TD-SCDMA下行小区快速搜索的关键问题研究

针对TD-SCDMA下行小区搜索中下行导频时隙(DwPTS)位置搜索、下行同步码(SYNC-DL)位置的确定以及控制复帧同步三个步骤中的关键问题提出了解决方法.第一个步骤中根据TD-SCDMA子帧结构特点采用功率模板法确定下行导频时隙的位置;第二个步骤中采用定义模板法确定下行同步码的位置;第三个步骤中通过快速的TD-SCDMA信道估计方法检测下行导频信道来控制复帧同步.以上方法简化了计算的复杂性,可实现快速高效的网络测量,满足TD-SCDMA网络规划及优化的需求,这些在仿真结果和现场测试中都得到了验证.     

Analysis of process models

Process modeling tools, such as the integrated definition (IDEF) methodology, allow for a systematic representation of processes in manufacturing, product development, and service applications. Most of the process modeling methodologies are based on informal notation, lack mathematical rigor, and are static and qualitative, and thus can be difficult to use for analysis. In this paper, a new analysis approach for process models based on signed directed graphs (SDGs) and fuzzy sets is presented. A membership function of fuzzy sets quantifies and transforms incomplete and ambiguous information of process variables into an SDG qualitative model. The effectiveness of the approach is illustrated with an industrial example. The architecture of an intelligent system for qualitative/quantitative analysis of process models is presented     

Do social media campaigns foster vaccination adherence? A systematic review of prior intervention-based campaigns on social media

The COVID-19 pandemic has demonstrated the importance of large-scale campaigns to facilitate vaccination adherence. Social media presents unique opportunities to reach broader audiences and reduces the costs of conducting national or global campaigns aimed at achieving herd immunity. Nonetheless, few studies have reviewed the effectiveness of prior social media campaigns for vaccination adherence, and several prior studies have shown that social media campaigns do not increase uptake rates. Hence, our objective is to conduct a systematic review to examine the effectiveness of social media campaigns and to identify the reasons for the mixed results of prior studies. Our methodology began with a search of seven databases, which resulted in the identification of 92 interventions conducted over digital media. Out of these 92 studies, only 15 adopted social media campaigns for immunization. We analyzed these 15 studies, along with a coding scheme we developed based on reviews of both health interventions and social media campaigns. Multiple coders, who were knowledgeable about social media campaigns and healthcare, analyzed the 15 cases and obtained an acceptable level of inter-coder reliability (> .80). The results from our systematic review show that only a few social media campaigns have succeeded in enhancing vaccination adherence. In addition, few campaigns have utilized known critical success factors of social media to induce vaccination adherence. Based on these findings, we discuss a set of research questions that informatics scholars should consider when identifying opportunities for using social media to resolve one of the most resilient challenges in public health. Finally, we conclude by discussing how the insights drawn from our systematic reviews contribute to advancing theories, such as social influence and the health belief model, into the realm of social media–based health interventions.     

Distributed database design methodologies

This paper surveys methodological approaches for distributed database design. The design of distribution can be performed top-down or bottom-up; the first approach is typical of a distributed database developed from scratch, while the second approach is typical of the development of a multi-database as the aggregation of existing databases. We review the design problems and methodologies along both directions, and we describe DATAID-D, a top-down methodology for distribution design. We indicate how the methodology is part of a global approach to database design; how to collect the requirements about the distribution of data and applications; and how to progressively build the distribution of a schema. Our approach is exemplified through one case study.     

Does the digital divide matter? Factors and conditions that promote ICT literacy

Individuals’ computer skills have long been noteworthy for both education and the labor market. Although the support provided through curricula in schools develops these skills to a certain extent, digital divide still exists for individuals with different socio-demographic characteristics. The concept of digital divide, used to define individuals who do not have equal access to digital technologies, has started to be seen as a determining factor for digital competencies with its expanding scope. The current study aims to take a perspective to investigate the effect of socio-demographic variables, which may cause digital divide, on students' ICT literacy. With this study, it is sought to explain the effect of current inequalities regarding digital access on students' ICT skills. To this end, the socio-demographic characteristics of the students in the sample of Korea and Chile from the participating countries of the International Computer and Information Literacy Study (ICILS) were examined in the context of ICT literacy. The characteristics of the models created were compared for both countries. While parents’ level of education variable stands out for the Chilean model, the internet connection variable is remarkable for the Korean model. It is anticipated that the findings of the research will contribute to understanding the dynamics of the digital divide and its possible consequences, and can be a source for preventive policy steps to be developed.     

