5,514 research outputs found
Power Imbalance Detection in Smart Grid via Grid Frequency Deviations: A Hidden Markov Model based Approach
We detect the deviation of the grid frequency from the nominal value (i.e.,
50 Hz), which itself is an indicator of the power imbalance (i.e., mismatch
between power generation and load demand). We first pass the noisy estimates of
grid frequency through a hypothesis test which decides whether there is no
deviation, positive deviation, or negative deviation from the nominal value.
The hypothesis testing incurs miss-classification errors---false alarms (i.e.,
there is no deviation but we declare a positive/negative deviation), and missed
detections (i.e., there is a positive/negative deviation but we declare no
deviation). Therefore, to improve further upon the performance of the
hypothesis test, we represent the grid frequency's fluctuations over time as a
discrete-time hidden Markov model (HMM). We note that the outcomes of the
hypothesis test are actually the emitted symbols, which are related to the true
states via emission probability matrix. We then estimate the hidden Markov
sequence (the true values of the grid frequency) via maximum likelihood method
by passing the observed/emitted symbols through the Viterbi decoder.
Simulations results show that the mean accuracy of Viterbi algorithm is at
least \% greater than that of hypothesis test.Comment: 5 pages, 6 figures, accepted by IEEE VTC conference, Fall 2018
editio
Overall Performance of Malaysian Futures Market: Evidence Using Crude Palm Oil and Stock Index Futures Contract
This research analysed four important issues relating to the efficiency of futures
market, namely pricing characteristics, informational role, arbitrage efficiency and
hedging performance of two important derivative products namely crude palm oil
futures (CPO) and stock index futures contracts (SIF). Daily data on CPO contracts
for the calendar years 1987 through 1998 and 1996 through 1999 for stock index
contracts were used.
Several hypotheses concerning the pricing behaviour of futures contracts (CPO
and SIF) were tested to ascertain whether the pricing behaviour is consistent with
theory in the context of an emerging market. The fmding suggests that the pricing
behaviour of CPO futures is consistent with theory over the whole period of
analysis. And the liquidity increased with volume for the CPO futures. Delivery
month does not have any significant impact on price volatility. For stock index
futures, the pricing behaviour is not stable over time possibly due to the financial
crisis (July 1997 to September 1998) and/or more importantly, due to the learning period effect. The liquidity of this contract did not increase with the increase in
volume probably due to the lack of speculators.
Excepting in a sub-period (1993-1995), the findings suggest that information is
a major determinant of cash price movement of CPO contracts. For stock index
futures, significant informational linkages between cash and futures prices is
observed only after the financial crisis. There was no informational link between
cash and futures markets before the crisis.
In terms of arbitrage efficiency, the CPO futures show weak arbitrage activity.
Spot volatility reduces the spread between cash and futures though it was not
simultaneous while futures volatility does not have an important role in reducing the
spread. For stock index futures, spot volatility as well as futures volatility
simultaneously reduces the spread in the post crisis period. In the pre crisis period,
these contracts showe
Application of particle swarm optimization for solving optimal generation plant location problem
The global demand for energy especially-in-developing-countries,-has-been witnessing a tremendous growth due to rapid population growth, economic growth and developing industrial sectors. Therefore, it is necessary to forecast the future energy needs and expand generation capacity to meet the increasing peak demand.-This-paper-presents-an-optimization approach to determine the optimal location for installing a new generator in which the technical, economic and environmental aspects are all taken into consideration. The location that yields the minimum fuel costs, total emission and system loss is considered as the optimal generation plant location. The- formulated- objective- function- and- its constraints compose an optimization problem is solved using particle swarm optimization (PSO). The proposed PSO based optimization approach is tested on IEEE 14-bus system and IEEE 30-bus system to illustrate the potential of the new approach. The simulation results have shown that the proposed approach is indeed capable of determining the optimal generation location that can save much overall fuel cost as well as reduce the total emissions of generators and losses in the network
Mawlana Mawdudi’s Concept of Political Islam: A Critique of Mawlana Wahiduddin Khan
Syed Abul A'la Mawdudi was a Muslim scholar, ideological thinker, philosopher, jurist and journalist. He worked for the revival of Islam and disseminated his understanding of ‘true Islam’. This paper is categorized into two sections. The first section of this paper aims to explore the concept of Mawlana Mawdudi regarding political Islam and his role as a 20th century Islamic revivalist. The second section deals with critique of Mawlana Wahiduddin Khan on Mawlana Mawdudi’s powerful Islamic ideology. Mawlana Mawdudi viewed Islam as the religion that is all-encompassing and Islamic state as universal that should not be limited to a particular geographical region and Muslims should strive for the establishment of Islamic state through Islamic revolution. In Mawlana Khan’s ‘The Political Interpretation of Islam’, he considered Mawlana Mawdudi’s distinctly political interpretation as problematic
