• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.4
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• pp.415-421
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• 2008

The purpose of this study is to provide a sensor based service model for traffic facilities in u-City through analysing the present condition of urban infrastructure, especially traffic facilities management. In order to achieve this purpose, we did a comparative analysis of internal and external situation of ITS(Intelligent Transport System) and classified service for traffic facilities to 3 categories, namely traffic flow management, traffic information offering, formation of road structure. Also, we examined technological trend of USN(Ubiquitous Sensor Network). Through this process, we present a sensor based service model of traffic facilities for building sustainable road environment.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.81.2-81.2
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• 2011

The gas diffusion layer (GDL) consists of two main parts, the GDL backing layer, called as a substrate and the micro porous layer (MPL) coated on the GDBL. In this process, carbon particles of MPL penetrates to the GDBL consequently forms MPL penetration part. In this study, the micro porous layer (MPL) penetration thickness is determined as a design parameter of the GDL which affect pore size distribution profile through the GDL inducing different mass transfer characteristics. The pore size distribution and water permeability characteristics of the GDL are investigated and the cell performance is evaluated under fully/low humidification conditions. Transient response and voltage instability are also studied. In addition, to determine the effects of MPL penetration on the degradation, the carbon corrosion stress test is conducted. The GDL that have deep MPL penetration thickness shows better performance in high current density region because of enhanced water management, however, loss of penetrated MPL parts is shown after aging and it induces worse water management characteristics.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2362-2364
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• 2009

We report Pt hexapod nanoparticles with $6.4\;{\sim}\;9.7$ nm in size by a polyol process in the presence of PVP as a stabilizer and additive as a kinetic controller. The structure and morphology of Pt nanostructures are confirmed by field-emission transmission electron microscopy. The morphological control over platinum nanoparticles is achieved by varying the amount of seeds in the polyol process, where platinum precursor is reduced by ethylene glycol to form Pt nanoparticle at $150\;{^{\circ}C}$. As volume ratio between precursor-solution and seed-solution is increased from 10 to 50, the shape of Pt nanostructures is evolved from small seeds to tripod and hexapod. In addition, the size-controlled platinum hexapod nanostructures are successfully obtained using seeding method.

• The Korean Journal of Pain
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• v.22 no.2
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• pp.181-185
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• 2009

Herpes zoster is a viral disease of the posterior root ganglion and sensory nerve fiber, which presents clinically with vesicular eruption of the skin, radicular pain and sensory changes in the distribution of the affected ganglion. However, involvement of the motor neurons can be seen as well. If classic cutaneous lesions are present, herpes zoster-related motor paresis is easily diagnosed. Otherwise, the diagnosis may be more difficult and suspicious, especially if weakness occurs as a symptom before cutaneous lesions appear, or abnormal findings on the MRI are consistent with the signs. There have been few reports of sciatica with motor loss preceding skin lesions. Here, we report a patient with herpes zoster-related motor paresis preceding skin lesions. In the preliminary diagnosis, the herpes zoster-related motor paresis was confused for some structural disorder.

• Bulletin of the Korean Chemical Society
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• v.24 no.1
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• pp.27-31
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• 2003

A Polythiophene-quinoline/glassy carbon (PTQ/GC) modified electrode was developed for the determination of trace mercury in industrial waste water, natural water, soil, and other media. The electrode was prepared by the cyclic voltammetric polymerization of thiophene and quinoline on glassy carbon (GC) electrode by the potential application from -0.6 V to +2.0 V (50 mV/sec) in a solution of 0.1 M thiophene, quinoline and tetrabutyl ammonium perchlorate (TBAP) in acetonitrile. Optimum thickness of the polymer membrane on the GC electrode was obtained with 20 repeated potential cyclings. The redox behavior of Cu(Ⅱ) and Hg(Ⅱ) were almost identical on this electrode. The addition of 4-(2-pyridylazo)resorcinol (PAR) to the solution containing Cu(Ⅱ) and Hg(Ⅱ) allowed the separation of the components due to the formation of the Cu(Ⅱ)-PAR complex reduced at -0.8V, which was different from the Hg(Ⅱ) reduced at -0.5 V on a saturated calomel electrode (SCE). The calibration graph of Hg(Ⅱ) shows good linear relationship with the correlation factor of 0.9995 and the concentration gradient of 0.33 ㎂/㎠/ppb down to 0.4 ppb Hg. The method developed was successfully applied to the determination of mercury in samples such as river, waste water, and sea water.

