There is a growing interest in the assessment of tangible skills and competence. Specifically, there is an increase in the offerings of competency-based assessments, and some academic institutions are offering college credits for individuals who can demonstrate adequate level of competency on such assessments. An increased interest has been placed on competency-based computer simulations that can assist learners to gain tangible skills. While computer simulations and competency-based projects, in general and particularly in management, have demonstrated great value, there are still limited empirical results on their benefits to e-learners. Thus, we have developed a quasi-experimental research, using a survey instrument on pre- and post-tests, to collect the set of 12 management skills from e-learners attending courses that included both competency-based computer simulations and those that didn’t. Our data included a total of 253 participants. Results show that all 12 management skills measures demonstrated very high reliability. Our results also indicate that all 12 skills of the competency-based computer simulations had higher increase than those that didn’t. Analyses on the mean increases indicated an overall statistically significant difference for six of the 12 management skills enhancements between the experimental and control groups. Our findings demonstrate that overall computer simulations and competency-based projects do provide added value in the context of e-learning when it comes to management skills.

Synchrotron light sources can provide the required spatial coherence, stability and control to support the development of advanced lithography at the extreme ultraviolet and soft X-ray wavelengths that are relevant to current and future fabricating technologies. Here an evaluation of the optical performance of the soft X-ray (SXR) beamline of the Australian Synchrotron (AS) and its suitability for developing interference lithography using radiation in the 91.8 eV (13.5 nm) to 300 eV (4.13 nm) range are presented. A comprehensive physical optics model of the APPLE-II undulator source and SXR beamline was constructed to simulate the properties of the illumination at the proposed location of a photomask, as a function of photon energy, collimation and monochromator parameters. The model is validated using a combination of experimental measurements of the photon intensity distribution of the undulator harmonics. It is shown that the undulator harmonics intensity ratio can be accurately measured using an imaging detector and controlled using beamline optics. Finally, the photomask geometric constraints and achievable performance for the limiting case of fully spatially coherent illumination are evaluated.

Signal-to-noise ratio and spatial resolution are quantitatively analysed in the context of in-line (propagation based) X-ray phase-contrast imaging. It is known that free-space propagation of a coherent X-ray beam from the imaged object to the detector plane, followed by phase retrieval in accordance with Paganin's method, can increase the signal-to-noise in the resultant images without deteriorating the spatial resolution. This results in violation of the noise-resolution uncertainty principle and demonstrates `unreasonable' effectiveness of the method. On the other hand, when the process of free-space propagation is performed in software, using the detected intensity distribution in the object plane, it cannot reproduce the same effectiveness, due to the amplification of photon shot noise. Here, it is shown that the performance of Paganin's method is determined by just two dimensionless parameters: the Fresnel number and the ratio of the real decrement to the imaginary part of the refractive index of the imaged object. The relevant theoretical analysis is performed first, followed by computer simulations and then by a brief test using experimental images collected at a synchrotron beamline. More extensive experimental tests will be presented in the second part of this paper.

The split-and-delay unit (SDU) at FLASH2 will be upgraded to enable the simultaneous operation of two temporally, spatially and spectrally separated probe beams when the free-electron laser undulators are operated in a two-color scheme. By means of suitable thin filters and an optical grating beam path a wide range of combinations of photon energies in the spectral range from 150 eV to 780 eV can be chosen. In this paper, simulations of the spectral transmission and performance parameters of the filter technique are discussed, along with a monochromator with dispersion compensation presently under construction.

Chalcopyrite, the world's primary copper ore mineral, is abundant in Latin America. Copper extraction offers significant economic and social benefits due to its strategic importance across various industries. However, the hydro­metallurgical route, considered more environmentally friendly for processing low-grade chal­co­py­rite ores, remains challenging, as does its concentration by froth flotation. This limited understanding stems from the poorly understood structure and reactivity of chal­co­py­rite surfaces. This study reviews recent contributions using density functional theory (DFT) calculations with periodic boundary conditions and slab models to elucidate chal­co­py­rite surface properties. Our analysis reveals that reconstructed surfaces preferentially expose S atoms at the topmost layer. Furthermore, some studies report the formation of di­sulfide groups (S22−) on pristine sulfur-terminated surfaces, accom­panied by the reduction of Fe3+ to Fe2+, likely due to surface oxidation. Additionally, Fe sites are consistently identified as favourable adsorption locations for both oxygen (O2) and water (H2O) mol­ecules. Finally, the potential of com­puter modelling for investigating collector–chal­co­py­rite surface inter­actions in the context of selective froth flotation is discussed, highlighting the need for further research in this area.

