Metric Based Evaluation and Improvement of Software Designs

The demand for quality software expands as the business environment grows internationally. Common to all software development methodologies is a design phase that focuses on the physical software model. Design criteria used to evaluate these models are important for refinement and improvement. The purpose of this research is to apply transformations of McCabe’s cyclomatic complexity as a means for improving software design and assessing risks within a design. In this research, two metrics, the management (CMGT) and maintenance (CMN) coefficients are introduced, and they are used to address the architectural, size, and quality dimensions of a software design.

Frequency Weighting Filter Design for Automotive Ride Comfort Evaluation

Few study gives guidance to design weighting filters according to the frequency weighting factors,and the additional evaluation method of automotive ride comfort is not made good use of in some countries.Based on the regularities of the weighting factors,a method is proposed and the vertical and horizontal weighting filters are developed.The whole frequency range is divided several times into two parts with respective regularity.For each division,a parallel filter constituted by a low-and a high-pass filter with the same cutoff frequency and the quality factor is utilized to achieve section factors.The cascading of these parallel filters obtains entire factors.These filters own a high order.But,low order filters are preferred in some applications.The bilinear transformation method and the least P-norm optimal infinite impulse response（IIR） filter design method are employed to develop low order filters to approximate the weightings in the standard.In addition,with the window method,the linear phase finite impulse response（FIR） filter is designed to keep the signal from distorting and to obtain the staircase weighting.For the same case,the traditional method produces 0.330 7 m · s^–2 weighted root mean square（r.m.s.） acceleration and the filtering method gives 0.311 9 m · s^–2 r.m.s.The fourth order filter for approximation of vertical weighting obtains 0.313 9 m · s^–2 r.m.s.Crest factors of the acceleration signal weighted by the weighting filter and the fourth order filter are 3.002 7 and 3.011 1,respectively.This paper proposes several methods to design frequency weighting filters for automotive ride comfort evaluation,and these developed weighting filters are effective.

Design and Evaluation of a Differential Accelerometer for Drop-Tower Equivalence Principle Test with Rotating Masses

A differential accelerometer comprising of two rotating masses made of the same material is proposed for drop tower-based free-fall testing of the spin-spin force between the rotating mass and the Earth. The measurement is performed by placing the two concentric masses of very different momenta in a vacuum drop capsule which is falling freely in the Earth＇s gravitational field. A nonzero output of the differential aeeelerometer is an indication of possible violation of new equivalence principle （NEP）. We present the conceptual design of a modified free-fall NEP experiment which can be performed at the Belting drop tower. Design and evaluation of the differential accelerometer with a hybrid electrostatic/magnetic suspension system are presented to accommodate for operation on ground and drop-tower tests. Details specific to the measurement uncertainty are discussed to yield an NEP test accuracy of 7.2×10^-9.

Aggregating Qualitative Verdicts: From Social Choice to Engineering Design

At first sight, the choice of a socially best economic policy and the choice of an optimal engineering design seem to be quite separate issues. A closer look, however, shows that both approaches which aim at generating a (set of) best alternative(s) have much in common. We describe and characterize axiomatically an aggregation method that uses a set of evaluations that are arranged on a common scale. This scale establishes a common language, so to speak, which conforms to the criteria that are deemed relevant in order to compare various design options. Two conditions are able to characterize the proposed aggregation mechanism. One is a simple dominance requirement, and the other called cancellation independence makes use of the fact that for any pair of objects, rank differences of opposite sign can be reduced without changing the aggregate outcome of the ranking procedure. The proposed method has its origin in voting theory but may have the potential to prove useful in engineering design as well.

Optical design and evaluation of Alvarez-type vision-training system

Myopia has become a noteworthy issue due to the increasing use of our eyes. We propose a continuous power variation vision-training device based on Alvarez lenses with the power ranging from -10D to ＋2D. First, we introduce the principle of Alvarez lenses and the evaluation method of dioptric power and astigmatism. Then, we optimize the optical system described by Zernike polynomials. Finally, we analyze the distributions of dioptric power and astigmatism with the overall surface analysis and fields of view（FOVs） analysis. The results show that the optical performance of an optimized system can meet the requirement within a 40° FOV.

