bluuebunny/crossref_metadata_2025 huggingface dataset:
Securing graph steganography by using Shamir’s secret sharing
Authors: Sari A N
Published: May 2020

Nowadays, information exchange becomes popular along with the development of information technology. To protect their confidential information, people usually use steganography because it hides the presence of the secret information in a media file called as cover. In 2008, Desoky et.al. proposed a method namely graphstega or graph steganography that conceals message as data points in a graph. However, this method is vulnerable since the value represented by the graph is not realistic and this will raise suspicion. To overcome the problem, this paper presents a novel approach by exploiting a graph built based on real data as the cover. To securing the position of the secret message, Shamir’s secret sharing scheme is used. The experiment showed that this method has better security than graphstega does.
Automatic battery charging system on android smartphones
Authors: Djuanda D S R , Ramdhani M , Ekaputri C
Published: May 2020

A smartphone needs a battery source to work well. During the battery charging process, the state of charge can be increased by up to 100%. One habit of charging batteries is to leave the smartphone connected to the charger all night long. Batteries that are already 100% but still connected to the charger will continue to receive an electric current even though a small value can cause a decrease in battery life and durability. This final project aims to create an automatic battery charging system based on the Android operating system. The result of this system is when the percentage limit that we have set is the same as the percentage of the battery on the smartphone, the system will automatically cut off the incoming current so that the charging process will stop. This system is designed using a microcontroller, Bluetooth module, relay module, Android apps, and smartphone with an Android operating system. The tests are the suitability of the apps with the smartphone, the charging and discharging conditions on the system, and automatic battery charging. From the results of the tests, the system can cut the current to a value of 0 amperes from the charger manually and automatically controlled through the apps, the apps can be used on smartphones that have Android version 2.1 or higher.
Implementation of fuzzy inference system algorithm in brooding system simulator with the concept of IoT and wireless nodes
Authors: Saputra D I , Rohmat A , Najmurrokhman A , Fakhri Z
Published: May 2020

This paper aims to implement the Fuzzy Inference System algorithm as a controller in an IoT-based observation system in a brooding system simulator. The system consists of sensor and actuator nodes that are connected to the internet using a microcontroller. The two nodes are connected wirelessly. Sensor nodes as devices that collect input data variables that are temperature and humidity. The value of the sensor readings is sent to Antares cloud storage by a microcontroller which functions as data storage so that it can be accessed by the user as well as an input controller. The Mamdani Fuzzy Inference System algorithm is implemented on the actuator node. The actuator node takes fuzzy input values from Antares and then outputs in the form of a PWM crisp value that aims to regulate blower speed and heating level. The experiments performed were comparing the calculation of the algorithm using MATLAB and the brooding system simulator. The results showed identical outputs with practical results with an average error of 0.11% for the PWM value of the blower and 0.22% for the PWM value of the heater. The scheme is expected to be an alternative solution for implementing the control algorithm on an IoT-based system.
Household energy usage pattern in 2200 VA
Authors: Abdurohman K O , Ekaputri C , Aprillia B S , Nurfaidah Y , Reza M
Published: May 2020

Household energy usage is important for us to know because we can use the data for energy saving and prototyping solar system installation. We could see what the maximum usage is and reduce it. In this research, power data logger is made to see the total energy usage and will get result discrete graph. The result for household energy usage for 2200 VA will get 9,82kWh/day.
Detection of level crossing barriers using the histogram of oriented gradients method and support vector machine
Authors: Sugiana A , Aprillia B S , Rifqi M N
Published: May 2020

Railroad crossing is a place where the railroad lines intersect with other roads, such as a highway. Referring to the Regulation of Minister of Transportation No. 36/2011, level crossing must be equipped with signs, markers and traffic signaling devices and crossing gate guards. However, 4600 of the 5800 level crossing points are without railroad keeper so that they are prone to traffic accidents. In addition, hazard information (danger signs) from the railroad keeper to the PUSDALOP and machinists sometimes cannot be seen at night and in a foggy situation. Therefore, this research aims to detect obstacles (cars) at a railroad crossing using the Histogram of Oriented gradient (HOG) method and the Support Vector Machine (SVM) classifier. HOG functions to extract object features (cars), while SVM is responsible for classifying car objects whether they fit the criteria of car features or not. The results show that an accuracy rate of car objects was 85%, 73% for empty train tracks and 91% for detection of passing trains.
Control system design of arc welding by hand machine based on Programmable Logic Controller (PLC) and CC-link master module
Authors: Ardi S , Diana F A
Published: May 2020

