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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.

Submarine pipelines are vital infrastructures in aviation fuel distribution, carrying high risks of operational disruption, safety issues, and environmental pollution. In 2025, the aviation fuel receiving submarine pipeline at Integrated Terminal Ampenan was deformed due to mechanical pulling by MT Anargya I, causing system shutdown. This incident created risks of seawater intrusion, marine pollution, and potential fuel shortages at Lombok International Airport. This study evaluates the effectiveness of applying a double-ended draining method combined with an oil bubble trap as a fast, safe, and sustainable solution for submarine pipeline repair. Using a case study and descriptive-analytical approach based on the Continuous Improvement Program (CIP), the research analyzed quality, cost, delivery, safety, environmental, and workforce aspects. The results showed the method effectively drained aviation fuel without seawater contamination, prevented marine spills, maintained fuel quality within specifications, and completed repairs before critical stock levels were reached. Additionally, it provided significant cost savings compared to emergency supply operations and achieved zero safety incidents and environmental pollution. The integration of double-ended draining and oil bubble trap proved to be an effective, adaptive innovation with strong potential for replication and standardization in other aviation fuel submarine pipeline systems.

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.

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.

This study aims to analyze the effect of direct learning on engine components toward students' vehicle diagnostic abilities in vocational education. Employing a quantitative approach with an ex post facto design, the sample consisted of 80 students selected using simple random sampling from a population of 100 students. Data were collected using validated and reliable questionnaires. The data analysis techniques included descriptive statistics, classical assumption tests, and simple linear regression analysis. The results show that direct learning has a positive and significant effect on students’ vehicle diagnostic abilities, with a significance value of 0.000 < 0.05 and a coefficient of determination (R²) of 0.264. This indicates that direct learning contributes 26.4% to the improvement of students' diagnostic abilities. The findings emphasize the importance of practical, hands-on learning approaches in vocational education. These approaches not only enhance students' understanding of automotive theory but also improve their diagnostic skills. The study highlights that systematic learning and direct interaction with engine components are key factors in developing students' competencies, making them more effective in real-world vehicle diagnostics.

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.

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.

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 is motivated by the importance tank cleaning process on tankers to prevent cargo contamination, maintain cargo quality, and ensure crew safety. MT. Marina Prosperity, a chemical/oil tanker, uses the Butterworth system as the primary method for tank cleaning at every cargo change. However, in practice, technical and operational constraints are still found that affect the results of tank cleaning. The research method used is descriptive qualitative with data collection techniques through direct observation on the ship, interviews with the Chief Officer and Boatswain, and documentation studies in the form of log books and SOPs. Data were analyzed by focusing on three aspects, namely work efficiency, work safety, and operational procedures for using Butterworth. The results show that the use of Butterworth can increase time and energy efficiency compared to manual methods, with an average cleaning time of 2–4 hours per tank depending on the type of cargo. From a safety aspect, Butterworth reduces the need for crew to enter the tank, thereby reducing the risk of exposure to chemicals and hazardous atmospheres. However, work effectiveness and safety are greatly influenced by the condition of the equipment, the stability of water pressure, and the crew's discipline in implementing the SOP. On several occasions, steps such as nozzle cleaning, manual mopping, and safety meetings were not consistently performed, resulting in residual load in certain areas. With routine equipment maintenance, close supervision, and ongoing crew training, Butterworth can be optimized to produce more effective, safe, and standards-compliant tank cleaning process.

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 rapid development of the Industrial Revolution (IR) 4.0  and the transition towards Society 5.0 demand an increase in digital literacy and a basic understanding of technology systems starting from secondary education. The Community Service (CS) Program conducted by the Department of Electrical Engineering Universitas Presiden aims to introduce the concepts of logic gates and digital systems to students of SMA 1 Cikarang Pusat. This CS integrates theoretical explanations and simulation practice using the online platform Circuitverse. This CS was evaluated using a Likert scale (1–4) questionnaire instrument, namely Expectation (Importance) and Performance, with a total of 40 student respondents. The analysis results show that all indicators received an average performance score above 3.30, with satisfaction indices ranging from 82.50% to 90.62%, which falls into the very high category. The indicator for the use of appropriate technology received the highest score of 90.62%, indicating the relevance of the material to current technological developments. The Importance–Performance Analysis (IPA) shows that most indicators are in the 'maintain performance' quadrant, indicating alignment between participants' expectations and the activity's performance. These findings suggest that the workshop is effective in enhancing students' understanding of basic digital system concepts while also fostering interest in engineering and technology fields. The activity underscores the strategic role of universities in bridging the technology literacy gap at the secondary education level in response to the challenges of the IR4.0 and Society 5.0.