Motivation effect of animated pedagogical agent's personality and feedback strategy types on learning in virtual training environment

Background The personality and feedback of an animated pedagogical agent(APA)are vital social-emotional features that render the agent perceptually believable.Their effects on learning during virtual training need to be examined.Methods In this paper,an explanation model is proposed to clarify the underlying mechanism of how these two features affect learners.Two studies were conducted to investigate the model.In Study 1,the effect of the APA's personality type and feedback strategy on flow experience and performance was reexamined,revealing significant effects of the feedback strategy on flow and performance and a marginally significant effect of the personality type on performance.To explore the mechanism behind these effects,a theoretical model is proposed by distinguishing between intrinsic and extrinsic motivation effects.In Study 2,the model was evaluated,and the APA's personality type was found to significantly influence the factors in the path of the extrinsic motivation effect rather than those in the path of the intrinsic motivation effect.Results In contrast,the feedback strategy affected factors in the path of the intrinsic motivation effect.Conclusions These results validated the proposed model.Further distinguishing the two motivation effects is necessary to understand the respective effects of an APA's personality and feedback features on learning experiences and outcomes.

Detection of scene-irrelevant head movements via eye-head coordination information

Background Accurate motion tracking in head-mounted displays(HMDs)has been widely used in immersive VR interaction technologies.However,tracking the head motion of users at all times is not always desirable.During a session of HMD usage,users may make scene-irrelevant head rotations,such as adjusting the head position to avoid neck pain or responding to distractions from the physical world.To the best of our knowledge,this is the first study that addresses the problem of scene-irrelevant head movements.Methods We trained a classifier to detect scene-irrelevant motions using temporal eye head-coordinated information sequences.To investigate the usefulness of the detection results,we propose a technique to suspend motion tracking in HMDs where scene-irrelevant motions are detected.Results/Conclusions Experimental results demonstrate that the scene-relevancy of movements can be detected using eye-head coordination information,and that ignoring scene-irrelevant head motions in HMDs improves user continuity without increasing sickness or breaking immersion.

An experimental analysis of situation awareness for cockpit display interface evaluation based on flight simulation

Aircraft cockpit display interface （CDI） is one of the most important human-machine interfaces for information perceiving. During the process of aircraft design, situation awareness （SA） is frequently considered to improve the design, as the CDI must provide enough SA for the pilot to maintain the flight safety. In order to study the SA in the pilot-aircraft system, a cockpit flight simulation environment is built up, which includes a virtual instrument panel, a flight visual display and the corresponding control system. Based on the simulation environment, a human-in-the-loop experiment is designed to measure the SA by the situation awareness global assessment technique （SAGAT）. Through the experiment, the SA degrees and heart rate （HR） data of the subjects are obtained, and the SA levels under different CDI designs are analyzed. The results show that analyzing the SA can serve as an objective way to evaluate the design of CDI, which could be proved from the consistent HR data. With this method, evaluations of the CDI design are performed in the experimental flight simulation environment, and optimizations could be guided through the analysis.

How Can We Make Disaster Management Evaluations More Useful?An Empirical Study of Dutch Exercise Evaluations

The evaluation of simulated disasters(for example,exercises)and real responses are important activities.However,little attention has been paid to how reports documenting such events should be written.A key issue is how to make them as useful as possible to professionals working in disaster risk management.Here,we focus on three aspects of a written evaluation:how the object of the evaluation is described,how the analysis is described,and how the conclusions are described.This empirical experiment,based on real evaluation documents,asked 84 Dutch mayors and crisis management professionals to evaluate the perceived usefulness of the three aspects noted above.The results showed that how evalua・tions are written does matter.Specifically,the usefulness of an evaluation intended for learning purposes is improved when its analysis and conclusions are clearer.In contrast,evaluations used for accountability purposes are only improved by the clarity of the con elusion.These findings have implications for the way disaster management evaluations should be documented.