Deletion Operations Research Articles

On sufficient statistics of least-squares superposition of vector sets.

The problem of superposition of two corresponding vector sets by minimizing their sum-of-squares error under orthogonal transformation is a fundamental task in many areas of science, notably structural molecular biology. This problem can be solved exactly using an algorithm whose time complexity grows linearly with the number of correspondences. This efficient solution has facilitated the widespread use of the superposition task, particularly in studies involving macromolecular structures. This article formally derives a set of sufficient statistics for the least-squares superposition problem. These statistics are additive. This permits a highly efficient (constant time) computation of superpositions (and sufficient statistics) of vector sets that are composed from its constituent vector sets under addition or deletion operation, where the sufficient statistics of the constituent sets are already known (that is, the constituent vector sets have been previously superposed). This results in a drastic improvement in the run time of the methods that commonly superpose vector sets under addition or deletion operations, where previously these operations were carried out ab initio (ignoring the sufficient statistics). We experimentally demonstrate the improvement our work offers in the context of protein structural alignment programs that assemble a reliable structural alignment from well-fitting (substructural) fragment pairs. A C++ library for this task is available online under an open-source license.

Gaps, ghosts and gapless relatives in spoken English

AbstractThis paper looks at the syntax of so‐called gapless relative clauses in spoken English. §1 contrasts gap relatives (like that italicised in ‘something which I said’, in which there is a gap internally within the relative clause associated with the relativised constituent) with gapless relatives (like that italicised in ‘They were clowning around, which I didn't really care until I found out they had lost my file’, in which there is no apparent gap within the relative clause). In §2, we note that a number of recent analyses take which to function as a subordinating conjunction in gapless relatives, but we argue against this view and provide evidence that the wh‐word in such clauses is indeed a relative pronoun. In §3, we argue that the relative pronoun in gapless relatives serves as the object of a ‘silent’ preposition. In §4, we present an analysis under which a preposition can be silent when it undergoes a type of deletion operation called Ghosting. §5 discusses gapless relatives which have a Topic‐Comment interpretation, and argues for an extended Ghosting analysis under which a TP containing a predicate of saying associated with the ghosted preposition is also ghosted. Our overall conclusion is that supposedly ‘gapless’ relatives are more properly analysed as containing a gap created by relativization of the object of a ghosted preposition.

Remark: Long‐Distance Reflexives, Blocking Effects, and the Structure of Mandarin Comparatives

AbstractDrawing on data concerning the long‐distance dependency of the Mandarin bare reflexive ziji ‘self’ in embedded comparatives, this remark compares two types of analyses of Mandarin comparatives—the Reduction Analysis and the Direct Analysis. The discussion shows that the long‐distance dependency of ziji in an embedded comparative can be easily captured in the Reduction Analysis, where a deletion operation is involved in the derivation; however, the Direct Analysis, where the constituent size of the standard of comparison is transparent, encounters challenges when facing the same data.

SSD에서의 TRIM 명령어 처리 성능 분석 및 Ext4 파일 시스템으로의 적용

In this paper, we analyze the performance of the TRIM commands on various SSDs and, based on our analysis results, we enhance the performance of these TRIM commands in the Ext4 file system. We observed that the performance of the TRIM commands improves as the size of the LBA-range increases, the sector number is aligned and continuous or more LBA-ranges are notified via a single TRIM command. However, although the performance is better when multiple LBA-ranges are informed by a single TRIM command, the Ext4 file system issues a single TRIM command for every LBA-range. In this paper, we modify the Ext4 file system to convey at most 64 LBA-ranges per TRIM command. Evaluations through Filebench show that the performance of file deletion operations is improved by up to 35%.

Efficient Hybrid Inline and Out-of-Line Deduplication for Backup Storage

Backup storage systems often remove redundancy across backups via inline deduplication, which works by referring duplicate chunks of the latest backup to those of existing backups. However, inline deduplication degrades restore performance of the latest backup due to fragmentation, and complicates deletion of expired backups due to the sharing of data chunks. While out-of-line deduplication addresses the problems by forward-pointing existing duplicate chunks to those of the latest backup, it introduces additional I/Os of writing and removing duplicate chunks. We design and implement RevDedup , an efficient hybrid inline and out-of-line deduplication system for backup storage. It applies coarse-grained inline deduplication to remove duplicates of the latest backup, and then fine-grained out-of-line reverse deduplication to remove duplicates from older backups. Our reverse deduplication design limits the I/O overhead and prepares for efficient deletion of expired backups. Through extensive testbed experiments using synthetic and real-world datasets, we show that RevDedup can bring high performance to the backup, restore, and deletion operations, while maintaining high storage efficiency comparable to conventional inline deduplication.

