• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.559-562
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• 2004

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 to the normal conducting counterpart.

• Journal of the Optical Society of Korea
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• v.8 no.4
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• pp.174-181
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• 2004

Various kinds of systems, that can do target recognition and position detection simultaneously by using infrared sensing detectors, have been developed. In this paper, the detection system TRSS (Thermal target Recognition by Spiral Scanning) adopts linear array shaped uncooled IR detector and uses spiral type fast scanning method for relative position detection of target objects, which radiate an IR region wavelength spectrum. It can detect thermal energy radiating from a 9 m-size target object as far as 200 m distance. And the maximum field of a detector is fully filled with the same size of target object at the minimum approaching distance 50 m. We investigate two types of lens systems. One is a singlet lens and the other is a doublet lens system. Every system includes one aspheric surface and free positioned aperture stop. Many designs of F/1.5 system with ${\pm}5.2^{\circ}$ field at the Efl=20, 30 mm conditions for single element and double elements lens system respectively are compared in their resolution performance [MTF] according to the aspheric surface and stop position changing on their optimization process. Optimum design is established including mechanical boundary conditions and manufacturing considerations.

• Korean Journal Plant Pathology
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• v.14 no.2
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• pp.115-119
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• 1998

Root rot of carnation caused by isolates of Phytophthora was found at Kongju, 1996. Infected plants appeared symptoms of wilting, brown discoloration on collar area and consequently led to death. The causal pathogen was identified as Phytophthora nicotianae based on morphological, cultural and physiological characteristics. Mycelium was grown to rosette colony pattern on corn meal agar and the growth was 10.2 mm/day on 10% clarified V8 medium at $25^{\circ}C$. Swelling with radiating hyphae was formed in water and on agar within 7 days. Chlamydospores were abundantly produced on agar within 7 days. Sporangium was prominent papillate, 2~3 apex, 1.2 : 1 l/b ratio, lateral attacment on sporangiospore and was rarely produced on solid media but produced in water. The shape of sporangium was spherical or ovoid, and the size was 34~73$\times$32~60 (av. 33$\times$66.5) ${\mu}{\textrm}{m}$ in dimension. The isolates were heterothallic, and mating type A2. Oogonium was spherical, ovoid, 26~36 (av. 36 ${\mu}{\textrm}{m}$) in diameter, and antheridium was amphygynious to oogonia. The fungus was able to grow 10~35$^{\circ}C$, and optimal temperature was 27$^{\circ}C$.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.138-145
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• 1997

Models of upward flame spread have been attempted in the past, but in the current work an emphasis has been placed on developing a practical model that will be useful across a broad range of materials. Some of the important aspects of the model we: the addition of external radiation to simulate a wall that is a part of an enclosure fire and has flaming walls radiating to it, the use of a correlation for flame heat feedback distribution to the sample surface based on data available in the literature, and the use of an experimentally measured mass loss rate for the sample material, In this paper, the development of the numerical model is presented along with predictions of flame spread for three materials: hardboard, a relatively homogeneous wood-based material; plywood, which is made of laminated wood bonded by adhesives; and a composite material made of fiberglass matrix embedded in epoxy. Predictions are compared with measured data at several levels of external radiation for each material. For the materials tested, the model correctly predicts trends and does a reasonable job predicting flame heights. The need for thermal property data for practical materials, which would be appropriate for flame spread models, is indicated by this work.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup1
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• pp.144-148
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• 2001

We report a rare case of Brown-Sequard syndrome associated with Horner's syndrome in cervical epidural hematoma caused by a ruptured arteriovenous malformation. A 54-year-old man developed sudden sharp neck pain, radiating to the interscapular area. Within hours, left side hemiplegia and decreased tactile sense and loss of contralateral pain sense ensued. Emergency cervical magnetic resonance image showed an epidural hematoma over the cervico-thoracic junction. The hematoma was located in the left posterolateral area of the cervical spinal canal. Emergent decompressive laminectomy and an evacuation of the hematoma were performed. A tangled soft tissue mass found in the hematoma was proven to be an arteriovenous malformation. To the authors, knowledge, this might be the first case of a Brown-Sequard syndrome associated with Horner's syndrome caused by ruptured cervical epidural arteriovenous malformation.

