• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.325-335
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• 2010

A new geothermal energy source obtained from a tunnel structure has been studied in this paper. The geothermal energy is extracted through a textile-type ground heat exchanger named "Energy Textile" that is installed between a shotcrete layer and a guided drainage geotexitle. A test bed was constructed in an abandoned railway tunnel to verify the geothermal heat exchanger system performed by the energy textile. To evaluate the applicability of the energy textile, we measured the thermal conductivity of shotcrete and lining samples which were prepared in accordance with a common mixture design. An overall performance of the energy textile installed in the test bed was evaluated by carrying out a series of in-situ thermal response test. In addition, a 3-D finite volume analysis (FLUENT) was adopted to simulate the operation of the ground heat exchanger being encased in the energy textile with the consideration of the effect of the shotcrete and lining thermal conductivity.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.588-591
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• 2009

Ground source heat pump system; GSHPs is close to most practical use for early stage investment cost and energy efficiency in new renewable energies, and currently considered utilizing to the heat and cooling system of a building. Particularly, the case to utilize 'Standing Column well heat source gathering method' in the open standards process to have the excellent capability of gathering geothermal source is increased. But the research for the optimal design technology and the assessment of a pollution level of the ground to utilize a single well for gathering geothermal is insignificant and the design is insufficient. The heating and cooling system and the equipment to utilize a large size residential development to have over 1000 households have not developed yet. Therefore, our company developed 'geothermal hybrid system' which can construct the heat and cooling system using geothermal energy for a large size residential development of over 1000 households and conducted the evaluation of economic feasibility. Moreover we developed automatic equipment for gathering geothermal source and PLC (Programmable logic controller) to have optimal efficiency and FCU (fan coil unit) considering the floors of large size apartments.

• Earthquakes and Structures
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• v.10 no.5
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• pp.1049-1066
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• 2016

An approximate analysis is presented for multi-story setback buildings subjected to ground motions. Setback buildings with mass and stiffness discontinuities are common in modern architecture and quite often they are asymmetric in plan. The proposed analysis provides basic dynamic data (frequencies and peak values of base resultant forces) and furthermore an overview of the building response during a ground excitation. The method is based on the concept of the equivalent single story system, which has been introduced by the author in earlier papers for assessing the response of uniform in height buildings. As basic quantities of the dynamic response of elastic setback buildings can be derived by analyzing simple systems, a structural layout of minimum elastic rotational response can be easily constructed. The behavior of such structural configurations, which is basically translational into the elastic phase, is also examined into the post elastic phase when the strength assignment of the various bents is based on a planar static analysis under a set of lateral forces simulating an equivalent 'seismic loading'. It is demonstrated that the almost concurrent yielding of all resisting elements preserves the translational response, attained at the end of the elastic phase, to the post elastic one.

• International Journal of High-Rise Buildings
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• v.3 no.3
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• pp.231-241
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• 2014

Ductile fracture is one of the most common failure modes of steel beam-to-column connections in moment resisting frames. Most proposed evaluation methods of the plastic deformation capacity of a beam until ductile fracture are based on steel beam tests, where the material's yield strength/ratio, the beam's moment gradient, and loading history are the most important parameters. It is impossible and unpractical to cover all these parameters in real tests. Therefore, a new attempt to evaluate a beam's plastic deformation capacity through analysis is introduced in this paper. Another important issue is about the loading histories. Recent years, the effect on the structural component under long-duration ground motion has drawn great attentions. Steel beams tends to experience a large number of loading cycles with small amplitudes during long-duration earthquakes. However, current research often focuses on the beam's behavior under standard incremental loading protocols recommended by respective countries. In this paper, the plastic deformation capacity of steel beams subjected to long duration ground motions was evaluated through analytical methodology.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.32-37
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• 2001

As increasing underground facilities, more effective management is needed nowadays. It is important to get an accurate information of underground facilities to manage that, so some methods of detecting location - electromagnetic induction method, ground penetration radar method, sonic method - are used to obtain the information of underground facilities. In this study, a magnetic method to detect underground facilities was developed. In the magnetic method, underground facilities are detected by a detector and the magnetic marker which is a permanent magnet and used to marking the location by attaching underground facilities. A proper characteristic of the magnetic marker was optimized by maxwell 20 magnetic field analysis tool, a test field was constructed with the magnetic marker, PVC pipe, and steel pipe under ground 1.5m, and the detector was made by modifying a common ferromagnetic detector. Magnetic strengths of the magnetic marker were measured by the detector at each location in the test field, and analyzed by magnetic field analysis tool in the same condition. In the result, the underground pipes were detectable within the deviation ${\pm}20cm$ at PVC pipe and ${\pm}10cm$ at steel pipe respectively. The steel pipe was more detectable by ferromagnetism. The developed magnetic method can be applied to maintain and manage underground facilities.

