Beam steering precision enhanced loudspeaker

This technology concerns a piezoelectric MEMS-based superdirectional loudspeaker and beam steering method.

In the case of audible sound, the frequency is low, so the sound is transmitted in all directions unless the transducer is very large, so this technology proposes a piezoelectric MEMS-based super-directional loudspeaker capable of precise steering of the sound wave beam using a parametric array in the air.

This technology enables independent driving of the transducer by implementing the transducer in a three-dimensional connection structure, improving beam steering precision by precisely controlling the phase and amplification gain of the driving signal. In addition, the performance of the loudspeaker can be improved by minimizing wiring length deviation and ensuring the precision of the driving signal.

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Key Features:

• The core principle of piezoelectric MEMS using a parametric array including multiple transducers that generate ultrasonic waves
• Obtained by measuring the output of each transducer while applying the same reference voltage to multiple transducers
• Modulating the input signal into a driving signal corresponding to each transducer using a carrier wave signal
• The driving signal applied to each transducer using a plurality of power amplifiers connected one-to-one amplification

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High CO2 hydration activity carbonic anhydrase'

This technology is about chimeric carbonic anhydrase derived from Dunaliella salina.

When trying to apply protein as a biocatalyst for removal and conversion of existing carbon dioxide, the low yield of Dsp-CA-c became a problem. To solve this problem, we propose carbonic anhydrase [Dsp-nCA-c] containing the amino acid sequence shown in SEQ ID NO: 4. The chimeric proteins Dsp-nCA-c and Dsp-nCA-c (G263S) of the invention show higher water-soluble expression and CO2 hydration activity than the existing Dsp-CA-c. The two proteins of this technology show increased soluble expression and CO2 hydration activity in Dsp-CA and CO2 mineralization, so they can be used in the CO2 removal process using CA catalysts and the production of various industrial raw materials using CO2 mineralization. They can also be used as catalysts in the synthesis of useful metabolites to increase synthesis yield.

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Key Features:

• Carbonic anhydrase containing the amino acid sequence shown in SEQ ID NO: 4 [Dsp-nCA-c]
• Carbonic anhydrase containing the amino acid sequence shown in SEQ ID NO: 5 [Dsp-nCA-c(G263S)]
• Capture of carbon dioxide containing carbonic anhydrase or Fixation
• Increase the amount of soluble expression by fusing part of the amino terminus to a protein with low soluble expression, such as Dsp-CA-c.

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This technology was developed through research support from the Korea Institute for Ocean Science and Technology Promotion for the development of marine silica biomineral-based synthetic bone graft materials.

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High-accuracy biosignal wearable device

This technology relates to a system and method for detecting user abnormalities based on biometric signals and wearable devices, which can prevent accidents in advance by classifying and detecting abnormal conditions of the driver in advance based on biological signals measured using the device and notifying them to the driver and passengers.

The biosignal-based method has the inconvenience of having to attach a measuring device to the driver's body to collect biosignals, so a wearable device was designed, but the existing method is based on the measurement device. Because it is very sensitive to movement and contains a lot of noise, there is a high possibility of incorrect status judgment when used for status determination due to the inaccuracy of the acquired signal. To solve this problem, this technology proposes a method of using Adaboost, one of the ensemble learning techniques that produces the final result.

This technology is capable of detecting abnormal conditions of the driver in advance and notifying them to the driver and passengers. In addition to preventing traffic accidents, the condition detection algorithm can be applied to various products such as various healthcare products or systems that monitor the condition of workers in other industrial sites.

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Key Features:

• After measuring several signals from the driver, inspecting the measured signals and performing a pre-processing process to check whether the signals can be used to detect abnormal conditions
• In order to have high-accuracy detection performance, use Adaboost, an ensemble learning technique that combines the results of multiple classifiers to produce the final result
• The driver's biological signals such as PPG signals, temperature, and GSR signals, and acceleration and gyro signals Measuring signals related to movement
• Designing a neural network-based classifier and combining the results of several trained classifiers to perform final state classification and detection

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This technology was developed through support from the National IT Industry Promotion Agency's bio-signal-based driver abnormality detection and notification system research project.

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Carbon precursor cathode electrode with improved electrical conductivity

This technology is related to a method of manufacturing a cathode electrode including a carbon structure with a three-dimensional network structure.

The goal to solve is to provide a cathode electrode with improved electrical conductivity during charging and discharging. To this end, we propose a carbon precursor cathode with a three-dimensional network structure in which main fibers randomly cross each other.

The lithium secondary battery into which the cathode electrode according to this technology is inserted performs a long charge and discharge cycle. Meanwhile, it shows excellent characteristics of improved CE (coulombic efficiency) and stability due to the pores and chalcogen functional groups provided on the surface and inside of the main fiber of the cathode electrode.

