• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.33
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• pp.111-118
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• 1995

This paper suggests a hybrid genetic algorithm for asymmetric traveling salesman problem(TSP). The TSP was proved to be NP-complete, so it is difficult to find optimal solution in reasonable time. Therefore it is important to develope an algorithm satisfying robustness. The algorithm applies dynamic programming to find initial solution. The genetic operator is uniform order crossover and scramble sublist mutation. And experiment of parameterization has been performed.

• LOGISTICS
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• v.1 no.2 s.2
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• pp.50-54
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• 2003

• Applied Chemistry for Engineering
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• v.21 no.4
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• pp.469-474
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• 2010

Wood has an essential drawback such as high combustion ability. The purpose of this paper is to examine the combustion properties of the quercus variabilis and zelkova serrata dried at room temperature. The cone calorimeter (ISO 5660-1) was used to determine the heat release rate (HRR) and fire smoke index, as well as CO/$CO_2$ production and smoke obscuration. The total heat release (THR), $140.2\;MJ/m^2$ of the quercus variabilis under an external $50\;kW/m^2$ was high in comparison with THR $85.7\;MJ/m^2$ for the zelkova serrata. Furthermore, the quercus variabilis has high total smoke production (TSP), $3.50\;m^2$ compared with TSP $0.65\;m^2$ of zelkova serrata. Thease results depend on the bulk density of tested wood species. In addition, the CO/$CO_2$ production ratio of zelkova serrata and quercus variabilis was measured as 0.053, 0.043, respectively. Also, zelkova serrata showed an increase of fire-resistance attributed to char formation compared with that of quercus variabilis.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.40 no.6
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• pp.87-94
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• 2003

One of the important fields for heuristic algorithm is how to balance between Intensification and Diversification. Ant Colony Optimization(ACO) is a new meta heuristic algorithm to solve hard combinatorial optimization problem. It is a population based approach that uses exploitation of positive feedback as well as Breedy search It was first Proposed for tackling the well known Traveling Salesman Problem(TSP). In this paper, we deal with the performance improvement techniques through balance the Intensification and Diversification in Ant Colony System(ACS). First State Transition considering the number of times that agents visit about each edge makes agents search more variously and widen search area. After setting up criteria which divide elite tour that receive Positive Intensification about each tour, we propose a method to do addition Intensification by the criteria. Implemetation of the algorithm to solve TSP and the performance results under various conditions are conducted, and the comparision between the original An and the proposed method is shown. It turns out that our proposed method can compete with the original ACS in terms of solution quality and computation speed to these problem.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.4
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• pp.347-361
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• 2003

Sulfur dioxide (SO$_2$), ozone, total suspended particulates (TSP) and PM$_{2.5}$ were measured at Deokjeok Island in the Yellow Sea during April 1999 to June 2000. Although the emission amount of air pollutants is quite low in this small island of 36 km$^2$ with 1.4 thousand inhabitants, there are pollutant sources such as an oil -firing power plant and a wharf for ferryboat. The island is also influenced from the emissions from the greater Seoul area in the east and from China in the west. In order to characterize the pollutant variations due to interactions between transport and local emissions. the correlation between variations of SO$_2$ and ozone was investigated. Mass and ion concentrations of TSP and PM$_{2.5}$ were examined on selected episode days of positive and negative correlations between the two gaseous species in spring and winter. The effects of transport were pronounced on the days of positive correlation in spring with higher concentrations of ozone and PM$_{2.5}$. TSP concentrations were also high on these days because of high wind speeds. On the days of negative correlation in spring, frequent fog associated with low wind speeds facilitated SO$_2$ oxidation and increased sulfate accompanied with decrease in nitrate in PM$_{2.5}$ and chloride in TSP. This latter phenomena was noticeable since it showed that chemical composition of fine particles could be significantly altered not only during the transport but also by local environment.ronment.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.7
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• pp.377-383
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• 2002

The TSP(Traveling Salesman Problem) has been known as NP-complete, there have been various studies to find the near optimal solution. The nearest neighbor heuristic is more simple than the other algorithms which are to find the optimal solution. This paper designs and implements a new distributed nearest neighbor heuristic with bounding function for the TSP using the master/slave model of PVM(Parallel Virtual Machine). Distributed genetic algorithm obtains a near optimal solution and distributed nearest neighbor heuristic finds an optimal solution for the TSP using the near optimal value obtained by distributed genetic algorithm as the initial bounding value. Especially, we get more speedup using a new genetic operator in the genetic algorithm.

• Journal of Environmental Science International
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• v.5 no.4
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• pp.453-462
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• 1996

This study was conducted to evaluate the level of atmospheric heavy metals and the relationship of that concentration with weather conditions. This research monitored the concentration of Total Suspended Particulates (TSP) at every three hours by using High Volume Air Sampler from December 24th, of 1995 to Febuary 20th, 1996 in Kimhae area, which recently became a rapidly growing residential and industrial sitc. The items such as air-temperature, relative humidity, radition, wind speed, and wind direction were monitored by using Atmospheric Weather System at the same time. From the collected TSP, the concentration of heavy metals were analyzed by using the Atomic Absorption Spcetrophotometry. The mean concentration of TSP was 110.4 $\mu\textrm{g}$/$m^3$, and the mean concentration of lead (Pb), copper(Cu), chromium (Cr), manganese (Mn), cadmium (Cd), were 0.837 $\mu\textrm{g}$/$m^3$, 0486 $\mu\textrm{g}$/$m^3$, 0.264$\mu\textrm{g}$/$m^3$). The concentration of Pb and Mn was higher in the moring and that of Cu, Cr and Cd was higher in the afternoon and the evening. Regarding the relationship between the concentration of pollutants and weather condition, the-concentration TSP revealed positive correlation with temperature, humidity, wind speed, but negative correlation with tradition (p<0.01). The concentration of Mn revealed positive correlation with temperature and humidity, but negative correlation with wind speed (p<0.01). And the the concentration of pollutants and weather condition revealed higher correlation within the same time period. In summary, the paralleled mornitoring of air conditions and weather condition should be recommended to. get the correct informations concerning the pollution and to prevent the deterioration of air conditions.

