• Journal of Biosystems Engineering
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• 제33권5호
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• pp.317-325
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• 2008

The electrocardiogram (ECG) measurement system consists of I/O interface to input the ECG signals from two electrodes, FPGA (Field programmable gate arrays) module to process the signal conditioning, and real time module to control the system. The algorithms based on wavelet transform were developed to remove the noise of the ECG signals and to determine the QRS-waves. Triangular wave tests were conducted to determine the optimal factors of the wavelet filter by analyzing the SNRs (signal to noise ratios) and RMSEs (root mean square errors). The hybrid rule, soft method, and symlets of order 5 were selected as thresholding rule, thresholding method, and mother wavelet, respectively. The developed wavelet filter showed good performance to remove the noise of the triangular waves with 10.98 dB of SNR and 0.140 mV of RMSE. The ECG signals from a total of 6 subjects were measured at different measuring postures such as lying, sitting, and standing. The durations of QRS-waves, the amplitudes of R-waves, the intervals of RR-waves were analyzed by using the finite impulse response (FIR) filter and the developed wavelet filter. The wavelet filter showed good performance to determine the features of QRS-waves, but the FIR filter had some problems to detect the peaks of Q and S waves. The measuring postures affected accuracy and precision of the ECG signals. The noises of the ECG signals were increased due to the movement of the subject during measurement. The results showed that the wavelet filter was a useful tool to remove the noise of the ECG signals and to determine the features of the QRS-waves.

• Advances in environmental research
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• 제9권1호
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• pp.65-84
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• 2020

The potential use of Sargassum boveanum algae for the removal of uranium from aqueous solution has been studied by varying three independent parameters (pH, initial uranium ion concentration, S. boveanum dosage) using a central composite design (CCD) under response surface methodology (RSM). Batch mode experiments were performed in 20 experimental runs to determine the maximum metal adsorption capacity. In CCD design, the quantitative relationship between different levels of these parameters and heavy metal uptake (q) were used to work out the optimized levels of these parameters. The analysis of variance (ANOVA) of the proposed quadratic model revealed that this model was highly significant (R² = 0.9940). The best set required 2.81 as initial pH(on the base of design of experiments method), 1.01 g/L S. boveanum and 418.92 mg/L uranium ion concentration within 180 min of contact time to show an optimum uranium uptake of 255 mg/g biomass. The biosorption process was also evaluated by Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models represented that the experimental data fitted to the Langmuir isotherm model of a suitable degree and showed the maximum uptake capacity of 500 mg/g. FTIR and scanning electron microscopy were used to characterize the biosorbent and implied that the functional groups (carboxyl, sulfate, carbonyl and amine) were responsible for the biosorption of uranium from aqueous solution. In conclusion, the present study showed that S. boveanum could be a promising biosorbent for the removal of uranium pollutants from aqueous solutions.

• Journal of Korean Biological Nursing Science
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• 제7권1호
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• pp.29-46
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• 2005

Purpose ; 본 연구는 X-염색체와 관련된 장애 중에서 가장 흔하고 심한 Duchenne Muscular Dystrophy(DMD)의 세포유전학 및 분자유전학적 특성을 설명하기 위해서 DMD에 영향을 받고 있는 두 가계의 13명을 대상으로 가계도 분석과 염색체 분석 및 DNA 분석을 하였다. Method ; DNA분석은 DNA probe을 이용한 Southern blotting method로써 RFLPs와 DMD유전자 부위의 exon소실 유무를 조사하여 아래와 같은 결과를 얻었다. Conclusion ; A 염색체 분석 : 말초혈액과 양수를 표본으로 High-Resolution GTG염색에서 A가계와 B가계의 염색체 분석에서 12명의 염색체는 정상 X-염색체였으나 B가계의 I-2(DMD여성)에서 46, x,-x,+t(2:x)(q 21.1 : p21.2)로 나타난다. B. DNA분석3 : 1) RFLPs의 분석 J66,XJ-1.1,754-11로써 B가계의 RELPs(Restriction Fragment Length Polymorphisms)에서 J66/Pst I은 1.7hb(E), 1.6kb(e)을 보여 주었고 XJ-1.1/Taq I은 3.6kb(F), 3.0kb(f), 754-11/EoR I은 4.2kb(G), 2.0kb(g)의 대립인자를 나타내었다. 이상의 결과를 바탕으로 영향을 받고 있는 남자 (II-2)의 haplotype는 보인자인 어머니의 한쪽 인자를 받았으며 어머니와 딸은 보인자이고 임산부의 태아는 남아였고 태아의 인자들은 그의 할아버지로부터 물려받아 DMD에 영향을 받지 않은 것으로 진단되었다. 2) DMD 유전자의 exon 소실에 대한 분석 cDNA probe 8과 cDNA probe 2b-3으로써 소실에 대한 진단은 영향을 받은 남자(II-2)는 cDNA probe 8에서 12, 7.3, 6.6, 4.2kb에 소실이 있고 cDNA 2b-3은 1.7kb에 소실에 나타났다.

