nyuuzyou/kompy huggingface dataset:
Table of Contents - Windows 2000 Disk io performance Leonard Chung

1 Overview 1
2 Introduction 4
2.1 Hardware Configuration 5
3 Device Internals Performance 6
3.1 System Memory Bus Throughput 6
3.2 SCSI and PCI bus Throughput 6
3.3 IDE controller and Throughput 6
3.4 Symmetric Multiprocessing (SMP) 8
3.5 DMA vs. PIO 10
4 Testing Methodology 11
4.1 Throughput measurement 11
4.2 Overhead Measurement 12
4.3 Zoned Disk and Variable Media Rates 13
4.4 File Pre-allocation 13
5 NT4SP6 vs. NT4SP3 Sequential IO Performance 15
6 Windows 2000 vs. NT4 20
7 Windows 2000 SCSI I/O Performance 23
7.1 Windows 2000 SCSI Random I/O 23
7.3 Windows 2000 Out-of-the-Box Sequential Buffered SCSI Throughput 26
7.4 Windows 2000 Unbuffered Sequential SCSI Throughput 28
7.5 Windows 2000 Multiple SCSI Disk Performance 30
8 Windows 2000 IDE I/O Performance 33
8.1 Windows 2000 IDE Random I/O 33
8.3 Windows 2000 Out-of-the-box Sequential Buffered IDE Throughput 37
8.5 Windows 2000 Sequential Unbuffered IDE Throughput 39
8.6 Windows 2000 Multiple IDE Disk Performance 41
9 Network IO Performance 48
11 Summary 52
12 Acknowledgements 53
13 References 53
-ishtirokchi: "Marketing nazorati tizimini joriy etishda qanday umumiy muammolar bor va ularni qanday hal qilish mumkin?"

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-ishtirokchi: "Marketing nazorati tizimini joriy etishda qanday umumiy muammolar bor va ularni qanday hal qilish mumkin?"
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bet | 13/13 | Sana | 27.11.2023 | Hajmi | 98,62 Kb. | | #106551 |
Bog'liq 7.Strategik va taktik rejalashtirish, marketing nazorati (2) 2-ishtirokchi: "Marketing nazorati tizimini joriy etishda qanday umumiy muammolar bor va ularni qanday hal qilish mumkin?" Javob: Marketingni nazorat qilish tizimlarini joriy qilish ma'lumotlarning aniqligi, o'zgarishlarga qarshilik va rivojlanayotgan bozor dinamikasiga moslashish kabi qiyinchiliklarga duch kelishi mumkin. Bularni hal qilish uchun maʼlumotlar aniqligini taʼminlash uchun mustahkam maʼlumotlarni yigʻish va tahlil qilish vositalariga mablagʻ sarflang. Qarshilikka kelsak, manfaatdor tomonlarni erta jalb qiling, foyda haqida xabar bering va kerakli treninglarni o'tkazing. Bozor o'zgarishlariga moslashish uchun boshqaruv tizimlaringizni moslashuvchan qilib loyihalashtiring va kerak bo'lganda strategiyalarni o'zgartirish uchun muntazam tekshiruvlarni o'z ichiga oling. 3-ishtirokchi: "Marketing nazorati marketing kampaniyasining turli bosqichlarida qanday rivojlanishi haqida batafsil ma'lumot bera olasizmi?" Javob: Marketing nazorati kampaniya davomida rivojlanadi. Dastlabki bosqichlarda oldindan nazorat qilish benchmarklarni belgilash va asosiy ishlash ko'rsatkichlarini (KPI) aniqlashni o'z ichiga oladi. Kampaniya davomida (bir vaqtning o'zida nazorat) real vaqt rejimida KPI monitoringi amalga oshiriladi, bu esa kerak bo'lganda strategiyalarni o'zgartirishga imkon beradi. Va nihoyat, post-nazorat kampaniyani oldindan belgilangan ko'rsatkichlar bo'yicha baholash, natijalarni tahlil qilish va kelajakdagi kampaniyalarda yaxshilash sohalarini aniqlashni o'z ichiga oladi. Har bir bosqich marketing tashabbuslarining umumiy muvaffaqiyati va doimiy takomillashtirilishi uchun juda muhimdir. E’TIBORINGIZ UCHUN RAHMAT!
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Bosh sahifa
Aloqalar
Bosh sahifa
-ishtirokchi: "Marketing nazorati tizimini joriy etishda qanday umumiy muammolar bor va ularni qanday hal qilish mumkin?"
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Case Study: Harakatda taktik rejalashtirish

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Case Study: Harakatda taktik rejalashtirish
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bet | 6/13 | Sana | 27.11.2023 | Hajmi | 98,62 Kb. | | #106551 |
Bog'liq 7.Strategik va taktik rejalashtirish, marketing nazorati (2) Case Study: Harakatda taktik rejalashtirish Maqsad: raqobatbardosh bozorda organik energetik ichimliklarning yangi liniyasini muvaffaqiyatli ishga tushirish. Taktik rejalashtirish bosqichlari: - Energetik ichimliklar sektoridagi iste'molchilarning afzalliklari va bozor tendentsiyalarini tushunish uchun bozor tadqiqotini o'tkazdi.
- Mavjud energetik ichimliklarga sog'lomroq muqobil sifatida joylashtirilgan, organik ingredientlardan iborat noyob mahsulot ishlab chiqildi.
- Narxga sezgir bo'lgan iste'molchilarni jalb qilish uchun asosiy raqobatchilardan bir oz pastroq raqobatbardosh narx strategiyasini amalga oshirdi.
- Tarqatish kanallari, shu jumladan onlayn platformalar, do'konlar va sport zallari va sog'likka yo'naltirilgan chakana savdo do'konlari bilan hamkorlikdan foydalanildi.
- Ijtimoiy tarmoqlar, ta'sir qiluvchi sheriklik va maqsadli raqamli reklamalardan foydalanish, sog'liq uchun foydalarga qaratilgan integratsiyalashgan reklama kampaniyasini boshladi.
Natija: - Birinchi chorakda bozor ulushini sezilarli darajada oshirish bilan mahsulotning muvaffaqiyatli chiqarilishiga erishildi.
- Mahsulotning ta'mi, sog'liq uchun foydalari va raqobatbardosh narxlari bo'yicha mijozlarning ijobiy fikrlari.
- Bozorda brendning ko'rinishi va tan olinishi ortdi.
Ushbu amaliy tadqiqot mahsulotni ishlab chiqish, narxlash, tarqatish va ilgari surish strategiyalarini o'z ichiga olgan samarali taktik rejalashtirish muvaffaqiyatli marketing kampaniyasi va bozorga kirishga olib kelishi mumkinligini ko'rsatadi. 4.Strategik va taktik rejalashtirishning integratsiyasi 4.Strategik va taktik rejalashtirishning integratsiyasi Strategik va taktik rejalashtirish tashkilot marketing tizimining muhim tarkibiy qismlari bo'lib, ularning har biri marketing maqsadlariga erishish va biznes muvaffaqiyatini ta'minlashda hal qiluvchi rol o'ynaydi. Biroq, ularning haqiqiy ta'siri tashkilotning umumiy marketing samaradorligini oshirish uchun uzluksiz ravishda birlashtirilgan va moslashtirilganda kuchayadi.
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Integratsiya nima uchun muhim?