This paper presents research conducted at an automotive manufacturing company that manufactures automotive components, including the rear axle. The housing assembly is one part of the rear axle assembly process that serves as a place to put other rear axle components, namely: axle shaft, differential, inner retainer bearings, brakes, drum brakes, and others. A new machine will be designed on the housing assembly production line with a larger capacity, which is 3000 pcs per month. The arc welding by hand machine was designed by adding a motor and an inverter, a pneumatic cylinder as a gripping, a reed switches as a controlling cylinder. The main function of this machine is to connect the upper-lower assembly parts with the housing tube and housing end and to keep the three parts fixed on one axis. If the three connected parts are not on the same axis, it can cause defects in the product. In this paper, we discuss the control system design of the housing assembly arc welding by hand machine using the PLC as its control, and the CC-Link master module which functions as the expand input-output of this machine. With a new machine control design, production targets can be achieved, and product defects have decreased from 0.96% to 0.06%.
A literature review of brain decoding research
Authors: Awangga R M , Mengko T L R , Utama N P
Published: May 2020

Brain Decoding is a popular topic in neuroscience. The purpose is how to reconstruct an object that came from a sensory system using brain activity data. There is three brain area generally use in brain decoding research. The somatosensory area generally using mice and touch they whisker. Auditory area using different sound frequency as stimuli. The visual area using shape, random image, and video. Take one example in the visual cortex. Using the retinotopic mapping concept, the object possible to reconstruct using visual cortex activity recorded by fMRI. Retinotopic mapping focus is to relate fMRI records into visual objects seen by the subject. This brain possibilities of decoding research come to the next level when combining using deep learning. The image seen by the subject can be reconstructed by using visual cortex activity. Make reconstruction come faster and realistic to predict the stimuli. This opportunity is opening the era of the brain-computer interface. Combine a method to analyze brain functionality related to the human sensory. Bring hope and increased human quality of life. This paper reviews research in the field of brain encoding. Divide into three sections, the first section is brain decoding research in somatosensory. The second section is brain decoding in the auditory cortex. For the last section, explain visual cortex reconstruction. Every section includes equipment devices to record brain activity and the source of datasets and methods to get the brain activity data.
The use of visual multimedia in moto cycle mechanics training for deaf students
Authors: Ramadhan F C , Sumarto S , Abdullah A G
Published: May 2020

A common problem in this study is that deaf students have communication problems in learning and students experience problems how to communicate with teachers. The purpose of this study is expected to be able to find out that the use of visual media in motorbike mechanics training can help the development, abilities and knowledge of deaf students. The procedure carried out was to analyze the communication skills of deaf students by interviewing deaf students by one researcher and one linguist. Five deaf students participated in this study. They are Deaf students with the classification of Profound Hearing Loss. Stage one, the Instructor provides learning without using visual multimedia. The second stage, the instructor gives an evaluation of learning to students. The third stage, is taking interview data related to how their perceptions of the learning process, namely what media should be used for deaf students. The results show that the students interviewed stated that visual multimedia with full language is very useful if used at every opportunity, be it during motorcycle training or other learning.
Analysis development of augmented reality in android-based computer learning in vocational schools
Authors: Adnan M T , Widiaty I , Mulyanti B
Published: May 2020

The making of this paper aims to analyze the latest technology used in Augmented Reality in vocational education. Augmented Reality is a merger between the virtual world and the real world which is projected in 2D or 3D form that is used for Entertainment, Engineering Design or as a learning medium. Augmented Reality is expected to be able to attract students’ interest compared to conventional learning methods. The method of making paper uses a literature review that is with 30 papers related to Augmented Reality starting in 2014-2019. Augmented Reality is built with a Blender 2.80 application, software Vuforia SDK, Corel Draw X9, Android Studio, and Unity 3D. Most of the research or development of Augmented Reality in 2014-2019 uses Blender 2.80, Vuforia and Unity 3D applications.
Competencies needed by civil engineering teachers in the digital era
Authors: Surya R E R , Mulyanti B
Published: May 2020

This study aims to obtain information about the competency of teachers needed to support learning in the digital era. The method of analysis used is a course of study by collecting the Journal of Research in 30 journals from 2015 – 2019. The obtained Data is compiled, analyzed and deduced. Data is attributed to competence in the technology of the tools, and to coordinate technology applications in learning. Findings of the analysis to visit that the competency of teachers in the application of tools such as computer or Laptop, Mobile Phone, camera, and the ability of teachers to activate applications such as Social Networking Service (SNS) or Social Media, Video Editor, Browser, Blogs and presentation applications are needed in the digital era.
Cyber Physical System in the industry
Authors: Kamaludin N , Mulyanti B
Published: May 2020

