Prioritizing Safety Climate Improvements in the Indonesian Construction Industry Using Supervised Classification

Despite its significance, the Indonesian construction industry has poor safety performance. Improving the safety climate has been seen as a way to improve safety in the industry. Research on safety climate in this context has identified a range of safety climate factors that require improvements. However, construction organizations face difficulties in implementing improvement recommendations due to resource constraints. In order to help construction organizations in their efforts to improve the safety climate, this research demonstrates the use of supervised classification approaches to identify specific safety climate factors that construction organizations should focus on. Data were collected from 311 construction practitioners in Indonesia using a 22-item safety climate survey. Supervised classification methods, comprising ensemble methods, Support Vector Machine, Naive Bayes, and Nearest Neighbor, were used. The analysis identified 14 safety climate items that can represent the original dataset with high accuracy (93%). These 14 items can be considered crucial items that should be prioritized in the Indonesian construction industry. These items revealed that, due to the high power distance culture in Indonesia, top-down approaches, such as giving clear instructions, providing training, and reminding people often about safety, are effective for engaging employees to focus on and participate in safety. The findings also suggest that understanding cultural context is important to determine effective strategies to improve safety. This research has also demonstrated the potential application of supervised classification approaches to help decision makers improve safety by focusing on crucial factors within a context

Impact of Water Injection System on Diesel Engine Brake Power and Exhaust Emissions

A series of experiments were carried out to study and clarify the effect of Water Injection system (WI) on diesel engine performance and exhaust gas emissions (Nitrogen Oxides, Sulfur Dioxide, and Carbon Monoxide). The results obtained showed that, water injection increases the power output of the engine. Adding water to the incoming air allows for greater charge density. The water absorbs a large amount of heat as it vaporizes, thus reducing peak temperature and Nitrogen Oxides (NOX) emissions. WI also decreases the emissions of Sulfur Dioxide (SO2); the presence of water converts some of SO2 gas into sulfuric acid (H2SO4). Similarly, WI system was found to decrease the emissions of Carbon Monoxide (CO)

Electrical performance study of a large area multicrystalline silicon solar cell using a current shunt and a micropotentiometer

In this paper, a new technique using a Current Shunt and a Micropotentiometer has been used to study the electrical performance of a large area multicrystalline silicon solar cell at outdoor conditions. The electrical performance is mainly described by measuring both cell short circuit current and open circuit voltage. The measurements of this cell by using multimeters suffer from some problems because the cell has high current intensity with low output voltage. So, the solar cell short circuit current values are obtained by measuring the voltage developed across a known resistance Current Shunt. Samples of the obtained current values are accurately calibrated by using a Micropotentiometer (μpot) thermal element (TE) to validate this new measuring technique. Moreover, the solar cell open circuit voltage has been measured. Besides, the cell output power has been calculated and can be correlated with the measured incident radiation

New proposed method for traceability dissemination of capacitance measurements

Capacitance measurements at the National Institute of Standards (NIS), Egypt, are traceable to the Bureau International des Poids et Mesures (BIPM). It calibrates the main NIS standard capacitors, AH11A. In this paper, traceability of the BIPM capacitance measurements could be used to evaluate a new accurate measurement method through an Ultra-Precision Capacitance Bridge. The new method is carefully described by introducing some necessary equations and a demonstrating chart. Verification of this new method has been realized by comparing its results for the 10 pF and 100 pF capacitance standards with the results obtained by the conventional substitution method at 1 kHz and 1.592 kHz. The relative differences between the two methods are about 0.3 µF/F, which reflect the accuracy of the new measurement method. For higher capacitance ranges, the new measurement method has been applied for the capacitance measurements up to 1 μF at 1 kHz. The relative differences between the two methods are in the range of 5.5 µF/F on the average which proves the acceptable accuracy and the reliability of the new method to be used

Transport and MAC cross-layer protocol for video surveillance over WIMAX

Video surveillance is an emerging application for activity and security monitoring. Outdoor surveillance applications can take advantage of a WiMAX network to provide installation flexibility and mobility. A WiMAX-based surveillance system can be implemented as a dedicated network which only serves surveillance nodes to ensure high reliability. However, wireless video transmission is prone to interferences which degrade video quality. This paper proposes a novel transport and MAC cross-layer (TMC) protocol which aims at reducing delay and increasing video quality by integrating a transport layer protocol and bandwidth allocation within WiMAX. The simulations show that the proposed protocol outperforms existing protocol

Dynamic Modeling and Simulation of a STATCOM/SMES Compensator in Power Systems

The advent of Flexible AC Transmission Systems (FACTS) is giving rise to a new family of electronic equipment emerging to controlling and optimizing the performance of power system, e.g. STATCOM. Static synchronous compensator (STATCOM) is one of the most widely used FACTS devices. This paper presents the integration of STATCOM coupled with superconducting magnetic energy storage (SMES) device in order to provide power oscillation damping in power systems. The additional of energy storage allows the combined compensator to exchange both reactive and active power with the ac network and also capability of the STATCOM is enhanced. This paper describes the structure and characteristics of STATCOM/SMES. In addition, using a proper control scheme, STATCOM/SMES is tested on an IEEE 3-bus system and more effective performance of the presented STATCOM/SMES compensator is evaluated with alone STATCOM through the dynamic simulation by using PSCAD/EMTDC software

Dynamic Modeling and Simulation of a STATCOM/SMES Compensator in Power Systems

The advent of Flexible AC Transmission Systems (FACTS) is giving rise to a new family of electronic equipment emerging to controlling and optimizing the performance of power system, e.g. STATCOM. Static synchronous compensator (STATCOM) is one of the most widely used FACTS devices. This paper presents the integration of STATCOM coupled with superconducting magnetic energy storage (SMES) device in order to provide power oscillation damping in power systems. The additional of energy storage allows the combined compensator to exchange both reactive and active power with the ac network and also capability of the STATCOM is enhanced. This paper describes the structure and characteristics of STATCOM/SMES. In addition, using a proper control scheme, STATCOM/SMES is tested on an IEEE 3-bus system and more effective performance of the presented STATCOM/SMES compensator is evaluated with alone STATCOM through the dynamic simulation by using PSCAD/EMTDC software

THERMO-PHYSICAL PROPERTIES OF LIGHT WEIGHT EPOXY FOAMED BY SILOXANE BLOWING AGENT

The purpose of this study is to investigate the direct effect of using a blowing agent of siloxane (1, 1, 3, 3-tetramethydisiloxane) on the thermo-physical properties of the foamed epoxy. These properties are: density, glass-transition temperature, thermal conductivity and thermal expansion. The work has been conducted experimentally by manufacturing several specimens with different siloxane contents as: 0, 5, 10, 15 and 20 wt%. The properties of the specimens have tested under suitable conditions using different reliable instruments: differential scanning calorimetry, Lee-discs apparatus, and push rod dilatometer. Scanning electron microscope was used as well to analysis the morphological characteristics of the epoxy with respect to the pores generated by the blowing agent. In general, the foamed epoxy has shown different sizes of pores and extra crosslinking which leads to increase the glass-transition temperature of the material. Results show that the addition of 20% siloxane to the neat epoxy (as maximum) leads to: decreasing by 50% in bulk density, increasing by 20% in glass-transition temperature, decreasing by 30% in thermal conductivity, and decreasing by 75% in thermal expansion.