• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.6
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• pp.144-151
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• 2020

The number of drones used in various fields expected to 50,000 commercial drones by 2026. is to purchase business liability insurance only for commercial drones, as the scope of use of drones expands, it necessary to improve the drone insurance system, which imposes legal obligations aircraft duties. In particular, due to the diversification of aircraft characteristics of drones, an insurance system according to the degree of risk is required. To this end, a survey on the current status of drone operation in Korea, a review of documents related to drone insurance at home and abroad, collection and analysis of drone-related data, insurance systems for each transportation method, and analysis of data on overseas drone insurance products. o derive an improvement plan for the drone insurance system for drone insurance by aircraft characteristics and operation missions, and establish insurance standards by aircraft characteristics and operation missions, derive implications through required insurance surveys by sector such as users, users, and insurance companies. Detailed insurance standards were established by calculating the degree of risk according to the physical characteristics of the aircraft, and the liability for damage according to the operation mission was specified.

• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.566-572
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• 2020

In a wireless power transmitter, the characteristics and effects of wireless power transmission between two induction coils are investigated, and a power converter circuit and a battery charger/discharger circuit using wireless power transmission technology are proposed. The advantage of wireless power transmitters and wireless chargers is that, instead of the existing plug-in-mounted wired charger (OBC; on-board charger), the user can wirelessly charge the battery without connecting the power source when charging power to the battery. There is. In addition, the advantage of wireless charging can bring about an energy efficiency improvement effect by using the secondary side rectifier circuit and the receiving coil, but the large-capacity long-distance wireless charging method has a limitation on the transmission distance, so many studies are currently being conducted. The purpose of the study is to study the transmitter circuit and receiver circuit of a wireless power transmission device using a primary coil, a secondary coil, and a half bridge series resonance converter, which can transmit power of a non-contact type power transmitter. As a result, a new topology was applied to improve the power transmission distance of the wireless charging system, and through an experiment according to each distance, the maximum efficiency (95.8%) was confirmed at an output of 3 kW at an 8 cm transmission distance.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.4
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• pp.338-347
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• 2021

In this paper, the beta-ray sensor circuit used in the true random number generator was designed using DB HiTek's 0.18㎛ CMOS process. The CSA circuit proposed a circuit having a function of selecting a PMOS feedback resistor and an NMOS feedback resistor, and a function of selecting a feedback capacitor of 50fF and 100fF. And for the pulse shaper circuit, a CR-RC2 pulse shaper circuit using a non-inverting amplifier was used. Since the OPAMP circuit used in this paper uses single power instead of dual power, we proposed a circuit in which the resistor of the CR circuit and one node of the capacitor of the RC circuit are connected to VCOM instead of GND. And since the output signal of the pulse shaper does not increase monotonically, even if the output signal of the comparator circuit generates multiple consecutive pulses, the monostable multivibrator circuit is used to prevent signal distortion. In addition, the CSA input terminal, VIN, and the beta-ray sensor output terminal are placed on the top and bottom of the silicon chip to reduce capacitive coupling noise between PCB traces.

• Journal of Environmental Health Sciences
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• v.47 no.6
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• pp.548-557
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• 2021

Background: Due to the emergence of new diseases such as COVID-19, an increasing number of people are struggling with stress and depression. Interest is growing in forest-based recreation for physical and mental relief. Objectives: A prediction model equation using meteorological factors and data was developed to predict the quantities of medicinal substances generated in forests (monoterpenes) in real-time. Methods: The concentration of phytoncide and meteorological factors in the forests near Chuncheon in South Korea were measured for nearly two years. Meteorological factors affecting the observation data were acquired through a multiple regression analysis. A model equation was developed by applying a linear regression equation with the main factors. Results: The linear regression analysis revealed a high explanatory power for the coefficients of determination of temperature and humidity in the coniferous forest (R²=0.7028 and R²=0.5859). With a temperature increase of 1℃, the phytoncide concentration increased by 31.7 ng/Sm³. A humidity increase of 1% led to an increase in the coniferous forest by 21.9 ng/Sm³. In the deciduous forest, the coefficients of determination of temperature and humidity had approximately 60% explanatory power (R²=0.6611 and R²=0.5893). A temperature increase of 1℃ led to an increase of approximately 9.6 ng/Sm³, and 1% humidity resulted in a change of approximately 6.9 ng/Sm³. A prediction model equation was suggested based on such meteorological factors and related equations that showed a 30% error with statistical verification. Conclusions: Follow-up research is required to reduce the prediction error. In addition, phytoncide data for each region can be acquired by applying actual regional phytoncide data and the prediction technique proposed in this study.

