Search results

In this paper, I synthesize the prior psychology literature on ego depletion and apply this literature to an auditing setting. Ego depletion refers to a reduced desire or ability to use self-control in task performance due to using self-control on prior tasks. I focus on the likely causes and consequences of depletion in an auditing setting, as well as means of mitigating depletion and recovering self-control resources. While ego depletion theory is prevalent in the psychology literature, little is known about whether or how ego depletion affects professionals on meaningful task performance. As a result, this synthesis is aimed at stimulating future ego depletion research in accounting, and specifically auditing, by surveying existing literature and applying this literature to an auditing setting. Further, I develop 13 questions for future research to investigate. My synthesis reveals that ego depletion likely has a pervasive effect in an auditing setting, and can hinder auditors’ judgment and decision-making (JDM) quality. Therefore, this synthesis helps to provide a greater understanding of the impact of auditing tasks on individuals, and refines both auditor JDM and ego depletion theories.

The role of debt in episodes of financial stability is a topic of increasing important as the global economy struggles to recover from the worst crisis since the Great Depression of the 1930s. The purpose of this paper is to examine the mortgage finance booms of the 1920s and 2000s as natural experiments, new insights into debt-driven financial crises are gained.

The general methodology is interpreting anomalous historical events as natural experiments. The specific methodology is the approach to natural experiments provided by Joseph A. Schumpeter and Milton Friedman. The hypothesis tested is that laxity in lending standards was the prime contributor to the mortgage debt booms. In each case, we explain why factors other than laxity in lending standards would be secondary factors, with the pre-boom and post-boom lending standards providing the control groups of natural experiments. The two episodes of mortgage debt booms occurring under very different general economic and financial conditions provide an especially strong test of the hypothesized functional relationship.

The results of the two natural experiments support the hypothesis that lax lending standards were the prime contributors to the two episodes of debt-driven financial crisis.

From a social economics perspective, the insights gained are important because a major social goal has been to encourage greater opportunities for home ownership. The results of these natural experiments provide guidance for policymakers in the search for a viable balance between achieving that social goal and maintaining financial stability.

This study is concerned with the formal assessment of a Distance Learning Environment (DLE) created to deliver a course on UML sequence diagrams to university‐level students, divided into control and treatment groups. An ad‐hoc DLE was constructed to deliver instruction to the treatment group, while the control group was taught in a traditional face‐to‐face way. The main point of concern is whether a DLE can be as effective for the treatment group, as the faceto‐ face lecture is for the control group, in terms of gaining mastery on the domain. So, a controlled experiment was organized and executed, in order to measure the participants’ performance in both groups. The results have shown no statistically significant difference for both groups of students. So, it can be argued that in the context of this experiment and by following a DLE‐design close enough to the traditional face‐to‐face approach, one can obtain equally good results using distance learning as with the traditional system. However, a number of concerns remain and more work is needed to generalize the results of this work on other domains.

In this, the second part of a two‐part paper (Part I, Personnel Review, Summer 1977, pp 21–34) a survey of instances of work system design (WSD) experiments will be continued. As described in the Introduction to Part I, cases chosen for inclusion report the economic and human results of actual physical or structural innovations in a set or series of human tasks which, taken together, form some meaningful technical whole. The term ‘experiment’ is used in both Part I and II to refer loosely to change or manipulation of actual work activities, and not necessarily to well controlled laboratory experiments. In fact, most cases reported here are ‘natural’ and very few are carefully controlled.

This paper aims to propose a novel system design and control algorithm of lower limb exoskeleton, which provides walking assistance and load sharing for the wearer.

In this paper, the valve-controlled asymmetrical hydraulic cylinder is selected for driving the hip and knee joint of exoskeleton. Pressure shoe is developed that purpose on detecting changes in plantar force, and a fuzzy recognition algorithm using plantar pressure is proposed. Dynamic model of the exoskeleton is established, and the sliding mode control is developed to implement the position tracking of exoskeleton. A series of prototype experiments including benchtop test, full assistance, partial assistance and loaded walking experiments are set up to verify the tracking performance and power-assisted effect of the proposed exoskeleton.

The control performance of PID control and sliding mode control are compared. The experimental data shows the tracking trajectories and tracking errors of sliding mode control and demonstrate its good robustness to nonlinearities. sEMG of the gastrocnemius muscle tends to be significantly weakened during assisted walking.

In this paper, a structure that the knee joint and hip joint driven by the valve-controlled asymmetrical cylinder is used to provide walking assistance for the wearer. The sliding mode control is proposed to deal with the nonlinearities during joint rotation and fluids. It shows great robustness and frequency adaptability through experiments under different motion frequencies and assistance modes. The design and control method of exoskeleton is a good attempt, which takes positive impacts on the productivity or quality of the life of wearers.

If we are to examine the role of “controls” in different experimental settings, it is appropriate that the word be defined carefully. The Oxford English Dictionary (Second Edition) defines the verb “control” in the following manner: “To exercise restraint or direction upon the free action of; to hold sway over, exercise power or authority over; to dominate, command.” So the word means something more active and interventionist than is suggested by it’s colloquial clinical usage. Control can include such mundane things as ensuring sterile equipment in a chemistry lab, to restrain the free flow of germs and unwanted particles that might contaminate some test.

