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การประชุมวิชาการAssessing Reservoir Reoperation Performances through Adapted Rule Curve and Hedging Policies under Climate Change Scenarios: In–depth Investigation of Case Study of Bhumibol Dam in Thailandผู้แต่ง: Khin Muyar Kyaw, Assoc.Prof.Areeya Rittima, Dr.Yutthana Phankamolsil, Dr.Allan Sriratana Tabucanon, Dr.Wudhichart Sawangphol, Dr.Jidapa Kraisangka,  Mr.Yutthana Talaluxmana, Assistant Professor , Dr.Varawoot Vudhivanich, Associate Professor , การประชุมวิชาการ:  
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 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Hedging Policy for Reservoir System Operation: A Case Study of Mun Bon and Lam Chae Reservoirs) ผู้เขียน:อารียา ฤทธิมา สื่อสิ่งพิมพ์:pdf AbstractA reservoir operation model of Mun Bon and Lam Chae reservoirs was developed to simulate reservoir operation using a hedging policy. A variety of common hedging forms was specified, including one-point hedging, two-point hedging and zone-based hedging. The simulated results were compared with the standard operating policy and probability based rule curve. The percentage of failure frequency, average annual shortage and end water availability were explored. Additionally, three reservoir performance indices, in terms of time-based reliability, vulnerability and resiliency were evaluated. The results indicated that two-point and three-point hedging performed well for all components of reservoir behavior compared with the standard operating policy and other hedging policies. The main outcome was that the risk of a water shortage during the simulation period could be reduced and some water could be retained for use in later periods. |
 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Hedging Effectiveness Comparison between Emerging and Developed Futures Exchanges) ผู้เขียน:ดร.ธนโชติ บุญวรโชติ, รองศาสตราจารย์ , สุวรรณา พนาพิทักษ์กุล สื่อสิ่งพิมพ์:pdf AbstractThis research estimated hedge ratios by using two econometric models: constant hedge ratios (ordinary least square technique, OLS; vector autoregressive model, VAR; and vector error correction model, VECM) and dynamic hedge ratios (DVEC-GARCH). These hedge ratios developed using these models were tested for hedging effectiveness by the amount of average variance reduction between the hedged and unhedged positions for indices, gold, and single stock futures contracts in three futures exchanges: the US exchange (CME) as a well-developed exchange, the Taiwan Futures Exchange (TFX) and the Thailand Futures Exchange (TFEX) as two emerging exchanges. The constant hedge ratio models were superior to the dynamic hedge ratios and the VECM model performed better than the VAR or OLS models, while, the DVEC-GARCH model could reduce the portfolio variance the least. Nevertheless, variance reduction of the portfolio can be efficiently done about 80 percent for every exchange. |
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หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Optimal Hedging Policies for Hydropower Generation at Ubolratana Reservoir) ผู้เขียน:อารียา ฤทธิมา สื่อสิ่งพิมพ์:pdf AbstractHydropower is regarded as an important source of electrical energy to enhance the efficiency of renewable energy use. However, the effects of the inflow uncertainty on a reservoir operation which cannot maintain the water level so that it is sufficient for generating power in some critical periods, makes reliable energy generation in certain periods unpredictable. Thus, this research developed different types of optimal hedging policies (one-point hedging, two-point hedging, three-point hedging, multiple hedging-non seasonal effects and multiple hedging-seasonal effects), which facilitate energy generation in association with basic operational concepts. The aim of the hedging policies was to reduce the water release in some periods even when there was enough water for serving all sectors of water demand. Consequently, the water level in the reservoir would be higher and this would be beneficial for energy generation. This research used the reservoir water balance concept to construct a reservoir operational model and applied the optimization approach with a genetic algorithm to find the optimal parameters of each policy. The Ubolratana Reservoir in Thailand was selected as the study area. The simulated results and their performance based on the reservoir operational model with the optimal hedging policies using daily long term data from 1970 to 2010 showed that using the various types of optimal hedging for the reservoir operation produced higher levels of firm energy. Moreover, the two types of multiple hedging gave better performance in terms of higher energy production compared to the existing rule curve. Additionally, using optimal multiple hedging with the seasonal parameters for operation increased energy production by controlling the reservoir water level so that it did not exceed the normal pool level and was not lower than the minimum pool level. In principle, when the optimal hedging policies were applied, the water storage in the reservoir was strictly limited and did not encroach the surcharge storage and inactive zones in some critical drawdown and fulfilled periods. Therefore, some water storage was kept in the active storage zone and was beneficial for energy generation together with other off-stream uses downstream. |
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