วารสารวิชาการเทคโนโลยีอุตสาหกรรม (J. Ind. Tech.) อยู่ในฐานข้อมูล TCI กลุ่ม 2 (2563) มีค่า JIF = 0.094 | The Journal of Industrial Technology (J. Ind. Tech.) is indexed in TCI Tier 2 (2020) with impact factor, JTIF 0.094

บทความ

5G: เทคโนโลยีการสื่อสารแห่งทศวรรษหน้า

วิศวกรรมไฟฟ้าและอิเล็กทรอนิกส์

บทความวิชาการนี้เป็นบทความที่นำเสนอภาพรวมและสถานการณ์เกี่ยวกับเทคโนโลยีการสื่อสารโทรคมนาคมยุคที่ 5 หรือที่เรียกว่า 5G ที่กำลังจะถือกำเนิดขึ้นในประเทศไทยภายในปี พ.ศ. 2563 ซึ่งเนื้อหาในบทความนี้เริ่มอธิบายตั้งแต่วิวัฒนาการของเทคโนโลยีโทรศัพท์เคลื่อนที่ จากนั้นทำการอธิบายถึงปัจจัยที่ขับเคลื่อนให้เกิดเทคโนโลยี 5G เทคโนโลยีสำคัญที่สนับสนุน 5G ข้อกำหนดที่สำคัญๆ สำหรับการพัฒนาเทคโนโลยี 5G ตลอดจนเนื้อหาที่เกี่ยวข้องกับสมรรถนะที่โดดเด่นของของเทคโนโลยีดังกล่าว (เช่น อัตราการรับส่งข้อมูลที่เร็วกว่า 4G ถึง 20 เท่า และการประวิงเวลาที่ตํ่ามาก เป็นต้น) และกรณีการใช้งาน 5G หรือการประยุกต์ใช้งานในด้านต่างๆ นอกจากนี้ บทความนี้ยังนำเสนอสถานการณ์ที่เกี่ยวกับ 5G ที่เกิดขึ้นทั้งในต่างประเทศและในประเทศไทย ดังนั้น บทความนี้จึงเหมาะสำหรับผู้ที่กำลังเริ่มต้นศึกษาหรือผู้อ่านที่สนใจเกี่ยวกับเทคโนโลยี 5G ที่กำลังจะมีการให้บริการภายในอนาคตอันใกล้นี้

A Water-Balance-Based Dual-Axis Sun Tracking System

วิทยาศาสตร์

This paper presents a new technique for solar tracking system with very low power consumption. In order to track the sunlight, the solar panels connecting to the floated-balls are moved by water level balance adjusting. The proposed system is controlled by micro-controller. The signals from light-dependent resistor (LDR) sensor and reference voltage are compared and used to control the 12 V DC windshield washer pump for adjusting the water level which corresponds to the sunlight perpendicular. As a result, the accuracy of solar tracking depending on water level varying is achieved. The proposed system has ability to control with 2 axes; north-south and east-west. A comparison result between the proposed system and conventional method with one solar panel shows that the improvement of the sun power harvest of 7.91 W or higher than 37.63 % is given by the proposed system. It is also found that by using one solar panel for five days operating with twelve hours per day, the proposed solar tracking system has ability to harvest the energy of 347.16 Wh/day with power consumption of 0.66 Wh/day. When three solar panels are employed, the energy harvest of 1212.84 Wh/day with power consumption of 1.76 Wh/day is obtained. Additionally, the power consumptions between the proposed system and the DC motor controller of solar tracking systems using for one solar panel are compared. The results show that the DC motor controller shows power consumption of 10.8 Wh/day or 1.147 % whereas the energy of 0.66 Wh/day or 0.19 % is consumed by the proposed system. It is reveal that the lower power consumption of 0.958 % is given by the proposed system. Therefore, the proposed system has ability to reduce the power consumption of the solar tracking system.

An (s,Q) Inventory Control Model with Return Cost and Price Discount

วิศวกรรมอุตสาหการ

The objective of this study is to construct an inventory control model for an inventory system single item single source by considering the (s,Q) inventory policy with returned items and find the optimal point of purchase (s*) and optimal order quantity (Q*) that minimizing the total cost. In case of regular order, the relationship between demand and returned items is considered into two cases which are 1) demand and returned items are independent 2) demand and returned items are dependent. Demand and return items have Poisson distribution. The results of numerical study show that the case of demand and returned items are independent, the optimal order quantity is greater than the case of demand and returned items are dependent. On the other way round, the previous case reveals lower the minimum of total cost than the latter case. Moreover, these two cases have the same optimal point of purchase. In case of adding price discount, the results show that the case of demand and returned items are independent is greater optimal order quantity than the case of regular order, and the minimum of total cost is decreasing. Demand and returned items are dependent, the case of adding price discount is greater total cost than the regular order. Then, optimal order quantity and the minimum of total cost remain the same.

