In this letter, we present a route discovery protocol for ad hoc multi-hop cellular networks which uses directional information towards the base station. The proposed protocol, based on the reactive approach, reduces flooding as much as possible. To quantify this, we analyze its performance in terms of how much progress it makes per hop and how much reduction in routing packet number it achieves per route discovery. The analytical, as well as simulation, results demonstrate that the proposed protocol significantly reduces flooding overheads and finds a route to the base station in a robust manner.

This paper proposes an efficient fingerprint recognition algorithm combining phase-based image matching and feature-based matching. In our previous work, we have already proposed an efficient fingerprint recognition algorithm using Phase-Only Correlation (POC), and developed commercial fingerprint verification units for access control applications. The use of Fourier phase information of fingerprint images makes it possible to achieve robust recognition for weakly impressed, low-quality fingerprint images. This paper presents an idea of improving the performance of POC-based fingerprint matching by combining it with feature-based matching, where feature-based matching is introduced in order to improve recognition efficiency for images with nonlinear distortion. Experimental evaluation using two different types of fingerprint image databases demonstrates efficient recognition performance of the combination of the POC-based algorithm and the feature-based algorithm.

An Optical Line Terminal (OLT) needs to find and register newly connected Optical Network Units (ONUs) in the proposed Ethernet Optical Switched Access Network (E-OSAN) as well as the Ethernet Passive Optical Network (E-PON). In this discovery process, OLT measures round trip time (RTT) between OLT and each ONU and then assigns a Logical Link Identification (LLID) to each ONU. For E-OSAN, the conventional discovery method takes up to N discovery periods for OLT to register all ONUs, where N denotes the number of switch ports of the Optical Switching Module (OSM). This paper proposes an efficient method that completes discovery in just one period. This paper also evaluates the maximum ranging completion time of the proposed discovery method in a comparison with E-PON.

This paper proposes a topic-independent method for automatically scoring essay content. Unlike conventional topic-dependent methods, it predicts the human-assigned score of a given essay without training essays written to the same topic as the target essay. To achieve this, this paper introduces a new measure called MIDF that measures how important and relevant a word is in a given essay. The proposed method predicts the score relying on the distribution of MIDF. Surprisingly, experiments show that the proposed method achieves an accuracy of 0.848 and performs as well as or even better than conventional topic-dependent methods.

A new construction method for polyphase sequences with two-valued periodic auto- and crosscorrelation functions is proposed. This method gives L families of polyphase sequences for each prime length L which is bigger than three. For each family of sequences, the out-of-phase auto- and crosscorrelation functions are proved to be constant and asymptotically reach the Sarwate bound. Furthermore, it is shown that sequences of each family are mutually orthogonal.

The synthesis of single- and double-wall carbon nanotubes by gas flow-modified, catalyst-supported chemical vapor deposition (CCVD) is reported. We have investigated the gas flow condition dependence on the synthesis of carbon nanotubes (CNTs) by placing blocks in the CCVD reactor. Carbon nanotubes having large diameters are preferentially grown under turbulent flow conditions. This indicates that the diameter distribution of CNTs can be controlled by modification of the gas flow condition in the CCVD.

The researches on predicting and removing of lithographic hot-spots have been prevalent in recent semiconductor industries, and known to be one of the most difficult challenges to achieve high quality detection coverage. To provide physical design implementation with designer's favors on fixing hot-spots, in this paper, we present a noble and accurate hot-spot detection method, so-called "leveling and scoring" algorithm based on weighted combination of image quality parameters (i.e., normalized image log-slope (NILS), mask error enhancement factor (MEEF), and depth of focus (DOF)) from lithography simulation. In our algorithm, firstly, hot-spot scoring function considering severity level is calibrated with process window qualification, and then least-square regression method is used to calibrate weighting coefficients for each image quality parameter. In this way, after we obtain the scoring function with wafer results, our method can be applied to future designs of using the same process. Using this calibrated scoring function, we can successfully generate fixing guidance and rule to detect hot-spot area by locating edge bias value which leads to a hot-spot-free score level. Finally, we integrate the hot-spot fixing guidance information into layout editor to facilitate the user-favorable design environment. Applying our method to memory devices of 60 nm node and below, we could successfully attain sufficient process window margin to yield high mass production.

We carried out degradation analysis of a blue phosphorescent organic light emitting diode by both impedance spectroscopy and transient electroluminescence (EL) spectroscopy. The number of semicircles observed in the Cole-Cole plot of the modulus became three to two after the device was operated for 567 hours. Considering the effective layer thickness of the initial and degraded devices did not change by degradation and combining the analysis of the Bode-plot of the imaginary part of the modulus, the relaxation times of emission layer and hole-blocking with electron transport layers changed to nearly the same value by the increase of the resistance of emission layer. Decay time of transient EL of the initial device was coincident with that of the degraded one. These phenomena suggest that no phosphorescence quenching sites are generated in the degraded device, but the number of the emission sites decrease by degradation.