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Integratsiya nima uchun muhim?
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bet | 7/13 | Sana | 27.11.2023 | Hajmi | 98,62 Kb. | | #106551 |
Bog'liq 7.Strategik va taktik rejalashtirish, marketing nazorati (2) Integratsiya nima uchun muhim? - Yagona qarash va maqsadlar:
- Integratsiya qisqa muddatli maqsadlar va harakatlarni (taktik rejalashtirish) tashkilotning uzoq muddatli qarashlari va missiyasi (strategik rejalashtirish) bilan moslashtiradi. Bu har bir taktik harakat kengroq strategik maqsadlarga erishishga hissa qo'shishini ta'minlaydi.
- Resurs optimallashtirish:
- Strategik va taktik rejalar birlashtirilsa, resurslar yanada samarali taqsimlanadi. Mablag'lar, ishchi kuchi va vaqt strategik maqsadlarni to'g'ridan-to'g'ri qo'llab-quvvatlaydigan, isrofgarchilik va ortiqcha ishlarning oldini oladigan taktikaga yo'naltiriladi.
- Moslashuvchanlik va sezgirlik:
- Integratsiya bozor dinamikasi va o'zgaruvchan sharoitlarga tezroq javob berishga imkon beradi. Taktik rejalar tashkilotning bozorda raqobatbardosh va dolzarb bo'lib qolishini ta'minlab, umumiy strategiyaga moslashish uchun tezda tuzatilishi mumkin.
Integratsiyaning asosiy bosqichlari Muloqot va hamkorlik: - Strategik va taktik rejalashtirish uchun mas'ul bo'lgan jamoalar o'rtasida ochiq muloqot va hamkorlikni rivojlantirish. Muntazam tushunchalar va yangilanishlar almashinuvi barchaning umumiy tashkiliy maqsadlarga mos kelishini ta'minlashga yordam beradi.
Funktsional seminarlar va uchrashuvlar: - Strategik va taktik guruhlar a'zolari rejalar va maqsadlarni muhokama qilish uchun yig'iladigan seminarlar va uchrashuvlarni tashkil qiling. Bu yaxlit yondashuvni rag'batlantiradi va taktik rejalar kengroq strategiya bilan hamohang bo'lishini ta'minlaydi.
Teskari aloqa davrlari: - Uzluksiz fikr-mulohazalar va baholash mexanizmlarini joriy etish. Uzoq muddatli strategiyani mos ravishda takomillashtirish va moslashtirish uchun strategik rejalashtiruvchilar bilan taktikani bajarish bo'yicha tushunchalar bo'lishish kerak.
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File Pre-allocation - Windows 2000 Disk io performance Leonard Chung

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Windows 2000 Disk io performance Leonard Chung
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bet | 14/47 | Sana | 30.03.2021 | Hajmi | 1,33 Mb. | | #13789 |
File Pre-allocation
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Figure 3 – File extension. The file system must balance the security verses performance. In order to prevent an application from allocating space on disk and then reading its previous contents, the file system serializes write requests. As the graph above shows, this leads to poor write performance on file extension unless one writes only at the end of the file. Applications concerned with good write performance should pre-allocate their files, or only append to them.
| For security reasons, Windows NT4 and Windows 2000 force writes to become synchronous if writing to a new file, writing to a newly extended area of a file, or writing beyond the end of a file. This is because C2 security requires a value of zero to be returned when reading data that has not been previously written. In order to prevent users from allocating storage and then reading its previous contents, like NT4, Windows 2000 must balance the need for performance with the need for security.
As Figure 3 shows, file extension severely impacts asynchronous unbuffered write performance -- unless writes are appended to the end of the file or the writes are to a pre-allocated file, write throughput decreases by 50%. Buffering can help reduce the impact of file extension, but for applications concerned with write throughput, files should be pre-allocated or writes should be to the end of the file. The figure shows that programs sequentially writing a file (writing at EOF) get the full disk speed. But, if a program first writes the last block and then sequentially writes the file, the write proceeds at half the speed because Windows2000 first zeros the file, and then writes it. When growing a file, it is important to write it in sequential order. Otherwise Windows writes each block twice: once to zero the “gap” and once to write the actual data when the need write finally is issued.
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Instruction How to Set Internet Explorer x to Accept Cookies

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Instruction How to Set Internet Explorer x to Accept Cookies
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Sana | 22.03.2020 | Hajmi | 2,05 Mb. | | #8385 |
Instruction How to Set Internet Explorer v6.x to Accept Cookies
The steps explained below will allow you to accept cookies from the Seattle MeterWatch website only and leave your cookie settings unchanged.
Print this instruction first
Open your Internet Explorer
Click on Tools
Select the Internet Options
Click on the Privacy tab. (see the screen below)
Click on the "Edit" button
When you click the Edit button, you will see the screen displayed below.
Type seattle.wa.us in the field (box) under "Address of Web site,"
Click the Allow button on the right side.
Click the "OK" button at the bottom of the screen.
That is it.
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Overview - Windows 2000 Disk io performance Leonard Chung

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Windows 2000 Disk io performance Leonard Chung
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bet | 3/47 | Sana | 30.03.2021 | Hajmi | 1,33 Mb. | | #13789 |
Overview
Much has changed in the three years since Riedel’s 1997 study of sequential I/O performance [Riedel]. Disk capacities have increased; today’s biggest hard drives are over four times larger than the largest drives available then. Single disk sequential I/O throughput has also improved with 10,000 RPM drives. Processors have increased in speed and number. SMP is now available for the desktop. Memory and system buses have improved. SCSI has also improved over the last two years with Ultra160 SCSI promising a four-fold improvement in adapter to disk bandwidth. With today’s technology, we were able to achieve almost 24 MBps of read throughput on a single disk. Write throughput on a single disk peaked out at 22.5 MBps. This represents a 2.5 to 3 times improvement over the throughput Riedel measured. The disks used for our study were representative of drives commonly available at this time but not necessarily the highest performance disks on the market. The fastest drives now exceed 30 MBps in sequential transfers.
The software landscape has also changed, as Windows 2000 is replacing Windows NT4. Windows 2000 introduced dmio, a new volume manager, to replace ftdisk. Despite the fact that dmio and ftdisk are very different in implementation, our IO performance measurements show only minor performance differences between them. Processor overhead for dmio is somewhat higher so a processor-bound application might see a slightly different picture.
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At servis yo‘nalishiu talabalariga Individual loyiha 2 bajarish topshirig‘i Individual loyiha maqsadi