• Journal of Korean Neurosurgical Society
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• v.29 no.4
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• pp.569-573
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• 2000

Spinal meningeal cyst of the sacrum is uncommon congenital lesion. We experienced two cases of sacral meningeal cyst, so called Tarlov's cyst, who presented with radiating pain. Magnetic resonance imaging is a highly effective way of locating and approximating the size of these entities, which generally appear as intraspinal masses of low intensity on T1-weighted and high intensity on T2-weighted images, similar to cerebrospinal fluid(CSF). We evaluated 2 patients who had Tarlov's cyst diagnosed with conventional MRI. The clinical features, radiological findings, gross appearances of the lesion at surgery, surgical technique, histopathological features of the cyst wall, and surgical outcome are described. We conclude that excellent result can be expected in the case of symptomatic Tarlov's cyst by surgical decompression.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.74-75
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• 2016

Various types of microstrip antennas can be used for many applications in wireless communication systems. In this paper, we studied a design method for a broadband dual-fed stacked microstrip patch antenna. The impedance bandwidth is improved by adjusting the sizes of main radiating patch and parasitic patch, the distance between the patches, the length of inset feed line, etc. The antenna is designed by simulation for an operation in the frequency range of 2.3-2.7 GHz, and the antenna characteristics such as return loss, gain, radiation patterns are examined.

• Journal of Acupuncture Research
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• v.38 no.4
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• pp.320-324
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• 2021

Lumbar spinal stenosis (LSS) is a common degenerative spinal condition that can have unpredictable improvement and worsening of symptoms which include low back pain, radiating pain, claudication, and degenerative lumbar scoliosis affecting quality of life. In this study, thread embedding acupuncture (TEA) was used as a conservative treatment for LSS in combination with complex Korean medicine treatments (acupuncture, herbal medicines, and physical therapy). The treatment was evaluated using the numerical rating scale, walking distance and duration, and inclination of radiological lumbar scoliosis according to antalgic posture. TEA was performed 27 times between June 8, 2020, and March 16, 2021. The patient showed improvement in numerical rating scale score from 7 to 2, pain-free walking distance from 10 m to 900 m, and scoliosis inclination following treatment. The findings of this study suggest that TEA may be helpful in the treatment of LSS.

• Korean Journal of Acupuncture
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• v.38 no.3
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• pp.189-195
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• 2021

Foot drop due to lumbar disc herniation is perceived to be an indication for surgery. A 44-year-old male presented with motor deficit in left ankle dorsiflexion along with radiating pain and paraesthesia. Motion Style Acupuncture Therapy (MSAT) was administered on the left side every other day. Acupuncture and Chuna were performed daily. Herbal medicine was taken 3 times a day. His symptoms rapidly improved throughout treatment, verified by decreased Numeric Rating Scale (NRS), Oswestry Disability Index (ODI), increased 5-level EuroQol-5 Dimension (EQ-5D-5L) scores, and improved motor grades. We suggest that a combination of MSAT with traditional Korean medicine could be a favorable option for foot drop in LDH patients in terms of rapid pain reduction and the improvement of quality of life.

• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.444-446
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• 2011

Nanosized polystyrene (PS) particles with the narrow size distribution were synthesized from styrene monomer at the presence of the surfactant (polyvinylpyrrolidone, PVP), the solvent of 95 % alcohol, and the initiator of benzoyl peroxide (BPO). Since the emulsion polymerization method was applied, many factors could have effects on the size of PS particles during polymeric process. Aside from the concentration of monomer, surfactant and initiator, the factors such as the stirring speed and the ultrasonic radiation were mainly studied. By adjusting the radiating time, PS particles with their size of about 400 nm were synthesized.