• 한국터널지하공간학회 논문집
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• 제15권5호
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• pp.469-481
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• 2013

워터젯 절삭기술을 이용한 자유면 생성에 있어서, 생성된 자유면 내부의 모니터링은 효율적인 작업 진행을 위해서 매우 중요하다. 본 연구에서는 레이저 센서를 이용하여 자유면 측정 실험을 수행하고 실질적 현장적용을 위한 변수의 영향 정도와 최적변수 범위를 제시하였다. 영향을 미치는 변수를 레이저의 분해각(angular resolution), 측정 이격거리(measurement distance), 그리고 자유면의 절삭형상(cutting shape)으로 나누어 실험 수행 및 결과 분석을 하였다. 그 결과 분해각과 측정 이격거리가 감소할수록 그리고 절삭 폭이 증가할수록 보다 정밀한 모니터링이 가능함을 확인할 수 있었다. 본 레이저 측정 시스템을 이용하면 자유면 형상과 깊이의 측정이 실제 현장에서 충분히 적용 가능할 것으로 판단된다.

• Ocean Systems Engineering
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• 제1권1호
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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.

• Archives of Plastic Surgery
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• 제34권4호
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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.

• Archives of Reconstructive Microsurgery
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• 제13권1호
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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.

• KSBB Journal
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• 제17권1호
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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.

• 한국정밀공학회지
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• 제17권4호
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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.

• 센서학회지
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• 제20권4호
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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.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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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.

• KSBB Journal
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• 제17권2호
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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

• 한국정밀공학회지
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• 제18권10호
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• pp.208-213
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• 2001

High speed milling(HSM) is one of the emerging cutting process having tremendous potential not only in increased metal removal rates but also in improved surface finish, burr free edge, dimensional accuracy and a virtually stress free component after machining. The High efficiency and accuracy in machining of die/mold materials can be obtained in high speed machining, so it is necessary to analytic the mechanism of high speed cutting process : cutting force, acoustic emission signal.