Single Matching Research Articles

Boyer-Moore 알고리즘을 위한 GPU상에서의 병렬 최적화

The Boyer-Moore algorithm is a single pattern string matching algorithm that is widely used in various applications such as computer and internet security, and bioinformatics. This algorithm is computationally demanding and requires high-performance parallel processing. In this paper, we propose a parallelization and performance optimization methodology for the BM algorithm on a GPU. Our methodology adopts an algorithmic cascading technique. This results in significant reductions in the mapping overheads for the threads participating in the parallel string matching. It also results in the efficient utilization of the multithreading capability of the GPU which improves the load balancing among threads. Our experimental results show that this approach achieves a 45-times speedup at maximum, in comparison with a serial execution.

The impact of orthopedic metal artifact reduction software on interreader variability when delineating areas of interest in the head and neck

PurposeMetal artifacts during computed tomography (CT) hinder the evaluation of diagnostic images and impair the delineation of tumor volume in treatment planning. Several solutions are available to minimize these artifacts. Our objective was to determine the impact of one of those tools on the interreader variability when measuring head and neck structures in the presence of metal artifacts. Methods and materialsEleven patients were retrospectively selected from an institutional review board–approved study based on the presence of metallic artifacts in the head and neck region. CT raw data were postprocessed using a metal artifact reduction tool. A single matching CT slice from the filtered backprojection and postprocessed data sets was selected in the region of the metal artifact. Areas of selected anatomical structures were measured by independent readers, including an anatomical structure selected from a CT slice with no metal artifact in each patient as control. The intraclass correlation coefficient was calculated. ResultsTwo extreme outliers were identified and the intraclass correlation coefficient was performed with and without them. The intraclass correlation on filtered backprojection, postprocessed, and control images was 0.903, 0.948, and 0.985 with outliers and 0.884, 0.971, and 0.989 without outliers, respectively, for all readers. On the other hand, the intraclass correlation on filtered backprojection, postprocessed, and control images for experienced readers was 0.904, 0.979, and 0.976 with outliers and 0.934, 0.975, and 0.990 without outliers, respectively. ConclusionsThe interreader variability of areas measured in the presence of metal artifact was greatly decreased by the use of the metal artifact reduction tool and almost matched the variability observed in the absence of the metal artifact.

A Novel Fast Layout Encoding Method for Exact Multilayer Pattern Matching With Prüfer Encoding

As design-for-manufacturability techniques have become widely used to improve the yield of nano-scale semiconductor technology in recent years, hotspot detection methods have been investigated with a view to calibrating layout patterns that tend to reduce yield. In this paper, we propose two graph models, i.e., skeleton graph and space graph, to formulate polygon topology and spatial relationship among polygons. In addition, a Prüfer encoding-based method is presented to encode each skeleton graph. Single polygon matching problem is then equivalent to the verification of graph isomorphism, which is realized by checking the identity of two enhanced Prüfer codes associated with two skeleton graphs. A branch and bound-based pattern anchoring algorithm is presented to resolve the vertex ordering problem for isomorphism checking. The general exact pattern matching problem can then be accomplished by adopting the space graph to identify the similarity of spatial relationship among polygons. Vias are one of the most device components that attract much attention in monitoring manufacturing variation due to via alignment issue, but hotspot detection rarely takes vias into consideration. Multilayer hotspot detection can also be realized by extending the skeleton graph to maintain the relations between adjacent layers through vias. Experimental results show that we can achieve 5.6 × runtime speedup than design-rule-based methodology in average for single layer hotspot detection while the runtime for multilayer hotspot is roughly equal to the summation of that for individual single layer hotspot detection.

센서 융합 기반 정밀 측위를 위한 노면 표시 검출

This paper presents camera-based road surface marking detection methods suited to sensor fusion-based positioning system that consists of low-cost GPS (Global Positioning System), INS (Inertial Navigation System), EDM (Extended Digital Map), and vision system. The proposed vision system consists of two parts: lane marking detection and RSM (Road Surface Marking) detection. The lane marking detection provides ROIs (Region of Interest) that are highly likely to contain RSM. The RSM detection generates candidates in the regions and classifies their types. The proposed system focuses on detecting RSM without false detections and performing real time operation. In order to ensure real time operation, the gating varies for lane marking detection and changes detection methods according to the FSM (Finite State Machine) about the driving situation. Also, a single template matching is used to extract features for both lane marking detection and RSM detection, and it is efficiently implemented by horizontal integral image. Further, multiple step verification is performed to minimize false detections.

Mass-spring matching layers for high-frequency ultrasound transducers: a new technique using vacuum deposition.

