Modelling exploratory research

Decision-making in exploratory research is an extremely difficult task and no single generally accepted and established methodology has emerged as yet from the different fields of Operations Research. Even monitoring exploratory research programmes gives rise to serious difficulties, for no standard method of project management can be applied. Moreover, the ultimate, tangible success of an R&D operation from the point of view of management is the introduction of a new product on the market, and that is a rare event.A method based on subjective probabilities and making use of statistical distributions has been developed, to provide the managers of exploratory research in the pharmaceutical industry with a means of facilitating their decision-making process and the business planners with both a system for testing the feasibility of corporate objectives and advance indicators for estimating success within the long-range strategic planning process. An empirical method and an a priori method have also been devised with the aid of which the progress of the research function can, within certain limits, be continuously monitored.These methods also appear to be of value in determining the time when the productivity of a research area may become critically unsatisfactory. They could conceivably be extended to other research-based industrial branches.     

网络RTK电离层误差研究现状分析

近年来,网络RTK电离层延迟改正成为高精度实时定位中最感兴趣的研究课题之一,对基准站电离层延迟改正和改正数内插算法两个方面的主要研究内容、研究方法和研究进展进行了讨论,并探讨了目前存在的问题及探索性解决方法.     

Strengthening of RC beams with an innovative timber-FRP composite system

The results of a theoretical and experimental research project on the use of an innovative technique for strengthening concrete beams are presented. A spacer element is inserted between the tension side of a beam and the composite material to increase its lever arm and to enhance the over all stiffness of the strengthened beam. The main aim of this exploratory project was to increase the ultimate failure load of strengthened beam specimens, whilst guaranteeing acceptable over all deflections at the serviceability limit states. This resulted into a significant reduction in the amount of FPR required and in a better utilization of the materials employed. A preliminary theoretical study was carried out to investigate the effect of Young’s modulus, failure strain, and thickness of the element to be used as a spacer in order to determine the best possible candidate material. Three tests on 2.5-m-long beams were carried out, and different anchorage techniques were used to try and prevent the debonding of the strengthening system. The results from this pilot study are very promising, as the strengthening system ensures an adequate initial stiffness along with an improved ultimate flexural capacity. Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 44, No. 3, pp. 403–416, May–June, 2008.     

Basic modelling of uncertainty: young students’ mental models

This paper focuses on a research programme that aims to explore students?? mental models when acting within elementary situations of uncertainty before stochastics have been addressed in school. In order to frame our research, we begin by reporting briefly on the recent history of research in stochastics education. Then, we discuss the main aspects of our theoretical foundation concerning the research programme. Afterwards we restrict our discussion to an exploratory study aiming to further develop our theoretical framework, describing the development of tasks representing situations of uncertainty and the method of the exploratory study involving students of grade 4 and grade 6. Finally, from the perspective of theory development, we discuss the results of analysing students?? solutions gained through quantitative analysis of tests and qualitative analysis of written rationales and of interviews. We conclude our paper with a discussion of our research results and potential future research questions.     

未知方向密度估计的收敛率

设Ｘ为ｐ维随机向量,对于未知的投影方向θｏ（‖θｏ‖＝１）,本文利用θｏ的估计与核密度估计相结合的方法给出了θ＾Ｔ０Ｘ的密度（方向密度）的核型密度估计,获得了此估计的逐点渐近正态性,逐点精确强收敛率,一致精确强收敛率以及均方误差收敛率,所得结果与最优性与已知方向上的核密度估计完全一致。作为例子,对θｏ为Ｘ协方差阵的最大特征值所对应的特征方向,我们给出了θｏ的满足条件的估计极其方向密度估计。     

Development of a fuzzy-expert system for incident detection and classification

This research presents the exploratory results of using fuzzy-expert systems for incident detection and classification. The proposed system functions to detect not only the occurrence of incidents, but also their located lanes, and the resulting type of severity. With such information, the traffic control center can better advise drivers to take necessary lane changes and take timely actions for minimizing the incident impacts on traffic conditions. Although the current research remains exploratory in nature, as both the fuzzy membership functions and key parameters were determined empirically rather than fine-tuned with a neural network or genetic algorithm, the preliminary results have confirmed the promising properties of the proposed system.     

