Model-based Specification and Analysis of Natural Language Requirements in the Financial Domain

Software requirements form an important part of the software development process. In many software projects conducted by companies in the financial sector, analysts specify software requirements using a combination of models and natural language (NL). Neither models nor NL requirements provide a complete picture of the information in the software system, and NL is highly prone to quality issues, such as vagueness, ambiguity, and incompleteness. Poorly written requirements are difficult to communicate and reduce the opportunity to process requirements automatically, particularly the automation of tedious and error-prone tasks, such as deriving acceptance criteria (AC). AC are conditions that a system must meet to be consistent with its requirements and be accepted by its stakeholders. AC are derived by developers and testers from requirement models. To obtain a precise AC, it is necessary to reconcile the information content in NL requirements and the requirement models. In collaboration with an industrial partner from the financial domain, we first systematically developed and evaluated a controlled natural language (CNL) named Rimay to help analysts write functional requirements. We then proposed an approach that detects common syntactic and semantic errors in NL requirements. Our approach suggests Rimay patterns to fix errors and convert NL requirements into Rimay requirements. Based on our results, we propose a semiautomated approach that reconciles the content in the NL requirements with that in the requirement models. Our approach helps modelers enrich their models with information extracted from NL requirements. Finally, an existing test-specification derivation technique was applied to the enriched model to generate AC. The first contribution of this dissertation is a qualitative methodology that can be used to systematically define a CNL for specifying functional requirements. This methodology was used to create Rimay, a CNL grammar, to specify functional requirements. This CNL was derived after an extensive qualitative analysis of a large number of industrial requirements and by following a systematic process using lexical resources. An empirical evaluation of our CNL (Rimay) in a realistic setting through an industrial case study demonstrated that 88% of the requirements used in our empirical evaluation were successfully rephrased using Rimay. The second contribution of this dissertation is an automated approach that detects syntactic and semantic errors in unstructured NL requirements. We refer to these errors as smells. To this end, we first proposed a set of 10 common smells found in the NL requirements of financial applications. We then derived a set of 10 Rimay patterns as a suggestion to fix the smells. Finally, we developed an automatic approach that analyzes the syntax and semantics of NL requirements to detect any present smells and then suggests a Rimay pattern to fix the smell. We evaluated our approach using an industrial case study that obtained promising results for detecting smells in NL requirements (precision 88%) and for suggesting Rimay patterns (precision 89%). The last contribution of this dissertation was prompted by the observation that a reconciliation of the information content in the NL requirements and the associated models is necessary to obtain precise AC. To achieve this, we define a set of 13 information extraction rules that automatically extract AC-related information from NL requirements written in Rimay. Next, we propose a systematic method that generates recommendations for model enrichment based on the information extracted from the 13 extraction rules. Using a real case study from the financial domain, we evaluated the usefulness of the AC-related model enrichments recommended by our approach. The domain experts found that 89% of the recommended enrichments were relevant to AC, but absent from the original model (precision of 89%)

Cranio-Orbito-Zygomatic Approach

The cranio-orbito-zygomatic (COZ) approach consists of an extension of the pterional approach characterized by the removal of the superolateral part of the orbital rim and zygoma. This key step tremendously increases the angular exposure to some deep targets and overall surgical freedom to the lesion. In this article we review the technical variations of the COZ approach, mainly focusing on the differential quantitative effects coming from the orbital osteotomy compared to the zygomatic one

Far Lateral Approach

The far lateral approach is an inferolateral extension of the lateral suboccipital approach. Designed for clipping of the aneurysms of the vertebrobasilar junction and proximal segments of the posterior inferior cerebellar artery, it became over the years a workhorse approach for ventral foramen magnum meningiomas and other intradural lesions located anterior to the dentate ligament.  This article summarizes the technical key aspects of the far lateral approach and transcondylar, supracondylar, and paracondylar extension

Cranio-Orbito-Zygomatic Approach: Core Techniques for Tailoring Target Exposure and Surgical Freedom

The cranio-orbito-zygomatic (COZ) approach is a workhorse of skull base surgery, and each of its steps has a precise effect on target exposure and surgical freedom. The present study overviews the key techniques for execution and tailoring of the COZ approach, focusing on the quantitative effects resulting from removal of the orbitozygomatic (OZ) bar, orbital rim, and zygomatic arch

On Systematically Building a Controlled Natural Language for Functional Requirements

