• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.39 no.1
• /
• pp.31-38
• /
• 2002

In order to improve the 0.35 $mutextrm{m}$-via hole etching process the etching characteristic of the gas $C_2F_{6}$ has been analyzed. The samples were triple-layer films(TEOS/SOG/TEOS) on 8-inch wafers and the orthogonal array matrix technique was used for the process. The equipment for etching was the transformer coupled plasma (TCP) source which is a type of high density plasma(HDP). This experiment showed the etching rate for $C_2F_{6}$ was 0.8 $mutextrm{m}$/min-1.1 $mutextrm{m}$/min and the measured uniformity was under $pm$6.9% in the matrix window. The CD skew comparison between pre and post-etching was under 10% which is an outstanding results in the window of profile in anisotropic etching. There was no problem in C2F6 with the flow rate of 20sccm, but when 14sccm of $C_2F_{6}$ was supplied there was a recess problem on the inner wall of SOG film. Consequently the etching characteristic of $C_2F_{6}$ shows a fast etching rate and a very wide process window in HDP TCP.

• Journal of the Korean Applied Science and Technology
• /
• v.32 no.3
• /
• pp.394-404
• /
• 2015

This study investigated the pharmacodynamics of betaine on the blood profile and short chain fatty acid levels in meat ducks exposed to heat wave. 400 heads of Cherry valley (Anasplatyrhynchos) meat ducks were completely randomized to 5 treatments (4 repetitions each), and were raised for 42 days. They were grouped into T1 (heat wave control group without betaine), T2 (betaine 400 ppm), T3 (betaine 800 ppm), T4 (betaine 1200 ppm), and T5 (normal control group without betaine). Compared to T1, the betaine addition groups showed higher body weight gain at shipment, with T3 showing the highest significant difference. For hematological indictors measured (red blood cells and platelets), the betaine addition groups showed significantly higher values than the heat wave control group. The pH of the former was lower but their electrolytes ($K^+$, $P^+$, and $Cl^-$) were significantly higher compared to the latter. For blood gas concentration, the former showed a significantly higher value than the latter. For the total short chain fatty acids, acetic acid, and propionic acid, the betaine addition groups and group fed broiler-high temperature diet showed higher values than the heat wave control group. On the other hand, the former showed significantly lower values in butyric acid, isobutyric acid, valeric acid, and isovaleric acid than the latter group. These results suggest that betaine has the pharmacodynamics that mediate heat stress, via the maintenance and control of the blood profile, osmotic pressure, gas concentration, and short chain fatty acid, of meat ducks under heat wave.

• Journal of Chest Surgery
• /
• v.46 no.3
• /
• pp.185-191
• /
• 2013

Background: Cardiopulmonary bypass (CPB) induces variable systemic inflammatory reactions associated with major organ dysfunction via polymorphonuclear neutrophils (PMNs). Ulinastatin, a urinary trypsin inhibitor, inhibits PMN activity and reduces systemic inflammatory responses. The aim of this study is to evaluate the effect of ulinastatin on postoperative blood loss and laboratory changes in patients undergoing open heart surgery. Materials and Methods: Between January 2008 and February 2009, 110 patients who underwent atrioventricular valve surgery through right thoracotomy were divided into two groups. Patients received either 5,000 U/kg ulinastatin (ulinastatin group, n=41) or the equivalent volume of normal saline (control group, n=69) before aortic cross clamping. The primary end points were early coagulation profile changes, postoperative blood loss, transfusion requirements, and duration of intubation and intensive care unit stay. Results: There were no statistically significant differences between the two groups in early coagulation profile, other perioperative laboratory data, and postoperative blood loss with transfusion requirements. Conclusion: Administration of ulinastatin during operation did not improve the early coagulation profile, postoperative blood loss, or transfusion requirements of patients undergoing open heart surgery. In addition, no significant effect of ulinastatin was observed in major organs dysfunction, systemic inflammatory reactions, or other postoperative profiles.

