User context and user location in particular play an important role in location-based services (LBS). The location can be determined by various positioning methods. These are typically evaluated with average positioning error or percentile values, which are not the most suitable metrics for evaluation of how a positioning method functions in the semantic space. Therefore, we propose a new method for evaluation of positioning accuracy in the semantic space. We focus on two types of semantic user locations that are widely available in urban areas: the street address and the categories of the surrounding points of interest (POIs). We demonstrate its use on ten different positioning methods: a standalone satellite navigation device, GPS module on a smartphone, two versions of Foursquare positioning service, Google positioning service, a positioning service of the local mobile operator, and four other possible variants of mobile operator-based positioning methods. The evaluation suggests that approach with the street addresses is more promising approach due to either sparse or unevenly distributed POIs. Furthermore, some of the positioning methods that are less accurate in Euclidean space, such as a combination of the GPS data with the mobile operator-based method that relies on the propagation models, performed comparably well in the semantic space as the methods that are using more accurate technologies, such as Google and Foursquare.

The Satellite/Terrestrial Integrated mobile Communication System (STICS), which allows terrestrial mobile phones to communicate directly through a satellite, has been studied [1]. Satellites are unaffected by the seismic activity that causes terrestrial damage, and therefore, the STICS can be expected to be a measure that ensures emergency call connection. This paper first describes the basic characteristics of call blocking rates of terrestrial mobile phone systems in areas where non-functional base stations are geographically clustered, as investigated through computer simulations that showed an increased call blocking rate as the number of non-functional base stations increased. Further simulations showed that restricting the use of the satellite system for emergency calls only ensures the STICS's capacity to transmit emergency communications; however, these simulations also revealed a weakness in the low channel utilization rate of the satellite system [2]. Therefore, in this paper, we propose increasing the channel utilization rate with a priority channel framework that divides the satellite channels between priority channels for emergency calls and non-priority channels that can be available for emergency or general use. Simulations of this priority channel framework showed that it increased the satellite system's channel utilization rate, while continuing to ensure emergency call connection [3]. These simulations showed that the STICS with a priority channel framework can provide efficient channel utilization and still be expected to provide a valuable secondary measure to ensure emergency communications in areas with clustered non-functional base stations during large-scale disasters.

In order to tackle the rapidly increasing traffic, the 5th generation (5G) mobile communication system will introduce small cells using higher frequency bands with wider bandwidth to achieve super high bit rate transmission of several tens of Gbps. Massive multiple input multiple output (MIMO) beamforming (BF) is promising as one of the technologies that can compensate for larger path-loss in the higher frequency bands. Joint analog fixed BF and digital precoding have been proposed to reduce the cost of a Massive MIMO transceiver. However, the conventional scheme assumes the transmission of a few streams using well-known codebook-based precoding as the digital precoding, and both a selection method of the fixed BF weights and a digital precoder design, which are suitable for super high bit rate transmission using multiple streams, have not been studied. This paper proposes a joint fixed BF and CSI-based precoding (called FBCP) scheme for the 5G Massive MIMO systems. FBCP first selects the analog fixed BF weights based on a maximum total received power criterion, and then it calculates an eigenmode (EM) precoding matrix by exploiting CSI. This paper targets a 5G system achieving over 20Gbps in the 20GHz band as one example. Throughput performances of the Massive MIMO using the proposed FBCP are evaluated by link level simulations using adaptive modulation and coding and it is shown that the proposed FBCP with the optimum number of selected beams (baseband chains) can use higher level modulation, up to 256QAM, and higher coding rates and achieve throughputs close to 30Gbps while the cost and complexity can be reduced compared with the fully digital Massive MIMO.

Non-verbal communication incorporating visual, audio, and contextual information is important to make sense of and navigate the social world. Individuals who have trouble with social situations often have difficulty recognizing these sorts of non-verbal social signals. In this article, we propose a training tool NOCOA+ (Non-verbal COmmuniation for Autism plus) that uses utterances in visual and audio modalities in non-verbal communication training. We describe the design of NOCOA+, and further perform an experimental evaluation in which we examine its potential as a tool for computer-based training of non-verbal communication skills for people with social and communication difficulties. In a series of four experiments, we investigated 1) the effect of temporal context on the ability to recognize social signals in testing context, 2) the effect of modality of presentation of social stimulus on ability to recognize non-verbal information, 3) the correlation between autistic traits as measured by the autism spectrum quotient (AQ) and non-verbal behavior recognition skills measured by NOCOA+, 4) the effectiveness of computer-based training in improving social skills. We found that context information was helpful for recognizing non-verbal behaviors, and the effect of modality was different. The results also showed a significant relationship between the AQ communication and socialization scores and non-verbal communication skills, and that social skills were significantly improved through computer-based training.