Talaba ushbu loyiha bajarish jarayonida uslubiy ko‘rsatmada berilgan talab va topshiriq asosida quyidagi LMS dagi variantlarga mos o’zining loyihasini ishlab chiqadi va LMS ga baholash uchun yuklaydi.
Variant
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Mavzu
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“Moliya” sohasida davlat interaktiv xizmatlarini loyihalashtirish.
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“Turizm” sohasida davlat interaktiv xizmatlarini loyihalashtirish.
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“Ta’lim” sohasida davlat interaktiv xizmatlarini loyihalashtirish.
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Adliya notarius” sohasida davlat interaktiv xizmatlarini loyihalashtirish
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“Sog‘liqni saqlash va ijtimoiy himoya” sohasida davlat interaktiv xizmatlarini loyihalashtirish.
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“O‘zbekiston havo yo‘llari” sohasida davlat interaktiv xizmatlarini loyihalash.
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“Adliya FHDY” sohasida davlat interaktiv xizmatlarini loyihalashtirish.
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“Madaniyat va sport” sohasida davlat interaktiv xizmatlarini loyihalashtirish.
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Uy-joy kommunal xizmat ko'rsatish sohasida davlat interaktiv xizmatlarini loyihalash.
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“Ko‘chmas mulk” sohasida davlat interaktiv xizmatlarini loyihalashtirish.
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“Transport” sohasida davlat interaktiv xizmatlarini loyihalashtirish.
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“Iqtisodiyot va biznes” yo‘nalishi bo‘yicha davlat interaktiv xizmatlarini loyihalashtirish.
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“Litsenziyalash” sohasida davlat interaktiv xizmatlarini loyihalashtirish.
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“Davlat soliq” sohasida davlat interaktiv xizmatlarini loyihalashtirish.
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“Davlat bojxona” sohasida davlat interaktiv xizmatlarini loyihalash.
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“Axborot va kommunikatsiya” sohasida davlat interaktiv xizmatlarini loyihalashtirish.
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“Ekologiya va geologiya” sohasida davlat interaktiv xizmatlarini loyihalashtirish.
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“Bank” sohasida davlat interaktiv xizmatlarini loyihalashtirish.
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“Madaniyat” sohasida davlat interaktiv xizmatlarini loyihalashtirish.
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“Sug‘urta” sohasida davlat interaktiv xizmatlarini loyihalashtirish.
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“Qishloq xo‘jaligi” sohasida davlat interaktiv xizmatlarini loyihalashtirish.
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“Qurilish” sohasida davlat interaktiv xizmatlarini loyihalashtirish.
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“Davlat statistika” sohasida davlat interaktiv xizmatlarini loyihalash.
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Soliq tizimiga onlayn murojaatlar bo'yicha davlat interaktiv xizmatlarini loyihalash.
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“O‘zbekiston temir yo‘llari” sohasida davlat interaktiv xizmatlarini loyihalash.
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Axborot-kommunikatsiya texnologiyalaridan foydalangan holda sotuvga qo‘yilgan ko‘chmas mulk obyektlarini reklama qilish bo'yicha axborot tizimini loyihalash.
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Bo‘sh ish o'rinlari uchun axborot tizimining axborot tizimini loyihalash.
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Konsert va teatrlarga chiptalarni onlayn xarid qilish uchun axborot tizimini
loyihalash.
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Gazeta va jurnallarga elektron obuna bo‘yicha axborot tizimini yaratish.
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Kommunal xizmatlarni onlayn to‘lash bo‘yicha interaktiv xizmatlarni loyihalash.
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Since its original release in 1985, Microsoft

The Windows 32-Bit API:
An Overview
Since its original release in 1985, Microsoft® WindowsTM has become the leading graphical system for IBM® compatible personal computers. Version 3.0, released in May 1990, was a milestone that broke the 640K barrier of the Microsoft MS-DOS® operating system by running applications in protected mode, thus making it possible to develop much more sophisticated applications. This innovation spawned myriad applications and is responsible for the huge success of the Windows environment in the marketplace showcased by the volume of graphical applications sold (see Figures 1 and 2).
Between May 1990 and May 1991, more than 4 million copies of Version 3.0 were sold. International Data Corporation estimates that an additional 7.8 million copies will be sold during 1992. In addition, more than 66 thousand Microsoft Windows Software Development Kits version 3.0 have been shipped, a clear indication of the number of applications likely to appear during the next 12 to 18 months. By spring 1991, more than 1200 Windows-based applications were shipping.
Building on this achievement and on the success of independent software developers, Microsoft is extending and expanding the Windows environment so that Windows-based applications can run on a broad range of computing platforms — from low-end battery-operated portables to high-end RISC workstations and multiprocessor servers.
We are expanding Windows to make it fully 32-bit, and are adding additional operating system services. Microsoft Windows for Pen Computing and Microsoft Windows with Multimedia Extensions will also take advantage of new hardware technologies.
Windows Today
Today many people think of Windows as a graphical add-on to the familiar MS-DOS operating system they have used for years. This perception took much of the fear out of upgrading to Windows for the end user. But in fact, Windows is not limited by MS-DOS.
Windows is a complete operating system that provides extra features on top of MS-DOS and replaces certain MS-DOS features. Windows Version 3.0 does not use MS-DOS screen or keyboard I/O, does not use MS-DOS memory management, and can even bypass MS-DOS file I/O with new Windows-specific device drivers. Version 3.0 Enhanced-mode can handle 32-bit device drivers that are not limited by the infamous 640K MS-DOS barrier. These drivers talk through Windows to applications that are also not limited by the constraints of MS-DOS.
The advantage of being able to work with MS-DOS is that it preserves the value added by MS-DOS’s long life span (in computer years). Windows can run with MS-DOS TSRs, MS-DOS device drivers, and of course, it can run MS-DOS applications. Future versions of Windows will continue to be available on MS-DOS.
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IDE controller and Throughput2

