• Journal of Korean Society for Atmospheric Environment
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• v.14 no.3
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• pp.191-208
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• 1998

Estimations of dry and wet depositions in Korea and the size distributions of yellow sand above Korea have been carried out using the Eulerian aerosol model with the simulated meteorological data from the SNU mesoscale meteorological model. The estimated particle size distribution in Korea shows a bimodal distribution with peak values at 0.6 pm and 7 pm and a minimum at 2 pm in the lower layer However, as higher up, the bimodal distribution becomes an unimodal distribution with a peak value at 4∼5mm. Among the total amount of yellow sand deflated in the source regions , the dry and wet deposition fluxes were about 92%, and about 1.3∼0.5%, repectively, and the rest(5∼6%) is suspended in the air, Most of dust lifted in the air during the clear weather is deposited in the vicinity of the source regions by dry deposition and the rest undergoes the long -range transport with a gradual removal by the wet deposition processes. Over Korean peninsula, the total amount of yellow sand suspended in the air was about 6∼8% of the emissions in the source region and the dry and wet deposition fluxes were about 0.005∼0.7% and 0.003∼0.051% of the total emitted amount, repectively. It is estimated that 2.7∼8.9 mesa-tons of yellow sand is transported annually over the Korean peninsula with the annual mean dry deposition of 2.1∼490 kilo-tons and the annual mean wet deposition of 1.5∼65 kilo-tons.

• Journal of Communications and Networks
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• v.9 no.4
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• pp.428-437
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• 2007

Along with the development of network, more and more functions and services are required by users, while traditional network fails to support all of them. Although overlay is a good solution to some demands, using them in an efficient, scalable way is still a problem. This paper puts forward a framework on how to construct an efficient, scalable overlay mesh in real network. Main differences between other overlays and ours are that our overlay mesh processes some nice features including class-of-service(CoS) and traffic engineering(TE). It embeds the end-to-end optimal traffic control law which can distribute traffic in an optimal way. Then, an example is given for better understanding the framework. Particularly, besides good scalability, and failure recovery, it possesses other characteristics such as routing simplicity, self-organization, etc. In such an overlay mesh, an applicable source routing scheme called hierarchical source routing is used to transmit data packet based on UDP protocol. Finally, a guideline derived from a number of simulations is proposed on how to set various parameters in this overlay mesh, which makes the overlay more efficient.

• Journal of Korean Society on Water Environment
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• v.39 no.1
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• pp.87-101
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• 2023

The constituents of a watershed control a wide range of ecosystem processes, such as, carbon sequestration, nutrient retention, and biodiversity preservation. Maintenance of a healthy watershed is advantageous to humans in many direct and indirect ways. Dissolved organic matter fluorescence analysis is one of the most commonly utilized parameters for water quality measurement, pollution source tracking, and determination of the ecological state of a watershed. Throughout the recent decades, the advancement in data processing, instrumentation, and methods has resulted in many improvements in the area of watershed study with fluorescence analysis. The current trend of coupling advanced instrumentations and new comparative parameters, such as, microplastics of different types, antibiotics, and specific bacterial contaminants have been reported in watershed studies. However, conventional methodologies for obtaining fluorescence excitation emission matrices and for calculating the fluorescence and spectral indices are preferred to advanced methods, due to their easiness and simple data collection. This review aims to gain a general understanding of the use of dissolved organic matter fluorescence analysis for diagnosis and source identification of watershed pollutions, by focusing on how the studies have utilized fluorescence analysis to improve existing knowledge and techniques in recent years.

• The Journal of Korean Institute of Next Generation Computing
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• v.13 no.6
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• pp.21-30
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• 2017

Physical computing is performed through interaction with the real world making it suitable for cultivating student abilities in computing knowledge and thought processes. Furthermore, if users can develop programs under block-coding environment, it will be more easy and more intuitive. However, the existing block coding environment has a problem that the physical devices must be continuously connected to the computer. Blockly is an open source library that adds a visual code editor linked with graphic blocks to demonstrate coding concepts through web and mobile apps. Using Blockly, we describe a development environment for physical computing on mobile platform, which combines physical computing with an established block-coding environment, and activates it through wireless communication.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1593-1596
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• 2003

In this paper, we propose mechanism of system call control, monitor, and manage by user level, and for this purpose we propose the mechanism using system call intercept and a logging system. Proposed mechanism is more convenient in that there is no necessity for modification of linux source code, so general users can actively apply and modify. As an application model for the mechanism, we can explain for the Daemon Process Protection System which can have a complete control on system daemon processes.

• Journal of environmental and Sanitary engineering
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• v.5 no.2
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• pp.15-21
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• 1990

Current analyses of tap water in Seoul metropolitan area prove the water is still safe, despite the Pollution of raw water source. However, it also significantly suggests that a feasibility study of apply, additional advanced technology to existing water treatment processes is needed in order to cope with future pollution. Also, the monitoring of water quality within private, multi-household buildings is important as the monitoring of public water distribution system.

• Korean Management Science Review
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• v.10 no.2
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• pp.61-77
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• 1993

This paper involves a study of developing the production scheduling system in a general job shop type mechanical factory. We consider realistic situations in the job-shop environments, such as alternative machines for operation, the new kinds of processes, the machining center with the plural pallet, the operational situation of each machine during the scheduling period, occurings of urgent orders and machine breakdowns. We also propose the methodology of re-schedule. It is very fast and acceptable for real time production control system. These all functions are implemented on IBM PC and program source is written in PASCAL language.

• Journal of Multimedia Information System
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• v.5 no.1
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• pp.43-46
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• 2018

The paper considers the main processes of evolution and convergence of information and communication technologies, which have a permanent source for creation and introduction of innovations in learning and education. The modern scientific and technological revolution gives new features to all modern activities, including activities in the sphere of education, influencing it and transforming its phases, form and content, and perhaps understanding in general. Consequently, general understandings about the essence of the provision of educational services and their technological support are also being transformed. Note that, according to scientists, convergence is a new determinant of the development of society, and evolution is a multidimensional natural process of development (becoming).

• Asia pacific journal of information systems
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• v.12 no.2
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• pp.69-98
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• 2002

With the development of the Internet, electronic commerce, electronic markets, and digital economy, new business paradigm and new ways of business have been emerging and developing. The development of right and robust business models for electronic markets is a key for e-business success. This paper reviews previous studies and successful cases for e-business models. This paper presents strategic factors such as the business value and the source of revenue, products and services, business processes and technologies, and the characteristics of markets and relationship with customers and partners as a framework for developing sustainable and robust business models.

• Korean Journal of Computational Design and Engineering
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• v.6 no.2
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• pp.125-132
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• 2001

An algorithm for generating all hexahedral meshes for three dimensional objects has been presented. This algorithm is based on the sweeping and the grafting method. In sweeping process internal nodes generating method has been modified by employing the distances between nodes on connecting surfaces and on source surfaces. In addition to the sweeping processes grafting algorithm is also modified to obtain more effective meshes by refining elements near grafting surfaces. With this method two and a half dimensional hexahedral meshes for three dimensional objects can be generated effectively. Sample meshes are constructed to demonstrate the mesh generating capability of the proposed algorithm.