A new intelligence-based approach for computer-aided diagnosis of Dengue fever

Identification of the influential clinical symptoms and laboratory features that help in the diagnosis of dengue fever (DF) in early phase of the illness would aid in designing effective public health management and virological surveillance strategies. Keeping this as our main objective, we develop in this paper a new computational intelligence-based methodology that predicts the diagnosis in real time, minimizing the number of false positives and false negatives. Our methodology consists of three major components: 1) a novel missing value imputation procedure that can be applied on any dataset consisting of categorical (nominal) and/or numeric (real or integer); 2) a wrapper-based feature selection method with genetic search for extracting a subset of most influential symptoms that can diagnose the illness; and 3) an alternating decision tree method that employs boosting for generating highly accurate decision rules. The predictive models developed using our methodology are found to be more accurate than the state-of-the-art methodologies used in the diagnosis of the DF.     

Influences on ICT teachers knowledge and routines in a technical e-safety context

The article presents the results of research on the knowledge and routines of ICT teachers in a technical e-safety context. Primary, lower secondary and high school teachers can have a significant impact on the e-safety of children and youngsters by raising their awareness of the risks associated with the use of technologies. Technical e-safety has roughly been acknowledged as an area where interpersonal relationships are not prioritised. A qualitative analysis of open-coded in-depth interviews with ICT teachers using the Grounded Theory method identified determinants that influence teachers’ knowledge and routines and a model of formation was developed. Firstly, there are external and internal influences. Another factor is teachers’ attitudes to e-safety rules that should support safe behaviour. Thirdly, teachers have barriers to protection in their minds and these could hinder their safe behaviour. Previous negative experiences have also been identified as another significant factor that affects a teacher’s e-safety habits. The developed theory describes causal and intervening relationships between the given categories. The developed theory will serve as a basis for proposing steps to improve ICT teachers’ knowledge of e-safety and ways teacher education might be adapted to achieve that.     

Competitive prospects of graduate program on the integration of ICT superiority,higher education,and international aid

Korea overcame the Asian financial crisis (1997–1998) with its governmental policies of informatization and the promotion of the information and communications technology (ICT) industry. It is a nation that has switched its international position from a recipient of international aid to a member of the OECD Development Assistance Committee (DAC). However, the level of official development assistance (ODA) by Korea is lower than the average of OECD DAC members. As a situational alternative, this study introduced a global information and telecommunication technology program (ITTP) that seems to integrate education on Korea’s superiority in ICT infrastructure and the industry with specialized ODA. In particular, this study analyzed the competitive environment of the ITTP by examining its structural strengths and weaknesses through an analysis of strengths, weaknesses, opportunities, and threats (SWOT). And then, this research illustrated the relationship diagram of major stakeholders and their impact using Porter’s five forces approach. Our analysis suggests that the ITTP needs to specialize in an “ICT for development” (ICT4D) program in the competitive environment of Asian-Pacific universities by combining education with techno-economic infrastructure projects in developing countries.     

Machine learning-based offline signature verification systems: A systematic review

The offline signatures are the most widely adopted biometric authentication techniques in banking systems, administrative and financial applications due to its simplicity and uniqueness. Several automated techniques have been developed to anticipate the genuineness of the offline signature. However, the recapitulate of the existing literature on machine learning-based offline signature verification (OfSV) systems are available in a few review studies only. The objective of this systematic review is to present the state-of-the-art machine learning-based models for OfSV systems using five aspects like datasets, preprocessing techniques, feature extraction methods, machine learning-based verification models and performance evaluation metrics. Thus, five research questions were identified and analysed in this context. This review covers the articles published between January 2014 and October 2019. A systematic approach has been adopted to select the 56 articles. This systematic review revealed that recently, the deep learning-based neural network attained the most promising results for the OfSV systems on public datasets. This review consolidates the state-of-the-art OfSV systems performances in selected studies on five public datasets (CEDAR, GPDS, MCYT-75, UTSig and BHSig260). Finally, fifteen open research issues were identified for future development.     

