受験番号：24IPE002問１）
1.

An alternating current arc welding device comprising:a welding controller;a storage unit;
an alternating current frequency setting unit for setting an alternating currentfrequency;
a reverse polarity period setting unit for setting a reverse polarity period;a calculation unit for calculating a positive polarity period and a reverse
polarity period to output the calculated positive polarity period and the calculated
reverse polarity period to the welding controller; anda selection unit for selecting an output from among a plurality of outputs fromthe storage unit to output the selected output to the calculation unit,
wherein the welding controller is configured to conduct, before a polarity
inversion occurs at which the positive polarity period ends, a positive polarity basecurrent that is lower than a peak current during the positive polarity period, andconducts, before a polarity inversion occurs at which the reverse polarity period ends, areverse polarity base current that is lower than a peak current during the reverse
polarity period,
the storage unit is configured to(a) store a plurality of combinations of, in the positive polarity period, a positive polarity
base ratio that is a ratio of a period during which the positive polarity base current isconducted and, in the reverse polarity period, a reverse polarity base ratio that is a ratioof a period during which the reverse polarity base current is conducted, or,(b) store a plurality of combinations of, in the positive polarity period, a positive polarity
peak period that is a period during which the peak current is conducted, and a positive
polarity base period that is a period during which the positive polarity base current isconducted, and, in the reverse polarity period, a reverse polarity peak period that is aperiod during which a peak current is conducted, and a reverse polarity base period thatis a period during which the reverse polarity base current is conducted, andthe selection unit is configured to select, based on an inductance on a welding
load side, a combination from among the plurality of combinations stored in the storage
unit.

問２）
（Ａ）
A conventional monitoring system is capable of, for example, when a sensor isinstalled on a gate of a parking lot, detecting a vehicle at the gate, causing a mobilerobot to move to the gate on which the sensor is installed, processing an image captured
and obtained during the mobile robot is moving to the gate, determining a vehicle colorof the vehicle, and sending information on the vehicle color to a center. At this time, itis advantageous that monitoring system captures the image including information
useful for identifying the vehicle.
However, it is difficult to estimate beforehand how a vehicle will be parked because acharacter of a thief and a situation of a parking lot might differ. Therefore, the mobile
robot sometimes faces difficulty in capturing an image of a vehicle with which a vehiclecolor of the vehicle can be identified.
For example, even when a color visible light camera is used to capture an image of avehicle to determine a vehicle color, there would be a difference in color due to sunlightbetween an image captured in a daytime and an image captured at dusk, and, even if avehicle color of a vehicle is white, the vehicle color would likely be determined as orange
with an image captured at dusk.

Further, even in a nighttime, depending on anillumination apparatus installed in a parking lot, or depending on light components
from an illuminated advertising apparatus installed on an outer wall of a nearby
commercial building, a color would have an impression that differs from an impression
when a human sees an identical object.
（Ａ）’問３）（Ｂ）
Upon a cancellation of overcooling is detected, a temperature Th_2 of a food productimmediately after the cancellation of overcooling corresponds to a freezing point of thefood product.

Based on this temperature, a target temperature Tc_set in a vessel

under a chilled room is set to a temperature at which an ice crystal can be melted to an
extent that there will be no cell damage, for example, Th_2+2 [°C] (S9). An inside set
temperature at which an ice crystal can be melted to an extent that there will be no cell
damage is referred to as an ice crystal melting set temperature.
Next, at a time when an ice crystal generated in the food product has been melted,
and a temperature of the food product starts to rise, the target temperature Tc_set inthe vessel under the chilled room is kept to Th_2+2 [°C] until, for example, atemperature Th of the food product rises to a temperature Th_2+1 [°C] that is lower
than the ice crystal melting set temperature and that is used for determining that anice crystal is melted (S10). To form this state, for example, a dumper is kept fully
closed to allow a temperature in the vessel under the chilled room to rise. Upon thetemperature Th of the food product after the cancellation of overcooling reaches Th_2+1[°C] or higher, a control from S1 to S8 is kept continued to confirm whether an
introduction of overcooling and a cancellation of overcooling are present.
（Ｂ’）