UNIMAS Journal (Universiti Malaysia Sarawak)
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Predicting Hydraulic Conductivity (k) of Tropical Soils by using Artificial Neural Network (ANN)
Full text linkHydraulic conductivity of tropical soils is very complex. Several hydraulic conductivity prediction methods have focused on laboratory and field tests, such as the Constant Head Test, Falling Head Test, Ring Infiltrometer, Instantaneous profile method and Test Basins. In the present study, Artificial Neural Network (ANN) has been used as a tool for predicting the hydraulic conductivity (k) of some tropical soils. ANN is potentially useful in situations where the underlying physical process relationships are not fully understood and well-suited in modeling dynamic systems on a real-time basis. The hydraulic conductivity of tropical soil can be predicted by using ANN, if the physical properties of the soil e.g., moisture content, specific gravity, void ratio etc. are known. This study demonstrates the comparison between the conventional estimation of k by using Shepard's equation for approximating k and the predicted k from ANN. A programme was written by using MATLAB 6.5.1 and eight different training algorithms, namely Resilient Backpropagation (rp), Levenberg-Marquardt algorithm (lm), Conjugate Gradient Polak-Ribiere algorithm (cgp), Scale Conjugate Gradient (scg), BFGS Quasi-Newton (bfg), Conjugate Gradient with Powell/Beale Restarts (cgb), Fletcher-Powell Conjugate Gradient (cgf), and One-step Secant (oss) have been compared to produce the best prediction of k. The result shows that the network trained with Resilient Backpropagation (rp) consistently produces the most accurate results with a value of R = 0.8493 and E2 = 0.7209
Potential Modeling Of Pavement Deterioration Rate Due To Cracking
Full text linkBitumen pavements tend to crack at some point of their life under the combined action of traffic and the environment. These cracks are defects in the pavement surfacing which weakens the pavement and allows water to penetrate and cause further weakening. Once initiated, cracking usually increases in extent, severity and intensity, leading eventually to pavement failure. Cracking has therefore been an important indicator for road pavement maintenance. In view of the extensive road network in Malaysia covering more than 80,000 kilometers in total, the government has to spend huge sums of money on the repair of cracks under its annual road maintenance program. However, the resurfacing works have not always been successful and cracks tend to reappear after some time. The accurate prediction of crack occurrence and the effectiveness of resurfacing works to control cracks are key factors in predicting the timing and costs of road maintenance. In view of this, it is imperative that a suitable model for the prediction of crack development be derived. This model will then be able to predict the deterioration rate of pavement cracking in the future. It in turn will enable effective road rehabilitation programs be implemented in time before cracking deteriorates and leads to eventual pavement failure
Determination of Level of Service (LOS) on Different Roads in Kuching Area (A Case study)
Full text linkThe concept of Level of Service (LOS) is originated from the Highway Capacity Manual (HCM). LOS is a qualitative assessment of the operational performance of a roadway facility based on quantitative performance measures. Many transportation infrastructure funding decisions are based on LOS analysis, and LOS designations are intended to represent user-perceived quality of service. This study has been carried out to determine the LOS on different roads. The profile of study area is in Kuching, Sarawak where five roads with different characteristics and posted speed of urban multilane with 80km/hr and 70km/hr, suburban two-lane two-way with 90 km/hr and 80km/hr had been selected for the studies. Substantial numbers of inputs are required for the LOS analysis and determination based on HCM procedures. These inputs are: a long list of traffic volume collected in different peak hours; traffic composition such as proportion of heavy vehicles in traffic; geometric characteristics such as number of lanes, lane width, shoulder width, and approach grades. Results of the study showed that LOS in the urban multilane is still in satisfactory range with LOS ranging from C to D except for most of the traffic congestion cases in urban multilane at the traffic light junctions and roundabouts. However, LOS in the suburban two-lane two-way is only satisfying in the range of LOS E; hence multilane should be introduced in such cases. Recommendations such as to provide various or multitude modes of transportation needs should be introduced in urban area. Furthermore, a suitable and efficient hierarchy in road system should be provided in suburban areas before turning into urban areas
A Study on Suitable Habitat for Swiftlet Farming
