• Geomechanics and Engineering
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• 제1권4호
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• pp.291-306
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• 2009

One-dimensional soil-column studies were carried out to understand the interaction of three industrial effluents namely amino acid ('highly acidic'), surfactant ('highly organic') and pharmaceutical ('organic and toxic') on the physicochemical behavior, index properties and shear strength of bentonite due to artificial contamination extending to nearly 300 days. Changes in inorganic and organic pollutants present in the effluents due to the interaction of the above effluents and soil were assessed to understand the physico-chemical behaviour. Batch and continuous modes of operation, 8 hrs and 16 hrs Hydraulic Retention Time [HRT] and 25%, 50% concentrations of effluents, were the parameters considered. Amino acid, surfactant and pharmaceutical effluents have shown a high variation in pH (7 to 8) after artificial contamination on bentonite that is their original characteristics of the above effluents have been completely reversed. Further, it is found that the shear strength of bentonite has reduced by about 20%, and with respect to liquid limit and plastic limit shows an increasing trend with time within the period of contamination.

• 공업화학
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• 제24권4호
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• pp.357-362
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• 2013

High efficiency particulate air (HEPA) 필터를 시험하기 위하여 단분산 polystyrene latex spheres (PLS) 및 PS-MPS/실리카복합 나노구체가 이용되었다. 사용된 모든 나노구체들은 필터시험 전에 평균입경과 변동계수 값을 측정하여 시험용 인조먼지로서 적정함을 평가하였다. PLS 및 복합 나노구체의 입경은 유화중합 중 반응온도와 안정제의 양을 조절하여 100~300 nm 범위에서 잘 조절되었으며, 변동계수의 경우도 단분산 입자분포로 판단되는 15%보다 낮은 3~7% 범위이었다. 한편 HEPA 필터시험 결과는 사용된 모든 나노구체들이 공기필터의 시험을 위한 시험용 인조먼지로서 아주 적절함을 보여주었다.

• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2403-2409
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• 2014

Absolute isotope ratio is a critical constituent in determination of atomic weight. To measure the absolute isotope ratio using a mass spectrometer, mass discrimination factor, $f_{MD}$, is needed to convert measured isotope ratio to real isotope ratio of gas molecules. If the $f_{MD}$ could be predicted, absolute isotope ratio of a chemical species would be measureable in absence of its enriched isotope pure materials or isotope references. This work employed gravimetrically prepared isotope mixtures of argon (Ar) to obtain $f_{MD}$ at m/z of 40 in the magnetic sector type gas mass spectrometer (gas/MS). Besides, we compare the nitrogen isotope ratio of nitrogen trifluoride ($NF_3$) with that of nitrogen molecule ($N_2$) decomposed from the same $NF_3$ thermally in order to identify the difference of $f_{MD}$ values in extensive m/z region from 28 to 71. Our result shows that $f_{MD}$ at m/z 40 was $-0.044%{\pm}0.017%$ (k = 1) from measurement of Ar artificial isotope mixtures. The $f_{MD}$ difference in the range of m/z from 28 to 71 is observed $-0.12%{\pm}0.14%$ from $NF_3$ and $N_2$. From combination of this work and reported $f_{MD}$ values by another team, IRMM, if $f_{MD}$ of $-0.16%{\pm}0.14%$ is applied to isotope ratio measurement from $N_2$ to $SF_6$, we can determine absolute isotope ratio within relative uncertainty of 0.2 %.

• Korean Chemical Engineering Research
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• 제58권2호
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• pp.248-256
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• 2020

본 연구에서는 폭발위험장소의 방폭설비 설치를 위해 필요한 가스폭발위험범위 예측모델 개발을 수행하였다. 이를 위해 12개의 가연성가스에 대한 1,200개의 폭발위험범위 데이터를 생성하였다. 가스폭발위험범위를 출력변수로 설정하였고 데이터 생성과정에서 필요한 12개의 변수를 입력변수로 설정하였다. 다중 회귀, 주성분 회귀, 인공신경망 기법을 이용해 예측모델을 개발하였다. 각각 모델의 예측 성능을 비교한 결과, 평균절대퍼센트오차(MAPE)는 각각 44.2%, 49.3%, 5.7%이고 평균제곱근오차(RMSE)는 1.389 m, 1.602 m, 0.203 m로 나타났다. 결과를 통해 인공신경망이 가장 우수한 성능을 보여주었고 가스폭발위험범위 예측을 위한 최적 모델이라는 것을 확인하였다.

