• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.10
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• pp.5149-5167
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• 2017

Reducing energy consumption in a wireless video sensor network (WVSN) is a crucial problem because of the high video data volume and severe energy constraints of battery-powered WVSN nodes. In this paper, we present an adaptive dynamic resizing approach for a SRAM communication buffer in a WVSN node in order to reduce the energy consumption and thereby, to maximize the lifetime of the WVSN nodes. To reduce the power consumption of the communication part, which is typically the most energy-consuming component in the WVSN nodes, the radio needs to remain turned off during the data buffer-filling period as well as idle period. As the radio ON/OFF transition incurs extra energy consumption, we need to reduce the ON/OFF transition frequency, which requires a large-sized buffer. However, a large-sized SRAM buffer results in more energy consumption because SRAM power consumption is proportional to the memory size. We can dynamically adjust any active buffer memory size by utilizing a power-gating technique to reflect the optimal control on the buffer size. This paper aims at finding the optimal buffer size, based on the trade-off between the respective energy consumption ratios of the communication buffer and the radio part, respectively. We derive a formula showing the relationship between control variables, including active buffer size and total energy consumption, to mathematically determine the optimal buffer size for any given conditions to minimize total energy consumption. Simulation results show that the overall energy reduction, using our approach, is up to 40.48% (26.96% on average) compared to the conventional wireless communication scheme. In addition, the lifetime of the WVSN node has been extended by 22.17% on average, compared to the existing approaches.

• Journal of Korea Trade
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• v.25 no.3
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• pp.65-86
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• 2021

Purpose - This paper empirically investigates the relationship between the corporate value chain and performance of non- financial businesses of South Korean stock market companies. It aims to explore the evidence that can be used to infer the relationship between value chains and corporate performance in the case of firms forming a value chain with other companies with the means of an equity investment or a special business relationship. Design/methodology - Non-financial corporations listed from 2011 to 2017 on the securities market of South Korea are analyzed. The data used for analysis are found for transactions with the related party by year for all the corporations of non-financial industries in the securities market. Multiple analysis attempts are conducted including the relationship between the value chain and productivity, corporate value, risk-adjusted corporate value, and mediation effects of productivity. The empirical model employs sixteen variables including the value chain index which identifies its impact on various aspects of business performances. Findings - The results of this study clearly supports the phenomenon that corporate productivity and value are enhanced when the corporation expands its value chain established with domestic related firms and overseas companies. Such a positive effect is statistically significant even after the possible risk factors that accompany the expansion of value chain were considered, and productivity plays the role as a medicating variable in the effect of the value chain on the corporation values. Originality/value - The findings of this study confirms that domestic companies' expansion of their value chain centered on the related firms overseas that helped them in terms of the maximization of their productivity and corporate values. This study shows that Korean government's policy on expanding the corporate GVC can enhance the productivity and value of firms. The expansion of value chain and its impact on business performance has not been explored thoroughly, although it is getting more and more important in the global trade operation.

• Asia-Pacific Journal of Business
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• v.13 no.1
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• pp.37-52
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• 2022

Purpose - The objective of this study is to investigate what motivates global FDI inflows in the different economic development level and to clarify the FDI motivation type in the level of qualitative economic growth. Design/methodology/approach - Major macroscopic social·economic factors induced FDI inflows were analyzed using fixed-effect panel regression with 30-year panel data of 28 countries from 1985 to 2014. For analysis in the stage of economic growth, two category of developed and developing countries was used. And to analyze FDI motivation type in the level of qualitative economic growth, 4 shares of GDP; consumption·government·investment expenditure and export, was used as explanatory variable. Findings - In developed country, TFP(total factor productivity) and GDP have a great influence on FDI inflows, and consumption and labor compensation have a slight effect. This result indicates that the market seeking-driven, horizontal type investment is shown along with efficiency seeking investment. In developing country, human capital and TFP is shown to have greater impact on FDI inflows and labor compensation, exports, investment and government expenditures also have impacts. Thus it has confirmed that not only efficiency-seeking vertical investment for using low cost well educated laborer, but also government-driven economic growth and export policies could affect the FDI inflows. Research implications or Originality - The FDI investment decision making of multinational companies is decided by their own purpose. But, in the concept of as follows; 1) FDI is a long-term capital flowing for maximization of economic utility with limited global resource, 2) Thus FDI could be affected by macro socio·economic factors of host country. 3) Also such macro factors is different by each economic growth qualitative level. Therefore macro socio·economic factors of each country could be affected by the qualitative level of their own economic growth. To attract FDI inflows, it is desirable to implement differentiated incentive policies in the qualitative level of economic growth. Furthermore in developing countries it is recommended to implement government driven economic growth policies as follows; fostering well educated human resources, improving technology productivity in the relative lower cost labor market compared to developed countries and boosting international export volume.

