• Title, Summary, Keyword: Free surface monitoring

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Monitoring of waterjet cutting free surface using laser sensor (레이저 센서를 이용한 워터젯 절삭 자유면 모니터링)

  • Oh, Tae-Min;Hong, Chang-Ho;Cho, Gye-Chun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.15 no.5
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    • pp.469-481
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    • 2013
  • The monitoring of a free surface generated by waterjet cutting technology is very important for an efficient construction process. In this study, experiments using a laser sensor were performed to provide a data processing method and to determine optimized parameters. The experimental parameters here are the angular resolution, measurement distance, and free surface cutting shape. The results show that the monitoring resolution increases with a decrease in the angular resolution and the horizontal measurement distance and with an increase in the cutting (free surface) width. This laser monitoring method can be applied during the measurement of free surface shapes and depths in situ.

Free spans monitoring of subsea pipelines

  • Elshafey, Ahmed A.;Haddara, M.R.;Marzouk, H.
    • Ocean Systems Engineering
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    • v.1 no.1
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    • pp.59-72
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    • 2011
  • The objective of this work is to investigate the possibility of using the longitudinal strain on the surface of a pipe to determine the inception of dangerous free spanning. The long term objective is to develop an online monitoring technique to detect the development of dangerous free spanning in subsea pipelines. This work involves experimental study as well as finite element modeling. In the experiments, the strains at four points on a cross section of a pipeline inside the free span zone are measured. Pipes with different boundary conditions and different diameter to length ratios were tested. The pipe is treated as a simple beam with fixed-fixed or simply supported boundary conditions. The variation of the strains as a function of the diameter to length ratio gives a pointer to the inception of dangerous free spanning. The finite element results agree qualitatively with the experiments. The quantitative discrepancy is a result of the difficulty to replicate the exact boundary conditions that is used by the finite element program.

Usefulness of External Monitoring Flap in the Buried Jejunal Free Flap (유리 공장 피판술 후 외부 감시 피판의 유용성)

  • Kim, Baek Kyu;Chang, Hak;Minn, Kyung Won;Hong, Joon Pio;Koh, Kyung Suck
    • Archives of Plastic Surgery
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    • v.34 no.4
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    • pp.432-435
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    • 2007
  • Purpose: The jejunal free flap has the shorter ischemic time than other flap and requires a laparotomy to harvest it. As the evaluation of the perfusion the buried flap is very important, the perfusion of the buried jejunal free flap requires monitoring for its salvage. We tried to improve the monitoring flap method in the jejunal free flap and examined its usefulness. Methods: From March 2002 to March 2006, the monitoring flap method was applied to 4 cases in 8 jejunal free flaps for the pharyngeal and cervical esophageal reconstructions. The distal part of the jejunal flap was exposed without suture fixation through cervical wound for monitoring its perfusion. The status of perfusion was judged by the color change of jejunal mucosa and mesentery. If necessary, pin prick test was performed. Doppler sonography was applied to mesenteric pedicle of the monitoring flap in case of suspicious abnormal circulation. Results: The monitoring flap shows no change in 3 cases, but the congestion happened in one case at the 12 hours after the operation. This congestion was caused by the twisting or kinking of the mesenteric pedicle of the monitoring flap. So, we fixed up the monitoring flap close to adjacent cervical skin for prevention of rotation. Finally, the main part of transferred jejunal flap was intact. Conclusion: The success of a jejunal free flap depends on close postoperative monitoring and early detection of vascular compromise. So, various monitoring methods have been tried, for instance, direct visualization using a fiberoptic pharyngoscope, through a Silastic window placed in the neck flap, or external surface monitoring with an Doppler sonography, use of a buried monitoring probe. But, all of the above have their own shortcomings of simplicity, non-invasiveness, reliability and etc. In our experience, monitoring flap can be a accurate and reliable method.

Label-free Detection of Biomolecular Specific Interaction by Optical Biosensors (광 바이오센서를 이용한 비표지 생계물질들의 특이 상호작용력의 측정)

  • 김의락;최정우
    • KSBB Journal
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    • v.17 no.1
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    • pp.1-13
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    • 2002
  • Label-free optical methods for the monitoring of interactions between biological molecules have become increasingly popular within the last decade. A rising number of publications have demonstrated the benefits of direct biomolecular interaction analysis(BIA) for biology and biochemistry, such as antigen-antibody Interactions, receptor-ligand interactions, protein-DNA, DNA- intercalator, and DNA-DNA interactions. This article gives an overview of the historical development, principle and application of label-free optical biosensor to examine the functional characteristics of biospecific interaction, such as kinetics, affinity, and binding position of biomolecular between an immobilized species at the transducer surface and its dissolved binding partner.

