• Proceeding of KASS Symposium
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• 2006.05a
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• pp.214-223
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• 2006

Membrane structures, a kind of lightweight soft structural system, are used for spatial structures. The material property of the membrane has strong axial stiffness, but little bending stiffness. The design procedure of membrane structures are needed to do shape finding, stress-deformation analysis and cutting pattern generation. In shape finding, membrane structures are unstable structures initially. These soft structures need to be introduced initial stresses because of its initial unstable state, and happen large deformation phenomenon. Therefore, in this study, to find the structural shape after large deformation caused by initial stress, we need the shape analysis considering geometric nonlinear term. And we investigate the evaluation of shape analysis technique's convergence and efficiency according to the control method

• Kyungpook Mathematical Journal
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• v.51 no.4
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• pp.353-364
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• 2011

Duality in the optimal harvesting for a nonlinear age-spatial structured population dynamic model is studied in the framework of optimal control problem. In this paper the duality theory that displays the conjugacy of the primal problem is established and an application is given. Duality theory plays an important role in both optimization theory and methodology and the results may be applied to a realistic biological system on the point of optimal harvesting.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.3
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• pp.331-345
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• 2009

This study aims to standardize the work classification system in spatial data. Up to now, a systematic standard for constructing process and quality management has not yet been established in Korea, thus, it is possible for the national budget to be wasted. The regulations related to constructing spatial data are also obscure, and absurd for feasible application to reality, which results in a lack of reliability of the quality of spatial data. This study was conducted by investigating and analyzing regulations related to spatial data quality and various literature, including studies on spatial data quality conducted by the NGII. And also, the study was conducted by investigating and analyzing the constructing processes and working methods of major firms that have experience in constructing a GIS for a local governing body. Based on the analyzed data, we standardized work classification and management methodology for control point surveying using GPS, leveling, aerial photographing, digital mapping, topographic mapping, digital elevation modeling, aerial photographic DB construction, digital orthophotomap.

• Journal of The Korea Institute of Healthcare Architecture
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• v.23 no.4
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• pp.27-36
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• 2017

Purpose: The characteristics of spatial allocation planning in dentistry through examining the dental hospitals in Korea and comparison between them are necessary for the development of planning of the dental healthcare system. This study has been started to provide basic informations such as zoning, allocation distribution, and space configuration for the planning of dental hospital architecture. Methods: Literature review of dental care departments and investigation on current status of dental hospital in Korea have been conducted. The spatial allocation and space configuration of eleven dental hospitals have been analyzed. Results: The result of this study can be summarized in three points. The first one is that dental hospitals in Korea are consisted with eight to eleven dental care departments and they are divided with the horizontal allocation type with three to four departments in a floor for the spatial communication or the vertical allocation type with a department in each floor for the independent space. The second one is that oral medicine and oral maxillofacial radiology are located near the main entrance, orthodontics and pedodontic dentistry in lower level, prosthodontics in upper level, and conservative dentistry and periodontics have no specific spatial consideration. The third one is that the factors to consider the allocation planning are zoning for examination & diagnosis, basic practice, adolescence, surgery, circulations for patient, dentist, staff, different access for department like as easy access for reception and pedodontic dentistry, enclosure space for prosthodontics and surgery, frequency of visit and treatment care time, and change of treatment concept from treatment department to disease control corporative practice. Implications: This study is the starting point for the research of spatial configuration in dentistry and it is necessary to analyze the architectural planning to develop the dental healthcare system.

• Structural Engineering and Mechanics
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• v.87 no.3
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• pp.255-272
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• 2023

Spatial cable systems can provide more transverse stiffness and torsional stiffness without sacrificing the vertical bearing capacity compared with conventional vertical cable systems, which is quite lucrative for long-span earth-anchored suspension bridges' development. Higher economy highlights the importance of refined form-finding analysis. Meanwhile, the internal connection between the lateral and vertical sags has not yet been specified. Given this, an analytic algorithm of form-finding for the earth-anchored suspension bridge with spatial cables is proposed in this paper. Through the geometric compatibility condition and mechanical equilibrium condition, the expressions for cable segment, the recurrence relationship between catenary parameters and control equations of spatial cable are established. Additionally, the nonlinear general reduced gradient method is introduced into fast and high-precision numerical analysis. Furthermore, the analytic expression of the lateral and vertical sags is deduced and discussed. This is very significant for the space design above the bridge deck and the optimization of the sag-to-span ratio in the preliminary design stage of the bridge. Finally, the proposed method is verified with the aid of two examples, one being an operational self-anchored suspension bridge (with spatial cables and a 260 m main span), and the other being an earth-anchored suspension bridge under design (with spatial cables and a 500 m main span). The necessity of an iterative calculation for hanger tensions on earth-anchored suspension bridges is confirmed. It is further concluded that the main cable and their connected hangers are in very close inclined planes.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.12 s.105
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• pp.1378-1388
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• 2005

Spatial control of sound is essential to deliver better sound to the listener's position in space. As it can be experienced in many listening environments. the quality of sound can not be manifested over every Position in a hall. This motivates us to control sound in a region we select. The primary focus of the developed method has to do with the brightness and contrast of acoustic image in space. In particular, the acoustic brightness control seeks a way to increase loudness of sound over a chosen area, and the contrast control aims to enhance loudness difference between two neighboring regions. This enables us to make two different kinds of zone - the zone of quiet and the zone of loud sound - at the same time. The other perspective of this study is on the direction of sound. It is shown that we can control the direction of perceived sound source by focusing acoustic energy in wavenumber domain. To begin with, the proposed approaches are formulated for pure-tone case. Then the control methods are extended to a more general case, where the excitation signal has broadband spectrum. In order to control the broadband signal in time domain, an inverse filter design problem is defined and solved in frequency domain. Numerical and experimental results obtained in various conditions certainly validate that the acoustic brightness, acoustic contrast, direction of wave front can be manipulated for some finite region in space and time.

