A Freedom of Writing: September 2011

This is one of my activity during Fast track scholarship program. I learn national language of germany as preparation if i pass the selection and continue my doctoral program in Germany (Amiinnnn :D). Taking course in CLC (Center of Laguage and Culture) ITS, my first class was inFriday, September 23^rd 2011. There were 15 students registered in my class, but in first meeting only 5 students presents (including me). Hmm, where is the others? i don’t know :p.

First lesson was about erste kontakte or or first contact. We learned how to make interaction with a person or peoples in the first time. It was like english subject during elementary school. For your information, my lecturer said that German usually introduce him/herself first before asking the others. Fundamental factor in erste kontakte was kennenternen or knowing internal, consist of begrüßung, name, herkunft, and wohnort

Now, i will explain each part (i hope you understand it well, because i still need learn much, hehe) . Some example of each part are given below :

A. Begrüßung (means welcome) :

1. Guten morgen! : Good morning!

2. Guten tag! : Good afternoon!

3. Guten abend! : Good evening!

4. Guten nacht! : Good night!

5. Hallo! : Hello!

6. Hi!

B. Name (similiar with english, also means name)

-Frage (to ask someone’s name)

1. Wie heißen sie?

2. Wie ist ihr name?

(Both means : what’s your name?)

3. Wer ist das? : Who is that?

- Einführen (introduce)

1. Ich bin... (name)

2. Ich heiße... (name)

3. Mein name ist....(name)

C. Herkunft (origin)

-Frage

1. Woher kommen sie? : Where do you come from?

-Antwort (Answer)

1. Ich come aus...(place, country, city, or town) : I come from...

D. Wohnort (domicile)

-Frage

1. Wo wohnen sie? : Where do you live?

-Antwort

1. Ich wohne in...(place, country, city, or town) : I live in...

Next lesson is about Alphabets and how to pronounce it. Well, it is not difficult to understand because German pronounce is similiar with indonesian. Only few letters has different pronouncations. In additions, there are some new letters such as Ü and ß. Letter in german and how to pronounce it (based on indonesian pronouncations)

Aa (a)

Bb (be)

Cc (ce)

Dd (de)

Ee (e)

Ff (ef)

Gg (ge)

Hh (ha)

Ii (i)

Jj (jot)

Kk (ka)

Ll (el)

Mm (em)

Nn (en)

Oo (o)

Pp (pe)

Qq (qu)

Rr (err - in german tounge ‘r’ is not clearly pronounced)

Ss (es, but pronounce ez in initial words)

Tt (te)

Uu (u)

Vv (vau)

Ww (we)

Xx (iks)

Yy (ypsilon)

Zz (zet but similiar with cet)

additional letters :

Üü (u umlaut - pronounce like lips shape of ‘u’, but the sound is ‘i’)

Ää (a umlaut – pronounce e, which the sound is like indonesian read ‘bebek’

Öö (o umlaut - pronounce like lips shape of ‘o’, but the sound is ‘e’)

ß (ss)

ei (ai)

eu (oi)

scn (sy)

Example

A : Gutten tag, wie ist ihr name? (Good afternoon, what’s your name?)

B : Mein name ist Schmidt (My name is schmidt)

A : Buchstabieren sie, bitte? (Spell it please?)

B : S-C-H-M-I-D-T

Well that’s all that i can share to you today, my next meeting will be in Wednesday, September 28^th. I hope it’s can help you to learn german, hehe.. Thank you and Auf wiedersehen!! hehee :D

Hello guys, i'm back. Today i'd like to share how to create mathematical modelling for optimation purpose. In optimations, some factors need to be calculated to obtain the maximum or minimum point.

INTRODUCTIONS

Sego Njamoer is a snack made from rice and mushroom served in onigiri style. The word ‘Sego Njamoer’ comes from Javanesse language means ‘Mushroom Rice’. Sego Njamoer also being used as trademark of the company owned by Njamoer Management, established in 2009 by Mahendra Ega Higuitta, Young Entrepreneur and student of Engineering Physics Department Sepuluh Nopember Institute of Technology. With many innovations, Sego Njamoer has collected many achievements and award in business competitions, such as LA Business contest, PIMNAS 24, Shell eco wire, and many others.

