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This study discusses the design and simulation of an automatic lighting system based on a photodiode sensor using an Arduino Uno microcontroller as the main controller. The system is designed to detect changes in ambient light intensity and automatically control the lamp without human intervention. The photodiode sensor is used as a light detector that converts light energy into an analog electrical signal, which is then processed by the Arduino to determine bright or dark conditions. The output from the Arduino subsequently controls a relay module that functions as an electronic switch to connect or disconnect the current to the light bulb. The research method employed is an experimental approach, which includes system planning, hardware design, software programming, simulation using Proteus, and system performance testing. The simulation results indicate that the system operates as expected, where the lamp automatically turns on when the light intensity decreases and turns off when the ambient brightness increases. This system is expected to improve electrical energy efficiency and provide ease of operation for lighting control, particularly in public facilitiesand workplace environments.

This study was conducted at PT. Asmin Bara Bronang, Sepan Uring Village, Kapuas Tengah District, Kapuas Regency, Central Kalimantan Province, with the aim of analyzing the productivity and influencing factors of the PC 300 excavator in coal getting activities to support the achievement of production targets. The objective of this research is to analyze the actual productivity and the factors affecting it in Sector 7 coal getting operations. The research method used field observation with a quantitative descriptive analysis approach. The results show that the productivity of the PC 300 excavator ranges from 127.12 to 224.29 tons/hour, with an average of 173.98 tons/hour. In several conditions, the productivity is still below the company’s target of 180 tons/hour. The analysis indicates that productivity is influenced by material conditions, particularly the Hardgrove Grindability Index (HGI) value of 47, which reflects relatively harder material with coarser particle size, and a moisture content of 22.71%, causing the material to be sticky and cohesive, thereby affecting the bucket filling process. In addition, operational factors such as bottom loading patterns, limited number of tailgate dump trucks, and suboptimal selection of dump truck types also contribute to productivity performance.  Based on the findings, it can be concluded that the productivity of the PC 300 excavator has not consistently met the company’s target. Therefore, improvement efforts are required, including the implementation of top loading methods, increasing the number of tailgate dump trucks, optimizing the selection of hauling equipment, and controlling material conditions that affect the digging process.    

Time delays and cost overruns remain major problems in building construction projects, particularly in concrete structural works that dominate project duration and cost. This study aims to evaluate the application of re-engineering in concrete structural work methods on the time and cost performance of multi-storey building projects. A quantitative approach using a case study method was employed through comparative analysis between the existing method and alternative methods. The analyzed alternatives include ready-mix concrete with Sika Viscocrete 8007 admixture and semi-system formwork as Alternative I, ready-mix concrete with system formwork as Alternative II, and ready-mix concrete with Sika Viscocrete 8007 admixture combined with system formwork as Alternative III. The results show that all alternatives perform better than the existing method with a duration of 243 days. Alternative I reduced the duration to 208 days with cost efficiency of IDR 55,781,730 or 0.214 percent. Alternative II reduced the duration to 203 days with cost efficiency of IDR 187,553,261 or 0.724 percent. Alternative III achieved the best performance with a duration of 168 days, accelerating 75 days and providing the highest cost efficiency of IDR 243,334,991 or 0.941 percent. The study concludes that re-engineering effectively improves project time and cost performance, with Alternative III as the optimal method.

Indonesia is in an earthquake-prone region, therefore, designing building constructions that can withstand seismic loads is crucial in civil engineering. Reinforced concrete shear walls are one of the vertical structural fundamentals that are effectively used in multi-story buildings to withstand lateral forces due to earthquake and wind loads. Structures that use shear walls can increase stiffness and reduce horizontal deviations (deflections) of buildings, which contribute to the stability and safety of structures based on the SNI 1726:2019 standard. This study aims to analyze the effect of shear wall configurations on deviation and torsion requirements in multi-story building planning. The study object is a 6-story reinforced concrete building model in a specific earthquake zone. The design and modeling were performed using structural analysis software, taking into account columns, beams, slabs, and shear walls. The analysis results show that optimal placement of shear walls at the building edges significantly reduces horizontal drift, torsion, and shear forces, and improves the structural performance level compared to structures without shear walls or those with less effective placement. Structures with shear walls have optimal stiffness in absorbing lateral forces, making them more resistant to damage from the planned earthquake.

