ORCID Profile
0000-0002-6774-0850
Current Organisation
Sampoerna University
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: American Scientific Publishers
Date: 30-04-2012
Publisher: IEEE
Date: 04-2011
Publisher: IGI Global
Date: 2011
DOI: 10.4018/978-1-60960-042-6.CH035
Abstract: In smart environment, making a location-aware personal computing working accurately is a way of getting close to the pervasive computing vision. The best candidate to determine a user location in indoor environment is by using IEEE 802.11 (Wi-Fi) signals, since it is more and more widely available and installed on most mobile devices used by users. Unfortunately, the signal strength, signals quality and noise of Wi-Fi, in worst scenario, it fluctuates up to 33% because of the reflection, refraction, temperature, humidity, the dynamic environment, etc. We present our current development on a light-weight algorithm, which is easy, simple but robust in producing the determination of user location using WiFi signals. The algorithm is based on “multiple observers” on ?k-Nearest Neighbour. We extend our approach in the estimation indoor-user location by using combination of different technologies, i.e. WiFi, GPS, GSM and Accelerometer. The algorithm is based on opportunistic localization algorithm and fuse different sensor data in order to be able to use the data which is available at the user position and processable in a mobile device.
Publisher: International Association of Online Engineering (IAOE)
Date: 26-06-2015
Abstract: The use of Information Communication Technology (ICT) in the classroom activities has become more famous to the teachers over the last decade. Many great deals of studies have proven the benefits of using ICT in the classroom. Unfortunately, there are evidences that the ICT reform efforts have failed due to teacher’s beliefs, skills and attitudes were never taken into consideration. The evidences found that most research only concern on students’ behalftowards ICT. Departing from that, this study tries to investigate the teachers’ perspectives and practices toward the use of ICT in their classroom activities. A survey was conducted to collect the data of the research. Using a revised expectancy-value theory called the Technology Implementation Questionnaire (TIQ), a questionnaire was administered among 20 elementary teachers. The findings revealed that there are still teachers who have more than 10 years experiences in teaching but they never got any formal training on using ICT. The lack of proficiency in ICT such as in using software, lack of technical support from the school also make them feel stressed out even though they have positive perspectives in applying ICT in their classroom activities.
Publisher: IGI Global
Date: 2011
DOI: 10.4018/978-1-60960-042-6.CH036
Abstract: Context-aware computing is a class of mobile computing that can sense its physical environment and adapt its behavior accordingly it is a component of the ubiquitous or pervasive computing environment that has become apparent with innovations and challenges. This chapter reviews the concept of context-aware computing, with focus on the user activities that benefit from context history. How user activities in the smart environment can make use of context histories in applications that apply the concept of context prediction integrated with user pro-activity is explored. A brief summary of areas which benefit from these technologies as well as corresponding issues are also investigated.
Publisher: IEEE
Date: 05-2012
Publisher: IEEE
Date: 12-2010
Publisher: Elsevier BV
Date: 12-2011
Publisher: IEEE
Date: 11-2011
Publisher: IEEE
Date: 10-2010
Publisher: IEEE
Date: 09-2014
Publisher: IEEE
Date: 10-2010
Publisher: IEEE
Date: 04-2011
Publisher: IEEE
Date: 12-2010
Publisher: IEEE
Date: 06-2010
Publisher: IGI Global
Date: 2015
DOI: 10.4018/978-1-4666-9438-5.CH009
Abstract: Attendance management for educational institutions is very important it gives clear picture of students who regularly attend classes. Participating in academic activities such as lectures, laboratory experiments by students affects their academic performance. However, the conventional way of attendance registration is time consuming and prone to proxy attendance. The process involves the lecturer passing a paper to the students in a class to write their names and sign, or find their names in the paper to sign along their names. Several technologies like Biometric, RFID, NFC, etc can be used to simplify and improve the attendance system, since user identification is the most important aspect that needs to be handled cautiously in this type of applications. In this work we propose a smart attendance system using NFC that will simplify the attendance process, by simply touching a poster or the lecturer's NFC based mobile device in the class.
