Changsoo Sohn

Development of e-service quality measure for internet-based financial institutions

In the early stage of internet markets, internet-based financial institutions competed with traditional financial institutions by providing services at lower prices. However, today, more and more companies are participating in internet markets, nullifying the initial price advantage and resulting in low prices becoming a minimum qualification to compete in the market. Therefore, companies operating in internet markets need something else in order to attract customers. What becomes important for internet-based financial institutions is to provide high quality ‘service’. This study raises a research question: ‘how do customers evaluate the quality of e-services provided by internet-based financial institutions?’ This study reveals six valid and reliable dimensions measuring perceived e-service quality: Trust, Customised communications, Ease of use, Website content and functionality, Reliability and Speed of delivery. These dimensions are validated using confirmatory factor analysis and criterion-related validity.

Linear programming system identification

We define a version of the Inverse Linear Programming problem that we call Linear Programming System Identification. This version of the problem seeks to identify both the objective function coefficient vector and the constraint matrix of a linear programming problem that best fits a set of observed vector pairs. One vector is that of actual decisions that we call outputs. These are regarded as approximations of optimal decision vectors. The other vector consists of the inputs or resources actually used to produce the corresponding outputs. We propose an algorithm for approximating the maximum likelihood solution. The major limitation of the method is the computation of exact volumes of convex polytopes. A numerical illustration is given for simulated data.

The effects of mobile CRM activities on trust-based commitment

This study analysed the effects of mobile CRM activities on trust-based commitment by evaluating mobile CRM activities from customer’s standpoint using three variables; contents differentiation, contact frequency, and contents repetition. The perceived evaluation of mobile CRM activities explains trust, which plays a role of creating stronger customer commitment. Commitment consists of three constructs; affective commitment, continuance commitment, and normative commitment. Questionnaire surveys were conducted to verify the research model. The data were used to test hypotheses by using structural equation modelling (SEM). The results showed that CRM activities (content differentiation and contact frequency) contribute to build trust-based commitment (affective commitment, continuance commitment, and normative commitment). The results from this research may serve as a guideline for companies aiming to more effectively build trust-based commitment through mobile CRM activities.

Linear programming system identification: The general nonnegative parameters case

Abstract By linear programming system identification, we mean the problem of estimating the objective function coefficient vector π and the technological coefficient matrix A for a linear programming system that best explains a set of input–output vectors. Input vectors are regarded as available resources. Output vectors are compared to imputed optimal ones by a decisional efficiency measure and a likelihood function is constructed. In an earlier paper, we obtained results for a simplified version of the problem. In this paper, we propose a genetic algorithm approach for the general case in which π and A are of arbitrary finite dimensions and have nonnegative components. A method based on Householder transformations and Monte Carlo integration is used as an alternative to combinatorial algorithms for the extreme points and volumes of certain required convex polyhedral sets. The method exhibits excellent face validity for a published test data set in data envelopment analysis.

Configuration and coordination of activities within a supply chain: exploring the synergy between modularity and information technology

This research studies the impact of information technology-enabled coordination on product modularisation in the automotive industry. A structural equation model is tested based on 177 responses to questionnaires from 177 Korean first-tier automotive suppliers. The results provide support for the hypothesis that high quality of exchanged information enables better supply chain coordination, which in turn supports product modularisation.