Achieved Accuracy Levels Research Articles

Procedural complexity underlies the efficiency advantage in abacus-based arithmetic development

The abacus is a counting frame designed to facilitate the process of arithmetic calculation. This paper focusses particularly on the Japanese ‘soroban’ abacus, examining the role of complementary numbers in its operation. We propose that the combination of quinary (base five) and decimal (base ten) systems, and the consequent use of complementary numbers (CN) in calculation, are transferred from physical to mental procedures. The more CN steps involved in a calculation, the more time it should take for mental abacus users to complete. This hypothesis was tested in Experiment 1: 146 Taiwanese abacus users aged 3–15, identified as either abacus learners (n=126) or abacus experts (n=20), were given parallel sets of serial addition and subtraction problems, matched on conventional metrics of difficulty level, but differing in the number of CN steps entailed in abacus calculation. An effect of CN was found whereby response times were significantly greater for the condition involving double CN steps. Experts were significantly faster than learners, but the effect of CN did not differ between groups. In Experiment 2, in order to test the specificity of the CN effect, a group of British children (n=20), with no experience of the abacus, was given the same mental calculation tasks. They achieved accuracy levels equivalent to the abacus experts, but their calculation speed was very much slower, and they showed no evidence of the CN effect.Our findings demonstrate the importance of complementary numbers in children’s mental abacus calculation. We found the CN effect to be equally strong in expert and non-expert users, and confirmed the specificity of the effect by showing it to be absent in participants not exposed to abacus use. We argue that the use of complementary numbers in mental abacus calculation provides learners, from the outset, with exposure to a dual-base system which, while procedurally complex, affords a representational advantage not enjoyed by learners working within the exclusively decimal system of Arabic numerals.

Polymorphic malware detection using sequence classification methods and ensembles

Identifying malicious software executables is made difficult by the constant adaptations introduced by miscreants in order to evade detection by antivirus software. Such changes are akin to mutations in biological sequences. Recently, high-throughput methods for gene sequence classification have been developed by the bioinformatics and computational biology communities. In this paper, we apply methods designed for gene sequencing to detect malware in a manner robust to attacker adaptations. Whereas most gene classification tools are optimized for and restricted to an alphabet of four letters (nucleic acids), we have selected the Strand gene sequence classifier for malware classification. Strand’s design can easily accommodate unstructured data with any alphabet, including source code or compiled machine code. To demonstrate that gene sequence classification tools are suitable for classifying malware, we apply Strand to approximately 500 GB of malware data provided by the Kaggle Microsoft Malware Classification Challenge (BIG 2015) used for predicting nine classes of polymorphic malware. Experiments show that, with minimal adaptation, the method achieves accuracy levels well above 95% requiring only a fraction of the training times used by the winning team’s method.

Road condition assessment by OBIA and feature selection techniques using very high-resolution WorldView-2 imagery

Accurate information on the conditions of road asphalt is necessary for economic development and transportation management. In this study, object-based image analysis (OBIA) rule-sets are proposed based on feature selection technique to extract road asphalt conditions (good and poor) using WorldView-2 (WV-2) satellite data. Different feature selection techniques, including support vector machine (SVM), random forest (RF) and chi-square (CHI) are evaluated to indicate the most effective algorithm to identify the best set of OBIA attributes (spatial, spectral, textural and colour). The chi-square algorithm outperformed SVM and RF techniques. The classification result based on CHI algorithm achieved an overall accuracy of 83.19% for the training image (first site). Furthermore, the proposed model was used to examine its performance in different areas; and it achieved accuracy levels of 83.44, 87.80 and 80.26% for the different selected areas. Therefore, the selected method can be potentially useful for detecting road conditions based on WV-2 images.

Computer-aided cephalometric landmark annotation for CBCT data.

