• Title/Summary/Keyword: process diagnostics

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Experimental analysis of flow field for laser shock wave cleaning (레이저 충격파 클리닝에서 발생되는 유동장의 실험적 해석)

  • 임현규;장덕석;김동식
    • Laser Solutions
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    • v.7 no.1
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    • pp.29-36
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    • 2004
  • The dynamics of laser-induced plasma/shock wave and the interaction with a surface in the laser shock cleaning process are analyzed by optical diagnostics. Shock wave is generated by a Q-switched Nd:YAG laser in air or with N$_2$, Ar, and He injection into the focal spot. The shock speed is measured by monitoring the photoacoustic probe-beam deflection signal under different conditions. In addition, nanosecond time-resolved images of shock wave propagation and interaction with the substrate are obtained by the laser-flash shadowgraphy. The results reveal the effect of various operation parameters of the laser shock cleaning process on shock wave intensity, energy-conversion efficiency, and flow characteristics. Discussions are made on the cleaning mechanisms based on the experimental observations.

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Analysis of nano-cluster formation in the PECVD process

  • Yun, Yongsup
    • Journal of Advanced Marine Engineering and Technology
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    • v.37 no.2
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    • pp.144-148
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    • 2013
  • In this paper, the ultra water-repellent thin films were prepared by RF PECVD. On the basis of surface morphology, chemical bonding states and plasma diagnostics, a formation model of clusters for the ultra water-repellent films was discussed from considerations of formation process and laser scattering results. Moreover, using laser scattering method, the relative change of quantity of nano-clusters or size of agglomerates could be confirmed. From the results, the films were deposited with nano-clusters and those of agglomerates, which formed in organosilicon plasma, and formation of agglomerates were depended on the deposition time.

Monitoring and Controlling Uniformity of Plasma Emission Intensity for IGZO Sputtering Process (IGZO박막 증착 공정에서 플라즈마 방출광 모니터링 및 플라즈마 균일도 제어)

  • Choi, Jinwoo;Hwang, Sang Hyuk;Kim, Woo Jae;Shin, Gi Won;Kwon, Heui Tae;Jo, Tae Hoon;Woo, Won Gyun;Cha, Sung Duk;An, Byung Chul;Park, Wan Woo;Do, Jae Chul;Kwon, Gi-Chung
    • Journal of the Semiconductor & Display Technology
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    • v.15 no.4
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    • pp.27-32
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    • 2016
  • In recent years, various researches have been conducted to improve process yields in accordance with miniaturization of semiconductor. APC(Advanced Process Control) is considered one of the methods to increase in process yields. APC is a process control technology that maintains optimal process conditions and improves the reliability of results by controlling and formulating the relationship among the various process parameters and results. We built up an optical diagnostic system with a three-channel spectrometer. The system detects signals those represent the changes of specific emission peaks intensity versus each reference and converts it into MFC control signals to get back the changes to the reference state. Controlling the MFC continues until the specific peak intensity changes into the normal state. Through this device, we tested a APC automatically responding to process changes during the plasma process. We could control gas flow while sputtering process on going and improve uniformity of plasma intensity with this system. Finally, we have got results those enhance the plasma intensity non-uniformity to 7.7% from 15.5%. Also, found unexpected oxygen flow what is estimated to be come out from IGZO target.

Process fault diagnostics using the integrated graph model

  • Yoon, Yeo-Hong;Nam, Dong-Soo;Jeong, Chang-Wook;Yoon, En-Sup
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10b
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    • pp.1705-1711
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    • 1991
  • On-line fault detection and diagnosis has an increasing interest in a chemical process industry, especially for a process control and automation. The chemical process needs an intelligent operation-aided workstation which can do such tasks as process monitoring, fault detection, fault diagnosis and action guidance in semiautomatic mode. These tasks can increase the performance of a process operation and give merits in economics, safety and reliability. Aiming these tasks, series of researches have been done in our lab. Main results from these researches are building appropriate knowledge representation models and a diagnosis mechanism for fault detection and diagnosis in a chemical process. The knowledge representation schemes developed in our previous research, the symptom tree model and the fault-consequence digraph, showed the effectiveness and the usefulness in a real-time application, of the process diagnosis, especially in large and complex plants. However in our previous approach, the diagnosis speed is its demerit in spite of its merits of high resolution, mainly due to using two knowledge models complementarily. In our current study, new knowledge representation scheme is developed which integrates the previous two knowledge models, the symptom tree and the fault-consequence digraph, into one. This new model is constructed using a material balance, energy balance, momentum balance and equipment constraints. Controller related constraints are included in this new model, which possesses merits of the two previous models. This new integrated model will be tested and verified by the real-time application in a BTX process or a crude unit process. The reliability and flexibility will be greatly enhanced compared to the previous model in spite of the low diagnosis speed. Nexpert Object for the expert system shell and SUN4 workstation for the hardware platform are used. TCP/IP for a communication protocol and interfacing to a dynamic simulator, SPEEDUP, for a dynamic data generation are being studied.

