受験番号：28IPE001

問１[Claim 1]
A head mounted display device comprising:
an image generation unit configured to generate afirst image for displaying a first virtual image, and asecond image serving as a viewpoint guidance image fordisplaying a second virtual image for assisting viewpoint
movement of a user to the first virtual image;an image display unit configured to display the firstimage and the second image that are generated, and output
light for displaying the first image and the second image;a projection see-through optical unit disposed in
front of eyes of the user, the projection see-throughoptical unit including a first part for projecting, on theeyes of the user, the light for displaying the first image
and the second image, and a second part that allows theuser to see an actual view therethrough; anda control unit configured to control the image
generation unit.
[Claim 4]
The head mounted display device according to
any one of claims 1 to 3, wherein
the second virtual image is displayed near the first
virtual image on a virtual image display plane of the first
virtual image, andthe second virtual image is a virtual image of a
viewpoint guidance object serving as the viewpoint guidance
image and varying in at least one of hue, brightness, and aposition on the virtual image display plane over time.
[Claim 5]
The head mounted display device according toclaim 4, wherein
the viewpoint guidance object varies in the positionon the virtual image display plane, andwhere a first direction is a frontward direction of
the user, a second direction is a right-left direction thatis perpendicular to the first direction and along a line
connecting right and left eyes of the user, and a third
direction is an up-down direction that is perpendicular to
the first direction and the second direction and along a
vertical line, the control unit moves the second virtual
image along a part of an arc that is line-symmetric in thesecond direction so that a position in the second direction
and a position in the third direction of the second virtual
image both vary on the virtual image display plane.

問2
Conventionally, energy charging/discharging systems
are known which supply power from a storage battery of anelectric vehicle to a home appliance load or charge astorage battery of an electric vehicle from a householdcommercial power supply.
In a case of charging a storage battery of anelectric vehicle from a commercial power supply, such a
conventional charging/discharging system performs thecharging while converting an AC voltage to a predetermined
DC voltage by an electric-vehicle power conditioner
provided as residential equipment, that is, converting AC
power to DC power. On the other hand, in a case of
supplying power from a storage battery of an electricvehicle to a home appliance load, the charging/discharging
system supplies power to the home appliance load whileconverting a DC voltage (DC power) outputted from thestorage battery of the electric vehicle, to an AC voltage(AC power) by the electric-vehicle power conditioner. An
example of such energy charging/discharging systems having
electric-vehicle power conditioners is disclosed in Patent
Document 1.
Such an electric-vehicle power conditioner used inthe conventional charging/discharging systems having afunction of charging a storage battery of an electricvehicle is configured such that, in a case of executing adischarge operation for performing discharge of a storage
battery DC voltage from the storage battery of the electricvehicle, first, a communication process is executed between
the electric-vehicle power conditioner and an electricvehicle communication unit, and establishment of thecommunication process is requirements for starting thedischarge operation, for the reason described below.
Therefore, in a case where the communication process is notestablished, execution of the discharge operation isimpossible.
The reason why establishment of the communication
process is requirements for starting the discharge
operation is that applying a voltage to a charge/discharge
terminal of the electric vehicle in a state in which thecommunication process has not been established yet can leadto a dangerous situation in which electric shock or thelike occurs.
問３(A)One of problems of the gradient descent method isdifficulty in selecting the learning rate. If the learning
rate is selected to be low, the accuracy (correct answer
rate or error) of the DNN is not readily improved and thus
the learning process takes a long time. On the other hand,
if the learning rate is selected to be high, progress of
the learning at an initial stage is fast and thus the time
until a certain degree of accuracy is achieved can beshortened. However, the learning might fail during theprocess and thus the accuracy might not be improved any
longer while remaining greatly reduced (deteriorated) on
the contrary.
(A')

(B)
In some cases, during the learning, the accuracy of
the DNN is greatly improved initially, and thereafter, isdeteriorated gradually. In such a case, it might bepossible to avoid the gradual deterioration by reselecting
the learning rate.
FIG. 6 illustrates problems of the gradient descentmethod. The curve of the error E in FIG. 6 is the same asthat in FIG. 5, but in the example shown in FIG. 6, thelearning rate η is set to be higher than that in FIG. 5,and is constant. In FIG. 6, t indicates the time of alearning cycle, and W at each time t indicates the weightat the time t. The curve of the error E in FIG. 6 has apoint (weight W min ) at which the error E is minimized and alocal minimum point (weight W local ) at which the error E is
not minimized. The target is the weight W min that minimizes
the error E, and the weight W local is a weight that brings
the error E into a local solution. Minimization of theerror E means that the accuracy of output of the DNN
becomes the best. In the DNN for which an initial weightW 1 is set at time t=1, the gradient ∂E/∂w is negative andthe absolute value thereof is great. Therefore, a weightW 2 after update greatly moves in the positive direction(rightward direction) and the error function E(w 2 ) also
greatly decreases.
(B')