hatim by Hatim Mohamad Tahir
Individual decision making based on a shared context
PLoS ONE, 2013
Treatment of stenosed coronary arteries by balloon angioplasty and stenting results in arterial i... more Treatment of stenosed coronary arteries by balloon angioplasty and stenting results in arterial injury including severe damage to the endothelium at the site of treatment and initiates a complex cascade of inflammatory processes that may lead to the development of in-stent restenosis (ISR). Many clinical and biological factors involved in the progression of restenotic lesions have been studied in detail over the past few years but the mystery behind the pathophysiological mechanisms of this disease is still unresolved. In the present work, the effects of re-endothelialization and nitric oxide release on neointimal growth are investigated in-silico using a two dimensional multi-scale model of ISR. The effect of stent deployment depths on the development of ISR is studied as a function of time after stenting. Two dimensional domains were prepared by deploying bare metal stent struts at three different deployment depths into the tissue. Shear stress distribution on endothelial cells, obtained by blood flow simulations, was translated into nitric oxide production that keeps the smooth muscle cells in quiescent state. The cellular growth trends were plotted as a function of time and the data indicate a positive correlation between the neointimal growths and strut deployment depths in the presence of a functional endothelium, in qualitative agreement with in-vivo data. Additionally, no ISR is observed if a functional endothelium appears much earlier. Citation: Tahir H, Bona-Casas C, Hoekstra AG (2013) Modelling the Effect of a Functional Endothelium on the Development of In-Stent Restenosis. PLoS ONE 8(6): e66138.
Endothelial repair process and its relevance to longitudinal neointimal tissue patterns: comparing histology with in silico modelling
Journal of The Royal Society Interface, 2014
Re-establishing a functional endothelium following endovascular treatment is an important factor ... more Re-establishing a functional endothelium following endovascular treatment is an important factor in arresting neointimal proliferation. In this study, both histology (in vivo) and computational simulations (in silico) are used to evaluate neointimal growth patterns within coronary arteries along the axial direction of the stent. Comparison of the growth configurations in vivo and in silico was undertaken to identify candidate mechanisms for endothelial repair. Stent, lumen and neointimal areas were measured from histological sections obtained from eight right coronary stented porcine arteries. Two re-endothelialization scenarios (endothelial cell (EC) random seeding and EC growth from proximal and distal ends) were implemented in silico to evaluate their influence on the morphology of the simulated lesions. Subject to the assumptions made in the current simulations, comparison between in vivo and in silico results suggests that endothelial growth does not occur from the proximal and distal ends alone, but is more consistent with the assumption of a random seeding process. This may occur either from the patches of endothelium which survive following stent implantation or from attachment of circulating endothelial progenitor cells.
Prevalensi Karsinoma Lambung Pada Pemeriksaan Endoskopi Saluran Cerna Bagian Atas
Abstract - Moving from Internet Protocol version Four (IPv4) to Internet Protocol version six (IP... more Abstract - Moving from Internet Protocol version Four (IPv4) to Internet Protocol version six (IPv6) is not straightforward because IPv4 and IPv6 are incompatible protocols. To enable the smooth integration between IPv4 and IPv6, several transition mechanisms have been pro-posed by IETF IPng Transition Working Group (NGTrans). One of them is Dual Stack Transition Mecha-nism (DSTM). This paper reviews the implementation of DSTM over our IPv6 test-bed (6iNet) in University Utara Malaysia (UUM). This paper also describes our experi-ence of configuring 6iNet. 6iNet is the first IPv6 test-bed in UUM and has become a platform for IPv6 research in UUM.
Papers by Hatim Mohamad Tahir
Wireless service at Public University: A survey of users perception on security aspects
2018 International Conference on Information and Communications Technology (ICOIACT), 2018
There is an important growth in the application to detect and protect network from the intrusion ... more There is an important growth in the application to detect and protect network from the intrusion and unauthorized party as well as create access control among users around the world through this decade. Contextually, the majority of users expected an integrated platform to address the challenges posed by cyber security while also enabling secure access to campus network. Not surprisingly, the large majority of enterprises also have implemented some form of protection mechanism to provide end-to-end security such as firewall, authentication or antivirus, which at some extent it is difficult to design, configure, manage, maintain and monitor. Therefore, many security breaches are occurred because of the misconfiguration resulted the vulnerabilities to be exploited by hackers or caused by compatibility issues between products used in the campus network to reduce budget. Arguably, many security aspects can be strengthen through the improvement of human resource strategy to handle the campus network. This study want to investigate the user perception on security aspect of Wi-Fi performance in Universiti Utara Malaysia to provide some insights on the indicators to be considered by the network administrator.
