• International Journal of Highway Engineering
• /
• v.17 no.4
• /
• pp.77-87
• /
• 2015

PURPOSES: It is theoretically well known all over the world, that porous hot mixed asphalt (HMA) with hydrated Lime improves moisture and rutting resistance, and reduces pothole occurrence frequency, as well as the life cycle cost (LCC). METHODS : Addictive in the two different formations of the liquid anti-stripping Agent and powder Hydrated-Lime was applied in this investigation in order to obtain relatively clear results according to their types and conditions. Firstly, the moisture conditions were set, and applied to the porous HMA mixtures with hydrated lime (anti-stripping agent). Next, it was followed by a non-destructive test with the application of three freeze-thaw cycles, which were individually carried out thrice to compare the results of the dynamic moduli. Lastly, the hydrated lime effect related to moisture sensibility to porous HMA has been verified through the analysis of the modulus results regarding the change rate of dynamic modulus per n-cycle. RESULTS: It is clear from this investigation, that the dynamic modulus is inversely proportional to the change in temperature, as the graph representing the rigidity of the thermorheologically simple (TRS) material showed gradual decline of the dynamic modulus with the increase in temperature. CONCLUSIONS: The porous HMA mixture with the anti-stripping agent (hydrated Lime) has been found to be more moisture resistant to freezing and thawing than the normal porous HMA mixture. It is clear that the hydrated lime helps the HMA mixture to improve its fatigue resistance.

• Journal of Computing Science and Engineering
• /
• v.7 no.4
• /
• pp.285-299
• /
• 2013

To enable hard real-time systems to take advantage of multicore processors, it is crucial to obtain the worst-case execution time (WCET) for programs running on multicore processors. However, this is challenging and complicated due to the inter-thread interferences from the shared resources in a multicore processor. Recent research used the combined cache conflict graph (CCCG) to model and compute the worst-case inter-thread interferences on a shared L2 cache in a multicore processor, which is called the CCCG-based approach in this paper. Although it can compute the WCET safely and accurately, its computational complexity is exponential and prohibitive for a large number of cores. In this paper, we propose three counter-based approaches to significantly reduce the complexity of the multicore WCET analysis, while achieving absolute safety with tightness close to the CCCG-based approach. The basic counter-based approach simply counts the worst-case number of cache line blocks mapped to a cache set of a shared L2 cache from all the concurrent threads, and compares it with the associativity of the cache set to compute the worst-case cache behavior. The enhanced counter-based approach uses techniques to enhance the accuracy of calculating the counters. The hybrid counter-based approach combines the enhanced counter-based approach and the CCCG-based approach to further improve the tightness of analysis without significantly increasing the complexity. Our experiments on a 4-core processor indicate that the enhanced counter-based approach overestimates the WCET by 14% on average compared to the CCCG-based approach, while its averaged running time is less than 1/380 that of the CCCG-based approach. The hybrid approach reduces the overestimation to only 2.65%, while its running time is less than 1/150 that of the CCCG-based approach on average.

• Steel and Composite Structures
• /
• v.23 no.3
• /
• pp.273-283
• /
• 2017

In this paper, it is aimed to present a detail investigation related to structural behavior of laterally unrestrained steel cantilever roof of tribune with slender cross section. The structure is located in Tutak town in $A{\breve{g}}r{{\i}}$ and collapsed on October 25, 2015 at eastern part of Turkey is considered as a case study. This mild sloped roof structure was built from a variable I beam, and supported on steel columns of 5.5 m height covering totally $240m^2$ closed area in plan. The roof of tribune collapsed completely without any indication during first snowfall after construction at midnight a winter day, fortunately before the opening hours. The meteorological records and observations of local persons are combined together to estimate the intensity of snow load in the region and it is compared with the code specified values. Also, the wide/thickness and height/thickness ratios for flange and web are evaluated according to the design codes. Three dimensional finite element model of the existing steel tribune roof is generated considering project drawings and site investigations using commercially available software ANSYS. The displacements, principal stresses and strains along to the cantilever length and column height are given as contour diagrams and graph format. In addition to site investigation, the numerical and analytical works conducted in this study indicate that the unequivocal reasons of the collapse are overloading action of snow load intensity, some mistakes made in the design of steel cantilever beams, insufficient strength and rigidity of the main structural elements, and construction workmanship errors.

• Journal of the Korean Vacuum Society
• /
• v.9 no.2
• /
• pp.110-115
• /
• 2000

Deposition conditions of diamond thin films were optimized using hot-filament chemical vapor deposition (HFCVD). Boron-doped diamond thin films with varying boron densities were then fabricated using B4C solid pellets. Current-voltage responses and field emission currents were measured to test the characteristics of field emission display (FED). With the increase of boron doping, the crystal size of diamond decreased slightly, but its quality was not changed significantly in case of small doping. The I-V characterization was performed for Al/diamond/p-Si, and the current of doped diamond film was increased $10^4\sim10^5$ times as compared with that of undoped film. In the field emission properties, the electrons were emitted with low electric field with the increase of doping, while the emission current increased. The onset-field of electron emission was 15.5 V/$\mu\textrm{m}$ for 2 pellets, 13.6 V/$\mu\textrm{m}$ for 3 pellets and 11.1 V/$\mu\textrm{m}$ for 4 pellets. With the incorporation of boron, the slope of Fowler-Nordheim graph was decreased, revealing that the electron emission behavior was improved with the decrease of the effective barrier energy.

