Standard LP Research Articles

A simple method for convex optimization in the oracle model

We give a simple and natural method for computing approximately optimal solutions for minimizing a convex function f over a convex set K given by a separation oracle. Our method utilizes the Frank–Wolfe algorithm over the cone of valid inequalities of K and subgradients of f. Under the assumption that f is L-Lipschitz and that K contains a ball of radius r and is contained inside the origin centered ball of radius R, using O(RL)2ε2·R2r2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$O\\left( \\frac{(RL)^2}{\\varepsilon ^2} \\cdot \\frac{R^2}{r^2}\\right) $$\\end{document} iterations and calls to the oracle, our main method outputs a point x∈K\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$x \\in K$$\\end{document} satisfying f(x)≤ε+minz∈Kf(z)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$f(x) \\le \\varepsilon + \\min _{z \\in K} f(z)$$\\end{document}. Our algorithm is easy to implement, and we believe it can serve as a useful alternative to existing cutting plane methods. As evidence towards this, we show that it compares favorably in terms of iteration counts to the standard LP based cutting plane method and the analytic center cutting plane method, on a testbed of combinatorial, semidefinite and machine learning instances.

A bicriteria approximation algorithm for the minimum hitting set problem in measurable range spaces

We consider the problem of finding a minimum-size hitting set in a range space F=(Q,R) defined by a measure on a family of subsets of an infinite set R. We observe that, under reasonably general assumptions, the infinite-dimensional convex relaxation can be solved (approximately) efficiently by multiplicative weight updates. As a consequence, we get an algorithm that finds, for any δ>0, a set of size O(αFzF⁎) that hits a (1−δ)-fraction of the ranges in R (with respect to the given measure) in time proportional to log⁡1δ, where zF⁎ is the value of the fractional optimal solution and αF is the integrality gap of the standard LP relaxation of the hitting set problem for the restriction of F on a set of points of size O(zF⁎log⁡1δ). Some applications of this result in Computational Geometry are given.

Reduced Frequencies of Post-Lumbar Puncture (LP) Headaches and Epidural Blood Patch Needs with Modifications of Standard LP Procedure (P10-4.002)

<h3>Objective:</h3> LP is one of the most frequently used diagnostic modalities in neurology and neurosurgery. Post-LP headache (PLPH) is the most common complication of LP (10–32%). Epidural blood patch is a treatment to cure severe and prolonged PLPH. <h3>Background:</h3> PLPH is a common complication associated with cerebrospinal fluid (CSF) leakage after a LP. Usually, patients exhibit headaches with upright body positions. Various prophylactic and therapeutic treatments have been used to reduce and treat PLPH including keeping a supine position for four hours post-LP, caffeine supplementation, aggressive oral or intravenous (IV) hydration, and bed rest. However, the most effective treatment for moderate to severe PLPH is the epidural blood patch. This study investigates an improved LP procedure that reduces PLPH and epidural blood patch rates in brain cancer patients. <h3>Design/Methods:</h3> A retrospective review of medical records over 12 years (2011–2022) was performed in patients who had a LP from one physician (JZ). Modifications from standard procedure include: 1) no reposition of the stylet in the spinal needle prior to removing the needle at the end of the procedure, 2) using a 22-gauge cutting spinal needle. Patient data was collected from all accessible electronic medical records. Complications post-procedure were noted, and incidence rates were calculated. <h3>Results:</h3> Among 341 LPs performed on 192 patients, 12 incidences of PLPH (3.52%) were identified. Five additional patients presented with headaches, but LP-related classification was unclear (1.47%). Epidural blood patches were utilized in two cases of headaches out of 17 total cases (11.76%). However, only one of these two incidences was identified as PLPH treatment (8.33%, 1/12). No infection or hemorrhage was identified. <h3>Conclusions:</h3> The modified LP procedure is associated with reduced PLPH and epidural blood patch rates. The data suggests decreased CSF leakage from equalized pressure gradients that reduces dural tears. Further investigations are warranted to evaluate the modified procedure prospectively. <b>Disclosure:</b> An immediate family member of Dr. Zhu has stock in Abbott lab. The institution of Dr. Zhu has received research support from NRG NIH. The institution of Dr. Zhu has received research support from Novocure, Inc. The institution of Dr. Zhu has received research support from Five Prime pharmaceutical. The institution of Dr. Zhu has received research support from Denovo, inc. The institution of Dr. Zhu has received research support from Boston Biomedical Sumitomo Dainippon Pharma Global Oncology. The institution of Dr. Zhu has received research support from CNS pharmaceutical. Dr. Ghosh has nothing to disclose. Mr. Nahm has nothing to disclose.

