• Journal of Electrical Engineering and Technology
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• v.12 no.5
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• pp.2021-2030
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• 2017

In this paper, the unipolar corona-needle charger was developed and its capabilities were both numerically and experimentally investigated. The experimental corona discharges and particle losses in the charger were obtained at different corona voltage, aerosol flow rate and particle diameter for positive and negative coronas. Inside the charger, the electric field and charge distribution and the transport behavior of the charged particle were predicted by a numerical simulation. The experimental results yielded the highest ion number concentrations of about $1.087{\times}10^{15}ions/m^3$ for a positive corona voltage of about 3.2 kV, and $1.247{\times}10^{16}ions/m^3$ for a negative corona voltage of about 2.9 kV, and the highest $N_it$ product for positive and negative coronas was found to about $7.53{\times}10^{13}$ and $8.65{\times}10^{14}ions/m^3$ s was occurred at the positive and negative corona voltages of about 3.2 and 2.9 kV, respectively, and the flow rate of 0.3 L/min. The highest diffusion loss was found to occur at particles with diameter of 30 nm to be about 62.50 and 19.33 % for the aerosol flow rate of 0.3 and 1.5 L/min, respectively, and the highest electrostatic loss was found to occur at particles with diameters of 75 and 50 nm to be about 86.29 and 72.92 % for positive and negative corona voltages of about 2.9 and 2.5 kV, respectively. The numerical results for the electric field distribution and the charged particles migration inside the charger were used to guide the description of the electric field and the behavior of charged particle trajectories to improve the design and refinement of a unipolar corona-needle charger that otherwise could not be seen from the experimental data.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.6 no.1
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• pp.38-44
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• 2013

The ultrasound can be used primarily to guide exact needle placement for aspirations of fluids, injections of steroid, and biopsies in musculoskeletal field. Recently, ultrasound-guided intervention is widely used because of several advantages such as real-time performance, relatively inexpensiveness, and getting multiple images without additional radiations. However, the modality is operator dependent and requires detailed knowledge of the relevant anatomy and there have been also reported serious complications related to the procedure. So, authors will discuss about the basic techniques, principles and cautions for the use of ultrasound-guided intervention in musculoskeletal field.

• Korean Journal of Bronchoesophagology
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• v.17 no.1
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• pp.9-13
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• 2011

Endobronchial ultrasound (EBUS), which enables visualization of lesions beyond the bronchus, broadens the fields of bronchoscopy. Two types of ultrasound, radial and linear, are used for bronchoscopy. Radial EBUS is performed by inserting an ultrasound mini-probe through the working channel of a flexible bronchoscope. Evaluation of the depth of invasion of early endobronchial lung cancers using radial EBUS is useful in deciding endobronchial treatment. A central tumor limited to within the cartilaginous layer is a good indication for endobronchial photodynamic therapy. EBUS-guide sheath (GS) technique is a sampling method assisted by localization of peripheral lesions using EBUS. The diagnostic yield of EBUS-GS method is higher than that of conventional transbronchial biopsy. High diagnostic values of EBSU-GS method are reported even in small (${\leq}2cm$) peripheral tumors. Linear EBUS is used for endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA). EBUS-TBNA has high diagnostic yields in mediastinal staging of lung cancer even in patients having radiologically early stage lung cancers with normal CT or PET findings in the mediastinum. EBUS is a valuable method in evaluating early endobronchial tumors and peripheral small lung cancers and as well as in mediastinal staging.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.600-603
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• 2000

Recently, Display devices have become important in the information-oriented society and flat display devices are greatly demanded. Liquid crystal display(LCD) represents one of the most promising devices for large size desk-top monitors, notebook PC and car navigation system. However LCD cannot give forth light itself and must have backlight system. The most popular backlighting system is composed of a lighting-guide plate and CCFL as a lighting source. The number of CCFL must increase up if the area of display is increased. So a new backlighting source with high luminance is needed for large LCDs. In this paper, we proposed a surface discharge FFL with the new electrode structure like the needle shaped electrode as the variation of cell structure to high luminance and low power consumption. In comparison with different electrode structure it has low discharge voltage and current and good optical characteristics. So it has better discharge characteristics than different surface discharge FFL and can be fungible for a backlight as a lighting source in LCDs.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.231-235
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• 2005