IDE controller and Throughput2
The 3ware 3W-5400 is a PCI card that supports four IDE/ATA drives. The newer 3W-5800 card supports up to 8 drives. Each IDE drive is set to master and given its own string. The 3ware card and its driver software presents the IDE drives to the Windows or Unix host as SCSI drives. The drives can be presented to the system as either just a bunch of disks (JBOD), or as large logical disks through RAID0 and RAID1. Since the 3ware card offloads much of the IO processing from the CPU, the processor overhead was similar to that seen on SCSI adapters.
All of our IDE measurements were taken with WCE as the 3W-5400 enables the drive write cache automatically.3 Unlike most SCSI controllers, the current 3ware card only allows WCE to be disabled on a per-request basis. At the time of our tests, it did not allow WCE to be disabled globally.
It is possible to measure the PCI and controller throughput by reading from the controller cache, rather than going to the disk media. We measured the peak throughput using the tool DiskCache program described in the Testing Methodology section. By reading directly from disk cache from four Fireball IDE drives, we were able to achieve 58.9 MBps from the 3ware card using 64KB requests. This is the card’s PCI limit and larger request sizes had no effect. Other experiments with SCSI controllers delivered as much as 84MBps. The first generation of 3ware cards were limited by their PCI implementation. Second generation 3W-6000 series cards, which were not available in time for this study, have a higher PCI throughput. Tests performed on a 3W-6800 show a peak
read throughput of 101 MBps and peak write throughput of 85 MBps read throughput when accessing
four Fireball IDE drives. For random workloads, the bandwidth demand of 4 drives is less than 5MBps, so the PCI bus speed is not an issue.
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Savollar Javoblar

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Savollar Javoblar
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bet | 1/45 | Sana | 07.01.2024 | Hajmi | 109,51 Kb. | | #131376 |
Bog'liq Savollar Javoblar (2)
№ Savollar Javoblar
2
№
Savollar
Javoblar
1.
Ma’lumotlar bazasiga ta’rif bering
*ma’lum bir sxema asosida saqlanuvchi
ma’lumotlarning strukturalashgan majmuasi
2.
Ko‘pchilik foydalanuvchilar tomonidan MBni yaratish, to‘ldirish va birgalikda foydalanish
uchun mo‘ljallangan dasturiy vositalar majmuasi nima deyiladi?
*MBBT
3.
Fayllarni boshqarishda nima yordam beradi
*Fayl tizimi
4.
O‘zaro bog‘langan ma’lumotlar … deyiladi
*ma’lumotlar tizimi
5.
Ma’lumotlar bazasi adminstratori
*bitta yoki bir nechta ma’lumotlar bazasi xaqida to‘liq tasavvurga ega mutaxassis bo‘lib,
ushbu ma’lumotlar bazasini loyihalash va qo’llanilishini nazorat qilish bilan shug‘ullanadi
6.
Atributlarda saqlanadigan xabarlar bu-
*ma’lumot qiymatlari
7.
Zamonaviy MBBTlar fayl tizimining qaysi muammosini hal qiladi
*ko‘p foydalanuvchilar bilan ishlash
8.
Ma`lumotlar bazasidagi axborotlar qanday bo`lishi kerak
*qarama – qarshi bo`lmasligi; xatosiz bo`lishi; yaxlit
bo`lishi kerak
9.
MBBT dagi foydalanuvchilarga yaqin abstraksiya bosqichini ko‘rsating
*tashqi
10.
Ma`lumotlar bazasi asosiy modellari nechta?
*3 ta
11.
Ma’lumotlarni tavsiflanishiga qarab nechchiga ajratish mumkin
*2
12.
Ma’lumotlar bazasini boshqarish tizimi deganda nimani tushunasiz ?
*ma'lumotlar bazalarini yaratish va foydalanish
uchun boshqarishni ta‟minlovchi, maxsus lingvistik
vositalar majmuiga ega bo`lgan dasturiy ta`minot
13.
Ma`lumotlar bazasidagi ma`lumotlarni xotiraga saqlanishi qaysi tavsivlashga tegishli
*fizik
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DMA vs. PIO - Windows 2000 Disk io performance Leonard Chung

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Windows 2000 Disk io performance Leonard Chung
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bet | 9/47 | Sana | 30.03.2021 | Hajmi | 1,33 Mb. | | #13789 |
DMA vs. PIO
IDE controllers have two protocols to transfer data to and from the disk to main memory: direct memory access (DMA) and programmed input/output (PIO). The main difference between them is that while PIO requires the processor to poll the drive repeatedly and places the burden of copying the data on the processor, DMA allows the processor to just initiate a transfer and places the burden of copying the data on the controller. While the controller is copying the bits, the processor can perform other tasks. PIO is 85 times more expensive than DMA – that’s 8,500%!
DMA and PIO can be selected through the Device Manager in Win2K. We connected one IDE drive to an IDE channel on the motherboard and measured the affects of DMA and PIO. Table 7 shows the dramatic performance penalty of PIO. Not only did throughput decrease by 75% for unbuffered 64KB reads, but also processor utilization jumped to 50% across both processors. The first step to good IDE performance is to ensure that DMA is enabled. Since the 3ware IDE RAID card masquerades as a SCSI adapter, DMA and PIO selection was not necessary.
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Introduction - Windows 2000 Disk io performance Leonard Chung

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Windows 2000 Disk io performance Leonard Chung
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bet | 5/47 | Sana | 30.03.2021 | Hajmi | 1,33 Mb. | | #13789 |
Introduction
We first sought to measure and compare the I/O performance on a workstation similar to that of Riedel’s running NT4SP6 and then Windows 2000 to compare performance between the two operating systems. We called these the old-old and old-new tests: signifying that we were testing old hardware and the old OS, and old hardware with the new OS. We then tested a modern workstation and the Windows 2000 operating system. These tests were called the new-new tests. The software and hardware test naming matrix is shown in Table 1.
The first old-old and old-new measurements were conducted on hardware similar to that used in the original study. The processor is faster, but the disks and controller that were the main bottlenecks in the original report, remain the same. We measured both Win2K and NT4SP6. Our objective for these tests was twofold: first, to compare the results of the original study by Riedel, et. al. with the most recent version of NT4 on comparable hardware to see if there have been any changes in performance. Second, to explore the differences and similarities between Windows NT4SP6 and Win2K.
The new-new measurements were taken on a Dell Precision 420 test machine with the latest processors, memory, and SCSI disks (When we started in January 2000): Dual Intel Pentium III processors running at 733 MHz, Rambus memory, an Ultra160 SCSI adapter, and four 10K RPM SCSI drives. Each of these has an advertised bandwidth of 1.6GBps, 160MBps, and 18 to 26MBps respectively. We also added a 3ware 3W-5400 IDE RAID card, along with four Quantum Fireball lct08 5400 RPM drives with an advertised internal throughput of 32MBps each.1 PAP (Peak Advertised Performance) however is often is quite different than RAP (Real Application Performance). We wanted to explore what kind RAP today’s hardware is actually able to achieve, along with how to achieve good performance with minimal effort.
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Peak Advertised Performance