Rice husk to charcoal converter machine (vertical type) / Mohd Khairul Anuar Shah Hassan
Rice husk charcoal converter machine is very important to our country because almost all citizens in Malaysia eat rice, then we need one machine to help the paddy industry grow easily and faster with high quality. This project is to design and fabricate a machine to convert the rice husk into char stage for the nursery growing process The first phase of the project is to identify the strategy in producing char so as to fulfill the requirements of paddy plantation. The solution here is to design and fabricate a prototype of converting rice husk based on problems and user requirements in the agriculture sector. From the information gathered and studied, problems had been identified and the user requirement had been listed. The user requirement will then be analyzed in order to get the important features and produce engineering specification of converting the rice husk. The analysis of the requirement and the design specification has been used to create the system and the design concept of the converting rice husk. Finally, the furnace of the rice husk converter machine has been fabricated successfully
DECLINING US STATUS AS A SUPERPOWER: IMPLICATIONS FOR THE WORLD ORDER
Since 1945, the US has been relishing the status of a superpower by following its interests through a no of means, including international order, global and regional security arrangements, and international organizations. Recently, emerging global powers have challenged the existing international order, whereas the US is on a declining trajectory. The US hegemonic obligations to use its preponderant power in global issues with the intent to cast events in its favour have brought an inevitable overstretch beyond its capacity. Furthermore. a visible shift in power centres, the backlash of political decisions, and economic recession are other factors that need to be studied. This paper, therefore, explores the highly debated and contested reasons for the US decline. While employing deductive reasoning through qualitative analysis, it evaluates the efficacy of existing international order, emerging multilateralism, and difficulties in obviating the attendant risks to US security and prosperity. Implications of a declining superpower and suggested course of action for Pakistan have also been discussed in this paper.
Bibliography Entry
Abbas, Muhammad, and Hassan Jalil Shah. 2021. “Declining US Status as a Superpower: Implications for the World Order.” Magalla Papers 25 (1): 131-142
A review of slicing techniques in software engineering
Program slice is the part of program that may take the program off the path of the desired output at some point of its execution. Such point is known as the slicing criterion. This point is generally identified at a location in a given program coupled with the subset of variables of program. This process in which program slices are computed is called program slicing. Weiser was the person who gave the original definition of program slice in 1979. Since its first definition, many ideas related to the program slice have been formulated along with the numerous numbers of techniques to compute program slice. Meanwhile, distinction between the static slice and dynamic slice was also made. Program slicing is now among the most useful techniques that can fetch the particular elements of a program which are related to a particular computation. Quite a large numbers of variants for the program slicing have been analyzed along with the algorithms to compute the slice. Model based slicing split the large architectures of software into smaller sub models during early stages of SDLC.
Software testing is regarded as an activity to evaluate the functionality and features of a system. It verifies whether the system is meeting the requirement or not. A common practice now is to extract the sub models out of the giant models based upon the slicing criteria. Process of model based slicing is utilized to extract the desired lump out of slice diagram. This specific survey focuses on slicing techniques in the fields of numerous programing paradigms like web applications, object oriented, and components based. Owing to the efforts of various researchers, this technique has been extended to numerous other platforms that include debugging of program, program integration and analysis, testing and maintenance of software, reengineering, and reverse engineering. This survey portrays on the role of model based slicing and various techniques that are being taken on to compute the slices
To Know the Effectiveness of Disc Excision in the Treatment of Herniated Lumbar Intervertebral Disc
OBJECTIVES
To evaluate the effectiveness of disc excision in the treatment of herniated lumbar intervertebral disc.METHODOLOGY
METHODOLGY
This study was conducted in the Department of Neurosurgery, Lady Reading Hospital, Peshawar. A total of 62 patients had moderate to severe radicular pain due to Prolapsed intervertebral disc at L4/5 or L5/S1. All the enrolled patients were subjected to disc excision surgery. Postoperatively the patients were kept for 48 hours for observation and then discharged. All the patients were advised to come after 2 weeks for the follow-up to check effectiveness.
RESULTS
The mean age of patients was 34.59± 7.49 years. There were 64.5% male and 35.5% female. 53.2% of patients had L4-L5, 33.9% of patients had L5-S1 and 12.9% of patients had both L4–L5 and L5–S1 level disc herniation. 85.5% of patients had no pain, 8.1% had mild pain and 04.8% had moderate pain. Postoperatively 79.0% of patients were satisfied.
CONCLUSION
As compared to conservative care limited disc excision is safe, effective, and reliable in terms of pain. Disc excision technique provides immediate relief from radicular pain
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