Structural analysis of long arm excavator boom for optimization performance under maximum breakout condition

Long Arm Excavators are widely used in the construction site for excavating deep holes or trenches. However, due to the often-severe work conditions, such as large lifting loads, poor ground conditions to sustain the machine’s self-weight, Long Arm Excavator parts are subjected to constant wear and tear, incurring downtime losses and safety issues. The boom is considered the most critically affected part of the machine in these work conditions, where the high forces and unpredictable elements at the worksite could severely affect the machine’s overall performance. A potential solution is the reinforcement of the boom to improve its robustness. As an industrial collaborative project, the present study examines the performance of an existing machine with simulated improvement of the boom with such an approach, i.e. incorporation of stiffener reinforcement. Simulation works were carried out with Ansys Workbench 19.2 to assess the boom’s performance in terms of resulting stress, strain and deformation under a series of improved conditions, which include varying the dimensions and positions of the stiffeners on the boom. The improved conditions were Improvement I: stiffeners thickness reduction to 10mm, Improvement II: a combination of different stiffeners thickness reduction which 10mm and 8mm at critical and non-critical part of the boom, Improvement III: removal of half intermediate stiffeners thickness 12mm and Improvement IV: removal of half intermediate stiffeners thickness 8mm. Structural analysis was conducted based on the maximum breakout condition in which the excavator generates maximum digging force. From the analysis, it was found that the maximum equivalent stress of the boom decreased with the number of stiffeners. The combination of different stiffeners thickness could also increase the boom’s strength while decreasing the maximum equivalent stress. The lowest maximum equivalent stress of the boom was achieved via Improvement II with a reduction of 26.1% maximum equivalent stress. Removal of non-critical part stiffeners also kept stress values under the designated stress limits against fatigue failure, i.e. 44.49 MPa and 42.47 MPa (Improvement III and IV). In summary, the optimal design could be obtained with improvement II. This would effectively save on the manufacturing costs while maximizing the machine’s performance on-site, simultaneously reducing downtime and hence operating costs and time

HYBRID FUZZY CONTROL AND ANT COLONY OPTIMIZATION BASED PATH PLANNING FOR WHEEL MOBILE ROBOT NAVIGATION

Wheeled Mobile Robot (WMR) is extremely important for active target tracking control and reactive obstacle avoidance in an unstructured environment. A WMR needs the best control performance an automatic path planning to maintain a very high level of accuracy. Therefore, the development of control strategies and path planning is very significant. Hence, research was carried out to investigate the control and path planning issues of WMR in dynamic environment. Several controllers such as conventional controller Proportional (P), Integral (I), Derivative (D) and Fuzzy Logic controller were investigated. A Hybrid Controller for differential WMR was proposed. Various aspects of the research on WMR such as kinematics model, conventional controller, fuzzy controller and hybrid controller were discussed. Overall it was found that on average the Hybrid Controller gives the best performance with 5.5s, 5.4s and 11s for target of 10x 10y, 30x10y and 60x20y respectively

A study on the relationship between emotional intelligence and the quality of work life at Pejabat Tanah Dan Jajahan Machang / Siti Nursyuwaibah Mohamad Rashid

The purpose of this study is to identify the relationship between emotional intelligence and quality of work life towards employees of Pejabat Tanah Dan Jajahan Machang. This study was descriptive and correlational research. The sample of the study was consisted of 63 respondents at Pejabat Tanah Dan Jajahan Machang who were selected through simple random sampling based on list name provided. The questionnaires consisted of the items regarding emotional intelligence and quality of work life was distributed to the respondents. The data then analyzed by using SPSS 22.0 software. In order to identify the objective of the study in which the factors of emotional intelligence, the highest and the lowest factor of emotional intelligence the result of descriptive statistic of mean and standard deviation was used. The relationship between emotional intelligence and quality of work life was identified through the result and outcomes of Pearson Correlations coefficient. Through the study, self-awareness, self-management, social awareness and relationship management was provided as the factors of emotional intelligence. The findings identify that all of the factors of emotional intelligence results in a positive strong relationship with quality of work life. Furthermore, results evident that, self-awareness as the highest factors and relationship management as the lowest factors of emotional intelligence towards quality of work life. The result of the study show, there was relationship between emotional intelligence and quality of work life towards employees of Pejabat Tanah Dan Jajahan Machang. This study was significant to employers, employees and also students in improving emotional intelligence among themselves as emotional intelligence can improve the quality of work life

