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The welding quality, as the product of manual or semi-automatic welding process, is highly affected by the hand motion of the welders. In the shipbuilding industry, the welding inspection process is commonly performed after the welding process is finished by the welding inspectors. The research aims to develop a realtime monitoring system for welder’s performance by recording their hand motion. The hand motion sensors and QR codes are integrated through the Internet of Things (IoT) to monitor the welder’s performance and weldment quality. The realtime monitoring concept was developed by designing the monitoring concept utilising the QR code and Android mobile smartphone. The welder’s hands are equipped with the Inertial Measurement Unit (IMU) sensor to record their hand motion. The motion data are transferred directly from the IMU sensor to the smartphone storage through a Bluetooth connection. The data then are uploaded to the cloud storage through the internet connection. The stored recorded data was then analysed and compared with the qualified welders’ hand motions. After welding ends, the welder reports the visual appearance of the weldment and its location as identified by the QR code through the Android system. Finally, the functionality of the application prototype is tested, and the results show that the system can be used practically for real-time monitoring of welder performance and welding quality.

A welder plays a crucial role in the construction of a new ship. Monitoring the performance of welders involved in the construction of a ship is particularly important for controlling dimensions. he competency and consistency of welders play a vital role, with specific hand movement patterns contributing to welding quality. This study aims to identify individual welders’ hand movement patterns using Deep Learning with CNN-LSTM configurations. Data was collected through IMU motion sensors attached to welders’ wrists, capturing acceleration, angular speed, magnetic force, and electric current changes. The data was classified using CNN-LSTM, which showed higher accuracy than SVM methods. Experimental results indicated an overall classification accuracy of 99.73% for identifying individual welders and 97.07% for determining welding positions.

Estimating investment costs for a shipyard requires a high level of expertise, which typically takes time and experience to develop. This research presents a computer-aided training framework to train intuitive skills in estimating investment costs for new shipyards. The study begins with a review of the parametric method, a relevant approach for estimating shipyard investment costs. Subsequently, the recognition-triggered decision method, a technique based on intuitive decision-making, is integrated into a predetermined estimation method. Program and application algorithms are developed accordingly. A prototype of the application is tested on ten participants using the “Two Mean Difference Test.” Prospective estimators undergo pre-test and post-test assessments to evaluate the improvement in their intuitive skills. The results demonstrate that the application effectively enhances the intuitive skills of prospective estimators in estimating the investment costs of new shipyards. This conclusion is supported by the values of “t” and “t of the table,” where 11.53 > 2.262, within a critical range of 5%.

The conversion of floating docks from single pontoon to multi pontoon is a beneficial alternative for shipyards to enhance the performance of the facilities owned. The objective of this research is to analyze technically and economically the conversion of single pontoon floating dock to multi pontoon. The results of calculations used the 2.2 Finite Element Method software was the amount of the stress at the floating dock after the conversion of 14.635 MPa is smaller than the permitted stress of 160 MPa. Besides that, the pump ballast filling capability after conversion is 54.16 minutes. The decrease in Ton Lifting Capacity (TLC) can be determined by the difference in the load that occurs in the floating dock. After the floating dock is converted using the same TLC, it changes from 2.07 m to 2.11 m. The freeboard height is >300 mm so it is still able to work on the same TLC. There are 4 stages at the production stage, making access to the pontoon, installing bulkhead and additional reinforcement, removing the pontoon, dismantling and installing the pump, and reconnecting with the sidewall. The analysis results found that the conversion costs was IDR 20,051,463,949, the economic analysis conducted also obtained savings for floating dock reparation costs of IDR 6,559,475,128 to IDR 4,143,346,112. When one pontoon is repaired, the rest of the pontoon can still be used and get an income of IDR 3,292,265,120 thus the total cost is IDR 851,080,992. Saving amounting to IDR 5,708,394,136 is used to pay off investment costs.

