• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.5
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• pp.491-503
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• 2014

In this paper, a $TM_{31}$ higher order mode half circular-ring microstrip antenna with monopole-like radiation characteristic for on-body communication is proposed. By using shorting vias, $TM_{31}$ resonance mode was excited, while achieving compact low-profile antenna with monopole-like radiation characteristics. To overcome the narrow bandwidth of a patch antenna, a C-shape half ring patch with shorting vias having $TM_{31}$ mode is closely located around a half circular patch. For size reduction, half mode is adopted. The proposed antenna has the overall dimensions of $0.25{\lambda}_0{\times}0.46{\lambda}_0{\times}0.025{\lambda}_0$ at the industrial, scientific, and medical(ISM) 2.45 GHz band(2.4~2.485 GHz) and the 10-dB return loss is 4.24 % ranging from 2.38 to 2.49 GHz. To verify body effect, two-thirds muscle equivalent semi solid phantom was fabricated and used to measure the antenna performance. A communication link is analysed to investigate the effect of human-body movements and antenna locations.

• Journal of Korean Neurosurgical Society
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• v.30 no.11
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• pp.1291-1299
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• 2001

Objectives : The authors present a retrospective analysis of 14 patients treated for spinal cord hemangioblastoma (SCH) between Dec. 1986 and Mar. 2000. This study was conducted to evaluate and compare the difference of the functional outcomes associated with the extent of surgical removal of SCH. Methods : Eleven patients were male and three patients were female. Their mean age was 37.2 years that ranged from 19 to 62 years. Preoperative magnetic resonance(MR) imaging of the spine was performed in all cases, and preoperative angiography in eleven cases. They were followed from 15 months to 161 months(median follow-up period, 47 months), and we investigated the change of neurological symptoms and functional outcomes with radiological features, especially on MR imaging. Results : Six patients were accompanied by von Hippel-Lindau disease, and three of them had multiple CNS tumors. Thirteen patients had intramedullary tumor, and the remaining one had extradural. Syringomyelia around the tumor was observed in ten cases. All patients underwent surgical removal, and gross total removal(GTR) was achieved in ten cases. Preoperative embolization was performed in four cases. In four patients who were treated with preoperative embolization, intraoperative loss of blood was minimal and GTR was possible. One patient developed a transient swallowing difficulty postoperatively without permanent postoperative neurological deficits. In three of four patients in whom GTR was not possible, their functional outcomes were worsened postoperatively. The functional status at discharge was improved in seven patients, stationary in four patients, and worse in three. At the last follow-up(15-161 months), one of four patients who had been stationary at discharge showed improvement but, the rest did not show any change. All patients who showed neurological improvement were patients with GTR, and the patients with GTR had significant better outcome than those without GTR(p=0.015). Conclusion : Surgical treatment, and especially, GTR is considered as treatment of choice for spinal cord hemangioblastoma. Preoperative embolization may prevent intraoperative bleeding and improve surgical outcome.

• Journal of Digital Convergence
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• v.11 no.12
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• pp.665-672
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• 2013

In radiology department, where patients with a variety of diseases receive their tests, there is a large possibility of cross contamination of nosocomial infection. Magnetic resonance imaging (MRI) tests take particularly more time than other tests do, which increases the possibility of being exposed to cross contamination. Therefore, this research examines the status of MRI equipment sterilization and investigates the bacterial distribution on head coils, which have the most frequent contact with patients, patient fixation blocks, and bores, which are confined spaces. The status of MRI equipment disinfection was examined by a survey targeting 150 employees, and the distribution of bacteria was measured in ten medical facilities. The result of bacterial distribution tests on MRI equipment showed various bacteria, including Staphylococcus, Acinetobacter, Sphingomona, Pantoea agglomeranss, Micrococcus, Bacillus, Saprophyticus, Brevundimona, and Myroidesspecies. The result of examining the stat us of MRI room disinfection showed that the disinfections of the head coil, block, and bore were implemented well, and the largest proportion was carried out once a day in the morning. The time and implementation of disinfection by the disinfection manager showed that they were implemented well when the manager was the MRI room examiner. The disinfection after examining a patient using an appropriate disinfectant is mandatory to prevent cross contamination.

