This paper investigated the throughput performance of a secondary user (SU) for a random primary user (PU) activity in a realistic experimental model. This paper proposed a sensing and frame duration of the SU to maximize the SU throughput under the collision probability constraint. The throughput of the SU and the probability of collisions depend on the pattern of PU activities. The pattern of PU activity was obtained and modelled from the experimental data that measure the wireless local area network (WLAN) environment. The WLAN signal has detected the transmission opportunity length (TOL) which was analyzed and clustered into large and small durations in the CTOL model. The performance of the SU is then analyzed and compared with static and dynamic PU models. The results showed that the SU throughput in the CTOL model was higher than the static and dynamic models by almost 45% and 12.2% respectively. Furthermore, the probability of collisions in the network and the SU throughput were influenced by the value of the minimum contention window and the maximum back-off stage. The simulation results revealed that the higher contention window had worsened the SU throughput even though the channel has a higher number of TOLs.
Collisions arising from lane departures have contributed to traffic accidents causing millions of injuries and tens of thousands of casualties per year worldwide. Many related studies had shown that single vehicle lane departure crashes accounted largely in road traffic deaths that results from drifting out of the roadway. Hence, automotive safety has becoming a concern for the road users as most of the road casualties occurred due to driver's fallacious judgement of vehicle path. This paper proposes a vision-based lane departure warning framework for lane departure detection under daytime and night-time driving environments. The traffic flow and conditions of the road surface for both urban roads and highways in the city of Malacca are analysed in terms of lane detection rate and false positive rate. The proposed vision-based lane departure warning framework includes lane detection followed by a computation of a lateral offset ratio. The lane detection is composed of two stages: pre-processing and detection. In the pre-processing, a colour space conversion, region of interest extraction, and lane marking segmentation are carried out. In the subsequent detection stage, Hough transform is used to detect lanes. Lastly, the lateral offset ratio is computed to yield a lane departure warning based on the detected X-coordinates of the bottom end-points of each lane boundary in the image plane. For lane detection and lane departure detection performance evaluation, real-life datasets for both urban roads and highways in daytime and night-time driving environments, traffic flows, and road surface conditions are considered. The experimental results show that the proposed framework yields satisfactory results. On average, detection rates of 94.71% for lane detection rate and 81.18% for lane departure detection rate were achieved using the proposed frameworks. In addition, benchmark lane marking segmentation methods and Caltech lanes dataset were also considered for comparison evaluation in lane detection. Challenges to lane detection and lane departure detection such as worn lane markings, low illumination, arrow signs, and occluded lane markings are highlighted as the contributors to the false positive rates.
Keusahawanan sering dianggap sebagai subjek yang lebih cenderung kepada pelajar dalam bidang perniagaan tetapi tidak untuk pelajar yang mempunyai pelbagai kemahiran yang terlibat dalam bidang teknikal. Namun, ini adalah satu tanggapan yang tidak seharusnya wujud kerana Malaysia seharusnya perlu mengenal pasti kesedaran keusahawanan dalam bidang teknikal. Pada masa kini, kesedaran keusahawanan dalam bidang teknikal tertentu adalah kurang lantaran program keusahawanan lazimnya lebih tertumpu kepada pelajar InstitusiPengajian Tinggi (IPT). Misalnya, Pembangunan Keusahawanan Bumiputera adalah lebih tertumpu kepada golongan siswazah IPT, belia dan wanita. Dasar Pembangunan Keusahawanan IPT juga diperkenalkan agar modal insan dengan daya pemikiran, atribut dan nilai keusahawanan dalam kalangan IPT tempatan dapat dilahirkan. Tujuan kajian ini dijalankan adalah untuk mengenal pasti tahap kesedaran keusahawanan dalam kalangan pelajar Institut Latihan Perindustrian (ILP) di Terengganu berhubung dengan faktor keusahawanan dari aspek individu usahawan yang berbeza serta struktur dan persekitaran perniagaan. Seterusnya, mengkaji hubungan antara kesedaran keusahawanan dengan pembolehubah tidak bersandar lain yang berkait dengan kajian seperti ciri keusahawanan dan cabaran keusahawanan. Kaedah kuantitatif telah digunakan dan borang soal selidik diedarkan kepada 280 orang pelajar. Hasil analisis regresi berganda menunjukkan bahawa cabaran keusahawanan merangkumi sikap dan minat, kemahiran keusahawanan serta pendidikan dan pengetahuan keusahawanan merupakan elemen paling signifikan yang mempengaruhi kesedaran keusahawanan dalam kalangan pelajar berkemahiran diILP untuk menjadi seorang usahawan. Oleh itu, adalah sangat penting bagi kerajaan Malaysiauntuk memberi perhatian terhadap cabaran yang dihadapi oleh para pelajar ini dan mengambil tindakan terhadap segala kemungkinan yang boleh mempengaruhi atau memberi kesan kepada minat pelajar terhadap keusahawanan pada masa akan datang.
