• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.281-285
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• 1990

Our N.C. sewing machine is a device that acts sewing automatically in reference to N.C. data made by data input device. Our N.C. sewing mechine is composed of induction motor that has electric clutch and brake, step motor that drives x-y table. Sewing area of our machine is 170 mm * 100 mm, maximum sewing speed is about 2000 spm, maximum stitch length 6.2 mm. In actual sewing, synchronization between motion of needle up-down and motion of x-y table is a critical factor. In this paper, technology about synchronization will be profoundly discussed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.855-858
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• 1995

A neural network has very simple construction (input, output and connection weight) and then it can be robusted against some disturbance. In this paper, we proposed a neuro-controller using a Multi-Layered neural network which is combined with PD controller. The proposed neuro-controller is learned by backpropagation learning rule with momentum and neuro-controller adjusts connection weight in neural network to make approximate dynamic model of DC Servo motor. Computer Simulation results show that the proposed neuro-controller's performance is better than that of origianl PD controller.

• 대한전자공학회논문지SD
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• 제41권10호
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• pp.69-75
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• 2004

본 논문에서는 온도 및 전원전압에 덜 민감한 기준전압을 위해 온-칩 필터를 사용하는 8b 220 MS/s 230 rnW 3단 파이프라인 CMOS A/D 변환기 (ADC) 회로를 제안한다. 제안하는 RC 저대역 필터는 기존의 큰 값을 가진 칩 외부의 바이패스 캐패시터를 사용하지 않고도 고속 동작 시 발생하는 여러 가지 잡음을 효과적으로 감쇄시키고 큰 R, C 부하에서도 기준전압의 정착시간을 줄인다. 시제품 ADC는 0.25 um CMOS 공정을 이용하여 설계 및 제작되었고, 입/출력단의 패드를 제외한 코어 면적은 2.25 ㎟ 이며 측정된 DNL 및 INL은 각각 -0.35～+0.43, LSB, -0.82～+0.71 LSB 수준을 보여준다. 또한, SNDR은 200 MS/s, 220 MS/s 샘플링 주파수에서 입력 주파수가 수 MHz에서 110 MHz까지 증가할 때 각각 43 dB 및 41 dB로 유지되었고, 입력주파수가 500 MHz 까지 증가할 때는 입력주파수가 110 MHz의 경우에 비해 3 dB 정도만 감소되었다.

• 정보통신설비학회논문지
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• 제2권4호
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• pp.64-70
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• 2003

IT산업의 기술발달이 하드웨어, 소프트웨어, 네트워킹에서 콘텐츠기술로 패러다임이 변화함에 따라 중소벤처기업들의 기술개발전략 또한 변화하고 있다. IT중소기업은 2002년말 GDP의 3.8%를 기여하고 있다. 정보통신부가 지원하고 있는 정보통신 산업경쟁력강화사업 및 우수신기술지정지원사업의 경우 컴퓨터, 소프트웨어 및 컨텐츠 등 정보기술분야의 기술개발이 각각 60%, 54%를 차지하고 기술개발사업화는 기술개발기간으로부터 3년정도 추가 소요됨을 알 수 있었다. 1996년부터 시작된 우수신기술지정지원사업의 경우 41%, 1999년부터 시작된 산업경쟁력강화사업은 18%의 사업화율을 보이고 있다. 중소기업들의 단기상용 기술개발전략은 정보기술분야를 우선적으로 검토할 필요가 있으며 단기 기술개발일지라도 기술개발 후 3년 정도 추가 상용기술개발 기간이 소요되는 점을 감안하여 기술개발에 접근하여야 한다.

• 한국연소학회지
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• 제20권2호
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• pp.36-39
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• 2015

The combustion characteristics of metal fiber burner fueled natural gas with tail gas produced from reforming process were analyzed on the point of flame stability and excess air conditions. Also, it was analyzed the effect of energy efficiency improvement due to decrease the fuel input in reforming system by using residue gases. As a results, it was confirmed that tail gas including hydrogen, CO and $CO_2$ could be directly injected without any change of air control system in natural gas burner and also energy efficiency was increased up to 30% maintained stable combustion.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 A
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• pp.225-230
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• 1992

In this paper, a new learning fuzzy logic controller(LFLC) is presented. The proposed controller is composed of the main control part and the learning part. The main control part is a fuzzy logic controller(FLC) based on linguistic rules and fuzzy inference. For the learning part, artificial neural network(ANN) is added to FLC so that the controller may adapt to unknown plant and environment. According to the output values of the ANN part, which is learned using error back-propagation algorithm, scale factors of the FLC part are determined. These scale factors transfer the range of values of input variables into corresponding universe of discourse in the FLC part in order to achieve good performance. The effectiveness of the proposed control strategy has been demonstrated through simulations involving the control of an unknown robot manipulator with load disturbance.