• Korean Journal of Food Science and Technology
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• v.44 no.5
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• pp.621-627
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• 2012

Assessment was made of the effects of Aralia cordata Thunb (DH) on the cell proliferation, inducible nitric oxide synthase (iNOS) mRNA gene expression and nitric oxide (NO) production in RAW 264.7 macrophage cells. For the screening of anti-inflammatory activities, ethanolic extracts of 55 species of traditional herbal medicines were examined for inhibitory effects, and it was confirmed that DH possessed inhibitory effects on NO production. As a result, DH significantly decreased the production of NO and iNOS gene expression at a concentration of $250{\mu}g/mL$. The chloroformsoluble fractionates have the strongest No synthesis inhibitory effect. It is presumed that the inhibition of NO production in LPS-stimulated RAW 264.7 cells by DH components occurred via the modulation of iNOS and DH, and that the active compound from DH may be useful for therapeutic management of inflammatory-associate diseases.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.12
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• pp.955-960
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• 2012

We fabricated piezoelectric unimorph cantilever generators (UCG) using $Pb(Zr_{0.54}Ti_{0.46})O_3$ + 0.2 wt% $Cr_2O_3$ + 1.0 wt% $Nb_2O_5$ (PZCN) piezoelectric thick films, which were produced by a tape casting method. The PZCN thick films were tailored with same width and thickness but different lengths from 7.7 to 57.7 mm in order to evaluate optimized UCG for energy harvesting device applications. When the length of PZCN film was increased, the resonance frequency of UCG was slightly increased from 7 Hz to 8 Hz, which could be due to enlarged area of the highly stiff piezo-ceramic film. However, the output power was proportionally increased with the length of PZCT film and it reached 4.68 mW (1.221 $mW/cm^3$) when the film's length was 57.7 mm under 25 g of tip mass at 8 Hz, which is sufficient for micro-scale device applications.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5299-5304
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• 2012

MRI signals are significantly reduced by the magnetic field inhomogenity result from human body itself being consisted of various materials like air, fat, muscle, bone and blood vessels. In this study we used silicon which is tissue equivalent to compensate wound body shapes. Objects were eight adults who do not have any special symptoms. Feet were scanned because of their complicated structures and consequently signal reduction occurs a lot. Thirty images were acquired from the middle of arcus pedis longitudinalis including five distal phalanges parallel to the line connecting metatarsal bone and phalanges. SNR data from bones and soft tissues were compared before and after sticking silion between toes and paired t test was performed. It was came out that SNR data from bone and soft tissue were both significantly higher after applying silicon on both T1 and T2 weighted images and it was statistically meaningful having positive corelation. As a result, this study dramatically increases SNR without affecting object by increasing the object volume inside the surface coil.

• Journal of the Korean Geotechnical Society
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• v.36 no.11
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• pp.157-165
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• 2020

At present, there are no clearly stated criteria or theories in calculating additional vertical dynamic loads that occur at the machine foundation due to vibration and reflecting them in the design at home and abroad. According to the domestic standard, although it is not a serious vibration condition, the additional dynamic load due to vibration is considered up to 100% of the static load. This is an extremely conservative design. The purpose of this study is to propose a model test method for evaluating the quantitative magnitude of additional dynamic loads that are generated at certain static loads due to vertical mechanical vibrations. As preliminary basic tests for the model tests, the test for evaluating the effects of reflective wave that may occur within a limited size soil box and the test for estimating the natural frequency of the devised model soil-foundation system were carried out. From the analysis of results for basic tests, a method to minimize the influence of the reflected wave was prepared, and the effect of the resonance of the model system was minimized during the model tests. After the basic tests, the main model tests were conducted. Through the proposed main test, the quantitative magnitude of additional dynamic loads caused by machine vibration on a shallow foundation for machine on medium dense sand foundations were evaluated. From the results of the model test, the feasibility of design applied at home and abroad was reviewed.

• Journal of Acupuncture Research
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• v.33 no.2
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• pp.11-20
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• 2016

