• International Journal of Highway Engineering
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• v.19 no.6
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• pp.175-182
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• 2017

PURPOSES : Road sectors contribute approximately 16 % of total GHG emission rates in South Korea. Engineers and experts expend significant efforts to identify countermeasures for the reduction of carbon emission. This study aims to determine how total carbon emission rates change depending on whether or not there is speed limit enforcement. METHODS : In this study, Lamm's travel speed profile theory is first adopted to select the hazard road, which sections are designated as speed limit enforcement. Second, Motor Vehicle Emission Simulator (MOVES) was used to simulate the carbon emission on the road. RESULTS : The total carbon emission rate under speed limit enforcement was 10,773 g higher than the condition without speed limit enforcement in the designated road. This might affect acceleration, which can lead to increased emissions. CONCLUSIONS : There would be no researches about proving the relationship how speed limit enforcement has an effect on carbon emission. The result of our study can provide valuable guidelines regarding road safety and eco-friendly roads.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.3
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• pp.39-45
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• 2014

Dust is mostly caused by human activity. The effect of natural factors on dust emission were studied in many research, but the little effort in researching artificial factors of dust emission. The object of study is to analysis dust emission characteristic by drop impact. Particle matter $10{\mu}m$ ($PM_{10}$) was measured by drop impact on paved soil with changing drop height, weight and drop size. Increasing drop height cause more $PM_{10}$ emission. Increasing drop weight cause more $PM_{10}$ emission but had limit weight for increasing dust emission. Because the exceed kinetic energy of drop weight penetrate the soil surface. The limit perimeter was exist that separating $PM_{10}$ emission aspect. Under limit perimeter, $PM_{10}$ emission was increasing while perimeter was increasing, but over limit perimeter showed the opposite aspect. Regression equations for estimating $PM_{10}$ with kinetic energy and perimeter were made under limit perimeter and over limit perimeter. The $R^2$ of those equations were 0.784, 0.743. The error has occurred between measured $PM_{10}$ and calculated $PM_{10}$ in the equation under limit perimeter. But using equation of case for over limit perimeter, PM10 can be estimated with kinetic energy and drop perimeter.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.1
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• pp.33-39
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• 2010

In order to operate the power system satisfactory for both system operators and customers, it is important to limit the harmonic currents to the allowable levels which injected into the system from the distorting installations. In this regard, the principles for the allocation of emission limits on individual customer were introduced in the technical report of IEC61000-3-6. According to these general principles, the emission limits are dependent on the agreed power of the customer, the power of the harmonic-generating equipment, and the system characteristics. The considerations in this report are very comprehensive and the process introduced is practical enough to implement as it is. However, there is a fact not appropriately dealing in the report that could be a very tickle but has a huge impact on determining the emission limit. This is the effect of non-harmonic load currents. More precisely, these are from the equipments which do not emit any harmonic or may emit harmonics but this specific order under the consideration by themselves if the source power is sinusoidal. The load currents originated from these equipments have an effect of active filter against the specific order of harmonic therefore, these should be dealt as a significant factoron the process of determining the emission limits for individual customer.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6602-6609
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• 2013

This study is expected to provide background data for establishing mitigation measures for malodor and for comparing complex odor criteria. The impact of malodor at the afflicted locations was analyzed using Industrial Source Complex Short Term 3 (ISCST3) model, which was recommended by the EPA. The Odor Emission Rates (ODR) for piglets and hogs were predicted based on the average, minimum, and maximum emission rates as classification. The forecasting result of the complex odor modelling of pigsty showed that tolerance limit was exceeded at an adjacent administration building, but tolerance limit was not surpassed at an afflicted location which was within 185m from the pigsty. The ISCST3 modelling of the satisfactory ODR for tolerance limit was accomplished at the administration building. From the prediction of this modelling, maximum emission rates based on 1hr at administration building were 10.59~52.93, 19.05~31.76, and 10.59 $OU/m^3/s/m^2$ at emission rates of 50%, 30%, and 10%. This emission rate was slightly higher than the tolerance limit of 10.00 $OU/m^3/s/m^2$. However, it was inferred that the tolerance limit could be satisfied if the emission rate of 10% was controlled.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.5
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• pp.23-29
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• 2001

This paper is the second of companion papers, which investigate port-masking effects on emission and fuel economy. Port-masking was applied to commercial SOHC 3-valve engine by inserting masking plates between manifold and port. To induce various conditions of stratification, six types of masking plates were applied. In this paper, main interest is focused on the influence of injection timing on emission and fuel economy. Various injection timing was applied to the six cases, under the stoichiometric and lean-limit air-fuel ratio. Under the stoichiometric condition, an explanation about the reason of the change in emission level due to injection timing change is given. It is observed that NOx emission under the LML condition varies significantly when the injection timing changes.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.97-97
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• 2012

