จำนวน Repository ( 1852 )

อิทธิพลของอัตราส่วนราคาตลาดต่อกำไรและมูลค่าราคาตามตลาด ต่ออัตราผลตอบแทนของหลักทรัพย์ในกลุ่มพลังงาน ในตลาดหลักทรัพย์แห่งประเทศไทย
อิทธิพลของอัตราส่วนราคาตลาดต่อกำไรและมูลค่าราคาตามตลาด ต่ออัตราผลตอบแทนของหลักทรัพย์ในกลุ่มพลังงาน ในตลาดหลักทรัพย์แห่งประเทศไทย

This research aimed to study the influence of P/E ratio and market capitalization on returns of the securities in the energy sector in the Stock Exchange of Thailand. In this research the researcher has studied and collected data from the closing prices of the securities in energy sector that are currently traded in the Stock Exchange of Thailand. From January 2015 to December 2019 from the Stock Exchange of Thailand 15 companies and used descriptive analysis mean and standard deviation to test the relationship between independent variables by using correlation analysis and multiple regression analysis to determine the influence of P/E ratio and market capitalization on returns of the securities in the energy sector. The results of the research showed that the P/E ratio had a significant positive influence on returns of the energy securities in the Stock Exchange of Thailand. The market capitalization factor also found that it had no influence on returns of the energy securities in the Stock Exchange of Thailand.

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การพัฒนาแบบจำลองและการพยากรณ์ดัชนีรังสีอัลตราไวโอเลตรายชั่วโมง โดยใช้โครงข่ายประสาทเทียมในจังหวัดสงขลา
การพัฒนาแบบจำลองและการพยากรณ์ดัชนีรังสีอัลตราไวโอเลตรายชั่วโมง โดยใช้โครงข่ายประสาทเทียมในจังหวัดสงขลา

In this work solar erythemal ultraviolet radiation (EUV) which affects human skin and skin cancer was investigated at Songkhla province (7.2°N 100.6°E). EUV was converted to UV index then the data was used for model development and forecasting of hourly UV index using Artificial Neural Network (ANN). The ANN model has one input layer two hidden layers and one output layer. This input layer consists of extraterrestrial erythemal ultraviolet radiation solar zenith angle aerosol optical depth and cloud index which affect ultraviolet radiation and the output layer is hourly UV index. The results show that hourly UV index obtained from ANN and that from the measurement are in reasonable agreement with root mean square difference of 12.8% and mean bias difference of -2.4%. For forecasting of the hourly UV index the data for 7 days earlier was used for forecasting the next UV index for one day or nine-hour (08:00 am.-16:00 pm.). Multi-layer perceptron and back propagation algorithm were used in the model forecasting. The results show that the UV index from the model forecasting is reasonable agrees with UV index from measurement with root mean square difference of 17.0% and mean bias difference of 0.3%.

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การจำลองทางคณิตศาสตร์เปรียบเทียบกับการปฏิบัติการโรงไฟฟ้าพลังงานแสงอาทิตย์ขนาดเล็กแบบกระจายตัวในระบบจำหน่าย
การจำลองทางคณิตศาสตร์เปรียบเทียบกับการปฏิบัติการโรงไฟฟ้าพลังงานแสงอาทิตย์ขนาดเล็กแบบกระจายตัวในระบบจำหน่าย

This paper presents a mathematical simulation to compared to operations a small distributed photovoltaic power plant in the distribution system. Practices transmission of electric power by small distributed solar energy With the PVSyst and IEC 61724 mathematical modeling programs the main objective was to study the % performance ratio photovoltaic power plants 5.95 MWp connected in the distribution system of the Provincial Electricity Authority voltage level 22 kV. Therefore this paper is presented as a mathematical simulation compared to operations a small distributed photovoltaic power plant in a distribution system. The results of the study show that the operation of small distributed solar power plants increases the efficiency to be able to produce the maximum electricity and continuously. The system was able to produce the highest power of 8954.9 MWh/year and had an average annual efficiency ratio of 77.84% receiving the highest solar radiation intensity and the highest annual total energy output of approximately 1837 kWh/m2

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การศึกษาเชิงทดสอบการใช้น้ำสำหรับระบายความร้อนออกจากแผงเซลล์แสงอาทิตย์
การศึกษาเชิงทดสอบการใช้น้ำสำหรับระบายความร้อนออกจากแผงเซลล์แสงอาทิตย์

This research aimed to experimentally study of solar panel efficiency with water cooling. Three mono-crystalline solar panels with the capacity of 80 W (for each panel) were used for this test. The first panel was a solar panel without water cooling. The second panel was a panel with water spray cooling. The last panel was a solar panel with water drop cooling. The cooling water flow rate was varied to 50 75 and 100 LPH. From the test it was found that the temperatures of all solar panels had the similar trends. The solar panel efficiency decreased when the temperature of solar panel increases. The solar panel efficiency increased when the cooling water flow rate was increased for both of water spray cooling and water drop cooling. For all water cooling flow rates the water spray cooling solar panel performed higher efficiency than water drop cooling solar panel. The highest solar panel efficiency in this test occurred when the water spray cooling flow rate of 100 LPH.

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การพัฒนาผลิตภัณฑ์ผัดไทยกรอบชนิดแท่ง
การพัฒนาผลิตภัณฑ์ผัดไทยกรอบชนิดแท่ง

The aim of this research was to develop Pad Thai crispy bar which is made from rice noodle (Chanthaburis noodle) tofu dried shrimp garlic chives and peanut that have been cooked and dried.Mixed with Pad Thai sauce then forming into a bar and dried. The study started with produced Pad Thai crispy bar made from three formula of Pad Thai sauce (A B and C). Sensory evaluation by using 9- point hedonic scale showed that the highest liking score of appearance ( 7. 36) taste ( 7. 56) and overall liking (7.68) were obtained from formula A. Mixture design was used to optimize the formula of the Pad Thai crispy bar. The effect of three variables: tofu (70-90%) dried shrimp (10-15%) and garlic chives ( 13- 25% ) on the physical chemical and sensory qualities of the product were investigated. The results showed that increasing the tofu decreased the lightness (L*) and hardness values of the product. Increasing the dried shrimp decreased the overall liking score. Optimum formula of tofu dried shrimp and garlic chives was 72% 13% and 15% respectively. At this formula had the highest score of all sensory attributes were in the range of 6. 86-7. 24 ( like slightly – like moderately) . The developed Pad Thai crispy bar had the value of aw and hardness value 0. 24 and 7.00 N respectively. In addition the developed product consisted of 9.17% moisture (wet weight basis) total carbohydrate fat ash and crude fiber which were 50.04% 30.80% 15.82% 3.34% and 1.98% (dry weight basis) respectively. The energy value determined by Bomb calorimeter which were 582.10 Kcal per serving (10 pieces) and the cost of Pad Thai crispy bar was 21.60 bath per serving (80 g).

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