• Korean Journal of Materials Research
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• v.11 no.6
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• pp.483-491
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• 2001

The recovery and recrystallization behavior of cold-rolled Zr-based alloys during isothermal annealing at temperatures from $575^{\circ}C$ to $650^{\circ}C$ was studied by thermoelectric power and Vickers microhardness measurement. The recovery and recrystallization resulted in the increase of TEP doe to the extinction of lattice defect, vacancy, dislocation and stacking fault during isothermal annealing after cold- rolling. The completion of recrystallization could be determined much clearly by TEP behavior than by microhardness change in Zr-based alloys. Especially, the recovery and recrystallization were classified separately by TEP behavior in Zr-0.4Nb-xSn alloys. From the analysis of TEP behavior and microhardness, the addition of Sn caused to form the interaction between stain field and dislocation, which resulted in the delay of recovery in Zr-based alloys. The precipitation due the addition of Nb suppressed the grain growth after recrystallization effectively in Zr-based alloys.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.392-395
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• 2007

Recently, the construction wastes rapidly increase because of redevelopment, the development of new urbanization of large housing development, the expansion of social infrastructure. With increase of the construction noise caused by these developments, environmental conflicts and civil appeals increase. Moreover, the Government will reduce construction noise level to 65dB from 70dB in January 2009. Therefore, it will be expected to increase environmental conflicts and civil appels related to construction noise. To minimize environmental conflicts and civil appels, this study compared and analyzed measured noisy values of a crusher for the site-recycling to predicted value of simple noisy prediction program developed by "National Institute of Environmental Research". Based on the results, a crusher for the site-recycling can be arranged to minimize the noise.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2003.05a
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• pp.165-170
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• 2003

Due to the impermeability of outer wall facilities such a Breakwaters which dissipates the wave energy and keeps harbor tranquility, the water exchange can be worse and increased enclosed at the harbor. Recent trends of port development protect water quality and emphasize Water-Front, so the method which enhances the circulation of harbor waters and the dilution of the water pollutants are studied. The best improvement of water quality is a remove of pollutant source on land, but an enclosed port must be enhanced the tidal exchange. To this hence, the best improvement may be made on drain-route on the existing outer wall facilities. In this study, the numerical computations were carried out to predict the circulation of harbor waters and the tidal exchange in the polluted harbor(Samchonpo-guhang) located at the east coast of South Sea. Computational models adopting FDM(Finite Difference Method) were used here and were already verified from the previous studies and ocean survey. As a result of this study, the tidal exchange in Samchonpo-guhang before and after installation of drain-route is assessed.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.6
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• pp.1103-1111
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• 2000

With the rapid industrial development, a railway has become a main traffic means. But, rail traffic noise and vibration have become a major problem in urban area as well as a very serious issue in the living environment. Especially, noise and vibration induced by the rail operation have influenced on the residents' living nearby railway tracks. Nevertheless, adequate guidelines for the railway vibration are not yet established because of the lack of basic data and insufficient research works. In this point, the present study attempt to survey the effect and subjective response of railway vibration in urban area using questionnaire. This study also presents a basic data in establishing effective vibration plans for railway vibration in the future.

• Applied Biological Chemistry
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• v.28 no.3
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• pp.124-130
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• 1985

Adsorption experiments of N-methylcarbamate insecticides on soils were carried out as a function of soil pH ana soil organic matter content with wet-and dry-land soils that were either oxidized or non-oxidized. The results obtained may be summarized as follows: The adsorption of N-methylcarbamate insecticides on soils was nearly leached to equilibrium after shaking for 12 hours. The adsorption of N-methylcarbamate insecticides was higher on sandy clay than sandy loam. The presence of organic matter in soil increased the adsorption of N-methrlcarbamate insecticides on soils. The mode of isothermal adsorption of N-methylcarbamate insecticides on soils was coincident with the Freundlich equation. Little effect of soil pH on the adsorption might be interpreted as that the adsorption was due to physical adsorption between N-methylcarbamate molecules and soil surface.

• International Journal of Highway Engineering
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• v.18 no.2
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• pp.103-110
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• 2016

PURPOSES: In this paper, the effectiveness of speed-maintained standardization in road geometry on environmental impact at a downward slope location, based on greenhouse gas (GHG) emission indicators, was studied. Specifically, the aim of this study was to ascertain whether speed-maintained standardization resulted in decreased $CO_2$ emissions as well as noise pollution, due to reduced vehicle speeds. METHODS : In this study, speed-maintained standardization in road geometry was proposed as a means to reduce vehicle speeds, with a view to reducing $CO_2$ emissions and noise pollution. This technique was applied at a downward slope location. The vehicle speeds, $CO_2$ emissions, and noise levels before and after application of speed-maintained standardization were compared. RESULTS: It was found that speed-maintained standardization was effective as a means to reduce speed, as well as $CO_2$ emissions and noise pollution. By applying speed-maintained standardization, it was confirmed that vehicle speeds were reduced consistently. As a result, $CO_2$ emissions and noise levels were decreased by 9% and 11%, respectively. CONCLUSIONS : This study confirmed that speed-maintained standardization in road geometry is effective in reducing vehicle speeds, $CO_2$ emissions, and noise levels. Moreover, there is further scope for the application of this method in the design of roads in urban and rural areas, as well as in the design of highways.

