• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.247-250
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• 2006

현재 고밀도 반도체제작 환경에서는 Reactive ion Etching (RIE) 과정에서의 생산성을 극대화하기 위해서 비이상적인 공정장비를 발견하는 것이 매우 중요하다. 생산과정에서 오류발견의 중요성을 설명하기 위해 Support Vector Machine (SVM)은 실시간으로 공정오류에 대한 판단에 대한 도움을 주기 위해 사용되었다. baseline run으로부터 얻은 데이터로 SVM 모델을 구성하고 정상인 run 데이터와 비정상 run 데이터로 SVM 모델을 검증한다. 통계적 공정제어에서 흔히 이용되는 control limits를 도입하여 정상데이터가 내재하고 있는 램덤 변화율이 반영된 SVM 모델 기반의 control limits를 수립하고, 그 control limits를 바탕으로 오류발견을 실행한다. SVM을 이용함으로써 RIE의 오류발견은 run to run 기반에 정상인 run데이터는 0% 오류율이 증명되었다.

• 한국환경과학회지
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• 제29권2호
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• pp.201-207
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• 2020

A new chemosensor based on a self-assembled system has been devised to detect Hg²⁺ions efficiently. We demonstrated that the amphiphilic building blocks consisting of pyrene and boronic acid (1) aggregate in aqueous solutions and provide an outstanding sensing platform for sensitive detection. The self-assembled 1 exhibited high selectivity and sensitivity for Hg²⁺ion detection via fluorescence quenching, where the Hg²⁺ion detection ensued from a fast transmetallation of 1. The Stern-Volmer (SV) quenching constant for its fluorescence quenching by Hg²⁺ions was approximately 1.58 × 10⁸ M^-1. In addition, self-assembled 1 exhibited excellent sensing abilities at nano-molar concentration levels when tap water and freshwater samples were contaminated with of Hg²⁺ ions.

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권3호
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• pp.1-5
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• 2016

Rhodamine B Hydrazide as a novel fluorescent and colorimetric probe exhibiting remarkably selective fluorescence enhancement toward Hg²⁺ ion over other 16 metal ions is herein introduced. The probe reacts with Hg²⁺ ion followed by its spirolactam ring-opening to give a remarkable enhancement of absorption maximum at 550 nm as well as an enhanced fluorescence intensity at 580 nm in aqueous media. Upon titration with Hg²⁺ ion in various concentration of 10~200 uM, we found that the probe shows a marked color change from colorless to pink, enabling naked-eye detection toward mercury ion. In addition, in the presence of Hg²⁺ ion, the probe gave rise to change from non-florescence to strong orange fluorescence (Off-On) with a good linearity of R²=0.97. This preliminary results demonstrate that the fluorescent chemosensor we herein introduced can open a new strategy for marked selective and sensitive detection of mercury ions in contaminated soil containing various metal ions.

• 한국환경과학회지
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• 제21권12호
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• pp.1449-1454
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• 2012

The ion selective microelectrodes (ISME) have been applied to observe the continuous profiles of NO3-N and NH4-N in bulk solutions or biofilms. In order to evaluate the performance and applicability of ion concentration measuring system, the characteristics, such as slope of calibration curve, detection limit and potentiometric selectivity coefficient were investigated. The slopes of calibration curve showed high degree of correspondence for each target ion concentrations. And the detection limits of nitrate and ammonia ion selective microelectrode were 10-4.7 M and 10-4.4 M, respectively. These ion selective microelectrodes were proved that their own performance could be maintained for 16 days after making. NO3-N and NH4-N selective microelectrodes were also adapted to detect the continuous ion profiles of cilia media packed MLE (Modified Ludzack-Ettinger) process. And the monitored nitrate and ammonia ion profiles with the ion selective microelectrode were stable and well corresponded to the results with conventional ion chromatograph. However, the electric potential was unstable until 8 hr because of the unknown noise. The tip shape and performance of the ion selective microelectrode was stably kept over 2 days continuous monitoring.

• 약학회지
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• 제34권3호
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• pp.215-218
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• 1990

An ion chromatographic method based on indirect photometric detection of UV transparent anions was developed. Separation of anion was accomplished on strong anion exchange column (Waters SAX) using UV detector at 254 nm. Among examined UV-active additives (Dns-H, Dns-glu, Dnsser, Dns-val), Dns-glu showed the highest sensitivity. Studies on the effects of the pH and ionic strength of eluent revealed that the increase of pH and ionic strength of the eluent decreased capacity factor. The best eluent for the separation of acetate, fluoride, chloride, nitrate and bromide was $1\;{\times}\;10^{-4}M$ Dns-glu in 5 mM phosphate buffer (pH 6.30). The detection limit of chloride ion was 2.1 ng in this condition.

