• Journal of electromagnetic engineering and science
• /
• v.7 no.3
• /
• pp.129-133
• /
• 2007

In this paper, we present the development of an antenna specialized for the maritime collision avoidance system. This antenna is configured as the dielectric rod partially embedded in the metal cavity to reduce the overall size, simultaneously assuring the mechanical sturdiness against the challenging oceanic weather conditions. More importantly, the design has been carefully done to meet the requirements on the radiation pattern(with the slope < 5 dB/deg in the elevation(E-plane), circular in the azimuth) suitable to receiving the reflected signals from the other objects on the sea. To find the optimal design parameters, the genetic algorithm has been used to meet the goals of the desired return loss and pattern. This design methodology is validated by the good agreement between the calculation and measurement.

• Nuclear Engineering and Technology
• /
• v.44 no.5
• /
• pp.535-542
• /
• 2012

A sodium-cooled demonstration fast reactor with the KALIMER-600 as a reference plant is under design by KAERI. The safety grade decay heat removal system (DHRS), which is important to mitigate design basis accidents, was changed in the reactor design. A loss of heat sink and a vessel leak in design basis accidents were simulated using the MARS-LMR system transient analysis code on two plant systems. In the analyses, the DHRS of KALIMER-600 had a weakness due to elevation of the overflow path for the DHRS operation, while it was proved that the DHRS of the demonstration reactor had superior heat transfer characteristics due to the simplified heat transfer mechanism.

• Korean Institute of Interior Design Journal
• /
• v.23 no.3
• /
• pp.11-20
• /
• 2014

This study is to suggest architectural types and identify design characteristics of traditional style public buildings of reinforced concrete structure. Because the types of such buildings are very diverse, proper classification criteria is essential for future design and evaluation. The demand for such buildings is increasing, however the quality of design is not quite satisfying, therefore it seems important to identify the present design condition, and being able to suggest desirable direction for better design. The research analyzed 44 examples of public buildings in Southern Jeolla Province, where there are large number of traditional style public buildings than anywhere else in korea. and tried to analyzed the Siteplan and Elevation, Elements and evaluated overall design level of the buildings. The study could be able to roughly identify the problems of existing design as well as the future possibility of design which could be improve in the future.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.5B
• /
• pp.501-509
• /
• 2006

The safety of levee that depends on the river flood elevation has been regarded as very important keys to build up various flood prevention systems. However, deterministic methods for computation of water surface profile cannot reflect the effect of possible inaccuracies in the input parameters. The purpose of this study is to develop a methodology of uncertainty computation of design flood level based on steady flow analysis and Monte Carlo simulation. This study addresses the uncertainty of water surface elevation by Manning's coefficients, design discharges, river cross sections and boundary condition. Monte Carlo simulation with the variations of these parameters is performed to quantify the variations of water surface elevations in a river. The proposed model has been applied to the Kumho-river. The reliability analysis was performed within 38.5 km (95 sections) reach considered the variations of the above-mentioned parameters. Overtopping risks were evaluated by comparing the elevations of the flood condition with the those of the levees. The results show that there is a necessity which will raise the levee elevation between 1 cm and 56 cm at 7 sections. The model can be used for preparing flood risk maps, flood forecasting systems and establishing flood disaster mitigation plans as well as complement of conventional levee design.

• Journal of the Korean Society of Radiology
• /
• v.18 no.2
• /
• pp.127-133
• /
• 2024

The elbow joint is made up of three different bones. X-rays or other radiological exams are commonly used to diagnose elbow injuries or disorders caused by physical activity and external forces. Previous research on the elbow joint reported a new examination method that meets the imaging evaluation criteria in the tilt position by Z-axis elevation of the forearm. Therefore, this study aims to design an optimized instrument and develop an aid applicable to other upper extremity exams. After completing the 2D drawing and 3D modeling design, the final design divided into four parts was fabricated with a 3D printer using ABS plastic and assembled. The developed examination aid consists of a four-stage Z-axis elevation tilt angle function (0°, 5°, 10°, and 15°) and can rotate and fixate 360° in 1-degree increments. It was designed to withstand a maximum equivalent stress of 56.107 Pa and a displacement of 1.6548e-5 mm through structural analysis to address loading issues caused by cumulative frequency of use and physical utilization. In addition to X-ray exams of the elbow joint, the developed aid can be used for shoulder function tests by rotating the humerus and also be applied to MRI and CT exams as it is made of non-metallic materials. It will contribute to the accuracy and efficiency of medical imaging diagnosis through clinical applications of various devices and medical imaging exams in the future.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.25 no.4
• /
• pp.238-246
• /
• 2015

A stepping motor is widely used to operate the elevation and azimuth stage of the X-band antenna with 2-axis gimbal system for effective image data transmission from a satellite to a ground station. However, such stepping motor also generates an undesirable micro-vibration which is one of the main disturbance sources affecting image quality of the high-resolution observation satellite. In order to improve the image quality, the micro-vibration isolation of the X-band antenna system is essential. In this study, the low rotational stiffness isolator has been proposed to reduce the micro-vibration disturbance induced by elevation direction operation of the X-band antenna. In addition, its structural safety was confirmed by the structure analysis based on the derived torque budget. The effectiveness of the design was also verified through the micro-vibration measurement test.

