Miracle-dz/UniFAR-FTUs huggingface dataset:
Postglacial adjustment of steep, low‐order drainage basins, Canadian Rocky Mountains

It is generally argued that Pleistocene glaciation results in increased sediment flux in mountain systems. An important, but not well constrained, aspect of Pleistocene glacial erosion is the geomorphic decoupling of cirque basins from main river systems. This study provides a quantitative link between glacier‐induced basin morphology, postglacial erosion, and sediment delivery for mountain headwaters (with basin area <10 km2). We analyze the morphology of 57 headwater basins in the Canadian Rockies and establish postglacial sediment budgets for select basins. Notable differences in headwater morphology suggest different degrees of erosion by cirque glaciers, which we classify into headwater basins with either cirque or noncirque morphology. Despite steeper slope gradients in cirque basins, higher‐mean postglacial erosion rates in basins with noncirque morphology (0.43–0.6 mm a−1) compared to those in cirques (0.19–0.39 mm a−1) suggest a more complex relationship between hillslope erosion and slope gradient in calcareous mountain environments than implied by the threshold hillslope concept. Higher values of channel profile concavity and lower channel gradients in cirques imply lower transport capacities and, thus, lower sediment delivery ratios (SDR). These results are supported by (i) postglacial SDR values for cirques and noncirque basins of <15% and >28%, respectively, and (ii) larger fan sizes at outlets of noncirque basins compared to cirques. Although small headwater basins represent the steepest part of mountain environments and erode significant postglacial sediment, the majority of sediment remains in storage under interglacial climatic conditions and does not affect large‐scale mountain river systems.
Design Patterns for Teaching Type Checking in a Compiler Construction Course

A course in compiler construction seeks to develop an understanding of well-defined fundamental theory and typically involves the production of a language processor. In a graduate degree in software engineering, the development of a compiler contributes significantly to the developer's comprehension of the practical application of theoretical concepts. Different formal notations are commonly used to define type systems, and some of them are used to teach the semantic analysis phase of language processing. In the traditional approach, attribute grammars are probably the most widely used ones. This paper shows how object-oriented design patterns represented in UML can be used to both teach type systems and develop the semantic analysis phase of a compiler. The main benefit of this approach is twofold: better comprehension of theoretical concepts because of the use of notations known by the students (UML diagrams), and improvement of software engineering skills for the development of a complete language processor.
EDUCATIONAL PEARL: A Nanopass framework for compiler education

A compiler structured as a small number of monolithic passes is difficult to understand and difficult to maintain. The steep learning curve is daunting, and even experienced developers find that modifying existing passes is difficult and often introduces subtle and tenacious bugs. These problems are especially frustrating when the developer is a student in a compiler class. An attractive alternative is to structure a compiler as a collection of many fine-grained passes, each of which performs a single task. This structure aligns the implementation of a compiler with its logical organization, simplifying development, testing, and debugging. This paper describes the methodology and tools comprising a framework for constructing such compilers.
Dynamic information flow analysis, slicing and profiling

Dynamic information flow analysis is concerned with the runtime monitoring and regulation of the flow of information among objects throughout a system and ultimately between the system and the outside world. A new approach to dynamic information flow analysis is presented that can be used to detect and debug insecure flows in programs. It can be applied offline to validate and debug a program against an information flow policy, or, when fast response is not critical, it can be applied online to prevent illegal flows in deployed programs. Dynamic mechanisms are inherently unable to detect implicit information flows; our approach incorporates an optional static preprocessing phase that identifies implicit flows and transforms them into explicit ones. The resulting hybrid mechanism is therefore capable of detecting both explicit and implicit information flows. Program slicing is an integral part of debugging against an information flow policy. Forward computing slicing algorithms, which do not require a previously stored execution trace, are especially suited for interactive debugging. This dissertation proposes a dynamic slicing algorithm, which is characterized as forward computing, precise and applicable to unstructured programs. Observation-based testing (OBT) is an approach in which executions of a program are profiled and then analyzed using cluster analysis and sampling methods to identify unusual or suspicious executions for manual auditing. This technique can be used to detect ordinary failures as well as intrusive behaviors. It can also be the basis for test-case filtering. This dissertation contributes to observation-based testing research by devising two profiling techniques that capture a relatively higher level of detail from a program execution namely, information flow profiling and slice profiling. In order to empirically verify their relative efficiency, we used them as well as other types of profiles such as function calls and data flow profiles to conduct test-case filtering experiments. The test-case filtering experiments involved OBT techniques as well as coverage-based techniques. The comparative results are presented and discussed. Finally, this dissertation presents a prototype tool for detecting and debugging insecure information flows in Java byte programs, it is also capable of generating information flow and slice execution profiles.
Soft Updates: A Technique for Eliminating Most Synchronous Writes in the Fast Filesystem

