Structural Engineering Commons^™

Wimax Implementation As Existing Hotspot Network Backhaul In Jakarta, Djamhari Sirat, Muhamad Asvial, Luther B. Marpaung

Makara Journal of Technology

WiMAX Implementation as Existing Hotspot Network Backhaul in Jakarta The development of Broadband Wireless Access (BWA), such as WiMAX, as a global standard for data transmission media has been used by high speed internet access provider. WiMAX application which supported by capabilities of interoperability, flexibility and commercial aspect make the internet services become more efficient, cheaper and easier to the customer. This phenomenon should be responded by ISPs. Based on technical and financial aspect in deciding the implementation of Wireless Network with WiMAX technology as a substitute, this research will observe and analyze the projection of WiMAX technology implementation as …

Plant Growth Modeling Using L-System Approach And Its Visualization, Atris Suyantohadi, Alfiyan Alfiyan, Mochamad Hariadi, Mauridhi Hery Purnomo

Makara Journal of Technology

The visualization of plant growth modeling using computer simulation has rarely been conducted with Lindenmayer System (L-System) approach. L-System generally has been used as framework for improving and designing realistic modeling on plant growth. It is one kind of tools for representing plant growth based on grammar sintax and mathematic formulation. This research aimed to design modeling and visualizing plant growth structure generated using L-System. The environment on modeling design used three dimension graphic on standart OpenGL format. The visualization on system design has been developed by some of L-System grammar, and the output graphic on three dimension reflected on …

Remote Sensing And Geographical Information System To Identify Drought Potency, Puguh Dwi Raharjo

Makara Journal of Technology

Remote Sensing and Geographical Information System to Identify Drought Potency. Kebumen regency was drought in year 2008, community clean water shortages and irrigation water following a decline in water resources. The use of remote sensing data and GIS can be used to identify the potential for drought-prone areas. Transformation of Landsat TM satellite imagery to obtain the brightness index, wetness index and vegetation index used to determine surface conditions in relation to drought. Brightness index and wetness index derived from the tasseled cap modifications, while the vegetation index derived from normalized difference vegetation index (NDVI) values. Other parameters such as …

Separation Study Of Titanomagnetite Fe3-Xtixo4 From Natural Sand At Indramayu, West Java, Sunaryo Sunaryo, Iwan Sugihartono

Makara Journal of Technology

Separation Study of Titanomagnetite Fe3-xTixO4 from Natural Sand at Indramayu, West Java. Titanomagnetite FeTiO4 has been obtained from metal sand which is separated from natural sand at Indramayu using magnetic separator with the magnetic field 0,3 Tesla. This method can improve titanomagnetite content from 32% to 63,6%. According to X-ray diffractometer (XRD) and data processing by general structure analyses system (GSAS) with χ2= 1,454 and Wrp = 0,1142 as correction factor of the peak to peak intensities, we conclude that χ2 about 0 and Wrp aproximately 10%. It indicates the datas with the error merely 0,1 can be accepted. Furthermore, …

Hydrogen Absorption Induced Slow Crack Growth In Austenitic Stainless Steels For Petrochemical Pressure Vessel Industries, Ronnie Higuchi Rusli

Makara Journal of Technology

Type 304L and type 309 austenitic stainless steels were tested either by exposed to gaseous hydrogen or undergoing polarized cathodic charging. Slow crack growth by straining was observed in type 304L, and the formation of α‘ martensite was indicated to be precursor for such cracking. Gross plastic deformation was observed at the tip of the notch, and a single crack grew slowly from this region in a direction approximately perpendicular to the tensile axis. Martensite formation is not a necessary condition for hydrogen embrittlement in the austenitic phase.

