Test Cubes Research Articles

Dynamic X-filling for Peak Capture Power Reduction for Compact Test Sets

Excessive test power consumption is one of the obstacles which the chip industry currently faces. Peak capture power reduction typically leads to high pattern counts which increase test costs. This paper proposes a new methodology to reduce peak capture power during at-speed scan testing. In this method, a novel dynamic X-filling technique Opt-Justification-fill which uses optimization techniques to compute promising X-bits for low-power filling is proposed. This method is tightly integrated into a dynamic compaction flow to create silent test cubes with high compaction ability. By this, X-filling for fault detection and reducing switching activity is balanced. The proposed methodology can be applied during initial compact test set generation as well as during a post-ATPG stage for a previously generated test set to reduce switching activity. Experiments show a significant reduction of peak capture power. At the same time, the pattern count increase is only small which leads to reduced test costs.

Utilizing ATE Vector Repeat With Linear Decompressor for Test Vector Compression

Previous approaches for utilizing automatic test equipment (ATE) vector repeat are based on identifying runs of repeated scan data and directly generating that data using ATE vector repeat. Each run requires a separate vector repeat instruction, so the amount of compression is limited by the amount of ATE instruction memory available and the length of the runs (which typically will be much shorter than the length of a scan vector). In this paper, a new and more efficient approach is proposed for utilizing ATE vector repeat. The scan vector sequence is partitioned and decomposed into a common sequence which is the same for an entire cluster of test cubes and a unique sequence that is different for each test cube. The common sequence can be generated very efficiently using ATE vector repeat. Experimental results demonstrate that the proposed approach can achieve much greater compression while using many fewer vector repeat instructions compared with previous methods.

Effects of Old Aggregate on Concrete Strength

The basic characteristics of recycled coarse aggregate are completely tested. Crushed the waste concrete through artificial crushing, configured recycled concrete by reference to the mix proportion of ordinary concrete . Through experiments, recycled concrete and ordinary concrete basic properties were tested, the performance of recycled concrete with different coarse aggregate were compared, calculated the strength and amount of mold of recycled concrete; results showed that the basic properties of recycled coarse aggregate and natural aggregate existed certain differences. compared to the pebble-based recycled aggregate concrete strength can reach ordinary concrete strength, and when the new coarse aggregate and recycled coarse aggregate were the half, the strength of concrete was not high, the stress - strain curve and the ordinary concrete stress - strain curves were similar, destructive phenomenons of test cubes were close with ordinary concrete .

Low-Power Test Generation by Merging of Functional Broadside Test Cubes

This paper describes a low-power test generation procedure, which targets the switching activity during the fast functional clock cycles of broadside tests. The procedure is based on merging of test cubes that it extracts from functional broadside tests. The use of test cube merging supports test compaction and it can be used for accommodating the constraints of test data compression. The use of functional broadside tests provides a target for the switching activity of low-power tests, which does not exceed the switching activity that is possible during functional operation, or that the circuit is designed for. The use of test cubes that are extracted from functional broadside tests is a unique feature of this procedure. It ensures that the low-power tests would create functional operation conditions in subcircuits that are defined by the test cubes. Experimental results show that the procedure detects all or almost all the transition faults that are detectable by arbitrary (functional and nonfunctional) broadside tests in benchmark circuits.

XStat: Statistical <I>X</I>-Filling Algorithm for Peak Capture Power Reduction in Scan Tests

Excessive power dissipation can cause high voltage droop on the power grid, leading to timing failures. Since test power dissipation is typically higher than functional power, test peak power minimization becomes very important in order to avoid test induced timing failures. Test cubes for large designs are usually dominated by don't care bits, making X-leveraging algorithms promising for test power reduction. In this paper, we show that X-bit statistics can be used to reorder test vectors on scan based architectures realized using toggle-masking flip flops. Based on this, the paper also presents an algorithm namely balanced X-filling that when applied to ITC'99 circuits, reduced the peak capture power by 7.4% on the average and 40.3% in the best case. Additionally XStat improved the running time for Test Vector Ordering and X-filling phases compared to the best known techniques.

