CURRENT nanometer manufacturing processes suffer from larger defective parts ratio, partly due to numerous emerging defect types. Understanding Requirements Driven Architecture Evolution in Social Networking SaaS: An Industrial Case Study While traditional fault models, such as the stuck-at and transition delay fault models are still widely used, they have been shown to be inadequate to handle these new defects. Understanding Requirements Driven Architecture Evolution in Social Networking SaaS: An Industrial Case Study One possible solution to this problem is to develop complex fault models to imitate defect behavior at either the logic or layout level of abstraction. The combination of the Understanding Requirements Driven Architecture Evolution in Social Networking SaaS: An Industrial Case Study large number of possible defect types together with the huge number of fault sites in a modern circuit implies that modeling these defects will give prohibitively large input for a systematic test generation methodology Moreover, detailed layout information is typically not Understanding Requirements Driven Architecture Evolution in Social Networking SaaS: An Industrial Case Study available until the fabrication phase, giving limited information to test engineers. Instead, previous work proposed the use of test sets targeting each modeled fault multiple times in order to increase the probability of detecting additional fault types as well as the defect coverage Test sets detecting each fault with different tests are known as -detect test sets. Understanding Requirements Driven Architecture Evolution in Social Networking SaaS: An Industrial Case Study A variety of multiple detect or –detect test set generation methods and their impact in the quality of the testing process have been proposed Some of these methodologies propose approaches that use metrics obtained by the probabilistic distribution that random defects are expected to follow The works in use single-detect test sets that are manipulated appropriately in an incremental fashion until they reach the desired multiple detect fault coverage. Understanding Requirements Driven Architecture Evolution in Social Networking SaaS: An Industrial Case Study The goal of the methodologies in is to differentiate the tests that target the same fault by enforcing propagation to different outputs. Finally, the work in tries to embed the -detect test set on the chip in order to provide high quality online testing attributes to the circuit considered. In order to alleviate extensive increase of the test set size due to the multiple detections of each stuck-at fault, several methods for -detect test set compaction and optimization have been proposed. derived lower bounds on -detect test set size using an integer-linear programming ILP approach Understanding Requirements Driven Architecture Evolution in Social Networking SaaS: An Industrial Case Study, similar to those followed in Reference improved in the complexity of the test set size minimization using LP and uses the concept of logic implication to compact -detect test sets. Existing methodologies for -detect test generation and compaction produce tests that are fully specified all the test set bits have a fixed value of This occurs since many of these techniques try to fix unspecified don’t care bits to logic values such that the number of detected faults is increased. Actually, even if bit fixing does not improve on the -detect fault coverage, it can improve on the coverage of non-targeted faultsand defects even by randomly fixing the unspecified bits. As a result, many existing test generation tools return fully specified test sets. This, however, limits the applicability of –detect test sets in several currently important problems. For instance, methods for compression schemes for on-chip or off-chip testset embedding as well as in compact test generation for high defect coverage  can benefit when relaxed test setsare used.

A source mobility management scheme in content-centric networking

identifying the one having the sample with the highest amplitude extracted from sample of the DoM  the number of EM traces used, sample of associated EM trace and A source mobility management scheme in content-centric networking  the selection function returning the value of the targeted bit according to the PTI and the sub-key guess. A source mobility management scheme in content-centric networking According to if the sub-key guess is correct the right and left hand terms of correspond to the averaged traces A source mobility management scheme in content-centric networking characterized by an effective targeted bit value of respectively.

Thus, the difference of these terms shows a bounce as illustrated by Contrarily, A source mobility management scheme in content-centric networking if the sub-key guess is wrong, the left and right terms are undistinguishable and a smaller bounce appears. A source mobility management scheme in content-centric networking Indeed, the selection function_ fails in sorting traces according to the targeted bit and these terms are expected to be less incoherent than for the right guess. Considering this, one may compute, for each sub-key guess, the Global Magnitude Squared Incoherence between these two means curves. A source mobility management scheme in content-centric networking Then, rather than computing the DoM, one may compute the DoM weighted by the and search the sample with the highest amplitude DGMSI WITH DEMA AND CEMA Let us denote by DGMSI, a DEMA attack considering the four output bits of and performed using the proposed weighting strategy.