Population growth and socio-economic activities increase traffic volume, affecting the performance of the Raden Kusno – A. Djaelani – Sujarwo signalized intersection. This study aims to analyze the intersection’s current performance, estimate its condition over the next five years, and formulate alternative treatment strategies. The research data include geometric characteristics, signal timing, vehicle speed, and traffic volume obtained from CCTV recording over a three-day observation period from moning to evening, as well as population and vehicle data for projection. The intersection performance was analyzed using the PKJI 2023 approach and VISSIM simulation. Under current conditions, the intersection operates at LOS E with delays of 45,12 seconds (PKJI 2023) dan 60,56 seconds (VISSIM). In the five-year projection, delays increase to 48,97 seconds with LOS E (PKJI 2023) and 131,29 seconds with LOS F (VISSIM). Modifying the signal from four to three phases with a 70-second cycle improves the current condition to LOS C, with delays of 24,50 seconds (PKJI 2023) and 29,43 seconds (VISSIM). For the five-year projection, adding a continuous left-turn lane results in LOS D with 27,04 seconds (PKJI 2023) and LOS C with 32,01 seconds (VISSIM).

Healthcare is an integral part of health development in Indonesia, which aims to optimally improve public health. Hospitals, as healthcare facilities, are required to provide quality, safe, and patient-centered services. Service quality is a key indicator of service success, as good service impacts patient satisfaction. One of the most important services in hospitals is obstetrics, which directly relates to maternal and infant health, making patient satisfaction a crucial aspect. Midwives, as professional healthcare workers, play a strategic role in providing comprehensive, sustainable, and patient-centered midwifery care. This study aims to analyze the influence of healthcare facilities and midwife performance on patient satisfaction through service quality. The method used is a quantitative study with an analytical approach and a cross-sectional design. The results of the multiple linear regression test indicate that midwife performance has a more dominant influence on service quality than healthcare facilities. Meanwhile, regarding patient satisfaction, service quality is the most dominant factor, followed by midwife performance and healthcare facilities. The conclusion of this study is that service quality reflects the overall patient experience and is a key factor in improving patient satisfaction.

This study aims to analyze the technical and economic impact of power evacuation work on the 20 kV distribution system at PT PLN (Persero) UP3 East Bali. The main problem studied is the high losses and poor voltage profile on the downstream side of the Kintamani feeder. The method used is load flow simulation using ETAP software with a comparative approach to conditions before and after power evacuation. The results showed that the active losses decreased from 1.017 MW to 0.626 MW (efficiency 38.45%), accompanied by an increase in the end voltage from 16.32 kV to 18.72 kV and 19.38 kV, thus meeting the SPLN 1:1995 standard. The reduction in losses resulted in energy savings of 3,425,160 kWh/year. From the economic side, a payback period (PBP) of 1.40 years was obtained, which shows that the project is financially feasible. In addition, the improvement of network performance also contributes to the reliability of the distribution system and the continuity of the distribution of electrical energy to customers. Thus, power evacuation work has been proven to be effective in improving power distribution efficiency, improving voltage quality, and providing significant economic benefits.

The increasing demand for electrical energy and the limited availability of fossil fuels have driven the development of renewable energy sources, including marine current energy, which remains underutilized in coastal and remote maritime regions. This study presents the design and realization of a small-scale marine current power generation prototype using a horizontal axis propeller turbine with a NACA S814 blade profile and analyzes the effect of turbine rotational speed on electrical power output. The system converts marine current kinetic energy into mechanical energy through turbine rotation and subsequently into DC electrical energy using a generator, which is stabilized by a Buck–Boost Converter and Maximum Power Point Tracking (MPPT) for charging a 12 VDC battery. Real-time monitoring of electrical and mechanical parameters is implemented using an Internet of Things (IoT)–based system comprising an ESP32 microcontroller, a PZEM-017 sensor, and an RPM sensor. Experimental results demonstrate a positive correlation between water flow rate, turbine rotational speed, and generator output voltage. The system begins operating at a minimum flow rate of 35.2 L/s at 56 RPM, producing 0.2 V, while optimal performance is achieved at 45.3 L/s and 516 RPM, generating up to 13.3 V. These results indicate that the proposed prototype is a viable alternative renewable energy source for marine applications.

