• Korean Management Science Review
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• v.26 no.3
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• pp.67-78
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• 2009

In this paper, I analyze the mobile broadband services market characterized by vertical and horizontal differentiation. Vertical differentiation as service quality differentiation is based on the transmission speed of mobile internet service and horizontal differentiation as spatial differentiation is based on the service coverage. Theoretical explanations for the competitive price policy have been developed in the game context of WiBro which represent the high quality within the limited service coverage and HSDPA which represent relatively low quality with nation-wide service. When the WiBro has a mobile broadband service quality advantage and the difference in quality is sufficiently low, the price of WiBro with limited service coverage is relatively lower than that of HSDPA. This occurs because the advantage of WiBro's vertical service differentiation is offset by the disadvantage of horizontal differentiation. The difference in the quality of mobile internet service, however, is not too high, the price of WiBro is relatively higher than that of HSDPA. Moreover, when the service quality of WiBro is sufficiently high, the low quality HSDPA service faces no demand.

• International Journal of Human Ecology
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• v.10 no.1
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• pp.47-59
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• 2009

This study investigates the relationship of self-differentiation with individualism and collectivism among college students. Special focus was on whether distinctions between vertical and horizontal individualism and collectivism were more useful in examining the relationship with self-differentiation. The results reveal that different aspects of individualism and collectivism were differently related to self-differentiation, indicating that self-differentiation was negatively associated with all aspects of collectivism and with vertical individualism, but positively with horizontal individualism. This study proved that four distinct constructs were more useful in explaining the effects on self-differentiation. The implications of the findings are discussed for clinicians and future research.

• Korean journal of communication and information
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• v.62
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• pp.200-222
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• 2013

A recent argument of network neutrality is converted by the differentiation of transmission and cost adjustment. However, It is raised that this phenomenon caused strategy for vertical integration operator to exclude a competitive operator. This study analyzed a number of instances about differentiation of transmission of ISP and problems of ISP that vertical integration in IX markets. The result of research, differentiation of transmission increased service differentiation about application programs used a best effort network like OTT or Smart TV. But this study was analyzed that a related law was vague for solving this issue. Besides, ISPs that is vertical integrated and commercial operated in an IX market discriminated competitive services, and this phenomenon can be proceeded plainly and orginated in an issue of a related law.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.2
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• pp.159-166
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• 2018

The proliferation of information technologies made it possible to produce information products of different versions at much lower cost comparing to traditional physical products. Thus it is common for information product manufacturers to consider vertically differentiated product line for more profit through improved market coverage. Another salient characteristic of most information product is network externality. Existing researches dealing with vertical differentiation and network externality usually assumed oligopolistic market where vertically differentiated products are provided by competing companies, respectively. Moreover, they analyzed the essentially dynamic characteristic of network externality statically. In this study, different from the previous researches, the vertical differentiation strategy of a monopolistic company under network externality is dynamically analyzed. We used a two-period model to accommodate the dynamic feature of network externality. Based on the two-period model, the profit maximizing solutions are analyzed. The results showed that a monopolistic company has no incentive to differentiate products vertically when the network externality is absent. On the contrary, when the network externality exists, the monopolistic company can derive more profit by vertically differentiating the product line. It is also shown that, for more profit, the monopolistic company should keep the quality difference between the high quality product and the low quality product as greater as possible.

• Journal of Families and Better Life
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• v.34 no.4
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• pp.111-125
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• 2016

The purpose of this study was to model the relations between male and female university students' self-differentiation, rejection sensitivity, and interpersonal anxiety. Questionnaires from 502 university students in Seoul were analysed. The findings are as follows. Firstly, self-differentiation, rejection sensitivity, and interpersonal anxiety were significantly different according to gender. Secondly, the level of differentiation from family regression was higher for both male and female students. And the lower the rejection sensitivity experiencing in vertical relations became, and the lower the rejection sensitivity on horizontal relations was, the lower the interpersonal anxiety became. Thirdly, it was confirmed that for male students, differentiation from family regression affected rejection sensitivity on horizontal relations, and for females, differentiation from emotional reactivity affected ejection sensitivity on both horizontal and vertical relations. Finally, rejection sensitivity played a full mediation parameter when self-differentiation affected interpersonal anxiety, and it was demonstrated differences by gender. This study was meaningful in that it confirmed the relations between male and female university students' self-differentiation, rejection sensitivity, and interpersonal anxiety.

