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A survey of methods for constructing covering arrays

PROGRAMMING AND COMPUTER SOFTWARE 2011年第3期37卷 121-146页

作者： Kuliamin, V. V. Petukhov, A. A. Russian Acad Sci Inst Syst Programming Moscow 109004 Russia

The paper presents a survey of methods for constructing covering arrays used in generation of tests for interfaces with a great number of parameters. The application domain of these methods and algorithms used in them are analyzed. Specific characteristics of the methods, including time complexity and estimates of the required memory, are presented. Various-direct, recursive, optimization, genetic, and backtracking-algorithms used for constructing covering arrays are presented. Heuristics are presented that allow one to reduce arrays without loss of completeness, and application domains of these heuristics are outlined.

关键词： INFORMATION technology COMPUTER programming technological complexity ALGORITHMS COMPUTER interfaces DOMAIN structure MATHEMATICAL optimization RECURSIVE functions COMPUTER storage devices

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Seasonal Ensemble Forecasts: Are Recalibrated Single Models Better than Multimodels?

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MONTHLY WEATHER REVIEW 2009年第4期137卷 1460-1479页

作者： Weigel, Andreas P. Liniger, Mark A. Appenzeller, Christof MeteoSwiss Fed Off Meteorol & Climatol CH-8044 Zurich Switzerland

Multimodel ensemble combination (MMEC) has become an accepted technique to improve probabilistic forecasts from short-to long-range time scales. MMEC techniques typically widen ensemble spread, thus improving the dispersion characteristics and the reliability of the forecasts. This raises the question as to whether the same effect could be achieved in a potentially cheaper way by rescaling single model ensemble forecasts a posteriori such that they become reliable. In this study a climate conserving recalibration (CCR) technique is derived and compared with MMEC. With a simple stochastic toy model it is shown that both CCR and MMEC successfully improve forecast reliability. The difference between these two methods is that CCR conserves resolution but inevitably dilutes the potentially predictable signal while MMEC is in the ideal case able to fully retain the predictable signal and to improve resolution. Therefore, MMEC is conceptually to be preferred, particularly since the effect of CCR depends on the length of the data record and on distributional assumptions. In reality, however, multimodels consist only of a finite number of participating single models, and the model errors are often correlated. Under such conditions, and depending on the skill metric applied, CCR-corrected single models can on average have comparable skill as multimodel ensembles, particularly when the potential model predictability is low. Using seasonal near-surface temperature and precipitation forecasts of three models of the Development of a European Multimodel Ensemble System for Seasonal-to-Interannual Prediction (DEMETER) dataset, it is shown that the conclusions drawn from the toy-model experiments hold equally in a real multimodel ensemble prediction system. All in all, it is not possible to make a general statement on whether CCR or MMEC is the better method. Rather it seems that optimum forecasts can be obtained by a combination of both methods, but only if first MMEC and then CCR

关键词： MODULES (Algebra) PROBABILITIES WEATHER forecasting STOCHASTIC analysis ATMOSPHERIC temperature technological complexity

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Morphological control in colloidal crystal templating of inverse opals, hierarchical structures, and shaped particles

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CHEMISTRY OF MATERIALS 2008年第3期20卷 649-666页

作者： Stein, Andreas Li, Fan Denny, Nicholas R. Univ Minnesota Dept Chem Minneapolis MN 55455 USA

Inverse opals or three-dimensionally ordered macroporous (3DOM) materials, prepared by colloidal crystal templating (CCT) methods, possess distinctive structural features that are important for the design of photonic crystals, sensors, power sources, catalysts, and various other applications. In the past decade, vast progress has been made in shaping these materials at various length scales. It is now possible to prepare 3DOM materials in a variety of simple and, complex compositions, in which pore sizes, pore shapes, and skeletal geometries can be adjusted statically and sometimes even dynamically to alter the physical properties of the material. Hierarchical pore structures can be achieved by combining CCT with additional templating techniques. Furthermore, shaped porous nanoparticles may be synthesized using CCT methods. This review will highlight recent advances in controlling both the internal structure of inverse opals and their external morphology, enhancing compositional complexity, endowing these solids with functionality, and incorporating them in integrated functional systems.