Although cryptographic security is often the main concern in e-voting system development, practical implementation failures are frequently associated with poor user interfaces that increase cognitive load and voting errors. This study evaluates the effectiveness of User-Centered Design (UCD) interventions in improving usability and voter confidence in an e-voting system. A one-group pretest-posttest design was applied to 36 respondents representing novice voters. Usability was measured using the System Usability Scale (SUS) before and after the interface redesign. The intervention focused on visual hierarchy, navigation consistency, status visibility, and error prevention. The results show a statistically significant improvement, with the mean SUS score increasing from 69.10 in the marginal category to 95.76 in the excellent category. The paired sample t-test produced t(35) = -7.3441 with p < 0.0001, while Cohen's d reached 1.2130, indicating a large practical effect. The standard deviation also decreased from 21.98 to 3.09, demonstrating a more consistent user experience. These findings indicate that interface optimization is essential for strengthening accessibility, voting accuracy, and user trust in digital democracy systems.

This study is motivated by the suboptimal use of intelligence tests in guidance and counseling services in schools, despite their important role in understanding students’ cognitive abilities as a basis for providing appropriate services. This study aims to examine the utilization of intelligence tests in guidance and counseling services to support the optimization of students’ academic development. The method used is a literature review with a qualitative approach through the analysis of 25 relevant scientific articles published between 2022 and 2026, using content analysis techniques. The results indicate that intelligence tests play an important role in identifying cognitive abilities, supporting the planning of guidance and counseling services, assisting in academic decision-making, and guiding interventions for students’ learning difficulties. In addition, intelligence is also related to academic achievement, although it is influenced by other factors such as motivation and the learning environment. However, the findings also reveal a gap between the theoretical potential of intelligence test utilization and its implementation in practice, which still faces limitations, particularly in the integration of assessment results and the accuracy of interpretation. The implications of this study highlight the need to improve counselors’ competence in the use of psychological assessments and to optimize the systematic use of test results in order to support more effective guidance and counseling services in developing students’ academic potential.

In the increasingly competitive manufacturing industry, the effectiveness of Management Control Systems (MCS) is heavily influenced by human factors, particularly leadership style. This study aims to analyze the impact of leadership style on the effectiveness of MCS from the employees' perspective. The research uses a qualitative descriptive approach with in-depth interviews conducted on employees of a manufacturing company in Surabaya. The results indicate that the applied leadership style tends to be directive yet supportive, combining firmness in rule enforcement with humane interpersonal relationships. However, the reward system is found to be inconsistent and less structured, emphasizing more on disciplinary control rather than positive reinforcement. The study concludes that leadership style has a significant effect on employee compliance and perception of control systems. Effective leadership creates goal congruence and transforms rules from being perceived as a burden into operational support. Conversely, inconsistency and lack of flexibility become obstacles to optimal control. These findings highlight the importance of adaptive communication and consistency in leadership to enhance MCS effectiveness.

This study aims to design and develop a web-based New Student Admission System (PPDB) Website at MIS Chairul Bariyyah Medan Krio to overcome the limitations of manual registration systems. The method used is Agile, as it supports iterative, flexible, and adaptive system development according to user needs. Data collection techniques include observation, interviews, literature study, and documentation. The system is developed using the Python programming language with the Django framework and MySQL database. The results show that the developed system improves the efficiency of the registration process, minimizes data recording errors, and facilitates real-time management of applicant data. In addition, the Website also serves as an information and promotional medium for the school that can be accessed anytime. Based on Blackbox testing and User Acceptance Test (UAT), the system is proven to run well and is easy to use. Therefore, this web-based PPDB system is effective in improving the quality of Administrative services at MIS Chairul Bariyyah.