Nowadays, with the increased diffusion of Cone Beam Computerized Tomography (CBCT) scanners in dental and maxillo-facial practice, 3D cephalometric analysis is emerging. Maxillofacial surgeons and dentists make wide use of cephalometric analysis in diagnosis, surgery and treatment planning. Accuracy and repeatability of the manual approach, the most common approach in clinical practice, are limited by intra- and inter-subject variability in landmark identification. So, we propose a computer-aided landmark annotation approach that estimates the three-dimensional (3D) positions of 21 selected landmarks. The procedure involves an adaptive cluster-based segmentation of bone tissues followed by an intensity-based registration of an annotated reference volume onto a patient Cone Beam CT (CBCT) head volume. The outcomes of the annotation process are presented to the clinician as a 3D surface of the patient skull with the estimate landmark displayed on it. Moreover, each landmark is centered into a spherical confidence region that can help the clinician in a subsequent manual refinement of the annotation. The algorithm was validated onto 18 CBCT images. Automatic segmentation shows a high accuracy level with no significant difference between automatically and manually determined threshold values. The overall median value of the localization error was equal to 1.99 mm with an interquartile range (IQR) of 1.22-2.89 mm. The obtained results are promising, segmentation was proved to be very robust and the achieved accuracy level in landmark annotation was acceptable for most of landmarks and comparable with other available methods.

Comparing Compact and Quadrature Polarimetric SAR Performance

The respective classification accuracy levels of compact and quadrature polarimetric synthetic aperture radars (SARs) are compared through results reported in the literature. Classification methodologies are critiqued. A faulty methodology compromises many of those studies. An appropriate methodology leads to trustworthy results. When correctly implemented, classifications from hybrid dual-polarimetric data achieve accuracy levels comparable to those from a quadrature-polarized SAR, to within a few percent.

Advanced Train Location Simulator (ATLAS) for developing, testing and validating on-board railway location systems

This article focuses on a novel Advanced Train LocAtion Simulator (ATLAS) for on-board railway location using wireless communication technologies, such as satellite navigation and location based systems. ATLAS allows the creation of multiple simulation environments providing a versatile tool for testing and assessing new train location services. This enhancement reduces the number of tests performed in real scenarios and trains, reducing the cost and development time of new location systems as well as assessing the performance level for given tracks. The simulation platform is based on modular blocks, where each block can be replaced or improved. The platform uses Monte Carlo Simulation to generate results with statistical significance. This implementation allows the modification of the development platform to cover multiple requirements, such as, ranging errors in the input parameters or including other positioning technologies. In this paper, the generated input parameter errors have been taken from the results of the field tests realized by the 3GPP ensuring the validity of the used parameter errors. However, these could be easily adapted by the user to particular characterized environments. Case studies for the validation of ATLAS will be also introduced, including preliminary results related to the use of Global System for Mobile communications in Railway (GSM-R) and Universal Mobile Telecommunications System (UMTS) technologies for positioning. The validation stage provides a way to test the platform functionalities and verify its flexibility. The versatility of the platform to perform simulations using same configuration parameters for different case studies can be highlighted. Furthermore, first conclusions are drawn from the obtained results. The characterization of the infrastructure for the simulation and the performance improvement of the location systems in the tunnels (e.g., by including Inertial Measurement Unit (IMU)) are necessary to achieve accuracy levels that can be valid for ETCS level 3.

Bringing AMS radiocarbon into the Anthropocene: Potential and drawbacks in the determination of the bio-fraction in industrial emissions and in carbon-based products

In the frame of the general efforts to reduce atmospheric CO2 emissions different efforts are being carried out to stimulate the use of non-fossil energy sources and raw materials. Among these a significant role is played by the use of waste in Waste to Energy (WTE) plants. In this case a relevant problem is related to the determination of the proportion between the bio and the fossil derived fraction in CO2 atmospheric emissions since only the share of energy derived from the bio-fraction combustion can be labelled as “renewable”. We discuss the potential of radiocarbon in this field by presenting the results of different campaigns carried out by analysing CO2 sampled at the stack of different power plants in Italy with different expected bio-content of the released carbon dioxide. The still open issues related to the calculation procedures and the achievable precision and accuracy levels are discussed.

Designing a graph-based framework to support a multi-modal approach for music information retrieval

In this paper, we propose a graph-based framework to organize low-level and high-level features of music objects in a unified way. The featured graph, called the power graph, is associated with operators to support a variety of music information retrieval applications, such as auto-tagging, link analysis, similarity measurement, and clustering. Among these operators, we have identified the node ranking by computing prestige value as one of the essential fundamental link analysis operators. For this particular operator, we propose two methods of computing prestige; they are the power method and the algebraic method. Although the algebraic method is originated from the symmetric graph, the algebraic method can be applied as an approximate but efficient alternative to the power method. To demonstrate the feasibility of our framework, we have carried out an auto-tagging experiment and a music object clustering experiment. According to the auto-tagging experimental results, we have observed that the algebraic method has achieved almost the same results as the power method with only a one-fifth elapsed time. In the experiments we have conducted, we have achieved accuracy levels up to 75 %.

