• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.11a
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• pp.136-140
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• 1992

The purpose of this research is to develop the lithium secondary battery. This paper describes the preparation, electrochemical properties of nontstoichiometric(NS)-$V_6O_{13}$ and characteristics of Li/$V_6O_{13}$ secondary battery. NS-$V_6O_{13}$ was prepared by thermal decomposition of $NH_4VO_3$ under Ar stream of 140ml/min~180ml/min flow rate. And then, this NS-$V_6O_{13}$ was used for cathode active material. Cathode sheet was prepared by compressing the composite of NS-$V_6O_{13}$, acetylene black(A.B) and teflon emulsion (T.E). Characteristics of the test cell are summarised as follows. Oxidation capacity of NS-$V_6O_{13}$ was about 20% less than its reduction capacity. A part of NS-$V_6O_{13}$ cathode active material showed irreversible reaction in early charge-discharge cycle. This phenomena seems to be caused by irreversible incoporation/discoporation of lithium cation to/from NS-$V_6O_{13}$ host. Discharge characteristics curve of Li/$V_6O_{13}$ cell showed 4 potential plateaus. Charge-discharge capacity was declined in the beginning of cycling and slowly increased in company with increasing of coulombic efficiency. Energy density per weight of $V_6O_{13}$ cathode material was as high as 522Wh/kg~765Wh/kg.

• Asia pacific journal of information systems
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• v.32 no.4
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• pp.728-749
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• 2022

The information and communication technology (ICT) value creation process is inherently unobservable. In addition to the direct effect of ICT on productivity, some information or knowledge can create value through other knowledge activities. In this paper, we study the impact of ICT on productivity through R&D. We tested the mediating effect of R&D between ICT and productivity using panel data from 47 US industries from 1987 to 2013 from the Bureau of Labor Statistics. The results show that R&D partially mediates ICT and productivity. That is, ICT directly increases productivity, and some of its effects can be realized through R&D. Recipients who acquire knowledge through ICT have to interpret codified ideas and apply them to practice. The increased absorptive capacity that can be developed through R&D improves interpretation ability, allowing employees to share more complex ideas. Thus, ICT helps people to effectively communicate, but some information and knowledge can be realized and applied through R&D knowledge activities. This is the first study empirically examining the process of ICT value creation through R&D. It also provides practical guidelines for knowledge management, such as making decisions about ICT and R&D investments that are better done concurrently rather than individually to maximize their impact on productivity.

• Journal of the Chungcheong Mathematical Society
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• v.26 no.2
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• pp.315-321
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• 2013

Let $D_0$, $D_1{\subset}\bar{R}^n$ be non-empty sets and let ${\Gamma}$ be the family of all closed curves which join $D_0$ to $D_1$. In this note, we introduce the concept of the mathematical conductance $C({\Gamma})$ of a curve family ${\Gamma}$ and examine some basic properties of mathematical conductance. And we obtain the inequalities in connection with capacity of condensers.

• Journal of Power Electronics
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• v.13 no.3
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• pp.429-436
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• 2013

Online simulations are utilized to reduce time and cost in the development and performance optimization of plug-in hybrid electric vehicle (PHEV) and electric vehicles (EV) systems. One of the most important factors in an online simulation is the accuracy of the model. In particular, a model of a battery should accurately reflect the properties of an actual battery. However, precise dynamic modeling of high-capacity battery systems, which significantly affects the performance of a PHEV, is difficult because of its nonlinear electrochemical characteristics. In this study, a dynamic model of a high-capacity battery cell for a PHEV is developed through the extraction of the equivalent impedance parameters using electrochemical impedance spectroscopy (EIS). Based on the extracted parameters, a battery cell model is implemented using MATLAB/Simulink, and charging/discharging profiles are executed for comparative verification. Based on the obtained results, the model is optimized for a high-capacity battery cell for a PHEV. The simulation results show good agreement with the experimental results, thereby validating the developed model and verifying its accuracy.

• Journal of the Korea Society of Computer and Information
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• v.23 no.12
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• pp.211-218
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• 2018

In this paper, we propose that investigating the relationship between the dynamic capacity and the technological innovation performance of firms. Based on the previous research, we divide the dynamic capacity into the adaptive capacity, absorption capacity, and productive capacity. Among the 3,400 companies responding to the technical statistics of SMEs in 2011, we performed multiple regression analysis with 2,807 except service industries. As a result, the absorptive capacity and productive capacity have a positive effect on the technological innovation performance at the 99% level, whereas the adaptive capacity has a negative effect on the technological innovation performance at the 95% level. The implications of this study are as follows. First, in order to improve the performance of technological innovation, it is important to strengthen the absorption capacity and productive capacity of companies. Absorption capacity shows that it is important to secure sufficient R & D manpower and R & D cost to utilize internal knowledge as well as to bring outside knowledge into the capacity to assimilate and utilize external knowledge. Second, the ability to commercialize a product is a capability to commercialize a technology that has succeeded in development, showing that the technology development organization must have the capability of post-development commercialization as well as technology development. Finally it shows the negative effect on adaptation capacity and innovation performance. Companies actively utilize external sources of information in order to respond to and adapt to the rapidly changing business environment. However, the results of this study show that a strategic approach is needed to use external sources of information and technology development resources. Especially as the use of external information resources and technology development resources increases.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.630-633
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• 1997

