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JURNAL SAINS INDONESIA
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Articles
Optimasi Pendistribusian Produk AQUA dengan Menggunakan Metode Least Cost dan Modifed Distribution (Studi Kasus di PT Tirta Sibayakindo)

Sembiring, Bani, Mansyur, Abil

Jurnal Sains Indonesia Vol 42, No 1 (2018): Jurnal Sains Indonesia
Publisher : Universitas Negeri Medan

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Abstract

This study aims to construct an initial consideration for decision maker to minimize the distribution costs at PT. Tirta Sibayakindo, a soft drink producer and  distributor in Indonesia. Least Cost methods was used to gain an initial solution and Modified Distribution methods was used to gain the final solution for this transportation problem. Data was analyzed using the Least Cost methods. Results showed that the distribution cost was Rp165.535.000,- when ordinary calculation was implemented. When Least Cost method was used, the distribution cost was Rp100.200.000,-, so the soft drink company can save the distribution cost of Rp65.335.000,-. From this results, we suggest the company to implement the transportation algorithm when they dealed with distribution cost optimization.

Pengaruh Suhu pada Ekspresi Pretrombin-2 Manusia Rekombinan di Escherichia coli ER2566

Silaban, Saronom, Simorangkir, Murniaty, Maksum, Iman Permana, Subroto, Toto, Hasan, Khomaini

Jurnal Sains Indonesia Vol 42, No 1 (2018): Jurnal Sains Indonesia
Publisher : Universitas Negeri Medan

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Abstract

Human recombinant prethrombin-2 (rhPT-2) was expressed in Escherichia coli. Previous studies reported that the expression of rhPT-2 in E. coli tends to formed inclusion body. This study aims to determine the effect of temperature on the expression of rhPT-2 in E. coli ER2566. This study begins with the isolation of recombinant plasmids, competent cell preparation and transformation of competent cells of E. coli ER2566 strain, and rhPT-2 gene expression with various induction temperatures 12, 18, 22 and 30°C. Characterization results showed that the induction temperature of 22°C was the optimum temperature of rhPT-2 gene expression as a soluble fraction in E. coli ER2566 with IPTG concentration 0.1 mM. These results prove that the temperature affects the expression of rhPT-2 in E. coli ER2566.

Pelabelan L(2,1) pada Graf Sierpinski S(n,k)

Sagala, Yuri C., Susiana, Susiana

Jurnal Sains Indonesia Vol 42, No 1 (2018): Jurnal Sains Indonesia
Publisher : Universitas Negeri Medan

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Abstract

Labeling L (2; 1) on a graph G is the function f of the set of vertices V (G) to the set of all non-negative numbers so that │f (u) - f (w) │ ≥ 2 if d (u; w) = 1 and │f (u) - f (w)│ ≥ 1 if d (u; w) = 2. The labeling number L (2; 1) of a graph G is the smallest k number so G has labeling L (2; 1) with max {f (v): v Є V (G) g} = k. The Sierpinski Graph is a form of expansion graph specifically from a complete graph. This study shows labeling on Sierpinski graph using Chang-Kuo algorithm and obtained the values L (2; 1) {S (n; 2)} = 4 and the value of L (2; 1) {S (n; 3)} = 6 for n ≥ 2, with L (2; 1) {G} is the smallest maximum number labeling L (2; 1) from a graph G.

Analisis Perilaku Solusi Sistem Dinamik Glukosa-Insulin dari Model Minimal Bergman

Manalu, Martha Devi, Sitompul, Pardomuan

Jurnal Sains Indonesia Vol 42, No 1 (2018): Jurnal Sains Indonesia
Publisher : Universitas Negeri Medan

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Abstract

Diabetes Mellitus is broadly classified into two categories, namely type 1 and type 2 diabetes. In this study, the model used was a model that interpreted the glucose-insulin dynamics in everyone, except for people who have type 1 diabetes. Bergman Minimal Model which interprets the dynamics of glucose-insulin in the human body is a non-linear autonomous system consisting of three equations and eight parameters. From the results of the study, it was concluded that in this model there is only one equilibrium point, namely x^*=(G_b,0,I_b ). This equilibrium point means that the glucose concentration over time will be as large as the basal concentration (G_b). Active insulin that is already in the body of every human being will go to zero, meaning that over time it will disappear, and the insulin that has been secreted by the pancreas will remain at the threshold (I_b). All eigenvalues of polynomials formed from the linearization process and the Jacobian matrix in the Bergman Minimal Model are of negative real value. Based on the Stability Criteria Theorem, the glucose-insulin system of the Bergman Minimal Model is asymptotically stable around its equilibrium point.