This research aims to design and develop a prototype wave power plant that utilizes the vertical motion of a buoy as a source of mechanical energy, which is then converted into electrical energy using a recoil starter mechanism. The system is designed to be installed at the stern of a prototype ship. The vertical movement of the buoy caused by ocean waves is transmitted to the recoil starter through a drive rope, producing a stable one-way rotational motion. This rotation is further transmitted to a gearbox to increase rotational speed before driving a DC generator. The electrical energy generated is stored in a 12 VDC battery, supported by a buck–booster converter to stabilize the output voltage. This study employs an experimental engineering approach to evaluate system performance based on empirical test data. The main components of the system include a buoy as a wave energy collector, a recoil starter as the initial rotating mechanism, a DC generator as the electrical energy producer, a buck–booster converter as a voltage regulator, a 12 VDC battery as an energy storage unit, and a monitoring system based on an ESP32 microcontroller integrated with a PZEM-017 sensor. Experimental results show that the recoil starter operates effectively in driving the generator under both no- load and buoy-loaded conditions. Increases in generator rotational speed are directly proportional to increases in output voltage and current. The PZEM-017 sensor demonstrates a high level of measurement accuracy, approaching 100% when compared with a multimeter. Overall, the proposed wave power generation system functions reliably and shows potential for further development as a small-scale alternative renewable energy source.

Sea Surface Temperature (SST) is an important parameter in oceanographic studies because it influences climate dynamics, ocean circulation, and marine ecosystems. Continuous monitoring of SST in open sea areas requires a reliable system capable of operating autonomously. This study develops a solar-powered ocean buoy designed to measure sea surface temperature while simultaneously evaluating the performance of a solar panel as the main energy source. The system uses a DS18B20 sensor to measure SST and an INA219 sensor to monitor the voltage, current, and power of the solar panel, while an ESP32 microcontroller functions as the central data processing unit. The results show that sea surface temperature tends to remain relatively stable with small daily variations, whereas the temperature and performance of the solar panel exhibit larger fluctuations due to direct exposure to solar radiation and changing weather conditions. Solar panel performance also shows significant variations in current and power depending on the intensity of sunlight. To analyze the influence of SST variations on solar panel performance, a statistical analysis using Analysis of Variance (ANOVA) was conducted. The ANOVA results, based on the calculated F-value and the significance value (p-value) at a confidence level of α = 0.05, indicate that SST variations have a significant effect on solar panel performance, demonstrating that the proposed solar-powered buoy system can operate autonomously and has potential for long-term SST monitoring in offshore areas.

Urban waste management has become a complex challenge due to population growth, urbanization, and economic activities contributing to higher waste generation. Effective waste management systems are required to reduce waste disposed at final disposal sites. This study aims to evaluate the effectiveness of waste management at the TPS 3R Pedalangan Bersinar facility in Semarang City by examining waste separation from the source. The research applied a quantitative approach using mass balance analysis to assess the balance between incoming waste, processed waste, and residual waste in the system. Primary data were collected through field observations, interviews, and operational monitoring for six consecutive days, while secondary data were obtained from the Semarang Environmental Agency. Results show community-based waste banks in Pedalangan demonstrate a high level of effectiveness with a recovery factor reaching 100%, indicating optimal recycling performance and strong community participation. Meanwhile, the TPS 3R facility processes an average waste volume of 16.61 m³/day with reduction of 10.32 m³/day and residual waste of 6.29 m³/day, resulting in a recovery factor of approximately 0.62 categorized as moderate effectiveness. Therefore, strengthening household waste separation, improving operational management, and increasing community participation are recommended to enhance waste reduction and support sustainable urban waste management systems.

The increasingly complex global energy problem drives the need for efficient, low-cost, and environmentally friendly energy storage systems. This study aims to analyze the power performance of two symmetric supercapacitor prototypes using Nitrogen-doped Graphene-Like Carbon (N-GLC) as the electrode material and 1 M  as the electrolyte, with different electrode substrates: aluminum and copper. Both prototypes were tested through charging and discharging processes using resistive loads of 470 ohms and 560 ohms for 5 minutes. The analyzed parameters include voltage, current, power, and output energy. The results show that the aluminum electrode achieved a higher maximum charging power of up to 18 mW; however, its energy discharge efficiency was very low at only 0.87%. In contrast, the copper electrode demonstrated a more balanced charging and discharging performance with an energy discharge efficiency of 19.4%. Analysis also indicates that the copper substrate maintains better voltage stability after 6 hours of storage compared to aluminum, which experienced significant degradation. Thus, the copper electrode is superior in maintaining the power and stability of a simple N-GLC-based symmetric supercapacitor system.

