Articles

MODEL REGRESI DATA PANEL SIMULTAN DENGAN VARIABEL INDEKS HARGA YANG DITERIMA DAN YANG DIBAYAR PETANI Falah, Bayyina Zidni; Mustafid, Mustafid; Sudarno, Sudarno
Jurnal Gaussian Vol 5, No 4 (2016): Jurnal Gaussian
Publisher : Departemen Statistika FSM Undip

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Abstract

Interdependent relationship (simultaneity) between endogenous variables, that?s Farmers Recieved and Paid Price Index, can?t be modeled in a single equation, but there are two equations in a system of simultaneous equations. Each of these equations can?t be estimated separately without entering information from other equations. The purpose of this research is modelling panel data regression simultaneously. The method that?s used is Common Effect Model (CEM), Fixed Effect Model (FEM), and Random Effect Model (REM) with estimation technique is Two Stages Least Square (2SLS). The modelling is done by a panel data consisting of 32 provinces in 2013, 2014, and 2015. Based on the results of the Chow test, Hausman test, F statistic, and the value of R2, the result is that REM is the most suitable model to model the simultaneity of the panel data. REM has different intercepts in each province. F statistic value for the first equation of 152,658 with a significance of 0.000, and R2 value of 83,2%. For the second equation, statistics F value of 44396,16 with siginifikansi 0,000, and R2 value of 99.9%. From the results of this modelling, the model that?s created can express the interdependent relationship between endogenous variables as well the diversity of variables between provinces.Keywords:      Panel data, CEM, FEM, REM, Farmers Recieved Price Index,Farmers Paid Price Index
OPTIMALISASI PARAMETER TEKNIK PENGELASAN FLUX CORED ARC WELDING (FCAW) MENGGUNAKAN METODE TAGUCHI MULTIRESPON PCR-TOPSIS Kusumawardani, Meilia; Mustafid, Mustafid; Yasin, Hasbi
Jurnal Gaussian Vol 4, No 3 (2015): Jurnal Gaussian
Publisher : Departemen Statistika FSM Undip

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Abstract

Multi response optimization case has encountered in industrial. Multirespon Taguchi TOPSIS PCR method is used to determine the optimal combination of factors/level and calculate the optimum performance for each response. Purpose of Taguchi method is to reduce the variability, and theory Process Capability Ratio (PCR) shows the process situation in which the parts produced are good or defective. Then Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) to determine the optimal combination multi response case. The case study using the technique of Flux Cored Arc Welding welding (FCAW) using characteristic larger is better. Performance optimal conditions for factor Welding  current at 280 ampere and factor Electrode stickout at 21 mm. Then optimal performance conditions for each responses are hardness=481.145 and deposition rate=3.813. These results have a higher value when compared with the initial conditions. So the case results meet the characteristics of larger is better. Keywords : Taguchi Method, PCR, TOPSIS, FCAW
KAJIAN SIX SIGMA DALAM PENGENDALIAN KUALITAS PADA BAGIAN PENGECEKAN PRODUK DVD PLAYERS PT X Shofia, Nailatis; Mustafid, Mustafid; Sudarno, Sudarno
Jurnal Gaussian Vol 4, No 1 (2015): Jurnal Gaussian
Publisher : Departemen Statistika FSM Undip

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Abstract

Increasingly rapid development period, many industry sectors are growing and developing in Indonesia. Quality basic consumer decision factor in selecting goods and services. In the process of checking the audio end section 8 types of defects found on the product DVD players. Damage that occurs due to several factors, including factors human, material factors, and factors machines. If the quality of a company is said to have good production systems with process control. Six Sigma method is a method that can be used for analysis of the defect rate to approach zero defect products. The procedures used for quality improvement towards the target that the concept of Six Sigma DMAIC. This study aims to apply Six Sigma methods in quality control by conducting case studies to improve product quality DVD player at the end of the audio process. The results obtained in this study is on the whole production process mengkasilkan DPMO value of 5487 with sigma quality level of 4.04 means that the product of one million DVD players there are 5487 units of product that does not fit in production. Keywords : Quality, Statistical Quality Control, Six Sigma
IMPLEMENTASI ALGORITMA MODIFIED GUSTAFSON-KESSEL UNTUK CLUSTERING TWEETS PADA AKUN TWITTER LAZADA INDONESIA Putri, Ratna Kencana; Warsito, Budi; Mustafid, Mustafid
Jurnal Gaussian Vol 8, No 3 (2019): Jurnal Gaussian
Publisher : Departemen Statistika FSM Undip

