Sebelas Maret University

About: Sebelas Maret University is a education organization based out in Surakarta, Indonesia. It is known for research contribution in the topics: Population & Public health. The organization has 10901 authors who have published 10832 publications receiving 33057 citations. The organization is also known as: Universitas Negeri Surakarta & Universitas Sebelas Maret.

Forecasting electricity load demand using hybrid exponential smoothing-artificial neural network model

Abstract: Short-term electricity load demand forecast is a vital requirements for power systems. This research considers the combination of exponential smoothing for double seasonal patterns and neural network model. The linear version of Holt-Winter method is extended to accommodate a second seasonal component. In this work, the Fourier with time varying coefficient is presented as a means of seasonal extraction. The methodological contribution of this paper is to demonstrate how these methods can be adapted to model the time series data with multiple seasonal pattern, correlated non stationary error and nonlinearity components together. The proposed hybrid model is started by implementing exponential smoothing state space model to obtain the level, trend, seasonal and irregular components and then use them as inputs of neural network. Forecasts of future values are then can be obtained by using the hybrid model. The forecast performance was characterized by root mean square error and mean absolute percentage error. The proposed hybrid model is applied to two real load series that are energy consumption in Bawen substation and in Java-Bali area. Comparing with other existing models, results show that the proposed hybrid model generate the most accurate forecast

Facebook as A Learning Media in TISOL (Teaching Indonesian to Speakers of Other Languages) Learning to Support The Independency of Foreign Students in Indonesia

Abstract: TISOL process is not merely conducted face-to-face, but also by using media, both printed media and non-printed, computer/internet, radio and television broadcast. By using this method the foreign students can independently adjust the suitability of time and place in studying the material. Learning and teaching process as a form of interaction between tutors and tutorial participants (foreign students) as well as between participants related to teaching and learning activities, forms a social network using a social media as a means of interaction to enable interaction in many directions (active participation of members) and flexible. One of the most popular social media in the world is Facebook. Facebook features as a social media can be utilized to support the implementation of teaching and learning process, especially online tutorials, among other facilities of various documents / modules with interactive discussions among participants arranged chronologically per topic. The purpose of this paper is to review the features of Facebook and simulate learning / Tutorial Online by using Facebook so features can be used with existing advantages and disadvantages as well as suggestions how to use Facebook to improve the quality of Online Tutorials in TISOL learning.

Multiwall carbon nanotubes filled polypropylene nanocomposites: Rheological and electrical properties

Abstract: Two types of commercial multiwall carbon nanotubes (MWCNTs), Baytubes® C70P and C150P were incorporated into polypropylene (PP) using melt blending technique that employs a twin screw extruder (TSE) to prepare the nanocomposites of two different concentrations (1 and 3 wt%). Subsequently, American Society for Testing and Materials (ASTM) standard samples were prepared with an injection molding machine. The prepared nanocomposites were characterized by their rheological and electrical properties using a rheometer and a picoammeter/voltage source, respectively. The effect of different types of MWCNTs and loading percentage in rheological and electrical properties was investigated in detail. The rheological analysis demonstrated a considerable dependence of the melt rheological properties of the PP/MWCNTs nanocomposites on the MWCNTs loading. The storage modulus (G′), loss modulus (G″) and complex viscosity |η*| increased with increasing MWCNTs loading. In addition, type C70P exhibited superior rheological properties compared to C150P. In terms of electrical properties, the addition of MWCNTs in the PP matrix decreased the volume resistivity of the matrix in a manner, proportional to the MWCNTs loading. No significant difference in volume resistivity was observed between the MWCNTs types. POLYM. ENG. SCI., 54:1134–1143, 2014. © 2013 Society of Plastics Engineers

Thermodynamics properties study of diatomic molecules with q-deformed modified Poschl-Teller plus Manning Rosen non-central potential in D dimensions using SUSYQM approach

Abstract: D-dimensional Dirac equation of q-deformed modified Poschl-Teller plus Manning Rosen non-central potential was solved using supersymmetric quantum mechanics (SUSY QM). The relativistic energy spectra were analyzed by using SUSY QM and shape invariant properties from radial part of D dimensional Dirac equation and the angular quantum numbers were obtained from angular part of D dimensional Dirac equation. The SUSY operators was used to generate the D dimensional relativistic wave functions both for radial and angular parts. In the non-relativistic limit, the relativistic energy equation was reduced to the non-relativistic energy. In the classical limit, the partition function of vibrational, the specific heat of vibrational, and the mean energy of vibrational of some diatomic molecules were calculated from the equation of non-relativistic energy with the help of error function and Mat-lab 2011.

Application of livelihood vulnerability index to assess risks for farmers in the Sukoharjo Regency and Klaten Regency, Indonesia

Abstract: This research tried to compare the level of farmers’ livelihood vulnerability to flooding in Sukoharjo and Klaten. Farmers are the most susceptible caused by climate change. The data used in this research are primary data, collected by interviewing 61 respondents who are farmers in the Sonorejo Village, Sukoharjo Regency and 72 respondents in the Jiwo Wetan Village, Klaten Regency. This data obtained by using non-probability sampling technique with purposive methods. Meanwhile mapping for hazard level was analysed by using Geographic Information System (GIS). Descriptive statistic was used for the livelihood vulnerability index’s (LVI) and the LVI-Intergovernmental Panel on Climate Change’s (IPCC) index calculation. The results show that the farmers’ livelihood vulnerability in the Sonorejo Village is medium level because of climate change based on the LVI index value at 0.363 and LVI-IPCC index value at 0.044. Meanwhile, the Jiwo Wetan Village has a lower index in LVI at 0.344 and LVI-IPCC index value at 0.038. Areas with similar physical characteristic and most of its community have a dependence on agriculture tend relatively the same level of vulnerability.