• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.11 no.1
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• pp.269-283
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• 1998

Paranasal sinusitis, especially chronic is one of the most common diseases in the field of otolaryngology. It is similar to Bee Yeun(鼻淵) in oriental medicine. Most cases of sinusitis are due to anatomical abnormalities within ostiomeatal unit or disturbed mucocilliary flow. The ostiomeatal unit is the first place of contact with bacteria and allergens during aspiration, and it can be obstructed easily by minute mucosal swelling due to anatomical narrowness. Therefore the treatment of paranasal sinusitis is not easy and often leads to recurrences in spite of long term treatment or surgical therapy. We studied 83 patients who had visited our hospital with complaints of nasal symptoms; they had been diagnosed as having paranasal sinusitis through an endoscopy or CT scan in another hospital and were diagnosed as the paranasal sinusitis through a PNS series. The results were as follows: 1. Age and sex distribution: The most common occurence was found between 6-10 and 1-5 years old. The Males Were 52($62.7\%$) and Females were 31($37.3\%$). 2. By residence 58 cases lived in apts: 25 lived in houses. 3. The longest duration of disease varied from a lower of 13 to a higher of 36 months in 22 cases and from 7 to 12 months in 21 cases. 4. The most common complication & past history with otolaryngologic or allergic disease were adenoid or tonsil hypertrophy & tonsillectomy and adenoidectomy (21 cases). In decreasing order the others were atopic dematitis, otitis media with effusion and allergic rhinitis. 5. Distribution of paranasal sinus disease was most common in both maxillary sinuses in 52 cases. 12 cases showed a normal PNS X-ray series but these had been diagnosed as paranasal sinusitis with an endoscopy or CT scan in another hospital. 6. Common sinusitis - related symptoms were from highest incidence to lowest nasal obstruction, postnasal drip rhinorrhea, frontal headache, cough with sputum. 7. The most administered of prescription was Gamibangpoongtongsungsan and Sunbangpaedoksan extract. 8. In 26 cases the subjects showed significant improvement symptoms in PNS X-ray series : In 21 case showed partial improvement symptoms.

• Korean Journal of Optics and Photonics
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• v.10 no.4
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• pp.311-317
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• 1999

Unidirectional single-mode operation of a diode-pumped Nd:YAG laser with a planar semimonolithic ring cavity has been demostrated at 1064 nm. The semimonolithic cavity consists of a laser active medium placed in a magnetic field, a crystal quartz plate, and an output coupling mirror. They form an optical diode by acting each part as a Faraday rotator, a reciprocal polarization rotator and a partial polarizer, respectively. An eigenpolarization theory for the cavity configuration was presented and losses for the eigenmodes were calculated. A pump-limited single-mode output power of 155 mW and a slope efficiency of 17% were obtained when the laser was pumped by a 1.2 W, 809 nm diode-laser. A laser linewidth of less than 100 kHz is inferred from a beat note frequency spectrum between two identical laser systems and continous single-mode tuning range was more than 2 GHz.

• Journal of Gastric Cancer
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• v.10 no.2
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• pp.63-68
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• 2010

Purpose: Remnant gastric cancer (RGC) are generally detected at advanced stages or infiltration of adjacent organs. We retrospectively reviewed the surgical outcomes and clinicopathologic results of remnant gastric cancers that have operated during fourteen years in one institution of Korea. Materials and Methods: 34 patients who were diagnosed with RGC at Ajou University Hospital from April 1995 to October 2009 were enrolled. We analyzed the features of previous operation, and according to these results, surgical outcomes and clinicopathologic results for RGC were analyzed. Results: Of 34 patients, 20 patients had previously undergone distal gastrectomy for malignant disease, and 14 patients for benign disease. The period between previous operation and surgery for RGC in the patients underwent operation for malignant disease was shorter than that in benign patients (P<0.001). In surgical field, 31 patients (91.0%) were resected and curative resection was possible in 23 patients (67.6%). When 31 patients who underwent resection for RGC were divided into previous malignant and benign disease, there was no significantly different in terms of surgical outcomes and pathologic findings between two groups. Meanwhile, the patients who recently (after 2005) underwent surgery for RGC showed less advanced stage compared with the patients who underwent surgery before 2004. Conclusions: Resection was possible in the higher proportion (91.0%) of patients diagnosed with RGC compared with previous reports. The cause of previous operation did not effect on the surgical outcomes for surgery of RGC. Recent trend of RGC is to increase the proportion of early stage gastric cancer. Therefore, surgeons should consider curatively surgical resection for RGC the regardless of pattern of previous operation.