• The Bulletin of The Korean Astronomical Society
• /
• v.43 no.2
• /
• pp.39.2-39.2
• /
• 2018

RR Tel is an interacting binary system in which a hot white dwarf (WD) accretes matter from a Mira variable via gravitational capture of the stellar wind. We present a high-resolution optical spectrum of RR Tel obtained with MIKE at Magellan-Clay telescope, Chile. We find broad emission features at 6825, 7082, 7023, and $7053{\AA}$, which are formed through Raman scattering of far-UV O VI ${\lambda}{\lambda}$ 1032 and $1038{\AA}$, C II ${\lambda}{\lambda}$ 1036 and $1037{\AA}$ with atomic hydrogen. Raman O VI 6825 and 7082 features are characterized by double-peaked profiles indicative of an accretion flow with a characteristic speed ~ 30km/s, whereas the Raman C II features exhibit a single Gaussian profile with FWHM ${\sim}10{\AA}$. Monte Carlo simulations for Raman O VI and C II are performed by assuming that the emission nebula around the WD consists of the inner O VI disk with a representative scale of 1 AU and the outer part with C II sphere. The best fit for Raman profiles is obtained with an asymmetric matter distribution of the O VI disk, the mass loss rate of the cool companion ${\dot{M}}{\sim}2{\times}10^{-6}M_{{\odot}/yr}$ and the wind terminal velocity v~10 km/s. We also find O VI doublet at 3811 and $3834{\AA}$, which are blended with other emission lines. Our profile decomposition shows that the O VI ${\lambda}{\lambda}$ 3811, 3834 doublet have a single Gaussian profile with a width ~ 25 km/s. A comparison of the restored fluxes of C II ${\lambda}{\lambda}$ 1036 and 1037 from Raman C II features with the observed C II ${\lambda}1335$ leads to an estimate of a lower bound of N(CII) > $9.87{\times}10^{13}cm^{-2}$ toward RR Tel, which appears consistent with the presumed distance D ~ 2.6 kpc.

• Journal of KIISE:Computer Systems and Theory
• /
• v.33 no.10
• /
• pp.709-721
• /
• 2006

The traditional broadcasting services over terrestrial, satellite and cable media have been unidirectional mass media regardless of TV viewer's preferences. Recently ich media streaming has become possible via the broadb and networks. Furthermore, since bidirectional communication is possible, personalcasting such as personalized streaming services has been emerging by taking into account the user's preference on content genres, viewing times and actors/actresses etc. Accordingly, personal media becomes an important means for content provision service in addition to the traditional broadcasting service as mass media. In this paper, we introduce a user profile reasoning method for target advertisement which is considered an important application in personalcasting service. The proposed user profile reasoning method predicts an unknown TV viewer's gender and ages by analyzing TV Viewing history data. Based on the estimated user's gender and ages, a target advertisement is provided with TV Anytime metadata. A proposed target advertisement system is developed based on the user profile reasoning and the target advertisement selection method. To show the effectiveness of our proposed methods, we present a plenty of experimental results by using realistic TV viewing history data.

• Journal of the Korean Ceramic Society
• /
• v.56 no.6
• /
• pp.589-595
• /
• 2019

The top-seeded solution growth (TSSG) method is an effective approach for the growth of high-quality SiC single crystals. In this method, the temperature gradient in the melt is the key factor determining the crystal growth rate and crystal quality. In this study, the effects of the aperture at the top of the hot-zone on the growth of the SiC single crystal obtained using the TSSG method were evaluated using multiphysics simulations. The temperature distribution and C concentration profile in the Si melt were taken into consideration. The simulation results showed that the adjustment of the aperture at the top of the hot-zone and the temperature gradient in the melt could be finely controlled. The surface morphology, crystal quality, and polytype stability of the grown SiC crystals were investigated using optical microscopy, high-resolution X-ray diffraction, and micro-Raman spectroscopy, respectively. The simulation and experimental results suggested that a small temperature gradient at the crystal-melt interface is suitable for growing high-quality SiC single crystals via the TSSG method.

