• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1026-1029
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• 1993

Inherent speed-torque performance of Switched Reluctance Motor is similar to that of series wound DC motor. Thus, the speed of the motor is extremely regulated according to load torque. For the purpose of controlling the speed and torque of SRM it is necessary to change the applied DC link voltage or the switch-ON and switch-OFF angles which control the phase current of the motor. This paper describes speed-torque characteristics of an integral horse power Switched Reluctance Motor by adjusting the switch-ON and switch-OFF angles. Speed at rated load torque can be regulated by adjusting the switching angles and the control scheme is applied to 2kW, 3 phase, 6/4 SRM.

• Journal of Integrative Natural Science
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• v.16 no.1
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• pp.39-45
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• 2023

P2X receptors are ATP-activated ion channels in the plasma membrane. P2X receptors have a role in a diverse range of disorders, making them a valuable therapeutic target. Hence, the present investigation employed homology modelling of the P2X receptor based on the crystal structure of 5SVJ, 6AH4, 5YVE and 5SVL. Twenty models, using both single- and multiple template-based methods, were developed, and the best model was chosen based on the validation result. We observed that a strategy based on multiple templates provided greater accuracy. Future studies involving binding site and docking analysis can make use of the produced structures.

• Analytical Science and Technology
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• v.21 no.6
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• pp.502-509
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• 2008

An ID LC/MS (isotope dilution liquid chromatography/mass spectrometry) was used as a primary method for the quantitative analysis of cholesterol in human serum. The separation of cholesterol was carried out by Thermo ODS hypersil $C^{18}$ column. The mobile phase was 100% methanol, and flow rate was $0.3m{\ell}/min$. Cholesterol and cholesterol-$3,4-13C_2$ were monitored at m/z 369.4 and 371.3, which correspond to $[M-H_2O+H]^+$ respectively. In order to verify the measurement method, NIST SRM 909b was analyzed. The results agreed well with certified values within uncertainty. The four kinds of serum certified reference material were prepared and certified. The repeatabilities of measurement were ranged from 0.1 to 0.8% (RSD), which were relatively good. The reproducibility between independent measurement run was below 0.24% (RSD). The expanded uncertainty was about 1.43% within the 95% confidence interval.

• Korean Journal of Optics and Photonics
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• v.9 no.4
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• pp.258-263
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• 1998

Quasi-elastic light scattering is utilized to measure the mean diameter of the 0.3 $\mu\textrm{m}$-dimeter polystyrene sphere. The mean diameter of the polystyrene sphere is required to be known within the uncertainty of a few per centages. The systematic error has been considerably reduced by improving the system for the angle alignment and temperature measurement of cell. NIST SRM 1691 (0.269$\pm$0.007 $\mu\textrm{m}$: TEM; 0.275$\pm$0.007 $\mu\textrm{m}$: QELS) is measured to be 0.273 $\mu\textrm{m}$$\pm$0.006 $\mu\textrm{m}$ in mean diameter. Detailed description is given of the improved method and the resultant uncertainty, and the comparison of results with NIST is followed.

• Journal of Integrative Natural Science
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• v.15 no.4
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• pp.145-152
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• 2022

Colon rectal cancer is one of the frequently diagnosed cancers worldwide. In recent times the drug discovery for colon cancer is challenging because of their speedy metastasis and morality of these patients. C-jun N-terminal kinase signaling pathway controls the cell cycle survival and apoptosis. Evidence has shown that JNK1 promotes the tumor progression in various types of cancers like colon cancer, breast cancer and lung cancer. Recent study has shown that inhibiting, JNK1 pathway is identified as one of the important cascades in drug discovery. One of the recent approaches in the field of drug discovery is drug repurposing. In drug repurposing approach we have virtually screened ChEMBL dataset against JNK1 protein and their interactions have been studied through Molecular docking. Cross docking was performed with the top compounds to be more specific with JNK1 comparing the affinity with JNK2 and JNK3.The drugs which exhibited higher binding were subjected to Conceptual - Density functional theory. The results showed mainly Entrectinib and Exatecan showed better binding to the target.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2000.04a
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• pp.12-12
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• 2000

우리 나라는 일본상공의 비행을 피하기 위하여 제주도와 남해안 근해로 발사장 선정이 국한되는 지정학적인 위치로 볼 때 발사장 선택에 제한이 없는 공중발사에 대한 가능성 연구가 필요한 시점에 있다. 본 연구는 우리 나라와 같은 분단 된 특수상황 그리고 지정학적 위치에서의 발사장을 고려한 우주 발사체 개발의 필요성에 따라 F-4에 장착 가능한 3단형 공중발사 로켓을 설계하고 1/3의 축소 모형을 제작하였다. 2kg의 payload를 갖는 발사체의 1단은 LRM ( Lox/kerosene )을 사용하였고 2, 3단은 SRM ( HTPB/AP/Al )을 사용하였으며 발사고도는 11-l2km 상공에서 F-4에 의해서 발사되고 31km지점에서 1단 분리가 이루어지며 62km지점에서 2단 분리와 nose fairing을 분리하게 된다. 전장은 6.85m 이며 전체 무게는 560.6kg 이고 전체 발사체 시스템의 CAD 도면은 아래 그림 1과 같이 주어져 있다. 그림 2에서는 F-4E phantom의 장착성을 검토해 본 결과 장착이 가능함을 알 수 있었으며 추진제 양의 감소로 크기를 대폭 줄일 수 있었다.

