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28,296 Article Results

Online Biped Walking Pattern Generation with Contact Consistency

10.11591/ijra.v4i1.pp19-30
Wenqi Hou , Jian Wang , Jianwen Wang , Hongxu Ma
In this paper, a novel online biped walking gait pattern generating method with contact consistency is proposed. Generally, it’s desirable that there is no foot-ground slipping during biped walking. By treating the hip of the biped robot as a linear inverted pendulum (LIP), a foot placement controller that takes the contact consistency into account is proposed to tracking the desired orbit energy. By selecting the hip’s horizontal locomotion as the parameter, the trajectories in task space for walking are planned. A task space controller without calculating the inversion of inertial matrix is presented. Simulation experiments are implemented on a virtual 5-link point foot biped robot. The results show the effectiveness of the walking pattern generating method which can realize a stable periodic gait cycle without slipping and falling even suffering a sudden disturbance.
Volume: 4
Issue: 1
Page: 19-30
Publish at: 2015-03-01

Soft Switching Boost Converter Solution for Increase the Efficiency of Solar Energy Systems

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/4224
Alireza Kaviani-Arani , Alireza Gheiratmand
Nowadays, renewable energies are considered as an important source of non-polluting and free energy. Solar energy in the form of photovoltaic systems is one of the most prominent of them. Using this type of energy can be an affordable and suitable solution to supply electricity to the consumers who do not have access to the distribution network due to geographical conditions. Regarding to low efficiency and high cost of installing solar panels, receiving the maximum power of them is taken into consideration. DC-DC converters are one of the key components of solar energy systems. These converters have the switching losses and their efficiency is not so high. This paper explores the switching losses in hard switching boost converter and by providing a soft switching boost converter, reduces switching losses and increases the efficiency of solar energy systems. The performance of the converter has been studied and simulations indicate its performance. DOI: http://dx.doi.org/10.11591/telkomnika.v13i3.7127 
Volume: 13
Issue: 3
Page: 449-457
Publish at: 2015-03-01

Saron Music Transcription Based on Rhythmic Information using HMM on Gamelan Orchestra

10.12928/telkomnika.v13i1.295
Yoyon K; Institut Teknologi Sepuluh Nopember Suprapto , Yosefine; Sekolah Tinggi Manajemen Informatika dan Teknik Komputer (STIKOM) Triwidyastuti
Nowadays, eastern music exploration is needed to raise his popularity that has been abandoned by the people, especially the younger generation. Onset detection in Gamelan music signals are needed to help beginners follow the beats and the notation. We propose a Hidden Markov Model (HMM) method for detecting the onset of each event in the saron sound. F-measure of average the onset detection was analyzed to generate notations. The experiment demonstrates 97.83% F-measure of music transcription. 
Volume: 13
Issue: 1
Page: 103-117
Publish at: 2015-03-01

A Detection Method for Transmission Line Insulators Based on an Improved FCM Algorithm

10.12928/telkomnika.v13i1.1319
BoWen; Northeast Dianli University Wang , Quan; University of Glasgow Gu
An improved segmentation Fuzzy C-Means algorithm (FCM) is proposed for the image recognition of transmission line insulators. In this paper, the improved Wiener filter algorithm is firstly used to filtrate and recover image in pre-processing. Then, the insulator image is segmented based on the improved algorithm FCM. Finally, the contour of insulator is labelled by using connected component labelling algorithm. Experimental results have shown that the improved Wiener filtering algorithm may effectively filter and recover the images; furthermore, the improved FCM image segmentation algorithm may accurately segment insulators from the image.
Volume: 13
Issue: 1
Page: 164-172
Publish at: 2015-03-01

Improved Leader Follower Formation controller for multiple Quadrotors based AFSA

10.12928/telkomnika.v13i1.994
Rabah; Beijing Institute of Technology Abbas , Qinghe; Beijing Institute of Technology Wu
In this paper, formation tracking in  plane with equal height for all quadrotors is discussed. Two controllers are necessary. First, PID controller is used to ensure the tracking of the desired trajectory by the first quadrotor named leader. The formation of the quadrotors in  plane is achieved by using the directed lyapunov controller. In order to improve the controller performances, the artificial fish swarm algorithm is used to ensure the dynamic optimization of the parameter controllers. When the desired shape formation is achieved, PID controller is used again to ensure the keeping of this formation shape. Finally, simulation results demonstrate the effectiveness of the proposed controllers compared to the ordinary controller and also compared to the static optimization by using the same algorithm.
Volume: 13
Issue: 1
Page: 85-92
Publish at: 2015-03-01