Publisher: IEEE
Date: 05-2012
Publisher: IEEE
Date: 09-2010
Publisher: IEEE
Date: 11-2011
Publisher: Springer Berlin Heidelberg
Date: 2013
Publisher: IEEE
Date: 10-2016
Publisher: IEEE
Date: 12-2014
Publisher: IEEE
Date: 10-2016
Publisher: Elsevier BV
Date: 07-2011
Publisher: IGI Global
Date: 07-2013
Abstract: Pathway analysis provided by current 3D maps in mobile devices that are intended for an interactive navigation aid, is simulated for what-if experiments against task and functional analysis, based on the problems faced from both technical and user-practices views. The aim of a navigation aid, in general, is to provide an optimal route from the current position to the destination. Unfortunately, the problem of most mobile device’s GPS signal accuracy and the display of pathways on 3D maps in the small screen of mobile devices affects the pathway architectural design from generating accurate initial positions to destinations. This paper presents both conceptual and experimental analysis of pathway determination designed for 3D maps in mobile devices for an interactive navigation aid, which is going to be added to an existing in idual cognitive map. The analytical outcomes are aimed at providing how environmental conditions come to be detected and how problems are resolved in helping people to navigate in unfamiliar locations by having positions and paths corrected to a reasonable degree of accuracy in order to overcome the problems of generating in-accurate locations and the weaknesses of conventional 2D maps, which requires users to interpret its various symbols and legends. Bent functions and fuzzy logic type 2 are used for simulating signal deviations from the precise values and Voronoi diagram/Delaunay triangulation are used for establishing experimental paths and locations. Finally, this technique will contribute to a well-defined positioning and pathway establishment of 3D maps in mobile devices for navigation aid.
Publisher: IEEE
Date: 09-2010
Publisher: IGI Global
Date: 2016
Publisher: IEEE
Date: 12-2010
Publisher: IEEE
Date: 11-2010
Publisher: Penerbit UTM Press
Date: 28-09-2016
DOI: 10.11113/JT.V78.9720
Abstract: The use of NFC technology is growing rapidly and implemented in various applications. It aims to reduce the steps needed to perform tasks by the user in day to day operations such as payment, electronic ticketing, attendance system, and other office related tasks. In this study, university smart environment is implemented using NFC for attendance monitoring system to reduce the need of tedious tasks. The application involves several different concerns in access control and managing physical and virtual components. These concerns are studied to create an easy-used attendance monitoring system using NFC to be applied in a smart university environment. A survey is conducted to measure students and lecturers acceptance in using NFC as an attendance monitoring system. The results provide insights on students and lecturers acceptance in using this technology. Additionally, it shows that both students and lecturers agree on the NFC attendance system should be implemented to ease attendance monitoring in the university.
Publisher: IGI Global
Date: 07-2012
Abstract: Many researches conducted in knowledge sharing have been focusing on organisational context. Yet, not many studies exist that explore knowledge sharing in education institutions. This paper provides an insight of how attitude, environment, motivation indicators, and in idual factors (culture, age, and gender) would help in determining the preferences of information and communication technology (ICT) based communication channels among the students in multicultural institutions. The study uses quantitative design approach where data is collected from students studying in International Islamic University Malaysia (IIUM) Gombak C us. The participants consisted of students originating from the regions of Middle East, West Africa, Southeast Asia and Eastern Europe. Information was solicited by the use of a survey. The survey was administered to a total of 184 participants. The research model designed for the study is based on the Theory of Planned Behaviour and Social Cognitive Theory. Factors involved in this study are attitude, environment, motivation, and demography, which includes cultural background. Six different communication channels have been looked through this study, i.e., instant messaging chat, social network, email, e-bulletin board, VOIP service, Telephone, and SMS. The results of the study can be used as a guide for identifying appropriate ICT based communication channels to be provided to the students for their knowledge sharing activities.
