• Journal of Climate Change Research
• /
• v.7 no.2
• /
• pp.157-167
• /
• 2016

This study aims to evaluate the effect of shortened final cutting age by estimating future $CO_2$ absorption in each different scenarios based on each final cutting ages before and after shortening. We used $5^{th}$ Forest Type Map and Forest Yield Table to obtain information to estimate $CO_2$ absorption of forest. We also designed a simulated future scenarios from 2010 to 2100 which repeats cutting and reforestation according to respected each final cutting ages. As the result, number of cuttings and total amount of $CO_2$ absorption of forest were increased with shortened final ages. Total cutting times increased up to 2 in both minimum and maximum amount for Quescus spp. and Larix kaempferi. Maximum number of cutting of Pinus densiflora and minimum number of Pinus koraiensis increased by 1. Total $CO_2$ absorption increased 12％ for Quercus spp. which had the largest number of increase in cutting times, while total $CO_2$ absorption of Pinus koraiensis only increased by 1％. The result could be used to evaluate the changes in forest management plans and policies and then develop optimal final age for efficient sustainable forest management plans.

• Journal of Korean Society of Forest Science
• /
• v.99 no.1
• /
• pp.136-143
• /
• 2010

This study was conducted to provide basic information on the management of natural deciduous forests by presenting suitable stand density over time for natural deciduous forests in Pyungchang Area. The stand density index(SDI) for the sampling point was also computed. The cutting scenarios were adopted by considering the SDI estimated in the sampling point. And then, simulation cutting was enforced to the stand. Cutting scenarios consisted of three cutting levels, with the period of 5 years where each suitable cutting level of selection system will not have the SDI over the maximum SDI throughout 30 years and consider harvest after 30 years. As a result of the simulation cutting, it was found that removing 12% and 14% of basal area per each time kept proper stand density while removing 10% exceed to the adequate basis. From an economic point of view, it was concluded that removal 12% of basal area would be the most suit cutting level in selection system.

• Nuclear Engineering and Technology
• /
• v.55 no.12
• /
• pp.4637-4641
• /
• 2023

For nuclear decommissioning applications, a study was conducted to investigate the feasibility of using a laser for long-distance cutting in complex structures. Cutting tests were performed on stainless steel plates with thicknesses ranging from 10 mm to 30 mm at distances of 300 mm-700 mm from the laser head, using a laser power of 6 kW. Remarkably, the 10 mm and 20 mm thick stainless-steel plates were successfully cut at a distance of 700 mm from the head. Based on the trends observed in the results, it is anticipated that these thicknesses could also be cut at distances of approximately 1 m. Similarly, the 30 mm thick stainless-steel plate was effectively cut at a distance of 500 mm from the head. To evaluate the amount of secondary waste generated, the kerf width was measured. Due to the long-distance cutting, the average kerf width ranged from 6 mm to 16 mm. Despite the wider kerf width, long-distance cutting holds promise for efficiently handling hard-to-reach targets in nuclear decommissioning scenarios.

• Nuclear Engineering and Technology
• /
• v.55 no.11
• /
• pp.4181-4190
• /
• 2023

Nuclear power plants are subjected to various processes during decommissioning, including cutting, decontamination, disposal, and treatment. The cutting of massive bio-shields is a significant step in the decommissioning process. Cutting is performed near the target structure, and during this process, workers are exposed to potential radioactive elements. However, studies considering worker exposure management during such cutting operations are limited. Furthermore, dismantling a nuclear power plant under certain circumstances may result in the unnecessary radiation exposure of workers and an increase in secondary waste generation. In this study, a cutting scenario was formulated considering the bio-shield as a representative structure. The specifications of a standard South Korean radioactive waste disposal drum were used as the basic conditions. Additionally, we explored the hot-to-cold and cold-to-hot methods, with and without the application of polishing during decontamination. For evaluating various scenarios, different cutting time points up to 30 years after permanent shutdown were considered, and cutting speeds of 1-10nullm²/h were applied to account for the variability and uncertainty attributable to the design output and specifications. The obtained results provide fundamental guidelines for establishing cutting methods suitable for large structures.

• Environmental Engineering Research
• /
• v.21 no.4
• /
• pp.355-364
• /
• 2016

Beijing, as a cradle of modern industry and the third largest metropolitan area in China, faces more responsibilities to adjust industrial structure and mitigate carbon emissions. The purpose of this study is aimed at predicting and comparing industrial carbon emissions of Beijing in ten scenarios under different policy focus, and then providing emission-cutting recommendations. In views of various scenarios issues, system dynamics has been applied to predict and simulate. To begin with, the model has been established following the step of causal loop diagram and stock flow diagram. This paper decomposes scenarios factors into energy structure, high energy consumption enterprises and growth rate of industrial output. The prediction and scenario simulation results shows that energy structure, carbon intensity and heavy energy consumption enterprises are key factors, and multiple factors has more significant impact on industrial carbon emissions. Hence, some recommendations about low-carbon mode of Beijing industrial carbon emission have been proposed according to simulation results.