Traditionally, filesystem consistency has been maintained across system failures either by using synchronous writes to sequence dependent metadata updates or by using write-ahead logging to atomically group them. Soft updates, an alternative to these approaches, is an implementation mechanism that tracks and enforces metadata update dependencies to ensure that the disk image is always kept consistent. The use of soft updates obviates the need for a separate log or for most synchronous writes. Indeed, the ability of soft updates to aggregate many operations previously done individually and synchronously reduces the number of disk writes by 40 to 70% for file-intensive environments (e.g., program development, mail servers, etc.). In addition to performance enhancement, soft updates can also maintain better disk consistency. By ensuring that the only inconsistencies are unclaimed blocks or inodes, soft updates can eliminate the need to run a filesystem check program after every system crash. Instead, the system is brought up immediately. When it is convenient, a background task can be run on the active filesystem to reclaim any lost blocks and inodes. This paper describes an implementation of soft updates and its incorporation into the 4.4BSD fast filesystem. It details the changes that were needed, both to the original research prototype and to the BSD system, to create a production-quality system. It also discusses the experiences, difficulties, and lessons learned in moving soft updates from research to reality; as is often the case, non-focal operations (e.g., fsck and "fsync") required rethinking and additional code. Experiences with the resulting system validate the earlier research: soft updates integrates well with existing filesystems and enforces metadata dependencies with performance that is within a few percent of optimal.
A Survey of Compiler Testing

ing with credit is permitted. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from permissions@acm.org. © 2019 Association for Computing Machinery. 0360-0300/2019/1-ART1 $15.00 https://doi.org/10.1145/3363562 ACM Computing Surveys, Vol. 1, No. 1, Article 1. Publication date: January 2019.
Using component metadata to regression test component‐based software

Increasingly, modern‐day software systems are being built by combining externally‐developed software components with application‐specific code. For such systems, existing program‐analysis‐based software engineering techniques may not directly apply, due to lack of information about components. To address this problem, the use of component metadata has been proposed. Component metadata are metadata and metamethods provided with components, that retrieve or calculate information about those components. In particular, two component‐metadata‐based approaches for regression test selection are described: one using code‐based component metadata and the other using specification‐based component metadata. The results of empirical studies that illustrate the potential of these techniques to provide savings in re‐testing effort are provided. Copyright © 2006 John Wiley & Sons, Ltd.
Aggregation Dynamics in Service Overlay Networks for File Sharing

This paper related to link monitoring. Restricts the selfish nodes and creates the network with only non selfish nodes. Non selfish nodes network maintains good link connectivity without any failure and provides stable and optimal solution. This network shows good performance and scalable solution. Previous network systems whenever create uses the immediate neighbour selection technique. This technique selects less distance of nodes for creation of network without any verification. Sometimes network failures are generated because of insufficient energy levels of nodes. Automatically packets are not delivering within time. In failure location add the node with new energy levels. This is called as a rewiring. Travelling the total number of packets takes more amounts of time and energy levels. To complete the packets transmission, network expects dynamic changes. It is not stable and don’t provide any kind of reliable solution. We introduce new design of network systems with the help of selfish neighbour selection technique. This technique uses the overlay routing for restrict the selfish nodes. After removing the selfish nodes, remaining non selfish nodes provides authentication network. All authentication nodes have asymmetric distance. Asymmetric distance nodes give the interference problems. Using EGOIST server implementation converts the asymmetric distance nodes to symmetric distance nodes. It is possible based on prototype design here. These symmetric distance nodes distribute the data efficiently without loss. These types of networks are called stable.
Multiple Equilibria in Complex Chemical Reaction Networks: II. The Species-Reaction Graph

