• Interaction and multiscale mechanics
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• 제6권4호
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• pp.395-409
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• 2013

Molecular dynamics (MD) systems are highly nonlinear and nonlocal, and the conventional model order reduction methods are ineffective for MD systems. The RBF-POD method (Lee and Chen, 2013) employed a radial basis function (RBF) approximated potential energies and inter-atomic forces of MD systems under the framework of the proper orthogonal decomposition (POD) method for the reduced-order modeling of MD systems. In this work, we focus on the numerical procedures of the RBF-POD method and demonstrate how to apply this approach to the modeling of ds-DNA molecules under stretching and bending conditions.

• 반도체디스플레이기술학회지
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• 제19권1호
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• pp.1-5
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• 2020

In this paper, a predictive maintenance of the robot trouble using the machine learning method, so called MT(Mahalanobis Taguchi), was studied. Especially, 'MD(Mahalanobis Distance)' was used to compare the robot arm motion difference between before the maintenance(bearing change) and after the maintenance. 6-axies vibration sensor was used to detect the vibration sensing during the motion of the robot arm. The results of the comparison, MD value of the arm motions of the after the maintenance(bearing change) was much lower and stable compared to MD value of the arm motions of the before the maintenance. MD value well distinguished the fine difference of the arm vibration of the robot. The superior performance of the MT method applied to the prediction of the robot trouble was verified by this experiments.

• Environmental Engineering Research
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• 제24권2호
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• pp.347-353
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• 2019

Although membrane distillation (MD) has great promise for desalination of saline water sources, it is crucial to improve its thermal efficiency to reduce the operating cost. Accordingly, this study intended to examine the thermal energy efficiency of MD modules in a pilot scale system. Two different modules of hollow fiber membranes were compared in direct contact MD mode. One of them was made of polypropylene with the effective membrane area of $2.6m^2$ and the other was made of polyvinylidene fluoride with the effective membrane area of $7.6m^2$. The influence of operation parameters, including the temperatures of feed and distillate, feed flow rate, and distillate flow rate on the flux, recovery, and performance ratio (PR), was investigated. Results showed that the two MD membranes showed different flux and PR values even under similar conditions. Moreover, both flow rate and temperature difference between feed and distillate significantly affect the PR values. These results suggest that the operating conditions for MD should be determined by considering the module properties.

• 상하수도학회지
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• 제30권3호
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• pp.343-350
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• 2016

Membrane distillation (MD) is a novel separation process that have drawn attention as an affordable alternative to conventional desalination processes. However, membrane fouling and pore wetting are issues to be addressed prior to widespread application of MD. In this study, the influence of ultrasonic irradiation on fouling and wetting of MD membranes was investigated for better understanding of the MD process. Experiments were carried out using a direct contact membrane distillation apparatus Colloidal silica was used as a model foulants in a synthetic seawater (35,000 mg/L NaCl solution). A vibrator was directed attached to membrane module to generate ultrasonic waves from 25 kHz (the highest energy) to 75 kHz (the lowest energy). Flux and TDS for the distillate water were continuously monitored. Results suggested that ultrasonic irradiation is effective to retard flux decline due to fouling only in the early stage of the MD operation. Moreover, wetting occurred by a long-term application of ultrasonic rradiation at 75 kHz. These results suggest that the conditions for ultrasonic irradiation should be carefully optimized to maximize fouling control and minimize pore wetting.

• 한국콘텐츠학회논문지
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• 제6권11호
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• pp.225-234
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• 2006

본 논문에서는 콘텐츠 보호의 암호화를 위해 ECC, MD-5, AES를 통합한 보안 프로세서를 SIP (Semiconductor Intellectual Property)로 설계하였다. 각각의 SIP는 VHDL RTL로 모델링하였으며, 논리합성, 시뮬레이션, FPGA 검증을 통해 재사용이 가능하도록 구현하였다. 또한 ARM9과 SIP들이 서로 통신이 가능하도록 AMBA AHB의 스펙에 따라 버스동작모델을 설계, 검증하였다. 플렛폼기반의 통합 보안 SIP는 ECC, AES, MD-5가 내부 코어를 이루고 있으며 각각의 SIP들은 ARM9과 100만 게이트 FPGA가 내장된 디바이스를 사용하여 검증하였으며 최종적으로 매그나칩 $0.25{\mu}m(4.7mm{\times}4.7mm$) CMOS 공정을 사용하여 MPW(Multi-Project Wafer) 칩으로 제작하였다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제18권1호
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• pp.66-70
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• 2015

Meckel diverticulum (MD) is one of the most common congenital gastrointestinal anomalies and occurs in 1.2-2% of the general population. MD usually presents with massive painless rectal bleeding, intestinal obstruction or inflammation in children and adults. Suppurative Meckel diverticulitis is uncommon in children. An experience is described of a 3-year-old girl with suppurative inflammation in a tip of MD. She complained of acute colicky abdominal pain, vomiting and periumbilical erythema. Laparoscopic surgery found a relatively long MD with necrotic and fluid-filled cystic end, which was attatched to abdominal wall caused by inflammation. Herein, we report an interesting and unusual case of a suppurative Meckel diverticulitis presenting as periumbilical cellulitis in a child. Because of its varied presentations, MD might always be considered as one of the differential diagonosis.

