Cheongju, South Korea

Chungbuk National University
Cheongju, South Korea

Chungbuk National University is one of ten Flagship Korean National Universities. It takes its name, Chungbuk, from the common abbreviated form of the province's Korean name. Wikipedia.

Time filter
Source Type

Chungbuk National University, Korea Institute of Science and Technology | Date: 2016-01-29

Provided are a neurovascular unit (NVU)-on-a-chip and a method of fabricating the same, which 3-dimensionally integrates various human brain cells in a microfluidic platform by using a brain cell co-culture technique so as to simulate a similar environment to the human brain in vitro. The NVU-on-a-chip includes an extracellular matrix (ECM) simulation material (70) in a gel state; and at least one channel (75) which passes through the ECM simulation material (70) and perfuses a culture medium, in which the ECM simulation material (70) contains a plurality of types of human brain cells on an outer side of the channel (75), a brain microvessel endothelial cell lining (91) is formed on an inner side of the channel (75), and the plurality of types of human brain cells and the brain microvessel endothelial cell lining (91) contact each other through the channel (75) to simulate a blood brain barrier (BBB) of a human brain and a neurovascular unit (NVU) of the human brain including the BBB.

News Article | May 23, 2017

Gravitational microlensing is an invaluable method of detecting new extrasolar planets and brown dwarfs, regardless of the light they emit. This technique is therefore sensitive to the mass of the objects, rather than their luminosity, which allows astronomers to study objects that emit little or no light at all. Hence, due to their extremely low luminosities, brown-dwarf systems seem to be ideal targets for microlensing observations. Now, a team of astronomers led by Cheongho Han of the Chungbuk National University in Cheongju, South Korea, reports the detection of a new brown-dwarf binary system from the analysis of the microlensing event OGLE-2016-BLG-1469. The discovery is the result of a joint effort of over 50 scientists working in three microlensing research groups. The team consists of researchers from the Korea Microlensing Telescope Network (KMTNet), the Optical Gravitational Lensing Experiment (OGLE) and the Microlensing Observations in Astrophysics (MOA). "In this paper, we present the microlensing discovery of another binary system composed of brown dwarfs," the astronomers wrote in the paper. For their observations of OGLE-2016-BLG-1469, MOA researchers employed the 1.8m telescope at the Mt. John University Observatory in New Zealand, while OGLE scientists used the 1.3m telescope located at the Las Campanas Observatory in Chile. When it comes to KMTNet, the astronomers utilized three identical 1.6m telescopes located at the Cerro Tololo Inter-American Observatory in Chile, the South African Astronomical Observatory in South Africa, and the Siding Spring Observatory in Australia. All these ground-based observatories located worldwide allowed the team to find that the light curve of the microlensing event showcased a short-term central anomaly. This irregularity turned out to be produced by a binary companion with a mass roughly equal to the primary. More importantly, the researchers were able to determine the mass of both brown dwarfs and estimate their projected separation. They found that the mass of one of the newly discovered objects is about 0.05 solar masses, while the second one has approximately 0.01 the mass of the sun. The projected separation between the binary components was estimated to be 0.33 AU. Moreover, the study revealed that the system is located about 14,670 light years away from the Earth. "By measuring both the angular Einstein radius and the microlens parallax, we could uniquely determine the masses and identified the substellar nature of the lens components," the paper reads. According to the authors of the paper, their discovery shows the importance of the microlensing technique when it comes to finding new brown-dwarf binary systems. "The lens was the third microlensing brown-dwarf binary with measured mass, demonstrating the usefulness of the microlensing method in detecting field brown-dwarf binaries," the researchers concluded. Explore further: Astronomers discover new substellar companion using microlensing Abstract We report the discovery of a binary composed of two brown dwarfs, based on the analysis of the microlensing event OGLE-2016-BLG-1469. Thanks to detection of both finite-source and microlens-parallax effects, we are able to measure both the masses M1∼0.05 M⊙, M2∼0.01 M⊙, and distance DL∼4.5 kpc, as well as the projected separation a⊥∼0.33 au. This is the third brown-dwarf binary detected using the microlensing method, demonstrating the usefulness of microlensing in detecting field brown-dwarf binaries with separations less than 1 au.

