• Journal of Chest Surgery
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• v.23 no.5
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• pp.1021-1026
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• 1990

The patients with tracheal stenosis have become more increasing in recent due to the increased use of tracheostomy and assisted ventilation Anesthetic management during tracheal reconstruction is a concern to the anesthetist and the surgeon, who must share the airway as a operation field and at the same time provide good gas exchange. Multiple technique such as the tube ventilation system or C \ulcornerP bypass method have been recommended to achieve this goals. However, these methods have disadvantages of poor surgical exposure and hemorrhagic complication from using C \ulcornerP bypass The technique for HFJV was first described for bronchoscopy, and it involves positive-pressure breathing with high flow[40 \ulcorner60L/min] of oxygen This flow is directed to a semirigid catheter inserted in the endotracheal tube and the tracheal reconstruction can be done without interruption. From Dec. 1986 to July 1990 we have experienced 6 patients of tracheal stenosis necessitating circumferential resection and end to end anastomosis; 5 patients with tracheal stenosis following cuffed tracheostomy or intubation, a patient with tracheal stenosis due to invasive thyroid cancer. The specific advantages during tracheal reconstruction are unobstructed field during surgical reconstruction and good gas exchange through the procedure.

• International Journal of Aeronautical and Space Sciences
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• v.15 no.3
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• pp.320-334
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• 2014

Over the last two decades, numerous experimental and numerical efforts have examined physical phenomena in plasma discharge devices. The physical mechanisms that govern the anomalous electron diffusion from the cathode to the anode in the Hall Effect Thruster (HET) are not fully understood. This work used 1-D numerical method to improve our understanding and gain insight into the effect of the anomalous electron diffusion in the HET. To this end, numerical solutions are compared with various experimental HET performance measurements and the effects of anomalous electron diffusion are analyzed. The relationships between the anomalous electron diffusion and important parameters of the HET are also studied quantitatively. The work identifies the cathode mass flow rate fraction, radial magnetic field distribution, and discharge voltage as significant factors that affect anomalous electron diffusion. Additionally, the study demonstrates a computational process to determine the radial magnetic field distribution required to achieve specific thruster performance goals.

• Korean Journal of Materials Research
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• v.15 no.3
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• pp.209-215
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• 2005

Titanium dioxide films $(TiO_2)$ doped cobalt transition metal were prepared on titanium metal by water spray pyrolysis technique. Micro-morphology, crystalline structure, chemical composition and binding state of sample groups were evaluated using field emission scanning microscope(FE-SEM), X-ray diffractometer(XRD), Raman spectrometer, X-ray photoelectron spectrometer(XPS). $TiO_2$ films of rutile structure were predominately formed on all sample groups and $Ti_2O_3$ oxide was coexisted on the surface of cobalt doped-sample groups. The optical absorption peaks measured by using UV-VIS-NIR spectrophotometer were observed at specific wavelength region in sample groups doped cobalt ion. This result could be analyzed by introducing crystal field theory.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.5
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• pp.635-640
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• 2016

Tunnel field-effect transistor (TFET) is a promising candidate for the next-generation electron device. However, technical issues remain for their practical application: poor current drivability, shor-tchannel effect and ambipolar behavior. We propose herein a novel recessed-channel TFET (RTFET) with the asymmetric source and drain. The specific design parameters are determined by technology computer-aided design (TCAD) simulation for high on-current and low S. The designed RTFET provides ${\sim}446{\times}$ higher on-current than a conventional planar TFET. And, its average value of the S is 63 mV/dec.

• Journal of Forest and Environmental Science
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• v.34 no.2
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• pp.192-195
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• 2018

To establish a management strategy of sediment-related disasters for adaptation to climate change, it is necessary to 1) understand the specific details and problems about the present status, 2) systematize related technologies by using exact numerical values obtained from physically-based analysis, and 3) ensure the basic guidelines are applied to field elastically. To achieve these successfully, detailed guidelines are required by scientifically considering the utilization and impact of related technology on the field. Here, detailed guidelines should include 1) the development of a basic plan, 2) enhancement of relevant technical instructions, 3) establishment of survey and inspection methods, 4) procedure of erosion control works in urban living sphere, and 5) proactive countermeasures against sediment-related disaster caused by earthquakes.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.09a
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• pp.79-82
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• 2001

Analytical solutions have been derived to delineate the capture zone created by pumping wells for the remediation design of contaminated groundwater. These previous analytical solutions are often restricted to pumping wells only, specific well locations, a limited number of wells, and an isotropic aquifer. Analytical solution was developed to deal with arbitrarily located multi injection-pumping wells in an anisotropic homogeneous aquifer. The solution presented in this study provides a simple, easy method for determining tile complex flow field caused by multi injection-pumping wells at different rates, and will consequently be useful in pump-and-treat design.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.509-522
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• 2010

There is a increasing trend in disaster occurrence due to steep-slope failures in urban area during typhoon and torrential rain season in Korea. The underlying hazards that cause slope failure are mainly linked with urbanization and industrialization. To minimize the disaster damages by slope failure, objective and unified evaluation approached are desired. Since currently available evaluation checklists are developed for specific purposed, there is a limitation to adapt those checklists for stability evaluation in natural terrain. This study proposes an improved evaluation checklist based on the comparison of previous checklists and applicability and feasibility are analyzed implementing field application.

• Journal of Environmental Science International
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• v.18 no.12
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• pp.1331-1338
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• 2009

Marine dinoflagellate Alexandrium minutum producing paralytic shellfish toxins is responsible for paralytic shellfish poisoning (PSP). To investigate its temporal distributions in Chinhae Bay where PSP occurs annually, SYBR Green I based A. minutum-specific real-time PCR probe was developed on the LSU rDNA region. Assay specificity and sensitivity were tested against related species, and its specificity was further confirmed by sequencing of field-derived samples. Ten months field survey in 2008 (a total 100 surface water samples) by using the real-time PCR probe showed that A. minutum was detected at very low densities of 1-4 cells $L^{-1}$ in May and June being spring in Chinhae Bay, Korea.

• Tuberculosis and Respiratory Diseases
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• v.75 no.2
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• pp.47-51
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• 2013

Interstitial lung diseases are heterogeneous entities with diverse clinical presentations. Among them, idiopathic pulmonary fibrosis and connective tissue disease-associated interstitial lung disease are specific categories that pulmonologists are most likely to encounter in the clinical field. Despite the accumulated data from extensive clinical trial and observations, we continue to have many issues which need to be resolved in this field. In this update, we present the review of several articles regarding the clinical presentation, prognosis and treatment of patients with idiopathic pulmonary fibrosis or connective tissue disease-associated interstitial lung disease.

• Journal of Korea Game Society
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• v.9 no.1
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• pp.3-10
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• 2009

This paper presents the effects on logical thinking of the Korean LOGO programming used in teaching for the second grade of middle school with regard to cognitive styles and specific sub-classifications of logical thinking. In result, the LOGO programming teaching method significantly affected logical thinking and its sub-classifications.