Publisher: IEEE
Date: 06-2010
Publisher: Emerald
Date: 28-06-2011
DOI: 10.1108/17427371111146446
Abstract: Prediction accuracies are usually affected by the techniques and devices used as well as the algorithms applied. This work aims to attempt to further devise a better positioning accuracy based on location fingerprinting taking advantage of two important mobile fingerprints, namely signal strength (SS) and signal quality (SQ) and subsequently building a model based on extreme learning machine (ELM), a new learning algorithm for single‐hidden‐layer neural networks. Prediction approach to location determination based on historical data has attracted a lot of attention in recent studies, the reason being that it offers the convenience of using previously accumulated location data to subsequently determine locations using predictive algorithms. There have been various approaches to location positioning to further improve mobile user location determination accuracy. This work examines the location determination techniques by attempting to determine the location of mobile users by taking advantage of SS and SQ history data and modeling the locations using the ELM algorithm. The empirical results show that the proposed model based on the ELM algorithm noticeably outperforms k‐Nearest Neighbor approaches. WiFi's SS contributes more in accuracy to the prediction of user location than WiFi's SQ. Moreover, the new framework based on ELM has been compared with the k‐Nearest Neighbor and the results have shown that the proposed model based on the extreme learning algorithm outperforms the k‐Nearest Neighbor approach. A new computational intelligence modeling scheme, based on the ELM has been investigated, developed and implemented, as an efficient and more accurate predictive solution for determining position of mobile users based on location fingerprint data (SS and SQ).
Publisher: IEEE
Date: 09-2012
Publisher: IEEE
Date: 03-2013
Publisher: IEEE
Date: 10-2009
Publisher: ACM
Date: 05-12-2011
Publisher: IGI Global
Date: 04-2012
Abstract: Hajj is a huge congregation of Muslims from all over the world which happens annually in Makkah, Kingdom of Saudi Arabia (KSA). It is one of the pillars of Islam and every able Muslim must perform this act at least once in their lifetime. Many challenges are faced by the organizers as well as the pilgrims during this massive religious gathering. Cases of missing Hajj pilgrims are not uncommon and although several tracking and navigation devices have been introduced, there is still a need for a better solution in overcoming the issue. There are several factors that prevent widespread use of the system, such as the operational costs, availability of the connections and the use in uncommon platform. This paper proposes a framework for tracking Hajj pilgrims in a crowded pervasive environment using a system called HajjLocator. A discussion on the prototype of HajjLocator, as a system to track and monitor pilgrims while performing Hajj and to save lives, with an SOS mechanism, is also presented in this paper.
Publisher: IEEE
Date: 03-2013
Publisher: ACM
Date: 05-12-2011
Publisher: IGI Global
Date: 2013
Abstract: Previous researches have highlighted the importance of web accessibility of a website. Its importance has made the W3C (World Wide Web Consortium) come up with Web Content Accessibility Guidelines (WCAG) as a guideline for developing an accessible website. Amongst websites available in the web wide world, many of them are fall under the education institution website category. These education institution websites are mostly the first door that people will go to visit to get information about education services and courses provided by the institution. Thus, to be accessible is an essential issue for these websites. Another issue that gets much attention in the current competitive internet world is to be visible by popular search engines and ranked at their top lists. For higher learning institutions there is an online ranking that they like to be in the top list, i.e. Webometrics. This paper attempts to address those two issues of web accessibility and being at the top list. It presents a study that investigates whether web accessibility has a contributing effect to ranking position in Webometrics and popular search engines. The research covers websites from higher learning institutions and education domains. Three popular search engines are used in this research, i.e. Google, Yahoo! and Bing. The study produces interesting results that would be useful as a guide for higher learning institutions that want to improve their online ranking.
Publisher: Springer Science and Business Media LLC
Date: 26-05-2021
DOI: 10.1038/S41597-021-00916-9
Abstract: We report high resolution measurements of the stable isotope ratios of ancient ice ( δ 18 O, δ D) from the N orth Greenland Eem ian deep ice core (NEEM, 77.45° N, 51.06° E). The record covers the period 8–130 ky b2k (y before 2000) with a temporal resolution of ≈0.5 and 7 y at the top and the bottom of the core respectively and contains important climate events such as the 8.2 ky event, the last glacial termination and a series of glacial stadials and interstadials. At its bottom part the record contains ice from the Eemian interglacial. Isotope ratios are calibrated on the SMOW/SLAP scale and reported on the GICC05 (Greenland Ice Core Chronology 2005) and AICC2012 (Antarctic Ice Core Chronology 2012) time scales interpolated accordingly. We also provide estimates for measurement precision and accuracy for both δ 18 O and δ D.
