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Manipulating optical signals in the mid-infrared (mid-IR) range is a highly desired task for applications in chemical sensing, thermal imaging, and subwavelength optical waveguiding. To guide highly confined mid-IR light in photonic chips, graphene-based plasmonics capable of breaking the optical diffraction limit offer a promising solution. However, the propagation lengths of these materials are, to date, limited to approximately 10 µm at the working frequency f = 20 THz. In this study, we proposed a waveguide structure consisting of multilayer graphene metamaterials (MLGMTs). The MLGMTs support the fundamental volume plasmon polariton mode by coupling plasmon polaritons at individual graphene sheets over a silicon nano-rib structure. Benefiting from the high conductivity of the MLGMTs, the guided mode shows ultralow loss compared with that of conventional graphene-based plasmonic waveguides at comparable mode sizes. The proposed design demonstrated propagation lengths of approximately 20 µm (four times the current limitations) at an extremely tight mode area of 10−6A0, where A0 is the diffraction-limited mode area. The dependence of modal characteristics on geometry and material parameters are investigated in detail to identify optimal device performance. Moreover, fabrication imperfections are also addressed to evaluate the robustness of the proposed structure. Moreover, the crosstalk between two adjacent present waveguides is also investigated to demonstrate the high mode confinement to realize high-density on-chip devices. The present design offers a potential waveguiding approach for building tunable and large-area photonic integrated circuits.

Inspired by the self-exploring learning approach, this paper proposes an object-learning system in which a robot interacts with objects to obtain their features and construct object concepts. The system consists of three kinds of features: interaction features, visual features, and intrinsic features. When the robot interacts with an object, it observes the changes in the object to obtain its interaction features. At the same time, the robot learns the visual features of the object. The intrinsic features are the properties of the object. Models of the relationships among the three kinds of features are constructed through an Artificial Bee Colony based Random Forest algorithm and a Convolutional Neural Network. The established models help the robot to predict the properties of new objects and to make decisions. Two experiments are constructed in this paper: the service-providing task and the stacking task. In the former, the robot decides on an appropriate object, using the object concept models, to accomplish an appointed task. In the second experiment, the robot uses a Gated Recurrent Neural Network to learn the stacking sequence of various objects. All the experimental results demonstrate that the robot can build object concept models by interacting with objects, and can utilize these models to accomplish various tasks.

With the development of online shopping and the demand for automated packaging systems, we propose an Internet of Things (IoT)-based automated e-fulfillment packaging system and a 3-D adaptive particle swarm optimization (PSO)-based packing algorithm. The proposed system leverages the IoT to connect the data collection and conversion layer, the packaging management layer, the decision-making layer, and the application layer. A cyber network connects each robot, sensor, and smart machine to achieve high velocity, flexibility of procedures, and real-time information exchange. When customers order merchandise online, the orders are received and rearranged, and the deployment of items in a box is planned by the system. The proposed packing algorithm controls the arrangement of items. It compares the size and volume of items and boxes to choose a box of suitable size, as well as deciding on the optimal arrangement of items. This algorithm solves the difficult 3-D Multiple Bin Size Bin Packing Problem (3-DMBSBPP) by integrating an adaptive PSO-based configuration algorithm. Our simulation results show that the packing algorithm can deploy items appropriately, with all items packed inside their box without overlap and with an overall center-of-gravity close to the bottom center of the box. When all the items cannot be packed into a single box, the proposed dividing strategies split the items into groups to pack into two or more boxes of similar size. Furthermore, comparing with the real packages we assessed, the proposed algorithm has a competitive performance. Lastly, our robotic experiments show that the proposed packing algorithm can be implemented and executed by a robot and a manipulator. It also demonstrates the efficiency of this system, in which all devices communicate well with each other and the robots accomplish the packaging task successfully and cooperatively.

Electroencephalograms can record wave variations in any brain activity. Beta waves are produced when an external stimulus induces logical thinking, computation, and reasoning during consciousness. This work uses the beta wave of major scale working memory N-back tasks to analyze the differences between young musicians and non-musicians. After the feature analysis uses signal filtering, Hilbert-Huang transformation, and feature extraction methods to identify differences, k-means clustering algorithm are used to group them into different clusters. The results of feature analysis showed that beta waves significantly differ between young musicians and non-musicians from the low memory load of working memory task.

This paper purposes on shading devices as natural daylight utilization component for building design. It was proved that a proper setting for shading device could conspicuously promote the room lighting performance. Natural daylight which includes directional sunlight, diffused skylight and reflected light can also exert as a perspective of energy conservation in buildings. In order to verify a simple approach can also be workable, a mini-scale model (1:20) is employed in this study. It reveals that when a suitable altitude and azimuth is maintained, in regards to the vertical shading device and the sun position, not only is shading achieved, but the area of the daylight zone can also be substantially increased. The experiment investigated and analyzed the details of this modeling data and subsequently proposed relevant design criterion for vertical shading devices that both users and designers can apply. Namely, it proved that a mini-scale model could also assist in natural daylight utilization and building energy-conservation design.