Flap Monitoring by Infra-red Thermometer (적외선 고막 체온계를 이용한 피판감시)

  • Kirk, Insoo;Hong, Joon-Pio
    • Archives of Reconstructive Microsurgery
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    • v.13 no.1
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    • pp.82-85
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    • 2004
  • Flap monitoring is important for flap salvage. Although there are many methods to observe the flap, practical methods mostly used are subjective methods. Recording flap surface temperature is one of the objective methods of flap monitoring. We used an infra-red thermometer to simplify monitoring of the flap temperature. 60 groin flaps of SD rats are used in the experiment. Artificial arterial or venous insufficiency was made and the surface temperature was checked and compared with body temperature. In the results, the temperature of the arterial clamped flaps was lower than that of body and the mean difference was $0.3^{\circ}C$ after 20 minutes of clamping. In the vein-clamped flaps, the mean decrease was $0.4^{\circ}C$ after 30 minutes of clamping. The all difference of the temperature between the flaps and body was statistically significant. Our results suggest that flap monitoring by infra-red thermometer is simple, useful and helpful to evaluate the flap status.

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Battery-free slotted patch antenna sensor for wireless strain and crack monitoring

  • Yi, Xiaohua;Cho, Chunhee;Wang, Yang;Tentzeris, Manos M.
    • Smart Structures and Systems
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    • v.18 no.6
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    • pp.1217-1231
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    • 2016
  • In this research, a slotted patch antenna sensor is designed for wireless strain and crack sensing. An off-the-shelf RFID (radiofrequency identification) chip is adopted in the antenna sensor design for signal modulation. The operation power of the RFID chip is captured from wireless reader interrogation signal, so the sensor operation is completely battery-free (passive) and wireless. For strain and crack sensing of a structure, the antenna sensor is bonded on the structure surface like a regular strain gage. Since the antenna resonance frequency is directly related with antenna dimension, which deforms when strain occurs on the structural surface, the deformation/strain can be correlated with antenna resonance frequency shift measured by an RFID reader. The slotted patch antenna sensor performance is first evaluated through mechanics-electromagnetics coupled simulation. Extensive experiments are then conducted to validate the antenna sensor performance, including tensile and compressive strain sensing, wireless interrogation range, and fatigue crack sensing.

Advanced Machining Technology for Die Manufacturing (금형의 고정도ㆍ고능률 가공기술)

  • 김정석;이득우;정융호;강명창;이기용;김경균;김석원
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.4
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    • pp.48-68
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    • 2000
  • The high-speed machining technology of difficult-to-cut material is needed to achieve the high-efficiency of die manufacturing. The high-speed machining is applied in automobile, airplane and electricityㆍelectro industry etc, because it can improve machining efficiency and productivity with high speed, high power and high rotation. In this study, high speed machinability, tool wear characteristics and its monitoring, characteristics of damaged layer, machinability of difficult-to-cut material, characteristics of a free curved surface and method of CAD/CAM system were introduced to acquire the shortening of machining time, the improvement of machining efficiency and the high quality of machined surface. Therefore, we establish the stabilization condition of difficult-to-cut material machining and present the optimal cutting condition for high-efficiency cutting.

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Characteristics of Protein G-modified BioFET

  • Sohn, Young-Soo
    • Journal of Sensor Science and Technology
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    • v.20 no.4
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    • pp.226-229
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    • 2011
  • Label-free detection of biomolecular interactions was performed using BioFET(Biologically sensitive Field-Effect Transistor) and SPR(Surface Plasmon Resonance). Qualitative information on the immobilization of an anti-IgG and antibody-antigen interaction was gained using the SPR analysis system. The BioFET was used to explore the pI value of the protein and to monitor biomolecular interactions which caused an effective charge change at the gate surface resulting in a drain current change. The results show that the BioFET can be a useful monitoring tool for biomolecular interactions and is complimentary to the SPR system.

A Study on the Remote Operation and the Monitoring systems for Automatic Polishing Robot (자동 연마로봇의 원격 조작 및 모니터링 시스템 개발에 관한 연구)

  • 김병수;고석조;이민철
    • 제어로봇시스템학회:학술대회논문집
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    • pp.122-122
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    • 2000
  • Polishing work of a free-curved surface die demands simple and repetitive operations but requires a considerable amount of time for high precision. In out previous study, to reduce the polishing time and solve the problem of the shortage of skilled workers, the automatic polishing system was developed. However, in the polishing process of die, workers have to stay still in factory to monitor the polishing process for a long time in the poor environment. Therefore, this study proposes the remote operation and monitoring system of the automatic polishing robot. The developing system offer worker monitoring functions and teleoperating functions, as following: system state check, manual manipulation mode, automatic mode, manual teaching mode, automatic teaching mode, simulation by virtual manufacturing device. And automatic teaching system is developed to easily obtain a teaching data.

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The Principles and Metrical Applications of Immunocsensors (면역센서의 원리와 의학적 응용)

  • 김의락;백세환
    • KSBB Journal
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    • v.17 no.2
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    • pp.121-136
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    • 2002
  • Immunosensors are of great interest because of their potential utility as specific, simple, label-free, direct detection means and provision of reduction in size, cost and time of analysis comparing with conventional immunoassay. In the last two decades, many reports have been published on the use of immunosensors for a wide range of applications to clinical diagnostics, pharmaceutical chemistry, environmental monitoring, biotechnology and food industries. There are also numerous transduction techniques developed such as electrochemical techniques, piezoelectric crystal, and surface plasmon resonance receiving much attention for the direct monitoring of immune reactions at solid surfaces. In this article, the principles, characteristics, structures, fonctions and clinical applications of immunosensors were reviewed