For mass action kinetics, the capacity for multiple equilibria in an isothermal homogeneous continuous flow stirred tank reactor is determined by the structure of the underlying network of chemical reactions. We suggest a new graph-theoretical method for discriminating between complex reaction networks that can admit multiple equilibria and those that cannot. In particular, we associate with each network a species-reaction graph, which is similar to reaction network representations drawn by biochemists, and we show that, if the graph satisfies certain weak conditions, the differential equations corresponding to the network cannot admit multiple equilibria {\em no matter what values the rate constants take}. Because these conditions are very mild, they amount to powerful (and quite delicate) necessary conditions that a network must satisfy if it is to have the capacity to engender multiple equilibria. Broad qualitative results of this kind are especially apt, for individual reaction rate constants are rare.
Multiple Equilibria in Complex Chemical Reaction Networks: Ii. the Species-reactions Graph

For mass action kinetics, the capacity for multiple equilibria in an isothermal homogeneous continuous flow stirred tank reactor is determined by the structure of the underlying network of chemical reactions. We suggest a new graph-theoretical method for discriminating between complex reaction networks that can admit multiple equilibria and those that cannot. In particular, we associate with each network a Species-Reaction Graph, which is similar to reaction network representations drawn by biochemists, and we show that, if the graph satisfies certain weak conditions, the differential equations corresponding to the network cannot admit multiple equilibria no matter what values the rate constants take. Because these conditions are very mild, they amount to powerful (and quite delicate) necessary conditions that a network must satisfy if it is to have the capacity to engender multiple equilibria. Broad qualitative results of this kind are especially apt, for individual reaction rate constants are rarely known fully for complex reaction networks (if they are known at all). Some concluding remarks address connections to biology. 1. Introduction. The purpose of this article is to provide theory for distinguishing between complex chemical reaction networks that have the capacity to admit multiple positive equilibria and those that do not. In particular, we shall be interested in networks governed by mass action kinetics and operating in the context of what chemical engineers call the continuous flow stirred tank reactor (CFSTR, [1]). Models in cell biology sometimes invoke pictures and mathematics reminiscent of CFSTRs [9, 12, 16, 17], so it not unreasonable to expect that theory presented here might ultimately provide insight that is useful in biological applications. Indeed, in biology one rarely has detailed knowledge of reaction rate constants; at the outset, then, it is especially appropriate to seek a qualitative understanding of the relationship between reaction network structure and the capacity for various kinds of behavior (e.g., bista-bility). As we indicated in the first article of this series, the connection between the two is quite delicate. The theory offered here is intended to render the relationship between reaction network structure and behavior more concrete. Our principal results will serve to describe very large classes of networks, including highly complex ones, that cannot give rise to multiple steady states regardless of parameter values. These results provide very strong necessary conditions that a network must satisfy if it is to have the capacity to give rise, for example, to bistable behavior. Denial …
Data report: major and trace element geochemistry of upper oceanic crust at IODP Site C0012 1

This data report presents the bulk rock major and trace element compositions analyzed by inductively coupled plasma–atomic emission spectroscopy (ICP-AES) and inductively coupled plasma–mass spectrometry (ICP-MS) of the upper oceanic crustal rocks recovered during Integrated Ocean Drilling Program Expedition 333.
Auditing buffer overflow vulnerabilities using hybrid static-dynamic analysis

Buffer overflow (BOF) vulnerabilities when present in code can be exploited to violate security objectives such as availability, confidentiality and integrity. They make up substantial portion of input manipulation attacks due to their common presence and ease of exploitation. In this study, the authors propose a hybrid approach combining static and dynamic program analysis with machine learning to audit BOFs. Simple rules to generate test data is proposed to confirm some of the vulnerabilities through dynamic analysis. Confirmed cases can be fixed by developers without further verification. Statements whose vulnerability is not confirmed by dynamic analysis are predicted by mining static code attributes. In the authors’ evaluation using standard benchmarks, their best classifier achieved a recall over 93% and accuracy >94%. Dynamic analysis itself confirmed 34% of known vulnerabilities along with reporting six new bugs, thereby reducing by third, otherwise needed manual auditing effort.
Equivalence Classes of Boolean Functions for First-Order Correlation