An Experimental Study of Performances and Emissions in a Small Fishery Boat s Engines Fuelled with Biodiesel B 5 and B 20

วิศวกรรมเครื่องกล

Energy and environmental crisis has leaded to many alternative eco-energy researches world widely. This research has surveyed small fishery boat populations which are incessantly affected by the fuel price. Researcher focused only on the 6-cylinder diesel engines which had higher fuel consumption. The result found that HINO engines were typically used. Consequently, the experiment was conducted on a 6-cylinder HINO diesel engine fuelled with biodiesel B 5 and B 20. The tested fuels in this research were certified by Department of Energy Business. The results show that biodiesel B 20 give lower torque, power and efficiency than that of biodiesel B 5 by 2.12%, 2.40% and 2.38% respectively. However, biodiesel B20 shows very apparent advantages in term of CO, HC, NOx and PM emissions. The reductions are 36.92%, 11.76%, 19.71% and 3.86% respectively. The result reveals that biodiesel B20 has a compatible potential to biodiesel B 5 and can be consider as one of the environmental friendly alternative fuel.

An Experimental Study of Performances in a Large Diesel Engine Fuelled with Diesel and LNG

วิศวกรรมเครื่องกล

According to the increase of energy demand and environmental crisis, natural gas has been studied and considered as one of the clean alternative fuels. However, knocking phenomena is unavoidable when large diesel engines operate with natural gas. This research aimed to investigate a large diesel engine fuelled with diesel – natural gas dual fuel system. Firstly, two natural gas vaporizers were tested to find the appropriate one. Then, a comparative experimental between diesel operation and dual-fuel operation was conducted. Output performance was considered and found that vaporizer with 3.8-metre internal length heat exchanger was more advantageous. Thus, this vaporizer was installed in the tested engine. The experiment was done over the speed range between 1,100 to 2,000 rpm. It was found that dual-fuel engine produced less torque and power than those of diesel engine around 2.10%, which was still acceptable in actual application. The result found that the amount of injected natural gas must be controlled as a function of engine speed to avoid engine knocking. Averagely, the natural gas was injected into the system around 71.32%. This leaded to the reduction of engine volumetric and thermal efficiencies around 2.73% and 3.5% respectively.

Analysis of Electric Arc Furnace Effects for Power Quality of System and Increasing Energy Efficiency to Reduce Heat Loss in The Energy Balance Condition of Steelmaking Process

วิศวกรรมไฟฟ้าและอิเล็กทรอนิกส์

This paper presents the research of an electric arc furnace classified into 2 part. The first is analysis of the impact of the electric arc furnace which is a harmonic source. It is caused by a disturbance in a system with nonlinear characteristics of the arcs is caused due to an electric arc furnace. Ripple voltage measurement relies on replication of Novel Arc Furnace model by using PSCAD/EMTDC help in the analysis, which is used as a guide to study the function of this furnace and how to fix the problem by installing the Static Var Compensate the system of industrial steel production. Measurement results signal that causes the ripple voltage signal changes in a small range, and the signal is reduced in the system. The second, presented to enhance energy efficiency by experimental melting steel to find the amount of heat loss through the wall furnace. Loss of heat from burning. Loss of heat from the stove to heat all the losses in energy homeostasis, a smelting process is controlled by the temperature of the steel which is poured from the furnace to the crucible and steel to reduce heat loss is reduced by approximately 2.89 kW, the resulting analysis and experiments to improve the energy of electric arc furnaces, this paper can increase energy efficiency by approximately 99.56 %.

Ant Colony System (ACS) Algorithm for Fleet Size and Mix Vehicle Routing Problem with Time Windows (FSMVRPTW)

วิศวกรรมอุตสาหการ

This study presented the Ant Colony System algorithm together with Local Search in solution of the fleet size and mix vehicle routing problem with time windows (FSMVRPTW). The purposes of this study were 1) to minimize the number of tours (or vehicles), and 2) to minimize the total travel distance where the objective of minimization of the number of tours takes precedence over the minimization of the total travel time. The FSMVRPTW is the planning of using various types of vehicles for the lowest cost of transportation which each type of vehicles have to load the limited goods and distribute them to the customers under the limited time. The researcher integrated the 2-Opt and Move-Exchange methods in the procedures to improve the initial solutions received from the Ant colony algorithm. The researchers employed the developed method to build up the algorithm through the use of Microsoft visual studio C++ version 6.0 with the 5 times of calculation for each problem data set. The parameter was set as a = 1.60, b = 0.1, and r = 0.1 respectively. The 15 Solomon problems including C1, R1, and RC1 sets were employed. The vehicles in this study were classified into two types namely 1) QA which has the maximum load for 200 units, and type QB having the maximum load for 100 units. The results revealed that the Ant Colony System algorithm together with Local Search gave the better solution that using the LINGO software developed by the researchers with the high quality of solution in general at the level of 1.47 percent.