Dark-field X-ray microscopy (DFXM) is a full-field imaging technique that non-destructively maps the structure and local strain inside deeply embedded crystalline elements in three dimensions. In DFXM, an objective lens is placed along the diffracted beam to generate a magnified projection image of the local diffracted volume. This work explores contrast methods and optimizes the DFXM setup specifically for the case of mapping dislocations. Forward projections of detector images are generated using two complementary simulation tools based on geometrical optics and wavefront propagation, respectively. Weak and strong beam contrast and the mapping of strain components are studied. The feasibility of observing dislocations in a wall is elucidated as a function of the distance between neighbouring dislocations and the spatial resolution. Dislocation studies should be feasible with energy band widths of 10−2, of relevance for fourth-generation synchrotron and X-ray free-electron laser sources.

Propagation-based phase contrast, for example in the form of edge enhancement contrast, is well established within X-ray imaging but is not widely used in neutron imaging. This technique can help increase the contrast of low-attenuation samples but may confuse quantitative absorption measurements. Therefore, it is important to understand the experimental parameters that cause and amplify or dampen this effect in order to optimize future experiments properly. Two simulation approaches have been investigated, a wave-based simulation and a particle-based simulation conducted in McStas [Willendrup & Lefmann (2020). J. Neutron Res. 22, 1–16], and they are compared with experimental data. The experiment was done on a sample of metal foils with weakly and strongly neutron absorbing layers, which were measured while varying the rotation angle and propagation distance from the sample. The experimental data show multiple signals: attenuation, phase contrast and reflection. The wave model reproduces the sample attenuation and the phase peaks but it does not reproduce the behavior of these peaks as a function of rotation angle. The McStas simulation agrees better with the experimental data, as it reproduces attenuation, phase peaks and reflection, as well as the change in these signals as a function of rotation angle and distance. This suggests that the McStas simulation approach, where the particle description of the neutron facilitates the incorporation of multiple effects, is the most convenient way of modeling edge enhancement in neutron imaging.

For a reliable characterization of materials and systems featuring multiple structural levels, a broad length scale from a few ångström to hundreds of nanometres must be analyzed and an extended Q range must be covered in X-ray and neutron scattering experiments. For certain samples or effects, it is advantageous to perform such characterization with a single instrument. Neutrons offer the unique advantage of contrast variation and matching by D-labeling, which is of great value in the characterization of natural or synthetic polymers. Some time-of-flight small-angle neutron scattering (TOF-SANS) instruments at neutron spallation sources can cover an extended Q range by using a broad wavelength band and a multitude of detectors. The detectors are arranged to cover a wide range of scattering angles with a resolution that allows both large-scale morphology and crystalline structure to be resolved simultaneously. However, for such analyses, the SANS instruments at steady-state sources operating in conventional monochromatic pinhole mode rely on additional wide-angle neutron scattering (WANS) detectors. The resolution must be tuned via a system of choppers and a TOF data acquisition option to reliably measure the atomic to mesoscale structures. The KWS-2 SANS diffractometer at Jülich Centre for Neutron Science allows the exploration of a wide Q range using conventional pinhole and lens focusing modes and an adjustable resolution Δλ/λ between 2 and 20%. This is achieved through the use of a versatile mechanical velocity selector combined with a variable slit opening and rotation frequency chopper. The installation of WANS detectors planned on the instrument required a detailed analysis of the quality of the data measured over a wide angular range with variable resolution. This article presents an assessment of the WANS performance by comparison with a McStas [Willendrup, Farhi & Lefmann (2004). Physica B, 350, E735–E737] simulation of ideal experimental conditions at the instrument.

Simulations of transport of time over packet networks

PITTSBURGH, Sept. 24, 2024 — Ansys and TSMC today announced a successful pilot with Microsoft that significantly speeds-up the simulation and analysis of silicon photonic components. Together, the companies achieved […]

The post TSMC Collaborates with Ansys and Microsoft to Accelerate Photonic Simulations appeared first on HPCwire.