• Journal of environmental and Sanitary engineering
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• v.18 no.3 s.49
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• pp.1-10
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• 2003

This study was aimed to investigate the influence on the vicinity by air pollutant generated from facility of the district heating located in local small town. We selected the seven areas arround the surroundings of facility of the district heating, compared the air quality evaluated before and after operations of the facility, and estimated the diffusion of air pollutant exhausted from the facility using a ISC model. The result was that the concentration of TSP before and after operations of the facility was 89${\sim}$94${\mu}$g/m$^3$,and 72${\sim}$81${\mu}$g/m$^3$, respectively and the latter showed a decline in concentration. Also, there was no relationship between straight distance from the facility of the district heating and the concentration of TSP. This result was applicable to cases of PM-10 and SO$_2$. We also investigated the influence on the air around the neighbored area by air pollutant produced from facility of the district heating using ISCLT3 model. The adding-concentrations of TSP, SO$_2$,NO$_2$, and CO were 0.0019${\sim}$0.00183${\mu}$g/m$^3$, 0.0029${\sim}$0.5648ppb, 0.2924${\sim}$l.9837ppb,and 0.0087${\sim}$0.0590ppb, respectively. It is predicted that each concentration is added to pollutant exhausted from facility of the district heating and is about 1/100${\sim}$1/180,000 of present air quality. This has a tiny influence on general air quality. According to this analysis, the concentration of air pollutant is less effected to pollutants expected by the facility of the district heating than other pollutants emitted from mobil source or industrial complex, and etc.

• Journal of Korean Society for Atmospheric Environment
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• v.3 no.2
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• pp.18-26
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• 1987

In order to investigate the character of air pollution by heavy metals and to elucidate the possible sources in Seoul city, this study was performed to measure the concentrations of heavy metals of total suspended particulate and air pollutants such as $SO_2, NO_2, CO, CH_4$, Non-methane hydrocarbon, ozone at the residential-traffic area (shinchon dong) in January and February, 1986. The results are as follows: 1. $SO_2$ and TSP concentration were 135ppb and 167 $\mug/m^3$ in average, respectively. 2. While concentrations of heavy metals such as Fe, Cu, Pb in the ambient air seems gradually decreasing annually, Ni compound has been shown the tendency of increasing. 3. Among heavy metals in TSP analysed, the iron was detected at the highest level, 0.905% and the cadimium was the lowest 0.004% in average, respectively. 4. V, Fe and Zn compounds in air were observed to be highly correlated with their correlation coefficients(r) higher than 0.7. Pb compound was highly correlated to the levels of Zn and Fe, however relatively less correlated to V compound. 5. Among concentrations of heavy metals in the particulates, V and Ni compounds were highly correlated with coefficient(r) of 0.8587; the cause might be imagined by the fact of releasing from combustion of fuel oil. Fe, Pb and Zn compounds were highly correlated $SO_2$ concentration. It might be explained that they were released by combustion of coal. 6. The level of $SO_2$ was highly correlated to most of heavy metals: especially correlation coefficient(r) to Pb compound was 0.9081. Pb compound was also highly correlated to NO, CO and TSP. TSP showed higher correlation to Pb and Cd compounds than to V and Ni compounds. It might be assumed that particulate was mainly produced by combusting coal from space heating and by exhausting gasoline and diesel oil from transportation rather than by burning fuel oil.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.2
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• pp.233-243
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• 2018

This study was carried out to characterize the ambient levels of PAH concentrations in Pohang city, where steel industry has been intensively developed. A large amount of PAH emissions from steel production and related industries in Pohang are concerned about the environmental health hazards of nearby residents. TSP samples were seasonally collected during 10 days at four sites in Pohang from April to December 2010. Each sample was collected for 24 hours using high-volume air sampler. All samples were extracted by $soxtec^{TM}$ before concentration of 1.0 mL. The concentrates were analyzed by GC/MS. The prevailing wind direction was southwest and west-southwest in Pohang during the measurement period. Variations of TSP concentrations appeared to be similar between four sites. The highest TSP concentration was found in fall, while the lowest in summer. The highest PAH concentration was found at an industrial site, while the lowest at a residential/commercial site. In the case of BaP, the average concentration at the industrial site was $0.63{\pm}0.66ng/m^3$, which was approximately 2 times of the residential/commercial site. The paired t-test (p<0.05) showed significant differences between industrial and residential area. Particulate PAH concentrations were higher in the winter and lower in the summer. The concentrations of BaP in winter were 2~10 times higher than those in the other three seasons. This study clearly demonstrated the impact of steel industry on the elevated levels of PAH in Pohang city.