The Industrial Revolution 4.0 greatly affects the activity patterns of human life. Many sectors are feeling the impact of the industrial revolution 4.0, especially industry and education sectors. One of the technologies developed in the era of the Industrial Revolution 4.0, namely Cyber Physical System. This technology that integrates communications, control, and physically through the Internet. This paper was prepared aims to determine the model and the application of Cyber Physical Systems in the industry. The method used in the preparation of this paper, by reviewing the literature in journals that are in the range of 2014 - 2019. The search results and study, there are different models and ways of working are applied Cyber Physical Systems in industry. Based on these results of the study, it is hoped that alternative CPS models can be applied in the same field or developed in other relevant fields.
Environmental determinants of destination competitiveness: A case study
Authors: Aji R R , Aviandro S , Hakim D R , Djabrail A F N
Published: May 2020

Environment is related to tourism as one of determinant to determine tourism destination competitiveness. Environmental determinants that can affect destination competitiveness are society, technology, culture, demographic, economy, geography, history, infrastructure, law, opponent, politics, and resources. This research aims to explain how environmental determinants take effect to destination competitiveness in Pentingsari tourism village. This research finds out that seven environmental determinants which are society, culture, economy, geography, infrastructure, opponent, and resources take effect on destination competitiveness by using nature and local value that live in Pentingsari tourism village. But some environmental determinants do not take effect in Pentingsari tourism village such as technology, demographic, history, law, and politics. Lack of nature relation is the main reason that five environmental determinants do not take effect on destination competitiveness. This research conclude that environmental determinants take effect to destination competitiveness in Pentingsari tourism village through seven determinants.
Identifying city park accessibility using geographic information system
Authors: Fardani I , Fatimah S
Published: May 2020

Bandung has about 2.5 million people that reside in 9.267 ha urban area. Bandung city has only about 189 hectares of urban park, which is not enough to serve all the settlements area. This study analyzed the level of accessibility of residents to the park services, in term of how far and wide the city park can serve the surrounding community. This research used Network Analysis in Geographic Information System (GIS) method to calculate the Services Area. The method used assumption that one park can be reached by residents walking in radius 1.250 km around their house. The result show that the existing of the park in Bandung City can only serve about 6.942 Ha of urban area, which is only serve 2/3 urban area in Bandung City. City parks in Bandung City have not been distributed well, especially in the eastern and western part of Bandung City, which have blank spot areas in which the residents are unable to reach to a city park. The result of this research can serve as an input to the local government in the planning of building new city parks, which will be beneficial for the residents of eastern and southern area of Bandung City.
The study of road network and environment in Indonesia
Authors: Mukhsin D , Agustina I H , Fernanda E
Published: May 2020

Bekasi Regency is a district that borders directly with Jakarta, Road Network is a strategic infrastructure as a link between the nodes of activity. Large administrative areas, sporadic centers of activity become a common problem in the area of regency. As a result, the integration of the road network and authority matter become a problem in the development of the regency. The urban area in Bekasi Regency covers seven subdistricts, namely: Central Cikarang, South Cikarang, North Cikarang, West Cikarang, East Cikarang, South Tambun, and Cibitung. Within those urban areas, the integration and authority of the road network become a problem. The aim of this research is to make an inventory of road network condition in the urban area of Bekasi. The method of approach used is by conducting field observations, doing institutional surveys to gather the secondary data, in institution such as subdistricts, the Public Works Office, and Binamarga Office, then doing descriptive analysis and overlaying maps using ArcGis linked to the policy of Regional Spatial Planning in Bekasi Regency. The results of the findings are input for policies on road network development in urban areas of Bekasi Regency.
Multi-variable forecasting model using ARIMA (P,Q,N) method to project number of population in Bandung, Indonesia
Authors: Setyawan E B , Novitasari N , Muttaqin P S
Published: May 2020

The focus of this research is to doing analysis and study of public cemeteries as supporters of green space in Bandung regency for 2018 until 2028 period with the aim to determine number of populations in Bandung Regency with considering total population, population growth rate, and mortality rate. The method used in this study is ARIMA (P,Q,N). Based on the results of the analysis and study of public cemeteries (TPU) as supporters of Green Open Space in the Bandung Regency area for the period 2018 to 2028, state that cemetery conditions in Bandung Regency require new grave yard sites. This is evidenced by the results of forecasting (forecasting) of the population per district in Bandung Regency from 2019 to 2028. In making forecasting there are special cases in certain districts.
Predicting consumer behaviour in tourism industry: Comparing Structural Equation Modelling (SEM) and multiple regression
Authors: Suhartanto D , Kusdibyo L , Chen B , Dean D , Setiawati L
Published: May 2020

