Phased Inspection Research Articles

Aspect graphs for three-dimensional object recognition machine vision systems

The purpose of this research is to seek evidence for viewer-centered (especially aspect-graph-based) visual processing in the elementary task of object understanding. Two homologous, bilaterally symmetrical three-dimensional (3-D) objects have been employed that differ in that one is based on parts with flat surfaces and the other on parts with curved surfaces. The following procedure has been followed, separately for each object. In the training (saturated free inspection and manipulation) phase, a location (identical for both objects) of the object is marked with a red strip and the subjects' task is to memorize the object structure as well as the position of the strip. In the test phase, two-dimensional views of the object without the strip are presented and the subjects' task is to determine whether the previously marked location should be visible or invisible in the particular view. Findings have been found consistent with an aspect-graph-based 3-D object representation: (a) the reaction times and errors show characteristic dependencies on viewpoint; (b) a number of views (corresponding to certain aspects and aspect transitions of the aspect graph) consistently produce faster and more accurate recognition; (c) the differences in the aspect graphs of the two objects are reflected in differing patterns of reaction times and errors; furthermore; (d) the subjects impose a standard orientation on the objects, whereby a strong inversion effect is observed; and (e) performance varies in a similar way for both objects as a function of tilt. It is concluded that object understanding is viewpoint dependent, that is, based on a number of views. The characteristics of the views found to be most important for object understanding can be employed for creating efficient 3-D object recognition machine vision systems. © 2005 Wiley Periodicals, Inc. Int J Int Syst 20: 47–72, 2005.

Modified CSP-C Continuous Sampling Plan for Consumer Protection

Dodge (1943) introduced a single level attribute continuous sampling plan designated as CSP-1 for the application of continuous production processes. Govindaraju & Kandasamy (2000) developed a new single level continuous sampling plan whose sampling inspection phase is characterized by a maximum allowable number of non-conforming units c, and a constant sampling rate f and was designated as CSP-C. In this paper, a modification is proposed on the CSP-C continuous sampling plan. In this modified plan, sampling inspection is continued until the occurrence of c+1 non-conforming units, provided the first m sampled units have been found conforming during the sampling phase. Using a Markov chain model, expressions for the performance measures of the modified CSP-C plan are derived. The main advantage of the modified plan is that it is possible to lower the average outgoing quality limit.

Optimization techniques for parallel irregular reductions

Different parallelization techniques have been proposed in the literature for irregular reductions in the context of shared memory multiprocessors. They may be classified into two broad families: those based on privatization of the reduction arrays and those based on the partitioning of the reduction arrays. Methods in the first family are simple but no data locality is exploited and their memory scalability is low. On the other hand, methods in the second family are more complex as they require an inspection phase but they exploit data locality and scale up better in memory. Focusing on partitioning-based methods, although they exhibit a good performance in a wide variety of irregular codes, some specific input data patterns may exist for which the performance is lowered. In particular these kind of access patterns may reduce the exploited parallelism by the method or introduce workload unbalances. In order to mitigate these negative effects, we propose three optimizations for a specific partitioning-based method (DWA–LIP). These optimizations try to increase the exploited parallelism, balance the workload and reduce the effect of high contention degree regions in the reduction arrays. Efficient implementations of the proposed optimizations for the DWA–LIP method have been tested experimentally, and compared with other methods for parallelizing irregular reductions.

A continuous sampling plan using sums of conforming run‐lengths

AbstractA continuous sampling plan, CSP‐SUM, is proposed based on the use of sums of run‐lengths of conforming items for deciding when to switch between the phases of sampling inspection and 100% inspection. The conventional measures of performance of CSPs such as the average outgoing quality, average fraction inspected, and the proportion passed under sampling inspection are evaluated for CSP‐SUM. Using these and other measures, comparisons with some standard CSPs are provided and indicate better performance for CSP‐SUM. Comparisons are also made with a recently‐proposed CSP utilizing CUSUMs, termed CSP‐CUSUM, and indicate that the performance of CSP‐SUM can be close to that of CSP‐CUSUM. A table is provided to aid the choice of parameters for the operation of CSP‐SUM. It is recommended that a conforming run‐length control chart be maintained in parallel with CSP‐SUM to detect significant upward shifts in the fraction defective of the process. Copyright © 2003 John Wiley & Sons, Ltd.

