Application Of Remote Sensing And Hydrological Model For Runoff Estimation And Prediction At Upper Langat Watershed

Rapid land development in recent years have degraded the environment and created a need for watershed modeling to quantify the impacts. During land development activities, natural flow paths in the watershed is normally being replaced or supplemented by paved gutters, storm sewers, or other form of artificial drainage. During rainfall, water remains above the land surface generating large amount of runoff within a short time. This study was carried out to evaluate the effectiveness of using HEC-HMS hydrologic model, developed in the United States for predicting surface runoff from tropical watershed. The current and future impacts of land development on runoff rate were studied. The Upper Langat River Basin with a total area of 385km2 was chosen for this study. The watershed is located in Selangor. For this study, various datasets including topographical, hydrometeorological, river cross-section and land use data were used. The land use map was derived from Landsat TM images. In order to extract land use information from remotely sensed data, two classification techniques were examined, namely pixel-based and object oriented classification. The result shows that the object oriented classification provides better accuracy (91.429%) as compared to pixel-based classification which has an overall accuracy of 81.667%. The results from model application and statistical analysis show that HEC-HMS estimated an average gap of 27% at moderate flow. During heavy rainfall, the designed model seriously overestimated the runoff with an average gap of 70%. As a conclusion, the HEC-HMS provides a conservative estimate of runoff output. It was also observed that the impact of land development on peak flow is directly proportional. Land development of 24.40km2 in year 1994 caused a peak flow of 74.62m3/s while in 1999, 50.23km2 of land development caused the peak flow of 84.04m3/s. In the proposed MSC land use plan for the year 2020, total area of 148.14km2 will be developed. This development is predicted to cause 128.15m3/s of peak flow. Therefore, it is important for urban planner to take into consideration the effect of the urbanization on the rate of runoff before developing a desired area. A well designed drainage system must be put in place during land development in order to prevent the flooding

Estimation of the Autoregressive Order in the Presence of Measurement Errors

Most of the existing autoregressive models presume that the observations are perfectly measured. In empirical studies, the variable of interest is unavoidably measured with various kinds of errors. Thus, misleading conclusions may be yielded due to the inconsistency of the parameter estimates caused by the measurement errors. Thus far, no theoretical result on the direction of bias of the lag order estimate is available in the literature. In this note, we will discuss the estimation an AR model in the presence of measurement errors. It is shown that the inclusion of measurement errors will drastically increase the complexity of the problem. We show that the lag lengths selected by the AIC and BIC are increasing with the sample size at a logarithmic rate.Autoregressive Process Measurement Error Akaike Information Criterion Bayesian Information Criterion

Do the technical indicators reward chartists? A study on the stock markets of China, Hong Kong and Taiwan

This paper studies the profitability of applying technical analysis that signals the entry and exit from the stock market in three Chinese stock markets - the Shanghai, Hong Kong and Taiwan Stock Exchanges. The Simple Moving Average (MA) and its extensions, Exponential MA, Dual MA, Triple MA, MACD and TRIX for both long and short strategies are examined. Applying the trading signals generated by the MA family to the Greater China markets, significantly positive returns are generated, which outperform the buy-and-hold strategy. The cumulative wealth obtained also surpasses that of the buy-and-hold strategy regardless of transaction costs. In addition, we study the performance of the MA family before and after the 1997 Asian Financial Crisis and find that the MA family works well in both sub-periods and in different market conditions of bull runs, bear markets and mixed markets. That technical analysis can forecast the directions of these markets implies that the three China stock markets are not efficient.Technical analysis, Moving Average, buy-and-hold strategy

Identification and Estimation of Structural-Change Models with Misclassification

Consider a simple change-point model with a binary regressor. We examine the consistency of the change-point estimator when the regressor is subject to misclassification. It is found that the time of change can always be identified. Further, special cases where the structural parameters can also be identified are discussed. Simulation evidence is provided.

In-context Example Selection with Influences

In-context learning (ICL) is a powerful paradigm emerged from large language models (LLMs). Despite its promises, ICL performance is known to be highly sensitive to input examples. In this work, we use $\textit{in-context influences}$ to analyze few-shot ICL performance directly from the in-context examples. Our proposed influence-based example selection method can identify both positive and negative examples, outperforming several baselines when evaluated on 9 SuperGLUE tasks. Our analysis uncovers up to a $16.3\%$ performance gap between using the most negative in-context examples compared to the most positive. In a case study, we apply our influence-based framework to quantify the phenomena of recency bias in example ordering for few-shot ICL

Are the Asian Equity Markets more Interdependent after the Financial Crisis?

This paper examines the impact of the 1997 Asian Financial Crisis on the linkages between the Singapore and five Asian-Pacific stock markets. We show that the interdependence between these markets has intensified after the crisis. Before the crisis, only the Malaysian stock market is found to be cointegrated with Singapore. However, after the onset of the crisis, the stock markets of Hong Kong, Japan, Malaysia and the US are found to be cointegrated with the Singapore stock market.

A study on the relationship between construction and the economy of Hong Kong

Thesis (B.Sc)--University of Hong Kong, 2005.published_or_final_versio

Lithium ion alters Ins(1,4,5)P3 production and mobilisation of intracellular free calcium in k-agonist stimulated rat ventricular myocytes

The effect of lithium ion on the generation of inositol phosphates and the mobilisation of intracellular free calcium in isolated adult rat ventricular myocytes stimulated with k-agonist was studied. Dynorphin1-13 stimulated an increase in the levels of Inositol 1,4,5-trisphosphate (InsP3) and intracellular free calcium ([Ca2+ ]i). Preincubation of the ventricular myocytes with lOmM Li+ for 20 minutes prior to stimulation by dynorphin1-13 reduce the increase of both InsP3 and [Ca2+]i. This effect of Li+ was not seen if 5mM inositol was also present during preincubation. It is concluded that (1) the inhibition of the k-agonist stimulated increase in InsP3 and [Ca2+]i, in Li+-pretreated ventricular myocytes was a result of a depletion of intracellular inositol, due probably to the inhibition by Li+ of inositol monophosphatase which participates in the recycling of intracellular inositol, and (2) the k-agonist induced increase in [Ca2+]i is a consequence of the production of InsP3 since altering the kinetics of production of this compound also altered [Ca2+]i.published_or_final_versio