关键词： INVERSE functions COLLOIDAL crystals technological complexity OPALS

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Broadband apparent permittivity measurement in dispersive soils using quarter-wavelength analysis

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SOIL SCIENCE SOCIETY OF AMERICA JOURNAL 2008年第5期72卷 1401-1409页

作者： Thomas, A. M. Chapman, D. N. Rogers, C. D. F. Metje, N. Atkins, P. R. Lim, H. M. Univ Birmingham Sch Engn Birmingham B15 2TT W Midlands England

Time-domain reflectometry (TDR) has, since the early 1980s, become a widely used and robust method for measuring the electromagnetic properties of soils. Although it allows use of relatively simple probes and measurement equipment that free users from complex analysis of small soil samples in the laboratory, it provides little information on the dispersive nature of fine-grained soils. Therefore, we developed a quarter-wavelength analysis (QWA) methodology that allows apparent permittivity spectra to be obtained for soils, while retaining the same range of cells and probes and the simplicity of data analysis associated with TDR. We tested the technique on clay soils across a wide water content range and found that it provided useful data for frequencies ranging from approximately 100 MHz to >1 GHz-the accuracy being considered no worse than two units of apparent permittivity. The results show that the methodology is capable of providing broadband dispersion data that give significantly greater detail on soil electromagnetic properties than can be expected from single-frequency TDR data. This has a number of important advantages including the potential to provide accurate water content measurements in clay soils, a means to extend TDR soil monitoring data, and the opportunity to validate research into the measurement frequency associated with simple TDR measurements and time- to frequency-domain inversions.

关键词： TIME-domain reflectometry ELECTROMAGNETIC compatibility PERMITTIVITY SOIL management technological complexity CLAY soils MICROPROBE analysis SPECTRUM analysis SCIENTIFIC experimentation

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Adaptive pulse compression of MIMO radar based on GSC

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ELECTRONICS LETTERS 2008年第20期44卷 1217-1219页

作者： Li, N. Tang, J. Peng, Y. N. Tsinghua Univ Dept Elect Engn Beijing 100084 Peoples R China

Adaptive pulse compression (APC) is an effective method for mitigating the mutual interference of the multiple waveforms transmitted in multiple-input multiple-output (MIMO) radar. But APC based on minimum mean-square error (MMSE) is computationally inefficient. Therefore, APC of MIMO radar based on a generalised sidelobe canceller (GSC) is proposed, which can effectively reduce the complexity. Numerical experiments show that the proposed method is superior to the matched filter (MF), and performs similarly as APC based on MMSE.

关键词： technological complexity HIGH technology RESEARCH MIMO systems ELECTRONIC systems ELECTRONIC pulse techniques NUMERICAL analysis

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Use of Evaluation Criteria and Innovation Performance in the Front End of Innovation

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JOURNAL OF PRODUCT INNOVATION MANAGEMENT 2011年第6期28卷 896-914页

作者： Martinsuo, Miia Poskela, Jarno Tampere Univ Technol Dept Ind Management FI-33101 Tampere Finland

Selecting the right ideas and concepts fir product development projects is among the major decisions that product development directors must make. Companies have adopted evaluation criteria at decision gates to offer the decision makers sufficient knowledge of the alternative ideas and concepts, and to promote choices that would result in the best possible business benefit. The actual benefits of using the different criteria in the front end of innovation have rarely been studied. The purpose of this paper is to explain how the use of evaluation criteria is associated with innovation performance in the front end of innovation. Also, we investigate the moderating impact of product complexity. We developed a set of hypotheses and constructs and a questionnaire instrument to measure the use of evaluation criteria and front end performance in idea and concept development in industrial firms. The results show that assessment formality is negatively but nonsignificantly associated with innovation performance, whereas the use of evaluation criteria has a significant role in promoting competitive and business potential in the front end of innovation. None of the moderating effects of product complexity are significant, but the use of evaluation systems and criteria mediate the link between product complexity and strategic opportunity. The study contributes to research regarding the use of different evaluation criteria particularly during idea and concept evaluation. As the use of different evaluation criteria is differently associated with the different strategic opportunity measures, the findings confirm the need to develop holistic but informal assessment systems and adapt the evaluation criteria in line with the development objectives of the firm. In order to fully benefit from radical strategic opportunities, firms need to focus on demanding product concepts that require a stretch in both technical and market competences as well as managerial work that proactively reduc

关键词： NEW product development INNOVATION management technological innovations RISK assessment technological complexity

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Reduced spatio-temporal complexity MMPP and image-based tracking filters for maneuvering targets

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IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS 2003年第4期39卷 1277-1291页

作者： Krishnamurthy, V Dey, S Univ British Columbia Dept Elect & Comp Engn Vancouver BC V6T 1Z4 Canada Univ Melbourne Dept Elect & Elect Engn Melbourne Vic 3010 Australia

We present reduced-complexity nonlinear filtering algorithms for image-based tracking of maneuvering targets. In image-based target tracking, the mode of the target is observed as a Markov modulated Poisson process (MMPP) and the aim is to compute optimal estimates of the target's state. We present a reduced complexity algorithm in two steps. First, a gauge transformation is used to reexpress the filtering equations in a form that is computationally more efficient for time discretization than naive discretization of the filtering equations. Second, a spatial aggregation algorithm with guaranteed performance bounds is presented for the time-discretized filters. A numerical example illustrating the performance of the resulting reduced-complexity filtering algorithms for a switching turn-rate model is presented.