This paper proposes an algorithm for exemplar-based image inpainting, which produces the same result as that of Criminisi's original scheme but at the cost of much smaller computation cost. The idea is to compute mean and standard deviation of every patch in the image, and use the values to decide whether to carry out pixel by pixel comparison or not when searching for the best matching patch. Due to the missing pixels in the target patch, the same pixels in the candidate patch should be omitted when computing the distance between patches. Thus, we first compute the range of mean and standard deviation of a candidate patch with missing pixels, using the average and standard deviation of the entire patch. Then we use the range to determine if the pixel comparison should be conducted. Measurements with well-known images in the inpainting literature show that the algorithm can save significant amount of computation cost, without risking degradation of image quality.

We investigate a quantization error improvement technique using a dual rail configuration for optical quantization. Our proposed optical quantization uses intensity-to-wavelength conversion based on soliton self-frequency shift and spectral compression based on self-phase modulation. However, some unfavorable input peak power regions exist due to stagnations of wavelength shift or distortions of spectral compression. These phenomena could induce a serious quantization error and degrade the effective number of bit (ENOB). In this work, we propose a quantization error improvement technique which can make up for the unfavorable input peak power regions. We experimentally verify the quantization error improvement effect by the proposed technique in 6 bit optical quantization. The estimated ENOB is improved from 5.35 bit to 5.66 bit. In addition, we examine the XPM influence between counter-propagating pulses at high sampling rate. Experimental results and numerical simulation show that the XPM influence is negligible under ∼40 GS/s conditions.

The Earth's ionosphere can hinder radio propagation with two serious problems: group delay and phase advance. Ionospheric irregularities are significantly troublesome since they make the amplitude and phase of the radio signals fluctuate rapidly, which is known as ionospheric scintillation. Severe ionospheric scintillation could cause loss of phase lock, which would degrade the positioning accuracy and affect the performance of navigation systems. Based on the phase screen model, this paper presents a novel power spectrum model of phase scintillation and a model of amplitude scintillation. Preliminary results show that, when scintillation intensity increases, the random phase and amplitude fluctuations become stronger, coinciding with the observations. Simulations of the scintillation effects on the acquisition of Beidou signals predict acquisition probability. In addition, acquisition probabilities of GPS and Beidou signals under different scintillation intensities are presented. And by the same SNR the acquisition probability decreases when the scintillation intensity increases. The simulation result shows that scintillation could cause the loss of the acquisition performance of Beidou navigation system. According to the comparison of Beidou and GPS simulations, the code length and code rate of satellite signals have an effect on the acquisition performance of navigation system.

This paper presents a cell-based all-digital phase-locked loop (ADPLL) with hierarchical gated digitally controlled oscillator (G-DCO) for low voltage operation, wide frequency range as well as low-power consumption. In addition, a new time-domain hierarchical frequency estimation algorithm (HFEA) for frequency acquisition is proposed to estimate the output frequency in 1.5MF (MF = 3 in this paper) cycles and this fast lock-in time is suitable to the dynamic voltage frequency scaling (DVFS) systems. A hierarchical G-DCO is proposed to work at low supply voltage to reduce the power consumption and at the same time to achieve wide frequency range and precise frequency resolution. The core area of the proposed ADPLL is 0.02635 mm2. In near-threshold region (VDD = 0.36 V), the proposed ADPLL only dissipates 68.2 µW and has a rms period jitter of 1.25% UI at 60 MHz output clock frequency. Under 0.5 V VDD operation, the proposed ADPLL dissipates 404.2 µW at 400 MHz. The fast lock-in time of 4.489 µs and the low jitter performance below 0.5% UI at 400 MHz output clock frequency in the proposed ADPLL are suitable in event-driven or DVFS applications.