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Peak Advertised Performance
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bet | 8/47 | Sana | 30.03.2021 | Hajmi | 1,33 Mb. | | #13789 |
Peak Advertised Performance
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Real Application Performance
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Memory bus
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1,600 MBps
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975 MBps read
550 MBps write
327 MBps copy
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PCI bus
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133 MBps
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98.5 MBps
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SCSI bus (Ultra160)
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160 MBps
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98.5 MBps @ 1 MB read req.
83.6 MBps @ 64KB read req.
50 MBps write
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3ware 3W-5400
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Greater than 55MBps
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58.9 MBps @ 64KB read
40 MBps write
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3Ware 3W-6800*
(Alpha test unit)
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100+ MBps
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101 MBps @ 256KB read
85 MBps @ 256KB write
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Hard disk
(Atlas 10K)
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18MBps to 26MBps
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17 MBps to 24 MBps
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Hard disk
(Fireball lct08)
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Up to 32 MBps
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12.4 MBps to 19 MBps
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Table 6 – PAP vs. RAP across multiple buses. The SCSI bus’s throughput was hampered by the adapter’s PCI bus interface, as the Ultra160 SCSI’s advertised PAP is higher than that of the PCI bus. The first generation 3ware card, despite being able to interface with four drives, has a limited throughput of 58.9MBps, or approximately the combined throughput of three of our Fireball IDE drives reading sequentially. However, in each of these cases, the half-power point was achieved.
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Symmetric Multiprocessing (SMP)
All of our tests were run on a dual processor system. We found SMP had little effect on our throughput measurements. Since the measurements are already IO bound, increasing the number of processor cycles available does little to improve performance. We tested the single CPU case by booting Win2K using /NUMPROC=1 as an argument. This causes Win2K to function in a uniprocessor mode, ignoring the second processor. Overhead increased slightly when two CPUs were used as there was now some additional overhead incurred by synchronization code. In addition, Windows 2000 only allows one outstanding deferred procedure call (DPC) per SCSI adapter. We only had one adapter. For each of these reasons, we weren’t able to take advantage of the additional parallelism offered by the additional processor.
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Mitre technical report

Android Secure Application Development Guidance for DoD
Michael Peck, Shawn Valle
30 September 2011
Sponsor: ESE Capstone
Dept. No.: G021 / E54A
Contract No.: W15P7T-12-C-F600
Project No.: 031280SE-D2
The views, opinions and/or findings contained in this report are those of The MITRE Corporation and should not be construed as an official government position, policy, or decision, unless designated by other documentation.
This document was prepared for authorized distribution only. Approved for Public Release: 12-3459. Distribution Unlimited
©2011 The MITRE Corporation.
All rights reserved.
Prepared By:
Signed
Robert “Pat” Benito, JC2 Pilot Task Lead 2/19/12
Approved By:
Signed
Josiah R. Collens, Jr. 2/20/12
Director of Integration for Joint C2
NSEC
This page intentionally left blank.
Executive Summary
Android applications developed for US Department of Defense (DoD), are required to go through a workflow process to evaluate and test for meeting expected Cyber Security and Information Assurance guidelines. Applications that meet the evaluation guidelines can be permitted into the enterprise application market, known as CAPStore, for user distribution. The following documentation identifies the technical requirements and guidance Android application developers should adhere to when developing applications for DoD.
The details within are technical and security focused, and should be made available to software engineers and IA engineers. The material is organized with a logical flow in mind, initially focusing on application permissions, then into securing code and data, and finally focusing on multiple application interaction.
Table of Contents
1Introduction 1
2Application Permissions 1
1.1Leverage Android Permissions Model 1
1.2Creating New Manifest Permissions 1
3General Application Authentication 2
1.3Password Guidance 3
4Data Protection 4
1.4Database Encryption 5
1.5SD Card Storage 5
1.6Android Application Package 6
1.7File Permissions 6
5Follow Secure Programming Practices 1
1.8Input Validation 1
2Avoiding SQL injection attacks 1
3Avoiding command injection attacks 2
1.9Sign Application Packages 2
1.10Avoid Android NDK or Java JNI Use, Unless Necessary 3
1.11Third-Party Libraries 3
6Secure Data Communication 1
1.12Leverage TLS/SSL 1
1.13Parameter Content 4
7Secure Inter-App Communication 1
1.14Securing Android Intents 1
1.15Securing Content Providers 4
8Application Update Process 1
9Non-Android SDK Applications 1
1.16Browser-based Apps 1
1.17Adobe Air Apps 1
List of Figures
Figure 3‑1 Potential Sample Authentication 2
Figure 3‑2 Standard DoD PED Banner 4
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Tuproq resurslarini holati va uni qo‟riqlash

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Tuproq resurslarini holati va uni qo‟riqlash
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bet | 3/3 | Sana | 16.01.2024 | Hajmi | 46,5 Kb. | | #139032 |
Bog'liq kimyoTuproq resurslarini holati va uni qo‟riqlash. Respublikada 95 % tuproq va 85 % suv resurslari qishloq ho‘jaligi ishlab chiqarishida ishlatiladi. Eng ahamiyatliysi sug‘orib ekishdir.
Ekin maydonining 15 % tashkil qilib, o‘simlikshunoslikdagi 95 % mahsulotni beradi.
Tuproq-suv resurslaridan oqilona foydalanish faqat iqtisodiy ahamiyatga ega emas, balqi ekologik ahamiyatga ham egadir.
Yangi yerlarni tinimsiz o‘zlashtirish natijasida, Respublika suv balansi keskin buzildi, buning natijasida Orol dengizi va uning atrofida ekologik muvozanat buzildi.
Yerdan noto‘gri foydalanish natijasida tuzning miqdori ortib ketdi, bu esa tuproqning meliorativ holatini buzishga olib keldi. Buning natijasida tuzsizlantirish uchun ko‘p mablag‘ va uni yuvish uchun ko‘p miqdorda suv sarflanmoqda.
Tuproqni zararlanishini boshqa tomoni ortiqcha kimyoviy moddalarni to‘planishi ya'ni pestitsid qoldiqlari va og‘ir metallarni to‘planishidir.
1993 yildan olib borilayotgan Davlat mahsus analitik nazorat inspeksiyasining tekshirishicha, qishloq ho‘jalik aerodromlari, omborhonalarni tekshirish bu joylarda ekologik holatni yahshi emasligi qo‘rsatdi. Tuproq shu joylarda DDT bilan 2-5 marta ortiq zararlangian (normaga nisbatan) gerbitsidlar dalapon, qatoran, reflan bilan zararlanishi uncha katta emas. Fosfororganik birikmalar-metafos, fazalon, tiadan qoldiqlari topilgan Respublikada tuproqlarni pestitsidlardan zararlashga qarshi choralar ko‘rilmoqda.
Masalan "O‘zbekiston qishloq ho‘jalik kimyosi" ma'lumotiga qaraganda 1993 yilda 57,7 ming tonna pestitsid ishlatilgan 1990 yilga nisbatan 1,5 barobar (85,9 ming tonna) ishlatilgan.
O‘zbekiston tuproq-suv resurslari jihatidan boy respublikadir, ammo undan hali unumli foydalanilayotgani yo‘q.
Adabiyotlar:
Н. А. Парпиев , Ҳ. Р. Раҳимов Муфтахов, А.Г. «Анорганик киме назарий асослари »,Т., Ўзбекистон, 2000й.
Қ.Aхмеров, А.Жалилов, Р. Сайфуддинов «Умумий ва анорганик кимё». Т., Ўзбекистон, 2003й.
Q. Ahmerov, A. Jalilov, R. Sayfuddinov, « Umumiy va anorganik kimyo». T. O‗zb, 2006.
Угай Я. А. «Общая и неоргнаническая химия», -М: «Высшая школа», - 1998.
X.X. Muhiddinov. «Kimyo». T. TDTU, 2005
Х.Х. Мухиддинов. Кимё, Маърузалар матни. Т. ТДТУ, 2004.
Н.Г. Коржуков ―общая и неорганическая химия‖, М., МиСиС/, 2004.
Н.Л.Глинка «Умумий кимёдан масала ва машқлар тўплами»,Т.,Ўқитувчи.
Н. В. Коровин, Э. И. Мингулин, Н. Г. Рыжова «Лабораторные работы по химии», М., Высшая школа». -1998.
I.I. ismoilov, X.X.Muxitdinov va boshqalar. ―kimyo‖ fanidan amaliy va laboratoriya mashgulot boyicha uslubiy qollanma.T.,TDTU.2007.
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Loyiha Maqsadi va Vazifalari

