Estimating the age of single nucleotide polymorphic sites in humans

Borštnik Branko,Pumpernik Danilo 한국유전학회 2021 Genes & Genomics Vol.43 No.10

Background Determining the ages of polymorphic sites in human genomes needs to be carried out in a careful balance between the degree of complexity of the approach and the desired accuracy. Objective We provide evidence that a simpler approach where age determination is based upon the degree to which the alternative allele is spread among the population can be competitive with more complex methods. Methods The information contained in the vcf fles of Phase 1 of the 1000 Genomes Project combined with the genomic sequences of seven non-human primate species was analyzed. The analyses were supplemented by a computer simulation of the mutational changes in 10,000 model chromosomes with a length of 10,000 nucleotides over a period of 16 million years. The list of the birth dates of the derived alleles of homozygous and heterozygous components of the derived alleles served as a yardstick to estimate the ages of human alternative alleles. Results The age of the derived alleles born in Africa before the “Out of Africa” event and not brought to other continents are estimated to be 0.17 Ma, the derived alleles present simultaneously on all continents are estimated to be 1.3 Ma old and the age of alleles arising in Europe or Asia is 0.06 Ma. Conclusion Our approach functions with polymorphisms that respect the “more frequent means older” principle. However, this shortcoming only leads to disagreement with the Atlas of Variant Age in about 20% of cases.

지난 30년의 루마니아 연극 혹은 연극의 패러다임 전환

오아나보르슈 ( Oana Borș ) 한국연극평론가협회 2023 연극평론 Vol.110 No.-

Association between physiological and agronomic traits and selection of tropical wheat

Henrique Caletti Mezzomo,Cleiton Renato Casagrande,Caique Machado e Silva,Aluízio Borém,Maicon Nardino 한국작물학회 2021 Journal of crop science and biotechnology Vol.24 No.2

The aims of this study are to verify the existence of canonical correlations between physiological and agronomic traits of 40 lines of tropical wheat using the REML/BLUP (restricted maximum likelihood/best linear unbiased prediction) method and select genotypes with the best performance using four selection indexes. For such, 40 tropical wheat genotypes were evaluated in a field experiment in Viçosa, MG, Brazil. The physiological traits (group I) of these genotypes were measured using an infrared gas analyzer, group II was formed by agronomic traits. The data were submitted to REML/BLUP and the predicted genotypic values (BLUP) were obtained to estimate genotypic correlation coeffi cients, canonical correlation coeffi cients between groups I and II, and to perform the selection of superior genotypes using the method of ranks summation index, multiplicative index, genotype-ideotype distance index and Z index. The maximum likelihood test revealed a significant effect of genotypes for all traits evaluated. Net photosynthetic rate it showed a positive correlation with stomatal conductance to H 2 O (0.32) and transpiration rate (0.79). Hectoliter weight has a significant association with physiological traits, positive for intercellular CO 2 concentration (0.56) and negative for leaf temperature (− 0.56) and transpiration rate (− 0.42). The correlation between groups was 0.78. The intercellular CO 2 concentration was directly related to disease note and hectoliter weight. The lines VI 14050, VI 14197 and VI 14950 coincide in the three selection indexes, with a potential for registration as a new cultivar.

New Three-Level PWM DC/DC Converter

Bor-Ren Lin,Chih-Chieh Chen 전력전자학회 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.1

This paper studies a new three-level pulse-width modulation (PWM) resonant converter for high input voltage and high load current applications. In order to use high frequency power MOSFETs for high input voltage applications, a three-level DC converter with two clamped diodes and a flying capacitor is adopted in the proposed circuit. For high load current applications, the secondary sides of the proposed converter are connected in parallel to reduce the size of the magnetic core and copper windings and to decrease the current rating of the rectifier diodes. In order to share the load current and reduce the switch counts, three resonant converters with the same active switches are adopted in the proposed circuit. Two transformers with a series connection in the primary side and a parallel connection in the secondary side are adopted in each converter to balance the secondary side currents. To overcome the drawback of a wide range of switching frequencies in conventional series resonant converters, the duty cycle control is adopted in the proposed circuit to achieve zero current switching (ZCS) turn-off for the rectifier diodes and zero voltage switching (ZVS) turn-on for the active switches. Finally, experimental results are provided to verify the effectiveness of the proposed converter.

