• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.1
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• pp.31-38
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• 2022

Due to the increasing consumer demands for the safety, shelf life, and quality of food, the application and development of active packaging in the food and packaging industry have been improved. According to the standards and specifications of the Republic of Korea for utensils, containers, and packages, the function of active packaging is to remove or alleviate factors that degrade food quality. Although extensive reviews regarding the development and commercialization of active packaging have been conducted, the legal regulations and safety assessments concerning active packaging have rarely been examined. This review provides information regarding the definition, structure, components, operational mechanisms, and applications for active packaging that actively removes oxygen, moisture, carbon dioxide, and ethylene. Furthermore, the legal regulations and research results related to the development of test methods for safety assessments of active packaging are investigated.

• Clean Technology
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• v.28 no.2
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• pp.163-173
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• 2022

Research and development of biofuels as one of the means to mitigate global warming and to avoid fossil fuel depletion has occurred for more than 30 years. However, there has only been limited distribution of a few first- and second-generation biofuels, and widespread supply and consumption of biofuels is still far from a reality. Although a relatively recently studied third-generation biofuel derived from seaweed biomass has been shown to have many advantages, it is yet to be deployed in commercial-scale seaweed biorefineries. This review paper examines the advantages and disadvantages of seaweed biorefineries for the entire value chain covering from seaweed and its cultivation to biofuel production based on an extensive literature search and the author's experience of conducting feasibility studies pertaining to seaweed biorefineries for over 10 years. For this purpose, the literature survey will cover the current status of seaweed production and its research and development worldwide, conversion technologies for biofuel production from seaweed based on bench-scale experiments, and large-scale techno-economic feasibility studies for seaweed conversion to biofuels and bioenergy. In addition, the main problems expected with the commercialization of seaweed-based biofuels will be identified. Finally, the current status of seaweed biorefinery technology and the author's views on its promising future will be summarized.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.673-688
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• 2023

Purpose: Fires that occur during construction are infrequent, but cause great damage. Recently, with the growth of the logistics and distribution industry, the number of construction sites for new logistics warehouses is increasing, so it was selected as a research subject and research was conducted to reduce accidents at construction sites through the development of a fire risk assessment tool to quantitatively approach fire prevention. Method: A comprehensive fire risk assessment tool was accumulated by classifying the work in progress, classifying combustibles and ignition sources by grade, excluding air (oxygen), which is difficult to control, and additionally substituting evacuation safety. Result: Using the developed and proposed fire risk evaluation tool, excavation work with low fire risk, facility construction with medium fire risk, and finishing work with high fire risk were sampled to derive the result (CGI). Conclusion: In this study, it was possible to establish specific preventive measures and evaluate evacuation safety by controlling physical conditions (combustibles) and energy conditions (ignition sources) according to the risk assessment by developing a tool that can evaluate the risk of 14fire occurrence at construction sites. It is expected that in the future, through the application of the fire risk evaluation tool at construction sites, it will be provided as a criterion for establishing a process plan that can reduce risk and evaluating the adaptability of firefighting equipment.14

• Nuclear Engineering and Technology
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• v.55 no.8
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• pp.2935-2940
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• 2023