• Journal of Biomedical Engineering Research
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• v.23 no.5
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• pp.375-383
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• 2002

Aneurysm embolisation method using coils have been widely used. Micro coils are introduced via a small catheter, and are packed inside of aneurysm sac, which induces intraaneurysmal flow stagnation and thrombus formation. When partial blocking of an aneurysm is inevitable, the location of coils is important since it changes the flow patterns inside the aneurysm, which affect the embolisation process. We measured the flow field inside the partially blocked lateral aneurysm models in vitro, and tried to suggest the effective locations of coils for aneurysm embolisation. Velocity fields are measured using a particle image velocitimeter for different coil locations- proximal neck, distal neck, proximal dome and distal dome. Flow into the aneurysm sac was significantly reduced in the distally blocked models, and coils at distal neck blocked inflow more effectively comparing to those at distal dome. This study suggests that distal neck should be the most effective location for aneurysm embolisation.

• Smart Structures and Systems
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• v.12 no.3_4
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• pp.251-269
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• 2013

Measurement of deflections of certain bridges is usually hampered by corruption of the GPS signal by multipath associated with passing vehicles, resulting to unrealistically large apparent displacements. Field data from the Gorgopotamos train bridge in Greece and systematic experiments revealed that such bias is due to superimposition of two major effects, (i) changes in the geometry of satellites because of partial masking of certain satellites by the passing vehicles (this effect can be faced with solutions excluding satellites that get temporarily blocked by passing vehicles) and (ii) dynamic multipath caused from reflection of satellite signals on the passing trains, a high frequency multipath effect, different from the static multipath. Dynamic multipath seems to have rather irregular amplitude, depending on the geometry of measured satellites, but a typical pattern, mainly consisting of a baseline offset, wide base peaks correlating with the sequence of main reflective surfaces of the vehicles passing next to the antenna. In cases of limited corruption of GPS signal by dynamic multipath, corresponding to scale distortion of the short-period component of the GPS waveforms, we propose an algorithm which permits to reconstruct the waveform of bridge deflections using a weak fusion of GPS and RTS data, based on the complementary characteristics of the two instruments. By application of the proposed algorithm we managed to extract semi-static and dynamic displacements and oscillation frequencies of a historical railway bridge under train loading by using noisy GPS and RTS recordings. The combination of GPS and RTS is possible because these two sensors can be fully collocated and have complementary characteristics, with RTS and GPS focusing on the long- and short-period characteristics of the displacement, respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.11
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• pp.2758-2764
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• 2015

In the field of electronic warfare applications, high voltage power supply(HVPS) for high power phased array transmitters must necessarily have an independent operating characteristics for driving mini TWTs. TWT independent operational characteristics, in order to run without interrupting the electronic warfare mission by maintaining the partial transmission function even when one of the TWT has occurred a failure, is known to be very important. In this paper, we describe the research on high-speed independent control system using a high-density HVPS, including FE modulators, hardware configuration and the FPGA in order to independently operate mini TWTs. Also, we have simulated some possible faults in phased array transmitters, and presents the test results to control a faulted TWT independently.

• Biomolecules & Therapeutics
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• v.20 no.4
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• pp.357-370
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• 2012

Radiation therapy, the most commonly used for the treatment of brain tumors, has been shown to be of major significance in tumor control and survival rate of brain tumor patients. About 200,000 patients with brain tumor are treated with either partial large field or whole brain radiation every year in the United States. The use of radiation therapy for treatment of brain tumors, however, may lead to devastating functional deficits in brain several months to years after treatment. In particular, whole brain radiation therapy results in a significant reduction in learning and memory in brain tumor patients as long-term consequences of treatment. Although a number of in vitro and in vivo studies have demonstrated the pathogenesis of radiation-mediated brain injury, the cellular and molecular mechanisms by which radiation induces damage to normal tissue in brain remain largely unknown. Therefore, this review focuses on the pathophysiological mechanisms of whole brain radiation-induced cognitive impairment and the identification of novel therapeutic targets. Specifically, we review the current knowledge about the effects of whole brain radiation on pro-oxidative and pro-inflammatory pathways, matrix metalloproteinases (MMPs)/tissue inhibitors of metalloproteinases (TIMPs) system and extracellular matrix (ECM), and physiological angiogenesis in brain. These studies may provide a foundation for defining a new cellular and molecular basis related to the etiology of cognitive impairment that occurs among patients in response to whole brain radiation therapy. It may also lead to new opportunities for therapeutic interventions for brain tumor patients who are undergoing whole brain radiation therapy.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.17 no.2
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• pp.71-76
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• 1981

