• The Journal of Bigdata
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• v.6 no.2
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• pp.85-98
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• 2021

The pandemic of COVID-19 further promoted the imbalance in the volume of imports and exports among countries using containers, which worsened the shortage of empty containers. Since it is important to secure as many empty containers as the appropriate demand for stable and efficient port operation, measures to predict demand for empty containers using various techniques have been studied so far. However, it was based on long-term forecasts on a monthly or annual basis rather than demand forecasts that could be used directly by ports and shipping companies. In this study, a daily and weekly prediction method using an actual artificial neural network is presented. In details, the demand forecasting model has been developed using multi-layer perceptron and multiple linear regression model. In order to overcome the limitation from the lack of data, it was manipulated considering the business process between the loaded container and empty container, which the fully-loaded container is converted to the empty container. From the result of numerical experiment, it has been developed the practically applicable forecasting model, even though it could not show the perfect accuracy.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.2
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• pp.71-77
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• 2023

Absorbable periodontal tissue regeneration barrier membranes (total 6; domestic 4; import 2) were comparatively analyzed. In the case of the xenograft barrier membrane, the collagen product had excellent tensile strength but low strain, and the porcine pericardial membrane had good mechanical properties, but its thickness was too thick to control. The synthetic PLLA membrane manufactured by the electrospinning had a relatively low water absorption capacity. However, the hybrid barrier membrane was able to control mechanical properties and biocompatibility through proper mixing of synthetic polymer and natural polymer. DA02 (PLLA/gelatin), a newly developed hybrid absorbable periodontal tissue regeneration membrane that is entirely dependent on imports, can be applied to an absorbable periodontal tissue regeneration barrier membrane due to suitable mechanical properties and biocompatibility.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.11-11
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• 2021

Ferns have been consumed as food in many countries for centuries. As rich sources of protein, fiber, minerals, vitamins, essential amino acids, and fatty acids, ferns provide important nutrients to humans. Eastern bracken (Pteridium aquilinum var. latiusculum (Desv.) Underw. ex A. Heller) is the most popular edible fern in South Korea where, additionally, it has long been used as an edible wild leaf vegetable. Recently, the production of eastern brackens in South Korea (2018) has reached 14,032 tons, for an annual revenue of 83.5 billion won, and even more eastern brackens are marketed if imports are taken into account as well. Most of the common ferns can be propagated using spores. However, fern farmers cultivate seedlings through traditional propagation methods, such as root pruning or rhizome division. These propagation methods exhibit limitations in forming roots and growing-points and are labor intensive. Quality seedlings of eastern bracken can be obtained through spore propagation, but the spores are fine and difficult to handle in the field. In addition, it would require appropriate environmental control. The production of synthetic seeds using encapsulation technology is easy to establish and it can be used to achieve high productivity at low cost. Synthetic seeds contain explants embedded into a seed foam, and they overcome the limitations of micropropagation and offer the possibility of using plug seedlings. Synthetic seed matrix, such as sodium alginate, has the advantages of low cost, low toxicity, and gel stability. The present study aimed to develop and produce synthetic seeds for the commercial exploitation of eastern bracken. Furthermore, we verified spore germination and the extent of gametophyte and sporophyte development achieved with our new synthetic seeds, whose production was intended to solve current problems with the handling, storage, and transportation of eastern bracken.

• Korea Trade Review
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• v.48 no.1
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• pp.307-329
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• 2023

This paper studies how the free trade agreements (FTAs) have changed the dynamics of Korea's imports since 1996. Specifically, the dynamic regression analysis on the transition of trade liberalization discovers three main findings: (1) import values of Korea increase gradually as FTAs enter into force; (2) the extensive margins of import work as a major source of the trade effect in the transition episode of FTAs; (3) the extensive margins of import tend to increase even before FTAs enter into force. This noble forward-looking effect suggests some potential foreign exporters or exporting goods enter the Korean market, especially when FTAs negotiation starts. It supports the early entry behavior of potential exporters found in recent international trade literature.

