Pair-wise testing is an effective test planning technique for finding interaction faults using a small set of test cases. Constraint elicitation is an important process in the pair-wise testing design since constraints determine the test space; however, the constraint elicitation process has not been well studied. It usually requires manual capturing and precise definition of constraints. In this paper, we propose a constraint elicitation process that helps combinatorial test design. Our elicitation process consists of two steps: parameter combination identification and value pair determination. We conduct experiments on some test models, and demonstrate that some extracted rules match constraints and others helps to define constraints.

We address the problem of entity identification on a microblog with special attention to indirect reference cases in which entities are not referred to by their names. Most studies on identifying entities referred to them by their full/partial name or abbreviation, while there are many indirectly mentioned entities in microblogs, which are difficult to identify in short text such as microblogs. We therefore tackled indirect reference cases by developing features that are particularly important for certain types of indirect references and modeling dependency among referred entities by a Conditional Random Field (CRF) model. In addition, we model non-sequential order dependency while keeping the inference tractable by dynamically building dependency among entities. The experimental results suggest that our features were effective for indirect references, and our CRF model with adaptive dependency was robust even when there were multiple mentions in a microblog and achieved the same high performance as that with the fully connected CRF model.

The electrical lubricants have been accepted to reduce friction of contacts and to prevent degradation of contact resistance. However, as the lubricant has an electrical insulation property it seems that application to contact surface is unsuitable for contact resistance. These mechanisms in contact interfaces have not fully understood. In this paper, relationships between contact resistance and contact load were examined with both clean and lubricated surfaces. Orientation of the lubricant molecules was observed by high magnification images of STM and AFM. There was no difference in contact resistance characteristics for both clean and lubricated surfaces in spite of lubricants thickness. The molecules were orientated perpendicular to the surface. This fact turns over an established theory of adsorption of non-polar lubricant to surface.

Since the first formal cryptographic study of order-preserving encryption (OPE) by Boldyreva et al., few OPE schemes with provable security have been published. In this paper, we analyze the security of Jho et al.'s OPE scheme, and show that it is not POPF-CCA secure in opposition to what they claim.

The limitation of the GPS in urban canyon has led to the rapid development of Wi-Fi positioning system (WPS). The fingerprint-based WPS could be divided into calibration and positioning stages. In calibration stage, several grid points (GPs) are selected, and their position tags and featured access points (APs) are collected to build fingerprint database. In positioning stage, real time measurement of APs are compared with the feature of each GP in the database. The k weighted nearest neighbors (KWNN) algorithm is used as pattern matching algorithm to estimate the final positioning result. However, the performance of outdoor fingerprint-based WPS is not good enough for pedestrian navigation. The main challenge is to build a robust fingerprint database. The received number of APs in outdoor environments has large variation. In addition, positioning result estimated by GPS receiver is used as position tag of each GP to automatically build the fingerprint database. This paper studies the lifecycle of fingerprint database in outdoor environment. We also shows that using long time collected data to build database could improve the positioning accuracy. Moreover, a new 3D-GNSS (3D building models aided GNSS) positioning method is used to provide accurate position tags. In this paper, the fingerprint-based WPS has been developed in an outdoor environment near the center of Tokyo city. The proposed WPS can achieve around 17 meters positioning accuracy in urban canyon.

In this paper, a new non-uniform weight-updating scheme for adaptive digital beamforming (DBF) is proposed. The unique feature of the letter is that the effective working range of the beamformer is extended and the computational complexity is reduced by introducing the robust DBF based on worst-case performance optimization. The robust parameter for each weight updating is chosen by analyzing the changing rate of the Direction of Arrival (DOA) of desired signal in LEO satellite communication. Simulation results demonstrate the improved performance of the new Non-Uniform Weight-Updating Beamformer (NUWUB).

In this letter, a method of wideband direction of arrival (DOA) estimation based on co-prime arrays with sub-Nyquist sampling is proposed. Previous works have employed co-prime arrays for wideband DOA estimation, which can increase the degrees of freedom (DOFs) in the spatial domain. However, they are all based on Nyquist sampling. Different from existing methods, we incorporate a sub-Nyquist sampling scheme called multicoset sampling for DOA estimation to relax hardware condition. Simulation results show the correctness and effectiveness.

In this paper, we propose a method for color error diffusion based on the Neugebauer model for color halftone printing. The Neugebauer model expresses an arbitrary color as a trilinear interpolation of basic colors. The proposed method quantizes the color of each pixel to a basic color which minimizes an accumulated quantization error, and the quantization error is diffused to the ratios of basic colors in subsequent pixels. Experimental results show that the proposed method outperforms conventional color error diffusion methods including separable method in terms of eye model-based mean squared error.

