Hong Yul Yang

Thinker

Feeler

email	hongyul@cs.auckland.ac.nz
Phone	+64 9 373 7599 ext 88237
Fax	+64 9 373 7453 Attn: Hong Yul Yang
Location	Building 731, Room 339 The University of Auckland Tamaki Campus 261 Morrin Rd. Glen Innes Auckland, New Zealand
Mail	Hong Yul Yang Department of Computer Science The University of Auckland Private Bag 92019 Auckland, New Zealand

I am a Research Programmer for the Department of Computer Science at the University of Auckland. I am interested in good software design, and the research & practice that goes into enforcing/evaluating it. I'm also fascinated by the challenges of applying good software design principles to different software domains, especially healthcare. When my fellow academics aren't looking, I don my alter-ego costume and undertake various stints (/stunts) as a musician.

Research

Data extraction and integration for chronic condition management

My current work as a part-time research fellow with Prof. Jim Warren involves implementing a framework that integrates an existing decision-support system for chronic condition management - called ChronoMedit - with heterogeneous sources of electronic medical records (EMR's), like different patient management systems (PMS) vendors and standards-based (e.g. HL7 and OpenEHR) clinical documents. The project is based on the work of Thusitha Mabotuwana, author of ChronoMedit. The goal of my work is to make ChronoMedIt work with as many of the existing tools used by healthcare providers out in the field as possible. The main challenge to making this work is in the diversity in the way patient data is stored across different PMS’s, so the bulk of my contribution is in the unification of these data formats. Publication about my work is on its way. THERE WILL BE PAPERS.

Implementation and maintenance evaluation of an open standards-based endoscopy reporting system (GastrOS)

This is a joint effort with Dr. Koray Atalag, who is the initiator and driver of the project. openEHR is a comprehensive, open methodology for defining and managing electronic health records (EHR's) and facilitates the building of flexible and future-proof healthcare systems. The goal of our project is twofold: 1) to implement an endoscopy reporting system using openEHR as a foundation and 2) evaluate the maintainability of this new system in order to provide concrete evidence for the benefits of using OpenEHR as compared to conventional software development methologies in the healthcare domain. Check out the Sourceforge page for details on the project.

Measuring Indirect Coupling (PhD thesis, 2009)

~~Overlord~~Supervisor: Assoc. Prof. Ewan Tempero

PDF: Read it here | Appendices (warning: 15MB!)

Synopsis: There is an increasing awareness on the importance of software measurement within the software engineering community, as well as the necessity of respecting the scientific basis of measurement. However there is little evidence for the latter as there is a tendency for researchers and practitioners to apply software metrics without a full awareness of what they mean. Coupling, which is the measure of the interdependence between parts of a software system (e.g. classes), is one important property for which many metrics have been defined. While it is widely agreed that there is a relationship between high coupling and poor maintainability, I argue that current empirical evidence toward this is insufficient to promote a full understanding of this relationship. Part of this is due to the lack of coverage of all forms of connections that comprise coupling. To illustrate this I identify a specific, indirect, form of coupling that manifests between two seemingly unrelated parts of the system through hidden connections. My thesis is that there is a relationship between indirect coupling and maintainability. To gather evidence for this I follow a methodology based on the philosophies of key software metrics researchers. This involves operationally defining indirect coupling so that it can be accurately measured, establishing an explanatory model as to the relationship between indirect coupling and maintainability, and finally empirically corroborating this model.

Publications

K. Atalag, H.Y. Yang and J. Warren (2010). "On the Maintainability of openEHR Based Health Information Systems - an Evaluation Study in Endoscopy". To appear in HIC 2010, Melbourne, Australia, August 24 - 26, 2010

B. Plimmer, H. Purchase, H.Y. Yang and L. Laycock (2009). "Preserving the Hand-drawn Appearance of Graphs". In Proc. International Conference on Distributed Multimedia Systems, pp. 347 - 352, San Francisco, USA, September 10 -- 12, 2009

H.Y. Yang and E. Tempero (2008). "An Empirical Study into the Effect of Data Flow Structure on Program Comprehension", Technical report, UoA-SE-2007-2, The University of Auckland

H.Y. Yang, E. Tempero and H. Melton (2008). "An Empirical Study into Use of Dependency Injection in Java", In Proc. 2008 Australian Software Engineering Conference (ASWEC’08), Perth, Australia, March 26 - 28, pp. 239 - 247.

A. Garcia, P. Greenwood, G. Heineman, R. Walker, Y. Cai, H.Y. Yang, E. Baniassad, C. V. Lopes, C. Schwanninger and J. Zhao (2007). "Assessment of Contemporary Modularization Techniques - ACoM'07: Workshop Report". ACM SIGSOFT Software Engineering Notes. Volume 32, Number 5, pp 31 - 37.

H.Y. Yang and E. Tempero (2007). "Indirect Coupling as a Criteria for Modularity". ACoM '07 Workshop, held in conjunction with the International Conference on Software Engineering, Minneapolis, MN.

H.Y. Yang and E. Tempero (2007). "Measuring the Strength of Indirect Coupling". In Proc. 2007 Australian Software Engineering Conference (ASWEC’07), Melbourne, Australia, April 11 - 13, pp. 319 - 328.

H.Y. Yang, E. Tempero and R. Berrigan (2005). "Detecting indirect coupling". In Proc. 2005 Australian Software Engineering Conference (ASWEC’05), Brisbane, Australia, March 29 - April 1, pp. 212 - 221.

H. Graham, H.Y. Yang, and R. Berrigan (2004). "A Solar System Metaphor for 3D Visualisation of Object Oriented Software Metrics". In Proc. Australasian Symposium on Information Visualisation, (invis.au'04), Christchurch, New Zealand. Conferences in Research and Practice in Information Technology, 35. N. Churcher, and C. Churcher, Eds., ACS. 53-59

Teaching

Lecturer

2008

SOFTENG 251: Object-oriented Software Construction

The course was taught in Java. Check out my lecture notes. Feel free to adapt them to your teaching needs - just let me know first:

I also wrote an assignment, and for this I developed a fairly substantial toy program called Personal Movie Database (PMDB). The assignment got students to "fill in the blanks" in the program that were intentionally ripped out. The point was to get them familiar with using Java collections and Generics while at the same time making it interesting. Check out the Javadoc and a mega "database" file you can load into the program so you end up with a complete personal movie database ;) Again feel free to reuse this little ditty for your teaching (or learning) benefits, on letting me know first.

Tutor

2004-2007

SOFTENG 351: Database Systems Fundamentals

SOFTENG 325: Software Architecture

SOFTENG 251: Object-oriented Software Construction

Et Cetera

Music is my other half. Here are some snapshots of my artistic (mis)demeanours.