Effect of Recycled Coarse Aggregate on the Compressive Strength and Modulus of Rupture of Concrete

The paper investigated the compressive strength and rupture modulus of recycled aggregate concrete when recycled aggregates from the regulated industry such as laboratories is used as partial substitute for natural coarse aggregates. The work determined and compared the compressive strength of recycled aggregate concrete with that of natural aggregate concrete. It applied the laboratory investigated technique. A standard mix ratio of 1:2:4:0.5 representing; cement, fine aggregate, coarse aggregate and water/cement ratio was used to produce the test cubes and beams, with subsequent 0%, 30%, 50%, 80% and 100% substitution of natural coarse aggregates with recycled coarse aggregates. The results showed that as the percentage content of recycled coarse aggregate in the mix increased, the compressive strength decreased. The natural coarse aggregate concrete gave a compressive strength of 43.6 N/mm and the recycled coarse aggregate concrete, 29.5 N/mm, a decrease of 40%. At early stages of substitution, there was no significant change in the modulus of rupture but at higher percentages of substitution, it became significant. The natural coarse aggregate concrete gave a modulus of rupture of 5.67 N/mm while the recycled coarse aggregate gave 3.84 N/mm. Recycled concrete has been shown to be a viable option to decrease the demand on high quality natural resources and to limit the amount of waste that is disposed in landfills. Original Research Article British Journal of Applied Science & Technology, 4(27): 4006-4013, 2014 4007

Enhancement of test data compression with multistage encoding

In this paper, we present two multistage compression techniques to reduce the test data volume in scan test applications. We have proposed two encoding schemes namely alternating frequency-directed equal-run-length (AFDER) coding and run-length based Huffman coding (RLHC). These encoding schemes together with the nine-coded compression technique enhance the test data compression ratio. In the first stage, the pre-generated test cubes with unspecified bits are encoded using the nine-coded compression scheme. Later, the proposed encoding schemes exploit the properties of compressed data to enhance the test data compression. This multistage compression is effective especially when the percentage of do not cares in a test set is very high. We also present the simple decoder architecture to decode the original data. The experimental results obtained from ISCAS'89 benchmark circuits confirm the average compression ratio of 74.2% and 77.5% with the proposed 9C-AFDER and 9C-RLHC schemes respectively.

On Test Compaction of Broadside and Skewed-Load Test Cubes

For a test set that consists of test cubes (incompletely specified tests), test compaction can be achieved by merging pairs of compatible tests (tests that do not conflict in any of their specified values). This paper describes a test compaction procedure that enhances the ability of test-merging to reduce the number of tests in an incompletely specified test set that consists of both broadside and skewed-load tests for transition faults. In a basic step, the procedure attempts to remove a test t by combining it with several other tests, even if the tests are not compatible or have different types. This increases the possibility that all the faults detected by t will be detected by other tests, and t will be removed. Simulation results demonstrate reductions in numbers of tests beyond those achieved by test-merging with the same or lower numbers of specified values.

On multi‐cycle test cubes

This article studies the generation of test sets that consist of multi-cycle test cubes. Such test cubes have partially-specified scan-in states, and several functional clock cycles between scan operations. Test cubes are important for test data compression. In addition, multi-cycle tests can detect delay defects that are not detected by single-cycle tests. The use of multi-cycle test cubes is shown to reduce the number of test cubes required for detecting single stuck-at faults compared with the case where single-cycle test cubes are used. This article also shows that a multi-cycle test cube for a single stuck-at fault can have fewer specified scan-in values than a single-cycle test cube for the same fault. As a result, multi-cycle test cubes can be more effective for test data compression. This article also discusses the conditions under which multi-cycle test cubes can be merged in order to further reduce the number of test cubes in a test set.

Computing Two-Pattern Test Cubes for Transition Path Delay Faults

Considering full-scan circuits, incompletely-specified tests, or test cubes, are used for test data compression. When considering path delay faults, certain specified input values in a test cube are needed only for determining the lengths of the paths associated with detected faults. Path delay faults, and therefore, small delay defects, would still be detected if such values are unspecified. The goal of this paper is to explore the possibility of increasing the number of unspecified input values in a test set for path delay faults by unspecifying such values in order to make the test set more amenable to test data compression. Experimental results indicate that significant numbers of such values exist. The proposed procedure unspecifies them gradually to obtain a series of test sets with increasing numbers of unspecified values and decreasing path lengths. Experimental results also indicate that filling the unspecified values randomly (as with some test data compression methods) recovers some or all of the path lengths associated with detected path delay faults. The procedure uses a matching of the sets of detected faults for the comparison of path lengths.