Algal communities possess many attributes as biological indicators of spatial and temporal environmental changes. Algal parameters, especially the community structural and functional variables that have been used in biological monitoring programs, are highlighted in this document. Biological indicators like algae have only recently been included in water quality assessments in some areas of Malaysia. The use of algal parameters in identifying various types of water degradation is essential and complementary to other environmental indicators.
Algal communities possess many attributes as biological indicators of spatial and temporal environmental changes. Algal parameters, especially the community structural and functional variables that have been used in biological monitoring programs, are highlighted in this document. Biological indicators like algae have only recently been included in water quality assessments in some areas of Malaysia. The use of algal parameters in identifying various types of water degradation is essential and complementary to other environmental indicators.
In order to manage blue swimming crabs in Pangkajene Kepulauan, management measures are required. Since the environment which affects the abundance of the blue swimming crab varies seasonally, it is necessary to take into account the seasonal nature with the aim of developing a management strategy. The objectives of this study are to define the abundance of and fishing season of blue swimming crabs in the Pangkajene Kepulauan waters, South Sulawesi, Indonesia. The fishing season was analysed using seasonal index analysis, while fish abundance was analysed by means of Equilibrium-Schaefer. The result of this study demonstrated that fishermen allocate their fishing gear all year, although the fish catch is seasonal. Based on analysis of the result, the fishing season for the blue swimming crabs is short. The peak fishing season starts in May and finishes in June. However, in order to enable their families to earn a living, fishermen operated their fishing gear throughout the year. As a result, both catch landing and effort were close to maximum sustainable yield (MSY). In order to reduce fishing pressure, it is necessary to reduce fishing gear and have a seasonal arrangement regarding fishing gear allocation.
The pursuit, initiation and establishment of multi-stakeholder partnerships, including with the private sector, is often a critical component of attaining and achieving the success and sustainability of many projects the world over. However, the soliciting and securing of socially, economically and environmentally constructive engagements between the private sector on the one hand, and the NGOs, CBOs and local communities on the other hand, is in reality much easier said than done. Notably, since most private sector corporations undoubtedly tend to leave behind various "ecological footprints", differing only in their size and depth, stemming from their respective forms and functions, and their ensuing impacts and implications. The interplay between the civil society and the private sector, especially for resource mobilization. (Copied from article).
Comet Lulin was discovered by Lin Chi-Sheng and Ye Quanzhi using the 16-inch telescope at Lulin Observatory in Nantou, Taiwan in 2007. According to Brian Marsden of the Smithsonian Astrophysical Observatory, it reached its perihelion on 10 January 2009 at a distance of 113 million
km from the Sun. It moves in a very nearly parabolic retrograde (‘backwards’ compared to the movement of the planets) orbit at an inclination of 1.6 degrees from the ecliptic (“Newfound Comet Lulin to Grace Night Skies”). http://www.space.com/spacewatch/090206-ns-cometlulin.html). It passed nearest to the Earth at a distance of 61 million km on 23 February 2009.
This paper presents an experimental characterization of millimeter-wave (mm-wave) channels in the 6.5 GHz, 10.5 GHz, 15 GHz, 19 GHz, 28 GHz and 38 GHz frequency bands in an indoor corridor environment. More than 4,000 power delay profiles were measured across the bands using an omnidirectional transmitter antenna and a highly directional horn receiver antenna for both co- and cross-polarized antenna configurations. This paper develops a new path-loss model to account for the frequency attenuation with distance, which we term the frequency attenuation (FA) path-loss model and introduce a frequency-dependent attenuation factor. The large-scale path loss was characterized based on both new and well-known path-loss models. A general and less complex method is also proposed to estimate the cross-polarization discrimination (XPD) factor of close-in reference distance with the XPD (CIX) and ABG with the XPD (ABGX) path-loss models to avoid the computational complexity of minimum mean square error (MMSE) approach. Moreover, small-scale parameters such as root mean square (RMS) delay spread, mean excess (MN-EX) delay, dispersion factors and maximum excess (MAX-EX) delay parameters were used to characterize the multipath channel dispersion. Multiple statistical distributions for RMS delay spread were also investigated. The results show that our proposed models are simpler and more physically-based than other well-known models. The path-loss exponents for all studied models are smaller than that of the free-space model by values in the range of 0.1 to 1.4 for all measured frequencies. The RMS delay spread values varied between 0.2 ns and 13.8 ns, and the dispersion factor values were less than 1 for all measured frequencies. The exponential and Weibull probability distribution models best fit the RMS delay spread empirical distribution for all of the measured frequencies in all scenarios.
