• International Journal of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.63-68
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• 2022

Two wavelength reconfigurable optical nodes are designed. One for 20km or shorter link length, and the other for up to 60km link length. While the first one requires no dispersion compensation, the latter needs dispersion compensation fiber included in the node, which requires additional optical amplifier to compensate the insertion loss of DCF. We calculate all the optical path losses in both cases using the typical value of optical components in the market to see the feasibility of the designed optical node. The minimum received power in the node is calculated to be -21.5dBm without DCF and -12.5dBm with DCF, respectively. These received powers are above the receiver sensitivity both for OC-48 and OC-192 according to the previous work.

• Journal of Life Science
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• v.24 no.2
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• pp.118-127
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• 2014

The kinetic properties and isozyme expression of lactate dehydrogenase (EC 1.1.1.27; LDH) in tissues from Rana catesbeiana I and II collected from February (I) and August (II) were studied. LDH activities, A4 isozyme, and LDH/citrate synthase (EC 4.1.3.7; CS) were high in skeletal muscle from R. catesbeiana I, and LDH $B_4$ isozyme increased in several tissues of R. catesbeiana II. In particular, LDH activities were high in heart and brain tissues from R. catesbeiana II. LDH eye-specific C isozyme, detected by native polyacrylamide gel electrophoresis after immunoprecipitation, was expressed in eye tissue and was more similar to the $B_4$ than $A_4$ isozyme. LDH $A_4$ isozyme was purified by oxamate-linked affinity chromatography, and the molecular weight of subunit A was 32.0 kDa. In R. catesbeiana II, levels of $Km^{PYU}$, $Vmax^{LAC}$, and tolerance to lactate of LDH were high in all tissues, and $Vmax^{PYU}$ of LDH in heart and brain tissue was highly detected. Purified $A_4$ isozyme and LDH in eye tissue were highly tolerate compared to others. The $Km^{LAC}$ value was highly measured compared to $Km^{PYU}$. The degree of inhibition by 10 mM of pyruvate on LDH activities in tissues from R. catesbeiana I and II was more pronounced as the ratio of subunit B increased. As a result, characteristic expression of LDH eye-specific C was found in R. catesbeiana. Anaerobic metabolism seemed to predominate as the LDH of skeletal muscle from I showed higher activity. It also appeared that R. catesbeiana II adapted well to incremental increases in LDH B, becoming tolerant to the lactate of LDH in tissues.

• Korean journal of applied entomology
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• v.34 no.3
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• pp.181-190
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• 1995

Malate dehydrogenase in the mosquito ovary after a blood meal, Aedes aegypti, was purified and characterized. MDH purification steps involved DEAE-Sepharose, S-Sepharose and Cibacron blue affinity chromatography. The purified MDH was 70,000 daltons in molecular weight and was a homodimer consisting of tow identical subunits. Optimal activity of purified MDH was obtained pH 9.0-9.2 in malate-oxaloacetate reaction and pH 9.8-10.2, in oxaloactate-malate reaction. With obtained pH 9.0-92 in malate-oxaloacetate reaction and pH 9.8-10.2, in oxaloactate-malate reaction. With malate as substrate, purified mitochondrial MDH (1.28$\times$${10}^{-4}$ M) had lower Km value than cytoplasmic MDH (8.92x${10}^{-3}$ M). MDH activity was inhibited by citrate, $\alpha$-ketoglutarate, and ATP. Inhibition of MDH activity by ATP and citrate was less in malate-oxaloacetate reaction and in oxaloacetate-malate reaction. MDH activity was completely inhibited by ATP in oxaloacetate-malate reaction and not inhibited by citrate in malate-oxaloacetate reaction. Temporal activity change of MDH is similar to that of isocitrate dehydrogenase in the ovary after blood feeding; their activities in the ovary began to rise at 18 hours after a blood meal, and reached at the maximal level at 48 hours.

• Journal of Drive and Control
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• v.17 no.2
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• pp.19-27
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• 2020

The purpose of this study was to suggest design criteria for the HMT (hydro-mechanical transmission) of a 55 kW-class agricultural tractor, develop a simulation model, and evaluate its performance such as axle rotational speed, tractor speed, and power transmission efficiency. In this study, the HMT comprised a compound planetary gear and a HSU (hydro-static unit), and the compound planetary gear comprised two planetary gear sets. The HMT has three gear stages, and the maximum tractor speed was selected as 40 km/h. The simulation time was set at 2736 hours considering the lifetime of the tractor, and the simulation was performed for each gear stage at the engine-rated power conditions. As a result of the simulation, the axle rotational speeds for each gear stage were 39, 77, and 158 rpm, respectively. The range of tractor speed for each gear stage were 1.05-10.22 km/h, 10.74-20.17 km/h, and 20.70-41.40 km/h, respectively. The APE (absolute percentage gear) for the tractor's maximum speed between target value and simulation results were 2.20%, 0.85%, and 3.50%, respectively. Also, the power transmission efficiency for each gear stage were 0-75%, 72-81%, and 69-81%, respectively. The simulation results for the power transmission efficiency of the HMT were similar with the results of the previous research. This was a basic study on the development of the HMT for an agricultural tractor. In future studies, it is necessary to develop a tractor platform and evaluate the performance. The comparison between the simulation model and the HMT tractor should be performed.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.1
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• pp.155-163
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• 2010

