Ralph Hefner


    Ralph Hefner specializes in business and data analysis — areas requiring coordination between business objectives, graphical and quantitative methods, and the design and deployment of Information Technology. Contracts, projects, partners and collaborators to further interests in the following areas are currently being sought:
       • database modeling and design
       • data integration
       • database applications including warehouses and marts
       • data mining
       • other complementary software or IT development

Skill Summary:

  • Data Analysis: Extensive experience with database technology spanning relational, dimensional, and legacy technologies. Experience as a database designer, modeler, analyst, and application developer. This includes related experience with extraction transformation and load methods, data cleansing and validation, data integration, data flow modeling, and other complementary skills.
  • Quantitative Methods: Regular academic training in mathematics, statistics, and economics re-enforced with real-world applications working as actuary, econometrician, statistician, and applied mathematician. Specialties include statistical methods, numerical analysis, and data visualization.
  • Software Development: Full SDLC experience on multiple platforms. Fluent in several programming languages. Good knowledge of Object Oriented analysis and design, UML, and software development methodologies. Legacy system evolution, client/server, Web applications, and scientific / mathematical applications. Scientific and mathematical development in areas of bio-statistics, chemistry, economics, econometrics, environmental studies, geophysics, numerical algorithms, and statistics.

Systems, Languages & Tools:

  • Quantitative: R, Ggobi, Gretl, Weka and other mathematical / statistical platforms
  • Visual Modeling Tools: ERWin, DBDesigner; Artisan Real Time, Poseidon, and other UML modeling tools.
  • Programming Languages: Java, C++, awk, HTML, Visual Basic (VB), VBA, SQL, Perl, REXX, CLIST
  • Operating Systems: Windows, UNIX, TSO-ISPF / MVS, CMS / VM
  • Database: SQL Server, MS Access, DB2, Oracle, FOCUS, ODBC, JDBC, ETL
  • Desktop Applications: Word, Excel, PowerPoint

Employment History:

2002-Present: Principal Consulltant — SigmaNomics, San Jose, CA
1990-2002: Principal Consultant — PROVISTA Software Intl, Fremont, CA
1988-1990: Mathmatics Prfessor — Naval Postgraduate School, Monterey, CA
1986-1988: Statistician / Actuary — Insurance Specialists Inc, Wheat Ridge, CO


MA, Mathematics: University of Colorado at Denver (UCD)
BA (high honors) Economics: Metropolitan State College at Denver (MSCD)

Project Portfolio — Sample:

Visual Basic / MS Access Development
MS Access, Visual Basic, Data Modeling, Database Design
• Worked with a commercial software company on a large re-engineering and defect-removal project involving a large MS Access application — 120K SLOC, approximately 200 Tables, 200 Forms, and 200 Reports. Re-designed database, and re-wrote or repaired numerous VB modules, Forms, and Reports.

Upsizing MS Access to SQL Server 2000
SQL Server, T-SQL, Stored Procedures, MS Access, Visual Basic
• Migration of an MS Access application to SQL Server 2000. Database redesign and normalization, conversion of VB code from DAO to ADO, implementation of stored procedures, and other refactoring to maximize the efficiency of the application while preserving the existing UI.

SQL Server Development
ERWin, C++, Visual Basic, MS Access, UI Design, Windows MFC
• Designed and developed an FTP interface between an external server and an internal server. The interface was based on a DLL wrapper around the WinInet.dll allowed an external SQL Server to use enhanced FTP services to send information to an internal server.

Medical Device Manufacturer
Database Design and Implementation
ERWin, C++, Visual Basic, MS Access, UI Design, Windows MFC
• OOA/OOD principles were used to redesign the database API used by the system. The new database API was developed in conjunction with a new database design that eliminated major design flaws in the original database. To maintain compatibility between the different database versions, it was necessary to write a rather tricky Extraction, Transformation, and Loading (ETL) utility. This utility was integrated with other database utilities that resulted in Field Technicians being much more productive and professional.

Medical Device Manufacturer
UML Modeling
UML, Aritsan Real Time, C++, OOD/OOA
• Utilized a UML tool to model and document a C++ system that was used to drive a laser surgical device. The UML models were used as supporting documentation in a filing for FDA approval (which was granted), and also were used as the basis for re-engineering and re-factoring the system in later releases of the product, to eliminate design flaws and bring the system into compliance with good design principles.

Demand Analysis and Modeling
Economics, Econometrics, Statistical Methods
• Construction, testing, and evaluation of demand models of telephone usage. Extensive use of maximum likelihood estimation, logit/probit and other discrete choice models. Technical papers and presentations at analytic conferences.

Actuarial / Statistical Analysis
Data Analysis, Statistical Methods, Numerical Analysis, Spread Sheet Tools, Data Visualization
• Developed innovative statistical models for the analysis of warranty contracts that were used for optimizing rates / prices and forecasting claims. Developed business and scientific software using a variety of language platforms and tools. Successful and effective technical presentations in support of sales and marketing to representatives from Lloyd's of London, Tillinghast, and other distinguished groups in the insurance industry.

Forecasting/Engineering Project
Java, Java GUI, Java Applets, SQL Server, T-SQL, Data Warehousing, 3270 Protocols, REXX, FOCU
• Designed, developed, and deployed a complex Intranet application to allow collaboration between a Forecasting Group and Network Design Engineering Group. Hybrid database design providing a data warehouse for the engineers, and an ODS for the engineers. Multiplatform effort involving IBM mainframes, corporate intranets, and desktops. Very complicated algorithm development.

State Government
Econometric Analysis
Economics, Econometrics, Statistical Methods, Algorithm Implementation
• Developed and implemented regional (SMSA) and statewide econometric models of labor markets for a state government. Performed statistical and econometric analysis, scientific programming, designed and implemented database and data structures, and wrote technical memoranda and system documentation.

Server-side Java Development
Java, Java Networking API, Internet Protocols
• Developed a "gate keeper" server to an interface between an AS/400 and a Java-based Validation Server. The product is a TCP/IP server to receive various transactions from the AS/400 system, and has an HTTPS Client to communicate with a call Validation Server. The product also includes a "rating" engine for the pricing of telephone calls. System implements a sophisticated logging system to monitor transactions, traffic, and billing information.

Mathematics Instructor / Professor
Mathematical Knowledge, Communication and Presentation Skills
• Courses taught include Advanced Calculus (I & II), Complex Variable, Numerical Analysis (I & II), Graph Theory, Set Theory, Mathematical Logic, Differential Equations, Linear Algebra, Applied Abstract Algebra, Calculus (I - IV), Economic Statistics, and Mathematics for Management. Won several outstanding teaching awards.

Contact Information:

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