• Journal of the Korean Magnetics Society
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• v.6 no.6
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• pp.367-374
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• 1996

The developmement of electronic machine industries requires miniature of size as well as increasement of driving frequency in electronic parts, recently. To realize micro-struture of magnetic devices, in this study, we fabricated thin film inductors by using thin film manufacturing techniques such as photolithography and wet etching process, and these devices are measured at high frequency range of 1 MHz~1 GHz. The results are as follows. The accurate measuring technique by using network analyzer system having microstrip line was established. The manufactured inductors are fabricated with several ten micrometers by means of wet etching process known as easier and more economic than dry etching process. VVhen the device size of two types (spiral, meander) is the same, inductance value L and quality factor Q of spiral type devices are larger than those of meander type, but driving frequency of spiral type is lower than that of meander type due to increasement of inductance L. It is necessary to decrease resistance value R by increasing cross section of the conductor film coil. Thus high frequency measuring method would be a very useful for another measuring fields of the range over several hundreds MHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.5
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• pp.648-658
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• 1998

In this paper, the effect of the gap in the ground plane on the electromagnetic interference (EMI) is analyzed quantitatively. Because of a lot of advantages compared to other numerical techniques, the FDTD (finite difference time domain) is applied to the EMI effect modeling. The analyzed model is the simplified PCB (printed circuit board) which has a microstrip and ground plane. The inductance induced by the gap is modeled and calculated by gridding the whole PCB based on the FDTD algorithm. When external cables are attached to the PCB, the common-mode current is induced along the attached cable and the resulting electric field strength is calculated and presented along with the FCC and CISPR EMI limits. The results show that the radiated field strength highly depends on the size of the ground plane gap. The numerical simulation results can be used as a reference in the practical PCB design with the ground plane gap.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.37 no.1
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• pp.63-69
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• 2000

The high-$T_c$ Superconducting (HTS) antenna which consists of "H" type resonator has the benefits for the miniaturization of antenna in comparison with the microstrip antenna of the similar dimension. To fabricate the "H" type antenna, HTS $YBa_2Cu_3O_{7-x}$ (YBCO) thin films were deposited on MgO substrates using rf-magnetron sputtering. Standard etching processes were performed for the patterning of the "H" type antenna. For comparison between normal conducting antennas and superconducting antennas, the gold antennas with the same dimension were also fabricated. An aperture coupling was used for impedance matching between $50{\Omega}$ feed line and HTS radiating patch. The diverse experimental results were reported in terms of the resonant frequency, the return loss and the characteristics impedance. The "H" type superconducting antenna showed the performance of 1.36 in SWR, 24% in efficiency, and 14.6 dB in the return loss superior of the normal conducting counterpart.

• Polymer(Korea)
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• v.33 no.1
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• pp.91-95
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• 2009

We fabricated the electromagnetic (EM) noise absorber films for high temperature use by blending a soft magnetic powder with poly(amide imide) (PAI). The EM noise absorber films of PAI/soft magnet composite were prepared by casting the solution of poly(amide amic acid)/soft magnet powder into glass substrate with casting applicator device and then thermal imidization. The obtained films were fully characterized and their physical properties including thermal behavior, thermal stability and mechanical properties were studied. The EM noise absorption ability was also investigated using micro-strip line method. At 1 GHz, the power loss of composite film with 150 ${\mu}m$ thickness was about 25%.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.1
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• pp.11-18
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• 2024

This paper presents a procedure to optimize the design of 70GHz band array antenna for automotive short range radar sensor applications using Chebyshev polynomials. SRR(: Short Range Radar) systems require a wide angle width and low Side lobe level to detect targets within close proximity while ensuring a high Field of View(FoV). The optimized antenna operates in the 76 to 81GHz frequency range, and to reduce the antenna size, we arranged 12 patches in series, achieving an SLL of 10dB, angle with of 112.5o, gain of 15.4dB and an input return loss of less than -10dB at 78GHz. In this paper, we proceed with antenna design for SRR using Chebyshev polynomials, and present an optimal design for antenna structures to be used in MRR(: Medium-Range Radar) and LRR(: Long Range Radar) applications based on this paper

• Korean Journal of Clinical Laboratory Science
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• v.47 no.3
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• pp.105-111
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• 2015