The present invention provides a novel use of hsvI-miR-H18 or hsv2-miR-H9-5p, which is microRNA, for the diagnosis of prostate cancer. According to hsvI-miR-H18 or hsv2-miR-H9-5p of the present invention, it is possible to accurately diagnose even a subject in the PSA gray zone in which accurate diagnosis though PSA is difficult. The present invention can be applied to various biological samples, and exerts accurate diagnostic ability even when a supernatant of the solution excluding, particularly, cell-derived materials is used, and thus a diagnostic procedure is simple and convenient. According to the present invention, the prostate cancer can be accurately and promptly diagnosed at low costs.

Chungbuk National University and Gangneung - Wonju National University | Date: 2014-06-05

Provided is a functional cosmetic composition of white rose extract and a gartanin derivative compound isolated therefrom, and specifically, to a cosmetic composition for skin whitening and skin wrinkle alleviation containing, as active ingredients, white rose petal extract and gartanin derivative compounds isolated therefrom. The white rose extract and gartanin derivative compound, according to the present invention, are safe without causing side effects on the skin, prevent melanin production through a mechanism inhibiting tyrosinase activity, thereby having a whitening effect, and exhibit a wrinkle alleviation effect by a mechanism inhibiting MMP-1 activity, and thus the composition, of the present invention, containing the same as active ingredients, can be utilized as a material for functional cosmetics for skin whitening and wrinkle alleviation without causing skin irritation.

Yang B.-D.,Chungbuk National University
IEEE Journal of Solid-State Circuits | Year: 2015

This paper proposes a low-power effective memory-size expanded ternary content addressable memory (TCAM). The IP address of IPv6 extends to 128 bits, where the prefix bits store '0' or '1' and the remaining bits store 'X' (don't care). Most prefixes are much shorter than 128 bits, so many TCAM cells store 'X'. The proposed data-relocation TCAM (DR-TCAM) increases the number of IP addresses stored in the TCAM by relocating the data in the prefix bits into 'X' cells. The DR-TCAM has four types of banks. The type-0 bank is empty and inactivated. The type-1 and type-2 banks store four 32 bit words and two 64 bit words instead of a 128 bit word in the type-3 bank, respectively. Therefore, the type-1 and type-2 banks store four and two times larger IP addresses, respectively. In the simulation, the area and power consumption of the DR-TCAM decreased to 34% and 36% of those of the conventional TCAM for 4 K IP addresses, respectively. The DR-TCAM chip with 256 × 128 bit TCAM cells and 8 banks was fabricated using a 1.2 V 0.13 μm CMOS process. Its area was 0.87 mm 2. Its energy/bit/search was 1.3 fJ at 200 MHz clock frequency when 4 banks were activated to store 256 IP addresses. © 1966-2012 IEEE.

No S.-Y.,Chungbuk National University
Renewable and Sustainable Energy Reviews | Year: 2011

The use of inedible vegetable oils as an alternative fuel for diesel engine is accelerated by the energy crisis due to depletion of resources and increased environmental problems including the great need for edible oil as food and the reduction of biodiesel production cost, etc. Of a lot of inedible vegetable oils which can be exploited for substitute fuel as diesel fuel, seven vegetable oils, i.e., jatropha, karanja, mahua, linseed, rubber seed, cottonseed and neem oils were selected for discussion in this review paper. The application of jatropha oil as a liquid fuel for CI engine can be classified with neat jatropha oil, engine modifications such as preheating, and dual fuelling, and fuel modifications such as jatropha oil blends with other fuels, mostly with diesel fuel, biodiesel, biodiesel blends and degumming. Therefore, jatropha oil is a leading candidate for the commercialization of non-edible vegetable oils. There exists a big difference in the fuel properties of seven inedible vegetable oils and its biodiesels considered in this review. It is clear from this review that biodiesel generally causes an increase in NOx emission and a decrease in HC, CO and PM emissions compared to diesel. It was reported that a diesel engine without any modification would run successfully on a blend of 20% vegetable oil and 80% diesel fuel without damage to engine parts. This trend can be applied to the biodiesel blends even though particular biodiesel shows 40% blend. In addition, the blends of biodiesel and diesel can replace the diesel fuel up to 10% by volume for running common rail direct injection system without any durability problems. © 2010 Elsevier Ltd.

