• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.864-867
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• 2003

GPS (Global Positioning System) made by the Department of Defense in U.S.A is positioning system to use satellite and initially it has been used only for the military forces but open to civilian in about 1987. This system has widely been used for not only surveying land, but also car navigation on the street and means to build up the data of the GIS. With GPS, recently our country is accelerating to make imbeded system and also the study on imbeded system is well under way. For example, Car navigation and the construction of the Seokang bridge between Willson Arch at Han river by using DGPS were evaluated as successful model to lead accurate location with the precision of the cm. The examples of the project performance with GPS has gradually been extended to the each department organization of the local and central government. for the example, It is true that BIS(Bus Information System) is widely spreading out. In addition, the study on the Distribution Maintenance System is expected to be well in progress to take advantage of GPS based on the data base of the NGIS(National Geography Institute System) of the NGI(National Geography Institute). This paper shows that we embodied not only the large imbeded system for car and finding the location in Korean Land Corporation but also the protype of the kinematics Wrist Held which is easily portable to pedestrian, climber and marathon runner.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.8-16
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• 2016

This study presents the visualization of shape information based on Octree using 3D laser scanning. The process of visualization was established to construct the Octree structure from the 3D scan data. The scan data was converted to a 2D surface through the mesh technique and the surface was then converted to a 3D object through the Raster/Vector transformation. The 3D object was transmitted to the Octree Root Node and The shape information was constructed by the recursive partitioning of the Octree Root Node. The test-bed was selected as the steel bridge structure in Sungkyunkwan University. The shape information based on Octree was condensed into 89.3%. In addition, the Octree compressibility was confirmed to compare the shape information of the office building, a computer science campus in Germany and a New College in USA. The basis is created by the visualization of shape information for double-deck tunnel and it will be expected to improve the efficiency of structural health monitoring and maintenance.

• Clinics in Shoulder and Elbow
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• v.13 no.2
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• pp.286-292
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• 2010

Purpose: Stability of joints and maintenance of range of motion are needed for optimum function. The most common complaint about the elbow joint is joint stiffness. Recent articles have reported good outcomes in the treatment of stiff elbow joints. However, deciding which procedure to use is always difficult. Materials and Methods: Morrey et al. reported that the functional range of motion of the elbow joint is $30-130^{\circ}$ of flexion-extension and $50^{\circ}C$ of supination and pronation. About 90% of daily activities are done using this range of motion. Stiff elbow joints can be classified according to the traumatic events that caused the problem or the location of the main pathology. Intraarticular pathology includes severe articular mismatch, intraarticular adhesions, loss of articular cartilage, mechanical blockade by osteophytes, loose bodies, and hypertrophied synovium. Extraarticular pathology includes severe capsular adhesion due to the trauma or to dislocation, contracture of the collateral ligaments or muscles, bony bridge. Results and Conclusions: The main pathology underlying the loss of extension is the fibrous contracture of the anterior capsule. In this pathology, an anterior capsulectomy would be helpful. The main pathology underlying the loss of flexion is the contracture of the posterior band of medial collateral ligament.

• Journal of Korean Society of Steel Construction
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• v.9 no.4 s.33
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• pp.489-500
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• 1997

The number of railway bridges in Korea reaches to about 3,000. Among them, the ratio of steel bridges is about 47%. Most of the long span railway bridges take the truss type, its number is 15 in Korea. These bridges have more than 30 years service life, it is expected that the damages of cracks and corrosion is going. Therefore, the estimation of fatigue life with random stress is considered as significant subject in maintenance. In this paper, the random stress was measured in bridges and counted the stress cycles using the rainflow counting method So, the stress range frequencies and their equivalent stress are obtained and the amplification factor for the span length, bridge types and traveling speed is assessed by the dynamic testing. From the results, the stress range of the stringer and the lower chord is higher than the other members and the characteristics of the stress histogram is varied to the loading system and the amount of the passing through trains. And the impact effects are depended on the traveling speed as well as the span length.

• Journal of Korean Society of Steel Construction
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• v.20 no.6
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• pp.723-730
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• 2008

Due to the higher ratio of live load to total loads of railway bridges, the accumulated damage by cyclic fatigue is significant. Moreover, it is highly possible that the initiated crack grows faster than that of highway bridges. Therefore, it is strongly needed to assess the safety for the accumulated damage analytically. The initiation and growth of fatigue-crack are related with the stress range, number of cycles, and the stiffness of the structural system. The stiffness of the structural system includes uncertainties of the planning, design, construction and maintenance, which varies as time goes. In this study, the authors developed the design and risk assessment techniques based on the reliability theories considering the uncertainties in load and resistance. For the probabilistic risk assessment of crack growth and the remaining life of the structures by the cyclic load of railway and subway bridges, response surface method (RSM) combined with first order second moment method were used. For composing limit state function, the stress range, stress intensity factor and the remaining life were selected as input important random variables to the RSM program. The probabilities of failure and the reliability indices of fatigue life for the considered specimen under cyclic loads were evaluated and discussed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.6
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• pp.569-576
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• 2011

