Primena Bežičnih Računarskih Mreža I Bezbednosni Problemi

Abstract

Radomir RegodićZavod za izdavanje udžbenika, Beograd, Srbija ©MESTE JEL Category: G32, L86 ApstraktSavremeni uslovi poslovanja i način života doveli su do komercijalne ekspanizije i povećanje broja korisnika bežičnih mreža i pojave upotrebe pametnih telefona. Paralelno sa povećanjem broja korisnika sve je veći broj onih koji nisu upoznati sa sigurnosnim problemima. Bežične računarske mreže nose sa sobom brojne sigurnosne probleme. Laptopovi, pametni telefoni, tableti, i drugi uređaji se danas ne mogu zamisliti bez podrške za povezivanje na bežičnu mrežu. Međutim, nisu svi korisnici bežičnih mreža dobronamerni. Postoje zlonamerni ljudi koji će iskoristiti svoja znanja o bežičnim mrežama, i ne samo kompromitovati podatke koji se šalju kroz mrežu, nego i ukrasti poverljive informacije koje korisnici šalju, kao što su brojevi kreditnih kartica, šifre, itd. nesvesni ko ih sve vidi. Zbog toga je neophodno znati koje opasnosti sa sobom nosi upotreba bežičnih mreža. Kako su napadači uvek korak ispred, neophodan je stalan rad na zaštiti i sigurnosti korisnika bežičnih mreža. Cilj istraživanja ovog rada je da se prikažu bezbednosni problemi u bežičnim računarskim mrežama, slabosti same infrastrukture, i nedovoljna razvijenost bezbednosnih protokola. Društveni cilj ovog rada je da se ukaže svim korisnicima na realne probleme, odnosno pretnje sa kojima se susreću korisnici bežičnih mreža. Sam problem istraživanja, brojne slabosti i bezbednosni problemi u bežičnim računarskim mrežama imaju za cilj podizanje nivoa svesti korisnika i unapređenje nedovoljne razvijenosti upotrebe bezbednosnih protokola.Ključne reči: Bežične računarske mreže, slabosti, pretnje, napadi, šifra. Abstract Modern business conditions and lifestyles have led to commercial expansion and the increase in the number of wireless network users and theAdresa autora zaduženog za korespodenciju: Dušan Regodić  emergence of smartphones. In parallel with the increase in the number of users, there is an increasing number of those who are not familiar with security issues. Wireless computer networks carry many security problems with them. Laptop computers, smartphones, tablets, and other devices today can not be imagined without an access to a wireless network. However, not all users of wireless networks are well-intentioned. There are malevolent people who will use their knowledge of wireless networks, to compromise data sent across the network. They also steal confidential information sent by users, such as credit card numbers, passwords, etc. Therefore, it is necessary to understand the dangers of using wireless networks. As attackers are always a step ahead, it is necessary to work continuously on the protection and security of wireless users. The aim of this paper is to present security issues in wireless computing networks, weaknesses of the infrastructure itself, and insufficient development of security protocols. The social goal of this work is to elaborate about the real problems or threats that wireless network users encounter. The main two problems of the...

Prediction of Drag Aerodynamic Coefficient of the 155mm Projectile Under Axisymmetric Flow Using Different Approaches

“…Where are: The axial force is in the opposite direction from the longitudinal axis of the body coordinate system, that is, the value of the coefficient is negative. The dependence of the coefficient on the angle of attack ( ) ( ) (Regodić, 2006):…”

“…The semi-empirical approach was carried out using the semi-empirical program solution AERODR of Regodić (2003) which is based on the computer program "MC DRAG" of McCoy (1981). AERODR determines the values of the total drag coefficient CD0 and its components ( CD1 , CD3 , CD4 , CDb and CDf ) according to the Mach number M a in axisymmetric flow ( σ = 0 ), whose input data (Table 1) are the dimensions that define the shape of the projectile as well as the position of its center of mass and the type of boundary layer.…”