• Journal of the Korean Operations Research and Management Science Society
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• v.34 no.4
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• pp.185-204
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• 2009

The USIM(universal subscriber identity module)-unlock introducing in July 1, 2008 might be led to a significant change that mobile service provider's dominance is considerably dispersed to the handset manufacturer and distributor. Under USIM-unlock environment, mobile service provider, handset manufacturer, and distributor have to make their decisions on their handset distribution channel strategies: the closed distribution channel strategy or the open distribution channel strategy. The change of distribution channel strategy between members in distribution channel can be understood as a matter of strategy choice, and we have developed a theoretical model and analyzed how to make a decision for the member's optimal distribution strategy based on 3-person game model between members of mobile phone distribution channel, under both of '1 subscriber-1 handset' and '1 subscriber-multiple handset' assumptions. Under '1 subscriber-1 handset' assumption, the closed strategy controlled by mobile service provider is all players' optimal solution because the maximum size of the mobile phone market is limited by subscribers. But, as total expected profit by the handset and distribution subsides is a deficit, mobile service provider have to choose the open strategy and consider the conversion to MNO(mobile network operator). Under '1 subscriber-multiple handset' assumption, mobile service provider is trying to find the way how to lock-in its service and mobile phone and how to maximize ARPU(average revenue per unit), while handset manufacturer and distributor have to look for the way how to maximize the mobile phone market using their own marketing efforts, because it is expected that total mobile handset demand for the open market is bigger than demand for the closed market under '1 subscriber-multiple handset' assumption.

• The Korean Journal of Franchise Management
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• v.9 no.1
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• pp.41-51
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• 2018

Purpose - In franchise system, how to build the relationship between the franchisor and franchisee through influence strategy is very important, because it affects on the long-term orientation like recontract intentions. Thus, this study examines the effect of mandatory influence strategy on relationship satisfaction, relationship trust, and recontract intentions in the context of food-service franchise industry. This study suggests the guidelines on how franchisor uses their influence strategy on franchisee to maintain and increase the recontract intentions. Research design, data, and methodology - This study examines the structural relationship between mandatory influence strategy, relationship satisfaction, relationship trust, and recontract intentions from the franchisee's perspective. Mandatory influence strategy divide into three sub-dimensions such as request, legalistic plea, threat. In order to test the purposes of this study, research model and hypotheses were developed. Every constructs were measured by multiple items tested and developed in the previous research. Also, the constructs utilized in this research are measured using 7-point scales anchored by "1=strongly disagree" and 7=strongly agree". The data were collected from 496 owner and owner manager franchisees and were analyzed using SPSS 21.0 and Smart PLS 3.0. program. Analysis of frequency was conducted to identify the demographics and general characteristics of the survey subjects. In order to measure the reliability and validity of the measurement tools, confirmatory factor analysis and correlation analysis were conducted and structural model analysis was conducted to verify the proposed research model. Result - The results of this study are as follows. First, this research found that mandatory influence strategy is positively related to relationship satisfaction and relationship trust, but not to recontract intention directly. Second, this research also found that the full mediating role of relationship satisfaction and relationship trust between the mandatory influence strategy and recontract intention. Conclusions - The findings of this research indicate that franchisor should use properly mandatory influence strategy to improve recontract intentions through relationship satisfaction and relationship trust. Due to the nature of food-service franchise industry, which needs high relationship quality, franchisor must manage their franchisee using influence strategy in order to improve satisfaction and trust. If franchisee perceives higher relationship quality, they will show higher intention to recontract. At the end of this paper, limitations and future research directions were suggested.