Interleaved ZVS DC/DC Converter with Balanced Input Capacitor Voltages for High-voltage Applications

Bor-Ren Lin,Huann-Keng Chiang,Shang-Lun Wa 전력전자학회 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.4

A new DC/DC converter with zero voltage switching is proposed for applications with high input voltage and high load current. The proposed converter has two circuit modules that share load current and power rating. Interleaved pulse-width modulation (PWM) is adopted to generate switch control signals. Thus, ripple currents are reduced at the input and output sides. For high-voltage applications, each circuit module includes two half-bridge legs that are connected in series to reduce switch voltage rating to Vin/2. These legs are controlled with the use of asymmetric PWM. To reduce the current rating of rectifier diodes and share load current for high-load-current applications, two center-tapped rectifiers are adopted in each circuit module. The primary windings of two transformers are connected in series at the high voltage side to balance output inductor currents. Two series capacitors are adopted at the AC terminals of the two half-bridge legs to balance the two input capacitor voltages. The resonant behavior of the inductance and capacitance at the transition interval enable MOSFETs to be switched on under zero voltage switching. The circuit configuration, system characteristics, and design are discussed in detail. Experiments based on a laboratory prototype are conducted to verify the effectiveness of the proposed converter.

A ZVS Resonant Converter with Balanced Flying Capacitors

Bor-Ren Lin,Zih-Yong Chen 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.5

This paper presents a new resonant converter to achieve the soft switching of power devices. Two full-bridge converters are connected in series to clamp the voltage stress of power switches at Vin/2. Thus, power MOSFETs with a 500V voltage rating can be used for 800V input voltage applications. Two flying capacitors are connected on the AC side of the two full-bridge converters to automatically balance the two split input capacitor voltages in every switching cycle. Two resonant tanks are used in the proposed converter to share the load current and to reduce the current stress of the passive and active components. If the switching frequency is less than the series resonant frequency of the resonant tanks, the power MOSFETs can be turned on under zero voltage switching, and the rectifier diodes can be turned off under zero current switching. The switching losses on the power MOSFETs are reduced and the reverse recovery loss is improved. Experiments with a 1.5kW prototype are provided to demonstrate the performance of the proposed converter.

Interleaved DC-DC Converters with Partial Ripple Current Cancellation

Bor-Ren Lin,Huann-Keng Chiang,Chih-Yuan Cheng 전력전자학회 2012 JOURNAL OF POWER ELECTRONICS Vol.12 No.2

An interleaved PWM converter is proposed to implement the features of zero voltage switching (ZVS), load current sharing and ripple current reduction. The proposed converter includes two ZVS converters with a common clamp capacitor. With the shared capacitor, the charge balance of the two interleaved parts is automatically regulated under input voltage and load variations. The active-clamping circuit is used to realize the ZVS turn-on so that the switching losses on the power switches are reduced. The ZVS turn-on of all of the switching devices is achieved during the transition interval. The interleaved pulse-width modulation (PWM) operation will reduce the ripple current and the size of the input and output capacitors. The current double rectifier (CDR) is adopted in the secondary side to reduce output ripple current so that the sizes of the output chokes and capacitor are reduced. The circuit configuration, operation principles and design considerations are presented. Finally experimental results based on a 408W (24V/17A) prototype are provided to verify the effectiveness of the proposed converter.