No S.-Y.,Chungbuk National University
Renewable and Sustainable Energy Reviews | Year: 2014

This review will be concentrated on the application of bio-oil produced from the cellulosic biomass among the various liquid biofuels to transport fuels, heat and power generation as substitute. Main application of bio-oil and biocrude from two main thermochemical processes, i.e., pyrolysis and liquefaction include boiler for heat and electricity production, diesel engine or gas turbine for power generation, and diesel engine for transportation fuel. Fast pyrolysis is the most popular process for converting cellulosic biomass to high yield of bio-oil with relatively low cost. For the application of bio-oils to transportation, heat and power generation, physical upgrading methods such as emulsions (bio-oil/diesel or bio-oil/biodiesel) and blends of bio-oil/oxygenated fuel (ethanol, diglyme) were mainly used and tested. The studies on the spray characteristics of emulsions and blends in diesel engine condition are not available in the literature. In most studies on the combustion and emission characteristics of emulsions and blends, CO emission was increased in most fuels and engines tested and HC was increased or comparable to diesel operation. However, NOx and soot emissions were decreased in most case of experiments. In the pressure-swirl nozzle for gas turbine application, preheating and blending techniques were employed to reduce the SMD of spray. In case of blend for the application of heat and power generation, E20 blend was mainly selected in most studies. Most studies related to bio-oil combustion in burners, diesel engines and gas turbines demonstrated the higher HC, CO and soot emissions than the original design fuel. Although the properties of bio-oil/methanol blend were widely investigated, there are no studies available about the application of bio-oil/methanol blend to transportation, heat and power generation in the literature. In addition, more research is required for the combustion of upgraded bio-oils for transportation application. © 2014 Elsevier Ltd.

This review will be concentrated on the application of hydrotreated vegetable oils (HVO) produced from the triglycerides based biomass such as vegetable oil, animal fat, waste cooking oil and algae to compression ignition (CI) engines. Main problem in the application of HVO to CI engines is the poor low-temperature properties. The upgrading technology of cold flow properties of HVO reported in the literature can be categorized with four ways as isomerization, addition of flow improver, reaction temperature control and co-processing with petroleum derived raw materials. The advantages of hydrotreating over transesterification are lower processing cost, compatibility with infrastructure, NOx emission reduction, and feedstock flexibility. Combustion and emission characteristics of neat HVO, blends of HVO with petrodiesel and HVO with additives were widely investigated by many researchers. The use of HVO enables appreciable reductions in NOx, PM, HC and CO emissions without any changes to the engine or its control in heavy-duty engines. HVO could play an important role in providing an sustainable source of transportation fuels during the coming decades. In addition, HVO obtained from inedible vegetable oil and application of it to CI engine will be the subjects of future research in the production and application of HVO. The technologies for the reduction of NOx and PM in CI engines fuelled with HVO can be categorized with engine optimization and fuel optimization. The engine optimization technology is more effective than the fuel optimization technology. © 2013 Elsevier Ltd. All rights reserved.

Kim J.-H.,Chungbuk National University
Automatica | Year: 2011

This note considers the stability of linear systems with a time-varying delay. We are interested in a simple LyapunovKrasovskii functional (LKF) approach without delay decomposition. In this category, all recent tractable results had a fixed bound on the allowable maximum size of the delay for years. We propose a new simple LKF including the cross terms of variables and quadratic terms multiplied by a higher degree scalar function, and present a new result expressed in the form of LMIs. We show, by two well-known examples, that our result overcomes the previous allowable maximum size of delay and it is less conservative than the previous results having a relatively small upper bound in the derivative of time-delay. © 2011 Elsevier Ltd. All rights reserved.

LG Corp and Chungbuk National University | Date: 2016-04-06

The application relates to a method for processing an audio signal including a suber wide band, the method comprising converting the audio signal into a plurality of frequency converted coefficients, determining whether to encode a high frequency band in a non tonal mode based on a harmonic-mode or non-harmonic mode determination. For the harmonic mode, encoding a position information of an harmonic track. For the non-harmonic mode encoding a fixed pulse information. A method of processing a signal encoded with an harmonic mode or non harmonic mode.

Loading Chungbuk National University collaborators
Loading Chungbuk National University collaborators