• Journal of Korean Society on Water Environment
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• v.33 no.1
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• pp.97-106
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• 2017

In this study, the characteristics of nonpoint source pollutant loads from separate sewer overflow (SSO) and combined sewer overflow (CSO) were evaluated during 2016 in Namyangju city, Korea. Five rainfall events were monitored during 2016 with ranging from 14.5 mm to 121.5 mm. The runoff ratio of CSO was higher than that of SSO because only design volume of maximum sanitary sewer ($1Q_h$) was transported and treated and $2Q_h$ was overflowed to waterbody during rainy day although combined sewer system was designed to transport $3Q_h$ to treatment system. The event mean concentrations (EMCs) and pollutant loads from CSO were higher than those from SSO. BOD and COD of CSO, and TOC and TN of SSO represented distinct first flush phenomena. The inadequate management in combined sewer system from which the untreated $2Q_h$ from CSO was overflowed to waterbody during rainy day could influence on high pollutant loads and first flushing. Treating $2Q_h$ from CSO, source control such as low impact development, and treating outflow from SSO were strongly recommended to control non-point source pollution in urban area.

• Magazine of the Korean Society of Agricultural Engineers
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• v.12 no.4
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• pp.2090-2123
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• 1970

This paper is a report on the research of experimental model test of Andong Fill Dam, which has been planned by the Government of Korea as a project, of its over-flowing capacity in spillway, creation of minus pressure and structure of anti-water impulse in over-flow weir. Andong Fill Dam is one of the project of master development plant for water resources, locating at Nakdong River side of Korea, and is aimed to have a multi-purpose dam for flood-control, irrigation, water power, urban and industrial water supply. This dam is planned to erect in fill-dam type due to the improper soil foundation and condition for concrete dam. The refore for the proper and advantageous points, this is designed as center core fill dam. By a model minimized of Andong Fill Dam, held an experimental model test on water quentity of reservir, discharges of overflow part, low pressure and anti-water impulse of overflow part, which was conducted an experiment by flowing aspects through each section of spillway to find the changes of water pressure and that of water level, and corrected the section of each part in order to conduct a check on the creation of minus pressure not to be over acted to the allowable bundary of the section structure; and for the prevention of concentated scouring at the down stream side of flow.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.11
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• pp.5271-5289
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• 2016

On large-scale data analysis platforms deployed on cloud infrastructures over the Internet, the instability of the data transfer time and the dynamics of the processing rate require a more sophisticated data distribution scheme which maximizes parallel efficiency by achieving the balanced load among participated computing elements and by eliminating the idle time of each computing element. In particular, under the constraints that have the real-time and limited data buffer (in-memory storage) are given, it needs more controllable mechanism to prevent both the overflow and the underflow of the finite buffer. In this paper, we propose an auto regulated data provisioning model based on receiver-driven data pull model. On this model, we provide a synchronized data replenishment mechanism that implicitly avoids the data buffer overflow as well as explicitly regulates the data buffer underflow by adequately adjusting the buffer resilience. To estimate the optimal size of buffer resilience, we exploits an adaptive buffer resilience control scheme that minimizes both data buffer space and idle time of the processing elements based on directly measured sample path analysis. The simulation results show that the proposed scheme provides allowable approximation compared to the numerical results. Also, it is suitably efficient to apply for such a dynamic environment that cannot postulate the stochastic characteristic for the data transfer time, the data processing rate, or even an environment where the fluctuation of the both is presented.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.10
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• pp.512-519
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• 2005

E-BLP security model considers the reliability of the processes that are real subjects in systems. This paper deals with the implementation of the E-BLP model for secure embedded systems. Implemented EBSM(E-BLP Based Security Module) consists of three components: identification and authentication, access control and BRC(Dynamic Reliability Check) that checks the process behavior dynamically. Access Control of EBSM ensures unreliable processes not to access the sensitive objects and the DRC detects the buffer overflow attack by normal user. Besides, the performance overhead of the embedded system applying the EBSM is introduced.

• Journal of Korea Foundry Society
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• v.29 no.5
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• pp.187-191
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• 2009

Microstructures and shape memory characteristics of $Ti_{50}Ni_{20}Cu_{30}$ alloy strips fabricated by arc melt overflow have been investigated by means of XRD, optical microscopy and DSC. The microstructure of as-cast strips exhibited columnar grains normal to the strip surface. X-ray diffraction analysis showed that one-step martensitic transformation of B2-B19 occurred in the alloy strips. According to the DSC analysis, it was known that the martensitic transformation temperature ($M_s$) of B2 $\rightarrow$ B19 in $Ti_{50}Ni_{20}Cu_{30}$ strip is $57^{\circ}C$. During thermal cyclic deformation with the applied stress of 60 MPa, transformation hysteresis and elongation associated with the B2-B19 transformation were observed to be $3.7^{\circ}C$ and 1.6%, respectively. The as-cast strip of $Ti_{50}Ni_{20}Cu_{30}$ alloy also showed a superelasticity and its stress hysteresis was as small as 14 MPa. These mechanical properties and shape memory characteristics of the alloy strips were ascribed to B2-B19 transformation and the controlled microstructures produced by rapid solidification of the arc melt overflow process.

