bluuebunny/crossref_metadata_2025 huggingface dataset:
Airborne Panel Series Circuit Module Test System Software Design
Authors: Shi Guo Qing , Zhang Jian Dong
Published: March 2013

Airborne panel series circuit modules are used to process and transform the information between the aircraft cockpit control panels and the avionics system. A kind of test system software design for the airborne panel series circuit modules using the PXI host system as the testing platform is introduced in this paper. The test system architecture, software design idea and realization method are also discussed. In order to test the airborne panel series circuit modules, whose all kinds of interface signals are needed to provide according to the circuit modules’ test requirements. The most important function of test system is to provide excitation signals to the tested object, while the response signals of the tested object is collected, so the test results can be formed by the test criterion. In the software design, the different test processes are used for the different test objects. The test work can be completed according to the test process, the test data and test results formed in the test can be saved to the database. In the test process, the connection between the test program and database is established. All test data and results are managed by the private database management system. The entire test system uses the top-down design methodology, and host computer adopts PXI system to control the tested modules. The test system has been well applied in project, and its stability and excellent performance have been proved in experimental work.
Analysis and Design of the Active Clamp Forward Converter as a Color LED Driver
Authors: Chang Chien Hsuan , Cheng Hung Liang , Cheng Chun An , Chang En Chih
Published: March 2013

Light emitting diodes (LEDs) have substituted for incandescent bulbs and fluorescent lamps gradually in the residential, industrial and commercial lighting applications. This paper proposes an active clamp forward converter with the sequential color display (SCD) control to drive red, green and blue (RGB) LED arrays. Both of the main switch and the auxiliary switch can turn on under zero voltage switching (ZVS), resulting in high system efficiency. RGB LED arrays are sequentially driven by the same converter, which can save components and reduce cost significantly. Besides, the pulse-width modulation (PWM) control is applied to achieve a large chromaticity variation. The operation principles of the proposed LED driver are addressed. Experimental results of a 100W laboratory prototype are used to verify the feasibility and validity of the theoretical predictions.
Coordinated Converter-Charger for Hybrid Fuel Cell-Battery Power Sources
Authors: Shieh Jenn Jong , Chao Chung Hsing
Published: March 2013

Both the fuel cell and battery have timely dynamic response to the step-profile load input. The current overshoot followed by a voltage undershoot behavior happen the step-up load, particularly. These phenomena are closely related to mass transfer mechanisms such as the water/gas transport by the redistribution of membrane water content in the fuel cell and the charge double-layer effect in the battery. When the load demand is beyond the rated power of the fuel cell system, the battery immediately powers to the load with a transient discharging current especially in the step-profile load power. This study presents a new control strategy for hybrid fuel cell-battery power sources with transient and overshoot considered. The results show that the proposed hybrid fuel cell-battery power source not only acting as a power stabilizer but also dynamically satisfying the step-profile load demand.
Titanium-Doped Indium-Tin-Oxide Anti-Reflection Coating for Poly-Si Solar Cells
Authors: Lin Jian Yang , Lien Shui Yang , Liao Heng Zih , Wang Chao Chun , Nautiyal Asheesh , Lin Yi Hsun
Published: March 2013

In this work, titanium-doped indium-tin-oxide (ITIO) films were deposited onto the glass substrates at room temperature by in-line RF magnetron sputtering. The deposition rate of the ITIO film increases with the RF power. The average transmittance of the deposited ITIO film is higher than 85% in the wavelength range of 350 - 950 nm. The resistivity of the sputtered ITIO has been reduced down to 7.03 × 10-4 Ω-cm. The poly-Si solar cell with ITIO film as the anti-reflection coating shows an efficiency improvement of 36.5% over that with AZO anti-reflection coating.
Low-Power Fast-Settling Low-Dropout Regulator Using a Digitally Assisted Voltage Accelerator for DVFS Application
Authors: Yang Wei Ben , Wang Chi Hsiung , Chang Hsiang Hsiung , Hong Ming Hao , Shen Jsung Mo
Published: March 2013

This paper presents a low-power fast-settling low-dropout regulator (LDO) using a digitally assisted voltage accelerator. Using the selectable-voltage control technique and digitally assisted voltage accelerator significantly improves the transition response time within output voltage switched. The proposed LDO regulator uses the selectable-voltage control technique to provide two selectable-voltage outputs of 2.5 V and 1.8 V. Using the digitally assisted voltage accelerator when the output voltage is switched reduces the settling time. The simulation results show that the settling time of the proposed LDO regulator is significantly reduced from 4.2 ms to 15.5 μs. Moreover, the selectable-voltage control unit and the digitally assisted voltage accelerator of the proposed LDO regulator consume only 0.54 mW under a load current of 100 mA. Therefore, the proposed LDO regulator is suitable for low-power dynamic voltage and frequency-scaling applications.
Interleaved Boost Converter with Boost-Type Snubber for PV Power System
Authors: Tseng Sheng Yu , Chang Geeng Kwei
Published: March 2013