Using frictional force microscopy (FFM), the friction surface characteristics were compared between twisted nematic (TN) mode and vertical alignment (VA) mode alignment films (AFs). The friction asymmetry was detected depending on temperature conditions on TN mode AF, but not on VA mode AF. The difference between two modes was explained by leaning intermolecular repulsion caused by the pre-tilt angle uniformity and the density of side chain. No level difference according to temperature conditions appeared when the pre-tilt angle were measured after liquid crystal (LC) injection.

Location Based Services (LBS) are expected to become one of the major drivers of ubiquitous services due to recent inception of GPS-enabled mobile devices, the development of Web2.0 paradigm, and emergence of 3G broadband networks. Having this vision in mind, Community Context-attribute-oriented Collaborative Information Environment (CCCIE) based Autonomous Decentralized Community System (ADCS) is proposed to enable provision of services to specific users in specific place at specific time considering various context-attributes. This paper presents autonomous community construction technology that share service discovered by one member among others in flexible way to improve timeliness and reduce network cost. In order to meet crucial goal of real-time and context-aware community construction (provision of service/ service information to users with common interests), and defining flexible service area in highly dynamic operating environment of ADCS, proposed progressive ripple based service discovery technique introduces novel idea of snail's pace and steady advancing search followed by swift boundary confining mechanism; while service area construction shares the discovered service among members in defined area to further improve timeliness and reduce network cost. Analysis and empirical results verify the effectiveness of the proposed technique.

This Paper presents the design of a wideband variable gain amplifier (VGA) using 0.18 µm standard CMOS technology. The proposed VGA realizes wideband flat gain using wideband flat negative capacitance. It achieves a 3 dB gain bandwidth of 1 GHz with a maximum gain of 23 dB. Also, it shows P1 dB of -33 to -6 dBm over the gain range of -28 to 23 dB. The overall current consumption is 5.5 mA under a 1.5 V supply.

An ICI (Inter-Cell Interference) mitigation algorithm for exploiting macroscopic diversity for an up-link OFDMA (Orthogonal Frequency Division Multiple Access) system is proposed. To reduce the influence of carrier collision, the order of resource allocation is coordinated based on the location of each MS (Mobile Station) and the associated carrier group. This consideration significantly reduces ICI and enhances throughput at the boundary region.

Recently, Kempf and Koodli have proposed a security protocol for Fast Mobile IPv6 (FMIPv6). Through the SEcure Neighbor Discovery (SEND) protocol, it achieves secure distribution of a handover key, and consequently becomes a security standard for FMIPv6. However, it is still vulnerable to redirection attacks. In addition, due to the SEND protocol, it suffers from denial of service attacks and expensive computational cost. In this paper, we present a security protocol, which enhances Kempf-Koodli's one with the help of the AAA infrastructure.

This paper discusses the discourse understanding process in spoken dialogue systems. This process enables a system to understand user utterances from the context of a dialogue. Ambiguity in user utterances caused by multiple speech recognition hypotheses and parsing results sometimes makes it difficult for a system to decide on a single interpretation of a user intention. As a solution, the idea of retaining possible interpretations as multiple dialogue states and resolving the ambiguity using succeeding user utterances has been proposed. Although this approach has proven to improve discourse understanding accuracy, carefully created hand-crafted rules are necessary in order to accurately rank the dialogue states. This paper proposes automatically ranking multiple dialogue states using statistical information obtained from dialogue corpora. The experimental results in the train ticket reservation and weather information service domains show that the statistical information can significantly improve the ranking accuracy of dialogue states as well as the slot accuracy and the concept error rate of the top-ranked dialogue states.

This work describes a 12-bit 100 MS/s 0.13 µm CMOS ADC for 3G wireless communication systems such as two-carrier W-CDMA applications. The proposed ADC employs a four-step pipeline architecture to optimize power consumption and chip area at the target resolution and sampling rate. Area-efficient gate-bootstrapped sampling switches of the input SHA maintain high signal linearity over the Nyquist rate even at a 1.0 V supply. The cascode compensation using a low-impedance feedback path in two-stage amplifiers of the SHA and MDACs achieves the required conversion speed and phase margin with less power consumption and area compared to the Miller compensation. A low-glitch dynamic latch in the sub-ranging flash ADCs reduces kickback noise referred to the input of comparator by isolating the pre-amplifier from the regeneration latch output. The proposed on-chip current and voltage references are based on triple negative TC circuits. The prototype ADC in a 0.13 µm 1P8M CMOS technology demonstrates the measured DNL and INL within 0.38LSB and 0.96LSB at 12-bit, respectively. The ADC shows a maximum SNDR and SFDR of 64.5 dB and 78.0 dB at 100 MS/s, respectively. The ADC with an active die area of 1.22 mm2 consumes 42.0 mW at 100 MS/s and a 1.2 V supply, corresponding to a figure-of-merit of 0.31 pJ/conversion-step.