Towards Automatic License Plate Recognition in Challenging Conditions

License plate recognition (LPR) is an integral part of the current intelligent systems that are developed to locate and identify various objects. Unfortunately, the LPR is a challenging task due to various factors, such as the numerous shapes and designs of the LPs, the non-following of standard LP templates, irregular outlines, angle variations, and occlusion. These factors drastically influence the LP appearance and significantly challenge the detection and recognition abilities of state-of-the-art detection and recognition algorithms. However, recent rising trends in the development of machine learning algorithms have yielded encouraging solutions. This paper presents a novel LPR method to address the aforesaid issues. The proposed method is composed of three distinct but interconnected steps. First, a vehicle that appears in an input image is detected using the Faster RCNN. Next, the LP area is located within the detected vehicle by using morphological operations. Finally, license plate recognition is accomplished using the deep learning network. Detailed simulations performed on the PKU, AOLP, and CCPD databases indicate that our developed approach produces mean license plate recognition accuracy of 99%, 96.0231%, and 98.7000% on the aforesaid databases.

Lower Bound Analysis of Lp+ Induced Norm for LTI Systems

In this paper, we focus on the lower bounds of the Lp (p ∈ [1,∞), p = ∞) induced norms of continuous-time LTI systems where input signals are restricted to be nonnegative. This induced norm, called the Lp+ induced norm, is particularly useful for the stability analysis of nonlinear feedback systems constructed from linear systems and static nonlinearities where the nonlinearities provide only nonnegative signals for the case p = 2. To have deeper understanding on the Lp+ induced norm, we analyze its lower bounds with respect to the standard Lp induced norm in this paper. As the main result, we show that the Lp+ induced norm of an LTI system cannot be smaller than the Lp induced norm scaled by 2(1-p)/p for ∈ [1,∞) (scaled by 2−1 for p = ∞). On the other hand, in the case where p = 2, we further propose a method to compute better (larger) lower bounds for single-input systems via reduction of the lower bound analysis problem into a semi-infinite programming problem. The effectiveness of the lower bound computation method, together with an upper bound computation method proposed in our preceding paper, is illustrated by numerical examples.

LP-based approximation for uniform capacitated facility location problem

In this paper, we study uniform hard capacitated facility location problem. The standard LP for the problem is known to have an unbounded integrality gap. We present constant factor approximation by rounding a solution to the standard LP with a slight (1+ϵ) violation in the capacities.Our result shows that the standard LP is not too bad.Our algorithm is simple and more efficient as compared to the strengthened LP-based true approximation that uses the inefficient ellipsoid method with a separation oracle. True approximations are also known for the problem using local search techniques that suffer from the problem of convergence. Moreover, solutions based on standard LP are easier to integrate with other LP-based algorithms.The result is also extended to give the first approximation for uniform hard capacitated k-facility location problem violating the capacities by a factor of (1+ϵ) and breaking the barrier of 2 in capacity violation. The result violates the cardinality by a factor of 21+ϵ.

Moderately elevated lipoprotein (a) levels are associated with an earlier need for percutaneous coronary intervention in recurrent cardiovascular disease.

