This book presents 25 structural design smells (indicators of common design problems), their role in identifying design issues, and potential refactoring solutions. Organized across common areas of ...software design, each smell is presented with diagrams and examples illustrating the poor design practices and the problems that result, creating a catalog of nuggets of readily usable information that developers or engineers can apply in their projects. This resource presents a unique naming scheme for smells that helps understand the cause of a smell as well as points toward its potential refactoring; covers pragmatic techniques for refactoring design smells to manage technical debt and to create and maintain high-quality software in practice; and presents insightful anecdotes and case studies drawn from the trenches of real-world projects. --
Robots are the next wave in service technology; however, this advanced technology is not perfect. This research examines how social perceptions regarding the warmth and competence of service robots ...influence consumer reactions to service failures and recovery efforts by robots. We argue that humanoid (vs. nonhumanoid) service robots are more strongly associated with warmth (whereas competence does not differ). This tendency to expect greater warmth from humanoid robots has important consequences for service firms: (i) consumers are more dissatisfied due to lack of warmth following a process failure caused by a humanoid (vs. nonhumanoid; Study 1); (ii) humanoids (but not nonhumanoids) can recover a service failure by themselves via sincere apology, restoring perceptions of warmth (Study 2A); (iii) humanoids (but not nonhumanoids) can also effectively provide explanations as a recovery tactic (Study 2B); and, importantly, (iv) human intervention can be used to mitigate dissatisfaction following inadequate recovery by a nonhumanoid robot (Study 3), supporting the notion of human-robot collaboration. Taken together, this research offers theoretical implications for robot anthropomorphism and practical implications for firms employing service robots.
This paper proposes a methodology for managing complex sewerage networks based on the concomitant use of two performance evaluation methods, namely, the failure modes, effects, and criticality ...analysis (FMECA) and the analytical hierarchy process (AHP). The FMECA is used to determine the risks of structural failures making it possible to establish a methodology for managing these failures. The AHP is used to check the relationship consistency between the performance indicators allowing the determination of the overall performance (OP). This proposed methodology was utilized for the urban sewerage network of Oued-Kniss in the city of Algiers, Algeria, as part of the efforts engaged in for sustainable and efficient management.
Coastal bridge piers exposed to marine environments always suffer from non-uniform corrosion along the elevation. Severe degradation in the splash and tidal zone would significantly affect the ...seismic performance of the structure with a specific phenomenon of the plastic hinge transferring from the column end to the splash and tidal zone. In a companion paper of the authors 1, a theoretical method to identify the time-dependent failure mode and equivalent plastic hinge length of the aging bridge piers under seismic excitation in the whole life cycle was conducted. In this study, cyclic loading tests of six reinforced concrete circular bridge piers with different levels of corrosion are carried out to investigate the seismic performance of such types of structures and validate the proposed method. The test specimens and the experimental setup are first introduced. Based on the measured hysteretic curves, the experimental results of the curvature distributions, hysteretic characteristics, loading-resistance capacity, ductility, energy dissipation, equivalent viscous damping ratio and equivalent plastic hinge length are analyzed and discussed. The test results demonstrate the accuracy of the analysis results for the seismic failure modes presented in the companion paper. It is also indicated that the seismic performance of the non-uniformly corroded columns exhibited a small variation before the transfer of the plastic hinge location, while an obvious reduction was observed for moderately and severely corroded structures.
•A cyclic experiment for coastal bridge piers with non-uniform corrosion is conducted.•Different seismic failure mode of corroded pier is investigated.•The strength, ductility and energy dissipation capacity are analyzed.•Previously proposed theoretical method is validated by the experimental results.
An introduction to the current state of failure frequency research for battery energy storage systems (BESS) is provided. The article discusses the many failure modes of BESS and how the reliability ...data are scarce and the design changes are fast‐paced. Current public resources available for overcycle datasets and battery datasets are summarized. Efforts are under way to better communicate failure rate research among stake holders. This is the second article in a six‐part series.