• Journal of Power Electronics
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• v.17 no.1
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• pp.136-148
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• 2017

In recent years, voltage source multilevel converters are very popular in medium/high-voltage industrial applications, among which the NPC/H-Bridge converter is a popular solution to the medium/high-voltage drive systems. The conventional finite control set model predictive control (FCS-MPC) strategy is not practical for multilevel converters due to their substantial calculation requirements, especially under high number of voltage levels. To solve this problem, a hierarchical model predictive voltage control (HMPVC) strategy with referring to the implementation of g-h coordinate space vector modulation (SVM) is proposed. By the hierarchical structure of different cost functions, load currents can be controlled well and common mode voltage can be maintained at low values. The proposed strategy could be easily expanded to the systems with high number of voltage levels while the amount of required calculation is significantly reduced and the advantages of the conventional FCS-MPC strategy are reserved. In addition, a HMPVC-based field oriented control scheme is applied to a drive system with the NPC/H-Bridge converter. Both steady-state and transient performances are evaluated by simulations and experiments with a down-scaled NPC/H-Bridge converter prototype under various conditions, which validate the proposed HMPVC strategy.

• Journal of Convergence for Information Technology
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• v.10 no.4
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• pp.46-54
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• 2020

This study aims to develop and analyze the performance of a selective option straddle strategy based on forecasted volatility to improve the weakness of typical straddle strategy solely based on negative volatility risk premium. The KOSPI 200 option volatility is forecasted by the SVM model combined with the asymmetric volatility spillover effect. The selective straddle strategy enters option position only when the volatility is forecasted downwardly or sideways. The SVM model is trained for 2008-2014 training period and applied for 2015-2018 testing period. The suggested model showed improved performance, that is, its profit becomes higher and risk becomes lower than the benchmark strategies, and consequently typical performance index, Sharpe Ratio, increases. The suggested model gives option traders guidelines as to when they enter option position.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.2
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• pp.1-11
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• 2013

This research proposed integrated expressway traffic management strategy using ramp metering and toll mainline metering. This research suggested a traffic signal optimization model for integrated operation of ramp and mainline metering based on Demand-Capacity Model that is used to optimize allowable input volume for ramp metering in FREQ model. The objective function of this model is sectional throughput volume maximization, and this model can calculate optimal signal timings for mainline metering and ramp metering. This study conducted an effectiveness analysis of integrated metering strategy using PARAMICS and its API. It targeted Seoul's Outer Ring Expressway between Gimpo and Siheung toll gate. As a simulation result, integrated operation of mainline and ramp metering provided more smooth traffic flow, and throughput volume of mainline increased to 14% in congested section. In addition, a queue of 400 meter was formed at metering point of toll gate. This research checked that integrated traffic management strategy facilitates more efficient traffic operation of mainline and ramp from diffused traffic congestion.

• Journal of Korea Trade
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• v.24 no.8
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• pp.81-100
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• 2020

Purpose - Based on complexity theory, this study develops a configurational model to predict the profitability of Halal cosmetics firms in the Indonesian and Malaysian markets. The proposed research model involves two level configurations-industry context and selling strategies-to predict high and low scores of a firm's profitability. The industry context configuration model comprises industry stability, product homogeneity, price sensitivity, and switching cost. Selling strategies include customer-focused, competitor-focused, and margin-focused approaches. Design/methodology - This is the first empirical study that calculates causal models using a combination of industry context and selling strategy factors to predict profitability. Data obtained from the marketing managers of cosmetics firms are used to test the proposed configurational model using fuzzy-set qualitative comparative analysis (fsQCA). It contributes to the current knowledge of business marketing by identifying the factors necessary to achieve profitability using analysis of condition (ANC). Findings - The results revealed that unique and distinct models explain the conditions for high and low profitability in the Indonesian and Malaysian halal cosmetic markets. While customer-focused selling strategy is necessary to attain a higher profit in both the markets, margin-focused selling strategy appears to be an essential factor only in Malaysia. Complexity of the interactions of selling strategies with industry factors and differences between across two study markets confirmed that complexity theory can support the research configurational model. The theoretical and practical implications are also illustrated. Originality/value - Despite the rapid growth of the global halal industry, there is little knowledge about the halal cosmetic market. This study contributes to the current literature of the halal market by performing a set of asymmetric analytical approaches using a complex theoretical model. It also deepens our understating of how the Korean firms can approach the Muslim consumer's needs to generate more beneficial turnover/revenue.

