A 12‐bit segmented resistor‐capacitor digital‐to‐analog converter for a display driver IC of a large TFT‐LCD panel system

Abstract— A 12‐bit segmented R‐C DAC to support a linear gamma curve has been proposed and fabricated in a 720‐channel LCD source driver with a 16‐V 1‐poly 3‐metal high‐voltage CMOS process. The proposed DAC has a global resistor string and sample‐and‐hold buffers. A MSB voltage selected by the upper 6 bits of input data and a LSB voltage selected by the lower 6 bits of input data are summed by using a sample‐and‐hold operation with offset cancellation in the proposed DAC. The measured DNL was less than 0.3 LSB, and the output voltage deviation was less than 3 mV in all gray levels. Although two sample‐and‐hold buffers were adopted to operate alternatively, the die size was as small as 24.9 mm², which was only an 8.3% increase compared to that of a conventional 8‐bit 720‐channel source driver. Because of its good performance with small area, the proposed DAC can be a good low‐cost solution for a 10‐bit TV system.     

10‐bit source driver with resistor‐resistor‐string digital‐to‐analog converter

Abstract— A 10‐bit gray‐scale source driver using a resistor‐resistor‐string digital‐to‐analog converter (RR‐DAC) is proposed for a TFT‐LCD source driver. The 10‐bit RR‐DAC consists of an 8‐bit resistor‐string DAC and a two‐bit resistor‐string DAC without an intermediate unity‐gain buffer to isolate the parallel‐connected resistor string. The output deviation of the proposed source driver is less than ±3 mV. The chip area of the proposed 10‐bit source driver with an RR‐DAC is increased to 29% of that of an 8‐bit source driver.     

A small‐area and low‐power data driver IC using two‐stage DAC with a capacitor array for active matrix flat‐panel displays

A small‐area and low‐power data driver integrated circuit (IC) using a two‐stage digital‐to‐analog converter (DAC) with a capacitor array is proposed for active matrix flat‐panel displays. The proposed data driver IC employs a capacitor array in the two‐stage DAC so as to reduce the DAC area and eliminate the need for a resistor string, which has high‐power consumption. To verify the proposed two‐stage DAC, a 20‐channel data driver IC with the proposed 10‐bit two‐stage DAC was fabricated using a 0.18‐μm complementary metal–oxide–semiconductor process with 1.8 and 6 V complementary metal–oxide–semiconductor devices. The proposed 10‐bit two‐stage DAC occupies only 43.8% of the area of a conventional 10‐bit two‐stage DAC. The measurement results show that the differential nonlinearity and integral nonlinearity are +0.58/?0.52 least significant bit and +0.62/?0.59 least significant bit, respectively. The measured interchannel deviation of the voltage outputs is 8.8 mV, and the measured power consumption of the 20‐channel data driver IC is reduced to 7.1 mW, which is less than half of the power consumed by the conventional one.     

Target point‐based path‐following controller for a car‐type vehicle using bounded controls

In this paper, we have studied the control problem of target point‐based path following for car‐type vehicles. This special path‐following task arises from the needs of vision‐based guidance systems, where a given target point located ahead of the vehicle, in the visual range of the camera, must follow a specified path. A solution to this problem is developed through a nonlinear transformation of the path‐following problem into a reference trajectory tracking problem, by modeling the target point as a virtual vehicle. The use of target point complicates the control problem, as the development produces a first‐order nonlinear nonglobally Lipschitz differential equation with finite escape time. This problem is solved by using small control signals. Bounded feedback laws are designed to control the real vehicle's angular acceleration and the virtual vehicle's velocity, to achieve stability. The resulting controller is globally asymptotically stable with respect to the origin, the proof of which is derived from Lyapunov‐based arguments and a bootstrap argument. It is also shown that the use of exponentially convergent observers/differentiators does not affect the stability of the closed‐loop system. The effectiveness of this controller has been illustrated through simulations. Copyright © 2014 John Wiley & Sons, Ltd.     

A timing controller embedded driver IC with 3.24‐Gbps eDP interface for chip‐on‐glass TFT‐LCD applications

This paper presents a timing controller embedded driver (TED) IC with 3.24‐Gbps embedded display port (eDP), which is implemented using a 45‐nm high‐voltage CMOS process for the chip‐on‐glass (COG) TFT‐LCD applications. The proposed TED‐IC employs the input offset calibration scheme, the zero‐adjustable equalizer, and the phase locked loop‐based bang‐bang clock and data recovery to enhance the maximum data rate. Also, the proposed TED‐IC provides efficient power management by supporting advanced link power management feature of eDP standard v1.4. Additionally, the smart charge sharing is proposed to reduce the dynamic power consumption of output buffers. Measured result demonstrates the maximum data rate of 3.24 Gbps from a 1.1 V supply voltage with a 7.9‐inch QXGA 60‐Hz COG‐LCD prototype panel and 44% power saving from the display system.     

