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Several bridges in Indonesia are designed using elastomeric bearing (ERB) with a low capability of reducing seismic responses. This results in a significant demand for larger pier cross-sectional dimensions and a greater number of reinforcements, necessitating the consideration of seismic isolation devices to optimize the pier configuration. Lead rubber bearing (LRB) has been widely used as a seismic isolation device due to the natural period shifting and sufficient energy dissipation, but it costs a lot. A shear panel damper equipped with a gap (SPDG) was proposed regarding its capability to provide high damping at low cost as an alternative device to LRB. This study compared the seismic performance of three structural systems of simply supported prestressed concrete (PSC) box girder bridges. Those were analyzed using Nonlinear Time History Analysis (NLTHA) with the OpenSees software. As a result, both SPDG and LRB increased the structural flexibility and generated similar relative pier responses to the conventional bridge with ERB. For example, SPDG generated the relative responses of the top pier displacement, base shear, and bending moment up to 64.76%, 83.55%, and 65.66%, while LRB was 64.92%, 83.39%, and 66.89%, respectively. Meanwhile, the bridge’s structural performance equipped with LRB and SPDG showed a fully operational and operational limit, while the one with ERB reached the life safety limit due to the longitudinal earthquake. The life safety limit due to the transverse earthquake was also observed in the three bridge models. In conclusion, SPDG is applicable in the seismic isolation system as it has a similar performance to the LRB.

Experimental study was carried out on three low confinement spun piles to pile cap connections. The detail followed the typically fixed connection in Indonesia. Reinforced concrete was filled to the spun pile to strengthen the connection region, except SPPC01. Different concrete types were used, shrinkage and non-shrinkage for SPPC02 and SPPC03, respectively. SPPC02 and SPPC03 could reach the targeted drift of 3.5% whereas SPPC01 was stopped at a drift of 2.75%. There was no shear failure detected during the test. The connection behaved as a fixed connection indicated by the fracture failure of the prestressed bars near the connection region. Analysis of the test results focused on displacement ductility. Two definitions of yield and ultimate displacement were employed to seek the possible ductility values. It varied from 3.05 to 6.04 for SPPC01 and from 3.01 to 4.95 for SPPC02 and SPPC03. The non-shrinkage concrete did not affect the strength of the connection but slightly improved the post-peak behavior. The ductility is 6–12% higher than spun piles with ordinary concrete. According to the limited ductility referring to ATC 96, JRA 2002, and AASHTO 2011, all specimens could achieve target ductility 3. Hence, it can be concluded that the low confinement spun pile connections performed well in displacement ductility.

Information and communication technology continues to develop and progress which demonstrated by the presence of gadget technology. Gadgets are smart electronic devices that assist in making it simple for users to accomplish various task. The use of gadget technology in children are unable to be separated. According to the 2020 KPAI survey, approximately 71,3% of school-age children own and have played with gadgets for a longer time. As a result, it is expected that early detection of gadget addiction can be carried out to ensure that mental and emotional disorders in children who use gadgets can be properly addressed. The aim of this research is to create a prototype expert system for early detection of gadget addiction levels in children using the fuzzy tsukamoto. The fuzzy tsukamoto method was used in this study. This study included 74 respondents aged 9 to 12 years old. The DAS (Digital Addiction Scale : For Children) was used as the data collection method in this study. The system’s as performance will be evaluated using 74 respondents data by comparing the result of expert calculations and fuzzy tsukamoto method calculations. Fuzzy Tsukamoto reasoning with 64 rule bases in used to build this expert system. According to evaluation with 74 respondent data, this expert system has a system acurracy rate of 87,83%, which indicates that it proceeds succesfully.