• Korea Trade Review
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• v.48 no.1
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• pp.165-191
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• 2023

The US and EU have imposed energy sanctions on the Russian oil and gas sector in response to the Ukraine crisis. One of the key measures is to cut oil and gas imports from Russia. The US and EU are both the senders of sanctions against Russia. However, there is a fundamental difference between them. While the US is the net oil and gas exporter, most EU member states are heavily dependent on Russian oil and gas. If the US and other major oil and gas exporting countries can replace Russia in the EU energy market, the effectiveness of energy sanctions against Russia can be guaranteed. Our result shows that it is difficult for the major oil and gas exporters to fully replace Russia in the short run because of the lack of additional production capacity and infrastructure. We conclude that the US and EU's energy sanctions against Russia can not guarantee its effectiveness. We argue that other measures, such as diplomacy, should be taken to settle the conflicts in Ukraine.

• Korea Trade Review
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• v.47 no.6
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• pp.247-267
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• 2022

Since the Korea-Vietnam FTA was signed in 2015, trade between the two countries has increased rapidly, accounting for 6.8% of Vietnam's exports and 17.9% of its imports in 2020. The two countries show differences in import and export items. Vietnam has a high export ratio of agri-food products or products with the low-middle level of technology, while Korea has a high export ratio of products with the upper-middle level. The purpose of this study is to present implications by analyzing changes in trade competitiveness between Vietnam and Korea by technology level (2002-2020). For this purpose, statistics from UN Comtrade were used, and methodologies such as market share, Export Market Share (EMS), Trade Specialization Index (TSI), Intra-Industrial Trade Index (IIT), Revealed Comparative Advantage (RCA), and BCG Matrix were used. The results of the study are as follows. First, when looking at Vietnam's trade structure with South Korea by technology level, it was analyzed that the trade deficit widened as it showed a competitive disadvantage in high-tech, ICT, middle- and low-level technology items, excluding low-end technology items. Second, in terms of market share, the market share of Vietnamese products in the Korean market is continuously increasing, while the Korean market share in Vietnam is gradually decreasing from 2017. Third, Vietnam's export competitiveness to Korea by technology level shows that low-level technologies are competitive, but they are inferior in competitiveness in all other technology level, and especially in areas with high technology level, the level of inferiority is high. In conclusion, the trade relationship between Vietnam and Korea has maintained a mutually complementary rather than competitive relationship, which is expected to continue in the future.

• Korea Trade Review
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• v.46 no.6
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• pp.93-107
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• 2021

The bill of lading serves to link imports and exports. It is the last document issued in the export process and is the most important document before import and export as it is the first document required for importers to take over goods. Transfer the right to the goods to be transported to another person through endorsement. The role and importance of the bill of lading has already been suggested in many previous studies and the trading partners are fully aware of it. In addition, all countries and international organizations recognized the importance and enacted various laws and systems in relation to possible legal problems and they have become customary in practice. However, trade fraud that exploits the characteristics of the bill of lading may occur. In order to solve this problem, various attempts related to the electronic rights transfer of the bill of lading began to be carried out, and many institutions and companies are still trying to develop a new system. As a result of these efforts, electronic bills of lading, such as bolero, appeared, and electronic bills of lading, which can transfer rights in an electronic way, appeared. Therefore, this study intends to present the feasibility of the introduction of smart bills of lading after examining the current status of electronic bills of lading and the introduction of block chain technology-based bills of lading.