In late December 2013, the Ebola virus emerged from West Africa. The outbreak started in Guinea and rapidly spread to Liberia and Sierra Leone. Initially, the virus is spread to the human population after contact with infected wildlife and then spread person-to-person through direct contact with body fluids such as blood, sweat, urine, semen, and breast milk. The Ebola virus infects endothelial cells, mononuclear phagocytes and hepatocytes. It causes massive damage to internal tissues and organs, such as blood vessels and the liver, and ultimately death. Most tests for the virus RNA rely on a technology called reverse-transcriptase polymerase chain reaction (RT-PCR). While this method is highly sensitive, it is also expensive, requiring skilled scientists, and delicate power supplies. The strip analytical technique (enzyme-linked immunosorbent assay or ELISA) detects antigens or antibodies to the Ebola virus. This test is cheap and does not require electricity or refrigeration. Despite ongoing efforts directed at experimental treatments and vaccine development, current medical work on the Ebola viral disease is largely limited to supportive therapy. Thus, rapid and reliable diagnoses of the Ebola virus are critically important for patient management, infections, prevention, and control measures.

• Applied Chemistry for Engineering
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• v.33 no.2
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• pp.173-178
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• 2022

A lateral flow immunoassay (LFIA) method using carbon nanodot@silica as a signaling material was developed for analyzing the concentration of retinol-binding protein 4 (RBP4), one of the lung cancer biomarkers. Instead of antibodies mainly used as bioreceptors in nitrocellulose membranes in LFIA for protein detection, aptamers that are more economical, easy to store for a long time, and have strong affinities toward specific target proteins were used. A 5' terminal of biotin-modified aptamer specific to RBP4 was first reacted with neutravidin followed by spraying the mixture on the membrane in order to immobilize the aptamer in a porous membrane by the strong binding affinity between biotin and neutravidin. Carbon nanodot@silica nanoparticles with blue fluorescent signal covalently conjugated to the RBP4 antibody, and RBP4 were injected in a lateral flow manner on to the surface bound aptamer to form a sandwich complex. Surfactant concentrations, ionic strength, and additional blocking reagents were added to the running buffer solution to optimize the fluorescent signal off from the sandwich complex which was correlated to the concentration of RBP4. A 10 mM Tris (pH 7.4) running buffer containing 150 mM NaCl and 0.05% Tween-20 with 0.6 M ethanolamine as a blocking agent showed the optimum assay condition for carbon nanodot@silica-based LFIA. The results indicate that an aptamer, more economical and easier to store for a long time can be used as an alternative immobilizing probe for antibody in a LFIA device which can be used as a point-of-care diagnosis kit for lung cancer diseases.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.2
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• pp.94-102
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• 2020

Precast concrete segment arch system has an economic and construct ability that combined with advantage of precast concrete and arch behavior. A precast concrete segment arch system with outrigger is consisted of segmented precast panels, a steel outrigger rib, and V-strip to connect precast panels with a steel outrigger rib and cast-in-place anchors in precast panels to connect V-strip should have sufficient pull-out capacity to form its arch shape by site lifting for assembled precast panels and outriggers. However, it is difficult to secure its embedment depth due to the relatively shallow thickness of precast panel. It can be also occurred that flexure deformation of precast panels caused by its pull-out behaviors. In this study, pull-out capacity of cast-in-place anchor was examined for construction of precast concrete segment arch system with outriggers. Therefore, a total of 24 precast panel specimens were fabricated to examine pull-out capacities of cast-in-place anchor in precast panels, and installation depth of anchors, diameter of anchors and wire mesh effects for the precast panel were examined. From this pull-out tests, its pull-out capacities and failure modes were evaluated and the type of the cast-in-place anchor applicable to the precast concrete segment panel arch system with outriggers was determined from comparison of the design specification values.

• Journal of the Korean Electrochemical Society
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• v.2 no.4
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• pp.227-231
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• 1999

Disposable, amperometric glucose sensor was constructed using platinised carbon paste electrode. The sensor response was studied by amperometry and cyclic voltammetry applying sample solutions on the strip-type electrode. Platinization of screen-printed carbon paste electrode effectively improved the electrochemical reversibility of a mediator and the analytical characteristics of the sensor. The heterogeneous rate constant for $[Fe(CN)_6]^{4-/3-}$ was $1.45\times10^{-2}cm{\cdot}s^{-1}$. An applied potential of 0.3V vs. Ag/AgCl resulted in the best selectivity for glucose. The apparent Michaelis-Menten constant for glucose on the strip sensor, $K_m^{app}$, was 24.5 mM. To evaluate the analytical performance of the glucose sensor strip, a correlation study was performed with the NOVA S.P, Ultra M analyzer for 30 serum samples containing $80\~297mg/dL$ of glucose: the correlation coefficient value was 0.983. It can be seen that the strip sensor has satisfactory precision and accuracy.