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Loyiha Maqsadi va Vazifalari
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bet | 3/7 | Sana | 21.05.2024 | Hajmi | 408,71 Kb. | | #247099 |
1. Loyiha Maqsadi va Vazifalari:
- 1 MHz chastota va 2 V amplituda bilan multivibrator prinsipial sxemasini loyihalash va mantaj platasida amalga oshirish
2. Nazariy Qism:
- Multivibratorning elektr sxemasi va ishlash prinsipi
Multivibrator, impuls va signal generatorlari sifatida keng qo'llaniladigan elektron qurilmadir. Uning asosiy vazifasi turli chastotalardagi impuls yoki to'lqinlarni ishlab chiqarishdir. Multivibratorlar asosan uch turga bo'linadi: bistabil, monostabil va astabil.
Bistabil Multivibrator
Bistabil multivibrator ikki barqaror holatga ega bo'lib, u faqat tashqi impuls orqali boshqa holatga o'tadi va shu holatda qoladi. Bu turdagi multivibratorlar elektron qurilmalarda qo'llaniladigan elektron qulf sifatida ishlatiladi.
Monostabil Multivibrator
Monostabil multivibrator bir barqaror va bir no-barqaror holatga ega. Ushbu qurilma tashqi impuls bilan no-barqaror holatga o'tadi va ma'lum bir vaqt o'tgach, yana o'zining barqaror holatiga qaytadi. Bu xil multivibratorlar vaqt davomida bir martalik signal yoki impuls ishlab chiqarishda foydalaniladi.
Astabil Multivibrator
Astabil multivibrator esa hech qanday barqaror holatga ega emas va doimiy ravishda ikki holat o'rtasida almashinib turadi. Bu turdagi multivibratorlar tebranish yoki oscilator sifatida ishlatiladi.
Astabil Multivibratorning Ishlash Prinsipi:
Astabil multivibrator ikkita tranzistor (Q1 va Q2), ikkita kondansator (C1 va C2) va to'rtta rezistor (R1, R2, R3, R4) dan iborat bo'lishi mumkin. Quyidagi qadamda ularning harakatini ko'rib chiqamiz:
1. Q1 tranzistori yoqilgan (on) holatda va Q2 tranzistori o'chgan (off) holatda boshlanadi. Bu holatda Q1 orqali oqim o'tadi va C2 kondansatori asta-sekin zaryadlanadi.
2. C2 ning zaryadi ma'lum darajaga yetgach, Q2 tranzistorini yoqadi. Bu holatda Q2 orqali ham oqim o'ta boshlaydi va endi C1 kondansatori zaryadlanishni boshlaydi.
3. C1 zaryadlangach, Q1 tranzistorini o'chiradi. Endi oqim Q1 orqali o'tmay qo'yadi va C2 kondansatori qayta zaryadlanishni boshlaydi.
4. Jarayon takrorlanadi: C2 qayta zaryadlangach, Q2 yana o'chadi va C1 qayta zaryadlanadi, shu tariqa sikl davom etadi.
Bu tarzda, astabil multivibrator doimiy ravishda ikkala tranzistor orqali almashinuvchi oqim ishlab chiqaradi, bu esa chiqishda mavjud bo'lgan kuchlanishni doimiy ravishda o'zgarib turishini ta'minlaydi. Chastota va amplituda esa kondansator va rezistorlarning qiymatlariga bog'liq bo'ladi.
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Foydalanilgan Adabiyotlar Ro'yxati

5. Foydalanilgan Adabiyotlar Ro'yxati:
- Manbalar ro'yxati
1. Horowitz, P., & Hill, W. (1989). "The Art of Electronics". Cambridge University Press.
- Bu kitob elektron qurilmalarning asosiy prinsiplari va ularni qo'llash usullari haqida keng ma'lumot beradi. Multivibrator sxemalarini loyihalash va ulardan foydalanish bo‘yicha ko‘plab misollar va tushuntirishlar mavjud.
2. Malvino, A. P., & Bates, D. J. (2006). "Electronic Principles". McGraw-Hill Education.
- Elektron prinsiplari bo'yicha klassik qo'llanma, u yerda tranzistorlarning ishlash prinsiplari, shu jumladan multivibratorlar va ularning turli sxemalari batafsil yoritilgan.
3. Floyd, T. L. (2014). "Electronic Devices (Conventional Current Version)". Pearson Education.
- Bu kitobda elektron qurilmalarning ishlash prinsiplari va qo'llanilishi haqida batafsil ma'lumot berilgan, jumladan multivibratorlarning turli sxemalari va ularni qo'llash sohalari keng yoritilgan.
4. Sedra, A. S., & Smith, K. C. (2010). "Microelectronic Circuits". Oxford University Press.
- Mikroelektronika sxemalari bo'yicha to'liq qo'llanma, unda turli xil multivibrator sxemalarini loyihalash va tahlil qilish usullari ko'rsatilgan.
5. Wakerly, J. F. (2005). "Digital Design: Principles and Practices". Prentice Hall.
- Raqamli dizayn prinsiplari va amaliyotlari bo‘yicha bu kitob, multivibrator kabi raqamli qurilmalarni loyihalash va ishlatish bo‘yicha qimmatli ma'lumotlarni taqdim etadi.
6. Gibilisco, S. (2013). "Teach Yourself Electricity and Electronics". McGraw-Hill Education.
- Ushbu o'quv qo'llanmada elektr va elektronika asoslari batafsil tushuntirilgan, shu jumladan astabil multivibratorlar kabi turli elektron sxemalar ham kiritilgan.
6. Ilovalar:
- Sxemalar, diagrammalar va boshqa hujjatlar
Multivibrator sxemasi.
Multivibratorning ishlash vaqt sxemalari.
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Parametr
  
