Actual Response Time Research Articles

Does a time-monitoring deficit influence older adults' delayed retrieval shift during skill acquisition?

The authors evaluated age-related time-monitoring deficits and their contribution to older adults' reluctance to shift to memory retrieval in the noun-pair lookup (NP) task. Older adults (M = 67 years) showed slower rates of response time (RT) improvements than younger adults (M = 19 years), because of a delayed strategy shift. Older adults estimated scanning latencies as being faster than they actually were and showed poor resolution in discriminating short from long RTs early in practice. The difference in estimated RT for retrieval and scanning strategies predicted retrieval use, independent of actual RT differences. Separate scanning and recognition memory tasks revealed larger time-monitoring differences for older adults than in the NP task. Apparently, the context of heterogeneous RTs as a result of strategy use in the NP task improved older adults' accuracy of RT estimates. RT feedback had complex effects on time-monitoring accuracy, although it generally improved absolute and relative accuracy of RT estimates. Feedback caused older adults to shift more rapidly to the retrieval strategy in the NP task. Results suggest that deficient time monitoring plays a role in older adults' delayed retrieval shift, although other factors (e.g., confidence in the retrieval strategy) also play a role.

Evolution of social norms with heterogeneous preferences: A general model and an application to the academic review process

The article presents a model of social norm evolution that suggests how the increase in optimal and actual first response times (FRT) of economics journals can be related. When the optimal FRT and the norm about how much time refereeing should take increase, it seems that the existence of a norm increases the average refereeing time. The model suggests the surprising result that this is not necessarily true. I also discuss applications of the model in other contexts, differences in the optimal FRT between disciplines, the effects of the FRT on the tenure process, and strategic behavior of referees.

Foundation of Correlation Parameters for Eliminating Pulse Shape Effects on Dynamic Plastic Response of Structures

Abstract The theoretical foundation of Youngdahl’s correlation parameters, which have been used to eliminate pulse shape effects in the dynamic plastic response of two-dimensional structural members, is studied in the present paper with the aid of bounds obtained for a rigid-plastic material. It is shown that Youngdahl’s empirical estimate for the structural response time is, in general, a lower bound on the actual response time. A lower bound expression is obtained for the maximum final displacement of a two-dimensional structural member when subjected to an axisymmetrically loaded transverse time-dependent pulse, which depends only on Youngdahl’s correlation parameters, and offers a theoretical foundation for the validity of Youngdahl’s correlation parameter method.

Method for determining automatic external defibrillator need at mass gatherings

Objectives: A method for determining the number of automatic external defibrillators (AEDs) required for a 3-min response at mass gatherings has been described previously. Our study sought to modify the method, replicate it, then validate the results. Methods: Emergency medical technicians (EMTs) were timed walking defined courses in a football stadium. Velocities were obtained for a horizontal distance and ascending/descending upper and lower decks. This was replicated in a basketball arena. To validate, actual response times were compared to predicted times for predetermined distances in each venue. Predicted response times were calculated using the second standard deviation velocities as the most pessimistic. Numbers of AEDs needed were calculated using predicted response times for each venue's longest distance. Results: Average velocities in m/s (football) were horizontal 1.7, lower deck 1.6 ascending and 1.4 descending, upper deck 1.0 ascending and 1.1 descending. Average velocities (basketball) were horizontal 1.7, lower deck 1.2 ascending and descending, upper deck 0.9 ascending and descending. In the validation phase, every EMT completed the four predetermined courses within the predicted intervals. Predicted response times were 363 s for the longest football stadium distance, and 187 s for the basketball arena. For a 3-min (180 s) response, the number of AEDs required can be calculated. Conclusion: This method was easily replicated and appears to be useful for determining the number of AEDs at mass gatherings. The number of AEDs needed for any desired response interval can be calculated using the predicted response time for the longest distance within an arena.

Optimization of the multienzyme system for sucrose biosensor by response surface methodology.

