• Journal of Power Electronics
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• v.18 no.3
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• pp.910-922
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• 2018

Conventional battery state-of-charge (SoC) estimation methods either involve sophisticated models or consume considerable computational resource. This study constructs an enhanced coulomb counting method (Ah method) for the SoC estimation of lithium-ion batteries (LiBs) by expanding the Peukert equation for the discharging process and incorporating the Coulombic efficiency for the charging process. Both the rate- and temperature-dependence of battery capacity are encompassed. An SoC mapping approach is also devised for initial SoC determination and Ah method correction. The charge counting performance at different sampling frequencies is analyzed experimentally and theoretically. To achieve a favorable compromise between sampling frequency and accumulation accuracy, a frequency-adjustable current sampling solution is developed. Experiments under the augmented urban dynamometer driving schedule cycles at different temperatures are conducted on two LiBs of different chemistries. Results verify the effectiveness and generalization ability of the proposed SoC estimation method.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.7
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• pp.607-611
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• 2000

The characteristics on the interface between Epoxy and EPDM which are materials of the underground insulation systems of power delivery have studied. The breakdown strength of specimens are observed by applying high AC voltage at the room temperature. The breakdown times under the constant voltage below the breakdown voltage were gained. As constant voltage is applied the breakdown time is proportion to the breakdown strength. The life exponent n is gained by inverse power law and the long breakdown life time can be evaluated. AC breakdown strength and life time is improved by oiling to the interface. When the low viscosity oil is spread interface has the highest life time.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.775-778
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• 2000

In this paper, the life-time of macro interface between Epoxy/EPDM which consists in underground power cable joints is predicted. The electrode system of specimen is designed by FEM(finite elements method). The breakdown strength of specimens are observed by applying high AC voltage at the room temperature. The breakdown times under the constant voltage below the breakdown voltage were gained. As constant voltage is applied, the breakdown time is proportion to the breakdown strength. The life exponent n is gained by inverse power law, and the long breakdown life time can be evaluated.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.296-297
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• 2006

In order to support wind power development, the wind resource database of Jejudo has been established by meteo-statistical analysis on meteorological-mast measurements of KIER. Analysis processes contain correlation of monthly wind speed and power-law exponent among neighboring sites, Measure-Correlated-Predict for long-term correlation, classification of exposure category using satellite image and so forth. It is found that the monthly variations of wind speed and power-law exponent depend on seasonal winds and characterize wind system of Jejudo.

• Structural Engineering and Mechanics
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• v.69 no.6
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• pp.637-649
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• 2019

In the current research paper, a quasi-3D beam theory is developed for free vibration analysis of functionally graded microbeams. The volume fractions of metal and ceramic are assumed to be distributed through a beam thickness by three functions, power function, symmetric power function and sigmoid law distribution. The modified coupled stress theory is used to incorporate size dependency of micobeam. The equation of motion is derived by using Hamilton's principle, however, Navier type solution method is used to obtain frequencies. Numerical results show the effects of the function distribution, power index and material scale parameter on fundamental frequencies of microbeams. This model provides designers with guidance to select the proper distributions and functions.

• Korea-Australia Rheology Journal
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• v.20 no.2
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• pp.59-63
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• 2008

A theoretical model was developed to describe the flow behavior of a filled polymer in the packing stage of reaction injection molding and predict the residual stress distribution of thin injection-molded parts. The model predictions were compared with experiments performed for phenol-formaldehyde resin filled with wood dust and cured by urotropine. The packing stage of reaction injection molding process presents a typical example of complex non-isothermal flow combined with chemical reaction. It is shown that the time evolution of pressure distribution along the mold cavity that determines the residual stress in the final product can be described by a single 1D partial differential equation (PDE) if the rheological behavior of reacting liquid is simplistically described by the power-law approach with some approximations made for describing cure reaction and non-isothermality. In the formulation, the dimensionless time variable is defined in such a way that it includes all necessary information on the cure reaction history. Employing the routine separation of variables made possible to obtain the analytical solution for the nonlinear PDE under specific initial condition. It is shown that direct numerical solution of the PDE exactly coincides with the analytical solution. With the use of the power-law approximation that describes highly shear thinning behavior, the theoretical calculations significantly deviate from the experimental data. Bearing in mind that in the packing stage the flow is extremely slow, we employed in our theory the Newtonian law for flow of reacting liquid and described well enough the experimental data on evolution of pressure.