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Online social media is a new kind of media which is steadily growing and has become publicly popular. Due to its ability to spread informations rapidly and its easiness to access for internet users, social media provides new alternative to conduct advertising and product segmentation. Twitter is one of the most favored social media with 19.5 million users in Indonesia to the date. In this research, the application of text mining to cluster tweets from the @LazadaID Twitter account is done using the Modified Gustafson-Kessel clustering algorithm. The clustering process is executed five times with the number of cluster starts from two to six cluster. The results of this research indicate that the optimum number of clusters formed based on the Partition Coefficient and Classification Entropy validation index are three clusters. Those three clusters are tweets containing electronic stuff offers, discounts, and prize quizes. Tweets with the most retweets and likes are prize quiz tweets. PT Lazada Indonesia could use this kind of tweet to conduct advertising on social media Twitter because the prize quiz tweets are liked by the @LazadaID Twitter account followers.Keywords: Twitter, advertising, Lazada Indonesia, Gustafson-Kessel Clustering algorithm, validation index
PENDEKATAN METODE SIX SIGMA-TAGUCHI DALAM MENINGKATKAN KUALITAS PRODUK (STUDI KASUS PT. ASAPUTEX JAYA SPINNING MILL TEGAL) Oktajayanti, Nesvi Intan; Mustafid, Mustafid; Sudarno, Sudarno
Jurnal Gaussian Vol 5, No 1 (2016): Jurnal Gaussian
Publisher : Departemen Statistika FSM Undip

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Abstract

The main factors to achieve business success in the era of globalization is the quality. In the business world, quality control is the key to maintaining customer loyalty. For a company doing quality control is expected to achieve the company's goals, related to the company's revenue. This is the purpose of PT. Asaputex Jaya Spinning Mill Tegal to make efforts to improve the production activities, especially in improving quality by reducing defects. Six Sigma-Taguchi method can be used to improve quality yarns product. From the analysis we found that the control diagram p, data of defects is uncontrolled, so the capability process is still low with capability value is 0,502. So, it need to be improved to enhance product quality yarns. By using the Taguchi method we can know factors and optimal level to improve the quality of the yarn. That Factor and level is TPI with the optimum level that can be used are Level 2 (13,5 rpm), level 1 (383 tpm) for Delivery Speed factor, for the weight of cotton the optimum level is level 1 (2,0 Kw) and factor Grain the optimal level is level 2 (400 Ne). Keywords: Six Sigma Method, Design Experiment of Taguchi, Capability Process
PENDEKATAN SERVQUAL-LEAN SIX SIGMA MENGGUNAKAN DIAGRAM KONTROL T2 HOTELLING UNTUK MENINGKATKAN KUALITAS PELAYANAN PENDIDIKAN (STUDI KASUS DI JURUSAN STATISTIKA UNIVERSITAS DIPONEGORO) Darwati, Lulus; Mustafid, Mustafid; Suparti, Suparti
Jurnal Gaussian Vol 4, No 2 (2015): Jurnal Gaussian
Publisher : Departemen Statistika FSM Undip

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Abstract

Measurement the service of quality has an important role in improving and evaluating the performance of a service process. Measuring the service of quality is not as easy as measuring the goods quality, because the assessment service is subjective. Therefore, ServQual dimension is used as a tool to measure the performance of service from the perspective of service?s users. Lean Six Sigma method is used to improve the performance of the services of quality that focused on the reduction of variations and the increasing of the speed of the process through the elimination of waste that occur in the flowing process. This research aims to implement the integration of ServQual and Lean Six Sigma method by controlling the process using Hotelling T2 control charts on the improvement of the quality of education services. The performance of the education services process overall is indicated by the value of the capabilities and the level of the sigma. The capability value amount 0.8407 and the level of sigma amount 2.748 indicates that the waste percentage in the process of educational services is about 10.6%. The waste of dominant on improving the quality of education services such as lecturer competencies, the status of departement accreditation, the speed in the administrative services, and the refinement of laboratory facilities especially the improvement on the computer facilities.Keywords : ServQual, Hotelling T2 control charts, Process Capability, Lean Six Sigma
PENERAPAN METODE STRUCTURAL EQUATION MODELING UNTUK ANALISIS KEPUASAN PENGGUNA SISTEM INFORMASI AKADEMIK TERHADAP KUALITAS WEBSITE (STUDI KASUS PADA WEBSITE SIA.UNDIP.AC.ID) Sasongko, Enggar Nur; Mustafid, Mustafid; Rusgiyono, Agus
Jurnal Gaussian Vol 5, No 3 (2016): Jurnal Gaussian
Publisher : Departemen Statistika FSM Undip

