An Intelligent Test Paper Generation Algorithm Based on Adjustment of Overall Difficulty Degrees

2013 ◽  
Vol 411-414 ◽  
pp. 2879-2882
Author(s):  
Gui Ying Han ◽  
Xi Zuo Li
Keyword(s):  
Success Rate ◽  
Test Paper ◽  
Intelligent Algorithm ◽  
Generation Algorithm ◽  
Online Examination ◽  
Long Time ◽  
Simulation Results

Intelligent test paper generation is an important factor for online examination systems, which determines whether the system can be used to effectively test the true levels of the testees. For the current algorithms of test paper generation that is low success rate, long time-consuming and the generated exam papers are difficult to meet actual demands, an intelligent algorithm of test paper generation is presented, that is based on adjusting of overall difficulty degrees of the test questions. According to the levels of difficulty degrees and the number of each type of questions required by the users, an appropriate number of questions for each level of the difficulty degree for the test paper is generated by the algorithm. Then, the corresponding questions are extracted randomly. Simulation results show that the intelligent test paper generation algorithm is faster, of good quality, the generated test papers can meet the actual demands.

scholarly journals Peering inside a cough or sneeze to explain enhanced airborne transmission under dry weather

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kai Liu ◽  
Majid Allahyari ◽  
Jorge S. Salinas ◽  
Nadim Zgheib ◽  
S. Balachandar
Keyword(s):  
High Fidelity ◽  
Substantial Variation ◽  
Ambient Conditions ◽  
Airborne Transmission ◽  
Social Distancing ◽  
Virtual Experiments ◽  
Long Time ◽  
Simulation Results ◽  
High Fidelity Simulations ◽  
Droplet Nuclei

AbstractHigh-fidelity simulations of coughs and sneezes that serve as virtual experiments are presented, and they offer an unprecedented opportunity to peer into the chaotic evolution of the resulting airborne droplet clouds. While larger droplets quickly fall-out of the cloud, smaller droplets evaporate rapidly. The non-volatiles remain airborne as droplet nuclei for a long time to be transported over long distances. The substantial variation observed between the different realizations has important social distancing implications, since probabilistic outlier-events do occur and may need to be taken into account when assessing the risk of contagion. Contrary to common expectations, we observe dry ambient conditions to increase by more than four times the number of airborne potentially virus-laden nuclei, as a result of reduced droplet fall-out through rapid evaporation. The simulation results are used to validate and calibrate a comprehensive multiphase theory, which is then used to predict the spread of airborne nuclei under a wide variety of ambient conditions.

Study of the Cause of Lost Circulation while Drilling Fractured Carbonates

2021 ◽  
Author(s):  
Alexey Ruzhnikov
Keyword(s):  
Success Rate ◽  
Drilling Fluid ◽  
Circulation Zone ◽  
Lost Circulation ◽  
Carbonate Formation ◽  
New Information ◽  
Fractured Carbonate ◽  
Long Time ◽  
The Difference ◽  
Fractured Carbonates

Abstract Fractured carbonate formations are prone to lost circulation, which affects the well construction process and has longtime effect on well integrity. Depending on the nature of losses (either induced or related to local dissolutions) the success rate is different when the induced losses can be cured with a high chance, and the one related to dissolutions may take a long time, and despite multiple attempts, the success rate is normally low. To have a better understanding of the complete losses across the fractured carbonates, a series of studies were initiated. First, to understand the strength of the loss zone, the fracture closing pressure was evaluated studying the fluid level in the annulus and back-calculating the effect of drilling fluid density. Second, the formation properties across the loss circulation zones were studied using microresistivity images, dip data, and imaging of fluid-saturated porous media. The results of the studies brought a lot of new information and explained some previous mysteries. The formation strength across the lost circulation zone was measured, and it was confirmed that it remains constant despite other changes of the well construction parameters. Additionally, it was confirmed that the carbonates are naturally highly fractured, having over 900 fractures along the wellbore. The loss circulation zone was characterized, and it was confirmed that the losses are not related to the fractures but rather to the karst, dissolution, and megafractures. The size and dip of the fractures were identified, and it was proven the possibility to treat them with conventional materials. However, the size of identified megafractures and karst zones exceeding the fractures by 10 times in true vertical depth, and in horizontal wells the difference is even higher due to measured depth. This new information helps to explain the previous unsuccessful attempts with the conventional lost circulation materials. The manuscript provides new information on the fractured carbonate formation characterization not available previously in the literature. It allows to align the subsurface and drilling visions regarding the nature of the losses and further develop the curing mechanisms.