Assessment of surface water quality using multivariate statistical techniques: A case study of the Nampong River Basin, Thailand

วิศวกรรมสิ่งแวดล้อมและวัสดุ

This study investigates the spatial water quality pattern of 13 stations located along the main Nampong River. Multivariate statistical methods, namely, the hierarchical agglomerative cluster analysis (HACA), the discriminant analysis (DA), the principal component analysis (PCA), and the factor analysis (FA), were used to study the spatial variations of the most significant water quality variables and to determine the origin of pollution sources. Sixteen water quality parameters were initially selected and analyzed. Two spatial clusters were formed based on HACA. These clusters are designated as upper part (U/P) of Nampong River and lower part (L/P) of Nampong River regions. Forward and backward stepwise DA managed to discriminate ten water quality variables, from the original 16 variables. PCA and FA (varimax functionality) were used to investigate the origin of each water quality variable due to land use activities based on the two clustered regions. Five principal components (PCs) were obtained with 69.806% total variation for the moderate-pollution source region, while five PCs with 69.327% total variances was obtained for the low-pollution source region. The pollution source for the L/P is of anthropogenic sources (industrial, municipal waste, and agricultural runoff). For the U/P region, the agricultural runoffs are the main sources of pollution. This study concluded the application of multivariate statistical methods to reduce the large number of water quality parameters down to manageable number.

Assessment of Wind Energy Potential in Thailand Based on Using the Multiple-Weibull Distribution

วิศวกรรมเครื่องกล

Wind energy potential analysis is a design key to maximize wind turbine efficiency and annual energy output. Typically, the annual wind speed frequency is represented by a Single-Weibull distribution curve in spite of strong and calm wind patterns could occur through a year in many regions in the world, Thailand for instance. For this reason, wind energy potential should be analyzed by Multiple-Weibull distribution curves which are the representative of the meteorological seasons due to the monsoon’s effect. Therefore the objective of this study is to compare the accuracy of the Single-Weibull distribution and the Multiple-Weibull distribution in assessment of wind energy potential. The comparison was made between these two statistical distribution functions and the actual wind speed distribution (measured wind speed frequency) in order to determine the level of credibility of these two distribution functions. The wind speed data employed in this study was measured at Lamtakhong dam site in Nakhon Ratchasima province, Thailand. As the results, the error between the Single-Weibull distribution was 16.46% where the error between the Multiple-Weibull distribution was 14.82%, it was revealed that the smaller error, the higher reliability. Two of the most widely used wind turbines (Enercon E-30 and Windspot) were selected to verify the Multiple-Weibull concept. Approximately 40% increase in annual energy yield by using this method. So, the results confirmed that the Multiple-Weibull distribution is valid for the assessment of the annual energy production of wind turbines. Therefore, this will be a practical method for achieving the optimal design of stall-regulated wind turbine in the further work.

Biocementation through Microbial Calcium Carbonate Precipitation

วิศวกรรมโยธา

Biocementation through microbial carbonate precipitation is a new branch of microbial geotechnology that deals with the applications of microbiological methods to produce cemented materials used in engineering. The primary consideration of these applications is to improve the geophysical properties of soil so that it will be suitable for construction and environmental purposes. The applications of biocementation would require an interdisciplinary research at the confluence of microbiology, ecology, geochemistry, civil and environmental engineering. This new field has the potential to meet society s expanding needs for innovative treatment processes that improve soil engineering properties. This paper presents an overview of biocementation, particularly through microbial calcium carbonate (CaCO3) precipitation, and non-destructive geophysical techniques for real-time monitoring of soil engineering properties. Focus is then narrowed to an example of laboratory-scale test of biocementation of sandy soil and measurement of strength development by shear wave velocity (Vs). Other analytical results included microscopic imaging by scanning electron microscope (SEM) and identification of CaCO3 precipitation presented in biocemented sand by X-ray diffactometer (XRD) were discussed. Potential advantages and envisioned applications of biocemented soil improvement are identified.

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