A source mobility management scheme in content-centric networkings

To evaluate its efficiency, we computed MTDwS and PRG cartographies using only rather than Tables IX and X give the results. As shown, a DGMSI performed with gave results quite similar to that of a DEMA performed with. One may conclude that DGMSI allows reducing by DEMA, the number of PTIs required to disclose the secret key. This demonstrates the interest of MSI to enhance EM analyses. One may wonder why DGMSI allows reducing MTDwS and increasing the PRG. Practically, the obtained enhancement is explained by the reduction of the set of key candidates during the key search by removing keys related to coherent means in the DoM. A source mobility management scheme in content-centric networking shows the DoM obtained with DGMSI and DEMA after the processing of the. As shown, the right key appears more clearly with DGMSI than for DEMA: the margin between the right and wrong keys is  times greater with DGMSI than with DEMA.

This is due to the low values of that flatten the DoM of wrong keys. In the previous section, the weighting strategy of DoM has been demonstrated efficient to reduce the number of EM traces required to disclose the secret key. However, during this experiment, we considered averaged EM traces. One may wonder if results hold in presence of noise. one shot EM traces, were thus acquired and processed using DEMA, CEMA and DGMSI. Note that successive attacks were done; each one differing from the other by the order considered to process data. Table gives the results. In this table, denotes the mean and the standard deviation obtained considering the processing orders. As shown, with one shot EM traces, DGMSI allows disclosing the right key with less PTI than with DEMA. A source mobility management scheme in content-centric networking Indeed, only of the traces are processed in average to reach for the first time the sequence of  successive right guesses of the full key with DGMSI while and are needed with DEMA and CEMA, respectively. Moreover the PRG of DGMSI is nearly twice the ones of DEMA and CEMA.

Note that the same PTI were processed at each position in the same order. Data acquisition achieved, WGMSI cartographies were computed considering two frequency bandwidths, and and EM traces corresponding A survey of Internet security risk over social networks IEEE Draft Standard for a Convergent Digital Home Network for Heterogeneous Technologies Amendment  Support of New MAC/PHYs and enhancements to the whole DES course IEEE Draft Standard for a Convergent Digital Home Network for Heterogeneous Technologies Amendment  Support of New MAC/PHYs and enhancements The first bandwidth is the full bandwidth of our acquisition chain, while the second one has been chosen to keep only the emissions of the P/G network according to Tables  and  give the WGMSI values in both cases after normalization done so that the maximum WGMSI value corresponds to and the minimum one to Note that black cells point out positions with WGMSI values lower than As shown, the DES and part of P/G rails in which flows its switching current generate data dependent EM emissions mainly in left side of the cartographies. In a second stage, DEMA and CEMA IEEE Draft Standard for a Convergent Digital Home Network for Heterogeneous Technologies Amendment  Support of New MAC/PHYs and enhancements, considering the Hamming IEEE Draft Standard for a Convergent Digital Home Network for Heterogeneous Technologies Amendment  Support of New MAC/PHYs and enhancements Distance Model were performed; both attacks targeted the last round of the Pearson’s correlation.The first criterion was the measurements to disclosure with stability  MTDwS adopted during the DPA contest Its evaluation resumes in detecting and storing, while the number of processed traces increases, the beginning of the first sequence of successive right guesses of the key. Tables IV and V show normalized MTDwS values forDEMAand CEMA. The normalization has been done so that a value means that of EM traces have been processed to reach the first sequence of successive right guesses. IEEE Draft Standard for a Convergent Digital Home Network for Heterogeneous Technologies Amendment  Support of New MAC/PHYs and enhancements Black cells indicate positions at which the MTDwS is greater than or positions at which the attack failed.Finally, the second criterion is the percentage of right guesses  PRG obtained after the processing of  traces. results. Black cells point out positions with a PRG value lower than Comparing these tables highlights of several results. First, indicate that the DES and part of the overall P/G network supplyingit are localized mainly on the left of the core as expected from the floorplan. show that WGMSI and MTDwS cartographies have similarities. Indeed, most positions with high MTDwS values are mainly on the right part of the cartographies as positions with low WGMSI values. IEEE Draft Standard for a Convergent Digital Home Network for Heterogeneous Technologies Amendment  Support of New MAC/PHYs and enhancements To better support this observation, correlations between WGMSI cartographies and, all other ones have been computed. gives the results. Note that to compute the correlations involving MTDwS, we considered MTDwS equal to BETWEEN WGMSI AND MTDWS, PRG VALUES DoM obtained positions where attacks were unsuccessful. As shown, there are correlations between these cartographies. This demonstrates the interest of WGMSI to localize hot spots. Note that higher correlation values are obtained for the frequency bandwidth According this means that the most leaking points are part of the P/G network. GLOBAL MAGNITUDE SQUARED INCOHERENCE If the above results have demonstrated the interest of the WGMSI, they also suggest using MSI to enhance DEMA. Attacking a DES sub-key by DEMA consists in computing DoM according to  and in .