Weblabs are an additional resource in the execution of experiments in control engineering education, making learning process more flexible both in time, by allowing extra class laboratory activities, and space, bringing the learning experience to remote locations where experimentation facilities would not be available. The purpose of this paper is to investigate and report on a weblab project where the speed of a DC motor is controlled in closed loop, being the control system parameters set by the remote user (student).

The engine control experiments are run and on‐line transmitted by videoconference over the internet, from a didactical plant physically located at the Systems and Automation Laboratory of the Control and Automation Engineering department of the Pontifical Catholic University of Parana. The system response (transient motor speed) to the user's choice of parameters is evaluated through performance indices (IAE, ITAE), which are used to qualify the ability of the student to tune PID and RTS control algorithms. There is an option to run experiments in open loop, so the student can perform preliminary analysis to identify the system dynamic model and then apply mathematical models and computational methods, learned in theoretical classes, to define best performance control parameters. A simulation function was implemented, to further help the student in the problem solution. Virtual instrumentation resources were used to implement the Weblab, using the DC motor of a laboratory didactical plant. A local server runs a LabVIEWTM application, which can be remotely accessed in the client side through a web browser, where the system front panel is reproduced. This remote interface is directly originated at the LabVIEWTM application, through an embedded web server. At the user request, the control of the remote system is granted. The user interface is cognitive, with motor speed, control signal, set point and all the pertinent information displayed in evolving charts and indicators. Microsoft™ Skype is used to establish a videoconference with the laboratory where the plant is located. Results of the user experiments are stored in local files, which can be e‐mailed to the user at his command by the end of the session.

Used as a platform in weblab projects, LabVIEW combined with Skype provides a suitable solution for the necessary software/hardware integration for communications with data acquisition systems and advanced connectivity resources. In virtual instrumentation Skype has proved to be efficient in establishing the right environment without the need for developing complex software for teaching practical control engineering concepts.

The level of performance (speed of acquisition, accuracy and number of parameters that could be evaluated) of the current system would need to be evaluated compared to some existing systems. The implication is the changes brought to the adopted approach to the development of, access to and the overall cost of producing virtual laboratory systems used for science, engineering and technology education.

With further effort, the current and similar systems could be further upgraded with user login control and server, so that results can be submitted to the tutor, thus acting as a learning evaluation instrument.

The originality of this research lies in the innovative integration of technology in education, which involves the implementation of a carefully designed, cost‐effective virtual laboratory for teaching and learning of concepts in control engineering.

Mobile manipulators offer great capability, but their teleoperation is often an overwhelming task for humans due to the many degrees‐of‐freedom of control available from both the mobile platform and the associated manipulator. The purpose of this paper is to address the question of how these controls should be mapped to the robotic mobile platform and its manipulator for “optimal teleoperation”, for the special case of an omnidirectional mobile platform and two joint (with wrist) planar manipulator.

In this paper, the authors summarize the results of a study to optimize the teleoperation interface for a two‐link planar manipulator with a wrist that was mounted on an omni‐directional mobile platform.

The research comprised a carefully‐controlled study using 33 human subjects in seven different treatments of possible control interfaces.

Users performed movement and manipulation tasks, and their performance was measured on several scales.

Based on this study, the authors present guidelines for optimizing mobile manipulator control interfaces and motivate future research using the method of controlled multi‐user trials.

This research has the potential to guide the improvement of interfaces for mobile robots in military, service, and security applications.

The value of this research extends to optimizing remote control schemes to relieve operator fatigue and optimize interface design.

The use of behavioral insights and experimental methods has recently gained momentum among health policy-makers. There is a tendency, however, to reduce behavioral insights applications in health to “nudges,” and to reduce experiments in health to “randomized controlled trials” (RCTs). We argue that there is much more to behavioral insights and experimental methods in health economics than just nudges and RCTs. First, there is a broad and rich array of complementary experimental methods spanning the lab to the field, and all of them could prove useful in health economics. Second, there are a host of challenges in health economics, policy, and management where the application of behavioral insights and experimental methods is timely and highly promising. We illustrate this point by describing applications of experimental methods and behavioral insights to one specific topic of fundamental relevance for health research and policy: the experimental elicitation and econometric estimation of risk and time preferences. We start by reviewing the main methods of measuring risk and time preferences in health. We then focus on the “behavioral econometrics” approach to jointly elicit and estimate risk and time preferences, and we illustrate its state-of-the-art applications to health.

Bayesian A/B inference (BABI) is a method that combines subjective prior information with data from A/B experiments to provide inference for lift – the difference in a measure of response in control and treatment, expressed as its ratio to the measure of response in control. The procedure is embedded in stable code that can be executed in a few seconds for an experiment, regardless of sample size, and caters to the objectives and technical background of the owners of experiments. BABI provides more powerful tests of the hypothesis of the impact of treatment on lift, and sharper conclusions about the value of lift, than do legacy conventional methods. In application to 21 large online experiments, the credible interval is 60% to 65% shorter than the conventional confidence interval in the median case, and by close to 100% in a significant proportion of cases; in rare cases, BABI credible intervals are longer than conventional confidence intervals and then by no more than about 10%.