Hinode/XRT has observed coronal mass ejections (CMEs) since it launched on Sep. 2006. Observing programs of Hinode/XRT, called 'CME watch', perform several binned observations to obtain large FOV observations with long exposure time that allows the detection of faint CME plasmas in high temperatures. Using those observations, we determine the upper limit to the mass of hot CME plasma using emission measure by assuming the observed plasma structure. In some events, an associated prominence eruption and CME plasma were observed in EUV observations as absorption or emission features. The absorption feature provides the lower limit to the cold mass while the emission feature provides the upper limit to the mass of observed CME plasma in X-ray and EUV passbands. In addition, some events were observed by coronagraph observations (SOHO/LASCO, STEREO/COR1) that allow the determination of total CME mass. However, some events were not observed by the coronagraphs possibly because of low density of the CME plasma. We present the mass constraints of CME plasma and associated prominence as determined by emission and absorption in EUV and X-ray passbands, then compare this mass to the total CME mass as derived from coronagraphs.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1134-1139
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• 2004

Recently, development of flame control scheme has been hot issues in the combustion engineering. It has been held that flame shape can be controllable by pressure inside combustor. The influence of combustor atmospheric pressure on flame shape was investigated in the present study. The flame shape, flammable limit, flame temperature and nitric oxide emission were measured as functions of combustor atmospheric pressure and equivalence ratio. The reaction region became longer and wider with decreasing combustor atmospheric pressure by direct photography, hence reduction of blow off limit. This tendency was also observed in the mean flame temperature distribution. Nitric oxide emission decreased with decreasing combustor atmospheric pressure. Low NOx combustion is ascribed to wide-spread reaction region in the low atmospheric pressure condition. These results demonstrate that flame shape and nitric oxide emission can be controllable with combustor atmospheric pressure.

• Journal of Korean Society for Quality Management
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• v.46 no.3
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• pp.739-752
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• 2018

Purpose: The purpose of this study was to investigate the relationship between kiln processing parameters and NOx emissions that occur in the sintering and calcination steps of the cement manufacturing process and to derive the main factors responsible for producing emissions outside emission limit criteria, as determined by category models and classification rules, using data mining techniques. The results from this study are expected to be useful as guidelines for NOx emission control standards. Methods: Data were collected from Precalciner Kiln No.3 used in one of the domestic cement plants in Korea. Thirty-four independent variables affecting NOx generation and dependent variables that exceeded or were below the NOx emiision limit (>1 and <0, respectively) were examined during kiln processing. These data were used to construct a detection model of NOx emission, in which emissions exceeded or were below the set limits. The model was validated using SPSS MODELER 18.0, artificial neural network, decision treee (C5.0), and logistic regression analysis data mining techniques. Results: The decision tree (C5.0) algorithm best represented NOx emission behavior and was used to identify 10 processing variables that resulted in NOx emissions outside limit criteria. Conclusion: The results of this study indicate that the decision tree (C5.0) can be applied for real-time monitoring and management of NOx emissions during the cement firing process to satisfy NOx emission control standards and to provide for a more eco-friendly cement product.

• Current Optics and Photonics
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• v.3 no.4
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• pp.292-297
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• 2019

We propose a ring resonator-based orbital angular momentum carrying vortex beam generator design with high vertical directional emission efficiency. By adopting a vertically asymmetric grating structure in the ring resonator, optimized for enhanced vertical emission, an emission efficiency in one direction reaches as high as 78%, exceeding the 50% theoretical limit of previously designed vertically symmetric grating-assisted ring resonator-based structures.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.1
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• pp.144-155
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• 2018

As the public interest in environmental issues increased, the "Act On The Integrated Control Of Pollutant-Discharging Facility" was enacted. Through the integrated environmental pollution prevention act in which 19 industries with large environmental impacts are sequentially applied, pollutants can be managed in a medium-integrated manner and integrated permission of the business unit is possible and BAT can be applied to enable a scientific and proactive environmental management system. In addition, if the facility with BAT works normally, the pollutant emission is offered with the range of lower limit to upper limit. This study analyzed the overview of Best Available Techniques-Associated Emission Levels (BAT-AEL), and its setting procedure and method, and then suggested the BAT-AEL of a waste incineration facility. In comparative analysis on Emission Limit Values (ELVs) of EU, this study tries to propose improvement matters and development directions if the relevant standard is revised.