Oving K-Means Clustering using discretization technique in Network Intrusion Detection System
2016 3rd International Conference on Computer and Information Sciences (ICCOINS), 2016
Network Intrusion Detection Systems (NIDSs) have always been designed to enhance and improve the ... more Network Intrusion Detection Systems (NIDSs) have always been designed to enhance and improve the network security issue by detecting, identifying, assessing and reporting any unauthorized and illegal network connections and activities. The purpose of this research is to improve on the existing Anomaly Based Intrusion Detection (ABID) method using K-Means clustering technique as to maximize the detection rate and accuracy while minimizing the false alarm. The problem with outliers may disturb the K-Means clustering process as it might be avoided in the clustering process from mixing with the normal data that make the NIDSs become less accurate. Thus this research aims to improve the performance of the ABID systems that balance the loss of information or ignored data in clustering. An integrated machine learning algorithm using K-Means Clustering with discretization technique and Naïve Bayes Classifier (KMC-D+NBC) is proposed against ISCX 2012 Intrusion Detection Evaluation Dataset. The outcome depicts that the proposed method generates better detection rate and accuracy up to 99.3% and 99.5% respectively and reduces the false alarm to 1.2% with better efficiency of 0.03 seconds time taken to build model.
Operating system is the heart of computing system. It is an important component of any computer s... more Operating system is the heart of computing system. It is an important component of any computer system. Although there are several operating systems in desktop environment, in this study we will focus on Windows operating system (OS). Windows based applications have clearly come to dominate the desktop environment. Window OS offers the full power of a modern operating system, including virtual memory, process, file protection and networking. The objectives of this study are to identify the vulnerabilities based on Window OS and to classify the vulnerabilities based on Window OS. Severity rating system from Microsoft Security Response Center (MSRC) will be used in order to identify the vulnerabilities. Meanwhile, we will use the classification scheme of intrusion technique to classify the vulnerabilities. This research expose about security flaws in Windows OS and how they can arise.
Mobile ad hoc networks (MANETS) are mobile nodes moving rapidly and they use wireless connections... more Mobile ad hoc networks (MANETS) are mobile nodes moving rapidly and they use wireless connections to connect to various networks or nodes. The dynamic nature of MANETs, make it vulnerable to attack by intruders. The sending and passing of nodes are based on several routing protocols. The packets do not reach the destination and some form of secure mechanism based on trust or friendship are deployed to protect the network integrity. Denial of service attacks is one of the typical attack type in mobile adhoc network. In this paper, we deployed Black hole and Grey hole attack. Black hole attack absord all data packets that are sent to its node whereas grey hole attack will drop some packet for a particular network destination based on packets type, time or randomly selected portion of packets. In this experiment we simulated several routing protocol to investigate the secure mechanism in protecting from the blackhole ad greyhole attack. The findings are presented and discussed.
Reusability Consideration to Improve Software Quality and Productivity in Object-Orient Web Application Development
2011 International Conference on Multimedia Computing and Systems, 2011
This paper conduct a comprehensive simulation study on the behavior of TCP-friendly Rate Control ... more This paper conduct a comprehensive simulation study on the behavior of TCP-friendly Rate Control (TFRC) protocol over Ad-Hoc On Demand Vector (AODV) routing protocol and Dynamic Source Routing (DSR) protocol. The aim are first, to measure the performance of TFRC in terms of throughput, delay and jitter. The second objective is to identify which Mobile Ad-Hoc Network (MANET) routing protocols work well with TFRC. We conduct the experiment by sending multimedia streaming traffic carried by TFRC over AODV and DSR respectively. Random-Waypoint mobility model is used for both experiments. Results obtained shows that in average TFRC over AODV has more throughput and less delay as compared with TFRC over DSR. However, in terms of jitter, TFRC over DSR gives better result.
Attitudes towards using computers in administration among school administrators
editlib.org, 2000
... Hatim Mohamad Tahir School of Information Technology Universiti Utara Malaysia 06010 Sintok, ... more ... Hatim Mohamad Tahir School of Information Technology Universiti Utara Malaysia 06010 Sintok, Kedah MALAYSIA Tel: (604)-700-3707 Fax: (604)- 700-5357 ... We managed to cover several studies by Chong (1995), Liong, Gan and Noran (1995) and Zainuddin (1997). ...
