• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.2
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• pp.430-439
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• 1990

Steady state turbulent airflow and unsteady characteristics of generation, transportation, and recovery behavior of contaminate particles in the simplified 2 dimensional Vertical Laminar Flow (VLF) type clean room was numerically simulated using the low Reynolds number k-over bar.epsilon- turbulent model. Characteristics of airflow in VLF type clean room are greatly affected by the recirculation zone around working surface. The recirculation zone must be considered at the time of clean room design because the recirculation zone whose area increases with increment of inlet velocity exerts bad influence upon the performance of clean room in terms of particle contamination. The location of maximum particle concentration changes from the location of particle source to the recirculation zone, while averaged particle concentration is reduced exponentially with time. Recovery time of clean room with spontaneous particle generation source is inversely proportional to inlet velocity. We introduce nondimensionalized recovery time through the dimensional analysis, which can indicates the general performance of clean room with design structure change. It was identified that .tau. is independent of inlet velocity and background concentration. Therefore .tau. can be the simple factor to compare the different structure of clean room in terms of dynamic response to contamination and becomes larger with better structure of clean room.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.05a
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• pp.31-34
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• 1995

The NO$_2$ gas-deteotion characteristics were investigated using the functional organic Langmuir-Blodgett(LB) files of Dilithium phthalocyanines(Li$_2$Pc). The optimum conditions for a film deposition were obtained through a study of $\pi$-A isotherms, and the deposited film status was confirmed by the ellipsometry measurements. A propel number of layers for the gas-detection was proved to be 9 layers from a measurement of a measurement of change in the electrical conductivities when the films were exposed to the 200 ppm of the NO$_2$ gases. A response time, recovery time, and reproducibility were also studied. A proper temperature which was able to activate gas interaction between NO$_2$ gases and Li$_2$Pc LB films was around 150$^{\circ}C$ judging from the electrical conductivities in a temperature range of 20 to 200$^{\circ}C$. It was found that at 150\ulcorner there are increments of electrical conductivities by 65 tines, 30 seconds of response time and 60 seconds of recovery tine when the filmswere exposed to the gasses.

• Management Science and Financial Engineering
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• v.8 no.1
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• pp.53-75
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• 2002

In this Paper, an attempt is made to establish a learning framework for robust planning and real-time execution control. Necessary definitions and concepts are clearly presented to describe real-time operational control in response to Plan disruptions. A general mathematical framework for disruption recovery is also laid out. Global disruption model is decomposed into suitable number of local disruption models. Execution Pattern is designed to capture local disruptions using decomposed-reverse neural mappings, and to further demonstrate how the decomposed-reverse mappings could be applied for solving disrubtion recovery problems. Two decomposed-reverse neural mappings, N-K-M and M-K-N are employed to produce transportation solutions in react-time. A potential extension is also discussed using the proposed mapping principle and other hybrid heuristics. Experimental results are provided to verify the proposed approach.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.353-356
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• 1999

The electrical characteristics of fatty acid LB films were investigated to develop the gas sensor using Langmuir-Blodgett(LB) films which have high ordered orientation and ordering structure. The deposition status of fatty acid LB films were verified by the measurements of UV absorbance. The conductivity of fatty acid LB films for horizontal direction at room temperature was about $10^8[S/cm]$,/TEX>, which was correspond to semiconductor material. The activation energy for fatty acid LB films with respect to variation of temperature was about l.O[eV]. The response characteristics for organic gas were confirmed by measuring the response time, recovery time, and reproducibility of the fatty acid LB films to each organic gas. Also, the penetration and adsorption behavior of gas molecule were confirmed through the organic gas response characteristics of fatty acid LB films with respect to temperature.

• Journal of Korean Academy of Nursing
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• v.36 no.4
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• pp.621-629
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• 2006

Purpose. The purpose of this study was to identify the clinical variables that predict functional and cognitive recovery at 1- and 6-month in both severe and moderate/mild traumatic brain injury patients. Methods. The subjects of this study were 82 traumatically brain-injured patients who were admitted to a Neurological Intensive Care Unit at a university hospital. Potential prognostic factors included were age, motor and pupillary response, systolic blood pressure, heart rate, and the presence of intracranial hematoma at admission. Results. The significant predictors of functional disability in severe traumatic brain injury subjects were, age, systolic blood pressure, the presence of intracranial hematoma, motor response, and heart rate at admission. In moderate/mild traumatic brain injury patients, motor response, abnormal pupil reflex, and heart rate at admission were identified as significant predictors of functional disability. On the other hand, the significant predictors of cognitive ability for severe traumatic brain injury patients were motor response and the presence of intracranial hematoma at admission, whereas those for moderate/mild patients were motor response, pupil reflex, systolic blood pressure at admission, and age. Conclusions. The results of the present study indicate that the significant predictors of TBI differ according to TBI severity on admission, outcome type, and outcome measurement time. This can be meaningful to critical care nurses for a better understanding on the prediction of brain injury patients. On the other hand, the model used in the present study appeared to produce relatively low explicabilities for functional and cognitive recovery although a direct comparison of our results with those of others is difficult due to differences in outcome definition and validation methods. This implies that other clinical variables should be added to the model used in the present study to increase its predicting power for determining functional and cognitive outcomes.

