• Korean Journal of Applied Biomechanics
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• v.12 no.2
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• pp.159-177
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• 2002

The purpose of this study was to investigate the relations between the segments of the body, the three dimensional anatomical angle and the angular velocity of the air born phase and understand the control mechanism of the high-bar movement, the somersault, the double somersault, the double somersault with full twist. For this study seven well trained university gymnastic volunteered, Zatsiorky and Seluyanov(1983, 1985)'s sixteen segment system anatomical model was used for this study. For the movement analysis three dimensional cinematographical method(Arial Performance Analysis System : APAS) was used and for the calculation of the kinematic variables a self developed program was used with the LabVIEW 5.1 graphical profromming(Johnson, 1999) program. By using Eular's equations the three dimensional anatomical Cardan angles of the joint and angular velocity were defined. As a result of this study 1. As the rotation of the body increased in the air born phase the projection angle of the CM of the total increased, this resulted the increased of the max hight of the CM. 2. In three dimensional angular velocity the Z axis(vertical direction) projection angular velocity increased as the rotation of the body increased in the airborn phase, but the Y axis and the X axis projection angular velocity did not show significant differences. 3. As the rotation of the body increased in the air born phase the angular movement of the shoulder and the hip showed significant change. These movement act as the starter in the preparation phase. 4. The somersault angle, the twist angle, the tilt angle of the upper body related to the global reference frame in the releas phase the average somersault angle of the three types of high-bar movement was $57.7^{\circ}$, $38.8^{\circ}$, $39.7^{\circ}$, the average tilt angle was $-1.5^{\circ}$, $-5.4^{\circ}$, $-8.4^{\circ}$, the average twist angle was $13.4^{\circ}$, $10.6^{\circ}$, $23.3^{\circ}$. This result showed that the somersault with full twist had the largest movement.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.12-16
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• 2012

Purpose : In conventional PET image reconstruction, iterative reconstruction methods such as OSEM (Ordered Subsets Expectation Maximization) have now generally replaced traditional analytic methods such as filtered back-projection. This includes improvements in components of the system model geometry, fully 3D scatter and low noise randoms estimates. SharpIR algorithm is to improve PET image contrast to noise by incorporating information about the PET detector response into the 3D iterative reconstruction algorithm. The aim of this study is evaluation of SharpIR reconstruction method in PET/CT. Materials and Methods: For the measurement of detector response for the spatial resolution, a capillary tube was filled with FDG and scanned at varying distances from the iso-center (5, 10, 15, 20 cm). To measure image quality for contrast recovery, the NEMA IEC body phantom (Data Spectrum Corporation, Hillsborough, NC) with diameters of 1, 13, 17 and 22 for simulating hot and 28 and 37 mm for simulating cold lesions. A solution of 5.4 kBq/mL of $^{18}F$-FDG in water was used as a radioactive background obtaining a lesion of background ratio of 4.0. Images were reconstructed with VUE point HD and VUE point HD using SharpIR reconstruction algorithm. For the clinical evaluation, a whole body FDG scan acquired and to demonstrate contrast recovery, ROIs were drawn on a metabolic hot spot and also on a uniform region of the liver. Images were reconstructed with function of varying iteration number (1~10). Results: The result of increases axial distance from iso-center, full width at half maximum (FWHM) is also increasing in VUE point HD reconstruction image. Even showed an increasing distances constant FWHM. VUE point HD with SharpIR than VUE point HD showed improves contrast recovery in phantom and clinical study. Conclusion: By incorporating more information about the detector system response, the SharpIR algorithm improves the accuracy of underlying model used in VUE point HD. SharpIR algorithm improve spatial resolution for a line source in air, and improves contrast recovery at equivalent noise levels in phantoms and clinical studies. Therefore, SharpIR algorithm can be applied as through a longitudinal study will be useful in clinical.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.5
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• pp.500-509
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• 2013

This study reports a numerical analysis of the internal flow characteristics of the integrated urea-SCR muffler system with the various geometries of the multi-perforated tube which is set up between the muffler inlet and in front of SCR catalysts. The multi-perforated tube is generally used to disperse uniformly the urea-water solution spray and to make better use of the SCR catalyst, resulting in the increased $NO_x$ reduction and decreased ammonia slip. The effects of the multi-perforated tube orifice area ratios on the velocity distributions in front of the SCR catalyst, which is ultimately quantified as the uniformity index, were investigated for the optimal muffler system design. The steady flow model was applied by using a general-purpose commercial software package. The air at the room temperature was used as a working fluid, instead of the exhaust gas and urea-water solution spray mixture. From the analysis results, it was clarified that the multi-perforated tube geometry sensitively affected to the formation of the bulk swirling motion inside the plenum chamber set in front of the SCR catalyst and to the uniformity index of the velocity distribution produced at the inlet of the catalyst.

