Is it possible to disregard obsolete requirements? a family of experiments in software effort estimation

Requirements Engineering - Expert judgement is a common method for software effort estimations in practice today. Estimators are often shown extra obsolete requirements together with the real ones...     

Return to Religion? Predictors of Religious Change among Baby-Boomers in their Transition to Later Life

In this paper, we investigated the correlates of change in religiosity among babyboomers as they aged from their 50s to their 60s. Change was assessed as a function of cognitive and behavioral manifestations of religious involvement, early religious participation, and challenges that emerged over this period of life. Using qualitative and quantitative data from 599 respondents in the 2016 wave of the Longitudinal Study of Generations, we examined retrospectively assessed religious change over the previous ten years and the precipitating reasons for such change. Religiosity was most likely to remain stable, but a significant minority of the sample became more religious over the past ten years; reasons included a shift away from worldly concerns, coping with loss and health problems, and intergenerational continuity. Structural equation modeling found that early exposure to religion strengthened religiosity through its association with both stronger cognitive and behavioral aspects of religious involvement. Losing of a partner, experiencing economic decline, and having health problems either increased or stabilized religiosity, complementing results from qualitative responses. In general, religious change, when it did occur, was in a positive direction and served as a resource for dealing with health and social losses. We anticipate this trend to intensify as baby-boomers advance to even later stages of the life-course.     

A simple proof of the necessity of the failure detector Σ to implement an atomic register in asynchronous message-passing systems

This paper presents a simple proof that shows that the quorum failure detector class (denoted Σ) is the weakest failure detector class required to implement an atomic read/write register in an asynchronous message-passing system prone to an arbitrary number of process crashes. This proof is based on a new reduction algorithm in which all the variables are bounded.     

Precise Coulomb wave functions for a wide range of complex ?, η and z

A new algorithm to calculate Coulomb wave functions with all of its arguments complex is proposed. For that purpose, standard methods such as continued fractions and power/asymptotic series are combined with direct integrations of the Schrödinger equation in order to provide very stable calculations, even for large values of |η| or |ℑ(?)|. Moreover, a simple analytic continuation for is introduced, so that this zone of the complex z-plane does not pose any problem. This code is particularly well suited for low-energy calculations and the calculation of resonances with extremely small widths. Numerical instabilities appear, however, when both |η| and |ℑ(?)| are large and comparable or smaller than |ℑ(?)|.

Program summary

Title of program: cwfcomplexCatalogue number:ADYO_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADYO_v1_0Program obtainable from: CPC Program Library, Queen's University of Belfast, N. IrelandLicensing provisions: noneComputers on which the program has been tested: DELL GX400Operating systems: Linux, WindowsProgramming language used: C++No. of bits in a word: 64No. of processors used: 1Has the code been vectorized?: noNo. of bytes in distributed program, including test data, etc.: 33 092No. of lines in distributed program, including test data, etc.: 3210Distribution format:tar.gzNature of physical problem: The calculation of Coulomb wave functions with all of their arguments complex is revisited. The new methods introduced allow to greatly augment the range of accessible ?, η, and z.Method of solution: Power/asymptotic series and continued fractions are supplemented with direct integrations of the Coulomb Schrödinger equation. Analytic continuation for is also precisely computed using linear combinations of the functions provided by standard methods, which do not follow the branch cut requirements demanded for Coulomb wave functions.Typical running time: N/AUnusual features of the program: none     

How to divide a territory? A new simple differential formalism for optimization of set functions

In many practical problems, we must optimize a set function, i.e., find a set A for which f(A)→max, where f is a function defined on the class of sets. Such problems appear in design, in image processing, in game theory, etc. Most optimization problems can be solved (or at least simplified) by using the fact that small deviations from an optimal solution can only decrease the value of the objective function; as a result, some derivative must be equal to 0. This approach has been successfully used, e.g., for set functions in which the desired set A is a shape, i.e., a smooth (or piece-wise smooth) surface. In some real-life problems, in particular, in the territorial division problem, the existing methods are not directly applicable. For such problems, we design a new simple differential formalism for optimizing set functions. ©1999 John Wiley & Sons, Inc.     

Gonokendra model: a response to “information poverty” in rural areas of Bangladesh

We argue that there is a need to understand impacts of information and communication technologies (ICT) projects in their local context, considering the participants' perspectives at the micro (community) level. Hence, this paper reports on the development and refinement of an extended framework to investigate ICT impact on development in three village areas in the developing country, Bangladesh. Through an interpretive study, we argue that previous studies failed to encapsulate many aspects such as mobility restriction, negative attitude towards female group and religious influences of ICT impact, especially at the micro level. Our extended framework demonstrates that ICT projects can lead to development, but only when social constraints are addressed.     

How sensitive is a vineyard crop model to the uncertainty of its runoff module?

