• Journal of Power Electronics
• /
• v.17 no.4
• /
• pp.892-904
• /
• 2017

A design of a Class-E inverter with only one inductor and one capacitor is presented. It is operated at the optimal operation mode for domestic cooker. The design principle is based on the zero-voltage derivative switching (ZVDS) of the Class-E inverter with a parallel load network, which is a parallel resonant equivalent circuit. An induction load characterization is obtained from a large-signal excitation test bench, which is the key to an accurate design of the induction cooker system. Consequently, the proposed scheme provides a more systematic, simple, accurate, and feasible solution than the conventional quasi-resonant inverter analysis based on series load network methodology. The derivative of the switch voltage is zero at the turn-on transition, and its absolute value is relatively small at the turn-off transition. Switching losses and noise are reduced. The parameters of the ZVDS Class-E inverter for the domestic induction cooker must be selected properly, and details of the design of the components of this Class-E inverter need to be addressed. A 1,200 W prototype is designed and evaluated to verify the validation of the proposed topology.

• Journal of Plant Biotechnology
• /
• v.49 no.3
• /
• pp.250-256
• /
• 2022

This study was conducted to measure changes in polyphenol components and antioxidant effects of Cirsium Lineare (Thunb.) after fermentation by lactic acid bacteria. First, Cirsium Lineare (Thunb.) extract (CE, unfermented) and Cirsium Lineare (Thunb.) extract fermented with Lactobacillus paracasei (FCE) were prepared. Changes in components resulting from fermentation were confirmed through changes in polyphenol compound content and silymarin derivative pattern, and antioxidant activity was confirmed using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, 2,2'azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, and ferric reducing antioxidant power (FRAP) analyses. As a result, polyphenol contents of CE and FCE were confirmed as 21.94 ± 1.15 and 67.90 ± 4.48 mg GAE/g, respectively. Both values were increased approximately three times by fermentation, and there was also a change in the silymarin derivative pattern. In the case of DPPH radical RC₅₀ values in particular, CE and FCE were confirmed to inhibit DPPH radicals by 50% at concentrations of 129.44 ± 5.85 and 50.00 ± 3.47 ㎍/mL, respectively, with the FCE value approximately 2.5 times lower than that of CE. In addition, ABTS radical scavenging and FRAP activity were confirmed to share similar trends as DPPH radical scavenging activity. When CE and FCE were compared, FCE showed a better antioxidant effect overall. In conclusion, this study suggested that FCE prepared through lactic acid bacteria fermentation may be utilized as a powerful antioxidant material.

• Journal of radiological science and technology
• /
• v.11 no.1
• /
• pp.25-31
• /
• 1988

Studies on the clinical significance with Amerlex $FT_{4}$ RIA kit observing the determination of $FT_{4}$ were investigated using a tracer as $^{125}I-T_{4}$ derivative which is not almostly bound to thyroxine binding globulin, etc. The results are followed; 1. $FT_{4}$ value($1,55{\pm}0.38ng/100ml$) of normal group was not accorded that of hyperthyroidism with Amerlex $FT_{4}$ RIA kit, and was higher than that of hypothyroidism. 2. $FT_{4}$ value was lower level in chronic-kidney disfunction syndrome whereas, it was normal in a cancer patient, a woman in pregnancy and a patient in TBG disfunction. 3. The value of this method is a good corelationship at that of equilibrium dialysis method. (r=0.931) 4. $FT_{4}$ value by this kit was linear relationship to those of the other kit (Gamma Coat and Liquisol), and the normal value of each methods was also similar. As mentioned above, this method is more simple and rapid, compared to the other method. Therefore, it was thought that this method is a very useful clinically.

• IEIE Transactions on Smart Processing and Computing
• /
• v.6 no.2
• /
• pp.117-123
• /
• 2017

N-continuous orthogonal frequency division multiplexing (OFDM) is a precoding method for sidelobe suppression of OFDM signals and seamlessly connects OFDM symbols up to the high-order derivative for sidelobe suppression, which is suitable for suppressing out-of-band radiation. However, it severely degrades the error rate as it increases the continuous derivative order. Two schemes for orthogonal precoding of N-continuous OFDM have been proposed to achieve an ideal error rate while maintaining sidelobe suppression performance; however, the large size of the precoder matrices in both schemes causes very high computational complexity for precoding and decoding. This paper proposes matrix decomposition of precoder matrices with a large size in the orthogonal precoding schemes in order to reduce computational complexity. Numerical experiments show that the proposed method can drastically reduce computational complexity without any performance degradation.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.40 no.5
• /
• pp.371-377
• /
• 2003

In this paper, comparison of feature parameters for emotion recognition using speech signal is studied. For this purpose, a corpus of emotional speech data recorded and classified according to the emotion using the subjective evaluation were used to make statical feature vectors such as average, standard deviation and maximum value of pitch and energy and phonetic feature such as MFCC parameters. In order to evaluate the performance of feature parameters speaker and context independent emotion recognition system was constructed to make experiment. In the experiments, pitch, energy parameters and their derivatives were used as a prosodic information and MFCC parameters and its derivative were used as phonetic information. Experimental results using vector quantization based emotion recognition system showed that recognition system using MFCC parameter and its derivative showed better performance than that using the pitch and energy parameters.

