The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
R Park - One of the best experts on this subject based on the ideXlab platform.
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a summary of results of simulated seismic Load Tests on reinforced concrete beam column joints beams and columns with substandard reinforcing details
Journal of Earthquake Engineering, 2002Co-Authors: R ParkAbstract:The results of some simulated seismic Load Tests on reinforced concrete one-way interior and exterior beam-column joints with substandard reinforcing details typical of buildings constructed in New Zealand before the 1970s are described. The Tests were conducted using both deformed and plain round longitudinal reinforcement. The interior beam-column joint cores lacked transverse reinforcement and the longitudinal bars passing through the joint core were poorly anchored. The exterior beam-column joint units contained very little transverse reinforcement in the members and in the joint core. In one exterior beam-column joint unit the beam bar hooks were not bent into the joint core. That is, the hooks at the ends of the top bars were bent up and the hooks at the ends of the bottom bars were bent down. This anchorage detail was common in many older buildings constructed before the 1970s. In the other exterior beam-column joint unit the hooks at the ends of the bars were bent into the joint core as in current...
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simulated seismic Load Tests on reinforced concrete columns
Journal of Structural Engineering-asce, 1994Co-Authors: S Watson, R ParkAbstract:Simulated seismic Load Tests conducted on 11 reinforced concrete columns are described. The columns had a 400-mm (15.7-in.) square or octagonal cross section and contained various quantities of transverse reinforcement. The columns were subjected to either low, moderate, or high axial compressive Loads and to reversible quasi-static lateral Loads that simulated severe earthquake Loading. The Tests were conducted to check an analytical approach for the determination of the available flexural ductility and the enhancement of flexural strength of columns with various levels of transverse confining reinforcement. The analytical approach for determining the quantities of transverse reinforcement required for confinement is shown to be conservative and to lead to equations more suitable for the design of transverse reinforcement for confinement than current code equations. Conclusions are also reached concerning the required length of the confined region in the potential plastic-hinge zones of reinforced concrete columns.
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seismic Load Tests on reinforced concrete columns strengthened by jacketing
Aci Structural Journal, 1994Co-Authors: Mario E Rodriguez, R ParkAbstract:Four reinforced concrete column units were tested subjected to simulated seismic Loading to investigate repair and strengthening techniques. The as-built columns were 350 mm sq and contained low quantities of transverse reinforcement as was typical of building columns designed and constructed prior to 1970. The units represented the column region between the midheights of successive stories. A stub was present at the midheight of each unit to represent a portion of the 2-way beams and slab at the beam-column joint. Two column units were tested, repaired and strenghtened by jacketing and retested. The other two column units were strengthened by jacketing and tested. The as-built columns displayed low available ductility and significant degradation of strength during testing, whereas the jacketed columns behaved in a ductile manner with higher strength and much reduced strength degradation. The retrofit of columns using reinforced concrete jackets was found to be successful but labor-intensive.
Irith Pomeranz - One of the best experts on this subject based on the ideXlab platform.
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Multicycle Broadside and Skewed-Load Tests for Test Compaction
IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, 2020Co-Authors: Irith PomeranzAbstract:This paper describes a test compaction procedure that combines the advantages of using multicycle Tests for test compaction with the advantages of using both broadside and skewed-Load Tests for increasing the fault coverage and achieving test compaction. The procedure is the first to combine these two concepts in a single procedure. The combination is made possible by a definition of a multicycle skewed-Load test that is suggested in this paper, and complements the definition of a multicycle broadside test. Experimental results demonstrate the effectiveness of multicycle broadside and skewed-Load Tests in achieving test compaction for benchmark circuits.
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Padding of Multicycle Broadside and Skewed-Load Tests
IEEE Transactions on Very Large Scale Integration (VLSI) Systems, 2019Co-Authors: Irith PomeranzAbstract:Multicycle Tests achieve test compaction by increasing the number of clock cycles between scan operations and reducing the number of Tests. Tests in a compact multicycle test set typically have different numbers of clock cycles between their scan operations. This creates an opportunity to improve the test set by increasing the numbers of clock cycles between the scan operations of the Tests, without increasing the number of Tests and without exceeding a bound L on the number of clock cycles. Motivated by this observation, this paper studies the padding of multicycle broadside and skewed-Load Tests for transition faults. After padding, all the Tests have L clock cycles between their scan operations. This paper makes several observations and defines new types of multicycle Tests that are supported by commercial tools to allow padding to be performed without losing fault coverage. The new types of Tests can be used for achieving a higher fault coverage, further test compaction, or an improved test set quality within the bound L. This paper develops padding procedures and presents experimental results for benchmark circuits to demonstrate these effects.
