• Journal of Gastric Cancer
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• 제5권1호
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• pp.52-56
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• 2005

Despite improvements in the surgical treatment of gastric adenocarcinomas, the recurrence rates remain high in patients with advanced-stage disease. Most of the recurrence occurs within 3 years of the surgical resection, and nearly $90\%$ of the patients with recurrence die within 2 years of the diagnosis of recurrence. A recent study analyzed recurrence patterns for patients who had undergone a potentially curative gastrectomy. For those patients, $33\%$ of the recurrences involved locoregional sites, $44\%$ the peritoneum, and $38\%$ distant sites. A 51-year-old female patient was diagnosed with stomach cancer and underwent a total gastrectomy with D2 lymph node dissection during Oct. 1999. The pathologic report indicated a T3N1M0 tumor. We performed immunochemotherapy for 2 years with regular follow up. A gastrofiberscopic examination done during sep. 2004, cancer recurrence was found at the Kim's tie site of the jejunual loop. We did an abdominal exploration and a segmental resection of cancer site with pathologically negative resection margins. After the operation, we started secondary chemotherapy with TS-1.

• Journal of the Korean Crystal Growth and Crystal Technology
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• 제10권1호
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• pp.17-22
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• 2000

A quaternary alloy film of $CoCr_{16.2}Pt_{10.8}Ta_4$was investigated for its magnetic properties and c-axis orientation with and without Ti underlayer. Additional elements such as Ta, Pt have been frequently introduced in CoCr alloy film for perpendicular recording as a means of improving magnetic performance. It has been reported that the addition of Pt and Ta in CoCr increase the coercivity and the magnetic isolation of columnar grains, respectively. However, CoCrPtTa perpendicular magnetic layer should be more increased its perpendicular magnetic anisotropy than at present for the application of ultrahigh recording density. The improvement of underlayers and substrate materials is one of the promised schemes to intensify the perpendicular magnetic anisotropy. In this study, the insertion of Ti underlayer shows the remarkable improvement of c-axis orientation compare with the direct deposition on the bare glass. The mechanism about this effect of Ti underlayer on CoCrPtTa is not to be clarified yet. Meanwhile, it is found that the magnetic domain of CoCrPtTa on 20 nm Ti underlayer has the continuous stripe pattern but the one of CoCrPtTa on 90 nm Ti underlayer shows the discrete mass type from the results of MFM investigation. This phenomenon is to be a distinct evidence that the improvement of perpendicular anisotropy by the adoption of Ti underlayer is originated from the reinforcement of the grain boundary segregation in CoCrPtTa alloy. Moreover, the transition of the M-H hysteresis pattern with the thickness of Ti underlayer indicates that the major contribution of Ti underlayer is not the magnetocrystalline anisotropy but the shape anisotropy due to the formation of uniform columnar grains by the nonmagnetic alloy segregation.

• Journal of the Korean Society of Propulsion Engineers
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• 제21권6호
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• pp.64-72
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• 2017

The longitudinal dynamic instability which can occur in the fueling process of a space launch vehicle is called pogo. It is caused by coupling between the fuselage and propulsion system and they would be formed as a closed-loop system. so that the amplitude of the response may increase or decrease. In this paper, a mathematical model which is applicable to the systematic pogo analysis of a general launch vehicle is developed for an example of space shuttle. The formulations are composed of the linearized second-order differential equation for the propulsion system, and of the pressure, weight displacement, and generalized displacement. Those are important parameters for pogo analysis, are derived through eigenvalue analysis. By the formulation suggested in this paper, it is expected that mathematical modeling method of the pogo system can be obtained and systematic pogo stability analysis for any launch vehicle will be enabled.

