• 대한전자공학회논문지
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• 제26권10호
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• pp.1545-1553
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• 1989

The ohmic contact behavior in HEMT structure was compared with that in MESFET one throughout the specific contact resistance and microstructural change in both structures. A Au-Ge-Ni based metallization scheme was used and the alloying temperature of the ohmic materials was changed from 330\ulcorner to 550\ulcorner. The alloying temperature to obtain the minimum specific contact resistance in HEMT structure was 60k higher than that in MESFET. The volume fraction of NiAs (Ge) in MESFET structure increases with alloying temperature and/or the alloying time, which makes the decrease of specific contact resistance at the initial stage of ohmic metallization. In contrast, the volume fraction of NiAs(Ge) in HEMT structure was not dependent upon the specific contact resistance, which implies that the ohmic contacts are dominantly formed by the Ge diffusion to 2-DEG(two dimensional electron gas) layer.

• The Korean Journal of Ceramics
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• 제5권3호
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• pp.270-277
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• 1999

The ballistic capability of an alumina-rich oxide armor ceramic against a shaped jet was characterized as a function of penetration depth in a layered target structure. The penetration resistance of the ceramic, based upon the determination of penetration velocity, was not equally realized throughout the depth of penetration. It was abnormally low at an early stage of penetration, followed by a sudden increase to reach ~16GPa thereafter. There was no apparent change in such a profile with respect to the lateral size of the specimen. Based upon 2-D flash x-ray radiography and 3-D Hull code simulation, the feasibility of forming a pressure-induced predamnaged zone in front of the jet tip was speculated to foster an increased penetration velocity in the initial stage penetration, resulting in the diminished penetration resistance. The disappearance of such a predamaged zone with penetration was interpreted to restore the resistance of the ceramic in the later penetration stage.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.886-892
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• 2007

This paper presents examples of trolley wire resistance influential on the movement of tensioning devices. Therefore, this study is on the examples of trolley wire resistance which keep tensioning devices from working properly to the expansion and contraction in accordance with temperature change of overhead trolley wire system such as messenger wire and contact wire. Trolley wire resistance interrupts the working of tensioning device and drops the capacity of trolley wire. Reduced trolley wire capacity lowers the performance of current collection and has a bad effect on electrical train operation. So it is desirable to reduce the factors increasing trolley wire resistance to the minimum from the designing and construction stage of overhead trolley wire system. This study will introduce this problem and suggest the solution.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.288-288
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• 2012

In this study, we investigated that the resistance switching characteristics of W-doped NbOx films with increasing W doping concentration. The W-doped NbOx based ReRAM devices with a TiN/W-doped NbOx/Pt/Ti/SiO2 were fabricated on Si substrates. The 50 nm thick W-doped NbOx films were deposited by reactive dc magnetron co-sputtering at $400^{\circ}C$ and oxygen partial pressure of 35%. Micro-structure of W-doped NbOx films and atomic concentration were investigated by XRD, TEM and XPS, respectively. The W-doped NbOx films showed set/reset resistance switching behavior at various W doping concentrations. The process voltage of set/reset is decreased and whereas the initial current level is increased with increasing W doping concentration in NbOx films. The change of resistance switching behavior depending on doping concentration was discussed in terms of concentration of metallic tungsten of oxygen of W-doped NbOx.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2005년도 추계 학술논문 발표대회
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• pp.33-38
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• 2005

It is applied in the high quality equipment construction by introduction of this high duality treating technology (ozone treating, activated carbon treating, high quality oxidation treating, UV treating etc.)waterproofing or corrosion proof method caused secondary economy damage of operation discontinuance and high quality treating equipment for applying existent waterproofing method that corrosion proof ability (ozone resistance performance, chemical resistance etc.) and abrasion resistance performance by comprehension insufficiency of user and designer. Therefor, In this study, we will analyze problem of waterproofing and corrosion material of existing construction application by high quality treating, and measure physical performance change by various condition. It is required to waterproofing and corrosion system and application of the field valuation.