We have developed a technique of applying multiple matching layers to high-frequency (>30 MHz) imaging transducers, by using carefully controlled vacuum deposition alone. This technique uses a thin mass-spring matching layer approach that was previously described in a low-frequency (1 to 10 MHz) transducer design with epoxied layers. This mass- spring approach is more suitable to vacuum deposition in highfrequency transducers over the conventional quarter-wavelength resonant cavity approach, because thinner layers and more versatile material selection can be used, the difficulty in precisely lapping quarter-wavelength matching layers is avoided, the layers are less attenuating, and the layers can be applied to a curved surface. Two different 3-mm-diameter 45-MHz planar lithium niobate transducers and one geometrically curved 3-mm lithium niobate transducer were designed and fabricated using this matching layer approach with copper as the mass layer and parylene as the spring layer. The first planar lithium niobate transducer used a single mass-spring matching network, and the second planar lithium niobate transducer used a single mass-spring network to approximate the first layer in a dual quarter-wavelength matching layer system in addition to a conventional quarter-wavelength layer as the second matching layer. The curved lithium niobate transducer was press focused and used a similar mass-spring plus quarter-wavelength matching layer network. These transducers were then compared with identical transducers with no matching layers and the performance improvement was quantified. The bandwidth of the lithium niobate transducer with the single mass-spring layer was measured to be 46% and the insertion loss was measured to be -21.9 dB. The bandwidth and insertion loss of the lithium niobate transducer with the mass-spring network plus quarter-wavelength matching were measured to be 59% and -18.2 dB, respectively. These values were compared with the unmatched transducer, which had a bandwidth of 28% and insertion loss of -34.1 dB. The bandwidth and insertion loss of the curved lithium niobate transducer with the mass-spring plus quarter-wavelength matching layer combination were measured to be 68% and -26 dB, respectively; this compared with the measured unmatched bandwidth and insertion loss of 35% and -37 dB. All experimentally measured values were in excellent agreement with theoretical Krimholtz-Leedom-Matthaei (KLM) model predictions.

Object Tracking across Non-Overlapping Cameras Based on Improved TLD and Multi-Feathers Object Matching

Object tracking across non-overlapping views is a hot and important research topic in compute vision. In this paper, a novel method to track the interested object continuously across non-overlapping cameras is presented. This challenging task is taken as two sub-problems: single camera object tracking and object matching across disjoint cameras. An object tracking algorithm which improves Tracking-Learning-Detection (TLD) algorithm by adding background extraction and Kalman filter is presented to deal with the first problem. A new object matching algorithm based on the fusion of global features and local features at the assistance of 3D GIS is also introduced for object matching across disjoint cameras. The proposed approach does not need a training phase and inter-camera calibration. Experiments are carried out on real world videos to validate the proposed approach.

Research of an Improved Double-Array Trie Tree Algorithm

This paper presents an improved algorithm-iDAT, which is based on Double-Array Trie Tree for Chinese Word Segmentation Dictionary. Chinese word segmentation dictionary based on the Double-Array Trie Tree has higher efficiency of search, but the dynamic insertion will consume a lot of time. After initialization the original dictionary. We implement a Hash process to the empty sequence index values for base array. The final Hash table stores the sum of the empty sequence before the current empty sequence. This algorithm adopt Sunday jumps algorithm of Single Pattern Matching. With slightly and reasonable space cost increasing, iDAT reduces the average time complexity of the dynamic insertion process in Trie Tree. Practical results shows it has a good operation performance.

Guidelines for MSAT and SNP panels that lead to high-quality data for genetic mark–recapture studies

Molecular markers with inadequate power to discriminate among individuals can lead to false recaptures (shadows), and inaccurate genotyping can lead to missed recaptures (ghosts), potentially biasing genetic mark–recapture estimates. We used simulations to examine the impact of microsatellite (MSAT) and single nucleotide polymorphism (SNP) marker-set size, allelic frequency, multitubes approaches, and sample matching protocols on shadow and ghost events in genetic mark–recapture studies, presenting guidance on the specifications for MSAT and SNP marker panels, and sample matching protocols necessary to produce high-quality data. Shadow events are controllable by increasing the number of markers or by selecting markers with high discriminatory power; reasonably sized marker sets (e.g., ≥9 MSATs or ≥32 SNPs) of moderate allelic diversity lead to low probabilities of shadow errors. Ghost events are more challenging to control and low allelic dropout or false-allele error rates produced high rates of erroneous mismatches in mark–recapture sampling. Fortunately, error-tolerant matching protocols, which use information from positively matching loci between comparisons of samples, and multitubes protocols to achieve consensus genotypes are effective at eliminating ghost events. We present a case study on Pacific walrus, Odobenus rosmarus divergens (Illiger, 1815), using simulation results to inform genetic marker choices.

