• Bulletin of the Korean Mathematical Society
• /
• v.60 no.4
• /
• pp.1003-1016
• /
• 2023

In this paper, we introduce the idea of twisted product lightlike submanifolds of semi-Riemannian manifolds and provide non-trivial examples of such lightlike submanifolds. Then, we prove the non-existence of proper isotropic or totally lightlike twisted product submanifolds of a semi-Riemannian manifold. We also show that for a twisted product lightlike submanifold of a semi-Riemannian manifold, the induced connection ∇ is not a metric connection. Further, we prove that a totally umbilical SCR-lightlike submanifold of an indefinite Kaehler manifold ${\tilde{M}}$ does not admit any twisted product SCR-lightlike submanifold of the type M_⊥×_ϕM_T, where M_⊥ is a totally real submanifold and MT is a holomorphic submanifold of ${\tilde{M}}$. Consequently, we obtain a geometric inequality for the second fundamental form of twisted product SCR-lightlike submanifolds of the type M_T×_ϕM_⊥ of an indefinite Kaehler manifold ${\tilde{M}}$, in terms of the gradient of ln ϕ, where ϕ stands for the twisting function. Subsequently, the equality case of this inequality is discussed. Finally, we construct a non-trivial example of a twisted product SCR-lightlike submanifold in an indefinite Kaehler manifold.

• Journal of Distribution Science
• /
• v.12 no.11
• /
• pp.67-76
• /
• 2014

Purpose - PB (Private Brand) refers to the product for which the distribution company plans the production independently, consigns the production to the manufacturer, or attaches the self-developed trademark and sells it. To reinforce competitiveness in such a market environment, diverse products development, systematic management activities, and marketing efforts to analyze and understand the consumers' behavior regarding PB products are emphasized. Therefore, this study aims to investigate the relationships among PB product attributes, consumption emotion, brand attitude, and brand loyalty in general supermarkets. First, PB product attributes were defined using the five categories of perceived price, store image, familiarity, perceived service, and perceived quality, based on preceding studies. This study examined the influence of PB product attributes on consumption. Further, this study examined the relation among consumption emotion, brand attitude, and brand loyalty. This study provides more detailed and concentrated strategic implications. Research design, data, and methodology - In this study, the research model was designed to examine the relation among PB product attributes, consumption emotion, brand attitude, and brand loyalty. For the data collection method, the questionnaire survey comprised multiple items for each component and the direct interview method was employed. To collect data, the questionnaire survey was conducted for customers who personally visited the general supermarket after verifying the PB product purchase experience. The questionnaire survey was performed for one month, May 2014. A total of 300 questionnaires were distributed and 240 questionnaires were used for the analysis, excluding the unanswered and insincere questionnaires. The data were analyzed using SPSS ver. 20.0. Results - First, PB product attributes had a significantly positive effect on consumption emotion. The PB product attributes perceived by the customer at the point of service contact are important to form the positive consumption emotion. Second, consumption emotion had a significantly positive effect on brand attitude. Third, the consumption emotion had a significantly positive effect on brand loyalty. Such consumption emotion is an important factor in causing the positive evaluation on the brand attitude perceived by the customer. Fourth, brand attitude had a significantly positive effect on brand loyalty. The consumption emotion was positively represented to invoke the relational continuance behavior. The relational continuance behavior accompanies the repetition of purchase, word of mouth, and recommendation activities, and influences trust regarding the brand, for which the customer maintains the transaction continuously. Conclusions - The PB product attributes perceived by the customer at the point of service contact are important factors to form the positive consumption emotion. Based on this result, the discount store service provider would prepare the measures that can make the customer recognize the positive value, and make more detailed efforts. Consumption emotion is an important factor to cause the positive evaluation on the brand attitude perceived by the customer. Based on this result, the general supermarket must make efforts to provide fun or convenience in the purchase process for consumers.

• Journal of Technology Innovation
• /
• v.28 no.1
• /
• pp.53-80
• /
• 2020

Recent studies focus on how open innovation strategies affect innovation in enterprises, but lack research related to the forms of openness. There is also a paradox that an entity should open up for open innovation but also protect its innovation. In this regard, the need for research on innovation protection has expanded. Therefore, this study looked at the effect of the form of openness on product innovation, and explored how the relationship between the form of openness and product innovation depends on the appropriation mechanisms. This study used data from the Korean Innovation Survey(KIS), which was developed and distributed by the OECD. The main findings of this study are summarized as follows. First, the forms of openness has a positive effect on product innovation. Specifically, external search has had a positive impact on exploitative innovation, and collaboration has shown to have a positive impact on exploratory innovation. Second, the appropriation mechanisms has a positive moderating effect on the relationship between the forms of openness and product innovation. Specifically, it was shown that formal appropriation mechanisms had a positive effect on the relationship between external search and product innovation, and that informal appropriation mechanisms had a positive effect on the relationship between collaboration and exploratory innovation. This study is expected to contribute to: First, this study has divided the forms of openness into external search and collaboration, unlike the existing method, and thus identified the type of product innovation and the appropriation mechanisms and forms of openness by identifying the impact on product innovation. Second, depending on the characteristics of the appropriation mechanisms, it was identified that it had the moderating effect on the forms of openness and the relationship of product innovation, so that depending on the type of openness and the type of product innovation, the type of appropriation mechanisms more suitable was identified.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.4 no.3
• /
• pp.33-42
• /
• 2002

