• Membrane and Water Treatment
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• v.10 no.5
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• pp.387-394
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• 2019

Membrane distillation (MD) is one of the water treatment processes which involves the momentum, heat and mass transfer through channels and membrane. In this study, CFD modeling has been used to simulate the heat and mass transfer in the direct contact membrane distillation (DCMD). Also, the effect of operating parameters on the water flux is investigated. The result shows a good agreement with the experimental result. Results indicated that, while feed temperature is increasing in the feed side, water flux improves in the permeate side. Since higher velocity leads to the higher mixing and turbulence in the feed channel, water flux rises due to this increase in the feed velocity. Moreover, results revealed that temperature polarization coefficient is rising as flow rate (velocity) increases and it is decreasing while the feed temperature increases. Lastly, the thermal efficiency of direct contact membrane distillation is defined, and results confirm that thermal efficiency improves while feed temperature increases. Also, flow rate increment results in enhancement of thermal efficiency.

• The Transactions of the Korea Information Processing Society
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• v.4 no.8
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• pp.1921-1929
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• 1997

This paper describes a direct transmission method of multimedia data stream between a multimedia data processor and a communication interface without using system memory. I propose the direct transfer method of multimedia data through the single data path, without additional data path between a multimedia data processor and a communication interface in multimedia platforms. The hardware architecture and functions for the direct transfer method is defined. Procedure to transfer multimedia data to and from the multimedia data processor is described by means of control flow chart. Comparing the proposed method with general methods, I show that the proposed method can decrease number of bus accesses and bus cycles.

• Journal of Korean Academy of Nursing
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• v.48 no.5
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• pp.554-564
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• 2018

Purpose: This study aimed to construct a management model for patient transfer in a multilevel healthcare system and to predict the effect of counseling with nurses on the patient transfer process. Methods: Data were collected from the electronic medical records of 20,400 patients using the referral system in a tertiary hospital in Seoul from May 2015 to April 2017. The data were analyzed using system dynamics methodology. Results: The rates of patients who were referred to a tertiary hospital, continued treatment, and were terminated treatment at a tertiary hospital were affected by the management fee and nursing staffing in a referral center that provided patient transfer counseling. Nursing staffing in a referral center had direct influence on the range of increase or decrease in the rates, whereas the management fee had direct influence on time. They were nonlinear relations that converged the value within a certain period. Conclusion: The management fee and nursing staffing in a referral center affect patient transfer counseling, and can improve the patient transfer process. Our findings suggest that nurses play an important role in ensuring smooth transitions between clinics and hospitals.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.12
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• pp.183-189
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• 2021

Transfer pricing is a matter of concern for countries. It affects the interests of the parties involved in the commercial transaction. Through manipulation of prices in transactions, businesses take advantage of tax rates in a country to adjust profits for economic gain. This affects the fairness and rationality of economic transactions between related parties. The article uses a two-year time series from 2018 to 2019 of 50 foreign direct investment enterprises in Vietnam. The article uses ordinary least squares to test the hypotheses of the research model. The article uses four independent variables related to ownership structure affecting transfer pricing decisions including total ownership, organization ownership, concentration ownership, and area ownership. Research results show that two variables have a positive influence on transfer pricing decisions including total ownership and organization ownership. Organization ownership has a higher degree of influence than total ownership. To be able to control transaction activities related to transfer pricing, Vietnam's state management agencies need to pay attention to perfecting the legal framework based on supplementing and amending regulations related to transfer pricing. Legal regulations need to be regulated based on international common practices to ensure uniformity on a global scale.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.9
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• pp.799-806
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• 2007

Direct Numerical Simulation was carried out to predict mass transfer in turbulent flow around a rotating stepped cylinder. This investigation is a follow-up study of DNS of turbulent flow in Nesic et al. [Corrosion, Vol. 56, No. 10, pp. 1005 - 1014] The original motivation of this work stemmed from the efforts to design a simple device which can generate flows of high turbulence intensity at low cost for corrosion researchers. Two cases were considered; Sc=1 and 10 both at Re=335. Here, Sc and Re stand for Schmidt number and Reynolds number, respectively, based on the step height and the surface speed of the cylinder upstream of the step. Main focus was placed on the correlation between turbulence and mass transfer. The spatio-temporal evolution of concentration field is discussed. The numerical results are qualitatively compared with those of the experiment conducted with a similar flow configuration.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2004.07a
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• pp.27-27
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• 2004