In early 2013, household broadband penetration in Malaysia has exceeded 66.7 per cent. However, t... more In early 2013, household broadband penetration in Malaysia has exceeded 66.7 per cent. However, the digital gap between urban and rural areas still exists. The rural communities still facing some issue in internet connectivity since many internet providers have less motivation to invest their resources in such areas. This project is undertaken with two objectives. First, to provide internet access to rural community with reasonable cost through the implementation of "Super Wi-Fi" technology. Second, to develop interactive internet local contents using Content Management System that can be utilised among rural folks. Two rural areas were selected as testing grounds, Bandar Baru Beris Jaya, Sik, Kedah and Kampung Oran, Mata Air, Perlis. Using existing infrastructure, the Streamyx, a high power modem antenna that called "Super Wifi" assist Streamyx to increase the coverage of current Wi-Fi signals being developed. The coverage of existing Wi-Fi signal is quite limit...
The performance of user verification using two fingerprints based on error rates
Biometric technology, especially fingerprint, attract users around the world to use it to secure ... more Biometric technology, especially fingerprint, attract users around the world to use it to secure their places or properties. On the current implementation of fingerprint based person verification, the system face several problems such as noisy finger and fingerprint misplacement by the user. When the problem only effected a small part of fingerprint, it is solved or minimized on the image processing and pattern recognition phase. But, when the problem involves a larger part of fingerprint, another approach needs to be used. To solve or minimize this kind of problem, the approach uses two fingerprints on the verification process have been experimented on this research. By not only referring to the thumbs which are usually used, the potential of the other fingerprint have been studied to find the two best fingerprints as used in this process. Using several simple methods to classify the decisions from both fingerprints; the best classifier have been used to study the performance level of the system compared to the current system used in single fingerprint. In this study, total error rate has been used as an indicator to the performance level of the system. Although the problems have not been totally solved, but the total error rates for fingerprint verification system has been minimized by using this approach.
A number of methods and measures have been used by researchers in software evaluation. Usability ... more A number of methods and measures have been used by researchers in software evaluation. Usability metrics is one of the approaches that has been used as a guideline to evaluate the quality of the system in many mobile applications.However, the metrics used for evaluation method keep changing due to new inventions of mobile phones.Thus, there is a need to create a dynamic model for evaluation that can grow together with new inventions and technology.In this paper, a dynamic usability metrics model for evaluation of mobile applications was designed.The model comprises usability goals, questions and metrics for evaluation of applications on mobile phones. To ensure that the model is reliable and effective, a usability study was conducted on two applications installed in different mobile phones.This model proves to be applicable for evaluation of mobile phone applications whereby its questions and metrics can be dynamically changed accordingly to comply with the requirements of the evalu...
Journal of Telecommunication, Electronic and Computer Engineering, 2018
Single Sign-on (SSO) was introduced to overcome the issue of password memorability among users as... more Single Sign-on (SSO) was introduced to overcome the issue of password memorability among users as researches have shown that users struggle to cope with too many sets of password as number of account increases. This is due to SSO relies on the usage of single authentication that allows users to access to multiple websites or services. As much as it has managed to solve the memorability issue to certain extend, users were found to have skeptical in its adoption due to security concerns. Among common issues of SSO is that it is prone to several attacks like spam, link manipulation, session hacking and particularly phishing. Despite of many efforts been placed to overcome phishing attack with regards to SSO, the effectiveness of the proposed solutions are yet to be proven by conducting extensive evaluation. Thus, this study intends to conduct an evaluation on a particular solution of phishing attack call page token. Page token was proposed recently which was claimed to be able to mitig...
Authenticate yourself once using OpenID
This paper presents a research concerning users' behaviours towards Web Single-Sign-On (SSO) ... more This paper presents a research concerning users' behaviours towards Web Single-Sign-On (SSO) for accessing e-learning applications.Many web application providers require users to subscribe to their services and authenticate themselves through the use of login credentials. The number of such applications is increasing exponentially which caused ineffective login credentials management among users.This may also contribute to various security issues to both users and application providers.Web SSO, a type of authentication service has been introduced to overcome the issues pertaining password management.However, the utilization of web SSO for accessing educational materials is still at its infancy stage; where many aspects of the technology has not been fully studied and developed.Hence, there is a need to study how users of e-learning applications behave towards web SSO. A course portal named CWS was developed with two authentication methods (i.e., OpenID and traditional). A focus ...
Uploads
hatim by Hatim Mohamad Tahir
Papers by Hatim Mohamad Tahir