Increased late mortality after coronary artery bypass surgery complicated by isolated new-onset atrial fibrillation: A comprehensive propensity-matched analysis

The association of new-onset postoperative atrial fibrillation (POAF) and late death after coronary artery bypass grafting (CABG) has been confounded by the frequent concomitant serious complications that co-occur with POAF. We aimed to define the magnitude and time dependence of the effect of isolated POAF on late survival after uncomplicated CABG to comprehensively account for comorbidity and perioperative confounding factors. Nonsalvage CABG patients with no history of AF, no concomitant aortic or valvular surgery, and no perioperative complications other than POAF were studied (n=6305). Patients were divided into AF (n=1211, 68 years old, 72% male) and no-AF (n=5094, 63 years old, 70% male) groups. Propensity matching was done using 55 patient variables, including coronary grafts, completeness of revascularization, and transfusion data. The AF effect was quantified using time-segmented hazard ratios by Cox regression analysis. Single (1-to-1), double (1-to-2), and triple (1-to-3) propensity matching of the AF and no-AF was achieved for 1196, 993, and 719 cases, respectively. The AF group showed significantly worse, yet time-varying, 0- to 18-year survival: 0 to 1 year, HR, 1.18 (95% confidence interval, 0.77-1.81); 1 to 6 years, HR, 1.37 (95% confidence interval, 1.12 to 1.67); and 6 to 17 years, HR, 1.25 (95% confidence interval, 1.05 to 1.49). Isolated POAF was associated with a time-varying increase in mortality after CABG. Given these findings and the high incidence of POAF, efforts to reduce POAF should be pursued to potentially improve resource usage, morbidity, and mortality.

평면 구조물의 단일점 일치를 이용한 2차원 레이저 거리감지센서의 자동 캘리브레이션

In this paper, we introduce an autonomous calibration method for a 2D laser displacement sensor (e.g. laser vision sensor and laser range finder) by matching a single point on a flat structure. Many arc welding robots install a 2D laser displacement sensor to expand their application by recognizing their environment (e.g. base metal and seam). In such systems, sensing data should be transformed to the robot's coordinates, and the geometric relation (i.e. rotation and translation) between the robot's coordinates and sensor coordinates should be known for the transformation. Calibration means the inference process of geometric relation between the sensor and robot. Generally, the matching of more than 3 points is required to infer the geometric relation. However, we introduce a novel method to calibrate using only 1 point matching and use a specific flat structure (i.e. circular hole) which enables us to find the geometric relation with a single point matching. We make the rotation component of the calibration results as a constant to use only a single point by moving a robot to a specific pose. The flat structure can be installed easily in a manufacturing site, because the structure does not have a volume (i.e. almost 2D structure). The calibration process is fully autonomous and does not need any manual operation. A robot which installed the sensor moves to the specific pose by sensing features of the circular hole such as length of chord and center position of the chord. We show the precision of the proposed method by performing repetitive experiments in various situations. Furthermore, we applied the result of the proposed method to sensor based seam tracking with a robot, and report the difference of the robot's TCP (Tool Center Point) trajectory. This experiment shows that the proposed method ensures precision.

Design of RF Diplexer for Mobile Communication

In this paper, a matching circuit for RF diplexer for mobile communication is proposed. Most wanted bands in wireless technologies like GSM and DCS is used. Both bands are designed by using stepped impedance resonators with single order and matching between this two are implemented by Yjunction method. Cutoff frequency for GSM and DCS band are 925 MHz and 1795 MHz. Microstrip Technology is proposed because it provides a better insertion loss, better return loss and good isolation between the passbands. The isolation between two operating bands is better than -50 dB. The overall insertion loss obtained in diplexer is -0.4 dB. The overall return loss is less than -20 dB.

Kangaroo: Accelerating String Matching by Running Multiple Collaborative Finite State Machines

String matching is a key technique for network security applications such as network intrusion detection systems and antivirus scanners, where the payload of every packet is inspected against thousands of patterns in real time. As the transmission rate of Internet links is getting higher and higher, the speed of matching engines is required to be faster and faster. Existing deterministic finite automaton (DFA)-based approaches achieve high throughput at the expense of extremely expensive memory cost; therefore, they are not suitable for the scenarios where only limited on-chip memory resources are available. To achieve fast matching speed while controlling memory expense, in this paper, we propose Kangaroo, a compact string matching scheme that scans multiple characters each time by running multiple small-sized finite state machines in parallel. Specifically, Kangaroo processes k consecutive characters mostly in one cycle by accessing k different memories in parallel, where k is a predefined factor that can be tuned based on the requirement of applications. Kangaroo is memory efficient. Experimental evaluations on Snort and ClamAV rule sets show that a tenfold increase in speed can be practically achieved by a single Kangaroo matching engine with a reduced memory cost comparing with the state-of-the-art DFA-based approaches.

