Software engineering is a value-based contact sport

The theory that most current students get covers may be 15 percent of the activities they encounter in practice. Most of it is based on a model of software engineering as a set-piece job of deriving and verifying code from a static set of requirements. This was a good model in the 1970s, but it is way out of date now. We should try to educate them for the software engineering situations they will encounter in the future.     

The effect of culture on requirements: a value-based view of prioritization

This paper examines how culture affects requirements and their prioritization. We analyze the requirements of a mobile service, which were collected from Helsinki, Hong Kong, and Las Vegas. We argue that the current prioritization techniques for requirements do not sufficiently account for the cultural effects, nor does the literature offer information on ways of prioritizing such requirements according to users’ values. We see this as problematic because the literature suggests that culture should be viewed as a set of values. Our findings support the argument that we should use a value-based approach in prioritizing requirements. Furthermore, by focusing on the links between needs and values, we should be able to develop prioritization techniques not only for multicultural settings but also for information systems (IS) development projects that involve subcultures, such as adolescent users or members of specific organizations. Our findings show that this can be a powerful way of understanding the differences between various subcultures of IS users. In addition, we demonstrate how the laddering interviewing technique can be used to support this work. The proposed value-based requirements prioritization approach is also ready for industry applications and it is agnostic to the underlying IS development method used by developers.     

Scenario-based and value-based specification mining: better together

Specification mining takes execution traces as input and extracts likely program invariants, which can be used for comprehension, verification, and evolution related tasks. In this work we integrate scenario-based specification mining, which uses a data-mining algorithm to suggest ordering constraints in the form of live sequence charts, an inter-object, visual, modal, scenario-based specification language, with mining of value-based invariants, which detects likely invariants holding at specific program points. The key to the integration is a technique we call scenario-based slicing, running on top of the mining algorithms to distinguish the scenario-specific invariants from the general ones. The resulting suggested specifications are rich, consisting of modal scenarios annotated with scenario-specific value-based invariants, referring to event parameters and participating object properties. We have implemented the mining algorithm and the visual presentation of the mined scenarios within a standard development environment. An evaluation of our work over a number of case studies shows promising results in extracting expressive specifications from real programs, which could not be extracted previously. The more expressive the mined specifications, the higher their potential to support program comprehension and testing.     

Engaging multiple perspectives: A value-based decision-making model

In some decision contexts, such as a crisis or when confronted by a new or novel set of circumstances, people may be forced to make decisions with limited information or time available for analysis. In such contexts, the set of alternative solutions developed may be greatly affected by the personal values and the perspective those values precipitate. Being able to view the decision environment from multiple perspectives enhances the decision-maker's ability to make better-informed choices. This article introduces the value-based decision-making model that suggests that multiple perspectives may be achieved by considering a foundation of individual values. Empirical testing indicates that this model provides a viable framework that decision-makers and researchers can use to better understand and facilitate multiple perspectives in decision-making.     

A value-based approach to the ex-ante evaluation of IT enabled business process improvement projects

In this study, we propose a value-based management approach for assessing the potential for process improvements enabled by an information technology (IT) solution. Based on activity based management concepts, we perform a granular, process level analysis on workflow structure and associated resource consumption to provide quantifiable measures of potential improvement prior to system implementation. The proof of concept of this approach is illustrated in a southern United States county in need of integrating different government branches through an ERP implementation. Based on prior research, we first provide a catalog of non-value added (NVA) activities that can be used in management control and governance procedures for the systematic identification of process inefficiencies. Next, by breaking down processes to the level of atomic activities, we show that minimizing NVA activities provides a systematic means to mitigate process inefficiencies. A significant observation is that different NVA activities may impact process performance to varying degrees. Consequently, line items in the request for proposals (RFP) should be weighted accordingly during the vendor selection process, contrary to the common practice of treating all line items equally.     

Detecting value-based scalar dependence

Precise value-based data dependence analysis for scalars is useful for advanced compiler optimizations. The new method presented here for flow and output dependence uses Factored Use and Def chains (FUD chains), our interpretation and extension of Static Single Assignment. It is precise with respect to conditional control flow and dependence vectors. Our method detects dependences which are independent with respect to arbitrary loop nesting, as well as loop-carried dependences. A loop-carried dependence is further classified as being carried from the previous iteration, with distance 1, or from any previous iteration, with direction <. This precision cannot be achieved by traditional analysis, such as dominator information or reaching definitions. To compute anti- and input dependence, we use Factored Redef-Use chains, which are related to FUD chains. We are not aware of any prior work which explicitly deals with scalar data dependence utilizing a sparse graph representation. A preliminary version of this paper appeared in theSeventh Anual Workshop on Languages and Compilers for Parallel Computing, August 1994. Supported in part by NSF Grant CCR-9113885 and a grant from Intel Corporation and the Oregon Advanced Computing Institute.     