An immobilized multienzyme- and cathodic amperometry-based biosensor for sucrose was constructed for the analysis of food and fermentation samples. The multienzyme system, comprising invertase, mutarotase and glucose oxidase (GOD), was immobilized by using glutaraldehyde as cross-linking agent. Operating parameters of the biosensor for the estimation of sucrose in the range 1–10% were standardized. Response surface methodology (RSM) based on three-factor, three-variable design was used to evaluate the effect of important variables (concentration of enzymes, (varied in the range invertase (10–50 IU), mutarotase (5–105 IU) and GOD (1–9 IU)) on the response of biosensor. In the range of parameters studied, response time decreased with decrease in the invertase and with increase in mutarotase and GOD. Mutarotase concentration above 75 IU was found to result in an increased response time due to inhibition of mutarotase by its product β-D-glucose. The optimal conditions achieved for the analysis of sucrose were: invertase 10 IU, mutarotase 40 IU, and GOD 9 IU. With these conditions, the predicted and actual experimental response time values were 2.26 and 2.35 min respectively, showing good agreement.

Actual vs perceived ems response time

Objective. To compare patients' perceptions of ambulance response times with the actual ambulance response times to aid quality assurance efforts in EMS management. Methods. A convenience sample of patients presenting to an urban ED via EMS were asked a series of four questions pertaining to response time, scene time, time to definitive care, and their expectations of response time. These times were then compared with actual times from the EMS dispatch center. Times were analyzed using multivariate analysis of variance (MANOVA) followed by discriminant analysis. Results. There was a significant difference between the perceived and actual times for all three questions, by both multivariate analysis and univariate analysis (p < 0.0001). Patients tended to overestimate the actual response times (12.4 min vs 9.1 min) but underestimate the on-scene times (9.1 min vs 12.4 min) and times to definitive care (29.4 min vs 35.0 min). Conclusion. Patients are inaccurate in their estimations of time. Response times are generally overestimated, while scene times and times to definitive care are underestimated. Actual response times often meet patients' expectations (mean 10.8 min), although the patients may not perceive that they have.

Optimization of signature file parameters for databases with varying record lengths

For signature files we propose a new false drop estimation method for databases with varying record lengths. Our approach provides more accurate estimation of the number of false drops by considering the lengths of individual records instead of using the average number of terms per record. In signature file processing, accurate estimation of the number of false drops is essential to obtain a more accurate signature file and therefore to obtain a better (query) response time. With a formal proof we show that under certain conditions the number of false drops estimated by considering the average record length is less than or equal to the precise ‘expected’ estimation which is based on the individual record lengths. The experiments with real data show that the proposed method accurately estimates the number of false drops and the actual response time. Depending on the space overhead, our approach obtains up to 33% and 20% response time improvements for the conventional sequential and new efficient multiframe signature file methods, respectively.

An Efficient Index Structure for Spatial Databases

In this paper, the authors propose an efficient spatial data structure called the Multi-R tree. The Multi-R tree is an improvement of the R-tree, R+-tree and R*-tree, and can be used as an index structure for spatial databases. The Multi- R tree improves performance by distributing spatial objects into several data spaces instead of one data space in the Rtree, the R+-tree or the R*-tree. Each data space is associated with a tree in the Multi-R tree. The structure of the Multi-R tree eliminates the node redundancy which appears in the R+-tree at leaf level and keeps disjoint intermediate rectangles. A set of new algorithms for the Multi-R tree is also proposed and implemented. Three popular spatial data structures, the R-tree, R+-tree and R*-tree, are implemented based on the algorithms given in original literature to be compared with the Multi-R tree. An experimental performance analysis for four implemented structures is given with various types of testing data sets: random data, uniformly distributed data, VLSI layout data and TIGER/Line file. Namely, the number of disk accesses and actual response time for each of those four data structures to process a query are compared. Construction times, space utilization and actual memory sizes of the four data structures are also given. Results show that the Multi-R tree requires fewer disk accesses and less processing time than the R-tree, R+-tree and the R*-tree do for a deletion operation and answering a range query in most cases except for a point query or a range query with very small size. In the cases of a point query or small size query processing, the performance of the Multi-R tree is still better than the performances of the Rtree and R*-tree but slightly worse than the R+-tree. Thus, the Multi-R tree may be used as an efficient index structure for spatial databases, e.g., geographical information system, CAD, and VLSI etc.