Oct. 25, 2024 — Aggregation of proteins underlies many human disorders, including Alzheimer’s. Teams from the New Jersey Institute of Technology and Princeton University joined forces to study how the amyloid […]

The post PSC: Anton Simulations Reveal How Alzheimer’s Fibril Growth May Accelerate appeared first on HPCwire.

David Radice, associate professor of physics and of astronomy and astrophysics, has been selected to receive a Sustainment Award from NASA to advance an open-source code called AthenaK for computational astrophysicists. The grant will provide nearly $920,000 over three years.

Hello Community,

I have encountered an issue that is a mystery to me and hope somebody could give me a clue about what is happening in Cadence and maybe even a solution?

I am running a test scripted in a SKILL file that sequentially opens two different projects with MC analyses and in between I get an error message box and also multiple logs in CIW with exactly the same text.

Both projects run a simulation with a call like this:

historyName = maeRunSimulation(?session sessionName ?waitUntilDone t)

After this the script closes the current project, opens the next project and executes the same line with maeRunSimulation() for the second project. Then immediately this error message happens, and also is logged repeatedly in the CIW window

The message box looks like this:

The logs I get in CIW:

nil
hiCancelProgressBox(_axlNetlistCreateProgressBar)
nil
hiCancelProgressBox(_axlUILoadForm)
nil
when(dwindow('axlDataViewessWindow1) hiMapWindow(dwindow('axlDataViewessWindow1)))
t
when(dwindow('axlRunSummaryessWindow1) hiMapWindow(dwindow('axlRunSummaryessWindow1)))
t
ERROR (ASSEMBLER-1600): Cannot find an active session named fnxSession0.
You can only modify an ADE Assembler session that is active.
Perhaps the session name was misspelled or has not yet been created.
Verify the session name matches an existing ADE Assembler session.

1>
ERROR (ASSEMBLER-1600): Cannot find an active session named fnxSession0.
You can only modify an ADE Assembler session that is active.
Perhaps the session name was misspelled or has not yet been created.
Verify the session name matches an existing ADE Assembler session.

*WARNING* hiDisplayAppDBox: modal dbox 'adexlMessageDialog' is already displayed!
ERROR (ASSEMBLER-1600): Cannot find an active session named fnxSession0.
You can only modify an ADE Assembler session that is active.
Perhaps the session name was misspelled or has not yet been created.
Verify the session name matches an existing ADE Assembler session.

*WARNING* hiDisplayAppDBox: modal dbox 'adexlMessageDialog' is already displayed!
ERROR (ASSEMBLER-1600): Cannot find an active session named fnxSession0.
You can only modify an ADE Assembler session that is active.
Perhaps the session name was misspelled or has not yet been created.
Verify the session name matches an existing ADE Assembler session.

Clinical Simulations are Center Stage in Keeping Patients Safe

Berlin, May 5: Several drugs approved for the treatment of hepatitis C viral infection have been identified as potential candidates against COVID-19 caused by the SARS-CoV-2 coronavirus, according to a study based on extensive calculations using supercomputer simulations.

Dynamical X-ray diffraction simulations of very asymmetric diffraction from single crystals of silicon were made to accompany an experimental rocking-curve topography study reported in a seperate paper. Effects on rocking curves were found and are reported. The development of Uragami [(1969), J. Phys. Soc. Jpn, 27, 147–154] for Takagi–Taupin simulations was followed and applied to the case of both convex and concave surface undulations.

Spiral galaxies are some of the most beautiful and photogenic residents of the universe. Our own Milky Way is a spiral. Our solar system and […]

The post Powerful computer simulations show how spiral galaxies get their arms appeared first on Smithsonian Insider.

Using new numerical simulations and observations, scientists may now be able to explain why the Sun’s magnetic field reverses every eleven years. This significant discovery […]

The post 3D simulations reveals why the Sun flips its magnetic field every 11 years appeared first on Smithsonian Insider.

