受験番号：28IPE008

問 1.
[Claim 1]
A head mount display device comprising:
an image generating unit configured to generate a first image for displaying afirst virtual image and a second image as an eye point guidance image for displaying asecond virtual image, the second virtual image being adapted to be used in assisting inmoving an eye point of a user toward the first virtual image;an image display unit configured to display the generated first and second
images and output display light beams of the first and second images;
a perspective projection optical unit arranged ahead of eyes of the user, theperspective projection optical unit including a first portion and a second portion, thefirst portion being configured to project the display light beams of the first and second
images onto the eyes of the user, the second portion being adapted to allow the user to
see through a real view; anda control unit configured to control the image generating unit.
[Claim 4]
The head mount 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 screen for the first virtual image, andthe second virtual image is a virtual image of an eye point guidance object
serving as the eye point guidance image, at least one of a color, luminance, or a positionon the virtual image display screen of the eye point guidance object being adapted tochange with time.
[Claim 5]
The head mount display device according to claim 4, wherein when theposition on the virtual image display screen of the eye point guidance object changes,
provided that a front direction of the user is a first direction, a left-right direction that isorthogonal to the first direction and is along a line segment connecting left and righteyes of the user is a second direction, and an up-down direction that is orthogonal toeach of the first and second directions and is along a vertical line is a third direction, thecontrol unit is configured to move the second virtual image along a part of an arc that is1

line-symmetrical in the second direction so that positions of the second virtual image inboth the second direction and the third direction change on the virtual image display
screen.
問 2.
Conventionally, there is known an energy charge and discharge system that
supplies power to a household load from a storage battery of an electric vehicle orcharges a storage battery of an electric vehicle from a commercial power supply forhousehold use.
When charging a storage battery of an electric vehicle from a commercial
power supply, the conventional charge and discharge system performs charging by
converting an AC voltage into a predetermined DC voltage using a power conditioner
for electric vehicles provided as home equipment, that is, converting AC power into DC
power. Conversely, when supplying power to a household load from a storage batteryof an electric vehicle, the conventional charge and discharge system supplies power tothe household load by converting a DC voltage (DC power) output from the storage
battery of the electric vehicle into an AC voltage (AC power) using the power
conditioner for electric vehicles. As an energy charge and discharge system havingsuch a power conditioner for electric vehicles, a charge and discharge system disclosed
in Patent Literature 1 is known, for example.
When the power conditioner for electric vehicles, which is used in theconventional charge and discharge system having a function of charging storage
batteries of electric vehicles, is caused to execute a discharge operation of releasing a
DC voltage from a storage battery of an electric vehicle, the power conditioner forelectric vehicles first executes a communication process with an electric vehicle, andestablishment of the communication process is used as a requirement to start theaforementioned discharge operation for the following reasons. Therefore, when thecommunication process fails, the discharge operation cannot be executed.
The establishment of the communication process is used as a requirement tostart the discharge operation because if a voltage is applied across the charge anddischarge terminals of the electric vehicle without the establishment of thecommunication process, there is a risk that dangerous conditions, such as electricshocks, may occur.
問 3.
(A)
2

One of the problems of the gradient descent method lies in its difficulty inselecting the learning rate. For example, selecting a low learning rate cannot improve
the accuracy (i.e., correct rate or errors) soon, and thus results in a long learning process.
Meanwhile, setting a high learning rate can expedite the progress of the initial learningand thus can shorten the time until a given accuracy level is reached. However, there
is a possibility that the learning may fail during the course of the process, which canresult in significantly decreased (deteriorated) accuracy, and the accuracy may remain
unimproved in some cases.
(A')(B)
In addition, there are also cases where the accuracy of DNN significantly
improves in the initial stage of learning, but then deteriorates gradually. Even in sucha case, reselecting the learning rate may be able to avoid such a circumstance.
Fig. 6 illustrates the problems of the gradient descent method. A curved lineof an error E in Fig. 6 is the same as that in Fig. 5, but in the example of Fig. 6, thelearning rate η is set higher than that in Fig. 5 and is also constant. In Fig. 6, symbol tindicates the time of the learning cycle, and symbol W at each time t indicates theweight at the time t. The curved line of the error E in Fig. 6 includes a point at which
the error E is the minimum (weight W min ) and a point at which the error E is ultrasmall(weight W local ), though it is not minimum. A target weight is the weight W min forminimizing the error E, and the weight W local is the weight for bringing the error E into
the local solution. Minimizing the error E corresponds to maximizing the output
accuracy of DNN. In DNN in which the initial weight W 1 at time t = 1 is set, thegradient ∂E/∂w is negative and the absolute value is large. Therefore, the updated
weight W 2 greatly shifts in the positive direction (rightward), and the error function
E(W 2 ) also decreases significantly.
(B’)

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