NKRAFA JOURNAL OF SCIENCE AND TECHNOLOGY

Top 2 Box score of the 7Ps satisfaction of Residential Business

2023-12-09T07:55:04+07:00

This research aims to 1) Study the level of the 7Ps marketing mix of housing estate and residential condominium customers. 2) Study the relationship between the “Arithmetic mean” and “The top two box score”. 7Ps Marketing Mix Level of Housing and Residential Condominium Customers. 3) To find the advantages and limitations of applying the arithmetic mean to the top two box score. The population is customers living in housing estates and residential condominiums in Bangkok and its vicinity and the region Using 1,000 samples by multistage random sampling. The instrument used was a 5-level estimating questionnaire, merging as a set, with a reliability value of 0.880. The statistics used were: Arithmetic mean, Top two Box Score, Pearson correlation coefficient, and Spearman correlation coefficient.

The Research discovered 1) the level of satisfaction in the 7 marketing mix (7Ps) was at a high level. (Sorted by average values from highest to lowest): Price, Products and Services, Place, Physical environment and/or employees in an organization, Process, and Promotion. 2) Arithmetic mean and top-two-box score 7Ps Marketing Mix Level of Housing and Residential Condominium Customers reveals that there was a statistical correlation at the significant level of 0.05 in the same direction with the Pearson correlation coefficient value and the Spearman rank correlation coefficient equal to 0.984 and 0.929 respectively. 3) The arithmetic mean has the advantage of using all observations and being able to find the distribution of the data. The limitation is that the data should be normally distributed. The top two box score does not depend on the distribution of the data. The limitation is that the spread of the data cannot be determined.

A Hybrid Model for Path Loss Estimation in Avenue Environment

2024-06-04T08:17:37+07:00

Diverse propagation mechanisms complicate propagation analysis and modeling for a foliage condition. Therefore, a simpler optimized hybrid propagation model, which maintains or improves accuracy but preserves a cooperative relationship with physics, would be insightful. We evaluate an approach for developing a radio-wave propagation prediction model in an avenue area by combining the path loss in free space and environment parameters. It is demonstrated that this two-mechanism hybrid model can provide an accurate fit to the profile of through forest propagation over a long distance, which is impossible with the definitive radiative energy transfer model. The predicted model results were validated using radio-wave propagation in the FM band measurement data.

Analyzing and Evaluating Aircraft Prediction Models based on Automatic Targets with Unidentified Orientation Data

2024-05-27T08:55:22+07:00

The aircraft prediction model has been developed to identify the type and model of aircraft based on unknown target data. This serves as a crucial factor in military strategic decision-making to gain a tactical advantage. The essential aircraft types encompass fighters, transporters, helicopters, and training aircraft. These aircraft types have the capability to cause harm and pose a threat to national security when identified as unidentified targets on radar screens. Each type of aircraft encompasses various models, each with distinct capabilities tailored for different mission profiles, such as long-range flight, cargo transport, bombing, attack, and reconnaissance. For this reason, effective air defense necessitates the accurate identification of aircraft types and models, enabling strategic decision-making for appropriate response strategies. Although there have been studies on constructing aircraft prediction models from past research, it was found that they primarily focused on predicting types or specific models of aircraft, revealing limitations in their practical application. Therefore, the aircraft prediction model is imperative to be considered based on methods that align with the requirements for identifying the type and model of aircraft. This research conducts an evaluation and analysis of an aircraft prediction model generated using contemporary methods, employing a diverse set of procedural steps to identify the type and model of aircraft. This is done to pinpoint and advocate the use of suitable and efficient procedural steps.

A Reduced scale spectrofluorometric method for determination of total petroleum hydrocarbon in seawater

2023-10-29T18:06:23+07:00

The Intergovernmental Oceanographic Commission (IOC) standard guide for determination of total petroleum hydrocarbon (TPH) in seawater was modified to conform to green analytical chemistry by reducing the volume of samples and extracted solvent. As a result, the pre-concentration factor was reduced from 800 to 20, which suitable to the normal high sensitivity spectrofluorometer currently available in the market. A calibration curve of chrysene without extraction was linear over a concentration range of 10-200 mg×L^-1. The regression equation was y=1.567x+2.524 with the coefficient of determination (R²) 0.9992. Limit of detection (3sd/m, n=10) and limit of quantitation (10sd/m, n=10) were 0.065 and 0.22 mg×L^-1, respectively. The proposed method was applied to determine TPH in seawater along Bangsean beach in Chonburi province, Thailand. A Collaborative Trials of this proposed method should be performed in order to accept it as a standard method.

Local gravity measurement by using the minimized period of rod pendulums

2024-05-21T08:58:04+07:00

In this paper, the results of determination of the local gravity by using the minimized period rod pendulums as the gravimeter have been presented. The studying used five rod pendulums of different lengths and test at a location that has the latitude of 18°39’43’’ N and elevation of 300 meters above MSL. Results from this study indicated that, by 12 trials of timing of 100 oscillation cycles of the rod pendulums with the initial angular amplitude less than 2°, the experimental local gravity obtained from the minimized period rod pendulum was 9.800 ± 0.008 m/s². Compared with the calculated local gravity, 9.7847 m/s², the error was 0.2 %, approximately.

The Design and create of a voltage divider with a vacuum-insulated capacitor type for 200 kilovolts maximum peak measuring.

