• Journal of the Korean Society for information Management
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• v.12 no.2
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• pp.151-169
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• 1995

The purpose of this research is to investigate the of multimedia university library system theoretical models and to design partial functions of this model using multimedia toolbook 3.0. The theoretical model is constructed based on several operating systems such as JANUS Virtual Library and The Book House. Knowledge base of the designed system is constructed by interviewing reference librarians. The designed system consists of six modules : Reference Expert system. Journal Browsing, Multimedia Database, OPAC, External Database and User' s Guide. Finally, four problems are discussed as several major problems in building up multimedia university library network

• Advances in environmental research
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• v.1 no.2
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• pp.143-151
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• 2012

Nitrate removal from aqueous solution was investigated using $ZnCl_2$ and phosphoric acid activated carbon developed from pomegranate peel with particle size 0.4 mm. Potassium nitrate solution was used in batch adsorption experiments for nitrate removal from water. The effects of activated carbon dosage, time of contact, and pH were studied. The equilibrium time was fond to be 45 min. Two theoretical adsorption isotherms namely Langmuir and Freundlich were used to describe the experimental results. The Langmuir fit the isotherm with the theoretical adsorption capacity ($q_t$) was fond 78.125 mg g-1. Adsorption kinetics data were modeled using the pseudo-first, pseudo-second order, and intraparticle diffusion models. The results indicate that the second-order model best describes adsorption kinetic data. Results show activated carbon produced from pomegranate is effective for removal of nitrate from aqueous solution.

• Journal of computational fluids engineering
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• v.11 no.2 s.33
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• pp.40-48
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• 2006

In the present, The theoretical and numerical results of gas flow characteristics inside a swirl injector are presented. For this purpose a one-dimensional (theoretical) model and 2D/3D CFD models are proposed for use in the design of the injector. It was found that contradictory to the classical theory about the compressible flow, the swirl has a significant effect on the mass flow rate and the choking conditions. It was found that the one-dimensional model provides reasonably accurate results compared with the 2D/3D numerical results, and thus can be used at the initial stage of the swirl-injector design process.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.154-160
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• 1998

This study describes a theoretical and experimental investigation of gas wave propagation in the pipe system. Most calculations of compressible flows in the pipe have been based on the method of characteristics. This technique has propensity to truncate waves and is difficult to apply to non-perfect gas. A method that describes the application of a two-step Lax-Wendroff acheme to solution of the unsteady one-dimentional flow in the pipe was developed. Theoretical calculations using both the method of characteristics and the two-step Lax-Wendroff method are presented including a realistic model for heat transfer and friction processes. In the present work, account is taken of the nonlinear behavior. For sections of parallel pipe, an one dimensional unsteady homentropic analysis is employed, and a numerical solution is obtained with the aid of a digital computer, using the method of characteristics and two-step Lax-Wendroff method. This analysis is then combined with boundary models, based on a quasi-steady flow approach, to give a complete treatment of the flow behavior in the pipe system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.8 no.2
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• pp.61-69
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• 2002

The relatively rapid rising trend of crime rates in marine situations leads to social concerns in Korea. This study reviews some theoretical backgrounds of the economics of crime and applies econometric models to Korean marine crimes. This research finds that there is a negative relationship between marine crime rates and unemployment rates and a positive relationship between the price level and marine crimes in Korea. The other finding results are that unemployment elasticities are higher in the 1980s and price elasticities are higher in th 1990s in comparison with the results of the other periods. This findings are incompatible with the previous theoretical researches in advanced countries. These findings show that In rapidly growing economy, marine crime occurrence is proportional to marine economic activity frequency. This result may reflect that marine crimes are different from land crimes.

• Journal of the Korean Chemical Society
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• v.6 no.2
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• pp.104-107
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• 1962

It is thought that the adsorption isotherms in dyeing of cellulose by the direct cotton dyes are consisted of combined type of Langmuir and Freundlich as the opinion of Fujino, et al;$[D]_F=ab[D]_S/(1+b[D]_S)+k[D]_S$where a,b,k; constants, $[D]_F$; dye adsorption on the fiber, $[D]_S$; dye concentration in the bath. This means that the dyes adsorbed in cellulose present in the state of partly mono molecular and partly aggregate; the characteristic fading order curve will be expressed as the combined system of uniform particle size distribution and assumed that the slope of the theoretical models of Baxter, et al., and assumed that the slope of curve will be changed near the point of a, the saturation value of Langmuir isotherms in the above equation. Firstly, the theoretical fading rate curve was treated with small colour difference as the one step of experimental of above consideration.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.12
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• pp.1085-1091
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• 2014

Recently, 3D printing has received increasing attention due to its boundless potentials. Because 3D printing starts from 3D geometry information, computer-aided design (CAD) is an essential technology to build 3D geometry data. These days, education of 3D CAD for engineering students has been changed from the theoretical lecture to practical design training using commercial CAD software. As a result, open-ended design projects have replaced the traditional theoretical examinations to evaluate students' outcomes. However, such design projects are not enough to evaluate students' outcomes because their results are expressed in two-dimensional ways. In this paper, applications of 3D printing in engineering design education are discussed by describing the procedure and outcomes of design projects. It was found that the use of 3D printing could improve students' outcomes by fabricating real physical models out of their designs.

• Korean Medical Education Review
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• v.16 no.2
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• pp.57-66
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• 2014

Burnout research has mostly been performed in human service fields. However, it has recently been expanded to cover diverse settings and even non-occupational samples, such as students. In this study, we defined the construct of academic burnout, which is the burnout experienced by students. Next, we described the concept of academic burnout by introducing measurements for assessing academic burnout. On the basis of the demand-control model (DCM) and effort-reward imbalance model (ERIM), which are the most predominant theoretical burnout models, we described the causal factors and the pathway to experiencing academic burnout symptoms. The ERIM was a more influential model than the DCM when explaining the academic burnout of Korean students. Based on the results of previous longitudinal studies on academic burnout, we recognized emotional exhaustion and academic inefficacy as the initial symptoms of academic burnout. Finally, we discussed the prevention and intervention programs with specific components that should be included in those programs.

• 한국전산유체공학회:학술대회논문집
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• 2005.04a
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• pp.207-212
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• 2005

In this paper, we present the theoretical and numerical results of flow characteristics of a gas in a swirl injector. Proposed in this study are one-dimensional (theoretical) model and 2D/3D CFD models for use in the design of the injector. It was found that contrary to the classical theory about the compressible flow, the swirl gives a significant effect on the mass flow rate and the choking conditions. The one-dimensional model was found to Provide reasonably accurate results compared with the 2D/3D numerical results, so that it can be employed in th initial stage of the swirl-injector design process.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.250-253
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• 2007

Korean Multi-Purpose SATellite 5 (KOMPSAT-5) will be the first high resolution X-band SAR satellite of Korea. A critical parameter necessary for interpreting SAR images over the ocean is surface wind field. SAR is the only system that can provide a synoptic view of wind fields over the ocean covering large areas. However, there has been no X-band wind retrieval model. In this study, we evaluate the development of an X-band wind retrieval model and show the possibility of KOMPSAT-5 SAR on wind estimations using a combination of theoretical models.