Journal of Engineering and Scientific Research (JESR)
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Enhancing Visual Abilities in Solving Mathematics Problems
Full text linkThis research is an experiment of categorizing visual abilities by representations of a solving problem through class experiment. The research is to investigate, explore, and enhance geometry thinking in solving mathematics problems presented visually. The tasks are cognitive strategies that rely on the visual representations and the genesis of the abilities with the assumption that the performance requires the manipulation of the visual representations. The model of the research developed from the students’ imagination of a visual problem or situations for accomplishing the solution and called binocular rivalry. The data are of interconnection for promoting visual abilities or senses, as the flexibility of thinking and the likelihood of having representations available in prior knowledge. The data analyzed by categorizing according to the visual abilities and by Control Chart of Attributes. The results are: 80% of the visual abilities are nonconforming index; the variation of visual representations is high in nonconforming index, but the depth struggle by the subjects and 70% select the general geometric figures that recognized. The conclusions are comprehensive, and the visual representations are nonconforming index, and the visual senses enhance in all categories.
Keywords: Visual representation; Visual ability; Categorize visual skills; Geometry thinking; Cognitive strategy
Modeling Stock Return Data using Asymmetric Volatility Models: A Performance Comparison based on the Akaike Information Criterion and Schwarz Criterion
Full text linkThe Generalized Autoregressive Conditional Heteroskedasticity (GARCH) model has been widely used in time series forecasting especially with asymmetric volatility data. As the generalization of autoregressive conditional heteroskedasticity model, GARCH is known to be more flexible to lag structures. Some enhancements of GARCH models were introduced in literatures, among themare Exponential GARCH (EGARCH), Threshold GARCH (TGARCH) and Asymmetric Power GARCH (APGARCH) models. This paper aims to compare the performance of the three enhancements of the asymmetric volatility models by means of applying the three models to estimate real daily stock return volatility data. The presence of leverage effects in empirical series is investigated. Based on the value of Akaike information and Schwarz criterions, the result showed that the best forecasting model for our daily stock return data is the APARCH mode
Similarity Analyzer for Semantic Interoperability of Electronic Health Records Using Artificial Intelligence (AI)
Full text linkThe introduction of Electronic Health Records (EHR) has opened possibilities for solving interoperability issues within the healthcare sector. However, even with the introduction of EHRs, healthcare systems like hospitals and pharmacies remain isolated with no sharing of EHRs due to semantic interoperability issues. This paper extends our previous work in which we proposed a framework that dealt with semantic interoperability and security of EHR. The extension is the proposal of a cloud-based similarity analyzer for data structuring, data mapping, data modeling and conflict removal using Word2vec Artificial Intelligence (AI) technique. Different types of conflicts are removed from data in order to model data into common data types which can be interpreted by different stakeholder
Identification of Geothermal Potential with Remote Sensing, Geochemistry, and Magnetotelluric Method in West Sumatera
Full text linkWest Sumatra is one of a geothermal potential in Indonesia because of interaction between Eurasian and Indo-Australian tectonic. The existence of volcanoes produces geothermal potential with lithology andesite, tuff, and lapilli lava in the Marapi Mountain complex, which elongated at NW-SE direction as a result of NE-SW subduction. The remote sensing method specifically with Composite Band 567 and Lineament Density Analysis (LDA) found anomaly with the permeability value of prospects ranged from 2.05 to 4.76% per km2 (highest density value) with general direction is in the southeast-northwest which in line with the Sumatra structural pattern. Based on geological data, argillic alteration was found with geothermal manifestations consisting of hot springs. Through geochemical analysis, the fluid type of hot water sample (temperature of 48.66oC) is in the immature water zone; occur with the presence of carbonate sinter. Geophysical analysis using the magnetotelluric (MT) method to identified geothermal systems such as cap rock with low resistivity (<30 ohm.m) and reservoirs with moderate resistivity (31-300 ohm.m). The correlation between remote sensing, geochemistry, and magnetotelluric could determine the geothermal potential in West Sumatra
The Influence of Geographical Factors on Extreme Rainfalls in Lampung Province
Full text linkMany people in Indonesia calculate design rainfall before calculating the design flood discharge. The design rainfall with a certain return period will eventually be converted into a design flood discharge by combining it with the characteristics of the watershed. However, the lack of a network of rainfall recording stations makes many areas that are not hydrologically measured (ungauged basin), so it is quite difficult to know the characteristics of rain in the area concerned. This study aims to analyze the characteristics of design rainfall in Lampung Province. The focus of the analysis is to investigate whether geographical factors influence the design rainfall that occurs in the particular area. The data used in this study is daily rainfall data from 15 rainfall recording stations spread in Lampung Province. The method of frequency analysis used in this study is the Gumbel method. The research shows that the geographical location of an area does not have significant effect on extreme rainfall events. The effect of rising earth temperatures due to natural exploitation by humans tends to be stronger as a cause of extreme events such as extreme rainfall
Fabricating and Testing of Porous Magnesium Through Powder Metallurgy Technique using TWSH (Titanium Wire Space Holder) for Biodegradable Bone Scaffold Material
