Engineering and Technology Horizons

Application of BIM and Virtual Reality of System Integration Design and Development in Medical Building Projects: A Case Study in China

Jiahao Chen — 2024-09-30

Design outcomes in the Medical Building Projects (MBPs) must satisfy the demand of the medical staff and stakeholders. However, they often do not have the relevant engineering expertise, so the design team is prone to misunderstandings when communicating with them using traditional two-dimensional (2D) Computer-Aided Design (CAD) drawings. The medical staff may not readily visualize and understand the design and then provide feedback to the designer through professional medical requirements or advice, which results in the need to redesign and carry out additional work during the design phase, thus delaying the progress of the MBPs. To address these challenges, this study aims to develop an integrated system based on BIM, advanced rendering engines, and VR technology for use in non-immersive and immersive VR environments. Moreover, in this study, the integrated system was applied to the infection-building project of the People's Hospital of Qingbaijiang District, Chengdu City, and semi-structured interviews were distributed to 16 engineers, designers, contractors, and medical staff who had been involved in the whole project to validate the practicality and effectiveness of the integrated system. The results indicate that this system integration is an efficient visual communication and simulation tool in medical design. Key advantages include enhanced communication efficiency between the design team and medical stakeholders, improved visual interaction, and streamlined decision-making processes within a 3D VR/BIM environment. The successful implementation of this integrated system is expected to significantly aid design teams and stakeholders in effectively managing medical design tasks in future projects.

Calibration of Bi-prism Stereo Systems: A Model Free Approach

Supun Dissanayaka — 2024-09-30

A simple stereo system can be constructed from a single camera using a prism in the optical path to provide the required two views of a system. The simplicity of these systems has several advantages, particularly if the target is an underwater robot, where compact size and ability to seal the optical components are key factors. However, dispersion by the prism, in addition to the lens distortion, makes calibration challenging. By using a model-free approach, we were able to calibrate a prism-based stereo system effectively. We also aimed to use readily available 45° prisms, which present significant dispersion in the system, but retain simplicity and reduce cost, compared to custom low angle prisms. Modern LEDs provide high intensity, low bandwidth light sources and we used a set of three sources, roughly centered on the RGB channels of a readily available commercial camera. Our system used a circular target pattern covering the binocularly visible region in the scene and collected sets of images at known distances, using three separate light sources. From these images, we generated two look-up tables, one for each pixel in the image and a disparity derived by matching corresponding points, Cp(u,v,du), which has three dimensions, and another look-up table, which has a single dimension, Cz(z), so are not quite large, and not beyond the memory capability of even small modern camera systems, but provide fast, O(1), lookup times, suitable for real-time systems. Our calibration strategy enables a simple stereo system built from a single camera to measure depths in a scene: the single camera requires no electronic synchronization and is built from a single, inexpensive, and readily available optical component – a right-angle prism.

The Quality Improvement of Tube Ice Production Process by using Central Composite Design

Nipas Leenatham — 2024-09-30

This research aimed to find optimum process conditions in tube ice production. The design of experiments was utilized to improve quality in the production process. The primary data were collected and found the substandard product size problem in large-tube ice manufacturing, averaging 159 tons per month and accounting for 83.25 percent of all production issues. These were the main problems of the research. According to the analysis to find a solution to the problem, the non-standard size issue was mainly caused by the temperature of raw feed water intake (A), the temperature of the ice-maker machine itself (B), the temperature inside the ice production plant (C), and the improper handling of production time parameters (D). In this study, the problematic issues were improved by applying the 2 step-design of experiments. The first step to experiment basically used the 2^k full factorial design for screening the nonrelated factors to the non-standard size proportion. Secondly, in order to determine the optimal factors of the tube ice production process, this step utilized the Central Composite Design (CCD). According to the experimental analysis, the optimum condition in tube ice production process was derived by regression equation. The percent proportion of the substandard large tube ice was represented by 7.72433 + 0.10813A + 0.12271B + 0.11729C - 0.09521D + 0.03877AA + 0.05252CC - 0.03844AC, which interpreted the most suitable equation in regression model. After incorporating the parameters in the process, the proportion of the substandard ice tube size was reduced by 8.37 percent and the non-standard remake production cost was decreased by 18,331.40 Baht a month.

