International Journal of Applied Management Science

Filed Under (Uncategorized) by arfa on 05-03-2015

A Fuzzy Collaborative Supply Chain Inventory Model with Controllable Setup Cost and Service Level Constraint for Imperfect Items


Nughthoh Arfawi Kurdhi*, Sri Maria Puji Lestari, Yuliana Susanti


Abstract. This paper presents a fuzzy collaborative vendor-buyer production-inventory model under service level constraint. The vendor’s production process is imperfect and an order lot may contain a certain number of imperfect items with a known probability density function. This article assumes that setup cost and lead time can be reduced at an investing cost and at a crashing cost, respectively. The fuzzy total joint cost under fuzzy average demand is also considered. In this study, we consider two cases of lead time demand that are normal distribution and distribution free. The objective is to simultaneously optimize the lot size, lead time, reorder point, setup cost and number of shipment in one production cycle, constrained on a service level, such that minimize the total joint cost. In distribution free case, we apply a minimax distribution free procedure to determine the optimal solution. Numerical examples are used to illustrate the benefits of integration.


Key words: fuzzy theory, collaborative model, imperfect process, service level, signed distance.

International Journal of Apllied Management Science, Vol. 7, No. 2, 2015 - Inderscience Publisher


International Journal of Services and Operations Management

Filed Under (Uncategorized) by arfa on 05-03-2015

Continuous Review Inventory Models under Service Level Constraint with Probabilistic Fuzzy Number during Uncertain Received Quantity


 Nughthoh Arfawi Kurdhi*, Sutanto, Kristanti, Maria Veany Alvitaria Prasetyawati, Sri Maria Puji Lestari


Abstract: This paper investigates continuous review inventory models involving service level constraint in which lead time, reorder point, ordering cost and order quantity are treated as decision variables and quantity received is uncertain. The lead time can be shortened at an extra crashing cost which has two different forms. First, it can be decomposed into several components; each has a crashing cost for the reduced lead time. Second, the lead time dependent cost follows a power function. The assumption of normal distribution on lead time demand was given and the uncertainty of average demand was handled with triangular fuzzy number. The signed distance method was employed to defuzzify the average demand. To obtain the optimal policies of the proposed models in partial backorder case, we construct Lagrange function, and solution algorithms are then derived. Moreover, two different examples were used to illustrate the proposed models and solution procedures.

Keywords: Inventory, fuzzy theory, lead time, service level, signed distance.


International Journal of Services and Operations Management – Inderscience Publisher [2015-Article in Press-Scopus]

Operations Research and Optimization x DressHead Bodycon Dress – Fit Scoop Neckline / Three Quarter Sleeve

Filed Under (Uncategorized) by arfa on 01-03-2015

This Operations Research and Optimization x DressHead Bodycon Dress – Fit Scoop Neckline / Three Quarter Sleeve is designed for numerous occasions. It can show off your sweet side at a wedding. It can show off your charming side at a get-together with friends. It can show off your feminine side at a graduation or class reunion. The piece looks delicate thanks to its divine rosy print. However, this piece is sure to stand up to a lot of wear and tear and will become a dress you reach for time and time again. The pleated skirt is a bonus as it gives the piece a more flared look with a shape that accents your natural curves without being too tight. The neckline is sweet and just deep enough to show off the right amount of curves at the chest. The look overall is designed for warm atmospheres as the thin straps and short skirt allow for more airflow. The Operations Research and Optimization x DressHead Bodycon Dress – Fit Scoop Neckline / Three Quarter Sleeve is a piece you will be proud to own.

Calculus Multivariable

Filed Under (Calculus Multivariable, My Course, Uncategorized) by arfa on 12-02-2015

Multivariable calculus (also known as multivariate calculus) is the extension of calculus in one variable to calculus in more than one variable: the differentiation andintegration of functions involving multiple variables, rather than just one. Multivariable calculus can be applied to analyze deterministic systems that have multiple degrees of freedom. Functions withindependent variables corresponding to each of the degrees of freedom are often used to model these systems, and multivariable calculus provides tools for characterizing the system dynamics.