Objectives : The purpose of this study is to investigate the clinical effectiveness of Korean medical combination treatment for cervical disc herniation. Methods : This is an observational study. 102 patients diagnosed with cervical disc herniation by MRI (Magnetic Resonance Imaging) were investigated from January, 2015 through to December, 2015 at Daejeon Jaseng Hospital of Korean Medicine. They were sorted according to the distribution of sex, age, causing factor, the period of disease, admission day and pain area. All patients were treated with acupuncture, Chuna treatment, and herbal therapy and physical therapy during the admission period. After treatment, NRS (Numeric Rating Scale), NDI (Neck Disability Index) and EQ-5D were assessed to evaluate the treatment efficacy. Results : There were more females than Males with a ratio of 1 : 1.37, the age of fifty was the most with 35.29 %, reason unknown was the most with 72.55 % and the subacute stage was the most with 38.24 %. According to disc herniation types, patients with protruded disc types were the most with 66.67 % and a lesion of C5/6 was the most with 41.18 %. For patients diagnosed with cervical disc herniation, neck and shoulder pain NRS decreased from $6.43{\pm}1.77$ to $3.96{\pm}1.96$(p<0.001) and radiating pain NRS decreased from $5.64{\pm}1.96$ to $3.57{\pm}1.88$ (p<0.001). NDI decreased from $41.72{\pm}14.04$ to $30.84{\pm}15.34$(p<0.001), and the EQ-5D index increased from $0.68{\pm}0.17$ to $0.79{\pm}0.14$(p<0.001) after treating cervical disc patients. Conclusion : Korean medical combination treatment might be effective in decreasing pain and raising the life quality of patients with cervical disc herniation.

• Bulletin of the Korean Chemical Society
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• v.24 no.4
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• pp.446-452
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• 2003

Some new nanohybrid materials have been synthesized by intercalating the oxotitanium(IV) meso-tetrakis(4- sulfonatophenyl) porphyrin$(O=Ti^{(IV)} TSPP)$ into the Zn/Al layered double hydroxides (LDHs), and their structures and photophysical properties have been investigated by various laser spectroscopic techniques. According to the XRD pattern of the synthesized nanohybrid materials, the macrocycle plane of $O=Ti^{(IV)}$ TSPP are grafted perpendicular to the LDH layers. The $O=Ti^{(IV)}$ TSPP-intercalated LDH exhibits band broadening of the absorption spectrum and a blue shift of Q-band as compared to that observed in solution. Resonance Raman spectral measurements demonstrate that the positively charged LDHs give rise to a slight decrease of the electronic density of the porphyrin ring accompanying a small change of the electronic distribution of the $O=Ti^{(IV)}$ TSPP. Consequently the LDH environment affects the energies of the two highest occupied molecular orbitals (HOMOs) of the $O=Ti^{(IV)}$) TSPP, $a_{1u}$ and $a_{2u}$, producing a mixed orbital character. Being consistent with these electronic structural changes of $O=Ti^{(IV)}$ TSPP in LDH, both the fluorescence spectral change and the fsdiffuse reflectance transient measurements imply that the photoexcitation of the $O=Ti^{(IV)}$ TSPP intercalated into LDH undergoes fast relaxation to the O=Ti(IV) $TSPP^+-LDH^- $charge transfer (CT) state within a few picoseconds, followed by a photoinduced electron transfer between the O=Ti(IV) TSPP and LDHs with a rate constant greater than %1×10^{10}S^{-1}$. No evidence is found for back electron transfer. In conclusion, the $O=Ti^{(IV)}$ TSPP intercalated LDH seems to be a possible candidate for an artificial reaction center for an efficient solar energy conversion system.

• Journal of the Korean Chemical Society
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• v.39 no.8
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• pp.627-634
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• 1995

Layered double hydroxides ($Mg-Al-CO_3$ systems, LDH), which are hydrotalcite-like anionic clay minerals, having different $Mg^{2+}\;to\;Al^{3+}$ ratio were synthesized by coprecipitation method. The subsequent products were characterized by the following methods; elemental analysis, X-ray powder diffraction, thermal analysis (DSC and TGA), FT-IR and $^{27}$Al-MAS NMR. X-ray powder patterns showed that the products formed were layered structure materials. Two heat absorption peaks were observed around 20 ∼280$^{\circ}C$ (surface water and interlayer water) and 280∼500$^{\circ}C$ (water from lattice hydroxide and carbon dioxide from interlayer carbonate) in DSC diagrams, and they were quantitatively analyzed by TGA diagrams (in case LDH4 16.2% and 28.6% respectively). FT-IR spectra indicate that the interlayer carbonate ions occupied symmetrical sites between two adjacent layers in a parallel direction. $^{27}$Al-MAS NMR spectra show only single resonance (8.6 ppm) of the octahedrally coordinated aluminum similar magnesium. When LDH4 was calcined at 560$^{\circ}C$ for 3 hours in air, its layered structure was destroyed giving a mixed metal oxide. However it readily became rehydrated in aqueous chromate solution to its original structure.