This study aims to analyze the influence of workforce agility, job satisfaction, and job engagement on employee adaptive performance at PT. MMT Buana Logistik. The dynamic logistics industry requires employees who have high adaptability to technological changes and operational demands. This type of research is quantitative causality with an explanatory approach. The population in this study were all employees of PT. MMT Buana Logistik, totaling 49 people, with the sampling technique used saturated sampling (census). Data were collected through questionnaires with a 5-point Likert scale. Data analysis techniques used included instrument testing (validity and reliability), testing of classical assumptions (normality, multicollinearity, and heteroscedasticity), and multiple linear regression analysis. Hypothesis testing was carried out through t-tests (partial), F-tests (simultaneous) and coefficient of determination (R2). The results showed that workforce agility, job satisfaction, and job engagement partially and simultaneously have a positive and significant influence on employee adaptive performance. These findings imply the importance of managing work flexibility, fulfilling employee satisfaction, and increasing work engagement to build adaptive human resources to support company competitiveness in the logistics industry.  

Self-Compacting Concrete (SCC) requires a high cement content, which contributes to increased carbon emissions; therefore, this study evaluates the effect of partial cement substitution with fly ash (5%, 10%, and 15%) and the addition of Polyethylene Terephthalate (PET) waste (0.5% and 0.7%) on the mechanical properties of SCC with a target strength of f’c 30 MPa. The research employed laboratory experimental methods, including fresh concrete tests (slump flow, L-box, and V-funnel) and hardened concrete tests (compressive, tensile, and flexural strength) at 7 and 28 days. The results indicate that fly ash substitution enhances compressive strength, with the highest value of 49.59 MPa achieved at 5% fly ash at 28 days, exceeding normal concrete (34.73 MPa). The addition of PET tends to reduce compressive strength due to increased porosity; however, it significantly improves flexural strength, as the combination of 5% fly ash and 0.5% PET achieved 4.7 MPa compared to 2.9 MPa for normal concrete. Overall, the combination of fly ash and PET waste shows potential for application in structural elements requiring high flexural performance.

Generators are one of the important auxiliary aircraft needed on ships for power generation. During the operation of a diesel generator, continuous rotation occurs resulting in friction and erosion of the moving parts. The supporting factor for the smooth running of a diesel engine is a lubrication system that is supported by good lubricating oil quality, besides that it also needs to be supported by an adequate and good cooling system. The use of lubricants is one of the most important factors to ensure the performance of diesel engines. The lubricant is in charge of maintaining the condition of the engine so that it remains stable. This study aims to analyze the effect of using lubricating oil beyond the operating hours limit on engine heat. Furthermore, it also discusses steps to ensure diesel engine temperatures remain normal. This research was carried out during the practice of sailing on a ship for approximately one year. This study uses a descriptive quantitative research method. The primary data obtained directly utilizes observation methods, and documentation. Secondary data was obtained from existing articles and journals. The data analysis techniques used are descriptive analysis and inferential analysis. The results of this study show that the working hours of lubricating oil use have a significant influence on the increase in the temperature of diesel generator engines as evidenced by hypothesis tests on two engine units, namely AE1 and AE2. In the AE1 unit, a t-value of 18.467 with a significance of 0.000 was obtained, while in AE2 the t-value was 14.289 with a significance of 0.000. The significance value in both units is less than 0.05 so it can be concluded that the working hours of lubricated oil have a significant influence on the temperature of the genarato diesel engine on the ship.

This study examines the transportation management flow at PT Xpresindo Logistik Utama Medan Warehouse and its impact on delivery accuracy. The research method used a qualitative approach through direct observation and interviews with warehouse managers and operational staff. The results showed that the distribution flow from receiving goods from Jakarta to shipping to customers in Medan was quite effective, although it was still dominated by manual systems such as the use of Delivery Notes and Excel records. The use of the Monstra tracking application was not evenly distributed, so fleet movement information was not always updated in real time, especially when demand volume increased at the end of the month. To improve efficiency, the study recommended the implementation of a Transportation Management System (TMS), digitalization of barcode/QR code-based inventory processes, and a Key Performance Indicator (KPI) dashboard to monitor delivery timeliness and fleet utilization periodically.