A New Evolutionary-Incremental Framework for Feature Selection

Feature selection is an NP-hard problem from the viewpoint of algorithm design and it is one of the main open problems in pattern recognition. In this paper, we propose a new evolutionary-incremental framework for feature selection. The proposed framework can be applied on an ordinary evolutionary algorithm (EA) such as genetic algorithm (GA) or invasive weed optimization (IWO). This framework proposes some generic modifications on ordinary EAs to be compatible with the variable length of solutions. In this framework, the solutions related to the primary generations have short length. Then, the length of solutions may be increased through generations gradually. In addition, our evolutionary-incremental framework deploys two new operators called addition and deletion operators which change the length of solutions randomly. For evaluation of the proposed framework, we use that for feature selection in the application of face recognition. In this regard, we applied our feature selection method on a robust face recognition algorithm which is based on the extraction of Gabor coefficients. Experimental results show that our proposed evolutionary-incremental framework can select a few number of features from existing thousands features efficiently. Comparison result of the proposed methods with the previous methods shows that our framework is comprehensive, robust, and well-defined to apply on many EAs for feature selection.

A Multi-Index Hybrid Trie for Lookup and Updates

\begin{abstract} High-performance routers require high-speed IP address lookup to achieve wire-speed packet forwarding. This study proposes a new data structure, the Multi-Index Hybrid Trie (MIHT), for dynamic router table designs. This data structure was constructed by combining the useful characteristics of the ${\rm B}^{+}$ tree and priority trie. IP lookup operations can be performed efficiently by associating each prefix with a key value in the MIHT. Furthermore, because the required tree height and number of prefixes were reduced, dynamic router table operations were performed efficiently using the MIHT. To reduce the memory requirement, each prefix stored its corresponding suffix in a node of the MIHT, rather than storing a full prefix. Experiments using IPv4 and IPv6 routing databases indicated that the proposed data structure has efficient memory usage and performs well for lookup, insertion, and deletion operations. This study reports the results of the experiments performed to compare the proposed data structure with other structures using the benchmark IPv4 and IPv6 prefix databases AS1221, AS4637, AS6447, AS65000, AS1221*, and AS6447* with 407,067, 219,581, 417,995, 406,973 , 12,155, and 12,278 prefixes, respectively, where AS1221* and AS6447* are IPv6 BGP routing tables. \end{abstract} \begin{IEEEkeywords} Classless inter domain routing (CIDR), dynamic router tables, IP address lookup, longest matching prefix, multi-index hybrid trie. \end{IEEEkeywords}

Computer aided product design tool for sustainable product development

A computer aided product design (CAPD) tool is proposed that finds mixtures matching target properties. Genetic algorithm crossover and mutation operators are completed with insertion or deletion operators adapted for side branches. A new substitution operator is devised for cyclic molecules. The mixture fitness is evaluated by a weighted sum of property performances. Molecules are represented by molecular graphs. They are split into molecular fragments which are built from polyatomic groups. Molecules or molecular fragments can be fixed, constrained or left free for building a new molecule. Building blocks are chemical functional groups or bio-sourced synthons. A specific coding of hydrogen-suppressed atoms is devised that can be used with various property estimation models where atom connectivity information is required. Illustration is provided through three case studies to find levulinic, glycerol and bio-based derivatives as substitute for chlorinated paraffin, methyl p-coumarate ester solvent and blanket wash solvent, respectively.

The Scalability of Disjoint Data Structures on a New Hardware Transactional Memory System

In this paper we present our experiences constructing and testing in-memory data structures designed to be disjoint enough for transactional memory to be profitable as a serialization mechanism with no fallback to traditional locking. Our goal was to restrict memory conflicts to actual contention situations so that transactional memory techniques could be used as efficiently as possible. We describe the hardware transactional execution facility in the IBM zEnterprise EC12 server. We present an order preserving hashed structure that permits insertion, deletion, and traversal operations typically supported by a sorted linked list. We also present a concurrent open addressing hash table structure. We measure the performance and scalability for these data structures on the IBM zEnterprise EC12 server. Our results show near linear scalability of the insertion and deletion operations for up to 96 CPUs. We also discuss transaction abort frequency and hardware/software interactions.