TU‐C‐WAB‐01: Accuracy Requirements and Uncertainty Considerations in Radiation Therapy

Recent years have seen major advances in the technology of radiation oncology allowing for a transition from 2‐D radiation therapy (RT) to 3‐D conformal RT, intensity modulated RT (IMRT), image‐guided RT (IGRT), adaptive RT (ART), and 4‐D imaging and motion management in RT. Brachytherapy procedures have evolved both for high dose rate (HDR) techniques as well as permanent implants, and image‐guided brachytherapy is the modern standard. While a number of publications have defined accuracy needs in radiation oncology, most of these reports were developed in an era with different radiation technologies and date back to the 1980s and 90s. In view of modern treatment procedures, improvements in dosimetry methodologies, and new clinical dose‐volume data, the AAPM 2011 summer school dealt with uncertainties in external beam radiation therapy and the International Atomic Energy Agency (IAEA) is completing a new guidance document on “Accuracy Requirements and Uncertainties in Radiation Therapy”. This symposium will review the latest information on accuracy requirements and uncertainty considerations in radiation therapy in terms of radiobiological rationale, clinical needs and a practical reality check.Learning Objectives:1. To review historical and current data related to accuracy and uncertainties in the overall radiation treatment process.2. To provide a radiobiological rationale for accuracy considerations in RT.3. To provide a clinical rationale for accuracy considerations in RT.4. To review recent data demonstrating realistically achievable accuracy levels in RT.

Application to air, and to mixtures of nitrogen, oxygen and argon, of three-parameter corresponding states models based on reference equations of state

In this work two three-parameter corresponding states models were applied to the prediction of thermodynamic properties of air and of mixtures of nitrogen, oxygen and argon. In one of the models the methodology was entirely analogous to that of a previously presented work for mixtures of major and minor components of natural gas systems but with argon and nitrogen as the reference fluids, with thermodynamic properties given by the corresponding reference equations of state. To improve even further the predictive capability of this kind of model, and to achieve accuracy levels that match those achieved with the current reference models for air and related systems, the second of the models incorporated three reference fluids, i.e. argon, oxygen and nitrogen. Thus, residual thermodynamic properties were obtained in this model by quadratic interpolation instead of linear interpolation as it is done in standard three-parameter corresponding states models with two reference fluids. By this novel device, the following percentage average absolute deviations were achieved: for binary mixtures, 0.167 in pρT data and 0.438 in bubble-point vapour pressures; for air, 0.079 in pρT data, 0.561 in isochoric heat capacities, 0.270 in speeds of sound, 0.197 and 0.315 in bubble- and dew-point saturation pressures, respectively, and 2.893 and 2.497 in bubble- and dew-point saturation densities, respectively. These results compared favourably with those obtained with three reference models currently available.

SU-E-T-605: Validation of a GPU-Based Fast Deformable Image Registration Platform for 4D Treatment Planning Application

Purpose: Computational speed and geometric accuracy are important considerations in the application of deformable image registration (DIR) in radiotherapy. The goal was to use clinical data to validate for geometric accuracy, a DIR and atlas‐based auto‐segmentation (ABAS, CMS‐Elekta) platform programmable on a Graphics Processing Unit (GPU) which is capable of improving registration speeds up to 100 fold. Methods: We restricted our validation to intra‐patient registration application although the platform can be used for inter‐patient registration. Ten respiratory phase‐ dependent 3DCT image‐sets per patient for 9 patients were used. Demon's algorithm, as implemented in the research release of ABAS, was used to propagate clinician‐contoured regions of interests (ROIs) from the reference phase, chosen as the exhale, to the rest of the phases via deformation vector fields (DVFs) generated by deformably registering each image‐set to the reference. These ROIs shall be called DVF‐generated ROIs. Using the same window/level setting, clinician‐contoured ROIs were created on the other phases. To compare two ROIs for overlap, we defined an overlap index (OI) as the ratio of overlapping volume to the overlapping plus non‐overlapping volume, a related but more conservative index compared to the commonly used dice coefficient (overlapping/average volume). Results: The average OI computed for the DVF‐generated ROIs and the clinician‐contoured ROIs on the inhale phase across all patients were tumor (80% +/−6.3%); esophagus (72.0% +/−5.7%); heart (87.1% +/−3.9%); liver (90.6% +/−1.2%); cord (77.1% +/−5.9%); right lung (94.5% +/−1.5%); left lung (94.6% +/− 1.7%). Further qualitative analysis via visual inspection by the same clinician resulted in the verification of the DVF‐generated ROIs across all phases with a total of 592 out of 594 ROIs receiving satisfactory accuracy scores. Conclusions: This work verifies that in addition to high registration speed capability, the ABAS‐platform programmed on the GPU can achieve accuracy levels required for intra‐patient image registration related applications.

