• Journal of Electrochemical Science and Technology
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• v.15 no.3
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• pp.414-420
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• 2024

Lithium-ion batteries are widely used in many applications due to their high energy density, high efficiency, and excellent cycle ability. Once an unknown Li-ion battery is reusable, it is important to measure its lifetime and state of health. The most favorable measurement method is the cycle test, which is accurate but time- and capacity-consuming. In this study, instead of a cycle test, we present an empirical model based on the C-rate test to understand the state of health of the battery in a short time. As a result, we show that the partially accelerated charge/discharge condition of the Li-ion battery is highly effective for the degradation of battery capacity, even when half of the charge/discharge conditions are the same. This observation provides a measurable method for predicting battery reuse and future capacity degradation.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.4
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• pp.226-231
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• 2000

In this paper, we present new method to analyze the space charge effect on the electrical characteristics in polymer. It is new measurement system and analysis method that have not reported yet. By using this measurement system, we make observation to space charge accumulated on the surface of polymer at AC voltage, so it is examined to verify the correlation of space charge and partial discharge(PD). In the result of experiment, it can be known that PD pattern is related more closely to space charge accumulated on the surface of polymer than in the inner part, and applied voltage in the air is ruled by this dynamic partial discharge. Also, above critical voltage, the space charge accumulated on the surface of polymer have no effect to the magnitude of PD and the applied voltage in the air. It has been known that the electric power of the dissolution system is proportioned to the frequency and the magnitude of applied voltage, but we can know by this result of the experiment that the efficiency of the dissolution is not related to the rise of voltage above critical voltage.

• Journal of electromagnetic engineering and science
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• v.18 no.1
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• pp.52-57
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• 2018

Surface dielectric barrier discharge (SDBD), which is widely used to control turbulence in aerodynamics, has a significant effect on the radar cross-section (RCS). A four-way linearly synthesized SDBD air plasma actuator is designed to bolster the plasma effects on electromagnetic waves. The diffraction angle is calculated to predict the RCS because of the periodic structure of staggered electrodes. The simplified plasma modeling is utilized to calculate the inhomogeneous surface plasma distribution. Monostatic RCS shows the diffraction in the plane perpendicular to the electrode array and the notable distortion by plasma. In comparison, the overall pattern is maintained in the parallel plane with minor plasma effects. The trends also appear in the bistatic RCS, which has a significant difference in the observation plane perpendicular to the electrodes. The peaks by Bragg's diffraction are shown, and the RCS is reduced by 10 dB in a certain range by the plasma effect. The diffraction caused by the actuator and the inhomogeneous air plasma should be considered in designing an SDBD actuator for a wide range of application.

• Journal of Astronomy and Space Sciences
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• v.35 no.2
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• pp.93-103
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• 2018

Non-specular, vertically upward transit, fast-moving radar echoes are observed in the summer polar upper mesosphere near 90 km using 52 MHz VHF radar at Esrange, Sweden. By resolving maximum echo power movement, the unusual meteor trails propagate vertically upward with taking horizontal displacements at an initial speed of 10 km/s exponentially decreasing with increasing height from 85-89 km, lasting for 3.5 sec. Another upward transit is observed as following a downward transit echo target in about ~1 sec, lasting over 5 sec. The upward motion cannot be explained with the dynamics of penetrating meteors or by atmospheric dynamics. The observation proposes that secondary produced plasma jets occurring from meteor trail are possibly responsible for upward fast moving echoes. The long-lasting (3-5 sec), ascending meteor trails at speeds of a few $10^4m/s$ are distinctive from any previous occurrences of meteors or upper atmospheric electrical discharges in the aspect of long-lasting upward/downward motions. This result possibly suggests a new type of meteor-trail leader discharge occurring in the summer polar upper mesosphere and lower thermosphere.

