• Proceedings of the KIPE Conference
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• 2001.12a
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• pp.175-178
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• 2001

This treatise is treatise about interception effect of electromagnetic waves that is becoming social problem 21th century. Analyzed incidental and value comparison after used a widely spread computer mouse and electricity floor covered with laminated paper by materials for experiments, and apply composition conductibility electromagnetic waves cover material to this products, and limp an experiment in everyday life in this treatise.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.2
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• pp.151-154
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• 2020

Radiation noise due to EMI noise generated by the driving circuits of LED lighting devices in a medical imaging room was reduced by decreasing the noise source in the driving circuits and changing the number of corrections in EMI filters. Noise attenuation and filter changes enabled driving circuits that reduced the electromagnetic waves. Such circuits were efficiently designed by using capacitors and inverters in a given space. Therefore, the malfunction of radiation devices can be minimized by using EMI-reduction filter circuits, and reliable operation of medical devices can be expected by blocking electromagnetic waves.

• Computers and Concrete
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• v.33 no.5
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• pp.621-630
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• 2024

This study presents novel electromagnetic wave-based methods for evaluating the integrity of cement-based structures using time domain reflectometry (TDR). Two cement-based plates with embedded rebars are prepared under sound and defective conditions. TDR tests are carried out using transmission lines with various numbers of artificial joints, and electromagnetic waves are measured to assess the integrity of the plates. The experimental results show that the travel time of electromagnetic waves is consistently longer in sound plates than in defective ones, and an increase in the reflection coefficients is observed in the defect zone of the defective plates. Electromagnetic wave velocities are higher in the defective plates, especially when connectors are present in the transmission line. A novel approach based on the area of the reflection coefficient provides larger areas in the defective plates, and the attenuation effect of the electromagnetic waves induces a difference in the areas of the reflection coefficient between the two defect conditions. An alternative method using the centroid of the defect zone slightly overestimates the location of the defect zone. The length of the defect zone is estimated using the defect ratio and wave velocities of cement, air, and plate. The length of the defect zone can also be calculated using the travel times within the plate, total measured length of the plate, and wave velocities in the cement and air. Therefore, the electromagnetic wave-based methods proposed in this study may be useful for estimating the location and length of defect zones by considering attenuation effects.

• Journal of Astronomy and Space Sciences
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• v.39 no.2
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• pp.67-77
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• 2022

The elements that impact the dynamics and collaborations of waves and particles in the magnetosphere of planets have been considered here. Saturn's internal magnetosphere is determined by substantiated instabilities and discovered to be an exceptional zone of wave activity. Interchanged instability is found to be one of the responsible events in view of temperature anisotropy and energization processes of magnetospheric species. The generated active ions alongside electrons that constitute the populations of highly magnetized planets like Saturn's ring electron current are taken into consideration in the current framework. The previous and similar method of characteristics and the perturbed distribution function have been used to derive dispersion relation. In incorporating this investigation, the characteristics of electromagnetic ion cyclotron wave (EMIC) waves are determined by the composition of ions in plasmas through which the waves propagate. The effect of ring distribution illustrates non-monotonous description on growth rate (GR) depending upon plasma parameters picked out. Observations made by Cassini found appropriate for modern study, have been applied to the Kronian magnetosphere. Using Maxwellian ring distribution function of ions and detailed mathematical formulation, an expression for dispersion relation as well as GR and real frequency (RF) are evaluated. Analysis of plasma parameters shows that, proliferating EMIC waves are not developed much when propagation is parallelly aligned with magnetosphere as compared to waves propagating in oblique direction. GR for the oblique case, is influenced by temperature anisotropy as well as by alternating current (AC) frequency, whereas it is much affected only by AC frequency for parallel propagating waves.

• Fashion & Textile Research Journal
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• v.6 no.4
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• pp.503-510
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• 2004

The study is one of fundamental researches for the development of future smart clothing and textile products with blocking properties from electromagnetic waves by analyzing human physical symptoms in using electromagnetic products in such an environments. Among various textiles in the experiment, nano silver has shown the best blocking performance from electromagnetic waves, which decreases depending on the distance. The power spectrum distribution and the incidence of electroencephalogram between blocking materials and aural stimuli has shown that, ${\beta}$, wave appeared to be active in all channels except for $T_4$, whereas all waves appeared with processed materials and especially with nano silver silk(NSS), ${\alpha}$, ${\beta}$, ${\theta}$, ${\gamma}$ waves appeared active in all regions. As for the brain mapping of ${\alpha}$ wave according to time, there found a strong activity in $P_3$, $P_4$ of the parietal lobe, with all materials on all time regions. With silk nylon metal(SNM) and NSS, it appeared strong in $F_3$, $F_4$ as well. As for ${\beta}$, wave, the activity appeared strong in frontal lobe before 7min. 30sec, where it tends to diminish abruptly in 7min. 30sec. to 13min. 30sec. region. After 13min., it regained gradually. With NSS, it appeared strong in all areas except for the farthest $T_4$. The appearance of ${\nu}$ wave can be deduced as it can affect human body with its toxic property while the silver particles become nano-sized. Therefore, the study conducted with human participants requires a proper particle size of it which would not penetrate cellular tissues and a proper binder and binding treatment for it, to prevent the physical fatigues and the potential diseases. However, it is highly required for back-up researches to verify various aspects in applying nano silver to textile products.

