• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.237-240
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• 2003

In biological cell manipulation, manual thrust or penetration of an injection pipette into an embryo cell is currently performed by a skilled operator, relying on visual feedback information only. Accurately measuring cellular forces is a requirement for minimally invasive cell injections. Moreover, the cellular farce sensing is essential in investigating the biophysical properties for cell injury and membrane modeling studies. This paper presents cellular force measurements for the force feedback-based biomanipulation. Cellular force measurement system using piezoelectric polymer sensor is implemented to measure the penetration force of a zebrafish egg cell. First, measurement system setup and calibration are described. Second, the force feedback-based biomanipulation is experimentally carried out. Experimental results show that it successfully supplies real-time cellular force feedback to the operator at several tens of uN and thus plays a main role in improving the reliability of biological cell injection tasks.

• Journal of the Korea Institute of Military Science and Technology
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• 제14권2호
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• pp.289-298
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• 2011

TMAH-based Py-MS has been investigated to apply for a real-time classification of biological agents in the field. Acquiring reproducible data from mass spectrometry is a key to biological detection in the field. Nevertheless, it has been little studied on what factors could affect to the reproducibility of the TMAH-based Py-MS spectrum patterns. Given the TMAH-based Py-MS applied to the field system, several factors which could affect to the reproducible pattern of TMAH-based Py-MS spectra are needed to be examined, including changes in TMAH injection volume, growth temperature for microorganism, and number of cells collected in pyrolyzer, and implication of stabilizer used for lyophilization. This study showed that the reproducibility of the spectrum patterns was significantly hindered by changes in TMAH concentration and cell number, and stabilizer implication but not by growth temperature. Among those at low TMAH concentration(0.015m) was not observed the significant alterations of the spectrum pattern even when its injection volume was changed, yet was in different cell numbers and stabilizer implication.

• The Transactions of the Korean Institute of Electrical Engineers B
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• 제51권2호
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• pp.69-76
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• 2002

To obtain a high performance in a vector controlled induction motor, it is essential to know the instantaneous position of the rotor flux which depends on the rotor time constant. But the rotor time constant mainly varies due to the temperature rise in the motor winding, so real time compensating algorithm is necessary. This paper proposes that it uses short duration pulses added to the constant flux command current and then resultant torque command current produced by speed controller is utilized for the rotor resistance estimation. This method has advantage with a low computational requirement and does not require voltage sensors. The proposed method is proved by simulations and experimentals.

• International Journal of Automotive Technology
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• 제4권3호
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• pp.109-117
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• 2003

The analysis and evaluation of the transient performance by the transient response specifications under various acceleration speeds and types based on driver's typical acceleration habit are implemented by the experimental study to provide the appropriate direction for the transient control in a gasoline engine. The concept of the transient response specifications which consist of delay time, rising time, maximum overshoot and settling time, and the analysis method using them are introduced to evaluate the characteristics of the transient performance quantitatively. Furthermore four acceleration speeds and four acceleration types are set respectively to realize the various transient states which are similar to the real drive. Several performance parameters in terms of engine speed, manifold absolute pressure, fuel injection duration and air excess ratio are measured simultaneously during the various acceleration using a throttle actuator controlled by a PC. The transient response specifications characterized well the transient performance for the various acceleration speed and types quantitatively. Delay and rising time with increment of the acceleration speed became shorter, but settling time did longer. Intensified acceleration type appeared to be the most economical in view of fuel consumption, and linear acceleration type was found to have the least harmful emission concentration.

• Proceedings of the KIEE Conference
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• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.285-287
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• 2001

To obtain a high performance in a vector controlled induction machine, it is essential to know the instantaneous position of the rotor flux which depends on the rotor time constant. But the rotor time constant mainly varies due to the temperature rise in the motor winding, so real time compensating algorithm is necessary. This paper proposes that it uses short duration pulses added to the constant flux command current and then resultant torque command current produced by speed controller is utilized for the rotor resistance estimation. This method has advantages with a low computational requirement and does not require voltage sensors. The proposed method is proved by simulations.