• Korean Journal of Veterinary Research
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• v.44 no.1
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• pp.143-150
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• 2004

This study was conducted to analyze the relationship between the occurrence of mastitis and the conformation of udders, teats, and teat tips of Holstein cows raised in Korea. Udders, teats, and teat tips were categorized by their conformation and the teat length, teat diameter and the distance from the tip of teat to the ground of 259 cows were measured. The most common shapes of udder, teats and teat tip were milking machine udder (27.4%), U-shaped teats (53.9%) and disk teat tip (53.8%), respectively. Mean teat length and diameters were 4.78 cm and 3.11 cm, respectively. The length and the diameter of front teats were significantly longer and wider than those of rear teats. However, the distance of the tip of teats to the ground was similar between front teats $(50.5{\pm}7.51cm)$ and rear teats $(50.7{\pm}8.83cm)$. The average daily milk yield was 26.4 kg/day, and the highest milk yield was observed from cows with large udder shape and above 4th lactation.

• Journal of architectural history
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• v.14 no.1 s.41
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• pp.7-19
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• 2005

The purpose of this paper is the study on the piazza plan of basilica S. Pietro. The results of study are as follows: 1. The piazza of the basilica S. Pietro was planned in relation to building-piazza-symbol of interior piazza-street as city planning characteristic of Baroque and architectural characteristic of elliptical piazza form. 2. The function of piazza of basilica S. Pietro was planned for religious meeting of a grand scale than a piazza for the common run of people. 3. In general, the disposition, ground, elevation and section plan of the piazza of basilica S. Pietro was planned by principle of spatial and formal composition, according to axis, symmetry, proportion, division and contrast. 4. The location, scale, shape of piazza for disposition and ground plan of the piazza of basilica S. Pietro was basically decided by not only elements of Basilica building, Vatican Palace, Street and Walls of surroundings with axis of the Basilica building, but Fountain and Obelisk as existing constituent elements. 5. The elevation of the piazza of basilica S. Pietro was composed of boundary that was enclosed from wall of trapezoid piazza and gallery of elliptical piazza with equal height as symmetry. And the section plan was planned to approach into the Basilica through slope and stairs of gentle angle, utilizing of existing land form.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.10
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• pp.1225-1231
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• 2014

This paper presents the performance characteristic of a Francis hydro turbine with an inline casing. This turbine is designed for city water supply system. Due to large changes in ground elevation with high points and low points, some systems may experience larger-than-normal required pressures in areas with low ground elevations. One way to dissipate these excess pressures is by the use of an inline-turbine instead of an inline-pressure reducing valve. For best applicability and minimal space consumption, the turbine is designed with an inline casing instead of the common spiral casing. As a characteristic of inline casing, the flow accesses to the runner in the radial direction, showing a low efficiency. The installation of vanes improves the internal flow and gives the positive encouragement to the output power. For the power transmission to the outside of the turbine casing from the runner axis, a belt passage is designed in the inline casing, as its influence, the region after the belt passage shows a relatively low output power. The clearance gap in the runner side space is considered, in which a small volume of flow is contracted into the clearance gap, forming the leakage flow. The leakage flow leads to a decrease in the efficiency.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.637-641
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• 2007

Airborne LIDAR (Light Detection and Ranging) technology has reached a degree of the required accuracy in mapping professions, and advanced LIDAR systems are becoming increasingly common in the various fields of application. LiDAR data constitute an excellent source of information for reconstructing the Earth's surface due to capability of rapid and dense 3D spatial data acquisition with high accuracy. However, organizing the LIDAR data and extracting information from the data are difficult tasks because LIDAR data are composed of randomly distributed point clouds and do not provide sufficient semantic information. The main reason for this difficulty in processing LIDAR data is that the data provide only irregularly spaced point coordinates without topological and relational information among the points. This study introduces an efficient and robust method for automatic extraction of building footprints using airborne LIDAR data. The proposed method separates ground and non-ground data based on the histogram analysis and then rearranges the building boundary points using convex hull algorithm to extract building footprints. The method was implemented to LIDAR data of the heavily built-up area. Experimental results showed the feasibility and efficiency of the proposed method for automatic producing building layers of the large scale digital maps and 3D building reconstruction.

• Explosives and Blasting
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• v.33 no.2
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• pp.25-39
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• 2015

The common underwater rock removal methods involve underwater blasting and crane's chisel dropping impact method. From an environmental point of view, these methods cause ground vibrations and underwater noise. At the site for this study, a method of dropping heavyweight chisel is selected to remove the underwater bedrock near the ferry rack in the course of improving the cargo handling ability of the loading dock. A prediction formula for the vibration was obtained based on the measurement and evaluation of the vibrations caused by the chisel dropping impacts during the test droppings. The prediction formula was successfully applied to the main construction for securing the stability of the structure.