A polystyrene phantom was developed following the guidance of the International Atomic Energy Association (IAEA) for gamma knife (GK) quality assurance. Its performance was assessed by measuring the absorbed dose rate to water and dose distributions. The phantom was made of polystyrene, which has an electron density (1.0156) similar to that of water. The phantom included one outer phantom and four inner phantoms. Two inner phantoms held PTW T31010 and Exradin A16 ion chambers. One inner phantom held a film in the XY plane of the Leksell coordinate system, and another inner phantom held a film in the YZ or ZX planes. The absorbed dose rate to water and beam profiles of the machine-specific reference (msr) field, namely, the 16 mm collimator field of a GK Perfexion^TM or Icon^TM, were measured at seven GK sites. The measured results were compared to those of an IAEA-recommended solid water (SW) phantom. The radius of the polystyrene phantom was determined to be 7.88 cm by converting the electron density of the plastic, considering a water depth of 8 g/cm². The absorbed dose rates to water measured in both phantoms differed from the treatment planning program by less than 1.1%. Before msr correction, the PTW T31010 dose rates (PTW Freiberg GmbH, New York, NY, USA) in the polystyrene phantom were 0.70 (0.29)% higher on average than those in the SW phantom. The Exradin A16 (Standard Imaging, Middleton, WI, USA) dose rates were 0.76 (0.32)% higher in the polystyrene phantom. After msr correction factors were applied, there were no statistically significant differences in the A16 dose rates measured in the two phantoms; however, the T31010 dose rates were 0.72 (0.29)% higher in the polystyrene phantom. When the full widths at half maximum and penumbras of the msr field were compared, no significant differences between the two phantoms were observed, except for the penumbra in the Y-axis. However, the difference in the penumbra was smaller than variations among different sites. A polystyrene phantom developed for gamma knife dosimetry showed dosimetric performance comparable to that of a commercial SW phantom. In addition to its cost effectiveness, the polystyrene phantom removes air space around the detector. Additional simulations of the msr correction factors of the polystyrene phantom should be performed.

• Journal of the Korean Society of Earth Science Education
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• v.16 no.2
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• pp.291-301
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• 2023

In this study, the STEAM elements and convergence types which appeared in the creative and convergent activities in authorized elementary school science textbooks for 5^th and 6^th graders were analyzed. For this study, creative and convergence activities presented in 9 different science textbooks for 5^th and 6^th graders were selected and the STEAM elements and convergence types were analyzed by each publisher, grade-semester, and science field. The results of this study are as follows. First, there was a large variation by publisher in the total frequency of STEAM elements and the frequency of each element in creative and convergence activities. Second, the ratio of convergence type consisting of two elements was very high, and the higher the number of fused elements, the lower the ratio appeared in overall. Third, the art (A) element had the highest frequency in all grade-semesters, and the technology (T), engineering (E), mathematics (M) elements differed in the distribution of frequency by grade-semesters. Fourth, the engineering (E) element in the 'integration' field, and the art (A) element in the fields of 'movement and energy', 'material', 'earth and universe', and 'life' had the highest frequency.

• Environmental and Resource Economics Review
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• v.31 no.1
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• pp.113-139
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• 2022

The iron and steel industry is a manufacturing industry with the largest greenhouse gases emissions and has a great ripple effect on the national economy as a core material industry. This study internationally compared the decoupling patterns of greenhouse gases emissions in the iron and steel industry from 1990 to 2019, focusing on Korea, Japan, and Germany. In particular, unlike previous studies that considered only fuel combustion emissions, this study considered all fuel combustion emissions, industrial process emissions, and indirect emissions from the use of electricity and heat. As a result of the analysis, Korea is interpreted as expansive coupling, Japan as decoupling, and Germany as unclear. Therefore, the decoupling path that the Korean iron and steel industry should take should not be in Germany, but in the form of seeking a decoupling method similar to Japan or more effective than Japan. In addition, this study considered the characteristics of the iron and steel industry as much as possible and presented the causes of the decoupling analysis results and implications for the Korean iron and steel industry through comparison with Japan and Germany. In particular, four factors were suggested as factors which has promoted decoupling in Japan: high value-added of Japanese iron and steel products, development of energy efficiency technology in the Japanese iron and steel industry, strategic M&A of the Japanese iron and steel industry, and maintaining competitiveness according to the closed distribution structure of Japanese iron and steel products. The Korean iron and steel industry should also use the case of Japan as a benchmark to further increase added value through quality uprade and product diversification of iron and steel products, while at the same time making efforts to fundamentally reduce greenhouse gas emissions through the development of new technologies.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.5 no.5
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• pp.461-470
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• 2015

