• The KIPS Transactions:PartB
• /
• v.9B no.5
• /
• pp.663-672
• /
• 2002

In this paper, Using an automatic tracking system, behavior of an aquatic insect, Chironomus sp. (Chironomidae), was observed in semi-natural conditions in response to sub-lethal treament of a carbamate insecticide, carbofuran. The fourth instar larvae were placed in an observation cage $(6cm\times{7cm}\times{2.5cm)}$ at temperature of $18^\circ{C}$ and the light condition of 10 time (light) : 14 time (dark). The tracking system was devised to detect the instant, partial movement of the insect body. Individual movement was traced after the treatment of carbofuran (0.1ppm) for four days 2days : before treatment, 2 days : after treatment). Along with the other irregular behaviors, "ventilation activity", appearing as a shape of "compressed zig-zag", was more frequently observed after the treatment of the insecticide. The activity of the test individuals was also generally depressed after the chemical treatment. In order to detect behavioral changes of the treated specimens, wavelet analysis was implemented to characterize different movement patterns. The extracted parameters based on Discrete Wavelet Transforms (DWT) were subsequently provided to artificial neural networks to be trained to represent different patterns of the movement tracks before and after treatments of the insecticide. This combined model of wavelets and artificial neural networks was able to point out the occurrence of characteristic movement patterns, and could be an alternative tool for automatically detecting presences of toxic chemicals for water quality monitoring. quality monitoring.

• Korean Journal of Construction Engineering and Management
• /
• v.15 no.5
• /
• pp.40-48
• /
• 2014

As CBR(Chemical, Biological, and Radiological) attack increases, the importance of CBR protective facilities is being emphasized. When CBR warfare emerges, a task force team, who exist outside of CBR protective facility, should enter the CBR protective facility through neutralizing process in CCA(Contamination Control Area) and TFA(Toxic Free Area). If a bottleneck occurs in the process or zones, the task force team cannot enter the CBR protective facility efficiently and may cause inefficiency in its operation performance or result in casualties. The current design criteria of the CBR protective facility is only limited to ventilation system and it does not consider how much time it takes to enter the facility. Therefore, this research aims to propose the entering time estimation model with discrete event simulation. To make the simulation model, the procedure performed through CCA and TFA is defined and segmented. The actual time of the procedure are measured and adapted for the simulation model. After running the simulation model, variables effecting the entering time are selected for alternatives with adjustments. This entering time estimation model for CBR protective facility is expected to help take time into consideration during the designing phase of CBR protective facility and help CBR protective facility managers to plan facility operation in a more realistic approach.

• Journal of Korean Society for Atmospheric Environment
• /
• v.26 no.5
• /
• pp.517-532
• /
• 2010

After establishment of Banwol industrial complex in 1987, Ansan city becomes the largest industrial sector development in Gyeonggi-do, Korea. As the population and industrial activity grow over this region, toxic air pollutants, particularly POPs (Persistent Organic Pollutants) from various emission sources have been major public concerns. Air samples for POPs monitoring were collected at the industrial sites ($A_2$), residential sites ($B_1$, $B_2$), commercial site (C), and rural/remote site (D) of the area of Ansan during 2008 with a prolonged industrial sampling site $A_1$ from 2001 to 2008. All samples were analysed for 2,3,7,8 substituted-polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs) and dioxin like polychlorinatd diphenyls (dl-PCBs). In site $A_1$, a steady decline of their concentrations from 2003 to 2008 was observed due to the reinforced emission guideline from waste incinerators. The average concentration of the PCDD/Fs and dl-PCBs ranged between 0.118 pg-TEQ/$m^3$ (rural/remote site D) and 0.532 pg-TEQ/$m^3$ (industrial area $A_2$). These level were generally consistent with previous studies in Gyeonggi-do, while higher than other places. Most of PCDD/Fs congener were partitioned into particle phase, whereas dl-PCBs were partitioned into gas phase. The logarithm of gas-particle partition coefficient $K_P$ of dl-PCBs and PCDD/Fs were well correlated with sub-cooled liquid vapor pressure $P_L$. The slope $m_T$ of log $K_P$ versus log $P_L$ for PCDD/Fs (-1.22) and dl-PCBs (-1.02) in industrial area ($A_2$) were high compared to other residential/commercial area. It suggests that this area was likely influenced by the direct emission source of PCDD/Fs and dl-PCBs. To simulate the partition of PCDD/Fs and dl-PCBs between gas and particle phase, Junge-Pankow model ($P_L$-base) and $K_{oa}$ model were applied. It was found that J-P model was more suitable than the $K_{oa}$ model in this study.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.22 no.5
• /
• pp.563-574
• /
• 2020

