• Steel and Composite Structures
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• v.43 no.4
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• pp.447-456
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• 2022

Recent experimental studies showed that deep steel I-shaped profiles classified as high ductility class sections in seismic design international codes exhibit low deformation capacity when subjected to cyclic loading. This paper presents an innovative retrofit solution to increase the rotation capacity of beams using bonded carbon fiber reinforced polymers (CFRP) patches validated with advanced finite element analysis. This investigation focuses on the flexural cyclic behaviour of I-shaped hot rolled steel deep section used as beams in moment-resisting frames (MRF) retrofitted with CFRP patches on the web. The main goal of this CFRP reinforcement is to increase the rotation capacity of the member without increasing the overstrength in order to avoid compromising the strong column-weak beam condition in MRF. A finite element model that simulates the cyclic plasticity behavior of the steel and the damage in the adhesive layer is developed. The damage is modelled using the cohesive zone modelling (CZM) technique that is able to capture the crack initiation and propagation. Details on the modelling techniques including the mesh sensitivity near the fracture zone are presented. The effectiveness of the retrofit solution depends strongly on the selection of the appropriate adhesive. Different adhesive types are investigated where the CZM parameters are calibrated from high fidelity fracture mechanics tests that are thoroughly validated in the literature. This includes a rigid adhesive commonly found in the construction industry and two tough adhesives used in the automotive industry. The results revealed that the CFRP patch can increase the rotation capacity of a steel member considerably when using tough adhesives.

• Journal of Software Assessment and Valuation
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• v.16 no.2
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• pp.1-8
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• 2020

The similarity detection to plagiarism or duplication of computer programs requires a different type of analysis methods and tools according to the programming language used in the implementation and the sort of code to be analyzed. In recent years, the similarity appraisal for the object code in the embedded system, which requires a considerable resource along with a more complicated procedure and advanced skill compared to the source code, is increasing. In this study, we described a method for analyzing the similarity of functional units in the assembly language through the conversion of object code using the reverse engineering approach, such as the reverse assembly technique to the object code. The instruction and operand table for comparing the similarity is generated by using the syntax analysis of the code in assembly language, and a tool for detecting the similarity is designed.

• Advances in concrete construction
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• v.14 no.1
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• pp.45-55
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• 2022

In this article, the flexural and shear capacity of ultra-high-performance fiber-reinforced concrete beams (UHPFRC) using two kinds of rebars, including GFRP and steel rebars, are experimentally investigated. For this purpose, six UHPFRC beams (250 × 300 × 1650 mm) with three reinforcement ratios (ρ) of 0.64, 1.05, and 1.45 were constructed using 2% steel fibers by volume. Half of the specimens were made of UHPFRC reinforced with GFRP rebars, while the other half were reinforced with conventional steel rebars. All specimens were tested to failure in four-point bending. Both the load-deformation at mid-span and the failure pattern were studied. The results showed that utilizing GFRP bars increases the flexural strength of UHPFRC beams in comparison to those made of steel bars, but at the same time, it reduces the post-cracking strain hardening. Furthermore, by increasing the percentage of longitudinal bars, both the post-cracking strain hardening and load-bearing capacity increase. Comparing the experiment results with some of the available equations and provisions cited in the valid design codes reveals that some of the equations to predict the flexural strength of UHPFRC beams reinforced with conventional steel and GFRP bars are reasonably conservative, while Khalil and Tayfur model is un-conservative. This issue makes it essential to modify the presented equations in this research for predicting the flexural strength of UHPFRC beams using GFRP bars.

• Journal of Korean Dental Hygiene Science
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• v.5 no.2
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• pp.113-121
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• 2022

Background: This study aimed to create and present content that can be used in the dental hygiene ethics process to help dental hygiene students develop desirable work ethics and ethical values. Methods: In order to operate the dental hygiene ethics course in all academic systems, one three-year dental hygiene professor and one four-year dental hygiene professor participated in setting core competencies and learning goals for the dental hygiene ethics course. The class consisted of two credits, two hours of theoretical classes, and class activity sheets developed according to the learning contents and learning topics for each week that can be operated for 15 weeks. Results: The contents of the dental hygiene ethics subject were developed to be conducted as theoretical education and case-oriented discussion classes. The 15-week class consisted of a theory lecture on dental hygiene work ethics (eight weeks), discussions and presentations for ethical decisions based on actual cases related to dental hygiene ethics (four weeks), and the design and presentation of individual professional mission statements and codes of conduct (three weeks). The class data for each week consisted of four stages: "Learning goal-thinking," "open-thinking," "learning content-thinking," and "according to learning goal." Conclusions: In order to establish desirable workplace ethics and ethical values for dental hygiene students, it is necessary to approach education in a way that values understanding and application of dental hygiene practices, legal and ethical standards, ethical decision-making models, and ethical principles.

• Journal of the Korea Society of Computer and Information
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• v.28 no.9
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• pp.167-176
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• 2023

In this paper, we designed and implemented a graph assessment module that can evaluate graphs in an programming assessment system based on text and numbers. The assessment method of the graph assessment module is self-evaluation that outputs two graphs generated by codes submitted by learners and by answers, automatic-evaluation that converts each graph image into an array, and gives feedback if it is wrong. The data used to generate the graph can be inputted directly or used from external data, and the method of generatng graph that can be evaluated is MATLAB style in matplotlib, and the graph shape that can be evaluated is presented in mathematics and curriculum. Through expert review, it was confirmed that the content elements of the assessment module, the possibility of learning, and the validity of the learner's needs were met. The graph assessment module developed in this study has expanded the evaluation area of the programming automatic asssessment system and is expected to help students learn data visualization.