Image Edge Feature Extraction and Refining Based on Genetic-Ant Colony Algorithm

10.12928/telkomnika.v13i1.1264
Xing; Henan University of Urban Construction Zhang , Shuai; Henan University of Urban Construction Liu
Edge is composed by a collection of its nearby pixels which has a step change or changes in roof, an image is an information system and most of its information comes from the edges. This paper gives a brief overview of the status and the importance of image edge detection and introduces the research status of the image edge detection. After that, it introduces the basic principle and the main steps of the genetic algorithm and ant colony algorithm. On the basis of these, the paper proposed a new hybrid algorithm for the image edge extraction and refining, which combined the genetic algorithm and ant colony algorithm. Through the analysis of the time-speed graph of the genetic algorithm and the ant colony algorithm, we can find the best fusion point between the genetic algorithm and the ant colony algorithm. The experiment indicated the proposed hybrid algorithm can make the full use of the image information, the simulation time is shorter, the image edge is more continuous, and preserved the outline of original image more completely.
Volume: 13
Issue: 1
Page: 118-127
Publish at: 2015-03-01

Modeling and Control of Standalone Direct-Driven PMSG WECS for Grid Compatibility at Varying Wind Speeds

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/4219
Shilpa Mishra , S Chatterji , Shimi S.L. , Sandeep Shukla
Wind energy is one of the most available and exploitable forms of renewable energy. Variable speed PMSG based Wind Energy Conversion System (WECS) offers many advantages compared to the fixed speed squirrel cage induction generators such as improved stator output operation at better power factor, no maintenance cost for gear box (as it is direct-driven) reduction in weight and losses, higher efficiency and ability to run at low speeds. The elimination of the gear box and brushes can enhance the efficiency of wind turbine by 10%. In this paper a Permanent Magnet Synchronous Generator (PMSG) is modeled whose stator is connected to the constant single phase load (in place of grid) through AC/DC thyristors based rectifier followed by capacitor (dc-link) and DC/DC converter control. Overall arrangement provides constant output to connected load if applied with proper controlling techniques. Hence this proposed wind generation system design can be extended for grid connection also via DC/AC inverter control. Results are simulated and verified in MATLAB/Simulink platform at constant rated (12m/s) and varying (stepped) wind speed for smooth and constant output voltage. DOI: http://dx.doi.org/10.11591/telkomnika.v13i3.7097
Volume: 13
Issue: 3
Page: 410-417
Publish at: 2015-03-01

Hierarchical-map Updating Approach for Simultaneous Localization and Mapping of Mobile Robots

10.12928/telkomnika.v13i1.1275
Yingmin; Xi’an University of Technology Yi , Zhimin; Xi’an University of Technology Wang
For the tremendously increasing of system state in wild field, the computational complexities of mobile robot system should be taken into account. This paper proposes a hierarchical-map updating approach for simultaneous localization and mapping of robots. The basic idea of hierarchical-map is defining two kinds of maps during the recursive updating process, namely local map (upper map) and global map (lower map). The system states will be updated by the preset maps. The hierarchical-map updating process is just for the upper map and the lower map is updated after a certain running term. In the calculation, the state data of the upper map is far less than that of the lower map. It is validated by the experiments that, the approach is more optimal than others in computational complexities while ensuring the consistency estimate.
Volume: 13
Issue: 1
Page: 93-102
Publish at: 2015-03-01

Data Partition and Communication On Parallel Heuristik Model Based on Clonal Selection Algorithm

10.12928/telkomnika.v13i1.728
Ayi; School of Electrical Engineering and Informatics, Bandung Institute of Technology Purbasari , Iping Supriana; School of Electrical Engineering and Informatics, Bandung Institute of Technology Suwardi , Oerip Slamet; School of Electrical Engineering and Informatics, Bandung Institute of Technology Santoso , Rila; School of Electrical Engineering and Informatics, Bandung Institute of Technology Mandala
Researchers conducted experiments on parallel algorithms, which are inspired by the clonal selection, called Clonal Selection Algorithm (CSA). This algorithm is a population-based heuristic solution. Course-grained parallelism model applied to improve the execution time. Inter-process communication overhead is addressed by adjusting the communication frequencies and size of data communicated. In this research, conducted experiments on six parallel computing models represent all possible partitions and communications. Experiments conducted using data of NP-Problem, Traveling Salesman Problem (TSP). The algorithm is implemented using the model of message passing libraries using MPJExpress. Experiments conducted in a cluster computation environment. Result shows the best parallelism model is achieved by partitioning the initial population data at the beginning of communication and the end of generation. Communication frequency can be up to per 1% of the population size generated. Using four dataset from TSPLib, this reseache shows effect of the communication frequency that increased the best cost, from 44.16% to 87.01% for berlin52.tsp; from 9.61% to 53.43%  for kroA100.tsp, and from 12.22% to 17.18% for tsp225.tsp. With eight processors, using communication frequency will be reduced the execution time e.g 93.07%, 91.60%, 89.60%, 74.74% for burma14.tsp, berlin52.tsp, kroA100.tsp, and tsp225.tsp respectively. We conclude that frequency of communication greatly affects the execution time, and also the best cost. It improved execution time and best cost.
Volume: 13
Issue: 1
Page: 193-201
Publish at: 2015-03-01

