611 research outputs found
Prediction-based compensation for gate on/off latency during respiratory-gated radiotherapy
During respiratory-gated radiotherapy (RGRT), gate on and off latencies cause
deviations of gating windows, possibly leading to delivery of low- and
high-dose radiations to tumors and normal tissues, respectively. Currently,
there are no RGRT systems that have definite tools to compensate for the
delays. To address the problem, we propose a framework consisting of two steps:
1) multi-step-ahead prediction and 2) prediction-based gating. For each step,
we have devised a specific algorithm to accomplish the task. Numerical
experiments were performed using respiratory signals of a phantom and ten
volunteers, and our prediction-based RGRT system exhibited superior performance
in more than a few signal samples. In some, however, signal prediction and
prediction-based gating did not work well, maybe due to signal irregularity
and/or baseline drift. The proposed approach has potential applicability in
RGRT, and further studies are needed to verify and refine the constituent
algorithms.Comment: 12 pages, 12 figures, accepted by Computational and Mathematical
Methods in Medicin
Oligometastases: history and future vision of breast cancer
Oligometastases, oligo-recurrence, sync-oligometastases and metachronous oligometastases were proposed based on the spectrum theory. This review article, first, described the history of cancer theory. Second, we described the history of the concepts of oligometastases, oligo-recurrence and sync-oligometastases. Finally, we prospect future visions of breast cancer of oligometastases
THE MARXIAN OPTIMAL GROWTH MODEL, REPRODUCTION SCHEME, AND GENERAL LAW OF CAPITALIST ACCUMULATION
As Professor Okishio proved the existence of exploitation mathematically, the birth,
growth and death of capitalism should also be proved mathematically, and for this
purpose we formulated the so-called Marxian optimal growth model. This is not a model
in value-term because peoples' direct interest is not value itself but utility and
firms' interest is not value but profit. However, a very important finding of this
article is that such a non-value-term model can be translated into a value-term model,
and we introduce a value-term reproduction scheme from the Marxian optimal growth
model. In this form, we confirm that our model fulfills the conditions of simple reproduction
and extended reproduction. However, a more important fact we found is that this optimal
path shows (1) rising organic composition of capital, (2) falling rate of profit,
and (3) falling ratio of output of the first sector. The second fact contradicts the
Okishio Theorem, and the third contradicts Lenin.
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A Proof of Labor Theory of Value Based on Marginalist Principle
Because anti-Marxist's criticism against Fundamental Marxian Theorem (FMT) is based
on an assertion that this proof can be understood as a “natural-resources exploitation,”
if we assume, for example, “natural-resources theory of value,” we should prove not
only exploitation but also labor theory of value itself. Therefore, this article aims
to prove labor theory of value mathematically by focusing on the historically conditional
proportionality between labor input and amounts of products which is assumed in labor
theory of value. By this proof of the conditional proportionality, we show that marginalist
principle does not disturb labor theory of value in capitalism at all. Furthermore,
marginalist principle is important to show the labor process as a subjective optimization
process which is not by the sun but only by human beings. In this way, we use anti-Marxist's
marginal principle to object anti-Marxist criticism against labor theory of value.
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THE ONGOING WORLD CRISIS AS ALREADY EXPLAINED BY CAPITAL IN 1868 AND IMPERIALISM IN 1917
In Marxian economics there are two ways of explaining the current world economic crisis:
(1) the idea that the crisis was caused by the "failure of neo-liberalism"; (2) the
view that explains this crisis as a matter of business cycle. However/view (2) does
not explain why the crisis has become an incident of historical proportions, a so-called
"once-in-a-century" event. On the other hand, view (1) cannot explain the crisis as
the failure of capitalism itself. Differently from the above two explanations, this
article explains that the current crisis is the result of the advanced countries (particularly
the US), which have come to be faced with zero growth, tending to avoid difficult
changes and instead opting for easy solutions for better utilizing nonproductive sectors.
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Superstructure Determined by Base
Marxian economics recognizes productive activities as the nature of the human being, but human beings create other dimensions of activities through ideology, religion, culture, and politics. All these activities comprise a sort of superstructure. It is very important for us to discuss how the superstructure is determined by social base directly and indirectly. The discussion will be on state, ideologies, and human characteristics itself
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