• Natural Product Sciences
• /
• v.21 no.4
• /
• pp.227-230
• /
• 2015

Chemical investigation of the fermentation broth of a Soft Coral-Derived fungus Pestalotiopsis sp., led to the isolation of a new phthalide derivative, pestalotiolide A (1), three known analogues (2, 3 and 4), along with 5'-O-acetyl uridine (5) first isolated as a natural product. The structure of the new compound (1) was established by comprehensive spectroscopic analysis and chemical methods. Compounds 1 - 4 possessed varying degrees of antiviral activities, which was reported for the first time. Compared to the positive control ribavirin ($IC_{50}=418.0{\mu}M$), pestalotiolide A (1) exhibited significant anti-EV71 activity in vitro, with an $IC_{50}$ value of $27.7{\mu}M$. Furthermore, the preliminary structure-activity relationship of antiviral activities was also discussed.

• Natural Product Sciences
• /
• v.26 no.1
• /
• pp.79-82
• /
• 2020

A new cinnamyl acid derivative, willughbein A (1) along with pinoresinol (2), alyterinate A (3), and scopoletin (4), were isolated from the roots of Willughbeia coriacea Wall. The structure of 1 has been determined based on HRESIMS, 1D, and 2D NMR spectral data. All of the isolates were evaluated for their cytotoxicity against three human cancer cells (HeLa, T47D, MCF-7, and P-388). Compound 3 showed moderate activity against P-388 cells with an IC₅₀ value of 3.04 ㎍/mL.

• Smart Structures and Systems
• /
• v.26 no.4
• /
• pp.469-480
• /
• 2020

This is the first research on the smart control and vibration analysis of a Graphene nanoplatelets (GPLs) Reinforced Composite (GPLRC) porous cylindrical shell covered with piezoelectric layers as sensor and actuator (PLSA) in the framework of numerical based Generalized Differential Quadrature Method (GDQM). The stresses and strains are obtained using the First-order Shear Deformable Theory (FSDT). Rule of the mixture is employed to obtain varying mass density and Poisson's ratio, while the module of elasticity is computed by modified Halpin-Tsai model. The external voltage is applied to sensor layer and a Proportional-Derivative (PD) controller is used for sensor output control. Governing equations and boundary conditions of the GPLRC cylindrical shell are obtained by implementing Hamilton's principle. The results show that PD controller, length to radius ratio (L/R), applied voltage, porosity and weight fraction of GPL have significant influence on the frequency characteristics of a porous GPLRC cylindrical shell. Another important consequence is that at the lower value of the applied voltage, the influence of the smart controller on the frequency of the micro composite shell is much more significant in comparison with the higher ones.

• Proceedings of the SCSK Conference
• /
• 2003.09b
• /
• pp.184-191
• /
• 2003

New pyranone derivative, 2-((3E)-4(2H, 3H, -benzo[3, 4-d] 1, 3-dioxolan-5-yl)-2-oxo-but-3-enyloxy)-5-hydroxy-4H-pyran-4-one (Seletinoid $G^{TM}$), was designed as a novel retinoid on the assumption that the pyranone ring may mimic the carboxylic acid moiety in retinoid structure. The enolic hydroxy of pyranone at five position was easily deprotonated to form an enolate. The role of enolate was similar to that of carboxylic acid. To evaluate the value of Seletinoid G as an anti-aging ingredient, various tests were performed for example inhibitory effect for MMP-l expression, anti-oxidative activity, procollagen synthesis in hairless mouse and primary skin irritation. The result of this study suggested that our new synthetic retinoid could be used as a safe material for anti-aging cosmetics.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.2
• /
• pp.460-464
• /
• 2013

Single-chain variable fragments of antibodies (scFv) specific to 2,4-dinitrotoluene (DNT) were isolated from a phage library displaying synthetic human scFv fragments with 6 diversified complementary determining regions (CDRs). A DNT derivative that contained an extended amine group was synthesized and conjugated to the NHS-group that was linked to magnetic beads. Phages specific to the immobilized DNT derivatives were isolated from the library after 4 rounds of sequential binding and elution processes. The displayed scFv fragments from the isolated phages showed consensus CDR sequences. One DNT-specific scFv was expressed in E. coli and purified using Ni-affinity chromatography. The purified DNT-specific scFv binds specifically to the immobilized DNT-derivative with $K_D$ value of $6.0{\times}10^{-7}$ M. The scFv and DNT interaction was not disrupted by the addition of 4-nitrotoluene or benzoic acid. These data demonstrate that the screened scFv from the phage displayed library could be used for selective and sensitive detection of explosives such as TNT.