• Journal of Advanced Navigation Technology
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• v.7 no.2
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• pp.180-190
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• 2003

By using accurate closed-form Green's functions obtained from real-axis integration method, the full-wave analysis of CPW discontinuities are performed in space domain. In solving MPIE(Mixed Potential Integral Equation), Galerkin's scheme is employed with the linear basis functions on the triangular elements in air-dielectric boundary. In the singular integral arising when the observation point and source point coincides, the surface integral is transformed into the line integral and the integral is evaluated by regular integration. By using the Green's function from the real-axis integration method, the discontinuities are characterized accurately.

• Journal of Korean Elementary Science Education
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• v.32 no.3
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• pp.250-259
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• 2013

This study was aimed at developing eco-STEAM educational programs based on smart learning, implementing the programs to verify their educational effectiveness, and exploring the possibilities for eco-education. The subjects of Science, Mathematics, Practical Arts, Arts, and Physical Education were analyzed to extract STEAM elements for the 5th and 6th grades at elementary school, and then 16 lessen plans were developed under 8 thematic strands. The programs were applied to classes of 5th and 6th graders, and then tested to see the effectiveness in terms of emotional experience, convergence, creative design and satisfaction. The average scores for post-test were statistically higher than those of pre-test(p<.001), showing positive effectiveness of the eco-STEAM programs developed. This study put out the following conclusions. First, the students got emotional experiences through inquiry and observation. Second, the programs helped students to learn about the environment in their contexts and provided a base for interdisciplinary approach. Third, the students in this study could have opportunities for improving their problem-solving abilities by using the creative design. Forth, the students' interests in the ecological topics were increased throughout regular curricula.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.04a
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• pp.97-100
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• 2004

The identification of the DNA structure as a double-stranded helix consting of two nucleotide chain molecules was a milestone in modern molecular biology. The DNA chip technology is based on reverse hybridization that follows the principle of complementary binding of double-stranded DNA. DNA chip can be described as the deposition of defined nucleic acid sequences, probes, on a solid substrate to form a regular array of elements that are available for hybridization to complementary nucleic acids, targets. DNA chips based on cDNA clons, oligonucleotides and genomic clons have been developed for gene expression studies, genetic variation analysis and genomic changes associated with disease including cancers and genetic diseases. DNA chips for gene expression profiling can be used for functional analysis in human eel Is and animal models, disease-related gene studies, assessment of gene therapy, assessment of genetically modified food, and research for drug discovery. DNA chips for genetic variation detection can be used for the detection of mutations or chromosomal abnormalities in cnacers, drug resistances in cancer cells or pathogenic microbes, histocompatibility analysis for transplantation, individual identification for forensic medicine, and detection and discrimination of pathogenic microbes. The DNA chip will be generalized as a useful tool in clinical diagnostics in near future. Lab-on-a chip and informatics will facilitate the development of a variety of DNA chips for diagnostic purpose.

• Journal of Environmental Health Sciences
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• v.31 no.5 s.86
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• pp.365-371
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• 2005

This study was peformed to explore the current situation of university environmental health and safety (EHS) system and evaluate the effects of such system on university EHS practices. Essential elements for the university EHS system were identified based on the representative examples of foreign universities, and Hey were incorporated into a questionnaire, which was used in this study. Among the academic institutions we surveyed in this study, 89% of the universities employed health and safety manager, and 65% kept departments. However, less than 50% of universities maintained EHS policies, maintained health and established safety committees within the university headquarters, and held health and safety meetings on regular basis. Several basic requirements such as chemical hygiene program and laboratory safety training program lacked in many universities. Some basic surveillance was performed in many universities, however, only few universities carried out surveillance on biological safety, medical examination, and chemical exposure monitoring. EHS system had significant influence on university EHS program (p<0.05). Performances of EHS activities were influenced by presence of EHS policies, and university health and safety committees.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.209-212
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• 2002

Since Berkhoff proposed the mild-slope equation in 1972, it has widely been used for calculation of shallow water wave transformation. Recently, it was extended to give an extended mild-slope equation, which includes the bottom slope squared term and bottom curvature term so as to be capable of modeling wave transformation on rapidly varying topography. These equations were derived by integrating the Laplace equation vertically. In the present study, we develop a finite element model to solve the Laplace equation directly while keeping the same computational efficiency as the mild-slope equation. This model assumes the vertical variation of wave potential as a cosine hyperbolic function as done in the derivation of the mild-slope equation, and the Galerkin method is used to discretize . The computational domain was discretized with proper finite elements, while the radiation condition at infinity was treated by introducing the concept of an infinite element. The upper boundary condition can be either free surface or a solid structure. The applicability of the developed model was verified through example analyses of two-dimensional wave reflection and transmission. .