This paper presents an interleaved boost converter with boost-type snubber for PV system. Paralleled converters working in interleaving manner are adopted to eliminate the pulsating current and increase powering capacity. Boost-type snubber is utilized for soft-switching of the power transistor to reduce switching losses. By switch integration, one boost-type snubber can be shared by N phases of boost converter to effectively reduce component counts and costs. The improved supply characteristics and conversion efficiency make it suitable for charging applications. A prototype for battery charger has been implemented to prove the feasibility of the proposed topology.
Fatigue Quality Index by Infrared Stress Measurement in Spot Weldment
Authors: Kim Kyung Jae , Yang Sung Mo , Yu Hyo Sun , Kang Hee Yong
Published: March 2013

Since the spot welding process was completed in a very short time and there were many factors affecting the generation of welding defects, it was difficult to control all experimental factors of welding. Additionally, it was hard to monitor the distribution of stress in practical cases such as vehicle bodies. The purpose of this study was to investigate the applicability of infrared thermography for the evaluation of spot weldability in the view of fatigue life. In this research, infrared(IR) stress analysis adopting an infrared thermography as nondestructive evaluation of spot weldability was investigated. Using temperature and IR stress distribution obtained by an infrared camera from adiabatic heat expansion under a repeated load of sinusoidal waves, we estimated the fatigue quality index(FQI) of spot welded specimens. We also evaluated in terms of FQI and corrected the S-N curve from the original fatigue life curve of base metals.
Resistive Switching Characteristics in Nanocrystalline Silicon Films for Conductive-Bridging Resistive Random-Access Memory Applications
Authors: Lin Jian Yang , Wang Bing Xun
Published: March 2013

In this paper, intrinsic nanocrystalline silicon thin films were deposited onto the ITO/glass substrates by PECVD and were used as the conduction material for the conductive-bridging random-access memory devices. The resistive switching characteristics of the nanocrystalline silicon thin films were investigated. Experimental results have shown that the stable bipolar resistive switching of the nc-Si films and retention time over 104s. In addition, the current conduction mechanism of the nanocrystalline silicon films was examined with XPS depth file analysis. It clearly indicates that the conduction mechanism for the resistive switching is formation metallic bridges come form metal cation migration in the nanocrystalline silicon films.
Predicting Equation of Transient Position-Probability Density for Nano-Tunnel Problem in SET
Authors: Lin Sheam Chyun , Shih Hsien Chang
Published: March 2013

This analytic investigation intends to study the nano-tunnel problem of the single electron transistor (SET), which is the most important component in the nano-electronics industry. With a combined effort of quantum mechanics and similarity parameter, the PDE equation of transient position-probability density is attained and can be applied to predict the electron’s position inside the nano tunnel. Also, appropriate initial and the boundary conditions are set up in accordance to the actual electron behavior for solving this PDE of probability density function. Thereafter, a simple, closed-form solution for the probability density is obtained and expressed in terms of the error function for a new similarity variable η. In conclusions, this is an innovative approach by using the Schrödinger equation directly to solve the nano-tunnel problem. Moreover, with the aids of this analytic position-probability-density solution, it is illustrated that the free single electron in the SET’s tunnel can only appear at some specified regions, which are defined by a dimensionless parameter η within a range of 0≤η≤2. This result can be served as a valuable design reference for setting the practical manufacture requirement.
Monte-Carlo Analysis of a New 6-T Full-Adder Cell for Power and Propagation Delay Optimizations in 180nm Process
Authors: Murthy G. Ramana , Senthilpari C. , Velrajkumar P. , Lim T.S.
Published: March 2013

This paper presents a 1-bit full adder by using as few as six transistors per bit in its design. It is designed with a combination of multiplexing control input and Boolean identities. The proposed design features lower operating voltage, higher computing speed and lower energy consumption due to the efficient operation of 6-transistor adder cell. The design adopts Multiplexing with Control input technique to alleviate the threshold voltage loss problem commonly encountered in pass transistor logic design. The proposed design successfully embeds the buffering circuit in the full adder design and the transistor count is minimized. The improved buffering helps the design operate under lower supply voltage compared with existing works. It also enhances the speed performance of the cascaded operation significantly while maintaining the performance edge in energy consumption. For performance comparison, the proposed full adder is evaluated along with four existing full adders via extensive BSIM4 simulation. The simulation results, 180nm process models, indicate that the proposed design has lowest energy consumption per addition along with the performance edge in both speed and energy consumption makes it suitable for low power and high speed embedded processor applications.
Analysis and Signal Recovery of Modulated Wideband Converter with Gain Mismatch
Authors: Wang You Hua , Zhang Jian Qiu
Published: March 2013

Recently, a sub-Nyquist sampling system, called as Modulated Wideband Converter (MWC), for sparse analog signals is proposed in [1]. In this paper, the gain mismatch, i.e. the gain variation of the mixers, the low pass filters and the low-date rate ADCs, in the MWC is, firstly, analyzed. A gain error matrix defined to model the gain mismatch is, then, proposed to formulate all of these non-idealities of the gains. Based on the gain error matrix, a more accurate signal reconstruction algorithm is presented. Numerical simulation results show that the proposed signal reconstruction algorithm outperforms the reference algorithm in the presence of gain mismatch, while the analytical results are verified.
A Study of Fabrication Nanopowders of Cu2ZnSnS4 for Solar Cells Absorbers
Authors: Wong King Leung , Chen Wen Lih , Wang Shing Hae
Published: March 2013

