• Journal of the Korean Mathematical Society
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• v.48 no.6
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• pp.1225-1248
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• 2011

The present paper is concerned with a two-competitor/oneprey population system with Holling type-II functional response and two discrete delays. By linearizing the system at the positive equilibrium and analyzing the associated characteristic equation, the asymptotic stability of the positive equilibrium and existence of local Hopf bifurcations are investigated. Particularly, by applying the normal form theory and the center manifold reduction for functional differential equations (FDEs) explicit formulae determining the direction of bifurcations and the stability of bifurcating periodic solutions are derived. Finally, to verify our theoretical predictions, some numerical simulations are also included at the end of this paper.

• Communications for Statistical Applications and Methods
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• v.9 no.1
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• pp.291-304
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• 2002

This article is concerned with an effective algorithm for the identification of multiple outliers in linear regression. It proposes a hybrid algorithm which employs the least median of squares estimator, instead of the least squares estimator, to construct an Initial clean subset in the stepwise forward search scheme. The performance of the proposed algorithm is evaluated and compared with the existing competitor via an extensive Monte Carlo simulation. The algorithm appears to be superior to the competitor for the most of scenarios explored in the simulation study. Particularly it copes with the masking problem quite well. In addition, the orthogonal decomposition and Its updating techniques are considered to improve the computational efficiency and numerical stability of the algorithm.

• Journal of Distribution Science
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• v.14 no.11
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• pp.91-102
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• 2016

Purpose - The objectives of this study are as follows. First, it aims to suggest an analysis model that has integrated the relationship between the two factors and export performance and conduct an empirical analysis of the factors. Second, the study seeks to analyze the mediating effect by setting direct channel governance as a specific activity to connect market orientation, a cultural asset, to export performance. Third, through these analyses, the study intends to apply the relationship between market orientation and direct channel governance that the existing studies have failed to observe comprehensively on SMEs in Korea. Based on these analyses, the study expects to expand the discussion of previous researches by analyzing the mediating effect of direct channel governance. Research design, data, and methodology - This study developed a model that has integrated market orientation, direct channel governance, and export performance. It established 7 hypotheses including the mediating effect of direct channel governance. Market orientation was consisted of customer orientation and competitor orientation, and 4 latent variables were measured by 18 questions. LISREL, an analysis tool of structural equation model, was used for hypothesis test and there were 183 sample for analysis. Results - The analysis results showed that customer orientation has a positive influence on direct channel governance, but competitor orientation did not have a statistically significant effect. On the contrary, export performance showed an opposite result. That is, customer orientation did not have any influence but competitor orientation had a significant influence on export performance. It was also confirmed that there was a significant influence in the relationship between channel governance and export performance. According to the analysis of mediating effect, direct channel governance had a full mediating effect between customer orientation and export performance. Conclusions - The study results demonstrated that it is important to build a direct channel governance on the export SMEs in Korea, especially since the direct channel governance complements the influence of customer orientation that does not directly influence export performance among market orientation activities. This implies that Korean export SMEs must strive to build an effective direct channel governance.

• BMB Reports
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• v.30 no.5
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• pp.326-331
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• 1997

To construct a competitive ELISA standard curve for the detection of glucose-6-phosphate debydrogenase (G6PD), we used highly purified native G6PD (nG6PD) as both immobilized and soluble antigens and anti-G6PD serum raised against nG6PD as antibody. The polystyrene cuvettes coated with nG6PD were challenged with a mixture of a limiting amount of anti-G6PD serum and various doses of nG6PD as competitors followed by incubation with alkaline phosphatase-anti-IgG conjugate. The competitive ELISA did not exhibit the typical sigmoidal dose-response curve characteristic of competition immunoassays under the optimal concentrations of antigen and antibody. The soluble nG6PD used as competitor failed to effectively inhibit the binding of antibodies to the immobilized nG6PD. The addition of NADP, a cofactor of G6PD enzyme, to coating buffer used for immobilizing nG6PD to the cuvettes and PBS-Tween-BSA buffer for diluting competitors did not improve the inhibition of antibody binding to immobilized nG6PD by soluble n/G6PD. The addition of BSA to coating buffer did not increase inhibition, either. Surprisingly, when partially active G6PD (paG6PD), obtained by repeated freeze-thawing, was used as competitor, the antibody binding to either immobilized nG6PD or immobilized paG6PD was inhibited 49-58%. We conclude that an effective competitive ELISA system with nG6PD enzyme and anti-G6PD serum for the detection of G6PD may not be established due to the poor inhibition of antibody binding to immobilized nG6PD by soluble nG6PD under the present assay conditions and that the inhibition may be improved by using an inactivated enzyme as competitor regardless of the type of immobilized antigen used. These results imply that the immobilized nG6PD may undergo denaturation upon binding to the polystyrene cuvettes and that our anti-G6PD serum may recognize denatured enzyme better than active enzyme.

