• Journal of Korean Society of Forest Science
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• v.85 no.3
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• pp.539-551
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• 1996

In this study, a number of distance-dependent competition indices on tree-level which incorporate the tree sizes and distances to competitors, and traditional stand-level density measures were estimated from the data compiled with position-dependent survey in a Pinus densiflora stand. The performance of the estimated competition indices was examined by comparing the relationship with the diameter growth, and a dbh growth function, in which the competition index is considered as a one of influence factors, are developed. In the searching method of competing trees, the competition index estimated with $30^{\circ}$ competition interrupting angle showed the highest correlation with the annual dbh growth, while the expanding the competing zone distance had no significant effect on the performance of competition index in estimating annual dbh growth. The most of the examined stand-level competition indices, based on distance-dependent single-tree competition indices, were evaluated to describe similarly the stand competition status. As a result of partial correlation analysis in which the effect of age and site index are eliminated, Alemdag's mean competition index and relative spacing index were determined to have the highest correlation with dbh. The relative spacing index, which can be easily measured in field without measuring the position of individual trees, was considered to be a better suited one for estimating mean dbh of a stand. Among distance-dependent competition indices on tree-level, Hegyi's competition index showed the best performance in their correlation with annual dbh growth, if eliminated the effect of site index and dbh. This enabled to derive the following annual dbh growth function of individual trees which incorporate age, dominant height, dbh and Hegyi's competition index as influence factors : $$dbh^{\prime}=3.975362676{\cdot}age^{-1.099274613}{\cdot}ho^{0.199893990}{\cdot}dbh^{0.269430865}{\cdot}HgCI^{-0.353643587}$$ This function is coincided to the growth principle in which site index has a positive effect on the annual dbh growth, while high age or competition causes to reduce the annual dbh growth, and can be used as a function in single tree growth model.

• Journal of architectural history
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• v.17 no.2
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• pp.27-45
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• 2008

This study examines the details and characteristics of prizewinning plans of Cho-Sun housing plan competition promoted by Daily Cho-Sun Company during Japanese colonial period. The main features of Cho-Sun housing plan competition were that the competition held with an application of popular newspaper readers and a judging committee was composed of only Korean architects, especially Park, Gil-Ryong as the president of the board of examiners. Cho-Sun housing plan competition put ideological factors for the improvement of living as like advancing to the cultured(modem) life, respecting for family life, respecting for privacy of family members and so on. First of all, the competition suggested the direction of the improvement of dwelling spaces which focused on making harmonious home life. This study found common characteristics of prizewinning plans of Cho-Sun housing plan competition as the result. First, Cho-Sun housing plan competition introduced a centralized house plan as a model of the improvement of small-sized houses. Second, architectural orders of western or Japanese style mingled with ones of korean traditional style in prizewinning plans as entrance hall, western style reception room(parlour), maid's room, bathroom for example. And a manner of seating using chairs was brought into the style of living which would be assumed in the prizewinning plans. Third, traditional way of composing dwelling spaces was maintained, receiving the characteristics of dwelling spaces of japanese style simultaneously, which central corridor was put at the heart of house for improving arrangement of rooms and flow lines. Fourth, lavatory and bathroom were placed inside of the house.

• Journal of Korea Trade
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• v.23 no.2
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• pp.1-13
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• 2019

Purpose - This paper empirically investigates the competition effect of exports between Korea and China in their common-export markets considering market sophistication. Modern market sophistication includes an importing country's aggregate demand for products of high quality, design, novelty, eco-friendliness, and even IPR protection. Using an empirical analysis to identify the demand for product quality across countries, this paper estimates the effects of market sophistication on the competition between Korean exports and Chinese products. Design/Methodology - Our empirical model considers the relationship between an importing country's consumer sophistication and the export competition between Korea and China. This study employs the existing theoretical framework to identify the aggregate demand for product quality across countries. Using a quite direct measurement (the consumer sophistication index, our analysis investigates the differential effects of Korea's export market sophistication, particularly in markets where Korean exports are in competition with similar Chinese products. Findings - Our main findings can be summarized as follows: the negative effects of the export competition between Korea and China on Korea's exports are stronger in third markets where consumers are less sophisticated while the effects are not as pronounced in markets where consumers are more sophisticated. This result, however, best applies to differentiated goods which significantly vary in product quality. Originality/value - Existing studies focus on the supply side of production and make the assumption that the market preference for export quality is identical across countries. This paper attempts to evaluate the export competition between Korea and China from the demand-side perspective. This area of trade studies is underexplored both empirically and in theory, although the issue has long been important to Korean and world trade.