Perceptions of responsiveness in service delivery.

The delivery of service quality has become a topic of increasing interest especially in the context of health care services marketing. The research investigated the responsiveness component of quality service. Both issues, the customers' perception of time as well as their expectations for responsiveness in quality service delivery were addressed. Specifically, an attempt was made to determine if the patients' perception of bell response time differed from the actual response time. In addition, this paper tried to determine if the difference between patient's perception of bell response time and actual response time had an effect on their perception of the responsiveness of the nurse.

Factors Governing Performance in a Visual Interception Task

Two experiments examined factors governing performance in a dynamic spatial task requiring object interception. In the two experiments, several variables were systematically manipulated, including target trajectory, decision time, and interceptor to target speed ratio. In both experiments a systematic linear relationship between actual response time and decision time was observed. The slope of this function was less than 1, indicating that subjects were less sensitive to variation in actual decision time than an “ideal” observer. Performance patterns further indicated that subjects utilized both speed and distance information to guide their judgements, but failed to adequately incorporate speed information.

Simulation of a distributed query processing algorithm on token ring networks

One network architecture which is being considered for information distribution in a Tactical Battle Data Management setting is the token ring network. In token ring local area networks, an information delivery algorithm is simulated which provides a strategy for answering a request for battle information, and also an estimate of the response time required to answer the request. The algorithm is simple, fast, and produces strategies that are competitive with other known algorithms in terms of actual response time. These facts are established through simulation experimentation. Our algorithm and a well established algorithm are analyzed using a computer to simulate their strategies. The relative performance of two retrieval processing strategies generated by these two algorithms are compared on the basis of actual and estimated response time. In order to be unbiased towards any particular algorithm, four different data distributions are used to produce examples of worse, average and best case data. Data for the simulated algorithms are randomly generated. On each run the same data are used to generate the estimated response times and the actual response times for the two algorithms. The evaluation consists of the following comparisons. The estimated response times of the two algorithms are compared. The actual response times of the two algorithms are compared. The actual response time and the estimated response time for each algorithm is compared. Using our algorithm the estimated response time and the actual response time are shown to be close. The result obtained for the well established algorithm show that the actual response time can be significantly larger than the estimated response time. The need for this type of algorithm arises in the Tactical Battle Data Management environment in which decisions must be based on predicted times at which information arrives. This kind of situation requires an algorithm with guaranteed response times. In C 2 real-time applications, where much time is spent checking for retrieval completion, valuable time can be saved since response times can be assured.

Making Progressive Transmission Adaptive

Progressive transmission hierarchically reorganizes the information in an image with the aim of increasing transmission efficiency on a low bandwidth channel. We have developed methods for adaptively choosing initial and successive approximations to be sent when the end user is a human telebrowsing through a database to find particular desired images. Because of progressive transmission overhead, it is desirable to send in one step the approximation which is just good enough to allow a user to make a positive decision (e.g., want/don't want). During past and present sessions of telebrowsing, positive response times are recorded and used to estimate the actual positive response time probability mass function. This estimate is used with a previously calculated overhead function to choose the best initial and successive approximations. We discuss the application of two-channel coding to progressive transmission and conclude that little is gained by further coding of the initial lowresolution approximation. However, the interpretation of these lowresolution images is enhanced if the displayed size is a function of image resolution. We present a method for determination of the best displayed image size which is based on the modulation transfer function of the human visual system.