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Abstract

Quality of website has an important role in giving effect to the website user's satisfaction. The quality of a website is measured by the adjusted WebQual dimensions include the dimensions of the system, dimension of information, dimension of interaction and dimension of services. Structural Equation Modeling is a method that used to examine complicated correlation simultaneously consisting of dependent variables and independent variables. This research aims to apply Structural Equation Modeling and Importance Performance Analysis methods in determining the influence of website quality factors on user satisfaction of academics Information System's website, and to find the performance of variables that need to be improved. This research is conducted at the University of Diponegoro, involving 200 students from Diponegoro University as the respondents. From the test of overall models, it obtained Goodness of Fit with the value of Chi Square = 68.748 and RMSEA = 0.084. From the analysis, it can be concluded that the dimension of interaction has the effect of 35%, dimension of information in amount of 35%, the dimension of service is 22.1%, and the dimensions of system in amount of 8.7%. And variables that need to improve performance are ease of website to be accessed's variable, variable of detail information, and ease of PBM evaluation's variable. Keywords: website quality, user satisfaction, Structural Equation Modeling
MODEL HUBUNGAN VOLUME LALULINTAS HARIAN DENGAN KECELAKAAN LALULINTAS DI JALAN TOL ANTAR-KOTA Haryadi, Bambang; Riyanto, Bambang; Mustafid, Mustafid; Budiwirawan, Agung
Jurnal Transportasi Vol 10, No 3 (2010)
Publisher : Jurnal Transportasi

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Abstract

Safety is one of the minimum criteria that should be met on the toll road operation. Ideally, the level of safety of highway sections can be predicted even if the highway is still on the design stage. This paper aims to develop mathematical models that could be used to predict the number of accidents, by its level of severity, on inter urban toll road sections based on its average daily traffic per lane and section length. Two yearperiod of traffic and accident data were obtained from Jagorawi, Jakarta-Cikampek, Padaleunyi, and Palikanci toll road operators. Models were developed using the negative binomial regression method. The reluts show that the negative binomial regression gives desirable properties in describing the relationshipbetween the accident frequency and the average daily traffic per lane on each toll road section observed.Keywords: toll road safety, accident model, negative binomial regression.
SOLVING A SYSTEM OF LINEAR EQUATIONS BY QR FACTORIZATION METHOD FOR TEMPERATURE AND ALTITUDE REGRESSION MODEL AGAINST SPONTANEOUS-POTENTIAL Widowati, Widowati; Setyawan, Agus; Mustafid, Mustafid; Nur, Muhammad; Sudarno, Sudarno; Harmoko, Udi; Adhy, Satriyo; Gunawan, Gunawan; Subagio, Agus; Tjahjana, Heru; Sulpiani, Ririn; Riyanto, Djalal Er; Suhartono, Suhartono; Mukid, Mochammad Abdul; Suseno, Jatmiko Endro
JURNAL SAINS DAN MATEMATIKA Volume 22 Issue 3 Year 2014
Publisher : JURNAL SAINS DAN MATEMATIKA

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Abstract

Many real problems can be represented in the form of multiple linear regression equation. One of those is the relationship between the variables of temperature and altitude of the spontaneous-potential. In order to determine the parameters of the regression equation, the least squares method was used. From here, there was obtained the system of linear equations. In this paper, to solve systems of linear equations, the exact method was used as the exact solution is certainly better than the approached solution. The method used was the QR factorization method. At the QR factorization, the system of linear equations was written in form of matrix equation. Then, the coefficient matrix which the number of rows is m and number of columns is n with linearly independent columns was factored into the matrix Q which has the same size with the matrix A, with orthonormal columns and matrix R was upper triangular. Furthermore, by backward substitution, it could be obtained the exact solution of linear equation system. As verification of this proposed method, a case study was given using data of temperature, altitude, and spontaneous-potential in the geothermal manifestations area, Gedongsongo, Mount Ungaran Semarang. From here, it was obtained the parameters of exact multiple linear regression model which states the relationship between temperature and altitude toward the spontaneous-potential.
MODEL HUBUNGAN VOLUME LALULINTAS HARIAN DENGAN KECELAKAAN LALULINTAS DI JALAN TOL ANTAR-KOTA Haryadi, Bambang; Riyanto, Bambang; Mustafid, Mustafid; Budiwirawan, Agung
Jurnal Transportasi Vol 10, No 3 (2010)
Publisher : Jurnal Transportasi