Hidden nominal structures in Japanese clausal comparatives

Recent studies of Japanese clausal comparatives have yielded several competing theoretical views of their syntax and semantics that have different implications for the issue of crosslinguistic variation in comparative constructions. This paper aims at contributing to this debate by offering a novel syntactic analysis of Japanese clausal comparatives. The main proposal is that despite their appearance, Japanese clausal comparatives involve a nominal structure whose nominal head is deleted by a syntactic deletion operation, and therefore are underlyingly phrasal comparatives. It is demonstrated that this analysis explains peculiar syntactic and semantic properties of Japanese (seemingly) clausal comparatives, some of which have been unidentified in the previous literature. The proposed account also allows us to dispense with the previously proposed semantic variation specific to degree constructions, and entertain a more conservative view of crosslinguistic variation where the differences between Japanese-type and English-type comparative constructions are solely attributed to their morphosyntactic properties.

Achieving Residential Connectivity and Density Goals with Computer-Generated Plans in a Greenfield Area

An algorithm has been developed to generate, without external intervention, a road and land-use plan for a regular or irregular site. It starts from an ‘embryo’ and grows a plan rather than trying to modify an initial solution. The basic modules are universal building blocks which change and adapt in a guided search with random selection of branching points followed by operations to add links or make connections. Deletion operators guide development by removing branches which do not improve the outcome. A hypothetical application, maximizing combined everyone-to-everyone connectivity and dwelling density, has evolved a highly interconnected street plan. However, no step is specific to the example; the operators will grow a road and land-use network under various specifications and constraints guided by an objective function. Making the process applicable to an actual development might require more constraints and certainly an enlarged objective function. Cost and other goals can be included so long as each goal is functionally related in some way to every change in the plan made by the search procedure.

Techniques for Understanding User Usage Behavior on the Internet

Techniques for Understanding User Usage Behavior on the Internet

A Hybrid Approach Based on ACO and Ga for Multi Objective Mobile Robot Path Planning

In this study, we developed an Ant Colony Optimization (ACO) - Genetic Algorithm (GA) hybrid approach for solving the Multi objectives Optimization global path planning (MOPP) problem of mobile robot. The ACO optimization algorithm is used to find the sub-optimal collision free path which then used as initial population for GA. In the proposed modified genetic algorithms, specific genetic operator such as deletion operator is proposed, which is based on domain heuristic knowledge, to fit the optimum path planning for mobile robots. The objective of this study is improving GA performance for efficient and fast selection in generating the Multi objective optimal path for mobile robot navigation in static environment. First we used the proposed approach to evaluate its ability to solve single objective problem in length term as well as we compared it with traditional ACO and simple GA then we extended to solve Pareto optimality ideas based on three criteria: length, smoothness and security, and making it Multi objective Hybrid approach. The proposed approach is tested to generate the single and multi objective optimal collision free path. The simulation results show that the mobile robot travels successfully from one location to another and reaches its goal after avoiding all obstacles that are located in its way in all tested environment and indicate that the proposed approach is accurate and can find a set Pareto optimal solution efficiently in a single run.

Generating and accepting P systems with minimal left and right insertion and deletion

In this paper we investigate the operations of insertion and deletion performed at the ends of a string. We show that using these operations in a P systems framework (which corresponds to using specific variants of graph control), computational completeness can even be achieved with the operations of left and right insertion and deletion of only one symbol, both in the generating as well as in the accepting case.

Complete monotonicity for inverse powers of some combinatorially defined polynomials

We prove the complete monotonicity on (0,∞)n for suitable inverse powers of the spanning-tree polynomials of graphs and, more generally, of the basis generating polynomials of certain classes of matroids. This generalizes a result of Szegő and answers, among other things, a long-standing question of Lewy and Askey concerning the positivity of Taylor coefficients for certain rational functions. Our proofs are based on two ab-initio methods for proving that P-β is completely monotone on a convex cone C: the determinantal method and the quadratic-form method. These methods are closely connected with harmonic analysis on Euclidean Jordan algebras (or equivalently on symmetric cones). We furthermore have a variety of constructions that, given such polynomials, can create other ones with the same property: among these are algebraic analogues of the matroid operations of deletion, contraction, direct sum, parallel connection, series connection and 2-sum. The complete monotonicity of P-β for some β>0 can be viewed as a strong quantitative version of the half-plane property (Hurwitz stability) for P, and is also related to the Rayleigh property for matroids.

