• Journal of the Korean Chemical Society
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• v.50 no.2
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• pp.163-177
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• 2006

Alpha Nickel hydroxide samples have been synthesized by electrodeposition on platinum and nickel substrates at current densities of 1, 5, 6, 7 and 10 mAcm？2 at a controlled temperature of 30.00 oC from Ni(NO3)2 bath. Platinum substrate shows a tendency to incorporate less nitrate ions with increase in current density thus producing less hydroxy-deficient nickel hydroxide layers. On the whole the interlayer distance (d003) is found to be inversely proportional to the amount of nitrate ions incorporated in-between the lattice. For the first time we have observed a decrease in lattice spacing with increase in concentration of intercalant (anions) and the reason for lattice contraction is attributed to the columbic attractive forces exerted by the oppositely charged nitrate ion and positively charged slabs. The Infrared spectra of the samples with expanded interlayers show two types of OH vibrations corresponding to hydrogen bonded and non-hydrogen bonded OH groups whereas the contracted interlayers show only hydrogen-boded OH groups. Although the faradaic efficiency is found to increase with increase in applied current there is a local minimum at 6.0 mAcm？2 current density on both platinum and nickel substrates. In this manuscript, GC-MS data is provided which clearly demonstrates the electrodeposited nickel hydroxide sample to consist of huge amount of carbonate ions although the electrolyte solution in nickel nitrate.

• Nuclear Engineering and Technology
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• v.13 no.2
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• pp.85-96
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• 1981

A preliminary study of the isotope hydrology of the Han River Valley is presented. This investigation is part of a project whose overall aim is to relate the levels of heavy metal ions to the dynamics of the groundwater movement in order to establish (i) whether there is any evidence for the deterioration in groundwater quality associated with the release of industrial effluents and (ii) if so, to determine the migration path-ways. Evidence is adduced that the recharge mechanism is principally determined by the degree of urbanisation. In the metropolitan area of Seoul, river recharge dominates probably due to the combined effects of reduced infiltration and increased pumpage. In the inter-urban region, the major source of recharge is local precipitation. During the spring sampling period when the river levels were low. evidence was obtained for appreciable groundwater infiltration in the vicinity of the upstream transect. No significant correlations were observed between the levels of heavy metals in the groundwater, and the recharge mechanism, the distance from the river or the electrical conductivity of the samples.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.1
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• pp.97-104
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• 2015

This study is a part of the high pressure injection system development on the Turbo GDI engine in order to reduce smoke emission in case of using the low volatile(high DI) fuel which is used as normal gasoline fuel in the US market. Firstly, theoretical approach was done regarding gasoline fuel property, performance, definition of particle matters and its creation as well as problems of the high DI fuel. In this experimental study, 2L Turbo GDI engine was selected and optimized system parameter was inspected by changing fuel, fuel injection mode (single/multiple), fuel pressure, distance between injector tip and combustion chamber, start of injection, intake valve timing in engine dyno at all engine speed range with full load. In case of normal gasoline fuel, opacity was contained within 2% in all conditions. On the other hands, in case of low volatile fuel (high DI fuel), it was confirmed that the opacity was rapidly increased above 5,000 rpm at 14.5 ~ 20 MPa of fuel pressure and there were almost no differences on the opacity(smoke) between 17 MPa and 20 MPa fuel pressure. According to the SOI retard, smoke decrease tendency was observed but intake valve close timing change has almost no impact on the smoke level in this area. Consequently, smoke decrease was observed and 16% at 6000rpm respectively with injector washer ring installed. By removing injector washer to make injector tip closer to the combustion chamber, smoke decrease was observed by 46% at 5,500 rpm, 42% at 6,000 rpm. It is assumed that the fuel injection interaction with cylinder head, piston head, intake and exhaust valve is reduced so that impingement is reduced in local area.