The Effect of Detention Pond’s Outlet Design to the Peak Discharge of a Watershed

Flood occurs when the water discharge of a watershed exceed the drain capacity. One of the solutions to avoid flood when this occurs is by having a detention pond to control the amount of water discharge below the discharge capacity of the drain. This research project is to explore further on the effect of detention pond built in terms of its outlet design base on simple outlet structures frequently used by JP

Challenges of ISO 9001:2015 Quality Management System Implementation in Malaysian Construction Companies

The purpose of this study is to investigate the barriers and challenges in the implementation of ISO 9001:2015 QMS in the Malaysian construction company. A random sample of 100 workers in construction companies in Malaysia has been used to identify these factors in a structured survey, resulting in a response rate of 49%. The measurement model's reliability and validity were evaluated using exploratory and conformity factor analysis. Structural Equation Modelling (SEM) was used to investigate the relationships between the latent constructs. The results show that surveyed construction companies implemented ISO 9001 QMS primarily for company performance and encountered numerous challenges during the implementation process. Furthermore, findings highlighted the importance of effective communication and organizational learning in enhancing company performance in construction organizations. According to the findings, these factors have a significant impact on companies in terms of effective communication, organizational learning, and company performance in construction organizations, at 95% confidence interval (p<0.05). The subjective data was based on individuals from a variety of organizations being surveyed, and the convenience sampling method was used due to the physical limitations from the most recent study. Previously, different researchers in different countries led studies on the barriers and challenges to ISO 9001 QMS implementation in particular. A few of these studies and research have been conducted in Malaysian construction firms. This study on the challenges to ISO 9001 QMS implementation in Malaysian construction companies will aid in the completion of the interlocking of difficulties encountered by organizations when implementing and retain the ISO 9001 certification. The results of this research provide Malaysian construction companies with a theoretical and practical understanding of the factors that challenge the company performance companies to retain ISO 9001 QMS certification. These challenges should be overcome by construction companies to achieve successful implementation and better performance of QMS. (Abstract by author

Preparation and Characterization of Activated Carbon using Rubber-seed Shell via Chemical Activation using Phosphoric Acid

Being known as an agricultural waste by-product, therefore the rubber-seed shell is being investigated to be used as alternative rawmaterial to produce activated carbon via chemical activation using phosphoric acid H3P04. Theinfluence of carbonization temperatures (400-600°C), impregnation ratios (1:1 - 1:20) and sample size (45um - 500um) of the prepared activated carbon on the pore development and yield were investigated. The raw materials and produced activated carbons were characterized by Nitrogen adsorption isothenns and Variable Pressure Field Emission Scanning electron microscope. Oil and grease adsorption results show that rubber-seed shell is a good precursor for activated carbon. The optimal activation temperature is: temperature 500°C, impregnation ratio of 1:10 and activation time of 1.5 hour. Characteristics of activated carbon shows H3P04 as a dehydrating agentthat moreto cleaning the surface of the activated carbon and promotes pore widening effect (1.09 nm - 6.53 nm) producing more shallow and wide mesoporous rich sites which makes a low specific surface area, thus low micropores sites. It is established that rubberseed shell is an attractive source of raw material for producing high capacity of mesoporous and macroporous activated carbon by chemical activation with phosphoric acid H3P04