• 반도체디스플레이기술학회지
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• 제6권2호
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• pp.25-28
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• 2007

Electroless Ni-P coating is widely used for chemical, electronic, and semiconductor equipment parts because of its corrosion resistance. The incorporation of chemically-inert PTFE particles into the Ni-P films improves properties such as, non-stick, anti-adhesive and better corrosion resistance. However, soft PTFE particles degrade the hardness, wear and abrasion resistance. In this study, effects of PTFE and W addition to the Ni-P-coatings were compared by the XRD, SEM, sheet resistance, contact angle, and microhardness measurements. The change in sheet resistance was negligible, but contact angle was doubled by the addition of PTFE and W. The microhardness was lower for Ni-P-PTFE, but higher for Ni-P-PTFE-W coatings, compared to that of Ni-P coatings.

• 대한임상전기생리학회지
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• 제2권1호
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• pp.101-109
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• 2004

We developed research strategies for measuring functional performance and proprioception. We determined whether resistance training improves functional performance in the older adult, whether resistance training improves proprioceptive sense, and whether improvement in functional performance and/or proprioception are a direct result of the resistance training or a result of movement independent of strength gains. The answer to these questions will enable those in the sport fitness industry and medical practioners to better advise the growing number of older adults about the benefits of specific types of exercise. The will also enable the medical practitioner to prescribe appropriate exercise to those with limitations in functional ability in attempts to restore independent living.

• The Plant Pathology Journal
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• 제26권4호
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• pp.421-423
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• 2010

New sources of barley (Hordeum vulgare L.) resistant to spot blotch, caused by Cochliobolus sativus, are needed to provide effective resistance because of the rapid change pathotype patterns of C. sativus in fields. The purposes of our study were to develop a method to screen barley for resistance to spot blotch disease and then use this methodology to screen barley genotypes for resistance to the major virulent pathotype Pt4 in barley populations in Syria. A transparent tape method, in which a conidial suspension of C. sativus was dropped onto transparent tape and placed, treated-side down, on the second leaf surface of barley plants. Disease symptoms of fungus were easily detected on the leaves covered by the transparent tape after 48h of inoculation. The transparent tape method was repeatable and the disease scores obtained were correlated (r = 0.91, P = 0.001) with those obtained by the seedling assay. This method may be beneficial in various plant pathology breeding programs.

• Clinical and Experimental Pediatrics
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• 제51권10호
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• pp.1031-1037
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• 2008

Macrolide antimicrobial agents including erythromycin, roxithromycin, clarithromycin, and azithromycin are commonly used in the treatment of respiratory tract infections in children. Newer macrolides that have structural modifications of older drug erythromycin show improved change in the spectrum of activity, dosing, and administration. However, recent studies reported that increasing use of macrolide antibiotics is the main force driving the development of macrolide resistance in streptococci. In particular, azithromycin use is more likely to select for macrolide resistance with Streptococcus pneumoniae than is clarithromycin use, a possible reflection of its much longer half life. Recently, erythromycin resistance rates of S. pneumoniae and Streptococcus pyogenes are rapidly increasing in Korea. Two main mechanisms of acquired macrolide resistance have been described, altered binding site on the bacterial ribosome encoded by the ermB gene and active macrolide efflux pump encoded by the mef gene. Relationship between the susceptibility of S. pneumoniae and the response to macrolides has been shown in studies of acute otitis media, but less clear in cases of pneumonia. This article reviews the spectrum of activity, pharmacokinetic properties, mechanisms of action and resistance, and clinical implication of resistance on the treatment of respiratory tract infections in children.

• 한국해안·해양공학회논문집
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• 제31권6호
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• pp.351-355
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• 2019

무공케이슨 방파제의 한계상태설계를 위한 하중저항계수를 제시하였다. 전국 항만의 16개 방파제에 대한 신뢰성해석을 수행하여 부분안전계수를 산출하였으며 이를 하중과 저항계수로 전환하였다. 개별적으로 구한 하중저항계수에 최적화기법을 적용하여 최종 하중저항계수를 보정하였다. 최종적으로 얻은 하중저항계수를 이용하여 방파제를 재설계한 후 목표수준을 만족하는지 검증하였다. 목표신뢰도수준의 변화에 따른 하중저항계수를 제시하여 한계상태설계가 용이하도록 하였다.