著者

Fumio HIAI

出版者

The Editorial Committee of the Interdisciplinary Information Sciences

雑誌

Interdisciplinary Information Sciences (ISSN:13409050)

巻号頁・発行日

vol.16, no.2, pp.139-248, 2010 (Released:2010-09-16)

参考文献数

80

被引用文献数

35 36

---

These lecture notes are concerned with several topics in matrix analysis covering the Löwner and Kraus theory on matrix/operator monotone and convex functions, the Kubo–Ando theory on operator means, spectral variation and majorization, and means for matrices. Matrix norm inequalities related to majorization and means for matrices are also discussed.

著者

Emmanuel Jesuyon DANSU Hiromi SENO

出版者

The Editorial Committee of the Interdisciplinary Information Sciences

雑誌

Interdisciplinary Information Sciences (ISSN:13409050)

巻号頁・発行日

vol.28, no.1, pp.75-93, 2022 (Released:2022-07-31)

参考文献数

24

被引用文献数

1

---

Mark Granovetter promoted the threshold model of social behavior in which the acceptance value of an action is determined by the proportion of a population that already accepted it. The model is about an individual embracing an idea once a sufficient number of people embrace it. In this paper, we propose a mathematically accurate population dynamics model based on Granovetter's idea for the spread of information in a population. Individual threshold values with respect to the acceptance of a piece of information are distributed throughout the population ranging from low (easily accepts information) to high (hardly accepts). Results from the mathematical analysis on our model show that critical values exist for initial knower population size, mean and variance of threshold values. These critical values are about the drastic difference in the proportion of the population that end up knowing the information, depending on respective features of the population according to the information spread.

著者

Masaaki HIGASHIJIMA Yujin WOO

出版者

The Editorial Committee of the Interdisciplinary Information Sciences

雑誌

Interdisciplinary Information Sciences (ISSN:13409050)

巻号頁・発行日

pp.2022.R.05, (Released:2022-12-27)

参考文献数

50

---

Refugee issues are among the most imminent and important problems facing modern societies. This review essay systematically reviews recent social scientific literature that quantitatively measures national refugee policies. In so doing, we compare several recent and prominent cross-national data sets on this topic, namely those constructed by de Haas, Natter, and Vezzoli (2015), Hatton (2016), Helbling et al. (2017), Blair, Grossman, and Weinstein (2022), and Savun (2022). We point to both the advantages and disadvantages of the respective data sets while providing suggestions on how to practically apply them and how to merge their scopes and perspectives in a more comprehensive manner in order to better fit researchers' and practitioners' scopes of interest. We conclude this article by suggesting future research agendas by highlighting the significance and feasibility of a compilation of a more extensive data set based on the existing ones.

著者

Yutaka SHIKANO

出版者

東北大学大学院情報科学研究科ジャーナル編集委員会

雑誌

Interdisciplinary Information Sciences (ISSN:13409050)

巻号頁・発行日

vol.23, no.1, pp.33-37, 2017 (Released:2017-03-31)

参考文献数

55

---

One-dimensional discrete-time quantum walks (DTQWs) can simulate various quantum and classical dynamics and have already been implemented in several physical systems. This implementation needs a well-controlled quantum dynamical system, which is the same requirement for implementing quantum information processing tasks. Here, we consider how to realize DTQWs by Dirac particles toward a solid-state implementation of DTQWs.

著者

Nurhadryani Yani Maslow Sebastian Yamamoto Hiraku

出版者

東北大学

雑誌

Interdisciplinary Information Sciences (ISSN:13409050)

巻号頁・発行日

vol.15, no.2, pp.211-222, 2009-08

被引用文献数

4

---

In recent years the Internet has changed dramatically. The 'Web 2.0' with its new technologies such as Twitter, Facebook, or YouTube is now an important tool for social-networking with significant implications for both, the online and offline realms of society and politics. At the same time, while the development of new information and communication technologies (ICTs) has advanced in an unprecedented speed, the spread of such technologies was accompanied with significant political changes in Indonesia since 1998, marking the collapse of the Suharto-regime and the move towards a democratic governance system. After more than three decades of authoritarian rule, 'democracy 1.0' has marked a fundamental reform process creating new political parties and allowing the free expression of opinion. While ICTs played a visible yet limited role in this transition process towards a mature democratic system, the role of 'Web 2.0' technologies is increasing, especially in election times facilitating the formation of public opinion while connecting citizens to the political process. In systematically analyzing the development of ICTs in Indonesia this study wishes to explain the role that new information technologies play in the political process of this country since 1998, while paying special attention to the most recent parliamentary and presidential elections of 2009. In studying the role of ICTs in political transformation processes and democratic development represents a widely unexplored question in the scholarship addressing the political developments in Southeast Asia. Therefore, this study attempts to address this important new field of research through taking a closer look at Indonesia while applying new theoretic insights generated from the discussion of the concepts of e-government, e-governance, and e-democracy and the links that bind them, online and offline.