The occurrence of rockburst is closely related to initial high stress state and excavation unloading effects. To investigate the effects of three-dimensional (3D) stress state and unloading rate on ...the rockburst mechanism, triaxial unloading compression tests were performed on cubic fine-grained granite specimens (50 mm × 50 mm × 50 mm). Two unloading rates (0.08 and 40 MPa/s) were employed in the tests with seven initial 3D confining pressures (5, 10, 20, 30, 40, 50, and 60 MPa). For comparison, triaxial and biaxial compression tests were conducted at the same initial confining pressures. The results show that, under the same confining pressures, the variations in peak strength of granite specimens are in the following order: triaxial compression test > biaxial compression test > triaxial unloading compression test under low unloading rate > triaxial unloading compression test under high unloading rate, which indicating that unloading induces an obvious strength-weakening effect on fine-grained granite. In the triaxial unloading compression test with the same unloading rate, a higher confining pressure results in a greater rock bearing strength and stress drop. More energy will be stored in the rock, and the rockburst intensity will be more serious when the rock is destroyed. When the confining pressure is constant, the lower unloading rate is beneficial for improving the rock bearing strength, and more elastic energy will be accumulated and stored in the rock. Once rockburst occurs, the energy released by rock is larger and the degree of rockburst is stronger. The failure mode of fine-grained granite specimens in triaxial unloading compression tests transforms from shear-tension failure to tension failure with increasing confining pressure, which is the main reason for the weakening of rock strength. Establishing a strength criterion for 3D rock considering the unloading effect is a key for understanding the mechanism of rockburst.
Collapses of braced or tied-back excavations have occurred frequently. However, the influence of the failure of some retaining structure members on the overall safety performance of a retaining ...system has not been studied. Model tests of failures of retaining piles, struts or anchors were conducted in this study and the load-transfer mechanisms underlying these conditions were analysed. When failures or large deformations occurred in certain piles, the increasing ratios of the bending moments in adjacent piles were much larger in the braced retaining system than in the cantilever system and more easily triggered progressive failure. When the strut elevation was lower or the excavation depth was greater, the degree of influence and range of pile failures became larger. When certain struts or anchors failed, their loads transferred to a few adjacent struts or anchors, possibly leading to further strut or anchor failure. The influence mechanisms of strut or anchor failure on piles were different from those of pile failure. As the number of failed struts or anchors increases, the bending moments of the piles in the failure zone first decrease and then increase to very high values. Therefore, the progressive failure path extends from struts or anchors to piles and will lead to large-scale collapse.
Climate change is increasing the occurrence of the so-called heatwaves with a trend that is expected to worsen in the next years due to global warming. The growing intensity and duration of these ...extreme weather events are leading to a significant number of power system failures, especially in urban areas. This is drastically affecting the reliability and normal operation of power distribution grids around the world, with high financial costs and huge negative impacts on people's life. Typically, the response to these failure events is approached by post-event analysis, aimed at identifying the grid areas that require resources to increase the resilience of the system and prevent future outages. Nevertheless, understanding the nature of heatwaves and forecasting their impact on power distribution systems can be useful to anticipate them and accelerate a reaction, possibly avoiding negative impacts on power systems and customers. In this study, a structured method to predict distribution grid disruptions caused by heatwaves is defined. The proposed method relies on machine learning to analyze previous failure data and forecast power grid outages using operational and meteorological information. The method is evaluated using real failure data from a large power distribution network located in southern Italy.
A phased-mission system (PMS) involves multiple, consecutive, non-overlapping phases of operation. The system structure function and component failure behavior in a PMS can change from phase to ...phase, posing big challenges to the system reliability analysis. Further complicating the problem is the functional dependence (FDEP) behavior where the failure of certain component(s) causes other component(s) to become unusable or inaccessible or isolated. Previous studies have shown that FDEP can cause competitions between failure propagation and failure isolation in the time domain. While such competing failure effects have been well addressed in single-phase systems, only little work has focused on PMSs with a restrictive assumption that a single FDEP group exists in one phase of the mission. Many practical systems (e.g., computer systems and networks), however may involve multiple FDEP groups during the mission. Moreover, different FDEP groups can be dependent due to sharing some common components; they may appear in a single phase or multiple phases. This paper makes new contributions by modeling and analyzing reliability of PMSs subject to multiple FDEP groups through a Markov chain-based methodology. Propagated failures with both global and selective effects are considered. Four case studies are presented to demonstrate application of the proposed method.
•Reliability of phased-mission systems subject to competing failure propagation and isolation effects is modeled.•Multiple independent or dependent functional dependence groups are considered.•Propagated failures with global effects and selective effects are studied.•Four case studies demonstrate generality and application of the proposed Markov-based method.
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