Mengatasi Bias pada Penduga Parameter Metode Kuadrat Terkecil dalam Analisis Regresi Linear Sederhana dengan Bootstrap Data Berpasangan

Pakpahan, Robinsar, Simamora, Elmanani

Jurnal Sains Indonesia Vol 42, No 1 (2018): Jurnal Sains Indonesia
Publisher : Universitas Negeri Medan

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Abstract

The assumption of normality wouldnt be fulfilled in regression analysis if there are outliers in observation data so that peduga parameters using LSM (Least Square Method) will produce biased estimators and not BLUE (Best Linear Unbiased Estimator). Based on this, the bootstrap method which is a repeat sampling method (resampling) that does not require distribution assumptions on the data can be used. In this study, paired bootstrap data method is used for simulation data with the number of outliers of 5%, 10% and 15%. This is to show how the influence of outliers on the distribution of data if the outliers given have different amounts. After estimating the parameters using paired bootstrap data, parameter estimator values and the resulting bias are not much different from the MKT parameter estimator values before being given an outlier. In this study at a 99% confidence interval for the case of simulation data with 10% and 15% of the parameter estimator outliers obtained in the previous study and in this study no longer produce BLUE estimators as in the simulation data with 5% outliers.

Penentuan Sebaran Situs Purbakala Candi Tandihat I Menggunakan Metode Geolistrik di Desa Tandihat, Kabupaten Padang Lawas

Pasaribu, Prastika Ayu, Kadri, Muhammad

Jurnal Sains Indonesia Vol 42, No 1 (2018): Jurnal Sains Indonesia
Publisher : Universitas Negeri Medan

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Abstract

Archaeological Site of Candi Tandihat I is one of the relics of the time of Hindu-Buddhist influence in Indonesia which has been in the form of ruins of biaro made of brick and mounds of soil overgrown with grass. Geoelectric and geomagnetic surveys are carried out as subsurface detection which aims to determine the distribution of the constituent rocks of the site based on resistivityvalue. Geoelectric research results obtained resistivity values of 24.1 - 583 Om, which is at a depth of 6.76 - 26.2 m with a distance of 15 - 65 m and 85 - 125 m interpreted as an alluvium layer consisting of silt - clay and sandy clay and sand which is a layer of rock composing sites. Based on the results of the interpretation, it can be seen that the subsurface main layer of the study area is alluvium which consists of clay, sandy clay and sand.

Perilaku Solusi Sistem Persamaan Diferensial Waktu Tunda Dinamika Virus HIV Dalam Sel Tubuh

Tambunan, Lidia Veronika, Sinaga, Lasker Pangarapen

Jurnal Sains Indonesia Vol 42, No 1 (2018): Jurnal Sains Indonesia
Publisher : Universitas Negeri Medan

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Abstract

The dynamics model of the HIV-virus without delay in the cells of the human body has a critical point in two conditions, namely virus-free conditions and endemic conditions. Based on stability analysis with eigenvalues and Routh Hurwitz criteria, these two critical points are asymptotically stable. With a graph of the behavior of the HIV-virus model dynamics solution with time delay shows asymptotic stable behavior. Observations were made with numerical simulations (Forward Euler method) based on the selection of parameter values randomly and the delay time randomly. Graph behavior of infected cell solutions and increased plasma viruses causes a graph of healthy cell solutions to decrease and vice versa. Based on the analysis and simulation conducted, it appears that the solution modeled the dynamics of the HIV-virus without delay and with the delay time moving towards the equilibrium point or called asymptotically stable. The provision of greater delay causes the number of infected cells and plasma viruses to decrease significantly and on this occasion, the number of healthy cells can increase.