• Geophysics and Geophysical Exploration
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• v.26 no.2
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• pp.52-61
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• 2023

The use of ultra-high-resolution (UHR) seismic surveys to preceisly characterize coastal and shallow structures have increased recently. UHR surveys derive a spatial resolution of 3.125 m using a high-frequency source (80 Hz to 1 kHz). A digital streamer system is an essential module for acquiring high-quality UHR seismic data. Localization studies have focused on reducing purchase costs and decreasing maintenance periods. Basic performance verification and application tests of the developed streamer have been successfully carried out; however, a comparative analysis with the existing benchmark model was not conducted. In this study, we characterized data obtained by using a developed streamer and a benchmark model simultaneously. Tamhae 2 and auxiliary equipment of the Korea Institute of Geoscience and Mineral Resources were used to acquire 2D seismic data, which were analyzed from different perspectives. The data obtained using the developed streamer differed in sensitivity from that obtained using benchmark model by frequency band.However, both type of data had a very high level of similarity in the range corresponding to the central frequency band of the seismic source. However, in the low frequency band below 60 Hz, data obtained using the developed streamer showed a lower signal-to-noise ratio than that obtained using the benchmark model.This lower ratio can hinder the quality in data acquisition using low-frequency sound sources such as cluster air guns. Three causes for this difference were, and streamers developed in future will attempt to reflect on these improvements.

• Atmosphere
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• v.23 no.2
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• pp.171-186
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• 2013

Recently, the number of observations used in a data assimilation system is increasing due to the enormous amount of observations, including satellite data. However, it is not clear that all of these observations are always beneficial to the performance of the numerical weather prediction (NWP). Therefore, it is important to evaluate the effect of observations on these forecasts so that the observations can be used more usefully in NWP process. In this study, the adjoint-based Forecast Sensitivity to Observation (FSO) method with the KMA Unified Model (UM) is applied to two high-impact weather events which occurred in summer and winter in Korea in an effort to investigate the effects of observations on the forecasts of these events. The total dry energy norm is used as a response function to calculate the adjoint sensitivity. For the summer case, TEMP observations have the greatest total impact while BOGUS shows the greatest impact per observation for all of the 24-, 36-, and 48-hour forecasts. For the winter case, aircraft, ATOVS, and ESA have the greatest total impact for the 24-, 36-, and 48-hour forecasts respectively, while ESA has the greatest impact per observation. Most of the observation effects are horizontally located upwind or in the vicinity of the Korean peninsula. The fraction of beneficial observations is less than 50%, which is less than the results in previous studies. As an additional experiment, the total moist energy norm is used as a response function to measure the sensitivity of 24-hour forecast error to observations. The characteristics of the observation impact with the moist energy response function are generally similar to those with the dry energy response function. However, the ATOVS observations were found to be sensitive to the response function, showing a positive (a negative) effect on the forecast when using the dry (moist) norm for the summer case. For the winter case, the dry and moist energy norm experiments show very similar results because the adjoint of KMA UM does not calculate the specific humidity of ice properly such that the dry and moist energy norms are very similar except for the humidity in air that is very low in winter.