A continuous sampling plan using CUSUMs

A Continuous Sampling Plan, CSP-CUSUM, is proposed based on the use of Cumulative Sums (CUSUMs) for deciding when to switch between the phases of sampling inspection and 100% inspection. The Geometric CUSUM, also termed the Run-length CUSUM, is chosen for this purpose, and two separate CUSUMs are to be operated, one for each inspection phase. The conventional measures of performance for CSPs such as average outgoing quality, average fraction inspected, and average proportion passed under sampling inspection are evaluated for CSP-CUSUM, and comparisons with some standard CSPs are presented. An additional performance-measure, Average Cycle Length, is proposed. A table is provided to aid the choice of parameters for the operation of CSP-CUSUM. It is recommended that a Geometric CUSUM control chart be maintained in parallel with CSP-CUSUM to detect significant upward shifts in the incoming fraction defective.

Aerobic metabolism during predation by a boid snake

We quantified the oxygen uptake rates ( V ̇ O 2 ) and time spent, during the constriction, inspection, and ingestion of prey of different relative sizes, by the prey-constricting boid snake Boa constrictor amarali. Time spent in prey constriction varied from 7.6 to 16.3 min, and V ̇ O 2 during prey constriction increased 6.8-fold above resting values. This was the most energy expensive predation phase but neither time spent nor metabolic rate during this phase were correlated with prey size. Similarly, prey size did not affect the V ̇ O 2 or duration of prey inspection. Prey ingestion time, on the other hand, increased linearly with prey size although V ̇ O 2 during this phase, which increased 4.9-fold above resting levels, was not affected by prey size. The increase in mechanical difficulty of ingesting larger prey, therefore, was associated with longer ingestion times rather than proportional increases in the level of metabolic effort. The data indicate that prey constriction and ingestion are largely sustained by glycolysis and the intervening phase of prey inspection may allow recovery between these two predatory phases with high metabolic demands. The total amount of energy spent by B. c. amarali to constrict, inspect, and ingest prey of sizes varying from 5 to 40% of snake body mass varied inversely from 0.21 to 0.11% of the energy assimilated from the prey, respectively. Thus, prey size was not limited by the energetic cost of predation. On the contrary, snakes feeding on larger prey were rewarded with larger energetic returns, in accordance with explanations of the evolution of snake feeding specializations.

Vision-based integrated system for object inspection and handling

Image-based effector servoing is a process of perception–action cycles for handling a robot effector under continual visual feedback. This paper applies visual servoing mechanisms not only for handling objects, but also for camera calibration and object inspection. A 6-DOF manipulator and a stereo camera head are mounted on separate platforms and are steered independently. In a first phase (calibration phase), camera features are determined like the optical axes and the fields of sharp view. In the second phase (inspection phase), the robot hand carries an object into the field of view of one camera, then approaches the object along the optical axis to the camera, rotates the object for reaching an optimal view, and finally the object shape is inspected in detail. In the third phase (assembly phase), the system localizes a board containing holes of different shapes, determines the hole which fits most appropriate to the object shape, then approaches and arranges the object appropriately. The final object insertion is based on haptic sensors, but is not treated in the paper. At present, the robot system has the competence to handle cylindrical and cuboid pegs. For handling other object categories the system can be extended with more sophisticated strategies of the inspection and/or assembly phase.