An “Instrumental Approach” to Study the Integration of a Computer Tool Into Mathematics Teaching: the Case of Spreadsheets

This article reports on research focused on the integration of a specific computer tool, the spreadsheet, into mathematics teaching. After presenting some important results obtained by research in this area, we revisit these in the light of an instrumental approach, which we perceive as essential to analyse the construction of mathematical meanings in spreadsheet environments and to understand better the questions of technological integration. Then, these theoretical elements are used in order to design an exploratory experiment with grade 7 pupils and analyse its results.     

Inferring final organizational outcomes from intermediate outcomes of exploration and exploitation: the complexity link

The difficulty in definitively linking outcomes of managerial action to organizational outcomes has been a festering issue in organizational research. The problem arises because it is not easy to separate the distinctive contributions of managers at intermediate stages, as well as the contribution of external factors beyond the control of managers. Specifically, certain managerial actions focusing on exploratory or exploitative innovation produce an intermediate output, organizational knowledge. From this base of organizational knowledge, further management actions craft the final output that eventually faces the market test. Drawing from complexity concepts, I argue that the probability of correctly fashioning the subset of key elements in the intermediate output may be a good measure of the probability of organizational success. I use March’s iconic computational simulation model to demonstrate the merits of this principle. I model the effect of complexity on managerial intentionality towards exploratory and exploitative innovation. I elicit important insights for research and practice by comparing organizational knowledge outcomes with the outcomes for probability of organizational success, in stable and moderately turbulent environment.     

Branch and win: OR tree search algorithms for solving combinatorial optimisation problems

Currently, most combinatorial optimisation problems have to be solved, if the optimum solution is sought, using general techniques to explore the space of feasible solutions and, more specifically, through exploratory enumerative procedures in trees and search graphs. We propose Branch and Win, a general formulation for understanding and synthesising the different tree search procedures that have been presented in the literature of operations research as well as in that of artificial intelligence. Several general ideas are also presented, whose application allows designing new hybrid search algorithms, in order to implement the procedure.     

Ethics outside,within, or beyond OR models?

Since ethical concerns are calling for more attention within Operational Research, we present three approaches to combine Operational Research models with ethics. Our intention is to clarify the trade-offs faced by the OR community, in particular the tension between the scientific legitimacy of OR models (ethics outside OR models) and the integration of ethics within models (ethics within OR models). Presenting and discussing an approach that combines OR models with the process of OR (ethics beyond OR models), we suggest rigorous ways to express the relation between ethics and OR models. As our work is exploratory, we are trying to avoid a dogmatic attitude and call for further research. We argue that there are interesting avenues for research at the theoretical, methodological and applied levels and that the OR community can contribute to an innovative, constructive and responsible social dialogue about its ethics.     

Using Metaphors to Unpack Student Beliefs About Mathematics

This paper reports on an exploratory study of the mathematical beliefs of a group of ninth and tenth grade students at a large, college preparatory, private school in the Southeastern United States. These beliefs were revealed using contemporary metaphor theory. A thematic analysis of the students' metaphors for mathematics indicated that students had well developed and complex views about mathematics including math as: an Interconnected Structure, a Hierarchical Structure, a Journey of Discovery, an Uncertain Journey, and a Tool. Another prevalent theme revealed by the metaphors was that students believe perseverance is needed for success in mathematics. The data also suggest an impact of gender and tracking on students beliefs about mathematics. Creating metaphors for mathematics provided a catalyst for student reflection, class discussion, and qualitative data, which could aid program evaluation. Several areas for future research were identified through this exploratory study.     

Searching for Appropriate Theory and Practice in Multi-Organizational Fields

To some kinds of social scientists and change agents, there is nothing new about the idea of working in multi-organizational fields. To others, however, exposure to such a field can be an unfamiliar, daunting and indeed often bewildering experience. This paper will argue that, despite some progress in recent years, there remains a paucity of well-grounded and well-articulated theory to guide the endeavours of researchers and change agents working between rather than within organizations. It will identify and review five contexts for learning in which relevant experiences have recently been accumulating: these are the contexts of exploratory social research, of implementation research, of community development, of organizational development and of operational research. It is suggested that the development of an appropriate theory calls for a drawing together of experiences and insights from those now working within these various contexts- and especially those who have opportunities to move between one context and another.     

