905 research outputs found
Is More Always Better? An Empirical Investigation of the CAPM and the Fama-French Three-factor Model in Indonesia
This study investigates the performance of the CAPM and the Fama-French threefactor model in Indonesia. This research employs time-series regression with monthly data from 2005 to 2015. The results reveal that the Fama-French three-factor model performs better than the CAPM in describing the excess return of stock portfolios in Indonesia. This result is robust to the equally-weighted method and the impact of the global financial crisis. Although the Fama-French three-factor model is superior to the CAPM, the results indicate that there are other factors to consider in determining asset pricing models that better capture stock return variations in the Indonesian stock market. This research implies that the investors should consider Fama-French factors when making their investment decisions. Furthermore, the investors should evaluate another factor impact the average returns.
Keywords: Asset pricing, CAPM, Three-factor model, Size factor, Book-to-market factor, JEL Code: G1
Design high frequency surgical robot controller: design FPGA-based controller for surgical robot manipulator simscape modeling
Recent developments of robotics allocated many of industrial and medical activities. So that most of industries turned to use surgical robots in their production line or in their surgery. Being precise, spent less time-consuming, present uniform quality with less cost and reducing waste and energy are some advantages of using robots in industry.
This paper has two important objectives: a) study on modeling and controlling of 4 degrees of freedom (DOF) based on Simscape software and b) design FPGA-based controller for this type of surgical robot manipulator. Simscape provides an environment for modeling and simulating physical systems. Simscape modeling can be designed to control and test system-level performance. Conventional PID controller is a stable linear type model-free controller that reduces the delay time in highly nonlinear system. In this research, linear controller need real time mobility operation, and one of the most important devices which can be used to solve this challenge is Field Programmable Gate Array (FPGA). FPGA can be used to design a controller in a single chip Integrated Circuit (IC). To design PID type FPGA-based controller two types algorithm are needed: derivative algorithm and integral algorithm. In HDL based derivative algorithm the minimum input arrival time before clock is 16.466 ns and the maximum frequency is 60.73 MHz, but in the best design action, the maximum frequency to design this single chip algorithm should be 63.629 MHz. In HDL integral algorithm the minimum input arrival time before clock is 15.599 ns and the maximum frequency is 64.1 MHz, but in the best design action, the maximum frequency to design this single chip algorithm should be 178.190 MHz
A Response-Time Analysis for Non-Preemptive Job Sets under Global Scheduling
An effective way to increase the timing predictability of multicore platforms is to use non-preemptive scheduling. It reduces preemption and job migration overheads, avoids intra-core cache interference, and improves the accuracy of worst-case execution time (WCET) estimates. However, existing schedulability tests for global non-preemptive multiprocessor scheduling are pessimistic, especially when applied to periodic workloads. This paper reduces this pessimism by introducing a new type of sufficient schedulability analysis that is based on an exploration of the space of possible schedules using concise abstractions and state-pruning techniques. Specifically, we analyze the schedulability of non-preemptive job sets (with bounded release jitter and execution time variation) scheduled by a global job-level fixed-priority (JLFP) scheduling algorithm upon an identical multicore platform. The analysis yields a lower bound on the best-case response-time (BCRT) and an upper bound on the worst-case response time (WCRT) of the jobs. In an empirical evaluation with randomly generated workloads, we show that the method scales to 30 tasks, a hundred thousand jobs (per hyperperiod), and up to 9 cores.info:eu-repo/semantics/publishedVersio
Response-Time Analysis for Non-Preemptive Global Scheduling with {FIFO} Spin Locks
Motivated by the lack of response-time analyses for non-preemptive global scheduling that consider shared resources, this paper provides such an analysis for global job-level fixed-priority (JLFP) scheduling policies and FIFO-ordered spin locks. The proposed analysis computes response-time bounds for a set of resource-sharing jobs subject to release jitter and execution-time uncertainties by implicitly exploring all possible execution scenarios using state-abstraction and state-pruning techniques. A large-scale empirical evaluation of the proposed analysis shows it to be substantially less pessimistic than simple execution-time inflation methods, thanks to the explicit modeling of contention for shared resources and scenario-aware blocking analysis
Information Technology Plan as an IT Governance Maturity Driver
Having an information technology (IT) plan is a minimum baseline for optimal IT governance. But, creating a plan is only one problem, executing it poses even more challenging problems. In this research, we investigate the correlation between an organization's IT plan and the organization's IT governance maturity level. We show that, on one hand, executing an IT plan requires a certain IT governance maturity level, on the other hand, the experience of executing an IT plan drives the organization IT governance maturity level. We compare the situations in two government institutions and found indications that the organization with an ambitious IT plan has more mature IT governance than the other whose IT plan is relatively modest. The results suggest that an effective IT plan should include plans for the development of IT governance mechanisms relevant to the goals that the plan is intended to achieve, and the plan's implementation schedule, also known as the IT roadmap, should take into consideration the growth of the IT governance mechanisms' maturity levels.