• Asia pacific journal of information systems
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• v.23 no.2
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• pp.67-86
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• 2013

This study first provides a stylized model that captures the essential features of the SC (Social Commerce) business and the competition process. The model focuses on the relationship between key decision issues such as marketing inputs and market value. As more SCs join the industry, they are inevitably faced with fierce competition, which may lead to sharp increase in the total marketing and advertising expenditure. This type of competition may lead the industry away from its optimal development path, and at worst, toward a disruption of the entire industry ecosystem. Such being the case, another goal of this study is to examine the possibility that the ToC (Tragedy of the Commons) may occur in the SC industry. We build game models, each of which assumes homogeneity and heterogeneity of SC providers, respectively, and derive explicit equilibrium solutions from both models. Our basic analysis presents Nash equilibria in both models and shows that SC providers are inevitably faced with fierce competition, which may lead to sharp increase in the total marketing expenses. We also compare the game outcomes with one with a hypothetical social planner who determines the total marketing level that optimizes the entire market value. Then, ToC can be defined to describe the situation where the total marketing efforts exceed the socially optimal level of marketing efforts. In both models, we examine the possibility of the ecosystem disruption and specify the conditions under which ToC may occur. However, the chance of avoiding ToC is higher with heterogeneous players than with homogeneous players. To supplement our analytical results, we develop a simulation model which incorporates a market dynamics based on the gap between actual marketing efforts and socially optimal marketing level. Simulation experiments present some lessons and insights which also confirm out findings from equilibrium analysis. For example, heterogeneity in SC providers alleviates the severity of ToC and makes it faster for survivors to escape from the ToC trap. As a result, the degree of industrial concentration tends to increase, which also explains the 'rich-get-richer' phenomenon observed in some empirical studies on the SC industry. Lastly, based on our analytical and experimental results, we come up with some measures to avoid ToC and overcome the shortcomings intrinsic to the current business model. And further discussions provide strategic implications and policy directions to overcome the possible trap of ToC in this ecosystem, and eventually help the industry to sustainably develop itself toward the next level. To name a few examples of policy measures, regulations on the marketing activities so that the overall marketing expenses cannot go beyond the socially optimal level; institutional guidelines and rules to straightening up the distortions in the way that SC providers view the marketing costs (the current marketing costs are underestimated, thereby encouraging SC providers to increase marketing expenditure); and so on.

• Proceedings of the Korea Port Economic Association Conference
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• 2006.08a
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• pp.1-12
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• 2006

As national economies globalize, demand for intercontinental container shipping services is growing rapidly, providing a potential economic boon for the countries and communities that provide port services. On the promise of profits, many governments are investing heavily in port infrastructure, leading to a possible glut in port capacity, driving down prices for port services and eliminating profits as ports compete for business. Further, existing ports are making strategic investments to protect their market share, increasing the chance new ports will be overcapitalized and unprofitable. Governments and port researchers need a tool for understanding how local competition in their region will affect demand for port services at their location, and thus better assess the profitability of a prospective port. We propose to develop such a tool by extending our existing simulation model of global container traffic to incorporate demand-side shipper preferences and supply-side strategic responses by incumbent ports to changes in the global port network, including building new ports, scaling up existing ports, and unexpected port closures. We will estimate shipper preferences over routes, port attributes and port services based on US and international shipping data, and redesign the simulation model to maximize the shipper's revealed preference functions rather than simply minimize costs. As demand shifts, competing ports will adjust their pricing (short term) and infrastructure (long term) to remain competitive or defend market share, a reaction we will capture with a game theoretic model of local monopoly that will predict changes in port characteristics. The model's hypotheses will be tested in a controlled laboratory experiment tailored to local port competition in Asia, which will also serve to demonstrate the subtle game theoretic concepts of imperfect competition to a policy and industry audience. We will apply the simulation model to analyze changes in global container traffic in three scenarios: addition of a new large port in the US, extended closure of an existing large port in the US, and cooperative and competitive port infrastructure development among Korean partner countries in Asia.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2067-2077
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• 2011

The recent trend in technology development is characterized as technology convergence, mainly between IT, BT and NT and also more and more industries are starting to use several technologies simultaneously or in a combined way theses days. As a result, the needs on technology interaction analysis is increasing for strategic technology management and policy-making. Responding to the needs, this research deals with technology innovation process in terms of technology competition, particularly focusing on the 17 new growth drivers in 3 areas, which has been announced by the Korean government as a new growth vision for Korean economy, and analyzing their co-evolutionary process. For the analysis, patent data, a representative data on technology innovation, is adopted. Then, Lotka-Volterra Competition model, a model frequently used to describe the dynamism of competitive innovation is applied to the data. The research results are expected to support strategic decision-makings such as effect policy-making or R&D priority-setting, by analyzing the relationship between the 3 areas, the 17 new growth drivers, or the particular technologies in the drivers.