This paper describes a design of a single phase PWM converter for high speed train. Parallel operation and control method of four Quadrant PWM converters are described. Simulation and modelling of the converters is performed. Capacity of the converter/inverter and power circuit for high speed traction system designed. And harmonic contents of AC line current's are analyzed. The results of the simulation are presented.

• STI Policy Review
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• v.8 no.1
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• pp.1-22
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• 2017

There has been a pronounced increase in research and development (R&D) expenditure in Singapore over the last two decades, with government spending accounting for a sizeable share. This increase has been spurred by public policy emphasis on research and innovation as engines of economic growth. This paper analyses the impact of R&D on economic performance in Singapore from 1978 to 2012 through the use of time series analysis. The Cobb-Douglas based analysis shows a long-run equilibrium relationship between Total Factor Productivity (TFP) and R&D investments. We found that the short-run productivity of R&D in Singapore is comparable to smaller advanced economies in the Organisation for Economic Co-operation and Development (OECD). However, in terms of long-run R&D productivity, Singapore lags slightly behind the smaller OECD nations and far behind the G7 countries. This suggests leakage of value capture and low absorptive capacity in local firms. Possibility of productivity improvements induced by policy changes in the 1990s was considered, but no evidence of significant structural breaks was found. Lastly, Granger causality analysis reveals that public sector R&D augments private sector R&D capital, thus playing an important role in generating externalities and spillover effects. Policy implications and lessons for other middle-income countries are discussed.

• Journal of Korean Public Health Nursing
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• v.30 no.3
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• pp.526-543
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• 2016

Purpose: The purpose of this study was to explore how public health nurses (PHNs) perceive their roles and duties (R&D), as well as to investigate the change of their R&D, how they manage and solve problems. Methods: The data were collected through focus group interviews. Data were analyzed using Morgan (1998) and Krueger (1998)'s four step analysis. A total of 17 experienced PHNs participated in this study. Results: The results found 5 themes and 19 sub-themes: R&D of health managers and health service providers, factors affecting the changes of PHN's R&D, R&D in adjusting with trends and expanding work field (R&D being reduced, increasing R&D, need to expand R&D), problem with the structure and quality of workforce (lack of nurse manpower, lack of promotion opportunities, increasing non-regular workers, lack of refinement as an expert), and strategies for solving personnel issues (strengthening the job capacity, cultivating professional refinement, strengthening outside activities and political activities, strengthening the roles of PHN-related associations and academy, engagement policy of non-regular workers, expansion of the activity area) Conclusion: PHNs need to recognize their changing R&D and ways they manage and solve problems to enhance their professionalism.

• Animal cells and systems
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• v.6 no.1
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• pp.19-22
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• 2002

Life table studies were conducted in the laboratory for the eulophid gregarious pupal parasitoid, Tetrastichus sp., on Hyphantria cunea Drury at a constant temperature of 28.2$\pm$2$^{\circ}C$, 50-60% RH to evaluate their impact on the host and their potential biological control. Development of immature stage took 20.1$\pm$2.7 d: adult females lived for 23.2$\pm$2.2 (range, 16-27)d and produced a mean of 53.6$\pm$26.6 adult progeny per female, with a sex ratio of 1: 9.5 (M:F). The intrinsic rate of natural increase (r$_{m}$) was 0.178/ female/day; the net reproductive rate (R$_{o}$), 46.74; the capacity for increase (r$_{c}$) 0.177; the finite rate of increase (λ) 1.19/female/day; thus each female contributed 46.74 individuals to the population in a mean generation time of 21.6 d. Biological factors in determining the life history trait variation of the parasitoid were discussed.d.d.d.

• Journal of Hydrogen and New Energy
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• v.22 no.6
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• pp.852-858
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• 2011

This paper is aiming to estimate the mutual influence of the stack cooling performances with the operation modes of the thermal management system for the hydrogen fuel cell vehicles. The heat capacity of the thermal management system was measured by varying the operating modes such as stack cooling heat exchanger only (Mode 1), stack cooling and electric devices cooling heat exchangers (Mode 2), and stack cooling and electric devices cooling heat exchangers with an operation of the condenser (Mode 3).As the results, Performance of the thermal management system (TMS) at Mode 3 decreased up to 34.0%, compared with the result of the Mode 1. In addition, in order to optimize the performance of TMS, the entropy change of stack cooling heat exchanger using irreversibility analysis technique was analyzed with the relationship between entropy generation and entering air velocity of the thermal management system.