The implementation of predictive maintenance supported by SAP Plant Maintenance (SAP PM) at PT Xyz has proven to be effective in reducing machine downtime, lowering maintenance costs, and improving asset reliability. The integration of SAP PM with Industry 4.0 technologies such as IoT sensors, AI-based analytics, and real-time notification systems strengthens operational efficiency and ensures continuous performance. Empirical results show improvements in key performance indicators, including a 20-25% reduction in downtime, a 30% reduction in maintenance costs, an increase in asset availability to 97%, an MTBF extension of up to 511 hours, and an OEE rate of 92.1%. These findings highlight the strategic role of digital predictive maintenance in increasing competitiveness and supporting long-term sustainability in manufacturing operations.

This study aims to analyze the aesthetic values of Ranggawis Dance as a form of regional creative dance that develops in Purbalingga Regency. This research employs a qualitative method with a descriptive approach, supported by a choreographic aesthetic approach. The theoretical framework used is the aesthetic theory proposed, which includes aspects of form, content, and performance. Data collection techniques were carried out through observation, interviews, and documentation involving choreographers, musicians, dancers, and related parties in the performance of Ranggawis Dance. The data were analyzed descriptively using a qualitative approach by linking field findings with the applied aesthetic concepts. The results show that the aesthetics of Ranggawis Dance are formed through the harmony of form aspects, including movement, musical elements, and dancer composition; content aspects reflecting values of togetherness and joy within the community; and performance aspects demonstrated through synchronization (rampak) and dancers’ expressions. The dance movements, which combine Banyumasan, Jaipong, and contemporary elements, create a dynamic and harmonious impression, while the use of pentatonic scales strengthens the traditional character. The collaborative creative process between choreographers and musicians also contributes to the overall aesthetic unity of the performance. Therefore, Ranggawis Dance possesses strong aesthetic values, reflects local cultural identity, and has the potential to be further developed as part of traditional art preservation.

Work discipline is a crucial element in improving employee performance, particularly in the Micro, Small, and Medium Enterprises (MSME) sector such as automotive workshops, which often face managerial and structural challenges. This study aims to explore the understanding, implementation, and influence of work discipline on employee performance at Gandi Jaya Motor Workshop, Jombang, within a local context characterized by religious values and informal work culture. The research employs a descriptive qualitative method with a case study approach. Data were collected through in-depth interviews, observation, and documentation, and were analyzed thematically. The findings reveal that work discipline is perceived as a form of personal responsibility driven by leadership example and religious values, rather than by formal systems alone. External factors such as limited infrastructure and the absence of a structured HR evaluation system also affect performance effectiveness. These findings expand the scope of Work Discipline and Employee Performance theories by incorporating social and cultural dimensions as determinants of work behavior. The study concludes by emphasizing the need for a humanistic approach to HR management in MSMEs and recommends further exploration with broader participant coverage and more diverse methodological approaches.

The practice of adulterating RON 92 (Pertamax) fuel has the potential to violate consumer rights and is contrary to applicable laws and regulations. The practice of mixing lower-quality fuel and then marketing it as RON 92 results in material and immaterial losses for users, including reduced vehicle performance and a loss of trust in business operators. This research aims to analyze the legal protections available to consumers regarding the practice of adulterating fuel based on Law Number 8 of 1999 concerning Consumer Protection and related provisions in Law Number 22 of 2001 concerning Oil and Gas. The research method used is normative legal research with a library research approach, through analysis of relevant laws and regulations, scientific literature, and secondary legal sources. The results indicate that the practice of adulterating fuel violates consumers' rights to comfort, security, safety, and accurate information as stipulated in Article 4 of the Consumer Protection Law, and violates the obligations of business actors as stipulated in Articles 7 and 8 of the Consumer Protection Law. Business actors can be held accountable for civil damages, dispute resolution through the Consumer Dispute Resolution Agency (BPSK), or subject to administrative and criminal sanctions in accordance with the Oil and Gas Law. Therefore, legal protection for consumers in cases of fuel adulteration requires an interconnectedness between effective government oversight, firm law enforcement, business actor accountability, and increased consumer legal awareness to ensure legal certainty and fairness in trade activities.