This paper proposes applying random (opportunistic) beamforming to base station (BS) cooperative multiuser multiple-input multiple-output (MIMO) transmission. This proposal comprises two parts. First, we propose a block-diagonalized random unitary beamforming matrix. The proposed beamforming matrix achieves better throughput distribution compared to the purely random unitary beamforming matrix when the average path loss determined by distance-dependent loss and shadowing loss is largely different among transmitter antennas, which is true in BS cooperative MIMO. Second, we propose an online update algorithm for a random beamforming matrix to improve the throughput compared to the purely random and channel-independent beamforming matrix generation, especially when the number of users is low. Different from conventional approaches, the proposed online update algorithm does not increase the overhead of the reference signal transmission and control delay. Simulation results show the effectiveness of the proposed method using a block-diagonalized random unitary beamforming matrix with online updates in a BS cooperative multiuser MIMO scenario.

This paper extends our previously proposed non-orthogonal multiple access (NOMA) scheme to the base station (BS) cooperative multiple-input multiple-output (MIMO) cellular downlink for future radio access. The proposed NOMA scheme employs intra-beam superposition coding of a multiuser signal at the transmitter and the spatial filtering of inter-beam interference followed by the intra-beam successive interference canceller (SIC) at the user terminal receiver. The intra-beam SIC cancels out the inter-user interference within a beam. This configuration achieves reduced overhead for the downlink reference signaling for channel estimation at the user terminal in the case of non-orthogonal user multiplexing and enables the use of the SIC receiver in the MIMO downlink. The transmitter beamforming (precoding) matrix is controlled based on open loop-type random beamforming using a block-diagonalized beamforming matrix, which is very efficient in terms of the amount of feedback information from the user terminal. Simulation results show that the proposed NOMA scheme with block-diagonalized random beamforming in BS cooperative multiuser MIMO and the intra-beam SIC achieves better system-level throughput than orthogonal multiple access (OMA), which is assumed in LTE-Advanced. We also show that BS cooperative operation along with the proposed NOMA further enhances the cell-edge user throughput gain which implies better user fairness and universal connectivity.

Recently ICT has been improved rapidly, and it is likely to make a contribution to effective disaster response. However, ICT is not utilized effectively in disaster response because the environment for ICT management is not considered enough. In this paper, we retrieve lessons learned from actual response at the past disasters in Japan, and introduce them following disaster response process model based on human psychological manner. In another point, we suggest significance of Common Operational Picture with spatial information following advanced case study in the United States of America, and identify two essential issues for effective information and technology management. One is information status, such as statics or dynamic information. The other one is five elements for ICT management in disaster response: Governance, Standard Operating Procedures, Technology, Training and Exercise and Use.

Order-Preserving Encryption (OPE) is an encryption system that preserves the numerical (or alphabetical) order of plaintexts. Since many operations of communications and databases are based on order relations of data (plaintexts), OPE is regarded as a core technique for various applications. However, the intrinsic property of OPE makes constructing an efficient and secure OPE system hard to achieve. In particular, OPE can guarantee only limited security compared to general encryption systems. Only a few results on OPE systems were presented, and no theoretical research based on provable security has been presented until recently. Lately, some approaches have been suggested. However, every known result is unsatisfactory for formalizing the provable security of OPE systems. In this paper, we propose a new OPE system that employs only a simple pseudorandom number function, and therefore has an advantage for practical usage.

Texture feature descriptors such as local binary patterns (LBP) have proven effective for ground-based cloud classification. Traditionally, these texture feature descriptors are predefined in a handcrafted way. In this paper, we propose a novel method which automatically learns discriminative features from labeled samples for ground-based cloud classification. Our key idea is to learn these features through mutual information maximization which learns a transformation matrix for local difference vectors of LBP. The experimental results show that our learned features greatly improves the performance of ground-based cloud classification when compared to the other state-of-the-art methods.

Graphical User Interfaces (GUIs) are critical for the security, safety and reliability of software systems. Injection attacks, for instance via SQL, succeed due to insufficient input validation and can be avoided if contract-based approaches, such as Design by Contract, are followed in the software development lifecycle of GUIs. This paper proposes a model-based testing approach for detecting GUI data contract violations, which may result in serious failures such as system crash. A contract-based model of GUI data specifications is used to develop test scenarios and to serve as test oracle. The technique introduced uses multi terminal binary decision diagrams, which are designed as an integral part of decision table-augmented event sequence graphs, to implement a GUI testing process. A case study, which validates the presented approach on a port scanner written in Java programming language, is presented.

