Azmi Jaafar

Data envelopment scenario analysis with imprecise data

In the existing DEA models, we have a centralized decision maker (DM) who supervises all the operating units. In this paper, we solve a problem in which the centralized DM encounters limited or constant resources for total inputs or total outputs. We establish a DEA target model that solves and deals with such a situation. In our model, we consider the decrease of total input consumption and the increase of total output production; however, in the existing DEA models, total output production is guaranteed not to decrease. Considering the importance of imprecise data in organizations, we define our model so as to deal with interval and ordinal data. A numerical illustration is provided to show the application of our model and the advantages of our approach over the previous one.

A load-aware weighted round-robin algorithm for IEEE 802.16 networks

The IEEE 802.16 standard was designed to provide quality-of-service (QoS) guarantees for various classes of traffic with diverse QoS requirements. Packet-scheduling algorithms play a critical role in providing such guarantees. Weighted round robin (WRR) is one of the most commonly used scheduling algorithms, because of its simplicity and low computational overhead. However, it suffers from performance degradation under bursty traffic conditions because of the static weights used to determine packet transmissions. We propose a new packet-scheduling discipline for downlink traffic in 802.16 networks to improve performance in such situations. It dynamically determines the weight of each queue in the various classes based on the current traffic characteristics using the static WRR weight at the beginning of each base station round. The goal is not only to reduce the average delay and packet loss but also to improve average throughput. Simulations are used to evaluate the performance of the proposed algorithm load-aware weighted round robin (LAWRR), and show that it reduces average delay and packet loss, as well as it improves average throughput compared with WRR. The effectiveness of LAWRR running under fixed buffer sizes is also investigated.

Software security characteristics for function point analysis

Software cost estimation (SCE) has been an important but difficult task since the beginning of the computer era. It considers list of parameters to estimate accurately the software cost. However, security cost is always excluded in most of the parametric cost estimation models. It is because of the security aspect is normally considered late in the software development. To overcome this problem, we proposed an enhancement to one of the parametric estimation models, which is Function Point Analysis (FPA), to address the security concerns. The enhancement suggests potential software security characteristics during system development life cycle (SDLC). These characteristics are then integrated into FPA calculation to encounter the security cost estimation. This paper also points to the validation of a survey findings and calibration of the FPA calculation.

An Efficient Battery Lifetime Aware Power Saving (EBLAPS) Mechanism in IEEE 802.16e Networks

The IEEE 802.16e standard is an emergent broadband wireless access technology that added the mobility feature to the original standard. This feature made battery life of an operated mobile subscribe station (MSS) a bigger challenge because an MSS is powered by a rechargeable battery. The battery lifetime mechanism has to be created in order to prolong the battery-life of an MSS. The battery lifetime-aware power saving (BLAPS) scheme has been created to prolong the battery life of an MSS by adaptively adjusting the three-sleep parameters named idle threshold, initial sleep window, and final sleep window according to the residual energy and the traffic load. However, the scheme minimized the energy consumption of the MSS at the expense of the average response delay due to the effect of the remaining energy. It also used the standard sleep mode algorithm where the MSS frequently goes to listening mode when the traffic is low which leads to the high-energy consumption. In this paper, a new energy mechanism called efficient battery life-aware power saving scheme has been proposed to enhance the parameters of BLAPS. The three-sleep parameters in BLAPS mechanism are analytically enhanced according to the downlink stochastic traffic arrival pattern of an MSS. Moreover, an improved sleep mode control algorithm has been introduced to reduce the frequent transition to listening mode in case of low traffic. The simulation has been extensively used to evaluate the proposed scheme. The results have shown that the proposed scheme outperforms the BLAPS significantly in terms of both the average response delay and the average energy consumption.

Knowledge Management system architecture in agricultural industries environment

Knowledge Management (KM) has emerged as the hottest topic in the entire global world of business. Its contributions toward the successful of the organizations are currently been proved and saluted. The power of KM as a system is no longer possesses any limitations. In fact, many KM system practitioners have claimed it as the most desired and demanded energizer to the organizations today, as the role it plays is absolutely important. The role of KM system could be determined by looking on technicalities issues, challenges and opportunities of how to make sure that the right knowledge could be disseminated to the right people at the right time for any purposes. Besides that, KM also could be looked on how the processes involved in gathering and storing the knowledge in the proper placing and formating it as well to be able to access or use when it is needed. While, the agriculture-based industries environment which deal with business of plantation, forestries, and animals, including soil cultivation, crop and livestock management as well as many other activities which have a lot of potential to promote knowledge sharing among its community of practice (CoP) in term of best practice and lesson learnt. This paper analyzes the concept and the system architecture of KM in the agriculture-based industries and discusses various aspects in terms of its technicalities of KM system (KMS) as well as issues, challenges and opportunities involved in this field that will help CoP to increase their productivity and quality as well as to gain return on investment (ROI).