A significant number of cardiovascular disease (CVD) patients, with the target lipid levels, as set by the guidelines, achieved, continue to remain at risk. In this setting, lipoprotein (Lp) a role in CVD prognosis is regaining interest. Although Lp(a) is related to the arteriosclerotic process, there is not currently an adequate amount of data for the inclusion of Lp(a) levels as a primary therapeutic target in the treatment of coronary artery disease (CAD) patients. In this framework, the current retrospective study aims to investigate the association of Lp(a) levels with the adverse cardiovascular (CV) events presented in a 10 year follow-up of CVD patients with dyslipidemia and its association with the major CV risk factors. A statistically significant reduction in Lp(a) levels was observed during the follow-up period (72.8±45.6 vs. 68.3±41.8 mg/dl; McNemar test; P<0.001). The vast majority of patients who suffered a new acute myocardial infarction during the follow up period had Lp(a) levels >30 mg/dl (24/28 patients, mean ± standard deviation Lp(a), 83.1±36.6 mg/dl, P=0.001). Kaplan-Meier survival analysis did not find statistically significant differences in a percutaneous coronary intervention (PCI) time occurrence during the follow-up period between patients with low (≤30 mg/dl) and high (>30 mg/dl) Lp(a) levels (log-rank P=0.305). On the other hand, when a second and third PCI conducted during the monitoring period were included in the Kaplan Meier analysis as events, the mean time for a PCI was significantly shorter (7.2%; P=0.01) for patients with Lp(a) levels >30 mg/dl. In conclusion, the current study reported that patients with high Lp(a) values are more prone to the occurrence of new myocardial infarction, while the Lp(a) cut-off value of 30 mg/dl was linked in CVD patients to an earlier need for PCI, especially in the most vulnerable group of patients with more than one (recurrent) revascularizations.

A refined approximation for Euclidean k-means

In the Euclidean k-Means problem we are given a collection of n points D in an Euclidean space and a positive integer k. Our goal is to identify a collection of k points in the same space (centers) so as to minimize the sum of the squared Euclidean distances between each point in D and the closest center. This problem is known to be APX-hard and the current best approximation ratio is a primal-dual 6.357 approximation based on a standard LP for the problem [Ahmadian et al. FOCS'17, SICOMP'20].In this note we show how a minor modification of Ahmadian et al.'s analysis leads to a slightly improved 6.12903 approximation. As a related result, we also show that the mentioned LP has integrality gap at least 16+515>1.2157.

Abstract 9768: Relationship of Atherogenic Lipoproteins with Insulin Resistance and Carotid Intimal Thickness in Youth at Risk for Cardiovascular Disease

Introduction: Youth with obesity and abnormal glucose tolerance (AGT) have an atherogenic lipoprotein (Lp) profile (small dense HDL and small LDL) and an increased risk for atherosclerotic disease, but the relative contributions of hyperglycemia and insulin resistance to the development of subclinical atherosclerosis in youth are not well defined. Hypothesis: Atherogenic Lp concentrations (ApoB, small LDLp, small HDLp) are associated with lower insulin sensitivity (Si) and greater carotid intimal thickness (cIMT), irrespective of glycemic status. Methods: In 155 youth with obesity (14.5±1.4y (mean±SD), 50% female; 42 lean (LC: BMI 25-85%ile), 44 insulin sensitive (OIS, fasting insulin ≤20μM/mL, BMI≥95%ile), 35 insulin resistant (OIR; fasting insulin&gt;20μM/mL, BMI≥95%ile) and 34 with AGT (23 prediabetes, 11 type 2 diabetes) we compared a standard lipid panel and Lp size and number. Linear regressions were used to test the associations between lipids/ NMR-derived Lp with Si index derived from a minimal model during an intravenous glucose test. cIMT was determined by ultrasonography. In a subset of 56 youth (21 LC, 19 OIS, 10 OIR, and 7 AGT) we explored the change in Si with the change in Lp and cIMT after 2 years. Results: OIR and AGT had higher triglycerides and lower HDL compared to LC, P &lt;0.01. Total cholesterol, LDL, and cIMT were comparable among all youth. ApoB, total triglyceride-rich Lp, LDLp and small LDLp) were similar in OIS, OIR, and AbGT and higher compared to LC. Among adolescents with obesity, Si was inversely associated with ApoB (β=-0.016), total LDLp (β=-0.91), small HDLp (β=-0.11) and cIMT (β= -2.99), all P &lt;0.001. There was no effect modification by obesity group. LnSi was associated with total HDL (β=1.30), large HDLp (β= 0.23) and small HDLp (β=-0.11), all P &lt;0.01) with steeper associations between AGT vs OIR and AGT vs OIS. After 2 years, the change in insulin sensitivity was not associated with changes in lipoproteins or cIMT. Conclusions: Among youth with obesity, insulin resistance was associated with atherogenic lipoproteins and cIMT, regardless of glucose tolerance status. Alterations in HDL particle number and size were distinct early manifestations that were observed in youth with AGT compared to their peers.