• 대한전자공학회논문지TC
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• 제38권5호
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• pp.9-15
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• 2001

원통형 공동 공진기를 이용한 유전체의 전자기적 특성들의 측정 방법에 대해 기술한다. 여기에 관련된 유전체의 전자기적 특성들은 비유전율, 손실 반젠트, Q factor 등이 있다. 동심 유전체 봉이 삽입된 원통형 공동 공진기에서 $TE_{011}$ 모드의 사용이 제한되었다. $TE_{011}$ 모드는 유전체 봉과 공진기 벽면 틈에 의한 공진주파수 민감도가 가장 덜 민감하게 변화하였다. 동심 유전체 봉이 삽입된 원통형 공동 공진기의 $TE_{011}$ 모드를 사용하는 방법과 새롭게 제안된 non-decaying 모드의 정확한 전자계 표현은 유전체의 전자기적 특성들의 정확한 측정을 위해 소개되었다.

• 한국의류산업학회지
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• 제18권6호
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• pp.766-775
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• 2016

In the era of globalization and unlimited competition, Korean universities need a breakthrough in their education system according to the changing education landscape, such as lower graduation requirements to cultivate more multi-talented convergence leaders. While each student has different learning capabilities, which results in different performance and achievements in the same class, the uniform education that most universities are currently offering fails to accommodate such differences. Blended learning, synergically combining offline and online classes, enlarges learning space and enriches learning experiences through diversified tools and materials, including multimedia. Recently, universities are increasingly adopting video contents and on-offline convergence learning strategy. Thus, this study suggests a teaching method based on blended learning to more effectively teach existing pattern CAD and virtual CAD in the Apparel Pattern CAD class. To this end, this researcher developed a teaching-learning method and curriculum according to the blended learning phase and video-based contents. The curriculum consisted of 2D CAD (SuperAlpha: Plus) and 3D CAD (CLO) software learning for 15 weeks. Then, it was loaded to the Learning Management System (LMS) and operated for 15 weeks both online and offline. The performance analysis of LMS usage found that class materials, among online postings, were viewed the most. The discussion menu most accurately depicted students' participation, and students who did not participate in discussions were estimated to check postings less than participating students. A survey on the blended learning found that students prefer digital or more digitized classes, while preferring face to face for Q&As.

• 한국정밀공학회지
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• 제18권11호
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• pp.51-57
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• 2001

A light beam reflected from a machined surface generally containes information concerning about its surface roughness. This study examines and proposes a surface roughness measurement technique for on-machine measurement of machined surfaces. The technique is based on the measurement of a reflected laser beam pattern and the statistical analysis of its light intensity distribution. The surface roughness was found to be closely related to the standard deviation of the light intensity on the primary axis of the reflected pattern. An image acquisition device is made up of a laser diode, a half mirror, a screen, and a CCD camera. The exact image with the primary and secondary axes of a reflected laser beam pattern is calculated through such image processing algorithm as thresholding, edge detection, image rotation, segmentation, etc. A median filter and a surrounding light correction algorithm are improve the image quality and reduce the measuring error. Using the developed measuring device the effect of screen materials and workpiece and workpiece materials was investigated. Experimental results regarding to relatively high-quality surfaces machined by grinding, polishing, lapping processes have shown the measurement error is within 10% in the range of $0.1{mu}m~0.8{\mu}m R_q.$Therefore, the proposed method is thought to be effectively used when quick measurements is needed with workpieces fixed on the machine.

• 대한화학회지
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• 제8권4호
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• pp.188-191
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• 1964

微量元素分析用 燃燒爐 內에서 內部酸化劑(酸化銀과 二酸化 망간의 混合物)와 함께 有機試料를 헤륨 氣流下에서 燃燒시키고 發生한 물은 칼슘카바이드管에 通하여 아세틸렌으로 變換시킨다. 二酸化炭素와 아세틸렌을 molecular sieve 5A 管에 室溫에서 吸着시킨 후 $340^{\circ}C$까지 溫度${\cdot}$프로그탬法으로 脫着시켜 실리카켈管을 通하여 分別流出시키고 熱傳導式 檢知器로 $CO_2$와 $C_2H_2$를 定量하는 方法을 發展시켰다. 벤조酸을 標準物質로 하여 作成한 檢量線을 使用하여 各種 有機試料中의 炭素 및 水素含量을 分析한 結果 平均誤差가 炭素의 경우 ${\pm}0.5%$, 水素인 경우${\pm}0.33%$ 이었다.

