• Journal of Life Science
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• v.32 no.7
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• pp.523-531
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• 2022

The purpose of this study was to evaluate the effect of antioxidant and anti-adipogenic activities in ethanol extracts from herb mixture (Ephedra sinica, Atractylodes lance, Gypsum fibrosum, and Theobroma cacao). DPPH, ABTS⁺ radical and xanthine oxidase scavenging activities were measured for antioxidant activity. Extracts of the herb mixture had 75.0, 100.8, and 79.5% scavenging activities at 1,000 ㎍/ml concentration, respectively. We investigated the inhibition of adipogenesis and adipocyte differentiation with an extract of an herb mixture in 3T3-L1 preadipocytes. An extract from the herb mixture at concentrations between 0 and 50 ㎍/ml did not affect 3T3-L1 cell viability. Treatment with herb mixture extracts of 25, 50, and 75 ㎍/ml in 3T3-L1 preadipocytes inhibited lipid accumulation in a dose-dependent manner. As a result of a Western blot experiment, it was shown that the herb mixture inhibited the differentiation transcription factors, PPARγ and C/EBPa, by 44.2 and 77.6%, respectively, at a concentration of 75 ㎍/ml in MDI-induced differentiated 3T3-L1 cells. As a result of RT-PCR, the gene expression of C/EBPa, SREBP-1c, and PPARγ was significantly inhibited by 43.4%, 59.6%, and 55.3%, respectively, at the concentration of 75 ㎍/ml of the herb mixture compared with the MDI-treated group. In addition, the expression of fatty acid synthase (FAS), a fatty acid synthesis regulator, was suppressed. These results can be applied to develop a functional food for anti-obesity with a herb mixture.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.1
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• pp.139-146
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• 2015

The amount of by-product from sulphur increases in domestic industrial facilities. However, the amount of its consumption is limited so that the amount of unused sulphur continues to increase. Therefore, in this study, the use sulfur polymer as the concrete surface protecting material was conducted. The compressive strength showed that as the substitution ratio of filler increased up to 40%, the compressive strength also increased. A high compressive strength was shown at the curing temperature of $40^{\circ}C$ (SS, FA) and $60^{\circ}C$ (OPC) according to the type of filler. The difference of compressive strength between air dry curing and water curing was insignificant so that there was no significant influence of moisture during curing process. The evaluation result of bond strength showed that the highest bond strength was shown at the air-dry condition of $40^{\circ}C$ regardless of type of filler. Bonding didn't occur properly during water curing in comparison to air dry curing. Also, in case of the specimen cured at $60^{\circ}C$, discoloration and hair cracks appeared due to the influence of temperature, and the highest bond strength was shown at the substitution ratio of 20% (SS, FA) and 30% (OPC) according to the type of filler. The releasing test result of harmful substance showed that no harmful substance was released, so there is no harmfulness in the surface protecting material using sulfur polymer. As a conclusion drawn in this study, it is most appropriate to substitute silica by approximately 20%, mix and cure at the air-dry condition of $40^{\circ}C$ in order to use sulfur polymer as the surface protecting material.

• Investigative Magnetic Resonance Imaging
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• v.3 no.2
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• pp.154-158
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• 1999

Purpose : The purpose of this study was to find the optimum TE value for enhancing $T_2^{*}$ weighting effect and minimizing the SNR degradation and to compare the BOLD effects according to the changes of TE in 1.5T and 3.0T MRI systems. Materials and Methods : Healthy normal volunteers (eight males and two females with 24-38 years old) participated in this study. Each volunteer was asked to perform a simple finger-tapping task (sequential opposition of thumb to each of the other four fingers) with right hand with a mean frequency of about 2Hz. The stimulus was initially off for 3 images and was then alternatively switched on and off for 2 cycles of 6 images. Images were acquired on the 1.5T and 3.0T MRI with the FLASH (fast low angle shot) pulse sequence (TR : 100ms, FA : $20^{\circ}$, FOV : 230mm) that was used with 26, 36, 46, 56, 66, 76ms of TE times in 1.5T and 16, 26, 36, 46, 56, 66ms of TE in 3.0T MRI system. After the completion of scan, MR images were transferred into a PC and processed with a home-made analysis program based on the correlation coefficient method with the threshold value of 0.45. To search for the optimum TE value in fMRI, the difference between the activation and the rest by the susceptibility change for each TE was used in 1.5T and 3.0T respectively. In addition, the functional $T_2^{*}$ map was calculated to quantify susceptibility change. Results : The calculated optimum TE for fMRI was $61.89{\pm}2.68$ at 1.5T and $47.64{\pm}13.34$ at 3.0T. The maximum percentage of signal intensity change due to the susceptibility effect inactivation region was 3.36% at TE 66ms in 1.5T 10.05% at TE 46ms in 3.0T, respectively. The signal intensity change of 3.0T was about 3 times bigger than of 1.5T. The calculated optimum TE value was consistent with TE values which were obtained from the maximum signal change for each TE. Conclusion : In this study, the 3.0T MRI was clearly more sensitive, about three times bigger than the 1.5T in detecting the susceptibility due to the deoxyhemoglobin level change in the functional MR imaging. So the 3.0T fMRI I ore useful than 1.5T.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.10
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• pp.59-68
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• 1993