Properties of Concrete with High-Volume Limestone Powder under Low Temperature Conditions

This paper studies the effects of high-volume composite mineral admixture made of limestone powder and low-quality fly ash on the properties of concrete,and studies the form of attack of cement-based material made of limestone powder at low water-binder ratio under low-temperature sulfate environment.Through experiments, this paper makes clear the workability of fresh concrete and analyzes the law of strength development of concrete. The experimental results indicate that the concrete with high-volume limestone powder as composite mineral admixture has good fresh properties; due to low water consumption per unit volume, medium-and-high-strength concrete can be prepared. As new type concrete mineral admixture, the composite mineral admixture made of limestone powder and low-quality fly ash will play an active role in the sustainable development of concrete industry. After the specimen with the water-binder ratio of less than 0.4 and the limestone powder volume of greater than 20% is soaked in 10% magnesium sulfate solution at low temperature at the age of 200d, gypsum attack-led destruction is caused to the concrete test cube, without thaumasite sulfate attack.

Scan to Nonscan Conversion via Test Cube Analysis

Increasing complexity of integrated circuits has forced the industry to abandon partial scan, which necessitates a computationally demanding and unaffordable sequential automatic test pattern generation (ATPG), and to instead adopt full scan, despite its costs. In this paper, we propose a partial scan scheme driven by a computationally efficient test cube analysis. We tackle the challenges associated with the identification of the conditions to restore the controllability and observability compromised due to partial scan, and with the formulation of these conditions in terms of test cube operations. Upon the identification of a maximal-sized set of scan flip-flops that are converted to nonscan, a simple postprocessing of the test cubes helps compute the values to be loaded into the scan flip-flops, eliminating the need to rerun ATPG, while at the same time ensuring the quality of full scan. We further enhance this framework through techniques that process the test data before and after the application of the proposed test cube analysis-driven partial scan technique, in order to enlarge the size of the nonscan flip-flop set. The proposed scheme combines the simplicity of the conventional ATPG flow with the area, performance, test time, and test power reduction benefits of partial scan. The proposed test cube analysis-driven partial scan scheme is orthogonal and thus fully compatible with other test cost-reduction techniques, such as test data compression and test power reduction, which can be applied in conjunction.

Test to Fly Ash Recycled Concrete under Different Water Cement Ratio

The recovery and utilization to building solid waste is the current hot issues in the construction of towns. In this paper, 30 groups of fly ash recycled concrete test cube were designed and produced, through the mechanical performance test research, we analysised the main influence factors to the strength and performances of fly ash regeneration concrete test cube,such as recycled aggregate category, water cement ratio, the admix proportion of recycled aggregate. The test results would lay a solid foundation for the test research and engineering application of recycled concrete.

Fiber Optic Sensors and Sensor Networks Using a Time-domain Sensing Scheme

Fiber loop ringdown (FLRD) has demonstrated to be capable of sensing various quantities, such as chemical species, pressure, refractive index, strain, temperature, etc.; and it has high potential for the development of a sensor network. In the present work, we describe design and development of three different types of FLRD sensors for water, cracks, and temperature sensing in concrete structures. All of the three aforementioned sensors were indigenously developed very recently in our laboratory and their capabilities of detecting the respective quantities were demonstrated. Later, all of the sensors were installed in a test grout cube for real-time monitoring. This work presents the results obtained in the laboratory-based experiments as well as the results from the real-time monitoring process in the test cube.

Scan Power Reduction for Linear Test Compression Schemes Through Seed Selection

XOR network-based on-chip test compression schemes have been widely employed in large industrial scan designs due to their high compression ratio and efficient decompression mechanism. Nevertheless, such a scheme necessitates high unspecified bit ratios in the original test cubes, resulting in quite significant difficulties in preprocessing test cubes for scan power reduction. The linear mapping from the original cubes to the compressed seeds typically provides extra degrees of flexibility as multiple seeds may reconstruct the test cube. Due to the highly divergent power impact of distinct seeds though, appreciable power reductions in the decompressed test data can be attained through the pinpointing of the power-optimal seeds during the compression phase. This work explores the aforementioned flexibility in the seed space, and outlines a mathematical and algorithmic framework for a power-aware linear test compression scheme. The proposed technique incurs no hardware overhead over the traditional linear compression scheme; it can be easily embedded furthermore into the industrial test compaction/compression flow. Experimental results confirm that the proposed technique delivers significant scan power reduction with negligible impact on the compression ratio.