• 공업화학
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• 제23권1호
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• pp.59-64
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• 2012

potassium persulfate (KPS)와 sodium dodecyl sulfonate (SDS)를 각각 개시제와 안정제로 사용한 유화중합에 의하여 인공먼지로 사용할 수 있는 polystyrene latex spheres (PLS)를 제조하였다. PLS입자의 크기를 조절하기 위한 변수로 반응온도와 개시제 및 안정제의 농도가 선택되었다. 반응온도의 증가에 따라 입자의 크기는 작아졌으며, KPS와 SDS의 농도를 변화시켜 PLS 입자의 크기 및 분포를 매우 미세하게 조절할 수 있었다. 본 연구에서 제조된 PLS입자는 변동계수 (CV) 값이 7% 이하인 단분산이며, 0.1~0.5 ${\mu}m$ 범위에 있어 인조 먼지로 사용하기에 적합한 것으로 밝혀졌다.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권2호
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• pp.118-122
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• 2005

Electro-chemo-mechanical devices or artificial muscles based on conducting polymers (CP) are presented as bilayers, CP/adhesive polymer, or as triple layers, CP/adhesive polymer/CP. Those soft and wet materials, working in aqueous solutions of a salt, mimic the composition of most organs from animals. Under electrochemical control, so working as new electrical machines, they produce continuous, reverse and elegant bending movements, mimicking those produce by animal muscles. By means of the current a perfect controls of the movement rate is attained giving soft and continuous movements. Muscles able to sense the chemical and mechanical conditions of work or muscle having tactile sense, as will be presented here, are being developed. All of them are founded on the non-stoichiometric nature of the soft and wet materials.

• International Journal of Control, Automation, and Systems
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• 제6권6호
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• pp.894-903
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• 2008

In this paper, we present an artificial muscle actuator producing rectilinear motion, called the Tube-Spring-Actuator(TSA). The TSA is supposed to be a prospective substitute in areas requiring macro forces such as robotics. It is simply configured from a synthetic elastomer tube with an inserted spring. The design of the TSA is described in detail and its analysis is conducted to investigate the characteristics of the actuator based on the derived model. In addition, the performance of the proposed actuator is tested via experiments.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.24-27
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• 2004

This paper describes the method how to control an autonomous robot remotely using Internet. The autonomous robot that has an artificial brain is called "Tarou". (1) It is able to move along the line on the floor based on processing the image data obtained from two CCD cameras. (2) It is able to understand dialogs between human being and it and is able to take actions such as turn right and lefts, go forward 1m and go backward 0.5m, etc. (3) It is able to recognize patterns of objects. (4) It is able to recognize human faces. (5) It is able to communicate human being and to speak according to contents written in the program. We show the techniques to control the autonomous robot "Tarou" remotely by personal computer and/or portable Phone via Internet. The techniques developed in our research could dramatically increase their performance for..the need of artificial life robot as the next generation robot and national homeland security needs.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1174-1179
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• 2003

Cast austenitic stainless steel is used for several components, such as primary coolant piping, elbow, pump casing and valve bodies in light water reactors. These components are subject to thermal aging at the reactor operating temperature. Thermal aging results in spinodal decomposition of the delta-ferrite leading to increased strength and decreased toughness. This study shows that ferrite content can be predicted by use of the artificial neural network. The neural network has trained learning data of chemical components and ferrite contents using backpropagation learning process. The predicted results of the ferrite content using trained neural network are in good agreement with experimental ones.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.405-405
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• 2000

We designed the artificial olfactory sensing system (Electronic Nose) using MOS type sensor array fur recognizing and analyzing odour. The response of individual sensors of sensor array, each processing a slightly different response towards the sample volatiles, can provide enough information to discriminate between sample odours. In this paper, we applied clustering algorithm for dimension reduction, such as linear projection mapping (PCA method), nonlinear mapping (Sammon mapping method) and the combination of PCA and Sammon mapping having a better discriminating ability. The odours used are VOC (Volatile chemical compound) and Toxic gases.