Development Of Technology Parameter Towards Shipbuilding Productivity Predictor Using Cubic Spline Approach, Bagiyo Suwasono, Sjarief Widjaja, Achmad Zubaydi, Zaed Yuliadi, I Nyoman Budiantara

Makara Journal of Technology

Development of Technology Parameter Towards Shipbuilding Productivity Predictor Using Cubic Spline Approach. Ability of production processes associated with state-of-the-art technology, which allows the shipbuilding, is customized with modern equipment. It will give impact to level of productivity and competitiveness. This study proposes a nonparametric regression cubic spline approach with 1 knot, 2 knots, and 3 knots. The application programs Tibco Spotfire S+ showed that a cubic spline with 2 knots (4.25 and 4.50) gave the best result with the value of GCV = 56.21556, and R2 = 94.03%.Estimation result of cubic spline with 2 knots for the PT. Batamec shipyard …

Shaft Torsional Vibration Response Of Vertical Axis Ocean Current Turbine Model Due To Torque Excitation, Adi Wirawan Husodo, I Ketut Aria Pria Utama, I Made Ariana

Makara Journal of Technology

Shaft Torsional Vibration Response of Vertical Axis Ocean Current Turbine Model Due to Torque Excitation. The current research aimed to study the torsional vibration response of Vertical Axis Ocean Current Turbine due to randomly torque excitation pattern, owing to the variety of ocean current velocity. The turbine model is composed of 3 aluminum blades of NACA 0018 connected to steel shaft. Turbine dimensions are 10 cm of chord, 1.8 cm of chamber and 100 cm of span. The variation of ocean current velocity is 0.5 m/s, 1.0 m/s, 1.5 m/s, 2.0 m/s, 2.5 m/s and 3.0 m/s. The Model has …

An Investigation Of The Influence Of Diaphragm Flexibility On Building Design Through A Comparison Of Forced Vibration Testing And Computational Analysis, Blake Alan Roskelley

Master's Theses

An assessment of the validity of idealizing a concrete diaphragm as rigid was performed through the modal analysis of three existing buildings. Modal analysis was performed both by physical experimentation and computational analysis. Experimental determination of the mode shapes shows that two of the three buildings’ diaphragms exhibited flexible behavior. The experimental results were compared to computational analysis results and were shown to be similar, confirming that that the two building diaphragms are not rigid. As a standard, diaphragms with aspect ratios less than three are permitted to be idealized as rigid per ASCE 7-05. To determine the effect of …

Plain And Steel-Reinforced Concrete Shear Walls With And Without Cfrp Retrofitting, Ali Mohammed Salih Al Aloosi

Civil & Environmental Engineering Theses & Dissertations

This thesis presents the outcome- of a study of the behavior and strength of plain and steel-reinforced concrete shear walls with and without a window opening and Carbon Fiber-Reinforced Polymer (CFRP) retrofitting. A total of seven tests were conducted using six different shear walls. Each wall was subjected to a gradually increasing static load at one of it's top corners until the maximum load was reached. The load-deflection relations and the walls' failure patterns were observed and recorded. It was found that the window opening in the plain concrete wall reduced the wall load capacity by 18 percent. For the …

Experimental Investigation Of Folded Plate Girders And Slab Joints Used In Modular Construction, Kyle A. Burner

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The folded plate girder, a newly proposed bridge girder, is investigated through this thesis. The folded plate girder is cold bent out of a single sheet of steel. The cold bending eliminates the costly and inconsistent shop welds found in traditional girders. The folded plate girder is meant for application in short span bridges. The girder was subjected to an equivalent 75 year lifetime loading to investigate the fatigue performance.

The rebar detail used in the closure region between adjacent slabs has been investigated in the past by the NCHRP 12-68 project. This thesis will proposes a hooked rebar detail …

Constructability Testing Of Folded Plate Girders, Luke A. Glaser

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

A new steel girder bridge system was developed at the University of Nebraska. The innovative girder design is a box girder folded from a single steel plate that has a trapezoid shape with an opening on the bottom. The girder has application in short span bridges and accelerated construction situations. The structural performance of the girder requires investigation in all stages of a bridge’s lifecycle. This thesis contains descriptions and results from the first two tests from a series of tests developed to evaluate this new girder shape. The objective of these two tests was to investigate the constructability of …

Modelling And Verification Of Response Of Rc Slabs Strengthened In Flexure With Mechanically Fastened Frp Laminates, Annalisa Napoli, Fabio Matta, Enzo Martinelli, Antonio Nanni, Roberto Realfonzo

