• Journal of Advanced Marine Engineering and Technology
• /
• v.40 no.5
• /
• pp.403-411
• /
• 2016

Usually shell and tube heat exchangers are employed to recover energy between fluids. Recently, numerous papers on these heat exchangers have been published; however, the velocity and temperature profiles or comparison of the features of the flow with or without inside tubes have rarely been described. In this research, experimental and numerical studies were carried out to investigate the characteristics of the flow around the spiral baffle plates without inside tubes in a horizontal circular tube using a particle image velocimetry method and ANSYS 14.0~15.0 version (Fluent). The results showed that swirling flow was produced between the spiral baffle plates. The tangential components were strong between the two spiral baffles; however, the axial or radial velocities components were indicating nearly zero. From the spiral motion in the space of the two baffles, it is considered that there were no dead zones between the spiral baffle.

• Journal of Ocean Engineering and Technology
• /
• v.17 no.6
• /
• pp.1-6
• /
• 2003

Wave energy dissipation and energy transfer between wave components, during the directional wave breakings, are investigated. Directional incipient and plunging breakers were generated by focusing the multi-frequency and multi-directional wave components at a designed location, based on a constant wave amplitude and a constant wave steepness frequency spectrum. The time series of surface wave elevation was measured at 9 different locations around the wave focusing point, using a wave gauge array. In order to examine the variation of the directional spreading function, the horizontal velocity of fluid motion was also measured. By comparing energy spectrums, before and after the breaking, the characteristics of energy dissipation and energy transfer, caused by wave breaking, are investigated. Their dependencies on directionality, as well as frequency, are analyzed. The breakings significantly dissipate wave energy, through energy transfer, in the upper region of the peak-frequency band, while enhancing wave energy in the low-frequency band.

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.12
• /
• pp.3675-3682
• /
• 1999

This paper proposes the method to extract face components without using the color information and the motion information in a gray image. A laplacian pyramid of the original image is built. Eye and nose candidates are extracted using only the gray information in a low resolution laplacian image and pairs are found that consist of two eye candidates and a nose one. At full resolution, horizontal and vortical edges are found in the regions of face components which are established using the candidates. Using those edge informations, face components are extracted. The experiments have been performed for images with various sizes and positions of face, and show very encouraging result.

• Journal of Positioning, Navigation, and Timing
• /
• v.1 no.1
• /
• pp.29-34
• /
• 2012

A software GNSS signal generator for the GPS L1/L2/L5 and Galileo E1/E5 signals is proposed in this paper. And this signal generator is designed and implemented with several components by considering the reuse and expansion of components for similar GNSS signals. The characteristics of the reusability of the components are confirmed with the carrier generation and the band-pass filter components. And the functionality of the GNSS multi-band IF signal generator is validated by using the commercial software GPS L1 receiver, and the performance of signal acquisition, tracking and accuracy of horizontal position error are analyzed for this validation. As a result, the GPS L1 signal generator operates successfully and it could be expected that other signal generators also operate well because most of components are the same as those of the GPS L1 signal generator.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.9
• /
• pp.3701-3720
• /
• 2015

A system for the recognition of machine printed Arabic script is proposed. The Arabic script is shared by three languages i.e., Arabic, Urdu and Farsi. The three languages have a descent amount of vocabulary in common, thus compounding the problems for identification. Therefore, in an ideal scenario not only the script has to be differentiated from other scripts but also the language of the script has to be recognized. The recognition process involves the segregation of Arabic scripted documents from Latin, Han and other scripted documents using horizontal and vertical projection profiles, and the identification of the language. Identification mainly involves extracting connected components, which are subjected to Principle Component Analysis (PCA) transformation for extracting uncorrelated features. Later the traditional K-Nearest Neighbours (KNN) algorithm is used for recognition. Experiments were carried out by varying the number of principal components and connected components to be extracted per document to find a combination of both that would give the optimal accuracy. An accuracy of 100% is achieved for connected components >=18 and Principal components equals to 15. This proposed system would play a vital role in automatic archiving of multilingual documents and the selection of the appropriate Arabic script in multi lingual Optical Character Recognition (OCR) systems.

• Earthquakes and Structures
• /
• v.10 no.1
• /
• pp.211-238
• /
• 2016

The Maximum seismic responses of steel buildings with perimeter moment resisting frames (MRF), modeled as complex MDOF systems, are estimated for several incidence angles of the horizontal components and the critical one is identified. The accuracy of the existing rules to combine the effects of the individual components is also studied. Two and three components are considered. The critical response does not occur for principal components and the corresponding incidence angle varies from one earthquake to another. The critical response can be estimated as 1.40 and 1.10 times that of the principal components, for axial load and interstory shears, respectively. The rules underestimate the axial load but reasonably overestimate the shears. The rules are not always inaccurate in the estimation of the combined response for correlated components. On the other hand, totally uncorrelated (principal) components are not always related to an accurate estimation. The correlation of the individual effects (${\rho}$) may be significant, even for principal components. The rules are not always associated to an inaccurate estimation for large values of ${\rho}$, and small values of ${\rho}$ are not always related to an accurate estimation. Only for perfectly uncorrelated harmonic excitations and elastic analysis of SDOF systems, the individual effects of the components are uncorrelated and the rules accurately estimate the combined response. The degree of correlation of the components, the type of structural system, the response parameter under consideration, the location of the structural member and the level of structural deformation must be considered while estimating the level of underestimation or overestimation.