• 대한화학회지
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• 제55권6호
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• pp.932-935
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• 2011

Using tetrabutyl titanate as precursor, $Eu^{3+}$ doped $TiO_2$ nano-powder was prepared by sol-gel method, the nature of luminescence of nano-powder was studied. The interaction of chlorpyrifos with $Eu^{3+}$ doped $TiO_2$ was studied by absorption and fluorescence spectroscopy. The results indicated the fluorescence intensity of $Eu^{3+}$ doped $TiO_2$ was quenched by chlorpyrifos and the quenching rate constant ($k_q$) was $1.24{\times}10^{11}\;L/mol{\cdot}s$ according to the Stern-Volmer equation. The dynamics of photoinduced electron transfer from chlorpyrifos to conduction band of $TiO_2$ nanoparticle was observed and the mechanism of electron transfer had been confirmed by the calculation of free energy change (${\Delta}G_{et}$) by applying Rehm-Weller equation as well as energy level diagram. A new rapid method for detection of chlorpyrifos was established according to the fluorescence intensity of $Eu^{3+}$ doped $TiO_2$ was proportional to chlorpyrifos concentration. The range of detection was $5.0{\times}10^{-10}-2.5{\times}10^{-7}mol/L$ and the election limit ($3{\sigma}$) was $3.2{\times}10^{-11}$ mol/L.

• Corrosion Science and Technology
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• 제2권6호
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• pp.283-288
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• 2003

The cathodic protection method is being widely used in marine structural steel, however a high tensile steel like RE 36 steel for marine structural steel is easy to get hydrogen embrittlement due to over protection during cathodic protection as well as preferential corrosion of HAZ(Heating Affected Zone) part. In this paper, corrosion resistance and mechanical properties such as elongation and hydrogen embrittlement were investigated with not only in terms of electrochemical view but also SSRT(Slow Strain Rate Test) method with applied constant cathodic potential, analysis of SEM fractography in case of both As-welded and PWHT(Post-Weld Heat Treatment) of $550^{\circ}C$. The best effect for corrosion resistance was apparently indicated at PWHT of $550^{\circ}C$ and elongation was increased with PWHT of $550^{\circ}C$ than that of As-welded condition. On the other hand. Elongation was decreased with applied potential shifting to low potential direction which may be caused by hydrogen embrittlement, however the susceptibility of hydrogen embrittlement was decreased with PWHT of $550^{\circ}C$ than that of As-welded condition and Q.C(quasi cleavage) fracture mode was also observed significantly according to increasing of susceptibility of hydrogen embrittlement. Eventually it is suggested that an optimum cathodic protection potential range not causing hydrogen embrittlernent is from -770 mV(SCE) to -850 mV(SCE) in As-welded condition while is from -770 mV(SCE) to -875 mV(SCE) in PWHT of $550^{\circ}C$.

• Journal of Ginseng Research
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• 제41권1호
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• pp.10-22
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• 2017

Background: Asian ginseng and American ginseng are functional foods that share a close genetic relationship and are well-known worldwide. This article aims to investigate the correlation between morphological characteristics and the inherent quality of Asian and American ginsengs. Methods: In this study, an ultra-HPLC-quadrupole/time-of-flight MS (UHPLC-Q/TOF-MS) method was established for the quantitative analysis of 45 ginseng samples. The method developed for determination was precise and accurate. Results: The results showed that Asian ginseng samples with the same growing time (with the same or similar number of stem scars) that had a thinner main root, a longer rhizome and more branch roots contained greater amounts of ginsenosides. For American ginseng, two tendencies were observed in the relationship between the diameter of the main root and contents of ginsenosides. One tendency was that samples with thinner main roots tended to contain higher levels of ginsenosides, which was observed in the samples sold under the commercial name pao-shen. Another tendency was that samples with thicker main roots contained higher contents of ginsenosides, which was observed in the samples sold under the commercial name pao-mian, as well as in samples of American ginseng cultivated in Jilin, China. Conclusion: An approach using ultra-HPLC-quadrupole/time-of-flight MS was successfully established to link morphology and active components for evaluating the quality of Asian and American ginsengs. Clear correlation between visible morphological features and quality of Asian and American ginsengs was found. People can see the difference; this means consumers and vendors can evaluate ginseng by themselves.