodes in a network. When a new record
is added to an existing record, blocks, which are units of record, are added one after another in achain-like fashion while inheriting the content (hash) of the previous block, hence the name. In
general, the term "blockchain" may refer to the structure of a database in which blocks areconnected in a chain, but it may also be used in a broader sense that also includes a mechanism for
operating as a P2P network, a mechanism for approving transactions, etc.

At present, thedefinition of the term is not clear. Therefore, in order to prevent confusion between the twodefinitions, this specification will refer to "blockchain" when used in the former, narrower sense,and "blockchain technology" when used in the latter, broader sense.
Since blockchain technology has many advantages such as zero downtime, being hard to tamper
with, and low cost, it is beginning to attract attention not only as a method for managing virtual
currencies including Bitcoin and its derivatives, but also as a method for managing information onvarious assets as transactions.

For example, Non-Patent Document 1 describes the use ofblockchain, which can play an important role in establishing trustworthiness, for a proof ofexistence and a proof of identity of various documents.
There are two main types of blockchain technology: a public node method and a private nodemethod. The public node method allows anyone to participate as a node in the network. On theother hand, the private node method allows only authorized persons to participate as nodes in thenetwork.

Q3<When a backfire occurs>
When a backfire R enters the burner 100 from the burner element 15, the heat of the backfire Rcauses the thermally expandable member 22 to thermally expand toward the inner circumferenceside, forming a thermally expandable member 222 with the opening 22H closed, as shown in Fig.
3(B).
As a result, the opening 22H of the thermally expandable member 222 (22) is blocked,
preventing the heat of the backfire R and the ultraviolet light L emitted by the flame F generated by

the burner element 15 from reaching the flame detection sensor 23.
In this embodiment, a control unit (not shown) is configured such that it determines, forexample, that the burner 100 is burning normally when the flame detection sensor 23 detects
ultraviolet light L, and determines that a backfire or misfire has occurred when the quantity of lightof the ultraviolet light L detected by the flame detection sensor 23 is below a set threshold(including zero).
As a result, when the burner 100 misfires and no longer emits ultraviolet light L, or when theflame detection sensor 23 no longer detects ultraviolet light L due to a thermal expansion of thethermally expandable member 22 as shown in Fig. 3(B), or when the quantity of light of thedetected ultraviolet light L is below the threshold value, it is judged that a misfire or a backfire has
occurred in the burner 100.