A viable system that can monitor the effective working time of welder in real-time is required to overcome the low use of effective welder time in the Shipbuilding Project in the Indonesian Shipyard. It is made possible by using a wearable sensor tri-axial accelerometer, gyroscope, and magnetometer. In this research, sensors are used to recognize typically hand motion of welder during welding activities: preparation, welding and cleaning slags, respectively in three welding positions 1G, 2G, and 3G. Initially, observations were made to recognize the relationship between welder activities and hand motion. Second, raw data containing hand movements from the welder is captured in the form of time-series signals using inertia sensors for various different activities. Third, the raw data of measurements for those activities is extracted and analyzed to identify significant features such as mean, root-mean-square, power spectral density using the welch method (autocorrelation, spectral peak, and spectral power). Finally, typical activities of welder are classified using the resulting feature data with Multi Layer Perceptron. The validation of results shows that the algorithm is capable to recognize the hand motion activities of the welder.

The conversion of floating docks from single pontoon to multi pontoon is a beneficial alternative for shipyards to enhance the performance of the facilities owned. The objective of this research is to analyze technically and economically the conversion of single pontoon floating dock to multi pontoon. The results of calculations used the 2.2 Finite Element Method software was the amount of the stress at the floating dock after the conversion of 14.635 MPa is smaller than the permitted stress of 160 MPa. Besides that, the pump ballast filling capability after conversion is 54.16 minutes. The decrease in Ton Lifting Capacity (TLC) can be determined by the difference in the load that occurs in the floating dock. After the floating dock is converted using the same TLC, it changes from 2.07 m to 2.11 m. The freeboard height is >300 mm so it is still able to work on the same TLC. There are 4 stages at the production stage, making access to the pontoon, installing bulkhead and additional reinforcement, removing the pontoon, dismantling and installing the pump, and reconnecting with the sidewall. The analysis results found that the conversion costs was IDR 20,051,463,949, the economic analysis conducted also obtained savings for floating dock reparation costs of IDR 6,559,475,128 to IDR 4,143,346,112. When one pontoon is repaired, the rest of the pontoon can still be used and get an income of IDR 3,292,265,120 thus the total cost is IDR 851,080,992. Saving amounting to IDR 5,708,394,136 is used to pay off investment costs.

Ship condition survey is a survey conducted by an Owner Surveyor for reporting the actual condition of the ship and parts. Presently, the condition survey is still done manually that Owner Surveyor has to survey based on survey list which is published by the ship’s owner company. The survey result will be presented in the form of a report, which will be submitted to ship’s owner as consideration for doing repair and maintenance. The survey process which done presently is not effective and many Owner Surveyors have not sufficient knowledge and experience, and also the process of presenting a survey report which takes a long time. This project was implemented by built an android-based computer application that can assist an Owner Surveyor in the process of a condition survey. This application containes of survey list, survey review, updating survey, and several menus to facilitate Owner Surveyor in the condition survey. This application has been tested by a few respondents who have experience in surveying ships and who have an educational background of naval architecture and shipbuilding engineering. This test was done in the form of a questionnaire aimed to determine the respondents assessment of this application. From the results of the questionnaire could be concluded that the application is very useful in supporting ship condition survey.

The conversion of floating docks from single pontoon to multi pontoon is a beneficial alternative for shipyards to enhance the performance of the facilities owned. The objective of this research is to analyze technically and economically the conversion of single pontoon floating dock to multi pontoon. The results of calculations used the 2.2 Finite Element Method software was the amount of the stress at the floating dock after the conversion of 14.635 MPa is smaller than the permitted stress of 160 MPa. Besides that, the pump ballast filling capability after conversion is 54.16 minutes. The decrease in Ton Lifting Capacity (TLC) can be determined by the difference in the load that occurs in the floating dock. After the floating dock is converted using the same TLC, it changes from 2.07 m to 2.11 m. The freeboard height is >300 mm so it is still able to work on the same TLC. There are 4 stages at the production stage, making access to the pontoon, installing bulkhead and additional reinforcement, removing the pontoon, dismantling and installing the pump, and reconnecting with the sidewall. The analysis results found that the conversion costs was IDR 20,051,463,949, the economic analysis conducted also obtained savings for floating dock reparation costs of IDR 6,559,475,128 to IDR 4,143,346,112. When one pontoon is repaired, the rest of the pontoon can still be used and get an income of IDR 3,292,265,120 thus the total cost is IDR 851,080,992. Saving amounting to IDR 5,708,394,136 is used to pay off investment costs.