Myungjae Kwak

A framework supporting dynamic workflow interoperation and enterprise application integration

In this paper, we propose a framework supporting dynamic interoperation between heterogeneous workflow systems and workflow-based dynamic enterprise application integration (EAI). To this end, based on a subflow task model and multi-tiered dynamic state transition model, four major components are defined: the workflow engine, adapter, service interface repositories (SIRs), and XML messages. The workflow engine provides a user with location transparency of subprocesses by encapsulating and dynamically binding both internal and external subprocesses. As middleware, the adapter achieves location and system transparency with the help of the workflow engine by encapsulating and dynamically binding external subprocesses to its superprocess. SIRs contain the service information of other systems. The local SIR (LSIR) within an organization is an important component for dynamic EAI. The adapter looks up the LSIR at run time when it tries to find external services. Several XML messages enable communications between heterogeneous workflow systems and enterprise applications.

Development and evaluation of a biomedical search engine using a predicate-based vector space model

Although biomedical information available in articles and patents is increasing exponentially, we continue to rely on the same information retrieval methods and use very few keywords to search millions of documents. We are developing a fundamentally different approach for finding much more precise and complete information with a single query using predicates instead of keywords for both query and document representation. Predicates are triples that are more complex datastructures than keywords and contain more structured information. To make optimal use of them, we developed a new predicate-based vector space model and query-document similarity function with adjusted tf-idf and boost function. Using a test bed of 107,367 PubMed abstracts, we evaluated the first essential function: retrieving information. Cancer researchers provided 20 realistic queries, for which the top 15 abstracts were retrieved using a predicate-based (new) and keyword-based (baseline) approach. Each abstract was evaluated, double-blind, by cancer researchers on a 0-5 point scale to calculate precision (0 versus higher) and relevance (0-5 score). Precision was significantly higher (p<.001) for the predicate-based (80%) than for the keyword-based (71%) approach. Relevance was almost doubled with the predicate-based approach-2.1 versus 1.6 without rank order adjustment (p<.001) and 1.34 versus 0.98 with rank order adjustment (p<.001) for predicate--versus keyword-based approach respectively. Predicates can support more precise searching than keywords, laying the foundation for rich and sophisticated information search.

A Dynamic k-Nearest Neighbor Method for WLAN-Based Positioning Systems

ABSTRACT The static k-Nearest Neighbor (k-NN) method for localization has limitations in accuracy due to the fixed k value in the algorithm. To address this problem, and achieve better accuracy, we propose a new dynamic k-Nearest Neighbor (Dk-NN) method in which the optimal k value changes based on the topologies and distances of its nearest neighbors. The proposed method has been validated using the WLAN-fingerprint data sets collected at COEX, one of the largest convention centers in Seoul, Korea. The proposed method significantly reduced both the mean error distances and the standard deviations of location estimations, leading to a significant improvement in accuracy by ~ 23% compared to the cluster filtered k-NN (CFK) method, and ~ 17% compared to the k-NN (k = 1) method.

Development and evaluation of a triple parser to enable visual searching with a biomedical search engine

We describe a new biomedical search engine that enables visual searching and utilises predicates instead of phrases. We report on the development and evaluation of the triple parser, the most essential component of the search engine, which extracts the necessary predicates from the biomedical text. Using texts from three biomedical related sites (N = 180), we compared the parser’s output with a gold standard independently created by a medical expert. The parser achieved more than 91% precision and recall. Its individual components showed different strengths with Finite State Automata being excellent for achieving high recall, while Support Vector Machines improved the precision.

A Calculus of Virtual Community Knowledge Intentions: Anonymity and Perceived Network-Structure

ABSTRACT This study investigates the underlying motivational factors of knowledge exchange intentions (intention to obtain and to provide knowledge) within virtual community contexts. Perceived virtual network structures, namely virtual network connectivity (CN) and virtual network closeness (CL), are suggested as the important antecedents of knowledge sharing intentions in the context of virtual knowledge exchange communities. Anonymity (AN), one of the unique characteristics of virtual communities, but controversial due to its multi-faceted effects, is considered in a structural model as a factor having an impact on a virtual network structure. Data collected from participants of virtual communities through online surveys are analyzed using Partial Least Squares (PLS) structural equation modeling (SEM) to empirically test the proposed hypotheses. The results reveal that both CN and CL have a significant impact on both of the knowledge exchange intentions although CL shows an opposite direction of the impact. The results also show that AN has a significant impact on CL as expected but not on CN. Implications of this study may shed some light on better understanding community participants’ intentions to obtain and provide knowledge, along with the impact of anonymity on the perceived network structure.

Applying Multi-Layered Analysis Framework on the Public Sector ICT Provision: An Illustration from a Municipal Wireless Network

As technology develops, local governments are increasingly becoming involved in providing municipal wireless service. However, many obstacles exist in municipal wireless provision which are economical, social, and political rather than technical. Therefore, we suggest a multi-layered analysis framework to analyze the Information Computer Technologies (ICT) provision in the public sector from the economic, social, and political perspectives. After the analysis from these perspectives, implications of each are discussed. We then conducted a textual analysis of journal papers and news magazine articles. The result showed that analysis of municipal wireless projects are mainly focused on the economic perspective, underestimating the political and social dynamics in the policy making processes.