• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.04a
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• pp.134-136
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• 2005

Homogenization method is adopted to predict the permeability tenor for glass fiber plain woven fabrics. Calculating the permeability tensor numerically is an encouraging task because the permeability tensor is a key parameter in resin transfer molding (RTM). Based on multi-scale approach of the homogenization method, the permeability for the micro-unit cell within fiber tow is computed and compared with that obtained from flow analysis for the same micro-unit cell. It is found that they are in good agreement. In order to calculate the permeability tensor of macro-unit cell for the plain woven fabrics, the Stokes and Brinkman equations which describe inter-tow and intra-tow flow respectively are employed as governing equations. The effective permeabilities homogenized by considering intra-tow flow are compared with those obtained experimentally. Control volume finite element method (CVFEM) is used as a numerical method. It is shown that the asymptotic expansion homogenization method is an attractive method to predict the effective permeability for heterogeneous media.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.9
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• pp.1149-1156
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• 2001

The objective of the present study is to investigate the performance of electronic scale mitigation unit(ESMU), which reduces the amount of scale in a heat exchanger. The circular tube with diameter of 19mm and plate-and-frame heat exchangers with 20 thermal plates were used for the tests. In order to accelerate the rate of scale in a laboratory test, artificial hard water of 1000ppm(as CaCO$_3$) was recirculated at a flow rate of 5 lpm, 7 lpm, and 9 lpm throughout the tests. The effect of ESMU on the scale thickness and overall heat transfer coefficients was examined. The test results showed that the ESMU could reduce the scale deposits even in the acceleated test.

• Journal of Biosystems Engineering
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• v.25 no.1
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• pp.19-24
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• 2000

This study was carried out to develop gripper which to adaptive variable tray and to develop automatic transplanting system for seedling-production system between tray. This system consisted of five set of gripper and end-effector, a planting-width control unit, a tray transfer unit, and gripper moving device which move gripper between nursing tray and growing tray. This system used push-out rod to grasp plant instead of pull-out end -effector. Several types of fingers, which physically grip seedlings, were also developed and tested to ensure reliable transplanting operation of the gripper. The transplanting system detaches seedlings from a tray with push-o0ut rods, which were installed under the tray transfer unit. The performance of the transplanting system was evaluated by successive transplanting experiments. Using the best type of finger , the transplanting system produced 94.6% of transplanting success rate.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.34C no.12
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• pp.9-19
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• 1997

This paper describes the design and FPGA implementation of a system control unit within a multiprocessor chip which can be used as a node processor ina massively parallel processing (MPP) caches, memory management units, a bus unit and a system control unit. Major functions of the system control unit are locking/unlocking of the shared variables of protected access, synchronization of instruction execution among four integer untis, control of interrupts, generation control of processor's status, etc. The system control unit was modeled in very high level using verilog HDL. Then, it was simulated and verified in an environment where trap handler and external interrupt controller were added. Functional blocks of the system control unit were changed into RTL(register transfer level) model and synthesized using xilinx FPGA cell library in synopsys tool. The synthesized system control unit was implemented by Xilinx FPGA chip (XC4025EPG299) after timing verification.

• Journal of Digital Convergence
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• v.19 no.4
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• pp.467-475
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• 2021

Purpose: When a patient with acute deterioration occurs in a ward, the decision to transfer to intensive care unit (ICU) is critical to improve the patient's outcomes. However, when available ICU resources limited, it is difficult to determine which of the deteriorating ward patients to transfer to the ICU. Therefore the purpose of this study was to identify risk factors in predicting deteriorating ward patients transferred to intensive care unit (ICU). Methods: We reviewed retrospectively clinical data of 2,945 deteriorating ward patients who referred medical emergency team. Data were analyzed with multivariate logistic regression. Results: The solid cancer that diagnosed at hospitalization (odds ratio[OR] 0.39; 95% confidence interval [CI] 0.32-0.47), when the cause of deterioration was respiratory problem (1.51; 95% CI 1.17-1.95), high MEWS (1.22; 1.17-1.28) and SpO2/FiO2 score (2.41; 2.23-2.60) were predictive of ICU transfer. Conclusion: These findings suggest that early prediction and treatment of patients with high risk of ICU transfer may improve the prognosis of patients.