Many crop models use the NRCS Curve Number method to estimate runoff, but the simplified assumptions of this method are rarely considered in model uncertainty assessments. The associated uncertainty may be high for cropping systems with a significant part of bare soil like vineyards, specifically under a Mediterranean climate. In this work, we evaluate for a vineyard crop model the structure uncertainty coming from its uncertain runoff module. We introduce a new method based on additional knowledge about the runoff process and on a mathematical property of the model structure. Situations characterized in terms of soil water content and mean runoff conditions are studied for two applications of the vineyard model and guidelines for model users are derived. This work shows that uncertainty quantification can benefit from the knowledge of mathematical properties of a model and provide clear guidelines to model users.     

Studies of angular correlations in the decays Bs→J/ψφ by using the SIMUB generator

The performance of the method of angular moments on the ΔΓ_s determination from analysis of untagged decays is examined by using the SIMUB generator. The results of Monte Carlo studies with evaluation of measurement errors are presented. The method of angular moments gives stable results for the estimate of ΔΓ_s and is found to be an efficient and flexible tool for the quantitative investigation of the B⁰_s→J/ψφ decay. The statistical error of the ratio ΔΓ_s/Γ_s for values of this ratio in the interval [0.03,0.3] was found to be independent on this value, being 0.015 for 10⁵ events.     

Evolutionary bi-objective optimization of a semi-arid vegetation dynamics model with NDVI and σ satellite data

Satellite radar backscattering coefficient σ⁰ data from ENVISAT-ASAR and Normalized Difference Vegetation Index (NDVI) data from SPOT-VEGETATION are assimilated in the STEP model of vegetation dynamics. The STEP model is coupled with a radiative transfer model of the radar backscattering and NDVI signatures of the soil and herbaceous vegetation. These models are driven by field data (rainfall time series, soil properties, etc.). While some model parameters have fixed values, some other parameters have target values to be optimized. The study focuses on a well documented 1 km² homogeneous area in a semi-arid region (Gourma, Mali).We here investigate whether departures between model predictions and the corresponding data result from field data errors, in situ data lack of representativeness or some model shortcomings. For this purpose we introduce an evolutionary strategy (ES) approach relying on a bi-objective function to be minimized in the data assimilation/inversion process. Several numerical experiments are conducted, in various mono-objective and bi-objective modes, and the performances of the model predictions compared in terms of NDVI, backscattering coefficient, leaf area index (LAI) and biomass.It is shown that the bi-objective ES leads to improved model predictions and also to a better readability of the results by exploring the Pareto front of optimal and admissible solutions. It is also shown that the information brought from the optical sensor and the radar is coherent; that the corresponding radiative transfer models are also coherent; that the representativeness of in situ data can be compared to satellite data through the modeling process. However some systematic biases on the biomass predictions (errors in the range 140 to 300 kg ha^− 1) are observed. Thanks to the bi-objective ES, we are able to identify some likely shortcoming in the vegetation dynamics model relating the LAI to the biomass variables.     

Characterizations of regular ordered semigroups in terms of (α, β)-fuzzy generalized bi-ideals

In this paper, the concept of an (α, β)-fuzzy generalized bi-ideal in an ordered semigroup is introduced, which is a generalization of the concept of a fuzzy generalized bi-ideal in an ordered semigroup. Using this concept, some characterization theorems are provided. The upper/lower parts of an (∈, ∈ ∨ q)-fuzzy generalized bi-ideal are introduced and some characterizations of regular ordered semigroups are given. Also, we consider the concept of implication-based fuzzy generalized bi-ideals in an ordered semigroup. In particular, the implication operators in Lukasiewicz system of continuous-valued logic are discussed.     

Social compensation or rich-get-richer? The role of social competence in college students’ use of the Internet to find a partner

Online dating continues to grow rapidly in popularity every day, yet the role of social competence in online dating behavior remains unclear. This study was designed to expand previous research and conduct a comprehensive investigation on how social competence is associated with college students’ online dating behaviors, perceptions, and attitudes. Two hypotheses were tested: The social compensation hypothesis (SCH)—socially incompetent individuals would engage in more online dating, and the rich-get-richer hypothesis (RGRH)—socially competent individuals would use online dating more than their incompetent counterparts. The results showed that incompetent individuals, despite their ability to see benefits in online dating, did not show a favorable attitude towards online dating. They indicated a more frequent use of and a stronger preference for face-to-face dating compared to online dating, which contradicted the SCH. There were weak associations between competence traits and online dating behavior. Socially competent individuals perceived less benefit and showed less interest in online dating, which disconfirmed the RGRH.     

Why do you play World of Warcraft? An in-depth exploration of self-reported motivations to play online and in-game behaviours in the virtual world of Azeroth

Massively multiplayer online role-playing games (MMORPGs) are video games in which players create an avatar that evolves and interacts with other avatars in a persistent virtual world. Motivations to play MMORPGs are heterogeneous (e.g. achievement, socialisation, immersion in virtual worlds). This study investigates in detail the relationships between self-reported motives and actual in-game behaviours. We recruited a sample of 690 World of Warcraft players (the most popular MMORPG) who agreed to have their avatar monitored for 8 months. Participants completed an initial online survey about their motives to play. Their actual in-game behaviours were measured through the game’s official database (the Armory website). Results showed specific associations between motives and in-game behaviours. Moreover, longitudinal analyses revealed that teamwork- and competition-oriented motives are the most accurate predictors of fast progression in the game. In addition, although specific associations exist between problematic use and certain motives (e.g. advancement, escapism), longitudinal analyses showed that high involvement in the game is not necessarily associated with a negative impact upon daily living.     