The purpose of this study was to find out criteria for classifying fashion brand from consumer point of view in order to develop strategy of fashion brands and to manage brand effectively and systematically, and to suggest theoretical frame for application of these criteria. Survey was used as a research method. Subject were 422 age of 20-30 women living in and near Seoul. Questionnaires was developed to based on 37 classification criteria, and SPSS package program were used to analyze data. The results of this study were as follows: First, factor analysis considering 37 classification criteria identified 8 factors as classification criteria. They were the level of brand form, the level of product concept, the level of management item, the level of brand sales ability, the level of customer management, the level of brand advertizing and awareness, the level of brand value, the level of product lead ability. Second, the most important factor was the level of customer management, but comparatively factor of the level of brand sales ability the level of brand value was less important. Third, consumer cognized difference of criteria for classifying fashion brands. And the level of product lead ability was the most important factor in women's wear category and the level of brand form was in general casual wear category.

• Journal of the Korean Society of Industry Convergence
• /
• v.25 no.2_2
• /
• pp.299-307
• /
• 2022

Wireless earphones, along with smart devices, are the most sought-after products by consumers. Compared to general earphones, wireless earphones do not have twisted wires and are easy to use, so various types of products are currently on the market. However, information on quality is somewhat lacking, so consumers tend to purchase products according to brand awareness, and manufacturers are delivering information to consumers using different standards for each product because there is no standard for quality control. In particular, the playback time of wireless earphones is a factor that directly affects consumers' purchases, so a standard measurement method is needed to properly measure it. In this paper, we present a method for measuring the audio playback time of wireless earphones derived from domestic wireless earphone status survey, commercial product measurement test, and research analysis, and a developed standard measurement method. In addition, this paper proposes a measurement result reporting format to provide accurate information to consumers and induce a fair competitive environment for each product to manufacturers.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.29B no.11
• /
• pp.56-64
• /
• 1992

The sum-of-product type MVL (Multiple-valued logic) functions can be directly transformed into the exclusive-sum-of-literal-product(ESOLP) type MVL functions with a substitution of the OR operator with the exclusive-OR(XOR) operator. This paper presents an algorithm that can reduce the number of minterms for the purpose of minimizing the hardware size and the complexity of the circuit in the realization of ESOLP-type MVL functions. In Boolean algebra, the joinable true minterms can form the cube, and if some cubes form a cube-chain with adjacent cubes by the insertion of false cubes(or, false minterms), then the created cube-chain can become a large cube which includes previous cubes. As a result of the cube grouping, the number of minterms can be reduced artificially. Since ESOLP-type MVL functions take the MIN/XOR structure, a XOR circuit and a four-valued MIN/XOR dynamic-CMOS PLA circuit is designed for the realization of the minimized functions, and PSPICE simulation results have been also presented for the validation of the proposed algorithm.

• East Asian mathematical journal
• /
• v.30 no.1
• /
• pp.1-14
• /
• 2014

The first purpose of this paper is to study contact CR submanifolds of Sasakian manifolds and investigate some properties concernig with ${\phi}$-holomorphic bisectional curvature. The second purpose is to show an existence theorem of mixed foliate proper contact CR submanifolds in the standard Sasakian space form $E^{2m+1}$(-3) with constant ${\phi}$-sectional curvature -3.

• Journal of the Korean Mathematical Society
• /
• v.42 no.5
• /
• pp.1101-1110
• /
• 2005

Recently, Chen studied warped products which are CR-submanifolds in Kaehler manifolds and established general sharp inequalities for CR-warped products in Kaehler manifolds. In the present paper, we obtain sharp estimates for the squared norm of the second fundamental form (an extrinsic invariant) in terms of the warping function for contact CR-warped products isometrically immersed in Kenmotsu space forms. The equality case is considered. Some applications are derived.

• Journal of Korean Institute of Industrial Engineers
• /
• v.28 no.1
• /
• pp.1-13
• /
• 2002

We study a multi-component production/inventory system in which individual components are made to meet various demand types. We assume that the demands arrive according to a Poisson process, but there is a fixed probability that a demand requests a particular kit of different components. Each component is produced by a flow line with several stations. The production of each component is operated by the CONWIP control mechanism. To analyse this system, we propose an approximation method based on aggregation method. In application of the aggregation method, a product-form approximation technique as well as a matrix-geometric method is used. Comparisons with simulation show that the approximation method provides fairly good results.

• IE interfaces
• /
• v.11 no.3
• /
• pp.55-63
• /
• 1998

In this study we consider a CONWIP system in which the processing times at each station follow an exponential distribution and the demands for the finished products arrive according to a compound Poisson process. The demands that are not satisfied instantaneously are assumed to be lost. We assume that the lot size at each station is greater than one. For this system we develop an approximation method to obtain the performance measures such as steady state probabilities of the number of parts at each station, average number of parts at each station and the proportion of lost demands. For the analysis of the proposed CONWIP system, we model the CONWIP system as a closed queueing network with a synchronization station and analyze the closed queueing network using a product form approximation method. A recursive technique is used to solve the subnetwork in the application of the product-form approximation method. To test the accuracy of the approximation method, the results obtained from the approximation method were compared with those obtained by simulation. Comparisons with simulation have shown that the accuracy of the approximate method is acceptable.