• Proceedings of the KSRS Conference
• /
• 2005.10a
• /
• pp.538-541
• /
• 2005

Tidal flats develop along the south coast ofthe Korean peninsula. These areas are famous for sea farming. Specially, strong and coherent radar backscattering signals are observed over oyster sea farms that consist of artificial structures. Tide height in oyster farm is possible to measure by using interferometric phase and intensity of SAR data. It is assumed that the radar signals from oyster farm could be considered as double-bouncing returns by vertical and horizontal bars. But, detailed backscattering mechanism and polarimetric characteristics in oyster farm had not been well studied. We could not demonstrate whether the assumption is correct or not and exactly understand what the properties of back scattering were in oyster farm without full polarimetric data. The results of AIRSAR L-band POLSAR data, experiments in laboratory and JERS-l images are discussed. We carried out an experiment simulating a target structure using vector network analyser (Y.N.A.) in an anechoic chamber at Niigata University. Radar returns from vertical poles are stronger than those from horizontal poles by 10.5 dB. Single bounce components were as strong as double bounce components and more sensitive to antenna look direction. Double bounce components show quasi-linear relation with height of vertical poles. As black absorber replaced AI-plate in bottom surface, double bounce in vertical pole decreased. It is observed that not all oyster farms are characterized by double bounced scattering in AIRSAR data. The image intensity of the double bounce dominant oyster farm was investigated with respect to that of oyster farm dominated by single bounce in JERS-l SAR data. The image intensity model results in a correlation coefficient (R2 ) of 0.78 in double bounce dominant area while that of 0.54 in single bouncing dominant area. This shows that double bounce dominant area should be selected for water height measurement using In8AR technique.

• Journal of Korean Academy of Nursing
• /
• v.24 no.3
• /
• pp.473-483
• /
• 1994

In order to prepare for the coming twenty first Century and to meet changing societal dedmands and health needs, it is necessary to develop a new conceptual framework for curriculum the colleges of nursing. The specific objectives of this project were to ; 1) address the problem areas of the existing curriculum which were identified in the first phase of this study ; 2) develop a conceptual framework which will meet faculty, student and societal needs : and 3) identify the content of the curriculum In order to accomplish the objectives, the curriculum committee held 30 weekly meetings during the period of October, 1992 and December, 1993, There also were two workshops with college of nursing faculty members. The Philosophy and objectives of education were revised on the basis of the essential concepts of nursing : human being, nursing, environment, and health. From these basic concepts, six essential components were identified for the conceptual framework. These were nuring process, communication, professional roles, client, and nursing. These six components are interrelated in the curriculum. The complex interrelationship among the six components were presented on horizontal and vertical axes. Concepts related to steady improvement were put on a vertical axis. For example, concepts of client, health, and nursing are included in all levels of nursing curriculum and students are expected to retain and accumulate more complex contents as they progress in curriculum. Concepts on the horizontal axis are nursing process, communication, and professional roles. These concepts are unique to nursing and are common to any level of curriculum. Students are expected to study these concepts through all levels of the curriculum. It is expected that the objectives of the college of nursing will be accomplished when the courses and content of the curriculum are based on this conceptual fremework.

• Steel and Composite Structures
• /
• v.31 no.6
• /
• pp.541-558
• /
• 2019

In Special Concentrically Braced Frames (SCBFs), vertical and horizontal components of the brace force must be resisted by column and beam, respectively but normal force component existing at the gusset plate-to-column and beam interfaces, creates out-of-plane action making distortion in column and beam faces adjacent to the gusset plate. It is a main concern in Hollow Structural Section (HSS) columns and beams where their webs and gusset plate are not in the same plane. In this paper, a new gusset plate passing through the HSS columns and beams, named as through gusset plate, is proposed to study the force transfer mechanism in such gusset plates of SCBFs compared to the case with conventional gusset plates. For this purpose, twelve SCBFs with diagonal brace and HSS columns and twelve SCBFs with chevron brace and HSS columns and beams are considered. For each frame, two cases are considered, one with through gusset plates and the other with conventional ones. Based on numerical results, using through gusset plates prevents distortion and out-of-plane deformation at HSS column and beam faces adjacent to the gusset plate helping the entire column and beam cross-sections to resist respectively vertical and horizontal components of the brace force. Moreover, its application increases energy dissipation, lateral stiffness and strength around 28%, 40% and 32%, respectively, improving connection behavior and raising the resistance of the normal force components at the gusset plate-to-HSS column and beam interfaces to approximately 4 and 3.5 times, respectively. Finally, using such through gusset plates leads to better structural performance particularly for HSS columns and beams with larger width-to-thickness ratio elements.

• Geophysics and Geophysical Exploration
• /
• v.27 no.1
• /
• pp.51-56
• /
• 2024

In this paper, the vector gravity and gravity gradient tensor of an elliptical disk are derived. The vector gravity of an elliptical disk is defined by differentiating the gravitational potential due to the elliptical disk expressed by a double integral with respect to each axial direction. The vector gravity defined by the double integral is then transformed into a line integral of a closed curve along the elliptical disk boundary using the complex Green's theorem. Finally, vector gravity due to the elliptical disk is derived by 1D parametric numerical integration along the elliptical disk boundary. The xz, yz, zz components of the gravity gradient tensor due to the elliptical disk are obtained by differentiating the vector gravity with respect to vertical direction. The xx, yy, xy components are derived by differentiating the horizontal components of the vector gravity in the form of a double integral with respect to horizontal directions and then using the complex Green's theorem.