Using the extension of DEMATEL to integrate hotel service quality perceptions into a cause–effect model in uncertainty

This study proposes an evaluation approach on assessing service quality perceptions based on the fuzzy measure and extension of decision-making trial and evaluation laboratory (EDEMATEL). This research comprises the perception of two study groups, namely, customers and employees, which include 22 evaluation criteria assessed by two groups from the top four English hotels in Taiwan. The human perception on service quality usually involves in imprecision and vagueness. The triangular fuzzy numbers presents the vagueness and subjectivity information, and use defuzzification method to handle the vagueness linguistic information into a crisp value. This study applies fuzzy set theory and EDEMATEL method to evaluate the interrelationships of service quality evaluation criteria and to compromise the group perceptions into a cause and effect model in uncertainty. The proposed approach is an effective method for assessing the group perceptions, and it integrates the different perceptions into a compromised cause and effect model of hotel service quality in uncertainty. The managerial implications are discussed.     

Mental rotation: a key to mitigation of motion sickness in the virtual environment?

Some of our recent observations suggest that mental rotation may be important for reduction of motion sickness in microgravity as well as in the microgravity simulator. Therefore, we suggest that development of the ability to perform mental rotation may be important for adaptation to many virtual environments. Training virtual environment operators to perform mental rotation may enhance operator performance both by increasing their ability to "locomote in" and manipulate that environment and by reducing motion sickness associated with transitions between virtual and normal environments.     

A fuzzy random resource-constrained scheduling model with?multiple projects and its application to a working procedure in?a?large-scale water conservancy and hydropower construction project

The aim of this paper is to deal with resource-constrained multiple project scheduling problems (rc-mPSP) under a fuzzy random environment by a hybrid genetic algorithm with fuzzy logic controller (flc-hGA), to a large-scale water conservancy and hydropower construction project in the southwest region of China, whose main project is a dam embankment. The objective functions in this paper are to minimize the total project time (that is the sum of the completion time for all projects) and to minimize the total tardiness penalty of multiple projects, which is the sum of penalty costs for all the projects. After describing the problem of the working procedure in the project and presenting the mathematical formulation model of a resource-constrained project scheduling problem under a fuzzy random environment, we give some definitions and discuss some properties of fuzzy random variables. Then, a method of solving solution sets of fuzzy random multiple objective programming problems is proposed. Because traditional optimization techniques could not cope with the rc-mPSP under a fuzzy random environment effectively, we present a new approach based on the hybrid genetic algorithm (hGA). In order to improve its efficiency, the proposed method hybridized with the fuzzy logic controller (flc) concept for auto-tuning the GA parameters is presented. For the practical problems in this paper, flc-hGA is proved the most effective and most appropriate compared with other approaches. The computer generated results validate the effectiveness of the proposed model and algorithm in solving large-scale practical problems.     

Will the experience of playing a violent role in a video game influence people’s judgments of violent crimes?

The present study investigates the impact of the experience of role playing a violent character in a video game on attitudes towards violent crimes and criminals. People who played the violent game were found to be more acceptable of crimes and criminals compared to people who did not play the violent game. More importantly, interaction effects were found such that people were more acceptable of crimes and criminals outside the game if the criminals were matched with the role they played in the game and the criminal actions were similar to the activities they perpetrated during the game. The results indicate that people’s virtual experience through role-playing games can influence their attitudes and judgments of similar real-life crimes, especially if the crimes are similar to what they conducted while playing games. Theoretical and practical implications are discussed.     

Out of fear or desire? Toward a better understanding of employees’ motivation to follow IS security policies

Given the significant role of people in the management of security, attention has recently been paid to the issue of how to motivate employees to improve security performance of organizations. However, past work has been dependent on deterrence theory rooted in an extrinsic motivation model to help understand why employees do or do not follow security rules in their organization. We postulated that we could better explain employees’ security-related rule-following behavior with an approach rooted in an intrinsic motivation model. We therefore developed a model of employees’ motivation to comply with IS security policies which incorporated both extrinsic and intrinsic models of human behavior. It was tested with data collected through a survey of 602 employees in the United States. We found that variables rooted in the intrinsic motivation model contributed significantly more to the explained variance of employees’ compliance than did those rooted in the extrinsic motivation model.     

How to design personalization in a context of customer retention: Who personalizes what and to what extent?

Personalization is a strategic tool for product or service differentiation, especially when competition is keen in the market. Many personalization strategies have been developed and realized with this in mind. Little is known about the impact of different personalization strategies, regarding different personalization dimensions on customer retention, however. This has resulted in a lack of consensus on how best to design personalization strategies. To address the related issues, this study identifies the dimensions of personalization, and investigates the effect of each dimension on customer retention. It does so by implementing actual personalization systems corresponding to two factorial design experiments involving 372 participants. Multiple analysis of covariance reveals the effectiveness of each dimension and interactions among them. This study consequently proposes the optimal combination of personalization dimensions that leads to customer satisfaction and loyalty.