• Journal of Korean Biological Nursing Science
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• v.16 no.4
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• pp.259-266
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• 2014

Purpose: The purpose of this study was to analyze risk factors in predicting medical patients transferred to Intensive Care Unit (ICU) on the general ward. Methods: We reviewed retrospectively clinical data of 120 medical patients on the general ward and a Modified Early Warning Score (MEWS) between ICU group and general ward group. Data were analyzed with multivariate logistic regression and the area under the receiver operating characteristic curves using SPSS/WIN 18.0 program. Results: Fifty-two ICU patients and 68 general ward patients were included. In multivariate logistic regression, the MEWSs (Odds Ratio [OR], 1.91; 95% confidence interval [CI], 1.32-2.76), sequential organ failure assessment score (OR, 1.28; 95% CI, 1.10-1.72), $PaO_2/FiO_2$ ratio (OR, 0.98; 95% CI, 0.98-0.99), and saturation (OR, 0.93; 95% CI, 0.88-0.99) were predictive of ICU transfer. The sensitivity and the specificity of the MEWSs used with a cut-off value of six were 80.8% and 70.6% respectively for ICU transfer. Conclusion: These findings suggest that early prediction and treatment of patients with high risk of ICU transfer may improve the prognosis of patients.

• Journal of Fashion Business
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• v.20 no.3
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• pp.30-42
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• 2016

The objective of this study was to perform 3D solid modeling from 3D scanned surface images of cotton and silk in order to calculate the thermal heat transfer responses using numerical simulations. Continuing from the previous methodology, which provided 3D surface data for a fabric through optical measurements of the fabric microstructure, a simplified 3D solid model, containing a defined unit cell, pattern unit and fabric structure, was prepared. The loft method was used for 3D solid-model generation, and heat transfer calculations, made for the fabric, were then carried out using the 3D solid model. As a result, comprehensive protocols for 3D solid-model generation were established based on the optical measurements of real fabric samples. This method provides an effective means of using 3D information for building 3D models of actual fabrics and applying the model in numerical simulations. The developed process can be used as the basis for other analogous research areas to investigate the physical characteristics of any fabrics.

• 한국전산유체공학회:학술대회논문집
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• 2004.03a
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• pp.183-189
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• 2004

The flow and the heat transfer about the cross-flow fin-tube heat exchanger in an out-door unit of a heat pump system has been numerically Investigated. Using the general purpose analysis code, FLUENT, the Navier-Stokes equations and the energy equation are solved for the three dimensional computation domain that encompasses multiple rows of the fin-tube. The temperature on the fin and tube surface is assumed constant but compensated later through the fin efficiency when predicting the heat-transfer rate. The contact resistance is also taken into consideration. The flow and temperature fields for a wide range of inlet velocity and fin-tube arrangements are examined and the results are presented in the paper. The details of the flow are very well captured and the heat transfer rate for a range of inlet velocity is in excellent agreement with the measured data. The flow solution provides the effective permeability and the inertial resistance factor of the heat exchanger if the exchanger were to be approximated by the porous medium. This information is essential in carrying out the global flow field calculation which, in turn, provides the inlet velocity lot the microscopic temperature-field calculation of the heat exchanger unit.

• Journal of Korean Academy of Nursing
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• v.40 no.3
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• pp.307-316
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• 2010

Purpose: The purpose of this study was to identify the levels of relocation stress syndrome (RSS) and influencing the stress experienced by Intensive Care Unit (ICU) patients just after transfer to general wards. Methods: A cross-sectional study was conducted with 257 patients who transferred from the intensive care unit. Data were collected through self-report questionnaires from May to October, 2009. Data were analyzed using the Pearson correlation coefficient, t-test, one-way ANOVA, and stepwise multiple linear regression with SPSS/WIN 12.0. Results: The mean score for RSS was $17.80{\pm}9.16$. The factors predicting relocation stress syndrome were symptom experience, differences in scope and quality of care provided by ICU and ward nursing staffs, satisfaction with transfer process, length of stay in ICU and economic status, and these factors explained 40% of relocation stress syndrome (F=31.61, p<.001). Conclusion: By understanding the stress experienced by ICU patients, nurses are better able to provide psychological support and thus more holistic care to critically ill patients. Further research is needed to consider the impact of relocation stress syndrome on patients' health outcomes in the recovery trajectory.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.6 no.4
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• pp.388-398
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• 1994

Computer simulation model for predicting more accurately the heat transfer performance of the evaporator and condenser which have significantly affected on the performance of air-conditioner has been suggested. In this model oil and micro-fin tube used in a actual unit are considered to simulate the more realistic case. The effects of oil and micro-fin tube on the performance of an air-conditioner have been investigated. It is found that the present model requires higher pressure than the existing model due to the characteristics of the tube considered. However, it turns out that the present model is very close to an actual cycle. As the amount of oil inside the tube increases, condensation heat transfer coefficient shows a linear decrease irrespective of a kind of oil, while evaporation heat transfer coefficient increases slightly in the oil with low viscosity and decreases exponentially in the oil with high viscosity. Pressure drop in both evaporator and condenser increases linearly irrespective of a kind of oil. It is also found that the effect of the variation of oil concentration on the magnitude of two-phase region is negligible.