• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.1
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• pp.46-53
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• 2023

In this paper, we evaluated the flexural performance of three types of reinforced concrete beams (SHCC-RB, SHCC-SB, SHCC-FRP) strengthened with ordinary steel rebar, very high strength (super strength) rebar, and FRP bars together with strain-hardening cement composite (SHCC). For this purpose, a series of beam specimens were manufactured and four-point load bending experiments were performed. As a result of the experiment, all specimens strengthened with SHCC exhibited tightly controlled flexural microcrakcs with the crack width of less than 100 ㎛. This is mostly due to the material properties of SHCC showing tensile strain hardening properties with multiple microcracks under uniaxial tension. The specimen SHCC-FRP showed lower initial cracking moment and yield flexural strength than SHCC-RB, whereas the maximum flexural strength of SHCC-FRP was superior to that of SHCC-RC. This is because the tensile strength of FRP bars is higher than that of ordinary steel reabr. The initial cracking moment of the beam specimen SHCC-SB was similar to that of SHCC-RB, but the yield flexural strength and maximum flexural strength of SHCC-SB were evaluated to be the highest.

• Journal of Intelligence and Information Systems
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• v.25 no.4
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• pp.35-52
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• 2019

As public services are provided in various forms, including e-government, the level of public demand for public service quality is increasing. Although continuous measurement and improvement of the quality of public services is needed to improve the quality of public services, traditional surveys are costly and time-consuming and have limitations. Therefore, there is a need for an analytical technique that can measure the quality of public services quickly and accurately at any time based on the data generated from public services. In this study, we analyzed the quality of public services based on data using process mining techniques for civil licensing services in N city. It is because the N city's building license complaint service can secure data necessary for analysis and can be spread to other institutions through public service quality management. This study conducted process mining on a total of 3678 building license complaint services in N city for two years from January 2014, and identified process maps and departments with high frequency and long processing time. According to the analysis results, there was a case where a department was crowded or relatively few at a certain point in time. In addition, there was a reasonable doubt that the increase in the number of complaints would increase the time required to complete the complaints. According to the analysis results, the time required to complete the complaint was varied from the same day to a year and 146 days. The cumulative frequency of the top four departments of the Sewage Treatment Division, the Waterworks Division, the Urban Design Division, and the Green Growth Division exceeded 50% and the cumulative frequency of the top nine departments exceeded 70%. Higher departments were limited and there was a great deal of unbalanced load among departments. Most complaint services have a variety of different patterns of processes. Research shows that the number of 'complementary' decisions has the greatest impact on the length of a complaint. This is interpreted as a lengthy period until the completion of the entire complaint is required because the 'complement' decision requires a physical period in which the complainant supplements and submits the documents again. In order to solve these problems, it is possible to drastically reduce the overall processing time of the complaints by preparing thoroughly before the filing of the complaints or in the preparation of the complaints, or the 'complementary' decision of other complaints. By clarifying and disclosing the cause and solution of one of the important data in the system, it helps the complainant to prepare in advance and convinces that the documents prepared by the public information will be passed. The transparency of complaints can be sufficiently predictable. Documents prepared by pre-disclosed information are likely to be processed without problems, which not only shortens the processing period but also improves work efficiency by eliminating the need for renegotiation or multiple tasks from the point of view of the processor. The results of this study can be used to find departments with high burdens of civil complaints at certain points of time and to flexibly manage the workforce allocation between departments. In addition, as a result of analyzing the pattern of the departments participating in the consultation by the characteristics of the complaints, it is possible to use it for automation or recommendation when requesting the consultation department. In addition, by using various data generated during the complaint process and using machine learning techniques, the pattern of the complaint process can be found. It can be used for automation / intelligence of civil complaint processing by making this algorithm and applying it to the system. This study is expected to be used to suggest future public service quality improvement through process mining analysis on civil service.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.4
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• pp.312-316
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• 2014

Purpose: The aim of this study was to compare the fracture toughness of currently available resin cements for zirconia restorations and evaluate the effect of water storage on fracture toughness of those resin cements. Materials and methods: Single-edge notched specimens ($3mm{\times}6mm{\times}25mm$) were prepared from three currently available dual cure resin cements for zirconia restorations (Panavia F 2.0, Clearfil SA luting and Zirconite). Each resin cement was divided into four groups: immersed in distilled water at $37^{\circ}C$ for 1 (Control group), 30, 90, or 180 days (n=5). Specimens were loaded in three point bending at a cross-head speed of 0.1 mm/s. The maximum load at specimen failure was recorded and the fracture toughness ($K_{IC}$) was calculated. Data were analyzed using one-way ANOVA and multiple comparison $Scheff{\acute{e}}$ test (${\alpha}$=.05). Results: In control group, the mean $K_{IC}$ was $3.41{\pm}0.64MN{\cdot}m^{-1.5}$ for Panavia F, 2.0, $3.07{\pm}0.41MN{\cdot}m^{-1.5}$ for Zirconite, $2.58{\pm}0.30MN{\cdot}m^{-1.5}$ for Clearfil SA luting respectively, but statistical analysis revealed no significant difference between them. Although a gradual decrease of $K_{IC}$ in Panavia F 2.0 and gradual increases of KIC in Clearfil SA luting and Zirconite were observed with storage time, there were no significant differences between immersion time for each cement. Conclusion: The resin cements for zirconia restorations exhibit much higher $K_{IC}$ values than conventional resin cements. The fracture toughness of resin cement for zirconia restoration would not be affected by water storage.