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An Experimental Study on the Flow Characteristics and the Stratification Effects in Visualization Engine Using the DPIV and the Entropy Analysis (DPIV와 엔트로피 해석방법을 이용한 가시화 엔진내의 유동 특성 및 성층효과에 관한 실험적 연구)

  • Lee Changhee;Lee Kihyung;Lee Changsik
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.1
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    • pp.9-18
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    • 2005
  • The objective of this study is to analyse the spray characteristics according to the injection duration under the ambient pressure condition, and the injection timing in the visualization engine. In order to investigate the spray behavior, we obtained the spray velocity using the PIV method that has been an useful optical diagnostics technology, and calculated the vorticity from spray velocity component. These results elucidated the relationship between vorticity and entropy which play an important role in the diffusion process for the early injection case and the stratification process for the late injection case. In addition, we quantified the homogeneous diffusion rate of spray using the entropy analysis based on the Boltzmann's statistical thermodynamics. Using these method, it was found that the concentration of spray droplets caused by the increase of injection duration is more effective than the increase of momentum dissipation. We also found that the homogeneous diffusion rate increased as the injection timing moved to the early intake stroke process and BTDC $50^{\circ}$ was the most efficient injection timing for the stratified mixture formation during the compression stroke.

EXPERIMENTAL STUDY ON THE FLOW AND MIXTURE DISTIBUTION IN A VISUALIZATION ENGINE USING DIGITAL PARTICLE IMAGE VELOCIMETRY AND ENTROPY ANALYSIS

  • Lee, K.H.;Lee, C.H.
    • International Journal of Automotive Technology
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    • v.8 no.2
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    • pp.127-135
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    • 2007
  • The objective of this study is to analyze the effect of velocity and vorticity on stratified mixture formation in the visualization engine. In order to investigate spray behavior, the pray velocity is obtained through the cross-correlation PIV method, a useful optical diagnostics technology and the vorticity calculated from the spray velocity component. These results elucidated the relationship between vorticity and entropy, which play an important role in the diffusion process for the early injection case and the stratification process for the late injection case. In addition, we quantified the homogeneous diffusion ate of spray using entropy analysis based on Boltzmann's statistical thermodynamics. Using these methods, we discovered that the homogeneous mixture distribution is more effective as a momentum dissipation of surrounding air than that of the spray concentration with a change in the injection timing. We found that the homogenous diffusion rate increased as the injection timing moved to the early intake stroke process, and BTDC $60^{\circ}$ was the most efficient injection timing for the stratified mixture formation during the compression stroke.

The Chinese Black Box - A Scientific Model of Traditional Chinese Medicine

  • Theodorou, Matthias;Fleckenstein, Johannes
    • Journal of Acupuncture Research
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    • v.36 no.1
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    • pp.1-11
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    • 2019
  • Models of traditional Chinese medicine (TCM) are still difficult to grasp from the view of a Western-cultural background. For proper integration into science and clinical research, it is vital to think "out of the box" of classical sciences. Modern sciences, such as quantum physics, system theory, and information theory offer new models, that reveal TCM as a method to process information. For this purpose, we apply concepts of information theory to propose a "Chinese black box model," that allows for a non-deterministic, bottom-up approach. Considering a patient as an undeterminable complex system, the process of getting information about an individual in Chinese diagnostics is compared to the input-process-output principle of information theory and quantum physics, which is further illustrated by Wheeler's "surprise 20 questions." In TCM, an observer uses a decision-making algorithm to qualify diagnostic information by the binary polarities of "yang" (latin activity) and "yin" (latin structivity) according to the so called "8 principles" (latin 8 guiding criteria). A systematic reconstruction of ancient Chinese terms and concepts illuminates a scattered scientific method, which is specified in a medical context by Latin terminology of the sinologist Porkert [definitions of the Latin terms are presented in Porkert's appendix [1] (cf. Limitations)].