An integrated approach to project evaluation and selection

Effective project evaluation necessitates incorporating the many conflicting objectives of decision maker(s) into decision models. Among the many proposed methodologies of multicriteria decision making, goal programming is perhaps the most popular and widely used. Although it incorporates multiple objectives and arrives at an optimal solution, its major drawback is that the decision maker(s) must specify goals and priorities a priori. To overcome this problem the Delphi method is suggested to be applied prior to goal programming formulation so that the objectives and their corresponding aspiration levels can be identified. Another drawback of goal programming is that it does not provide a systematic approach to set priorities and trade-offs among objectives. For this purpose an analytical hierarchy process is used. The application of the proposed methodology is then discussed and illustrated through an example     

GA and Lyapunov theory-based hybrid adaptive fuzzy controller for non-linear systems

In this present article, a new hybrid methodology for designing stable adaptive fuzzy logic controllers (AFLCs) for a class of non-linear system is proposed. The proposed design strategy exploits the features of genetic algorithm (GA)-based stochastic evolutionary global search technique and Lyapunov theory-based local adaptation scheme. The objective is to develop a methodology for designing AFLCs with optimised free parameters and guaranteed closed-loop stability. Simultaneously, the proposed method introduces automation in the design process. The stand-alone Lyapunov theory-based design, GA-based design and proposed hybrid GA–Lyapunov design methodologies are implemented for two benchmark non-linear plants in simulation case studies with different reference signals and one experimental case study. The results demonstrate that the hybrid design methodology outperforms the other control strategies on the whole.     

A methodology to design the link cost functions for impairment aware routing algorithms in optical networks

We propose a methodology to design the link cost function and, consequently, a systematic form to design a RWA algorithm. We call this methodology link cost function design (LCFD) and it consists of four steps: The choice of the link cost function input variables, the expansion of the cost function in terms of a series, the selection of an overall network performance indicator as the optimization target, and finally, the execution of an optimization process to find the series coefficients that optimize the network performance indicator based on off-line network simulations. The optimization process is performed by a computational intelligence technique, the particle swarm optimization. The proposed methodology (LCFD) is used to design an adaptive IA-RWA algorithm, which we call Power Series Routing (PSR). The effectiveness of both methodology and IA-RWA algorithm is investigated. The PSR is compared with other algorithms found in the literature by means of computational simulations and our proposal presented lower blocking probabilities with shorter computation time. Furthermore, we investigate the sensitivity and the ability of the proposed PSR to adapt itself to topological changes in the network due to both link/node addition/failure. We also investigate the behavior of the PSR in a scenario where the traffic load distribution is randomly chosen (non-uniform traffic), and we compared it to other three routing algorithms.     

Unified simulation evaluation for mobile broadband technologies - [Modeling and simulation: a practical guide for network designers and developers]

System-level simulation has been widely used to evaluate system performance. Simulation methodologies have also been comprehensively discussed in different organizations or institutions. Most of the simulation methodologies proposed, however, mainly focus on one area of specific technologies. How to evaluate the performance of multiple air interface systems (e.g., cdma2000, WCDMA, WiMAX, and their evolutions) in a fair and comprehensive manner has not been addressed extensively. This article presents a unified simulation methodology, including fading channel models, system configurations, and how to consider technology-dependent algorithms such as scheduling, overhead modeling, interference margin definition, and resource allocation based on system loading. This article uses this framework to compare three major existing radio technologies: cdma2000 1x EV-DO Rev. A, WCDMA HSPA, and mobile WiMAX based on 802.16e. Key simulation results based on our suggested system models and settings are presented and analyzed. It is shown that under our unified framework, the two CDMA systems exhibit higher spectrum efficiency than mobile WiMAX, especially on the downlink, while mobile WiMAX provides a higher peak rate.     

