• Title/Summary/Keyword: Stabilized Approach

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Complex sternal and rib reconstruction with allogeneic material

  • Maliska, Charles Miles III;Archer, Robert Lloyd;Tarpley, Sharon Kaye;Miller III, Archibald Sanford
    • Archives of Plastic Surgery
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    • v.45 no.6
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    • pp.593-597
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    • 2018
  • Sternal malunion, or loss, developed after a median sternotomy cannot only be difficult to manage and treat, but also may diminish one's quality-of-life drastically. The technique presented here represents a multispecialty approach in one stage for the reconstruction of an unstable thoracic cage. The procedure utilized a donated sternum and ribs. The sternum with ribs harvested from a single donor included adipose derived stromal vascular fraction (ADSVF) cells with marrow also from the same donor. Autologous muscle flaps, stabilized with acellular dermal matrix were utilized to provide a robust blood supply to the ADSVF cells and bone grafts. Acellular dermal matrix was used to construct the ribs and stabilize the plugs of stem cells and bone. These procedures, in the hands of multispecialty physicians, have led to several successful reconstructions involving complex chest wall deformities. This surgical intervention was performed in a one stage operation. This represents the first successful complete sternal transplant in a patient with return to normal activities and increased quality-of-life.

A theoretical study on the extinction of the premixed flame in a tube caused by a logitudinal velocity variation (축방향 유속변동에 의한 관내 예혼합화염의 소화특성에 관한 이론적 연구)

  • Kim, Nam-Il;Shin, Hyun-Dong;Bae, Choong-Sik
    • 한국연소학회:학술대회논문집
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    • 2001.11a
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    • pp.111-118
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    • 2001
  • Many previous researches on the premixed flame in a tube have treated the unsteady flame behaviors but more detailed and fundamental research has been necessary. The study on the flame stabilization condition in a tube and the unsteady behaviors were carried out in recent years. In this paper, a mean velocity variation larger than the burning velocity was introduced to the stabilized flame for a period longer than the reaction time scale in order to examine the unsteady behavior of flame propagation. Through our previous work it was found that the effects of non-unity Lewis number on the flame extinction was negligible in the extinction by the boundary layer even though they were important in the extinction by the acoustic instability. In this paper we carried out an analytic approach to explain the previous experimental results. It showed that the heat loss, from a flame to the wall, is not a sufficient condition but a required one for the growth of the extinction boundary layer. In addition, the quenching and the flame stretch, under a strong unsteady flow field, are the main causes of the eventual extinction.

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THE NUTATION DAMPING CONTROL OF A SPACECRAFT (인공위성의 미동현상 제어에 관한 연구)

  • 이창훈
    • Journal of Astronomy and Space Sciences
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    • v.11 no.2
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    • pp.281-295
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    • 1994
  • In this paper, the Variable Structure System(VSS) theory with new continuous switching dynamic equation is used to design an automatic controller for the active nutation damping in momentum bias stabilized spacecraft. In the application of VSS theory to a linearized multivariable system with the nutation damping systems, there exist some disadvantages such as how to determine the switching gains and how to reduce the chattering phenomina and reaching phase in input and state trajectories. To solve these drawbacks, this paper presents the continuous switching dynamic equation instead of the discontinuous switching logics to obtain the sliding mode. The new design approach is much simpler than the VSS theory. And there do not exist chattering phenomina in this method because the obtained control inputs are continuous. Simultaneously the reaching phase is reduced by a suitable choice of design factor.

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Probability Sampling Method for a Hidden Population Using Respondent-Driven Sampling: Simulation for Cancer Survivors

  • Jung, Minsoo
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.11
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    • pp.4677-4683
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    • 2015
  • When there is no sampling frame within a certain group or the group is concerned that making its population public would bring social stigma, we say the population is hidden. It is difficult to approach this kind of population survey-methodologically because the response rate is low and its members are not quite honest with their responses when probability sampling is used. The only alternative known to address the problems caused by previous methods such as snowball sampling is respondent-driven sampling (RDS), which was developed by Heckathorn and his colleagues. RDS is based on a Markov chain, and uses the social network information of the respondent. This characteristic allows for probability sampling when we survey a hidden population. We verified through computer simulation whether RDS can be used on a hidden population of cancer survivors. According to the simulation results of this thesis, the chain-referral sampling of RDS tends to minimize as the sample gets bigger, and it becomes stabilized as the wave progresses. Therefore, it shows that the final sample information can be completely independent from the initial seeds if a certain level of sample size is secured even if the initial seeds were selected through convenient sampling. Thus, RDS can be considered as an alternative which can improve upon both key informant sampling and ethnographic surveys, and it needs to be utilized for various cases domestically as well.

Electrochemical Approach in Plasma Display Panel Glass Melts doped with Sulfate and Sulfide I. Oxygen Equilibrium Pressure

  • Kim, Ki-Dong;Kim, Hyo-Kwang
    • Journal of the Korean Ceramic Society
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    • v.45 no.2
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    • pp.90-93
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    • 2008
  • The oxygen gas behavior in PDP (plasma Display Panel) glass melts doped with sulfate ($SO_4^{-2}$) or blast furnace slag (BFS, $S^{2-}$) or both by means of yttria-stabilized zirconia (YSZ) electrodes was observed after the first fining. The temperature dependence of oxygen equilibrium pressure ($P_{O2}$) in each melt showed typical behavior, namely $P_{O2}$ decreased as temperature decreased. This suggests that an oxidation of $S^{4+}$ to $S^{6+}$ took place. However, the $P_{O2}$-value at constant temperature increased in the following order: BFS$P_{O2}$ of the melt doped with sulfate+BFS was much lower than that of the melt with only sulfate, although only 10% of sulfur was added by the BFS. This behavior can be explained by the redox reaction between sulfide ions in the BFS and dissolved oxygen ions in the melt during the first fining.