• Journal of Life Science
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• v.32 no.7
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• pp.501-509
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• 2022

Pollen corrected from Quercus species is abundant in Korea and has been used to treat anemia and inflammation of the prostate gland. It is also used for hemostasis in oriental medicine. In this study, the ethanol extract of the acorn pollen and its subsequent organic solvent fractions using hexane, ethylacetate, butanol, and water residue were prepared, and their antioxidant, anti-thrombosis, and hemolysis activities were evaluated. The ethylacetate fraction of acorn pollen (EF-AP) showed the highest polyphenol content (225.0 mg/g) and strong antioxidant activity among the solvent fractions. The RC₅₀ of EF-AP against DPPH, ABTS, and nitrite radicals was 72.2, 27.7, and 62.6 ㎍/ml, respectively. The blood coagulation activities of the all-solvent fractions determined by thrombin time, prothrombin time, and activated partial thromboplastin time were negligible up to 5 mg/ml. Platelet aggregation inhibitory activities were observed in the EF-AP, butanol fraction, and water residue, whereas hexane fraction induced strong platelet aggregation. The EF-AP has no hemolysis activity against human RBC up to 1 mg/ml. UPLC/MS/MS analysis of the EF-AP revealed that rutin, isoquercitrin, and astragalin are major compounds for antioxidant and anti-thrombosis activities. Our results suggest that EF-AP could be developed as a noble antioxidant and anti-thrombosis agent.

• Journal of Korea Entertainment Industry Association
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• v.15 no.4
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• pp.73-87
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• 2021

Special theaters were created to provide a sense of immersion and spectacles due to differentiated screens, sound, seating facilities, and advanced services, and also expanded screens. The purpose of this study is to perform comparative analysis of the technical characteristics formats shown in special theaters(3D film, 4DX, IMAX, ScreenX, and VR) in order to identify and find ways to overcome the technological limitations in production. The various formats show differences in field of view depending on the exhibition technology and these differences affect the mise-en-scene, narrative, and editing of the film and consequently result in changes in the production environment and process. Therefore, directors and creators must understand the technological features and limitations of the new formats before making their approach. However, a new format encounters limitations on production sets due to the decline of technical education and succession. In situations where shooting with a special camera is essential, the particular characteristics of each format should be carefully considered from the planning stage but financial problems arise due to increase in production period and cost. To overcome these various obstacles, it is essential to first identify problems and present alternatives through in-depth research on the production set of each format. Finally, this research aims to explore the prototype of each format and analyze the current state of production technology with formats that have not been adapted to the market trends by combining with the other formats and showing that they can survive in new ways.

• Resources Recycling
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• v.31 no.5
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• pp.42-51
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• 2022

Aggregate resources in Korea are expected to run out owing to an increase in development demand and construction investment. Recycled concrete aggregates (RCA), extracted from waste concrete, have a lower quality than natural aggregates. However, RCA can produce concrete similar in quality to the normal concrete by aggregate pretreatment, use of admixtures, and quality control. RCA are most suitable for use in precast concrete products such as sidewalk blocks and revetment blocks. Herein, the feasibility of producing revetment blocks using recycled aggregate concrete (RAC), similar in quality to normal concrete, was analyzed. The amount of RCA was varied, and moderate high early strength cement and steam curing were used to produce the concrete test blocks. In the block test, the load resistance characteristics of the blocks were evaluated to determine optimal RAC and glass fiber reinforced polymer (GFRP) rebar compositions. Thus, the variable that reduced the cement content was determined at the same level as that of natural aggregate concrete by the control of steam curing. In the concrete block test, although this depends on the reinforcement ratio, the RAC block exhibited the same or better performance than a normal concrete block. Therefore, the low quality of RCA in RAC is no longer a problem when concrete mixing and curing are controlled and appropriate reinforcement is used.