Publisher: IGI Global
Date: 2015
DOI: 10.4018/978-1-4666-9438-5.CH010
Abstract: Water meter reader is an essential tool for water company, which is responsible for the distribution of clean water to the public and monitor its customer's water consumption. Theoretically water meter should collect water consumption data in accurate and accountable manners. The problem is, in practice, sometimes the record is inaccurate and makes the customers feel uncertain of the water bill that they have to pay. Several factors contributed to this problem, including the officers made mistake in recording the number from water meter or sometimes the officer did not visit the customers and reporting based on the estimation of the water consumption. This chapter proposed a framework to record the water meter data by capturing images in a small mobile device. A prototype, as a proof of concept, of water meter mobile apps was developed to allow the water meter data to read and collected easily to make the billing processed in a more accurate manner but less hassle.
Publisher: IGI Global
Date: 10-2011
Abstract: The widespread of Internet usage has resulted in a greater number and variety of applications involving different types of private information. In order to diminish privacy concerns and strengthen user trust, security improvements in terms of authentication are necessary. The solutions need to be convenient, entailing ease of use and higher mobility. The suggested approach is to make use of the already popular mobile phone and to involve the mobile network, benefiting from Subscriber Identity Module (SIM) card’s t er resistance to become trusted entities guarding personal information and identifying users. Mobile phone’s SIM card is convenient for safely storing security parameters essential for secured communication. It becomes secure entity compulsory for getting access to privacy sensitive Internet applications, like those involving money transfers. Utilizing the NFC interface passes the personal user keys only when needed, giving additional strength to the traditional public key cryptography approach in terms of security and portability.
Publisher: Springer Berlin Heidelberg
Date: 2011
Publisher: Springer Berlin Heidelberg
Date: 2011
Publisher: IEEE
Date: 12-2010
Publisher: IEEE
Date: 12-2011
Publisher: Elsevier BV
Date: 2012
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2001
DOI: 10.1109/76.946522
Publisher: IEEE
Date: 11-2011
Publisher: Springer Science and Business Media LLC
Date: 21-05-2010
Publisher: Emerald
Date: 21-06-2013
DOI: 10.1108/IJMF-07-2011-0056
Abstract: This paper aims to evaluate the risk‐adjusted performance of the management styles of Malaysian mutual funds using nine modified performance evaluation measures generated by the maximum drawdown risk measure (M‐DRM) based on the modern portfolio theory. The purpose is to report the findings in a manner which is realizable by the average investors and portfolio managers. This paper evaluates the performance of more than 400 Malaysian mutual funds using risk‐adjusted returns over the two sub‐periods of 2000‐2005 and 2006‐2011. The M‐DRM, as a different measure from downside risk, is applied to improve nine risk‐adjusted performance measures of Sortino, Treynor, M‐squared, Jensen's alpha, information ratio (IR), MSR, upside partial ration (UPR), FPI, and leverage factor. It proposes a new single‐factor model to test the maximum drawdown beta and alpha in the M‐DRM framework. The evidence clearly indicates that the replacement framework in terms of MDB, the maximum drawdown beta, and the maximum drawdown CAPM can be replaced by the conventional frameworks in terms of MVB, beta, and the CAPM and also MSB, downside beta, and D‐CAPM for modifying nine performance evaluation measures from the management styles of Malaysian mutual funds. The research evidence reported in this paper can be applied as input in the process of decision making by small and average investors and portfolio managers who are seeking the possibility of participating in the global stock market through mutual funds. This paper is the first study to estimate a new regression model in the M‐DRM framework to evaluate the performance of Malaysian mutual funds. In addition, it proposes nine modified performance evaluation measures in the M‐DRM framework for the first time.