• Korean Chemical Engineering Research
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• v.61 no.4
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• pp.591-597
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• 2023

Pakistan depends heavily on imports for its fuel requirements. In this experiment, catalytic pyrolysis of a blend of feedstock's consisting of date seed, wheat straw, and corn cob was conducted in a fixed bed reactor to produce oil that can be used as an alternative fuel. The main focus was to emphasize the outcome of important variables on the produced oil. The effects of operating conditions on the yield of bio-oil were studied by changing temperature (350-500 ℃), heating rate (10, 15, 20 ℃/min), and particle size (1, 2, 3 mm). Moreover, ZnO was used as a catalyst in the process. First, the thermal degradation of the feedstock was investigated by TGA and DTG analysis at 10 ℃/min of different particle sizes of 1, 2, and 3mm from a temperature range of 0 to 1000 ℃. The optimum temperature was found to be 450 ℃ for maximum degradation, and the oil yield was indicated to be around 37%. It was deduced from the experiment that the maximum production of bio-oil was 32.21% at a temperature of 450 ℃, a particle size of 1mm, and a heating rate of 15 ℃/min. When using the catalyst under the same operating conditions, the bio-oil production increased to 41.05%. The heating value of the produced oil was 22 MJ/kg compared to low-quality biodiesel oil, which could be used as a fuel.

• Journal of Sensor Science and Technology
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• v.32 no.5
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• pp.290-294
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• 2023

Among various types of harmful gases, hydrogen sulfide is a strong toxic gas that is mainly generated during spillage and wastewater treatment at industrial sites. Hydrogen sulfide can irritate the conjunctiva even at low concentrations of less than 10 ppm, cause coughing, paralysis of smell and respiratory failure at a concentration of 100 ppm, and coma and permanent brain loss at concentrations above 1000 ppm. Therefore, rapid detection of hydrogen sulfide among harmful gases is extremely important for our safety, health, and comfortable living environment. Most hydrogen sulfide gas sensors that have been reported are electrical resistive metal oxide-based semiconductor gas sensors that are easy to manufacture and mass-produce and have the advantage of high sensitivity; however, they have low gas selectivity. In contrast, the electrochemical sensor measures the concentration of hydrogen sulfide using an electrochemical reaction between hydrogen sulfide, an electrode, and an electrolyte. Electrochemical sensors have various advantages, including sensitivity, selectivity, fast response time, and the ability to measure room temperature. However, most electrochemical hydrogen sulfide gas sensors depend on imports. Although domestic technologies and products exist, more research is required on their long-term stability and reliability. Therefore, this study includes the processes from electrode material synthesis to sensor fabrication and characteristic evaluation, and introduces the sensor structure design and material selection to improve the sensitivity and selectivity of the sensor. A sensor case was fabricated using a 3D printer, and an Ag reference electrode, and a Pt counter electrode were deposited and applied to a Polytetrafluoroethylene (PTFE) filter using PVD. The working electrode was also deposited on a PTFE filter using vacuum filtration, and an electrochemical hydrogen sulfide gas sensor capable of measuring concentrations as low as 0.6 ppm was developed.

• International journal of advanced smart convergence
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• v.12 no.4
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• pp.208-216
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• 2023

The purpose of our study is to design datasets for Artificial Intelligence learning for cold sea fish farming. Salmon is considered one of the most popular fish species among men and women of all ages, but most supplies depend on imports. Recently, salmon farming, which is rapidly emerging as a specialized industry in Gangwon-do, has attracted attention. Therefore, in order to successfully develop salmon farming, the need to systematically build data related to salmon and salmon farming and use it to develop aquaculture techniques is raised. Meanwhile, the catch of pollack continues to decrease. Efforts should be made to improve the major factors affecting pollack survival based on data, as well as increasing the discharge volume for resource recovery. To this end, it is necessary to systematically collect and analyze data related to pollack catch and ecology to prepare a sustainable resource management strategy. Image data was obtained using CCTV and underwater cameras to establish an intelligent aquaculture strategy for salmon and pollock, which are considered representative fish species in Gangwon-do. Using these data, we built learning data suitable for AI analysis and prediction. Such data construction can be used to develop models for predicting the growth of salmon and pollack, and to develop algorithms for AI services that can predict water temperature, one of the key variables that determine the survival rate of pollack. This in turn will enable intelligent aquaculture and resource management taking into account the ecological characteristics of fish species. These studies look forward to achievements on an important level for sustainable fisheries and fisheries resource management.