In this study, fixed mole number proportion of CuCl, ZnCl2, SnCl2‧2H2O and sulfide compounds and the reacted solution are added to the autoclave, then the CZTS powders are prepared by changing the heating temperature and time. It is found from the experimental results that better result with less secondary phase can be obtained at the heating temperature 250°C and heated time of 36 hours.
Behavioral Modeling and Design of Predistortion for Wireless Transmitters with Multi-Branch RF Power Amplifier
Authors: Kang Won Shil , Lim Jong Gyun , Lee Kang Yoon , Ku Hyun Chul
Published: March 2013

In this paper, behavioral modeling approach and predistortion design methods are proposed for wireless transmitters with multi-branch radio frequency (RF) power amplifiers (PAs). Multi -branch RF PA architectures are studied such as balanced RF PA systems and linear amplification with nonlinear component (LINC) systems. Conventional behavioral modeling using single input and single output data cannot extract the behaviors of RF PAs in each branch. The behavioral modeling method using separated input signals and weighted input identification is proposed to extract accurate behavioral models for each branch. A decentralized predistortion structure that consists of multi-branch memory polynomial architecture predistortion components is proposed. The proposed behavioral modeling method is used for the design of decentralized predistortion using indirect learning method. The performances of proposed modeling and predistortion method are evaluated by comparing the normalized mean square error (NMSE) values with conventional single-branch behavioral modeling and predistortion. The input signal is 10MHz long-term evolution (LTE) signal. The results show that the proposed behavioral modeling and decentralized predistortion architecture are suitable for wireless transmitters with multi-branch RF PAs.
A Cooperative Relay Scheme Based on Constellation Expansion
Authors: Park Jong In , Lee Young Po , Kim Sun Yong , Jee Gyu In , Yoon Seok Ho
Published: March 2013

In this paper, a novel cooperative relay scheme based on a symbol constellation expansion is addressed in multipath fading channels. The proposed scheme expands the symbol constellation through a unique combination of the original symbols, thus increasing the minimum distance among the single points. Numerical results demonstrate that the proposed scheme achieves the fourth order cooperative diversity with two relays and has a better bit error rate performance than those of the conventional schemes.
Estimation of OFDM Carrier Frequency Offset Robust to Offset Variation
Authors: Yu Chang Ha , Lee Young Po , Kim Sun Yong , Jee Gyu In , Yoon Seok Ho
Published: March 2013

In this paper, we propose a novel carrier frequency offset (CFO) estimation scheme for orthogonal frequency division multiplexing (OFDM) systems. The proposed scheme has much wider estimation range compared with that of the conventional scheme, making it more robust to the fractional FO variation. Numerical results demonstrate that the proposed scheme has better estimation performance than the conventional scheme for wider fractional FO range.
Effect of PAO-Based γ-Fe2O3 and Surfactant Concentration on Viscosity Characteristic
Authors: Leong Siti Asma’ Nikmat , Samin Pakharuddin Mohd , Idris Ani , Azizul Muhamad Asri , Misran Effaliza
Published: March 2013

This is a preliminary study on the viscosity characteristics of polyalphaolefin (PAO)-based γ-Fe2O3 under zero magnetic fields. By varying the concentration of magnetic nanoparticles (MNPs), PAO-based γ-Fe2O3 with different concentrations were synthesized by co-precipitation method. The effect of this factor on the viscosity characteristic of γ-Fe2O3 (< 30 nm) was investigated on the basic of a series of rheological measurement. The use of oleic acid (OA) as a coating agent and surfactant was also investigated by varying its concentration. The results show the concentration of MNPs and the amount of OA has obvious effect on viscosity characteristics of PAO-based γ-Fe2O3. In the case of comparison between the concentrations of MNPs, higher concentration of MNPs increased the viscosity of the PAO-based γ-Fe2O3 and exhibit nearly Newtonian behavior. The large amount of OA also exhibits the increment on viscosity characteristic of MNPs. The experimental data were compared with the Bingham and Casson model and the results revealed that the rheology of the polyalphaolefin (PAO)-based γ-Fe2O3 fitted the Casson model better.
The Performance Comparison of Sub-1GHz Wireless Personal Area Monitoring Systems
Authors: Lin Wei Cheng , Lan Ching Chun , Lee Long Kun , Luo Kai Yang , Hong Wei Zhou
Published: March 2013

This paper presents a brand new hardware framework of wireless personal area monitoring system (WPAMS) in order to form a point-to-point simply connected personal area identification network with the applications of ubiquitous monitoring personal valuable belongings. The WPAMS consists of sub-1GHz radio frequency identification (RFID) interrogator subsystem, antenna subsystem and passive RFID transponder subsystem with salient features of low-cost, tiny and power-efficient. The hardware frameworks of two commercial interrogator prototypes have been identified and simulated. With the connection of 5.7dBi right-hand circularly polarized antenna and in the adherence of local power regulation (within 1watt), the identified range of all types of commercial transponders from sideward and upward directions can be reached to 2 meters. The current PCB size of interrogator is 88mm45mm and can be reduced in the near future.
A Study of Modified Prime Codes Optical CDMA for Wired-Wireless System
Authors: Yen Chih Ta , Chen Wen Bin
Published: March 2013