There has been a significant increase in the amount of research on reducing the lighting power consumption of buildings and also an increasing demand for technological development. Light shelf has been recognized as one of the most efficient solutions to this issue and related researches have been conducted, which have mostly focused on factors related to simple light shelves and are not suitable as an appropriate basis for the design of light shelves. Thus this study aims to establish the proper design basis for light shelves by evaluating the performance of shelves per reflection rate in indoor areas. Power consumption rate and indoor illumination intensity distribution of a testbed built based on actual living conditions were calculated for the performance evaluation, of which the results are as following: 1) Reduction of reflection rate of ceiling and walls caused average illumination intensity in summer, winter and median seasons, and evenness per reflection rate of indoor areas was found to be different in summer, winter and median seasons, making it a necessary consideration for designing light shelves. 2) Calculation of power consumption from lighting control showed that a high reflection rate of indoor areas may be suitable for power consumption reduction, and that reflection rates higher than 80% for ceilings and higher than 75% for walls in terms of the efficiency of researches on the indoor reflection rate and its application would be appropriate. This study is meaningful as the research focuses on light shelves based on considering indoor environmental factors. More studies will be required that consider a variety of factors.

• Journal of the Korean Geotechnical Society
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• v.39 no.7
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• pp.69-76
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• 2023

Cavity causes settlement and its remediation after an accident results in significant time and economic losses. This study aims to experimentally evaluate the prospect of using infrared camera to detect and measure underground subsidence. Emissivity is necessary to detect the energy emitted from an object and accurately assess temperature using an infrared camera. The emissivity in laboratory tests is fixed to evaluate a reasonable distance between the infrared camera and the object, and temperature values are assessed at various distances. In field experiments, the cavity of the field experiment is simulated using a PVC pipe with a diameter of 5 cm, artificially buried at depths of 5 and 25 cm from the surface. The infrared camera measurements are taken from 4 PM to 3 PM of the next day (a total of 23 h). The analysis included the time-series temperature distribution and the cooling rate index assessment, which represents the temperature change rate per unit of time. The results showed that various temperature trends are observed depending on the location of the subsidence. This study demonstrates that the infrared camera can be used to assess the condition of the subsurface.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1B
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• pp.89-100
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• 2010

The performance evaluation of a conventional Wave Resonator at the entrance of harbors against solitary wave has been performed using 3D numerical wave flume. A wave resonator has been designed for the attenuation of the transmitted wave energy by trapping the short periodic incident waves only. In this study, however, the controlled performance of the wave resonator by its various widths has been numerically investigated for solitary waves. Source distribution method based on the Green function and the 3D one-field Model for immiscible TWO-Phase flows (TWOPM-3D) using 3D numerical wave flume were used for the short-periodic waves and the solitary waves, respectively, and these models were verified through the comparisons with the previous experimental and numerical results by other researchers. It was confirmed that the wave resonator is effective enough to control the solitary waves as well as the periodic waves when it compares with the case of no resonance system. Further, it was found that there is the optimal width of a wave resonator to attenuate the target solitary waves.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3B
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• pp.285-293
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• 2010

Soil moisture is a key factor to control the exchange of water and energy between the surface and the atmosphere. In recent, many researches for spatial and temporal variability analyses of soil moisture have been conducted. In this study, we analyzed the spatio-temporal variability of soil moisture in Walnut Gulch Experimental Watershed, Arizona, U.S. during the Soil Moisture Experiment 2004 (SMEX04). The spatio-temporal variability analyses were performed to understand sensitivity of five observation sites with precipitation and relationship between mean soil moisture, and its standard deviation and coefficient of variation at the sites, respectively. It was identified that log-normal distribution was superior to replicate soil moisture spatial patterns. In addition, precipitation was identified as a key physical factor to understand spatio-temporal variability of soil moisure based on the temporal stability analysis. Based on current results, higher spatial variability was also observed which was agreed with the results of previous studies. The results from this study should be essential for improvement of the remotely sensed soil moisture retrieval algorithm.