• Journal of Korean Association for Spatial Structures
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• v.7 no.5
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• pp.49-56
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• 2007

Passive, active and semi-active control system are classified in floor vibration control system by providing control force. This paper discusses the application of a new class of semi-active TMD(MR-TMD), for the reduction or floor vibrations due to machine and human movements. This MR-TMD consists of passive TMD and MR damper. Here, displacement-based control methods are used to assess the performance of this STMD(MR-TMD). And, skyhook and the groundhook algorithm are applied to a single degree of freedom system representative of building floors. If the allowed operation space of tuned mass is limited in MR-TMD system, skyhook algorithm is more efficient than groundhook algorithm for floor vibration control. Hybrid control method demonstrates the efficiency of MR-TMD with respect to another methods.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.803-814
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• 2020

Managing erosion control dams requires the annual average sediment yield to determine their storage capacity and time to full sediment-fill and dredging. The GeoWEPP (Geo-spatial interface for Water Erosion Prediction Project) model can predict the annual average sediment yield from various land uses and vegetation covers at a watershed scale. This study assessed the GeoWEPP to determine the annual average sediment yield for managing erosion control dams by applying it to five erosion control dams and comparing the results with field observations using ground-based LiDAR (light detection and ranging). The modeling results showed some differences with the observed sediment yields. Therefore, GeoWEPP is not recommended to determine the annual average sediment yield for erosion control dams. Moreover, when using the GeoWEPP, the following is recommended :1) use the US WEPP climate files with similar latitude, elevation and precipitation modified with monthly average climate data in Korea and 2) use soil files based on forest soil maps in Korea. These methods resulted in GeoWEPP predictions and field observations of 0 and 63.3 Mg·yr-1 for the Gangneung, 142.3 and 331.2 Mg·yr-1 for the Bonghwa landslide, 102.0 and 107.8 Mg·yr-1 for the Bonghwa control, 294.7 and 115.0 Mg·yr-1 for the Chilgok forest fire, and 0 and 15.0 Mg·yr-1 for the Chilgok control watersheds. Application of the GeoWEPP in Korea requires 1) building a climate database fit for the WEPP using the meteorological data from Korea and 2) performing further studies on soil and streamside erosion to determine accurate parameter values for Korea.

• Journal of Advanced Navigation Technology
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• v.19 no.6
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• pp.507-514
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• 2015

The Spatial information research institute of the LX Korea land and geospatial informatix corporation manages infrastructure for the LX global navigation satellite system (GNSS), which comprises 30 monitoring stations nationwide. Since 2014, it has conducted network real-time kinematic (RTK) tests using the master-auxiliary concept (MAC). This study introduces the infrastructure of LX GNSS and presents the results of a performance analysis of the LX RTK service. The analysis was based on a total of 25 cadastral topographic control points in Jeonju, Seoul, and Incheon. For each point, performance was measured over one observation, two repeated observations, and five repeated observations. The measurements obtained from LX MAC and the VRS of the National Geographic Information Institute were compared with the announced coordinates derived from cadastral topographic control points. As a result, the two systems were found to have similar performance with average error and standard deviation differing only by 1 to 2 cm.

• Korean Institute of Interior Design Journal
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• v.20 no.5
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• pp.178-187
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• 2011

This research suggested the hygienic spatial composition of sell-service restaurants applying HACCP(Hazard Analysis and Critical Control Point System). The circulation of the food, dishes, waste, workers and customers were each fractionated and arranged according to the hygienic sequence of cooking food in kitchen and process for eating food within the customer space. The spaces were separated by the degree of cleanness(clean area, semi-clean area, contaminated area). After that, hygiene facilities to remove contamination and pass facilities intended to control moving were added at the possible points of cross-contamination in oder to prevent the cross-contamination. For hygienic spatial composition of self-service restaurant, the following should be acknowledged: In the kitchen, spaces in which the food is handled after being heated should be located in the clean area. As of the customer space, spaces where dishes are prepared, food and water is received, and the table hall should be located in the clean area. Food circulation should flow from the contaminated area to the clean area. Food, dishes, waste should be moved through pass facilities so that workers do not have to come and go between other areas of cleanness. Also lockers for private clothes and lockers for uniforms should be separated. Hygiene facilities should be easily accessible so that workers can use them whenever they enter their working area. The contaminated area where dirty dishes are dealed with should be separated from the clean area. Waste should be thrown out without crossing cooking areas. As of customer circulation, the hygiene facility for hand washing should be located near the space where dishes for self-service are placed. The customer circulation should lead customers to leave restaurants after giving back the dirty dishes in the contaminated area.