Countering Node Misbehavior Attacks using Trust Based Secure Routing Protocol

10.12928/telkomnika.v13i1.1181
Adnan; Universiti Teknologi Malaysia (UTM), Skudai, Johor Bahru, Malaysia Ahmed , Kamalrulnizam; Universiti Teknologi Malaysia (UTM), Skudai, Johor Bahru, Malaysia Abu Bakar , Muhammad Ibrahim; Department of Information Technology, Quaid-e-Awam University of Engineering, Science and Technology, Nawabshah Channa , Khalid; Universiti Teknologi Malaysia (UTM), Skudai, Johor Bahru, Malaysia Haseeb
Wireless sensor networks have gained remarkable appreciation over the last few years. Despite significant advantages and tremendous applications, WSN is vulnerable to variety of attacks. Due to resource constraint nature of WSN, applicability of traditional security solutions is debatable. Although cryptography, authentication and confidentiality measures help in preventing specific types of attacks but they cannot safeguard against node misbehavior attacks and come at significant cost. To address this problem, we propose a Trust Based Secure Routing Protocol (TBSRP) which adopts on-demand routing principle and relies on distributed trust model for the detection and isolation of misbehaving nodes. The TBSRP aims to establish shortest path that contain all trusted nodes, identify packet forwarding misbehavior caused by malicious and faulty nodes and reroute the traffic to other reliable paths. The performance of TBSRP is evaluated in terms of packet delivery ratio, average end-to-end delay, normalized routing load and average throughput. Simulations results show that TBSRP can achieve both high delivery ratio and throughput in presence of various numbers of misbehaving and faulty nodes.
Volume: 13
Issue: 1
Page: 260-268
Publish at: 2015-03-01

A Low Complexity Navigation Data Estimation Algorithm for Weak GNSS Signal Tracking

10.12928/telkomnika.v13i1.1268
Shunxiao; National University of Defense Technology Wu , Yangbo; National University of Defense Technology Huang , Shaojie; National University of Defense Technology Ni , Gang; National University of Defense Technology Ou
The computation load of traditional navigation data estimation algorithms for weak GNSS signal tracking increases exponentially with respect to the number of data bits needed to be estimated. To solve this problem, by adopting the dynamic programming philosophy, a navigation data bits estimation algorithm is proposed. The proposed algorithm uses the partial sum of correlation values as data bit combination searching branches. It can predict and exclude searching branches of data bit combination which have small coherent accumulated energy as soon as possible by angle quantification, thus reducing its computation load to be linearly related to the number of data bits needed to be estimated. Simulation results show that for signal of 500bps navigation data rate, the carrier track loop with a frequency discriminator implementing 0.12s coherent accumulation by navigation data estimation improves the tracking sensitivity up to 7 dB compared with traditional frequency discriminator under the same track accuracy constraint.
Volume: 13
Issue: 1
Page: 238-249
Publish at: 2015-03-01

Low zinc serum affects insulin-like growth factor-1 level in dehydrated pregnant women