A survey of Internet security risk over social networks

We that consider the signal as a reference whereis the number of frequency values at which the coefficients are computed, is the considered frequency bandwidth  is the power spectrum amplitude at the frequency WGMSI has values between A high value indicates that have perfectly incoherent spectra, while a low value indicates the contrary. Note that the second term of is a key term. Indeed, it weights values such that incoherent and high amplitude harmonics have more impact on the A survey of Internet security risk over social networks final WGMSI value than incoherent but low amplitude harmonics.

This reduces significantly the impact of noise.To illustrate these definitions, time domain EM traces were acquired during  different data processing of a DES. A survey of Internet security risk over social networks These traces see have been collected with a  diameter probe placed respectively above a DES and above a clock wire see As a result, one may expect that curves are data dependent traces while,waveforms are completely data independent. To validate this assumption, were computed. gives the  evolution with respect to frequency for both data dependent and fully data independent traces. As shown, the values obtained considering traces collected above some clock nets have, as expected, values closer to  A survey of Internet security risk over social networks over a wider frequency range than the values computed with traces collected above the DES, validating the above discussion.

A survey of Internet security risk over social networks

The obtained  values were gathered to compute theWGMSI coefficients. As expected, WGMSI values see Table corresponding to acquisitions above clock nets are two magnitude order lower than those acquired above the DES. A survey of Internet security risk over social networks Considering these results, one may assume that theWGMSIcriterion appears efficient to differentiate a data dependent behavior from a data independent one and may be used during a magnetic NFS to localize area with data dependent EM emissions expected to be hot spots for EM analysis. Coupling WGMSI and EM Near Field Scan Coupling WGMSI with NFS system to localize points characterized by data-dependent EM emissions is straightforward. The idea is to collect at each  coordinates above the IC at least two different time To validate the effectiveness of the WGMSI analysis, two kinds A survey of Internet security risk over social networks of validation were performed. One aimed at correlating the obtainedWGMSI cartographies with design floorplans while the second aimed at demonstrating that spots with the highest WGMSI values are good candidates for DEMA and CEMA. Results related to the first validation step being available inwe give here only the results related to the second validation step.

Note however, that the t validation step allowed us concluding A survey of Internet security risk over social networks that WGMSI technique is an efficient technique to localize a cryptographic system and its power/ground network, within noise. Note finally that both validation steps have been carried out with the experimental setup described in annex A and were performed considering a design mapped into a FPGA circuit and more precisely a Spartan board. The mapped design  integrated: a tocommunicate with the PC, a finite-state machine that manages the communications and the behavior of the chip and a DESTo evaluate the efficiency of WGMSI cartographies in disclosing hot spots for EMA, we scanned a area of the package centered on the Spartan core with a displacement step. The core size A survey of Internet security risk over social networks was estimated to be roughly of -ray photography, while the package has a size of each of the  resulting positions,  averaged traces  trials for each PTI were collected corresponding to the ciphering of  different PTI.

Popularity-based congestion control in named data networking

However, this would result, in collecting traces during  days at first order and with the setup presented in annex A. Popularity-based congestion control in named data networking This leads to the question: how efficiently and quickly position tiny probes  One may think, to solve this problem, by performing a EMnear field scan NFS to localize the cryptographic block. However this is often insufficient. As an illustration, shows a peak to peak cartography obtained with the setup introduced in annex A of the EM emissions measured at several coordinates above the FPGA package during a DES ciphering.  is an X-Ray photography of the package containing the circuit under attack.