Agile MERODE: a model-driven software engineering method for user-centric and value-based development

Agile is often associated with a lack of architectural thinking causing technical debt but has the advantage of user centricity and a strong focus on value. Model-driven software engineering (MDSE) strongly performs for building a quality architecture and code, but lacks focus on user requirements and tends to consider development as a monolithic whole. The combination of Agile and MDSE has been explored, but a convincing integrated method has not been proposed yet. This paper addresses this gap by exploring the specific combination of MERODE—as an example of a proven MDSE method—with Scrum, a reference agile method offering a concrete (sprint-based) life cycle management on the basis of user stories. The method resulting of this integration is called Agile MERODE; it is driven by user stories, themselves associated with behavior-driven development scenarios. It allows for domain-driven design and permits fast development from domain models by means of code generation. An illustrative example further clarifies the practical application of Agile MERODE, while a case study shows the planning game application in the case’s context. While the approach, in its entirety, allows reducing technical debt by building the architecture in a logical, consistent and complete manner, introducing MDSE involves a trade-off with pure value-driven development. Agile MERODE contributes to the state of the art by showing how to increase user centricity in MDSE, how to align model-driven engineering with the Scrum cycle, and how to reduce the technical debt of agile developments yet remaining value-focused.

     

E-business differentiation through value-based trust

For e-business, location is irrelevant and competition is intense. To succeed in this environment, organizations must find new ways to differentiate themselves from their competition. One way to achieve e-business differentiation is to foster trust by building a perception of value congruence and avoiding a perception of value conflict. We explore how value congruence contributes to and how value conflict decreases trust in e-businesses. An experiment was conducted to examine the respective impacts of value congruence and value conflict on trust in an e-commerce setting. Our results show that, for e-businesses, value congruence has an enabling effect on trust while value conflict reduces trust. Such effects are strong enough to suggest that value congruence can be employed as an effective way for e-businesses to differentiate themselves while creating and sustaining competitive advantage. Managerial implications are drawn from our results.     

A reinforcement learning approach to competitive ordering and pricing problem

This study analyses simultaneous ordering and pricing decisions for retailers working in a multi‐retailer competitive environment for an infinite horizon. Retailers compete for the same market where the market demand is uncertain. The customer selects the winning agent (retailer) in each term on the basis of random utility maximization, which depends primarily on retailer price and random error. The complexity of the problem is increased by competitiveness, necessity for simultaneous decisions and uncertainty in the nature of increases, and is not conducive to examination using standard analytical methods. Therefore, we model the problem using reinforcement learning (RL), which is founded on stochastic dynamic programming and agent‐based simulations. We analyse the effects of competitiveness and performance of RL on three different scenarios: a monopolistic case where one retailer employing a RL agent maximizes its profit, a duopolistic case where one retailer employs RL and another utilizes adaptive pricing and ordering policies, and a duopolistic case where both retailers employ RL.     

An adaptive reasoning approach towards efficient ordering of composite hypotheses

A Bayesian network is a knowledge representation framework for encoding both qualitative and quantitative probabilistic dependencies among a set of propositional (or random) variables. An important type of probabilistic inference in a Bayesian network is the derivation of the most probable composite hypotheses — a set of hypotheses composed of multiple variables in a network. Such a type of probabilistic inference, however, is computationally intractable. In this paper an adaptive reasoning approach based on qualitative interval arithmetic is proposed as a method of dealing with the computational problem. Using this approach, a qualitative boundary, which reflects the upper and lower limits of a posterior likelihood, can be derived for each composite hypothesis. The advantage ofbounding each composite hypothesis qualitatively is that the quantitative values of the posterior likelihoods are not all necessary in the course of an inference. Consequently, an exhaustive evaluation can be avoided. The complexity of the proposed approach can be demonstrated to be no worse than that of a direct computation and in some cases, the computation is only a small fraction of that required in a straightforward direct computation.This work was supported in part by a grant to Queens College from the General Research Branch, National Institute of Health under grant No. RR-07064, and in part by a grant from the City University of New York PSC-CUNY Research Award Program.     

基于位置信息的序列模式挖掘算法*

PrefixSpan算法在产生频繁序列模式时会产生大量的投影数据库,其中很多投影数据库是相同的。提出了基于位置信息的序列模式挖掘算法——PVS,该方法通过记录每个已产生投影数据库的位置信息,避免了重复产生相同的投影数据库,从而提高了算法的运行效率。通过实验证明,该算法在处理相似度很高的序列数据时比PrefixSpan算法有效。     

From a simple elimination ordering to a strong elimination ordering in linear time

We present a linear time algorithm for transforming a simple elimination ordering of a strongly chordal graph into a strong elimination ordering.     

Robo-advisors and investment intention: A perspective of value-based adoption

Financial robo-advisors have been widely used to assist individuals in their investment decisions, making it important to reduce uncertainties in the assistance process. Existing empirical studies rarely explore uncertainty reduction strategies and their implications on users’ investment intentions in the context of financial robo-advisors; our study attempts to address this gap. We construct a model to explain how uncertainty reduction strategies affect users’ investment intention in using financial robo-advisors. By collecting and analyzing a sample of 307 financial robo-advisor users, we find that algorithmic interpretability, structural assurance, and interactivity as uncertainty reduction strategies are positively related to users’ investment intention through the value-based adoption mechanism. Our research extends the value-based adoption model and uncertainty reduction theory in the financial robo-advisor context. We provide insights to financial robo-advisor service providers about focusing on improving algorithmic transparency, third-party assurance, and interactivity of financial robo-advisors to enhance perceived value and investment intention.     