Mars Express tracking and orbit determination trials with Chinese VLBI network

With strong support from European Space Agency (ESA), Shanghai Astronomical Observatory (SHAO) organized a tracking and orbit determination trails using Chinese VLBI Network (CVN) to track Mars Express, the first Mars probe launched by ESA. Using a high-resolution VLBI software correlator and Doppler measurement system developed in-house, two sets of tracking data, VLBI and Doppler, were acquired. The trials represent the first successful foray held in China to track a probe about 360 million kilometers away from the Earth. The tracking data are analyzed using a Mars satellite orbit determination software system developed at SHAO. The results show that the accuracy of 5 s integrated three-way-Doppler data is about 0.3 mm/s, or roughly the same accuracy as ESA’s tracking data. Position discrepancies between the Doppler-based orbit solution of 8 h arc-length (about 1 orbital revolution) and ESA’s reconstructed orbit are of the order of several hundred meters. In preparing for the Russia-China co-sponsored Mars exploration mission Phobos-Grunt-YingHuo, simulations were carried out to evaluate the achievable orbital accuracy levels and the contributions of VLBI and Doppler data respectively. Results show that Doppler data provide better orbit accuracy, so that for VLBI to be able to provide kilometer level orbit solutions, the accuracy of VLBI measurement needs to be improved by at least one order of magnitude.

Markerless human articulated tracking using hierarchical particle swarm optimisation

In this paper, we address markerless full-body articulated human motion tracking from multi-view video sequences acquired in a studio environment. The tracking is formulated as a multi-dimensional non-linear optimisation and solved using particle swarm optimisation (PSO), a swarm-intelligence algorithm which has gained popularity in recent years due to its ability to solve difficult non-linear optimisation problems. We show that a small number of particles achieves accuracy levels comparable with several recent algorithms. PSO initialises automatically, does not need a sequence-specific motion model and recovers from temporary tracking divergence through the use of a powerful hierarchical search algorithm (HPSO). We compare experimentally HPSO with particle filter (PF), annealed particle filter (APF) and partitioned sampling annealed particle filter (PSAPF) using the computational framework provided by Balan et al. HPSO accuracy and consistency are better than PF and compare favourably with those of APF and PSAPF, outperforming it in sequences with sudden and fast motion. We also report an extensive experimental study of HPSO over ranges of values of its parameters.

Visuomotor adaptation of voluntary step initiation in older adults

It has been suggested that feedforward planning of gait and posture is diminished in older adults. Motor adaptation is one mechanism by which feedforward commands can be updated or fine-tuned. Thus, if feedforward mechanisms are diminished in older adults, motor adaptation is also likely to be limited. The purpose of the study was to compare the ability of healthy older versus young adults in generating a voluntary stepping motor adaptation in response to a novel visual sensory perturbation. We recorded stepping movements from 18 healthy older and 18 young adults during baseline and adaptation stepping blocks. During baseline, the stepping target remained stationary; in adaptation, a visual perturbation was introduced by shifting the target laterally during mid-step. We compared adaptation between groups, measured by improvements in endpoint accuracy and movement duration. Older adults adapted stepping accuracy similarly to young adults (accuracy improvement: 29.7 ± 27.6% vs. 37.3 ± 22.9%, older vs. young group respectively, p = 0.375), but showed significant slowness during movement. Thus older adults were able to achieve accuracy levels nearly equivalent to younger adults, but only at the expense of movement speed, at least during the early adaptation period (movement duration: 1143.7 ± 170.6 ms vs. 956.0 ± 74.6 ms, p < 0.001). With practice, however, they were able to reduce movement times and gain speed and accuracy to levels similar to young adults. These findings suggest older adults may retain the ability for stepping adaptations to environmental changes or novel demands, given sufficient practice.