• Journal of Electrochemical Science and Technology
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• v.1 no.2
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• pp.75-80
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• 2010

We report Co-tetramethoxyphenylporphyrin on carbon particles (Co-TMPP/C) as a non-Pt catalyst for tri-iodide reduction in dye-sensitized solar cells (DSSCs). The presence of well-dispersed carbon and cobalt source in the catalyst surface is confirmed by transmission electron microscopy, scanning electron microscopy, and energy dispersive X-ray analysis. In the C 1s, Co 2p, and N 1s peaks measured by X-ray photoelectron spectroscopy, the C-N, Co-$N_4$, and N-C are assigned to the component at 285.7, 781.8, and 401 eV, respectively. Especially, the Co-TMPP/C shows improved current density, diffusion coefficient, and charge-transfer resistance in the ${I_3}^-/I^-$ redox reaction compared to conventional catalysts. Furthermore, in the DSSCs performance, the Co-TMPP/C shows increased short circuit current density, higher open circuit voltage, and improved cell efficieny in comparison with Pt/C.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.37.1-37.1
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• 2014

There exists strong evidence supporting the co-evolution of central supermassive black holes and their host galaxies; however it is still under debate how such a relation comes about and whether it is relevant for all or only a subset of galaxies. An important mechanism connecting AGN to their host galaxies is AGN feedback, potentially heating up or even expelling gas from galaxies. AGN feedback may hence be responsible for the eventual quenching of star formation and halting of galaxy growth. A rich multi-wavelength dataset ranging from the X-ray regime (Chandra), to far-IR (Herschel), and radio (WSRT) is available for the North Ecliptic Pole field, most notably surveyed by the AKARI infrared space telescope, covering a total area on the sky of 5.4 sq. degrees. We investigate the star-formation properties and possible signatures of radio feedback mechanisms in the host galaxies of 237 radio-AGN below redshift z=2 and at a radio 1.4 GHz flux density limit of 0.1 mJy. Using broadband SED modeling, the nuclear and host galaxy components of these sources are studied simultaneously as a function of their radio luminosity. Here we present results concerning the AGN content of the radio sources in this field, while offering evidence supporting a "maintenance" type of feedback from powerful radio-jets.

• Journal of Information Technology Applications and Management
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• v.20 no.3
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• pp.79-92
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• 2013

Word-of-mouths (WOMs) are now an important information source for purchase decision. Due to the advance in internet technology, people now can share online their consumption experience, both positive and negative, to others. The WOMs may diffuse to not only their friends but also enormous online users. When consumers dissatisfy the product or service, they may share the dissatisfactory experience to others as WOM, which may bring out discussions for the product or service. The discussions on the negative WOM may help to communicate the negative information to enormous others, which may damage the sale of the product or service. The diffusion and life cycle of negative WOM is an important issue for managers. However, few studies focus on it. Thus, the current study focuses on the discussion pattern and life cycle of negative WOMs by observing the 782 discussion articles in a large online community.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.813-818
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• 2007

Construction productivity is a key factor for efficiency evaluation of construction work process, project performance measurement, and basic data of work plan in construction industry. However, although construction productivity is important in construction industry, gathering methodology and analyzing methodology of productivity data are not well-organized therefore productivity data is not utilized in the construction industry The purpose of this study is to develop productivity prediction system using data mining technology based on activities and to suggest frameworks about productivity data collection, accumulation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.4
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• pp.134-141
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• 1999

Ths paper describes on the stability improvement of output voltage control on the power suwJy for railway. On the transient states such as input voltage sudden change, the inpJt and output voltage beccxre unstable by L-C resonance occurred due to constant output voltage control. In this paper, the new clamping circuit for system stability is proposed, and control method using band attenuated filter and feed-forward terms is introduced. The propoesd damping circuit is composed with sma1l size R-L. Also, the 3 level PWM method is adopted to decrease distortion of output voltage. The output voltage is controlledl with variation under 10% without oscillation at transient states and have total hanmnic distortion under 3%.der 3%.