In this study, we propose optical code-division multiple-access (OCDMA) network for the radio-over-fiber (RoF) transmissions. The network encoder/decoders (codecs) are structured on the basis of arrayed-waveguide-grating (AWG) routers coded with modified prime codes (MPCs). Performances are numerically evaluated with the effect of phase-induced-intensity-noise (PIIN). It showed that the new code families with lower cross correlation can suppress the intensity noise and cancel out the multiple-access interference (MAI) in balanced detection process effectively and hence improve the system performance. By the proposed MPC-coded OCDMA ROF network codecs, each network requires only two AWG routers to accomplish spectral coding of radio base station (RBS) and decoding of control station (CS), thus, resulting in a simpler and lower cost system. It is possible to accomplish interference- and crosstalk-free optical CDMA system for RoF transmissions.
Optimization Algorithm of the Repeaters Distribution by Square and Cellular Model
Authors: Pang Shan Chen , Wu Hong Yue , Sun Xiao Wei , Zhang Yong Jun
Published: March 2013

Very high frequency (VHF) is widely used in radio and television broadcasting. In order to improve the quality of service (QoS) and signal transmission distance, the repeaters be applied to lengthen the transmitting distance of VHF and expand the coverage of radio stations. Under ensuring the QoS, the reduction cost is very important. In this paper, focusing on the different coverage of repeaters, we discuss the minimum number of repeaters to cover a whole circular area, and the square model and cellular model are proposed. Then we analyze the case in view of the simplex communication and duplex communication. Furthermore, the influence of the location of the radio station to the minimum number of repeaters needed is discussed. Finally, we discuss how the minimum number of repeaters changes with the change of the numbers of radio stations. The minimum number of repeaters to cover the circle area will increase as the radius of the repeaters coverage decreases. The radio station in the center of the circle flat can broadcast to the farthest area and the radio station in the fringe area can’t broadcast to farther area. In simplex communication, the minimum number of repeaters with n radio stations in the circle are is n-1 times greater than that with only one radio station.
A Tracking System with Location-Based Delivering for Reducing Short Message Transmissions
Authors: Yeh Yi Hsuah , Lai Yuan Cheng , Lin Jian Wei , Lai Ching Neng , Weng Hui Chuan
Published: March 2013

Combining Short Message Service (SMS) and Global Position System (GPS), this paper proposes a novel method, called Location-based Delivering (LBD), and further develops a realistic system to tracking target's moving. LBD can reduce the number of short message transmissions while maintaining location accuracy within an acceptable range. LBD mainly adopts two proposed techniques: location prediction and dynamic threshold. Location prediction utilizes the current target's location, moving speed, bearing to predict its next location. When the distance between the predicted location and the actual location exceeds a threshold, the target sends a short message of the actual location to the tracker for updating. According to the target’s moving speed, dynamic threshold dynamically adjusts the threshold in order to balance the location accuracy and the amount of short messages. Experiment results show that LBD indeed outperforms other methods because it sends the least number of short messages and also maintains the satisfactory location accuracy.
Robust MVDR Estimation via Polynomial Rooting for MC-CDMA Carrier Frequency Offset
Authors: Su Ing Jiunn , Huang Chiao Chan
Published: March 2013

In this letter, we present a blind carrier frequency offset (CFO) estimator by exploiting the polynomial rooting technique for multicarrier-code division multiple access (MC-CDMA) systems. Relative high accuracy and low-complexity to the CFO estimation can be achieved by rooting a polynomial. Simulation results are provided for illustrating the effectiveness of the proposed blind polynomial rooting estimator.
Cell Planning for Base Station in Mobile Communication Using an Improved Genetic Algorithm
Authors: Liao Hung Jen , Lin Chun Hung Richard , Tung Kuang Yuan , Lin Ying Chih , Tsai Cheng Fa , Yang Tzer
Published: March 2013

Cell planning problem is one of the most important issues in mobile communication networks. To tackle the problem, one should address the location management issue because it significantly affects the cost of cell planning in mobile networks. The partition of location areas is developed to minimize the total costs of considering user location and search operation simultaneously in cellular networks, which has been shown to be NP-complete and is commonly solved by metaheuristics in previous works. In this paper, we propose novel cell planning methods for base stations using genetic algorithms with initialization, local search, and particular mechanisms of area and cell crossovers. Several simulations are conducted on various cell networks with previous, random and real configurations. The simulation results reveal that our schemes are superior to the considered algorithms.
Design of Precise Lightweight Mirror
Authors: Vít Tomáš , Melich Radek , Václavík Jan , Lédl Vít
Published: March 2013

The presented paper shows results from the mechanical design of lightweight mirrors for space applications, where demand for maximum weight loss goes together with demands for sufficient strength, shape accuracy, and surface quality of optical surfaces. The paper illustrates the material properties of different materials, which are often used for manufacturing precise optics. It compares three materials – e.g. optical glass such as NFS-15, optical ceramic such as Zerodur, and Silicon-infiltrated sintered Silicon Carbide – from the point of view of suitability for machining and their mechanical and thermal properties. It also shows the possibility of mass reduction by using different geometries of lightweight structure. Paper shows the results of numerical simulations of specified load-cases and comparison of different lightweight structures and different materials with respect to their strength and stiffness.
Design of the Light-Emitting Diode Vehicle Projector Headlamp System without Shield
Authors: Hsieh Chi Chang , Li Yan Huei
Published: March 2013