Finally, discloses the floorplan of the circuit, running at and integrating a DES module,v Popularity-based congestion control in named data networking a finite-state machine and a interface for communication purpose. As shown, it appears impossible to correlate even if the die area is known thanks to the X-ray photography. It appears all the more difficult to localize the DES module and thus decide where to position the magnetic sensor to perform a successful focused DEMA or CEMA to avoid potential global hardware countermeasures. Basics of Global Magnitude Squared Incoherence DEMAexploits the data dependent behavior of theEMemissions radiated by Popularity-based congestion control in named data networkingcircuits during cryptographic operations. EM emissions are generated by flows of electrical charges through the wires connecting logic gates but also trough wires supplying the circuit  Since the switching of gates generates a current flow through the circuit interconnect, we may conclude that gates generate some data dependentEM emissions at different points above the circuit according to the power distribution network. These data dependent behaviors is exploited by statistical means to retrieve the secret key. Even if the timing and power characteristics of CMOS gates are known, it is difficult to deduce any characteristic about the EM emissions generated of actual IC due to the complexity of their power distribution grid.

Popularity-based congestion control in named data networkings

Thus, the only conclusion we may consider is that gates generate some EM perturbations, i.e., generate some data dependentharmonics Popularity-based congestion control in named data networkinglocated somewhere in the whole EM emission spectrum. Within this context, the proposed technique allows disclosing the data dependent behavior of EM emissions in the frequencydomain without making any assumption on the EM emission characteristics. It is based on spectral incoherence analysis of two time domain signals as detailed below. The only observation on which is based the method is: considering two successive hardware operations, we are sure that some gates switch during one computation and do not switch during the other, while some gates switch during both operations.

This leads to the following intuitive conclusion that guides the development of our proposal: Popularity-based congestion control in named data networking between two cryptographic operations some characteristics of the EM emissions remain constant coheren from one operation to another, while some characteristics completely change are incoherent Such a data dependent behavior is disclosed by the WGMSI technique. The magnitude squared coherence MSC between two signals is a real-valued function of frequency with values It is defined by where are the power spectral density of is the cross power spectral density of At a given frequency value of 1 indicates that the two spectra are exactly the same while, a value of  means that the spectra are different, i.e., incoherent. Alternatively, one may compute the Magnitude Squared Incoherence This criterion has also its values between  and  but indicates rigorously the contrary of Considering the whole spectra of two time domain signals, one may compute the WGMSI coefficients between them according to

Among side-channel attacks some exploit the timing behavior of IC while others exploit the power consumption or the EM emissions EMside channel efficiency is due to the inner properties ofEMemissions. Investigating Effects of Monetary Reward on Information Disclosure by Online Social Networks Users Their ability to propagate through different materials is the most striking one. Indeed, it allows attackers targeting the bounded hardware area integrating the crypto-module under attack or part of it. Investigating Effects of Monetary Reward on Information Disclosure by Online Social Networks Users This is all the more interesting because it allows getting round global hardware countermeasures against power analysis by focusing the analysis on reduced silicon die areas thanks to tiny probes. Investigating Effects of Monetary Reward on Information Disclosure by Online Social Networks Users Moreover, replacing the large probe of  by the tiny one shown allows dividing the number of EM traces required to disclose the key of standard iterative Data Encryption Standard DES mapped into a field-programmable gate array FPGA. However, this requires localizing beforehand the crypto-module that may occupy onlya small fraction of the device area Investigating Effects of Monetary Reward on Information Disclosure by Online Social Networks Users However, focusing EM attacks, using small sensors, requires localizing leaking spots to overcome the quadratic increase with the square  of package/probe sizes of the number of points to be attacked using either differential EM analyses DEMA or correlation EM analyses CEMA. Investigating Effects of Monetary Reward on Information Disclosure by Online Social Networks Users Within this context, the contribution of this paper is twofold. First, a localization technique based on spectral coherence analyses is introduced. It allows finding positions where EM attacks might be successful with a reduced set of traces. The technique, called weighted global magnitude squared incoherence WGMSI analysis, has several interesting properties. Investigating Effects of Monetary Reward on Information Disclosure by Online Social Networks Users First, it requires only few EM measurements to be efficiently applied. Investigating Effects of Monetary Reward on Information Disclosure by Online Social Networks Users Thirdly, this noninvasive and contactless technique can be applied even if the circuit under attack is encapsulated. The second contribution is a spectral coherence-based technique allowing performing successful DEMA with a reduced set of traces. This technique, which accelerates the convergence of DEMA based on difference of means  DoM  test, is denoted by differential global magnitude square incoherence DGMSI analysis afterward. This paper is organized as follows. Section II highlights the localization problem and gives details about the proposed localization technique.This section ends with experimental results demonstrating that WGMSI is efficient to localize the less robust positions against EMattacks. Section III highlights how Spectral Coherence can be furtherused to enhance DEMA based on DoM by reducing the number of traces to be collected and processed to disclose the secret key.Note that DoM is not the sole statistical test that can be used during an EM attack. Indeed there are many other tests; a classification of test is given in Conclusion is drawn in Section IV. WEIGHTED GLOBAL MAGNITUDE SQUARED INCOHERENCE Performing a DEMA, requires collecting a large number of traces. Itis thus time consuming even if the analysis is done at a single position above the device, with a large probe. The situation becomes unpractical when tiny sensors are used by an attacker or an evaluator aiming at demonstrating the robustness of a design against EM analyses.A. Problem Considering an iterative DES mapped onto an FPGA, one may plan collecting, at   positions above and around the Spartan core displacement step of EM traces, using a  diameter magnetic loop, to determine if EM emissions may be exploited or not.

