• Journal of ILASS-Korea
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• v.19 no.1
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• pp.9-14
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• 2014

Performance of DI diesel engine with high-pressure fuel injection equipment is directly related to its emission characteristics and fuel consumption. So, the electro-hydraulic injector for the common-rail injection system should be designed to meet the precise high fuel delivery control capability. Currently, most high pressure injector in use has a needle driven by the solenoid coil energy or the piezo actuator controlled by charge-discharge of output pulse current. In this study, macroscopic spray approaching method was applied under constant volume chamber to research the performance of three different injectors : solenoid, indirect-acting piezo and direct-acting piezo type for CR direct-injection. LED back illumination for Mie scattering was applied on the liquid spray visible of direct-acting piezo injector, including hydraulic-servo type solenoid and piezo-driven injectors. As main results, we found that a direct-acting piezo injector had better a spray tip penetration than hydraulic-servo injectors in spray visualization.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.2
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• pp.170-173
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• 2001

The objective of this study was to investigate the effect of selenium (Se) on in vitro development of bovine embryos. In CR1BSA, FBS-free medium, the bovine embryos could not proceed past the developmental block more efficiently to morula stage than in chemically undefined media. Addition of glutathione precursor, cysteine, with $\beta$-mercaptoethanol did not improve the development in chemically defined medium and neither did glutathione alone. Exogenous selenium improved the embryonic development to the morula and blastocyst stages at 6 days post-insemination (dpi) significantly (67.1% vs 57.5%, p<0.05), and blastocyst stage at 8 dpi (30.1% vs 20.5%, p>0.05). These improvements might be induced by elevated glutathione peroxidase activity due to addition of Se, and a possible mechanism of selenium to elevate the activity of glutathione peroxidase is discussed.

• Journal of Korean Society for Geospatial Information Science
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• v.15 no.2 s.40
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• pp.15-23
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• 2007

This paper presents a shoreline change analysis on a reclaimed land, using a pair of aerial photographs taken before and after the reclamation. Shorelines that are defined by a tide datum, i.e. Approximately Highest High Water Level, were mapped by both analytical and digital photogrammetric methods. The past shorelines were overlapped with digital cadastral map from which areas of retracted and protruded lands were computed. Magnitude of shoreline changes was estimated by calculating areas between the past and present shorelines. Comparisons in terms of areas showed a fairly good agreement between the two methods. However, particularly in the estuary of complex morphology, shoreline mapping by digital photogrammetric method requires images to be scanned at a resolution higher than 1200 dpi.

• Parasites, Hosts and Diseases
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• v.37 no.4
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• pp.289-292
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• 1999

BALB/c mice infected with a high virulent strain of Trypanosoma brucei gambiense IL3707 were treated intraperitoneally (ip) with either Melarsoprol （Mel-B) or PSG(+) buffer as controls. The mice were subsequently monitored regularly for parasites by direct microscopic examination of their tail blood or buffy coat and by polymerase chain reaction (PCR). Mel-B was found to be an effective drug for treatment against T.b. gambiense because at the end of the first treatment schedule, all treated mice were negative for parasites even by PCR, while all the control animals were positive. Three of the five Mel-B treated mice, while parasitologically negative, were PCR positive between 53 and 80 days post infection (DPI), indicating that they still harbored an infection. All treated mice were subsequently negative for parasites even by PCR at 88 DPI. A combination of conventional microscopic examination and PCR offers a good prediction of cure following treatment of trypanosomosis.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.8
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• pp.3804-3819
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• 2018

The increasing popularity of HTTP adaptive video streaming services has dramatically increased bandwidth requirements on operator networks, which attempt to shape their traffic through Deep Packet inspection (DPI). However, Google and certain content providers have started to encrypt their video services. As a result, operators often encounter difficulties in shaping their encrypted video traffic via DPI. This highlights the need for new traffic classification methods for encrypted HTTP adaptive video streaming to enable smart traffic shaping. These new methods will have to effectively estimate the quality representation layer and playout buffer. We present a new machine learning method and show for the first time that video quality representation classification for (YouTube) encrypted HTTP adaptive streaming is possible. The crawler codes and the datasets are provided in [43,44,51]. An extensive empirical evaluation shows that our method is able to independently classify every video segment into one of the quality representation layers with 97% accuracy if the browser is Safari with a Flash Player and 77% accuracy if the browser is Chrome, Explorer, Firefox or Safari with an HTML5 player.

