• Transactions of Materials Processing
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• v.30 no.1
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• pp.5-15
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• 2021

The effects of heat treatments (T6 and T73) on the microstructure, mechanical properties, and high cycle fatigue behavior of modified AA7075 alloys were investigated. A modified 7075 alloy was manufactured using modified-Mg (Mg-Al2Ca) instead of the conventional element Mg. Based on the microstructure, the average grain size was 4.5 ㎛ (T6) and 5.2 ㎛ (T73). Regardless of heat treatment, the modified AA7075 alloys consisted of Al matrix containing homogeneously distributed Al2CuMg and MgZn2 phases with reduced Fe-intermetallic compound. Room temperature tensile tests showed that the properties of modified 7075-T6 (Y.S.: 622MPa, T.S: 675MPa, elongation: 15.4%) were superior to those of T73 alloy (Y.S.: 492MPa, T.S: 548MPa, elongation: 12.8%). Experimental data show that the fatigue life of T6 was 400 MPa, about 64% of its yield strength. However, the fatigue life of T73 alloy was 330 MPa and 67%. Irrespective of the stress level, all crack initiation points were located on the specimen surface, and no inclusions acting as stress concentrators were seen. Superior mechanical properties and high cycle fatigue behavior of modified AA7075-T6 alloy are attributed to the fine grains and homogeneous distribution of small second phases such as MgZn2 and Al2CuMg, in addition to reduced Fe-intermetallic compounds.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.5
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• pp.659-666
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• 2021

This research will apply the environmental characteristics of physical computing to game development, which has the concept of giving substantial materiality to digital media that do not exist in reality. The processing process of physical computing is digital input and digital output, and analog input and analog output, which mainly uses Malik controllers. Therefore, we select development elements by analyzing research cases in the field of digital art and information education where physical computing is studied a lot, and by analyzing games that borrowed some physical computing elements. The derived elements are verified by the Delphi's research methodology through agreement with experts. 12 elements are selected in this study, and the importance is shown in order of the physical properties in the virtual world, the suitability of the implementation technology, and the conformity between real and virtual players.

• Journal of Advanced Navigation Technology
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• v.22 no.2
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• pp.168-172
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• 2018

HACCP is scientific Sanitary control system to ensure food safety with autonomous, systematic and effective way by analysing hazard element that can be occurred in each steps until an end consumer takes food including raw material status, manufacturing, processing, storing, distributing, cooking and specifying the critical control point. In this paper, the temperature and humidity are measured during the transport of food, the stage of its distribution, to ensure systematic and effective management of HACCP, and we designed a monitoring terminal that uses this information to send it to servers periodically and a firmware that implements it. We have confirmed that the data transmitted by the terminal, including the information measured in sub-net, was well stored on the server and the response from the server is well received by the terminal. It is expected to be used for the management of food history, data tracking and statistical data in the future. This system is also considered to be an applicable system for group cafeteria such as schools or workplaces and logistics warehouses for raw materials or food storage and so on.

• Transactions of Materials Processing
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• v.30 no.3
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• pp.142-148
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• 2021

In hot forging analysis, the interfacial heat transfer coefficient (IHTC) is a very important factor defining the heat flow between the die and the material. In particular, in the hot forging analysis of aluminum 6xxx series alloy, which are used in automobile parts, differences in load and microstructure occur due to changes in surface temperature according to the IHTC. This IHTC is not a constant value but changes depends on pressure. This study derived the IHTC under low load using aluminum 6082 alloy. An experiment was performed by fabricating a compression die, and a heat transfer analysis was performed based on the experimental data. The heat transfer analysis used DEFORM-2D, a commercial finite element analysis program. To derive the IHTC, heat transfer analysis was performed for the IHTC in the range of 10 to 50 kW/m²℃ at intervals of 10kW/m²℃. The heat transfer analysis results according to the IHTC and the actual experimental values were compared to derive the IHTC of the aluminum 6082 alloy under low load.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.8
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• pp.1095-1102
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• 2021

A scalable ECC architecture with high scalability and flexibility between performance and hardware complexity is proposed. For architectural scalability, a modular arithmetic unit based on a one-dimensional array of processing element (PE) that performs finite field operations on 32-bit words in parallel was implemented, and the number of PEs used can be determined in the range of 1 to 8 for circuit synthesis. A scalable algorithms for word-based Montgomery multiplication and Montgomery inversion were adopted. As a result of implementing scalable ECC processor (sECCP) using 180-nm CMOS technology, it was implemented with 100 kGEs and 8.8 kbits of RAM when N_PE=1, and with 203 kGEs and 12.8 kbits of RAM when N_PE=8. The performance of sECCP with N_PE=1 and N_PE=8 was analyzed to be 110 PSMs/sec and 610 PSMs/sec, respectively, on P256R elliptic curve when operating at 100 MHz clock.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.1
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• pp.43-47
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• 2022

In this study, we demonstrated an eco-friendly thin-metallic-film-based heater which can be operated in water. Based on the materials stability, Mo was selected as the heating element to secure long-term stability. Using a magnetron sputtering, 40 nm-thick Mo layers were deposited onto a glass substrate, followed by the deposition of 60-nm-thick ZnO layer to prevent oxidation during the heater fabrication process. Then, PVB (Polyvinyl Butyral) was applied on top of ZnO layer and an additional glass substrate was placed, which were heated at 150℃ for 2 hr. The PVB was cured with strong adhesion by the processing condition. We operated the Glass/Mo/ZnO/Glass heater in water, and it was shown that the water temperature reached 50℃ within 2 minutes, with a minimal resistance change of the heater. Finally, the heaters exhibit a semi-transparency, and this aesthetic advantage is expected to contribute to the added value of the heater.