This research focuses on the ASTER DEM generation for visual and mathematical analysis of topography, landscapes and landforms, as well as modeling of surface processes of Central Alborz, Iran. ASTER DEM 15 m generated using tie points over the Central Alborz and Damavand volcano with 5671 m height from ASTER (Advanced Space borne Thermal Emission and Reflection Radiometer) satellite data using PCI Geomatica 9.1. Geomorphic parameters are useful to identify and describe geomorphologic forms and processes, which were extracted from ASTER DEM in GIS environment such as elevation, aspect, slope angle, vertical curvature, and tangential curvature. Although the elevation values are slightly low in altitudes above 5500 m asl., the ASTER DEM is useful in interpretation of the macro- and meso-relief, and provides the opportunity for mapping especially at medium scales (1:100,000 and 1:50,000). ASTER DEM has potential to be a best tool to study 3D model for to geomorphologic mapping and processes of glacial and per glacial forms above 4300 m asl.
The nature, extent and definition of a collaboration varies between individuals, disciplines, departments and institutions. It depends upon such factors as the people involved, the nature of the research problem, the research environment, the institutional culture and demographic factors. This paper will examine the concept of collaborative research and discuss its place and position in an evolving university.
Frequency hopping spread spectrum (FHSS) systems with partial band interference require appropriate compounding of spread spectrum modulation, error correcting code, diversity and decoding method to receive improved transmission signal. In this paper, a fast FHSS system with regular low-density parity-check codes was employed to cater some anti-jamming competence by using good waterfall and error floor performance. The performance evalution of the previously mentioned system was conducted in the presence of partial band noise jamming. The best possible design of the system was achieved with the combination of diversity level L=2 with a probability rate of at 0.7 dB which showed the robustness of the system.
The incidence of dengue in Malaysia has increased from 15.2 per 100,000 in 1973 to 361.0 per 100,000 population by the year 2014. The same trend was seen in case fatality rates that went up from 0.16% to 0.62% between 2000 to 2013.1,2 More than 60% of the cases were from the Klang Valley region. In Pahang the dengue incidence rates from 2004 to 2014 showed a similar increase from 40.9 to 193.8 per 100,000 population and an increase in case fatality rates from 0.07% to 0.3% too was observed between 2000-2014. Fortunately these figures were below the national average.3
In recent years image acquisition in close range photogrammetry relies on digital sensors such as digital cameras, video cameras, CCD cameras etc that are not specifically designed for photogrammetry. This study is performed to evaluate the compatibility of the digital metric camera and non-metric camera for the purpose of mapping meandering flume, using close range photogrammetric technique and further, to determine the accuracy that could be achieved using such a technique. The meandering flume provides an opportunity to conduct an experimental study in a controlled environment. In this study, the digital images of the whole meandering flume were acquired using a compact digital camera - Nikon Coolpix S560, a Single Lens Reflex (SLR) Nikon D60 and also a metric digital camera Rollei D30. A series of digital images were acquired to cover the whole meandering flume. Secondary data of ground control points (GCP) and check points (CP), established using the Total Station technique, was used. The digital camera was calibrated and the recovered camera calibration parameters were then used in the processing of digital images. In processing the digital images, digital photogrammetric software was used for processes such as aerial triangulation, stereo compilation, generation of digital elevation model (DEM) and generation of orthophoto. The whole process was successfully performed and the output produced in the form of orthophoto. The research output is then evaluated for planimetry and vertical accuracy using root mean square error (RMSE). Based on the analysis, sub-meter accuracy is obtained. It can be concluded that the differences between the different types of digital camera are small . As a conclusion, this study proves that close range photogrammetry technique can be used for mapping meandering flume using both the metric digital camera and non-metric digital camera.