3 2


Sumber Gambar:


Multivariable calculus is used in many fields of natural and social science and engineering to model and study high-dimensional systems that exhibit deterministic behavior. Non-deterministic, or stochastic systems can be studied using a different kind of mathematics, such as stochastic calculus. Quantitative analysts in finance also often use multivariate calculus to predict future trends in the stock market. [wikipedia]


Lecture 1   :  Function of two variables

Lecture 2   :  Partial Derivative

Lecture 3   :  Minimum Local and Global

Lecture 4   :  Lagrange Multiplier 

Tugas KD 1 – KPB – 2015

Tugas Kelompok KD 2 – KPB – 2015

Tugas Kelompok KD 2 – KPB – 2015 – Baru

Tugas KD 3 – KPB – 2015

Tugas KD 4 – KPB – 2015

Probabilistic Operation Research

Filed Under (My Course, Probabilistic OR) by arfa on 06-02-2015

Tagged Under : , , , , ,

Riset Operasi Probabilistik. Mata kuliah Riset Operasi Probabilistik memberi bekal kepada mahasiswa untuk memilih dari beberapa alternatif pemecahan persoalan yang paling optimal dalam rangka pengambilan keputusan yang tepat. Misalnya mahasiswa mampu membentuk sistem antrian optimal sehingga meminimumkan biaya yang dikeluarkan dan memaksimumkan kepuasan pelanggan


Sumber Gambar:


Materi yang akan dibahas dalam mata kuliah Riset Operasi Probabilistik meliputi: Teori Antrian, Teori Permainan, Analisis Markov, dan Program Dinamik Probabilistik.

Download files: Group 2015

Lecture 1  : Game Theory [Concept of Game Theory]

Lecture 2  : Game Theory [Pure Strategy]

Lecture 3  : Game Theory [Minimax Theorem]

Lecture 4  : Game Theory [Mixed Strategy: Algebraical Method]

Lecture 5  : Game Theory [Mixed Strategy: Graphical Method]

Lecture 6  : Game Theory [Mixed Strategy: Linear Programming Method]

Lecture 7  : Game Theory [Zero Sum Game of n Person]

Lecture 8  : Queuing Theory [Concept of Queuing Theory]

Lecture 9  : Queuing Theory [Pure Birth Model-Pure Death Model]

 Tugas KD II ROP 2015

 Remidi KD1 dan KD2 ROP-2015

Deterministic Operation Research

Filed Under (Deterministic OR, Uncategorized) by arfa on 05-02-2015

Riset Operasi Deterministik. Mata kuliah Riset Operasi Deterministik memberi bekal kepada mahasiswa untuk memilih dari beberapa alternatif pemecahan persoalan yang paling optimal dalam rangka pengambilan keputusan yang tepat. Misalnya mahasiswa mampu membentuk sistem distribusi barang dari pemasok ke pelanggan secara optimal, sehingga meminimumkan biaya yang dikeluarkan dan memaksimumkan keuntungan.



Sumber Gambar:


Materi yang akan dibahas dalam mata kuliah Riset Operasi Deterministik meliputi: masalah arus maksimum, tansportasi, penugasan, pengangkutan, minimum spanning tree, rute terpendek, integer linear programming, dan program dinamik deterministik.

Download files: Group 2015

Task 1 – Maximum flow and Transportation Problem

Task 2 – Assignment and Transshipment Problem

Tugas KD 1 ROD – 2015

Tugas KD 2 ROD – 2015

NonLinear Programming

Filed Under (My Course) by arfa on 04-02-2015

Program Tak Linear adalah bagian dari matematika terapan khususnya bidang riset operasi yang materinya meliputi masalah optimasi untuk fungsi tak linear. Mata kuliah ini memperkenalkan beberapa metode optimasi untuk fungsi satu variabell maupun multi variabel, yang terkendala maupun tidak terkendala menggunakan search method dan approximation method.



Sumber Gambar:


Mahasiswa diharapkan dapat memodelkan masalah-masalah real ke bentuk program tak linear dan dapat menyelesaikannya secara teoritis maupun praktis menggunakan program komputer.