10.11591/ijphs.v14i1.24431
Erry Yudhya Mulyani , Hardinsyah Hardinsyah , Dodik Briawan , Budi Iman Santoso , Idrus Jus'at
Maternal body fluids imbalance affects amniotic fluid, serum sodium-potassium, edema, and preeclampsia. Insulin-like growth factor-1 (IGF-1) is a growth hormone and a regulator in sodium balance regulation. This study aimed to determine the correlation of IGF-1, zinc, calcium, and sodium with hydration status and the nutrients impact to IGF-1 based on hydration status of pregnant women at Kebon Jeruk Health-Center, West Jakarta. This cohort-prospective study was conducted in December 2016 to January 2018. A total of 66 pregnant women in the second trimester were examined. Urine color, urine specific gravity, serum sodium, serum osmolality and urine were used as hydration status indicators. Zn, Ca, Na, and IGF-1 levels as the growth indicator from mother to fetus. Pearson correlation test, independent t-test and linear regression were used in statistical analysis. There were no differences in IGF-1, Zn, Ca, and Na serum between the two groups (p³0.05). There was no relationship between Ca, Na and IGF-1 level (p³0.05). The regression results show a possitive relation that low zinc serum affect IGF-1 level in dehydrated pregnant women. Therefore, it is necessary for pregnant women to consume zinc-rich foods to increase IGF-1 level and keep hydration status with water consume 3.0 L per-day.
Volume: 14
Issue: 1
Page: 175-182
Publish at: 2015-03-01

A meta-analysis of long-term COVID-19 symptoms

10.11591/ijphs.v14i1.24087
Shi D. Prantilla , Cesar G. Demayo , Mark Anthony J. Torres , Orven E. Llantos
This meta–analysis examines the far–reaching effects of long COVID (LC), highlighting the need for welfare strategies emphasizing the Parity of Esteem. The analysis of clinical studies reveals the prevalence of LC across various demographic factors, including age, gender, infection type, and severity. The findings highlight persistent pulmonary impairments that result in post-COVID pulmonary fibrosis (PCPF), long-term cardiovascular symptoms, gastrointestinal issues, dermatological concerns, and neuropsychiatric outcomes. These effects continue beyond the acute phase of COVID-19, affecting both symptomatic and asymptomatic people. The study emphasizes that LC is not only a physical ailment but also has a significant impact on mental health, necessitating a holistic approach to healthcare. Psychological and emotional distress among LC patients necessitates empathetic support. This study concludes by emphasizing the significance of LC and advocating for data-driven healthcare policies and assistance programs to address the unique challenges encountered by COVID-19 survivors. For managing the long-term effects of LC on both physical and mental health, an unwavering commitment to parity of esteem is crucial.
Volume: 14
Issue: 1
Page: 311-321
Publish at: 2015-03-01

Analysis of risk factors and prevention strategy in accidents among coal hauling trucks: a scoping review

10.11591/ijphs.v14i1.24795
Adenan Adenan , Zulkifli Djunaidi
Powered hauling equipment is one of the most critical operational elements in the mining sector. Haulage is a significant hazard for the mining industry, accounting for over half of all mining-related fatal accidents yearly. Identifying safety risk variables is the foundation of risk assessment and accident prevention. This study aimed to identify risk variables and prevention techniques to reduce occurrences among truck drivers in coal mining. This research approach is a scoping review with the PRISMA Extension for Scoping Reviews (PRISMA-ScR). Thirty-five articles were reviewed based on the results of inclusion and exclusion criteria. Data analysis was performed using content analysis. The results show that human, environmental, machine and organizational factors contribute to the risk among truck drivers in coal mining. Safety culture, staffing and scheduling, training and education, policy and procedure implementation, and technology deployment are all part of the accident prevention plan. The central government should pay particular attention to the employment conditions of workers in cities with decreased resources and develop policies to prevent mining-related diseases in local communities.
Volume: 14
Issue: 1
Page: 183-191
Publish at: 2015-03-01

The role of technological pedagogical and content knowledge on career adaptability among teachers in Indonesia and Malaysia

10.11591/ijphs.v14i1.24230
Rosita Endang Kusmaryani , Tria Widyastuti , Siti Rohmah Nurhayati , Hazalizah Hamzah
Since the COVID-19 pandemic, face-to-face learning has been transformed into online learning. This phenomenon was really challenging for teachers because they were not used to it. The adaptability of the teacher becomes an indispensable aspect to face the problem. The ability to integrate materials, pedagogy and technology or technological pedagogical and content knowledge (TPACK) supported the adaptability in implementing online learning. The purpose of this study was to investigate the impact of TPACK on professional adaptability. A sample of 457 junior and senior high school teachers in Indonesia and Malaysia completed the technological pedagogical and content knowledge scale and the career adaptability scale. Based on partial least square analysis, this study found that TPACK played a role in predicting four dimensions of career adaptability: concern, control, curiosity, and confidence. This structural model was also supported with path analysis. Therefore, TPACK becomes an essential aspect in influencing teachers' career adaptability.
Volume: 14
Issue: 1
Page: 361-370
Publish at: 2015-03-01
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