Periodic adjoints and anisotropic mesh adaptation in rotating frame for high-fidelity RANS turbomachinery applications

The scope of this paper is to demonstrate the viability and efficiency of metric-based unstructured anisotropic mesh adaptation techniques to turbomachinery applications. The main difficulty in turbomachinery is the periodicity of the domain that must be taken into account in the mesh-adaptive solution process. The periodicity is strongly enforced in the flow solver using ghost entities to minimize the impact on the source code. For the mesh adaptation, the local remeshing is done in two steps. First, the inner domain is remeshed with frozen periodic frontiers, and, second, the periodic surfaces are remeshed after moving geometric entities from one side of the domain to the other. One of the main goal of this work is to demonstrate that mesh-independent certified numerical solutions can be obtained thanks to anisotropic mesh adaptation and that it is possible to run high-fidelity CFD on unstructured adapted meshes composed only of tetrahedra. This paper demonstrates how mesh adaptation, thanks to its automation, is able to generate meshes that are extremely difficult to envision and almost impossible to generate manually, leading to highly accurate numerical solutions. This study considers feature-based error estimate based on the standard multi-scale Lp interpolation error estimate and goal-oriented error estimate using an adjoint state to control the error on turbomachinery output functionals. A description of the flow solver and the adjoint solver is given in this work, as they are very different from what is encountered in the turbomachinery community. We also present all the specific modifications that have been introduced in the adaptive process to deal with periodic simulations used for turbomachinery applications. The periodic mesh adaptation strategy is then tested and validated on the LS89 high pressure axial turbine vane and the NASA Rotor 37 test cases.

Evaluation of the airway mechanics of modified toggle laryngoplasty constructs using a vacuum chamber airflow model.

To evaluate the airway mechanics of modified toggle LP constructs in an airflow chamber model and compare these to the airway mechanics of standard LP constructs. Ex-vivo experimental study. Fifty-one equine cadaveric larynges. Bilateral LP constructs were performed using a modified toggle (n=23) or a standard (n=21) LP technique. Constructs were tested in an airflow model before and after cyclic loading which was designed to mimic postoperative swallowing. The cross-sectional area (CSA), peak translaryngeal airflow (L/s), and impedance (cmH2 0/L/s) were determined and compared between LP constructs before and after cycling. The mean CSA of the rima glottidis of the modified toggle LP constructs was 15.2 ± 2.6cm2 before and 14.7 ± 2.6cm2 after cyclic loading, and the mean CSA of the rima glottidis of the standard LP constructs was 16.4 ± 2.9cm2 before and 15.7 ± 2.8cm2 after cyclic loading. The modified toggle LP constructs had similar peak translaryngeal impedance before and after cyclic loading (p=.13); however, the standard LP constructs had higher peak translaryngeal impedance after cyclic loading (p=.02). The modified toggle and standard LP constructs had comparable airway mechanics in an ex-vivo model. Further investigation is warranted to determine the extent to which the modified toggle LP technique restores normal airway function in horses with RLN.

Feature-based and goal-oriented anisotropic mesh adaptation for RANS applications in aeronautics and aerospace

The scope of this paper is to demonstrate the viability of unstructured anisotropic mesh adaptation for commercial aircraft drag and high-lift prediction studies. The main achievement of this work is to demonstrate that mesh-independent certified numerical solutions can be achievable thanks to anisotropic mesh adaptation and that it is possible to run high-fidelity CFD on unstructured adapted meshes composed only of tetrahedra which is fundamental to design robust meshing process for complex geometries. It also points out the early capturing property of the solution-adaptive process in the sense that accurate output functional values are obtained on relatively coarse adapted meshes. On a more practical point of view, this paper demonstrates how mesh adaptation, thanks to its automation, is able to generate meshes that are extremely difficult to envision and almost impossible to generate manually, leading to highly accurate numerical solutions. Moreover, as the process can start from any coarse initial mesh, it greatly simplifies the overall meshing process. This study also analyze the influence of different strategies in the mesh adaptation algorithm and in the error analysis which are key components of the process. Several error estimates are considered: feature-based ones which are based on the standard multiscale Lp interpolation error estimate and goal-oriented ones to control the error on output functionals which rely on an accurate computation of the adjoint state. The adjoint problem proves to be a stiff problem for RANS equations, failing to converge the adjoint state to machine zero may impact negatively the adaptive process. The maturity of the solution-adaptive process is demonstrated on numerous drag and high-lift prediction cases. It has also excelled in sonic boom and turbomachine applications.