Sustainability is an important factor in designing vernacular architecture, including vernacular palace architecture; the latter refers to low-rise buildings similar to Traditional Malay Houses (TMH). However, the Istana Lama Seri Menanti is a 4-storey mid-rise vernacular palace which was designed with sustainability in mind. This mid-rise element of the palace communicates the vernacular architecture of TMH in Negeri Sembilan whereas sustainable designs are factored in environmentally friendly materials, construction methods, and the environmental impact of the building culturally and economically. This research was aimed at examining the sustainability approach of Istana Lama Seri Menanti as a mid-rise vernacular palace in the early 20th Century, and its impact on the current generation after 109 years. The research methodologies include case and precedent studies of vernacular palaces in Malaysia as well as interviews with experts in the field. In conclusion, the architectural sustainability of Istana Lama Seri Menanti had taken into account timber availability, consumption of naturally available resources, designs with minimal environmental impact and high cultural importance in the building design with the ultimate aim of conserving it for future generations.
This paper describes the culture of Traditional Malays, in particular the use of sustainable furniture inside a Traditional Malay House (TMH). The sample houses for this study were retrieved from archived reports, from the Centre for Built Environment in the Malay World (KALAM), Universiti Teknologi Malaysia (UTM). Data collected were analysed using Componential Analysis for the presence of components (based on drawings of archival reports as well as photographic evidence from site visits). The findings showed that the Malays used a variety ofsustainable furniture in their houses. Additionally, their homes had built-in furniture, which indicated the houses were pre-designed based on its user.
Prolonged drought conditions have adverse environmental and socio-economic impacts due to unmet water demands. Defining drought is difficult because of its onset and ending time. Therefore, characterisation of drought is essential for drought management operations. Thus, drought indices come in handy and are a practical approach to assimilate large amounts of data into quantitative information which can then be applied for drought forecasting, declaring drought levels, contingency planning and impact assessments. This study analyses drought events using indices, namely SPI and Deciles Index, computed with DrinC software program but are not popular in Malaysia. It is observed that both indices are identical and suitable for drought occurrences.
The walking of a humanoid robot needs to be robust enough in order to maintain balance in a dynamic environment especially on uneven terrain. A walking model based on multi-sensor is proposed for a Robotis DARwIn-OP robot named as Leman. Two force sensitive resistor (FSRs) on both feet equipped to Leman to estimate the zero moment point (ZMP) alongside with accelerometer and gyrosensor embedded in the body for body state estimation. The results show that the FSRs can successfully detect the unbalanced walking event if the protuberance exists on the floor surface and the accelerometer and gyrosensor (Inertial Measurement Unit, IMU) data are recorded to tune the balancing parameter in the model.
Contaminated and ageing transmission line insulators often suffer from temporary or permanent loss of their insulating properties due to flashover resulting in power system failure. Surface discharges are precursors to flashover. To pre-empt any occurrence of flashovers, utility companies monitor the conditions of their insulators. There are numerous insulator surface monitoring techniques such as Leakage Current, Acoustics, and Infrared. However, these techniques may not be suitable for in-situ condition monitoring of the insulators as they are prone to noise, affected by environmental conditions or contact methods. Monitoring of the UV signals emitted by the surface discharges of these insulators has been reported to be a promising technique. However, comprehensive studies on this technique is lacking, especially on aged insulators. This paper investigated the UV signals of contaminated and aged insulators detected during surface discharge activities using UV pulse method. The time and frequency domain of the UV signals were analysed for a group of insulator samples having varying levels of contamination and phases of ageing. Results show that there is a strong correlation between the contamination level and ageing of the insulators with the amplitude and harmonic components of the UV signals. This correlation can useful to monitor in-service insulator surface conditions.
In this paper, cap and pin porcelain insulator was studied under an environment with different levels
of humidity. The electric field strength and voltage distribution profile along the insulator string was
simulated using a computational software package. In this study, ANSYS Maxwell based on the Finite
Element Method (FEM) was used to simulate the short standard insulator string. The short standard
insulator string was modelled as a five-unit cap and pin porcelain insulator that was stacked according
to the IEC 60383 standard. Different humidity levels measured using relative humidity is applied to
the insulator. From this simulation, the locations within the insulator under high electric field stress are
identified when different humidity is applied.