The booming developments in embedded sensor technique, wireless communication technology, and information processing theory contribute to the emergence of Internet of Things (IoT), which aims at perceiving and connecting the physical world. In recent years, a growing number of Internet-connected sensors have published their real-time state about the real-world objects on the Internet, which makes the content-based sensor search a promising service in the Internet of Things (IoT). However, classical search engines focus on searching for static or slowly varying data, rather than object-attached sensors. Besides, the existing sensor search systems fail to support the search mode based on a given measurement range. Furthermore, accessing all available sensors to find sought targets would result in tremendous communication overhead. Thus an accurate matching estimation mechanism is proposed to support the search mode based on a given search range and improve the efficiency and applicability of existing sensor search systems. A time-dependent periodical prediction method is presented to periodically estimate the sensor output, which combines with the during the period feedback prediction method that can fully exploit the verification information for enhancing the prediction precision of sensor reading to efficiently serve the needs of sensor search service. Simulation results demonstrate that our prediction methods can achieve high accuracy and our matching estimation mechanism can dramatically reduce the communication overhead of sensor search system.

In this paper, we propose an RFID distance bounding protocol that uses m-ary challenges. Recently, Kim and Avoine proposed two distance bounding protocols with mixed challenges that are pre-determined or random. We generalize the first scheme of Kim and Avoine's random scheme as a distance bounding protocol with m-ary challenges. The generalized formula for success probabilities for mafia fraud and distance fraud attacks is derived. Our scheme using m-ary challenges reduces the mafia fraud success probability from (3/4)n for m=2 to (7/16)n for m=4 and the distance fraud success probability from $(1-rac 1 4 cdot P_r)^n$ for m=2 to $(1 - rac {189}{256} cdot P_r)^n$ for m=4, where Pr is the probability that a challenge is random.

Silver contacts are separated at constant speed and break arcs are generated in a 300V-450V DC and 10A resistive circuit. The transverse magnetic field of a permanent magnet is applied to the break arcs. Motion of the break arcs, arc duration and the number of reignitions are investigated when side surfaces of the contacts are covered with insulator pipes. Following results are shown. The motion of the break arcs and the arc duration when the anode is covered with the pipe are the same as those without pipes. When the cathode is covered with the pipe, the motion of break arcs change from that without the pipes and reignitions occur more frequently. The arc duration becomes longer than that without the pipes because of the occurrence of reignitions. The number of reignition increases with increasing the supply voltage in 300V-400V. The period of occurrence of the reignition with pipes is shorter than that when the cathode is covered with the pipe.

Break arcs are rotated with the radial magnetic field formed by a magnet embedded in a fixed cathode contact. The break arcs are generated in a 48VDC resistive circuit. The circuit current when the contacts are closed is 10A. The depth of the magnet varies from 1mm to 4mm to change the strength of the radial magnetic field for rotating break arcs. Images of break arcs are taken by two high-speed cameras from two directions and the rotational motion of the break arcs is observed. The rotational period of rotational motion of the break arcs is investigated. The following results are obtained. The break arcs rotate clockwise on the cathode surface seen from anode side. This rotation direction conforms to the direction of the Lorentz force that affects to the break arcs with the radial magnetic field. The rotational period gradually decreases during break operation. When the depth of magnet is larger, the rotational period becomes longer.

A 50-Gb/s optical transmitter, consisting of a 25-Gb/s-class lens-integrated DFB-LD (with -3-dB bandwidth of 20GHz) and a LD-driver chip based on 0.18-µm SiGe BiCMOS technology for inter and intra-rack transmissions, was developed and tested. The DFB-LD and LD driver chip are flip-chip mounted on an alumina ceramic package. To suppress inter-symbol interference due to a shortage of the DFB-LD bandwidth and signal reflection between the DFB-LD and the package, the LD driver includes a two-tap pre-emphasis circuit and a high-speed termination circuit. Operating at a data rate of 50Gb/s, the optical transmitter enhances LD bandwidth and demonstrated an eye opening with jitter margin of 0.23UI. Power efficiency of the optical transmitter at a data rate of 50Gb/s is 16.2mW/Gb/s.