• ETRI Journal
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• 제27권2호
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• pp.206-218
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• 2005

We measure and compare externalities of IT and R&D capital stocks in different Korean industry sectors using inter-industry input-output tables of 1985, 1990, 1995 and 2000. We also compute the multiplier effects that relate to the directions of future economic effects. The key findings are as follows. First, we observed continuous capital deepening in all nine industries over the period of 1985 to 2000. Second, the backward multipliers of IT capital were the highest in the manufacturing industry. As for inter-industry externalities, the indirect backward multipliers, which exclude intra-industry backward multiplier effects within the industry, were also the highest in the manufacturing industry. Third, the forward multiplier effects of IT capital stock were the most substantial in the construction industry during the 1980s and in the manufacturing industry thereafter. Finally, using the transition multiplier matrix reflecting the backward effects of the two capitals in the past, the economic backward effects, especially the external economic effects, are predicted to increase through 2010 among all industries. The above findings suggest that, in order to maximize the forward and backward effects of the ever-increasing IT capital, we need to formulate an industry policy reducing the cost of capital accumulation in the manufacturing industry through improvement in productivity of the IT industry.

• Corrosion Science and Technology
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• 제3권4호
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• pp.154-160
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• 2004

The Sulfide Stress Corrosion Cracking (SSCC) resistance of structural steels is one of the critical concerns for the operators, material designers, and fabricators of oil-field equipment, especially treating sour gas (H2S) containing fluids. As far as its fabricators concerned, the systematic care of welding parameters should be taken to obtain comparable SSCC resistance of their weldment to that of its base material. In this respect, every different type of welding joint design for this use should be verified to be SSCC-proof with relevant test procedures. In this study, the welding parameters to secure a proper SSCC resistance of steel pipe's weldments were reviewed on the Welding Procedure Qualification Records (WPQR), which had been employed for actual fabrication of an offshore structure for oil and gas production. Based on this review, a guideline of welding parameters, such as, heat input, welding consumable for Y.S. 65 ksi class steel pipe material is proposed in terms of the NACE criteria for SSCC resistance.

• Design & Manufacturing
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• 제14권3호
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• pp.1-7
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• 2020

This paper predicts the mass and the length of injection-molded products through the Artificial Neural Network (ANN) method. The ANN was implemented with 5 input parameters and 2 output parameters(mass, length). The input parameters, such as injection time, melt temperature, mold temperature, packing pressure and packing time were selected. 44 experiments that are based on the mixed sampling method were performed to generate training data for the ANN model. The generated training data were normalized to eliminate scale differences between factors to improve the prediction performance of the ANN model. A random search method was used to find the optimized hyper-parameter of the ANN model. After the ANN completed the training, the ANN model predicted the mass and the length of the injection-molded product. According to the result, average error of the ANN for mass was 0.3 %. In the case of length, the average deviation of ANN was 0.043 mm.

• 한국전자거래학회지
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• 제10권1호
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• pp.41-60
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• 2005

본 논문에서는 국방CALS의 구현을 위한 표준방법론인 ID EF1/1X를 무기체계 연구개발 절차에 적용하여 연구개발 수행과정에서의 연구목표, 정보의 입력, 산출, 제약조건에 대한 정보모델링을 제시하였다. ID EF1/1X를 실행하는 프로그램인 SmartER를 이용하여 연구개발 수행기관 내부에 존재하는 모든 정보자원의 관리에 대한 요구분석을 실시하여 관리해야 할 정보를 식별한 후 TO-BE모델에 대한 정보모델링을 제시한 것이다. ID EF 적용대상인 무기체계 연구개발의 절차는 개념연구, 탐색개발, 체계개발, 그리고 시제품 제작을 거쳐 연구개발 결과 보고서 작성 단계로 구성되어 있다. 본 연구의 정보모델링 결과로 무기체계 통합데이터베이스(IWSDB)를 이용하여 정보를 공유하고 연구개발업무를 수행하는 것을 제시하였다. 무기체계 연구개발사업과 같은 대형 체계개발 사업에 대한 프로세스의 효율성을 기하기 위해서 적절한 방법론으로 알려진 IDEF에 대한 본격적인 연구가 진행되어 국방CALS를 구현하는 계기가 되었으면 한다.