• Journal of KIISE
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• v.44 no.5
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• pp.476-485
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• 2017

The tactical operation centers of future anti-aircraft missile systems provide the environment for the research on future air threats, tactical information, integrated battlefield environment creation and management, engagement control and command and control algorithms. To develop the key functional elements of integrated battlefield situation creation and processing and tactical operation automation processing operations, battery/battalion tactical operation control and reconfiguration design software are required. Therefore, the algorithm software of each function and the tactical operation display software and link software for interworking between equipment were developed as reconfigurable through a data-centric design. In this paper, a tactical operation display framework that can be reconfigured on the operation display of the tactical operations according to the battery/battalion is introduced. This tactical operation display framework was used to develop a common data model design for the reconfigurable structure of multi-role tactical operations with battery / battalion and mission views, and a display configuration tool that provides a tactical operation display framework for view development was also developed using the MVC pattern. If the tactical operation display framework is used, it will be possible to reuse the view design through the common base structure, and a view that can be reconfigured easily and quickly will also be developed.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.1
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• pp.93-106
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• 2016

This study aimed to estimate and evaluate the thermal mitigation of the urban tree canopy on the summer outdoor environment by quantitative use of mean radiant temperature. This study applied the SOLWEIG model based $T_{mrt}$ comparison method by using both (1) urban tree canopy presence examples and (2) urban tree canopy absence examples as constructed from airborne LiDAR system based three-dimensional point cloud data. As a result, it was found that an urban tree canopy can provide a decrease in the entire domain averaged daily mean $T_{mrt}$ about $5^{\circ}C$ and that the difference can increase up to $33^{\circ}C$ depending both on sun position and site conditions. These results will enhance urban microclimate studies such as indices (e.g., wind speed, humidity, air temperature) and biometeorology (e.g., perceived temperature) and will be used to support forest based public green policy development.

• Tunnel and Underground Space
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• v.11 no.4
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• pp.319-327
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• 2001

Introduction of new design tools has been required to optimally design and operate the ventilation system of long vehicle tunnels.. The demand has led to wide spread use of the simulation technique throughout the would to analysis the dynamic relationship among the variables associated with vehicle tunnel ventilation. This paper aims at performing on-site study at local tunnels to test the applicability of NETVEN, a simulation model vehicle tunnel ventilation. The study was carried out at four urban as well as highway tunnels model of vehicle tunnel ventilation. The study was carried out at four urban as well as highway tunnels employing different ventilation systems as well as traffic methods. There were some discrepancies sound between the simulation output and measurements and the following four factors are considered to mainly cause those disagreement. (1) The real situation shows distinctive transient and retarding characteristics with respect to air flow and contaminant dispersion, while ventilation forces are not steady-state and in particular those traffic and climatic variables show significant instantaneous variation. (3) Near the exit portal, the CO levels show bigger differences. The general trend is that data with higher CO concentrations carry bigger discrepancies. Turbulent diffusion is though to be the main reason for it and also contribute to the fact hat the highest CO concentrations are found at the locations somewhat inward, not at the exit portals. (4) Higher traffic rate results in higher discrepancies of ventilation velocity. Along with the exhaust characteristics, the vehicle aerodynamic characteristics need to be studied continuously in order to reduce the velocity disagreement.

• Journal of the Korean Institute of Gas
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• v.2 no.4
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• pp.60-66
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• 1998

The hot stove system is a process that is continuously and constantly generating the hot combustion air required for the blast furnace. The hot stove process is considered as a main energy consumption process because it consumes about $20\%$ of the total energy in steel making works. So, many researchers have interested in the improvement of the heat efficiency of the hot stove to reduce the energy consumption. But they have difficulties in improving the heat efficiency of the hot stove because there is no precise information on heat transformation occurring during the heating period. In order to model the relationship between the operating conditions and heat efficiencies, we propose a neural network using feature extraction as one of experimental modeling methods. In order to show the performance of the model, we compare it with Partial Least Square (PLS) method. Both methods have similarities in using the dimension reduction technique. And then we present the simulation results on the prediction of the heat efficiency of the hot stove.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.189-194
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• 2010

A multi line electric tube consisted of XL pipes contained with 2~4 hot wires and water in it. The specification of one meter length multi-line electric tube was investigated and the proper number in the multi-line electric tube was determined. A multi line electric tube with three hot wires were found to be the most efficient for the media heating control system. Temperature rise of medium in the rice hulls media was faster than that in the perlite media, showed better insulation effect of rice hulls media. Temperature rise of medium with mulching on the top of the bed was faster than without mulching, resulted in the beneficial effect of temperature rise with mulching. The regression model for the rice hulls media with mulching air temperature of $5^{\circ}C$ were a = -0.1458 and b = -0.1088. Using the model, the temperature rise of medium during low temperature season can be predicted for the various media according to the different depths.