著者

Kazunori D YAMADA Samy BALADRAM Fangzhou LIN

出版者

The Editorial Committee of the Interdisciplinary Information Sciences

雑誌

Interdisciplinary Information Sciences (ISSN:13409050)

巻号頁・発行日

vol.28, no.1, pp.95-105, 2022 (Released:2022-07-31)

参考文献数

40

被引用文献数

1

---

Thus far, we have experienced three artificial intelligence (AI) booms. In the third one, we succeeded in developing AI that partially surpassed human capabilities. However, we are yet to develop AI that, like humans, can perform a series of cognitive processes. Consciousness built into devices is called machine consciousness. Related research has been conducted from two perspectives: studying machine consciousness as a tool to elucidate human consciousness and achieving the technological goal of furthering AI research with conscious AI. Herein, we survey the research conducted on machine consciousness from the second perspective. For AI to attain machine consciousness, its implementation must be evaluated. Therefore, we only surveyed attempts to implement consciousness as systems on devices. We collected research results in chronological order and found no breakthroughs that could deliver machine consciousness soon. Moreover, there is no method to evaluate whether an implemented machine consciousness system possesses consciousness, thus making it difficult to confirm the certainty of the implementation. This field of research is a new frontier. It is an exciting field with many discoveries expected in the future.

著者

Takako ENDO Hikari KAWAI Norio KONNO

出版者

東北大学大学院情報科学研究科ジャーナル編集委員会

雑誌

Interdisciplinary Information Sciences (ISSN:13409050)

巻号頁・発行日

vol.23, no.1, pp.57-64, 2017 (Released:2017-03-31)

参考文献数

22

被引用文献数

2

---

This study is motivated by the previous work [14]. We treat 3 types of the one-dimensional quantum walks (QWs), whose time evolutions are described by diagonal unitary matrices except at one defected point. In this paper, we call the QW defined by diagonal unitary matrices, ``the diagonal QW'', and we consider the stationary distributions of general 2-state diagonal QW with one defect, 3-state space-homogeneous diagonal QW, and 3-state diagonal QW with one defect. One of the purposes of our study is to characterize the QWs by the stationary measure, which may lead to answer the basic and natural question, ``What are stationary measures for one-dimensional QWs?''. In order to analyze the stationary distribution, we focus on the corresponding eigenvalue problems and the definition of the stationary measure.

著者

Yusuke HIGUCHI Norio KONNO Iwao SATO Etsuo SEGAWA

出版者

東北大学大学院情報科学研究科ジャーナル編集委員会

雑誌

Interdisciplinary Information Sciences (ISSN:13409050)

巻号頁・発行日

vol.23, no.1, pp.75-86, 2017 (Released:2017-03-31)

参考文献数

23

被引用文献数

1

---

In this paper we discuss the periodicity of the evolution matrix of Szegedy walk, which is a special type of quantum walk induced by the classical simple random walk, on a finite graph. We completely characterize the periods of Szegedy walks for complete graphs, compete bipartite graphs and strongly regular graphs. In addition, we discuss the periods of Szegedy walk induced by a non-reversible random walk on a cycle.

著者

Masaaki HIGASHIJIMA Yujin WOO

出版者

The Editorial Committee of the Interdisciplinary Information Sciences

雑誌

Interdisciplinary Information Sciences (ISSN:13409050)

巻号頁・発行日

vol.29, no.2, pp.109-117, 2023 (Released:2023-07-14)

参考文献数

50

---

Refugee issues are among the most imminent and important problems facing modern societies. This review essay systematically reviews recent social scientific literature that quantitatively measures national refugee policies. In so doing, we compare several recent and prominent cross-national data sets on this topic, namely those constructed by de Haas, Natter, and Vezzoli (2015), Hatton (2016), Helbling et al. (2017), Blair, Grossman, and Weinstein (2022), and Savun (2022). We point to both the advantages and disadvantages of the respective data sets while providing suggestions on how to practically apply them and how to merge their scopes and perspectives in a more comprehensive manner in order to better fit researchers' and practitioners' scopes of interest. We conclude this article by suggesting future research agendas by highlighting the significance and feasibility of a compilation of a more extensive data set based on the existing ones.