On the pth moment integral input‐to‐state stability and input‐to‐state stability criteria for impulsive stochastic functional differential equations

In this paper, several new Razumikhin‐type theorems for impulsive stochastic functional differential equations are studied by applying stochastic analysis techniques and Razumikhin stability approach. By developing a new comparison principle for stochastic version, some novel criteria of the pth moment integral input‐to‐state stability and input‐to‐state stability are derived for the related systems. The feature of the criteria shows that time‐derivatives of the Razumikhin functions are allowed to be indefinite, even unbounded, which can loosen the constraints of the existing results. Finally, some examples are given to illustrate the usefulness and significance of the theoretical results.     

A 13‐bit universal column driver for various displays of OLED and LCD

A universal column driver is implemented in a 0.13‐µm high‐voltage CMOS process for not only TFT‐LCD but also OLED applications. The proposed column driver employs 13‐bit linear DAC to cover all gamma curves of display applications and address‐based configuration for intra‐ panel interface protocol to support both TV and IT applications. Measured results demonstrate the average voltage of output channels (AVO) is under 1mv, which satisfies 1‐LSB resolution at 18.5V of AVDD.     

Improved closed‐loop stability for fixed‐point controller realizations using the delta operator

A stable discrete‐time control system may achieve a lower than predicted performance or even become unstable when the discrete‐time control law is implemented with a fixed‐point digital control processor due to the finite word length (FWL) effects, which depends on the control law state‐space realization and the discrete‐time operator (e.g., the delta operator or the forward‐shift operator) used to represent the control law. To improve the closed‐loop stability (and as a byproduct, performance) when the control law is implemented, a state‐space approach that selects the control law realization to optimize a stability‐related objective function is developed using the delta operator. Analytical and numerical comparison of the fixed‐point performance of delta control laws with the performance of the corresponding forward‐shift control laws quantifies the improved closed‐loop stability of the delta realizations over those of the corresponding forward‐shift realizations. It is also shown that there exists a simple mapping between the optimal FWL forward‐shift control law realizations and the optimal FWL delta control law realizations. The results are illustrated by delta and forward‐shift control law realizations of a discrete‐time H_∞ control law designed for a teleoperation motion‐scaling system. Copyright © 2001 John Wiley & Sons, Ltd.     

A column‐generation‐based approach to fleet design problems mixing owned and hired vehicles

We look at the problem of choosing a fleet of vehicles to carry out delivery tasks across a long time horizon. The delivery quantities may vary significantly from day to day, and from season to season, and the underlying routing problem may have rich constraints, for example, time windows, multiple compartments, multiple commodities, and compatibility constraints. We consider the option of hiring extra vehicles from external carriers in order to efficiently carry out the day‐to‐day operations while containing the costs of owning the fleet. The goal is to design a fleet so as to minimize the sum of costs of routing the fleet every day of the horizon, the acquisition costs, the maintenance costs, and the costs of hiring external vehicles. In the literature, there is no previous work on fleet design for a long time horizon, which also considers the hiring options. We propose to tackle the problem using column generation and develop three different heuristics. The methods proposed are tested and compared on a set of real‐world problems. It is also shown how introducing the possibility of hiring helps reducing the overall cost and the number of idle vehicles over the planning horizon.     

Compact and power‐saving polysilicon data driver with common‐decoder DA converter (CD‐DAC)

Abstract— A common‐decoder architecture for a data‐driver circuit fabricated by using a polysilicon process has been developed. The architecture achieves a compact circuit and low‐power consumption. In application to an integrated polysilicon data driver for small‐sized displays, this architecture reduces the area of the data driver by removing the vertical bus lines that occupy a large area. It also suppresses the power consumption of the data bus by reducing the number of driven lines in the data bus during word‐to‐word transitions from six to two. By using a conventional 4‐μm design rule, we fabricated an active‐matrix OLED (AMOLED) panel with an integrated six‐bit data‐driver circuit with 384 outputs. The driver circuit had a height of 2.6 mm and a pitch between output lines of 84 μm. The maximum power consumption of the driver was only 5 mW, i.e., 3.8 mW for logic‐data transfer and 1.2 mW for reference‐voltage source. Furthermore, we also fabricated an active‐matrix LCD (AMLCD) panel including driver circuits of the same type as the integrated elements. Six‐bit full‐color images were successfully displayed on both panels.     