• Journal of the Korean Society for Railway
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• v.5 no.1
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• pp.40-47
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• 2002

In this study, and analytical method for ride sensitivity analysis of a train with non-linear suspension elements are proposed. Non-linear characteristics of springs and dampers for primary and secondary suspensions of a train are parameterized using polynomial interpolation. Vertical dynamic model of a three-body train running on straight rail with the predetermined roughness expressed in terms of spectral density function is set up and its equations of motion for ride analysis are derived. Using the direct differentiation method, sensitivity equations of the vertical dynamic model with respect to design parameters associated with non-linearity of suspensions are obtained. Based on the sensitivity analysis, improvement of ride is achieved by varying appropriate suspension parameters.

• Environmental and Resource Economics Review
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• v.13 no.1
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• pp.119-131
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• 2004

A green market refers to a market that consists of environmentally aware consumers. A few researches have been carried out on the effects of environmental policy measures in a green market. These existing researches were based on a vertical differentiation model with firms' price-setting behavior, and derived that unit emission standard and environmental product taxes could not reduce the amount of pollution emission. This note considers a vertical differentiation model with firms' quantity-setting behavior, and shows that, contrary to the previous result, the amount of pollution emission is reduced by the introduction of unit emission standard. This implies the importance of the nature of firms' interaction in figuring out the pollution abatement effect of environmental policy measures in a green market.

• Environmental and Resource Economics Review
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• v.23 no.4
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• pp.553-581
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• 2014

This paper analyzes competition among service stations in the Korean gasoline market. We consider spatial differentiation as a source of product differentiation as well as the characteristics of the stations and vertical contracts between refiners and retailers as factors causing changes in equilibrium prices in the Korean gasoline retail market. The effect of the government's price disclosure policy on the retail market competition is also analyzed. Moran's I test indicates that the prices of neighboring gas stations are spatially correlated in the market. It is also found that gasoline prices for vertically integrated stations are much lower than those for independent stations. In addition, unbranded stations charge lower prices than branded stations but also induce branded stations to price more competitively. Meanwhile, the government's price disclosure policy did intensify price competition in the retail gasoline market. It is inferred that the price disclosure policy contributed to retailers gaining more bargain power in price negotiation with refiners, causing an eventual increase in retail prices.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.407-407
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• 2014

Nanotechnology, especially vertically grown silicon nanowires, has gotten great attentions in biology due to characteristics of one dimensional nanostructure; controllable synthetic structure such as lengths, diameters, densities. Silicon nanowires are promising materials as nanoelectrodes due to their highly complementary metal-oxide-semiconductor (CMOS) - and bio-compatibility. Silicon nanowires are so intoxicated that are effective for bio molecular delivery and electrical stimulation. Vertical nanowires with integrated Au tips were fabricated for electrical intracellular interfacing with PC-12 cells. We have made synthesized two types of nanowire devices; one is multi-nanowires electrode for bio molecular sensing and electrical stimulation, and the other is single-nanowires electrode respectively. Here, we demonstrate that differentiation of Nerve Growth Factor (NGF) treated PC-12 cells can be promoted depending on different magnitudes of electrical stimulation and density of Si NWs. It was fabricated by both bottom-up and top-down approaches using low pressure chemical vapor deposition (LPCVD) with high vacuuming environment to electrically stimulate PC-12 cells. The effects of electrical stimulation with NGF on the morphological differentiation are observed by Scanning Electron Microscopy (SEM), and it induces neural outgrowth. Moreover, the cell cytosol can be dyed selectively depending on the degree of differentiation along with fluorescence microscopy measurement. Vertically grown silicon nanowires have further expected advantages in case of single nanowire fabrication, and will be able to expand its characteristics to diverse applications.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.1
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• pp.7-15
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• 2020

It is a general phenomenon for manufacturers to provide vertically differentiated product line for more profit through improved market coverage. For such manufacturers, the compatibility between vertically differentiated products is an important decision issue. Some manufacturers provide full compatibility between high and low version products, whereas some provide only downward compatibility for the purpose of recommending high version product. In this study, the two representative compatibility strategies, full or downward, between vertically differentiated products produced by a single manufacturer are analyzed, especially under network externality and in the viewpoint of profit maximization. To do this we used a market model which captures the basic essence of vertical differentiation and network externality. Based on the proposed market model, the profit maximizing solutions are derived and numerically analyzed. The results can be summarized as follows : (1) Regardless of compatibility strategy, under network externality, vertical differentiation is always advantageous in terms of profit. (2) The full compatibility strategy is shown to be the most advantageous in terms of profit. In addition, it is necessary to make quality difference between differentiated products as wide as possible to maximize profit. (3) To gradually drive low version product out of the market and shift the weight pendulum of market to high version product, it is shown that the downward compatibility strategy is essential. Unlike intuition, however, it is also shown that in order to drive low version product out of market, it is necessary to raise the quality of the low version product rather than to lower it.