Taxes are a primary source of state revenue and play a crucial role in supporting national development. However, increasing tax revenue still faces several challenges, particularly the lack of public awareness in fulfilling tax obligations. This study aims to examine the role of public awareness in improving taxpayer compliance and its impact on state revenue. The approach used in this research is qualitative, reviewing literature from various previous studies. Research findings indicate that tax awareness, understanding, and knowledge have a positive impact on taxpayer compliance. Other economic factors such as inflation, population, and economic growth also play a role in influencing tax revenue. However, external factors such as socialization and tax sanctions show inconsistent results. Consequently, increasing public awareness through tax education is a key strategy for sustainably improving the country's performance. In addition, transparent tax management and effective government communication are important factors in strengthening public trust and encouraging voluntary taxpayer compliance. Therefore, collaboration between the government and society is needed to create a sustainable and effective taxation system that supports national economic growth.

This study was conducted to analyze and examine the influence of individual characteristics, career development, and the quality of human resources on employee performance at PT. Prima Vista Solusi using a quantitative approach through a survey method. Data were collected by distributing questionnaires to 70 respondents who are employees and were analyzed using multiple linear regression with the assistance of SPSS software. The results show that individual characteristics and the quality of human resources have a significant effect on improving employee performance, while the career development variable does not have a significant effect on performance. This indicates that although the career development system has been well implemented, it has not yet become a primary factor in improving performance. Therefore, the company is advised to place greater focus on human resource management policies aimed at enhancing employees’ competencies, skills, and professionalism so that performance can be continuously improved in a sustainable manner.  

This study examines the effectiveness of legal protection for victims of cyberbullying in Indonesia from a victimological perspective. The rapid development of information technology and social media has led to an increase in cyberbullying cases, which significantly impact victims psychologically, socially, and emotionally. However, existing legal protections are often considered inadequate in addressing the needs of victims. This research aims to analyze the existing legal framework, evaluate its effectiveness, and assess the position of victims within the criminal justice system. The method used is normative legal research with statutory, conceptual, and victimological approaches, relying on secondary data from relevant legal literature and scientific journals. The findings indicate that although regulations such as the Electronic Information and Transactions Law (ITE Law) provide a legal basis, their implementation remains ineffective due to weak law enforcement, lack of victim-oriented approaches, and limited awareness of victims’ rights. Therefore, strengthening victim protection through a victimological approach, legal reform, and the application of restorative justice is necessary to ensure justice and recovery for victims.           

The development of Artificial Intelligence (AI) integrated with biometric technology has opened new opportunities in leadership development, particularly in enhancing emotional regulation capabilities within high-stakes environments. This study aims to analyze the role of AI-driven biometric feedback in improving self-awareness, emotional regulation, and decision-making quality among leaders. The study employs a systematic literature review approach by examining recent reputable scientific publications related to AI, biometrics, and leadership. The findings indicate that physiological data such as heart rate variability (HRV) and galvanic skin response (GSR), when processed through AI systems, can provide real-time feedback that enhances individuals’ ability to recognize and regulate emotions adaptively. Furthermore, the integration of this technology contributes to improved accuracy and consistency in decision-making under pressure. The results also reveal that the effectiveness of implementation is influenced by both technical and non-technical factors, including data quality, algorithm accuracy, and user acceptance. This study contributes to strengthening the integration of psychological and technological approaches in modern leadership research and offers practical implications for developing data-driven leadership training programs in the digital era.

Children with Autism Spectrum Disorder (ASD) face unique challenges in building attachment relationships, due to ASD children experiencing impairments in communication, social interaction, and emotional regulation. This study aims to identify effective intervention strategies to improve the quality of attachment between parents and children with ASD through a Systematic Literature Review (SLR) approach. The review findings indicate that several interventions have proven effective in enhancing attachment between parents or primary caregivers and children with ASD, including the following interventions: DIR/Floortime, Focused Playtime Intervention (FPI), Parent-Child Interaction Therapy (PCIT), Circle of Security (COS), Positive Behavior Support (PBS), play training, massage therapy, and psychoeducation. The results of these interventions show that changes occur before and after the intervention, including strengthening two-way communication, increasing parental sensitivity, and improving the child's emotional responses. These findings have practical implications for parents, educators, and therapists in designing attachment-based approaches to support the social and emotional development of children with ASD. Responsive and supportive designing attachment-based approaches to support the social and emotional development of children with ASD. Responsive and supportive relationship-based interventions can build secure attachments between children with ASD and their parents and serve as an important reference in attachment-based parenting and therapy practices.