Influence of wall charge distribution on time lag of address discharge in AC plasma display panels

The influence of wall charge distribution on the time lag of address discharge in an AC plasma display panel is investigated using two different reset waveforms: one (typical reset) induces both face and surface discharges and the other (TR reset) induces face discharges only. The measured formative time lag and statistical time lag of address discharge for TR were 21–31 ns and 31–74 ns shorter than the one for the typical reset, respectively. The TR reset resulted in much less increase of statistical time lag than the typical reset when the reset-to-address time interval was increased, and 70 ns smaller deviation of the statistical time lag among different color cells. Calculations show that the TR reset forms a much smoother wall charge profile, which is less susceptible to cell parameter variations, than the typical reset. The observed differences in the time lags of address discharge between different scan lines and color cells are strongly correlated to the differences of the wall charge profile, indicating that a smooth wall charge profile formed by the reset using face discharges only reduces the time lag of address discharge and minimizes the susceptibility of address discharge to cell parameter variation.     

Hermite interpolation with simple planar PH curves by speed reparametrization

We introduce a new method of solving C¹ Hermite interpolation problems, which makes it possible to use a wider range of PH curves with potentially better shapes. By characterizing PH curves by roots of their hodographs in the complex representation, we introduce PH curves of type K(t−c)²ⁿ⁺¹+d. Next, we introduce a speed reparametrization. Finally, we show that, for C¹ Hermite data, we can use PH curves of type K(t−c)²ⁿ⁺¹+d or strongly regular PH quintics satisfying the G¹ reduction of C¹ data, and use these curves to solve the original C¹ Hermite interpolation problem.     

Characterization for High Dynamic Range Imaging

In this paper we present a new practical camera characterization technique to improve color accuracy in high dynamic range (HDR) imaging. Camera characterization refers to the process of mapping device‐dependent signals, such as digital camera RAW images, into a well‐defined color space. This is a well‐understood process for low dynamic range (LDR) imaging and is part of most digital cameras — usually mapping from the raw camera signal to the sRGB or Adobe RGB color space. This paper presents an efficient and accurate characterization method for high dynamic range imaging that extends previous methods originally designed for LDR imaging. We demonstrate that our characterization method is very accurate even in unknown illumination conditions, effectively turning a digital camera into a measurement device that measures physically accurate radiance values — both in terms of luminance and color — rivaling more expensive measurement instruments.     

DRAMA: A framework for domain requirements analysis and modeling architectures in software product lines

One of the benefits of software product line approach is to improve time-to-market. The changes in market needs cause software requirements to be flexible in product lines. Whenever software requirements are changed, software architecture should be evolved to correspond with them. Therefore, domain architecture should be designed based on domain requirements. It is essential that there is traceability between requirements and architecture, and that the structure of architecture is derived from quality requirements. The purpose of this paper is to provide a framework for modeling domain architecture based on domain requirements within product lines. In particular, we focus on the traceable relationship between requirements and architectural structures. Our framework consists of processes, methods, and a supporting tool. It uses four basic concepts, namely, goal based domain requirements analysis, Analytical Hierarchy Process, Matrix technique, and architecture styles. Our approach is illustrated using HIS (Home Integration System) product line. Finally, industrial examples are used to validate DRAMA.     

Continuous collision detection for adaptive simulation of articulated bodies

We perform continuous collision detection (CCD) for articulated bodies where motion is governed by an adaptive dynamics simulation. Our algorithm is based on a novel hierarchical set of transforms that represent the kinematics of an articulated body recursively, as described by an assembly tree. The performance of our CCD algorithm significantly improves as the number of active degrees of freedom in the simulation decreases.     

