• Proceedings of the KSME Conference
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• 2001.06e
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• pp.576-581
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• 2001

When a liquid is supplied through a nozzle onto a relatively nonwetting inclined solid surface, a narrow rivulet forms. This work provides novel physical insights into the following phenomena in the rivulet flow that have not been well understood to date. Firstly, the fundamental mechanism behind the transition of a linear rivulet to a droplet flow is investigated. The experiments show that the droplet flow emerges due to the necking of a liquid thread near the nozzle. Based on the observation, it is argued that when the retraction velocity of a liquid thread exceeds its axial velocity, the bifurcation of the liquid thread occurs, and this argument is experimentally verified. Secondly, a discussion on the curved motion of a meandering rivulet is given. This study proposes the contact angle hysteresis as a primary origin of the centripetal force that enables the rivulet's curved motion A simple scaling analysis based on this assumption predicts a radius of curvature which agrees with the experimental observation.

• Journal of Korean Institute of Industrial Engineers
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• v.35 no.1
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• pp.15-39
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• 2009

Advanced planning and scheduling (APS) refers to a manufacturing management process by which raw materials and production capacity are optimally allocated to meet demand. APS is especially well-suited to environments where simpler planning methods cannot adequately address complex trade-offs between competing priorities. However, most scheduling problems of APS in the real world face both inevitable constraints such as due date, capability, transportation cost, set up cost and available resources. In this survey paper, we address three crucial issues in APS, including basic scheduling model, job-shop scheduling (JSP), assembly line balancing (ALB) model, and integrated scheduling models for manufacturing and logistics. Several evolutionary algorithms which adapt to the problems are surveyed and proposed; some test instances based on the practical problems demonstrate the effectiveness and efficiency of evolutionary approaches.

• Journal of Korean Institute of Industrial Engineers
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• v.14 no.1
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• pp.119-131
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• 1988

Vehicle Scheduling Problem (VSP) is a generic name given to a whole class of problems involving the visiting of "stations" by "vehicles," where a time is associated with each activity. The studies performed to date have the common feature of a single objective while satisfying a set of restrictions and known customer supplies or demands. However, VSPs may involve relevant multiple objectives and probabilistic supplies or demands at stations, creating multicriteria stochastic VSPs. This paper proposes a heuristic algorithm based on goal programming approach to schedule the most satisfactory vehicle routes of a bicriteria VSP with probabilistic supplies at stations. The two relevant objectives are the minimization of the expected travel distance of vehicles and the minimization of the due time violation for collection service at stations by vehicles. The algorithm developed consists of three major stages. In the first stage, an artificial capacity of vehicle is determined, on the basis of decision maker's subjective estimates. The second one clusters a set of stations into subsets by applying an efficient cluster method developed. In the third one, the stations in each subset are scheduled by applying an iterative goal programming heuristic procedure to each cluster.

• Journal of Environmental Science International
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• v.6 no.6
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• pp.579-588
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• 1997

In order to see the stratification related to the heat flux In Deukryang Bay, the oceanographic data on July 12, 1994 and the meteorological data of Kohung and Kwangju meteorological stations were analysed. The temperature durerences between the sea surface and the near bottom were 1~3 ton spring tide (July 12, 1994) In Deukryang Bay. The temperature anomalies were high about 3t during summer In 1994. These mean that the non mixing was not effective In destroying the stratification due to the sea surface heating by the solar radition, even though it was on spring tide. The maximum solar radiation was about 600 ly/day, which was the value of the same date of oceanographic observation. The sensible and the latent heat flux which are 0~100 ly/day were not so varied during summer. The absorbed heat flux through the sea surface was mostly lost by the back radiation. which ranges are about 0~-400 ly/day. The dimensionless mixing parameter related to the buoyancy flux was 5~150$\times$$10^{-5}$. The efficiency of tidal mixing to destroy the stratecation was 0.4~0.6%.