• Journal of Information Technology Applications and Management
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• v.18 no.3
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• pp.1-30
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• 2011

InnovVizwas designed and developed anew as avisualization and simulationtool to present innovation and strategy information. The InnovViz system employs two key types of technology, namely mixed reality (MR) and neural network (NN). An experiment was conducted to examine the usability, acceptance and possible adoption of this new system. Participants comprised 4 experts from 4 top performing entrepreneurial firms and 161 master degree students from 2 leading universities. The study used a modified UTAUT model and a cognition and perception model. The results revealed that when the InnovViz was introduced, the key drivers to adoption are Facilitating Conditions (FC) and Voluntary to Use (VOL). Adequate knowledge and sufficient resources were found to strongly affect FC construct. The expert's rating of a firm's innovation and performance was more congruent with senior students with a technology-background than with a finance and accounting-background. InnovViz was seen as providing complex information with an ease of use and usefulness for showing data and assessment. Among the three types of visuals depicted by InnovViz, experts rated their usefulness in descending order as follows: Cube, Tetrahedron and Saturn. Finally, experts found backward simulation to be slightly more useful for assessment than forward simulation.

• Journal of The Korean Association of Information Education
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• v.20 no.2
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• pp.131-138
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• 2016

We have developed a UMC (Use-Modify-Create) strategy for the improvement of computational thinking in SW education. UMC model is an instructional strategy that students analyze examples of algorithms, modify-expand it and to develop new SW. First, we applied the UMC classes during 1 semester targeting pre-service teachers. To explore the effectiveness of the proposed model, we conducted a t-test for improving students' self-CT. Through a result, we found that is the UMC teaching-learning strategy helped the CT concepts and practice skills. In addition, we could see the Use and Create steps help to improve the ability of students' CT than directly teaching and Modify steps.

• Journal of Communications and Networks
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• v.7 no.4
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• pp.471-477
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• 2005

This paper proposes an efficient constraint-based optimization model for the design of 3G mobile networks, such as universal mobile telecommunications system (UMTS). The model concerns about finding a set of sites for locating radio network controllers (RNCs) from a set of pre-defined candidate sites, and at the same time optimally assigning node Bs to the selected RNCs. All these choices must satisfy a set of constraints and optimize an objective function. This problem is NP-hard and consequently cannot be practically solved by exact methods for real size networks. Thus, this paper proposes a hybrid search strategy for tackling this complex and combinatorial optimization problem. The proposed hybrid search strategy is composed of three phases: A constraint satisfaction method with an embedded problem-specific goal which guides the search for a good initial solution, an optimization phase using local search algorithms, such as tabu algorithm, and a post­optimization phase to improve solutions from the second phase by using a constraint optimization procedure. Computational results show that the proposed search strategy and the model are highly efficient. Optimal solutions are always obtained for small or medium sized problems. For large sized problems, the final results are on average within $5.77\%$ to $7.48\%$ of the lower bounds.

• Journal of Korean Port Research
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• v.15 no.1
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• pp.1-18
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• 2001

The purpose of this study is to explore the nature of the relationship between several factors representing perceived port service quality and the adaptability to the marketing strategy of container terminal. An empirical study was carried out to examine not only the determinants of port service quality using PZB's SERVQUAL model but also its implications to the service marketing strategy. The data investigating the determinants of port service quality were collected from 136 managers from shipping companies by the use of questionnaire method. Factor analysis and t-test were carried out to analyze the data. The results of this study were as follows ; First, Shipping companies perceive the port service quality on two the dimensions of personnel and material aspects. Second, Shipping companies put more emphasis on the reliance of port service quality even though the port authority offers good facilities and materials as parts of port shipping quality. Third, There is a significant relationship between the purchase intention and the customer satisfaction. These findings help not only to formulate service marketing strategy based on service quality but also to be a concept tool to enhance port service quality.