• Journal of Radiation Protection and Research
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• 제13권2호
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• pp.52-56
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• 1988

수중의 방사능을 측정하기 위한 전처리과정으로서 이온교환농축법과 증발건조법을 서로 비교하였다. 시료를 증발건조법으로 처리하였을때 방사성물질의 손실율은 이온교환농축법에 비해 20% 정도 많았다. 또, 1리터의 시료를 처리하는 데 소요된 증발시간은 $70^{\circ}C$에서 증발시킨 경우 약20시간이었으나 이온교환농축법으로 같은 양의 시료를 처리하는데 소요된 시간은 약6시간이었다. 따라서 이온교환농축법이 증발건조법에 비해 효과적이며 특히 수중의 저준위 방사성물질 측정에 적합한 것으로 나타났다.

• 한국산업보건학회지
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• 제7권2호
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• pp.223-232
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• 1997

The accuracy and precision of a modified method of NIOSH Method 7600 and EPA method 218.6 was determined for analyzing hexavalent chromium, Cr(VI), collected on PVC filter from workplace air. The method was designed to extract from Cr(VI) on PVC filter with a alkali solution, 2% NaOH/3% $Na_2CO_3$, and to analyze it using ion chromatography/visible absorbance detection(IC/VAD). The results and conclusion are as the following. 1. The peak of Cr(VI) was separated sharply on chromatogram and was linearly related with Cr(VI) concentration in sloution. The correlation coefficient was 0.9999 in a calibration curve. The limit of detection was 0.25 $0.25{\mu}g/sample$. 2. The accuracy(% recovery) was 93.3% in a set of sample($9-50{\mu}g$) stored for a day, and 100.1%($10-60{\mu}g$) in another set of samples stored for 2 hours. It is assumed that the difference in recovery by storage time was due to reduction of Cr(VI) to Cr(III). 3. The precision(coefficient of variation, CV) of the method was 0.015 in spiked samples with Cr(VI) standard solution, and 0.010 in spiked samples with plating solution from a chrome electroplating factory. The overall CV in all types of samples was 0.0013. 4. The Cr(VI) was stable in 2% NaOH/3% $Na_2CO_3$ at least for 10 hours. In conclusion, the IC/VAD method is appropriate for determining low-level Cr(VI) in workplace air containing various interferences.

• Bulletin of the Korean Chemical Society
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• 제24권7호
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• pp.948-952
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• 2003

New approach for the determination of Ag(I) ion was performed by using a carbon paste electrode (CPE) containing N,N'-Diphenyl oxamide (DPO) with anodic stripping voltammetry. The CMEs have been prepared by making carbon paste mixtures containing an appropriate amount of DPO salt coated onto graphite particles to analyze trace metal ions via complexation followed by stripping voltammetry. Various experimental parameters affecting the response, such as pH, deposition time, temperature, and electrode composition, were carefully optimized. Using differential pulse anodic stripping voltammetry, the logarithmic linear response range for the Ag(I) ion was 1.0 × $10^{-7}$ - 5.0 × $10^{-9}$ M at the deposition time of 10 min, with the detection limit was 7.0 × $10^{-10}$ M. The detection limit adopted from anodic stripping differential pulse voltammetry was 7.0 × $10^{-10}$ M for silver and the relative standard deviation was ± 3.2% at a 5.0 × $10^{-8}$ M of Ag(I) ion (n = 7). The proposed electrode shows a very good selectivity for Ag(I) in a standard solution containing several metals at optimized conditions.

• 한국교육논총
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• 제37권1호
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• pp.33-45
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• 2016

본 연구는 다양한 치환기를 포함하고 있는 3종의 보레인 화합물을 합성하고, UV/Vis 하에서 합성된 화합물이 내는 흡광을 이용하여 유기 용매 하에서 매우 적은 농도로 존재하는 불소 이온($F^-$)의 검출에 적용하고자 하는 것이다.

• Bulletin of the Korean Chemical Society
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• 제35권5호
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• pp.1541-1544
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• 2014