A Discussion About Some of the Principles/Practices of Wireless Communication Under a Maxwellian Framework

There has been a plethora of papers dealing with wireless communication that use techniques, which when viewed from the perspective of a Maxwellian framework raise more questions than they answer. By Maxwellian framework we imply not only the relevance of electromagnetics in studying communication systems but also the proper interpretation of an ensemble processing in mathematical physics which was first introduced by Maxwell to study the behavior of an aggregate of molecules rather than the property of individuals. Initially, most of the modern signal processing techniques was developed for scalar acoustic problems. However, with the advent of wireless, these same techniques are being applied to the vector electromagnetics problem, which is fundamentally different in concept with respect to the scalar acoustic problem. The objective is to discuss some of these concerns associated with some of the current modeling methodologies particularly related to propagation modeling and antenna diversity. A goal is to initiate a dialog about the scientific merits of these new applications. One of the points to be made is that an incorrect use of probability theory can often lead to erroneous conclusions that directly contradict the principles of physics. A few examples are presented to initiate this dialog, mainly the applicability of scalar techniques to the vector wireless problem, including a proper interpretation of the Shannon channel capacity theorem. A methodology is also presented to illustrate how a simple multiple-input-multiple-output system can be based on the principles of reciprocity. Integration of the electromagnetic principles in some of the current methodologies of signal processing and communications theory may lead to a better system     

Development of robust interconnect model based on design ofexperiments and multiobjective optimization

When designing an integrated circuit, it is important to take into consideration random variations arising from process variability. Traditional optimization studies on VLSI interconnect attempt to find the deterministic optimum of a cost function but do not take into account the effect of these random variations on the objective. We have developed an effective methodology based on TCAD simulation and design of experiments to optimize interconnect including the effects of process variations. The aim of the study is to search for optimum designs that both meet the performance specification and are robust with respect to process variations. A multiobjective optimization technique known as Normal Boundary Intersection is used to find evenly-spaced tradeoff points on the Pareto curve. Designers can then select designs from the curve without using arbitrary weighting parameters. The proposed methodology was applied to a 0.12 μm CMOS technology; optimization results are discussed and verified using Monte Carlo simulation     

A solution methodology for exact design space exploration in athree-dimensional design space

This paper describes an exact solution methodology, implemented in Rensselaer's Voyager design space exploration system, for solving the scheduling problem in a three-dimensional (3-D) design space: the usual two-dimensional (2-D) design space (which trades off area and schedule length), plus a third dimension representing clock length. Unlike design space exploration methodologies which rely on bounds or estimates, this methodology is guaranteed to find the globally optimal solution to a 3-D scheduling problem. Furthermore, this methodology efficiently prunes the search space, eliminating provably inferior design points through the following: 1) a careful selection of candidate clock lengths and 2) tight bounds on the number of functional units or on the schedule length. Both chaining and multicycle operations are supported     

A simplified procedure for the analysis of Safety Instrumented Systems in the process industry application

International Standards and Guidelines propose qualitative and quantitative methodologies for the safety assessment of the Safety Instrumented System (SIS). However, some of these methodologies are often complex and not very easy to apply. In fact, some criticalities are found by technicians voted to the functional safety such as the study of SIS for complex architectures, calculation of safety parameters, difficulties in the identification of the SIS subsystem during the design review to guarantee the safety requirements, and so on.The aim of this paper is to propose a simplified and more efficient methodology for safety assessment of electromechanical SIS in compliance with the Standards IEC 61508 and IEC 61511. The proposed technique is based on an alternative implementation of the Reliability Block Diagram (RBD) approach for the performance analysis of the Safety Instrumented System. In order to demonstrate the advantages of the proposal, a case study of some of the safety functions is considered. With respect to other methodologies normally used for safety analysis, the results proved the proposed approach both easier in the application and time-saving. In addition, such results are comparatively close to those obtained by using the Standard methods.