• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.10
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• pp.733-740
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• 2004

In this paper, an improved algorithm for the extraction of respiration signal from the electrocardiogram (ECG) is proposed. The whole system consists of two-lead electrocardiogram acquisition (lead Ⅰ and Ⅱ), baseline fluctuation elimination, R-wave detection, adjustment of sudden change in R-wave area using moving average, and optimal lead selection. In order to solve the problem of previous algorithms for the ECG-derived respiration (EDR) signal acquisition, we proposed a method for the optimal lead selection. An optimal EDR signal among the three EDR signals derived from each lead (and arctangent of their ratio) is selected by estimating the instantaneous frequency using the Hilbert transform, and then choosing the signal with minimum variation of the instantaneous frequency. The proposed algorithm was tested on 15 subjects, and we could obtain satisfactory respiration signals that shows high correlation (r>0.9) with the signal acquired from the chest-belt respiration sensor.

• Bulletin of the Korean Chemical Society
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• v.24 no.10
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• pp.1433-1436
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• 2003

A new method for the simultaneous determination of heavy metal ions in cigarette material by microwave digestion and reversed-phase high-performance liquid chromatography (RP-HPLC) has been developed. The cigarette material was digested by microwave digestion. Lead, cadmium, mercury, nickel and tin ions in the digested samples were pre-column derivatized with tetra-(2-chlorophenyl)-porphyrin ($T_2$-CPP) to form color chelates, which were then enriched by solid phase extraction with a $C_{18}$ cartridge. The chelates were separated on a Waters Xterra$^{TM}RP_{18}$ column by gradient elution with methanol (containing 0.05 mol/L pyrrolidine-aceticacid buffer salt, pH = 10.0) and acetone (containin0.05 mol/L pyrrolidine-acetic acid buffer salt, pH = 10.0)as mobile phase at a flow rate of 0.5mL/min and analyzed with a photodiode array detector from 350-600 nm. The detection limits of lead, cadmium, mercury, nickel and tin were 4,3,3,8 and 5 ng/L, respectively, in the original samples. This method was afforded good results.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.325-327
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• 2004

ECG limb lead II signal widely used to diagnosis heart diseases and it is essential to detect ECG events (onsets, offsets and peaks of the QRS complex P wave and T wave) and extract them from ECG signal for heart diseases diagnoses. However, it is very difficult to develop standardized feature extraction formulas since ECG signals are varying on patients and disease types. In this paper, simple feature extraction method from normal and abnormal types of ECG signals is proposed. As a signal features, heart rate, PR interval, QRS interval, QT interval, interval between S wave and baseline, and T wave types are extracted. To show the validity of proposed method, Right Bundle Branch Block (RBBB), Left Bundle Branch Block (LBBB), Sinus Bradycardia, and Sinus Tachycardia data from MIT-BIH arrhythmia database are used for feature extraction and the extraction results showed higher extraction capability compare to conventional formula based extraction method.

• Journal of the Korean GEO-environmental Society
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• v.2 no.3
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• pp.17-35
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• 2001

In this study, we conducted a combined adsorption-sequential extraction analysis(CASA) to investigate temperature effects of single adsorption of lead, copper, zinc and cadmium on natural clays. As a result, it was found that in a single adsorption of lead and copper, about 50% of adsorption was occluded in carbonate phase, and in case of cadmium, about 80% of adsorption was occluded in exchangeable phase. At temperature below $25^{\circ}C$ about 60% of zinc was occluded in exchangeable phase but above $40^{\circ}C$ about 50% of zinc was occluded in carbonate phase. The effect of temperature on each occluded phase was largely observed in Fe-oxide, Mn-oxide and organic occluded phases. Besides, the adsorption of metals on natural clays was an endothermic reaction with the exception of exchangeable phase adsorption.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.6
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• pp.18-26
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• 2009

In this paper, we proposed multipurpose signal detection methods for ECG (electrocardiogram) based u-healthcare systems. For ECG based u-healthcare system, QRS signal extraction for cardiovascular disease diagnosis is essential. Also, for security and convenience reasons, it is desirable if u-healthcare system support biometric identification directly from user's bio-signal such as ECG for this case. For this, from Lead II signal, we developed QRS signal detection method and also, we developed signal extraction method for biometric identification using Lead II signal which is relatively robust from signal alteration by aging and diseases. For QRS signal detection capability from Lead II signal, ECG signals from MIT-BIH database are used and it showed 99.36% of accuracy and 99.68% of sensitivity. Also, to show the performance of signal extraction capability for biometric diagnosis purpose, Lead III signals are measured after drinking, smoking, or exercise to consider various monitoring conditions and it showed 99.92% of accuracy and 99.97% of sensitivity.