This paper describes implemation of 'General-purpose ETRI MAP interface module' (GEM) for Mini-MAP network. GEM operates as a Mini-MAP node in our FA system. To communicate between GEM and programmable devices(PD) such as PLC and CNC, serial communication is used. Application programs of a MiNi-MAP host system control and monitor programmable devices via GEM. GEM is implemented and tested on the basis of the MAP 3.0. TBC in the Nini-MAP board performs the function of the MAC sublayer. The LLC sublayer is implemented according to the specification of Class 3 that includes Type 1 and 3. And the MMS services are designed within the scope of implementation class MAP3. All the softwares are implemented under the real-time multitask OS for real-time application of the Mini-MAP and they are loaded into PROMs at the network board of GEM. We tested the LLC functions to make use of a protocol analyzer for the token-passing protocol. Also the MMS conformance test was carried out by exchanging primitives between GEM and a MMS product that had already passed the conformance test. Therefore GEM is proposed as a network tool of Computer Integrated Manufacturing (CIM) to integrate PDs which don't support MAP functions.

• International Journal of Advanced Culture Technology
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• v.8 no.1
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• pp.135-140
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• 2020

The main battlefield of 'made in China 2025' proposed by the Chinese government is the deep integration of industrialization and informatization, among which intelligent manufacturing and new energy vehicles are the key links. New energy vehicle refers to the use of unconventional automotive fuel as a power source (or use conventional automotive fuel, the use of new vehicle-mounted power plant), integrated vehicle power control and driving aspects of advanced technology, the formation of advanced technical principles, with new technology and the structure of the vehicle. BYD's success in the battery, I T and automobile industries has attracted the attention of the industry, making it a shining new star in the Chinese business community. BYD 's innovation, diversification and corporate culture construction have certain enlightenment to the development of China's small and medium-sized enterprises. Therefore, by looking at the Chinese network literature, about BYD's research mainly focused on the development strategy, corporate finance, corporate performance, and corporate marketing, etc. This paper will take BYD as the research object and focus on corporate culture. Through literature analysis and qualitative analysis, it will summarize and further analyze the unique corporate culture of BYD, its important role, and provide relevant theoretical references for the construction and development of corporate culture in other industries.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1992.04b
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• pp.436-443
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• 1992

Presented in the paper is a systematic approach to constructing a Petri net model of FAS (flexible assembly system). Petri net is widely used in modeling automated manufacturing systems. But, it found to be very difficult for an FA engineer to build a correct model of an FAS with Petri net symbols (ie, place, transition, and token) from the beginning. An automated manufacturing system in general is built from a set of "standard" hardware components. An FAS in particular is usually composed of assembly robots, work tables, conveyor lines, buffer storages, part feeders, etc. In the proposed modeling scheme, each type of standard resources is represented as a standard "module" which is a sub Petri net. Then, the model of a FAS can be conveniently constructed using the predefined modules the same way the FAS itself is built from the standard components. The network representation of a FAS is termed a JR-net (job resource relation net) which is easy to construct. This JR net is then mechanically converted to a formal Petri net (to simulate the behavior of the FAS). The proposed modeling scheme may easily be extended to the modeling of other types of automated manufacturing systems such as FMS and AS/RS.ch as FMS and AS/RS.