• Earthquakes and Structures
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• v.22 no.5
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• pp.503-515
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• 2022

This paper presents the development of seismic fragility curves for a precast reinforced concrete bridge instrumented with a structural health monitoring (SHM) system. The bridge is located near an active seismic fault in the Dominican Republic (DR) and provides the only access to several local communities in the aftermath of a potential damaging earthquake; moreover, the sample bridge was designed with outdated building codes and uses structural detailing not adequate for structures in seismic regions. The bridge was instrumented with an SHM system to extract information about its state of structural integrity and estimate its seismic performance. The data obtained from the SHM system is integrated with structural models to develop a set of fragility curves to be used as a quantitative measure of the expected damage; the fragility curves provide an estimate of the probability that the structure will exceed different damage limit states as a function of an earthquake intensity measure. To obtain the fragility curves a digital twin of the bridge is developed combining a computational finite element model and the information extracted from the SHM system. The digital twin is used as a response prediction tool that minimizes modeling uncertainty, significantly improving the predicting capability of the model and the accuracy of the fragility curves. The digital twin was used to perform a nonlinear incremental dynamic analysis (IDA) with selected ground motions that are consistent with the seismic fault and site characteristics. The fragility curves show that for the maximum expected acceleration (with a 2% probability of exceedance in 50 years) the structure has a 62% probability of undergoing extensive damage. This is the first study presenting fragility curves for civil infrastructure in the DR and the proposed methodology can be extended to other structures to support disaster mitigation and post-disaster decision-making strategies.

• Journal of Distribution Science
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• v.20 no.1
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• pp.1-11
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• 2022

Purpose: Increasing advancements in the technology industry are forcing people to become more accustomed to digital financial transaction activities. The need for fast and secure payment mechanisms has birthing new idea to digital financial transaction services. Along with increasing access to technology in digital payments, new service is developed in the form of digital wallets as the successor for electronic money. Research design, data and methodology: This research aims to find out whether using QR code as digital payment tool can build customer loyalty in consumers, especially to measure the factors of satisfaction, trust and commitment of customers to do payments with QR Codes. The QR code in this study is refer to the Quick Response Code Indonesian Standard (QRIS) which was officially implemented by Bank Indonesia starting on January 1, 2020 as a means of payment for digital transactions nationally. The research method uses a quantitative approach by way of surveying questionnaires using Likert scale of 100 samples. Results: The hypothesis analysis proved that the variables of satisfaction, trust and commitment together have positive and significant influences on customer loyalty. Conclusion: This research found that there are high interest in Millennials to do transaction using QRIS because it is deemed to be more easy, quick and safe. If a customer achieves a level of loyalty in the usage of digital transaction using QRIS then cashless society lifestyle can be considered successful and can be used in the future.

• Journal of the Korea Institute of Building Construction
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• v.23 no.4
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• pp.405-416
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• 2023

Recent seismic activities in countries like China and Turkey have underscored the widespread and severe damages that earthquakes can inflict globally. Being situated in a seismically active zone, South Korea can no longer regard itself as immune to earthquake hazards, necessitating the urgent adoption of proactive measures against such threats. The government has been proactive in evaluating, formulating processes, and methods for the seismic retrofitting of public buildings lacking in earthquake resistance. However, enforcement mechanisms for privately-owned apartment complexes are absent, and in the face of insufficient previous research and guidelines, preemptive measures for public safety remain alarmingly inadequate. With over 48% of residential structures in Korea aged over 30 years, and apartment complexes constituting more than 80% of these, the gravity of the situation is undeniable. This study deduces key factors for seismic retrofitting of apartment buildings like earthquake zones, soil type, building significance, aging degree, vulnerability, etc., based on building seismic design codes. It further proposes an algorithm for a more succinct and efficient determination of the priority of seismic reinforcements for apartment buildings.

• Journal of the Korea Society of Computer and Information
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• v.28 no.7
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• pp.85-93
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• 2023

Software birthmark refers to a unique feature inherent in software that can be extracted from program binaries even in the absence of the original source code of the program. Like human genetic information, the similarity between programs can be calculated numerically, so it can be used to determine whether software is stolen or copied. In this paper, we propose a new birthmark technique for Android applications developed using Unity. The source codes of Unity-based Android applications use C# language, and since the core logic of the program is included in the DLL module, it must be approached in a different way from normal Android applications. In this paper, a Unity birthmark extraction and comparison system was implemented, and reliability and resilience were evaluated. The use of the Unity birthmark technique proposed in this paper is expected to be effective in preventing illegal copy or code theft of the Unity-based Android applications.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5A
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• pp.823-832
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• 2006

To ensure the serviceability requirements of PSC composite girder bridges, it is essential to predict the stresses and deformations of the structure under service load conditions. Stresses and deformations vary continuously with time due to the effects of creep and shrinkage of concrete and relaxation of prestressing steel. The importance of these time-dependent effects is much more pronounced in precast prestressed concrete structures built in stages than in those constructed in one operation. In this paper, time-dependent analyses for PSC composite bridges using 30m standard girders have been conducted considering with the variation of the times of introducing initial prestressing forces and casting concrete. A computer program has been developed for the time-dependent analysis of simple or continuous PSC composite girders and parametric studies are conducted. Based on the numerical results, it is investigated the long-term behaviors of PSC composite girder bridges and discussed the limitations of the current codes for the prestress loss.