The light-emitting diode (LED) has been applied extensively to various kinds of applications according to the advantages of its small dimension, low energy consumption and strong reliability. The projector headlamp system proposed in this study was composed of four main critical components including focused LED, asymmetric metal-based plate, freeform surface and condenser lens. It was designed, developed and simulated under low energy consumption to save more energy. Only five 3-Watt focused LEDs without a shield or baffle inside the projector headlamp system was designed to provide the low-beam cutoff in order to meet the requirements of international Economic Commission for Europe (ECE) R112 regulation. Eventually, the prototype of this LED vehicle projector headlamp system was also fabricated to perform the correct light pattern.
Dynamic Throughput Optimization in Wireless Multi-Hop Networks
Authors: Liu Jain Shing
Published: March 2013

In this paper, we study the throughput optimization problem in wireless multi-hop networks. For this problem, we introduce a cross-layer formulation to accommodate routing, scheduling and stream control from different layers of network with relevant constraints. Specially, by using a Lagrangian approach and a Markov Chain Monte Carlo method, we extend the programming-based formulation to a distributed algorithm that can dynamically approximate the optimal solution without the overhead of centralization. Finally, through computational results, we discuss the insight that can be gained from the cross-layer optimization and the distributed algorithm.
Gateway Placement under the Consideration of the Starvation of TCP Flows in Wireless Mesh Networks
Authors: Liu Chuan Gang , Chiang Chi Hui , Liao Ya Wen
Published: March 2013

Wireless mesh networks are expected to provide wireless broadband access to Internet. In such networks, gateway placement is an important topic, which usually dominates the overall wireless performance, and hence there have been lots of the related works. However, recent paper even discovers that the starvation of TCP flows usually occurs near wireless gateways. Some TCP flows will starve just due to TCP flows of the node next to the gateway. Hence, possible ways to improve this critical issue should be developed urgently. However, until now, there have not been the feasible ways without modifying MAC and TCP mechanisms. Hence, in this paper, we plan the gateways placement under the consideration of this issue. To the best of our knowledge, this paper is the first work to plan gateway placement under considering the starvation of TCP flows. Our work also provides a new view in the field of planning wireless mesh networks.
High-Sensitivity Sensor Using Frequency Sweeping Generated Ringing Effect in Single-Mode Fiber-Loops
Authors: Zhang Yun Dong , Wang Ying , Gai Yu Long , Zhang Xue Nan , Yuan Ping
Published: March 2013

In this article, we present propose a simple method to detect the minor fluid-environmental changes using ringing phenomenon generated by frequency sweeping in a single mode optical fiber resonator. The method is based on the fact that the insertion loss of the optical fiber resonator is determined by the environmental changes alone, which leads to the changes of cavity ringdown time of the fiber resonator. The method has several conspicuous advantages over the frequency-domain method, using which the minimal detectable optical loss is in the order of .We also show that the sensing system is insensitive to the temperature drifting, which overcome the main defect of fiber loop resonator, that it is extremely sensitive to temperature changes. The structure of the sensor is compact and stable due to the characteristic of optical fiber resonator, and it is easy to apply because the structure is not delicate and is easy to construct.
The Effect of the Broken Edge on the Concentricity of the Micro-Polished Optical Fiber End-Face
Authors: Tsai Ying Chien , Huang Guang Miao , Chen Jun Hong , Chen Shih Wei
Published: March 2013

The concentricity of the optical fiber micro lens affects the coupling efficiency of a laser module a lot. In this paper, the effect of the perpendicularity of the broken edge on the concentricity of the micro optical fiber end-face during the micro polishing process is studied. A mathematical model is derived to describe the variation of the material removal rate (MRR) when the tilt angles and amount of feed of the optical fiber are changed. An experiment is built to measure the concentricity of optical fiber with different tilt angles and feeds. The result shows that both of the dimensionless factor QAB and measured concentricity have the same tendency. The concentricity is better when the tilt angle is smaller and the amount of feed is larger. An improved polishing process is suggested. A good concentricity within 1μm can be achieved when fabricate the double-variable curvatures end-face of the optical fiber.
A Field Emission Light Source Using Reflective Metal Groove Anode and Long Narrow Stripe Cathode
Authors: Chang Chih Chieh , Pan Yi Jui , Tsai Woo Hu
Published: March 2013

A novel reflective metal anode with different groove structures and a set of parallel long narrow stripe Carbon nanotube (CNT) cathodes to fabricate a 7 inches field emission backlight unit (CNT-FEBLU) has been carried out in this paper. In comparison with a simple diode structure, which has the same stripe cathode unit with screen printing phosphor layer on ITO glass surface as the anode, the reflective metal anode has some advantages such as sustaining high field emission current, no unexpected arcing, and high illumination and uniformity without phosphor degradation. The results show that a reflective metal anode not only conducts the residual charges and heat from the phosphor surface effectively, but also reflects the light to one side of the panel through the cathode end and exhibits high illumination without obvious obstacle by the narrow stripe cathodes. The luminance of the reflective metal groove anode we proposed is 11530 cd/m2, with the emission current density of 1.52 mA/cm2 under the electric field about 1.07 V/μm.
Trim Down Redundant Transmission in Data Synchronization
Authors: Wen Chun Hao , Lin Richard Chun Hung
Published: March 2013