Multifractal fluctuations in joint angles during infant spontaneous kicking reveal multiplicativity-driven coordination

Previous research has considered infant spontaneous kicking as a form of exploration. According to this view, spontaneous kicking provides information about motor degrees of freedom and may shape multijoint coordinations for more complex movement patterns such as gait. Recent work has demonstrated that multifractal, multiplicative fluctuations in exploratory movements index energy flows underlying perceptual-motor information. If infant spontaneous kicking is exploratory and occasions an upstream flow of information from the motor periphery, we expected not only that multiplicativity of fluctuations at the hip should promote multiplicativity of fluctuations at more distal joints (i.e., reflecting downstream effects of neural control) but also that multiplicativity at more distal joints should promote multiplicativity at the hip. Multifractal analysis demonstrated that infant spontaneous kicking in four typically developing infants for evidence of multiplicative fluctuations in multiple joint angles along the leg (i.e., hip, knee, and ankle) exhibited multiplicativity. Vector autoregressive modeling demonstrated that only one leg exhibited downstream effects but that both legs exhibited upstream effects. These results confirm the exploratory aspect of infant spontaneous kicking and suggest chaotic dynamics in motor coordination. They also resonate with existing models of chaos-controlled robotics and noise-based interventions for rehabilitating motor coordination in atypically developing patients.     

On the roles of OR/MS practitioners in supporting strategy

This paper presents an exploratory account of how Operational Research/Management Science (OR/MS) practitioners understand their role in supporting an organisational strategy process. The role of strategy support is characterised by five dimensions: the activities supported within the strategy process; the nature of support provided; the orientation of the support provided; the tools used in providing support; and the nature of the relationship between consultant and client. The research draws on case studies of four OR/MS practitioners working as internal and as external consultants. The work of the practitioners is mapped onto the framework and gaps are identified. The research proposes a further dimension, namely, ‘the purpose of the support provided’, and suggests four purposeful support roles adopted by practitioners in supporting strategy within organisations: sensemaking/sensegiving; decision support tool development; problem solving/solution exploration; and process facilitation. The paper concludes with suggestions for further research.     

Strategies of node selection in search procedures for solving combinatorial optimization problems: A survey and a general formalization

Currently, most combinatorial optimization problems have to be solved, if the optimum solution is sought, using general techniques to explore the space of feasible solutions and, more specifically, through exploratory enumerative procedures in trees and search graphs. The objective of this work is to propose a survey and a general formalization of the selection strategy of the next node to explore, a feature that is common to all these optimization procedures. This research has been partially supported by TAP98-0494 project     

Using math magic to reinforce algebraic concepts: an exploratory study

An exploratory study was conducted to investigate the use of magic activities in a math course for prospective middle-school math teachers. This research report focuses on a lesson using two versions of math magic: (1) the 5-4-3-2-1-½ Magic involves having students choose a secret number and apply six arithmetic operations in sequence to arrive at a resultant number, and the teacher-magician can spontaneously reveal a student’s secret number from the resultant number; and (2) the Everyone-Got-9 Magic also involves choosing a secret number and applying arithmetic operations in sequence, but everyone will end up with the same resultant number of 9. These magic activities were implemented to reinforce students’ understanding of foundational algebra concepts like variables, expressions, and inverse functions. Analysis of students’ written responses revealed that (1) all students who figured out the trick in the first magic activity did not used algebra, (2) most students could apply what they learned in one trick to a similar trick but not to a different trick, and (3) many students were weak in symbolic representations and manipulations. Responses from a survey and a focus group indicate that students found the magic activities to be fun and intellectually engaging.     

What do teachers need? Math and special education teacher educators’ perceptions of essential teacher knowledge and experience

Special education and mathematics education are becoming increasingly intertwined in inclusive classrooms. However, research and practice in these two fields are not always aligned. We discuss, in the context of extant research on pedagogical theory, concepts of access, and the findings of an exploratory study, how these two education sub-fields view teacher expertise. Teacher educators (from math and special education) were asked to rank the importance of different types of expertise for effectively posing purposeful mathematical questions. The groups differed significantly in their rankings of the importance of knowing individual students and general teaching experience. There were also notable differences between the groups’ rankings of the importance of knowing the needs of students with disabilities and mathematical content knowledge. The possible reasons for this are discussed, along with suggestions for improving professional collaboration.