Loop Handling Research Articles

UAF-GUARD: Defending the use-after-free exploits via fine-grained memory permission management

The defense of Use-After-Free (UAF) exploits generally could be guaranteed via static or dynamic analysis, however, both of which are restricted to intrinsic deficiency. The static analysis has limitations in loop handling, optimization of memory representation and constructing a satisfactory test input to cover all execution paths. While the lack of maintenance of pointer information in dynamic analysis may lead to defects that cannot accurately identify the relationship between pointers and memory. In order to successfully exploit a UAF vulnerability, attackers need to reference freed memory. However, main existing schemes barely defend all types of UAF exploits because of the incomplete check of pointers. To solve this problem, we propose UAF-GUARD to defend against the UAF exploits via fine-grained memory permission management. Specially, we design two key data structures to enable the fine-grained memory permission management to support efficient relationship search for pointers and memory, which is the key design of our defending scheme against UAF exploits. In addition, UAF-GUARD can precisely locate the position of UAF vulnerabilities, so that malicious programs can be terminated in the place where the abnormality is discovered. We implement UAF-GUARD on a 64-bit Linux system, and further use UAF-GUARD to transform a program into a suitable version that can defend against UAF vulnerabilities exploits. Compared with main existing schemes UAF-GUARD is able to effectively and efficiently defend against all the three types of UAF exploits with acceptable space overhead (26.4% for small programs and 0.3% for large programs) and time complexity (21.9%).

Fighter Aircraft Closed Loop Handling Quality Simulation on Lateral-Directional Modes

Fighter Aircraft Closed Loop Handling Quality Simulation on Lateral-Directional Modes

La-CTP: Loop-Aware Routing for Energy-Harvesting Wireless Sensor Networks.

In emerging energy-harvesting wireless sensor networks (EH-WSN), the sensor nodes can harvest environmental energy to drive their operation, releasing the user’s burden in terms of frequent battery replacement, and even enabling perpetual sensing systems. In EH-WSN applications, usually, the node in energy-harvesting or recharging state has to stop working until it completes the energy replenishment. However, such temporary departures of recharging nodes severely impact the packet routing, and one immediate result is the routing loop problem. Controlling loops in connectivity-intermittent EH-WSN in an efficient way is a big challenge in practice, and so far, users still lack of effective and practicable routing protocols with loop handling. Based on the Collection Tree Protocol (CTP) widely used in traditional wireless sensor networks, this paper proposes a loop-aware routing protocol for real-world EH-WSNs, called La-CTP, which involves a new parent updating metric and a proactive, adaptive beaconing scheme to effectively suppress the occurrence of loops and unlock unavoidable loops, respectively. We constructed a 100-node testbed to evaluate La-CTP, and the experimental results showed its efficacy and efficiency.

Translating Algorithms to Handle Fully Homomorphic Encrypted Data on the Cloud

Cloud provides large shared resources where users (or foundations) can enjoy the facility of storing data or executing applications. In spite of gaining convenience of large resources, storing critical data in cloud is not secured. Hence, cloud security is an important issue to make cloud useful at the enterprise level. Data encryption is a primary solution for providing confidentiality to sensitive data. However, processing of encrypted data requires extra overhead, since repeated encryption-decryption need to be performed for every simple processing on encrypted data. Hence, direct processing on encrypted cloud data is advantageous, which is supported by homomorphic encryption schemes. Fully Homomorphic Encryption (FHE) provides a method of performing arbitrary operations directly on encrypted data. This seemingly magical idea is a welcome to cloud computing. However, there are several challenges to overcome for making the technology viable in practical applications. In this paper, we make an initial effort to highlight the problem of translating algorithms that can run on unencrypted or normal data to those which operate on encrypted data. Here, we show that although FHE provides the ability to perform arbitrary computations, its complete benefit can only be obtained if they also allow to execute arbitrary algorithms on encrypted data. In this pursuit, we provide techniques to translate basic operators (like bitwise, arithmetic and relational operators), which are used for implementation of algorithms in any high level language like C. Subsequently, we address decision making and loop handling and related data structures which are vital to realize when the controlling variables are encrypted. Since, termination is a major challenge while handling encrypted data, we propose a method of handling termination by message passing between server and client.