• Journal of Korean Academy of Nursing
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• v.35 no.5
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• pp.842-849
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• 2005

Purpose: The main purpose of this study was to establish a nursing intervention data base to improve maternal attachment. Method: The first group of mothers( control group), experienced their first physical contact with their infants after being discharged from the hospital. The second group (experimental group) practiced early initial mother-infant postpartum contact known as the most sensitive period for founding maternal-infancy attachment. The subjects of this study gave birth to normal infants at M hospital from Aug.25 to Sept.30, 2004. During the same time, data was collected through direct observation, with instruments designed by Cropley et al., to assess the behaviors of normal attachment. The statistical methods for data analysis were percentage, mean, standard deviation and t-test with an SPSS program. Result: The group practicing initial mother-infant contact, showed a higher degree of physical and functional bonding than the group experiencing the first contact after discharge from the :10spital (control group)(p<.0l). The group practicing initial mother-infant contact, showed higher degrees of bonding attachment assessments than the group experiencing their first initial contact after their discharge from the hospital(p<.01). Conclusion: The group practicing early mother-infant contact, showed more maternal-infant interaction than the group experiencing their initial contact after their discharge from the hospital. These results show that maternal attachment behavior increases according with an early initial mother-infant contact.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.563-566
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• 2003

The conventional testing as IEC-60587 is widely used in suface aging measurement of outside insulator those testing can carry out very short time in Lab testing. Also IEC-60587 testing is able to offer the standard judgement of relative degradation level of out side HV machine. Therefore it is very useful method compare to previous conventional tracking testing method and effective Lab testing method, But surface discharges(SD) have very complex characteristics of discharge pattern so it is required estimation research to development of precise analysis method. In recent, the study of IRR Camera is carrying out discover of temperature of power equipment through condition diagnosis and system development of degradation diagnosis.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1798-1802
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• 2007

The practice of business estimate flood discharge by rainfall-flow relation that is easy collection of observation data. The important factor is rainfall, coefficient of runoff, and drainage area for analysis of runoff-flow relation.The practice of business usually use probability rainfall that use a weighted average value after each observation post estimate probability of non-same time. It has more error than same time probability rainfall, and it can excess of estimation because it can't consider space distribution of rainfall.The study of result showed similar aspect with existing ARF but width of coefficient become smaller. And the comparison of peak flow did not different what used by ARF and same time probability rainfall(A group). But non-same time probability rainfall is bigger 25% more than another(B group). Between A group and B group of the difference increased with the lapse of time.

• Journal of Industrial Technology
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• v.27 no.A
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• pp.95-102
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• 2007

The practice of business estimate flood discharge by rainfall-flow relation that is easy collection of observation data. The important factor is rainfall, coefficient of runoff, and drainage area for analysis of runoff-flow relation. The practice of business usually use probability rainfall that use a weighted average value after each observation post estimate probability of non-same time. It has more error than same time probability rainfall, and it can excess of estimation because it can't consider space distribution of rainfall. The study of result showed similar aspect with existing ARF but width of coefficient become smaller. And the comparison of peak flow did not different what used by ARF and same time probability rainfall(A group). But non-same time probability rainfall is bigger 25% more than another(B group). Between A group and B group of the difference increased with the lapse of time.

• Journal of Korean Academy of Nursing Administration
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• v.20 no.5
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• pp.545-557
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• 2014

Purpose: The purpose of this study was to develop a patient classification system based on nursing care intensity for patients with acute stroke-related symptoms and verify its validity and reliability. Methods: Data were collected between November, 2013 and February, 2014. The verification for content validity of the patient classification system was conducted by a group of seven professionals. Both interrater reliability and concurrent validity were verified at stroke units in tertiary hospitals. Results: The intensive nursing care for acute stroke patients consisted of 14 classified domains and 56 classified contents by adding 'neurological assessment and observation' and 'respiratory care': 'hygiene', 'nutrition', 'elimination', 'mobility and exercise', 'education or counselling', 'emotional support', 'communication', 'treatment and examination', 'medication', 'assessment and observation', 'neurological assessment and observation', 'respiratory care', 'coordination between departments', and 'discharge or transfer care'. Each domain was classified into four levels such as Class I, Class II, Class III, and Class IV. Conclusion: The results show that this patient classification system has satisfactory validity for content and concurrent and verified reliability and can be used to accurately estimate the demand for nursing care for patients in stroke units.

• Journal of Korean Vacuum Science & Technology
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• v.7 no.1
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• pp.18-22
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• 2003

The optogalvanic effect is proposed and demonstrated as a technique for Penning ionization in a discharge of mixtures of metal vapors and rare gases. The gadolinium and argon mixture is used as a prototype. The lowest metastable of argon, 3P$_2$ (ls$\_$5/ in Paschen notation) at 93144 cm$\^$-1/, is within kT from the excited states of Gd ion. Thus Penning ionization occurs to an excited states of the ion. This process strongly alters the optogalvanic signal and has its own signatures.