• The Journal of Advanced Prosthodontics
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• v.4 no.3
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• pp.139-145
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• 2012

PURPOSE. To evaluate the shear bond strength of resin luting agent to dentin surfaces cleansed with different agents like pumice, ultrasonic scaler with chlorhexidine gluconate, EDTA and the influence of these cleansing methods on wetting properties of the dentin by Axisymmetric drop Shape Analysis - Contact Diameter technique (ADSA-CD). MATERIALS AND METHODS. Forty coronal portions of human third molar were prepared until dentin was exposed. Specimens were divided into two groups: Group A and Group B. Provisional restorations made with autopolymerizing resin were luted to dentin surface with zinc oxide eugenol in Group A and with freegenol cement in Group B. All specimens were stored in distilled water at room temperature for 24 hrs and provisional cements were mechanically removed with explorer and rinsed with water and cleansed using various methods (Control-air-water spray, Pumice prophylaxis, Ultrasonic scaler with 0.2% Chlorhexidine gluconate, 17% EDTA). Contact angle measurements were performed to assess wettability of various cleansing agents using the ADSA-CD technique. Bond strength of a resin luting agent bonded to the cleansed surface was assessed using Instron testing machine and the mode of failure noted. SEM was done to assess the surface cleanliness. Data were statistically analyzed by one-way analysis of variance with Tukey HSD tests (${\alpha}$=.05). RESULTS. Specimens treated with EDTA showed the highest shear bond strength and the lowest contact angle for both groups. SEM showed that EDTA was the most effective solution to remove the smear layer. Also, mode of failure seen was predominantly cohesive for both EDTA and pumice prophylaxis. CONCLUSION. EDTA was the most effective dentin cleansing agent among the compared groups.

• Analytical Science and Technology
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• v.18 no.5
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• pp.396-402
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• 2005

We try to look for optimum conditions of pre-reductants like L-Cysteine, KI and $FeSO_4$ when analyzing inorganic arsenic by using hydride generation-atomic absorption spectrometry, and run a comparative study of effect in the analysis of them. Also, we separated and analyzed only inorganic arsenic by using $H_2SO_4$-trap to eliminate organic arsenic which are MMA(monomethylarsonate) and DMA(dimethylarsinate). Under the conditions of mixture acid of 1.8 M HCl and 0.08 M $HNO_3$, arsenic standard solution of 20 ppb have more higher absorbance than without adding acid. In case of L-Cysteine, As(V) completely reduces into As(III) when 0.5 g of L-Cysteine is reacted more than 30 mins. in weak acid condition of approximately 0.07 M $HNO_3$ or HCl. In the event of KI, As(V) completely reduces into As(III) when 3 g of KI is reacted more than 1hour in acid condition of 0.8 M $HNO_3$. On the occasion of $FeSO_4$, the inside of tube is blocked by precipitation by mixture reaction of $NaBH_4$ and $Fe^{2+}$, therefore, comparing to other pre-reductants, reproducibility of efficiency of reducing As(V) to As(III) is low. To evaluate the accuracy of the analytical results, we use NIST SRM 1643C Trace Elements in Water ($82.1{\pm}1.2ng/mL$). The results are satisfactory.

• Journal of Information Science Theory and Practice
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• v.3 no.4
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• pp.35-48
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• 2015

The aim of this study is to compare country output and citation impact as well as to assess the level of interdisciplinarity in the field of tribology research during the period 1998-2012, based on the SCOPUS database. Macro-level scientometric indicators such as growth rate, share of international collaborative papers, citation per paper, share of un-cited papers, and publication efficiency index were employed. Further, the Simpson Index of Diversity was used to measure the level of interdisciplinarity. The performance of top countries contributing more than 1000 papers during the study period was discussed. Contributions and share of continents and countries by income groups were examined. Further research contributions and citation impact of selected country groups were analyzed. This study reveals that high levels of interdisciplinarity exist in tribology research. Asia outperforms the other world regions and China contributes most of the papers (25%), while the United States receives most of the citations (22%).

• Analytical Science and Technology
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• v.29 no.4
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• pp.170-178
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• 2016

Accuracy and precision of ID methods for different spike isotopes of ⁷⁶Se, ⁷⁷Se, and ⁷⁸Se were compared for the analysis of Selenium using quadrupole ICP/MS equipped with Octopole reaction cell. From the analysis of Se inorganic standard solution, all of three spikes showed less than 1 % error and 1 % RSD for both short-term (a day) and long-term (several months) periods. They showed similar results with each other and ⁷⁸Se showed was a bit better than ⁷⁶Se and ⁷⁷Se. However, different spikes showed different results when NIST SRM 1568a and SRM 2967 were analyzed because of the several interferences on the m/z measured and calculated. Interferences due to the generation of SeH from ORC was considered as well as As and Br in matrix. The results showed similar accuracy and precisions against SRM 1568a, which has a simple background matrix, for all three spikes and the recovery rate was about 80% with steadiness. The %RSD was a bit higher than inorganic standard (1.8 %, 8.6 %, and 6.3 % for ⁷⁸Se, ⁷⁶Se and ⁷⁷Se, respectively) but low enough to conclude that this experiment is reliable. However, mussel tissue has a complex matrix showed inaccurate results in case of ⁷⁸Se isotope spike (over 100 % RSD). ⁷⁶Se and ⁷⁷Se showd relatively good results of around 98.6 % and 104.2 % recovery rate. The errors were less than 5 % but the precision was a bit higher value of 15 % RSD. This clearly shows that Br interferences are so large that a simple mathematical calibration is not enough for a complex-matrixed sample. In conclusion, all three spikes show similar results when matrix is simple. However, ⁷⁸Se should be avoided when large amount of Br exists in matrix. Either ⁷⁶Se or ⁷⁷Se would provide accurate results.