2N3904 - «elektron apparaturalarni ishlab chiqarish texnalogiyalari»

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«elektron apparaturalarni ishlab chiqarish texnalogiyalari»
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bet | 5/7 | Sana | 21.05.2024 | Hajmi | 408,71 Kb. | | #247099 |
Bu sahifa navigatsiya:
- Izoh
Parametr
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2N3904
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2N2222
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BC547
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KT315
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Maksimal ruxsat etilgan kollektor oqimi (Ic max)
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200 mA
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800 mA
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100 mA
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100 mA
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Maksimal ruxsat etilgan teskari kollektor oqimi (I CBO)
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50 µA
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10 µA
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15 µA
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50 µA
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Maksimal kollektor-emitter kuchlanishi (Vceo)
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40 V
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30 V
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45 V
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30 V
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Maksimal emitter-base kuchlanishi (Vebo)
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6 V
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5 V
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6 V
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5 V
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Maksimal kollektor dissipation (Pc)
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625 mW
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500 mW
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500 mW
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150 mW
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h21e (Minimal)
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30
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100
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110
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50
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Izoh: Guruh jurnalidagi 1-dan 5-raqamga bolgan talaba 2N3904,6-dan 10-gacha talaba 2N2222, 11-dan 15-gacha bolgan talaba BC547,16-dan 21-gacha bolgan talaba esa KT315 nomerdagi tranzistorlar tanlanadi.
3. Transistorlarning kollektor zanjirlarida R1 va R4 qarshiliklarni aniqlang
bu erda I K imax - maksimal ruxsat etilgan kollektor oqimi;
I KBO - maksimal ruxsat etilgan teskari kollektor oqimi.
Amaliy fikrlarga asoslanib, kam quvvatli tranzistorlar uchun (0,5 ... 1) kOhm dan katta R K ni tanlang va yuqori quvvatli tranzistorlar uchun - (20 ... 30) kOhm dan ko'p emas.
KT315 tranzistori kam quvvatli bo'lgani uchun biz R K = 3,3 kOm ni tanlaymiz.
4. Transistorlar tayanch zanjirlarida R2, R3 rezistorlarining qarshiligini tanlang
Keling, R2 = R3 = R b = 165 kOm ni tanlaymiz
5. C1 va C2 kondansatkichlarining quvvatini tanlang
Hisoblash turli xil impuls davomiyligi t i bo'lgan assimetrik multivibrator uchun amalga oshirilsa , u holda C1 va C2 kondansatkichlari alohida hisoblanadi.
Multivibratorlarni qo'llash
Amalda multivibratorlar to'rtburchak impuls generatorlari sifatida, tranzistorlar va arra tish shakllari kollektorlaridan kuchlanishni olib tashlashda, tranzistorlar asoslaridan kuchlanishni olib tashlashda ishlatiladi . Kutish multivibratorlari vaqt bilan boshqariladigan vaqtni kechiktirish va sozlanishi davomiylik bilan impulslarni ishlab chiqarish uchun ishlatiladi .
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Xulosa - «elektron apparaturalarni ishlab chiqarish texnalogiyalari»

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«elektron apparaturalarni ishlab chiqarish texnalogiyalari»
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bet | 6/7 | Sana | 21.05.2024 | Hajmi | 408,71 Kb. | | #247099 |
4. Xulosa:
- Loyihaning natijalari va ularning ahamiyati
Loyihaning Natijalari
1. Multivibrator Sxemasining Yaratilishi va Sinovdan O'tkazilishi: Mantaj platasida sxemani to'g'ri yig'ish va sozlash orqali, siz astabil multivibrator yaratdingiz. Bu sxema 1 MHz chastotada va 2 V amplituda bilan ishlaydigan impulsli signal ishlab chiqara oladi.
2. Texnik Ko'nikmalar Oshirilishi: Elektron qurilmalarni loyihalash va qurish jarayonida muhandislik ko'nikmalarini rivojlantirish. Bu jarayon, shuningdek, muammolarni hal qilish, sxematik dizayn va amaliy montaj ko'nikmalarini o'z ichiga oladi.
3. Amaliy Tahlil va Optimizatsiya: Loyihani amalga oshirish jarayonida turli xil komponentlarning ta'siri va ularning sxema ishlashiga qanday ta'sir qilishi tahlil qilinadi. Bu, o'z navbatida, sxemani yanada optimallashtirish imkonini beradi.
4. O'sillograf Orqali Signal Sifatining Baholanishi: Chiqish signallarini osillograf yordamida tekshirish, signal sifati va ishonchliligi haqida ma'lumot beradi. Bu, sxema parametrlarini aniq sozlash imkonini yaratadi.
Ularning Ahamiyati
1. Ta'limiy Ahamiyat: Multivibrator sxemasini loyihalash va qurish orqali siz elektronika sohasidagi nazariy bilimlarni amaliyotda qo'llash imkoniyatiga ega bo'ldingiz. Bu sizning o'quv kursingiz doirasida qo'l keladi.
2. Amaliy Qo'llanilishi: Astabil multivibratorlar ko'plab ilovalarda qo'llaniladi, masalan, timerlar, avtomatik qayta ishga tushirish tizimlari, va impuls generatorlari sifatida. Sizning loyihangiz bu turdagi qurilmalarni qanday loyihalash va qurish mumkinligini ko'rsatadi.
3. Innovatsion Yechimlar: Sizning loyihangiz elektronika sohasida innovatsion yechimlarni ishlab chiqishda muhim qadam bo'lishi mumkin. Bu yechimlar keyinchalik yanada murakkab elektron tizimlarni ishlab chiqishda foydalanilishi mumkin.
4. Kasbiy Mahoratning Oshirilishi: Ushbu loyiha orqali kasbiy mahoratlar va muhandislik yondashuvlarini rivojlantirish imkoniyati mavjud bo'lib, bu kelajakda muhandislik faoliyatingizda katta ahamiyatga ega.
Ushbu loyiha sizning ta'lim va kasbiy tajribangizni boyitishga yordam beradi va kelajakdagi muhandislik loyihalari uchun poydevor qo'yadi.
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Kompyuterlarning uzaro axborot almashish imkoniyatlarini beruvchi kurilmalar majmuiga kompyuter tarmoqlari deyiladi