著者

Masaki JUMONJI Hajime URAKAWA

出版者

The Editorial Committee of the Interdisciplinary Information Sciences

雑誌

Interdisciplinary Information Sciences (ISSN:13409050)

巻号頁・発行日

vol.14, no.2, pp.191-223, 2008 (Released:2008-08-30)

参考文献数

19

---

In this paper, we show new formulas on finite element method (FEM) and three dimensional FEM. By making use of them, we give several computer visions for the eigenvalue problems of the Laplacian for bounded domains and embedded compact surfaces in the three dimensional Euclidean space. As its applications, we can examine several examples to Yau’s problem on the eigenvalues between embedded surfaces and their enclosed three dimensional bounded domains.

著者

Ryuhei UEHARA

出版者

The Editorial Committee of the Interdisciplinary Information Sciences

雑誌

Interdisciplinary Information Sciences (ISSN:13409050)

巻号頁・発行日

pp.2022.R.06, (Released:2022-12-27)

参考文献数

112

被引用文献数

2

---

Since the 1930s, mathematicians and computer scientists have been interested in computation. While mathematicians investigate recursion theory, computer scientists investigate computational complexity based on Turing machine model to understand what a computation is. Beside them, there is another approach of research on computation, which is the investigation of puzzles and games. Once we regard the rules used in puzzles and games as the set of basic operations of computation, we can perform some computation by solving puzzles and playing games. In fact, research on puzzles and games from the viewpoint of theoretical computer science has continued without any break in the history of theoretical computer science. Sometimes the research on computational complexity classes has proceeded by understanding the tons of puzzles. The wide collection of complete problems for a specific computational complexity class shares a common property, which gives us a deep understanding of the class. In this survey paper, we give a brief history of research on computational complexities of puzzles and games with related results and trends in theoretical computer science.

著者

Yukihiro TSUTSUMI

出版者

The Editorial Committee of the Interdisciplinary Information Sciences

雑誌

Interdisciplinary Information Sciences (ISSN:13409050)

巻号頁・発行日

vol.9, no.1, pp.53-60, 2003 (Released:2003-06-04)

参考文献数

8

被引用文献数

5 6

---

A universal bound on the number of mutually disjoint non-parallel genus one Seifert surfaces for hyperbolic knots in non-Haken manifolds is given.

著者

ABE Koji TAKANE Shouichi SATO Sojun

出版者

東北大学

雑誌

Interdisciplinary Information Sciences (ISSN:13409050)

巻号頁・発行日

vol.21, no.2, pp.151-157, 2015

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Adding a sound to a certain environment is likely to be effective for design of impression there in acoustical point of view. However, until now, little is known about the effectiveness of additional sound on the change in impression. In order to investigate the effect of additional sound, an experiment was conducted by using three kinds of audio-visual materials offering three environments and five kinds of additional sounds. The audio-visual materials were respectively recorded at ``forest,'' ``park,'' and ``shopping street.'' They represent ``natural,'' ``artificial green,'' and ``urban'' environments, respectively. Five kinds of sound stimuli were respectively chosen as: ``bird singing,'' ``sound of stream,'' ``roaring of waves,'' ``traffic noise,'' and ``hum of voices.'' The former three stimuli are regarded as sounds in nature, while the latter two are regarded as artificial ones. The experiment was based on the method of paired comparison, consisting of the unprocessed original audio-visual material and that with one of the additional sounds. The subjects evaluated relative comfortableness and naturalness of each pair. Sound pressure level of the additional sound was controlled in order to discuss the influence of the loudness of the additional sound to the evaluation. The experimental results showed that the comfortableness was improved when the additional sound was `bird singing' or `sound of stream' categorized in the nature sound and its sound pressure level was a little lower than that at the original environment. Moreover, it was found out that the naturalness is degraded gradually for almost of the additional sound stimuli, as their sound pressure level is increased.

著者

Akihiro MUSA Yoshiei SATO Ryusuke EGAWA Hiroyuki TAKIZAWA Koki OKABE Hiroaki KOBAYASHI

出版者

The Editorial Committee of the Interdisciplinary Information Sciences

雑誌

Interdisciplinary Information Sciences (ISSN:13409050)

巻号頁・発行日

vol.15, no.1, pp.51-66, 2009 (Released:2009-03-25)

