• Title/Summary/Keyword: Stable process

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Logic for the use of stable structural superimposition method and introduction of its application (안정골구조물 중첩법(stable structural superimposition method)을 사용해야 하는 합리적 근거 및 그 중첩방법의 소개)

  • Chun, Youn-Sic;Hwang, Chung-Ju
    • The korean journal of orthodontics
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    • v.27 no.5 s.64
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    • pp.669-682
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    • 1997
  • [$Bj\ddot{o}rk$] and Skieller concluded after following facial growth patterns using implants in upper and lower jaw bones that stable structures, which are not influenced by the growth do exist and so these must be the reference landmarks in the process of superimposition. In spite of such facts, for the last 40 years since the discovery of stable structures, most orthodontists have preferred best fit superimposition method to structural method. Cases such as Angle's Class II division 2 malocclusion that show characteristic forward and upward growth or one under long period of post-treatment observation demonstrate that distinct differences exist between the two methods of superimposition. Today, ethical concerns prohibit further growth studies that use implants, md so there is no choice but to use stable structural superimposition method based on $Bj\ddot{o}rk's$ data. Thus, to encourage clinical use of stable structural superimposition method, logic for the use of stable structural superimposition method will be demonstrated, and its technical methods of application will be introduced step by step.

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Real-time Control of Biological Animal Wastewater Treatment Process and Stability of Control Parameters (생물학적 축산폐수 처리공정의 자동제어 방법 및 제어 인자의 안정성)

  • Kim, W.Y.;Jung, J.H.;Ra, C.S.
    • Journal of Animal Science and Technology
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    • v.46 no.2
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    • pp.251-260
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    • 2004
  • The feasibility and stability of ORP, pH(mV) and DO as a real-time control parameter for SBR process were evaluated in this study. During operation, NBP(nitrogen break point) and NKP(nitrate knee point), which reveal the biological and chemical changes of pollutants, were clearly observed on ORP and pH(mV)-time profiles, and those control points were easily detected by tracking the moving slope changes(MSC). However, when balance of aeration rate to loading rate, or to OUR(oxygen uptake rate), was not optimally maintained, either false NBP was occurred on ORP and DO curves before the appearance of real NBP or specific NBP feature was disappeared on ORP curve. Under that condition, however, very distinct NBP was found on pH(mV)-time profile, and stable detection of that point was feasible by tracking MSC. These results might mean that pH(mV) is superior real-time control parameter for aerobic process than ORP and DO. Meanwhile, as a real-time control parameter for anoxic process, ORP was very stable and more useful parameter than others. Based on these results, a stable real-time control of process can be achieved by using the ORP and pH(mv) parameters in combination rather than using separately. A complete removal of pollutants could be always ensured with this real-time control technology, despite the variations of wastewater and operation condition, as well as an optimization of treatment time and capacity could be feasible.

Improvement of Process for Sorbitol Production with Cetyltrimethylammoniumbromide Permeabilized Cells of Zymomonas mobilis through Glutaraldehyde Crosslinking (Cetyltrimethylammoniumbromide로 투과성을 높힌 Zymomonas mobilis의 Glutaraldehyde Crosslinking에 의한 Sorbitol 생산 안정성의 향상)

  • 장기효;박철진전억한
    • KSBB Journal
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    • v.6 no.3
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    • pp.249-254
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    • 1991
  • Permeabilization of Zymomonas mobilis with CTAB(Cetyltrimethylammoniumbromide) was investigated in order to obtain stable process for sorbitol production in the immobilized system. The optimum conditions for sorbitol formation were obtained in the case of using cells treated with 0.2% CTAB at$ 4^{\circ}C$ for 10 min. Permeabilized cells were treated with glutaraldehyde to cross-link the internal enzyme for the improvement of the enzyme stability. In this way, no significant loss of enzyme activity was apparent during 30-day operation in a continuous process. The productivity of the continuous process at dilution rate 0.2h-1 was 6.51g/1/h for sorbitol. The CTAB permeabilized cells could be used to produce sorbitol in the long term continuous process.

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Thermoelectric Properties of PbTe Sintered Body Fabricated by Mechanical Alloying Process (기계적합금화 공정에 의해 제조된 PbTe 소결체의 열전특성)

  • 이길근;정해용;이병우
    • Journal of Powder Materials
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    • v.8 no.2
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    • pp.110-116
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    • 2001
  • Abstract To investigate the effect of mechanical alloying process to thermoelectric properties of PbTe sintered body, Pb-Te mixed powder with Pb : Te : 1 : 1 composition was mechanically alloyed using tumbler-ball mill. Thermoelectric properties of the sintered body were evaluated by measuring of the Seebeck coefficient and specific electric resistivity from the room temperature to 50$0^{\circ}C$. Sintered body of only mechanically alloyed PbTe powder showed p-type behavior at the room temperature, and occurred type transition from p-type to n-type at about 30$0^{\circ}C$. PbTe sintered body which was fabricated using heat treated powder in $H_2$ atmosphere after mechanical alloying showed stable n-type behavior under 50$0^{\circ}C$. N-type PbTe sintered body fabricated by mechanical alloying process had 4 times higher power factor than that fabricated by the melt-crushing process. Application of a mechanical alloying process to fabricate of n-type PbTe thermoelectric material seemed to be useful to increase the power factor of PbTe sintered body.

