• Journal of IKEEE
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• v.25 no.1
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• pp.37-41
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• 2021

In this paper, a low-profile and broadband bowtie antenna using multi-layer substrate for UWB sensor application is presented. A compact bowtie antenna is designed and implemented on two multi-layered substrate with total thickness of 4.5 mm. The antenna consists of bowtie radiator and planar-type balun. The designed radiator and balun are connected to each other so that it can be easily implemented in various structures. The implemented antenna provides 3 to 6 dBi of gain for whole frequency range from 6.8 to 10 GHz.

• Current Optics and Photonics
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• v.2 no.1
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• pp.85-89
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• 2018

This paper presents a new, efficient hybrid photonic-plasmonic structure. The proposed structure efficiently and with very high accuracy combines the resonant mode of a low-mode-volume photonic-crystal nanocavity with a bowtie nanoantenna's plasmonic resonance. The resulting enormous enhancement of light intensity of about $1.1{\times}10^7$ in the gap region of the bowtie nanoantenna, due to the effective optical-resonance combination, is realized by subtle optimization of the nanocavity's optical characteristics. This coupled structure holds great promise for many applications relying on strong confinement and enhancement of optical field in nanoscale volumes, including antennas (communication and information), optical trapping and manipulation, sensors, data storage, nonlinear optics, and lasers.

• Journal of IKEEE
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• v.10 no.1 s.18
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• pp.1-9
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• 2006

This paper presents the characteristics of a half-bowtie-shaped meander-type antenna for the 5-GHz band. Its design is based on a modified meander line width and bowtie shape with coaxial feeding. Its maximum measured impedance bandwidth (-10 dB below) is approximately 1.055 GHz (5.01-6.065 GHz) or 19.05%. Radiation patterns at different frequencies are presented. The measured gain was 2.26-8.86 dBi.

• Journal of Microbiology and Biotechnology
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• v.32 no.2
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• pp.149-159
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• 2022

Cancers of the lung and liver are the top 10 leading causes of cancer death worldwide. Thus, it is essential to identify the genes specifically expressed in these two cancer types to develop new therapeutics. Although many messenger RNA (mRNA) sequencing data related to these cancer cells are available due to the advancement of next-generation sequencing (NGS) technologies, optimized data processing methods need to be developed to identify the novel cancer-specific genes. Here, we conducted an analytical comparison between Bowtie2, a Burrows-Wheeler transform-based alignment tool, and Kallisto, which adopts pseudo alignment based on a transcriptome de Bruijn graph using mRNA sequencing data on normal cells and lung/liver cancer tissues. Before using cancer data, simulated mRNA sequencing reads were generated, and the high Transcripts Per Million (TPM) values were compared. mRNA sequencing reads data on lung/liver cancer cells were also extracted and quantified. While Kallisto could directly give the output in TPM values, Bowtie2 provided the counts. Thus, TPM values were calculated by processing the Sequence Alignment Map (SAM) file in R using package Rsubread and subsequently in python. The analysis of the simulated sequencing data revealed that Kallisto could detect more transcripts and had a higher overlap over Bowtie2. The evaluation of these two data processing methods using the known lung cancer biomarkers concludes that in standard settings without any dedicated quality control, Kallisto is more effective at producing faster and more accurate results than Bowtie2. Such conclusions were also drawn and confirmed with the known biomarkers specific to liver cancer.

• Journal of electromagnetic engineering and science
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• v.14 no.3
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• pp.299-305
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• 2014

A wideband circularly polarized (CP) antenna with a single feed is proposed for use in global navigation satellite systems. Its primary radiation elements are composed of two orthogonal bowtie dipoles, which are equipped with double-printed vacant-quarter rings to allow direct matching of the antenna to a single $50-{\Omega}$ coaxial line and to produce CP radiation. The crossed bowtie dipole is appropriately incorporated with a planar metallic reflector to produce the desired unidirectional radiation pattern as well as to achieve a wideband characteristic in terms of impedance matching and axial ratio (AR) bandwidths. The designed antenna was fabricated and measured. The prototype antenna with an overall 1.2-GHz frequency size of $0.48{\lambda}_o{\times}0.48{\lambda}_o{\times}0.25{\lambda}_o$ produced a measured ${\mid}S_{11}{\mid}$<-10 dB bandwidth of 1.05-1.79 GHz and a measured 3-dB AR bandwidth of 1.12-1.64 GHz. It also showed right-hand CP radiation with a small gain variation (${\pm}0.3dB$) and high radiation efficiency (>93%) over the operational bandwidth.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.9
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• pp.961-966
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• 2003