• Journal of ILASS-Korea
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• v.21 no.3
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• pp.121-129
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• 2016

The advantages of the common rail fuel injection system architecture have been recognized since the development of the diesel engine. In common rail systems, a high-pressure pump stores a reservoir of fuel at high pressure up to and above 2000 bar. And solenoid or piezoelectric valves make possible fine electronic control over the fuel injection time and quantity, and the higher pressure that the common rail technology makes available provides better fuel atomization. In this study, the direct needle-driven piezo injector was investigated for accomplishing injection pressure of 1800 bar by optimal design by simplification of component and changing number of springs and plates of DPI. It was found that a direct needle-driven piezo injection system features the prototype DPI for passenger vehicle to operate at 1800 bar of injection pressure.

• Spatial Information Research
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• v.7 no.2
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• pp.283-303
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• 1999

Airphotos taken for the management of unauthorized houses in large cities like Seoul are very important material for understanding periodic change of topogrpahy. A research on construction of digital database using airphoto are required for the efficient management of existing airphotos, for the easy and better understanding of topography together with 1; 1,000 digital topographic map, and for the easy updating of topographic data. Digital data using 1 ; 5, 000 scale airphoto scanned 1,000 dpi has been experimentally constructed from georeferenced images to orthorectified images. The technical and economical possibilities for the construction of digital database using apripjoto have been checked based on the experimentation and future direction of how to make digital database using existing airphoto has been suggested.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.10
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• pp.1131-1146
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• 1992

In this paper, we suggest a new algorithm applied to the segmentation of published documents to obtain constituent and layout information of document. Firstly, we begin the process of blocking and labeling on a 300dpi scanned document. Secondly, we classify the blocked document by individual sub-regions. Thirdly, we group sub-regions into graphic areas and text areas. Finally, we extract information for layout recognition by using the data. From an experiment on papers of an academic society, we obtain the above 98% of region classification rate and extraction rate of information for the layout recognition.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.137.1-137
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• 2003

A pepper strain of Cucumber mosaic virus (Pf-CMV) induces a mild chlorotic spot symptom in zucchini squash at 9 days post-inoculation (dpi), wile Fny strain of CMV causes severe mosaic and stunting symptom at 4 dpi in this host. Pseudorecombinants were constructed between the two strains, and assessments of symptom severity were indicated that both RNA2 and RNA3 were responsible for both mildness and the slow appearance of symptom elicited by Pf-CMV in zucchini squash. With various RNA2 and RNA3 chimeras between two strains of CMV, the genetic symptom determinants of phenotype of Pf-CMV were mapped to Tyr residue at positions amino acid 267 in 2a protein and at positions amino acid 168 in 3a movement protein (MP). Chimeras changed the sequences (both changed Tyr to lie) in the codons of both amino acid 168 of 3a MP and amino acid 267 of 2a protein were resulted in the high RNA accumulation, severity of symptom, and the rapid systemic spread, suggesting that 2a replicase as well as MP is involved in virus movement. The RNA accumulation pattern of all pseudorecombinants and chimeras are identical in protoplast of zucchini squash, indicating the virus movement is responsible for the phenotypes of two CMV strains rather than virus replication.

• Research in Plant Disease
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• v.29 no.1
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• pp.82-87
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• 2023

Exogenous ferrous chloride (FeCl₂) suppressed in vitro growth of Ralstonia pseudosolanacearum, causing bacteria for tomato bacterial wilt. More than 50 μM of FeCl₂ reduced the in vitro bacterial growth in dosedependent manners. Two to 200 μM of FeCl₂ did not affect the fresh weight of detached tomato leaves at 3 and 5 days after the petiole dipping without the bacterial inoculation. The bacterial wilt of the detached tomato leaves was evaluated by inoculating two different inoculum densities of R. pseudosolanacearum (10⁵ and 10⁷ cfu/ml) in the presence of FeCl₂. Bacterial wilt in the detached leaves by 10⁵ cfu/ml was efficiently attenuated by 10-200 μM of FeCl₂ at 3 and 5 days post-inoculation (dpi), but bacterial wilt by 10⁷ cfu/ml was only reduced by 200 μM of FeCl₂ at 3 and 5 dpi. These results suggest that iron nutrients can be included in the integrated disease management of tomato bacterial wilt.