• Journal of information and communication convergence engineering
• /
• v.19 no.3
• /
• pp.131-135
• /
• 2021

The interference between closely placed co-coverage satellites was analyzed. In general, a satellite network may use different orthogonal polarizations and frequencies to increase the throughput of a satellite. However, when orthogonal linear polarization (horizontal polarization and vertical polarization) or orthogonal circular polarization (left-handed circular polarization and right-handed circular polarization) is used, the signal from one polarization sense to another may be coupled, resulting in cross-polarization interference. This signal-coupling arises due to the finite value of the cross-polarization discrimination of the earth station. In this study, field equations were used to analyze the interference between adjacent satellites using co-frequency. The level of interference was compared to that when two adjacent satellites used the same polarization. The simulation results show that the interference mainly depends on the off-axis co-polar pattern and the cross-polar pattern of the earth station antenna.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.48 no.2
• /
• pp.117-126
• /
• 1999

The environmental impact of the KEPCO 765-kV transmission line was studied using a full scale test line in order to develop the design technology. Therefore this paper describes an environmental design summary of the audible noise, hum noise, wind noise, radio interference, TV interference and electric field measurement from the KEPRI 765-kV double circuit transmission test line with a bundle of $6-480mm^2$ conductors per phase. The analysis of the test results shows that 6-Rail and 6-Cardinal conductors bundle satisfy the audible noise criterion & TV interference under the stable rainy weather condition and the radio interference level under the fair weather. And the other items are also agreed with the design level criterion for KEPCO 765-kV transmission line.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.23 no.8
• /
• pp.645-650
• /
• 2010

The continuous increase demand for electric power leads to the additional construction of transmission facilities, but it is not easy to acquire right-of-way for transmission facilities. Therefor, there is a need for compact tower that can be built on a narrow right-of-way the compact tower with polymer insulation arm is a solution. It can be upgrading conventional 154 kV transmission line voltages to 345 kV levels. However transmission voltage is increasing, environment interference (corona noise, radio interference, etc.) will occur gradually. This environment interference is depending on the electrical clearances of tower and configuration of conductors. Therefore the analysis of the factors of environmental interference is necessary in order to upgrading transmission voltage. This paper presents the design factor of a compact tower to meet the environmental interference standard.

• Aerospace Engineering and Technology
• /
• v.2 no.1
• /
• pp.153-163
• /
• 2003

Electronic equipments and make other electronic systems to operate abnormally by means of electromagnetic interference, or can operate abnormally themselves by electromagnetic interference of other electronic systems. Therefore, electronic equipments are required to reduce their electromagnetic interference as small as for other systems to operate properly and operate properly within electromagnetic interference from other electronic systems. In order to prove that electronic equipments meet such requirements, they should undergo electromagnetic environmental test. In this study, we introduce electromagnetic environmental requirements, test procedures and test results of gimbal engine actuation system of KSR-III.

• Journal of Environmental Science International
• /
• v.18 no.8
• /
• pp.911-918
• /
• 2009

Electromagnetic interference (EMI) is defined as the interaction phenomena of electromagnetic waves scattered from a large structure or complex terrain. In this study, the propagation of linear wave is modeled with ray theory, direct simulation Monte Carlo (DSMC), and some classical theories on flat plates. The wave physics of reflection, refraction, and diffraction are simulated for the investigation of front and back scattering of the one-dimensional plane wave from a tower with ray theory and DSMC, respectively. The effect of rotating disk idealized from the real wind-turbine blades is modeled with a simplified version of the classical electromagnetic theory as well as DSMC based on the ray theory.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.6
• /
• pp.1689-1692
• /
• 2013

Food is a common source of chromium (Cr) exposure. However, it is difficult to analyze Cr in complex food matrices by using inductively coupled plasma mass spectrometry (ICP-MS) because the major isotope, $^{52}Cr$, is masked by interference generated by the sample matrix and the plasma gas. Among the systems available to minimize interference, the recently developed collision-reaction interface (CRI) has a different structure relative to that of other systems (e.g., collision cell technology, octopole reaction system, and dynamic reaction cell) that were designed as a chamber between the skimmer cone and quadrupole. The CRI system introduces collision or reaction gas directly into the plasma region through a modified hole of skimmer cone. We evaluated the use of an CRI ICP-MS system to minimize polyatomic interference of $^{52}Cr$ and $^{53}Cr$ in various foodstuffs. The $^{52}Cr$ concentrations measured in the standard mode were 2-3 times higher than the certified values. This analytical method based on an ICP-MS system equipped with a CRI of helium gas was effective for Cr analysis in complex food matrices.

• Journal of Environmental Impact Assessment
• /
• v.20 no.6
• /
• pp.787-795
• /
• 2011

Noise barrier is generally used with welding of joint rail for railway noise reduction in our country. But the noise barrier for high speed railway has weak point in low frequencies about 315Hz band. In this study, For developing of Interference-type Noise Reduction Device(INRD), acoustic analysis were performed using commercial software. For verifying the improvement in the noise reduction, noise measurement before and after installing of INRD were performed in Anechoic Chamber. From these acoustic analysis and noise measurement, it was known that developed INRD has a good noise reduction performance and can be used efficiently with conventional noise barrier.

• Journal of Environmental Science International
• /
• v.16 no.8
• /
• pp.1001-1009
• /
• 2007

Passive sampler is a simple and cost-effective measuring equipment for ambient and indoor air pollution. We studied the performance of a short term (1 hour mean concentration) ozone passive sampler which was coated with a colorant (indigo carmine) to a filter substrate. Acetone and sulfamic acid added ozone passive sampler was investigated to measure short term mean ozone concentration. Ozone response and interference of criteria air pollutant($SO_2,\;NO_2$, CO) on a short term ozone passive sampler was tested through experimental chamber. The results show sulfamic acid added passive ozone sampler have good response in ozone exposure. Interference of $NO_2$ gas is larger than other two criteria gases.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.10
• /
• pp.5035-5048
• /
• 2016

Nano scale networks are futuristic networks deemed as enablers for the Internet of Nano Things, Body area nano networks, target tracking, anomaly/ abnormality detection at molecular level and neuronal therapy / drug delivery applications. Molecular communication is considered the most compatible communication technology for nano devices. However, connectivity in such networks is very low due to inter-symbol interference (ISI). Few research papers have addressed the issue of ISI mitigation in molecular communication. However, many of these methods are not adaptive to dynamic environmental conditions. This paper presents an enhancement over original Memory-1 ISI cancellation scheme using maximum likelihood estimation of a channel parameter (λ) to make it adaptable to variable channel conditions. Results of the Monte Carlo simulation show that, the connectivity (P_conn) improves by 28% for given simulation parameters and environmental conditions by using enhanced Memory-1 cancellation method. Moreover, this ISI mitigation method allows reduction in symbol time (Ts) up to 50 seconds i.e. an improvement of 75% is achieved.

• Journal of the Korean Geosynthetics Society
• /
• v.13 no.3
• /
• pp.11-19
• /
• 2014

This paper describes interference effect analysis of transverse member based on large-scale pullout test results of steel strip reinforcement with '${\sqcap}$' type transverse member. The maximum passive resistance has a difference according to the installed location of transverse member, and the total pullout resistance is increased, when transverse member was closed to the wall facing. The degree of interference confirmed that the install location of transverse member cannot reflect the pullout force differential, if S/B is equal. However, The interference factor based on maximum passive resistance reflected the differential of maximum passive resistance and install location of transverse member.