Robust Tracking Under Nonlinear Friction Using Time-Delay Control With Internal Model

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> In this paper, the robustness problem in time-delay control (TDC) is considered in the presence of the nonlinear friction dynamics of robot manipulators. As a remedy for this problem, the TDC is enhanced with a compensator based on internal model control (IMC). The robustness and stability of the proposed method have been analyzed to be effective against friction while preserving the positive attributes of the TDC: It is simple, efficient, and easily applicable because it does not require a complete plant model. Through experiments, the proposed method achieves accuracy levels that are 10–20 times better than that of the TDC, thereby confirming its effectiveness under friction. </para>

Compilation of an idiom example database for supervised idiom identification

Some phrases can be interpreted in their context either idiomatically (figuratively) or literally. The precise identification of idioms is essential in order to achieve full-fledged natural language processing. Because of this, the authors of this paper have created an idiom corpus for Japanese. This paper reports on the corpus itself and the results of an idiom identification experiment conducted using the corpus. The corpus targeted 146 ambiguous idioms, and consists of 102,856 examples, each of which is annotated with a literal/idiomatic label. All sentences were collected from the World Wide Web. For idiom identification, 90 out of the 146 idioms were targeted and a word sense disambiguation (WSD) method was adopted using both common WSD features and idiom-specific features. The corpus and the experiment are both, as far as can be determined, the largest of their kinds. It was discovered that a standard supervised WSD method works well for idiom identification and it achieved accuracy levels of 89.25 and 88.86%, with and without idiom-specific features, respectively. It was also found that the most effective idiom-specific feature is the one that involves the adjacency of idiom constituents.

Pairagon: a highly accurate, HMM-based cDNA-to-genome aligner

The most accurate way to determine the intron-exon structures in a genome is to align spliced cDNA sequences to the genome. Thus, cDNA-to-genome alignment programs are a key component of most annotation pipelines. The scoring system used to choose the best alignment is a primary determinant of alignment accuracy, while heuristics that prevent consideration of certain alignments are a primary determinant of runtime and memory usage. Both accuracy and speed are important considerations in choosing an alignment algorithm, but scoring systems have received much less attention than heuristics. We present Pairagon, a pair hidden Markov model based cDNA-to-genome alignment program, as the most accurate aligner for sequences with high- and low-identity levels. We conducted a series of experiments testing alignment accuracy with varying sequence identity. We first created 'perfect' simulated cDNA sequences by splicing the sequences of exons in the reference genome sequences of fly and human. The complete reference genome sequences were then mutated to various degrees using a realistic mutation simulator and the perfect cDNAs were aligned to them using Pairagon and 12 other aligners. To validate these results with natural sequences, we performed cross-species alignment using orthologous transcripts from human, mouse and rat. We found that aligner accuracy is heavily dependent on sequence identity. For sequences with 100% identity, Pairagon achieved accuracy levels of >99.6%, with one quarter of the errors of any other aligner. Furthermore, for human/mouse alignments, which are only 85% identical, Pairagon achieved 87% accuracy, higher than any other aligner. Pairagon source and executables are freely available at http://mblab.wustl.edu/software/pairagon/

On the calibration of continuous, high‐precision δ18O and δ2H measurements using an off‐axis integrated cavity output spectrometer

