An operational system for subject switching between controlled vocabularies: A computational linguistics approach

The NASA Lexical Dictionary (NLD), a system that automatically translates input subject terms to those of NASA, was developed in four phases. Phase One provided Phrase Matching, a context sensitive word-matching process that matches input phrase words with any NASA Thesaurus posting (i.e., index) term or Use reference. Other Use references have been added to enable the matching of synonyms, variant spellings, and some words with the same root. Phase Two provided the capability of translating any individual DTIC term to one or more NASA terms having the same meaning. Phase Three provided NASA terms having equivalent concepts for two or more DTIC terms, i.e., coordinations of DTIC terms. Phase Four was concerned with indexer feedback and maintenance. Although the original NLD construction involved much manual data entry, ways were found to automate nearly all but the intellectual decision-making processes. In addition to finding improved ways to construct a lexical dictionary, applications for the NLD have been found and are being developed

An operational system for subject switching between controlled vocabularies

The NASA system of automatically converting sets of terms assigned by Department of Defense indexers to sets of NASA's authorized terms is described. This little-touted system, which has been operating successfully since 1983, matches concepts, rather than words. Subject Switching uses a translation table, known as the Lexical Dictionary, accessed by a program that determines which rules to follow in making the transition from DTIC's to NASA's authorized terms. The authors describe the four phases of development of Subject Switching, changes that have been made, evaluating the system, and benefits. Benefits to NASA include saving indexers' time, the addition of access points for documents indexed, the utilization of other government indexing, and a contribution towards the now-operational NASA, online, interactive, machine aided indexing

An Interactive Empirical Approach to the Validation of Software Package Specifications

The objective of this research is the development of a practical system to manipulate and validate software package specifications. The validation process developed is based on consistency checks. Furthermore, by means of scenarios, the customer will be able to interactively experience the specified system prior to its implementation. Functions, data, and data types constitute the framework of our validation system. The specification of the Graphical Kernel System (GKS) is a typical example of the target software package specifications to be manipulated

Computer Supported Indexing: A History and Evaluation of NASA's MAI System

Computer supported indexing systems may be categorized in several ways. One classification scheme refers to them as statistical, syntactic, semantic or knowledge-based. While a system may emphasize one of these aspects, most systems actually combine two or more of these mechanisms to maximize system efficiency. Statistical systems can be based on counts of words or word stems, statistical association, and correlation techniques that assign weights to word locations or provide lexical disambiguation, calculations regarding the likelihood of word co-occurrences, clustering of word stems and transformations, or any other computational method used to identify pertinent terms. If words are counted, the ones of median frequency become candidate index terms. Syntactical systems stress grammar and identify parts of speech. Concepts found in designated grammatical combinations, such as noun phrases, generate the suggested terms. Semantic systems are concerned with the context sensitivity of words in text. The primary goal of this type of indexing is to identify without regard to syntax the subject matter and the context-bearing words in the text being indexed. Knowledge-based systems provide a conceptual network that goes past thesaurus or equivalent relationships to knowing (e.g., in the National Library of Medicine (NLM) system) that because the tibia is part of the leg, a document relating to injuries to the tibia should he indexed to LEG INJURIES, not the broader MeSH term INJURIES, or knowing that the term FEMALE should automatically be added when the term PREGNANCY is assigned, and also that the indexer should be prompted to add either HUMAN or ANIMAL. Another way of categorizing indexing systems is to identify them as producing either assigned- or derived-term indexes

Computer Supported Indexing: A History and Evaluation of NASA's MAI System

Computer supported or machine aided indexing (MAI) can be categorized in multiple ways. The system used by the National Aeronautics and Space Administration's (NASA's) Center for AeroSpace Information (CASI) is described as semantic and computational. It's based on the co-occurrence of domain-specific terminology in parts of a sentence, and the probability that an indexer will assign a particular index term when a given word or phrase is encountered in text. The NASA CASI system is run on demand by the indexer and responds in 3 to 9 seconds with a list of suggested, authorized terms. The system was originally based on a syntactic system used in the late 1970's by the Defense Technical Information Center (DTIC). The NASA mainframe-supported system consists of three components: two programs and a knowledge base (KB). The evolution of the system is described and flow charts illustrate the MAI procedures. Tests used to evaluate NASA's MAI system were limited to those that would not slow production. A very early test indicated that MAI saved about 3 minutes and provided several additional terms for each document indexed. It also was determined that time and other resources spent in careful construction of the KB pay off with high-quality output and indexer acceptance of MAI results

Machine aided indexing from natural language text

The NASA Lexical Dictionary (NLD) Machine Aided Indexing (MAI) system was designed to (1) reuse the indexing of the Defense Technical Information Center (DTIC); (2) reuse the indexing of the Department of Energy (DOE); and (3) reduce the time required for original indexing. This was done by automatically generating appropriate NASA thesaurus terms from either the other agency's index terms, or, for original indexing, from document titles and abstracts. The NASA STI Program staff devised two different ways to generate thesaurus terms from text. The first group of programs identified noun phrases by a parsing method that allowed for conjunctions and certain prepositions, on the assumption that indexable concepts are found in such phrases. Results were not always satisfactory, and it was noted that indexable concepts often occurred outside of noun phrases. The first method also proved to be too slow for the ultimate goal of interactive (online) MAI. The second group of programs used the knowledge base (KB), word proximity, and frequency of word and phrase occurrence to identify indexable concepts. Both methods are described and illustrated. Online MAI has been achieved, as well as several spinoff benefits, which are also described