• Journal of Energy Engineering
• /
• v.16 no.3
• /
• pp.93-102
• /
• 2007

This paper presents a scenario evaluation model of the AHP (Analytic Hierarchy Process) to evaluate dismantling scenarios considering quantitative and qualitative considerations. And decommissioning information producing modules which can obtain a dismantling schedule, quantify radioactive waste, visualize a radioactive inventory, estimate a decommissioning cost, and estimate a worker's exposure was developed to assess qualitatively decommissioning information. The digital mock-up (DMU) system was developed to verify dismantling processes and find error of scenarios in virtual space. It combines and manages the decommissioning information producing modules, the decommissioning DB, and the dismantling evaluation module synthetically. By using AHP model and DMU system, the thermal column in KRR-1 was evaluated on plasma arc cutting scenario and nibbler cutting scenario using the developed decommissioning DMU system.

• Wind and Structures
• /
• v.28 no.4
• /
• pp.203-213
• /
• 2019

The topography and geomorphology are complex and changeable in western China, so the railway transition section is common. To investigate the aerodynamic effect of the subgrade-tunnel transition section, including a cutting-tunnel transition section, an embankment-tunnel transition section and two typical scenarios for rail infrastructures, is selected as research objects. In this paper, models of standard cutting, embankment and CRH2 high-speed train with the scale of 1:20 were established in wind tunnel tests. The wind speed profiles above the railway and the aerodynamic forces of the vehicles at different positions along the railway were measured by using Cobra probe and dynamometric balance respectively. The test results show: The influence range of cutting-tunnel transition section is larger than that of the embankment-tunnel transition section, and the maximum impact height exceeds 320mm (corresponding to 6.4m in full scale). The wind speed profile at the railway junction is greatly affected by the tunnel. Under the condition of the double track, the side force coefficient on the leeward side is negative. For embankment-tunnel transition section, the lift force coefficient of the vehicle is positive which is unsafe for operation when the vehicle is at the railway line junction.

• Journal of Animal Science and Technology
• /
• v.62 no.6
• /
• pp.912-921
• /
• 2020

We examined the rates of pathogenic bacterial cross-contamination from gloves to meat and from meat to gloves during pork processing under meat-handling scenarios in transfer rate experiments of inoculated pathogens. The inoculated pork contained ~5-6 Log10 CFU/g pathogenic bacteria like Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), Listeria monocytogenes (L. monocytogenes), and Salmonella enterica subsp. enterica (Sal. enteritidis). On cotton gloves, after cutting the pork, the cutting board, knife, and cotton gloves showed 3.07-3.50, 3.29-3.92 and 4.48-4.86 Log10 CFU/g bacteria. However, when using polyethylene gloves, fewer bacteria (3.12-3.75, 3.20-3.33, and 3.07-3.97 Log10 CFU/g, respectively) were transferred. When four pathogens (6 Log10 CFU/g) were inoculated onto the gloves, polyethylene gloves showed a lower transition rate (cutting board 2.47-3.40, knife 2.01-3.98, and polyethylene glove 2.40-2.98 Log10 CFU/g) than cotton gloves. For cotton gloves, these values were 3.46-3.96, 3.37-4.06, and 3.55-4.00 Log10 CFU/g, respectively. Use of cotton gloves, polyethylene gloves, knives and cutting boards for up to 10 hours in a meat butchering environment has not exceeded HACCP regulations. However, after 10 h of use, 3.09, 3.27, and 2.94 Log10 CFU/g of plate count bacteria were detected on the cotton gloves, cutting board, and knives but polyethylene gloves showed no bacterial count. Our results reveal the transfer efficiency of pathogenic bacteria and that gloved hands may act as a transfer route of pathogenic bacteria between meat and hands. The best hand hygiene was achieved when wearing polyethylene gloves. Thus, use of polyethylene rather than cotton gloves reduces cross-contamination during meat processing.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.14 no.6
• /
• pp.14-20
• /
• 2015

The Korea ministry of land, infrastructure and transport set the goal of cutting greenhouse gas emissions from the transport sector by 34.3% relative to the business as usual scenario by 2020. In order to achieve this goal, support is being given to education and information regarding eco-driving. As a practical measure, however, a vehicle control strategy for decreasing fuel consumptions and emissions is necessary. Therefore, this paper presents an optimized driving model in order to decrease fuel consumption. Scenarios were established by driving mode. The speed profile for each scenario applied to Comprehensive Modal Emission Model and then each fuel consumption was estimated. Scenarios and speed variation with the least fuel consumption were derived by comparing the fuel consumptions of scenarios. The optimized driving model was developed by the derived the results. The speed profiles of general driver were collected by field test. The speed profile of the developed model and the speed profile of general driver were compared and then fuel consumptions for each speed profile were analyzed. The fuel consumptions for optimized driving were decreased by an average of 11.8%.

• Korean Journal of Culture and Social Issue
• /
• v.20 no.2
• /
• pp.107-131
• /
• 2014

This driving simulation study examined relative differences in driving anger as the functions of drivers' gender and driving experiences, and actor-observer perspectives when they were exposed in two anger-provoking driving scenarios(cutting-in and sudden stop). The results showed the followings. First, neither drivers' gender nor driving experience, when they were considered independently of the driving situation types and actor-observer perspectives, yielded significant difference in driving anger. Second, actor-observer effect on driving anger was observed only in the cutting-in condition where other driver's intension was emphasized. Third, the female drivers of low driving experience tended to show the strongest tendency of actor-observer bias in the cutting-in condition. These results suggested that the levels of driving anger as the functions of drivers' gender and driving experience can be differed by types of driving situation as well as perspectives of drivers' interpreting the situations.