受験番号：32PE012【問 1】
1. A cardiothoracic ratio calculating device for calculating a cardiothoracic ratio basedon a chest X-ray image, comprising:a measurement position estimator for estimating a position of a right edge of alung, a position of a left edge of a lung, a position of a right edge of a heart, and a positionof a left edge of a heart in the chest X-ray image; anda cardiothoracic ratio calculator for calculating the cardiothoracic ratio basedon the estimated position of the right edge of the lung, the estimated position of the leftedge of the lung, the estimated position of the right edge of the heart, and the estimatedposition of the left edge of the heart,
wherein the measurement position estimator divides the chest X-ray image into
a plurality of areas in a horizontal direction, and, for each area in the horizontal direction,
detects a candidate of a right edge of a lung and a candidate of a left edge of a lung basedon a pixel value, and detects a candidate of a right edge of a heart and a candidate of aleft edge of a heart based on a differential value in the horizontal direction of the pixel
value, andwherein the measurement position estimator selects a specific area of thehorizontal direction based on either a distance between a lung midpoint determined by
the candidate of the right edge of the lung and the candidate of the left edge of the lung,and a heart midpoint determined by the candidate of the right edge of the heart and thecandidate of the left edge of the heart, or a ratio of the distance to a width of a lungdetermined by the candidate of the right edge of the lung and the candidate of the leftedge of the lung, and estimates the candidate of the right edge of the lung, the candidateof the left edge of the lung, the candidate of the right edge of the heart, and the candidateof the left edge of the heart in the selected area of the horizontal direction to be theposition of the right edge of the lung, the position of the left edge of the lung, the positionof the right edge of the heart, and the position of the left edge of the heart.
2.

The cardiothoracic ratio calculating device according to claim 1, wherein
when the pixel value becomes higher as the transmission rate of the X-ray

becomes higher,
the measurement position estimator detects a position with the lowest pixelvalue within an area of a specific range from the right edge of the area in the horizontal
direction to be the candidate of the right edge of the lung, anddetects a position with the lowest pixel value within an area of a specific range
from the left edge of the area in the horizontal direction to be the candidate of the leftedge of the lung.
3.

The cardiothoracic ratio calculating device according to claim 1 or claim 2,wherein
the measurement position estimator detects a position having the largest
differential value in the negative direction between the candidate of the right edge of thelung and the candidate of the left edge of the lung in the area in the horizontal direction
to be the candidate of the right edge of the heart, anddetects a position having the largest differential value in the positive direction
between the candidate of the right edge of the lung and the candidate of the left edge ofthe lung in the area in the horizontal direction to be the candidate of the left edge of theheart.

【問 2】
There is a conventional technology known as block chain, which synchronizes
the same record between numerous nodes on a network. The term block chain is usedbecause when adding a new record onto an existing record, the recording unit block
succeeds the contents (hash) of the immediately preceding block, and blocks are added
successively like a chain. Generally, the term block chain refers to a database structure
where blocks are connected like chains; however, the term may also be used in a broader
sense, including a structure operating as a P2P network or a structure approving
transactions. Because the definition is unclear as of now, to avoid confusion between
the meanings, we will call the former “block chain” when referring to the narrower
definition, and the latter “block chain technology” when referring to the broader
definition in the present specification.
Block chain technology is starting to receive attention as a method to manage
not just virtual currencies including Bitcoins or its derivatives but also various asset
related information as transactions, because of its many merits such as zero downtime,difficulty in falsification, and low cost. For example, non-patent literature 1 discloses
using block chains that could play an important role in establishing authenticity to provethe existence of various documents or prove one’s identity.
Block chain technology mainly has a public node method and a private node
method. In the public node method, anyone can participate as a node on a network. Incontrast, in the private node method, only permissioned persons can participate as anode on a network.

【問 3】＜When a flashback occurs＞
As shown in Figure 3 (B), when a flashback R extends from the burner element
15, the heat-expandable unit 22 of the burner 100 thermally expands inwards to theinner circumference by the heat from flashback R. This forms a heat-expandable unit
222 that blocks the opening 22H.
This in turn blocks the opening 22H of the heat-expandable unit 222 (22), andprevents the heat from the flashback R and the ultraviolet light L emitted from the flame
F generated by the burner element 15 from reaching the flame detection sensor 23.
In this embodiment, for example, when the flame detection sensor 23 detects anultraviolet light L, the controller (not shown) is configured to determine that the burner
100 is operating properly, and when the flame detection sensor 23 detects the intensityof ultraviolet light L to be equal to or less than the threshold value or the intensity to bezero, the controller is configured to determine that there is a flashback or misfire.
Consequently, when the burner 100 misfires and does not emit ultraviolet lightL, or, as shown in Figure 3 (B), when the heat-expandable unit 22 thermally expands
and the flame detection sensor 23 fails to detect the ultraviolet light or the intensity ofthe detected ultraviolet light L is equal to or less than the threshold value, it isdetermined that the burner has misfired or has had a flashback.