• Journal of Mechanical Science and Technology
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• v.15 no.8
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• pp.1165-1173
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• 2001

This paper deals with dynamic analysis of Pipeline Inspection Gauge (PIG) flow control in natural gas pipelines. The dynamic behaviour of PIG depends on the pressure differential generated by injected gas flow behind the tail of the PIG and expelled gas flow in front of its nose. To analyze dynamic behaviour characteristics (e.g. gas flow, the PIG position and velocity) mathematical models are derived. Tow types of nonlinear hyperbolic partial differential equations are developed for unsteady flow analysis of the PIG driving and expelled gas. Also, a non-homogeneous differential equation for dynamic analysis of the PIG is given. The nonlinear equations are solved by method of characteristics (MOC) with a regular rectangular grid under appropriate initial and boundary conditions. Runge-Kutta method is used for solving the steady flow equations to get the initial flow values and for solving the dynamic equation of the PIG. The upstream and downstream regions are divided into a number of elements of equal length. The sampling time and distance are chosen under Courant-Friedrich-Lewy (CFL) restriction. Simulation is performed with a pipeline segment in the Korea gas corporation (KOGAS) low pressure system. Ueijungboo-Sangye line. The simulation results show that the derived mathematical models and the proposed computational scheme are effective for estimating the position and velocity of the PIG with a given operational condition of pipeline.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.231-238
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• 2001

To investigate the underground structure of shallow water, Han-river near Yangsou-Ri, high resolution hydroacoustic measurements were carried out for the engineering design of railroad bridge. The acoustic source was a Boomer with an energy of 90 to 280J and in a frequency range up to about 16KHz. The reflected signals were received by using both traditional hydrophones(passive element) and a specially devised receiver unit(active element) mainly composed of piezofilms and preamplifier. They are connected to the "SUMMIT" data acquisition system(DMT-GeoTec company), where the sampling interval was set to 1/32㎳. The source position was continuously monitored by a precision DGPS system whose positioning accuracy was on the order of loom. For the quality control purposes, two different source-receiver geometries were taken. That is to say, the measurements were repeated along the profile everytime depending on the different source energy(175J, 280J), the receiving elements(passive, active) and two different source-receiver geometries. It was shown that the data resolution derived from a proper arrangement with the active hydrophone could be greatly enhanced and hence the corresponding profile section caused by the regular data processing system "FOCUS" accounted excellently for the underground formation below the shallow water.w the shallow water.

• Korean Institute of Interior Design Journal
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• v.19 no.3
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• pp.13-21
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• 2010

Early mosque architecture is time that islam attempts fixing since hjira by Muhammad. Before Umayyad dynasty is established a country since islam occurrence, islamic influence was not extended much and stayed in Mecca area. Of course, when is Patriarchal Caliphate period, although there was part territorial expansion, was in existing islam influence still. Regular territorial expansion to Umayyad dynasty several influences and religious conflict happen. Change about islamic architecture occurred much fatally. Therefore, can find islamic archetype about islamic architecture until Prophet Muhammad period and Patriarchal Caliphate period. Also, Muhammad that is Islamic originator participated to mosque architecture directly in life. Can understand philosophy about islamic architecture that Muhammad seeks in mosque architecture. Was age that seek Muhammad's philosophy department religious succession strongly to Patriarchal Caliphate period. Therefore, can understand role of religion, mosque architecture's meaning and role that seek in Islam. It was just before that early mosque architecture receives effect of conquest area or the surrounding country. Therefore, characteristic of mosque received much effect of Prophet Muhammad and qur'an. Do construction according to qur'an's notice based on Prophet's house's function to early mosque. qur'an is no direct delineation as form or architecture element. qur'an refers thing about spiritual aspect or function about special quality of mosque, role etc..

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.448-448
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• 2000

This paper deals with dynamic behaviour analysis for pipeline inspection gauge (PIG) flow control in natural gas pipeline. The dynamic behaviour of the PIG is depending on the different Pressure between the rear and nose parts, which is generated by injected gas flow behind PIG's tail and expelled gas flow in front of its nose. To analyze the dynamic behaviour characteristics such as gas flow in pipeline, and the PIG's position and velocity, mathematical model is derived as two types of a nonlinear hyperbolic partial differential equation for unsteady flow analysis of the PIG driving and expelled gas, and nonhomogeneous differential equation for dynamic analysis of PIG. The nonlinear equation is solved by method of characteristics (MOC) with the regular rectangular grid under appropriate initial and boundary conditions. The Runge-Kuta method is used when we solve the steady flow equations to get initial flow values and the dynamic equation of PIG. The gas upstream and downstream of PIG are divided into a number of elements of equal length. The sampling time and distance are chosen under Courant-Friedrich-Lewy (CFL) restriction. The simulation is performed with a pipeline segment in the Korea Gas Corporation (KOGAS) low pressure system, Ueijungboo-Sangye line. The simulation results show us that the derived mathematical model and the proposed computational scheme are effective for estimating the position and velocity of PIG with different operational conditions of pipeline.

• Journal of Biosystems Engineering
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• v.18 no.1
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• pp.60-70
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• 1993

In this study, the environment variations and distributions in different types of greenhouses were measured and analyzed. The elements of environment analyzed were temperature, relative humidity, illumination, carbon dioxide and wind velocity. The analyzed greenhouse types were auto-multi type which has an automatic environment control system and multiple continuous arches, regular-multi type which has an temperature control system and multiple continuous arches, and single arch type which has no environment control system without manual temperature keeping method. The results of this study can be used for the greenhouse building and managements.