A Flexible electronic‐paper display with an ultra‐thin and flexible LSI driver using quick‐response liquid‐powder technology

Abstract— A thin and flexible LSI driver with a thickness of less than 35 μm for a passive‐matrix‐driven Quick‐Response Liquid‐Powder Display (QR‐LPD?) was successfully mounted onto the flexible printed circuit (FPC) and the back substrates of a flexible QR‐LPD?. Amounted LSI driver on a plastic substrate shows no significant degradation in the driving performances and maintains physical flexibility without any connection failures. This technology can realize a fully flexible electronic paper in combination with a plastic‐substrate QR‐LPD? fabricated by a roll‐to‐roll process.     

A telematics service discovery platform using the distributed peer‐to‐peer networking system

In this paper, a distributed telematics peer‐to‐peer networking system is proposed to provide an efficient and feasible service discovery mechanism for mobile users. When mobile users travel on the road, they may request for some services from service providers to meet their demands. Mobile users in vehicles are assumed to go through a lot of regions, in which each region is associated with a region server. Related information of all service providers in a region is stored in its region server, and each region server is in charge of the service discovery requests from all vehicles located in its region. This paper focuses on the issues of developing a distributed peer‐to‐peer telematics service discovery networking system over the vehicular network environment for mobile users. To provide the communication mechanism for telematics service discovery among region server, mobile users, and service providers, the Telematics Service Markup Language is proposed. According to clients' demands, three types of query scenarios are proposed, which are (1) reference point based query, (2) continual query, and (3) route‐based query. Finally, we present usage examples and system implementation of distributed telematics peer‐to‐peer. Copyright © 2012 John Wiley & Sons, Ltd.     

A distributed leader‐following tracking controller using delayed control input information from neighbors

In this paper, we propose a simple, continuous, and distributed controller for the second‐order multiagent system to achieve leader‐following trajectory tracking, by exploiting the control input information of neighbors (CIIN) and using proportional‐derivative (PD) control in terms of local neighborhood synchronization error. A constant time delay is introduced in the CIIN as a design parameter to avoid the algebraic loop issue arising from the control input coupling. We develop an easily testable condition on the PD gains to ensure that the resulting neutral‐type error system is input‐to‐state stable for an arbitrary bounded delay, and prove that when the leader's acceleration is a Lipschitz continuous function with respect to time, the ultimate bound of tracking errors is strictly increasing with respect to the introduced time delay. Moreover, we analyze the robustness of the controller with respect to model uncertainties and show its potential advantages over two existing controllers in balancing the steady‐state tracking precision, the communication cost, and the continuity of controller signal. Finally, extensive simulations are conducted to show the effect of the delay on system stability, to verify the condition on PD gains, to confirm the robustness of the controller, and to demonstrate the detailed advantages.     

A reduced‐voltage differential signaling (RVDS) interface for chip‐on‐glass TFT‐LCD applications

Abstract— Reduced‐voltage differential signaling (RVDS) is a novel interface for TFT‐LCD panels with a chip‐on‐glass (COG) structure, which has a point‐to‐point topology and a voltage mode differential signaling scheme. The voltage‐driving interface scheme has advantages in high‐speed operation owing to its relatively small time constant for the resistive channel condition. And reduced‐voltage signaling can reduce the power consumption of a transmitter. The display source driver IC with an RVDS interface, which is fabricated by using a 0.25‐μm CMOS process with a 2.5‐V logic supply voltage, offers a high data rate up to 500 Mbps, low‐current consumption of 2.2 mA, and good EMI characteristics. Also, an RVDS interface has programmable options that control the bandwidth, system power, and EMI performance. Therefore, the RVDS interface is a competitive solution for low‐power, low‐cost, and slim notebook applications.     

Optical filters for plasma‐display panels using organic dyes and conductive mesh layers by using a roll‐to‐roll etching process

Abstract— Optical filters with a high shielding capability against electromagnetic (EM) radiation for plasma‐display panels (PDPs) have been studied. We developed optical filters with high conductivity by utilizing a copper‐mesh layer, which was processed by using roll‐to‐roll photolithography and roll‐to‐roll etching. The copper‐mesh layer has a cross‐striped pattern with a surface resistance of 0.05Ω/□ and an opening ratio of approximately 93%. In combination with the copper‐mesh layer, organic dyes were applied to reduce the PDPs unfavorable emissions, such as near‐infrared light, and to control the transmission properties to improve the PDPs picture quality.     