Publisher: ACM Press
Date: 2012
Publisher: IEEE
Date: 04-2014
Publisher: Springer Science and Business Media LLC
Date: 09-11-2011
Publisher: IEEE
Date: 03-2011
Publisher: IEEE
Date: 10-2009
Publisher: IEEE
Date: 12-2014
Publisher: Wiley
Date: 11-10-2013
Publisher: IEEE
Date: 09-2011
Publisher: International Association of Online Engineering (IAOE)
Date: 26-07-2016
Abstract: 3D map for mobile devices provide more realistic view of an environment and serves as better navigation aid. Previous research studies shows differences in 3D maps effect on acquiring of spatial knowledge. This is attributed to the differences in mobile device computational capabilities. Crucial to this, is the time it takes for 3D map dataset to be rendered for a required complete navigation task. Different findings suggest different approach on solving the problem of time require for both in-core (inside mobile) and out-core (remote) rendering of 3D dataset. Unfortunately, studies on analytical techniques required to shows the impact of computational resources required for the use of 3D map on mobile device were neglected by the research communities. This paper uses Support Vector Machine (SVM) to analytically classify mobile device computational capabilities required for 3D map that will be suitable for use as navigation aid. Fifty different Smart phones were categorized on the bases of their Graphical Processing Unit (GPU), display resolution, memory and size. The result of the proposed classification shows high accuracy
Publisher: IEEE
Date: 09-2011
Publisher: Wiley
Date: 30-01-2012
DOI: 10.1111/J.1438-8677.2011.00545.X
Abstract: The non-invasive leaf patch cl pressure (LPCP) probe measures the attenuated pressure of a leaf patch, P(p) , in response to an externally applied magnetic force. P(p) is inversely coupled with leaf turgor pressure, P(c) , i.e. at high P(c) values the P(p) values are small and at low P(c) values the P(p) values are high. This relationship between P(c) and P(p) could also be verified for 2-m tall olive trees under laboratory conditions using the cell turgor pressure probe. When the laboratory plants were subjected to severe water stress (P(c) dropped below ca. 50 kPa), P(p) curves show reverse diurnal changes, i.e. during the light regime (high transpiration) a minimum P(p) value, and during darkness a peak P(p) value is recorded. This reversal of the P(p) curves was completely reversible. Upon watering, the original diurnal P(p) changes were re-established within 2-3 days. Olive trees in the field showed a similar turnover of the shape of the P(p) curves upon drought, despite pronounced fluctuations in microclimate. The reversal of the P(p) curves is most likely due to accumulation of air in the leaves. This assumption was supported with cross-sections through leaves subjected to prolonged drought. In contrast to well-watered leaves, microscopic inspection of leaves exhibiting inverse diurnal P(p) curves revealed large air-filled areas in parenchyma tissue. Significantly larger amounts of air could also be extracted from water-stressed leaves than from well-watered leaves using the cell turgor pressure probe. Furthermore, theoretical analysis of the experimental P(p) curves shows that the propagation of pressure through the nearly turgorless leaf must be exclusively dictated by air. Equations are derived that provide valuable information about the water status of olive leaves close to zero P(c) .
Publisher: IEEE
Date: 04-2016
Publisher: IEEE
Date: 08-2012
Publisher: Institute of Advanced Engineering and Science
Date: 12-2019
DOI: 10.11591/IJEECS.V16.I3.PP1555-1561
Abstract: Sentiment analysis has been popularly used in analyzing data from the internet. One of the techniques used is lexicon based sentiment analysis. Generating lexicon is not an easy process, and lexicon in Bahasa Indonesia is rarely available. This paper proposes an automatic lexicon generation in Bahasa Indonesia for sentiment analysis purpose. Experiments were performed using the generated lexicon for doing sentiment analysis on Indonesian political news about the 2018 governor election in three provinces in Indonesia. The conducted experiments show promising results where it can predict the candidate’s rank, the election winner, and the percentage of votes for each candidate with better accuracy than the previous work which used manually generated lexicon.
Publisher: Springer Berlin Heidelberg
Date: 2012
Publisher: IEEE
Date: 10-2009
No related grants have been discovered for Media Ayu.