• Journal of Gastric Cancer
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• 제20권3호
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• pp.313-327
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• 2020

Purpose: Nodal downstaging after preoperative therapy for gastric cancer has been shown to impart excellent prognosis, but this has not been validated in a national cohort. The role of neoadjuvant chemoradiation (NACR) in nodal downstaging remains unclear when compared with that of neoadjuvant chemotherapy alone (NAC). Furthermore, it is unknown whether the prognostic implications of nodal downstaging differ by preoperative regimen. Materials and Methods: Using the National Cancer Database, overall survival (OS) duration was compared among natural N0 (cN0/ypN0), downstaged N0 (cN+/ypN0), and nodepositive (ypN+) gastric cancer patients treated with NACR or NAC. Factors associated with nodal downstaging were examined in a propensity score-matched cohort of cN+ patients, matched 1:1 by receipt of NACR or NAC. Results: Of 7,426 patients (natural N0 [n=1,858, 25.4%], downstaged N0 [n=1,813, 24.4%], node-positive [n=3,755, 50.4%]), 58.2% received NACR, and 41.9% received NAC. The median OS durations of downstaged N0 (5.1 years) and natural N0 (5.6 years) patients were similar to one another and longer than that of node-positive patients (2.1 years) (P<0.001). In the matched cohort of cN+ patients, more recent diagnosis (2010-2015 vs. 2004-2009) (odds ratio [OR], 2.57; P<0.001) and NACR (OR, 2.02; P<0.001) were independently associated with nodal downstaging. The 5-year OS rate of downstaged N0 patients was significantly lower after NACR (46.4%) than after NAC (57.7%) (P=0.003). Conclusions: Downstaged N0 patients have the same prognosis as natural N0 patients. Nodal downstaging occurred more frequently after NACR; however, the survival benefit of nodal downstaging after NACR may be less than that when such is achieved by NAC.

• JSTS:Journal of Semiconductor Technology and Science
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• 제2권3호
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• pp.197-204
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• 2002

DRAM, SRAM, and FLASH memory are three major memory devices currently used in most electronic applications. But, they have very distinct attributes, therefore, each memory could be used only for limited applications. MRAM (Magneto-resistive Random Access Memory) is a promising candidate for a universal memory that meets all application needs with non-volatile, fast operational speed, and low power consumption. The simplest architecture of MRAM cell is a series of MTJ (Magnetic Tunnel Junction) as a data storage part and MOS transistor as a data selection part. To be a commercially competitive memory device, scalability is an important factor as well. This paper is testing the actual electrical parameters and the scaling factors to limit MRAM technology in the semiconductor based memory device by an actual integration of MRAM core cell. Electrical tuning of MOS/MTJ, and control of resistance are important factors for data sensing, and control of magnetic switching for data writing.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.656-659
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• 2006

MD (DLP, LCoS) Projection TV is appropriate for large screen display with high definition at a relatively low price and thus, has been popular in the digital TV market. In order to realize high resolutions in the DLP projection TV, we successfully developed the Pixel Enhancement Actuator. Furthermore, it is also required that the contrast ratio of projected video signals onto a large screen should be improved. Therefore, we propose a contrast enhancer which adjusts the amount of projected lights by a dynamic aperture and a attached position sensor.

• 한국가금학회지
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• 제34권4호
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• pp.301-318
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• 2007

Marek's disease (MD) is a highly contagious lymphoproliferative disease of poultry caused by the oncogenic herpesvirus designated Marek's disease virus (MDV). MD has a worldwide distribution and is thought to cause an annual loss over US$ one billion to the poultry industry. Originally described as a paralytic disease, today MD is mostly manifested as an acute disease with tumors in multiple visceral organs. MD is controlled essentially by the widespread use of live vaccines administered either in ovo into 18-day-old embryos or into chicks immediately after they hatch. In spite of the success of the vaccines in reducing the losses from the disease in the last 30 years, MDV strains have shown continuous evolution in virulence acquiring the ability to overcome the immune responses induced by the vaccines. During this period, different generations of MD vaccines have been introduced to protect birds from the increasingly virulent MDV strains. However, the virus will be countered each new vaccine strategy with ever more virulent strains. In spite of this concern, currently field problem from MD is likely to be controled by strategy of using bivalent vaccine. But, potential risk factors for outbreak of MD are still remained in this condition. The major factors can be thought that improper handling and incorrect administration of the vaccine, infection prior to establishment of immunity, suppression of immune system by environmental stress and outbreaks of more virulent MDV strain by using vaccine and genetic resistance of host.