• Journal of Energy Engineering
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• v.27 no.3
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• pp.41-47
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• 2018

Bauxite is the principal raw material to produce alumina. Bauxite mining industry has grown gradually due to the rising demand for alumina. U.S Geological Surveys (USGS 2018) estimates the world's reserves of bauxite roughly 55-75 billion tonnes. Vietnam holds up to 3.7 billion tonnes, the third after Guinea and Australia. Most of bauxite reserves are located in Tay Nguyen (Central Highlands), and have only been minimally mined to date. The approved master plan in 2007 of the Government of Vietnam licenses bauxite mining and alumina production projects in Central Highlands through six projects until 2025. These projects constitute many potentially enormous economic, social and environmental impacts.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.694-696
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• 2003

The KOMPSAT/OSMI remote sending data of 800 km swath are collected by whisk broom method employing 96 charge coupled devices (CCDs). The stripping noise in the OSMI imageries, which arise mainly due to the non-uniform sensitivities of 96 CCDs, are the major hindrance for oceanographic applications of the OSMI data. The OSMI images are corrected by 'Ensemble Smoothness' method which is based on an assumption that the series of the averages and variances of digital numbers in each line should vary smoothly. The data of each line are corrected by linear regression model of which coefficients are obtained by Ensemble Smoothness method. Our algorithm can be applied not only to OSMI data but also for other remote sensing date collected by whisk broom or push broom.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.4
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• pp.212-230
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• 2001

Recent advances in recombinant DNA technology have resulted in development of many new protein drugs. Due to the unique properties of protein druges, they have to be delivered by parenteral injection Although delivery of protein drugs by other routes, such as pulmonary and nasal routes, has shown some promises, to date most protein drugs are administered by par-enteral routs. For long-term delivery of protein drugs by parenteral administration, they have been formulated into biodegradable microspheres. A number of microencapsulation methods have been developed, and the currently used microencapsulation methods are reviewed here, The microen-capsulation methods have been divided based on the method used. They are: solvent evapora-tion/extraction; phase separation (coacervation);spray drying; ionotropic gelation/polyelectrolyte complexation; interfacial polyumerization and supercritical fluid precipitation. Each method is de-scribed fro its applications, advantages, and limitations.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1289-1293
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• 2010

A slipring or FORJ are usually adopted in order for power supply of Geo-centrifuge and input/output data acquisition. Since using slipring causes quite a lot electrical noise, an optical communication using FORJ becomes more general for data acquisition. Such data acquisition devices, however, require frequent maintenance and replacement due to deterioration by long term usage. DICT has set up a real-time wireless date acquisition system using wireless communication technology instead of FORJ. The system enables a remote measurement at any inertial acceleration field up to 100g level and provides as same performance as FORJ. The priority of this system is to use a normal modem substituting a special FORJ.

• The Mathematical Education
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• v.50 no.3
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• pp.329-335
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• 2011

There has been an ongoing symbiotic relationship between the history of the International Commission on Mathematical Instruction(ICMI) and the broader history of mathematics education since 1908. Similarly, the International Congress on Mathematical Education(ICME) has played an important role in the direction of Mathematics education since its first congress in 1969. ICME-12 is due to be held in Seoul, Korea from July $8^{th}$ to $15^{th}$ 2012. To date, there has been no research paper concerning the history of the ICMI published in any Korean journal. In readiness for the upcoming ICME-12, this paper aims to provide a comprehensive overview of the history of the IMCI from the perspective of Mathematics education.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.35-35
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• 2011

The design and preparation of novel dye rotaxanes have gained much interest recently, since such structure usually exhibits peculiar spectral and optical changes. In spite of the promising results to date, increasing pressure remains to develop novel supramolecular structures based on stimuli-responsive systems. This presentation covers the study of inclusion complexes of cyclodextrins and various chromophores, with an emphasis on our most recent outcome of anisotropic hydrogel. In this system, physical gelation prepared from simple mixture of CD and a azo dye is completed through specific host-guest interaction. The obtained hydrogel exhibits respective morphological transitions based on supramolecular assembly and dissociation, leading to either precipitation or a sol-to-gel transition. It can identify different classes of metal ions, and, among them, naked-eye differentiation of lead ion is possible due to the coordination-induced unthreading of dye molecules. Accompanying structural changes were verified by numerous characterization techniques, including 2D-ROESY, HR-MAS, UV-Visible absorption, small-angle X-ray scattering, and induced circular dichroism measurements. Such properties discussed here will find useful in analytical applications, such as metal ion sensing and removal applications.