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The Laminating process for Single Substrate Flexible LCD

  • Bae, Kwang-Soo;Choi, Yoon-Seuk;Kim, Hak-Rin;Kim, Jae-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1125-1128
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    • 2007
  • The laminating technique for developing flexible liquid crystal display was demonstrated by using a thin UV curable polymer film and a plastic substrate with patterned polymer wall structure. We adopted the rigid wall structure to provide a solid mechanical support for the stable molecular alignment of liquid crystals (LCs) in the device. The cover film was prepared to have an ability of aligning LC molecules by patterning a micro-groove structure using the soft-lithographic process. These two substrates can be assembled tightly by the laminating and one-step UV irradiation process because of the adhesive nature of the used UV curable polymers. Proposed method can be used to fabricate the flexible LC display with simplicity and also be applicable for a cost-effective roll-to-roll process.

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Design of Cross Wedge Rolling Die for a Non-heat-treated Cold Steel using CAD and CAE (CAD/CAE를 이용한 냉간 비조질강용 회전전조 금형설계)

  • Lee H. W.;Yoon D. J.;Lee G. A.;Choi S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2004.05a
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    • pp.400-403
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    • 2004
  • A non-heat기leafed steel does not need quenching and tempering processes that are called a heat treatment differently from conventional steel. Since the tensile strength of this steel is higher than 900MPa, a conventional forming process should be changed to incremental forming process such as a cross wedge rolling that requires lower load capacity than conventional ones. In this paper, the cold cross wedge rolling (CWR) die has been designed using CAD/CAE In order to produce near-net-shaped component of ball stud of non-heat-treated cold steel. Finite element analyses were applied in order to investigate process parameters of CWR. Results provide that the stretching angle and the forming angie at knifing zone in CWR process is important parameter to be the stable process under the low friction coefficient condition.

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Optimum Design of Draw-bead Force in Sheet Metal Stamping using Rigid-plastic FEM and Responses Surface Methodology (강소성 유한요소해석과 반응표면분석법을 이용한 박판성형공정에서의 드로우 비드력 최적설계)

  • Kim, Se-Ho;Huh, Hoon;Tezuka, Akira
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1999.03b
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    • pp.143-148
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    • 1999
  • Design optimization is performed to calculated the draw-bead force for satisfying the design re-quirements. For an analysis tool a rigid-plastic finite element method with modified membrane element is adopted. response surface methodology is utilized for constructing the approximation surface for the optimum searching of draw bead force in sheet metal forming process. the algorithm developed is ap-plied to a design of the draw bead forces in a deep drawing process. The results show that the design of process parameters is applicable in complex metal forming analysis. It is also noted that the present algo-rithm enhances the stable optimum solution with small times of optimization iteration.

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Efficient Auto Measure Sampling Method for Semiconductor Line (반도체 라인의 효율적 계측을 위한 자동 계측 샘플링 방식에 관한 연구)

  • Kim, Tae-Yeob;Sun, Dong-Seok;Lee, Jee-Hyung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.12
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    • pp.2505-2510
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    • 2009
  • Semiconductor processes need measurement to confirm where there are problems in quality after progresses manufacturing process. This paper suggests equipment and automatic measure sampling method that control monitoring ratio according to change point occurrence availability of process that is not measure method by the existent simple ratio rate. This paper defines measure section as ailment section, metastable section and stability section by change point standard and create statistical model of each section and developed suitable measure rate model by section. As a result, we have accomplished maximum throughput and minimum sampling number that needs to maintain constant level of quality. Proposed method minimizes load of measure process by brings production quality sophistication and decrease of process badness and lowers measure rate in stable section making perception about problem occurrence quick heightening measure rate at change point occurrence.

Evolutionary Operation with Many Process Variables (다수의 공정변수가 있는 경우의 진화적 조업법)

  • Byun Jai-Hyun;Rhee Chang-Kwon
    • Proceedings of the Korean Society for Quality Management Conference
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    • 2004.04a
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    • pp.513-516
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    • 2004
  • Evolutionary operation is useful to improve on-line full-scale manufacturing processes by systematically changing the levels of the process variables while meeting production schedule. Evolutionary operation was developed using two or three process variables for process operators who are not good at statistics. Recently, when a product is developed, it is very important for the engineers to make the production line stable as soon as possible. And there are many causes which have influences to the product performance. This paper presents an evolutionary operation procedure with many process variables using saturated two level fractional factorial designs including Plackett-Burman design.

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SiH4 Soak Effects in the W plug CVD Process (텡스텐 플러그 CVD 공정에서 SiH4 Soak의 영향)

  • 이우선;서용진;김상용;박진성
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.1
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    • pp.1-4
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    • 2003
  • The SiH$_4$soak step is widely used to prevent the WF$_{6}$ attack to the underlayer metal using the chemical vapor deposition (CVD) method. Reduction or skipping of the SiH$_4$soak process time if lead to optimizing W-plug deposition process on via. The electrical characteristics including via resistance and the structure of W-film are affected by the time of SiH$_4$soak process. The possibility of elimination of SiH$_4$soak process is confirmed In the case of W- film grown on the stable Ti/TiN underlayer.