Determining Reconstruction Variables and Parameters on Improved Multi-Objective Immune Algorithm

Aimed at multi-dimension of evaluating reconstruction effect and the correlation between reconstruction variables and reconstruction parameters, improved multi-objective immune algorithm (IMOIA) was proposed to simultaneously determine reconstruction variables and parameters in multivariate time series phase space. In IMOIA, antibody coding was binary strings cascade of multi-parameter, antibody evaluating was three functions, and a new population evaluating S - is presented. Immune operators were designed: overall clone operator to improve speed, mutation operator with multiple changing probability on gene loci and S enhanced local and global search capability to ensure algorithm convergence, Clonal Selection operator on Rank and Crowding-distance to ensure solutions uniformity, repetitive antibodies determination and deletion operator to ensure solutions diversity. Use our method to two benchmarking chaos system, simulation results showed that our method can simultaneously solved multiple combinations of optimal reconstruction variables and parameters and had obvious superiority to other intelligent optimization algorithms and determining reconstruction parameter methods.

Born empty

Chinese seems to allow argument ellipsis in object but not subject positions according to interpretive contrasts between null subjects and objects. It has been claimed that this contrast can be captured by allowing only a null subject to be a pro, which is licensed by agreement. The presence of agreement means the absence of argument ellipsis. This line of analysis would require Chinese to have subject agreement. However, it will be shown that this language does not have agreement. Moreover, there are constructions disallowing missing objects, challenging the available analyses. It will be argued that these complex facts, including the noted subject/object asymmetry and the impossibility of missing objects in various constructions, can be accommodated if a base-generated true empty category is possible when a pro is not available. Interestingly, the arguments supporting this proposal would lead us to claim that VP-ellipsis should be the result of a deletion operation; i.e., not all ellipsis constructions are derived via the same mechanisms.

분산 공간 데이터 스트림 시스템에서 연산 처리율 기반의 적응적 업스트림 백업 기법

Abstract In distributed spatial data stream processing, processed tuples of downstream nodes are replicated to the upstream node in order to increase the utilization of distributed nodes and to recover the whole system for the case of system failure. However, while the data input rate increases and multiple downstream nodes share the operation result of the upstream node, the data which stores to output queues as a backup can be lost since the deletion operation delay may be occurred by the delay of the tuple processing of upstream node. In this paper, the adaptive upstream backup scheme based on operation throughput in distributed spatial data stream system is proposed. This method can cut down the average load rate of nodes by efficient spatial operation migration as it processes spatial temporal data stream, and it can minimize the data loss by fluid change of backup mode. The experiments show the proposed approach can prevent data loss and can decrease, on average, 20% of CPU utilization by node monitoring.

One-dimensional Array Grammars and P Systems with Array Insertion and Deletion Rules

We consider the (one-dimensional) array counterpart of contextual as well as insertion and deletion string grammars and consider the operations of array insertion and deletion in array grammars. First we show that the emptiness problem for P systems with (one-dimensional) insertion rules is undecidable. Then we show computational completeness of P systems using (one-dimensional) array insertion and deletion rules even of norm one only. The main result of the paper exhibits computational completeness of one-dimensional array grammars using array insertion and deletion rules of norm at most two.

Refinements of machine translation by automatic editorial operations

The performance of state-of-the-art machine translation (MT) systems is still far from being perfect. In this article, we investigate the combination of on-line MT systems to produce better outputs. The basic idea is to apply editorial operations of substitution, insertion, and deletion to candidate outputs in an automatic fashion. The proposed methods are evaluated on the translation task in the travel domain from Chinese to English as defined in the International Workshop on Spoken Language Translation evaluation campaign. Outputs of three on-line MT engines are combined. The proposed method is evaluated on Chinese-to-English MT tasks in the tourism domain. An overall improvement of 1.4 in the BLEU score over the best single-system baseline has been achieved.