The Indonesian creative tourism industry is currently flouring and competitive. In this competitive industry, the industry players’ capability to predict their tourist behaviour is imperative. However, research to examine method of predicting tourist behaviour in this industry is limited. This study is designed to assess the applicability of SEM compared to Multiple Regression to predict tourist behaviour. This study uses a survey of 403 tourists from tourism attractions in Bandung. The model of tourist loyalty behaviour was assessed and compared using software AMOS (SEM) and SPSS (Multiple Regression). The results show that the model of tourist behaviour tested by using SEM has a sound Goodness of Fit Index. Further, the coefficient of determination of tourist behaviour in the SEM model is higher compared to that of multiple regression model. In addition, this study confirms the effect of experience quality on tourist behaviour. This study reveals that applying SEM has offered a better prediction on tourist behaviour compared to Multiple Regression. This finding improves the theoretical and managerial understanding on the application of SEM in tourism industry.
Scheduling evaluation in construction projects using the critical chain project management method
Authors: Sembiring N , Putra A
Published: May 2020

PT. A is a company engaged in construction, EPC (Engineering, Procurement and Construction), infrastructure investment, property and real estate. The case study that was raised in this study was the construction project of the retaining wall and the ABC dock that was carried out by PT. A. The problem in the project is that the project scheduling is not good, causing delays in project completion. The purpose of this research is to evaluate the scheduling of the project so that the optimum schedule can be obtained in project implementation. The method used in this study is Critical Chain Project Management (CCPM). CCPM is a project scheduling method that can optimize the schedule due to the absence of multitasking. The CCPM begins by estimating the time without safeguarding the existing time on each job by using the Cut & Paste Method. The critical path serves to find out the critical or non-critical work or activity. Critical activities on wall construction projects anchoring land and ABC dock namely work keep directors. Based on buffer consumption monitoring indicators due to the potential for the emergence of waste will end in use of project buffer duration consumed during the 19-35 period day and immediately take action if the buffer is consumed in the period of 36-53 days. Based on evaluation with critical application Project chain management obtained one feeding 4-day buffer and duration of the buffer project 53 days with the existing scheduling period 432 days to 379 days without buffer consumption.
Performance analysis of cogeneration energy conversion system design for RDE
Authors: Irianto I D , Dibyo S , Sriyono S , Salimy D H , Kusumastuti R , Pancoko M
Published: May 2020

An Experimental Power Reactor called RDE is a non-commercial power reactor with the thermal power of 10 MW. RDE is being designed based on the high-temperature gas-cooled reactor (HTGR). The purpose of the RDE designed is to supply thermal energy for experimental purposes and to generate electricity for supplying the electricity in Serpong research area. The energy conversion system of RDE is designed in cogeneration configuration with a Rankine cycle. The outlet reactor coolant temperature of RDE is 700 °C, and the steam temperature at the outlet of the steam generator is 530 °C. The performance analysis of the RDE energy conversion system is concentrated on two parameters are the thermal efficiency and the energy utilization factor (EUF). This research aims to calculate and analyse the optimal of the two parameters in the RDE energy conversion system. Calculation and analysis of the performance of the RDE energy conversion system are performed by simulation using computer code ChemCad. The simulation results show that the energy utilization factor of the cogeneration for the RDE energy conversion system can increase by more than 60%. It can be concluded that the energy conversion system in a cogeneration configuration can increase the EUF.
Collaboration of sustainability and digital supply chain management of achieving a successful company
Authors: Sembiring N , Tambunan M M , Ginting E
Published: May 2020

The high demand from consumer for environmental welfare issues is a driving factor for increased research in management of sustainable supply chain (SSC). The researches in SSC field show that SSC are needed by companies and organization in making the decisions that important to produce products and services related to sustainability. Performance measurement of a SSC, not only measured economically, but also related to social and environmental performance. All stages in the form of planning and managing all activities involved in Supply Chain Management (SCM) such as procurement, conversion, logistics, communication, and collaboration with partners, must be carried out with high quality. The entire management process, especially those relating to supply and demand in and throughout the company must be carried out integrative. This paper indicated that SSCM strategies effects of these collaborative impact considering sustainability in supply chain management to achieve the successful company.
Measurement of operator reliability level using the Human Error Assessment and Reduction Technique (HEART) method
Authors: Rejeki Y S , Achiraeniwati E , Wanda A
Published: May 2020

Workers can cause harm to the company caused by human error. Human error has a close relationship with the level of reliability of a worker. One result of the low level of reliability of workers is product defects. PT. X is a company that manufactures engine and molding spare parts and dies, using automatic machinery. There are defective products on production, with an average number of defects of 1.2% per month above the disability tolerance set by the company of 0.2%. The types of defects in the product are corrugated surfaces, rough surfaces, mismatched pieces, inaccurate sizes, and the presence of foreign matter attached to the product. This product defect occurs in the milling machine. This study aims to determine the level of operator reliability at the milling work station that affects production results. This research is a descriptive qualitative research using the Human Error Assessment and Reduction Technique (HEART) method to determine the level of operator reliability. The biggest HEP measurement results experienced by each operator is when the activity is set up and operating the machine by the program, which ranges from 0.7936 to 0.9104. The level of reliability (Rm) for operators 1, 2, 3 has a value of Rm in succession of 0.4350; 0.3627; 2005. Rm value <0.5 indicates the level of reliability which is categorized as low. This low level of reliability is caused by the absence of work procedure standards, lack of supervision of operator performance, low work morale, lack of operator experience, and no effective communication between the operator and programmer when inputting coding on the machine.
Minimization of WIP inventory cost at CNC-machining centers through assignment of m serial machines and transfer batch size reduction
Authors: Muhammad C R , Nu’man A H , Shofia N
Published: May 2020

