Tokyo, Japan
Tokyo, Japan

Seikei University is a private university in the Kichijōji neighborhood of the city of Musashino, Tokyo, Japan. Its name derives from a passage in the Records of the Grand Historian by Sima Qian. Its campus is noted for its rows of zelkova trees. Wikipedia.


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Le H.,University of Cape Town | Van Eck J.,University of Cape Town | Takizawa M.,Seikei University
IEEE Transactions on Industrial Electronics | Year: 2013

A schedule-based approach, such as time division multiple access, is more efficient than a contention-based approach in terms of energy saving by switching sensors into sleeping mode. However, it does not use the transmission media effectively as each time slot is dedicated to a sensor and therefore cannot be used by others should it be idle. Moreover, a schedule-based approach requires a central node to manage and broadcast the schedule to other members, causing high delay and unscalability. On the other hand, contention-based protocols can be used in a distributed fashion. However, contention-based protocols such as IEEE 802.11 waste a lot of energy in idle listening. In this paper, we propose a hybrid approach between contention-and schedule-based protocols. The preliminary results using simulation and a test bed show that our proposed approach uses transmission media more efficiently, leading to lower delay while preserving energy for wireless sensor networks. © 2012 IEEE.


Hongo T.,Seikei University | Yamazaki A.,Waseda University
Microporous and Mesoporous Materials | Year: 2011

Mesoporous titania was synthesized using the evaporation-induced self-assembly method. The sample calcined at 300 °C had a wormhole-like structure with uniform mesopores consisting of TiO2(B). The sample calcined at 350 °C consisted of a mixed phase of TiO2(B) and anatase; however, the mesoporous structure showed little change compared with that of the sample calcined at 300 °C because the phase transition from TiO2(B) to anatase has a displasive phase transition mechanism with no atomic diffusion and accompanying no crystallite growth. When calcined above 400 °C, the mesoporous structure collapsed, and aggregates of anatase nanoparticles that were highly crystalline and had high specific surface area were obtained because the mesopores at several nm intervals inhibit anatase particle growth. Samples calcined at 300, 350, 400, and 450 °C showed 1.5, 2.4, 2.5, and 1.8 times higher photocatalytic activity than commercial titania P-25 in acetic acid decomposition. © 2010 Elsevier Inc.


Shinmura S.,Seikei University
Statistics, Optimization and Information Computing | Year: 2016

The discriminant analysis is not the inferential statistics since there are no equations for standard error (SE) of error rate and discriminant coefficient based on the normal distribution. In this paper, we proposed the "k-fold cross validation for small sample" and can obtain the 95% confidence interval (CI) of error rates and discriminant coefficients. This method is the computer-intensive approach by statistical and mathematical programming (MP) software such as JMP and LINGO. By the proposed approach, we can choose the best model with the minimum mean of error rate in the validation samples (Minimum M2 Standard). In this research, we examine the sixteen linear separable models of Swiss banknote data by eight linear discriminant functions (LDFs). M2 of the best model of Revised IP-OLDF is the smallest value of all models. We find all coefficients of six Revised IP-OLDF among sixteen models rejected by the 95% CI of discriminant coefficients (Discriminant coefficient standard). We compare t-values of the discriminant scores. The t-value of the best model has the maximum values among sixteen models (Maximum t-value Standard). Moreover, we can conclude that all standards support the best model of Revised IP-OLDF. © 2016 International Academic Press.


Takao K.,Seikei University | Bell T.J.,Tokyo Institute of Technology | Ikeda Y.,Tokyo Institute of Technology
Inorganic Chemistry | Year: 2013

This Forum Article provides an overview of the reported studies on the actinide chemistry in ionic liquids (ILs) with a particular focus on several fundamental chemical aspects: (i) complex formation, (ii) electrochemistry, and (iii) extraction behavior. The majority of investigations have been dedicated to uranium, especially for the 6+ oxidation state (UO2 2+), because the chemistry of uranium in ordinary solvents has been well investigated and uranium is the most abundant element in the actual nuclear fuel cycles. Other actinides such as thorium, neptunium, plutonium, americium, and curiumm, although less studied, are also of importance in fully understanding the nuclear fuel engineering process and the safe geological disposal of radioactive wastes. © 2012 American Chemical Society.


Enokido T.,Rissho University | Takizawa M.,Seikei University
Proceedings - International Conference on Advanced Information Networking and Applications, AINA | Year: 2012

The power consumption of information systems, especially servers has to be reduced to realize green eco-society. A client first selects a server in a collection of possible servers and issues a request to the server. The request is performed as a process in the server. In this paper, we consider a computation type of application where CPU resource is mainly used in a server. It is critical to discuss how to select a server for each request from clients in order to reduce the total power consumption. The power consumption laxity based (PCLB)algorithm for selecting a server is discussed in this paper, where a server to consume the minimum power to perform a process is selected. In a server, cooling devices like CPU fans consume the electronic power in addition to CPU and other devices. In our previous studies, we assume the cooling devices consume the constant power and propose the simple power consumption model. In the simple power consumption model, if at least one application process is performed on a server, the electric power is maximally consumed on the server. Otherwise, the electric power consumption is minimum. The rotation speed of a fan is controlled in servers based on the temperature of CPU and in the server's case. Thus, the total power consumption of a server depends on not only the power consumption of computational devices like CPU but also the power consumption of cooling devices like fans. In this paper, we extend the simple power consumption model to take into account the power consumption of cooling devices. We improve the PCLB algorithm based on the extended simple power consumption model. © 2012 IEEE.