Modal Theory of Skin Effect in Single and Multiple Turn Coils

The skin effect in circularly symmetric structures is formulated in terms of an integral equation, which may be solved in terms of the normal modes of the corresponding integral equation eigenvalue problem. The necessary modal functions are computed numerically, using a simple discrete model of the coil. The modal series solution easily accounts for electrical excitation of the coil as for external magnetic fields. A comparison with so-called "direct" calculation methods, as well as with published experimental results, shows that the method is capable of good accuracy, while effecting substantial economies in computation

A Graphics Function Standard Specification Validator

A validation methodology is proposed and implemented for natural language software specifications of standard graphics functions. Checks are made for consistency, completeness, and lack of ambiguity in data element and function descriptions. Functions and data elements are maintained in a relational database representation. The appropriate checks are performed by sequences of database operations. The relational database manager INGRES was used to support a prototype implementation of the proposed technique. The methodology supports the development of a scenario-based prototype from the information available in the specification. This permits various function sequences to be checked without implementation of the environment specified. The application of a prototype implementation of the proposed methodology to the specification of the Graphics Kernel System (GKS) software package demonstrates the practicability of the method. Several inconsistencies in GKS related to the definition of data elements have been identified

Nitrogenase activity associated with codium species from New Zealand marine habitats

Nitrogenase activity, measured as acetylene reduction, was recorded at rates up to 1028 nmol.h \g * dry weight for Codium adhaerens (Cabr.) Ag. var. convolutum Dellow and Codium fragile (Sur.) Hariot subsp. tomentosoides (Van Goor) Silva collected from New Zealand habitats. In both species the ability to reduce acetylene is invariably associated with the presence of a heterocystous blue-green alga, Calothrix sp., epiphytic or embedded in the Codium thallus. A highly significant (P < 0.001) correlation between heterocyst frequency and nitrogenase activity was found. Nitrogenase and net photosynthesis of the Codium-Calothrix system have different steady-state responses to light intensity, and the kinetics of the two processes also differ in that nitrogenase is slow to respond to illumination or darkening. Glucose additions to Codium did not significantly increase nitrogenase activity. Nitrogenase is relatively insensitive to oxygen tension over the range 0-1.0 atm (0-1.033 kgf.cnT2) and still occurs at 1.5 atm (1.55 kgf.cm"2); this condition is unique in all nitrogenase systems thus far reported. Collectively these facts suggest that Calothrix is the agent primarily responsible for nitrogenase activity in these Codium species

Pengaruh Financial Distress Dan Koneksi Politik Terhadap Praktik Tax Avoidance (Studi Kasus Pada Perusahaan Sektor Industri Pertambangan Tahun 2016– 2019)

Perusahaan yang sedang dalam kondisi financial distress perlu mengembangkan strategi untuk mengurangi jumlah pajak yang dibayarkan, salah satunya dengan melakukan tax avoidance. Hal ini dilakukan untuk mempertahankan legitimasi dan credit ratings perusahaan. Perusahaan dengan koneksi politik memiliki dampak positif dan negatif. Salah satu dampak positifnya ialah perusahaan memenuhi syarat sebagai PKP Berisiko Rendah. Tujuan penelitian ini untuk mengetahui pengaruh financial distress dan koneksi politik terhadap praktik tax avoidance dengan studi kasus pada perusahaan sektor industri pertambangan. Tax avoidance menggunakan pengukuran Cash Effective Tax Rates, Financial distress diukur dengan Altman’s Z–score, koneksi politik diukur dengan kepemilikan saham utama oleh pemerintah dengan persentase 25% atau lebih. Peneliti menggunakan data sekunder berupa laporan keuangan dan laporan tahunan perusahaan dengan teknik pengumpulan data dokumentasi pada situs resmi BEI dan situs resmi perusahaan. Populasi penelitian adalah perusahaan sektor industri pertambangan yang terdaftar di BEI tahun 2016–2019. Sampel ditentukan menggunakan metode purposive sampling, sehingga diperoleh 14 perusahaan. Penelitian ini menggunakan analisis regresi linear berganda sebagai metode analisis data. Hasil penelitian menunjukkan bahwa financial distress berpengaruh negatif terhadap tax avoidance, hasil ini bertentangan dengan hipotesis yang dirumuskan, yaitu berpengaruh positif. Sedangkan koneksi politik berpengaruh negatif terhadap tax avoidance, hasil ini menerima hipotesis. Hal ini terjadi karena selama tahun 2016–2019 pemerintah mengeluarkan kebijakan insentif pajak, sehingga terjadi penurunan persentase pembayaran pajak oleh perusahaan dan hasil koneksi politik dapat dijelaskan sebagai Bureaucratic Incentive Effec