In the batch production, the use of a single machine for several stages of the processes will result in waiting time of production batch to be long. It will cause an increase in work in process (WIP) inventory cost. CNC-machining centre is a type of CNC machine that can carries out several stages of processes singly. In some cases, this machine is often single used to make a product through several stages of processes, from raw material to end product. One of the reasons to use a single machine is to avoid transfer from one stage (machine) to next machine. However, single use causes inventory to accumulate due to long waiting times. The objective of this research is to reduce the WIP inventory cost at the CNC-machining centre. Scheduling to minimize WIP inventory cost is done through two steps. First step, divide number of stages of processes to be assigned tomserial CNC-machining centers. Second step, determine transfer batch size is smaller than the production batch size to be transferred to the next stages. The results of this research indicate that there is a reduction in WIP inventory cost by 53.47 percent. Scheduling multi-stage batch production onmmachines with small transfer batch size will reduce WIP inventory cost.
Sustainable supply chain model by using digital partial least square method
Authors: Sembiring N , Dewi I S
Published: May 2020

The high level of demand for crumb rubber had caused a shortage of raw materials used for production. It also causes the greater the quantity of waste produced. This will have an impact on the environment. In addition, the social impact of the waste generated from production will cause restlessness to the surrounding community. Handling this will have an impact on the economic aspects. This study aims to model a sustainable supply chain at PT. X is based on environmental, social and economic performance using the Partial Least Square method. Data analysis was performed by testing validity, reliability testing, and analysis. The results of the study show that the sustainable supply chain model produces a positive relationship with environmental, social, and economic performance.
Multiple item batch scheduling model on a batch processor to minimize total actual flowtime parts through the shop
Authors: Hidayat N P A , Oktaviani T D A , Halim A H
Published: May 2020

This research is to address a problem of scheduling batches consisting of multiple item parts processed on a batch processor where each item requires a certain processing time which may differ from others. A number of parts are defined as a batch and processed simultaneously with sharing a set up time. A batch can be formed of the parts with different type of item and the processing time of batch equals the longest processing time of parts in the batch. It is assumed that an excessive duration of processing the parts will not lead to any defect, but increase the operating cost. The completed part must simultaneously be delivered at common due date, d. The objective is to minimise total actual flowtime of parts through the shop. A solution procedure to solve the problem is proposed and numerical examples are shown.
Modification of Poly Lactid Acid (PLA)/Chitosan with cinnamon essential oil for antibacterial applications
Authors: Suryani S , Rihayat T , Nurhanifa N , Riskina S
Published: May 2020

The active packaging material used for the manufacture of food packaging that has antimicrobial properties. The purpose of this research is to inhibit the growth of microorganisms on food surfaces, to improve nutritional quality and to extend the shelf life of food and reduce the environmental impact of packaging. The preparation is done Cinnamon essential oil (CEO) is a natural antimicrobial being investigated for food packaging as a substitute for synthetic chemicals due to consumer concerns over food safety. In this study, lactic acid poly (PLA) and chitosan were successfully modified with essential oil (CEO) at concentrations (1.5%, 2%, 2.5%, and 3% v/v) that formed composite fibres with using a simple electrospinning method. The morphology of the composite fibres can be seen from PLA / CS-CEO-2.5 showing good stability of the CEO so that the antimicrobial activity is increased compared to other blends. PLA / CS-CEO fibre shows a high level of long-term inactivation against Escherichia coli and Staphylococcus aureus due to the CEO’s ongoing release, indicating that advanced PLA / CS-CEO fibres have great potential for active food packaging applications.
Combination of poly lactid acid zinc oxide nanocomposite for antimicrobial packaging application
Authors: Ridwan R , Rihayat T , Suryani S , Ismi A S , Nurhanifa N , Riskina S
Published: May 2020