This paper presents a complete characterization of the first order correlation immune Boolean functions that includes the functions that are 1-resilient. The approach consists in defining an equivalence relation on the full set of Boolean functions with a fixed number of variables. An equivalence class in this relation, called a first-order correlation class, provides a measure of the distance between the Boolean functions it contains and the correlation-immune Boolean functions. The key idea consists on manipulating only the equivalence classes instead of the set of Boolean functions. To achieve this goal, a class operator is introduced to construct a class with n variables from two classes of n - 1 variables. In particular, the class of 1-resilient functions on n variables is considered. An original and efficient method to enumerate all the Boolean functions in this class is proposed by performing a recursive decomposition of classes with less variables. A bottom up algorithm provides the exact number of 1-resilient Boolean functions with seven variables which is 23478015754788854439497622689296. A tight estimation of the number of 1-resilient functions with eight variables is obtained by performing a partial enumeration. It is conjectured that the exact complete enumeration for general n is intractable.
Evolution of a Java just-in-time compiler for IA-32 platforms

JavaTM has gained widespread popularity in the industry, and an efficient Java virtual machine (JVMTM) and just-in-time (JIT) compiler are crucial in providing high performance for Java applications. This paper describes the design and implementation of our JIT compiler for IA-32 platforms by focusing on the recent advances achieved in the past several years. We first present the dynamic optimization framework, which focuses the expensive optimization efforts only on performance-critical methods, thus helping to manage the total compilation overhead. We then describe the platform-independent features, which include the conversion from the stack-semantic Java bytecode into our register-based intermediate representation (IR) and a variety of aggressive optimizations applied to the IR. We also present some techniques specific to the IA-32 used to improve code quality, especially for the efficient use of the small number of registers on that platform. Using several industry-standard benchmark programs, the experimental results show that our approach offers high performance with low compilation overhead. Most of the techniques presented here are included in the IBM JIT compiler product, integrated into the IBM Development Kit for Microsoft Windows®, Java Technology Edition Version 1.4. 0.
An Efficient Compiler Framework for Cache Bypassing on GPUs

Graphics processing units (GPUs) have become ubiquitous for general purpose applications due to their tremendous computing power. Initially, GPUs only employ scratchpad memory as on-chip memory. Though scratchpad memory benefits many applications, it is not ideal for those general purpose applications with irregular memory accesses. Hence, GPU vendors have introduced caches in conjunction with scratchpad memory in the recent generations of GPUs. The caches on GPUs are highly configurable. The programmer or compiler can explicitly control cache access or bypass for global load instructions. This highly configurable feature of GPU caches opens up the opportunities for optimizing the cache performance. In this paper, we propose an efficient compiler framework for cache bypassing on GPUs. Our objective is to efficiently utilize the configurable cache and improve the overall performance for general purpose GPU applications. In order to achieve this goal, we first characterize GPU cache utilization and develop performance metrics to estimate the cache reuses and memory traffic. Next, we present efficient algorithms that judiciously select global load instructions for cache access or bypass. Finally, we present techniques to explore the unified cache and shared memory design space. We integrate our techniques into an automatic compiler framework that leverages parallel thread execution instruction set architecture to enable cache bypassing for GPUs. Experiments evaluation on NVIDIA GTX680 using a variety of applications demonstrates that compared to cache-all and bypass-all solutions, our techniques improve the performance from 4.6% to 13.1% for 16 KB L1 cache.
An Efficient Certificateless Encryption for Secure Data Sharing in Public Clouds

: Cloud computing is one of the emerging technology, as it provides huge storage of information which is then requested by the end user. This pairing free system ensures security and integrity of the data which is stored on to the cloud. The susceptible in formation is rest encrypted and then uploaded on to the cloud and that information is half decrypted by the cloud and given to the requested end user for the full decryption process. In case of the data having same access control policy is requested by multiple users then our system generates a single encryption key whereas previous system was supporting single key for an individual whether they are requesting for the data having same access control policies. Therefore in our system, time for accessing same data by multiple requesters will reduce automatically and also key management will be easy. As only half decryption process is done on to the cloud, the confidentiality of the data is maintained over cloud. After uploading of data the authentication is maintained by encryption whereas the integrity is ensured by auditing technique. In the case of any changes done to the uploaded data, will generate an alert message for the data owner. If considered the properties of confidentiality and integrity with respect to cloud then definitely there will be take in its performance graph as compared to the existing system.
Jun 01, 2022 Biosynthesis of Phenylnannolone A, a Multidrug Resistance Reversal Agent from the Halotolerant Myxobacterium of

of [44] liberate the PPant arm (calculated m / z 261.1267). To verify that these ions (measured m / z 261.1277) really represent the PPant arm, they were subjected to an additional round of fragmentation (MS 4 ), and the ions obtained were analyzed for the typical PPant signature. [20]