• Journal of the Korean Magnetics Society
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• 제8권3호
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• pp.156-160
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• 1998

Crystal structures and magneto-optical properties of $(Mn_{0.5-Z}Sb_{0.5+Z})_{100-y}Pt_y$ (0$(Mn_{0.5-Z}Sb_{0.5+Z})_{100-y}Ag_y$ (0$^{\circ}C$ are C1b-type with fcc and NiAs-type with hcp, respectively. The MnSbAg films have a texture which the c-axis orientation is perpendicular to the film plane by annealing at 300 $^{\circ}C$ for less than 3 hours. The perpendicular anisotropy constants of the $Mn_{47.4}Sb_{47.5}Ag_{5.1}$ film annealed at 300 $^{\circ}C$ for 3 hours are $K_1=6.6{\times}10^5 \; erg/cm^3\;and\;K_2=1.9{\times}10^5\; erg/cm^3$. The Kerr rotation angle of MnSbPt films increases but that of MnSbAg film decreases by decreasing incident wavelength within the range of 700$\leq$ λ$\leq$1000 nm. High polar Kerr angles of 1.7$^{\circ}$ (λ =700 nm) and 0.6$^{\circ}$ (λ =1000 nm), 0.2$^{\circ}$ (λ =700 nm) and 0.97$^{\circ}$ (λ =1000 nm) have been obtained from $Mn_{41.1}Sb_{44,9}Pt_{14.0}$ and $Mn_{47.4}Sb_{47.5}Ag_{5.1}$ alloy films, respectively.

• Journal of the Korean Magnetics Society
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• 제18권1호
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• pp.24-27
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• 2008

We have prepared $MnFe_2O_4$ nanoparticles with polyol method. The crystallographic and magnetic properties were measured by using X-ray diffraction(XRD), vibrating sample magnetometer(VSM) and $M\"{o}ssbauer$ spectroscopy. The high resolution transmission electron microscope(HRTEM) shows uniform nanoparticle-sizes with $6{\sim}8$ nm. The crystal structure is found to be single-phase cubic spinel with space group of Fd3m. The lattice constant of $MnFe_2O_4$ nanparticles is determined to be $8.418{\pm}0.001{\AA}$. $M\"{o}ssbauer$ spectrum of $MnFe_2O_4$ nanparticles at room temperature(RT) shows a superparamagnetic behavior. In VSM analysis, the diagnosis of the superparamagnetic behavior is also shown in hysteresis loop at RT. $M\"{o}ssbauer$ spectrum at 4.2K shows that the well developed two sextets are with different hyperfine field $H_{hfA}=498$(A-site) and $H_{hfB}=521$(B-site) kOe.

• Journal of the Society of Cosmetic Scientists of Korea
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• 제35권2호
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• pp.103-110
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• 2009

The objective of this study is to analyze the influences of fatty alcohols and fatty acids on rheological properties of oil in water (O/W) emulsions using viscosity and rheograms. As the chain length of fatty alcohols and fatty acids lengthened, the viscosity of emulsions was increased. The influence of fatty alcohols on viscosity enhancement was stronger than that of fatty acids. Both stearyl alcohol and cetearyl alcohol, which have carbon chain length similar to lipophilic portion of surfactant used in emulsion preparation, had showed the best increase in viscosity of O/W emulsions. O/W emulsions prepared with fatty alcohols and fatty acids were pseudo-plastic fluid and they showed shear thinning behaviour like as the common cosmetic emulsions. O/W emulsions prepared with cetyl alcohol, cetearyl alcohol and stearyl alcohol were thixotropic fluids and thixotropy increased with an increase in the concentration of fatty alcohols and fatty acids. Also O/W emulsions prepared with fatty alcohols were more thixotropic than those prepared with fatty acids. For the sake of viscosity increase related to O/W emulsions stability and spreadability enhancement related to payoff, it is thought that fatty alcohols are more useful than fatty acids in the O/W emulsions as the emulsion stabilizer.

