In this work, fluctuation patterns of ReRAM current are classified automatically by proposed fluctuation pattern classifier (FPC). FPC is trained with artificially created dataset to overcome the difficulties of measured current signals, including the annotation cost and imbalanced data amount. Using FPC, fluctuation occurrence under different write conditions is analyzed for both HRS and LRS current. Based on the measurement and classification results, physical models of fluctuations are established.

The modeling of random telegraph noise (RTN) of MOS transistors is becoming increasingly important. In this paper, a novel method is proposed for realizing automated estimation of two important RTN-model parameters: the number of interface-states and corresponding threshold voltage shift. The proposed method utilizes a Gaussian mixture model (GMM) to represent the voltage distributions, and estimates their parameters using the expectation-maximization (EM) algorithm. Using information criteria, the optimal estimation is automatically obtained while avoiding overfitting. In addition, we use a shared variance for all the Gaussian components in the GMM to deal with the noise in RTN signals. The proposed method improved estimation accuracy when the large measurement noise is observed.

We propose FuzzyCoop, a cooperative MAC layer protocol employing a fuzzy logic partner selection algorithm. The protocol is based on the Distributed Coordination Function (DCF) protocol used in the IEEE 802.11 standard. There are three inputs to the fuzzy system: the Signal to Noise Ratio (SNR), the error ratio between two neighbors and the time the most recent packet was received from a neighbor. The fuzzy output is the partnership probability of a neighboring terminal. Besides, we introduce a cooperation incentive to the stations by providing them with the right to transmit their own data without contention after a successful cooperation. The protocol is evaluated through extensive simulations in different scenarios and is compared to the DCF protocol and a previously proposed cooperative protocol. Simulation results show that FuzzyCoop improves the performances of a wireless network and provides a more robust partner selection scheme.

The public safety spectrum is generally under-utilized due to the unique traffic characteristics of bursty and mission critical. This letter considers the application of dynamic spectrum access (DSA) to the combined spectrum of public safety (PS) and commercial (CMR) users in a common shared network that can provide both PS and CMR services. Our scenario includes the 700 MHz Public/Private Partnership which was recently issued by the Federal Communications Commission. We first propose an efficient DSA mechanism to coordinate the combined spectrum, and then establish a call admission control that reflects the proposed DSA in a wideband code division multiple access based network. The essentials of our proposed DSA are opportunistic access to the public safety spectrum and priority access to the commercial spectrum. Simulation results show that these schemes are well harmonized in various network environments.

In this paper we show some new look at large deviation theorems from the viewpoint of the information-spectrum (IS) methods, which has been first exploited in information theory, and also demonstrate a new basic formula for the large deviation rate function in general, which is expressed as a pair of the lower and upper IS rate functions. In particular, we are interested in establishing the general large deviation rate functions that are derivable as the Fenchel-Legendre transform of the cumulant generating function. The final goal is to show, under some mild condition, a necessary and sufficient condition for the IS rate function to be derivable as the Fenchel-Legendre transform of the cumulant generating function, i.e., to be a rate function of Gartner-Ellis type.

Cooperation can increase the system performance by obtaining the spatial diversity. While most of the present works concentrate on the analysis of the cooperation based on the inter-user channel response and developing a scheme for higher cooperative diversity, in this paper, we focus on practical resource allocation in OFDMA systems. Since the user who uses the same center frequency can not receive the signal when transmitting, this constraint should be considered to apply the cooperation to OFDMA systems. In this paper, we propose the pair-based OFDMA frame structure that overcomes this constraint. Also in this frame structure to achieve the minimum outage probability of system, we select the best partner among the candidate neighbors and allocate the suitable subchannels to bandwidth requested users through a cooperative subchannel allocation (CSA) algorithm. In order to evaluate the proposed resource allocation scheme, we carry out simulations based on IEEE 802.16e. The simulation results show that our proposed algorithm offers smaller outage probability than one based on non-cooperative communications and we get the minimum outage probability when a threshold for selection of candidate neighbors is 10 dB. We analyze that these results can be achieved by helping users located around the edge of the cell.

Accurate extraction of the trap position in the oxide in deep-submicron MOSFET by RTN measurement has been investigated both theoretically and experimentally. The conventional equation based on the ratio of emission time and capture time ignores two effects, that is, the poly gate depletion effect and surface potential variation in strong inversion regime. In this paper, by including both of the two effects, we have derived a new equation which gives us more accurate information of the trap depth from the interface and the trap energy. With experimental result, we compare the trap depth obtained from the new equation and that of the conventional method.

This paper describes the formation of ultra-thin tantalum oxide capacitors, using rapid thermal nitridation (RTN) of the storage-node polycrystalline-silicon surface prior to low-pressure chemical vapor deposition of tantalum oxide, using penta-ethoxy-tantalum [(Ta(OC2H5)5) and oxygen gas mixture. The films are annealed at 600-900 in dry O2 atmosphere. Densification of the as-deposited film by annealing in dry O2 is indispensable to the formation of highly reliable ultra-thin tantalum oxide capacitors. The RTN treatment reduces the SiO2 equivalent thickness and leakage current of the tantalum oxide film, and improves the time dependent dielectric breakdown characteristics of the film.

Japan's PARTNERS Project, one of the programmes of ISY advocated by UN, has just started. This letter is a brief introduction of the trials being carried out by the partners in the University of Electro-communications under the Project. The focus is on the distance education and training via ETS-V overcoming the geographical extent and the cultural diversity of the Asia-Pacific Region.