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.6 s.183
• /
• pp.151-159
• /
• 2006

This paper describes a design process of end-milling cutters: solid model of the designed cutter is constructed along with computation of cutter geometry, and the wheel geometry as well as wheel positioning data f3r fabricating end-mills with required cutter geometry is calculated. In the process, the main idea is to use the cutting simulation method by which the machined shape of an end-milling cutter is obtained via Boolean operation between a given grinding wheel and a cylindrical workpiece (raw stock). Major design parameters of a cutter such as rake angle, inner radius can be verified by interrogating the section profile of its solid model. We studied relations between various dimensional parameters and proposed an iterative approach to obtain the required geometry of a grinding wheel and the CL data for machining an end-milling cutter satisfying the design parameters. This research has been implemented on a commercial CAD system by use of the API function programming, and is currently used by a tool maker in Korea. It can eliminate producing a physical prototype during the design stage, and it can be used for virtual cutting test and analysis as well.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2009.03a
• /
• pp.620-625
• /
• 2009

The seismic slope stability is most often evaluated by the pseudo-static limit analysis, in which the earthquake loading is simplified as static inertial loads acting in horizontal and/or vertical directions. The transient loading is represented by constant acceleration via the pseudostatic coefficients. The result of a pseudostatic analysis is governed by the selection of the value of the pseudostatic coefficient. However, selection of the value is very difficult and often done in an ad hoc manner without a sound physical reasoning. In addition, the maximum acceleration is commonly estimated from the design guideline, which cannot accurately estimate the dynamic response of a slope. There is a need to perform a 2D dynamic analysis to properly define the dynamic response characteristics. This paper develops the modified one-dimensional seismic site response analysis. The modified site response analysis adjusts the density of the layers to simulate the change in mass and weight of the layers of the slope with depth. Multiple analyses are performed at various locations within the slope to estimate the change in seismic response of the slope. The calculated peak acceleration profiles with depth from the developed procedure are compared to those by the two-dimensional analyses. Comparisons show that the two methods result in remarkable match.

• Journal of Korean Neurosurgical Society
• /
• v.29 no.11
• /
• pp.1505-1513
• /
• 2000

Objectives : Many surgical procedures have been introduced to a symptomatic lumbar stenosis. Most of these procedures still have been regarded as an extensive surgical intervention with respect to normal aging process of the lumbar spine. We adopted a microsurgical decompression procedure via unilateral exposure as a minimally invasive intervention for symptomatic lumbar stenosis without instability. Materials and Methods : Fifty-seven patients with symptomatic lumbar stenosis underwent microsurgical decompression via unilateral laminotomy between March 1998 and December 1999. The conceptual modification and technical refinements were added to the previously reported microsurgical decompression procedure. Bilateral decompression through a unilateral laminotomy hole was performed in 11 patients. These patients profile also included 9 cases of degenerative spondylolisthesis(Grade I) without instability. Results : Preoperative neurogenic intermittent claudication(NIC) was more notably improved than low back pain, 60% to 82% during the follow-up period. Overall clinical results were excellent in 20(35%), good in 29(51%), fair in 6(11%) and poor in 2(3%). Conclusions : Microsurgical decompression for lumbar stenosis with stable spine provided a satisfactory symptomatic improvement without extensive destruction of the weight-bearing structures and functional mobile segments, even bilateral symptoms existed.

• Nuclear Engineering and Technology
• /
• v.52 no.5
• /
• pp.1013-1021
• /
• 2020

A combination of simultaneous thermal analysis, evolved gas analysis and non-ambient XRD techniques was used to characterise and investigate the conversion reactions of ammonium uranates into uranium oxides. Two solid phases of the ternary system NH₃ - UO₃ - H₂O were synthesised under specified conditions. Microspheres prepared by the sol-gel method via internal gelation were identified as 3UO₃·2NH₃·4H₂O, whereas the product of a typical ammonium diuranate precipitation reaction was associated to the composition 3UO₃·NH₃·5H₂O. The thermal decomposition profile of both compounds in air feature distinct reaction steps towards the conversion to U₃O₈, owing to the successive release of water and ammonia molecules. Both compounds are converted into α-U₃O₈ above 550 ℃, but the crystallographic transition occurs differently. In compound 3UO₃·NH₃·5H₂O (ADU) the transformation occurs via the crystalline β-UO₃ phase, whereas in compound 3UO₃·2NH₃·4H₂O (microspheres) an amorphous UO₃ intermediate was observed. The new insights obtained on these uranate systems improve the information base for designing and synthesising minor actinide-containing target materials in future applications.