633 research outputs found
"A Factor Allocation Approach to Optimal Bond Portfolio"
This paper proposes a new method to a bond portfolio problem in a multi-period setting. In particular, we apply a factor allocation approach to constructing the optimal bond portfolio in a class of multi-factor Gaussian yield curve models. In other words, we consider a bond portfolio problem in terms of a factors' allocation problem. Thus, we can obtain clear interpretation about the relation between the change in the shape of a yield curve and dynamic optimal strategy, which is usually hard to be obtained due to high correlations among individual bonds. We first present a closed form solution of the optimal bond portfolio in a class of the multi-factor Gaussian term structure model. Then, we investigate the effects of various changes in the term structure on the optimal portfolio strategy through series of comparative statics.
"A Factor Allocation Approach to Optimal Bond Portfolio"
This paper proposes a new method to a bond portfolio problem in a multi-period setting. In particular, we apply a factor allocation approach to constructing the optimal bond portfolio in a class of multi-factor Gaussian yield curve models. In other words, we consider a bond portfolio problem in terms of a factors' allocation problem. Thus, we can obtain clear interpretation about the relation between the change in the shape of a yield curve and dynamic optimal strategy, which is usually hard to be obtained due to high correlations among individual bonds. We first present a closed form solution of the optimal bond portfolio in a class of the multi-factor Gaussian term structure model. Then, we investigate the effects of various changes in the term structure on the optimal portfolio strategy through series of comparative statics.
Term Structure of Interest Rates under Recursive Preferences in Continuous Time ( Revised in February 2008, subsequently published in "Asia-Pacific Financial Markets", Vol.15-3,4, 273-305. )
This paper proposes a testable continuous-time term-structure model with recursive utility to investigate structural relationships between the real economy and the term structure of real and nominal interest rates. In a representative-agent model with recursive utility and mean-reverting expectations on real output growth and inflation, this paper shows that, if (1) real short-term interest rates are high during economic booms and (2) the agent is comparatively risk-averse (less risk-averse) relative to time-separable utility, then a real yield curve slopes down (slopes up, respectively). Additionally, for the comparatively risk-averse agent, if (3) expected inflation is negatively correlated with the real output and its expected growth, then a nominal yield curve can slope up, regardless of the slope of the real yield curve.
Building Secure and Anonymous Communication Channel: Formal Model and its Prototype Implementation
Various techniques need to be combined to realize anonymously authenticated
communication. Cryptographic tools enable anonymous user authentication while
anonymous communication protocols hide users' IP addresses from service
providers. One simple approach for realizing anonymously authenticated
communication is their simple combination, but this gives rise to another
issue; how to build a secure channel. The current public key infrastructure
cannot be used since the user's public key identifies the user. To cope with
this issue, we propose a protocol that uses identity-based encryption for
packet encryption without sacrificing anonymity, and group signature for
anonymous user authentication. Communications in the protocol take place
through proxy entities that conceal users' IP addresses from service providers.
The underlying group signature is customized to meet our objective and improve
its efficiency. We also introduce a proof-of-concept implementation to
demonstrate the protocol's feasibility. We compare its performance to SSL
communication and demonstrate its practicality, and conclude that the protocol
realizes secure, anonymous, and authenticated communication between users and
service providers with practical performance.Comment: This is a preprint version of our paper presented in SAC'14, March
24-28, 2014, Gyeongju, Korea. ACMSAC 201
歯周組織構成細胞から産生される液性因子によるヒストン脱アセチル化酵素の発現および活性への影響
広島大学(Hiroshima University)博士(歯学)Doctor of Philosophy in Dental Sciencedoctora
Equivalence between definitions of the gravitational deflection angle of light for a stationary spacetime
The Gibbons-Werner-Ono-Ishihara-Asada method for gravitational lensing in a
stationary spacetime has been recently reexamined [Huang and Cao,
arXiv:2306.04145], in which the gravitational deflection angle of light based
on the Gauss-Bonnet theorem can be rewritten as a line integral of two
functions and . The present paper proves that the Huang-Cao line
integral definition and the Ono-Ishihara-Asada one [Phys. Rev. D 96, 104037
(2017)] are equivalent to each other, whatever asymptotic regions are. A remark
is also made concerning the direction of a light ray in a practical use of
these definitions.Comment: 4 pages, 1 figure, text improved, accepted for PR
Adversarial Patch Attacks on Monocular Depth Estimation Networks
Thanks to the excellent learning capability of deep convolutional neural
networks (CNN), monocular depth estimation using CNNs has achieved great
success in recent years. However, depth estimation from a monocular image alone
is essentially an ill-posed problem, and thus, it seems that this approach
would have inherent vulnerabilities. To reveal this limitation, we propose a
method of adversarial patch attack on monocular depth estimation. More
specifically, we generate artificial patterns (adversarial patches) that can
fool the target methods into estimating an incorrect depth for the regions
where the patterns are placed. Our method can be implemented in the real world
by physically placing the printed patterns in real scenes. We also analyze the
behavior of monocular depth estimation under attacks by visualizing the
activation levels of the intermediate layers and the regions potentially
affected by the adversarial attack.Comment: Publisher's Open Access PDF with the CC-BY copyright. Associated
video, data and programs are available at
https://www.fujii.nuee.nagoya-u.ac.jp/Research/MonoDepth
Games of Nim with Dynamic Restrictions
The authors present formulas for the previous player's winning positions of
two variants of restricted Nim.
In both of these two games, there is one pile of stones, and in the first
variant, we investigate the case that in k-th turn, you can remove f(k) stones
at most, where f is a function whose values are natural numbers. In the second
variant, there are two kinds of stones. The Type 1 group consists of stones
with the weight of one, and the Type 2 group consists of stones with the weight
of two. When the total weight of stones is a, you can remove stones whose total
weight is equal to or less than half of a
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