• IEIE Transactions on Smart Processing and Computing
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• v.5 no.2
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• pp.100-106
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• 2016

Spectrum sensing is an integral part of cognitive radio, which seeks to address the perceived spectrum scarcity that is caused by inefficient utilization of the available spectrum. In this paper, a spectrum sensing system using energy detection for analog TV and FM broadcast transmitters as well as modified Integrated Services Digital Broadcasting Terrestrial (ISDB-T) signals is implemented on a software-defined radio platform using GNU' Not Unix (GNU) radio and the N200 Universal Software Radio Peripheral (USRP). Real-time implementation and experimental tests were conducted in Metro Cebu, a highly urbanized area in the southern part of the Philippines. Extensive tests and measurements were necessary to determine spectrum availability, particularly in the TV band. This is in support of the Philippine government' efforts to provide internet connectivity to rural areas. Experimental results have so far met IEEE 802.22 requirements for energy detection spectrum sensing. The designed system detected signals at -114 dBm within a sensing time of 100 ms. Furthermore, the required $P_d({\geq}90)$ and $P_{fa}({\leq}10)$ of the standard were also achieved with different thresholds for various signal sources representing primary users.

• Journal of computational fluids engineering
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• v.2 no.1
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• pp.1-7
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• 1997

A FA-FD hybrid method, developed for solving three-dimensional incompressible Navier-Stokes equations, is applied to calculate three-dimensional laminar flows through a square duct with a 90° bend. The method discretizes the convective terms in the primary flow direction with 3rd-order upwind finite-differences and the convective and diffusive terms in the transverse directions with the two-dimensional finite analytic method. The non-staggered grid system is used and the pressure-velocity coupling is achieved by a global iteration procedure based on the PISO algorithm. Detailed comparisons between the computed solutions and the available experimental data are given mainly for the velocity distributions at cross-sections in a 90° bend of a square duct with both fully developed and developing entry flows. Although the computational result shows generally a good agreement with the experimental data, there are some significant discrepancies underlining the necessity of more accurate numerical methods as well as reliable experimental data for their validation.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1599-1603
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• 2012

Objectives: Since methylenetetrahydrofolate reductase (MTHFR) maintains the balance of circulating folate and methionine and blocks the formation of homocysteine, its regulation in relation to different cancers has extensively been studied in different populations. However, information on Pakistani breast cancer patients is lacking. The MTHFR gene has two most common mutations that are single nucleotide additions which result in change of amino acids C677T to Ala222val and A1298C to Glu429Ala. Methodology: 110 sporadic breast patients with no prior family history of cancer or any other type of genetic disorders along with 110 normal individuals were screened for mutations in exons 1 to exon 9 using single strand conformational polymorphism, RFLP and sequencing analyzer. Results: The p values for the 677CC, 677CT, and 677TT genotypes were 0.223, 0.006, and 0.077, respectively. Those for the 1298AA, 1298AC, and 1298CC genotypes were 0.555, 0.009, and 0.003, respectively. Conclusions: We found an overall a significant, weak inverse association between breast cancer risk and the 677TT genotype and an inverse association with the 1298C variant. These results for MTHFR polymorphism might be population specific in sporadic breast cancer affected patients but many other factors need to be excluded before making final conclusions including folate intake, population and disease heterogeneity.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.393-400
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• 1992

The DC(Direct-Current) servo motor has widely used for many application areas, FA(Factory Automation), OA(Office Automation) and home applications. But DC servo motor needs periodical inspection because it has brush and commutator. Recently, AC servo motor has expanded it's application areas due to for the development of the power semi-conductor and control technology. But it has large torque ripple for it's small number of commutation. And it also has cogging torque due to permanent magenet rotor. Therefore it can't run balence rotarion. Many torque ripple reduction methods are published. In this paper, phase advanced method adopted for torque ripple reduction of AC servo motor. In this research, AC servo motor torque characteristic variation surveied under the phase advance control through the computer simulation. Under the simulation, the load inertia varied from 0.0001[Kg.m$^{2}$] to 0.0314[Kg.m$^{2}$]. The result os nonlinear simulation, torque and speed ripple of AC servo motor under the phase advance control reduced approximately 50[%] and 10[%]. And maximum torque of AC servo motor under phase advance control condition increased about 5[%] as compare with fixed switching time.