• 제목/요약/키워드: Free School

검색결과 4,886건 처리시간 0.039초

감각 신경을 포함한 견갑 피판술의 결과 (Scapular Free Flap with Sensory Function)

  • 정덕환;황원준;박준영
    • Archives of Reconstructive Microsurgery
    • /
    • 제14권1호
    • /
    • pp.18-23
    • /
    • 2005
  • Purpose: To report the results and the efficacy of the sensory bearing scapular free flap which is known as non-sensible flap. Materials and Methods: Authors underwent 24 cases of sensory bearing scapular free flap to the hands and feet from March 1995 to November 2002. average follow-up period was six year three months. The used flaps were a ordinary scapular flap in fifteen cases, and a parascapular flap in nine. Sensibility of the flaps were checked every one month. Actual sensory evaluation was mostly depends on objective feeling of the patients. Two point discrimination test was performed in all cases. Results: 23 flaps had good skin circulation after microvascular anastomosis among 24. Objective deep touch sensation were observed about three months later after the operation in three cases, between three and six months in nine. In three case whose results were excellent than others, two point discrimination was 2.7 cm at last follow-up. Most of the sensory recovery is confined in deep touch, temperature and light touch sensation was recovered limitedly in 3 cases during our follow-up period. Conclusion: Authors can propose that sensory bearing free scapular flap was considered as one of useful methods for the reconstruction to hand with soft tissue defect and mutilating hand.

  • PDF

피드백이 없는 유체진동기에서 분사되는 Sweeping jet의 유동 특성 (Flow Characteristics of Sweeping Jet Issued by a Feedback-free Fluidic Oscillator)

  • 남상현;김동욱;김경천
    • 한국가시화정보학회지
    • /
    • 제18권1호
    • /
    • pp.50-58
    • /
    • 2020
  • This paper presents flow characteristics of a sweeping jet issued by a feedback-free fluidic oscillator. Overall flow characteristics of feedback-free sweeping jet (FFSJ) were analyzed using flow visualization. The feedback-free sweeping jet has a sinusoidal external flow pattern. The oscillating frequency of the FFSJ is three times higher than that of a conventional sweeping jet at the same Reynolds number. Flow structure and turbulence characteristics were investigated using time-resolved particle image velocimetry (TR-PIV). In instantaneous velocity fields, the flow did not stay at ends but changed the direction continuously in contrast to the conventional sweeping jet. Velocity distributions at each plane which were extracted from mean velocity field has Gaussian distribution, which is similar with a circular jet. The sweep angles were constant as 45° at all Reynolds numbers in the high flow rate regime.

Backstepping Sliding Mode-based Model-free Control of Electro-hydraulic Systems

  • Truong, Hoai-Vu-Anh;Trinh, Hoai-An;Ahn, Kyoung-Kwan
    • 드라이브 ㆍ 컨트롤
    • /
    • 제19권1호
    • /
    • pp.51-61
    • /
    • 2022
  • This paper presents a model-free system based on a framework of a backstepping sliding mode control (BSMC) with a radial basis function neural network (RBFNN) and adaptive mechanism for electro-hydraulic systems (EHSs). First, an EHS mathematical model was dedicatedly derived to understand the system behavior. Based on the system structure, BSMC was employed to satisfy the output performance. Due to the highly nonlinear characteristics and the presence of parametric uncertainties, a model-free approximator based on an RBFNN was developed to compensate for the EHS dynamics, thus addressing the difficulty in the requirement of system information. Adaptive laws based on the actor-critic neural network (ACNN) were implemented to suppress the existing error in the approximation and satisfy system qualification. The stability of the closed-loop system was theoretically proven by the Lyapunov function. To evaluate the effectiveness of the proposed algorithm, proportional-integrated-derivative (PID) and improved PID with ACNN (ACPID), which are considered two complete model-free methods, and adaptive backstepping sliding mode control, considered an ideal model-based method with the same adaptive laws, were used as two benchmark control strategies in a comparative simulation. The simulated results validated the superiority of the proposed algorithm in achieving nearly the same performance as the ideal adaptive BSMC.