• Journal of Broadcast Engineering
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• v.17 no.1
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• pp.165-178
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• 2012

In most conventional video codecs, such as MPEG-2 and MPEG-4, inter coding is performed with the fixed motion vector resolution. When KTA software was developed, resolution for MVs can be selected in each slice. Although KTA codec uses a variety of resolutions for ME, the selected resolution is applied over the entire pixels in the slice and the statistical property of the local area is not considered. In this paper, we propose an adaptive decision scheme for motion vector resolution which depends on region, where MV search area is divided to multiple regions according to the distance from PMV. In each region, the assigned resolution is used to estimate MV. Each region supports different resolution for ME from other regions. The efficiency of the proposed scheme is affected from threshold values to divide the search area and the entropy coding method to encode the estimated MV. Simulation results with HM3.0 which is the reference software of HEVC show that the proposed scheme provides bit rate gains of 0.9%, 0.6%, and 2.9% in Random Access, Low Delay with B picture, and Low Delay with P picture structures, respectively.

• Archives of Plastic Surgery
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• v.38 no.4
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• pp.477-484
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• 2011

Purpose: Retro-orbicularis oculi fat (ROOF) and preseptal fat pad (PSF) are deep fat structures of frontal and supraorbital area, that encounter galeal fat pad (GFP). If galeal wall is weakened by aging process, GFP loses its anchoring structure, moved downward pushing ROOF and PSF. This especially occur in lateral brow area. As a result of drooping, eyebrow affects the eyelid covering PSF as a sac descended to a lateral hooding and ptotic eyelid simultaneously. Consequently, in the case of lateral hooding and brow ptosis, besides the skin, deep fat structures (ROOF and PSF) should be corrected as well. Methods: ROOF-PSF repositioning technique in subbrow resection were performed. 21 cases of patients from April, 2007 to January, 2008. Before surgery, all patients were examined carefully to evaluate the degrees of dermatochalasia, drooping of the eyebrow, marginal reflex distance 1 (MRD1), eyelid crease height. Surgery was performed under local anesthesia, then excised the drooped eyelid skin by lateral subbrow resection, removed proper amount of ROOF, repositioned ROOF-PSF at the supraorbital rim, and fix it on periosteum. During follow up periods, the patients were surveyed of the satisfaction of surgery, and postoperative MRD1 was evaluated. Results: One patient had a hematoma on left eyebrow, and another one patient had a numbness on left forehead for two months. Except for these two patients, all patients had good results without any significant complications. The mean follow up period was about 5 months, and the position of lateral eyebrow maintained above the supraorbital rim in all cases. Postoperatively, MRD1 increased by 0.8 mm in 5-months mean follow up period. Conclusion: In patient with lateral brow ptosis and lateral hooding, the ROOF-PSF repositioning technique in sub-brow resection could be a good operative option.

• Journal of Korean Society on Water Environment
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• v.22 no.3
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• pp.431-436
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• 2006

This study was conducted in the summer of 2005 in Shindong-myeon, Chuncheon-si, Gangwon-do to assess the quality of drinking water and to evaluate their potential pollutants. Ninety four water samples were collected from three classes of water supplies such as simple piped water, supplied own water and others (Supplied local water). Most residents used simple piped water (72.63%). 31.25% residents thought the water quality was bad and landfill was the main source of pollution that affected water quality. To correspond this perception, water quality was measured according to Drinking Water Quality Standard. The general bacteria, coliforms, and $NO_3-N$ exceeded the standard but the water qualities in these four areas were suitable for Drinking Water Quality Standard. The simple piped water showed low mean concentration of excess rate compared to supplied own piped water except general bacteria. Hardness, pH, and $NO_3-N$ showed significantly higher effects on drinking water quality. To evaluate the effect of effluent from landfill, water quality was measured according to distance and altitude. However, there was no effect of landfill effluent. To find out the effect of rainfall, we compared water quality of the year 2003 with that of 2005. The result showed significant differences in hardness and $NO_3-N$ concentration. This study confirmed that $NO_3-N$, coliforms, and general bacteria are main pollutant of water supply in rural community. Therefore, it is necessary to regularly maintain simple piped water supply, supplement sewer facilities, and educate residents about public health risk associated with drinking water in rural area.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.3
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• pp.175-186
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• 2017