• The Journal of Korean Academy of Prosthodontics
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• v.32 no.3
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• pp.445-454
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• 1994

Osseointegrated implant prostheses are to provide normal function without compromising the unique interaction between the tissue and the implant. The essential requirement for the osseointegrated implant prostheses is passive fit of abutment. Therefore, the impression must be accurate and reproduciable since the resultant master cast precisely duplicates the clinical condition. The purpose of this study was to compare the accuracy of the master casts obtained from five impression techniques. Group 1 : To take impression with indirect technique and Impregum F. Group 2 : To take impression with unsplinted direct technique and Impregum F. Group 3 : To take impression with splinted direct technique and Impregum F. Group 4 : To take impression with unsplinted direct technique and Xanthano. Group 5 : To take impression with splinted dierct technique and Xanthano. The results were as follow : 1. In taking impression of Impregum F, there was no significant difference between to use of indirect technique and unsplinted direct technique.(p<0.05) 2. Unsplinted direct technique with Impregum F is less accurate than splinted direct technique with Impregum F or Xanthano and unsplinted direct technique with Xanthano.(p<0.05). 3. There was no significant difference between splinted direct technique with Impregum F and unsplinted direct technique with Xanthano.(p<0.05) 4. Splinted direct technique reproduce more accurate than unsplinted direct technique.(p<0.05) 5. Impression plaster produced less distortion than polyether.(p<0.05) As a result, splinted direct technique with Xanthano was the most accurate technique. As a result, splinted direct technique with Xanthano was the most accurate technique in this study. In addition to dimensinal changes in the materials used, positional errors were also attributed to the mechanical components used in the transfer porocess. Although the errors measured were relatively small, this study demonstrates the potential for distortions with the transfer technique used. Further study is indicated that ?the technique will be able to reproduce the intraoral relationship of implant fixtures reliably and predictably.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2004.10a
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• pp.64-64
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• 2004

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.11
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• pp.1302-1314
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• 2004

Turbulent heat transfer to $CO_2$ at supercritical pressure flowing in vertical tubes is investigated using direct numerical simulation (DNS). A conservative space-time discretization scheme for variable-density flows at low Mach numbers is adopted in the present study to treat steep variations of fluid properties at supercritical pressure just above the thermodynamic critical point. The fluid properties at these conditions are obtained using PROPATH and used in the form of tables in the simulations. The buoyancy influence induced by strong variation of density across the pseudo-critical temperature proved to play a major role in turbulent heat transfer at supercritical state. Depending on the degree of buoyancy influence, turbulent heat transfer may be enhanced or significantly deteriorated, resulting in local hot spots along the heated surface. Based on the results of the present DNS combined with theoretical considerations, the physical mechanism of this local heat transfer deterioration is elucidated.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.2
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• pp.75-83
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• 2013

Objectives: This study was conducted to estimate quartz concentrations in the airborne respirable dust from concrete manufacturing industries and to compare performance of two analytical methods, direct on filter(DOF) and the transfer methods in the Fourier Transform Infrared Spectroscopy(FTIR). Methods: Total 36 area samples were collected from 8 concrete manufacturing industries. Each respirable dust sample was collected by a 25 mm cassette attached to a 10 mm Dorr-Oliver nylon cyclone. The quartz content was estimated using the intensity of the absorption peak of quartz at $799cm^{-1}$ by FTIR. Results: By the comparison of quartz content in respirable dust between the two methods, the results of using DOF method were higher than that of transfer method. And the result of quartz concentrations in respirable dust estimated by DOF method were mostly higher than those by transfer method. Statistically significant difference of quartz concentrations in respirable dust were not found in shakeout, input, loading and transporting processes by two methods. But quartz concentrations in the molding process had the statistically significant difference between DOF and transfer method. Conclusions: The results of the study is suggested that, it be needed to correct the influence of the interferences in order to establish the DOF method when interfering minerals have an effect on quantitative analysis of quartz in respirable dust by the direct on filter method with FTIR.