Faculty Publications

Mechanically fastened fibre-reinforced polymer laminate systems are emerging as a promising means for the repair and strengthening of reinforced concrete members. This technology entails the use of pultruded carbon- and glass- vinyl ester fibre-reinforced polymer laminates with enhanced longitudinal bearing strength that are connected to the concrete substrate by means of steel anchors. Attractive applications are those for emergency repairs where constructability and speed of installation are critical requirements. In this paper, an experimental investigation is first presented that included laboratory testing of scaled reinforced concrete slabs strengthened with four different combinations of laminate lengths and fastener layouts to study …

Comparison Of The Properties Of Portland Cement And Portland-Limestone Cement, Alex Lyatonga Mrema

Tanzania Journal of Engineering and Technology (TJET)

A study was made in a cement factory in Dar es Salaam, Tanzania, where Ordinary Portland Cement (CEM I 42.5N) and Portland-limestone cement (PLC) which has the brand name Twiga Cement Extra (CEM II/A-L/32.5R) are produced and conforming to the Tanzania Standard TZS 727 (Part1): 2002, which is equivalent to EN 197 published by the committee for European normalization (CEN). A comparison was made between the two types of cements in terms of physical, chemical and mechanical properties. It was found out that they all complied with the standards, that there was no significant difference in their setting times and …

The Effect Of Service Installations On Structural Integrity Of Slabs In Buildings, Ladislaus Lwambuka

Tanzania Journal of Engineering and Technology (TJET)

In building construction industry service installations, usually housed in conduit pipes, are commonly mounted inside reinforced concrete structural elements. This practice is adopted to attain aesthetical outlook at both interior and exterior surfaces of the buildings. Depending on the extent of service installations, the cross sectional area of the load bearing structural member is substantially reduced. However, the current structural design guidelines have no provision to accommodate the extent to which the existence of conduit pipes impairs the load bearing capacity of the structural element though reduced cross sectional area. This study has attempted to address this gap in structural …

Achieving The Vision Through High Ethical Standards, Sarah E. Bertke

Ohio Valley Regional Student Conference

No abstract provided.

Ontology-Based Automatic Classification For News Articles In Indonesian Language, Prajna Wira Basnur, Dana Indra Sensuse

Makara Journal of Technology

Ontology-Based Automatic Classification for News Articles in Indonesian Language. Searching specific information will be difficult if relying only on query. Choosing less specific queries will result in a lot of irrelevant information fetched by the system. One of the most successful ways to overcome this problem is to perform document classification based on the topic. There are many methods that can be used to conduct such a classification, such as using statistical and machine learning approaches. However, those document classification methods require training the data or learning the documents. In this study, the authors attempted to classify documents using a …

A Simple Technique For Surface Area Determination Through Supercritical Co2 Adsorption, Mahmud Sudibandriyo

Makara Journal of Technology

The measurement of specific surface area of porous materials has long been important in physical sciences and is currently growing in importance in applied and environmental science. Numerous systems have been developed for surface area measurement by gas adsorption. Commercial systems are available which can measure a wide range of absolute surface area with relative ease. However, their cost is often prohibitive. In this study, an inexpensive apparatus for surface area measurement has been set up to be used for measuring supercritical adsorption of CO2. The Ono-Kondo Lattice model was used to represent the adsorption isotherm and to determine the …

Fishing Catch And Catch Rate Assesment Of Mini Trawl, Trapnet And Setnet Fisheries, Muhammad Firdaus

Makara Journal of Technology

Fishing Catch and Catch Rate Assesment of Mini Trawl, Trapnet and Setnet Fisheries. This paper is aimed at assessing fishing catch and catch rate of the dragged gear on shrimp, trapnet, and setnet fisheries in Tarakan. The catch and effort data (number and species) and the fishing time of captured units were used in this qualitative analysis of fishing catch and catch rate to describe catch composition and catch rate from three catch fishery units in Tarakan. The result of the research shows that in the catching operation the dragged gear on shrimp has two main catch targets, which are …

Particle Filter With Binary Gaussian Weighting And Support Vector Machine For Human Pose Interpretation, Indah Agustien, Muhammad Rahmat Widyanto, Sukmawati Nur Endah, Tarzan Basaruddin