Correlation Clustering in Data Streams

Clustering is a fundamental tool for analyzing large data sets. A rich body of work has been devoted to designing data-stream algorithms for the relevant optimization problems such as k-center, k-median, and k-means. Such algorithms need to be both time and and space efficient. In this paper, we address the problem of correlation clustering in the dynamic data stream model. The stream consists of updates to the edge weights of a graph on n nodes and the goal is to find a node-partition such that the end-points of negative-weight edges are typically in different clusters whereas the end-points of positive-weight edges are typically in the same cluster. We present polynomial-time, O(ncdot {{,mathrm{polylog},}}n)-space approximation algorithms for natural problems that arise. We first develop data structures based on linear sketches that allow the “quality” of a given node-partition to be measured. We then combine these data structures with convex programming and sampling techniques to solve the relevant approximation problem. Unfortunately, the standard LP and SDP formulations are not obviously solvable in O(ncdot {{,mathrm{polylog},}}n)-space. Our work presents space-efficient algorithms for the convex programming required, as well as approaches to reduce the adaptivity of the sampling.

A Constant-factor Approximation Algorithm for the Asymmetric Traveling Salesman Problem

We give a constant-factor approximation algorithm for the asymmetric traveling salesman problem (ATSP). Our approximation guarantee is analyzed with respect to the standard LP relaxation, and thus our result confirms the conjectured constant integrality gap of that relaxation. The main idea of our approach is a reduction to Subtour Partition Cover, an easier problem obtained by significantly relaxing the general connectivity requirements into local connectivity conditions. We first show that any algorithm for Subtour Partition Cover can be turned into an algorithm for ATSP while only losing a small constant factor in the performance guarantee. Next, we present a reduction from general ATSP instances to structured instances, on which we then solve Subtour Partition Cover, yielding our constant-factor approximation algorithm for ATSP.

Improving on Best-of-Many-Christofides for [formula omitted]-tours

The T-tour problem is a natural generalization of TSP and Path TSP. Given a graph G=(V,E), edge cost c:E→R≥0, and an even cardinality set T⊆V, we want to compute a minimum-cost T-join connecting all vertices of G (and possibly containing parallel edges).In this paper we give an 117-approximation for the T-tour problem and show that the integrality ratio of the standard LP relaxation is at most 117. Despite much progress for the special case Path TSP, for general T-tours this is the first improvement on Sebő’s analysis of the Best-of-Many-Christofides algorithm (Sebő, 2013).

Slightly improved upper bound on the integrality ratio for the [formula omitted] Path TSP

In this paper we investigate the integrality ratio of the standard LP relaxation for the Metrics−tPath TSP. We make a near-optimal choice for an auxiliary function used in the analysis of Traub and Vygen which leads to an improved upper bound on the integrality ratio of 1.5273.

OPTIMIZATION IN SELECTION OF AN APPROPRIATE VARIABLES OF SUPPLIERS USING INTERPRETIVE STRUCTURAL MODELLING (ISM) FOR DEA BASED SCM

In the concept of traditional management, suppliers are selected based on certain element/components like i) ability to fulfill quality demanded, ii) delivery pattern/services to the customer or third party and iii) price of an offered. ISM is just one of variety of tools which make up the process known as “structural modelling”. Judgments of preference are obtained using this tool. Data Envelopment Analysis [DEA] is one of the competent and powerful non-parametric tools/methods to measure the relative- competence/efficiency for each decision-making-units (called DMU’s) of the system.This research work has been completed in two stage. In first stage objective focused on to ascertain an important decision criterion pertinent to present worldwide business situation at initial stage and then stipulates an operative tool to approve the preferences of suppliers One over another, in addition to the prerequisite of organization. In the second stage of this paper shows that DEA Lingo based Model for Supply Chain Method can provide more details than standard LP approach with Simulation Modeling approach barring. This approach has the benefits of modesty, versatility and visualisation. Comparing the variables will allow company management to choose the supplier on a larger scale, too.

Spinal needle size and traumatic neonatal lumbar puncture: an observational study (neo-LP).