Data synchronization distributes data to users of various configurations, and poses many challenges in today’s collaborative networks. In this paper, we propose a data synchronization scheme to reduce the finish time of distributing data with the understanding that users are free to join late or leave, which is common if the desired data is received. Our scheme involves a heuristic algorithm to push-and-pull segments of data. The numerical results yield significant lesser finish time than the conventional P2P approaches. Besides, there are no redundant transmissions and no need of searching data pieces in our approach, which help to reduce the network traffic and receiving time of data.
Time-Efficient Route Optimization in PMIPv6
Authors: Jin Dong Xu , Shi Fei , Chin Joon Sup , Song Joo Seok
Published: March 2013

With the development of the wireless internet, there are more and more mobile terminals. Without a mobility management protocol a mobile terminal could not communicate with other terminals when it is away from its home network. Mobile IPv6 is proposed which is host-based mobility management protocol. But it has several drawbacks, such as wireless link resource waste, load or consumption of power in mobile terminal is large. To overcome the weakness of host-based mobility management protocol, network-based mobility management protocol called Proxy Mobile IPv6 (PMIPv6) is standardized by the IETF NETLMM working group, and it is starting to attract considerable attentions. Although several proposals have been made for Route Optimization (RO), they still need too many communications and it may cause communication delay. In this paper we proposed a time-efficient RO in PMIPv6 by optimize the procedure of it. We use the characteristic of anycast to achieve the time efficiency. By the mathematical analysis we prove that the proposed protocol has shorter latency and supports faster mobility of the mobile terminals.
Throughput Analysis for IEEE 802.11e Enhanced Distributed Channel Access
Authors: Lee Yu Tae
Published: March 2013

With the increasing demand of wireless local area networks, the support of differentiated Quality of Service (QoS) has become one of the critical issues on IEEE 802.11 medium access control protocols. To support the differentiated QoS requirements, IEEE 802.11e has been standardized. IEEE 802.11e defines Enhanced Distributed Channel Access (EDCA) for access mechanism, which is a contention based channel access method and delivers traffic based on differentiated access categories for the support of QoS. This paper introduces a three dimensional Markov chain model to evaluate the performance of IEEE 802.11e EDCA mechanism with an arbitrary number of different access categories. The proposed analytical model captures the major QoS specific features in the IEEE 802.11e EDCA and hence can provide a numerical approach to pick the set of EDCA parameter values to meet the QoS requirements of each access category. The results of our proposed analytical model are verified using simulations.
The Yellow-Ring Measurement of White LED by the Reflective Lightspot Method (RLM)
Authors: Yang Ching Ching , Tsai Hsin Yi , Hsiao Wen Tse , Huang Kuo Cheng
Published: March 2013

The yellow-ring (YR) is a chromatism phenomenon which is caused by the inhomogeneous phosphor layer of the white-light LED (WLED). The characterized lightspot with YR is that the yellow light appears in the periphery of white lightspot zone. The lightspot image of WLED can be acquired from two approaches; projective lightspot method (PLM) and transmissive lightspot method (TLM). By the PLM system, the lightspot could be projected on the spot screen (wall or others) and its image is acquired by a CCD camera. However, the working distance between camera and sample WLED must be larger (~ 2 m) to obtain the lightspot image without tilt aberration. For the convenience of automatic inspection, the working distance in the TLM system can be modified to 0.3 m. Since the light travels through the spot screen, such as copier paper or acrylic plate, etc., the camera cannot obtain the real lightspot image in the TLM system. In practice, the material of spot screen will absorb and scatter the WLED light, and in the image color would be a bit different between the real lightspot and the acquired lightspot. In order to improve the above disadvantages, the study presents the reflective lightspot method (RLM) that the camera acquires the reflective lightspot image from the 50/50 beam splitter at the same optical axis. The RLM system is not only able to capture the tilt-less lightspot image, but also obtain readily the non-saturated image. The experiment results show the RLM system has the better evaluation of YR index (YRI), and is more suitable for the automatic inspection of WLEDs.
The Telescope Primary Mirror Isostatic Mount Bonding Position Analysis
Authors: Hsu Ming Ying , Lin W.C. , Chan Chia Yen , Ho C. F. , Chang S.T. , Huang Ting Ming
Published: March 2013

The telescope primary mirror Isostatic Mount (ISM) design is an important issue for optical performance. The ISM bonding position will affect the telescope performance. The primary mirror reflection surface is parallel with gravity force during telescope alignment process. Thus, the distance between ISM geometry center and primary mirror center of gravity will lead mirror surface deformation. The ISM mounting mainly aberration is astigmatism at mirror surface. This study is applied Finite Element (FEM) simulate mirror surface deformation and using Zernike polynomial fitting the mirror surface aberration. The simulation result show the ISM bonding at mirror neutral plane the aberration will minimum at 1G gravity. The ISM bonding position errors also affect aberration distribution.
The Optical Response of Trapezoidal Comb-Like Nanostructures
Authors: Zhang Yun Dong , Li Jin , Li Han Yang , Yuan Ping
Published: March 2013