Pickup and Delivery Vehicle Routing Problem with Hybrid Missions and Third-Party Vehicle Rentals: A Case Study of Animal Feed Industry

Punyawich Sessomboon — 2024-09-30

The vehicle routing problem for small and medium-sized animal feed manufacturers is a complex challenge because each transport route can vary significantly between delivering products to customers and picking up raw materials to return to the factory. Currently, businesses lack well-planned management for utilizing a limited number of trucks. As a result, they often incur additional costs by relying on third-party vehicle rentals. This research aims to reduce transportation costs for small and medium-sized animal feed manufacturers by solving a formulated mixed-integer linear programming (MILP) model, using experimental data that accurately reflects the actual problems faced. The MILP model results help reduce transportation costs by up to 18.5% compared to current practices by optimizing route sequences and incorporating the use of third-party vehicle rentals. This also serves as a guideline for reducing transportation costs in other similar industries.

Studying Performance of Wire Electrical Discharge Machining for Multi-pass Cutting Strategy on the Tool Steel SKD 61 Using Recommended Parameters of Machine

Kamonpong Jamkamon — 2024-09-30

This research aims to study the machining efficiency of wire electrical discharge machining for multi-pass cutting. The recommended parameters of the machine are employed for cutting test tool steel grade SKD 61 with the thickness of 40 mm. The brass wire electrode with the diameter of 0.25 mm was used in the cutting test. The recommended parameters for multi-pass tool path cutting consisted of 4 operations. The 1^st cut was defined as a full cut that required the removal of a large amount of workpiece material, with the cutting speed set at 2.60 mm/min. The 2^nd, 3^rd, and 4^th cuts involve cutting on the edge of the workpiece to remove only a small amount of work material, with the cutting speed set at 3.20, 3.60, and 6.80 mm/min, respectively. The experimental test showed that the machining performance of the cutting speed for the 1^st cut was lower than the expected value by approximately 18.01 percent. The 2^nd, 3^rd, and 4^th cuts found that the cutting speed higher than expected value by approximately 104.34, 128.89 and 4.12 percentage for each cutting pass, respectively. In addition, the surface roughness and dimensional error of the machined part decrease as the number of cutting passes increases. The difference between the expected values and the experimental results is very useful in planning decisions and quality control for cutting workpieces by the process of wire electrical discharge machining.

Cost-Effective High Gain Wideband Antenna with Dual Partially Reflective Surface for 5G-mmWave Application

Nuttaphat Prasert — 2024-09-30

This research presents the performance improvement of the of rectangular patch microstrip antenna. The purpose is to increase gain and bandwidth with design on the PRS (Partially Reflective Surface) dual layer technique. There is a developing the low-cost substrate-based antennas suitable for 5G millimeter-wave. The prototype antenna achieves a maximum gain of 11.8 dBi at a frequency of 25.5 GHz. The gain increases by 6 dB throughout its operational frequency range, with an OBW (Overlap bandwidth) of 20.9%, covering frequencies from 24.0 GHz to 29.9 GHz. The performance achieved results indicate that the prototype antenna can be effectively utilized for 5G millimeter-wave communication applications in Thailand.

Fast Hybrid Approach for Thai News Summarization

Kietikul Jearanaitanakij — 2024-09-30

News summarization presents a significant challenge in Natural Language Processing (NLP). Lengthy news articles not only consume valuable time but also lead to confusion regarding key points. The ideal news summarization should swiftly produce a succinct summary while retaining the essence of the information conveyed by the news writer. While intelligent chatbots like ChatGPT and Gemini offer user-friendly text summarization, their embedded Large Language Model (LLM) cannot be downloaded for private use. Moreover, implementing them in a business process can be expensive, both in terms of pay-per-use costs and response time. The objective of this research is to develop a private Thai news summarization that effectively extracts sentences encapsulating the main idea and abstractly summarizes them. The proposed model consists of two components. The first extracts a contiguous region containing important sentences using the TextRank algorithm, while the second employs the finetuned mBART as an LLM to generate the abstractive summary from the previously extracted sentences. In other words, the proposed model extracts an important news region before passing it to mBART. This approach produces a news summary with key information and a syntactic style akin to the natural Thai language. We evaluate the summarization quality by ROUGE scores and BERTScore (precision, recall, and F1-score). The evaluation metrics Experimental results on the ThaiSum dataset show relatively high ROUGE scores and BERTScore for the proposed model compared to most of the other approaches. Furthermore, it significantly reduces the runtime, keeping it within a reasonable limit.