Implementation of an Interleaved AC/DC Converter with a High Power Factor

Bor-Ren Lin,Li-An Lin 전력전자학회 2012 JOURNAL OF POWER ELECTRONICS Vol.12 No.3

An interleaved bridgeless buck-boost AC/DC converter is presented in this paper to achieve the characteristics of low conduction loss, a high power factor and low harmonic and ripple currents. There are only two power semiconductors in the line current path instead of the three power semiconductors in a conventional boost AC/DC converter. A buck-boost converter operated in the boundary conduction mode (BCM) is adopted to control the active switches to achieve the following characteristics: no diode reverse recovery problem, zero current switching (ZCS) turn-off of the rectifier diodes, ZCS turn-on of the power switches, and a low DC bus voltage to reduce the voltage stress of the MOSFETs in the second DC/DC converter. Interleaved pulse-width modulation (PWM) is used to control the switches such that the input and output ripple currents are reduced such that the output capacitance can be reduced. The voltage doubler topology is adopted to double the output voltage in order to extend the useable energy of the capacitor when the line voltage is off. The circuit configuration, principle operation, system analysis, and a design example are discussed and presented in detail. Finally, experiments on a 500W prototype are provided to demonstrate the performance of the proposed converter.

Half-Bridge Zero Voltage Switching Converter with Three Resonant Tanks

Bor-Ren Lin,Wei-Jie Lin 전력전자학회 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.5

This paper presents a zero voltage switching (ZVS) converter with three resonant tanks. The main advantages of the proposed converter are its ability to reduce the switching losses on the power semiconductors, decrease the current stress of the passive components at the primary side, and reduce the transformer secondary windings. Three resonant converters with the same power switches are adopted at the low voltage side to reduce the current rating on the transformer windings. Using a series-connection of the transformer secondary windings, the primary side currents of the three resonant circuits are balanced to share the load power. As a result, the size of both the transformer core and the bobbin are reduced. Based on the circuit characteristics of the resonant converter, the power switches are turned on at ZVS. The rectifier diodes can be turned off at zero current switching (ZCS) if the switching frequency is less than the series resonant frequency. Therefore, the reverse recovery losses on the rectifier diodes are overcome. Experiments with a 1.6kW prototype are presented to verify the effectiveness of the proposed converter.

매체형 전동밀의 실제 분쇄장에서 분쇄매체의 거동과 DEM 시뮬레이션의 비교연구

BOR AMGALAN,자갈사이항 바트체첵,이재현,최희규 한국화학공학회 2019 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.57 No.6

This study was performed the real motion and DEM simulation of ball motion using three different types of grinding media with different size and materials in media formation for optimization of process conditions in a traditional ball mill (media ball mill). In the simulation, the rotational speed of the mill, the material of the medium, the velocity of the medium, and the coefficient of friction between the media and the wall of pot were fixed into the actual experimental conditions. The motion of various kinds of grinding media was quantitatively measured by setting the grinding zone defined in the present study on the photographs taken and the snapshot images analyzed in the simulation. In addition, we observed the quantitatively measured value and the changed morphology of the sample and examined the correlation. Therefore, it is suggested to optimize the grinding media which has the greatest influence on the grinding zone under specific experimental conditions. 매체형 전동밀의 실제 분쇄장에서 분본 연구는 매체형 전동밀(전동 볼 밀)에서 매체선정에 관한 공정조건 최적화를 위하여, 직경과 재질이 각각 다른 3 가지 종류의 분쇄매체를 이용, 매체의 움직임을 실제 촬영하고 DEM 시뮬레이션을 병행하여 비교 연구하였다. 시뮬레이션에서는 밀의 회전속도, 매체의 재질, 매체의 운동속도, 매체와 포트 벽면과의 마찰계수 등을 실제 실험조건과 동일하게 조건을 맞추었다. 다양한 종류의 분쇄매체의 움직임을 실제 촬영된 사진 및 시뮬레이션에서 해석된 스냅샷 사진 위에, 본 연구에서 정의한 분쇄장을 설정하여 해석함으로써 그 값을 정량적으로 측정하였다. 또한, 정량적으로 측정된 값과 분쇄시료의 변화된 모습을 관찰하여 그 상관관계를 검토하였다. 따라서 특정 실험조건에서 분쇄장에 가장큰 영향을 주는 분쇄매체의 최적화를 제언 하고자 하였다.쇄매체의 거동과 DEM 시뮬레이션의비교연구