• The Journal of the Convergence on Culture Technology
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• v.9 no.2
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• pp.285-294
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• 2023

The trade dispute between China and the U.S. began before Corona and is easing at this time by bringing new changes to the pendemic, and the development of the Chinese manufacturing industry has increased interdependence between the U.S. and China. However, the overall global trade should be less than before pendemic, and Korea's response strategy should be made serious at this time.However, new changes are taking place again these days. With the recent outbreak of COVID-19 in Shanghai, China, new changes are expected to occur in China's industrial chain. As the Chinese government strictly creates quarantine figures for COVID-19, many factories and companies among industries are forced to close for a while. As economic globalization and division of labor continue to deepen, multinationals choose suppliers and industrial chains within the world to form a global supply chain structure to pursue cost minimization and profit maximization. China is an indispensable part. Whether it is China, the U.S. or Korea, it can be a risk and an opportunity now.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.9
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• pp.764-775
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• 2002

A kinematic and dynamic optimal design of a new parallel-type rolling mill based upon Stewart platform manipulator is investigated. To provide sufficient degrees-of-freedom in the rolling process and the structural stability of each stand, a parallel manipulator with six legs is considered. The objective of this new parallel-type rolling mill is to permit an integrated control of the strip thickness, strip shape, pair crossing angle, uniform wear of the rolls, and tension of the strip. By splitting the weighted Jacobian matrices Into two parts, the linear velocity, angular velocity, force, and moment transmissivities are analyzed. A manipulability measure, the ratio of the manipulability ellipsoid volume and the condition number of a split Jacobian matrix, is defined. Two kinematic parameters, the radius of the base and the angle between two neighboring Joints, are optimally designed by maximizing the global manipulability measure in the entire workspace. The maximum force needed in the hydraulic actuator is also calculated using the structure determined through the kinematic analysis and the Plucker coordinates. Simulation results are provided.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.11 s.353
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• pp.1-7
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• 2006

This paper consider a code-division multiple-access(CDMA) wireless ad-hoc network in low-SINR regime. In previous research [6], there has been proposed a algorithm for achieving global optimum at high SINR regime, but has not been fully investigated at low-SINR regime. In this paper, we focus on a case where SINR is much smaller than 1, and propose a algorithm that is suitable for low-SINR regime.

• Journal of Communications and Networks
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• v.16 no.1
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• pp.18-25
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• 2014

In this paper, we propose a codebook-based interference alignment (IA) scheme in the constant multiple-input multiple-output (MIMO) interference channel especially for the uplink scenario. In our proposed scheme, we assume cooperation among base stations (BSs) through reliable backhaul links so that global channel knowledge is available for all BSs, which enables BS to compute he transmit precoder and inform its quantized index to the associated user via limited rate feedback link. We present an upper bound on the rate loss of the proposed scheme and derive the scaling law of the feedback load to maintain a constant rate loss relative to IA with perfect channel knowledge. Considering the impact of overhead due to training, cooperation, and feedback, we address the effective degrees of freedom (DOF) of the proposed scheme and derive the maximization of the effective DOF. From simulation results, we verify our analysis on the scaling law to preserve the multiplexing gain and confirm that the proposed scheme is more effective than the conventional IA scheme in terms of the effective DOF.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.10a
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• pp.321-333
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• 2005

With the limited frequency spectrum and an increasing demand for cellular communication services, the problem of channel assignment becomes increasingly important. However, finding a conflict free channel assignment with the minimum channel span is NP hard. As demand for services has expanded in the cellular segment, sever innovations have been made in order to increase the utilization of bandwidth. The innovations are cellular concept, dynamic channel assignment and hierarchical network design. Hierarchical network design holds the public eye because of increasing demand and quality of service to mobile users. We consider the frequency assignment problem and the base station placement simultaneously. Our model takes the candidate locations emanating from this process and the cost of assigning a frequency, operating and maintaining equipment as an input. In addition, we know the avenue and demand as an assumption. We propose the network about the profit maximization. This study can apply to GSM(Global System for Mobile Communication) which has 70% portion in the world. Hierarchical network design using GA(Genetic Algorithm) is the first three-tier (Macro, Micro, Pico) model, We increase the reality through applying to EMC (Electromagnetic Compatibility Constraints). Computational experiments on 72 problem instances which have 15${\sim}$40 candidate locations demonstrate the computational viability of our procedure. The result of experiments increases the reality and covers more than 90% of the demand.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.6
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• pp.691-698
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• 2015

Recently, the power industry has a great interest in the superconducting energy storage device as a way to maximize energy efficiency to cope with global warming. A superconducting energy storage device can archive maximization of electric energy use efficiency by storing in the form of a magnetic field energy or a kinetic energy without loss a large amount of electrical energy at the non-peak load and then converting it again into electric energy at the peak load. Therefore, in this study, such as the concept of the superconducting energy storage technologies, the present state of its research and development and its applications are surveyed and analyzed to establish methodology applying the superconducting energy storage technologies to power system.

• Journal of Arbitration Studies
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• v.10 no.1
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• pp.115-133
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• 2000

All kinds of commerces are begun from the contract and the claims are frequently raised by the problem in the contracts. Therefore, the negotiation is very important to make a contract and resolve the claim. This article analyzed the negotiation practice of Chinese in order to render help to negotiators who enter into negotiations with Chinese business people so that they can enhance their chance for success. Based on this examination on the negotiating style, this paper also provides the some guidelines in working-level negotiating with Chinese. For the purpose this study applies "global negotiation flowchart" and twelve important factors suggested by stephen & stripp to analyze the characteristics of Chinese business negotiating style. The results suggest some useful criteria for negotiators First, In the preparation, the negotiator need a thorough study about the Chinese negotiating style and counter party. Second, In the negotiation with the Chinese, making the personal relationship and, if possible, frequent contact with the person who is the most powerful negotiator in decision-making. Third, since the Chinese has a sense of value that money is very important, it is very necessary that the negotiator persuade him by mutual profits. Finally, negotiators must aim at long-term profit maximization not at short-term.