• Applied Chemistry for Engineering
• /
• v.22 no.4
• /
• pp.343-347
• /
• 2011

Due to the strong dependence on fossil fuels within the history of human progress, it leads to disaster of the whole world like flood, shortage of water and extinction of the species. In order to curb carbon dioxide emissions, many technologies are being developed. Among them, porous carbon materials have important advantages over other absorbent, such as high surface area, thermal and chemical resistance, low cost, various pore distribution and low energy requirement for their regeneration. Carbon capture and storage (CCS) has attracted the significant research efforts for reducing green house gas emission using several absorbent and process. Moreover, the absorbent are used for the separation of bio mass gas that contains methane which is considered a promising fuel as new green energy resource. In this review, we summarized the recent studies and trend about the porous carbon materials for CCS as well as separation from the biogas.

• Maritime Security
• /
• v.4 no.1
• /
• pp.115-138
• /
• 2022

The Korean military is preparing for successful manpower reduction using advanced science and technology, in addition to carrying out the initiative of the Defense Innovation 4.0. Accordingly, studies on core technologies related to defense reform have been conducted both internally and externally in the military, and the corresponding results have also been applied. Nevertheless, compared to the development of such technologies, it is considered necessary to have more preparation for the policies related to the operation of the newly introduced equipment. As for the placement of personnel and the organization of time in service (TIS) with respect to the operation of surveillance equipment, there has been a tendency to sustain the conventional practice. Therefore, this study intends to suggest the schemes for facilitating policy improvements in the operation of manpower and security regulations in the field of information for the purpose of introducing a successful next-generation coastal guard system. To do this, the approach of this study was focused on the policies for the operation of the guard system. This is in contrast to previous studies that centered on its equipment and technologies. In addition, how to efficiently operate the guard system was also studied in view of cognitive science by deriving the most efficient time for a person to execute surveillance through the monitor based on the previous studies.

• Journal of Broadcast Engineering
• /
• v.27 no.1
• /
• pp.31-43
• /
• 2022

Traditional video compression has developed so far based on hybrid compression methods through motion prediction, residual coding, and quantization. With the rapid development of technology through artificial neural networks in recent years, research on image compression and video compression based on artificial neural networks is also progressing rapidly, showing competitiveness compared to the performance of traditional video compression codecs. In this paper, a new method capable of improving the performance of such an artificial neural network-based video compression model is presented. Basically, we take the rate-distortion optimization method using the auto-encoder and entropy model adopted by the existing learned video compression model and shifts some components of the latent information that are difficult for entropy model to estimate when transmitting compressed latent representation to the decoder side from the encoder side, and finally compensates the distortion of lost information. In this way, the existing neural network based video compression framework, MFVC (Motion Free Video Compression) is improved and the BDBR (Bjøntegaard Delta-Rate) calculated based on H.264 is nearly twice the amount of bits (-27%) of MFVC (-14%). The proposed method has the advantage of being widely applicable to neural network based image or video compression technologies, not only to MFVC, but also to models using latent information and entropy model.

• Journal of the Korean Institute of Gas
• /
• v.27 no.3
• /
• pp.59-71
• /
• 2023

Carbon capture, and storage (CCS) is important for the reduction of greenhouse gases and achieving carbon neutrality. CCS focuses on storing captured CO₂ permanently in underground reservoirs. CO₂-enhanced oil recovery (CO₂-EOR) is one form of CCS, where CO₂ is injected into the underground to enhance oil recovery. CO₂-EOR not only aids in the extraction of residual oil but also contributes to carbon neutrality by storing CO₂ underground continuously. CO₂-EOR can be classified into miscible and immiscible methods, with the CO₂-water alternating gas (CO₂-WAG) technique being a representative approach within the miscible method. In CO₂-WAG, water and CO₂ are alternately injected into the reservoir, enabling oil production and CO₂ storage. The WAG method allows for controlling the breakthrough of injection fluids, providing advantages in oil recovery. It also induces hysteresis in relative permeability during the injection and production process, expanding the amount of trapped CO₂. In this study, the effects of enhancing oil recovery and storing CO₂ underground during CO₂-EOR were presented. Additionally, cases of CO₂-EOR application in relation to CCS were introduced.

