受験番号：32IPE007

問１．
1.

A cardiothoracic ratio calculation device for calculating a cardiothoracic ratio

based on a chest X-ray image, the cardiothoracic ratio calculation device comprising:a measurement position estimating unit configured to estimate a lung rightedge position, a lung left edge position, a heart right edge position, and a heart left edge
position in the chest X-ray image; anda cardiothoracic ratio calculating unit configured to calculate the cardiothoracic
ratio based on the estimated lung right edge position, lung left edge position, heart rightedge position, and heart left edge position, wherein
the measurement position estimating unit divides the chest X-ray image into aplurality of transverse regions and, for each of the plurality of transverse regions,detects a lung right edge candidate and a lung left edge candidate based on a pixel value
and detects a heart right edge candidate and a heart left edge candidate based on ahorizontal-directional derivative of a pixel value,
the measurement position estimating unit further extracting a particulartransverse region of the plurality of transverse regions based on a distance between alung intermediate point defined by the lung right edge candidate and the lung left edge
candidate and a heart intermediate point defined by the heart right edge candidate andthe heart left edge candidate, or a ratio of the distance to a lung width defined by thelung right edge candidate and the lung left edge candidate, and estimating the lungright edge candidate, the lung left edge candidate, the heart right edge candidate, andthe heart left edge candidate in the extracted particular transverse region as the lungright edge position, the lung left edge position, the heart right edge position, and theheart left edge position, respectively.
2.

The cardiothoracic ratio calculation device according to claim 1, wherein
when a larger pixel value indicates a higher degree of X-ray transmittance,
the measurement position estimating unit detects, as the lung right edge

candidate, a position at which the pixel value is smallest in a region within apredetermined range from a right edge of the transverse region, and detects, as the lungleft edge candidate, a position at which the pixel value in smallest in a region within apredetermined range from a left edge of the transverse region.
3.

The cardiothoracic ratio calculation device according to claim 1 or 2, whereinthe measurement position estimating unit detects, as the heart right edge
candidate, a position at which the derivative is largest in a negative direction between
the lung right edge candidate and the lung left edge candidate in the transverse region,and detects, as the heart left edge candidate, a position at which the derivative islargest in a positive direction between the lung right edge candidate and the lung leftedge candidate in the transverse region.

問２．
A technology called “blockchain” is conventionally known. This technology
provides a way of synchronizing identical records between a plurality of nodes on anetwork. When a new record is added to existing records, a block being one record unit
is added to the other blocks like a chain while inheriting the content (hash) of theprevious block, hence the name “blockchain”. While the term “blockchain” is used torefer to the structure of a database in which blocks are linked in the form of a chain, it
can also have a broader meaning to include a system that operates as a P2P network
and a system for approving transactions. At present, the term “blockchain” generally
does not have a clear definition. Herein, in order to avoid confusion, “blockchain” is used
when intending the narrow meaning above, while “blockchain technology” represents
the wider meaning encompassing other systems.
Blockchain technology affords many benefits such as zero downtime, difficultyof forging data, and low costs. Therefore, blockchain technology has started to gain
attention as a method of managing transactions for not only virtual currency including
Bitcoin and other cryptocurrencies based on Bitcoin but also various asset-related
information. For example, Non-Patent Document 1 describes that blockchain plays animportant role in ensuring reliability and is used to prove the existence and identity ofvarious documents.
Blockchain technology mainly employs two methods being a public node
method and a private node method. The public node method is a method that allows
anyone to participate as a node on the network, while the private node method is amethod where only permitted persons can participate as a node on the network.
問３．
When Backfire Occurs
In the burner 100, when the backfire R enters from the burner element 15, heatof the backfire R causes the thermal expansion members 22 to thermally expand inwardas illustrated in FIG. 3(B), thereby forming the thermal expansion member 222 thatcloses the opening 22H.
As a result, heat of the backfire R and the ultraviolet light L emitted by theflame F generated by the burner element 15 are suppressed from reaching the flame
detection sensor 23 because the opening 22H is closed by the thermal expansion
member 222 (22).
In this embodiment, a control unit (not shown) is configured to determine thatthe burner 100 is burning normally when, for example, the flame detection sensor 23
detects the ultraviolet light L, and determine that backfire or loss of flame has occurred
when the quantity of the ultraviolet light L detected by the flame detection sensor 23 isless than or equal to a set threshold value (including zero).
Thus, if the quantity of the detected ultraviolet light L is less than or equal tothe threshold value, such as when the burner 100 loses its flame and no longer emits
the ultraviolet light L or when the thermal expansion member 22 thermally expands
and the flame detection sensor 23 no longer detects the ultraviolet light L as illustrated
in FIG. 3(B), the control unit determines that loss of flame or backfire has occurred in
the burner 100.