参考文献数

21

被引用文献数

2 3

---

Thanks to the highly effective memory bandwidth of the vector systems, they can achieve the high computation efficiency for computation-intensive scientific applications. However, they have been encountering the memory wall problem and the effective memory bandwidth rate has decreased, resulting in the decrease in the bytes per flop rates of recent vector systems from 4 (SX-7 and SX-8) to 2 (SX-8R) and 2.5 (SX-9). The situation is getting worse as many functions units and/or cores will be brought into a single chip, because the pin bandwidth is limited and does not scale. To solve the problem, we propose an on-chip cache, called vector cache, to maintain the effective memory bandwidth rate of future vector supercomputers. The vector cache employs a bypass mechanism between the main memory and register files under software controls. We evaluate the performance of the vector cache on the NEC SX vector processor architecture with bytes per flop rates of 2 B/FLOP and 1 B/FLOP, to clarify the basic characteristics of the vector cache. For the evaluation, we use the NEC SX-7 simulator extended with the vector cache mechanism. Benchmark programs for performance evaluation are two DAXPY-like loops and five leading scientific applications. The results indicate that the vector cache boosts the computational efficiencies of the 2 B/FLOP and 1 B/FLOP systems up to the level of the 4 B/FLOP system. Especially, in the case where cache hit rates exceed 50%, the 2 B/FLOP system can achieve a performance comparable to the 4 B/FLOP system. The vector cache with the bypass mechanism can provide the data both from the main memory and the cache simultaneously. In addition, from the viewpoints of designing the cache, we investigate the impact of cache associativity on the cache hit rate, and the relationship between cache latency and the performance. The results also suggest that the associativity hardly affects the cache hit rate, and the effects of the cache latency depend on the vector loop length of applications. The cache shorter latency contributes to the performance improvement of the applications with shorter loop lengths, even in the case of the 4 B/FLOP system. In the case of longer loop lengths of 256 or more, the latency can effectively be hidden, and the performance is not sensitive to the cache latency. Finally, we discuss the effects of selective caching using the bypass mechanism and loop unrolling on the vector cache performance for the scientific applications. The selective caching is effective for efficient use of the limited cache capacity. The loop unrolling is also effective for the improvement of performance, resulting in a synergistic effect with caching. However, there are exceptional cases; the loop unrolling worsens the cache hit rate due to an increase in the working space to process the unrolled loops over the cache. In this case, an increase in the cache miss rate cancels the gain obtained by unrolling.

著者

Hitoshi ARAI Shinobu ARAI

出版者

東北大学大学院情報科学研究科ジャーナル編集委員会

雑誌

Interdisciplinary Information Sciences (ISSN:13409050)

巻号頁・発行日

vol.13, no.2, pp.255-273, 2007-09-15 (Released:2007-09-18)

参考文献数

32

被引用文献数

2 2

---

As is well known in neuroscience, simple cells of the mammalian’s striate cortex possess both orientation and spatial-frequency selectivity, and are similar to the Gabor filters or Gaussian derivative filters in shape. The purpose of this paper is to propose a method of designing perfect reconstruction 2D filterbanks which act on finite dimensional linear spaces consisting of 2D signals of a certain size, and have several analogous features to simple cells: (1) the filterbanks consist of several spatial-frequency channels with orientation selectivity, (2) the filterbanks have shift-invariant multiresolution (multiscale) structures, (3) filters contained in them are FIR, and are similar in appearance to not only Gaussian derivatives of 1st and 2nd order, but also ones of higher order. Moreover, they are constructed by finite linear combinations of separable filters. As is described in the text, by virtue of these properties, our 2D filterbanks can become bases of constructing computational nonlinear models of visual information processing. In this paper we construct the 2D filterbanks, and discuss them from the viewpoint of vision science. For example we disclose a possible role of “Gaussian-derivative-like” filters of higher order in our filterbanks. Practical applications of our 2D filterbanks to vision science and image processing will be given in our subsequent papers.

著者

Norio KONNO Hideo MITSUHASHI Iwao SATO

出版者

東北大学大学院情報科学研究科ジャーナル編集委員会

雑誌

Interdisciplinary Information Sciences (ISSN:13409050)

巻号頁・発行日

vol.23, no.1, pp.9-17, 2017 (Released:2017-03-31)

参考文献数

14

---

We define the quaternionic quantum walk on a finite graph and investigate its properties. This walk can be considered as a natural quaternionic extension of the Grover walk on a graph. We explain the way to obtain all the right eigenvalues of a quaternionic matrix and a notable property derived from the unitarity condition for the quaternionic quantum walk. Our main results determine all the right eigenvalues of the quaternionic quantum walk by using complex eigenvalues of the quaternionic weighted matrix which is easily derivable from the walk. Since our derivation is owing to a quaternionic generalization of the determinant expression of the second weighted zeta function, we explain the second weighted zeta function and the relationship between the walk and the second weighted zeta function.