The incidence of 'traumatic' lumbar puncture (LP; CSF red cells > 500/mm) has been reported to be 35-46% in the neonatal period. A traumatic LP incurs challenges in diagnosis and management of the underlying condition and increases the risk of complications. We aimed to assess the benefits of a smaller outer diameter, larger gauge 25G needle in reducing the incidence of traumatic LPs compared with the standard 22G LP needle. This prospective observational study compared data from two consecutive epochs. Epoch 1 (Control, April 2016-October 2016), 22G needle for LP as standard practice. Epoch 2 (Intervention, November 2016-October 2017) 25G needle used for LP. Primary outcome was the incidence of traumatic LP. Multiple logistic regression analyses were conducted adjusting for corrected gestational age (CGA) at LP, proceduralist experience and need for ventilation as an indicator of illness. There were 240 LPs during the study period involving 361 attempts (22G, n = 228; 25G, n = 133). Median gestation at birth (P = 0.617) and CGA at LP (P = 0.163) were comparable. Multivariate analysis revealed lower incidence of traumatic LP using 25G needle (P < 0.001). Incidence of obtaining a successful CSF sample was similar between groups (P = 0.944). Proceduralist experience (P = 0.189) and neonatal illness (P = 0.801) were not significant factors.Conclusion: Our results showed that traumatic LPs were ~ 50% less common with 25G vs 22G needles while retaining a comparable success rate. Dry taps were more likely among the 25G group.What is Known:• The incidence of neonatal 'traumatic' lumbar puncture (CSF red cells > 500/mm) has been reported to be 35-46%.• A traumatic lumbar puncture incurs challenges in diagnosis and management of the underlying condition and increases the risk of complications.What is New:• Multivariate analysis revealed lower incidence of traumatic lumbar puncture using 25G needle (vs 22G).• Incidence of obtaining a successful CSF sample was similar between groups.

The pointwise convergence of Fourier Series (II). Strong L1 case for the lacunary Carleson operator

We prove that the lacunary Carleson operator is bounded from Llog⁡L to L1. This result is sharp.The proof is based on two newly introduced concepts:(1)the time-frequency regularization of a measurable set and(2)the set-resolution of the time-frequency plane at 0-frequency. These two concepts will play the central role in providing a special tile decomposition adapted to the interaction between the structure of the lacunary Carleson operator and the corresponding structure of a fix measurable set.Another key insight of our paper is that it provides for the first time a simultaneous treatment of families of tiles with distinct mass parameters. This should be regarded as a fundamental feature/difficulty of the problem of the pointwise convergence of Fourier Series near L1, context in which, unlike the standard Lp,p>1 case, no decay in the mass parameter is possible.

Attenuate Locally, Win Globally: Attenuation-Based Frameworks for Online Stochastic Matching with Timeouts

Online matching problems have garnered significant attention in recent years due to numerous applications in e-commerce, online advertisements, ride-sharing, etc. Many of them capture the uncertainty in the real world by including stochasticity in both the arrival and matching processes. The online stochastic matching with timeouts problem introduced by Bansal et al. (Algorithmica, 2012) models matching markets (e.g., E-Bay, Amazon). Buyers arrive from an independent and identically distributed (i.i.d.) known distribution on buyer profiles and can be shown a list of items one at a time. Each buyer has some probability of purchasing each item and a limit (timeout) on the number of items they can be shown. Bansal et al. (Algorithmica, 2012) gave a 0.12-competitive algorithm which was improved by Adamczyk et al. (ESA, 2015) to 0.24. We present several online attenuation frameworks that use an algorithm for offline stochastic matching as a black box. On the upper bound side, we show that one framework, combined with a black-box adapted from Bansal et al. (Algorithmica, 2012), yields an online algorithm which nearly doubles the ratio to 0.46. Additionally, our attenuation frameworks extend to the more general setting of fractional arrival rates for online vertices. On the lower bound side, we show that no algorithm can achieve a ratio better than 0.632 using the standard LP for this problem. This framework has a high potential for further improvements since new algorithms for offline stochastic matching can directly improve the ratio for the online problem. Our online frameworks also have the potential for a variety of extensions. For example, we introduce a natural generalization: online stochastic matching with two-sided timeouts in which both online and offline vertices have timeouts. Our frameworks provide the first algorithm for this problem achieving a ratio of 0.30. We once again use the algorithm of Bansal et al. (Algorithmica, 2012) as a black-box and plug it into one of our frameworks.