Metal nanostructures can be used to control light transmission on the nanometer scale. In this paper, we propose a ladder-type comb-like metal nano-grating structure, based on optical filtering properties of the comb-like nanostructures and surface plasmon resonance effect of the metal nano-structures. The comb part of the structure is the silver nano-grating with the width of 20nm and a depth difference of 5nm between the adjacent gratings. We use the 532nm CW laser as the incident light source to study the reflective properties of the P polarized light and calculate the reflected power spectrum of the structure in three different parameters, which are the silver nano-grating, the silver-air nano-grating (silver grating are separated by air) and silver-SiO2 nano-grating. The experimental results show that the light wave oscillation modes are closely related to the comb-like structure parameters (including the depth and width) on the power spectrum. Meanwhile, we also draw conclusions that different intervention media does not change the position of the light wave oscillation modes, but only a significant effect on the reflection intensity of the different modes. Furthermore, we also noted that the depth of silver nano-gratings can affect the position of the resonance peak. As the waveguide depth of the silver nano-gratings increasing, the spacing of different modes’ oscillation peak is becoming larger. Based on the finding, we can modulate the light wave oscillation modes in a very wide spectral range. The results of this paper will promote the development of the optical filter, light wave mode selection and random laser excitation.
The Characteristics of All-Optical Switching and Modulation in Phenoxy-Phthalocyanines Liquid
Authors: Zhang Yun Dong , Yao Cheng Bao , Yin Hai Tao , Yu Chang Qiu , Li Jin , Yuan Ping
Published: March 2013

We present our experimental results on the measurements of excited state dynamics in 2, 9, 16, 23-phenoxy-phthalocyanine (Pc1) and 2, 9, 16, 23-phenoxy-phthalocyanine-zinc (Pc2) using the pump-probe experiment. The results show that the All-Optical Switching (A-OS) response time of Pc2 longer than that of Pc1, and switch-off and -on times of A-OS for Pc2 are 1.2 and 11.6 μs and for Pc1 are 2.3 and 7.8 μs at the same intensity. Moreover, analysis of modulation characteristics of A-OS shows that the stronger the light intensity of the pump light is, the smaller the normalized transmittance is and the shorter the response time of A-OS is. The consequences of such short lifetimes are also discussed in view of the strong A-OS properties of these molecules.
Simulation of Thermal-Optical Effects on a PMMA Fresnel Lens Used in Solar Concentrators
Authors: Chen Yi Cheng , Su Chia Hsun
Published: March 2013

This study presents an integrated opto-mechanical analysis of a PMMA Fresnel lens used in solar concentrators for concentrated photovoltaic systems. The temperature dependence of refractive index of the PMMA lens was analyzed based on its temperature coefficient of refractive index dn/dT. In addition, the thermal distortion of the Fresnel lens under various temperature rises was computed by finite element analysis (FEA). Then, the temperature induced effects, variation of refractive index and the deformed lens geometry, were imported into ray tracing simulation simultaneously. Finally, the thermal-optical effects on the optical performance of a flat Fresnel lens were successfully investigated and discussed, including the maximum irradiances on the receiver and the optical efficiencies under different temperature rises.
Performance Analysis and Improvement on SIP-Based VoIP Server
Authors: Shen Li Te , Hwang Shaw Hwa , Huang Chi Jung , Yeh Cheng Yu
Published: March 2013

The performance improvement on SIP-based VoIP server is given in this paper. The signaling server “SIP Proxy Server” and media streaming server “Media Relay Server” are applied. Firstly, the performance of VoIP server is analyzed and evaluated in detail. Then the effective method is applied to improve the performance of VoIP server. In the analysis results of SIP Proxy Server, the CPU time for the registration and call-setup sessions need 3.241 ms and 7.985 ms respectively. Moreover, in the Media Relay Server system, when the packet size from 1 to 32 bytes, the maximum throughput of packet is about 82,000 and 16,000 per second for UDP and TCP respectively. The large the packet, the less throughput is tenable. There are three methods applied to improve the performance. The capacity by 31 times is achieved. The capacity with 3,524 calls for each Media Relay Server is achieved. The improved method proposed in this paper is reasonable.
Partial Bit Strings Pruning Channel Assignment in Multi-Rate Multi-Channel Wireless Networks
Authors: Kuo Tai Wei , Lin Chun Hung Richard , Lin Ying Chih
Published: March 2013

IEEE 802.11 based wireless networks are extensively used in mesh, ad hoc, and sensor networks due to less expense and easier deployment. IEEE 802.11a/b/g standard supports multi-rate and multi-channel settings to facilitate network transmissions. Many researchers focus on maximizing network throughput and propose channel assignment algorithms in IEEE based multi-rate multi-channel (M2) wireless networks. Less works are devoted to the study of network capacity in M2 wireless networks. In our observation, static channel assignment algorithms for maximizing network throughput may limit network capacity, and the improvement on network capacity comes mainly from higher data rate communication links. Therefore, we model the optimization problem and derive the optimization formula in detail. Subsequently, we propose an efficient channel assignment algorithm, Partial Bit Strings Pruning (PBSP) channel assignment to maximize network capacity. The results of associated simulations show that the performance of our PBSP channel assignment algorithm is superior to the algorithm based on the well-know minimum-interference approach.
Packet Loss Concealment Using Dual-Side Waveform Similarity Overlap-and-Add
Authors: Yeh Jui Feng , Kuo Min Da , Hsu Zhong Hua
Published: March 2013