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Key Features:

• The core principle is a three-dimensional network structure in which the main fibers of the carbon structure randomly intersect each other.
• Provides secondary pores and chalcogen functional groups larger than the size of the primary pores on the surface and inside the main fibers.
• Chalcogen functional groups contain chalcogen elements (S, Te, Se), carbon, or oxygen.
• During charge-discharge cycles, the generation of byproducts containing Li2CO3 is reduced due to the chalcogen functional groups within the cathode electrode.

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This technology was developed through research support from the National Research Foundation of Korea to identify the formation mechanism and redox characteristics of highly functional pyropolymers rich in pi electrons.

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Seaweed biomass with excellent carbon dioxide absorption capacity

This technology concerns a method of producing D-glucaric acid, which can be used as a monomer for bio-based plastic, and a method of converting D-glucuronic acid obtained from green algae to D-glucaric acid using recombinant microorganisms introduced with D-glucaric acid production genes.

The existing starch-based raw material is grains, which are edible crops. The use of lignocellulose from woody or herbaceous plants, which is an inedible biomass, has the disadvantage of requiring a complex and expensive pretreatment process to remove lignin, a non-degradable aromatic polymer. To solve this problem, this technology introduces only two genes using seaweed, a non-edible biomass, so it can shorten the existing complex reaction and proposes a method to effectively produce D-glucaric acid.

The seaweed biomass used in this technology has a faster growth rate than terrestrial biomass, can be cultivated in large quantities in the ocean, and has an excellent carbon dioxide absorption ability, allowing it to be used as a raw material for next-generation bioplastics. Since it does not contain lignin, it is easy to saccharify, so it will be in the spotlight as a biomass.

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Key Features:

• Green algae raw material is washed in cold water and dried to minimize leakage and deformation of sugar content.
• Recombinant microorganisms convert D-glucuronic acid into D-glucarate lactone
• Polypeptide acts as D-glucuronic acid dehydrogenase
• D-glucuronic acid dehydrogenase has SEQ ID NO. 2 and amino acid sequence 80% based on ClustalW method. Using genes with the above similarity

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This technology was developed through support from the Korea Institute for Ocean Science and Technology Advancement's research project to produce next-generation BIO-BASED POLYMER through the development of new technology for bioconversion of sugars derived from green algae.'

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Dentrite-suppressed mesoporous structure cathode electrode

This technology is related to metal cathode electrodes and secondary batteries using them.

The problem that this technology aims to solve is a metal cathode electrode with suppressed dendrite growth. To this end, we propose a mesoporous structure in which the surface area is increased by nanopores on the inner surface of the concave part.

This technology not only inhibits the growth of lithium ions into lithium metal dendrites by nanopores and oxygen functional groups, but also suppresses the generation of by-products within the cathode electrode, and the effect of this is to prevent long-term charge and discharge cycles. It has outstanding advantages of high efficiency and stability.

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Key Features:

• Among the concave and convex portions of the metal substrate structure, selectively form nanopores and oxygen functional groups within the concave portion
• Make the inner surface of the concave portion lithiophilic and provide an oxidizing solution to the metal substrate structure
• Provide a mask on the convex portion of the metal substrate structure
• The inner surface of the concave portion has a mesoporous structure by nanopores have

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This technology was developed through the support of the National Research Foundation of Korea's research project to identify the formation mechanism and redox characteristics of highly functional pyropolymers rich in pi electrons.

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Device capable of collecting small-area underwater samples

This technology is about a device that can collect samples existing in the water.

The importance of deep-sea exploration is emerging due to the depletion of energy resources on land and various reasons, but the method of collecting large quantities of samples by dragging the existing trawl net by boat has the problem of not only being inconvenient in having to do the work with a large boat, but also being unsuitable when collecting samples in a narrow area. In order to solve these problems, this technology proposes a new underwater sampling device that can collect samples that exist underwater or in the deep sea.

This technology not only makes it possible to easily collect samples from the deep sea using a small amount of force, and easily collects deep sea samples in a narrow area, but also makes it possible to easily collect deep sea samples without a separate external power supply.

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Key Features:

• The sample inlet is located on one side of the internal space of a chamber having a connected internal space.
• A support member and a support force removal member that removes the support force inside the internal space open the inlet so that the blocking member can block the inlet.
• An underwater sample flows into the inlet due to the pressure difference between the internal space and the outside of the chamber.
• The blocking member is formed so that it can be accommodated within the receiving groove in the event that the support member bursts or contracts.