• The Journal of the Korea Contents Association
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• v.14 no.7
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• pp.468-479
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• 2014

This paper aims to examine structural relationship between the influence factors of company performance, hypothesizing that strategic orientations and entrepreneurship plays a crucial role in achieving organizational performance in small-medium sized and ventures manufacturing firms. For this research, data were collected from 205 firms. By using Structure Equation Modeling(SEM) method, it was found that competitor orientation, technology orientation directly affect company performance but, customer orientation were not affected company performance. Furthermore, it was also found that the relationship between strategy orientation and company performance is differentiated by entrepreneurship. Especially, this finding confirms that the entrepreneurship moderately affects the relationship between competitor orientation, technology orientation and company performance on the small-medium sized and ventures manufacturing firms.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.4 no.1
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• pp.73-79
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• 1968

In order to investigate varietal competition effects on yield of rice, two experiments were conducted under paddy field condition. In experiment I, two leading varieties were grown in pure and mixed stands and examined the influence of spacings and nitrogen levels on the varietal competition effects and competitive ability of two varieties. In experiment II, three leading varieties were grown in pure and mixed stands with different combinations and examined the competition effects on yield in different combinations. The results are summarized as follows: 1. No significant differences were found in grain yield between varietal mixture and pure stands, though the level of nitrogen and spacings affected plot yield. 2. In the mixture of Suwon ＃82 and Shin ＃2, Suwon ＃82 appeared to be a better competitor to the Shin #2 in terms of grain yield. 3. The performance of mixtures were determined by the balance of the increment of better competitor and the decrement of poorer competitor. Here, the increment of Suwon ＃82 due to competition did not much exceeded the decrement of Shin ＃2. 4. Spacings and Nitrogen levels, tested here, did not affect significantly to the varietal competition effects. 5. Jaekun, Paltal and Norin ＃6 showed no varietal difference in competing ability.

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.4
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• pp.53-64
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• 2019

This research explored the main and interactive effects of service employee market orientation, service creativity, and national culture(Korea and Japan). To test the hypotheses, responses were collected from 196 Korean and 195 Japan hotel service employee samples. The results showed that service employee market orientation(customer orientation, competitor orientation, and interfunctional coordination) has a positive relationship with service creativity. Also, national culture moderates the relationship between service employee market orientation and service creativity, thereby implying the positive relationship between competitor orientation and service creativity is stronger in Korea than in Japan. In contrast, the positive relationship between interfunctional coordination and service creativity is stronger in Japan than in Korea. Theoretical implications of our findings and practical recommendations for how to address the impact of market orientation on service creativity are discussed.

• Journal of Information Technology Services
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• v.21 no.2
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• pp.27-41
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• 2022

In a fiercely competitive environment, quality is a key factor that enables dashboard camera makers to maintain their competitive advantage. Quality affects consumer satisfaction, brand loyalty, and firm performance. Therefore, to remain competitive, it is important that manufacturers maintain product quality that meets consumer expectations. To this end, it is necessary to investigate customer preferences and product performance in terms of product quality and to properly allocate resources to improve the quality level such that the firm can maintain a competitive advantage. In this paper, we proposed the various ways in which manufacturing firms can determine which quality dimensions need improvement in order to secure competitiveness. To this end, we analyzed a case study of Urive to develop a quality improvement strategy through importance performance competitor analysis (IPCA). Urive's IPCA results showed that 14 quality dimensions, namely performance, size, price, ease of use, country of origin, manufacturer, brand, product certificate, warranty, distribution channel, market share, reliability, durability, and conformance, were not absolutely competitive compared with those of Mando, Inavi, and Finevu. In terms of color, Urive had an absolute competitive advantage over Mando, but not Inavi and Finevu. Urive's appearance was more competitive than Mando's, but not Inavi's and Finevu's. In terms of advertisement and serviceability, Urive was absolutely less competitive than Mando and Inavi, but had a competitive advantage over Finevu. Therefore, it is necessary to put resources and time as the first priority for performance, reliability, and durability, which have a large performance difference in common among the three brands. The quality dimensions in which resources and time need to be put in second place are price and ease of use, which have a large performance difference in common among the two brands.

• Journal of Korean Society of Forest Science
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• v.107 no.2
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• pp.193-204
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• 2018

This study was carried out to select the optimal method of competition index computation according to the competitor selection methods and distant-dependent competition index models, and to analyze the characteristics of competition indices in terms of thinning intensity and tree density targeting Pinus densiflora, Pinus koraiensis, and Larix kaempferi, which are the major coniferous species in Korea. Data was the re-investigated tree information from 240 permanent plots of 80 sites in the stands of P. densiflora, P. koraiensis, and L. kaempferi, which were located in the national forest of Gangwon and North Gyeongsang provinces. The number of subject trees with competition index calculated were 1126 trees for P. densiflora, 4093 trees for P. koraiensis, and 3399 trees for L. kaempferi. For the best competition index computation method, three kinds of competitor selection methods were considered: basal area factor, angle of height, angle of height to crown base. Also, six kinds of competition index models were compared: Lorimer, Martin-EK, Braathe, Heygi, Daniels, and Modified Daniels, which was developed in this study. Correlation coefficient was the best when the competitor selection method of basal area factor $4m^2/ha$ and the competition index model of Modified Daniels were used, and thus, it was selected as the best method for computing competition index. According to the best method by stand characteristics, competition index decreased in all species as thinning intensity was high and tree density was low.

• Journal of Intelligence and Information Systems
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• v.9 no.3
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• pp.137-153
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• 2003

Comparison shopping is the most popular functionality in the e-Marketplace. Most of their revenue has been generated kent the Internet advertisement, but the ad earning was declined as the ad costing per action method widespread. Seller less familiar to the customer shrinks from chances for advertising and exposing their products. So, we need an efficient methodology subject to the seller's ad budget and other constraints, and it also has to increase comparison broker's earning in the e-Marketplace. Our research proposed and developed an ad planning methodology using comparison challenge approach which can be applied by 3$^{rd}$ party comparison brokers. Comparison challenge planning is organized with challenge policy of competitor level, product level and specification level. With that policies and basic challenge propositions, we measure the quantified value of functional distance between the specifications of my product and competitor's product. My product challenges the comparison using the comparative ad format to the similar but inferior competitor's product based on quantified valuation. Comparison challenge planning system has two phases of comparative value generation and optimization. We developed a prototype system and applied it to the desktop PC market of five major manufacturers. Our performance was emphasized by comparing to other comparative ad methods such as random display method and minimum distance method..