Expressions for the effective diffusivity in materials with interphase boundaries

2004 ◽  
Vol 819 ◽  
Author(s):  
Irina V. Belova ◽  
Graeme E. Murch
Keyword(s):  
Polycrystalline Material ◽  
Effective Diffusivity ◽  
Poor Agreement ◽  
Two Phase ◽  
Interphase Boundaries ◽  
Long Time ◽  
Simulation Results ◽  
The Individual ◽  
Individual Grains ◽  
Good Agreement

AbstractWe address the problem of calculating the long-time-limit effective diffusivity in stable two- phase polycrystalline material. A phenomenological model is used where the high diffusivity interphase boundaries are treated as connected “coatings” of the individual grains. Derivation of expressions for the effective diffusivity with segregation is made along Maxwell lines. Monte Carlo simulation using lattice-based random walks is used to test the validity of the expressions. It is shown that for the case analysed the derived expressions for the effective diffusivity are in very good agreement with simulation results. The equivalent of the Hart equation is also derived. It is shown to be in poor agreement with simulation results.

Intelligent Generating Examination Paper from Item Bank Based on Improved Genetic Algorithm

2014 ◽  
Vol 926-930 ◽  
pp. 3637-3640
Author(s):  
Li Feng ◽  
Qian Wu ◽  
Jing Shao Zhang
Keyword(s):  
Genetic Algorithm ◽  
Mathematical Model ◽  
Computational Study ◽  
Item Bank ◽  
Test Paper ◽  
Improved Genetic Algorithm ◽  
Fitness Evaluation ◽  
Simulation Results ◽  
The Mathematical Model ◽  
Examination Paper

In this paper, we analyze the disadvantage of common generating test paper algorithm. An improved genetic algorithm (IGA) is proposed and used in auto-generating examination paper algorithm. We design the mathematical model of auto-generating test paper algorithm and improved the traditional GA fitness evaluation form. A computational study is carried out to verify the algorithm. Simulation results demonstrate that the performance of IGA can work efficiently than traditional ones.

Strategy and Applied Research of Multi-Constrained Model of Automatic Test Paper Based on Genetic Algorithm

2010 ◽  
Vol 37-38 ◽  
pp. 1223-1230 ◽  
Author(s):  
Zhi Feng Liu ◽  
Ji Shi ◽  
Jia Liu ◽  
Yang Li
Keyword(s):  
Genetic Algorithm ◽  
Optimization Problem ◽  
Applied Research ◽  
Genetic Manipulation ◽  
Initial Population ◽  
Test Paper ◽  
Examination System ◽  
Automatic Test ◽  
Online Examination ◽  
Constrained Model

Test paper problem is a typical multi-constrained objective optimization problem. By using genetic algorithm, this paper analyzes the initial population generation, the chromosome coding and its genetic manipulation, control parameters. Solving that by natural-coded genetic algorithm, improves test paper success rate and convergence rate. This genetic algorithm is applied successfully on NHibernate architecture, and developed "automatic test paper" Online Examination system.

Research on Statistics Based Multi-Priority MAC Protocol for Ad Hoc Networks

2014 ◽  
Vol 644-650 ◽  
pp. 3103-3107
Author(s):  
Peng Wang ◽  
Hai Li ◽  
Ben Li Ye ◽  
Chen Chen ◽  
Yu Bao Wang
Keyword(s):  
Ad Hoc Networks ◽  
Success Rate ◽  
Ad Hoc ◽  
Mac Protocol ◽  
Medium Access ◽  
Critical Data ◽  
Low Delay ◽  
Simulation Results ◽  
Hoc Networks ◽  
Application Diversification

With the growing application diversification in Ad Hoc networks, it is particularly important to support prioritization of traffic and ensure that critical data can be delivered more reliably and faster in an emergency scene. We mainly study on the improvement of statistics based multi-priority medium access control (MAC) protocol, including the channel occupancy statistic and the backoff mechanism. We conduct comprehensive simulations based on the OPNET Modeler and account for the success rate results with theoretical analysis. The simulation results show that the proposed algorithm can simultaneously guarantee high success rate and low delay for high-priority packets.

An Efficient Search Scheme in Unstructured Peer-to-Peer Networks

2011 ◽  
Vol 211-212 ◽  
pp. 295-299 ◽  
Author(s):  
Ya Dong Gong ◽  
He Ping Deng ◽  
Zhan Ran Gu ◽  
Ji Ye Hu ◽  
Yong Xiang Wen
Keyword(s):  
Success Rate ◽  
System Performance ◽  
Peer To Peer ◽  
Query Answering ◽  
Peer Networks ◽  
Search Efficiency ◽  
P2p Networks ◽  
Peer To Peer Networks ◽  
High Bandwidth ◽  
Simulation Results