A Fifty-year challenge in managing drug addiction in Malaysia

The history of substance abuse in Malaysia can be divided into pre- and post-independent era. In pre-independence, the main drug of abuse was opium which was initially consumed by immigrants from China who were introduced by the British colonialist to work in \ud Malaya. The post-independence era began in the 1960s when young adults were inß uenced by the “Hippy” subculture. At this time, consumption patterns changed where more Malays were involved in drug abuse compared to other ethnic groups (1, 2). \ud By the early 1980s, the prevalence of drug addiction increased and this increasing trend made the Malaysian government consider heroin addiction as a national threat. The national anti-drug task force was formed to control trafÞ cking and to rehabilitate addicts who \ud were involved in heroin addiction (3). Legislation was introduced where mandatory death sentence was implemented for those who smuggled more than 15 grams of heroin. Drug addicts found to be positive for heroin were forced to undergo compulsory \ud rehabilitation for two years (4). Nationwide, up to 28 government drug rehabilitation centres were established, and at any particular period, each centre accommodated up to 500 inmates. Approximately RM50 million a year was spent to run these centres (5). The centres were initially managed on a total abstinence philosophy; however this approach produced poor results. The latest survey showed that 85% of drug addicts relapsed after completing their rehabilitation at these centres (4, 6). In view of the poor results, substitute treatment with methadone was introduced recently to these centres (7).One of the visions of the Malaysian government was to create a drug addiction free nation by the year 2015. However, the increasing number of drug addicts has caused a surge in demand for rehabilitation centres, resulting in the inability of these centres to cope. For example, the number of drug addicts increased by 1% from year 2001 to 2002, but the number of drug addicts detected in year 2003 was 36,996, a 16% jump from the previous year (31,893). Furthermore, the National Drug Agency reported that 45% of the cases were repeat addicts. As for distribution of new cases, by ethnic group the Malays constituted 71%, Chinese 10.6% and Indian 8.2%. The majority (70%) were in the socially and economically most productive age group (20-39 years) and almost 98% of the addicts who occupied these rehabilitation centres were male. Currently, the number of drug users in the country is estimated to be 250,000 but the number is predicted to reach half a million by year 2015 (3, 8-10). The resulting economic,human resource and social loss is not quantiÞ able as the vacuum left by these people in various employment sectors are currently being Þ lled by migrant workers. Thus, it is evident that the increasing trend in drug addiction poses a threat to the future of the nation (1, 6, 9)

Kajian Korelasi Emosi Malu Dengan Pencapaian Akademik Di Kalangan Mahasiswa Melayu

Artikel ini melaporkan tentang pembinaan soal selidik 46 item berkenaan malu dan kajian yang dijalankan untuk menentukan tahap perhubungan malu dan pencapaian akademik di kalangan mahasiswa Melayu. Sejumlah 140 pelajar (63 lelaki dan 77 perempuan) yang berumur antara 20 hingga 36 tahun telah diambil sebagai sampel dalam kajian ini. Daripada jumlah itu, 56 orang adalah pelajar tahun kedua, 79 orang pelajar tahun ketiga dan 5 orang pelajar tahun keempat. Seramai 43 orang adalah pelajar sains dan 97 orang pelajar sastera. Pelajar-pelajar ini datangnya daripada berbagai-bagai latar belakang seperti Sastera, Pengajian Melayu, Bahasa Inggeris, Sejarah, Geografi, Perniagaan, Matematik, Biologi dan Kimia. Dapatan kajian menunjukkan soal selidik yang digunakan mempunyai kebolehpercayaan yang tinggi dengan koefisien Cronbach Alpha 0.9. Lima faktor berkenaan malu telah diperoleh. Ia diistilahkan sebagai: (a) kesekatlakuan wibawa, (b) kesekatlakuan sosial, (c) persepsi sinis, (d) pengelakan sosial dan (e) kebimbangan komunikasi-interaktif. Malu mempunyai korelasi negatif yang rendah (–0.23) dengan keputusan purata nilai gred (PNG) semester yang sebelumnya dan korelasi negatif yang sama (0.22) dengan purata nilai gred keseluruhan (PNGK). Terdapat korelasi negatif yang rendah antara Kesekatlakuan Wibawa dengan PNG (–0.27). Keduadua Kesekatlakuan Sosial dan Kebimbangan Komunikasi-Interaktif mempunyai korelasi yang lebih rendah dengan PNG (SI = –0.21; Ic-A = –0.14) dan PNGK (SI = –0.17; Ic-A = –0.12). Tidak terdapat korelasi antara Persepsi Sinis dan Pengelakan Sosial dengan PNG (PS = –0.01; PSs = 0.09) dan PNGK (CP = –0.06; SE = 0.09). Secara keseluruhannya arah korelasi antara malu dengan pencapaian akademik adalah negatif. Walau bagaimanapun, trend aspek Pengelakan Sosial adalah positif. Ini menunjukkan walaupun malu mempunyai hubungan negatif dengan pencapaian akademik, pelajar yang pemalu boleh meningkatkan pencapaian akademik mereka jika dapat menggunakan strategi yang sesuai dengan naluri Pengelakan Sosial seperti berkomunikasi dengan pensyarah, rakan kursus melalui e-mel dan melayari laman web untuk mendapatkan sumber maklumat kursus tambahan secara peribadi