Today’s post is by Owen Paul, who is a Student Ambassador Technical Program Specialis. He himself was a student ambassador before joining MathWorks, and he was featured in the Community... read more >>

In a previous post, I introduced a model simulating the exponential spread of a phenomenon like COVID-19. With more and more talks in the news about deconfinement plans, I thought it would be interesting to run multiple simulations with different deconfinement scenarios and observe the potential outcomes.... read more >>

Tags: coronavirus, Marcel Salathé, Nicky Case, simulation

Methods, systems, and apparatus, including computer program products, for determining energy indicator values for a plurality of thermoplastic materials. An energy indicator value represents expected energy requirements for performing an injection of the material in a mold cavity. An injection of each of a plurality of thermoplastic materials in a first modeled mold cavity is simulated. A respective value of a first expected energy parameter is determined for each of the plurality of thermoplastic materials based on the simulated injections. A respective energy indicator is determined, for each of the plurality of thermoplastic materials, based at least on the corresponding value of the first expected energy parameter. The respective energy indicator value of one or more of the plurality of thermoplastic materials is presented.

For $20, fans of German soccer club Borussia can have a cut-out of themselves placed in the stands at BORUSSIA-PARK. According to the club, over 12,000 cut-outs have been ordered and 4,500 have already been put in place. Here is the tweet and photo. And some sports bettors are betting on simulated sporting events.  (Again, […]

The post Coronavirus sports markets in everything, multiple simulations edition appeared first on Marginal REVOLUTION.

The Kings have found a way to stay connected with fans amid the coronavirus shutdown by replicating its schedule through video games.

Roles & Responsibilities Using Maxwell magnetic models, perform magnetic simulation of the wireless charging system Organize simulation results and create analysis of the simulation results Typical tasks - Perform a sweep of ferrite losses over a range of operating conditions Key Skills:

Roles & Responsibilities Using Maxwell magnetic models, perform magnetic simulation of the wireless charging system Organize simulation results and create analysis of the simulation results Typical tasks - Perform a sweep of ferrite losses over a range of operating conditions Key Skills:

(DOE/Oak Ridge National Laboratory) Using ORNL's now-decommissioned Titan supercomputer, a team of researchers estimated the combined consequences of many different extreme climate events at the county level, a unique approach that provided unprecedented regional and national climate projections that identified the areas most likely to face climate-related challenges.

(George Mason University) Nathan Sleeter, Research Assistant Professor, Roy Rosenzweig Center for History and New Media (RRCHNM), is directing a project in which RRCHNM will create three classroom simulations based on events from the history of diplomacy for secondary education instructors.

The post Perform Abaqus High-End Simulations from Home with Structural Mechanics Engineer appeared first on The SOLIDWORKS Blog.

Lehigh Valley's Practical Nursing Program has moved to the Shadow Health Digital Clinical Experience so students can continue clinical rotations through virtual simulations.

Hi Folks, A question that I've often received from designers, "Is there a method to determine the amount of memory required before I submit a job? I use distributed processing and need to provide an estimate before submitting jobs." The answer...(read more)

Hello,

I am trying to use calcVal for creating a spec condition from a simulated parameter and although this works perfectly fine in corner simulations, I am having some difficulties in Monte-Carlo (and I will explain).

(I have also read "Using calcVal() and its arguments with ADE Assembler" in Resources > Rapid Adoption Kits but couldn't find any relevant information that would help me address the "issue").

In the above example I am performing a MC simulation which has 2 corners of 10 runs each. I would like to get the minimum value of variable "OC_limit_thres" out of those 10 runs and pass it as my upper limit to a range argument for variable "OC_flag_thres", so the CPK can be calculated.

So the range statement should in reality be like this:

range 32m 44.34m (for corner 0)

range 32m 43.14m (for corner 1)

If I open the Detail - Transpose view in the Results tab, the calcVal("OC_limit_thres" "Currlim_TurnOn_C11") is calculated perfectly fine for each run but here I need one single value out of those 10 runs - in this case the minimum - in order for calcVal to evalute on multiple runs of 1 corner.

How can this be done please?

Thank you in advance for your time.

Key Findings: Advantest, in mixed-signal SoC design, sees 50X speedup, 25 day test reduced to 12 hours, dramatic test coverage increase.

Trolling through the CDNLive archives, I discovered another gem. At the May 2013 CDNLive in Munich, Thomas Henkel and Henriette Ossoinig of Advantest presented a paper titled “Timing-accurate emulation of a mixed-signal SoC using Palladium XP”. Advantest makes advanced electronics test equipment. Among the semiconductor designs they create for these products is a test processor chip with over 100 million logic transistors, but also with lots of analog functions.They set out to find a way to speed up their full-chip simulations to a point where they could run the system software. To do that, they needed about a 50X speed-up. Well, they did it!