• Land and Housing Review
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• v.13 no.4
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• pp.105-114
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• 2022

Non-fire activated fire alarms caused by such actions as cigarette smoke, cooking, and high humidity are fire safety risk factors. In such instances, it is important to quickly locate and replace the actuated detector. However, it is difficult to locate those detectors because most do not have an address function. While new apartments can incorporate addressable fire alarm detectors, in existing apartments there are limitations in converting over to addressable detectors due to cost and power line issues. This study developed an efficient address function for fire alarms in existing apartments. The newly developed system consists of the existing receiver, and a proposed addressable repeater and detector. Utilizing an experimental setup, the performance of the proposed address monitoring system was confirmed to be stable and compatible with the receiver and existing detectors.

• Korean journal of applied entomology
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• v.24 no.2 s.63
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• pp.61-64
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• 1985

This study was carried out to investigate the seasonal occurrence and developmental periods of Rice stem maggot (RSM), Chlorops oryzae Matsumura, at laboratory and in the fields in $1980{\sim}1982$. RSM occurred three generations a year. Peak of the first, second, and third generation was middle to late May, early July and middle September. Longevity of the first generation adult averaged 18.9 days and the oviposition was 50 eggs per fly. The eggs, larval and pupal period was 7, 25, 14 days respectively.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.12
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• pp.1293-1303
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• 2006

This paper represents a comparison the difference between existence and nonexistence of soundproof trees for road traffic noise. Also we suggested that the simple equation has been derived using a single regression analysis for predicting levels of $Leq_{th}$ at a given distance from a road in terms of the flow rate, the mean speed of the traffic, and the percentage of the type vehicles in the existence and nonexistence of soundproof trees. We classified a vehicle into four and analyzed contribution rate to traffic volume. As a result, the order showed as followed: light vehicle>medium vehicle>heavy vehicle>motorcycle. However, the results of analyzing contribution rate with between traffic volume and traffic noise by the each type showed as followed; Motorcycle>Light vehicle>Medium vehicle>Heavy vehicle. This study showed that the most a lof of traffic volumes of the three vehicles(light vehicle, medium vehicle and motorcycle) and heavy vehicle were existed in 67 km/h and 61 km/h of car speed, respectively. The total traffic noise to the mean car speed decreased because of the inflow a lot of traffic volumes between 2016 and 2388 in the range of 67 km/h of light vehicle speed, in traffic composition of 4.75% heavy vehicles, and 1.11% motorcycle. the final result for this study showed that statistical paired t-test for between existence and nonexistence of soundproof trees was significant(p<0.05) and the difference between daytime and night in the location of the nonexistence of plant communities with the independent sample T-test was significant(p<0.05). However, the independent sample T-test for analyzing the variance of traffic noise between daytime and night was not significant(p>0.05).

• Korean journal of applied entomology
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• v.48 no.2
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• pp.203-209
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• 2009

This study was conducted to investigate the relationship between the climbing up event of Luciola lateralis larvae and water temperature. In the laboratory condition, the larvae did not come out of water at constant temperature condition of 19.3${\pm}$$0.3^{\circ}C$ and tried to climb up at varying temperature condition of 20${\sim}$$22^{\circ}C$ (mean temperature 20.9${\pm}$$0.9^{\circ}C$) without success. However, they climbed up at constant temperature condition of 20.8${\pm}$$0.6^{\circ}C$. The frequency of the larval climbing up was highest as 63.6% at 20${\sim}$$21^{\circ}C$. The most larvae climbed up at approximately $21^{\circ}C$ of average daily water temperature, In the natural condition, the larvae climbed up at 19.8${\sim}$$21.7^{\circ}C$ and the frequency of the larval climbing up was high as 80.4% at 20${\sim}$$21^{\circ}C$. The larval climbing up was also little observed at 19${\sim}$$20^{\circ}C$ at which no larval climbing up was found in the laboratory experiment. No larvae attempted to climb up when water temperature was below $19^{\circ}C$ and above $22^{\circ}C$. It took 18 days from climbing up of larvae to appearance of adults. In its habitat, the range of water temperature required for larvae to climb up is assumed to be 19.6${\sim}$$21.8^{\circ}C$ and the most suitable water temperature may be 20.4${\pm}$$2.3^{\circ}C$. Therefore, the range of water temperature required for larvae to climb up is assumed to be 19.8${\sim}$$21.7^{\circ}C$, and the suitable water temperature range for larvae may be 20${\sim}$$21^{\circ}C$, and the most suitable temperature is thought to be $21^{\circ}C$.