Packet loss is one of the most essential problems in speech communication. It will cause the information loss and uncomfortable for listeners in voice over IP. This investment proposed an approach based on waveform similarity measure using overlap-and-Add algorithm. The waveform similarity overlap-and-add (WSOLA) technique is an effective algorithm to deal with packet loss concealment (PLC). For real-time time communication, the WSOLA algorithm is widely used to deal with the length adaptation and packet loss concealment of speech signal. Time scale modification of audio signal is one of the most essential research topics in data communication, especially in voice of IP (VoIP). Herein, we proposed the dual-side WSOLA that is derived by standard WSOLA. Instead of only exploitation one direction speech data, the proposed method will reconstruct the lost voice data according to the preceding and cascading voice. The dual-side WSOLA can use both the past and future speech signal waveform to reconstruction voice waveform of lost packet. The evaluations show that the quality of the reconstructed speech signal of the dual-side WSOLA is higher than that of the standard WSOLA and GWSOLA on different packet loss rate and length using the metrics: PESQ and MOS. The significant improvement is obtained by dual side information in the proposed method. The proposed dual-side waveform similarity overlap-and-add (DSWSOLA) outperforms the traditional approaches.
Near-Infrared Electro-Optics Modulation Coding Technology Using the Aperture Module with the Changeable Stop
Authors: Chen Der Chin , Su Jing Yuan
Published: March 2013

In this paper we demonstrate a new technology in which we use the spatial optical modulation with trigger pulse width and pulse width modulation of light source (LED,LD) to build the near-infrared electro-optics modulation coding system (NIEOMCS). Using the optical coupler to let the pulse modulation near infrared LED collimated light of transmitter enter into an optical fiber and spatial optical modulator, the electro-optics modulation signal is then detected by the photodiode of the receiver. Because of aperture module with three changeable stop sizes and three duty cycles of light signal, there are 27 kinds of code modes in this system. When the receiver aperture is smaller than the correlation length of fading and the observation interval is shorter than the correlation time of fading, the modulation code error rate of the modulation system occurring is less than 0.2%.
Multimode-Interference-Based Waveguide Crossing in Two-Dimensional Cubic Photonic Crystal
Authors: Lin Yih Bin , Cheng Jen Hao , Chen Rei Shin , Yu Ting Chung , Liu Ju Feng , Lin Han Bin
Published: March 2013

A novel design of photonic crystal waveguide crossing based on multimode-interference (MMI) structure is proposed. Two structures of difference device lengths are simulated and studied. The proposed structures have high transmission efficiency for a wide bandwidth. The crosstalk is -26dB with device length of 12 lattice periods and -39dB with device length of 24 lattice periods. The plane wave expansion method and finite-difference time-domain method are used to calculate the modal dispersion curve and field propagation, respectively. The proposed MMI-based waveguide crossing has the potential to be practical in high-density optical integrated circuits.
Microsphere Coupled Mach-Zehnder Interferometer for Biochemical Sensor
Authors: Zhang Yun Dong , Zhang Jing , Tian He , Yuan Ping
Published: March 2013

We present the microsphere coupled Mach–Zehnder interference structure. We theoretically calculate that spectral responses of this structure vary with the glucose solution concentrations. It can produce the sharply asymmetric Fano resonance line shape related to the slope between zero and unity transmission. The variation of the normalized transmission is linearly related to the solution concentration. This structure is the promising highly sensitive biochemical sensor due to high quality factor resonance and steep slope over a very narrow frequency range
Measurement and Analysis of Loss for Long-Period Photonic Crystal Fiber Gratings
Authors: Chiang Jung Sheng , Lin Shih Yuan , Chen Chia Ming , Sun Nai Hsiang , Liu Wen Fung
Published: March 2013

In this work, we used a fiber splicer to fabricate a long-period grating (LPG) in a photonic crystal fiber (PCF) for power loss measurement. Photonic crystal fiber grating (PCFG) is long-period grating which is produced by using electric arc to heat the PCF. For the measurement of power loss, we will use beam profile and power meter to analyze in detail the phenomenon of loss factor and parameter of the measurement. We will also do experiment on both polished and unpolished long-period photonic crystal fiber grating and compare the results. Utilizing two long-period grating of photonic crystal fiber (polished and unpolished) to analyze and compare the difference of optical field distribution and power loss. The unpolished PCFG shows the equally filed distribution with wavelength by beam profile measurement. But, the polished PCFG is sensitive with wavelength that the field distribution of wavelengths 1520 and 1530nm are concentrated on the upper half of field distribution and the wavelength 1530nm is more concentrated on the side. The wavelength of polished long-period grating of photonic crystal fiber has sensitive response and loss with wavelength increase and increment. Another measurement is probing photonic crystal fiber grating of power loss measurement using power meter. The PCFG can be evaluated by field distribution and power for operating wavelength and power loss. The measurement of operating wavelength of the long-period fiber grating is 1550nm.