• The Korean Journal of Pharmacology
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• 제32권2호
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• pp.269-281
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• 1996

Pharmacokinetics of prednisolone and prednisone undergoing reversible interconversion were analyzed from the model including this metabolic process. Blood samples were drawn serially upto 12 hours after I,V. bolus injection of 1 mg/kg prednisolone sodium phosphate and prednisone into 8 dogs as a crossover manner. Plasma concentrations of those two steroids were simultaneously measured with the method of HPLC. After injection, plasma concentrations of administered prednisolone and prednisone were declined with a biexponential pattern and their metabolic partner was rapidly formed. Plasma concentrations of those metaboite were decayed in parallel with their parent steroids throught the elimination phase. Apparent clearances of prednisolone and prednisone were $11.1{\pm}2.0\;ml/min/kg$ and $45.9{\pm}6.4\;ml/min/kg$, and they were underestimated by 29.4% and 33.6% compared to their real clearances$(15.7{\pm}4.4\;and\;69.2{\pm}17.7\;ml/min/kg)$ estimated using reversible interconversion model. Apparent volume of distribution of prednisolone$(1.32{\pm}0.43\;L/kg)$ and prednisone$(4.81{\pm}2.75\;L/kg)$ were overestimated by 53.5 and 52.7% and were compared to the real volumes $(0.86{\pm}0.30\;and\;3.15{\pm}2.13\;L/kg)$. Mean residence time of prednisolone$(2.0{\pm}0.61\;h)$ and prednisone$(1.74{\pm}0.74\;h)$ were much longer than the real sojourn time$(0.93{\pm}0.26\;and\;0.88{\pm}0.54\;h)$. Essential clearances In the reversible interconversion were greater as following orders: $Cl_{21}$(44.3 ml/min/kg) > $Cl_{20}$(24.2 ml/min/kg) > $Cl_{12}$ (7.9 ml/min/kg) > $Cl_{10}$(7.8 ml/min/kg). Estimated mean values of RF, EE, $%X^1_{ss}$ and $RHO^2_1$ were $0.31{\pm}0.10$, $1.49{\pm}0.23$, $69.3{\pm}16.7%$ and $0.65{\pm}0.10$, respectively. These results suggested that true pharmacokinetic parameters estimated from the model including reversible interconversion were significantly different from the apparent parameters estimated from the conventional mamillary model, and disposition of these two steroids seemed to be well explained by the model including reversible interconversion.

• Transactions of the Korean Society of Automotive Engineers
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• 제18권5호
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• pp.108-114
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• 2010

The injection nozzle of an electro-hydraulic injector is being opened and closed by movement of a injector's needle which is balanced by pressure at the nozzle seat and at the needle control chamber, at the opposite end of the needle. In this study, the effects of needle movement in a piezo-driven injector on unsteady cavitating flows behavior inside nozzle were investigated by cavitation numerical model based on the Eulerian-Lagrangian approach. Aimed at simulating the 3-D two-phase flow behavior, the three dimensional geometry model along the central cross-section regarding of one injection hole with real design data of a piezo-driven diesel injector has been used to simulate the cavitating flows for injection time by at fully transient simulation with cavitation model. The cavitation model incorporates many of the fundamental physical processes assumed to take place in cavitating flows. The simulations performed were both fully transient and 'pseudo' steady state, even if under steady state boundary conditions. As this research results, we found that it could analyze the effect the pressure drop to the sudden acceleration of fuel, which is due to the fastest response of needle, on the degree of cavitation existed in piezo-driven injector nozzle.

