• Journal of the Korea Society of Computer and Information
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• v.26 no.1
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• pp.11-17
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• 2021

In this paper, we demonstrate a performance boost by parallelizing a purely functional bisimulation algorithm on a multicore processor machine. The key idea of this parallelization is exploiting the referential transparency of purely functional programs to minimize refactoring of the original implementation without any parallel constructs. Both original and parallel implementations are written in Haskell, a purely functional programming language. The change from the original program to the parallel program is minuscule, maintaining almost original structure of the program. Through benchmark, we show that the proposed parallelization doubles the performance of the bisimulation test compared to the original non-parallel implementation. We also shaw that similar performance boost is also possible for a memoized version of the bisimulation implementation.

• Journal of the Korea Society of Computer and Information
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• v.27 no.4
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• pp.1-8
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• 2022

In this paper, we propose a more effective unique identifier allocation method for macro expansion in a single-process multicore parallel computing environment that does not require locks. Our key idea for such an allocation method is to remove sequential dependencies using the remainder operation. We confirmed that our lock-free method is suitable for improving the performance of parallel macro expansion through the following benchmark: we patched an existing library, which is based on a sequential unique identifier allocation, with our proposed method, and compared the performances of the same program but using two different versions of the library, before and after the patch.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1209-1216
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• 2022

The majority of construction site incidents occur due to a lack of hazard awareness among workers on job sites. This lack of awareness is despite mandatory construction safety training, typically in the form of written content (safety manuals) or of images depicting hazards. To reduce job-site injuries and fatalities, general contractors have started adopting Virtual Reality (VR) to impart safety training to job site personnel. VR safety training can take the form of an immersive simulation comprising potential safety hazards intentionally embedded into a virtual job site; users are required to identify these hazards within a specified time frame with the expectation that they will be more adept at recognizing hazards on an actual job-site, resulting in fewer accidents. This research study seeks to identify the actual impacts of VR on construction safety awareness among participants. The research addresses the following question: Does VR improve hazard recognition awareness? The primary objective is to evaluate participants' performance of past construction safety awareness against present construction safety awareness after receiving VR training. Participants were asked to complete a multiple-choice Qualtrics™ questionnaire. The results of the study showed a statistically significant knowledge gain advantage with respect to hazard recognition and construction safety awareness with the use of interactive, immersive VR over a more conventional and passive safety training method.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.1 s.47
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• pp.17-23
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• 2006

The research on strong ground motions became important recently due to more severe requirement of seismic design for the domestic buildings and structures. The empirical Green's function method, which uses similarities between small and large earthquakes, was applied to make synthetic ground motions. That method was applied to the 2 earthquakes which occurred sequently in time within narrow area in Japan. The strong ground motions for the virtual earthquake (magnitude 6.5) were synthesized using those observed from the magnitude 4.7 earthquake. Then, the synthesized ground motions (acceleration, velocity, and displacement) were compared to those observed from real earthquake (magnitude 6.5). The results showed that the general shapes of waveforms in time domain and the Fourier spectrum In frequency domain from synthesized ground motions (acceleration, velocity, and displacement) are similar to the observed strong ground motions within acceptable degree. The peak values of 3 kinds of synthesized strong ground motions in time domain are comparable between the synthesized and the real strong ground motions, especially only about 9% difference in acceleration peak value.