Querying routing information is all-call-based during the process of translating portable numbers. Long delays in database searches make portable number translation the bottleneck of providing mobile number portability (NP) service. In this article we propose the mitigation of the traffic load through querying an NP database (NPDB) to alleviate the portable number translation delay. We also present a mechanism that utilizes the routing information on dual-mode MSs to alleviate the traffic load of NPDB and thus enhances the efficiency of mobile NP service. To conclude, we evaluate the performance of the proposed mechanism by simulation

In this letter, an efficient subphthalocyanine (SubPc)/C60 heterojunction organic photovoltaic device was demonstrated. The power conversion efficiency was improved from 2.7% to 4.3% by the sublimation of SubPc. The atomic force microscopic images showed that the crystallinity was improved with the sublimation of the SubPc, leading to the significantly enhanced hole mobility of SubPc in orders of magnitude as estimated by the space-charge limited current. The external quantum efficiency spectra further confirmed the improved charge collection efficiency as a result of the increase in the hole mobility of SubPc due to the unchanged spectral shape over the entire spectrum.

Machine-to-machine (M2M) communication technologies have been rapidly developed in recent years to support different kinds of applications, such as automatic monitoring from user equipments (UEs) to home devices. Unfortunately, such applications introduce heavy traffic in both the radio access networks and core networks (CNs). 3rd generation partnership project (3GPP) has defined its local IP access (LIPA) solution, which provides UEs with the ability to access home networks directly without traversing CNs. However, 3GPP LIPA can not support the universal LIPA service. Specifically, a UE's home LIPA service can not be accessed when the UE moves into the coverage area of a visited LIPA network or a macrocell. On the other hand, the recently developed traffic offload enhancements for 3GPP networks did not consider the authentication issue. This paper proposes a telecom-based universal LIPA solution, uLIPA, for 3GPP networks. To completely offload both the UE's traffic and control signaling messages from the CN, uLIPA first enhances the existing 3GPP LIPA architecture and routing path establishment procedure by incorporating the concept of local SGSN and local GGSN. Then, an effective one-pass signaling procedure is devised for mutual authentication among the UE, the visited LIPA network, and the home LIPA network. Since this authentication procedure is based on the 3GPP authentication framework, it can readily be adopted by the 3GPP and compatible mobile networks.

In this report, we demonstrate an efficient planar-mixed heterojunction organic photovoltaic (OPV) device employing a mixed structure of subphthalocyanine (SubPc) donor and C70 acceptor. Compared to a SubPc:C60 cell, the SubPc:C70 cell exhibits high performance with a fill factor (FF) of 52%, short-circuit current density (JSC) of 8.8 mA/cm2, open-circuit voltage (VOC) of 1 V, and power conversion efficiency of 4.6% under air-mass 1.5 G illumination (1 sun). The high VOC is mainly due to the wide interface gap between SubPc and C70 as in the SubPc:C60 device. On comparing the absorption spectra of C70 and C60, C70 shows the higher absorption coefficient and wider absorption band, leading to the significantly improved JSC. Moreover, the FF of the device using C70 is enhanced to 52%; by comparison it is 45% when using C60. In order to understand this phenomenon, the space-charge limited current is measured for estimating the carrier mobility of SubPc, C70, and C60. It reveals that the electron mobility of C70 is lower than that of C60 by orders of magnitude but is close to the hole mobility of SubPc. As a result, a better charge balance condition is achieved when SubPc is blended with C70 and therefore a higher FF is obtained. Consequently, C70 seems to be a more suitable acceptor for the mixed structure to develop a highly efficient OPV device due to the improvements in both electrical and optical properties.

Smartphones and flat rate mobile services encourage the growth of mobile traffic. Operators are motivated to enhance the network and service architecture to cope with the explosion of mobile multimedia traffic. In this article a 3GPP Local IP Access (LIPA) based peer-to-peer mobile networking solution is proposed to improve user experiences in mobile multimedia transmissions and to enhance the transmission efficiency between mobile users. The performance improvement of mobile live-streaming services and the enhancement of the network utilization are illustrated in this paper.