Rapid One-pot, Four Component Synthesis of Pyranopyrazoles Using Heteropolyacid Under Solvent-free Condition

  • Chavan, Hemant V.;Babar, Santosh B.;Hoval, Rahul U.;Bandgar, Babasaheb P.
    • Bulletin of the Korean Chemical Society
    • /
    • 제32권11호
    • /
    • pp.3963-3966
    • /
    • 2011
  • A series of pyranopyrazoles, was efficiently synthesized via one-pot, four component reaction of ethyl acetoacetate, hydrazine hydrate, aldehydes and malononitrile in the presence of catalytic amount silicotungstic acid under solvent free condition. NOE experiments confirmed that the product exist exclusively in the 2H form. The present protocol offers the advantages of clean reaction, short reaction time, high yield, easy purification and economic availability of the catalyst.

Dynamic Range Improvement of IM-DD Optical Link using Dual-Wavelength Dual-Parallel Modulation

  • Li, Xianghua;Yang, Chun;Zhou, Zhenghua;Chong, Yuhua
    • Journal of the Optical Society of Korea
    • /
    • 제18권4호
    • /
    • pp.330-334
    • /
    • 2014
  • In this paper, we present an incoherent dual-parallel modulation linearized optical link employing two different optical wavelengths. Comparing with previous dual-parallel modulation, this linearization method prevents the recreation of distortion products and can be readily implemented. Furthermore, a dual-wavelength dual-parallel modulation linearized optical link constructed with the commercially available devices is experimentally demonstrated with a spurious-free dynamic range of $122.5dB.Hz^{4/5}$. More than 25 dB suppression of the intermodulation distortion, 15.6 dB improvement of spurious-free dynamic range and 1.5 dB improvement of compression dynamic range are achieved after linearization.

Cobalt Oxide Nanorods Prepared by a Template-Free Method for Lithium Battery Application

  • Kim, Seong-Jun;Kim, Eun-Ji;Liu, Meilin;Shin, Heon-Cheol
    • Journal of Electrochemical Science and Technology
    • /
    • 제7권3호
    • /
    • pp.206-213
    • /
    • 2016
  • Transition metal oxide-based electrodes for lithium ion batteries have recently attracted much attention because of their high theoretical capacity. Here we report the electrochemical behavior of cobalt oxide nanorods as anodes, prepared by a template-free, one-step electrochemical deposition of cobalt nanorods, followed by an oxidation process. The as-deposited cobalt has a slightly convex columnar structure, and controlled thermal oxidation produces cobalt oxides of different Co/O ratios, while the original shape is largely preserved. As an anode in a rechargeable lithium battery, the Co/O ratio has a strong effect on initial capacity and cycling stability. In particular, the one-dimensional Co@CoxOy core shell structure obtained from a mild heat-treatment results in superior cycling stability.

워터쉐드를 이용한 피부암 영역 추출 (A Skin Cancer Region Extraction Using Watershed)

  • 한재복;김진영;유홍연;홍성훈
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2006년도 하계종합학술대회
    • /
    • pp.877-878
    • /
    • 2006
  • In this paper, we propose a skin lesion detection to develop the system of fluorescence image analysis to identify the fluorescence of topical methyl aminolevulinate(MAL) idduced PpIX in patients with BCC accurately. By fluorescence image analysis we define the border between tumo and tumor-free areas on fluorescence image after topical application of MAL ointment. We excised both the tumor and peri-tumoral areas widely from the 10 patients with BCC, and divided tissue samples into 3 area, such as tumor area, suspected tumor area, tumor-free area, respectively. Our proposed method migt play a role as an adjunctive tool to define the border between tumor and tumor-free areas for Mohs' micrographic surgery.