Symmetric Encryption Algorithm Inspired by Randomness and Non-Linearity of Immune Systems

In data encryption, the security of the algorithm is measured based on Shannon’s confusion and diffusion properties. This paper identifies the correspondences and highlights the essential computation elements on the basis of randomness and non-linearity of immune systems. These systems can be applied in symmetric encryption algorithm that satisfies the properties in designing a new symmetric encryption block cipher. The proposed symmetric encryption block cipher called the 3D-AES uses components of the Advanced Encryption Standard (AES) symmetric encryption block cipher and the new core components based on immune systems approaches. To ensure adequate high security of the systems in the world of information technology, the laboratory experiment results are presented and analyzed. They show that the randomness and non-linearity of the output in the 3D-AES symmetric encryption block cipher are comparable to the AES symmetric encryption block cipher.

Potential security factors in software cost estimation

Software houses are now keen to provide secure software as requested by customerspsila desire with respect to security and quality of their products especially related to the software costing estimation in the software development and implementation environment. Therefore, there is a need to identify the potential security risks while estimating the application cost. In this paper, we provide a list of potential security risks throughout the system development life cycle (SDLC). This list provides useful insights for software developers and practitioners in identifying security risks so that it can be encountered as security cost in the application.

Immune Systems Approaches for Cryptographic Algorithm

This paper proposed immune-inspired approaches in designing a new function for cryptographic algorithm named as 3D-AES. The immune systems approaches were selected on the basis of complex features that are desirable for substitution and permutation process to ensure adequate security and confidentiality of the systems in the world of information technology. This paper will identify the correspondences and highlight essential computation elements that can be applied in cryptographic algorithm that satisfies with Shannons confusion and diffusion properties. The 3D-AES uses components in Advanced Encryption Standard(AES) algorithm and new core components based on immune systems approaches. Cryptographic strength in the context of this paper is related to the ability of the algorithm to produce a random output. The empirical findings are presented and identified that the randomness of the output in the 3D-AES algorithm are comparable with AES algorithm.

Extended function point analysis prototype with security costing estimation

Software cost estimation is a complex activity that requires knowledge of a number of key attributes about the project for which the estimate is being constructed. Nevertheless, security is becoming more and more important in most of the software construct. Reviews on several widely recognized parametric estimation models found the insufficient of current estimation in software security costing. Comparison of common security standards successfully highlighted software security characteristics to be considered in cost estimation. A survey based on the rating of these characteristics has been conducted. Analysis results from RASCH have validated the relative importance of these characteristics based on Multimedia Super Corridor (MSC) software developers perspective. These validated characteristics are then extended the calculation and implemented in a Function Point Analysis prototype. The paper also points to the steps of calibrating the calculation through this prototype by conducting controlled experiments.

A QoS-Aware CAC with Bandwidth Reservation and Degradation Scheme in IEEE 802.16e Networks

Call admission control (CAC) schemes play a critical role in providing quality-of-service (QoS) guarantees for various classes of traffic with diverse QoS requirements in IEEE 802.16e networks. The dynamic CAC and bandwidth reservation scheme is one of the current schemes that simultaneously provides efficient utilization of network resources and guarantees QoS for admitted connections. However, its admission criteria starved high and low service classes due to its linear adaptation policy to accommodate more users into the network under moderate-to-heavy traffic load conditions. Its adaptive threshold for handoff connections is adjusted based on the arrival of new and handoff connections, that results in a waste of resources when the new and handoff connection arrival rate occurs frequently. In this paper, a new CAC scheme for Mobile WiMAX networks is proposed to prevent starvation of service classes and enhance the efficient utilization of network resources. The scheme determines a new admission criteria based on a scheduling service class. In the admission criteria, bandwidth degradation policy is used to admit more users when there is no available bandwidth to admit a more users. The adaptive threshold has been introduced dynamically to adjust the quantity of reserved bandwidth for handoff connections based on the traffic intensity of handoff requests. In addition, an analytical model for the proposed scheme is also developed. Extensive simulation experiments have been conducted to evaluate the performance of our proposed approach. The simulation results illustrate that the proposed scheme significantly improves the network efficiency compared to other schemes in terms of accepting more connections into the network and assuring QoS for all service classes. The numerical results have shown similar performance to the simulation results.