• Journal of Aerospace System Engineering
• /
• v.14 no.5
• /
• pp.130-138
• /
• 2020

In this paper, a plan to expand the scale of the domestic MRO industry was proposed by finding the technical common points between the aviation MRO and naval vessel MRO industries. The aviation MRO industry is led by Europe, North America, and Singapore. Europe and North America have very large aviation industries. The reason for the development of the MRO industry in Singapore is that the aviation MRO and ship MRO industries gathered to expand the industrial scale. The MRO field is an industry that spans all fields from research & development, production, manufacturing, operation, disposal, and crew training. The MRO industry is divided into military and civilian use. However, most of them are only differences in the needs of users, and there are no significant technical differences. The weapon system used by the military is steadily developing. It is impossible for the military to maintain all equipment at a time when troops are reduced. For that reason, it is necessary to share roles in each field. There is a need for an MRO industry in which civil and military operations cooperate to maintain all weapon systems at optimal performance. And the MRO industry development should be based on the civil market. The scale of the MRO industry should be expanded by gathering equipment commonly used in aircraft and naval vessels. This can increase military availability and reduce maintenance budgets.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.11
• /
• pp.33-43
• /
• 2019

Considerable efforts have been made to reduce greenhouse gas emission around the world to cope with climate change. The government is implementing G-SEED certification to promote energy efficient building design. This study aims to verify the effectiveness of the G-SEED certification system by analyzing the actual energy use of certified and non-certified office buildings. For this purpose, the energy consumption of 135 certified and 142 non-certified office buildings was analyzed according to the seasonal characteristics, building size and number of floors, approval year, and certification grade. The energy saving effects of certified buildings was about 50% higher than that of non-certified buildings. The seasonal energy consumption of buildings is closely related to the heating degree-days. The energy consumption of certified and non-certified buildings decreases with increasing approval year. On the other hand, the energy consumption according to building size and certification grade is not related. This study provides meaningful basic data of G-SEED certification system for future improvement. As the building energy performance standards are strengthened over the years, it is necessary to make the individual score of G-SEED certified projects open to the public to configure the factors of energy efficiency.

• The Journal of Engineering Geology
• /
• v.28 no.2
• /
• pp.207-215
• /
• 2018

Almost all countries of the world have recently made great efforts to reduce green-house gases to alleviate the global warming threatening human survival, because a huge amount of carbon dioxide as one of the main green-house gases has been emitted from the combustion processes of fossil fuels such as coal and oil. $CO_2$ capture and storage (CCS) technology is a representative method to diminish the green-house gases, and actively investigated by many countries. This study focuses on the design and construction of a high pressure $CO_2$ injection facility to store it to underground, which is the first $CO_2$ injection in Korea following the steps of the $CO_2$ capture from large $CO_2$ emission sources and transportation to the sea. Injection tests of $CO_2$ on the platform on the sea were carried out in Yeongil Bay of Pohang city in the early 2017. Thus, we were able to perceive the necessary operating conditions of the injection facility, injection characteristic, and knowhow of the injection facility. The results obtained from the injection test shall be utilized for facility upgrades and scale-ups.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.10
• /
• pp.625-632
• /
• 2018

This study was done to reduce total energy demand based on resource shortage problems and to provide improvement points for more efficient adjustment of the high insulation standards for saving energy in Korea. The demand sensitivity was fully considered by varying the slope of each building. The energy performance of the building was maximized by the introduction of outdoor air at night. A final low-energy building model was developed with the two measures combined, and the short-term operation of the night-fuzzy ventilation system was simulated. The result showed a reduction of about 6 to 7 percent compared to the base model. The results could have many implications in terms of the need to conduct demand sensitivity analyses in architectural design.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.7
• /
• pp.168-175
• /
• 2020

Recently, there has been an increasing need to expand the supply of renewable energy as a solution to greenhouse gas emissions. Therefore, as a measure to promote domestic renewable energy investment and gradual expansion, this study analyzed the investment value of renewable energy projects utilizing the unoccupied spaces of public enterprise's facilities and presented a strategic decision-making framework to support efficient national land development and government measures. The NPV was estimated to be 286 million won if the expansion of the facility was not considered, but it is reasonable to postpone the expansion decision because the value of -130 million won was calculated if the expansion was considered. On the other hand, the real-option value was estimated to be 444 million won, taking SMP uncertainty, expansion, and abandonment options into account, and an additional value of 288 million won was calculated from an analysis of the expansion project using the existing NPV analysis.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.24 no.4
• /
• pp.11-20
• /
• 2016

Depletion of natural resources and reduction of greenhouse gas emissions are an important issue which we have to solve. The recycling of waste has emerged as a global concern. In Korea, the development of cost-effective treatment and recycling technologies also need to be improved. In this study, we compared and analyzed the cost per unit of treatment and recycling of organic waste, and presented an effective recycling scheme. We investigated the current status of treatment and costs for six types of organic wastes from 80 workplaces, including organic wastewater treatment sludge, processed organic sludge, and plant residues. In addition, environmental costs for greenhouse gas reduction were calculated. It's an economic way that organic waste is composted and used as cement additives. In particular, the economic analysis was done by realistic results of the survey target companies. In conclusion, in order for reliable processing and recycling of organic wastes, wastewater treatment sludge and sewage sludge need to be classified based on hazard characteristics. Finally, technical difficulties need to be further resolved such as odors, leachate, and debris on recycling organic wastes.