Experimental Study of Mix Proportion of Magnesium Oxychloride Cement

Based on the results of compression and bending tests of fifty eight magnesium oxychloride cement test cubes, the influences of two factors on compression and bending strength have been analyzed which includes the mole ratio of magnesium oxide and magnesium chloride and Baum degree of magnesium chloride solution. Softening coefficient of magnesium oxychloride cement and its influence factor have been studied by immersion test of twelve test cubes. The results show when the mole ratio of magnesium oxide and magnesium chloride is 7.0, the strength and water resistance performance of magnesium oxychloride cement is best. This work is very important to the application and dissemination of magnesium oxychloride cement bearing structural member in southern wetter areas of china.

Form and mechanism of sulfate attack on cement-based material made of limestone powder at low water-binder ratio under low temperature conditions

The development of strength and the form of attack of cement-based material made of limestone powder at low water-binder ratio under low-temperature sulfate environment were studied. The results indicate that when water-binder ratio is lower than 0.40, the cement-based material with limestone powder has insignificant change in appearance after being soaked in 10% magnesium sulfate solution at low temperature for 120 d, and has significant change in appearance after being soaked at the age of 200 d. Expansion damage and exfoliation occur on the surface of concrete test cube at different levels. When limestone powder accounts for about 28 percent of cementitious material, with the decrease of water-binder ratio, the compressive strength loss has gradually decreased after the material is soaked in the magnesium sulfate solution at low temperature at the age of 200 d. After the specimen with the water-binder ratio of less than 0.4 and the limestone powder volume of greater than 20% is soaked in 10% magnesium sulfate solution at low temperature at the age of 200 d, gypsum attack-led destruction is caused to the concrete test cube, without thaumasite sulfate attack.

Experimental Study on Post-Anchoring Pulling-Out Bearing Capacity of Inorganic Materials in Concrete Test Cubes

Through the test and observe the failure deformation in concrete test cube, the paper analyze the influence of concrete strength, concrete cover thickness, internal reinforcement cage(transverse reinforcement), reinforcement diameter on the inorganic material reinforcement adhesive property, providing theoretical basis for the code of Technical specification for post-anchoring used in concrete structure with inorganic anchoring material.

Suitability of Flood Plain Deposits for the Production of Burnt Bricks in Parts of Benue State, Central Nigeria

In Benue State, Central Nigeria, flood plain soil deposits along the banks of major rivers and seasonal streams are used as raw materials in the local manufacture of burnt bricks for the construction of houses. This work evaluates the compositional characteristics of the soils and engineering properties of derived bricks to assess their suitability and as al- ternatives to sandcrete as load bearing materials in the construction of houses. The soils are composed of varying proportions of sand, silt and clay. While the sand fraction is mainly fine to medium grained, the clays are of low plasticity. The chemistry of the soils show that the order of abundance of the major oxides is CaO > Fe2O3 > MgO > TiO2 > PbO > MnO > Al2O3 > P2O5 > K2O >Na2O > SiO2 >AgO. Test cube bricks produced under standard compaction methods gave cold water absorption of 3-4%, ignition loss of 31-36 % and compressive strength of between 38 and 111N/mm 2 . These parameters satisfy the requirements specified by relevant Nigerian Standards for burnt bricks. The locally made bricks by the natives on examina- tion exhibited cracks and shades of different colours due to thermal stress suggesting that low compactive efforts were ap- plied during kneading of the soil into the molds and also that the bricks were not adequately fired. This quality deficiency is due to non -standardization of the hand production process. If properly harnessed, these widely available raw materials and their cheap products will readily substitute cement bricks for most housing and other structural work.

Research on Determining the Pose Errors in a Robot Welding Cell Using Theodolits

In this article, the authors aim to develop a method for determining the components errors of a robotic welding cell, using coordinate transformations between the reference systems attached to the cells components. Errors are expressed as matrices, as it is usual in the mathematical expressions used in robotics. Errors mathematical modeling refers to the positioning error and also to the orientation error. Therefore, a test cube is used. The experiments presented in the paper, approaches only the positiong error (AP). The method is used for measuring the pose errors of a welding cell, using two theodolits. The method is based on measuring the coordinates of a target characteristic point TCP, the corner of a test cube, relative to a coordinate system attached to one of the two theodolits. It is part of the no contact measurement methods. The main principles of the method and its theoretical basis are validated by experiments, conducted in a welding cell, using a robot CLOOS-Romat in the Robotics Laboratory of the University "Politehnica" of Timisoara.