• Archives of Plastic Surgery
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• v.32 no.6
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• pp.753-756
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• 2005

In the cases of severe arrythmia and conduction failure, a permanent implanted pacemaker is considered an essential treatment modality with less complication rate, broad indications and low morbidity. However, some pacemakers needs to be removed or replaced due to infection, in need of a lead upgrade, elective replacement, conduction failure or insulation failure. The most common indication for pacemaker extraction is infection. Conservative treatments such as administration of intravenous antibiotics and limitation of debridement are not effective and the removal of the entire pacing system is considered to be the best approach to pacemaker pocket infection. Although a locking stylet, a laser sheath and other newer methods of transvenous lead extraction have been proven to be effective, all leads cannot be removed. Moreover, major complications such as, cardiac tamponade and respiratory arrest during leads extraction procedure should not be ignored. We experienced two cases of exposed pacemakers in the subclavicular region. After removing the pacemaker body, exposed proximal lead was pulled out and cut off. The end of remnant external insulation tube was tied to prevent infection propagation between external insulation tube and inner metalic coil. Wounds were covered by local flap coverage. No other problems were detected during the one-year follow-up. Since there are few reports on lead-preserving method of treating limited infection of exposed pacemakers, we would like to present our new method for treating exposed pacemakers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.3
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• pp.169-175
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• 1976

A solvent extraction-atomic absorption spectrophotometry for determination of trace amount of cadmium, copper, lead and zinc and a flameless atomic absorption spectrophotometry for mercury in sea water were studied. The optimum pH range for solvent extraction was pH 4-7. A better solvent extraction efficiency was obtained with MIBK solvent than nitrobenzene, benzene, isoamylalcohol, n-buthylacetate. DDTC was more advantageous than APDC as chelating agent. The metals, chelated with DDTC and concentrated into MIBK by solvent extraction with a volume of $1\iota$ of sea water for cadmium, copper and lead, and 200m1 for zinc, were determined simultaneously by atomic absorption spectrophotometry. For mercury determination, 500ml of sea water was digested with permanganate-sulfuric acid and mercury( II ) was reduced by stannous chloride and aerated the solution with air pump until the absorbance reached a constant value. The precisions, in standard deviation, of these methods were 0.058ppb for cadmium, 0.084 ppb for copper, 0.44ppb for lead, 2.49ppb for zinc and 0.08 ppb for mercury. The sensitivities, expressed in $ppb/1\%$ absorption, were 0.058 ppb cadmium, 0. 15 ppb copper, 0.6 ppb lead, 1.2 ppb zinc and 0.01 ppb mercury respectively. No significant adsorption on the wall of polyethylene sample bottle occurred during 30 days of storing by acidification to pH 1.5 with nitric acid except zinc. Poor reproducibility was found for zinc with this method.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.241-246
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• 1999

In this research, electrokinetic remediation test was experimented with contaminated kaoline specimen at below, above the cation-exchange capacity of the mineral. The changes of the flow in electro-osmosis with open electrodes and current were presented, and lead removal results were evaluated through the extraction test. As a result, it was showed that removal efficiency was 20-30%, 67-87% In the anode As lead transport continues, the lead precipitation within a narrow zone very close to the cathode can go significantly high. This high lead precipitation near the cathode could block the flow path, decrease the conductivity, and thus the electroosmotic flow. The net effect will cause a decrease in the efficiency of electrokinetic processing. Therefore, in this study, citric acid and surfactant solution was used at the cathode as enhancement techniques.

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.899-902
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• 2003

Chip Pin Parasitic은 실제 Chip Pad에서부터 Bonding Wire를 통한 Package Lead Frame까지를 의미한다. 여기서, Lead Frame 및 Bonding Wire에서 Inductance 및 작은 저항이 보이고, Chip Pad에서의 Capacitance, 그리고 Pad 부터 Ground까지의 Return Path에서 발생하는 저항이 보인다. 이들을 모두 합하면 L, R, C의 Series로 나타낼 수 있다. 본 논문에서는 이런 Chip Pin Parasitic을 추출 하기 위해서 TDR(Time Domain Reflectometer)과 NA(Network Analyzer)를 사용하였는데, TDR의 경우 PCB를 제작하여 Chip을 Board위에 붙인 후 Time Domain에서 측정 하였고 NA의 경우 Pico Probe를 이용하여 Chip pin에 직접 Probing해서 Smith Chart를 통하여 Extraction 값을 추출했다. 이 경우, NA를 이용한 측정이 좀 더 정확한 Parasitic 값을 추출할 수 있으리라 예상되겠지만, 실제로 Chip이 구동하기 위해서는 Board위에 있을 때의 상황도 고려해야 하기 때문에 TDR 추출 값과 NA 추출 값을 모두 비교하였다.

• Journal of Environmental Science International
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• v.9 no.5
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• pp.437-441
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• 2000

A study on the removal of Pb ion from Pb-contaminated soil was carried out using ex-site extraction process. Tartaric acid (TA) and iminodiacetic acid sodium salt(IDA) as a washing agent were evaluated as a function of concentration reaction time mixing ratio of washing agent and recycling of washing agent. TA showed a better extraction performance than IDA. The optimum washing condition of TA and IDA were in the ratio of 1:15 and 1:20 between soil and acid solution during 1 hr reaction. The total concentrations of Pb ion by TA and IDA at three repeated extraction were 368.8 ppm and 267.5 ppm respectively. The recovery of Pb ion from washing solution was achieved by adding calcium hydroxide and sodium sulfide form the precipitation of lead hydroxide and lead sulfide and optimum amounts of sodium sulfide and calcium hydroxide were 7 g/$\ell$ for the TA washing solution and 4 g/$\ell$, 5g/$\ell$ for the IDA washing solution respectively. The efficiency of recycle for TA and IDA washing solution were 78.8% , 95.1%, and 89.2%, 96.6% at third extractions under $Na_2S$ and $Ca(OH)_2$, respectively.