Bowtie shaped meander slot antenna with harmonic suppression is designed and demonstrated experimentally. A substrate with height of 0.508 mm and relative permittivity of 2.5 is used, and the fundamental resonant frequency is 5.536 GHz. With thin conductor line in the antenna, harmonic suppression characteristic is obtained, and return losses at the 2nd and 3rd harmonic frequencies are -0.56 dB and -1.9 dB, respectively. Also, bowtie shape is applied to the antenna design for bandwidth enhancement, and the resulting bandwidth is 3.7 %, which is about three times wider than the reported meander slot antenna with harmonic suppression$\^$[1],[2]/.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.6
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• pp.1057-1062
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• 2016

In this paper, a design method for a compact log-perio dic half-bow-tie dipole array antenna for an operation in a UWB band(3.1-10.6 GHz) is studied. The proposed antenna is miniaturized by using half-bow-tie shaped dipole elements instead of strip-type dipole elements, which are commonly used in a general log-periodic dipole array(LPDA) antenna, and by reducing the element spacing. The effects of the flare angle of the half-bow-tie elements and the spacing factor on input reflection coefficient and realized gain characteristics of the proposed log-periodic antenna are analyzed. The optimized antenna is fabricated on an FR4 substrate, and the experiment results show that the antenna has a frequency band of 2.95-11.31 GHz for a VSWR < 2, which assures the operation in the UWB band. In addition, the length and width of the proposed antenna are reduced to 32.1 % and 18.3 %, respectively, compared to the LPDA antenna.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.2
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• pp.143-151
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• 2012

Purpose: The present study was conducted to investigate whether there is any difference in the centration of spherical RGP lens on cornea according to corneal types, corneal astigmatism and lens fitting states. Methods: Spherical RGP lens was fitted on 29 eyes of round-typed cornea and 45 eyes of symmetric bowtie-typed cornea with 0.00~2.75 D of corneal astigmatism in alignment, steep or flat. Their lens centrations on cornea were analyzed by taking photographs. Results: The centration of spherical RGP lens in the vertical direction was decentrated to downward direction in all cases, and the degree of decentration was not consistent. The lens centration in horizontal direction was significantly more-decentrated to the temporal meridian as base curve of lens was increased, and the degree of decentration was different according to the corneal type, corneal astigmatism and fitting states. With the same degree of astigmatism, the lens decentration to the temporal meridian was bigger in round-typed cornea than that in symmetirc bowtie-typed cornea. Conclusions: The centration of spherical RGP lens varies depending on lens fitting states, corneal astigmatism, and corneal types. Thus, the consideration of these factors may improve the success rate in RGP lens prescription.

• Proceedings of the Korean Society of Crop Science Conference
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• 2019.09a
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• pp.148-148
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• 2019

Wheat is a very important crop as a food source worldwide, but gluten in wheat causes a variety of allergic reactions. Previous studies have developed ${\omega}-5$ gliadin deleted O-free, known as the central antigen of WDEIA (wheat-dependent exercise-induced anaphylaxis). In this study, we performed RNA sequencing on the grains and leaves of the allergic-reduced species O-free and their cultivars, Keumkang and Olgeuru, to analyze differentially expressed genes (DEG) based on different cultivars and tissues. Tissues of all species were biologically repeated three times. We used bowtie2 version 2.3.5.1 to get sequence data from RNAseq and used cufflinks and Tophat programs to find DEG. When comparing leaf and grain tissues, a total of 1,244 DEGs were found in the leaf tissues while only 563 DEGs were found in the grain tissues. As a result of gene ontology analysis of differentially expressed genes, the leaf tissues were mostly included in the "catalytic activity" part of molecular function, "metabolic process" part of biological process, and "membrane" part of cell component. The grain tissues were mostly included in the "metabolic process" part of biological process, "binding" and "catalytic activity" part of molecular function, and "membrane, cell, cell part" parts of cell component. Based on these results, we present information on the differentially expressed genes of the three cultivars of leaves and grains. This study could be an important basis for studying the characteriztion of O-free.

• Journal of Sensor Science and Technology
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• v.27 no.5
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• pp.311-316
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• 2018

An antenna-coupled bolometer-type terahertz sensor was designed, fabricated, evaluated, and utilized to obtain terahertz transmission images. The sensor consists of a thin film bowtie antenna that resonates accordingly in response to an incident terahertz beam, a heater that converts the applied current in the antenna into heat, and a microbolometer that converts the rise in temperature into a change in resistance. The device is fabricated by a bulk micromachining process on a 4-inch silicon wafer. The fabricated sensor chip has a size of $2{\times}2mm$ and an active area of $0.1{\times}0.1mm^2$. The temperature coefficient of resistance (TCR) of the bolometer film (VOx) is 2.0%, which is acceptable for bolometer applications. The output sensor signal is proportional to the power of the incident terahertz beam. Transmission images were obtained with a 2-axis scanning imaging system that contained the sensor. The small active area of the sensor will enable the development of highly sensitive focal plane array sensors in terahertz imaging cameras in the future.