受験番号：24IPE018問１）
1.

An alternating current welding device comprising:a welding controlling section;a storage section;an alternating current frequency setting section that sets analternating current frequency;
a reverse polarity period setting section that sets a reverse polarityperiod;a calculating section that calculates a positive polarity period and thereverse polarity period and outputs to the welding controlling section; anda selecting section that selects one among a plurality of outputs of thestorage section and outputs the selected one to the calculating section,
whereinthe welding controlling section passes a positive polarity base current
that is lower than a peak current during the positive polarity period before apolarity inversion happens when the positive polarity period is over, andpasses a reverse polarity base current that is lower than the peak current
during the reverse polarity period before a polarity inversion happens when
the reverse polarity period is over,the storage section(a) stores therein a plurality of types of combinations of apositive polarity base ratio that is a ratio of a period for passing the positive
polarity base current during the positive polarity period, and a reverse
polarity base ratio that is a ratio of a period for passing the reverse polarity
base current during the reverse polarity period, and(b) stores therein a plurality of types of combinations of apositive polarity peak period that is a period for passing the peak current
during the positive polarity period, a positive polarity base period that is aperiod for passing the positive polarity base current, a reverse polarity peak
period that is a period for passing the peak current in the reverse polarityperiod, and a reverse polarity base period that is a period for passing thereverse polarity base current, andthe selecting section selects one combination among the plurality of
combinations stored in the storage section based on an inductance on a

welding load side.

問２）
In a conventional monitoring system, for example, when a sensor isinstalled at a gate of a parking lot, a car is detected at the gate, a mobile
robot is caused to move to the gate where the sensor has been installed, animage obtained during the movement is processed, a body color of the car isdetermined, and information about the color is transmitted to a center. In
this case, it is desirable that the monitoring system acquires an image that
contains information that is useful for identifying the car.
However, the way a car is parked can vary depending on thecharacter of the thief, a status of the parking lot, and the like, and cannot bepredicted in advance. Therefore, it may be difficult for the mobile robot toacquire an image of a car that allows determination of the body color of thecar.
For example, when a visible-light color camera is used to acquire animage of a car and determine a body color of the car, the colors may bedifferent because of the sunlight in an image obtained during a day time andan image obtained in the evening, and even if the car is white, it may bedetermined to be orange from an image thereof acquired in the evening.
Besides, even during the night, depending on the lights installed in theparking lot and/or the lights from the electric signboards installed on theouter walls of the neighborhood commercial buildings, there is a drawbackthat the colors may appear different than when seen with human eyes.

問３）
When supercooling cancellation is detected, a food temperature Th_2
just after the supercooling cancellation is equivalent to a freezing point of thefood. Based on this temperature, a target temperature Tc_set in a chilled
room lower vessel is set to a temperature at which ice crystals will melt to an
extent where the cells will not be damaged, for example, to Th_2+2 [℃] (S9).
Note that an inside set temperature at which ice crystals will melt to anextent where the cells will not be damaged is referred to as an ice-crystal
melting inside temperature.

Subsequently, when the melting of the ice crystals generated in thefood is finished and the food temperature begins to rise, for example, until
the food temperature Th rises to a temperature Th_2+1 [℃] that is lower
than the ice-crystal melting inside temperature and at which the melting of
the ice crystal can be determined, the target temperature Tc_set of thechilled room lower vessel is maintained at Th_2+2 [℃] (S10). To achieve
this state, for example, a closed state of a damper is maintained leading torising of the temperature in the chilled room lower vessel. When the foodtemperature Th after the supercooling cancellation crosses Th_2+1 [℃], theconfirmation of presence/absence of the supercooling implementation and thesupercooling cancellation is continued again by the control at S1 to S8.