Advances in mechatronics and artificial intelligence make robots play important roles in modern life. Path planning is an important issue in mobile robotics. In an environment with obstacles, path planning is to find a suitable collision-free path, which satisfies certain optimization criteria, for a mobile robot to move from a start location to a target location. Most researches associated with collision-free path planning have focused on finding the shortest path, the minimum-time path, or the safest path etc., and the generated paths may be discontinued. Smoothness of the path is essential for mobile robot navigation, because non-smooth motions can cause slippage of wheels which degrades the robot's deadreckoning ability. The smoothness property of the path also is extremely important for car-like vehicles, which are constrained with their motion abilities. Therefore an approach for smooth and collision-free path planning using genetic algorithm with B-spline curve is proposed to give the mobile robot the abilities of global path planning in static environment with obstacles.

In this paper we propose a rapid-deployment service platform to facilitate the development and the distribution of communication services over IMS network. The mechanism and the architecture to achieve a rapid-deployment platform are discussed. Furthermore, we implemented the platform in an IMS application server (IP-SMS), which provides IP-based short message service over IMS networks. On top of IP-SMS, the interoperation model of add-on services and the IMS network is presented.

Applications of the network control system (NCS) improve the efficiency, the flexibility, and the reliability of large-scale systems in modern industries. In the same time, applications of NCS for remote control and monitoring reduce the time and cost of installation, reconfiguration, and maintenance. This study integrates the Ethernet, the control area network (CAN) network, and the wireless 802.11b in the present NCS. The TCP/IP and the CAN protocols are adopted as the communication gateway in a remote control system for an AC 400 W servo motor. The time delay between the application layer of the client and the application layer of the remote control target has been measured and analyzed in this study. Experimental results indicate that different sampling rates and the environments will greatly affect the delayed time. Also, results indicate that the distance will not affect the delay time in wireless communication. However, as the sampling period reduces, the delay time of the network increases dramatically. In the wireless network, the delay time may change suddenly by the environment interferences. Finally, with a serious time delay, a Smith predictor has been successfully applied to control the servo motor from Kaohsiung which is in 300 km away to verify the feasibility of the proposed NCS.

In this paper, garage parking for a PC-based model car with the design of fuzzy logic controller is explored. At first, the realization of a PC-based model car is described. The authors set up a 1/10th-scale car with front driven and steering wheels. It has four-wheels with four points of suspension. In the PC-based model car, which is completely autonomous, all sensing, computation and control is done on-board. In the second topic, the authors investigate and simulate logic control methods such that the developed model car is able to park in the garage appropriately and automatically from any initial location. The real-time motion of the fuzzy garage-parking controlled model car is implemented in the last topic. By considering practical situations, the authors modify and redesign the fuzzy logic control strategies. Both simulation and experiment demonstrate the feasibility and effectiveness of the proposed intelligent garage-parking control system.

This paper is devoted to the design and implementation of a complete intelligent mechatronic system-a mobile robot possessing autonomous parallel parking capability. In this paper, the configuration of the overall system is firstly introduced. The intelligent parallel-parking control method is addressed in the second topic, where a feasible reference path is provided for the fuzzy logic controller to maneuver the steering angle of the robot. The simulation results illustrate the effectiveness of the developed control algorithm. The authors not only investigate intelligent parallel-parking control methods but also real-time maneuvering of the developed sensor-based mobile robot. The real-time control of the parallel parking system demonstrates the feasibility of the fuzzy control scheme.

Here, an efficient subphthalocyanine (SubPc)/C60 heterojunction organic photovoltaic device is demonstrated by using MoO3 as the anodic buffer. In comparison with the device without any treatments, the insertion of MoO3 leads to a significant increase in open-circuit voltage due to a better energy level alignment of the SubPc, which is similar to the use of oxygen-plasma. In addition, MoO3 serves as an optical spacer to tune the SubPc/C60 interface at the optimum optical field distribution. As a result, the short-circuit current density is considerably improved as predicted using the simulation model based on the transfer matrix. A slightly increased fill factor implies the efficient hole extraction after the insertion of MoO3. Moreover, the device with MoO3 as anodic buffer shows an elongated lifetime as compared with the device with oxygen-plasma treatment.

The authors report the impact of the crystallinity property of the electron donor on the performance of a pentacene/C60 organic photovoltaic device. After subjecting pentacene to sublimation twice, all the photovoltaic parameters showed significant improvements leading to enhancement of the power conversion efficiency from 0.9 to 2.2% under air mass 1.5G solar illumination. This is attributed to the well-packed molecular structure in the pentacene thin film, as observed by X-ray diffraction, which leads to high carrier mobility and hence high photocurrent. Moreover, the elimination of microscopic pinholes or defect sites due to the improvement in the degree of the pentacene thin film reduces the dark current and therefore increases the photovoltage. The external quantum efficiency and space-charge limited current are used to analyze the relationship between the quality of thin film electron donor and device performance.