• Journal of Korea Port Economic Association
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• v.38 no.3
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• pp.151-164
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• 2022

According to the "2021 Trade Statistics" released by the Korea Customs Service, the number of domestic export companies has decreased by 2,400 since COVID-19, and the number of importers has increased by 10,000. Exporting companies are making a great contribution to the economic development of Korea along with the creation of domestic jobs. At a time when the logistics environment changes rapidly, there are insufficient papers analyzing the impact of eco-friendly logistics strategies of domestic exporters on logistics performance. In order for exporting companies to continue to have global competitiveness and improve logistics performance, it is necessary to analyze the impact of eco-friendly logistics strategies on the logistics performance of exporting companies. The purpose of this study is to analyze the effect of eco-friendly logistics strategies of domestic export companies on logistics performance. The eco-friendly logistics strategy is divided into an internal strategy and a supply chain management strategy. As a result of the analysis, it was analyzed that the internal strategy has a positive effect on the logistics performance of exporting companies, and the supply chain management strategy has a positive effect on the logistics performance of exporting companies. As such, it was analyzed that the eco-friendly logistics strategy of exporting companies is an important resource for companies and serves as the basis for improving the logistics performance of companies.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.3
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• pp.197-212
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• 2022

This study was conducted to empirically analyze the effects and interactions among beneficial bacteria, commensal bacteria, and acne bacteria, which are factors in the skin microbiomes, on detrimental bacteria by 289 people, who are 20 to 49 years old among Koreans. As a result of multiple regression models using bio big data of skin microbiomes, when the difference in skin microbiomes according to the sex and age of the subjects was controlled, the beneficial bacteria showed a negative (-) effect on the detrimental bacteria, while the commensal and acne bacteria showed a positive (+) effect. Particularly, the negative (-) effect of beneficial bacteria on detrimental bacteria was different through interaction with acne bacteria according to the level of commensal bacteria. These results demonstrate that the activation of beneficial bacteria inhibits detrimental bacteria, and the effect of skin microbiomes on detrimental bacteria is balanced with skin microbiomes through interaction with independent influence. Therefore, it is suggested that when studying skin microbiomes products to help the proliferation of beneficial bacteria and to create a skin environment that inhibits detrimental bacteria in the personalized cosmetics manufacturing industry, it is necessary to consider the independent effects and interactions among skin microbiome factors together.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.530-536
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• 2021

This paper presents the performance measurement results of a hybrid sheet with both shielding and heat dissipation functions developed by laminating copper mesh sheets and natural graphite sheets, which are used widely as electromagnetic shielding and heat-dissipating materials in electronic devices, without a pressure-sensitive adhesive (PSA). The results were compared by measuring the vertical and horizontal thermal conductivity with two other products to confirm the heat dissipation performance. A radiation emission test confirmed the electromagnetic shielding performance using a 3m electromagnetic anechoic chamber according to the CISPR 11 standard. In the case of vertical thermal conductivity, the proposed hybrid sheet was approximately 8.63 times higher than that of an aluminum sheet with heat dissipation coating and 18.7 times higher than that of a copper sheet laminated with artificial graphite with PSA. The proposed hybrid sheet was approximately 0.64 times that of the sheet, and approximately 1.76 times that of the heat-dissipated aluminum sheet in case of horizontal thermal conductivity. Measurements after applying each sheet in the same heat source revealed the proposed hybrid sheet to have the best heat dissipation performance. The radiation emission test showed that significantly radiation noise had been removed.