Recently the establishment of high accuracy 3D spatial information has been largely stimulated according to the increase in need of such 3D spatial information. In the fields of constructions and civil works, studies on increasing the productivity in these fields through converging them with other fields using the established 3D spatial information have been conducted. In such a tendency, BIM (Building Information Modeling) technologies have been rapidly applied to the fields of constructions and civil works. In particular, in the fields of constructions and civil works that represent a life span of plan-design-construction-maintenance, some BIM application methods and plans for the characteristics in each step have been proposed. Thus, the objective of this study is to simulate a project that is reasonable and can be optimized in connection with 3D spatial information and BIM technologies escaped from the conventional civil construction process that is based on empirical, statistical DB, and 2D information. For achieving this objective, 3D terrain data for the subject area engaged in this study using aerial photographs and airborne LiDAR was established. Also, a counter plan for the issues, which cannot be solved in the conventional methods for managing civil work projects, is applied through implementing bridge-based civil structure BIM by combining them with objective information.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.6
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• pp.541-547
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• 2017

Climate change has become the main cause of the exacerbation in natural disasters. Social Overhead Capital(SOC) structure needs to be checked for displacement and crack periodically to prevent damage and the collapse caused by natural disaster and ensure the safety. For efficient structure maintenance, the optical image technology is applied to the Structure Health Monitoring(SHM). However, optical image is sensitive to environmental factors. So it is necessary to verify its validity. In this paper, the accuracy of estimating the vertical displacement was verified with respect to environmental condition such as natural light, measurement distance, and the number of image sheets. The result of experiments showed that the effect of natural light on accuracy of estimating vertical displacement was the greatest of all. The measurement angle which was affected by the change in measurement distance was also important to check the vertical displacement. These findings will be taken into account by applying appropriate environmental condition to minimize errors when the bridge was measured by camera. It will also enable the application of optical images to the SHM.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.539-546
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• 2022

The current ｢Detailed guidelines for the safety and maintenance of facilities (performance Evaluation)｣ prescribes that the durability of surface concrete is evaluated by comparing the measuring the surface rebound value between sound parts and non-sound parts that have surface damage due to winter rain or leakage on concrete. However, this evaluation method was proposed by analyzing the correlation with an experimental DB obtained under freeze-thaw simulation promoting the environment without reviewing on-site applicability. Therefore, this study reviewed on-site application appropriateness of the concrete freeze-thaw damage evaluation method for the 21 concrete bridges in Korea. From the results, it was clearly confirmed that there was a difference in the surface rebound value between the sound part and the non-sound on the concrete surface; the current evaluation method is considered appropriate for application at the site. In addition, the necessity of adding a specific method and a measurement position of surface rebound value were also analyzed, and the effectiveness of the current evaluation method was also analyzed when targeting the entire concrete bridge, not the evaluation of some sections.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.6
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• pp.751-762
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• 2022

Welded head studs are mainly used as shear connectors to bond steel girders and concrete slabs in steel-concrete composite bridges. For welded shear connectors, environmental problems include noise and scattering dust which are generated during the removal of damaged or aged slabs. Therefore, it is necessary to develop demountable shear connectors that can easily replace aged concrete slabs for efficient maintenance and thus for better management of environmental problems and life cycle costs. The buried nut method is commonly studied in relation to bolted shear connectors, but this method is not used in civil structures such as bridges due to low rigidity, low shear resistance, and increased initial slip. In this study, in order to mitigate these problems, a demountable bolted shear connector is proposed in which the buried nut is integrated into the stud column and has a tapered shape at the bottom of an enlarged column shank. To verify the performance of the proposed demountable stud bolts in terms of static shear strength and slip displacement, a horizontal shear test was conducted, with the performance outcomes compared to those of conventional welded studs. It was confirmed that the proposed demountable bolted shear connector is capable of excellent shear performance and that it satisfies the slip displacement and ductility design criteria, meaning that it is feasible as a replacement for existing welding studs.

• Animal Bioscience
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• v.35 no.10
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• pp.1461-1478
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• 2022

The maintenance of poultry gut health is complex depending on the intricate balance among diet, the commensal microbiota, and the mucosa, including the gut epithelium and the superimposing mucus layer. Changes in microflora composition and abundance can confer beneficial or detrimental effects on fowl. Antibiotics have devastating impacts on altering the landscape of gut microbiota, which further leads to antibiotic resistance or spread the pathogenic populations. By eliciting the landscape of gut microbiota, strategies should be made to break down the regulatory signals of pathogenic bacteria. The optional strategy of conferring dietary fibers (DFs) can be used to counterbalance the gut microbiota. DFs are the non-starch carbohydrates indigestible by host endogenous enzymes but can be fermented by symbiotic microbiota to produce short-chain fatty acids (SCFAs). This is one of the primary modes through which the gut microbiota interacts and communicate with the host. The majority of SCFAs are produced in the large intestine (particularly in the caecum), where they are taken up by the enterocytes or transported through portal vein circulation into the bloodstream. Recent shreds of evidence have elucidated that SCFAs affect the gut and modulate the tissues and organs either by activating G-protein-coupled receptors or affecting epigenetic modifications in the genome through inducing histone acetylase activities and inhibiting histone deacetylases. Thus, in this way, SCFAs vastly influence poultry health by promoting energy regulation, mucosal integrity, immune homeostasis, and immune maturation. In this review article, we will focus on DFs, which directly interact with gut microbes and lead to the production of SCFAs. Further, we will discuss the current molecular mechanisms of how SCFAs are generated, transported, and modulated the pro-and anti-inflammatory immune responses against pathogens and host physiology and gut health.