Breast cancer is a serious disease across the world, and it is one of the largest causes of cancer death for women. The traditional diagnosis is not only time consuming but also easily affected. Hence, artificial intelligence (AI), especially neural networks, has been widely used to assist to detect cancer. However, in recent years, the computational ability of a neuron has attracted more and more attention. The main computational capacity of a neuron is located in the dendrites. In this paper, a novel neuron model with dendritic nonlinearity (NMDN) is proposed to classify breast cancer in the Wisconsin Breast Cancer Database (WBCD). In NMDN, the dendrites possess nonlinearity when realizing the excitatory synapses, inhibitory synapses, constant-1 synapses and constant-0 synapses instead of being simply weighted. Furthermore, the nonlinear interaction among the synapses on a dendrite is defined as a product of the synaptic inputs. The soma adds all of the products of the branches to produce an output. A back-propagation-based learning algorithm is introduced to train the NMDN. The performance of the NMDN is compared with classic back propagation neural networks (BPNNs). Simulation results indicate that NMDN possesses superior capability in terms of the accuracy, convergence rate, stability and area under the ROC curve (AUC). Moreover, regarding ROC, for continuum values, the existing 0-connections branches after evolving can be eliminated from the dendrite morphology to release computational load, but with no influence on the performance of classification. The results disclose that the computational ability of the neuron has been undervalued, and the proposed NMDN can be an interesting choice for medical researchers in further research.

An adaptively phase-shift controlled self-injection locked VCO is described. A self-injection locking technique is effective to reduce phase noise. However, a conventional self-injection locked VCO has drawbacks of discontinuous frequency sweep which means narrow bandwidth, and large variation of phase noise. Our proposed adaptively phase-shift controlled self-injection locked VCO overcomes these drawbacks by detecting phase-shift of the self-injection feedback and controlling the phase-shift depending on sweep of the oscillation frequency. This paper describes analysis of relationships between the discontinuity and feedback phase-shift of the self-injection locked VCO. In addition, a VCO-IC which includes a Ka-band VCO and a phase detector is designed and fabricated in 0.18um SiGe BiCMOS technology. Measurement results of the proposed self-injection locked VCO using the fabricated IC show the improvement to the drawbacks. In the proposed self-injection locked VCO, the oscillation frequency sweep is continuous and the phase noise variation is less than 5 dB.

In this paper, a 97-mW 8-phase CMOS voltage-controlled oscillator (VCO) and dividers covering the entire VCO oscillation range for a 134-GHz phase-locked loop (PLL) synthesizer are presented. The dividers have two injection-locked frequency dividers (ILFDs), one with and one without an inductor, and a pulse-swallowing counter with a differential dual-modulus prescaler. The VCO has a fundamental oscillation frequency range of 131.8 GHz to 134.3 GHz, achieved by controlling the back-gate voltage, which is also used to tune the locking range of divide-by-2 and divide-by-3 dividers. The ratio between the measured VCO oscillation frequencies and output frequencies of dividers is in good agreement with the target ratio. This indicates that the dividers covered the entire VCO oscillation range. We fabricated the VCO and dividers with a chip core area of 180 µm × 100 µm implemented in a 65-nm CMOS process. The total power consumption was 97 mW at a 1.2-V supply voltage.

In this letter, we derive two lower bounds for the number of terms in a double-base number system (DBNS), when the digit set is {1}. For a positive integer n, we show that the number of terms obtained from the greedy algorithm proposed by Dimitrov, Imbert, and Mishra [1] is $Thetaleft(rac{log n}{log log n} ight)$. Also, we show that the number of terms in the shortest double-base chain is Θ(log n).

This paper presents a constant-current-controlled class-C VCO using a self-adjusting replica bias circuit. The proposed class-C VCO is more suitable in real-life applications as it can maintain constant current which is more robust in phase noise performance over variation of gate bias of cross-coupled pair comparing to a traditional approach without amplitude modulation issue. The proposed VCO is implemented in 180,nm CMOS process. It achieves a tuning range of 4.8--4.9,GHz with a phase noise of -121,dBc/Hz at 1,MHz offset. The power consumption of the core oscillators is 4.8,mW and an FoM of -189,dBc/Hz is achieved.

In this letter, we propose a secrecy criterion for outsourcing encrypted databases. In encrypted databases, encryption schemes revealing some information are often used in order to manipulate encrypted data efficiently. The proposed criterion is based on inference analysis for databases: We simulate attacker's inference on specified secret information with and without the revealed information from the encrypted database. When the two inference results are the same, then secrecy of the specified information is preserved against outsourcing the encrypted database. We also show that the proposed criterion is decidable under a practical setting.