• Journal of the Institute of Electronics Engineers of Korea SD
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• 제48권2호
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• pp.7-13
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• 2011

This paper presents a Time-to-Digital Converter which is a key block of an All-Digital Phase Locked Loop. In this work, a Vernier Delay Line is added in a conventional Gated Ring Oscillator, so it could get multi-phases and a high resolution. The Gated Ring Oscillator uses 7 unit delay cell, the Vernier Delay Line is used each delay cell. So proposed Time-to-Digital Converter uses total 21 phases. This Time-to-Digital Converter circuit is designed and laid out in $0.13{\mu}m$ 1P-6M CMOS technology. The proposed Time-to-Digital Converter achieves 26ps resolution, maximum input signal frequency is 100MHz and the digital output of proposed Time-to-Digital Converter are 8-bits. The proposed TDC detect 5ns phase difference between Start and Stop signal. A power consumption is 8.4~12.7mW depending on Enable signal width.

• Journal of the Institute of Electronics Engineers of Korea SC
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• 제49권4호
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• pp.17-22
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• 2012

Convolution filtering methods have been widely applied to various digital signal processing fields for image blurring, sharpening, edge detection, and noise reduction, etc. According to their application purpose, the filter mask size or shape and the mask value are selected in advance, and the designed filter is applied to input image for the convolution processing. In this paper, we proposed an image processing acceleration method for the convolution processing by using two-dimensional Look-up table (LUT) and overlap-region buffering technique. First, based on the fixed convolution mask value, the multiplication operation between 8 or 10 bit pixel values of the input image and the filter mask values is performed a priori, and the results memorized in LUT are referred during the convolution process. Second, based on symmetric structural characteristics of the convolution filters, inherent duplicated operation region is analysed, and the saved operation results in one step before in the predefined memory buffer is recalled and reused in current operation step. Through this buffering, unnecessary repeated filter operation on the same regions is minimized in sequential manner. As the proposed algorithms minimize the computational amount needed for the convolution operation, they work well under the operation environments utilizing embedded systems with limited computational resources or the environments of utilizing general personnel computers. A series of experiments under various situations verifies the effectiveness and usefulness of the proposed methods.

• Journal of the Institute of Electronics and Information Engineers
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• 제51권11호
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• pp.94-100
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• 2014

In this paper, a design of low power Current-Reuse Voltage Controlled Oscillator (VCO) which has wide tuning range about 1.95 GHz ~ 3.15 GHz is presented. Class-C type is applied to improve phase noise and 2-Step Auto Amplitude Calibration (AAC) is used for minimizing the imbalance of differential VCO output voltage which is main issue of Current-Reuse VCO. The mismatch of differential VCO output voltage is presented about 1.5mV ~ 4.5mV. This mismatch is within 0.6 % compared with VCO output voltage. Proposed Current-Reuse VCO is designed using CMOS $0.13{\mu}m$ process. Supply voltage is 1.2 V and current consumption is 2.6 mA at center frequency. The phase noise is -116.267 dBc/Hz at 2.3GHz VCO frequency at 1MHz offset. The layout size is $720{\times}580{\mu}m^2$.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• 제14권3호
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• pp.9-23
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• 2015

A lane change maneuver which has a high driver cognitive workload and skills sometimes leads to severe traffic accidents. In this study, the Advanced Lane Change Assist System (ALCAS) was developed to assist with the automatic lane changes in merging sections which is mainly based on an automatic control algorithm for detecting an available gap, determining the Optimal Lane Change Start Point (OLCSP) in various traffic conditions, and positioning the merging vehicle at the OLCSP safely by longitudinal automatic controlling. The analysis of lane change behavior and modeling of fundamental lane change feature were performed for determining the default parameters and the boundary conditions of the algorithm. The algorithm was composed of six steps with closed-loop. In order to confirm the algorithm performance, numerical scenario tests were performed in various surrounding vehicles conditions. Moreover, feasibility of the developed system was verified in microscopic traffic simulation(VISSIM 5.3 version). The results showed that merging vehicles using the system had a tendency to find the OLCSP readily and precisely, so improved merging performance was observed when the system was applied. The system is also effective even during increases in vehicle volume of the mainline.