Makara Journal of Technology

This paper proposes human pose interpretation using particle filter (PF) with Binary Gaussian Weighting and support vector machine (SVM). In the proposed system, particle filter is used to track a human object, then this human object is skeletonized using thinning algorithm and classified using SVM. The classification is to identify human pose, whether it is normal or abnormal behavior. Here particle filter is modified through weight calculation using Gaussian distribution to reduce the computational time. The modified particle filter consists of four main phases. First, particles are generated to predict target’s location. Second, the weight of certain particles is calculated …

Maintenance Activity Planning By Reability Centered Maintenance Ii Method, Rachmad Hidayat, Nachnul Ansori, Ali Imron

Makara Journal of Technology

Maintenance Activity Planning by Reability Centered Maintenance II Method. This research discusses maintenance activity planning using the RCM II method to evaluate failure function risk on compresor screw. The calculation of maintenance time is performed by considering maintenance and repair costs. The risk evaluation result with RPN shows that the critical component that needs to get the main priority in applying maintenance on compresor screw is function disorder on timeworn piston and on the broken outgoing air sponge’s filter that receives RPN 45. The optimum maintenance time calculation is applied on components that undergo scheduled restoration and scheduled discard task …

Software Design Of Mobile Antenna For Auto Satellite Tracking Using Modem Correction And Elevation Azimuth Method, Djamhari Sirat, Muhamad Asvial, Arman Djohan Diponegoro, Himawan Sidharta

Makara Journal of Technology

Software Design of Mobile Antenna for Auto Satellite Tracking Using Modem Correction and Elevation Azimuth Method. Pointing accuracy is important in satellite communication. Because the satellite’s distance to the surface of the earth's satellite is so huge, 1 degree of pointing error will make the antenna unable to send data to satellites. To overcome this, the auto-tracking satellite controller is made. This system uses a microcontroller as the controller, with the GPS as the location indicator of the antenna, a digital compass as the beginning of antenna pointing direction, a rotary encoder as azimuth and elevation censor, and a modem …

Petroleum Degradation In Soil By Thermophilic Bacteria With Biopile Reactor, Astri Nugroho, Edison Effendi, Yulius Karonta

Makara Journal of Technology

Crude oil degradation has been carried out using biopile reactor in total petroleum hydrocarbon (TPH) concentration of 5%, 10% and 15%. The thermophilic microorganisms used from isolation result and identification are Aeromonas salmonicida, Bacillus pantothenticus, and Stenotrophomonas maltophilia. The biodegradation of biopile reactor is done by various concentrations of TPH, total plate count (TPC), and volatile suspended solid (VSS) per day for 30 days. The biodegradation of kinetic parameter calculated consists of μ, μm, Y, Yt, Yobs, Kd, Ks from TPH concentration decision, and TPC and VSS in every microorganism with t (observation time) of 0 hour to 168 hours. …

Ergonomic Analysis Of Ui’S Bicyclesusing Posture Evaluation Index (Pei) Method In Virtual Environment, Erlinda Muslim, Boy Nurtjahyo, Zulkarnain Zulkarnain, Liza Afrinotha

Makara Journal of Technology

Ergonomic Analysis of UI’s Bicycles Using Posture Evaluation Index (PEI) Method in Virtual Environment. This research was conducted to study the ergonomic aspect of University of Indonesia’s bicycles in virtual environment. Software Jack 6.0 was used to analyze it. PEI was used as an approach that integrated the results of three methods: lower back analysis (LBA), ovako working posture analysis (OWAS), and rapid upper limb assessment (RULA). The research objective is to evaluate the existing design of University of Indonesia’s bicycles and to determine the most ergonomic redesign which concerns handlebar height and saddle height modification. The result showed that …

Identification Of Physical Changes To A Steel Frame, Daniel Eric Means

Master's Theses

The thesis utilized physical testing and computer modeling to determine the feasibility of identifying a change to the mass or stiffness of a steel frame. Physical testing was performed using an accelerometer, linear shaker, and arbitrary function generator. Two methods of laboratory testing were developed: ambient vibration testing (AVT) and forced vibration testing (FVT). AVT was able to preliminarily identify the natural frequencies and mode shapes of the frame. FVT was able to precisely identify four distinct natural frequencies, mode shapes, and damping ratios. The baseline frame then underwent two physical changes: the addition of mass to its roof, and …