The scan segmentation method is an efficient solution to deal with the test power problem; However, the use of multiple capture cycles may cause capture violations, thereby leading to fault coverage loss. This issue is much more severe in at-speed testing. In this paper, two scan partition schemes based on complex networks clustering ara proposed to minimize the capture violations without increasing test-data volume and extra area overhead. In the partition process, we use a more accurate notion, spoiled nodes, instead of violation edges to analyse the dependency of flip-flops (ffs), and we use the shortest-path betweenness (SPB) method and the Laplacian-based graph partition method to find the best combination of these flip-flops. Beyond that, the proposed methods can use any given power-unaware set of patterns to test circuits, reducing both shift and capture power in at-speed testing. Extensive experiments have been performed on reference circuit ISCAS89 and IWLS2005 to verify the effectiveness of the proposed methods.

In a scenario-based software development, a lot of scenarios should be described in order to clarify the whole behaviors of the target software. By reusing scenarios of similar software systems, it becomes more efficient to newly describe scenarios of the target software. A differential scenario includes the difference between sequences of events of the two scenarios and the difference between nouns in the scenarios. If the nouns of the two scenarios are commonly used in the two scenarios, we regard the two scenarios specify the same or similar system. If the sequences of the events of the two scenarios are corresponding each other, we regard behavior of the two scenarios are similar. In this paper, we derive differential information including different words and events from two scenarios. Then, we propose a method of scenario retrieval using differential information between two scenarios. This method enables to detect similar scenarios for a given scenario. The proposed retrieval method and a prototype system for creating and visualizing differential scenario will be illustrated with examples.

This paper proposes a method of incrementally constructing semantic representations. Our method is based on Steedman's Combinatory Categorial Grammar (CCG), which has a transparent correspondence between syntax and semantics. In our method, a derivation for a sentence is constructed in an incremental fashion and the corresponding semantic representation is derived synchronously. Our method uses normal form CCG derivation. This is the difference between our approach and previous ones. Previous approaches use most left-branching derivation called incremental derivation, but they cannot process coordinate structures incrementally. Our method overcomes this problem.

The automation of traceability links or traceability matrices is important to many software development paradigms. In turn, the efficiency and effectiveness of the recovery of traceability links in the distributed software development is becoming increasingly vital due to complexity of project developments, as this include continuous change in requirements, geographically dispersed project teams, and the complexity of managing the elements of a project - time, money, scope, and people. Therefore, the traceability links among the requirements artifacts, which fulfill business objectives, is also critical to reduce the risk and ensures project‘s success. This paper proposes Autonomous Decentralized Semantic based Traceability Link Recovery (AD-STLR) architecture. According to best of our knowledge this is the first architectural approach that uses an autonomous decentralized concept, DBpedia knowledge-base, Babelnet 2.5 multilingual dictionary and semantic network, for finding similarity among different project artifacts and the automation of traceability links recovery.

In this letter, we present an efficient resource allocation algorithm for proportional fair schedulers in mobile multihop relay (MMR) networks. We consider a dual-hop cellular network assisted with a decode-and-forward relay station (RS). Since additional radio resources should be allocated in the wireless link between a base station (BS) and an RS, it is very important to determine the optimal amount of resources for this BS-to-RS link. The proposed resource allocation algorithm maximizes the utility of the overall MMR network in a proportionally fair point of view.

One problem in the use of wireless Content Centric Networks (CCNs) is the need for substantial overhead to achieve reliability in content delivery due to the requirement for a request packet per each data packet transmission. This paper introduces a novel protocol to reduce overhead and achieve reliability. The protocol allows an interest packet to request multiple data packets and an intermediate node, rather than the provider, to send the data packet. Simulation results show that the proposed protocol improves the performance of wireless CCN.

Due to the increasing demand for 3D video transmission over wireless networks, managing the quality of experience (QoE) of wireless 3D video clients is becoming increasingly important. However, the variability of compressed 3D video bit streams and the wireless channel condition as well as the complexity of 3D video viewing experience assessment make it difficult to properly allocate wireless transmission resources. In this paper, we discuss the characteristics of H.264 3D videos and QoE assessment of 3D video clients, and further propose a transmission scheme for 3D video transmission over a wireless communication system. The purpose of our scheme is to minimize the average ratio of stalls among all video streaming clients. By taking into account the playout lead and its change, we periodically evaluate the degree of urgency of each client as regards bitstream receipt based on fuzzy logic, and then allocate the transmission resource blocks to clients jointly considering their degrees of urgency and channel conditions. The adaptive modulation and coding scheme (MCS) is applied to ensure a low transmission error rate. Our proposed scheme is suitable for practical implementation since it has low complexity, and can be easily applied in 2D video transmission and in non-OFDM systems. Simulation results, based on three left-and-right-views 3D videos and the Long Term Evolution (LTE) system, demonstrate the validity of our proposed scheme.