• The Korean Journal of Pain
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• 제21권3호
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• pp.217-223
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• 2008

Background: Lumbar transforaminal epidural injections (LTEIs) have been utilized in the treatment of radicular pain, and LTEIs have the advantage of target-specificity. However, there have not been enough studies on the contrast patterns in LTEIs with using fluoroscopy. The purpose of this study was to evaluate the spreading epidural contrast patterns that are seen during real-time fluoroscopic guided LTEIs. Methods: A total of 131 patients who underwent fluoroscopic guided LTEIs were studied. The inclusion criteria were those patients with low back pain and/or lower extremity pain that was caused by a herniated nucleus pulposus, lumbar spinal stenosis, failed back surgery syndrome, and herpes zoster-associated pain. We classified the contrast patterns in regard to the contrast flow spreading to the nerve root and/or the unilateral, bilateral or cylinderic type of epidural spreading on the AP view of the fluoroscopy and the ventral or dorsal epidural filling on the lateral view. In addition to the pattern analysis, we evaluated the range of contrast spreading from the cranial to the caudal epidural filling and the incidence of an intravascular flow pattern. Results: Epidural spreading was seen in 126 cases (96.2%) of the total patients through the nerve root. Ventral spreading occurred in 120 cases (95.2%). On the AP view, a nerve root with unilateral, bilateral and cylinderic epidural filling was noted for 108 (85.7%), 9 (7.1%) and 9 (7.1%) cases, respectively. The contrast spreading to vertebral segments was smaller for the patients with lumbar spinal stenosis and failed back surgery syndrome than for the other groups (P < 0.0083). The incidence of intravascular injection was 11.1% (14/126). Conclusions: LTEIs using fluoroscopic visualization provided excellent assessment of the ventral epidural filling as well as nerve root filling. However, unilateral epidural spreading was prominent for the LTEIs.

• Tunnel and Underground Space
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• 제23권6호
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• pp.572-580
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• 2013

In this case study, I examined the microseismic safety management system of Deep Heat Mining Basel (DHMB) as EGS Geothermal Project which was conducted in Basel, Switzerland. EGS Geothermal Power projects which require induced seismic event by stimulation for creation of EGS geothermal reservoir have to be controlled pressure and flow rate of stimulation by establishment of microseismic safety management system. Traffic light system and Communication response procedure of DHMB project to respond step by step corresponding microseismic event intensity through continuous monitoring during stimulation period have been managed and established in advance of stimulation. However, the project was discontinued because of an earthquake to occur larger than expected one due to post-injection seismicity occurring in the geothermal reservoir after completion of injection for stimulation. The result of post analysis, Real-time traffic light system was verified to need a establishment of new microseismic safe management system to be considered post-injection seismicity phenomenon.

• Journal of Korean Society of Industrial and Systems Engineering
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• 제38권3호
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• pp.100-107
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• 2015

Recently as the manufacturers want competitiveness in dynamically changing environment, they are trying a lot of efforts to be efficient with their production systems, which may be achieved by diminishing unplanned operation stops. The operation stops and maintenance cost are known to be significantly decreased by adopting proper maintenance strategy. Therefore, the manufacturers were more getting interested in scheduling of exact maintenance scheduling to keep smooth operation and prevent unexpected stops. In this paper, we proposedan integrated maintenance approach in injection molding manufacturing line. It consists of predictive and preventive maintenance approach. The predictive maintenance uses the statistical process control technique with the real-time data and the preventive maintenance is based on the checking period of machine components or equipment. For the predictive maintenance approach, firstly, we identified components or equipment that are required maintenance, and then machine parameters that are related with the identified components or equipment. Second, we performed regression analysis to select the machine parameters that affect the quality of the manufactured products and are significant to the quality of the products. By this analysis, we can exclude the insignificant parameters from monitoring parameters and focus on the significant parameters. Third, we developed the statistical prediction models for the selected machine parameters. Current models include regression, exponential smoothing and so on. We used these models to decide abnormal patternand to schedule maintenance. Finally, for other components or equipment which is not covered by predictive approach, we adoptedpreventive maintenance approach. To show feasibility we developed an integrated maintenance support system in LabView Watchdog Agent and SQL Server environment and validated our proposed methodology with experimental data.