Currently, road tunnels and railroad tunnels are building smoke control systems to emit toxic gases and smoke from fires. Among the various smoke control systems, the transverse smoke control system has the disadvantage that air supply or exhaust is performed on only half of the cross-section, rather than air supply or exhaust on the entire cross-section of the tunnel as air is supplied or exhausted by partitioning the wind path. Therefore, this study analyzed the effect of exhaustion through numerical analysis and scaled model tests on the zoning smoke control system, which improved the limitations of the transverse smoke control system. As a result of the scaled model test, the transverse ventilation system exhibited a 25.6% smoke control rate based on the state where no smoke was controled, and zoning smoke control system showed a smoke control rate of 40.8%. In addition, as a result of numerical analysis, it was found that transverse ventilation system did not control fire smoke spreading from the tunnel and continued to spread. On the other hand, zoning smoke control system was found to be smoke controled within a certain section due to the air curtain effect and the flue gas effect.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.25 no.6
• /
• pp.111-120
• /
• 2021

When a fire occurs in a commercial building, the evacuation route is complicated and the direction of smoke and flame is similar to that of the egress route of occupants, resulting in many casualties. Performance-based evacuation design for buildings is essential to minimize human casualties. In order to apply the performance-based evacuation design to buildings, it requires a complex fire simulation for each building, demanding a large amount of time and manpower. In order to supplement this, it would be very useful to develop an Available Safe Egress Time (ASET) prediction model that can rationally derive the ASET without performing a fire simulation. In this study, the correlations between fire temperature with visibility and toxic gas concentration were investigated through a fire simulation on a commercial building, from which databases for the training of artificial neural networks (ANN) were created. Based on this, an ANN model that can predict the available safe egress time was developed. In order to examine whether the proposed ANN model can be applied to other commercial buildings, it was applied to another commercial building, and the proposed model was found to estimate the available safe egress time of the commercial building very accurately.

• Analytical Science and Technology
• /
• v.24 no.6
• /
• pp.544-555
• /
• 2011

The acute toxicity in the rainbow trout (Oncorhynchus mykiss) was analyzed and predicted using quantitative structure-activity relationships (QSAR). The aquatic toxicity, 96h $LC_{50}$ (median lethal concentration) of 275 organic pesticides, was obtained from EU-funded project DEMETRA. Prediction models were derived from 558 2D molecular descriptors, calculated in PreADMET. The linear (multiple linear regression) and nonlinear (support vector machine and artificial neural network) learning methods were optimized by taking into account the statistical parameters between the experimental and predicted p$LC_{50}$. After preprocessing, population based forward selection were used to select the best subsets of descriptors in the learning methods including 5-fold cross-validation procedure. The support vector machine model was used as the best model ($R^2_{CV}$=0.677, RMSECV=0.887, MSECV=0.674) and also correctly classified 87% for the training set according to EU regulation criteria. The MLR model could describe the structural characteristics of toxic chemicals and interaction with lipid membrane of fish. All the developed models were validated by 5 fold cross-validation and Y-scrambling test.

• Journal of the Korean Applied Science and Technology
• /
• v.36 no.4
• /
• pp.1188-1197
• /
• 2019

Exposure to stress can lead to sympathetic hyperactivity, which include a systemic disease with lesions in a broad spectrum of organs and a psychiatric condition. The purpose aimed to evaluate the effect of the korea ginger essential oil on stress hormone and brain tissue response in chronic mild stress-induced rats model of sympathetic hyperactivity. Evaluation method carried out cytotoxicity assessment and component analysis, what observe the effects based on serum biomarker and histopathological analysis of brain tissue. As this time, the korea ginger essential oil was treatment at doses of 100 nl/㎖ for 2 weeks after make a chronic mild stress-induced rats model of sympathetic hyperactivity. As a result, the korea ginger essential oil was not toxic at less than 100 nl/㎖, contents of 6-gingerol was 345 ppm. Compared to the control rats, the korea ginger essential oil treatments significantly reduced the serum concentrations of stress hormone (i.e., ACTH, corticosterone, melatonin). Furthermore, The korea ginger essential oil treatments effectively preserved the TH-immune response was occasionally interrupted in the ventral tegmental area (VTA) and the substantia nigra pars compacta (SNpc). The results indicate that the korea ginger essential oil improved sympathetic hyperactivity. Thus, the korea ginger may be a novel material of aroma oils for the management of sympathetic hyperactivity.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.10
• /
• pp.1090-1098
• /
• 2005