The Combustion Characteristics of a New Cyclone Jet Hybrid Combustor for Low Pollutant Emission and High Flame Stability (저공해와 고안정성을 위한 신개념의 사이클론 제트 하이브리드 연소기의 연소특성)

  • Jung, Won-Suk;Hwang, Chul-Hong;Lee, Gyou-Young;Lee, Chang-Eon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.2
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    • pp.146-153
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    • 2004
  • A Promising new approach to achieve low pollutant emissions and improvement of flame stability is tested experimentally using a cyclone jet hybrid combustor employing both premixed and diffusion combustion mode. Three kinds of nozzle are tested for mixing enhancement of fuel and air. The LNG (Liquified Natural Gas) is used as a fuel. The combustor is operated by two methods. One is DC (Diffusion Combustion) mode generated swirl flow by air as general swirl combustor, and the other is HC (Hybrid Combustion) mode. The HC mode consists of diffusion jet flame of axial direction and premixed cyclone flame of tangential direction in order to stabilized the diffusion jet flame. The results showed that the flame stability of HC mode is significantly enhanced than that of DC mode through the change of mixing characteristics by modifications of fuel nozzle. In addition, the reductions of CO and NOx emission in HC mode, as compared with that for the DC mode, is large than about 50% in stable region. Also, even using the low calorific fuel as $CO_2$-blended gas, it is identified that the cyclone jet hybrid combustor has the high performance of flame stability.

Combustion Stability Characteristics of Fuel-Rich Gas Generators (연료 과농 가스발생기의 연소 안정성 특성 연구)

  • Seo, Seong-Hyeon;Han, Yeoung-Min;Choi, Hwan-Seok
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2007.11a
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    • pp.119-122
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    • 2007
  • The present study employs experimental approach to identify combustion stability characteristics of fuel-rich gas generators. The gas generator of interest, fueled by LOx and Jet A-1, experienced combustion instability coupled to a longitudinal resonant mode of the combustion chamber at about 1200 Hz. The occurrence of instability is strongly associated with acoustic boundary condition at the exit .and axial location of maximum heat release. As a result, stretching heat release zone in the axial direction by increase of the fuel nozzle diameter has dramatically stabilized combustion.

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A Study on Improvement of Means of Realization of Train Destination Equipment System (열차행선안내게시시스템 개선방안 연구)

  • Yoon, In-Young;Yeo, Yong-Joo;Kim, Kwang-Hwi;Kim, Ho-Chang
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.1566-1573
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    • 2007
  • Urban railway system that leads the urban public transportation enables the passengers to use the subway system safely and conveniently by indicating the destination of, status of approach of and other information on train through Train Destination Equipment(TDE), which is one of the important passenger services. The existing system is composed of Host Station Equipment(HSE) and operator panel that receives necessary input on train information from Total Traffic Control System(TTC), Local Station Equipment(LSE) that controls Train Destination Indicator(TDI) installed at each station, and Train Destination Indicator that ultimately displays train information to the passengers using the train system. This study aims to realize stabilized and reliable announcement system for destination of train by considering processing procedure and method of expression of inputted information of the existing system of notification of announcement of destination of train that can be applied in the RFID, which is the base technology of USN for which service expansion is easy, and to realize system that considers interface with USN and expandability with other facilities in the future.

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Oscillation Amplitude-controlled Resonant Accelerometer Design using Aautomatic Gain Control Loop (자동이득 제어루프를 이용한 진폭제어방식의 공진형 가속도계 설계)

  • Yun, Suk-Chang;Sung, Sang-Kyung;Lee, Young-Jae;Kang, Tae-Sam
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.7
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    • pp.674-679
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    • 2008
  • In this paper, we introduce a new design approach for self-sustained resonant accelerometer, that takes advantage of the automatic gain control (AGC) loop to achieve a stabilized oscillation dynamics. Fundamental idea of this accelerometer is to maintain uniform amplitude of oscillation under input accelerations. Through system modeling and loop transformation considering the envelope of oscillation, the controller is designed to maintain uniform amplitude in oscillation under dynamic input acceleration. The simulation results demonstrate the feasibility of the proposed accelerometer design, which is applicable to control grade inertial measurement system in industrial and civil application fields.

Treatment Approach of Instable Scapular by Proprioceptive Neuromuscular Facilitation (고유수용성 신경근 촉진법에 의한 견갑골 불안정 치료 접근)

  • Bae, Sung-Soo;Kim, Sang-Soo;Kim, Soo-Min;Kim, Mi-Hyun;Kim, Sik-Hyun
    • PNF and Movement
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    • v.4 no.1
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    • pp.1-7
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    • 2006
  • Objective : The purpose of this study was conducted to find scapular movement instability related with shoulder complex and provide strengthening the scapular muscles with proprioceptive neuromuscular facilitation(PNF). Methods : This is a literature study with books and articles, seminar note and book for PNF international course. Results : The scapular serve as the platform for humeral motions. The scapulothoracic articulation is stabilized and controlled, in part, by the scapular muscles. Therefore, if scapular muscle function is altered, then dysfunctional scapulothoracic kinematics may result. Strengthening exercise for scapular muscles are a common part of rehabilitation programs designed for patients with scapular instability. Conclusion : Treatment of the scapular instability is provided. It is that treatment with combination of isotonic, stabilize reversal on different patient's positions.

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