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Skewed-Load Tests for Transition and Stuck-at Faults
IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, 2019Co-Authors: Irith PomeranzAbstract:Test generation procedures target a variety of fault models in order to produce test sets that are effective for defect detection. This paper considers the likely scenario where two-cycle skewed-Load Tests are generated to detect single transition faults, and the test set is complemented with Tests for single stuck-at faults that are not detected by the transition fault test set. For this scenario, this paper makes several unique observations that can be utilized to produce a single compact test set that consists only of two-cycle skewed-Load Tests for both fault models. The first observation is that a single-cycle test for a stuck-at fault can be transformed into a skewed-Load test that is guaranteed to detect the stuck-at fault without performing logic or fault simulation. The second observation is that skewed-Load Tests, which are transformed from single-cycle Tests for stuck-at faults, sometimes detect more transition and stuck-at faults than Tests that were generated for transition faults. The third observation is that a static test compaction procedure, which is based on the modification and removal of Tests, is effective in this context because it allows Tests for stuck-at faults to detect more transition faults and vice versa. This paper describes a test compaction procedure based on these observations and presents experimental results for benchmark circuits to demonstrate the effectiveness of the procedure.
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Input Test Data Volume Reduction for Skewed-Load Tests by Additional Shifting of Scan-In States
IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, 2014Co-Authors: Irith PomeranzAbstract:Test data compression methods reduce the input test data volume by allowing compressed Tests to be stored on a tester. Additional reductions in the input test data volume can be achieved if each stored test is used for producing several different Tests. Skewed-Load Tests create a unique opportunity to expand a stored test into several different skewed-Load Tests by continuing to shift the scan-in state for one or more additional clock cycles. This opportunity for test data volume reduction beyond test data compression is introduced in this paper. The paper describes a procedure that starts from a given skewed-Load test set. The procedure removes Tests from the test set and recovers the fault coverage by applying several Tests based on every stored test.
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Broadside and Skewed-Load Tests Under Primary Input Constraints
IEEE Transactions on Very Large Scale Integration (VLSI) Systems, 2013Co-Authors: Irith PomeranzAbstract:Tester limitations may impose certain constraints on the primary input vectors applicable as part of a two-pattern test for delay faults. Under these constraints, the primary input vectors may be held constant, or the second primary input vector of a test may be obtained by a single shift of a scan chain relative to the first. The goal of this brief is to study the differences in achievable transition fault coverage between various primary input constraints that are similar to the commonly used ones of holding or shifting primary input vectors. This brief also studies the possibility of combining the constraints in order to increase the transition fault coverage. The combination requires a fixed and circuit-independent hardware structure similar to the case where shifting of primary input vectors is used. This study is done using test sets that consist of both broadside and skewed-Load Tests in order to maximize the transition fault coverage.
S Watson - One of the best experts on this subject based on the ideXlab platform.
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simulated seismic Load Tests on reinforced concrete columns
Journal of Structural Engineering-asce, 1994Co-Authors: S Watson, R ParkAbstract:Simulated seismic Load Tests conducted on 11 reinforced concrete columns are described. The columns had a 400-mm (15.7-in.) square or octagonal cross section and contained various quantities of transverse reinforcement. The columns were subjected to either low, moderate, or high axial compressive Loads and to reversible quasi-static lateral Loads that simulated severe earthquake Loading. The Tests were conducted to check an analytical approach for the determination of the available flexural ductility and the enhancement of flexural strength of columns with various levels of transverse confining reinforcement. The analytical approach for determining the quantities of transverse reinforcement required for confinement is shown to be conservative and to lead to equations more suitable for the design of transverse reinforcement for confinement than current code equations. Conclusions are also reached concerning the required length of the confined region in the potential plastic-hinge zones of reinforced concrete columns.
Parminder Flora - One of the best experts on this subject based on the ideXlab platform.
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Improving the Testing Efficiency of Selenium-Based Load Tests
2019 IEEE ACM 14th International Workshop on Automation of Software Test (AST), 2019Co-Authors: Shahnaz Mohammedi Shariff, Heng Li, Cor-paul Bezemer, Ahmed E. Hassan, Thanh H.d. Nguyen, Parminder FloraAbstract:Web applications must be Load tested to analyze their behavior under various Load conditions. Typically, these Load Tests are automated using protocol-level HTTP requests (e.g., using JMETER). However, there are several disadvantages to using protocol-level requests for Load Tests. For example, protocol-level requests are only partially representative of the true usage of a web application, as the web application is not actually executed in a browser. It can be difficult to abstract complex behavior, such as a login sequence, into requests without executing the application. Browser-based Load testing can be used as an alternative to protocol-level requests. Using a browser-based testing framework, such as SELENIUM, Tests can be executed more realistically - inside a browser. Unfortunately, because a browser instance must be started to conduct a test, browser-based testing has a high performance overhead which limits its applicability for Load Tests. In this paper, we propose an approach for reducing the performance overhead of running SELENIUM-based Load Tests. Our approach shares browser instances between test user instances, thereby reducing the performance overhead that is introduced by launching many browser instances during the execution of a test. Our experimental results show that our approach can significantly increase the number of user instances that can be tested on a test machine without overLoading the Load driver. Our approach and the experiences that we share in this paper can help software practitioners improve the efficiency of their own SELENIUM-based Load Tests.