The (18)O and (2)H of water vapor serve as powerful tracers of hydrological processes. The typical method for determining water vapor delta(18)O and delta(2)H involves cryogenic trapping and isotope ratio mass spectrometry. Even with recent technical advances, these methods cannot resolve vapor composition at high temporal resolutions. In recent years, a few groups have developed continuous laser absorption spectroscopy (LAS) approaches for measuring delta(18)O and delta(2)H which achieve accuracy levels similar to those of lab-based mass spectrometry methods. Unfortunately, most LAS systems need cryogenic cooling and constant calibration to a reference gas, and have substantial power requirements, making them unsuitable for long-term field deployment at remote field sites. A new method called Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS) has been developed which requires extremely low-energy consumption and neither reference gas nor cryogenic cooling. In this report, we develop a relatively simple pumping system coupled to a dew point generator to calibrate an ICOS-based instrument (Los Gatos Research Water Vapor Isotope Analyzer (WVIA) DLT-100) under various pressures using liquid water with known isotopic signatures. Results show that the WVIA can be successfully calibrated using this customized system for different pressure settings, which ensure that this instrument can be combined with other gas-sampling systems. The precisions of this instrument and the associated calibration method can reach approximately 0.08 per thousand for delta(18)O and approximately 0.4 per thousand for delta(2)H. Compared with conventional mass spectrometry and other LAS-based methods, the OA-ICOS technique provides a promising alternative tool for continuous water vapor isotopic measurements in field deployments.

Benchmarking natural-language parsers for biological applications using dependency graphs.

BackgroundInterest is growing in the application of syntactic parsers to natural language processing problems in biology, but assessing their performance is difficult because differences in linguistic convention can falsely appear to be errors. We present a method for evaluating their accuracy using an intermediate representation based on dependency graphs, in which the semantic relationships important in most information extraction tasks are closer to the surface. We also demonstrate how this method can be easily tailored to various application-driven criteria.ResultsUsing the GENIA corpus as a gold standard, we tested four open-source parsers which have been used in bioinformatics projects. We first present overall performance measures, and test the two leading tools, the Charniak-Lease and Bikel parsers, on subtasks tailored to reflect the requirements of a system for extracting gene expression relationships. These two tools clearly outperform the other parsers in the evaluation, and achieve accuracy levels comparable to or exceeding native dependency parsers on similar tasks in previous biological evaluations.ConclusionEvaluating using dependency graphs allows parsers to be tested easily on criteria chosen according to the semantics of particular biological applications, drawing attention to important mistakes and soaking up many insignificant differences that would otherwise be reported as errors. Generating high-accuracy dependency graphs from the output of phrase-structure parsers also provides access to the more detailed syntax trees that are used in several natural-language processing techniques.

Validation of a New Model-Based Tracking Technique for Measuring Three-Dimensional, In Vivo Glenohumeral Joint Kinematics

Shoulder motion is complex and significant research efforts have focused on measuring glenohumeral joint motion. Unfortunately, conventional motion measurement techniques are unable to measure glenohumeral joint kinematics during dynamic shoulder motion to clinically significant levels of accuracy. The purpose of this study was to validate the accuracy of a new model-based tracking technique for measuring three-dimensional, in vivo glenohumeral joint kinematics. We have developed a model-based tracking technique for accurately measuring in vivo joint motion from biplane radiographic images that tracks the position of bones based on their three-dimensional shape and texture. To validate this technique, we implanted tantalum beads into the humerus and scapula of both shoulders from three cadaver specimens and then recorded biplane radiographic images of the shoulder while manually moving each specimen's arm. The position of the humerus and scapula were measured using the model-based tracking system and with a previously validated dynamic radiostereometric analysis (RSA) technique. Accuracy was reported in terms of measurement bias, measurement precision, and overall dynamic accuracy by comparing the model-based tracking results to the dynamic RSA results. The model-based tracking technique produced results that were in excellent agreement with the RSA technique. Measurement bias ranged from -0.126 to 0.199 mm for the scapula and ranged from -0.022 to 0.079 mm for the humerus. Dynamic measurement precision was better than 0.130 mm for the scapula and 0.095 mm for the humerus. Overall dynamic accuracy indicated that rms errors in any one direction were less than 0.385 mm for the scapula and less than 0.374 mm for the humerus. These errors correspond to rotational inaccuracies of approximately 0.25 deg for the scapula and 0.47 deg for the humerus. This new model-based tracking approach represents a non-invasive technique for accurately measuring dynamic glenohumeral joint motion under in vivo conditions. The model-based technique achieves accuracy levels that far surpass all previously reported non-invasive techniques for measuring in vivo glenohumeral joint motion. This technique is supported by a rigorous validation study that provides a realistic simulation of in vivo conditions and we fully expect to achieve these levels of accuracy with in vivo human testing. Future research will use this technique to analyze shoulder motion under a variety of testing conditions and to investigate the effects of conservative and surgical treatment of rotator cuff tears on dynamic joint stability.