[Context] Natural language (NL) is pervasive in software requirements specifications (SRSs). However, despite its popularity and widespread use, NL is highly prone to quality issues such as vagueness, ambiguity, and incompleteness. Controlled natural languages (CNLs) have been proposed as a way to prevent quality problems in requirements documents, while maintaining the flexibility to write and communicate requirements in an intuitive and universally understood manner. [Objective] In collaboration with an industrial partner from the financial domain, we systematically develop and evaluate a CNL, named Rimay, intended at helping analysts write functional requirements. [Method] We rely on Grounded Theory for building Rimay and follow well-known guidelines for conducting and reporting industrial case study research. [Results] Our main contributions are: (1) a qualitative methodology to systematically define a CNL for functional requirements; this methodology is intended to be general for use across information-system domains, (2) a CNL grammar to represent functional requirements; this grammar is derived from our experience in the financial domain, but should be applicable, possibly with adaptations, to other information-system domains, and (3) an empirical evaluation of our CNL (Rimay) through an industrial case study. Our contributions draw on 15 representative SRSs, collectively containing 3215 NL requirements statements from the financial domain. [Conclusion] Our evaluation shows that Rimay is expressive enough to capture, on average, 88% (405 out of 460) of the NL requirements statements in four previously unseen SRSs from the financial domain

Classification and Management of Pontecerebellar-Petrosal Bridging Veins

The risks and benefits of coagulating intradural venous elements during a retrosigmoid approach for trigeminal neurovascular decompression has not been accurately established. The objectives of this study were to identify the veins that drain into the superior petrosal sinus, classify them in relation to the suprameatal tubercle, and determine the implication of their coagulation

Optic Foraminotomy for Clipping of Superior Carotid-Ophthalmic Aneurysms

Background: Carotid-ophthalmic aneurysms usually cause visual problems. Its surgical treatment is challenging because of its anatomically close relations to the optic nerve, carotid artery, ophthalmic artery, anterior clinoid process, and cavernous sinus, which hinder direct access. Despite recent technical advancements enabling risk reduction of this complication, postoperative deterioration of visual function remains a significant problem. Therefore, the goal of preserving and/or improving the visual outcome persists as a paramount concern. Objective: We propose optic foraminotomy as an alternative microsurgical technique for dorsal carotid-ophthalmic aneurysms clipping. As a secondary objective, the step by step of that technique and its benefits are compared to the current approach of anterior clinoidectomy. Methods: We present as an example two patients with superior carotid-ophthalmic aneurysms in which the standard pterional craniotomy, transsylvian approach, and optic foraminotomy were performed. Surgical techniques are presented and discussed in detail with the use of skull base dissections, microsurgical images, and original drawings. Results: Extensive opening of the optic canal and optic nerve sheath was successfully achieved in all patients allowing a working angle with the carotid artery for correct visualization of the aneurysm and further clipping. Significant visual acuity improvement occurred in both patients because of decompression of the optic nerve. Conclusion: Optic foraminotomy is an easy and recommended technique for exposing and treating superior carotid-ophthalmic aneurysms and allowing optic nerve decompression during the first stages of the procedure. It shows several advantages over the current anterior clinoidectomy technique regarding surgical exposure and facilitating visual improvement

Análisis de la evolución de la fibra de alpaca peruana del 2010 al 2019

This research explores the Peruvian alpaca industry in the period between 2010 and 2019. The alpaca industry has seen growth in recent years, not only in terms of consumption but also in terms of exports, presenting new challenges and opportunities for the industry and stakeholders. The research details the levels presented by alpaca fiber in terms of production and exports, as well as some of the conflicts present in the industry in the recent years. For the analysis, quantitative information regarding alpaca industry was extracted as well as the collection of qualitative information about the production process or the conflict present in the industry for its development. Although the research allows to conclude that the alpaca industry presents a positive trend, it is important to note that competition from other countries, as well as conflicts inherent to the industry and the country, can lead to a reduction in the value of the fiber in the market international.El presente trabajo de investigación explora la industria alpaquera del Perú en el periodo comprendido entre el 2010 y el 2019. La industria alpaquera ha visto un crecimiento en los últimos años, no solo en cuanto a consumo sino también en cuanto a exportaciones, presentando nuevos retos y oportunidades para la industria y las partes involucradas. En la presente investigación se detallarán los niveles presentados por la fibra de alpaca en cuanto a producción y exportación, así como algunos de los conflictos presentes en la industria e los últimos años. Para el análisis realizado se extrajo información cuantitativa referente a la industria alpaquera, así como la recolección de información cualitativa referente al proceso productivo o los conflictos presentes en la industria para su desarrollo. Si bien la investigación permite concluir que la industria alpaquera presenta una tendencia positiva, es importante destacar que la competencia de otros países, así como los conflictos propios de la industria y el país, pueden conllevar a una reducción del valor de la fibra en el mercado internacional

Surgical corridors to foramen magnum meningiomas: a mini-review

Gross-total resection of foramen magnum meningiomas remains the gold standard of treatment and should be performed whenever possible. The transcondylar approach (and its variations) represents the most used approach for meningiomas located in the lateral or anterior borders of the foramen magnum. Endoscopic transclivus approaches represent a useful option in selected cases of anterior midline foramen magnum meningiomas, to be performed in centers with advanced experience in endoscopic skull base surgery, with the caveats of increased risk of postoperative cerebrospinal fluid leak. Alternatively, radiosurgery remains an option for well-selected cases, especially for the management of asymptomatic patients with small enlarging tumors. Advances in molecular profiling, as well as genetic analysis, may guide adjuvant treatment