In this study was to survey method of national/public land actual condition survey to utilization of UAV, in order to evaluate the economic and accuracy. we carried out the comparative evaluation of the cadastral status surveying in terms of accuracy of parcel checkpoint, economical costs. The results are summarized as follows. First, average position error of the orthoimage was 0.033m in X error, 0.023m in Y error when the RMSE average calculated 0.046m from the intersection of plane distance connections. Secondly, it was appeared the accuracy of the orthophotograph is 0.076m at the maximum RMSE of the UAV orthoimage check point and 0.042m at the minimum RMSE compared with the VRS-GNSS survey results. Thirdly, when the allowable error specified in the implementing regulation of the current cadastral survey is applied, all of the checkpoint of 0.360m tolerance corresponding to the scale of 1/1,200 is satisfied. Finally, UAV utilization method in national/public land actual condition survey is 26,497,436(KRW) cheaper than cadastral survey method for In the economic evaluation of national/public land actual condition survey. Therefore, as a result of this study shows that the method of utilizing UAV in the national/public land actual condition survey satisfies legal standards in terms of accuracy and economical aspect is a way to further reduce the local government budget.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.6
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• pp.95-102
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• 2012

In this paper, we propose a method that can construct efficiently a P2P overlay multicast network composed of many heterogeneous peers in communication bandwidth, processing power and a storage size by selecting a peer in a distributed fashion using an ant-colony theory that is one of the computational intelligence methods. The proposed method considers not only the capacity of a peer but also the number of children peers supported by the peer and the hop distance between a multicast source and the peer when selecting a parent peer of a newly joining node. Thus, an P2P multicast overlay network is constructed efficiently in that the distances between a multicast source and peers are maintained small. In addition, the proposed method works in a distributed fashion in that peers use their local information to find a parent node. Thus, compared to a centralized method where a centralized server maintains and controls the overlay construction process, the proposed method scales well. Through simulations, we show that, by making a few high capacity peers support a lot of low capacity peers, the proposed method can maintain the size of overlay network small even there are a few thousands of peers in the network.

• The Journal of Engineering Geology
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• v.29 no.3
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• pp.265-277
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• 2019

Changes in the amount, intensity, frequency, and type of precipitation, in conjunction with global warming and climate change, critically impact groundwater recharge and associated groundwater level fluctuations. Monthly gravity levels by the Gravity Recovery and Climate Experiment (GRACE) are acquired to monitor total water storage changes at regional and global scales. However, there are inherent difficulties in quantitatively relating the GRACE observations to groundwater level data due to the difficulties in spatially representing groundwater levels. Here three local interpolation methods (kriging, inverse distance weighted, and natural neighbor) were implemented to estimate the areal distribution of groundwater recharge changes in South Korea during the 2002-2016 period. The interpolated monthly groundwater recharge changes are compared with the GRACE-derived groundwater storage changes. There is a weak decrease in the groundwater recharge changes over time in both the GRACE observations and groundwater measurements, with the rate of groundwater recharge change exhibiting mean and median values of -0.01 and -0.02 cm/month, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.604-609
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• 2019

A variety of complaints about road signs have occurred for various reasons, such as new road facilities, new road signs such as road name signs, and an increase in nearby important facilities. In addition, there are many road signs that are in violation of road sign regulations. The basic principles of road signs, the connectivity of guide names, the location suitability, and a consistent road sign guidance system have not implemented. To solve these problems, various errors were investigated on major road signs on eight national highways, including direction signs, distance signs, boundary signs, and route signs. In addition, we classified the errors on road signs by grade to give them maintenance priority. We also analyzed the error status of signs for each route and grade. Based on the data, the problems of the road signs were derived, and an improvement plan is discussed. Based on this research, more systematic installation and management of road signs through cooperation between the government and local governments could increase the efficiency of road signs, as well as provide safer and more convenient road sign guidance systems for road users.