关键词： technological complexity FILTERING software ACCESS control ALGORITHMS ELECTROMAGNETISM GAUGE invariance TARGET acquisition

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Technical environment matters: The effect of dynamic network capability on innovation based on a moderated mediation analysis

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TECHNOVATION 2024年 138卷

作者： Wang, Yan Yang, Naiding Sharif, Sayed Muhammad Fawad Zhang, Mingzhen Guo, Min Northwestern Polytech Univ Sch Management Xian Peoples R China Southeast Univ Sch Econ & Management Nanjing Peoples R China Xian Univ Posts & Telecommun Coll Econ & Management Xian Peoples R China

In the era of networked research and development, where the environment is continuously changing and evolving, complex product innovation requires the ongoing configuration of external partnerships. This necessity highlights the growing importance of dynamic network capability (DNC). However, the existing literature on how DNC influences innovation remains inadequate, which significantly hinders both the theoretical and practical development of DNC. Drawing on dynamic capabilities theory and social embeddedness theory, this paper investigates the effect of DNC on innovation, focusing on the mediating role of dynamic positioning and the moderating role of the technical environment. Based on data from a sample of 270 complex product firms across eight key cities in China, the results indicate that DNC is significantly and positively correlated with complex product innovation. Moreover, dynamic positioning, characterized by increased centrality (CI), acts as a mediator in this relationship. The technical environment plays a dual role in this context: externally (industry), technological turbulence (TT) amplifies the impact of DNC on CI, while internally (product), technological complexity (TC) diminishes this impact. Further moderated mediation analysis supports these findings, showing that TT enhances the mediating effect of CI on the relationship between DNC and innovation, whereas TC weakens this effect. Interestingly, TT and TC do not jointly moderate the above relationship. When both internal (product) and external (industry) technical environments are considered simultaneously, the moderating effect of external (industry) TT proves to be more significant.

关键词： Dynamic network capability Dynamic positioning Innovation performance technological turbulence technological complexity

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APPROPRIABILITY AND THE RETRIEVAL OF KNOWLEDGE AFTER SPILLOVERS

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STRATEGIC MANAGEMENT JOURNAL 2016年第7期37卷 1263-1279页

作者： Alnuaimi, Tufool George, Gerard Imperial Coll London Imperial Coll Business Sch London England Singapore Management Univ Lee Kong Chian Sch Business Singapore Singapore

Research summary: Firms create and capture value through innovation. In technology-driven firms, there has been an explicit emphasis on appropriability through imitation deterrence and cumulative inventions that build on prior firm innovation. We introduce systematic empirical evidence for a third mechanism of appropriability namely, knowledge retrieval, which is defined as the re-absorption of previously spilled knowledge. We extend previous studies which consider technological complexity and organizational coupling as predictors of appropriability by examining their impact on knowledge retrieval. We find that technological complexity has a curvilinear relationship with retrieval while organizational coupling has a negative relationship. We discuss the implications of these findings for theories of absorptive capacity, organizational design and appropriability of innovation. Managerial summary: It is a widely held assumption that knowledge should be protected and held tightly within the firm to ensure value creation and value capture. The implicit recognition is that knowledge spillovers, or knowledge leakage, is detrimental to performance. By examining the patterns of citations among patents of 142 semiconductor firms, we study how organizational structure and technological complexity play a role. We find that moderate technological complexity improves appropriability. If imitation deterrence is paramount, then the optimal structure would be a tightly-coupled organization. In other instances, loosely-coupled organizations may be superior because they foster internal cumulative innovations and, if spillovers were to occur, they also maximize knowledge retrieval. Our findings suggest that all is not lost when spillovers occur and that firms can continue to benefit in downstream innovations. Copyright (C) 2015 John Wiley & Sons, Ltd.

关键词： appropriability technological complexity coupling knowledge retrieval patents innovation

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The many roles of molecular complexity in drug discovery

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DRUG DISCOVERY TODAY 2017年第1期22卷 120-126页

作者： Mendez-Lucio, Oscar Medina-Franco, Jose L. Univ Nacl Autonoma Mexico Fac Quim Dept Farm Ave Univ 3000 Mexico City 04510 DF Mexico

Molecular complexity is becoming a crucial concept in drug discovery. It has been associated with target selectivity, success in progressing into clinical development and compound safety, among other factors. Multiple metrics have been developed to quantify molecular complexity and explore complexity property relationships. However, there is no general agreement regarding how to measure this molecular feature. Herein, we have surveyed the many roles of molecular complexity in drug discovery discussing in a critical manner different quantification methods. Through the analysis of various reference compound databases, common pitfalls and workarounds of the quantification of molecular complexity are discussed.

关键词： DRUG development DRUG targeting MEDICATION safety DRUG analysis technological complexity

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