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on-board the NASA's Terra spacecraft provides along-track digital stereo image data at 15m resolution with a base-height ratio 0.6. Automated stereocorrelation procedure was implemented using the ENVI 4.1 software to derive DEMs with $15m{\times}15m$ in 43km long and 50km wide area using the ASTER stereo images. The accuracy of DEMs was analyzed in comparison with those which were obtained from digital topographic maps of 1:25,000 scale. Results indicate that RMSE in elevation between ${\pm}7$ and ${\pm}20m$ could be achieved. Excluding cloud, water and building areas as the factors which make RMSE value exceeding 10m, the accuracy of DEMs showed RMSE of ${\pm}5.789m$. Therefore for the purpose of elevating accuracy of topographic information, we intended to detect the cloud areas and shadow areas by a landcover classification method, remove those areas on the ASTER DEM and then replace with those areas detached from the cartographic DEM by band math.

• International Journal of Highway Engineering
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• v.20 no.3
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• pp.85-92
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• 2018

PURPOSES : In this study, analyze the characteristics of IOC indicator 'threshold' which is needed when evaluating the traffic signal operation status with ESPRESSO in various grade road traffic environment of Seoul metropolitan city and derive suggested value to use in field practice. METHODS : Using the computerized database program (Postgresql), we extracted data with regional characteristics (Arterial, Collector road) and temporal characteristics (peak hour, non-peak hour). Analysis of variance and Duncan's validation were performed using statistical analysis program (SPSS) to confirm whether the extracted data contains statistical significance. RESULTS : The analysis period of the main and secondary arterial roads was confirmed to be suitable from 14 days to 60 days. For the arterial, it is suggested to use 20 km/h as the critical speed for PM peak hour and weekly non peak hour. It is suggested to use 25 km/h as the critical speed for AM peak hour and night non peak hour. As for the collector road, it is suggested to use 20 km/h as the critical speed for PM peak hour and weekly non peak hour. It is suggested to use 30 km/h as the critical speed for AM peak hour and night non peak hour. CONCLUSIONS : It is meaningful from a methodological point of view that it is possible to make a reasonable comparative analysis on the signal intersection pre-post analysis when the signal operation DB is renewed by breaking the existing traffic signal operation evaluation method.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.1
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• pp.60-65
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• 2017

We designed and fabricated the engine oil monitoring sensor to measure engine oil deterioration through increased vehicle mileage. Since the condition of the engine oil can be affected by the state of the vehicle and its operating conditions, it should be directly measured and determined in every vehicle. The fabricated sensor has an aluminum parallel capacitor structure that measures capacitance related with the dielectric constant, which is one of the indices of oil deterioration. The size of the capacitor is small enough that it could be easily adapted on the oil level gauge without introducing any change in the design. The fabricated device is installed in the diesel engine to measure the change in capacitance accurately as the vehicle moved from 0 km (new engine oil state) to 11,364 km. The results showed the maximum value at around 5,000 km, and the values plateaued as mileage increased, corresponding with the measurement result of the TAN (Total Acid Number). Based on the results, the condition of the oil must be monitored regularly though oil change is recommended once the vehicle has traveled the distance of around 10,000 km.

• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.3
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• pp.3840-3847
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• 1975