Asano M.,Seikei University | Kato M.,University of Tokyo
Nuclear Physics B | Year: 2013

We propose a new gauge field theory which is an extension of ordinary string field theory by assembling multiple state spaces of the bosonic string. The theory includes higher-spin fields in its massless spectrum together with the infinite tower of massive fields. From the theory, we can easily extract the minimal gauge-invariant quadratic action for tensor fields with any symmetry. As examples, we explicitly derive the gauge-invariant actions for some simple mixed symmetric tensor fields. We also construct covariantly gauge-fixed action by extending the method developed for string field theory. © 2013 Elsevier B.V.


We propose a systematic procedure for extracting gauge invariant and gauge fixed actions for various higher-spin gauge field theories from covariant bosonic open string field theory. By identifying minimal gauge invariant part for the original free string field theory action, we explicitly construct a class of covariantly gauge fixed actions with BRST and anti-BRST invariance. By expanding the actions with respect to the level N of string states, the actions for various massive fields including higher-spin fields are systematically obtained. As illustrating examples, we explicitly investigate the level N≤3 part and obtain the consistent actions for massive graviton field, massive 3rd rank symmetric tensor field, or anti-symmetric field. We also investigate the tensionless limit of the actions and explicitly derive the gauge invariant and gauge fixed actions for general rank n symmetric and anti-symmetric tensor fields. © 2012 Elsevier B.V.


Enokido T.,Rissho University | Aikebaier A.,Seikei University | Takizawa M.,Seikei University
IEEE Transactions on Industrial Electronics | Year: 2011

Information systems are composed of various types of computers interconnected in networks. In addition, information systems are being shifted from the traditional clientserver model to the peer-to-peer (P2P) model. P2P systems are scalable and fully distributed without any centralized coordinator. Here, it is getting more significant to discuss how to reduce the total electric power consumption of computers in addition to developing distributed algorithms to minimize the computation time and memory space. In this paper, we do not discuss microlevel models like the hardware specifications of computers like low-energy CPUs. We rather discuss a macrolevel model to show the relation of the amount of computation and the total power consumption of multiple peer computers to perform Web types of application processes. We also discuss algorithms for allocating a process to a computer so that the deadline constraint is satisfied and the total power consumption is reduced. © 2010 IEEE.


Enokido T.,Rissho University | Takizawa M.,Seikei University
IEEE Transactions on Industrial Electronics | Year: 2011

Cyber engineering is getting more significant in not only manufacturing but also business applications. Information management technologies play a key role in cyber engineering. In order to realize the cyber engineering, objects in information systems are required to be not only secure but also consistent in the presence of security threats and multiple conflicting transactions. There are so far many discussions on each of the security management and concurrence control. However, there is no discussion on synchronization mechanisms to realize both of them. In this paper, we discuss a novel synchronization protocol to make an information system not only secure but also consistent. In the role-based access control model, authorized access requests are specified in roles which are collections of access rights. A transaction issued by a subject is assigned with a subfamily of the roles granted to the subjects, which are named purpose. We first define legal information flow relations among purposes. Based on the legal information flow relations, we discuss a purpose-marking (PM) protocol to prevent illegal information flow to occur by performing conflicting transactions in a serializable way. We evaluate the PM protocol in terms of the number of transactions to be aborted. © 2010 IEEE.


Enokido T.,Rissho University | Takizawa M.,Seikei University
IEEE Transactions on Industrial Electronics | Year: 2013

In order to realize green ecosocieties, the total electric power consumption of computers and networks is required to be reduced. In applications on distributed systems, clients issue service requests to servers and then servers send replies to clients. Here, we discuss how much electric power a server consumes since the power consumption of a client is neglectable compared with a server. We classify applications into transaction- and communication-based ones. A server mainly consumes CPU resources to perform the transaction-based applications. On the other hand, a server consumes communication resources to transmit a large volume of data to a client in communication-based applications. In our previous studies, the power consumption laxity-based and extended power consumption-based algorithms are proposed to select one of servers so that the total power consumption of servers is reduced for transaction- and communication-based applications, respectively. However, most applications are mixed types, i.e., composed of both the transaction and communication processing modules. Hence, we consider the mixed types of applications in this paper. First, we integrate the power consumption models of transaction- and communication-based applications into a modified simple power consumption (MSPC) model of a server. Based on the MSPC model, we propose an algorithm to select one of servers for mixed types of applications so that the total power consumption of servers can be reduced. We show the power consumption of servers can be reduced in the algorithm through the simulation. © 2012 IEEE.

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