Full text linkSwiftlet farming is a new industry in Sarawak as compared to other long-standing industries such as rubber, palm oil and timber. It is one of the businesses that involved a small capital investment that could generate enormous returns in the future. Swiftlet farming involves the conversion of human-centric building into structures for Swiftlet. The purpose of this conversion is to let Swiftlet for nesting and protect them. The design and construction of such building will also helps to accommodate Swiftlets' population. The nest of the Edible-nest Swiftlet rank amongst the world's most expensive animal products. Therefore, in order to increase the productivity of bird nest, study of the suitable habitat for Swiftlet should be done thoroughly. Environmental factors such as air temperature, surface temperature, relative humidity, air velocity and light intensity are the key factors for a successful Swiftlet farm house. Internal air temperature of building should be maintained from 26°C to 35°C, relative humidity from 80% to 90%, low air velocity and light intensity less than 5 LUX. Proper ventilation and installation of a humidifier could help the building to achieve the desirable range of environment factors. Location of structure will also be considered from direct sunlight direction to reduce the internal temperature. Only licensed Swiftlet farming is legal
Adequacy of Quality Provisions in Standard Forms of Local and International Construction Contracts
Full text linkStandard forms of contracts have been in use in the Malaysian construction industry as a means to expedite contractual and legal duties for the clients who wish to avoid expensive and complex legal endeavors to arrive at an agreement with their contractors. Various forms have been drafted by various professional bodies and organizations, both locally and internationally, to meet the demands of the local construction market for standard forms. Quality provisions are among the topics/issues covered in the standard forms. However, evidently, it is noted that the quality and its standards in the Malaysian construction industry has consistently remained as the root for many construction disputes. Whether or not standard forms of construction contracts have sufficiently cater for quality, remains a question. If the "one-size fits all" postulate does not hold especially when it comes to ensuring quality on site, the question of validity and effectiveness of standard forms becomes a pertinent one. This paper presents a study of various quality related clauses in local and international standard forms and comparisons were made among the chosen forms. Experts opinion within this field are sought as well in order to improve the robustness of this study. This paper also investigates the adequacy of the provision of these forms and suggests suitable changes to the current standard forms, where necessary, within the study
Study on Generation and Composition of Solid Waste Produced in UNIMAS Cafeterias
Full text linkUNIMAS's cafeterias generate solid waste everyday and there are 11 cafeterias operating in UNIMAS. The study involved two main cafeterias which are located at Bunga Raya and Alamanda colleges. The objective of the study was to determine the waste generation and composition of solid waste generated by the cafeterias. The study was done by collecting data from both cafeterias on Monday, Wednesday and Friday. The collected waste were weight, mixed, quartered and the composition of the samples were then determined. The amount of waste generated daily in Bunga Raya cafeteria was more compared to that generated in Alamanda cafeteria. Food scraps were the highest component in the solid waste for both cafeterias, followed by plastics, papers, and non-ferrous metal. The energy that can be generated from waste from the whole cafeterias in UNIMAS was estimated at 95, 444.33 kJ/kg/day. According to the study, the solid waste management can be more efficient by minimizing the food preparation by the cafeteria operators. Besides that, the study can create awareness among students regarding the potential energy that can be harvested from the solid waste
Modified Cement System: Durability and Aesthetics
Full text linkConcrete deterioration is one of the most concern matters in construction world. The concrete deterioration such as efflorescence should not be ignored. The efflorescence is a deposit salts, usually white, formed on a surface of concrete. The efflorescence is not a major problem that leads to structural defects but it can build unattractiveness to the structure such as brick wall and concrete mortar. The way to prevent the efflorescence occurrence is by studying the results of testing such as absorption and efflorescence itself to reduce the efflorescence. The non-modified cement system can reduce the efflorescence but cannot avoid it because of the reaction of cement hydration itself. This study is to prove that by using a modified cement system such as Pulverized Fly Ash (PFA) and Polymers (water based latex grade 29Y46), the efflorescence of the mortar can be prevented. The results from this study proved the modified mortar which is a sample with PFA and Polymers has higher strength, durability, and less efflorescence compared with the non-modified cement system