• Wind and Structures
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• v.34 no.2
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• pp.185-197
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• 2022

This study aimed to analyze the wind-induced mechanical energy (WME) of a proposed super high-rise and long-span transmission tower-line system (SHLTTS), which, in 2021, is the tallest tower-line system with the longest span. Anew index - the WME, accounting for the wind-induced vibration behavior of the whole system rather than the local part, was first proposed. The occurrence of the maximum WME for a transmission tower, with or without conductors, under synoptic winds, was analyzed, and the corresponding formulae were derived based on stochastic vibration theory. Some calculation data, such as the drag coefficient, dynamic parameters, windshielding areas, mass, calculation point coordinates, mode shape and influence function, derived from wind tunnel testing on reducedscale models and finite element software were used in calculating the maximum WME of the transmission tower under three cases. Then, the influence of conductors, wind speed, gradient wind height and wind yaw angle on WME components and the energy transfer relationship between substructures (transmission tower and conductor) were analyzed. The study showed that the presence of conductors increases the WME of transmission towers and changes the proportion of the mean component (MC), background component (BC) and resonant component (RC) for WME; The RC of WME is more susceptible to the wind speed change. Affected by the gradient wind height, the WME components decrease. With the RC decreasing the fastest and the MC decreasing the slowest; The WME reaches the its maximum value at the wind yaw angle of 30°. Due to the influence of three factors, namely: the long span of the conductors, the gradient wind height and the complex geometrical profile, it is important that the tower-line coupling effect, the potential for fatigue damage and the most unfavorable wind yaw angle should be given particular attention in the wind-resistant design of SHLTTSs

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.5 s.108
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• pp.461-475
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• 2006

In this paper, it is described about the tri-band mobile antenna system design to provide broadband multimedia and direct broadcasting services using goo-stationary Koreasat 3, simultaneously operated in Ka/K/Ku band. The radiating part of the antenna system with a fan beam characteristic in the elevation plane is composed of the quasi-offset dual shaped reflector and the tri-band feeder. The tri-band feeder is also composed of the Ka/K dual band feeder with the protruding dielectric rod, the circular polarizer, the ortho-mode transducer and the circular-polarized Ku band feed array. Especially, the Ka/K dual band circular polarizer was realized firstly using the comb-type structure. For fast satellite-tracking on the movement, the Ku band feed array has the structure of the $2{\times}2$ active phased array which can make electrical beams. And, the circular-polarized characteristic in the feed array was improved by $90^{\circ}$ rotating arrangement of four radiating elements polarized circularly by a $90^{\circ}$ hybrid coupler, respectively. Four beam forming channels to make electrical beams at Ku band are divided into the main beam channel and the tracking beam channel in the output, and noise temperature characteristics of each channel were analyzed on the basis of the contributions of internal sub_units. From the fabricated antenna system, the output power at $P_{1dBc}$ of Ka_Tx channel was measured more than 34.1 dBm and the measured noise figures of K/Ku_Rx channels were less than 2.4 dB and 1.5 dB, respectively, over the operating band. The radiation patterns with co- and cross-polarization in the tri-band were measured using a near-field measurement in the anechoic chamber. Especially, Ku radiation patterns were measured after correcting each initial phase of active channels with partial radiation patterns obtained from the independent excitation of each channel. The antenna gains measured in Ka/K/Ku band of the antenna system were more than 39.6 dBi, 37.5 dBi, 29.6 dBi, respectively. And, the antenna system showed good system performances such as Ka_Tx EIRP more than 43.7 dBW and K/Ku_Rx G/T more than 13.2 dB/K and 7.12 dB/K, respectively.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.2
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• pp.21-31
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• 2010

This paper presents a design of PLL and SSCG for reducing the EMI effect at the electronic machinery and tools for DisplayPort application. This system is composed of the essential element of PLL and Charge-Pump2 and Reference Clock Divider to implement the SSCG operation. In this paper, 270MHz/162MHz dual-mode PLL that can provide 10-phase and 1.35GHz/810MHz PLL that can reduce the jitter are designed for 2.7Gbps/162Gbps DisplayPort application. The jitter can be reduced drastically by combining 270MHz/162MHz PLL with 2-stage 5 to 1 serializer and 1.35GHz PLL with 2 to 1 serializer. This paper propose the frequency divider topology which can share the divider between modes and guarantee the 50% duty ratio. And, the output current mismatch can be reduced by using the proposed charge-pump topology. It is implemented using 0.13 um CMOS process and die areas of 270MHz/162MHz PLL and 1.35GHz/810MHz PLL are $650um\;{\times}\;500um$ and $600um\;{\times}\;500um$, respectively. The VCO tuning range of 270 MHz/162 MHz PLL is 330 MHz and the phase noise is -114 dBc/Hz at 1 MHz offset. The measured SSCG down spread amplitude is 0.5% and modulation frequency is 31kHz. The total power consumption is 48mW.

• Current Research on Agriculture and Life Sciences
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• v.12
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• pp.29-34
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• 1994

A leading sweet pepper cultivar, Keystone Resistant Giant #3, was crossed with a line with resistance to Phytophthora capsici, PI201232, for incorporation of the resistance and to study the inheritance of resistance to the disease. Seedlings of parents, $F_1$, $F_2$ and backcross populations of a cross between Keystone Resistant Giant #3 and PI201232 were inoculated with zoospore suspension of P. capsici at 36 days after seeding. Most of the $F_1$ seedlings survied the inoculation and this suggested that resistance is dominant over susceptibility. The number of survived plants in $F_2$ population was, however, much less than the killed. All the plants in a backcross to Keystone Resistant Giant #3 were killed. Therefore, the observed numbers did not fit the expected ratio for segregation of one or two dominant alleles as previously reported. The resistance to P. capsici appeared to be inherited in a quantitative mode in evaluation of root rot. Resistant individuals in $F_2$ population were selected and a breeding program for incorporation of the resistance to P. capsici by backcross method is continued.

• Current Research on Agriculture and Life Sciences
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• v.12
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• pp.23-28
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• 1994

A leading sweet pepper cultivar, Keystone Resistant Giant #3, was crossed with a line with resistance to Xanthomonas campestris pv. vesicatoria, PI271322, for incorporation of the resistance and to study the inheritance of resistance to the disease. Seedlings of parents, $F_1$, $F_2$ and backcross populations of a cross between Keystone Resistant Giant #3 and PI271322 were inoculated with race 1 and race 3 of Xanthamonas campestris pv. vesicatoria by infiltrating bacterial suspension into abaxial side of leaves. PI271322 was carrying a gene ($Bs_3$) for hypersensitive resistance to race 1 of X. c. pv. vesicatoria and also a component of non-hypersensitive resistance to race 3 inheriting in a quantitative mode. Correlation coefficient between disease indices to race 1 and race 3 of non-hypersensitive plants in $F_2$ population was highly significant, thus indicating that a component of non-hypersensitive general resistance in PI271322 acted consistently to both races. Individual plants with resistance to both race 1 and race 3 of X. c. pv. vesicatoria were selected and a breeding program for incorporation of the resistance is continued.