Memiliki rencana untuk teknologi informasi (TI) adalah base line untuk tata kelola TI yang optimal. Tapi, membuat rencana hanyalah satu masalah, melaksanakannya akan menciptakan masalah baru yang lebih menantang. Dalam penelitian ini, kami menyelidiki korelasi antara rencana TI suatu organisasi dengan tingkat maturity tata kelola TI-nya. Kami menunjukkan bahwa, di satu sisi, untuk melaksanakan rencana TI memerlukan tingkat kematangan tata kelola TI tertentu, di sisi lain, pengalaman dalam menjalankan rencana TI mendorong organisasi dalam meningkatkan tata kelola TI. Kami membandingkan situasi di dua lembaga pemerintah dan menemukan indikasi bahwa organisasi dengan rencana TI yang ambisius memiliki tata kelola TI lebih matang dari organisasi yang rencana TI-nya relatif sederhana. Hasil penelitian menunjukkan bahwa perencanaan TI yang efektif harus mencakup rencana untuk pengembangan mekanisme tata kelola TI yang relevan dengan tujuan yang ingin dicapai, dan jadwal pelaksanaan rencana atau roadmap TI, harus mempertimbangkan pertumbuhan tingkat mekanisme tata kelola TI
Measuring the Effectiveness of a Simplified Cobit-based IT Process Maturity Assessment Method
We propose a simplified method for measuring the maturity levels of an organization's information technology (IT) processes that is based on IT Governance Institute's COBIT (Control Objectives for Information and Related Technology) framework. The method is designed for quickly assessing an organization's IT process maturity in situations where the availability of information for a more thorough assessment method is very limited. To investigate the accuracy of the proposed method, we evaluate the consistency between the result of the IT process maturity assessment of an organization and the conditions reported by the organization as impediment to the achievement of its IT goals. The underlying assumption is that a condition that is perceived by an organization as a problem will drive the organization to develop a process that can effectively deal with the condition. We show that there is good enough consistency to support the use of the proposed maturity assessment method.
Kami mengusulkan sebuah metode sederhana untuk mengukur tingkat kematangan (maturity) dari proses teknologi informasi (TI) suatu organisasi yang didasarkan pada IT Governance Institute's COBIT framework (Control Objectives for Information and Related Technology). Metode ini dirancang untuk melakukan penilaian dengan cepat dari tingkat kematangan proses TI suatu organisasi dalam situasi di mana ketersediaan informasi untuk metode penilaian yang lebih menyeluruh sangat terbatas. Untuk mengetahui ketepatan metode yang diusulkan, kami mengevaluasi konsistensi antara hasil penilaian kematangan proses TI dari suatu organisasi dan kondisi yang dilaporkan oleh organisasi sebagai rintangan bagi tercapainya tujuan IT. Asumsi yang mendasarinya adalah bahwa suatu kondisi yang dirasakan oleh organisasi sebagai masalah akan mendorong organisasi untuk mengembangkan sebuah proses yang dapat secara efektif menangani kondisi tersebut. Kami menunjukkan bahwa ada konsistensi yang cukup baik untuk mendukung penggunaan metode penilaian kematangan yang diusulkan
Effect of growth stages on phenolics content and antioxidant activities of shoots in sweet marjoram (Origanum majorana L.) varieties under salt stress
We investigated the contributions of salinity and development stage on total polyphenols, flavonoids, condensed tannins contents, phenolic content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide scavenging activities at three phenolic stages: early vegetative stage (EVS), late or prefloral vegetative (LVS) stage and flowering stage (FS). The total phenolic, flavonoids and condensed tannins contents were more important in the presence and absence of salt at prefloral or building stage than at EVS and FS. In addition, salt stress increased total polyphenol and individual phenolic contents in shoots of Origanum majorana. This increase was more important in LVS than in EVS and FS. Moreover, the antiradical activity of the shoots (DPPH) decreased with the addition of NaCl. In fact, LVS extracts showed the highest antioxidant properties. Furthermore, at LVS, marjoram grown at 75 mM showed a higher antiradical ability against DPPH radical and antioxidant activity, compared to EVS and LVS. Data reported here revealed the variation of phenolic compound contents at different stages of growth of O. majorana, and the possible role of these changes in the response of the plant to salt was also discussed.Key words: Antiradical activity, Origanum majorana, early vegetative stage (EVS), late or prefloral vegetative (LVS) stage and flowering stage (FS), phenolic content
Contamination métallique de Gambusia holbrooki au niveau du lac Fouarat et de l’estuaire Sebou dans la région du Gharb (Maroc)
Situés dans l’agglomération de Kénitra, l’estuaire de Sebou et le lac Fouarat, sont soumis en permanence à de nombreux rejets d’eaux uséeset de déchets. L’impact de cette activité anthropique sur la qualité de cesmilieux a été estimé à travers le suivi spatio-temporel des teneurs corporelles en fer, du manganèse, du chrome, du cuivre, du zinc et duplomb chez Gambusia holbrooki. Ce poisson omnivore, constitue désormais un des maillons de la chaîne trophique au sein du lac et del’estuaire. Les résultats obtenus ont mis en évidence la contamination et l’accumulation des métaux par ce poisson avec une charge métalliqueimportante par rapport à celle des témoins et des autres poissons de l’estuaire. Par ailleurs, l’évolution saisonnière des teneurs a montré desdifférences de faible importance entre les deux milieux, liées essentiellement aux variations climatiques. Les résultats reflètent unedégradation croissante de la qualité de ces milieux qui ne cessent d’être le réceptacle de nombreux rejets divers. Cette situation peut engendrer des conséquences toxicologiques inquiétantes sur la santé, dans la mesure où le risque de contamination de la nappe phréatique qui alimente toute la région en eau potable n’est pas exclue. L’irrigation courante des parcelles agricoles avec les eaux contaminées du lac comporte aussi des risques qu’il convient d’éviter et surtout d’évaluer.Mots-clés : contamination métallique, Gambusia, lac Fouarat, estuaire Sebou, effluent, rejet
Phenomenology of a Light Cold Dark Matter Two-Singlet Model
We study the implications of phenomenological processes on a two-singlet
extension of the Standard Model we introduced in a previous work to describe
light cold dark matter. We look into the rare decays of and
mesons, most particularly the invisible channels, and study the decay channels
of the Higgs particle. Preferred regions of the parameter space are indicated,
together with others that are excluded. Comments in relation to recent Higgs
searches and finds at the LHC are made.Comment: 16 pages, 8 figure
- …