Download files: Kelompok 

Lecture 1    : Introduction o f NLP

Lecture 2    : Optimization of Function of one Variable

Lecture 3    : Fibonacci Search

Lecture 4    : Golden-Section Search

Lecture 5    : Approximation Method

Lecture 6    : DSC Method

Lecture 7    : Quadratic Approximation

Lecture 8    : Newton Method Univariable

Lecture 9    : Multivariable Without Constraint

Lecture 10  : Univariate Method

Lecture 11  : Steepest Descent Method

Lecture 12  : Newton Method Multivariable

Lecture 13  : Fletcher Reeves Method

Tugas KD 2 PTL 2015-Baru

Nilai KD 1 PTL 2015

Tugas Praktikum PTL 2015

Tugas KD 3 PTL-2015

Nilai KD 3 PTL 2015

Nilai KD 4 PTL 2015

Calculus 1 (Mat-Das)

Filed Under (Calculus) by arfa on 13-07-2014

Tagged Under : , , , , , ,


Kalkulus. Kalkulus (Bahasa Latin: calculus, artinya “batu kecil“, untuk menghitung) adalah cabang ilmu matematika yang mencakup limit, turunan, integral, dan deret takterhingga. Kalkulus adalah ilmu mengenai perubahan, sebagaimana geometri adalah ilmu mengenai bentuk dan aljabar adalah ilmu mengenai pengerjaan untuk memecahkan persamaan serta aplikasinya. Kalkulus memiliki aplikasi yang luas dalam bidang-bidang sains, komputer, ekonomi, dan teknik; serta dapat memecahkan berbagai masalah yang tidak dapat dipecahkan dengan aljabar elementer.


cal  1

Sumber Gambar:


Kalkulus memiliki dua cabang utama, kalkulus diferensial dan kalkulus integral yang saling berhubungan melalui teorema dasar kalkulus. Materi yang akan dipelajari dalam Kalkulus I adalah sistem bilangan real, fungsi, limit, turunan, aplikasi turunan, integral, aplikasi integral, fungsi transenden, teknik pengintegralan, bentuk tak tentu dan integral tak wajar. Pelajaran kalkulus adalah pintu gerbang menuju pelajaran matematika dan komputer lainnya yang lebih tinggi. 


Download files: Syllabus, RPP

Lecture 1  : Set of Real Numbers

Lecture 2  : Coordinat System in Plane

Lecture 3  : Function (A)

-          -  : Function (B)

-          -  : Function (C)

Lecture 4  : Limit (A)

-          -  : Limit (B)

-          -  : Limit (C)

Lecture 5  : Derivative (A)

-          -  : Derivative (B)

-          -  : Derivative (C)

-          -  : Derivative (D)

-          -  : Derivative (E)

Lecture 6 : Definite Integration (A)

Tugas MatDas Jur Fisika FMIPA UNS 2015

Materi Fungsi-a

Materi Fungsi-b

Materi Fungsi-c

Materi Garis dan Bidang-a

Materi Garis dan Bidang-b

Materi Garis dan Bidang-c


Hasil Nilai UTS dan UAS MatDas Fisika 2015


International Journal of Systems Science

Filed Under (Uncategorized) by arfa on 08-04-2014


Nughthoh Arfawi Kurdhi1, Joko Prasetyo1Sri Sulistijowati H1

 1Department of Mathematics, Faculty of Mathematics and Natural Science, Sebelas Maret University, Surakarta, Indonesia




Sumber Gambar:


Abstract. This paper presents and analyzes the continuous review inventory model with order quantity, safety factor, backorder price discount, ordering cost and lead time as decision variables. Our work is based on the paper of Huang (2010). We extend the model to incorporate the situation when the amount received is uncertain. The lead time demand is assumed follows a normal distribution. A solution procedure is developed to find the optimal solution. A numerical example is given to illustrate the model. A sensitivity analysis is also included to describe the effects of changes in the model parameters on the expected annual cost.

Keywords lead time, ordering cost reduction, backorder price discount, order quantity, reorder point, crashing cost.


International Journal of Systems Science, 2014 [Scopus]

AKCE Int. Journal Graphs Comb.

Filed Under (Uncategorized) by arfa on 07-04-2014


Mania Roswitha1, Edy Tri Baskoro2, Tita Khalis Maryati3,
Nughthoh Arfawi Kurdhi1 and Ika Susanti1

1Faculty of Mathematics and Natural Sciences
Sebelas Maret University, Surakarta, Indonesia
2Combinatorial Mathematics Research Group
Faculty of Mathematics and Natural Sciences
Institut Teknologi Bandung, Indonesia
3Mathematics Education
Universitas Islam Negeri Syarif Hidayatullah, Jakarta, Indonesia


AKCE Int. J. G raphs Comb., 10, No. 2 (2013), pp. 211-220 [Scopus]