With 30 excisting reservoirs in the Chin-Young area, the Sedimentation of the reservoirs has been calculated by comparing the present capacity with the original value, which revealed its reduced reservoir capacity. The reservoirs has a total drainage area of 3l4l ha, with a total capacity of 43.23 ha-m, and are short of water supply due to reduction of reservoir capacity, Annual sedimentation in the reservoir is relation to the drainage area, the mean of annual rainfall, and the slop of drainage area. The results of obtained from the investigation are summarized as follows: (1) A Sediment deposition rate is high, being about 7.03㎥/ha of drainage area, and resulting in the overage decrease of reservoir capacity by 16.1%. This high rate of deposition coule be mainly attributed to the serve denudation of forests due to disorderly cuttings of tree. (2) An average unit storageof 116mm as the time of initial construction is decreased to 95.6mm at present. This phenomena cause a greater storage of irrigation water, sinceit was assumed that original storage quantity itself was already in short. (3) A sediment deposition rate as a relation to the capacity of unit drainge area is as follow: Qs=1.27(C/A)0.6 and standard deviation is 185.5㎥/$\textrm{km}^2$/year. (4) A sediment deposition rate as a relation to the mean of annual rainfall is as follow: Qs=21.9p10.5 and the standard deviation is 364.8㎥/$\textrm{km}^2$/year. (5) A sediment deposition rate as a relation to the mean slop of drainage area is follow: Qs=39.6S0.75 and the standard deviation is 190.2㎥/$\textrm{km}^2$/year (6) Asediment deposition rate as a relation to the drainage area, mean of rainfall, mean of slope of drainage area is: Log Qs=0.197+0.108LogA-6.72LogP+2.20LogS and the standard deviation is 92.4㎥/$\textrm{km}^2$/year

• The Korean Journal of Ecology
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• v.18 no.3
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• pp.307-321
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• 1995

Division of ecoregions having respective functions was attempted through quantitative and qualitative analysis on vegetation diversity, and heterogeneity and on soil environment of the study sites. Field research was carried out in a square of 81 ㎢ around Andongpo (126°38'E, 37°30'N), Kimpo-gun, Kyonggi provice. Conventional methods applied are as follows: classical syntaxonomy by the Zurich-Montpellier School, interpolation method to determine the degree of diversity, heterogeneity and distribution pattern of vegetation, and correlation analysis between soil properties and plant communities. 41 plant communities were identified and composed of 6 forests, 4 mantle and 31 herb communities including 6 saltmarsh plant communities. In a mesh, number of plant communities was highly correlated to the number of species. The highest number of plant community and species was 25 communities·km-2·mesh-1 and 381 species· km-2·mesh-1 ,and the highest value of vegetation heterogeneity was 28.1 species· community-1·mesh-1. Their lowest numbers were 4 communities·km-2·mesh-1. and 28 species·km-2·mesh-1. and 7 species·community-1·mesh-1, respectively. Contour map on vegetation diversity and heterogeneity enabled us to establish two regions; coastal and inland vegetation. Isoline 〔150〕,〔10〕and〔10〕and〔15〕on the species diversity, the community diversity and the vegetation heterogeneity, respectively, were regarded as ecolines in the study area. Cl- content was recognized as the most important factor from correlation analysis between soil properties. Ordination of sites indicated that the study area be divided into two edaphic types: inland and coastal habitats. It was considered that the extent of desalinization in soil played a major role in determining the species composition in the reclamed area. By matching edaphic division of habitats with division of vegetation structures, designation of ecoregion was endorsed. The approach of current study was suggested as an effective tool to implement an assessment of the vegetation dynamics by the disparity of natural environment and anthropogenic interferences.

• Journal of Environmental Science International
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• v.9 no.3
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• pp.253-259
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• 2000

The purpose of this study is to investigate the physicochemical characteristics of salinization of groundwater at the estern area of Cheju island. For this purpose, the major ions of groundwater, spring water are analyzed. The concentration of $Cl^-$ and Na^++K^+$/ contained in the groundwater at near the coastline are higher than those at inland area away from the coastline. The water quality components of groundwater observed at this area can be classified into 4 types such as Na-Cl, $HCO_3, Na-Cl-HCO_3$ and Ca-HCO$_3$. The concentration ratio of $SO_4^1 to Cl^- is 0.1354(R^2=0.972)$ at this area. This value is very similar with Dittomer's ratio of 0.13. For Na^+, K^+, and Mg^{2+}/ versus Cl^-$, their ratios also show a significant relationship between sea water and groundwater in this area. From the chloride-bicarbonate ratio, it can be estimated that the intrusion distance of seawater from coastline to inland area is 2.8km at Onpyung-Nansan, Sangdo and Pyungdae areas, and 5.4km at Kosung-Susan area. The mixing ratio between seawater and fresh water by the intrusion of seawater is decreased with the distance toward inland from coastline. This ratio(fresh water : seawater) is 80:20 in spring water adjacent the coastlines, Onpyung area and 99.8:0.2 in the well at No.3 of Susan located at inland away from the coastline. The concentration of $Na^+$ observed at field is 25~45% lower than that theoretically calculated by this mixing ratio. Based on the data of EC, the equipotential line of 500$\mu$mhos/cm is located at 4~5km poing at Kosung-Susan area and 2.5km point at the other area. The equation of correlation between $Cl^-$ concentration and EC values is $Cl^-$=0.1927EC-16.683 for the area lower than 500 $\mu$mhos/cm and $Cl^-$=0.2773EC for the area beyond 500 $\mu$mhos/cm.