Production House of Sego Njamoer addressed in Gebang Wetan, stored main ingerdients of the product : Rice and Mushroom, storedhouse of the package, plastic spoon, and product seasoning (such as flour, salt, pepper, etc). Not only for warehouse, PH also used as outlet that sell Sego Njamoer Product.

Figure 1 Sego njamoer and its mascot (called Jembi)

Since June 2011, Sego Njamoer owned nine outlets in Surabaya. Four outlets located in ITS area (Ria Swalayan, BEM FTI, Center Canteen, and Gebang), and the others are located in Faculty of Medicine Airlangga University (Unair A), Faculty of Economy and Business Airlangga University (Unair B), Surabaya State University (Unesa), Stella Maris Senior High School (SMA Stella Maris), and Computer High School (Stikom). Based on managers data report, each outlet has different average amount demand in each day. Highest demand of the product is in BEM FTI outlet with 350 product per day. Followed by Unair A (260 portions), Outlet with the lowest demand is SMA Stella Maris which is 80 products. Complete report of each Sego Njamoer daily demand are listed in Table 1 below :

Figure 2 Map of sego njamoer outlet

Table 1 List of product average demand for each outlet

No	Outlet	Average demand in one day
1	Ria Swalayan	150
2	BEM FTI	350
3	Center Canteen	200
4	Gebang	200
5	Unair A	260
6	Unair B	150
7	Unesa	100
8	SMA Stella Maris	80
9	Stikom	150

Main ingerdients (rice and mushroom) is not produced by the company. Rice are collected from many food stall, and mushroom is providable from market. Based on main ingerdients supply, maximum product that can be served and selled are 1500 portions. Package of the prduct ordered from print shop which is printed 100.000 packages per month. Fuel cost is one variable that should be calculated because some outlet is far from production house. Fuel cost for each oulet is shown in Table 2

Table 2 Daily fuel cost for each oulet

No	Outlet	Fuel cost per day (x1000 rupiahs)
1	Ria Swalayan	1
2	BEM FTI	1
3	Center Canteen	1
4	Gebang	0
5	Unair A	3
6	Unair B	3
7	Unesa	5
8	SMA Stella Maris	10
9	Stikom	4

Based on the explanation above, how to obtain the maximum profit in one day?

SOLUTIONS :

Maximum supply in 1 day :

1500 products

Income in one day based on maximum supply :

1500 x 3000 = 4.500.000 = 4.500 (x1000)

Package ordered in 1 month are 100.000 packages, assume that there are 30 days in one month

Objective : How to obtain the maximum profit in 1 day?

Modeling :

Step 1 : Decision Variables :

Let x_i = Amount of product selled in each outlet (i)

x₁= Ria Swalayan

x₂= BEM FTI

x₃= Center Canteen

x₄= Gebang

x₅= Unair A

x₆= Unair B

x₇= Unesa

x₈= SMA Stella Maris

x₉= Stikom

Step 2 : Objective Functions Maximize profit per each day :

z = x₁ + x₂ + x₃ + x₄ + x₅ + x₆ + x₇ + x₈ + x₉

Step 3 : Define the Constrains :

Maximum demand in each outlet

x₁< 150

x₂< 350

x₃< 200

x₄< 200

x₅< 260

x₆< 150

x₇< 100

x₈< 80

x₉< 150

Maximum product that can be supplied :

x₁ + x₂ + x₃ + x₄ + x₅ + x₆ + x₇ + x₈+ x₉< 1500

Fuel cost for each outlet (fuel cost greater than income is not allowed) :

x₁ + x₂ + x₃ + 3x₅ + 3x₆ +5x₇ +10x₈+4x₉< 4200

Maximum package :

30 (x₁ + x₂ + x₃ + x₄ + x₅ + x₆ + x₇ + x₈ + x₉) < 100.000

Each variable should be positive

x₁> 0

x₂> 0

x₃ > 0

x₄> 0

x₅> 0

x₆> 0

x₇> 0

x₈> 0

x₉> 0

Complete model :

z(x_i) = x₁ + x₂ + x₃ + x₄ + x₅ + x₆ + x₇ + x₈ + x₉