• Journal of Environmental Impact Assessment
• /
• v.7 no.1
• /
• pp.49-61
• /
• 1998

Zoning areas within national parks in Korea are classified into Natural Preservation Zone(NPZ). Natural Environment Zone(NEZ), Settlement Zone(SZ) and Mass Facility Zone(MFZ) based on the Natural Park Act Large-scale development which might cause permanent destruction of natural resources are being done in NEZ which covers 90% of the total natural park area. Thus it is necessary to examine National Park Act which refers the authorized criteria and development activities of NEZ. However, the current environmental impact statement(EIS) does not cover the full impact of the development inside the national park area. Based on these concepts, the study examines the appropriate resources to distinguish the NPZ and NEZ in Mt. Teogyu National Park, then compare the distribution of resource characteristics between two area by using GIS. Through this study, the conclusions are as follows; (1) In terms of scenic resource analysis, the current NPZ does not meet the criteria on the National Park Act Rather, most of the resources which should be located within the NPZ are located within the NEZ. (2) In terms of elevation analysis, Mt. Teogyu National Park, most of NPZ are located on high altitude which is more than l,200m above the mean sea level. Therefore, it shows the elevation is the only criteria for distinguishing NPZ and NEZ. (3) In terms of Degree of Green Naturality(DGN), the second forest areas, the eighth grade of DGN in Mt. Teogyu National Park are distributed much more in the NEZ than NPZ. (4) After examining five factors - scenic resources, elevation, slope and DGN, vegetation- it was found out that zoning of Mt. Teogyu National Park is not adequatly designated. Zoning of national parks should be accomplished based on the precise inventory of the current resources.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.4 no.3
• /
• pp.217-227
• /
• 2002

Geostatistical methods were used for the groundwater flow analysis on the ${\bigcirc}{\bigcirc}$ tunnel area. Linear regression analysis shows that the topographic elevation and ground water level of this area have very high correlation. Groundwater-level contour maps produced by ordinary kriging and cokriging have little differences in mountain areas. But, comparing two maps on the basis of an elevation contour map, a groundwater-level contour map using cokring is more accurate. Analyzing the groundwater flow on two groundwater-level contour maps, the groundwater of study area flows from the north-west mountain areas to near valleys, and from the peak of the mountain to outside areas. In the design steps, the groundwater-level distribution is reasonably considered in the tunnel construction area by cokriging approach. And, geostatistics will provide quantitative information in the unknown groundwatrer-level area.

• Korean Journal of Geomatics
• /
• v.2 no.1
• /
• pp.47-55
• /
• 2002

Remote sensing is the science and art of obtaining information about an object, area or phenomenon through the analysis of data acquired by a device that is not in contact with the object, area, or phenomenon under investigation./sup 1)/ EOC (Electro -Optical Camera) sensor loaded on the KOMPSAT-1 (Korea Multi- Purpose Satellite-1) performs the earth remote sensing operation. EOC can get high-resolution images of ground distance 6.6m during photographing; it is possible to get a tilt image by tilting satellite body up to 45 degrees at maximum. Accordingly, the device developed in this study enables to obtain images by photographing one pair of tilt image for the same point from two different planes. KOMPSAT-1 aims to obtain a Korean map with a scale of 1:25,000 with high resolution. The KOMPSAT-1 developed automated feature extraction system based on stereo satellite image. It overcomes the limitations of sensor and difficulties associated with preprocessing quite effectively. In case of using 6, 7 and 9 ground control points, which are evenly spread in image, with 95% of reliability for horizontal and vertical position, 3-dimensional positioning was available with accuracy of 6.0752m and 9.8274m. Therefore, less than l0m of design accuracy in KOMPSAT-1 was achieved. Also the ground position error of ortho-image, with reliability of 95%, is 17.568m. And elevation error showing 36.82m was enhanced. The reason why elevation accuracy was not good compared with the positioning accuracy used stereo image was analyzed as a problem of image matching system. Ortho-image system is advantageous if accurate altitude and production of digital elevation model are desired. The Korean map drawn on a scale of 1: 25,000 by using the new technique of KOMPSAT-1 EOC image adopted in the present study produces accurate result compared to existing mapping techniques involving high costs with less efficiency.

• Fire Science and Engineering
• /
• v.22 no.1
• /
• pp.10-15
• /
• 2008

In this study, seismic design in sprinkler head pipeline of water extinguishing system has been carried out. This study describes a generation of artificial earthquake wave compatible with seismic design spectrum, and also analyzed the dynamic response spectra by the simulated earthquake motion. This study constructed powerful engineering base for seismic design, and presented seismic design techniques of water and gas extinguishing piping system. Also, this study readied basis that can apply seismic design and performance estimation of fire fighting system and performance rating as well as pipeline of water extinguishing system from result of this research. Hereafter, if additional research by earthquake magnitude and ground kind is approached, reliance elevation, safety raising and performance based design of fire fighting system see to achieve.