A partially delay‐dependent and disordered controller design for discrete‐time delayed systems

This paper considers the stabilization problem for a class of discrete‐time delayed systems by exploiting a partially delay‐dependent controller whose gains suffer a disordering phenomenon simultaneously. Two stochastic variables are used to describe the partially delay‐dependent and disordering properties, which are not independent, and referred to the original operation modes here. By introducing an augmented Markov chain, the corresponding closed‐loop system is transformed into a Markovian jump system with four new operation modes (NOMs). Based on the proposed model, a kind of controller depending on NOMs is firstly proposed with linear matrix inequalities forms. Moreover, without designing a controller containing NOMs directly, another kind of stabilizing controller referring to one depending on original operation modes is developed, which is composed of a series of NOM‐dependent controllers and satisfies a minimum variance approximation. Finally, two numerical examples are used to demonstrate the utility and superiority of the proposed methods. Copyright © 2016 John Wiley & Sons, Ltd.     

A distributed and multi‐tiered software architecture for assessing e‐Commerce recommendations

Recently, an ever increasing number of e‐Commerce tools has been made available that are able to help customers by generating purposed recommendations. Many of them are centralized so that they have to face problems related to efficiency and scalability. A few of them are distributed, but in this case, the complexity of the e‐Commerce process implies computation overhead on the client side, which is often unsuitable if mobile devices are used by customers. In this paper, we study how the software distribution in recommender systems affects their performances, depending on the characteristics of the e‐Commerce population. To this end, we present a distributed testbed architecture for e‐Commerce recommender systems using a multi‐tiered agent‐based approach to generate effective recommendations without requiring such an onerous amount of computation per single client. We use such a testbed to study the main advantages and limitations associated with the problem of distributing the computation of recommendations. Copyright © 2016 John Wiley & Sons, Ltd.     

A highly modular and extensible architecture for an integrated IMS‐based authoring system: the <e‐Aula> experience

The <e‐Aula> platform is a new experimental e‐learning environment that adheres closely to IMS Global Learning Consortium, Inc. e‐learning standards in order to facilitate their applicability in different learning scenarios. <e‐Aula> is equipped with an integrated modular and extensible architecture for the authoring of IMS‐compliant learning materials focused on the IMS manifest. This manifest‐driven architecture facilitates maintenance and promotes the evolution of the authoring system in <e‐Aula>, both of which are mandatory requirements in the successful production and maintenance of content for many different specialized learning domains. In this paper, we describe this authoring system, its manifest‐driven architecture and its implementation using well‐known and robust Java‐based Web technologies. Copyright © 2006 John Wiley & Sons, Ltd.     

A multi‐layered architecture for managing graphical interfaces and tutoring mixed‐strategy dialogues

This paper describes a tool set that allows a courseware author to design a student interface. These tools produce systems dedicated to intelligent computer aided learning, with a better balance between planned tutoring and free‐exploration of micro‐worlds. Mixing these two approaches leads to a distinction between the pedagogical objectives and the presentation elements. Reactive graphical interfaces are better suited to develop micro‐worlds, while the tutoring relies on pedagogical strategies. Then, a multi‐layered architecture is designed in order to use such a graphical student interface under the control of teaching strategies and intentional dialogues. Tutoring rules drive these dialogues by combining several types of functions: predefined strategies, interaction management primitives and pedagogical tactics. These functions are means to articulate the reactive and graphical level with the logical and intentional one. Copyright © 1999 John Wiley & Sons, Ltd.     

A novel low‐cost high‐gain antenna design from cuboids and differential strips

This article proposed a novel broadband high‐gain antenna designed by suspended cuboids and differential shorting strips on a circular ground plane. The design structure of the proposed antenna is simple and all its components such as cuboids, strips, and ground plane are fabricated by a copper sheet of thickness 0.5 mm. The proposed antenna has measured ?10 dB impedance bandwidth (IBW) 45% (2.35‐3.7 GHz) with broadside gain of 10.1 ± 0.4 dBi over IBW. The use of differential strips in inner cuboid improved the cross polarization and enhanced the broadside gain. The measured antenna has low cross polarization is below 25 dB in the broadside direction over IBW. The proposed antenna has 1 dB gain‐bandwidth 53% (2.2‐3.8 GHz) in the broadside. The antenna has been fabricated and measured; the results show a good agreement with simulated results.