• Journal of the Korea Convergence Society
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• v.12 no.11
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• pp.319-328
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• 2021

The purpose of this study is to develop core competencies for gifted education by utilizing Delphi survey methods and to present behavioral element selection and scale questions based on the definition of competencies. First, the core competence for gifted education was selected through literature analysis, and the first Delphi survey was conducted to verify that the definition of each competency is suitable for the competency name. Subsequently, through a second Delphi survey, detailed questions were developed and verified by expressing the capabilities required to develop core competencies as behavior elements. Through two rounds of Delphi surveys, eight key competencies were finally selected: attitude and practice willingness, communication and collaboration, information processing and tool utilization, creative problem solving, convergence and application, higher-order inference, community spirit, and learning achievement orientation. This study is meaningful in that it selects core competencies and behavior elements for gifted education that are necessary to pursue goals that meet social needs and it presents tools to measure the degree of competency improvement for gifted education.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.12
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• pp.595-602
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• 2021

The robot is developing into a software-oriented shape that recognizes the surrounding situation and is given a task. Cloud Robotics Platform is a method to support Service Oriented Architecture shape for robots, and it is a cloud-based method to provide necessary tasks and motion controllers depending on the situation. As it evolves into a humanoid robot, the robot will be used to help humans in generalized daily life according to the three robot principles. Therefore, in addition to robots for specific individuals, robots as public goods that can help all humans depending on the situation will be universal. Therefore, the importance of information security in the Cloud Robotics Computing environment is analyzed to be composed of people, robots, service applications on the cloud that give intelligence to robots, and a cloud bridge that connects robots and clouds. It will become an indispensable element for In this paper, we propose a Security Scheme that can provide security for communication between people, robots, cloud bridges, and cloud systems in the Cloud Robotics Computing environment for intelligent robots, enabling robot services that are safe from hacking and protect personal information.

• Korean Journal of Food Science and Technology
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• v.53 no.2
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• pp.149-153
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• 2021

Mandarin peel (MP) is a by-product of the processing of citrus juice or other products. This study aimed to investigate the potential anti-obesity effect of an enzymatic extract of MP on the inhibition of adipogenesis in 3T3-L1 adipocytes. The enzymatic extract (MPCE) was prepared using the commercial food-grade carbohydrase Celluclast. Lipid accumulation and triglyceride levels were significantly lower in MPCE-treated cells than in untreated cells. In addition, MPCE treatment reduced the protein expression levels of peroxisome proliferator-activated receptor-γ, CCAAT/enhancer-binding protein α, sterol regulatory element-binding protein 1, and fatty acid-binding protein 4. These results suggest that MPCE inhibits adipogenesis by downregulating the expression levels of adipogenesis-related proteins. Therefore, the current findings demonstrate that MPCE possesses potent anti-obesity properties and could be a potential ingredient in functional food industries.

• Biomolecules & Therapeutics
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• v.29 no.3
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• pp.295-302
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• 2021

Microglial priming is the process of microglial proliferation and activation in response to neurodegeneration and abnormal protein accumulation. Priming makes microglia susceptible to secondary inflammatory stimuli and causes exaggerated inflammatory responses. In the present study, we established a microglial priming model in mice by administering a single injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 20 mg/kg). MPTP induced microglial activation without dopaminergic degeneration; however, subsequent treatment with a sub-toxic dose of lipopolysaccharides (LPS) induced an amplified inflammatory response and caused nigrostriatal dopaminergic degeneration. These pathological and inflammatory changes, including microglial activation and dopaminergic cell loss in the substantia nigra (SN) area were reversed by papaverine (PAP) administration. In addition, MPTP/LPS enhanced interleukin-1β (IL-1β) expression and processing via nod-like receptor protein 3 (NLRP3) inflammasome activation in the SN region of mice. However, PAP treatment suppressed inflammasome activation and subsequent IL-1β maturation. Moreover, PAP inhibited nuclear factor-κB (NF-κB) and enhanced cAMP-response element binding protein (CREB) activity in the SN of MPTP/LPS mice. These results suggest that PAP inhibits the activation of NLRP3 inflammasome by modulating NF-κB and CREB signaling pathways, which results in reduced microglial activation and neuronal cell death. Thus, PAP may be a potential candidate for the treatment of Parkinsons's disease, which is aggravated by systemic inflammation.