Benzoyl peroxide is very toxic to aquatic organisms but environmental concentration or exposure effects were not studied. Distribution of the chemical among multimedia environment was estimated using EQC(Equilibrium Criterion) model based on the physical-chemical properties to evaluate the risk of benzoyl peroxide in environment. Level I describes a situation that 100,000 kg of benzoyl peroxide is emitted into the environment which is equilibrium and steady-state without degradation and advection condition. Level II describes a situation that a constant rate of 1,000kg/h of benzoyl peroxide is continuously discharged into the environment which is equilibrium and steady-state with degradation and advection condition. Level III describes a situation that 1,000 kg/h of benzoyl peroxide is continuously introduced in each air, water, soil, and sediment compartment which are non-equilibrium and steady-state with degradation, advection, and inter-media transfer condition. In Level I and II calculations the chemical was distributed to soil(68.3%) and water(28.7%). In Level III calculation it was primarily distributed to soil(99.9%) and overall residence time was estimated to be 3.4 years. Benzoyl peroxide can be persistent in environment.

• Journal of Oriental Neuropsychiatry
• /
• v.26 no.3
• /
• pp.319-336
• /
• 2015

Objectives: The object of this study was to evaluate the cognition and motor function recovery effects of Sungshim-san (SSS), a traditional Korean cardio-protective polyherbal formula in the severe rat stroke, permanent middle cerebral artery occlusion (pMCAO) model. Methods: The experimental animals were divided into 6 groups. SSS aqueous extracts (yield=16.82%; 400, 200 and 100 mg/kg) were administered orally by using Sonde, once daily, for 28 continuous days from 24 hrs post-pMCAO. Donepezil 10 mg/kg, a representative drug for dementia, was used as a reference drug. The body weight changes, infarct/defect sizes, sensorimotor function and cognitive motor behavior were serially monitored. Limb placing and body-swing test for sensorimotor functions were conducted at 1 day before operation (base line), and 1, 3, 7, 14, 21 and 28 days post-pMCAO; and water maze test for the cognitive motor behavior was conducted at 14 and 28 days post-pMCAO, respectively. Results: Focal cerebral cortex infarct and defects due to pMCAO resulted in marked decreases of body weight, disorders of sensorimotor functions and cognitive motor behaviors. However, the pMCAO-related ischemic damages were markedly and dose-dependently inhibited by treatment with SSS 400 and 200 mg/kg, respectively. Donepezil markedly decreased the body weight and gains, as compared with pMCAO control rats; however, SSS 400 and 200 mg/kg favorably ameliorated the pMCAO-induced decreases in body weight and gains. SSS 100 mg/kg treated rats did not show any favorable effects on the pMCAO-related ischemic damages, as compared with pMCAO control rats. Conclusions: The results of the study indicated that oral administration of SSS 400 and 200 mg/kg accelerated cognition and motor function recovery in the rat pMCAO model. The treatment effect was potentially mediated by neuroprotection via the known augmentation of cerebral antioxidant defense system of SSS itself or its individual herbal components. Especially, the overall effects of SSS 200 mg/kg were similar to those of donepezil 10 mg/kg, but less toxic.

• Korean Journal of Environmental Agriculture
• /
• v.10 no.2
• /
• pp.167-177
• /
• 1991

O-ethyl S-methyl ethylphosphonothioate [$LD_{50}$ (rat, oral) 4.6mg/kg ; $K_i$(bovine erythrocyte acetylcholinesterase) 303 $M^{-1\;min-1}$] was selected as a model compound to study the mode of action of O, S-dialkyl alkylphosphonothioates which have been hypothesized to be toxic via a bioactivation process. Two chemical oxidants, meta-chloroperoxybenzoic acid and monoperoxyphthalic acid, and rat liver microsomal oxidases were used to mimic the action of mixed function oxidases on the model compound. The formation of S-oxide, a very unstable active intermediate, was proposed based on the identification of metabolic products.Furthermore, a trapping experiment with ethanol showed that the unstable intermediate S-oxide had the ability to phosphorylate acetylcholinesterase which is an important enzyme in nerve systems. The S-oxide intermediates are presumed to be responsible for the toxicity of O,S-dialkyl alkylphosphonothioates.