Full text linkMagnesium (Mg) and its alloys seem to be a potential biodegradable bone scaffold materials as their biocompatibility and mechanical properties fit to natural bone. Magnesium alloys as biomaterials have higher mechanical properties that may close to cancellous bone once composed and produced in a specific production route. Fabricating porous magnesium for bone scaffold material aims to reduce the rigidity and strength of the material by which the porous density can be adjusted to the original nature of the bone. It forms interconnected porosity, has physical and mechanical properties similar to cancellous bone. This paper describes the production and characterization of porous magnesium material for the potential application as bone scaffold through powder metallurgy technique with pieces of Titanium Wire Space Holder. Mg containing titanium pieces were then compacted and sintered before immersed in hydro fluoride acid solution to form a porous magnesium structure. Density and porosity, micro Vickers hardness, micro structure test and SEM-EDX were performed to prove the existing porous structure inside Mg metal. The result finds out that a good cooperation and a potential application for the fabrication of an inter-connected porous magnesium samples for cancellous bone implant
Improvement of Hardness of Hydroxyapatite by the Addition of Silica from Tin Tailings
Full text linkThe application of bone scaffolding in bone therapy is an alternative solution developed in bone tissue engineering technology to avoid bone donors' scarcity. The main requirement for a material that can be used as a scaffold is that it is biocompatible. Hydroxyapatite is a calcium phosphate ceramic that is often used as the primary material for scaffolding because it has good biocompatibility properties. However, like most ceramics, hydroxyapatite has low mechanical properties. In this study, we synthesized hydroxyapatite from cockleshell waste. To improve hydroxyapatite's mechanical properties (hardness), we added silica from tin tailings to hydroxyapatite. Through the analysis of the x-ray diffraction (XRD) pattern, it was found that hydroxyapatite was successfully synthesized from cockleshell using the co-precipitation method. Analysis of the diffraction pattern of tin tailings also shows that most of the crystals comprising tin tailings sand are silica in the ?-quartz phase. The addition of silica to hydroxyapatite followed by compaction and sintering at a temperature of 800 ? did not produce a new crystal phase. The addition still has a diffraction pattern consisting of a combined XRD pattern of hydroxyapatite and silica. Based on the hardness test using the Vickers hardness method, it is known that the addition of silica can increase the hardness of hydroxyapatite
GIS-Based Area Suitability Analysis for Development Planning Purposes Campus: Case Study Banyuwangi State Polytechnic
Full text linkIn the context of the ecological relationship between humans and the academic environment, success in obtaining high-quality graduations influenced by the quality of the building's space system and other supporting facilities as a place for students to study. So the construction site's design becomes an essential factor to consider in the educational environment. Banyuwangi state polytechnic has not implemented and developed SIG to determine the construction site. Hence, it causes campus spatial planning problems for the future, like puddles, floods, noisy classrooms, and difficult access to each building. Banyuwangi State Polytechnic, as a twelve-year-old college in Banyuwangi, is in desperate need of regional development planning as one of the efforts to ensure the continuity of academic activities that are adequate and comfortable for students. This study aims to ?nd out the area suitability for determining Banyuwangi State Polytechnic development's best location choice. Banyuwangi State Polytechnic, located in the middle of the public road on the east side and the railway in the west to the north, causes noise levels to be a critical issue to consider to achieve a fair learning process. Area suitability assessment is a critical determinant in campus planning development. The suitability assessment is carried out through the AHP (analytical hierarchy process) model covering all land, buildings, noise levels, soil slope, road access, and availability of irrigation channels. The data obtained mapped into the Geographic Information System using Quantum GIS (QGIS) software. Land-use suitability is calculated based on criteria in the form of noise level (NL), land elevation (EL), ease of access (RA), and irrigation channel (ICA). There are 4 points obtained after discussions with the development planning unit management for alternative locations for development sites. The highest weight of the best criteria for determining location is the NL criteria of 0.566 and PSI of 0.283. The best location for development is in the second alternative location with a weight of 0,20176, followed by the third alternative location with a weight of 0,12028
The Engine Performance Characteristics of an IDI Diesel Engine Fueled by Soybean Oil Methyl Esters
Full text linkAn experimental investigation was conducted to evaluate the performance of an indirect injection (IDI) diesel engine using diesel(D100) and diesel-biodiesel blends (BD25, BD45, BD65) separately. The engine was run in various engine loads at constant engine speed ranging from 1000 to 2400 rpm with an interval 200 rpm. The results showed that the biodiesel content decreased the engine torque and power. This might be mainly affected by the lower LHV of the biodiesel, and also the worse combustion due to higher density of the biodiesel compared to the diesel fuel. The loss of power due to lower heating value of biodiesel were notas high as the difference in their heating value that might be down to the better lubricity of biodiesel as proved in the higher brake thermal efficiency and mechanical efficiency when using the biodiesel blends. The brake specific fuel consumption is higher with the increase of biodiesel content but the diesel fuel delivered the highest energy to run the engine. The maximum pressure inside cylinder and the heat release rate of D100 is slightly higher than those of biodiesel blends. Keywords: diesel engine, biodiesel, engine performance, emission
Designing Model for Truck Assignment Problem in Beef Delivery Using DBSCAN Algorithm
Full text linkIn beef route delivery, many logistics companies have problems in making delivery plans correctly. Most logistics companies have a limited number of trucks, but there are shipping schedules, locations and volumes of demand is not fixed, in addition to returning products with various reasons that must be collected. Therefore the purpose of this study is to assign trucks to fulfill all beef delivery activities at a minimum cost. One reason for research on truck assignments in beef delivery is the high cost of shipping because it uses cold chains. This study uses the DBSCAN method to obtain density values based on customer distance to the central warehouse and the number of delivery requests, the data used in this study is the data of product delivery to customers for 6 months. Clustering research results using DBSCAN show the maximum values for epsilon 0.7 and Minpoints 2 are 3 clusters with 6 noises. with these results divided of trucks based on clusters is 2 trucks for the area of Banten, 7 trucks forthe area of Jakarta, Bogor, and Bekasi, 2 trucks for Malang, and Surabaya, and 1 truck for the Bali area and noise or non-permanent delivery