As expected, the tones due to the  instruction cycle loop are no longer present in either spectrum. For further analysis, the synchronous and asynchronous were loaded with programs that exploit different classes  of instructions: Developing a cost-effective OpenFlow testbed for small-scale Software Defined Networking the rand program uses pseudo-random loop lengths, the add program exploits the ADD instruction, the logic program contains various Boolean instructions, the transfer program writes to the RAM, and the arithmetic program consists of multiply and increment instructions. The results of this experiment are shown in Developing a cost-effective OpenFlow testbed for small-scale Software Defined Networking As seen in this table, the differences in the measured substrate noise are not significantly different for different classes of instructions. The programs with the largest RMS noise are the transfer and the add programs and the program with the lowest RMS noise is the arithmetic program. This trend again suggests that the RAM is the most dominant block since the former program requires frequent memory accesses while the latter does not. SUBSTRATE NOISE EFFECTS ON A DSM Developing a cost-effective OpenFlow testbed for small-scale Software Defined Networking The analysis thus far has been exclusively focused on the measured waveform in the substrate.However, the ultimate goal of substrate noise analysis is to determine the detrimental effects of this noise to other circuitry. In this section, the effects of substrate noise on the signal-to-noise ratio SNR performance of a DSM is examined when the CBL  and NCL  are used as noise generators.Afully differential second-orderDSM, , was also included on the chip with the CBL and NCLfor this analysis. For this DSM, a sampling frequency was used with an OSR of The nominal DSM SNR with substrate noise from the synchronous clocked Developing a cost-effective OpenFlow testbed for small-scale Software Defined Networking close to the DSM sampling frequency. SNR of this delta-sigma was found to be for an input signal of. Measurement of the DSMwith the asynchronous  active showed no noticeable effect on the SNR performance. However, the same was not found to be true when the synchronous  was active. shows the nominal DSM spectrum and the spectrum when the CBL  is clocked at below the sampling frequency. As seen in this figure, there are a lot of noise tones in the passband of the DSM spectrum. These noise tones are apart which indicates that this noise is most likely aliasing noise. In order to verify this, a series of measurements was made with the DSM when the clock frequency was swept around the DSM sampling frequency. shows the measurement with the CBL clock swept above and below the sampling frequency. As seen in this plot, SNR degradation up to occurs for a narrow band around the DSMclock. In fact, the width of the dip in this SNR sweep is equal to twice the input band of the DSM. Noise outside of this band will also be aliased down, but since it will fall outside the input frequency band, it does not affect the DSM performance. One anomaly in this curve is when the CBL Developing a cost-effective OpenFlow testbed for small-scale Software Defined Networking  clock is exactly equal to the DSM sampling frequency. At this point, all of the aliasing noise wraps down to DC and can easily be removed, leaving the DSM SNR largely unaffected. This result is consistent with previously published work Since the degradation in SNR performance is due to aliasing, it was also confirmed that the behavior seen in was generally true whenever the noise frequency was close to integer multiples of the DSM sampling frequency. Developing a cost-effective OpenFlow testbed for small-scale Software Defined Networking

A networking perspective on self-organizing intersection management

Architectural Contribution to Substrate Noise Considering the numerous types of possible implementations for any given architecture, it would be very difficult to simply generalize the contribution of the architecture to the injected substrate noise. However, from a purely system level point of view, many large digital blocks A networking perspective on self-organizing intersection management tend to exhibit similar high level structures and flow of operation the main system-level blocks for the microprocessor are: the arithmetic logic unit  ALU, the datapath, the register file, and the RAM.