  • PDF

Underlying mechanisms of phosphodiesterase 10A and glutamate-ammonia ligase genes that regulate inosine monophosphate deposition and thereby affect muscle tenderness in Jingyuan chickens

  • Wang, Weizhen;Zhang, Juan;Hu, Honghong;Yu, Baojun;He, Jintong;Yao, Tingting;Gu, Yaling;Cai, Zhengyun;Xin, Guosheng
    • Animal Bioscience
    • /
    • 제35권11호
    • /
    • pp.1771-1786
    • /
    • 2022
  • Objective: Inosine monophosphate (IMP) is a key factor that imparts of meat flavor. Differences in the IMP content in the muscles were evaluated to improve chicken meat quality. Methods: For this study, the IMP content was detected by high performance liquid chromatography. The gene expression profiles of Jingyuan chickens with different feeding patterns and different sexes were analyzed by RNA-sequencing (RNA-seq). Results: Breast muscle IMP content in free-range chickens was extremely significantly higher than that of caged chickens (p<0.01). Breast muscle IMP content in hens was also higher than that of cocks, but the difference was not significant. Correlation analysis showed that the breast muscle IMP content in caged hens and cocks was negatively correlated with the shear force, and the breast muscle IMP content in free-range hens was significantly negatively correlated with the shear force (p<0.05). The two key genes associated with IMP synthesis in chickens with different feeding patterns were glutamate-ammonia ligase (GLUL) and phosphodiesterase 10A (PDE10A). Bioinformatics analysis revealed that the GLUL and PDE10A genes are involved in glutamine biosynthesis and purine salvage pathways respectively. In addition, GLUL expression was positively correlated with the IMP content in caged and free-range chickens, and PDE10A expression was significantly positively correlated with the IMP content in caged and free-range chickens (p<0.05). Conclusion: These findings will facilitate the comprehension of the deposition of IMP in the muscles and thereby aid the process of selection and breeding of good quality local chickens.

이송되는 컵 형상에 따른 자유표면의 거동 특성에 관한 연구 (A Study on the Behavior of the Free Surface in a Moving Cup of Different Shape)

  • 김윤선;홍태협;김창녕
    • 대한설비공학회:학술대회논문집
    • /
    • 대한설비공학회 2009년도 하계학술발표대회 논문집
    • /
    • pp.1220-1225
    • /
    • 2009
  • A manipulator is operated for the motion of mechanical hands or arms. When a cup including liquid inside is shifted by a manipulator, it is important to know how a free surface of the liquid moves. In this study, non dimensional parameters have been found that affect the rise of the free surface in a cup moving with constant acceleration. The non-dimensional parameters are the dimensionless time, the ratio of inertia effect to viscous effect (the Reynolds number), aspect ratio of the liquid inside the cup and the acceleration ratio (the Froude number). Through this study, the height of the free surface rise in a cup has been predicted and the detailed velocities in the liquid have been examined. Generally, the maximum rise of the free surface is dependent on the Reynolds number and Froude number strongly, but on the aspect ratio weakly. However, the influence of the aspect ratio on the maximum rise of the free surface is not negligible in the range of 10 < Re < 100.

  • PDF

이송되는 컵 내부의 자유 표면의 거동 특성에 대한 수치해석 (A Numerical Analysis of the Behavior of the Free Surface in a Moving Cup)

  • 김윤선;홍태협;김창녕;임성수
    • 설비공학논문집
    • /
    • 제21권7호
    • /
    • pp.394-401
    • /
    • 2009
  • A manipulator is operated for the motion of mechanical hands or arms. When a cup including liquid inside is shifted by a manipulator, it is important to know how a free surface of the liquid moves. In this study, non dimensional parameters have been found that affect the rise of the free surface in a cup moving with constant acceleration. The non-dimensional parameters are the dimensionless time, the ratio of inertia effect to viscous effect (the Reynolds number), the aspect ratio of the liquid inside the cup and the acceleration ratio (the Froude number). Through this study, the height of the free surface rise in a cup has been predicted and the detailed velocities in the liquid have been examined. Generally, the maximum rise of the free surface is dependent on the Reynolds number and Froude number strongly, but on the aspect ratio weakly. However, the influence of the aspect ratio on the maximum rise of the free surface is not negligible in the range of 10 < Re < 100.