• International Journal of Fuzzy Logic and Intelligent Systems
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• 제1권1호
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• pp.87-94
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• 2001

Silicon nitride films grown by plasma-enhanced chemical vapor deposition (PECVD) are useful for a variety of applications, including anti-reflecting coatings in solar cells, passivation layers, dielectric layers in metal/insulator structures, and diffusion masks. PECVD systems are controlled by many operating variables, including RF power, pressure, gas flow rate, reactant composition, and substrate temperature. The wide variety of processing conditions, as well as the complex nature of particle dynamics within a plasma, makes tailoring SiN film properties very challenging, since it is difficult to determine the exact relationship between desired film properties and controllable deposition conditions. In this study, SiN PECVD modeling using optimized neural networks has been investigated. The deposition of SiN was characterized via a central composite experimental design, and data from this experiment was used to train and optimize feed-forward neural networks using the back-propagation algorithm. From these neural process models, the effect of deposition conditions on film properties has been studied. A recipe synthesis (optimization) procedure was then performed using the optimized neural network models to generate the necessary deposition conditions to obtain several novel film qualities including high charge density and long lifetime. This optimization procedure utilized genetic algorithms, hybrid combinations of genetic algorithm and Powells algorithm, and hybrid combinations of genetic algorithm and simplex algorithm. Recipes predicted by these techniques were verified by experiment, and the performance of each optimization method are compared. It was found that the hybrid combinations of genetic algorithm and simplex algorithm generated recipes produced films of superior quality.

• 한국세라믹학회지
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• 제41권5호
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• pp.388-394
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• 2004

균일하게 혼합된 LiNO$_3$와 Co 금속분말을 알곤 분위기 하에서 SHS 공정으로 리튬이차전지용 양극활물질인 LiCoO$_2$분말을 합성하였다. 여러 가지 반응변수에 따라 제조된 분말의 특성과 전기화학적 특성평가를 수행하였는데, 반응온도 및 속도와 제조된 분말의 입도는 각각 Li/Co 몰비와 시료의 냉각속도 변화로 제어 가능하였다. Li/Co 몰비가 1.05일 때 최대방전용량인 145 mAh/g을 나타냈으며, 10회 충ㆍ방전 실험 후 6.4%의 낮은 용량감소를 갖는 비교적 안정된 cycling 특성을 보였다.

• Transactions on Control, Automation and Systems Engineering
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• 제3권4호
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• pp.223-228
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• 2001

We have been developed an intelligent mobile robot with an artificial olfactory function to recognize odours and to track odour source location. This mobile robot also has ben installed an engine for speech recognition and synthesis and is controlled by wireless communication. An artificial olfactory system based on array of 7 gas sensors has been installed in the mobile robot for odour recognition, and 11 gas sensors also are located in the obttom of robot to track odour sources. 3 optical sensors are also in cluded in the intelligent mobile robot, which is driven by 2 D. C. motors, for clash avoidance in a way of direction toward an odour source. Throughout the experimental trails, it is confirmed that the intelligent mobile robot is capable of not only the odour recognition using artificial neural network algorithm, but also the tracking odour source using the step-by-step approach method. The preliminary results are promising that intelligent mobile robot, which has been developed, is applicable to service robot system for environmental monitoring, localization of odour source, odour tracking of hazardous areas etc.

• Fisheries and Aquatic Sciences
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• 제18권1호
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• pp.89-98
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• 2015

A synthesis method for a chitosan-coated magnetic drug-delivery system of cisplatin is proposed. Here, cisplatin was conjugated to the surface of Magnetite ($Fe_3O_4$) nanoparticles via a (3-Aminopropyl)-trimethoxysilane (APTS) coupling agent. To reduce the cytotoxic effect of cisplatin, the magnetic drug was then encapsulated in chitosan (CS-cisplatin-$Fe_3O_4$) through the water/oil (W/O) emulsion method. The CS-cisplatin-$Fe_3O_4$ nanoparticles were synthesized in a spherical shape with a diameter of 190 nm. The cytotoxicity assay was performed using HeLa cells. The cisplatin uptake of the cells was determined using High Performance Liquid Chromatography (HPLC) to calculate the drug content. The controlled release of cisplatin was demonstrated by regulating the dissolution and diffusion of the drug through the chitosan matrix.

• 한국음향학회지
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• 제13권5호
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• pp.69-76
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• 1994

국어 자음을 단어내 음운환경별로 실험해 본 결과, 국어의 자음변이 규칙이 반영된 일관성있는 음가변화를 발견하였다. 발견된 음가변화는, ⅰ) 장애음의 길이는 모음간보다 단어초가 길고, ⅱ) 공명음의 길이는 단어초와 모음간보다 단어말이 길며, ⅲ) /ㄹ/의 F2와 F3는 모음간이 낮고 단어말은 높다는 것이다.ⅰ) 이들 음향특징의 근거가 되는 국어의 자음변이 규칙은, ⅰ) 평음의 유성화 현상, ⅱ) 음절말 불파음화 현상, ⅲ) 단어초 기음화 현상, ⅳ) /ㄹ/ 음소의 [r]과 [l] 교체현상이다. 본 실험결과 제시된 변화값은 음성인식 및 합성에 응용될 때 인식의 정확성과 합성의 자연성을 향상시킬 수 있다.