Although the substrate noise from any one of these blocks is not any more unique than the others, the order and timing of their operation creates noticeable frequency components in the substrate noise spectrum. This contribution can readily be seen where the frequency axis has been expand A networking perspective on self-organizing intersection management ed to show more resolution in the noise spectra from the. In the synchronous implementation, each instruction cycle is four clock cycles long. Since the processor will be performing similar tasks for each p A networking perspective on self-organizing intersection management ortion of this instruction cycle, a strong frequency component can be seen at a quarter of the clock frequency and its harmonics.

A networking perspective on self-organizing intersection managements

In the time domain, this instruction cycle is visible as slightly larger spikes A networking perspective on self-organizing intersection management for every fourth clock edge. Another architecture induced feature that is noticeable in the measurements are the memory accesses in the RAM. From the time-domain plot in the two large noise spikes seen in this portion of the measurement were determined to be caused by memory accesses. An expanded look at the time axis shows that these large spikes coincide with the instruction fetches from the RAM. Recall that the two  cores share a common block of memory. The reason the RAM was not implemented separately for the is because of the combinational nature of the memory circuit. Due to the relatively large size of the RAM itself compared to the it can be seen that the effect of thememory accesses are very pronounced in the substrate noise measurement. In fact, from the magnitude of these spikes, the RAM is the dominant noise source for. A networking perspective on self-organizing intersection management The presence of this larger, more synchronized source of noise in the reflects the smaller improvement seen in this experiment comparedto the PRNG case.

For the CBL, the corresponding memory accesses are embedded in the synchronous A networking perspective on self-organizing intersection management switchingof the microprocessor so it is not as discernable from the measurement.Software Contribution to Substrate Noise The second component of substrate noise that is often present in large digital blocks is the component caused by the software or the algorithm. Whereas the architectural contribution to the substrate noise will be present regardless of the function of the, the contribution due to software is more instantaneous in nature. The software induced noise for this experiment can be recognized by noticing that the PRNG program loaded in each processor is instruction cycles long. As the program is looping through this section of code, there will be an additional frequency component equivalent to the total run time of the loop. A networking perspective on self-organizing intersection management This is seen in both the CBL and NCL  spectra as small tones at and its harmonics. In order to verify that these tones are due to the software loop, the CBL and were loaded with an equivalent PRNG algorithm where the loop length is determined by the output of the pseudo-random sequence. shows the spectrum of the measured substrate noise using this program.

Observable differences in the time domain measurements were lower peak magnitudes and more dampening in the parasitic ringing of the substrate noise. Another technique that is commonly used to reduce substrate noise is through the application of guard rings. For this part of the experiment, the effectiveness of a die perimeter ring and a guard ring were explored. In the nominal case previous measurements both rings were left floating. The die perimeter ring is a ring that surrounds the periphery of the chip. Multi-user context inference based on neural networks The large effective area of this ring reduces the impedance between the substrate and ground. The guard ring, on the other hand, simply encloses all of the PRNGs. Its close proximity to the noise source provides a shunt path for noise currents injected into the substrate. the changes in the RMS voltages of the measured substrate noise when the die perimeter ring is grounded, when the guard ring is grounded, and when both are grounded. Multi-user context inference based on neural networks As seen in this figure,  a grounded guard ring reduces the substrate noise slightly more than the die perimeter ring. In general, a combination of both shows more improvement than either alone. MICROPROCESSOR CORES Although the PRNG blocks are useful to analyze the differences in the substrate noise injected by a synchronous and an asynchronous circuit, these blocks are in general not a goo measure of the substrate noise that would be present in a typical mixed-signal chip. A more practical comparison in terms Die photograph of the synchronous CBL and asynchronous NCL The die area of the respectively. of substrate noise can be found with a microprocessor. Multi-user context inference based on neural networks Microprocessors are commonly incorporated onto large mixed-signal chips as application specific functional blocks. In order to extend this analysis, another test chip was fabricated with a synchronous and an asynchronous version of a generic microprocessor. The die photo of the test chip is This chip was fabricated in a heavily-doped process and packaged in a. The respective die areas for the two microprocessor cores for the NCL. Aside from the two microprocessor cores, the designs share a program memory, Multi-user context inference based on neural networks a data memory, and an external memory interface for reading and writing from an off-chip source. The common components of the design are physically placed between the two cores to maintain layout symmetry for substrate noise comparisons between the CBL and NCL designs pins and peripherals have also been kept to a bare minimum to maintain the integrity of the substrate noise analysis. For this portion of the experiment, the  processors are loaded with a software equivalent of the pseudo random number algorithm used in the PRNGs. The is clocked at to obtain the equivalent operating speed of the NCL show the measured substrate noise from the two processors in the time and the frequency domains, respectively. Multi-user context inference based on neural networks From these measurements, the RMS substrate noise generated by the asynchronous design was found to be less than that generated by the synchronous design. As seen in these plots, the noisewaveforms and their corresponding spectra exhibit similar characteristics to those seen in the PRNG measurements. However, there are a number of additional features here that cannot be solely attributed to the noise mechanisms of synchronous and asynchronous circuits that were discussed earlier. Multi-user context inference based on neural networks Multi-user context inference based on neural networks In this section, further analysis of these measurements will demonstrate how the substrate noise from larger, more complex digital blocks also reflects the architectural implementation of the digital block and the software or algorithm that is used.