A hybrid particle swarm optimization approach for the sequential ordering problem

The sequential ordering problem is a version of the asymmetric travelling salesman problem where precedence constraints on vertices are imposed. A tour is feasible if these constraints are fulfilled, and the objective is to find a feasible solution with minimum cost.     

Partial ordering of information granulations: a further investigation

The notion of information systems provides a convenient tool for knowledge representation of objects in terms of their attribute values, while partial ordering is usually used to research the rough monotonicity of an uncertainty measure in information systems. In this paper, we first reveal the limitations of existing partial orderings to describe information granulations in information systems with several illustrative examples. Then, a generalized partial ordering with a set‐size nature is proposed to overcome their shortcoming and some of its important properties are derived. Finally, we prove that several existing information granulations all satisfy the granulation monotonicity induced by the proposed partial ordering. The presented partial ordering appears to be well suited to characterize the nature of information granulations in an information system. These results will be very helpful for studying granular computing and uncertainty in information systems.     

Genetic algorithm approach to a production ordering problem in an assembly process with constant use of parts

An optimal production scheduling problem for an assembly process with buffers at the input and output sides of a machine is dealt with. The problem has two kinds of constraints. One constraint is that the buffers' capacity is limited. The other constraint is that the cycle time of the worker is constant without waiting time. An optimal production ordering is determined, subject to these constraints, in such a way that the rate of use of parts to produce each product should be as constant as possible. A procedure to apply the genetic algorithm to this problem is shown. The operations of reproduction, crossover and mutation are presented. It is observed from numerical results that the genetic algorithm gives a better suboptimal solution than the greedy method.     

Estimating,planning and managing Agile Web development projects under a value-based perspective

ContextThe processes of estimating, planning and managing are crucial for software development projects, since the results must be related to several business strategies. The broad expansion of the Internet and the global and interconnected economy make Web development projects be often characterized by expressions like delivering as soon as possible, reducing time to market and adapting to undefined requirements. In this kind of environment, traditional methodologies based on predictive techniques sometimes do not offer very satisfactory results. The rise of Agile methodologies and practices has provided some useful tools that, combined with Web Engineering techniques, can help to establish a framework to estimate, manage and plan Web development projects.ObjectiveThis paper presents a proposal for estimating, planning and managing Web projects, by combining some existing Agile techniques with Web Engineering principles, presenting them as an unified framework which uses the business value to guide the delivery of features.MethodThe proposal is analyzed by means of a case study, including a real-life project, in order to obtain relevant conclusions.ResultsThe results achieved after using the framework in a development project are presented, including interesting results on project planning and estimation, as well as on team productivity throughout the project.ConclusionIt is concluded that the framework can be useful in order to better manage Web-based projects, through a continuous value-based estimation and management process.     

基于CIS值的非合作-合作两型博弈的理论研究

针对Brandenburger和Stuart提出的非合作-合作两型博弈中的不足,提出一种基于转归集中心值(CIS值)的非合作-合作两型博弈理论框架.用CIS值作为合作博弈阶段的解,进而构造获得非合作博弈阶段的纯策略纳什均衡解,并证明该类两型博弈解存在的条件.所提出的非合作-合作两型博弈的求解方法降低了非合作-合作两型博弈的解和有效策略存在的要求,适合于联盟外局中人的策略对联盟具有外部影响时的非合作-合作两型博弈问题,使非合作-合作两型博弈模型的应用更具有一般化,为供应链管理等问题提供新的理论依据.最后,通过数值实例表明所提出模型和方法的有效性和实用性.     

NBmalloc: Allocating Memory in a Lock-Free Manner

Efficient, scalable memory allocation for multithreaded applications on multiprocessors is a significant goal of recent research. In the distributed computing literature it has been emphasized that lock-based synchronization and concurrency-control may limit the parallelism in multiprocessor systems. Thus, system services that employ such methods can hinder reaching the full potential of these systems. A natural research question is the pertinence and the impact of lock-free concurrency control in key services for multiprocessors, such as in the memory allocation service, which is the theme of this work. We show the design and implementation of NBmalloc, a lock-free memory allocator designed to enhance the parallelism in the system. The architecture of NBmalloc is inspired by Hoard, a well-known concurrent memory allocator, with modular design that preserves scalability and helps avoiding false-sharing and heap-blowup. Within our effort to design appropriate lock-free algorithms for NBmalloc, we propose and show a lock-free implementation of a new data structure, flat-set, supporting conventional “internal” set operations as well as “inter-object” operations, for moving items between flat-sets. The design of NBmalloc also involved a series of other algorithmic problems, which are discussed in the paper. Further, we present the implementation of NBmalloc and a study of its behaviour in a set of multiprocessor systems. The results show that the good properties of Hoard w.r.t. false-sharing and heap-blowup are preserved.