• 전자공학회논문지SC
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• 제37권5호
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• pp.34-45
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• 2000

이 논문에서는 부분관측하에서 직렬생산시스템에 대한 멀티에이젼트 내고장성 관리제어기법을 제안한다. 이를 위해 기존의 이산사건시스템에 대한 내고장성 관리제어기법에 멀티에이젼트 제어기법의 개념을 도입한다. 특히, 직렬연결된 프로세서 사이의 상호 내고장성 개념을 정립하며 제어결과의 상이정보를 이용한 관측불능 고장 식별에 관해 다룬다. 그리고 정립된 개념을 바탕으로 에이젼트 관리제어기의 설계기법을 정형화한다. 또한 제안하는 제어기법의 효용성을 검증하기 위해 폴리프로필렌의 예비중합공정과 중합공정에 있어서의 고장파급제어에 대한 사례연구를 살펴본다.

• Elastomers and Composites
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• 제47권1호
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• pp.30-35
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• 2012

새로운 스타폴리머인 바이오폴리부타디엔은 리빙 음이온중합이라는 고분자의 정밀 합성법을 통하여 분자량, 분자량분포, 조성 및 세부구조를 제어하였다. 리빙 음이온중합에 의해 n-BuLi으로 개시된 polybutadienyllithium(PBDLi)의 연쇄말단이 ESO(Epoxidized Soybean Oil)의 기능성 그룹과 커플링 반응을 일으키며 스타폴리머를 합성한다. 분자량이 1,000/5,000/10,000(g/mol)인 PBDLi을 중합하여 THF존재하에서 반응 후 GPC에 의한 분자량 및 arms분석과 $^1H$-NMR, FT-IR에 의한 고분자 구조 분석을 통하여 바이오폴리부타디엔의 합성을 확인하였다.

• 한국세라믹학회지
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• 제51권3호
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• pp.201-207
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• 2014

High-purity aluminum nitride nanopowders were synthesized using an RF induction thermal plasma instrument. Ammonia and nitrogen gases were used as sheath gas to control the reactor atmosphere. Synthesized AlN nanopowders were characterized by XRD, SEM, TEM, EDS, BET, FTIR, and N-O analyses. It was possible to synthesize high-purity AlN nanoparticles through control of the ammonia gas flow rate. However, additional process parameters such as plasma power and reactor pressure had to be controlled for the production of high-purity AlN nanopowders using nitrogen gas.

• 폴리머
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• 제26권2호
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• pp.253-259
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• 2002

본 연구는 내열성, 저광학손실 광도파로용 고분자재료를 합성하고 그 물성을 조사한 것이다. 열안정성을 높이고 광학손실을 줄이기 위한 pentafluorophenylmaleimide와 복굴절률을 낮추기 위한 두가지 methacrylate 유도체와 가교제 역할을 하는 glycidylmethacrylate를 삼원 공중합하여 광가교가 가능한 poly(maleimide-co-methacrylate)를 합성하였다. 합성된 고분자들은 높은 열안정성을 나타내었고, 열처리에 의해서 가교가 됨을 확인하였다. 고분자의 굴절율은 공중합 비율에 의해서 조절가능하였고, 1.45~l.49 범위의 고분자가 합성되었다. 복굴절은$6{ imes}10^{-4}$ ~ $1{ imes}10^{-4}$ 범위의 낮은 값을 나타내었다. 이 고분자와 광개시제를 사용하여 접촉 인쇄 방식에 의한 노광과 습식 현상을 통해 깨끗한 광도파로 패턴을 얻을 수 있었다.

• 대한의용생체공학회:의공학회지
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• 제8권1호
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• pp.87-92
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• 1987

In order to evaluate the artificial skin for burn would covering materials, copoly(N. carbobenzoxy-L-Iysine-L-leucine)s were prepared by Ipolymerization of N - carbobenzoxy-L- I sine anhydride and L-leucine anhydride in homogeneous solvents using triethylamine as an initiator. The synthetic polypeptides and the oxter type polyurethane(PV)of medical grade were used as the sheet type membranes were prepared ; monolayer membrances were composed of only the polypeptides, bilayer membranes and blend membranes were controlled by composition of the polypeptides and PU. Test of the swelling degree, mechanical tensile strength, elongation, oxygen permeability, water-vapor loss and In vitro degradation treated by pretense TV of samples of artificial skin were measured by adequate methods so as to mechanical, physincal characterization and biodegradation. As a result, all the values of samples were found to be similar to desired value of skin which was nature. The Artificial skin based on polypeptides can be considered as ideal burn wound covering materials.