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Automated Verification of Load Tests Using Control Charts
2011 18th Asia-Pacific Software Engineering Conference, 2011Co-Authors: Thanh H.d. Nguyen, Ahmed E. Hassan, Bram Adams, Zhen Ming Jiang, Mohamed Nasser, Parminder FloraAbstract:Load testing is an important phase in the software development process. It is very time consuming but there is usually little time for it. As a solution to the tight testing schedule, software companies automate their testing procedures. However, existing automation only reduces the time required to run Load Tests. The analysis of the test results is still performed manually. A typical Load test outputs thousands of performance counters. Analyzing these counters manually requires time and tacit knowledge of the system-under-test from the performance engineers. The goal of this study is to derive an approach to automatically verify Load Tests' results. We propose an approach based on a statistical quality control technique called control charts. Our approach can a) automatically determine if a test run passes or fails and b) identify the subsystem where performance problem originated. We conduct two case studies on a large commercial telecommunication software and an open-source software system to evaluate our approach. Our results warrant further development of control chart based techniques in performance verification.
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Using Load Tests to Automatically Compare the Subsystems of a Large Enterprise System
2010 IEEE 34th Annual Computer Software and Applications Conference, 2010Co-Authors: Haroon Malik, Ahmed E. Hassan, Parminder Flora, Bram Adams, Gilbert HamannAbstract:Enterprise systems are Load tested for every added feature, software updates and periodic maintenance to ensure that the performance demands on system quality, availability and responsiveness are met. In current practice, performance analysts manually analyze Load test data to identify the components that are responsible for performance deviations. This process is time consuming and error prone due to the large volume of performance counter data collected during monitoring, the limited operational knowledge of analyst about all the subsystem involved and their complex interactions and the unavailability of up-to-date documentation in the rapidly evolving enterprise. In this paper, we present an automated approach based on a robust statistical technique, Principal Component Analysis (PCA) to identify subsystems that show performance deviations in Load Tests. A case study on Load test data of a large enterprise application shows that our approach do not require any instrumentation or domain knowledge to operate, scales well to large industrial system, generate few false positives (89% average precision) and detects performance deviations among subsystems in limited time.
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Automatic Comparison of Load Tests to Support the Performance Analysis of Large Enterprise Systems
2010 14th European Conference on Software Maintenance and Reengineering, 2010Co-Authors: Haroon Malik, Ahmed E. Hassan, Parminder Flora, Bram Adams, Zhen Ming Jiang, Gilbert HamannAbstract:Load testing is crucial to uncover functional and performance bugs in large-scale systems. Load Tests generate vast amounts of performance data, which needs to be compared and analyzed in limited time across Tests. This helps performance analysts to understand the resource usage of an application and to find out if an application is meeting its performance goals. The biggest challenge for performance analysts is to identify the few important performance counters in the highly redundant performance data. In this paper, we employed a statistical technique, Principal Component Analysis (PCA) to reduce the large volume of performance counter data, to a smaller, more meaningful and manageable set. Furthermore, our methodology automates the process of comparing the important counters across Load Tests to identify performance gains/losses. A case study on Load test data of a large enterprise application shows that our methodology can effectively guide performance analysts to identify and compare top performance counters across Tests in limited time.
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Automated performance analysis of Load Tests
2009 IEEE International Conference on Software Maintenance, 2009Co-Authors: Zhen Ming Jiang, Ahmed E. Hassan, Gilbert Hamann, Parminder FloraAbstract:The goal of a Load test is to uncover functional and performance problems of a system under Load. Performance problems refer to the situations where a system suffers from unexpectedly high response time or low throughput. It is difficult to detect performance problems in a Load test due to the absence of formally defined performance objectives and the large amount of data that must be examined. In this paper, we present an approach which automatically analyzes the execution logs of a Load test for performance problems. We first derive the system's performance baseline from previous runs. Then we perform an in-depth performance comparison against the derived performance baseline. Case studies show that our approach produces few false alarms (with a precision of 77%) and scales well to large industrial systems.
Zbigniew Manko - One of the best experts on this subject based on the ideXlab platform.
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static Load Tests of posttensioned prestressed concrete road bridge over reservoir water plant
Transportation Research Record, 2008Co-Authors: Arkadiusz Mordak, Zbigniew MankoAbstract:This paper presents the results of field Load Tests on four spans of a posttensioned, prestressed concrete road bridge over a reservoir water plant on the Nysa Klodzka River in Topola, Poland, under static Loads. The spans were especially designed for B-class Loads (400 kN) according to Polish Load standards. They underwent a whole range of research, which included testing bridge deck slab deflections under trial static (and dynamic) Loads. The Tests were performed on October 28, 2002.