Root Cause Diagnosis of Process Fault Using KPCA and Bayesian Network

This paper develops a methodology to combine diagnostic information from various fault detection and isolation tools to diagnose the true root cause of an abnormal event in industrial processes. Limited diagnostic information from kernel principal component analysis, other online fault detection and diagnostic tools, and process knowledge were combined through Bayesian belief network. The proposed methodology will enable an operator to diagnose the root cause of the abnormality. Further, some challenges on application of Bayesian network on process fault diagnosis such as network connection determination, estimation of conditional probabilities, and cyclic loop handling were addressed. The proposed methodology was applied to Fluid Catalytic Cracking unit and Tennessee Eastman Chemical Process. In both cases, the proposed approach showed a good capability of diagnosing the root cause of abnormal conditions.

Analysis funerary ceramics of the Plotnikovo burial ground (on the basis of the excavation 2007-2015)

The article analyzes the pottery Plotnikovo burial ground,which belongs to theRodanovskayaculture.Material culture this time has not been well studied.Finds discovered during the excavations,it was quite diverse.Jewelry, weapon, tools and household items represent it. Some things are similar to the materials of the Russian North, the Volzhskaya Bulgaria and Perm Vychegodskaya. The study was conducted typological and technological analysis of the fragments of52vessels.For the site is characterized by proliferation of cup-shaped vessel with a flattened bottom and a loop handle,weak ornamentation dishes with the prevalence of the use of a comb stamp for applying the patterns,the use of clay in the wet state with the addition of crushed shells in the molding composition.A comparison with ceramic complexes chronologically simultaneous sites Vymskaya and Chepetskaya culture revealed both similarities and differences. These differences indicate the presence of its own tradition of producing ceramics in funerary XIIXV centuries of the population, left the Plotnikovo burial ground. The study material of the Plotnikovo burial ground is great interest to address the issues of ethno genesis Permian Komis and clarify the chronology of late stage rodanovskaya culture.

Nodal control of grass trimmer handle vibration

Imposing node technique is applied to the grass trimmer shaft in order to achieve very low vibration (node) at the handle location. The optimum tuning frequencies of the two tuned vibration absorbers (TVAs) attached at 0.74L and 0.85L along the shaft of the grass trimmer are determined using the imposing node technique. Transverse deflection, experimental modal analysis and operating deflection shape analysis of the grass trimmer were carried out, and the results indicated that nearly zero deflection (node) was induced at the position very close the loop handle location. Moreover, the vibration along the segment of the shaft (0.70L–0.94L) was also found to have relatively small amplitude. The TVAs were found to have best performance with 71% reduction on the frequency weighted rms acceleration at the loop handle and 72% for the rear handle. The results from the experimental modal analysis and operating deflection shape revealed that the presence of the two TVAs has successfully reduced the large deformations of the loop and rear handle where the node was shifted nearer to the handle location. The effects of TVAs were also evaluated during the field test involving grass trimming operation and subjective rating. The results indicated that average reduction of frequency-weighted rms acceleration was by 25%, 69%, 17%, 58% in Xh-, Yh-, Zh- axes and vibration total value respectively during the cutting operation. From the field test, subjective rating of vibration perception consistently rate better for the controlled grass trimmer. Relevance to industryLarge numbers of workers are employed to perform grass trimming job in maintenance of parks and areas with undergrowth. This paper presents the imposing node technique to control handle vibration to the lowest value.

A biomechanical and subjective assessment and comparison of three ambulance cot design configurations

Effects of ambulance cot design features (handle design and leg folding mechanism) were evaluated. Experienced ambulance workers performed tasks simulating loading and unloading a cot to and from an ambulance, and a cot raising task. Muscle activity, ratings of perceived exertion, and performance style were significantly affected by cot condition (p < 0.05). Erector Spinae activity was significantly less when using Cot-2's stretcher-style handles. Shoulder muscle activity was significantly less when using Cot-2's loop handle. During loading and unloading, operators allowed the cot to support its own weight most often with Cot-2's stretcher-style handles. Preference for Cot-2 (either handles) over Cot-1 (with loop handle) was consistent across tasks. Handle effects were influenced by operator stature; taller participants received more benefit from Cot-2's stretcher-style handles; shoulder muscles’ demands were greater for shorter participants due to handle location. Providing handle options and automatic leg folding/unfolding operation can reduce cot operator's effort and physical strain. Practitioner Summary: Paramedics frequently incur musculoskeletal injuries associated with patient-handling tasks. A controlled experiment was conducted to assess effects of ambulance cot design features on physical stress of operators, as seen through muscle activity and operator's perceptions. Differences between cots were found, signalling that intentional design can reduce operator's physical stress.