A fully integrated CMOS wideband Low Noise Amplifier (LNA) operating over 2.3-7 GHz is designed and fabricated using a 0.18 µm CMOS process. The proposed structure is a common source-common source (CS-CS) cascode amplifier with a coupling capacitor. It realizes both low voltage drop at load resistor (Rload) and high gain over 2.3-7 GHz with simultaneous noise and input matching and low power consumption. This paper presents the proposed design technique of a wideband LNA, and verifies its performance by simulation and measurement. This wideband LNA achieves an average gain (S21) of 16.5 (dB), an input return loss (S11) less than -8 dB, a noise figure (NF) of 3.4-6.7 dB, and a third order input interception point (IIP3) of -7.5-3 dBm at 2.3-7 GHz with power consumption of 10.8 mW under 1.8 V VDD.

A data analysis technology of atomic force microscopy for atomically flat silicon surfaces has been developed. Atomically flat silicon surfaces composed of atomic terraces and steps are obtained on (100) orientation 200 mm diameter wafers by annealing in pure argon ambience at 1,200 for 30 minutes. Atomically flat silicon surfaces are lead to improve the MOS inversion layer mobility and current drivability of MOSFETs and to decrease the fluctuations in electrical characteristics of MOSFETs. It is important to realize the technology that evaluates the flatness and the uniformity of atomically flat silicon surfaces. The off direction angle is calculated by using two straight edge lines selected from measurement data. And the off angle is calculated from average atomic terrace width under assumption that height difference between neighboring terraces is equal to the step height, 0.135 nm, of (100) silicon surface. The analyzing of flatness of each terrace can be realized by converting the measurement data using the off direction angle and the off angle. And, the average roughness of each terrace is about 0.017-0.023 nm. Therefore, the roughness and the uniformity of each terrace can be evaluated by this proposed technique.

The 3GPP LTE-Advanced has been attracting much attention recently, where the channel bandwidth would be beyond the maximum bandwidth of LTE, 20 MHz. In LTE, single carrier-frequency division multiple access (SC-FDMA) was accepted as the uplink access scheme due to its advantage of very low cubic metric (CM). For LTE-A wideband transmission, multicarrier access would be more effective than single carrier access to make use of multi-user diversity and can maintain the physical channel structure of LTE, where the control information is transmitted on the edges of each 20 MHz. In this paper, we discuss the access schemes in bandwidth under 20 MHz as well as over 20 MHz. In the case of bandwidth under 20 MHz, we propose the access schemes allowing discontinuous resource allocation to enhance average throughput while maintaining cell-edge user throughput, that is, DFT-spread-OFDM with spectrum division control (SDC) and adaptive selection of SC-FDMA and OFDM (SC+OFDM). The number of discontinuous spectrums is denoted as spectrum division (SD). For DFT-S-OFDM, we define a parameter max SD as the upper limit of SD. We evaluate our proposed schemes in bandwidth under 20 MHz and find that SC+OFDM as well as SDC with common max SD or UE-specific max SD can improve average throughput while their cell-edge user throughput can approach that of SC-FDMA. In the case of bandwidth over 20 MHz, we consider key factors to decide a feasible access scheme for aggregating several 20 MHz-wide bands.

In the OTS/CafeOBJ method, software specifications are described in CafeOBJ executable formal specification language, and verification is done by giving scripts to the CafeOBJ system. The script is called a proof score. In this study, we propose a test case generator from an OTS/CafeOBJ specification together with a proof score. Our test case generator gives test cases by analyzing the proof score. The test cases are used to test whether an implementation satisfies the specification and the property verified by the proof score. Since a proof score involves important information for verifying a property, the generated test cases are also expected to be suitable to test the property.

Motion estimation (ME) is a computation and data intensive module in video coding system. The search window reuse methods play a critical role in bandwidth reduction by exploiting the data locality in video coding system. In this paper, a search window reuse method (Level C+) is proposed for MPEG-2 to H.264/AVC transcoding. The proposed method is designed for ultra-low bandwidth application, while the on-chip memory is not a main constraining factor. By loading search window for the motion estimation unit (MEU) and applying motion vector clipping processing, each MB in MEU can utilize both horizontal and vertical search reuse. A very low bandwidth level (Rα<2) can be achieved with an acceptable on-chip memory.