• Korean Journal of Veterinary Research
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• v.31 no.3
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• pp.271-277
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• 1991

To investigate the epidemiological trait of listeriosis, Listeria spp were isolated from poultry meat, products and environmental specimens in chicken slaughterhouse. Also determined were isolation rates by the different enrichment procedures, the biochemical properties of isolates. In a total of 307 samples including poultry meat, liver, feathers, feces, chiller water, scalding water overflow and slaughterhouse floor, Listeria spp were isolated predominantly from scalding water overflow (90.0%), body skin before washing (66.7%), liver (20.0%) and feathers(15.0%) However, few Listeria spp were isolated from body skin after washing and feces. The higher isolation rates were obtained in the secondary enrichment procedure (7.2%) than in the primary enrichment (3.9%); after stored the secondary enrichment cultures for 2 weeks at $4^{\circ}C$, Listeria spp were present in 9.8%. The majority of the isolated Listeria spp were identical to those of the standards strains in biochemical and cultural properties. Overall, Listeria spp were present in 13.4% of the specimens tested, and were in order of prevalence of L innocua(11.1%), L monocytogenes(3.3%), L grayi(0.7%) and L murrayi(0.3%).

• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.3
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• pp.216-222
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• 2017

The rotor position of a PM synchronous motor is commonly estimated from the mathematical model for the sensorless control without rotor position sensors. For the magnet flux-based rotor position estimator in the stationary reference frame, the magnet flux estimator for estimating rotor position and speed includes the integrator. The integrator in the magnet flux estimator may accumulate the offset of the current sensors and the voltage drift. This continuous accumulation of the offset may cause the drift and overflow in the integrator, such that the estimated rotor position and speed may fail to track the real rotor position and speed. In this paper, the magnet flux estimator without integrator is proposed to avoid overflow in the integrator. The proposed rotor position and speed estimator based on magnet flux estimator are verified through simulation and experiment.

• Journal of the Korean Society of Safety
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• v.34 no.4
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• pp.41-48
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• 2019

In October 2018, a large fire occurred after an explosion in an internal floating roof tank (IFRT) that stores gasoline by wind lantern in Goyang city, Gyeonggi-do. Although there was no casualty damage, the fire inside the tank lasted for 17 hours, and caused a great wave socially, and it was a chance to review the safety of the atmospheric storage tank. In this study, the necessity of installing a flame arrester at peripheral vents was examined through the calculation of the size of ventilation pipe and ventilation rate of internal floating roof tanks in terms of the function of the peripheral vent. Next, the necessity of the emergency shut-off valve linked with the high-level alarm to prevent the overflow of the atmospheric storage tank was confirmed by LOPA. Finally, safety measures to prevent overpressure, flame propagation and overflow which cause major accidents in atmospheric storage tank are suggested.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.158-158
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• 2019

Recent studies show the possibility of more frequent extreme events as a result of the changing climate. These weather extremes, such as excessive rainfall, result to debris flow, river overflow and urban flooding, which post a substantial threat to the community. Therefore, an effective flood model is a crucial tool in flood disaster mitigation. In recent years, a number of flood models has been established; however, the major challenge in developing effective and accurate inundation models is the inconvenience of running multiple models for separate conditions. Among the solutions in recent researches is the development of the combined 1D-2D flood modeling. The coupled 1D-2D river flood modeling allows channel flows to be represented in 1D and the overbank flow to be modeled over two-dimension. To test the efficiency of this approach, this research aims to assess the capability of HEC-RAS model's implementation of the combined 1D-2D hydraulic simulation of river overflow inundation, and compare with the results of GERIS and FLUMENS 2D flood model. Results show similar output to the flood models that had used different methods. This proves the applicability of the HEC-RAS 1D-2D coupling method as a powerful tool in simulating accurate inundation for flood events.

• Journal of Ocean Engineering and Technology
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• v.33 no.3
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• pp.280-288
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• 2019

A submerged breakwater is one of the coastal structures used to reduce wave energy and coastal erosion. However, a submerged breakwater has a negative aspect in that a strong rip current occurring around an open inlet due to a difference in mean water levels at the front and rear sides of the structure leads to scouring. Such scouring has a bad effect on its stability. In order to eliminate this kind of demerit, this study investigated an artificial reef of the overflow type with openings. We also developed a program where the flows around the artificial reef of the overflow type could be analyzed numerically. An unstructured grid system was used to cover the various geometries, and the level set method was applied to treat the movement of the free surface. To verify these numerical schemes, hydraulic physical tests were performed on the submerged breakwater and double breaking type artificial reef. Then, the wave height and velocity distribution around the reef were examined using the experimental results. Comparisons between the results of hydraulic and numerical tests showed reasonable agreement.