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (216.834 KB) | DOI: 10.26593/jt.v10i3.393.%p

Abstract

Safety is one of the minimum criteria that should be met on the toll road operation. Ideally, the level of safety of highway sections can be predicted even if the highway is still on the design stage. This paper aims to develop mathematical models that could be used to predict the number of accidents, by its level of severity, on inter urban toll road sections based on its average daily traffic per lane and section length. Two yearperiod of traffic and accident data were obtained from Jagorawi, Jakarta-Cikampek, Padaleunyi, and Palikanci toll road operators. Models were developed using the negative binomial regression method. The reluts show that the negative binomial regression gives desirable properties in describing the relationshipbetween the accident frequency and the average daily traffic per lane on each toll road section observed.Keywords: toll road safety, accident model, negative binomial regression.
Co-Authors Abdul Hoyyi Adian Fatchur Rochim Agung Budiwirawan Agus Prasetyo Utomo Agus Rusgiyono Agus Setyawan Agus Subagio Ahmad Lubis Ghozali, Ahmad Lubis Alan Prahutama Alfahari Anggoro, Alfahari Alfrianus Papuas Anastasia Arinda, Anastasia Andi Gunawan Ari Fakhrus Sanny, Ari Fakhrus Aris Sugiharto Ayudya Tri Wahyuningtyas, Ayudya Tri Bambang Haryadi Bambang Riyanto Bayu Surarso Bayyina Zidni Falah, Bayyina Zidni Beta Noranita Budi Warsito Catur Edi Widodo Cynthia Damayanti Daniel Alfa Puryono, Daniel Alfa Deria, Aulia Desy Dewi Erliana Diah Safitri Dian Andhika Prameswara Dina Rosmalia Listya Utami Djalal Er Riyanto Dwi Ispriyanti Dwi Putri Handayani Dwinta Rahmallah Pulukadang, Dwinta Rahmallah Dyna Marisa Khairina Edi Widodo, Edi Eko Adi Sarwoko Enggar Nur Sasongko, Enggar Nur Farikhin Farikhin Ferry Jie, Ferry Fina Fitriyana Gunawan Gunawan Hanikmah, Yunanur Hasbi Yasin Heru Tjahjana Ibnu Widiyanto Imam Nur Sholihin Irfan Ismail Sungkar Isowedha Widya Dewi Jatmiko Endro Suseno Khair, Rizaldy Kristy, Nathasa Erdya Lulus Darwati, Lulus Maharani, Adestya Ayu Mariska Srihardianti, Mariska Meilia Kusumawardani, Meilia Moch. Abdul Mukid Mochammad Abdul Mukid, Mochammad Abdul Mohamad Reza Pahlevi, Mohamad Reza Muhammad Nugroho Karim Amrulllah, Muhammad Nugroho Karim Muhammad Nur Nailatis Shofia Nesvi Intan Oktajayanti, Nesvi Intan Pipin Widyaningsih Pratama Ganang Widayaka, Pratama Ganang Prihati Prihati Putri, Ratna Kencana R. Rizal Isnanto Ririn Sulpiani Rita Rahmawati Rizani, Nurul Fitria Fitria Rohalidyawati, Windy Rosmiati Rosmiati Rukun Santoso Satriyo Adhy Sinta Tridian Galih Siregar, Muhammad Akhir Sri Mulyani Sudarno Sudarno Sugito Sugito Suhartono Suhartono Suparti Suparti Supriyati Supriyati Supriyono Supriyono Tarno Tarno Tatik Widiharih Triastuti Wuryandari Udi Harmoko Utami, Puspita Ayu widowati widowati Wulandari, Heni Dwi Yudie Irawan