In order to make a numerical modeling for the one dimensional unsteady flow which expressed by Saint Venant partial differential equations, Preissmann's implicit scheme was used, and it's stability and accuracy was mentioned. By introducing recurrence relations make it possible to use double sweep algorithm. Effective parameters to the result were the values of the $\Delta$t/$\Delta$x, $\theta$ and the chezy coefficient. In oder to get numerical solutions with enough accuracy, $\Delta$t/$\Delta$x should not be far from the value of 1, and the criteria of the $\theta$ was 0.6<$\theta$<1.0 for the stability without condition. This model should be calibrated by real field data, and expected to be developed for the simulation of the river system and to the long wave analysis for one dimensional coastal zone problem.

• Journal of Korean Neurosurgical Society
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• v.37 no.5
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• pp.357-363
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• 2005

Objective: The microvascular decompression(MVD) for trigeminal neuralgia(TN) is known as an effective surgical technique. But the failed MVD cases have been reported in long term follow-up studies. This study is to evaluate the efficacy of MVD through our operative techniques, offending vessels in operative field, failed cases with the review of the literatures. Methods: We analyzed total 63 cases of TN which underwent MVD from 1955 to 2003 according to characters of pain, operative findings, operative results related to causative vessel compression and operative method, progonotic factor. Statistical analysis was performed using paired t-test with SPSS Ver 11.0. Results: In TN, the most common offending vessel was superior cerebellar artery(45.0%). In compression group of nerve root by offending vessel, the cure rate was 91.7%. However, the cure rate of the contact group was 64.7% and the cure rate of the negative group was 37.5%. There was no statistical significance between the degree of compression by vessel and the operative result(p=0.076). In 51 cases with MVD only, the cure rate was 84.3% and in 3 cases with PSR only, 42.8% and in 2 cases with PSR(partial sensory rhizotomy) with MVD, 50.0%. TN recurred in 7 cases within the follow-up period and reoperations(PSR) were added in 2 cases of them. Conclusion: This study shows that MVD provided a high rate of success with a minor risk of complications, which has been regarded as the most safe and effective procedure for trigeminal neuralgia. Additional MVD in recurred TN by severe adhesion of teflon showed poor outcome. But, revisional operation(PSR) in recurred TN showed relatively good outcome. PSR should be considered for treatment of recurrent TN after MVD.

• Structural Engineering and Mechanics
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• v.76 no.3
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• pp.311-324
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• 2020

Until now, a comparative study on fully and partially-connected steel shear walls leading to enhancing strength and stiffness reduction of partially-connected steel plate shear wall structures has not been reported. In this paper a number of 4-story and 8-story steel plate shear walls, are considered with three different connection details of infill plate to surrounding frame. The specimens are modeled using nonlinear finite element method verified excellently with the experimental results and analyzed under monotonic loading. A comparison between initial stiffness and shear strength of models as well as percentage of shear force by model boundary frame and infill plate are performed. Moreover, a comparison between energy dissipation, ductility factor and distribution of Von-Mises stresses of models are presented. According to the results, the initial stiffness, shear resistance, energy dissipation and ductility of the models with beam-only connected infill plates (SSW-BO) is found to be about 53%, 12%, 15% and 48% on average smaller than those of models with fully-connected infill plates (SPSW), respectively. However, performance characteristics of semi-supported steel shear walls (SSSW) containing secondary columns by simultaneously decreasing boundary frame strength and increasing thickness of infill plates are comparable to those of SPSWs. Results show that by using secondary columns as well as increasing thickness of infill plates, the stress demands on boundary frame decreases substantially by as much as 35%. A significant increase in infill plate share on shear capacity by as much as 95% and 72% progress for the 4-story SSW-BO and 8-story SSSW8, respectively, as compared with non-strengthened counterparts. A similar trend is achieved by strengthening secondary columns of 4-story SSSW leading to an increase of 50% in shear force contribution of infill plate.