Influence of accuracy constraints on bimanual coordination during a goal-directed task in children with hemiplegic cerebral palsy

Previously we found that children with hemiplegic cerebral palsy (CP) have impaired bimanual coordination compared to typically developing children during a functional drawer-opening task. However, performance of the task under time constraints (fast-as-possible) facilitated better bimanual coordination for these children. Accuracy is another important task constraint that could influence the coordination of the two hands during such tasks. The effect of accuracy constraints on bimanual coordination in children with hemiplegic CP is not well understood. In the present study, children were asked to reach forward and open a drawer with one hand and then activate a light switch inside the drawer with the contralateral hand. Task accuracy constraints (different handles and switch sizes) were manipulated in order to determine their effect on upper extremity coordination. Eleven children with hemiplegic CP (age 8-16 years) and eleven age-matched typically developing children participated in this study. The results show that higher accuracy constraints prolong the total movement completion time for both groups of children. However, children with hemiplegic CP demonstrated less sequential movement with a higher accuracy constraint (a smaller knob handle) than a lower accuracy constraint (a larger loop handle). Nevertheless, presentation of both higher accuracy constraints (handle and switch) at the same time was detrimental to their performance. These influences of task constraints were similar regardless of which hand was used to open the drawer. The results suggest that performance may not be linearly related to the constraints, and in some cases "more is not better".

Focus on software

Focus on software

Scheduling for improving productivity of the automated manufacturing system

In this paper jobshop scheduling problem was considered on automated manufacturing systems with the closed loop and unidirectional material handling system. The objective of this research is to develop and evaluate heuristic scheduling procedures to improve productivity by minimizing makespan. Especially travel time of material handling system as well as processing time was considered in the proposed alogorithm. The heiristic algorithms are implemented for various cases. The results show that the proposal algorithms provide better solutions in productivity, frequency, job waiting time and the number of waiting jobs than the random scheduling algorithm.

Offsetting 3D Contours on Parametric Surfaces

Offsetting 3D contours on parametric surfaces is used in various design and manufacturing purposes such as shrinking and expanding trimmed surfaces, tolerancing and NC machining. The approach presented in this paper is coordinate-reference independent and allows the iterative calculation of interference-free 3D offset contours. The main elements in this approach are the iterative offset of parametric segments, their trimming and connection, and the handling of loops. The preliminary offsetting is achieved in the Cartesian domain associated with the surface. The interferences are then handled in parametric space.

The dynamic domain reduction procedure for test data generation

Test data generation is one of the most technically challenging steps of testing software, but most commercial systems currently incorporate very little automation for this step. This paper presents results from a project that is trying to find ways to incorporate test data generation into practical test processes. The results include a new procedure for automatically generating test data that incorporates ideas from symbolic evaluation, constraint-based testing, and dynamic test data generation. It takes an initial set of values for each input, and dynamically ‘pushes’ the values through the control-flow graph of the program, modifying the sets of values as branches in the program are taken. The result is usually a set of values for each input parameter that has the property that any choice from the sets will cause the path to be traversed. This procedure uses new analysis techniques, offers improvements over previous research results in constraint-based testing, and combines several steps into one coherent process. The dynamic nature of this procedure yields several benefits. Moving through the control flow graph dynamically allows path constraints to be resolved immediately, which is more efficient both in space and time, and more often successful than constraint-based testing. This new procedure also incorporates an intelligent search technique based on bisection. The dynamic nature of this procedure also allows certain improvements to be made in the handling of arrays, loops, and expressions; language features that are traditionally difficult to handle in test data generation systems. The paper presents the test data generation procedure, examples to explain the working of the procedure, and results from a proof-of-concept implementation. Copyright © 1999 John Wiley & Sons, Ltd.