Many food packages (plastic wrappers) today cannot be broken down by the environment. therefore, it is necessary to add natural substances that can make the food package decompose and be resistant to contamination with bacteria. Poly lactic acid (PLA) is one of the natural polymers produced by several bacteria that grow in crops rich in carbohydrates (such as sugar beets, corn and others). This research aims to insert ZnO nanoparticles and chitosan into a plastic layer of PLA (poly lactic acid) which can improve the antibacterial properties of the resulting packaging. The method used in making PLA-ZnO-chitosan Nano composite is the precipitation method and the heating method. PLA-ZnO Nano composites were obtained by varying ZnO nanoparticles 0.5% by weight, 2% by weight, and 3.5% by weight. The results obtained in SEM images show that nanoparticles are homogeneously distributed on the plastic surface. Antimicrobial tests show nanocomposites work effectively in deactivating E. coli and S. aureus. where it was found that E. coli was more susceptible to this type of nanocomposite, where there was a reduction of 3.4 logs to 3.5% ZnO loading in the PLA layer.
Voltage generation characteristics of an Axial Flux Permanent Magnet (AFPM) generator
Authors: Rusmana R , Melkias A A , Nurrohman N , Kastawan I M W
Published: May 2020

A specially designed low-speed generator was enveloped based on low-speed turbines. The axial flux permanent magnet (AFPM) generator type is chosen to meet these needs. The generator consists of a stator and a rotor. The distance between the stator and rotor was studied to determine the characteristics of the AFPM generator. Besides, the impact of rotational speed on the output voltage also considers - the stator armatures made of copper wire with a diameter of 0.2 mm. The number of turns of a winding was 200 turns, which produced a resistance of 100 ohms. The shape of the armatures adjusted to the shape of the magnet. The rotor discs occupied by 18 magnets arranged symmetrically. The size of the magnet was 50 mm long, 30 mm wide and 13 mm thick. The laboratory test conducted by placing the rotor ranging from 23 mm to 15 mm, with changes in the distance of 2 mm each, from the stator. From the measurement, the linear equation of output voltage versus the rpm curve obtained as well as the output voltage versus the stator-rotor distance equation. The results show that the increase of rpm and the closer the rotor-stator distance, the higher the output voltage.
Implementation of the use of AutoCAD applications in increasing basic competence in describing techniques in vocational education
Authors: Saputro B E , Supratno S
Published: May 2020

Technology helps a drafter speed up work completion, including CAD (Computer Aided Design) applications. Auto CAD which is an application (CAD software) is used to draw, design drawings, even analyse a design to realize a commercially viable product. This program has advantages and convenience to make images visually, accurately and precisely. The lecture strategy with the help of a computer is a lecture method via computer where, the user (User) can more easily & quickly understand & apply what information is learned through an attractive image display. The product design of a gear with a cycloide (Cycloide) gear profile is used as an instrument to realize student competencies in machine element courses. An evaluation of the previous material provided an initiative in the development of the module. The module development referred to uses the term 4-D or better known as (Four-D). The 4-D development model has 4 stages: defining, designing, developing, and disseminating. The final results of the development of CAD learning modules with the 4-D method received a very good response from students and lecturers of PTM Study Program STKIP Eleven April Sumedang.
Stress analysis in pedicle screw and bone interface by various contact models in scoliotic spine fixation
Authors: Rusli M , Dahlan H , Sahputra R E , Bur M
Published: May 2020

Scoliosis is a musculoskeletal condition that has an abnormal lateral spinal curvature as its main feature. By a level curvature condition, the scoliotic spine has to treat by surgery process to install an instrument or implant consists of pedicle screws, rods, and connectors in fixation of the spinal curvature. However, it is observed in many cases that several types of failure occur in the instrument and the bone - pedicle screw interface. One of the problems was related to screw loosening and pulled out from the spine. This paper observes and discusses the stress distribution numerically in the screws and bone interface in scoliotic spine fixation using finite element analysis. The contact interface is modeled variously by bonded contact and friction contact. It is found that in bonded connection between screws and bone generates lower maximum stress than friction contacts. The maximum stress is working in the screw and the stress distribution is more uniform along the contact surface. Therefore, the risk of pulling out the screws will be minimized. On the other hand, friction contact with low friction coefficients makes the stress distribution is concentrated in a specific region and increase the maximum stress in bone.
Chatter detection in turning process using sound signal and simple microphone
Authors: Huda F , Darman D , Rusli M
Published: May 2020

Chatter is a problem that frequently found in the area of a machining process, which brings down machining productivity and surface quality. Therefore, reliable and intense chatter detection methods are needed to maintain machining quality. In this study, turning chatter detection approach by using sound signals and a simple microphone is proposed to get an accurate, simple, and low-cost detection method. For that purpose, an experimental set-up which consists of an operating turning machine, simple microphone, and Personal Computer (PC) with sound card was arranged. The chatter in the turning process was stimulated by applying artificial wear to the cutting tool. The sound signal data from normal and with chatter turning process were then grabbed by a simple microphone and PC with a sound card. The sound signals were then evaluated by Fast Fourier Transform (FFT) and Wavelet Transform (WT) for normal and chatter conditions. Both conditions data were then compared to get the characteristic of the sound signal in chatter. It is found that signals in the frequency domain, time-frequency and spectrogram have a significant magnitude spike in chatter condition. The results demonstrated that the proposed method could conscientiously identify the chatter.
Cutting tool wear analysis using sound signal and simple microphone
Authors: Huda F , Karjuni K , Rusli M
Published: May 2020