Zoned-partitioning of tree-like access methods

The performance of access methods and the underlying disk system is a significant factor in determining the performance of database applications, especially with large sets of data. While modern hard disks are manufactured with multiple physical zones, where seek times and data transfer rates vary significantly across the zones, there has been little consideration of this important disk characteristic in designing access methods (indexing schemes). Instead, conventional access methods have been developed based on a traditional disk model that comes with many simplifying assumptions such as an average seek time and a single data transfer rate. The paper proposes novel partitioning techniques that can be applied to any tree-like access methods, both dynamic and static, fully utilizing zoning characteristics of hard disks. The index pages are allocated to disk zones in such a way that more frequently accessed index pages are stored in a faster disk zone. On top of the zoned data placement, a localized query processing technique is proposed to significantly improve the query performance by reducing page retrieval times from the hard disk.     

A simulation-based heuristic algorithm for disposition of direction finders

A direction finder is a military weapon that is used to find locations of targets that emit radio frequencies. Multiple direction finders are used in a direction finder system for finding locations of targets in an area of interest. We present a two-stage heuristic algorithm for disposing direction finders in a direction finder system for the objective of maximizing the accuracy of estimation of the location of a target that is assumed to be located in the area of interest. In the suggested heuristic algorithm, a simulation-based method is used for estimating the probability of coverage, the probability that a target is in a given region (of a given size) surrounding the estimated location of the target, and another simulation-based method and a local search method are used to determine locations of direction finders that result in the maximum probability of coverage. Performance of the suggested algorithm is evaluated through computational experiments and results show that the algorithm gives a good disposition plan in a reasonable amount of computation time.     

Computer-aided measurement plan for an impeller on a coordinate measurement machine with a rotating and tilting probe

This paper presents a computer-aided measurement plan (CAMP) for an impeller on a coordinate measurement machine (CMM) with a rotating/tilting probe. The blade surfaces of a machined impeller were measured exactly to secure the machining tolerance and surface finish of the impeller. CMM with a rotating and tilting probe is commonly used for this measurement. However, it is not easy to evaluate all the points on the impeller surfaces due to the time-consuming nature of the CMM measurement. In addition, many points cannot be easily accessed by the CMM probe due to the interference between the probe and the impeller blades. Furthermore, the inherent complexity of the existing teaching operation of a probe using a joystick suggests the necessity of developing a new method for the measurement planning of an impeller. Thus, this paper proposes a CAMP for effectively gauging the inspection points based on the ruled line information of the impeller blade surfaces. The proposed plan partitions the surfaces into several measurement regions based on the ruled lines of a blade surface and the approach vectors of the probe. Finally, a case example for an impeller is presented to demonstrate the effectiveness of the proposed strategy.     

Guest Editors' Introduction: The Evolution of RFIC Design and Test

There are several challenges facing RFIC design and test. The demand in the wireless market will drive RFIC products. For RFIC chipsets, improvements are needed for the elimination of passive components, better integrated passives, power reduction, modeling of devices and interconnects, packaging, and cost-effective testing. However, this innovation cannot come at the cost of time to market for new products. Also, development costs must be driven to a minimum, as average selling prices for RFICs remain flat or decline. Moreover, one of the biggest challenges in moving from low GHz to higher frequencies is the lack of integration between the production testing infrastructure, EDA tools, and device designs. Advancements in device and test equipment modeling and simulation technology are beginning to bridge this gap. Finally, RF measurement requires specialized capital equipment investments and highly skilled engineers with many years of experience. This special issue on design and test of RFIC chips describes some of these challenges and proposes some interesting solutions.     

Factors affecting the implementation of electronic data interchange in Korea

Although there have been a number of studies of the determinant factors of Electronic Data Interchange (EDI) implementation, most studies were carried out in the United States or Europe. The purpose of this study is to identify the determinant factors which affect implementation of EDI systems by Korean companies. Decentralization, EDI standards, technical compatibility, technical support by EDI vendors, education and training and participation of trading partners positively affect the extent of EDI usage. Formalization, technical compatibility, user involvement and participation of trading partners affect EDI integration with internal applications. Top management support and the participation of trading partners promote the extent of EDI operations. This study provides evidence of the effect of important determinant factors such as participation of trading partners and technical compatibility replicating previous EDI studies conducted in that US and Europe. For policy makers ad EDI developers, this study provides insights as to appropriate measures and incentives system designed to encourage EDI and B2B implementation.