Most tissue engineering strategies for creating functional replacement tissues or organs rely on the application of temporary three-dimensional scaffolds to guide the proliferation and spread of seeded cells in vitro and in vivo. Scaffolds should be satisfied following requirements; macrostructure to promote cell proliferation, pore interconnectivity, pore size ranging from 200 to $400{\mu}m$, surface chemistry and mechanical properties. Rapid prototyping techniques have often been used as an useful process that fabricates scaffolds with complex structures. In this study, a new process to fabricate a three-dimensional scaffolds using bio-compatible polymer has been developed. It employs a highly accurate three-dimensional positioning system with pressure-controlled syringe to deposit biopolymer structures. The pressure-activated microsyringe is equipped with fine-bore nozzles of various inner-diameters. In order to examine relationships between line width and process parameters such as nozzle height, applied pressure, and speed of needle, experiments were carried out. Based on the experimental results, three-dimensional scaffold was fabricated using the apparatus. It shows the validity of the proposed process.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.23 no.1
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• pp.182-198
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• 2010

Background : The varieties of manifestations referred to oral, glottal, labial and dental diseases has been long complicated physicians in the efficient diagnosis and treatment of these diseases. Acupuncture has been widely used in Korea throughout the history and provides an efficient method in the treatment of them Objectives : Establish a distinctive and efficient acupuncture method for the treatment of oral, glottal, labial and dental diseases based in literature research Method : We reviewed four Korean medical literature, "Guide to Swollen Sore Treatment", "Treasured Mirror of Eastern Medicine", "Experiential Prescriptions of Acupuncture and Moxibustion", and "Essential Rhymes on Acupuncture and Moxibustion by Master Sa-am", and analyzed the therapeutic characteristics in the treatment of oral, glottal, labial and dental diseases Result : 1. According to "Guide to Swollen Sore Treatment", we could noted frequent application of blood letting methods in the affected area, then rinse ones mouth with salty water and further application of taro plaster. Also found acupuncture methods utilizing heated mole cricket or silkworm in the sublingual region. Regarding herbal method, Realgar was rubbed in the affected area. Mainly used acupuncture points in the treatment of oral, glottal, labial and dental diseases were GV20, GB20, LU5, and auricular anterior hairline 2. In "Treasured Mirror of Eastern Medicine", blood letting method in the sublingual region and burning needle searing method were the most frequently applied in the treatment of oral, glottal, labial and dental diseases. Moxibustion was also applied in the treatment of labial and dental diseases. Particularly, said to apply 3 moxa cones in ear zones of both sides, when no medicine is effective. This demonstrates how emphasized the importance of moxibustion in this kind of disease. Mainly used acupuncture points were GV16, CV24, LI4, EX-HN12, and EX-HN13 3. In "Experiential Prescriptions of Acupuncture and Moxibustion", no other methods beside wrist. Superstitious methods like applying moxibustion on the tooth picture drawn on the roofing tile need further confirmation. Mainly used acupuncture points were LI4, ST36, and HT7. 4. "Essential Rhymes on Acupuncture and Moxibustion by Master Sa-am", identified the cause of diseases according to visceral pattern identification. Stomach and Spleen in charge of vocal, lingual, and labial disease, Kidney for dental disease, and further scrutinizing identification according to Liver, Heart, Stomach, Lung, and Kidney manifestations. Used supplementation and draining needling methods of self meridians and other correlating meridians. Conclusions : After previous study on stroke and eye diseases, we could also find various efficient methods according to oral, glottal, labial and dental diseases, through literature research of korean medical classics. This study will concurrently result in establishing distinctive therapeutic method characteristic of Korea.

• Annals of Clinical Neurophysiology
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• v.10 no.2
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• pp.83-97
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• 2008