A Study of Contact Network Generation for Cyber-bullying Detection

The two observable differences here are the lower magnitudes and the difference in the shape of the envelope formed by the secondary noise tones. Since the shape of this envelope is caused by the resonant ringing due to system parasitics, this implies that the shape of the envelope should somewhat flatten and shift slightly higher frequencies for the COB measurements. a closer look at the ringing characteristics in the time domain. The waveforms seen here exhibit very similar characteristics with the noise waveforms for the high inductance package in As before, there is a smaller higher frequency ringing due to the capacitive coupling component and larger spikes due to the switching noise from the CBL PRNG. These components can be easily seen in the middle plot when the clock frequency is reduced to For the NCL plot on the bottom, the waveform actually looks very different than the one from In this case, there seems to be a much higher frequency ringing than before.

This observation appears to contradict our previous argument regarding the shape of the waveform since the operating speed of the NCL PRNG should not have changed so drastically when the package parasitics are reduced.The explanation for this difference lies in the assumption made above where the offset in switching times is a small fraction of the resonant period. This resonant period is equivalent to the resolution of the switching transitions seen in the time domain. A lower inductance package means that finer and more abrupt changes in the switching distribution will be visible in the substrate noise. Referring back to it can be seen that right after each switching peak, there is a slight dip in the number of transitions followed by a secondary peak.

A Study of Contact Network Generation for Cyber-bullying Detections

These secondary peaks are the sources of the additional ringing seen in the NCL PRNG time domain waveform of Comparison of the RMS value of the substrate noise in heavily and lightly doped substrates top synchronous PRNG, middle synchronous PRNG with a clock, and bottom asynchronous PRNG. C. Lightly Doped Substrate A technique often employed to reduce substrate noise coupling for SOC applications is a lightly doped process. The increased resistivity for the substrate in this process compared to the traditional heavily-doped substrate serves to attenuate and/or isolate the coupling to the analog circuits. Whereas a heavily doped substrate can be modeled with a single node approximation, physical separation becomes more of a factor for lightly doped substrates.

In order to quantify the improvement of the substrate noise of CBL and NCL circuits for this process, the equivalent PRNG chip was also fabricated in a lightly-doped process. a summary of the measured RMS value of the substrate noise for both the high inductance and low inductance cases for the two processes. The top plot compares the substrate noise for the heavily and lightly doped processes when the CBL PRNGs are clocked at the same equivalent operating speed as their respective NCL PRNGs. Note that for this process, the equivalent operating speed for the lightly doped NCL PRNG is As seen in the figure, the measured substrate noise in the high inductance package is slightly lower for the lightly doped chip. When both of the CBL PRNGswere clocked at a slightly larger improvement was seen. In the low inductance package, however, there is no noticeable improvement between the coupled noise in the two different substrates. This same trend was also found to be true for the NCL PRNGs.