Economic and Ecological Product Evaluation in Disassembly

This paper describes decision processes for recycling and disassembly of technical worn out products. The decision process concern product inspection and product disassembly. During the inspection phase, the global recycling direction is established: repair for reuse, disassembly for spare part reuse or shredding for material reuse. During disassembly the decision process has to detennine the recycling activities to apply and the level for stopping disassembly. The decisions are based on economical and ecological evaluation criteria. The relevant mathematical formulations are proposed and illustrated on an application example.

Applying Code Inspection to Spreadsheet Testing

:In programming, reliability requires an extensive testing phase. Spreadsheet development, which has about the error rate as program development, also needs to be followed by an extensive testing phase if spreadsheets are to be reliable. In this study, sixty undergraduate MIS students code-inspected a spreadsheet seeded with eight errors. They first inspected the spreadsheet working alone. They then met in twenty groups of three to reinspect the spreadsheet together. Effort was made to prevent hasty inspection.Individual code inspection, consistent with past studies of both spreadsheet and program code inspection, caught only 63 percent of the errors. Group inspection raised this to 83 percent. However, the group phase never found new errors; it merely pooled the errors found during the individual phase by the three members. One group even “lost” an error found during the individual phase. This raises the question of whether a group code inspection phase is really necessary. Other findings were that subjects were overconfident when inspecting alone, that certain types of errors are especially difficult to detect, and that the benefits of the group phase is greatest for these difficult-to-detect types of errors.

Effect of experience on predatory behaviour of dogwhelks

We used an acoustic transducer to monitor the radular activity of dogwhelks, Nucella lapillus , drilling mussels, Mytilus edulis , in the laboratory and we examined the effect of dietary experience on prey-handling behaviour. For the first time, phases of inspection, penetration and ingestion could be distinguished directly, and consequently the prey-handling process analysed in detail. Dogwhelks with different field-based experience of mussels showed different handling behaviour. Those collected from a mussel-dominated shore more readily adopted the faster method of penetrating between the slightly gaping valves, instead of the slower method of drilling through the shell. Those collected from a barnacle-dominated shore took significantly longer to attack the mussel and then were unable to switch from drilling to penetrating through the gape between valves. Experience of specific prey in the field, by reducing handling time, could promote fitness by reducing exposure to environmental hazards. Laboratory attempts to train dogwhelks from the barnacle-dominated shore to use the gape penetration method failed, suggesting that functional constraints, such as injection of a relaxant when penetrating through the gape and/or genetically controlled behavioural traits, could limit the ability to learn handling skills.

FEATURE: Design/Build Alternative: A Contracting Method

The emergence of design/build as a popular alternative delivery system is perhaps the most significant trend within the construction industry in the past 20 years. In design/build, a single entity is responsible for both a project's design and its construction. The process can be broken into four phases: preconstruction preliminary design, bidding, construction, and a postconstruction phase of inspection, transfer of the completed facility, and administering of guarantees. Government agencies have shown an increasing acceptance of design/build in recent years. In addition to providing unified responsibility, the design/builder can proceed with early procurement of critical materials, schedule labor and subcontractors for greater effectiveness, and maintain high project quality at all levels. Design/build's many benefits include single-source accountability, fast-track scheduling, early guarantee of project costs and schedule, ongoing value engineering, and construction review.

SENSITIVITY OF THE ABX DISCRIMINATION TEST

The ABX test or matching‐to‐sample is a discrimination procedure involving presentation of both test and control items, and then presentation of one of the two items as a blind sample. The third (blind sample) must then be identified correctly to match it to the one correct alternative from the inspection phase. We hypothesized that the ABX test might have an advantage over other discrimination methods due to a warm‐up effect arising from the inspection phase containing both test and control items. Furthermore, the ABX test might prove generally useful like the triangle test since it can be used when there is no specified attribute to be discriminated. The ABX test was compared to several other discrimination procedures. No advantage was observed in a variety of stimuli varying in complexity and in the difficulty of the discrimination.