Cutting tool is an important part of machining processes which in the operation frequently runs into wear. The wear cutting tool produces an imprecise product with low quality surface, may endanger machine tools by stimulating chatter. In this study, low cost and fast analysis of the wear of cutting tools in turning and drilling processes are proposed. For that purpose, the experimental set-up which consists of operating turning and drilling machine, simple microphone and Personal Computer (PC) with a sound card are set out. The wear of cutting tools are made by applying artificial wear. The sound data from normal and wear cutting tools of operating turning and drilling machines are recorded by using simple microphone and PC with a sound card. The obtained sound signals are then analyzed in the form of time and frequency domain, spectrogram by Wavelet Transform (WT). It is found that sound signals in time and frequency domain have a significant rise of amplitudes in wear conditions. The spectrograms exhibit the special contours which sign the existence of wear. The results demonstrate that the proposed method can analyze the cutting tool wear very well.
Performance of a residential air conditioning unit under constant outdoor air temperature and varied relative humidity
Authors: Setyawan A , Badarudin A
Published: May 2020

An experiment on the effect of the relative humidity variations of outdoor air on the performance of an air conditioning system under constant dry-bulb temperature has been performed. In this experiment, the outdoor air temperature was maintained at 35°C while the relative humidity was varied from 40% to 70%. As a result, the operating conditions were slightly changed. In general, the suction temperature decreases with the increase of relative humidity. On the other hand, the condensing temperature slightly increases with the increase of relative humidity. Other findings for the experiment are almost constant of cooling capacity, with a variation of only 1.2%. An important evidence is that the condenser capacity increases by 15.2% for the relative humidity variation from 40% to 70%.
Enhancing performance of wall mounted split air conditioner using capillary tube in a tube heat exchanger
Authors: Berman E T , Komaro M , Miftakhudin M , Mutaufiq M , Suherman A
Published: May 2020

The high cost of electricity rates has affected the demands of the public for the availability of energy-efficient air conditioning systems. This study aims to obtain data on improving performance of air conditioner using capillary tube in tube heat exchangers. Tests were carried out on a wall mounted split AC capacity of 9000 Btu/h which was modified using a heat exchanger with capillary tube in tube heat exchanger. The results showed that the installation of a capillary tube in tube heat exchanger on a wall mounted split AC resulted in an increase RE and COP of 13.2% and 14.9%, respectively. In addition, the room cooling time in the TiTHX capillary mode testing is shorter. So it has implications for lighter compression work and saves the power consumption required by AC.
Optimization of B-series propeller geometry dimension to improve traditional fishing ship performance
Authors: Mulyana D , Koeshardono F , Sudradjat A , Widiatmoko R Y
Published: May 2020

The fishing ship propulsion system will affect the performance of the ship and impact the fishermen’s income. A crucial factor is the level of efficiency produced by propellers mounted on fishing vessels. In B-series propellers, propeller efficiency can be optimized by varying the size of the geometric dimensions. This propeller optimization process can be done after the ship resistance value is known. In Cirebon waters, as in other regions in Indonesia, the selection of propellers by fishermen is still unclear. Most are only based on the availability of goods on the market, without looking at how big the actual ship resistance occurs. In this research, one of the fishing boats that will be built will be chosen to estimate the ships’ resistance. After that, by considering the engine used as its driving source, the geometry dimensions that can produce the highest efficiency are sought. Estimation of ship resistance is sought by the Holtrop method, and propeller optimization is carried out with the help of software. From the results of this study, the value of ship resistance commonly used by Cirebon waters fishermen is 2.608 kN at an operational speed of 7 knots. Optimized propeller design provides a 6 percent increase in efficiency compared to previously used propellers.
Correlation of rock characteristics to gold content in the Honje Formation and Cipacar Formation, Pandeglang, Banten
Authors: Usman D N , Sulaksana N , Hirnawan F , Haryanto I , Widayati S , Sriyanti S , Pulungan L
Published: May 2020