Distinction of Hot-Cold Using Fuzzy Inference (퍼지 추론에 의한 한열 판별)

  • Jang, Yun Ji;Kim, Young Eun;Kim, Chul;Song, Mi Young;Rhee, Eun Joo
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.19 no.3
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    • pp.141-149
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    • 2015
  • Objectives Recently the fuzzy logic is widely used in the decision making, identification, pattern recognition, optimization in various fields. In this study, we propose the fuzzy logic as the objective method of distinguishing hot and cold, the basis of diagnosis in Korean medicine. Methods We developed fuzzy inference system to distinguish whether the subjects had hot or cold. The cold and hot questionnaire of Korean traditional university textbook, the pulse rate and the DITI value of face used in the system. These three kinds of information were defined as 'fuzzy sets,' and 54 fuzzy rules were established on the basis of clinical practitioners' knowledge. The fuzzy inference was performed by using the Mamdani's method. To evaluate the usefulness of the fuzzy inference system, 200 cases of data measured in the Woosuk university hospital of oriental medicine were used to compare the determining hot, normal, cold results obtained from the experts and from the proposed system. Results As a result, 100 cases of "cold", 54 cases of "normal", and 34 cases of "hot" were matched between the experts and the proposed system. This fuzzy system showed the conformity degree of 94%(${\kappa}=0.853$). Conclusions In this study, we could express the process of distinguishing hot-cold using the fuzzy logic for objectification and quantification of hot-cold identification. This is the first study that introduce a fuzzy logic for distinguish pattern identification. The degree of the heat characteristic of the patients inferred by this system could provide a more objective basis for diagnosing the hot-cold of patients.

Comparison of the Properties of Yeongdong and Yeongseo Heavy Rain (영동과 영서 호우의 특성 비교)

  • Kwon, Tae-Yong;Kim, Jae-Sik;Kim, Byung-Gon
    • Atmosphere
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    • v.23 no.3
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    • pp.245-264
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    • 2013
  • Heavy rain over the Gangwon region has distinct characteristics in the temporal and spatial distribution of rainfall, most of which are concentrated on a very short period of time and either part of Yeongdong and Yeongseo regions. According to its regional distribution, heavy rain events over the Gangwon region may be classified into Yeongdong and Yeongseo heavy rain in which rainfalls of more than 110 mm $(6 hrs)^{-1}$ (heavy rain warning) have been observed in at least one of the weather stations over only Yeongdong or Yeongseo region, but over the other region the rainfalls are less than 70 mm $(6 hrs)^{-1}$ (heavy rain advisory). To differentiate between Yeongdong and Yeongseo heavy rain, 9 cases for Yeongdong heavy rain and 8 cases for Yeongseo heavy rain are examined on their synoptic and mesoscale environments using some meteorological parameters and ingredients. In addition, 8 cases are examined in which heavy rain warning or advisory are issued in both Yeongdong and Yeongseo regions. The cases for each heavy rain type have shown largely similar features in some meteorological parameters and ingredients. Based on an ingredient analysis, there are three common and basic ingredients for the three heavy rain types: instability, moisture, and lift. However, it is found that the distinct and important process producing strong upward vertical motions may discriminate among three heavy rain types very well. Yeongdong heavy rain is characterized by strong orographic lifting, Yeongseo heavy rain by high instability (high CAPE), and heavy rain over both regions by strong synoptic-scale ascent (strong 850 hPa Q-Vector convergence, diagnostics for ascent). These ingredients and diagnostics for the ingredients can be used to forecasting the potential for regional heavy rain. And also by knowing which of ingredients is important for each heavy rain type, forecasters can concentrate on only a few ingredients from numerous diagnostic and prognostic products for forecasting heavy rain events.

Basic Study on the Image Instrument of the Facial-form by the 3D-facial Scanner (얼굴스캐너를 활용한 안면형상 영상진단기의 기초 연구)

  • Kim, Gyeong-Cheol;Lee, Jeong-Won;Kim, Hoon;Shin, Soon-Shik;Lee, Hai-Woong;Lee, Yong-Tae;Chi, Gyoo-Yong;Kim, Jong-Won
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.22 no.2
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    • pp.497-501
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    • 2008
  • 3D facial scanner for an accurate analysis is measured precisely a distance in straight, a distance in curved line, an angle in 3D data, the area of surface. We can easy acquire 3D data by the method of 0.8sec in each scan with easy handling, simple merge to whole face, harmless and fast process. In the HyungSang medicine, the inspection of the facial shape includes the Dam(gall bladder) - Bang Kwang(urinary bladder) body, the Jung${\cdot}$Gi${\cdot}$Shin${\cdot}$Hyul, the six merdian types etc. And we will collect the evidence based date verifing in the HyungSang clinical medicine. As we will analyze the facial whole form and the size${\cdot}$length${\cdot}$angle of the facial part, put the facial form's standardization on a solid foundation.