• East Asian mathematical journal
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• v.14 no.2
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• pp.329-341
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• 1998

In this paper, we investigate the existence of the two dimensional surface in four dimensional equiaffine space and characterize that surface.

• Bulletin of the Korean Mathematical Society
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• v.58 no.2
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• pp.527-535
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• 2021

The fundamental group of a high dimensional graph manifold canonically has a graph of groups structure. We analyze the group action on the associated Bass-Serre tree and study the algebraic ranks of the fundamental groups of high dimensional graph manifolds.

• Korean Journal of Mathematics
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• v.7 no.2
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• pp.235-244
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• 1999

We will derive some identities related to p-scalars, p-vectors, and non-holonomic frames in a generalized 2-dimensional Riemannian manifold $X_2$.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.421-425
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• 2007

The application of 3 dimensional virtual reality continuously pursues 3 dimensional system implementation in geographical information system, and is applied and studied in various fields like visualization, simulation, and 3 dimensional analysis. Orthoimage produced to construct basic data of virtual city is evaluated in accuracy, to fall in allowable error of the specification of image map generation. In this paper, 3 dimensional virtual city is constructed and evaluated around Bucheon University using 3 dimensional virtual reality technique and digital photogrammetry. Consequently, the constructed 3 dimensional virtual city around Bucheon University can visualize 3 dimensional reality, to help making decision. It can be substituted for existed 2 dimensional GIS in public and private sectors, and be helpful to decision makers.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3300-3305
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• 2007

Ignition delay of second injection of HSDI diesel engine was usually much shorter than that of first injection. It is due to the interaction between radicals generated during the combustion process, and mixed gas of second injection. In this paper, To analyze combustion phenomena of multiple injection mode in HSDI diesel engine effectively, two-dimensional flamelet combustion model was modified. To reduce calculation time, two-dimensional flamelet equations were only applied near stoichiometric region. If this region was ignited, species and temperature of other region were changed to the steady-state solutions of one dimensional flamelet equations. By this method calculation time for solving flamelet equations was reduced to 20 percents, thought the results were almost same. Modified flamelet combustion model was coupled to commercial CFD code interactively using user subroutine.

• Progress in Medical Physics
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• v.2 no.2
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• pp.121-128
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• 1991

Radiosurgery treatment in the brain requires detailed information on three-dimensional dose distribution. A three-dimensional treatment planning is a prerequisite for treatment plan optimization. It must cover 3-D methods for representing the patient, the dose distributions, and beam settings. Three-dimensional dose models for non-coplanar moving arcs were developed using measured single beam data and efficient 3-D dose algorithms for circular fields. The implementation of three dimensional dose algorithms with stereotactic radiosurgery and the application of the algorithms to several cases are discussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.543-546
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• 2001

So far, the design methods of quartz crystal resonator have been developed. Recently, as the electronic package and semiconductor modules become smaller, the need to minimize the sizes of crystal components grows larger. but Minimizing crystal plate sizes has limitations because its temperature-frequency characteristics is worse and unwanted resonances occur. so appropriate design of electrode size and crystal plates is necessary. In this palter, Two-dimensional governing equations for electroded piezoelectric crystal plates with general symmetry have been solved from deduced equations from three-dimensional equations of linear piezoelectricity in most cases. In practice, electroded piezoelectric crystal plates have three-dimensional geometry, so simplified 2-dimensional equations and 2-D modeling are insufficient for explaining its resonance modes and characteristics. So, three-dimensional FEM(finite element method) analysis is done and its effectiveness is verified from analyzing practical crystal resonator model.

• IEMEK Journal of Embedded Systems and Applications
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• v.1 no.2
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• pp.31-36
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• 2006

As two dimensional bar code can collect data and information quickly, it is used and recognized as a useful tool for the many industrial application field. But the information capacity of two dimensional bar code is still limited. Recently, the two dimensional AD bar code (analog-digital code) that can increase its application range and overcome capacity limitation is developed. In this paper, we implement an effective system which can transform text information into voice using two dimensional AD bar code and TTS(Text To Speech). It can be transmitted to blind people by capturing the AD bar code on the papers or the books.

• Spatial Information Research
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• v.12 no.1
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• pp.1-12
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• 2004

The 3-dimensional GIS data provider system manages and retrieves 2, 3-dimensional spatial and time data. This system provides the standard interfaces which help developers to omit additional works to do modify or convert a format of 2 or 3-dimensional spatial data, which has been already accumulated, into that dependent on a specified system. This system consists of a data provider and data access component. The former deals with the connections with some databases and manages the meta data, so that the various GIS or software can access to 3-dimensional spatial and time data via the same method, and the latter takes charge of index management and spatial operations on GIS data for consumers. The system offers the diverse spatial operations and analysis functions for 3-dimensional GIS.

• Journal of Digital Contents Society
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• v.16 no.5
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• pp.835-847
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• 2015

Photo scanning can create point cloud and polygon models like 3D scanners bringing an object into the 3 dimensional world by combining several sheets of photographic information. The created data give us information about planes and sectional forms required for a 2 dimensional survey as well as 3 dimensional figures of buried cultural property. It requires a lot of time to record buried cultural property in the field, however, the photo scanning technique does not need additional equipment and manpower so the work may begin immediately while the property is protected. Moreover, it reduces financial burdens as it creates 3 dimensional data using images acquired by photography but provides the optimal condition to check 3 dimensional information quickly and easily.