A VLSI Image Processing Architecture Dedicated to Real-Time Quality Control Analysis in an Industrial Plant

In this paper, we present a VLSI architecture for real-time image processing in quality control industrial applications: automation of the visual inspection phase of mechanical parts treated by the Fluorescent Magnetic Particle Inspection method for structural-defect detection. The VLSI architecture implements a highly constrained neural network tailored for this specific application: the multi-layer perceptron with strictly local connections. The learning of the weights is performed off line by using the adaptive simulated-annealing algorithm. The neural network has been trained on real plant data: recognition results of the training and classification tasks compare favorably with those obtained by expert human operators.The VLSI architecture receives as input the image (taken on-line on the plant) of a mechanical part and it will find out if at least one structural surface defect is present. The VLSI architecture was optimized, through a set of transformations on the high-level VHDL specifications of the neural network algorithm, to reach real-time operating conditions. Following the proposed approach and the designed architecture, we designed and successfully tested a custom VLSI chip for the real-time implementation of the recognition task.

Präferierte mentale Modelle beim räumlich-relationalen Schließen: Empirie und kognitive Modellierung

The theory of mental models is the most prominent approach for explaining the underlying cognitive processes in spatial relational inference. Of the three phases of model construction, model inspection, and model variation, this article focuses mainly on the first one. The phase of model construction in spatial relational inference tasks based on the interval relations of Allen (1983) is investigated in two experiments. The first experiment corroborated the hypothesis of the existence of generally preferred mental models. The second experiment showed evidence for the causal influence of preferred mental models in verification tasks of three-term series problems. Based on these results, the issue concerning the kind of representation of spatial information in mental models is tackled. Cognitive modeling based on insertion operations for beginning and end-points of intervals by means of a spatial focus, i. e., using only ordinal information, corresponds clearly to the empirical preferences. Finally, we discuss the results with respect to the prediction of inferences in other inference tasks and problems concerning the processes in the phases of model inspection and model variation.

Measuring Grade-School Children's Ability to Represent the Euclidean Horizontal Coordinate

Seventy-five grade-school children were administered three tasks that measured their ability to represent the Euclidean horizontal coordinate: a traditional water-level test (WLT) that used a square-shaped vessel, a WLT that used a spherical vessel, and a task that used a crossbar apparatus. The latter two tasks differed from the traditional task in terms of the degree to which the apparatus presented a frame of reference that conflicted with environmental Euclidean coordinates. Performance was analyzed according to Piaget and Inhelder's (1956) stage-scoring system; that is, the testing procedures (a) allowed children to inspect the apparatus when it was rotated to discrete orientations; (b) corrected initial errors; and (c) included 0 degrees, 30 degrees, 60 degrees, and 90 degrees trials. Age-related stages were identified on each task. Levels of performance on one task were significantly correlated with levels on each of the other two tasks. Performance was less accurate on the traditional WLT than on either of the other two measures. These results provide evidence of the validity of the alternative tasks to measure children's horizontality representation. The findings suggest that horizontality assessment procedures should include orthogonal and oblique rotations and contain an inspection phase. Use of apparatuses with conflicting frames of reference renders tasks more difficult but is not necessary to observe age-related developmental progress during the grade-school years.

Satiation or availability? Effects of attention, memory, and imagery on the perception of ambiguous figures.

The prolonged-inspection technique has been used to demonstrate effects of satiation on the perception of ambiguous figures. We propose that the inspection phase, in which subjects view an unambiguous version of the stimulus prior to observing the ambiguous figure, does not create neural fatigue but rather provides a context in which the alternative percept is apprehended and gains perceptual strength through processes such as imagination or memory. The consequent availability of the alternative organization drives the perceptual phenomena that have been thought to reflect satiation. In Experiment 1, we demonstrated that (1) preexperimental exposure to the target figures and (2) allocation of attention to the inspection figures were both necessary in order to obtain results similar to those predicted by the satiation model. In Experiment 2, we obtained similar results, finding that effects of prior inspection were greater the greater the amount and availability of information regarding the alternative percept during the inspection phase. Subjects who generated visual images of the noninspected alternative during inspection yielded results comparable to those from subjects to whom both versions were presented visually.