Gold deposits are economic deposits, the formation of gold deposits in nature is one of them epithermal gold deposits in the Au-Ag mineralized zone. Gold mineralization is influenced by a hydrothermal solution that flows through rock permeability, resulting in an alteration process that changes the chemical composition, mineralogy, and texture of the original rock. One variable that affects the presence of veins carrying valuable ore minerals is fracture structure. This study aims to determine and analyse the relationship /correlation of rock solids to the level of gold deposits using the correlation regression method. The methodology used is massive data collection through geological mapping, log-drill data analysis, Data Assay analysis, data processing and analysis assisted by using correlation regression through validation and verification of drill data. The results of processing and analysis of muscular data notified by the RQD value and log-drill data obtained the results of multivariate normality test based on the Au model = 8,219-2761 RQD and Ag = 90,388 + 0.977 RQD as follows: 1) When the RQD is zero, then the Au will be valued amounting to 8,219. However, when the RQD increases by 1 unit, the Au will decrease by 2,761. 2) When the RQD is zero, then Ag will be worth 90,388. However, when the RQD rises by 1 unit, then Ag will rise by 0.977. Then the Meaning Mean Test is performed where the result H0 is Received, with the understanding that there is a significant relationship between RQD on Au-Ag levels, understanding that the change in thickness of a thicker ore is followed by an increase in the higher Au level, tcount = 0.382 and the significance is 0.703. The understanding is that Au levels are correlated with the presence and presence of hefty that is notified by RQD.
Coal handling quality from pits to stockpiles to market specifications
Authors: Pulungan L , Arbianto V
Published: May 2020

In the coal trade, coal quality becomes the main thing that must be consider. The quality of coal that is not following the specifications desired by consumers causes coal prices below. Parameters of coal quality consist of calorific value, water content, an ash content of flying substances, and sulfur content. The quality of this coal will always recheck with every change of place. Before coal is sold, it is better to monitor the quality of the coal starting from the pit. At the coal quality monitoring location, there are four seams, including seam A1, seam A2, seam B and seam C. Monitoring of coal quality is carried out at seam C to be mined. Monitoring of coal quality from the pit to the stockpile is done by taking representative samples from drilling, mining, and stockpile activities. Then the samples were analysed by proximate analysis. Drilling samples was taken by coring sampling from eight drill points. Sample from the pit are taken by channel sampling method, in the mining pit sample are divided into three parts, namely the upper part (coal with 10 cm thick clay insert, called layer 1), the second middle part (coal with 20 cm thick clay insert, called layer 2 ) and the bottom three (coal without clay insertion, called layer 3). The purpose of the division is carried out as a handling coal from being mixed into three parts. Samples from the stockpiles are taken by grab sampling method from three stockpiles originating from layer one, layer two, and layer three. For layer one coal, the difference in ash content in pits and stockpiles is 1.6%, the difference in total sulfur content in pits and stockpiles is 0.7%. For layer two coal, the difference in ash content in pits and stockpiles is 1.5%; the difference in total sulfur content in pits and stockpiles is 0.7%. In layer three. The difference in ash content in pits and stockpiles is 1.5%, the difference in total sulfur content in pits and stockpiles is 0.7%.
Monitoring of mine waste from copper ore flotation
Authors: Pulungan L , Usman D N , Kurniawan E A , Galiano R A
Published: May 2020

The copper ore flotation conducted by PT XYZ produces copper, and other metal concentrates as tailings. The copper concentrate will then be processed as industrial raw material, while the tailing waste is dumping a waste dump. The copper ore flotation tailings must follow the tailings waste management rules. Monitoring tailings quality testing must be done, which includes physical and chemical parameters. The results of the analysis of copper ore flotation tailings are comparing with the provisions issued by the Ministry of Environment No. 92 of 2011. And 382 in 2016. Furthermore, to monitor the state of seawater around the mining site, water quality testing is divided into three zones, Zone A with into> 120 m, Zone B 0 - 120, and Zone C (tailings free). Seawater quality monitoring is carrying out in zone B. The quality test results tailing flotation Copper ores how physical and chemical parameters are below the threshold set by the Ministry of Environment. Whereas monitoring of seawater quality carried out in zone B, TDS exceeds the intensity at S15B, while dissolved metal concentrations are below the threshold at all stations.
Optimization and slope stability coal mine with dewatering system using limit equilibrium method
Authors: Iswandaru I , Isniarno N F , Hirnawan R F
Published: May 2020

Mining activities related to excavation or landfill will always face problems with slopes, both in the form of working slope and final slope, in addition the groundwater factor in the rock layer increases the burden by filling pores and reducing friction inter-grain influences the slope stability. The slopes must be analyzed for stability to prevent landslide hazards because they involve work safety, equipment safety, and smooth production. PT. XYZ is a coal mining company located in the Lilin river, South Sumatra, planning to optimize and stabilize the final slope to a depth of 120 m. Geotechnical drilling has been carried out as many as 3 points with a total depth of 270 m and 80 samples of rock and soil testing. The results of optimization and stability of the slope by conducting dewatering at each elevation to obtain optimal slope conditions at PT. XYZ can be done up to elevation of -130 meters above sea level with a depth of 142 meters with an angle of 35° with the condition of the ground water level must be maintained at the halfway point of the slope (GWL Chart No. 3). Under water saturated conditions (GWL Chart No. 5) at the same elevation the permissible angle is only 25° with a final slope height of 136 m.