Reducing Downtime Loss in the Automotive Parts Stamping Process Using Why-Why Analysis: A Case Study.

Jaturong Meemak — 2024-09-30

This research aims to reduce downtime in the production process of automotive part stamping and to enhance the overall efficiency of the machinery, the case study focuses on an 800-ton stamping press in a factory. Data were collected by analyzing the overall equipment efficiency (OEE) using the developed program named Thingworx and observing employees' operations from October to December 2022. The results showed that the OEE was below the target value set by the factory. Most problems occurred during mode change activities with waste investigation such as overprocessing and waiting. It was found that the main factors impacting downtime during the production process are issues from mold changeovers, problems with metal scraps stuck in the machinery, and mold repair issues. Why-Why analysis technique and lean tools including SMED, visual control, and continuous improvement, were used to decrease time spent on non-value added activities. The results from the research showed that the average time for mold changeovers decreased from 8.77 minutes to 3.51 minutes, a reduction of 60.22%. The average time for removing metal scraps decreased from 4.72 minutes to 0.81 minutes, a reduction of 82.76%. Additionally, the time for mold repairs decreased from 1,404 minutes to 448 minutes, a reduction of 68.09%. These improvements led to an overall equipment effectiveness of the 800-ton stamping press increasing from 55.85% to 65.65%, representing a 9.8 percentage point increase. Furthermore, it enabled a reduction in production downtime costs by 298,025 baht per month.

Comparison of YOLOv8 Models for Aircraft Detection in Airport Apron Using Digital Image Processing

Nitipoom Wiangkam — 2024-09-30

Airport safety can be improved by efficient air traffic management, which monitors aircraft parking spots and controls their movement into them more efficiently. In addition to emergency situations, it can assist in accurately inspecting airport areas. Management costs can be reduced by reducing the workload of personnel in controlling and helping manage air and ground traffic. This research focuses on comparing the performance of various YOLOv8 models (YOLOv8n, YOLOv8s, YOLOv8m, YOLOv8nl, and YOLOv8nx) in an automated aircraft detection system using digital image processing techniques. The methodology involves collecting a dataset of 1,000 airport apron images with parked aircraft, dividing them into 900 training images and 100 testing images. The YOLOv8 models are trained on the training dataset, and their performance is evaluated on the testing dataset using confusion matrices. Experimental results reveal that YOLOv8nx achieves the highest average aircraft detection performance, with a precision of 0.94, recall of 0.74, and f1-score of 0.83. Additionally, YOLOv8n demonstrates the highest processing speed at 0.95 milliseconds. Consequently, YOLOv8n is suitable for applications requiring high-speed processing, while YOLOv8nx is ideal for tasks demanding the utmost performance efficiency.

A Comparative Study of Precast and Cast-in Place Concrete in Construction Home Project by Life Cycle Cost Analysis

Ratchanon Aiemrod — 2024-09-30

Construction industry plays a significant role in economic growth, and the industry will continue to grow with the economic expansion. However, the industry is known for its labor-intensiveness, In order to shorten construction time and address labor issues, developers have explored new systems of construction such as a precast system. This paper is to present a comparative study of precast and cast-in place concrete system in construction home project by life cycle cost analysis by dividing project period into 3 phase (Preparing phase, Construction phase and O&M phase). In modelling life cycle costs, sensitivity analysis and Monte Carlo simulation will be employed to incorporate uncertainty of material and labor costs into the proposed model. The study also found that in 6 home projects, there have risk factors that impact to life cycle cost by using sensitivity analysis are construction cost, major repair and minor repair. The result from this study is life cycle cost from precast and cast -in place systems