• Fashion & Textile Research Journal
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• v.6 no.6
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• pp.810-814
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• 2004

This study is one of the fundamental researches for the development of future smart clothing and textile products using silver(Ag) nano powder. Our study was focused on the blocking or insulating effects of nano-processed textiles from electromagnetic waves. Also, for the surveying of the actual effect to human body, we measure the variation of electroencephalogram which is an indication of human physical symptoms. Among various textiles in this experiment, nano silver processed case has shown the best blocking performance from the electromagnetic waves, which decreases depending on the distance. As a reference model of working environment, we setup the visual stimuli object on the computer that is a source of electromagnetic wave. The power spectrum distribution and the incidence of electroencephalogram was measured. The analysed data has shown that, with nano-processed textiles, ${\beta}$ wave does not appear very often where ${\beta}$ wave appears only to illustrate the stable states of human's body. However, as for the materials without nano processing, the ratio of ${\gamma}$ waves in the total level of electroencephalogram becomes higher in spite of short exposure to visual stimuli in work environment, which shows that the worker becomes stressed. The ${\beta}$ wave electroencephalogram of all materials is drawn in calcarine fissure of occipital lobe to show the convergent distribution, and stronger with block-processed Nano Silver Silk(NSS). The study based on the potential risks of human diseases such as physical fatigue by electromagnetic waves, and has shown that the application of Nano Silver textile for human uses require a proper particle size of it which would not penetrate cellular tissues, and a proper binder and binding treatment for it. However, it is highly required for back-up researches to verify various aspects in applying nano silver to textile products.

• Computers and Concrete
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• v.31 no.4
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• pp.293-306
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• 2023

This study proposes and demonstrates a smart monitoring system that uses transmission lines embedded in a reinforced concrete structure to detect the presence of defects through changes in the electromagnetic waves generated and measured by a time-domain reflectometer. Laboratory experiments were first conducted to identify the presence of voids in steel-concrete composite columns. The results indicated that voids in the concrete caused a positive signal reflection, and the amplitude of this signal decreased as the water content of the soil in the void increased. Multiple voids resulted in a decrease in the amplitude of the signal reflected at each void, effectively identifying their presence despite amplitude reduction. Furthermore, the electromagnetic wave velocity increased when voids were present, decreased as the water content of the soil in the voids increased, and increased with the water-cement ratio and curing time. Field experiments were then conducted using bored piles with on-center (sound) and off-center (defective) steel-reinforcement cage alignments. The results indicated that the signal amplitude in the defective pile section, where the off-center cage was poorly covered with concrete, was greater than that in the pile sections where the cage was completely covered with concrete. The crosshole sonic logging results for the same defective bored pile failed to identify an off-center cage alignment defect. Therefore, this study demonstrates that electromagnetic waves can be a useful tool for monitoring the health and integrity of reinforced concrete structures.

• Biomolecules & Therapeutics
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• v.22 no.6
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• pp.570-576
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• 2014

Studies have demonstrated that electromagnetic waves, as the one of the most important physical factors, may alter cognitive and non-cognitive behaviors, depending on the frequency and energy. Moreover, non-ionizing radiation of low energy waves e.g. very low frequency waves could alter this phenomenon via alterations in neurotransmitters and neurohormones. In this study, short, medium, and long-term exposure to the extremely low frequency electromagnetic field (ELF-EMF) (1 and 5 Hz radiation) on behavioral, hormonal, and metabolic changes in male Wistar rats (250 g) were studied. In addition, changes in plasma concentrations for two main stress hormones, noradrenaline and adrenocorticotropic hormone (ACTH) were evaluated. ELF-EMF exposure did not alter body weight, and food and water intake. Plasma glucose level was increased and decreased in the groups which exposed to the 5 and 1Hz wave, respectively. Plasma ACTH concentration increased in both using frequencies, whereas noradrenaline concentration showed overall reduction. At last, numbers of rearing, sniffing, locomotor activity was increased in group receiving 5 Hz wave over the time. In conclusions, these data showed that the effects of 1 and 5 Hz on the hormonal, metabolic and stress-like behaviors may be different. Moreover, the influence of waves on stress system is depending on time of exposure.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.6
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• pp.94-101
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• 2007

This paper, we analyzed that the measured data of the radiated power spectrum of electromagnetic waves and the standing wave ratio(SWR) of the spark plug cable and spark plug. The measured data are the power strength of the electromagnetic waves radiated from the spark ignition system, the measured frequency ranges are 110 to 610MHz. The results show that the strength of radiated power spectrum and bandwidth have relation to the SWR of the the spark plug cable and spark plug, and the SWR of them is different because of the characteristics of resistor at the spark plug is different with the manufacturers. From the analyzed results, it can be concluded that the less SWR is little, the less maximum level of power spectrum is weak and bandwidth above the reference level is small.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1747-1749
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• 2001

This paper simulated discharge progress and partial discharge using needle-plan electrodes system in $SF_6$, studied the distribution of frequency spectrum of the radiated electromagnetic waves using biconical antenna and spectrum analyzer. From results of this study, a method was introduced for measurement and analysis of the radiated electromagnetic waves in accordance with discharge progress in $SF_6$. Besides, according to the consideration of the mutual relation between frequency spectrum of the radiated electromagnetic waves and discharge progress, it was confirmed that detecting partial discharge and estimating discharge progress in $SF_6$ can be possible.