Sirindhorn International Institute of Technology

About: Sirindhorn International Institute of Technology is a based out in . It is known for research contribution in the topics: Supply chain & Combustion. The organization has 1048 authors who have published 1678 publications receiving 30067 citations.

Utilization of green waste from vegetable market for biomethane production: influences of feedstock to inoculum ratios and alkalinity

Abstract: In this study, biogas yields and methane contents of vegetable wastes from Thailand’s largest agricultural market were investigated. Granular sludge from an up-flow anaerobic sludge blanket (UASB) reactor was used as inoculum. To determine the influences of the feedstock to inoculum (F/I) ratio and alkalinity, batch experiments were conducted at three different F/I ratios (i.e., 0.5, 1.0, and 2.0 g VSfeedstock/g VSinoculum), and five NaHCO3 concentrations (i.e., 0, 300, 500, 600, and 900 mg/g VSadded). The reuse of digestate from previous anaerobic reactors, as sources of alkalinity and inoculum, was also investigated. After 53 days of the experiment, without adding NaHCO3, an F/I of 0.5 gave the highest biogas yield of 851 mL/g VS and a CH4 content of 52.3%. Adding external alkalinity significantly helped to improve the biogas production and methane contents at F/I ratios of 1.0 and 2.0. The results from using the recycled digestate as inoculum were comparable with reactors using UASB sludge and helped to decrease the amount of NaHCO3 to 150 mg/g VS. The high anaerobic digestion performance in the study demonstrated the potential of utilizing the organic waste from a vegetable market as a renewable energy source.

Calculation of electromagnetic field components for a fundamental Gaussian beam.

Abstract: Using a perturbative method, we carefully calculate seventh- and ninth-order expressions for electromagnetic field components for a fundamental Gaussian beam (i.e., a focused ${\mathrm{TEM}}_{00}$ mode laser beam) propagating in the medium analogous to vacuum. The interaction of a single electron and a focused laser pulse in vacuum has a promising application in the design of a powerful electron accelerator which could compete with the traditional ones. For this, ninth-order accuracy in the expansion describing the focused laser beam is required. When the vector potential corresponds to polarization along the direction of propagation, the number of electromagnetic field components can be reduced from 5 or 6 to 3. Furthermore, we find two rules obeyed by all orders of the vector potential, which greatly simplify the calculation procedure of the vector potential order by order, and make it possible to investigate the behavior of high orders.

Audio Watermarking Scheme Based on Singular Spectrum Analysis and Psychoacoustic Model with Self-Synchronization

Abstract: This paper proposes a blind, inaudible, and robust audio watermarking scheme based on singular spectrum analysis SSA and the psychoacoustic model 1 ISO/IEC 11172-3. In this work, SSA is used to analyze the host signals and to extract the singular spectra. A watermark is embedded into the host signals by modifying the singular spectra which are in the convex part of the singular spectrum curve so that this part becomes concave. This modification certainly affects the inaudibility and robustness properties of the watermarking scheme. To satisfy both properties, the modified part of the singular spectrum is determined by a novel parameter selection method based on the psychoacoustic model. The test results showed that the proposed scheme achieves not only inaudibility and robustness but also blindness. In addition, this work showed that the extraction process of a variant of the proposed scheme can extract the watermark without assuming to know the frame positions in advance and without embedding additional synchronization code into the audio content.

Facilitating Job Recruitment Process Through Job Application Support System

Abstract: Job recruitment and selection process is one of the most tedious tasks that human resource department in every organization has to perform. The recruitment and selection process consists of several steps. This paper focuses mainly on the step in which the applicants have to fill out application forms and undergo an initial screening interview. This step is very important because human resource recruiters must choose qualified candidates out of many applicants to be interviewed with the supervisors responsible for the job. Recruiters of many companies face a lot of problems performing this step especially when they have to perform it manually. Thus we were motivated to develop a more efficient way in filling out and processing application forms and develop job application support system to aid interviewers during the preliminary interview process. Job application support system consists of three main components including electronic application form, electronic telephone interview and electronic interview. The application module is constructed based on the competency matrix derived at each level of employment. Interview questions are determined based on the chosen competencies and are used to screen out candidates during a competency-based behavioral interview. A quantitative multi-objective decision model and job assignment model are developed for job-applicant matching process. The models are used to manage the data from the job application forms and evaluate the results from job interviewers. Job application support system is expected to bring about many positive changes. It can speed up the recruitment process by filtering out unwanted applicants and allow a better facilitation of the interview process by providing interviewers with guidelines and forms with which they could fill out. Cost can be saved because there are less paperwork. The quantitative multi-objective decision model and job assignment model that are developed can provide a more efficient way for job-applicant matching process