Hydrogeological parameter estimations by partial type curve matching methodology

During an aquifer test, the depression cone covers various geological formations, and hence, their reflections in time-drawdown data yield noncontinuous scatter of points on double logarithmic paper for type curve matching so as to obtain the aquifer parameters. In this way, transmissivity and storativity parameters are subject to local changes. Although changes are more obvious during the early stages of pumping, as the depression cone expands, the aquifer parameters become more stable, since they represent the average values for the aquifer material under the influence domain of the depression cone. In practice, single type curve matching is sought for the aquifer parameter identification. This paper presents a partial matching for aquifer parameter variation determinations. The application of the methodology is presented for extensive aquifer test data from the Chad Doab area in Pakistan. The partial matching procedure provides a set of aquifer parameter estimations, and the final parameters can be taken as simple as the arithmetic average, but better in the form of weighted average by adapting matching durations as weights. The percentage differences between the classical and partial type curve matching transmissivity (storativity) estimates are about 23 % (40 %). In conclusion, the classical type curve matching procedure yields under estimations in the aquifer parameter values.

태그쌍의 의미유사도 기반 태그 랭킹 시스템

기존의 태그 기반 시스템들은 콘텐츠에 태깅된 태그들을 활용한 단일 태그 매칭을 통해 검색결과를 제공함에 따라 정확도가 낮은 검색결과를 제공하고 있으며, 또한 사용자들이 콘텐츠에 태깅 시 태그간의 연관관계 및 우선순위는 고려하지 않아 태그가 가지고 있는 콘텐츠와 관련된 정보들을 효율적으로 제공하지 못하고 있다. 이에 본 논문에서는 위의 문제점을 해결하기 위해 태그 기반 시스템에 적합한 태그간 의미 유사도를 추출하여 콘텐츠에 태깅된 태그들을 재 랭킹하기 위한 태그 랭킹 시스템을 제안하였다. 제안 시스템의 성능 평가는 이미지에 태깅된 태그(baseline)와 태그 동시출현 빈도수 기법을 적용한 랭킹(frequency) 결과를 본 논문에서 제안한 태그 랭킹 시스템에 의해 추출된 랭킹 결과와 비교 실험하였다. The existing tag based system deducts a retrieval result with low accuracy through the usage of a single tag matching by using tags tagged in contents. And the system doesn't provide effectively contents related information which the tags have, as the users place tags on contents without considering the priority and associative relation between tags. For a solve of above problems, this paper suggests a tag ranking system which extracts semantic similarity between tags and re-ranks the tags tagged in contents. In order to evaluate the performance of suggested system, this paper experiments and compares the ranking result of this paper's tag ranking system with the result of baseline method using tags tagged in images and frequency method adapting tag co-appearance frequency.

EYE DETECTION USING COMPOSITE CROSS-CORRELATION

This study presents a new eye detection method depending on composite template matching for facial images. The objective of this study is to utilize t emplate match method to detect the eyes from given images and to improve this method to obtain higher rate of detection. The idea of our method is to integrate cross correlations of various eye templates. Thus, the co rrect values of single template matching based eye detection dominated the final output. It also contr ibuted to the re-correct the detection in the event of failure of all single templates. The study also presents a method to obtain candidate eye pixels which contrib ute to abbreviate the time required to implement up to 91% . The formula of composite cross correlation has be en generalized taking into account the differences bet ween the sizes, shifts and irregular single templat es. The experiments applied on PICS database reported 98.76% as eye detection rate.

Network Design for Multiple Frequency Impedance Matching by the Frequency Transformation Technique

It is shown that the application of frequency transformation to a single frequency impedance matching network simplifies the design of networks for impedance matching at any number N of frequencies. The required design procedure has been presented in formal network theoretic terms. A systematic procedure is given for generating all the equivalent networks for this purpose, from which the best one can be chosen according to a predefined criterion. Illustrative designs and some of the relevant circuits are given for some low values of N.