Figure 1: Advantest SoC Test Products

To skip the commentary, read Advantest's paper here. 

Problem Statement

Software is becoming a bigger part of just about every hardware product in every market today, and that includes the semiconductor test market. To achieve high product quality in the shortest amount of time, the hardware and software components need to be verified together as early in the design cycle as possible. However, the throughput of a typical software RTL simulation is not sufficient to run significant amounts of software on a design with hundreds of millions of transistors.  

Executing software on RTL models of the hardware means long runs  (“deep cycles”) that are a great fit for an emulator, but the mixed-signal content posed a new type of challenge for the Advantest team.  Emulators are designed to run digital logic. Analog is really outside of the expected use model. The Advantest team examined the pros and cons of various co-simulation and acceleration flows intended for mixed signal and did not feel that they could possibly get the performance they needed to have practical runtimes with software testbenches. They became determined to find a way to apply their Palladium XP platform to the problem.

Armed with the knowledge of the essential relationship between the analog operations and the logic and software operations, the team was able to craft models of the analog blocks using reduction techniques that accurately depicted the essence of the analog function required for hardware-software verification without the expense of a continuous time simulation engine.

The requirements boiled down to the following:

• Generation of digital signals with highly accurate and flexible timing

• Complete chip needs to run on Palladium XP platform

• Create high-resolution timing (100fs) with reasonable emulation performance, i.e. at least 50X faster than simulation on the fastest workstations

Solution Idea

The solution approach chosen was to simplify the functional model of the analog elements of the design down to generation of digital signal edges with high timing accuracy. The solution employed a fixed-frequency central clock that was used as a reference.Timing-critical analog signals used to produce accurately placed digital outputs were encoded into multi-bit representations that modeled the transition and timing behavior. A cell library was created that took the encoded signals and converted them to desired “regular signals”. 

Automation was added to the process by changing the netlisting to widen the analog signals according to user-specified schematic annotations. All of this was done in a fashion that is compatible with debugging in Cadence’s Simvision tool.  Details on all of these facets to follow.

The Timing Description Unit (TDU) Format

The innovative thinking that enabled the use of Palladium XP was the idea of combining a reference clock and quantized signal encoding to create offsets from the reference. The implementation of these ideas was done in a general manner so that different bit widths could easily be used to control the quantization accuracy.

Figure 2: Quantization method using signal encoding

Timed Cell Modeling

You might be thinking – timing and emulation, together..!?  Yes, and here’s a method to do it….

The engineering work in realizing the TDU idea involved the creation of a library of cells that could be used to compose the functions that convert the encoded signal into the “real signals” (timing-accurate digital output signals). Beyond some basic logic cells (e.g., INV, AND, OR, MUX, DFF, TFF, LATCH), some special cells such as window-latch, phase-detect, vernier-delay-line, and clock-generator were created. The converter functions were all composed from these basic cells. This approach ensured an easy path from design into emulation.

The solution was made parameterizable to handle varying needs for accuracy.  Single bit inputs need to be translated into transitions at offset zero or a high or low coding depending on the previous state.  Single bit outputs deliver the final state of the high-resolution output either at time zero, the next falling, or the next rising edge of the grid clock, selectable by parameter. Output transitions can optionally be filtered to conform to a configurable minimum pulse width.

Timed Cell Structure

There are four critical elements to the design of the conversion function blocks (time cells):

                Input conditioning – convert to zero-offset, optional glitch preservation, and multi-cycle path

                Transition sorting – sort transitions according to timing offset and specified precedence

                Function – for each input transition, create appropriate output transition

                Output filtering – Capability to optionally remove multiple transitions, zero-width, pulses, etc.

Timed Cell Caveat

All of the cells are combinational and deliver a result in the same cycle of an input transition. This holds for storage elements as well. For example a DFF will have a feedback to hold its state. Because feedback creates combinational loops, the loops need a designation to be broken (using a brk input conditioning function in this case – more on this later). This creates an additional requirement for flip-flop clock signals to be restricted to two edges per reference clock cycle.

Note that without minimum width filtering, the number of output transitions of logic gates is the sum of all input transitions (potentially lots of switching activity). Also note that the delay cell has the effect of doubling the number of output transitions per input transition.