Cervical and thoracic radiculopathies are among the most common causes of neck pain. The most common causes are cervical disc herniation and cervical spondylosis in patients with cervical radiculopathy, and diabetes mellitus and thoracic disc herniation in thoracic radiculopathy. A thorough history, physical examination, and testing that includes electrodiagnostic examination and imaging studies may distinguish radiculopathy from other pain sources. Although various electrodiagnostic examinations may help evaluate radiculopathy, needle electromyography is the most important, sensitive, and specific method. Outcome studies of conservative treatments have shown varying results and have not been well controlled or systematic. When legitimate incapacitating symptoms continue despite conservative treatment attempts, more invasive spinal procedures and intradiscal treatment may be appropriate. Surgery has been shown to have excellent clinical outcomes in patients with disc extrusion and neurological deficits. However, patients with minimal disc herniation have fair or poor surgical outcomes. In addition, conventional open disc surgery entails various inadvertent surgical related risks. Although there has not yet been a non-surgical interventional procedure developed with the therapeutic efficacy of open surgery, conservative procedures can offer substantial benefits, are less invasive, and avoid surgical complications. While more invasive procedures may be appropriate when conservative treatment fails, prospective studies evaluating cervical and thoracic radiculopathies treatment options would help guide practitioners toward optimally cost-effective patient evaluation and care.

• The Korean Journal of Pain
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• v.13 no.1
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• pp.93-96
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• 2000

Background: Psoas compartment block with local anesthetics and corticosteroids is one of the treatments which provides long term analgesia of the lower back and anterior thigh unilaterally, and its technical easiness and safety allows blind application without C-arm guidance in the out-patient clinic. This study aimed to evaluate the mean of the depth from the skin to the psoas compartment, and its correlation to the following attributes: age, weight, height and PI (Ponderal Index). Methods: We investigated 28 patients who underwent psoas compartment block. All blocks were performed using Chayen's method (punctured at the point of 3 cm caudally and 5 cm laterally from the 4th lumbar vertebral spinous process) with a 22 G, 8 cm Tuohy needle under C-arm guidance. We recorded the depth from skin to the psoas compartment, height, weight and PI (weight (kg)/height (cm)$\times100$ (%)). Data were analyzed using the Pearson product-moment correlation coefficients. The correlations between the depth and other attributes identified by p-value of less than 0.05 were considered statistically significant. Results: The mean depths from skin to the psoas compartment were $6.02{\pm}0.28$ cm in men, $5.44{\pm}0.22$ cm in women. There is no significant correlation between the depth and other patient's attributes. Conclusions: The mean depths from skin to the psoas compartment may be one of the guide for psoas compartment block in outpatient clinics without C-arm guidance.

• The Korean Journal of Pain
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• v.13 no.2
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• pp.202-207
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• 2000

Background: Superior hypogastric plexus block has been advocated as a useful technique for the treatment of cancer related pelvic pain. The aim of this study was to evaluate the effect of neurolytic trans-intervertebrodiscal superior hypogastric plexus block for pelvic cancer pain. Methods: Twenty-eight patients with gynecologic, colorectal or genitourinary cancer who suffered intractable pain were studied. We performed superior hypogastric plexus block by trans-intervertebrodiscal approach at L5/S1 level under the C-arm fluoroscopic guide unilaterally or bilaterally. Ten ml of 100% dehydrated alcohol was injected through each needle. We evaluated the change of visual analog pain score (VAS; 0~100 mm) and daily dose of oral morphine sulphate at the time of pre-block and 7 days after the block. Results: Fourteen patients (50%) had satisfactory pain relief (VAS<30) while five patients (18%) had moderate pain control (VAS 30~60). The remaining nine patients (32%) had mild or little pain relief (VAS>60) and their daily oral morphine doses were above 160 mg. Additional pain control method may be needed for those patients who received high dose of opioid before neurolytic block. Conclusions: We conclude trans-intervertebrodiscal neurolytic superior hypogastric plexus block was effective in relieving pelvic cancer pain. Neurolytic block, earlier stage, may provide better effects for more comfortable life at the end stage for cancer patients.

• The Korean Journal of Pain
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• v.11 no.2
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• pp.307-310
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• 1998

Selective lumbosacral radiculography and nerve root block techniques are very useful in determining the nerve root involved. We have done the lumbar root block to 61-year-old female who had suffered from low back pain radiating to right lower leg which was not relieved by epidural steroid injection two times. $L_5$ root block was performed under the fluoroscopic C-arm guide. When the needle was in correct position, we injected contrast medium (Isovist$^{(R)}$ - 300, Schering, Germany). After we injected 1.5 cc isovist, the S1 root was figured but L5 root was not figured. When we reinjected 1.5 cc isovist, $S_1$ root was enhanced and $L_5$ root was slightly visible due to severe disc bulging and lateral spinal stenosis.