• Korean Journal of Agricultural Science
• /
• v.46 no.4
• /
• pp.955-969
• /
• 2019

Analyzing on-line consumer responses is directly related to the management performance of food companies. Therefore, this study collected and analyzed data from an on-line portal site created by consumers about food companies with issues and examined the relationships between the data and the management performance. Through this process, we identified consumers' awareness of these companies obtained from big data analysis and analyzed the relationship between the results and the sales and stock prices of the companies through a time-series graph and correlation analysis. The results of this study were as follows. First, the result of the text mining analysis suggests that consumers respond more sensitively to negative issues than to positive issues. Second, the emotional analysis showed that companies' ethics issues (Enterprise 3 and 4) have a higher level of emotional continuity than that of food safety issues. It can be interpreted that the problem of ethical management has great influence on consumers' purchasing behavior. Finally, In the case of all negative food issues, the number of word frequency and emotional scores showed opposite trends. As a result of the correlation analysis, there was a correlation between word frequency and stock price in the case of all negative food issues and also between emotional scores and stock price. Recently, studies using big data analytics have been conducted in various fields. Therefore, based on this research, it is expected that studies using big data analytics will be done in the agricultural field.

• The Journal of Bigdata
• /
• v.4 no.2
• /
• pp.207-220
• /
• 2019

Recent developments in information and communication technology has enabled the deployment of sensor based data to provide real-time services. In Korea, The Korea Transportation Safety Authority is collecting driving information of all commercial vehicles through a fitted digital tachograph (DTG). This information gathered using DTG can be utilized in various ways in the field of transportation. Notably in autonomous driving, the real-time analysis of this information can be used to prevent or respond to dangerous driving behavior. However, there is a limit to processing a large amount of data at a level suitable for real-time services using a traditional database system. In particular, due to a such technical problem, the processing of large quantity of traffic big data for real-time commercial vehicle operation information analysis has never been attempted in Korea. In order to solve this problem, this study optimized the new database server system and confirmed that a real-time service is possible. It is expected that the constructed database system will be used to secure base data needed to establish digital twin and autonomous driving environments.

• The Transactions of the Korea Information Processing Society
• /
• v.5 no.6
• /
• pp.1522-1536
• /
• 1998

In this paper, we present a modeling method for the real-time systems. This method is based on the DARTS (Design Approach for Real-Time Systems) and widely extended to analysis phase. The DARTS method provides a good guideline for the real -time software design, but it uses structured analysis and does not provide a specification language. So. this paper provides extended DARTS modeling techniques to the analysis area based on the objects. Internal behavior of system showed by means of a NPN (Numerical Petri Net) for analysis, and the specification language is provided based on the temporal logic for transition synchronization sequence control. By the example, we identified the proposed method was applied well. And through the reachability graph, we verified whether the deadlocks may occur or not in the analysis phase before the design phase. Thus. it gives easy way to analysis, so that it will lead to the design phase naturally.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.27 no.2
• /
• pp.121-128
• /
• 2014

In this study, The purpose of this study is to experimentally investigate the shear behavior of reinforced flat plate embedded with GFRP(glass fiber reinforced polymer) plate with openings. The GFRP shear reinforcement is manufactured into a plate shape with several openings to ensure perfect integration with concrete. The test was performed on 7 specimens. the parameters include the type of reinforcement and amount of the shear reinforcement., From the test, we analysed the crack, failure mode, Strain, load-displacement graph. a calculation of the shear strength of reinforced flat plate with GFRP plate based on the ACI 318-11 was compared with the test results. The results of the experiment indicate that GFRP plate is successfully applied as a shear reinforcement in the flat plate under punching shear.

• Journal of Magnetics
• /
• v.21 no.2
• /
• pp.215-221
• /
• 2016

We conducted a phased electromagnetic forming process analysis (EFPA) over time through a coupling of electromagnetic analysis and structural analysis. The analysis is conducted through a direct linkage between electromagnetic analysis and structural analysis. The analysis process is repeated until the electric current is completely discharged by a formed coil. We calculate the forming force that affects the workpiece using MAXWELL, a commercial electromagnetic finite element analysis program. Then, we simulate plastic behavior by using the calculated forming force data as the forming force input to ANSYS, a commercial structure finite element analysis program. We calculate the forming force data by using the model shape in MAXWELL, a commercial electromagnetic finite element analysis program. We repeat the process until the current is fully discharged by the formed coil. Our results can be used to reduce the error in data transformation with a reduced number of data transformations, because the proposed approach directly links the electromagnetic analysis and the structural analysis after removing the step of the numerical analysis of a graph describing the forming force, unlike the existing electromagnetic forming process. Second, it is possible to simulate a more realistic forming force by keeping a certain distance between nodes using the re-mesh function during the repeated analysis until the current is completely discharged by the formed coil, based on the MAXWELL results. We compare and review the results of the EFPA using the peak value of the forming force that acts on the workpiece (which is the existing analysis method), and the proposed phased EFPA over time approach.

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.9
• /
• pp.2384-2392
• /
• 1999

Software engineers are used to analyse the error behavior of computer programs using test cases which are collected for the testing phase when software errors are detected. In actual software testing and debugging, it is important to adopt dynamic slicing technique which is concerned on all the statements to be affected by the variables of current inputs and to use technique of its implementations. The traditional dynamic slicing has focused on the single slicing criterion algorithm. It has been thought that it is needed to develope and implement algorithm for used multiple criteria variables program slicing, which finds every slicing criterion variable where it is used multiple criteria variables. In this paper, we propose an efficient algorithm to make dynamic program slices when it has used multiple criteria variables. The results of the implementation are presented by the making table on execution history and the dynamic dependence graph. Also we can find that the proposed dynamic program slicing approach using multiple criteria variables is more efficient than the traditional single case algorithm on the practical testing environment.