著者

Norio KONNO Yuki SHIMIZU Masato TAKEI

出版者

東北大学大学院情報科学研究科ジャーナル編集委員会

雑誌

Interdisciplinary Information Sciences (ISSN:13409050)

巻号頁・発行日

vol.23, no.1, pp.1-8, 2017 (Released:2017-03-31)

参考文献数

17

被引用文献数

5

---

The present paper treats the period TN of the Hadamard walk on a cycle CN with N vertices. Dukes (2014) considered the periodicity of more general quantum walks on CN and showed T2=2, T4=8, T8=24 for the Hadamard walk case. We prove that the Hadamard walk does not have any period except for his case, i.e., N = 2,4,8. Our method is based on a path counting and cyclotomic polynomials which is different from his approach based on the property of eigenvalues for unitary matrix that determines the evolution of the walk.

著者

Shimpei ENDO Takako ENDO Norio KONNO Etsuo SEGAWA Masato TAKEI

出版者

東北大学大学院情報科学研究科ジャーナル編集委員会

雑誌

Interdisciplinary Information Sciences (ISSN:13409050)

巻号頁・発行日

pp.2016.R.01, (Released:2016-03-25)

参考文献数

24

被引用文献数

6

---

We attempt to analyze a one-dimensional space-inhomogeneous quantum walk (QW) with one defect at the origin, which has two different quantum coins in positive and negative parts. We call the QW ``the two-phase QW with one defect'', which we treated concerning localization theorems. The two-phase QW with one defect has been expected to be a mathematical model of topological insulator which is an intense issue both theoretically and experimentally. In this paper, we derive the weak limit theorem describing the ballistic spreading, and as a result, we obtain the mathematical expression of the whole picture of the asymptotic behavior. Our approach is based mainly on the generating function of the weight of the passages. We emphasize that the time-averaged limit measure is symmetric for the origin , however, the weak limit measure is asymmetric, which implies that the weak limit theorem represents the asymmetry of the probability distribution.

著者

Ian G. GLEADALL M. Alejandro SALCEDO-VARGAS

出版者

東北大学大学院情報科学研究科ジャーナル編集委員会

雑誌

Interdisciplinary Information Sciences (ISSN:13409050)

巻号頁・発行日

vol.10, no.2, pp.113-142, 2004 (Released:2004-11-12)

参考文献数

116

被引用文献数

1 3

---

A catalogue of the extant specimens of recent Cephalopoda in the Museum of Tokyo University is here presented including 50 lots of recently designated type material, mostly from species described by Sasaki. Also identified are the specimens of many other species described by Sasaki in his monograph of 1929. An Appendix provides an English summary of a largely ignored nineteenth century list of the oldest specimens in the ZUMT collection, published in Japanese, for comparison with the present collection.

著者

Muhammad AAMIR Mustafa Ali ZAIDI

出版者

東北大学大学院情報科学研究科ジャーナル編集委員会

雑誌

Interdisciplinary Information Sciences (ISSN:13409050)

巻号頁・発行日

vol.19, no.2, pp.173-200, 2013 (Released:2013-11-22)

参考文献数

157

被引用文献数

1 21

---

Distributed Denial of Service (DDoS) attacks exhaust victim's bandwidth or services. Traditional architecture of Internet is vulnerable to DDoS attacks and an ongoing cycle of attack & defense is observed. A recent attack report of year 2013 –- `Quarter 1' from Prolexic Technologies identifies that 1.75 percent increase in total number of DDoS attacks has been recorded as compared to similar attacks of previous year's last quarter. In this paper, different types and techniques of DDoS attacks and their countermeasures are surveyed. The significance of this paper is the coverage of many aspects of countering DDoS attacks including new research on the topic. We survey different papers describing methods of defense against DDoS attacks based on entropy variations, traffic anomaly parameters, neural networks, device level defense, botnet flux identifications, application layer DDoS defense and countermeasures in wireless networks, CCN & cloud computing environments. We also discuss some traditional methods of defense such as traceback and packet filtering techniques, so that readers can identify major differences between traditional and current techniques of defense against DDoS attacks. We identify that application layer DDoS attacks possess the ability to produce greater impact on the victim as they are driven by legitimate-like traffic, making it quite difficult to identify and distinguish from legitimate requests. The need of improved defense against such attacks is therefore more demanding in research. The study conducted in this paper can be helpful for readers and researchers to recognize better techniques of defense in current times against DDoS attacks and contribute with more research on this topic in the light of future challenges identified in this paper.