Performance Improvement of BMH and BMHS using PDJ (Possible Double Jump) and MValue (Match Value)

BM (Boyer-Moore) string matching algorithm and its enhanced versions like BMH and BMHS are a standard benchmark for single pattern string matching. Based on BMH and BMHS algorithms we have developed improved algorithms EBMH(Enhanced BMH)and EBMHS(Enhanced BMHS). These algorithms uses the newly introduced PDJ (possible double jump) and MValue(Match Value) concepts. While searching these concepts helps to provide longer jump of characters. The algorithm EBMH emphasize on BMH algorithm with the inclusion of PDJ and MValue and the algorithm EBMHS emphasize on BMHS algorithm with the inclusion of PDJ and MValue. Through these algorithm the number of comparison of characters between text and pattern are reduced to a significant amount. In this paper PDJ, MValue, EBMH and EBMHS are described and analyzed. Experimental results show that in the algorithms searching time is reduced as compared to BM, BMH, and BMHS. The algorithms are analyzed on the basis of time requirement in best, worst and average case.

ClinicalTrials.gov registration can supplement information in abstracts for systematic reviews: a comparison study

BackgroundThe inclusion of randomized controlled trials (RCTs) reported in conference abstracts in systematic reviews is controversial, partly because study design information and risk of bias is often not fully reported in the abstract. The Association for Research in Vision and Ophthalmology (ARVO) requires trial registration of abstracts submitted for their annual conference as of 2007. Our goal was to assess the feasibility of obtaining study design information critical to systematic reviews, but not typically included in conference abstracts, from the trial registration record.MethodsWe reviewed all conference abstracts presented at the ARVO meetings from 2007 through 2009, and identified 496 RCTs; 154 had a single matching registration record in ClinicalTrials.gov. Two individuals independently extracted information from the abstract and the ClinicalTrials.gov record, including study design, sample size, inclusion criteria, masking, interventions, outcomes, funder, and investigator name and contact information. Discrepancies were resolved by consensus. We assessed the frequencies of reporting variables appearing in the abstract and the trial register and assessed agreement of information reported in both sources.ResultsWe found a substantial amount of study design information in the ClinicalTrials.gov record that was unavailable in the corresponding conference abstract, including eligibility criteria associated with gender (83%; 128/154); masking or blinding of study participants (53%, 82/154), persons administering treatment (30%, 46/154), and persons measuring the outcomes (40%, 61/154)); and number of study centers (58%; 90/154). Only 34% (52/154) of abstracts explicitly described a primary outcome, but a primary outcome was included in the “Primary Outcome” field in the ClinicalTrials.gov record for 82% (126/154) of studies. One or more study interventions were reported in each abstract, but agreed exactly with those reported in ClinicalTrials.gov only slightly more than half the time (88/154, 56%). We found no contact information for study investigators in the abstract, but this information was available in less than one quarter of ClinicalTrial.gov records (17%; 26/154).ConclusionRCT design information not reported in conference abstracts is often available in the corresponding ClinicalTrials.gov registration record. Sometimes there is conflicting information reported in the two sources and further contact with the trial investigators may still be required.

Aircraft Recognition in High-Resolution Satellite Images Using Coarse-to-Fine Shape Prior

Automatic aircraft recognition in high-resolution satellite images has many important applications. Due to the diversity and complexity of fore-/background, recognition using pixel-based methods usually does not perform well. In this letter, we propose a new method integrating the high-level information of a shape prior, which is considered as a coarse-to-fine process. In the coarse stage, the pose of an aircraft is roughly estimated by a single template matching with a defined score criterion. In the fine stage, we derive a parametric shape model by applying principal component analysis and kernel density function, which have good effects on both dimension reduction and sample space description; then, a new variational formulation combining region information and a shape prior is proposed to segment the object using a level set method. Finally, the parameters of the segmentation result are directly applied to verify aircraft type with two <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$k$</tex></formula> -nearest neighbor steps. Experiments on QuickBird images demonstrate the robustness and accuracy of the proposed method.

No longer sick: what does it convey? An empirical analysis of post‐bankruptcy performance

Purpose – The purpose of this paper is to empirically investigate the stock return and operating performance of the firms which emerged from bankruptcy during 1992‐2006 in India.Design/methodology/approach – The paper uses single factor model and matching firm approach to assess the stock return performance. It employs the level as well as change expectation models to examine the operating performance.Findings – The paper shows that the sample firms, after emerging from bankruptcy, report declining stock return as well as operating performance.Practical implications – Findings of the study raise doubts over the efficiency of Indian corporate bankruptcy reorganizing mechanism.Originality/value – Apparently, no previous study examined the post‐bankruptcy performance of the firms, particularly in the context of emerging markets, which are plagued with the principal agent problems aggravated by owner managers. Given the potential vulnerability of the bankruptcy process for the inefficient wealth transfers amo...