• IE interfaces
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• v.22 no.3
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• pp.205-213
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• 2009

Warfare information system is a core factor of future combat operation under NCW(Network centric Warfare) environment. In this paper, we proposed a new MOE(Measure of Effectiveness) that can assess the combat power synergistic effect of warfare information system in the theater-level joint fire operation. This new MOE uses the rule of Newton's second law($F=(m{\Delta}{\upsilon})/{\Delta}t{\Rightarrow}(M{\upsilon}I)/T$). Four factors considered in combat power evaluation are network power(M), movement velocity(v), information superiority(I), command and control time(T). We applied this new MOE to the JFOS-K(Joint Fire Operating System-Korea) to assess its combat power effect and compared with other's effects obtained from different MOE.

• The Korean Journal of Air & Space Law and Policy
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• v.22 no.1
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• pp.29-54
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• 2007

Nuclear Power Sources(NPS) have been used since 1961 for the purpose of generating energy for space objects and have since then been recognized as particularly suited essential to some space operations. In January 1978 a malfuctioning Soviet nuclear powered satellite, Cosmos 954, re-entered the earth's atmosphere and disintegrated, scattering radioactive debris over a wide area of the Canadian Northwest Territory. This incident provided some reasons to international legal scholars to make some principles to regulate using NPS in outer space. In 1992 General Assembly adopted "Principles Relevant to the Use of Nuclear Power Sources in Outer Space". These NPS Principles set out certain legal and regulatory requirements on the use of nuclear and radioactive power sources for non-propulsive purposes. Although these principles, called 'soft laws', are not legal norms, they have much enfluences on state practices such as 1983 DBS Principles(Principles Governing the Use by States of Artificial Earth Satellites for International Direct Television Broadcasting), 1986 RS Principles(Principles Relating to Remote Sensing of the Earth from Space) and 1996 Declaration on International Cooperation in the Exploration and Use of Outer Space for the Benefit and in the Interests of all States, Taking into Particular Account the Needs of Developing Countries. As far as 1963 Declaration of Legal Principles Governing the Activities of States in the Exploration and Use of Outer Space is concerned the main points such as free use of outer space, non-appropriation of celestial bodies, application of international law to outer space etc. have become customary international law binding all states. NPS Principles might have similar characters according to states' willingness to respect them.

• The Korean Journal of Air & Space Law and Policy
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• no.spc
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• pp.35-58
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• 2007

Nuclear Power Sources(NPS) have been used since 1961 for the purpose of generating energy for space objects and have since then been recognized as particularly suited essential to some space operations. In January 1978 a malfuctioning Soviet nuclear powered satellite, Cosmos 954, re-entered the earth's atmosphere and disintegrated, scattering radioactive debris over a wide area of the Canadian Northwest Territory. This incident provided some reasons to international legal scholars to make some principles to regulate using NPS in outer space. In 1992 General Assembly adopted "Principles Relevant to the Use of Nuclear Power Sources in Outer Space". These NPS Principles set out certain legal and regulatory requirements on the use of nuclear and radioactive power sources for non-propulsive purposes. Although these principles, called 'soft laws', are not legal norms, they have much enfluences on state practices such as 1983 DBS Principles(Principles Governing the Use by States of Artificial Earth Satellites for International Direct Television Broadcasting), 1986 RS Principles(Principles Relating to Remote Sensing of the Earth from Space) and 1996 Declaration on International Cooperation in the Exploration and Use of Outer Space for the Benefit and in the Interests of all States, Taking into Particular Account the Needs of Developing Countries. As far as 1963 Declaration of Legal Principles Governing the Activities of States in the Exploration and Use of Outer Space is concerned the main points such as free use of outer space, non-appropriation of celestial bodies, application of international law to outer space etc. have become customary international law binding all states. NPS Principles might have similar characters according to states' willingness to respect them.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.597-605
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• 2012

This research examines whether religions can explain differences in the rule of law across nations. It finds that several religious groups can explain much of the variation in the rule of law while others have no explanatory power.