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Shuttle effect suppressing telulium nanotube electrode active material

This technology relates to an electrode active material containing tellurium nanotubes with a conductive polymer layer and a method of manufacturing electrodes for secondary batteries.

The technology of using sodium, aluminum, zinc, etc. in the negative electrode is attracting attention as it increases the stability of secondary batteries and is highly price competitive, but there is a problem in that intermediate materials dissolve in the electrolyte during the charging and discharging process, creating a shuttle effect that travels between both electrodes. In order to solve this problem, this technology proposes a technology to synthesize tellurium material in the form of nanotubes and coat it with a conductive polymer.

By using tellurium nanotubes formed with a conductive polymer layer through this technology as an electrode active material, it is more economical than the existing technology of manufacturing electrode active materials by supporting them in a host material to suppress the elution of intermediate materials, and can further contribute to commercialization. The advantage is that the specific gravity of the active material in the electrode does not decrease, increasing energy density. There is.

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Key Features:

• The core principle is a conductive polymer layer formed between tellurium nanotubes, which are formed by stacking tellurium atoms.
• Polypyrrole, polyaniline, polyacetylene, and polyphenylene vinylene (PPV) are used as conductive polymers.
• At the interface between the conductive polymer layer and the tellurium nanotubes, tellurium particles are encapsulated within the conductive polymer matrix.
• Tellurium nanotubes have a hexagonal prism structure formed by single-walls.

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Metal chalcogen thin film electronic device implemented on glass substrate

This technology relates to a method of manufacturing a high-quality, large-area metal chalcogenide thin film with uniform thickness and composition by coating a polymer-precursor solution containing a polymer and a metal chalcogenide compound precursor on a substrate, and a method of manufacturing an electronic device containing the metal chalcogenide thin film.

Semiconductor metal chalcogenide has an appropriate band gap and an electron mobility of hundreds of cm2/V·s. Since it is visible, it is suitable for application in semiconductor devices such as transistors and has great potential for flexible transistor devices, but there is a problem in that it is difficult to satisfy these conditions when making a thin film in a solution. To solve this problem, this technology proposes a new concept of forming a polymer thin film layer on the substrate to ensure that all reactions occur only at the interface of the substrate.

The method of manufacturing metal chalcogenide thin films according to this technology is not only effective in providing high-quality thin films with a large area of ​​6 inches or more with uniform thickness and composition through low production costs and simple processes, but also electronic devices containing large-area metal chalcogenide thin films can have high charge mobility and modulate band structure according to thickness, and can implement flexible substrates, so they can be applied to various fields such as high-performance transistors, optical devices, catalysts, and energy materials.

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Key Features:

• Preparing a polymer-precursor solution containing a polymer and a metal chalcogenide compound precursor
• Polyalkyleneimine polymer is ionic bonded with a metal chalcogenide compound precursor in a polymer-precursor solution
• R3 to R18 are the same or different from each other, and are each independently a hydrogen atom, or an aminoalkyl group of C1 to C5
• The heat treatment step is performed with 4 mol% hydrogen and Performed without additional supply of sulfur under a reducing atmosphere mixed with 96 mol% argon gas

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This technology was developed through support from the National Research Foundation of Korea's research project on solution-based direct growth and micropatterning of metal chalcogen ultrathin films on large-area flexible substrates.'

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Stability-enhanced material for lithium metal anode

This technology is about the manufacturing method of the electrode material for the negative electrode of lithium metal secondary battery.

The use of lithium metal as the negative electrode for high-performance next-generation secondary batteries is attracting attention, but it has stability problems such as ignition and explosion due to dendrite metal growth. To solve these problems, this technology proposes a method of synthesizing nitrogen-doped pseudo-capacitance nanocarbon through arc discharge.

This technology proposes a method of synthesizing nitrogen-doped pseudo-capacitance nanocarbon through arc discharge. It is expected to contribute to the development of the secondary battery industry as a groundbreaking lithium metal secondary battery anode electrode that can not only improve the performance of secondary batteries by reducing phase transition resistance and concentration resistance, but also secure high coulombic efficiency and stability even during repeated charge and discharge cycling through secondary battery electrodes with a solid electrolyte interface layer with high ion conductivity.

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Key Features:

• Synthesis of pseudo-capacitance nanocarbon doped with nitrogen through arc discharge on graphite material
• Performing pre-lithiation process based on lithium metal on nanocarbon
• Nanocarbon with doped three-dimensional nano-porous structure
• Formation of lithium-containing inorganic solid electrolyte interfacial layer (L I-SEI) on the surface of nanocarbon

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This technology was developed through the support of the National Research Foundation of Korea's research project to identify the formation mechanism and redox characteristics of highly functional pyropolymers rich in pi electrons.

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