In peer-to-peer (P2P) networks, nodes are quite different from each other in many aspects, such as sharing resources, online time and bandwidth. Some approaches have been introduced to take advantage of the query forwarding and answering heterogeneity such that the high bandwidth and query answering capability of nodes can be fully utilized to improve the system performance. In this paper, we suggest using the online time heterogeneity to improve the search efficiency of P2P networks. In our proposed Differentiated Index (Diff-Index) algorithm, the nodes with long online time will have higher priority to be queried. Because the online time is quite different among nodes, much search traffic can be saved by querying only a small portion of a network. The query success rate can be kept high because the nodes sharing a great amount of resources tend to have long online time. Our simulation results show that the Diff-Index algorithm can save 66 percent of search traffic.

scholarly journals Reference Current Generation for Active Power Filtering in Single-Phase Power System

2021 ◽  
Vol 2120 (1) ◽  
pp. 012024
Author(s):  
Siew Ting Chew ◽  
Yap Hoon ◽  
Hafisoh Ahmad
Keyword(s):  
Steady State ◽  
Power System ◽  
Power Factor ◽  
Single Phase ◽  
Active Power ◽  
Dynamic State ◽  
Current Generation ◽  
Generation Algorithm ◽  
Reference Current Generation ◽  
Simulation Results

Abstract The study presents a new proposed reference current generation algorithm based on the synchronous reference frame (SRF) conventional algorithm in single-phase power system for an active power filtering. Shunt active power filter (SAPF) is often used as it can mitigate harmonic currents in the AC networks due to its superiority in dynamic-state conditions. The reference current generation algorithm is the most important control algorithms to control SAPF as it has the simplest implementation features. A proposed STF-based fundamental component identifier (STF-FCI) algorithm is implemented for the major improvements such as the removal of the unnecessary cosine function to reduce complexity of algorithm, employment of self-tuning filter (STF) to extract accurate fundamental component and to generate a sinusoidal reference current. The purpose of developing STF-FCI algorithm is to replace low pass filter (LPF) with a mean as it can generate a fast and accurate fundamental reference current to operate the SAPF in reducing the harmonics content of the power system and provide a fast response time in the dynamic-state conditions. This paper is presented under both steady-state which is capacitive (RC) load or inductive (RL) load as well as dynamic condition where capacitive load change to inductive load. The performance of steady-state condition will be evaluated in terms of THD values, ripple factor, power factor and phase difference. Under dynamic-state condition, the dynamic speed will be evaluated to capture the speed of the amplitude change in nonlinear load in a period of time. MATLAB-Simulink is used to design and evaluate the proposed STF-FCI algorithm with mean algorithm and LPF algorithm for comparison purpose. The simulation results had shown the major improvement when THD values, ripple factor, power factor and phase difference are reduced. The response time of the changing load is shorter by using mean algorithm compare to LPF algorithm. The simulation results obtained proved success when the proposed STF-FCI algorithm using mean algorithm are much better than LPF algorithm in steady-state and dynamic conditions under two voltage conditions i.e. ideal and distorted voltage.

scholarly journals Breaking CAS-Lock and Its Variants by Exploiting Structural Traces

2021 ◽  
pp. 418-440
Author(s):  
Abhrajit Sengupta ◽  
Nimisha Limaye ◽  
Ozgur Sinanoglu
Keyword(s):  
Intellectual Property ◽  
Success Rate ◽  
Turning Point ◽  
Boolean Satisfiability ◽  
Point Function ◽  
Extensive Simulation ◽  
Logic Locking ◽  
Simulation Results ◽  
The Cost ◽  
Intellectual Property Theft

Logic locking is a prominent solution to protect against design intellectual property theft. However, there has been a decade-long cat-and-mouse game between defenses and attacks. A turning point in logic locking was the development of miterbased Boolean satisfiability (SAT) attack that steered the research in the direction of developing SAT-resilient schemes. These schemes, however achieved SAT resilience at the cost of low output corruption. Recently, cascaded locking (CAS-Lock) [SXTF20a] was proposed that provides non-trivial output corruption all-the-while maintaining resilience to the SAT attack. Regardless of the theoretical properties, we revisit some of the assumptions made about its implementation, especially about security-unaware synthesis tools, and subsequently expose a set of structural vulnerabilities that can be exploited to break these schemes. We propose our attacks on baseline CAS-Lock as well as mirrored CAS (M-CAS), an improved version of CAS-Lock. We furnish extensive simulation results of our attacks on ISCAS’85 and ITC’99 benchmarks, where we show that CAS-Lock/M-CAS can be broken with ∼94% success rate. Further, we open-source all implementation scripts, locked circuits, and attack scripts for the community. Finally, we discuss the pitfalls of point function-based locking techniques including Anti-SAT [XS18] and Stripped Functionality Logic Locking(SFLL-HD) [YSN+17], which suffer from similar implementation issues.

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