• Korean Management Science Review
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• v.32 no.1
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• pp.83-100
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• 2015

We analyze a duopoly competition when two firms face input cost increases. The objective of this study is to determine the firms' optimal strategy between a price increase and downsizing under conditions of a spatially differentiated market and consumers' diminishing utility on the product size. We develop a theoretical model of two competing firms offering homogenous products using the standard Hotelling model to determine how firms' optimal strategies change when facing input cost increases. In this paper, there are two types of duopoly competitions: symmetric and asymmetric. In the symmetric case, the two firms have the same marginal cost and are producing and selling identical products. In the asymmetric case, the two firms have different marginal costs. The results show that the optimal strategy decision depends on the size of the input cost increase and the cost differences between the two firms. We find that when two firms are asymmetric (i.e., they have different marginal costs), the two firms might choose asymmetric pairs of strategies in equilibrium under certain conditions. When the cost differences between the two firms are sufficiently large and the cost increase is sufficiently small, the cost leader chooses price increase, and the cost-disadvantaged firm chooses downsizing in equilibrium. This asymmetric strategy reduces price competition between two firms, and consumers are better off. When the cost differences between the two firms are sufficiently large, downsizing is the dominant strategy for the cost-disadvantaged firm. The cost-disadvantaged firm finds it more profitable to reduce the product size than to increase its price to reduce price competition, because consumers prefer downsizing to price increases. This paper might be a good starting point for further analytical research in this area.

• Journal of Distribution Science
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• v.15 no.12
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• pp.53-60
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• 2017

Purpose - This paper analyzes the effect of the handset subsidy and the Mobile Number Portability subscriber subsidy regulation, which are the main regulation adopted in "Law on the Improvement of the Mobile Terminal Distribution System" (Mobile Terminal Distribution Act), on the social surplus, the consumer surplus and profits of telecommunications carriers. We focus our analysis on whether the service charge competition is stimulated enough so that it can compensate for the loss of subsidies. Research design, data, and methodology - We use simple economic model to assess the impact of the handset subsidy and the Mobile Number Portability subscriber subsidy regulation. Unlike the former researches on this topic, we depart from using Hotelling model, and instead use the switching cost model, which uses switching cost as a parameter of market powers of telecommunications carriers. We also study the effect of the two different regulations when they are adopted both independently and concurrently. Results - If the market powers of telecommunications carriers are over certain threshold, contrary to the regulatory agency's assertion, the service charge competition would not be stimulated enough to compensate for the deduction in the subsidies, and thus the consumer surplus is compromised. Number Portability subsidy, especially, undermines the rival's market power and thus reduces the service charge. On the other hand, the regulations will also increase the profits of telecommunications carriers. However, social surplus is maximized when both of the regulations are present because the regulations reduces the frequency of switching handsets inefficiently. Conclusions - In enacting the Mobile Terminal Distribution Act, the telecommunications regulatory agency asserted that the regulation on subsidies will stimulate service charge competition, and in the long run, enhance the consumer surplus. However, contrary to the regulatory agency's assertion, subsidy regulation, especially the regulation on Number Portability subsidy, reduces consumer surplus. On the other hand, the Mobile Terminal Distribution Act can also increase the profits of telecommunications carriers because it decreases competition among the telecommunications carriers. However, the Mobile Terminal Distribution Act can increase the social surplus because it reduces inefficient switching of handsets.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9B
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• pp.822-831
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• 2008

This paper examines the theoretical and empirical technology diffusion processes to understand the Korean success in the internet access service markets. In order to do this, first, we propose an integrated demand diffusion model in terms of competition of inter-and intra-technologies and market structure as represented by the number of operators in the market. Second, by using the proposed model, we analyze the dynamic diffusion processes of Korean internet access services such as Narrow-band technology including Dial modem vs. Broad-band technology including ISDN, xDSL and Cable modem. The competition of inter-and intra-technologies as well as the extent of market competition has made a positive effect on the diffusion patterns of internet access demand. And also we propose, based on the proposed model and its empirical results, several implications for diffusion strategies and policies in the future of ICT market in Korea.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.4B
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• pp.234-245
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• 2007

There are lots of controversies over the introduction of MVNO(Mobile Virtual Network Operator) policy to Korean mobile telecommunications market. MVNO is a kind of service-based competition in mobile market. This paper attempts to analyze the ripple effect of MVNO regulation and also desirable ways of implementing the policy. Based on Laffont, Rey and Tirole(1998), Armstrong (1998) model, theoretical MVNO model is defined and derived implications of price, quantity in the market. According to the model, the fact that MNOs have one-way access profit leads the static efficiency by lowering its market price. In regarding the most desirable way to enhance social welfare is revealed as 'two MNOs conduct MVNO' other than 'One MNO does' or 'Structurally divided network'.