• Asian Journal of Atmospheric Environment
• /
• v.11 no.3
• /
• pp.153-164
• /
• 2017

Odor dispersion around a cubic building from rooftop odor emissions was investigated using computational fluid dynamics (CFD). The Shear Stress Transport (here after SST) $k-{\omega}$ model in FLUENT CFD code was used to simulate the flow and odor dispersion around a cubic building. The CFD simulations were performed for three different configurations of cubic buildings comprised of one building, two buildings or three buildings. Five test emission rates were assumed as 1000 OU/s, 2000 OU/s, 3000 OU/s, 4000 OU/s and 5000 OU/s, respectively. Experimental data from wind tunnels obtained by previous studies are used to validate the numerical result of an isolated cubic building. The simulated flow and concentration results of neutral stability condition were compared with the wind tunnel experiments. The profile of streamline velocity and concentration simulation results show a reasonable level of agreement with wind tunnel data. In case of a two-building configuration, the result of emission rate 1000 OU/s illustrates the same plume behavior as a one-building configuration. However, the plume tends to the cover rooftop surface and windward facet of a downstream building as the emission rate increases. In case of a three-building configuration, low emission rates (<4000 OU/s) form a similar plume zone to that of a two-building configuration. However, the addition of a third building, with an emission rate of 5000 OU/s, creates a much greater odorous plume zone on the surface of second building in comparison with a two-building configuration.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.19 no.4
• /
• pp.382-390
• /
• 2013

The efforts for improving 'Maritime Traffic Safety Assessment Scheme(MTSA scheme)' have continued to the present. At this point, it needs to establish sound MTSA scheme to proceed acceleration step through the comprehensive review and systematic approach. In this study, it aimed to design of Metaevaluation Model for the comprehensive analysis of MTSA scheme with applying theory of the Metaevaluation, that is the evaluation of evaluation. To put it concretely, This research draw a basic model by using Metaevaluation methods like as literature studies, expert reviews, surveys and etc. and proposed a available 'PIP'OU' Metaevaluation Model through verified validity and reliability. This PIP'OU Model is the first proposed Metaevaluation Model in maritime field and it is expected to be used as framework to draw up improvement measure with deriving problem for the MTSA scheme.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2007.05a
• /
• pp.84.1-84.1
• /
• 2007

• Journal of Navigation and Port Research
• /
• v.37 no.4
• /
• pp.383-390
• /
• 2013

After forming a institutional framework with specified in Maritime Safety Law(ex. Maritime Traffic Safety Law) on May 27th, 2009, The efforts for improving 'Maritime Traffic Safety Assessment Scheme(MTSA scheme)' have continued to the present. But there's no review with the comprehensive and systematic approach for proceeding acceleration step of MTSA scheme. At this point, this study analyzed current status and derived improvement measures using by 'PIP'OU model' which was designed for the comprehensive analysis in accordance with metaevaluation theory, like as question investigation and etc. Consequently, it mainly needs to improve 'Assessment Plan' domain and minimized the difference in views between concerned parties. This study is expected to be used to develop systematic maritime policy by proposing the order of priority in improvement matters.

• Journal of Environmental Science International
• /
• v.25 no.1
• /
• pp.155-161
• /
• 2016

In this study, field experiment, odor simulator, and dispersion modeling were used to evaluate the odor impact from J sewage sludge treatment facility. The height and flow rate of exhaust stack at this facility were 22.3 m and $100Nm^3/min$. The mean odor concentrations of the wet scrubber inlet and exhaust stack were $267{\pm}160$ and $93{\pm}44OU/m^3$, respectively. The odor removal efficiency of wet scrubber showed 65%. The odor simulator is used for the regulated standard calculation of the exhaust pipe(stack). Resulting odor emission rate(OER) by odor simulator was $2.4{\times}10^6(24,000OU/m^3)$. The forecasting result by Screen3 modeling showed that odor exhaust concentration up to $30,000OU/m^3$ was't exceeded maximum allowable emission level on site boundary($15OU/m^3$).

• The Korean Journal of Applied Statistics
• /
• v.31 no.6
• /
• pp.801-810
• /
• 2018

Diffusion is a random process used to model financial and physical phenomena. When we construct statistical models for repeatedly observed diffusion processes, the idea of random effects needs to be considered. In this research, we introduce random parameters for an Ornstein-Uhlenbeck diffusion model and geometric Brownian motion diffusion model. In order to apply the maximum likelihood estimation method, we tried to build likelihoods in closed-forms, by assuming appropriate distributions for random effects. We applied the random effect models to data consisting of Dow Jones Industrial Average indices recorded daily over 27 years from 1991 to 2017.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2007.05a
• /
• pp.83.2-83.2
• /
• 2007

• Knowledge Management Research
• /
• v.16 no.2
• /
• pp.227-248
• /
• 2015

SPI (Software Process Improvement) activities have been considered one of the crucial approaches to achieve high quality, productivity and timely delivery of software products and services. The basic premise of SPI model is that higher maturity levels lead to better performance. In this research, the relationships between SPI results and performance were empirically investigated with Korean software companies. CMM key process areas were categorized into two dimensions, "Process Implementation" and "Quantitative Management". The relationship between process implementation and performance was significant, but the relationship between quantitative management and performance was insignificant. The control variable, size of OU(Organizational Unit), did not have significant impact on the relationships between SPI activities and OU performance.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.31 no.1
• /
• pp.37-53
• /
• 2006

SPI (Software Process Improvement) activities have been considered one of the crucial approaches to achieve high quality, productivity and timely delivery of software products and services. The basic premise of SPI model is that higher maturity levels lead to better performance. In this research, the relationships between SPI results and performance were empirically investigated with Korean software companies. CMM key process areas were categorized into two dimensions, 'Process Implementation' and 'Quantitative Management'. The relationship between process implementation and performance was significant, but the relationship between quantitative management and performance was insignificant. The control variable, size of OU(Organizational Unit), did not have significant impact on the relation ships between SPI activities and OU performance.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2008.12a
• /
• pp.217.2-217.2
• /
• 2008