Site Specific Modelling Of Traffic Loading On Highway Bridges, Bernard Enright, Eugene J. Obrien

Conference papers

Accurate traffic loading models based on measured weigh-in-motion (WIM) data are essential for the accurate assessment of existing bridges. Much work has been published on the Monte Carlo simulation of single lanes of heavy vehicle traffic, and this can easily be extended to model the loading on bridges with two streams of traffic in opposing directions. However, a typical highway bridge will have multiple lanes in the same direction, and various types of correlation are evident in measured traffic, such as groups of very heavy vehicles travelling together and heavy vehicles being overtaken by lighter ones. These traffic patterns affect …

Characteristic Dynamic Increment For Extreme Traffic Loading Events On Short And Medium Span Highway Bridges, Eugene J. Obrien, Daniel Cantero, Bernard Enright, Arturo González

Articles

More accurate assessment of safety can prevent unnecessary repair or replacement of existing bridges which in turn can result in great cost savings at network level. The allowance for dynamics is a significant component of traffic loading in many bridges and is often unnecessarily conservative. Critical traffic loading scenarios are considered in this paper with a model that allows for vehicle-bridge interaction and takes into account the road surface condition. Characteristic dynamic allowance values are presented for the assessment of mid-span bending moment in a wide range of short to medium span bridges for bi-directional traffic.

The Influence Of Correlation On The Extreme Traffic Loading Of Bridges, Eugene J. Obrien, Bernard Enright, A. T. Dempsey

Conference papers

Accurate traffic loading models based on measured data are essential for the accurate assessment of existing bridges. There are well-established methods for the Monte Carlo simulation of single lanes of traffic, and this can easily be extended to model the loading on bridges with two independent streams of traffic in opposing directions. However, a typical highway bridge will have multiple lanes in the same direction, and various types of correlation are evident in measured traffic. This paper analyses traffic patterns using multi-lane WIM data collected at two European sites. It describes an approach to the Monte Carlo simulation of this …

Management Strategies For Special Permit Vehicles For Bridge Loading, Bernard Enright, Eugene J. Obrien

Conference papers

An examination of weigh-in-motion data collected recently at sites in five European countries has shown that vehicles with weights well in excess of the normal legal limits are found on a daily basis. These vehicles would be expected to have permits issued by the responsible authorities. It can be seen from the measurements that most of them are travelling at normal speeds. Photographic evidence indicates that, while many are accompanied by an escort vehicle, normal traffic is flowing alongside in other lanes. As European freight volume grows, the frequency of these special vehicles can be expected to increase. Hence, the …

Optimal Design Of Trusses With Geometric Imperfections, Mehdi Jalalpour, Takeru Igusa, James K. Guest

Civil and Environmental Engineering Faculty Publications

The present paper focuses on optimization of trusses that have randomness in geometry that may arise from fabrication errors. The analysis herein is a generalization of a perturbation approach to topology optimization under geometric uncertainties. The main novelty in the present paper is in the consideration of potential buckling due to misaligned structural members. The paper begins with a brief review of the aforementioned perturbation approach, then proceeds with the analysis of the nonlinear effects of geometric imperfection. The paper concludes with some numerical examples.

Importance Of The Tail In Truck Weight Modeling For Bridge Assessment, Eugene J. Obrien, Bernard Enright, Abraham Getachew

Articles

To predict characteristic extreme traffic load effects, simulations are sometimes performed of bridge loading events. To generalize the truck weight data, statistical distributions are fitted to histograms of weight measurements. This paper is based on extensive WIM measurements from two European sites and shows the sensitivity of the characteristic traffic load effects to the fitting process. A semi-parametric fitting procedure is proposed: direct use of the measured histogram where there are sufficient data for this to be reliable and parametric fitting to a statistical distribution in the tail region where there are less data. Calculated characteristic load effects are shown …