• Journal of Internet Computing and Services
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• v.3 no.5
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• pp.95-106
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• 2002

In current storage system environment, we use disk mirroring or Chained-declustering scheme to improve data availability and reliability. If disk error is occurred when these schemes are used. we need efficient recovery schemes for these situations. In this paper, it is proposed that a recovery method of disk mirroring that guarantees I/O performance similar to normal state during disk failure, Also, we execute performance evaluation for our recovery scheme and existing schemes in various environments. We show through the simulation that our algorithm outperforms the classic schemes in terms of I/O response time.

• Journal of Radiation Industry
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• v.10 no.4
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• pp.243-248
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• 2016

Argonaute 2 (AtAGO2) is a well characterized effector protein in Arabidopsis for its functionalities associated with DNA double-strand break (DSB)-induced small RNAs (diRNAs) and for its inducible expression upon ${\gamma}$-irradiation. However, its transcriptional regulation depending on the recovery time after the irradiation and on the specific response to DSBs has been poorly understood. We analyzed the 1,313 bp promoter sequence of the AtAGO2 gene ($1.3kb_{pro}$) to characterize the transcriptional regulation of AtAGO2 at various recovery times after ${\gamma}$-irradiation. A stable transformant harboring $1.3kb_{pro}$ fused with GUS gene showed that the AtAGO2 is highly expressed in response to ${\gamma}$-irradiation, after which the expression of the gene is gradually decreased until 5 days of DNA damage recovery. We also confirm that the AtAGO2 expression patterns are similar to that of ${\gamma}$-irradiation after the treatments of radiomimetic genotoxins (bleomycin and zeocin). However, methyl methanesulfonate and mitomycin C, which are associated with the inhibition of DNA replication, do not induce the expression of the AtAGO2, suggesting that the expression of the AtAGO2 is closely related with DNA DSBs rather than DNA replication.

• Structural Engineering and Mechanics
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• v.47 no.5
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• pp.599-622
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• 2013

Seismic response of two dimensional liquid tanks is numerically simulated using fully nonlinear velocity potential theory. Galerkin-weighted-residual based finite element method is used for solving the governing Laplace equation with fully nonlinear free surface boundary conditions and also for velocity recovery. Based on mixed Eulerian-Lagrangian (MEL) method, fourth order explicit Runge-Kutta scheme is used for time integration of free surface boundary conditions. A cubic-spline fitted regridding technique is used at every time step to eliminate possible numerical instabilities on account of Lagrangian node induced mesh distortion. An artificial surface damping term is used which mimics the viscosity induced damping and brings in numerical stability. Four earthquake motions have been suitably selected to study the effect of frequency content on the dynamic response of tank-liquid system. The nonlinear seismic response vis-a-vis linear response of rectangular liquid tank has been studied. The impulsive and convective components of hydrodynamic forces, e.g., base shear, overturning base moment and pressure distribution on tank-wall are quantified. It is observed that the convective response of tank-liquid system is very much sensitive to the frequency content of the ground motion. Such sensitivity is more pronounced in shallow tanks.

• Korean Chemical Engineering Research
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• v.54 no.6
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• pp.753-761
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• 2016

Liquid-liquid extraction (LLE) can be used for the recovery of acetic acid from black liquor prior to bioethanol fermentation. Recovery of value-added chemicals such as acetic-, formic- and lactic acid using LLE from Kraft black liquor was studied. Acetic acid and formic acid have been reported to be strong inhibitors in fermentation. The study elucidates the effect of three reaction parameters: pH (0.5~3.5), temperature ($25{\sim}65^{\circ}C$), and reaction time (24~48 min). Extraction performance using tri-n-octylphosphine oxide as the extractant was evaluated. The maximum acetic acid concentration achieved from hydrolyzates was 69.87% at $25^{\circ}C$, pH= 0.5, and 36 min. Factorial design was used to study the effects of pH, temperature, and reaction time on the maximum inhibitor extraction yield after LLE. The maximum potential extraction yield of acetic acid was 70.4% at $25.8^{\circ}C$, pH=0.6 and 37.2 min residence time.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.647-649
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• 2013

This paper is the study of effective recovery system in the android set-top box, using NTP (Network Time Protocol). Because of Response to the user react quickly in case of a set-top box, needs compared to other electronic products, set-top box is one of always powered features to work at home. But general-purpose OS such as Android-based set-top box have to reset for cache & main memory initialization. In this paper, we introduce system reset & recovery by NTP client utilizing.