Qualitative analysis of physical and mathematical approximations necessary for induced radioactivity calculations in fusion devices

When engineers and designers of fusion research and power reactors require information related to the induced radioactivity in the first wall, blanket and shield, they turn to one of many codes to generate a solution. Unfortunately, these codes all make physical and mathematical approximations in order to turn a functionally infinite and highly complicated problem into a more manageable, simple problem. This paper examines these approximations, namely, the handling of loops in the decay scheme, the truncation of the decay scheme, and the modeling of pulsed/intermittent operation histories, as physical approximations and the choice of a solution method as a mathematical approximation. The final recommendation is a code that uses an exact representation of the pulsing history, handles loops by unraveling, truncates the decay schemes with a relative sub-tree production rule modified by a stable truncation restriction and uses an adaptively chosen analytical or Laplace inverse mathematical solution method.

Avoiding recomputation in linkage analysis.

We describe four improvements we have implemented in a version of the genetic linkage analysis programs in the LINKAGE package: subdivision of recombination classes, better handling of loops, better coordination between the optimization and output routines, and a checkpointing facility. The unifying theme for all the improvements is to store a small amount of data to avoid expensive recomputation of known results. The subdivision of recombination classes improves on a method of Lathrop and Lalouel [Am J Hum Genet 1988;42:498-505]. The new method of handling loops extends a proposal of Lange and Elston [Hum Hered 1975;25:95-105] for loopless pedigrees with multiple nuclear families at the earliest generation. From a practical point of view, the most important improvement may be the checkpointing facility which allows the user to carry out linkage computations that are much longer than the mean-time-to-failure of the underlying computer.

Automated Josephson integrated circuit test system

An automated test system for complex superconductive integrated circuits has been developed. Its low-speed capability consists of 96 identical input/output (I/O) channels controlled by a PC-486 computer. Each channel is capable of driving currents and reading voltages at frequencies up to 40 kHz. Integrating this low-speed I/O capability with high-speed test equipment controlled over the IEEE bus allows measurements at frequencies up to the limits of the test equipment. The system can automatically set biases, display I-V curves, measure parameter margins, plot threshold curves, extract experimental circuit values, and collect statistical data on parameter spreads and error rates. Issues of noise suppression, ground loop handling, and autocalibration are discussed. >

Flexible robot models with revolute and prismatic joints — Handling of closed loops

Modele mathematique d'un robot avec des articulations prismatiques et des articulations de revolution en tenant compte des deformations elastiques. Cas d'un mecanisme en boucle fermee

A micro-processor interfaced 1 MBIT bubble memory

Compact solid-state read-write memories with non-volatility are much desired for micro-processor applications. 1) Recently, we have realized a very compact and convenient 1Mbit bubble memory board, using newly developed controller LSI (BMC: Bubble Memory Controller) and high density 256 kbit bubble memory chips (8μ period). The memory board is only 18cm × 15cm size and activated by a single power source of +5V. An outstanding feature of this memory is a perfect protection of memory contents against power supply accidents (+5V, open or short) . This protection is realized using a new method by BMC and a peripheral circuit on the board. Another feature is a new automatic handling of defect loops in the bubble memory chips. A defect loop map is stored in the special page address of bubble chip itself and BMC reads this map and stores it into an internal RAM of BMC, when power switch is turned on. Using this information, BMC masks the defect loop automatically. The compactness of this board originates from the realization of BMC-LSI ( n-Mos ) . BMC contains about 15k transistors and controls the bubble chip using the data of 6 kbit internal ROM. Present memory can be connected directly to bus lines of micro-processor 6800 series and 8080 series. A 256 kbit bubble chip employs a block-replicator and even-odd organization and is composed of 280 minor loops with 1135 positions. Its high density (8μ period) was achieved by the introduction of a new planer process using PIQ resins. The performances of this memory board will be described.

Current Techniques of Adjustable Strabismus Surgery

Adjustable strabismus surgical procedures provide the opportunity to reposition a surgically altered muscle position, which is often necessary for nonaverage cases of strabismus correction. The usual surgical procedure is extended into the postoperative period (same hospitalization) so that the surgeon may satisfactorily monitor the total end result (by cover test and rotations) at the time of adjustment. Adjustable techniques should be considered whenever a desired goal is unlikely to be reached in one surgical session. Recent technical improvements allow satisfactory globe position control during the adjustment stage for ease of recession or resection adjustment. Globe stabilization is attained during surgery and the postoperative adjustment by means of a scleral loop handle, placed near the corneoscleral limbus. Millimeters of adjustment are easily estimated by means of a sliding suture knot technique.