Identification of Homogeneous Areas for Drought Frequency Analysis

Owing to high spatial and temporal rainfall variability, rationale water management decision-making is complex. Hence, it is essential to identify homogeneous areas to assist water management. This paper focusses on separating the study area into homogeneous groups to predict the risk of occurrence of a drought event. The severity-duration-frequency (SDF) curves were developed to determine the relationship between the probability of a drought occurring with a certain severity and frequency at the selected stations in Victoria, Australia. Two techniques namely cluster analysis and modified Andrews curve were used in grouping study area that have similar climate characteristics with respect to risk of occurrence of drought (i.e. rainfall variability). The study area was divided into six clusters and they adequately covered the study area. A mean drought frequency curve was developed for each homogeneous group to determine the probability of vulnerability to a drought event with a certain severity. The advantage of separating stations into homogenous groups based on similar drought characteristics is that it eliminates the necessity to carry out a detailed drought characteristic analysis for any location of interest. The measurable characteristics of this station will determine its best match with the existing cluster groups

Impact of Intracavity Power Variations toward Ultrashort Pulse Generation

This study demonstrates a passive mode-locked erbium-doped fiber laser with a graphene nanoplatelet-saturable absorber (GNP-SA) that generates ultrashort pulses within femtosecond pulse duration. The GNP-SA is fabricated via a direct transfer approach by mechanically exfoliated graphene on a fiber ferrule. Its characteristics include 0.8% modulation depth, 8.7 MW/cm2 saturation fluence, and 36.8% absorbance. The quality of ultrashort pulses is studied with a variation of intracavity circulating powers that is controlled through an optical coupler. By changing the light intensity in the cavity, the optical amplification property in the erbium-doped fiber is also impacted. The increment of the output coupling ratio increases the population inversion in the active gain medium, which leads to the change of lasing wavelength from 1558 to 1532 nm. Using a 50% output coupling ratio, the fiber laser generates 960 fs pulse duration, 11.08 MHz repetition rate, and 6.05 mW output power. This study contributes to the understanding of oscillating light behavior while changing its intracavity power that affects the optical amplification properties

Ownership structure, corporate governance and firm performance in Malaysia

Highly corporate concentrated ownership was among the significant factor that brought Malaysia into the 1997/98 financial crisis. Concentrated ownership, as agency theory states, has contributed to lower the effectiveness of corporate governance by considering the interests of majority shareholders at the expense of minorities, having the motivation and power to punish management and either appointing independent directors or sitting personally on the board to protect their interests. To overcome the problem, the MCCG, which largely followed recommendations of the United Kingdom (UK) code, was issued in 2001. However, it was argued that the same requirements of corporate governance practices in the UK code many not work effectively in a country which has a different legal system, business culture and corporate structure. Despite many studies have been conducted to examine the influence among the ownership structure corporate governance and firm performance, the results of the previous studies are still indeterminate. Unlike many previous studies, this study aimed to examine corporate governance in Malaysia by investigating ownership structure independently of corporate governance. Ownership structure was measured by government ownership, local nominees, and foreign nominees, while corporate governance was measured by CEO's duality, number of independent directors, board size, frequency of board meetings, number of women directors and audit committee. Firm performance was measured by return on assets and earnings per share. Data on ownership structure and corporate governance were collected from companies' annual reports, while data regarding firm performance were gathered from Bloomberg database sources and Annual Reports. Data were collected from secondary sources for the period 2003 to 2013 involving 341 Malaysian Public Listed Companies selected using a purposive sampling method involving the companies that have been existed throughout the period of 2003 to 2013. The data were analyzed using descriptive statistics, correlation and panel data regression model. Results of testing the influences among ownership structure, corporate governance and firm performance are found to be mixed. For example, local nominee, CEO duality and board meeting showed weak and negative influences on return on asset while foreign nominee and independent directors had weak and positive influences on earnings per share. The same mixed results were also found between concentrated ownership and corporate governance. This study has added to the body of knowledge from a different perspective of considering ownership structure as an independent variable separated from corporate governance. Finally, the findings of this study expect to assist the relevant authorities to evaluate the present listing requirements, corporate governance practices and the current ownership structure trends in enhancing future corporate performance

Energy-Efficient Federated Learning With Resource Allocation for Green IoT Edge Intelligence in B5G

An edge intelligence-aided Internet-of-Things (IoT) network has been proposed to accelerate the response of IoT services by deploying edge intelligence near IoT devices. The transmission of data from IoT devices to the edge nodes leads to large network traffic in the wireless connections. Federated Learning (FL) is proposed to solve the high computational complexity by training the model locally on IoT devices and sharing the model parameters in the edge nodes. This paper focuses on developing an efficient integration of joint edge intelligence nodes depending on investigating an energy-efficient bandwidth allocation, computing Central Processing Unit (CPU) frequency, optimization transmission power, and the desired level of learning accuracy to minimize the energy consumption and satisfy the FL time requirement for all IoT devices. The proposal efficiently optimized the computation frequency allocation and reduced energy consumption in IoT devices by solving the bandwidth optimization problem in closed form. The remaining computational frequency allocation, transmission power allocation, and loss could be resolved with an Alternative Direction Algorithm (ADA) to reduce energy consumption and complexity at every iteration of FL time from IoT devices to edge intelligence nodes. The simulation results indicated that the proposed ADA can adapt the central processing unit frequency and power transmission control to reduce energy consumption at the cost of a small growth of FL time

Dual-wavelength mode-locked oscillation with graphene nanoplatelet saturable absorber in erbium-doped fiber laser

In this work, we demonstrate a dual-wavelength passively mode-locked erbium-doped fiber laser employing graphene nanoplatelet as saturable absorber. The dual-wavelength laser is generated in ~1530 nm and ~1550 nm wavelength regions by splitting the main signal into two separate laser oscillations via a red/blue wavelength division multiplexer. Both the unidirectional and bidirectional dual-wavelength oscillation scheme are investigated, and it is found that the latter is advantageous in providing narrower pulse widths of 890 fs and 980 fs for the respective wavelength region, on top of boosting the pulse energy to the maximum value of 139 pJ and 155 pJ, respectively. It is believed that the bidirectional dual-wavelength oscillation scheme can minimize the overlapping effect between the neighboring pulses that cause pulse distortion as well as signal attenuation compared with unidirectional dual-wavelength oscillation. This work expands the dynamics of cavity structure design for synchronized dual-wavelength mode-locked fiber laser generation