2024-08-13T13:57:53+07:00

This research presents the design and create of a voltage divider with a vacuum-insulated capacitor type for measuring a voltage of 200 kilovolts peak. The voltage reduction ratio is 1000:1, achieved by using sub-capacitors made of polypropylene film capable of withstanding high voltage and temperature. The high-voltage section uses sub-capacitors of 47 nano farads, connected in series to achieve a total capacitance of 97.91 pico farads, encapsulated within a thick-walled PVC cylindrical housing and insulated with vacuum. The low-voltage section uses the same type of sub-capacitors connected in parallel, resulting in a total capacitance of 97.92 nanofarads. The design and testing conform to the IEC 60060-2 (2010) standard.Experimental results showed that the simulated operation using Matlab/Simulink software, with an input voltage of 200 kilovolts and output voltage of 200 volts, consistent with the designed 1000:1 voltage reduction. This setup was used for actual testing of high-voltage AC measurements in a high-voltage electrical laboratory. Comparative measurements at a voltage level of 100 kV_rms, the measured values exhibit a deviation from the standard of 0.000594, and the measured voltage values from the measurement system differ from the reference system by no more than ±1%. Therefore, the designed and constructed voltage divider meets the specified standards.

Development of a Prototype Data Transmission Device Using Radio Over IP Principles for CNR 900 Military Radios

2024-06-04T08:34:51+07:00

The purpose of this research is to develop a prototype communication system using the CNR 900 military radio model to enhance digital data transmission channels utilizing Radio Over Internet Protocol (RoIP). This system integrates with the mobile radio system of armored vehicles in the Black Panther Battalion's E-ARMY, allowing for command and control operations in disaster-stricken or hard-to-reach areas by extending the communication range through radio relay stations. The research involves directly converting Digital Encrypted Voice signals with the CNR 900 military radio set and interfacing it with a Raspberry Pi4 microprocessor. The voice signals are then filtered using CMOS Wideband technology to connect to the internal telephone system of the army. Additionally, the RoIP system is connected to the internal Internet network through a Private Server on a Linux operating system. Testing is conducted using Morse code transmission programs to assess the accuracy of the radio voice signals passed through the prototype. The results demonstrate accurate transmission and decoding of Thai and English alphabets and numerals, with every word decoded correctly. Furthermore, the Signal to Noise Ratio (SNR) is measured to evaluate the quality of the radio voice signals connected to the telephone set, with values exceeding 25 dBm, indicating suitable support for voice signal transmission through the prototype system.

Keywords: Radio Over Internet Protocol, CNR 900 Military Radio

Equipment Invention and Protocol Production of Hypochlorous Acid Solution for Disinfection Using in Chulachomklao Royal Military Academy

2024-08-20T14:17:59+07:00

The purposes of this research include: to invent an equipment set and to produce a protocol for generating Hypochlorous acid (HOCl) solution from electrochemical reaction by using electrolysis of Sodium chloride solution (NaCl) to obtain HOCl solution, which is effective in disinfection for using in Chulachomklao Royal Military Academy (CRMA). A researcher has invented equipment set, a tank capacity of 12 liters, providing easily available and low-cost materials, tools, and substances, including qualitative and quantitative analysis of HOCl solution, and has produced a suitable formula to use as protocol for this equipment set. The results of the research found that using a formula of the starting solution, which is (1) tap water produced by CRMA, 10 liters at pH 6.5 (2) NaCl 1%w/v and (3) vinegar 0.3%v/v and then provide current of 12V, 5A DC at least 35 minutes to obtain HOCl solution. The HOCl solution has an approximately available chlorine concentration (ACC) of 200 ppm at pH 4.51, which this pH-value has found to be all the HOCl species or one hundred percentage of available chlorine concentration (100%ACC). Oxidation-reduction potential (ORP) is +934 mV, which is effective enough to disinfect. Therefore, this invented equipment set with the protocol for generating HOCl solution can be practical.

Development of Lotus Yarn Using Natural Dyeing Techniqye

2024-06-17T07:48:23+07:00

This study aims to develop lotus yarn using natural dyeing technique and natural dyes such as lac, garcinia skin, and indigo, in four steps, with three shades (0.5, 1 and 2 kilograms) per one kilogram of lotus yarn. This is a model natural lotus yarn dyeing technique that influences the dye adhesion quality of lotus yarns, as well as chemical properties. It was found that the dye adhesion against washing, compared to the Community Product Standard that required at least 2-3 out of 5 in terms of natural dye washing resistance, met the standard. The dye resistance against sweat, in both acidic and basic conditions, compared to the Community Product Standard, that required at least 2-3 out of 5 in terms of natural dye washing resistance, met the standard.

Determining Factor Influencing Consumer Behavior During The Covid19 Pandemic : Omicron Variant

2024-08-13T13:54:23+07:00

This research aimed to determining factors affecting consumer behavior refer to Thai people during

the COVID-19 pandemic, especially Omicron variant. Structural Equation Modeling was utilized to find casual relationships under the behavioral decision of Thai people. Total of 2,939 Thais around Bangkok and metropolitan provinces were participated and filled 45 online questionnaires under strictly prevention and control of COVID-19. SEM shows that Appetite has a directly significant on Menu Options, which leads to Perceived Severity, Perceived Vulnerability, and Budget, Moreover, it also leading to Convenience, Health Conditions, and lastly, Consumer Behavior. It is also a very first study that integrated the Protection Motivation Theory and Theory of Planned Behavior together. In addition, this research could be substantial findings that can be used as a preliminary model for other decision-making of Thai people during COVID-19 pandemic for beneficial and pandemic mitigation as well.

Keywords: Structural equation modeling, Consumer behavior, COVID-19 pandemic