An Experimental Study of the Building Behaviour Sequence of a Shell-Breeding Cichlid-Fish From Lake Tanganyika (Lamprologus Ocellatus)

The cichlid-fish Lamprologus ocellatus (POLL, 1986) digs empty snail shells into sandy substratum, using them for dwelling and breeding. The sequence of building behaviour was analysed. It can be divided into three phases: (1) in the inspection phase the fish swims into and around the snail shell; (2) while during the digging phase sand is moved away from the shell; (3) in the subsequent oversanding phase, the shell is covered with sand. In the analysis of the building behaviour sequences of eight individuals, each of which performed five trials, interindividual differnces were found, but there were no differences among repeated trials of one individual. In the comparison of building procedures on small- and medium-sized shells we noted a dependence of the number of building actions and of the building duration on the size of the snail shell. By offering an artificial sandpit, the digging-phase may be shortened or not take place at all. By enlarging the interior of the the oversanding-phase can be lengthened. This led to the conclusion that the behaviour sequence, especially onset and end of the individual phases, is induced and controlled by the change in the external stimulus situation, which is influenced by the performance of the building actions. Information on the progress of building is perceived through the shell-contact-act (cont) in which the fish swims to the snail shell. It alternates with the building activities. The results of the experiments in an artificial steep-walled pit (2,2) indicate a visually controlled orientation.

Illusion decrement and transfer of illusion decrement in obtuse- and acute-angle variants of the Poggendorff illusion

Illusion-decrement and transfer-of-illusion-decrement procedures were used to examine the contribution of the obtuse- and acute-angle components of the Poggendorff pattern to the standard Poggendorff illusion. In the first four experiments, subjects were required to scan between the oblique lines of the Poggendorff pattern during the inspection phase of the decrement procedure. However, because of a possible confound associated with this procedure, a different decrement technique was used in Experiment 5. The results of Experiment 5 confirm and extend MacKay and Newbigging's (1977) finding that similar amounts of transfer to the standard pattern are obtained from the obtuse- and acute-angle patterns as from the standard pattern itself: In showing that the acute- and obtuse-angle components both contribute to the illusion, these findings question the plausibility of those theories of the Poggendorff illusion which do not assign any significant role to the acute-angle component. Furthermore, the potential confound associated with the decrement procedure of Experiments 1-4 suggests that the results of other studies obtained with similar procedures need to be reevaluated.

Memory for topographic contour maps

Map reading is becoming recognized as an information processing task. This research compared the memory for topographic contour maps in experimental samples who had answered questions about contours during a 20‐minute inspection phase, and in control samples who had answered questions about distances on the map and determined several six‐figure map references during a similar inspection period. The samples were selected from 13–15‐year‐old pupils and university students. Sixty‐three per cent of the subjects in the experimental samples correctly recognized the original map from a collection of five similar maps after a 20‐minute time interval whereas only 11 per cent of those in the control samples could do so. Geography experience was not a factor in this result. The principal unit or chunk for encoding seemed to be valleys rather than hill tops. It was concluded that map reading can legitimately be treated as an information processing activity and that memory processes relating to contour maps have similar characteristics to those demonstrated in other more traditional information processing tasks in psychology.

A system for the automatic visual inspection of bare-printed circuit boards

A system for automatic inspection of bare printed circuit boards is described that uses three concepts: multiple inspection systems; learn and inspect phases of inspection; a hierarchy of detection processes to satisfy the four basic criteria for a successful inspection system, namely detection performance, speed, cost, and flexibility. The system has reached a stage at which industrial implementation can be considered.