Figure 3: Edge doubling will increase switching during execution

SimVision Debug Support

The debug process was set up to revolve around VCD file processing and directed and viewed within the SimVision debug tool. In order to understand what is going on from a functional standpoint, the raw simulation output processes the encoded signals so that they appear as high-precision timing signals in the waveform viewer. The flow is shown in the figure below.

Figure 4: Waveform post-processing flow

The result is the flow is a functional debug view that includes association across representations of the design and testbench, including those high-precision timing signals.

Figure 5: Simvision debug window setup

Overview of the Design Under Verification (DUV)

Verification has to prove that analog design works correctly together with the digital part. The critical elements to verify include:

• Programmable delay lines move data edges with sub-ps resolution

• PLL generates clocks with wide range of programmable frequency

• High-speed data stream at output of analog is correct

These goals can be achieved only if parts of the analog design are represented with fine resolution timing.

Figure 6: Mixed-signal design partitioning for verification

How to Get to a Verilog Model of the Analog Design

There was an existing Verilog cell library with basic building blocks that included:

- Gates, flip-flops, muxes, latches

- Behavioral models of programmable delay elements, PLL, loop filter, phase detector

With a traditional simulation approach, a cell-based netlist of the analog schematic is created. This netlist is integrated with the Verilog description of the digital design and can be simulated with a normal workstation. To use Palladium simulation, the (non-synthesizable) portions of the analog design that require fine resolution timing have to be replaced by digital timing representation. This modeling task is completed by using a combination of the existing Verilog cell library and the newly developed timed cells.

Loop Breaking

One of the chief characteristics of the timed cells is that they contain only combinational cells that propagate logic from inputs to outputs. Any feedback from a cell’s transitive fanout back to an input creates a combinational loop that must be broken to reach a steady state. Although the Palladium XP loop breaking algorithm works correctly, the timed cells provided a unique challenge that led to unpredictable results.  Thus, a process was developed to ensure predictable loop breaking behavior. The user input to the process was to provide a property at the loop origin that the netlister recognized and translated to the appropriate loop breaking directives.

Augmented Netlisting

Ease of use and flow automation were two primary considerations in creating a solution that could be deployed more broadly. That made creating a one-step netlisting process a high-value item. The signal point annotation and automatic hierarchy expansion of the “digital timing” parameter helped achieve that goal. The netlister was enriched to identify the key schematic annotations at any point in the hierarchy, including bit and bus signals.

Consistency checking and annotation reporting created a log useful in debugging and evolving the solution.

Wrapper Cell Modeling and Verification

The netlister generates a list of schematic instances at the designated “netlister stop level” for each instance the requires a Verilog model with fine resolution timing. For the design in this paper there were 160 such instances.

The library of timed cells was created; these cells were actually “wrapper” cells comprised of the primitives for timed cell modeling described above. A new verification flow was created that used the behavior of the primitive cells as a reference for the expected behavior of the composed cells. The testing of the composed cells included had the timing width parameter set to 1 to enable direct comparison to the primitive cells. The Cadence Incisive Enterprise Simullator tool was successfully employed to perform assertion-based verification of the composed cells versus the existing primitive cells.

Mapping and Long Paths

Initial experiments showed that inclusion of the fine resolution timed cells into the digital emulation environment would about double the required capacity per run. As previously pointed out, the timed cells having only combinational forward paths creates a loop issue. This fact also had the result of creating some such paths that were more than 5,000 steps of logic. A timed cell optimization process helped to solve this problem. The basic idea was to break the path up by adding flip-flops in strategic locations to reduce combinational path length. The reason that this is important is that the maximum achievable emulation speed is related to combinational path length.

Results

Once the flow was in place, and some realistic test cases were run through it, some further performance tuning opportunities were discovered to additionally reduce runtimes (e.g., Palladium XP tbrun mode was used to gain speed). The reference used for overall speed gains on this solution was versus a purely software-based solution on the highest performance workstation available.

The findings of the performance comparison were startlingly good:

• On Palladium XP, the simulation speed is 50X faster than on Advantest’s fastest workstation

• Software simulation running 25 days can now be run in 12 hours -> realistic runtime enables long-running tests that were not feasible before

• Now have 500 tests that execute once in more than 48 hours

• They can be run much more frequently using randomization and this will increase test coverage dramatically

Steve Carlson