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121.
Mohd Mustaqim Mohd-Nordin Ki-Il Song Gye-Chun Cho Zainab Mohamed 《Rock Mechanics and Rock Engineering》2014,47(2):561-573
Geophysical site investigation techniques based on elastic waves have been widely used to characterize rock masses. However, characterizing jointed rock masses by using such techniques remains challenging because of a lack of knowledge about elastic wave propagation in multi-jointed rock masses. In this paper, the roughness of naturally fractured rock joint surfaces is estimated by using a three-dimensional (3D) image-processing technique. The classification of the joint roughness coefficient (JRC) is enhanced by introducing the scan line technique. The peak-to-valley height is selected as a key indicator for JRC classification. Long-wavelength P-wave and torsional S-wave propagation across rock masses containing naturally fractured joints are simulated through the quasi-static resonant column (QSRC) test. In general, as the JRC increases, the S-wave velocity increases within the range of stress levels considered in this paper, whereas the P-wave velocity and the damping ratio of the shear wave decrease. In particular, the two-dimensional joint specimen underestimates the S-wave velocity while overestimating the P-wave velocity. This suggests that 3D joint surfaces should be implicated to obtain the reliable elastic wave velocity in jointed rock masses. The contact characteristic and degree of roughness and waviness of the joint surface are identified as a factor influencing P-wave and S-wave propagation in multi-jointed rock masses. The results indicate a need for a better understanding of the sensitivity of contact area alterations to the elastic wave velocity induced by changes in normal stress. This paper’s framework can be a reference for future research on elastic wave propagation in naturally multi-jointed rock masses. 相似文献
122.
Safari Muhammad Aslam Mohd Masseran Nurulkamal Majid Muhammad Hilmi Abdul 《Theoretical and Applied Climatology》2022,148(3-4):1085-1110
Theoretical and Applied Climatology - In this study, the Weibull distribution with various numerical estimation methods is utilized for the assessment of wind energy potential in Mersing and Port... 相似文献
123.
This paper will discuss the computerised development control and approval system being developed for the Planning and Development Control Department. City Hall of Kuala Lumpur, with stress on the GIS architecture developed within the system. The prospects and challenges towards implementation of the system are also discussed. 相似文献
124.
In Malaysia, the endemic level of dengue fever (DF) has already changed morbidity indicators, and the magnitude of these incidences in the last few years has surpassed the incidences of all other diseases of compulsory notification. The reasons for the dramatic emergence of DF are complex and not well understood. There are many factors that contribute to the epidemiological conditions that favour viral transmission by the main mosquito vector. This study, therefore, is filling this gap by analysing the impact of dengue incidence at a local (Subang Jaya) scale using environmental factors. Meteorological data and land-use pattern were consolidated using geographic information system (GIS) and its components as an analytical tool. We have shown that weather variables (relative humidity, temperature and precipitation) have significant correlation with DF incidence with seasonal variation. Besides land-use pattern, DF incidence shows the higher distribution in the residential area, followed by commercial and industrial area. This is due to the higher population density in residential area as well as favourable places for the breeding of dengue-carrying Aedes mosquitos created by humans in the residential area, especially one-storey houses. The analysis on the trends of DF incidence towards various housing types indicate that most of the victims’ houses fall into interconnection houses and mixed houses types compared to the independent houses area. The outcome driven from this analysis suggested that each character of the environmental factors has their own risk towards dengue incidence. In line with that, it is possible to develop a dynamic model of DF transmission using the knowledge produced by this comprehensive time series data and the results provided by the different analyses. 相似文献
125.
Very broadband seismic background noise analysis of permanent good vaulted seismic stations 总被引:2,自引:1,他引:1
Abd el-aziz Khairy Abd el-aal 《Journal of Seismology》2013,17(2):223-237
This paper describes the results of a preliminary study conducted to analyze seismic background noise at sites of recently deployed very broadband stations of the Egyptian National Seismological Network (ENSN). The main purpose of the study is to assess the effects of permanent seismic vault construction and also to establish characteristics and origin of seismic noise at those sites. Another goal of this study is to determine the time needed for noise at those sites to stabilize. The power spectral densities of background noise at short period band (SP), very broadband (VBB), and ultra long period band (ULP) for each component of each broadband seismometer deployed in the different investigated sites are calculated. A MATLAB code has been developed that manages data processing and data analysis and compares the results with the high-noise model (NHNM) and low-noise model (NLNM) of Peterson (1993). Based on the obtained analysis, the noise stability and the efficiency of each station to record regional and teleseismic events are measured. The results of this study could be used in the future to evaluate station quality, to improve those processes that require background noise values, such as automatic association, and to improve the estimation of station and network detection and location thresholds. 相似文献
126.
Mina Kaboudarahangi Osman Mohd Tahir Mustafa Kamal M.S. 《The Australian geographer》2013,44(2):197-213
Malaysia has a complex multiracial population, predominantly defined by three major ethnic groups: Malay, Chinese and Indian races, with diverse cultural backgrounds. Despite this, the country has a vision to be the most beautiful garden nation, and its National Landscape Policy (NLP) puts emphasis on creating a unique landscape and garden identity. Because of ethnic and cultural differences, there are differences between preferences for developing a garden identity for Malaysia. Hence, this study focused on the visual quality of gardens. Representative images of four well-established gardens of the world including Persian-Islamic, English, Japanese and Chinese gardens were presented to the study's respondents through preference photo surveys. Respondents from the three major ethnic groups in Malaysia were asked to rate their preferred garden types, elements and scenes that they would like to see in Malaysian gardens. The results pinpointed expectations of the visual quality of gardens. These highlighted some similarities and differences between the three major ethnic groups in their preferences for the scenes and elements that they sought in gardens. Diverse factors must be considered when creating Malaysian gardens that will be accepted by Malaysians of different ethnic groups. Garden development reveals preferences attached to visual qualities and emphasises cultural differences between garden users. 相似文献
127.
Hamizan Yusof Muhammad Saad Shahbudin Naim Mohd Azrul Khodzori Mohd Fikri Akmal Hanapiah Muhammad Faiz Mohd 《Ocean Science Journal》2021,56(3):317-325
Ocean Science Journal - Previous studies indicated that artificial live rock (ALR) has the potential to be used as a substrate for coral juveniles. The present study reported a potential of ALR as... 相似文献
128.
El Zeit Bay is a semi-closed area with a rectangular shape which south side is connected witu northwestern side of Red Sea.
The study was done to detect the characteristics of the bottom facies at El Zeit Bay. Single-beam seabed echoes combined with
diving survey and sediments analyses were used to detect sea bed characteristics. The seabed floor of the study area is characterized
by three physiographical distinct bottom facies; sand facies: floral facies and coral patches facies. Sand facies lies at
very shallow water it extended from shore line to depth about 2 m. It has very fine sand size intercalated by mud sediments.
It is characterized by very poor benthos. Floral bottom facies has medium sand which characterized by rich floral vegetation
this flora appear in scattered and irregular forms. It is observed at an average depth from 4 m to 6 m. Coral patches facies
is characterized by the presence of coarse sediments. The coral reef covers about 40% of the study area (29.5% hard corals
and 10.5% is soft ones) while the rest of the area (60%) is characterized by different benthos. In communities general, his
area characterized by high biodiversity. 相似文献
129.
130.