• Journal of the Korean Data and Information Science Society
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• v.21 no.5
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• pp.841-852
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• 2010

An integrated process control (IPC) procedure is a scheme which simultaneously applies the engineering control procedure (EPC) and statistical control procedure (SPC) techniques to reduce the variation of a process. In the IPC procedure, the observed deviations are monitored during the process where adjustments are repeatedly done by its controller. Because the effects of the noise, the special cause, and the adjustment are mixed, the use and properties of the SPC procedure for the out-of-control process are complicated. This paper considers efficiency of EWMA charts for detecting special causes in an ARMA(1,1) noise model with a minimum mean squared error adjustment policy. And we propose the readjustment procedure after having a true signal. This procedure can be considered when the elimination of the special cause is not practically possible.

• Communications for Statistical Applications and Methods
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• v.16 no.3
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• pp.429-436
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• 2009

This paper considers the integrated process control procedure for detecting special causes in an IMA(1,1) process that is being adjusted automatically after each observation using a minimum mean squared error adjustment policy. When the control chart signals after the occurrence of a special cause, the special cause will be detected and eliminated from the process by the rectifying action. However, when the elimination of the special cause costs high or is not practically possible, an alternative action is to readjust the process with appropriately modified adjustment scheme. In this paper, we propose the readjustment procedure after having a true signal, and show that the use of the readjustment can reduce the deviation of a process from the target.

• Journal of the Korean Data and Information Science Society
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• v.22 no.6
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• pp.1123-1135
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• 2011

This paper considers the multivariate integrated process control procedure for detecting special causes in a multivariate IMA(1, 1) process. When the multivariate control chart signals, the special cause will be detected and eliminated from the process. However, when the elimination of the special cause costs high or is not practically possible, an alternative action is to readjust the process with approximately modified adjustment scheme. In this paper, we propose the readjustment procedure after having a true signal, and show that the use of the readjustment can reduce the deviation of a process from the target.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1158-1165
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• 2004

This paper describes the design of a two stage 1V power supply SiGe Low Noise Amplifier operating at 5.25㎓ for 802.lla wireless LAN application. The achieved performance includes a gain of 17㏈, noise figure of 2.7㏈, reflection coefficient of 15㏈, IIP3 of -5㏈m, and 1-㏈ compression point of -14㏈m. The total power consumption of the circuit was 7㎽ including 0.5㎽ for the bias circuit.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.4
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• pp.292-299
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• 2012

The line-of-sight(LOS) rate is estimated using Kalman filter in Radio-Frequency(RF) seeker. For the two axis gimbaled seeker, proper system modeling is considered and the basic filter structure is set up. The main issue for Kalman filter is choosing the proper process and measurement noise. For the measurement process, the signal to noise ratio(SNR) and other components are introduced. To cope with the eclipse problem or other abnormal seeker status, the pseudo input signal concept is proposed. By conditioning abnormal signals, the LOS rate estimation performance is increased. The process noise is also an important factor in the propagation phase. The analytical approach on a process noise component is performed and a reliable region for the filter is calculated based on the eigenvalue analysis. Some numerical simulations are performed to check the validity of suggested algorithm.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.2
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• pp.199-207
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• 2011

A Ku-band low noise amplifier has been designed and fabricated by using 0.25 um SiGe BiCMOS process. The developed Ku-band LNA RFIC which has been designed with hetero-junction bipolar transistor(HBT) in the BiCMOS process have noise figure about 2.0 dB and linear gain over 19 dB in the frequency range from 9 GHz to 14 GHz. Optimization technique for p-tap value and electro-magnetic(EM) simulation technique had been used to overcome the inaccuracy in the PDK provided from the foundry service company and to supply the insufficient inductor library. The finally fabricated low noise amplifier of two fabrication runs has been implemented with the size of $0.65\;mm{\times}0.55\;mm$. The pure amplifier circuit layout with the reduced size of $0.4\;mm{\times}0.4\;mm$ without the input and output RF pads and DC bais pads has been incorporated as low noise amplication stages in the multi-function RFIC for the active phased array antenna of Ku-band satellite VSAT.

• Journal of IKEEE
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• v.3 no.2 s.5
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• pp.226-235
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• 1999

To investigate SPICE noise model and the behavior of its parameters, 1/f noise of NMOS devices fabricated by BiCMOS process is measured and compared to the various noise models and measured results. For the long channel devices, bias dependence of the drain current noise power spectral density $S_{Id}$ of NMOS is similar to the previous results. Equivalent gate noise power spectral density $S_{Vg}$ shows weak dependence on the gate and drain voltages in long channel NMOS as the previous results. However, it is shown that most of published noise models are difficult to apply to short channel devices. Therefore, in this study, with comparison of our experimental results, we have tried to find the model of 1/f noise, appropriate for our NMOS device fabricated by BiCMOS process.

• Journal of the Korean Data and Information Science Society
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• v.24 no.6
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• pp.1275-1283
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• 2013

This paper considers the multivariate integrated process control procedure for detecting special causes in a multivariate IMA(1, 1) process. When the multivariate control chart signals, the special cause will be detected and eliminated from the process. However, when the elimination of the special cause costs high or is not practically possible, an alternative action is to readjust the process with approximately modified adjustment scheme. In this paper, we estimate parameters in the readjustment procedure after having a true signal in the multivariate integrated process control.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.86-91
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• 2006

본 연구는 M사의 제조공정에서 얻어진 대 용량 데이터를 사용하여 실리콘 웨이퍼의 중요 품질특성 중 하나인 Warp 불량원인을 분석한 사례이다. 이론적으로는 많은 양의 데이터를 확보하고 있을 경우 검출력의 향상으로 공정의 미세한 변화를 보다 민감하게 탐지할 수 있을 것으로 생각된다. 그러나 현실적으로는 불필요한 정보 혹은 많은 잡음 요인들의 개입으로 인하여 공정에 대한 올바른 이해가 더 어려울 수도 있다. 본 연구는 공정에 대한 경험과 기술적인 지식을 활용하여 분석의 기본 방향을 설정하고 많은 양의 데이터를 체계적으로 분석한 후 분석 결과를 실질적인 측면에서 재검토하여 의미 있는 결과를 도출하는 순서로 진행되었다. 데이터 분석의 과정 및 결과는 공정의 자동화로 수많은 데이터가 실시간으로 기록되는 상황에서 잡음요인들로 인한 영향을 배제하고 핵심요인에 의한 영향을 파악하는데 참고할 수 있을 것으로 사료된다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.1
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• pp.7-12
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• 1984

In this paper, the authors applied the method of hydrogen chloride gettering oxidation to fabricate the low noise bipolar transistor. The results of measurements of the effect of guttering on the variation of flicker noise spectral intensity for variable HCI concentrations indicate that flicker noise in bipolar than-sistor is dependent on the surface condition and that the gettering in a mixture of 2% HCI in oxidation produced the optimal results in the fabrication of the low noise device. In addition, it was also noted that the PSG layer formed by the emitter source (phosphorus) did not have so much guttering effect as in the process with HCl getterinng.