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Kompyuterlarning uzaro axborot almashish imkoniyatlarini beruvchi kurilmalar majmuiga kompyuter tarmoqlari deyiladi
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bet | 4/5 | Sana | 26.06.2024 | Hajmi | 25,91 Kb. | | #265839 |
Bog'liq Ma\'ruza 2Kompyuterlarning uzaro axborot almashish imkoniyatlarini beruvchi kurilmalar majmuiga kompyuter tarmoqlari deyiladi.
Tarmoqning asosiy imkoniyatlari tarmoqka ulangan kompyuterlar va axborot ashyolariga boglik. Axborot ashyolari deganda arxiv, kutubxona, fondlar, ma’lumotlar ombori va boshka axborot tizimlaridagi xujjatlar yigindisi tushuniladi.
Kompyuterlar soniga karab tarmoqlar lokal, Mintaqaviy va global tarmoqlarga bulinadi.
Lokal tarmoqlar bir binoda yoki bir – biriga yakin binolarda joylashgan kompyuterlarda uzaro axborot almashish imkonini beruvchi tarmoq xisoblanadi. Bunday tarmoqlarda axborot almashinish aloka kabellari orkali amalga oshiriladi. Lokal tarmoqda kompyuterlar orasidagi masofa yakin bulganligi bois, telefon kanallaridan foydalanmasdan axborotni uzatish tezligini oshirish mumkin. Lokal tarmoqda axborotni uzatish uchun axborotni marshrutlash va seleksiyalash lozim buladi.
Marshrutlash bu – kerakli manzilga axborot blokini uzatish yulini aniklash jarayonidir.
Seleksiyalash – tegishli manzildagi axborotni saralash demakdir.
Mintaqaviy tarmoq – biror tuman, viloyat yoki Respublika miqyosidagi kompyuterlarni uzida mujassamlashtirgan tarmoq. Bunday tarmoqda bir nechta markazlashgan juda kuvvatli serverlar mavjud buladi va bunday serverlar o‘rtasidagi axborot aloka kabeli, optik tolali yoki sun’iy yuldosh radioaloka kanallari yordamida uzatiladi.
Lokal tarmoq – dunyoning ixtiyoriy davlatidagi kompyuterlarni uzida birlashtirish imkoniga ega bulgan tarmoq. Bu tarmoq internet deb yuritiladi. Internet bilan birga intranet tushuchasi xam ishlatiladi.
Intranet – bu internet texnologiyasi, dastur ta’minoti va bayonnomalari asosida tashkil etilgan, ma’lumotlar ombori va elektron jadvallar bilan jamoa bulib ishlash imkonini beruvchi korxona yoki tashkilot miqyosidagi yangi axborot muxitini tashkil etuvchi kompyuter tarmog‘idir. Intranet boshka kompyuter tarmoqlaridan kuyidagi jixati bilan farklanadi: bir yoki bir nechta serverdan tashkil topgan tarmoq mijozi undagi ma’lumotlardan foydalanish uchun ularning kaysi serverda, kaysi katalogda, kanday nom bilan saklanayotganligini, ularga kirish usul va shartlarini bilishi zarur buladi.
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Kompyuter tarmoqlari - Mavzu: Kompyuter tarmoqlari va ularda ishlash asoslari

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Mavzu: Kompyuter tarmoqlari va ularda ishlash asoslari
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bet | 5/5 | Sana | 26.06.2024 | Hajmi | 25,91 Kb. | | #265839 |
Bog'liq Ma\'ruza 2Kompyuter tarmoqlari server, konsentrator, axborot uzatish kabellari va modemdan tashkil topgan.
Server – tarmoq ishini ta’minlovchi maxsus kompyuter. Server disklarida kompyuterlarni birgalikda ishlash imkonini buruvchi dasturlar, ma’lumolar ombori va boshkalar saklanadi.
Konsentrator – tarmoqda kompyuterlarni uzaro axborot almashinuvini ta’minlovchi maxsus kurilma. Ular 8, 12, 16 ta kompyuterni uzaro boglashi mumkin.
Axborot uzatish kabellari – tarmoqda axborotni bir kompyuterdan boshkasiga uzatish uchun xizmat kiladi.
Modem – axborotni kompyuterdan uzatish kabeliga utkazuvchi maxsus elektron kurilma. Modem «modulyator» va «demodulyator» suzlari birikmasidan xosil bulgan. Zamonaviy modemlarning tezligi 2400, 9600, 14400, 19200, 22880, 33600 boddan iborat.
Darsga doir nazorat savollari
1. Kompyuter tarmog‘i deb nimaga aytiladi?
2. Kompyuter tarmoqlarining kanday turlari bor?
3. Lokal tarmog‘i haqida gapirib bering?
4. Global tarmoq haqida gapiring?
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Axborot muhitida tezlik tushunchasi, birliklari va axborot kanallari sig‘imi

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Axborot muhitida tezlik tushunchasi, birliklari va axborot kanallari sig‘imi
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bet | 3/5 | Sana | 26.06.2024 | Hajmi | 25,91 Kb. | | #265839 |
Bog'liq Ma\'ruza 2Axborot muhitida tezlik tushunchasi, birliklari va axborot kanallari sig‘imi. Ma’lum vaqt oralig‘ida aloqa muhitlari orqali uzatiladigan axborot hajmi - uning uzatilish tezligini belgilaydi.
Xar qanday harakatlanuvchi jism va modda uchun tezlik tushunchasi va uning o‘lchov birliklari mavjud bo‘lganidek, axborotning ham uzatish tezligi hamda o‘lchov birliklari mavjuddir, bular:
Bit/sekund – bir soniyada aloqa muhiti orqali uzatiladigan bitlar soni;
Kbit/sekund – bir soniyada aloqa muhiti orqali uzatiladigan minglab yaxlitlangan bitlar soni;
Mbit/sekund – bir soniyada aloqa muhiti orqali uzatiladigan millionlab yaxlitlangan bitlar soni;
Gbit/sekund – bir soniyada aloqa muhiti orqali uzatiladigan milliardlab yaxlitlangan bitlar soni.
Axborot kanallarining sihimi ular orqali ma’lum vaqt oralig‘ida uzatiladigan axborot hajmi bilan belgilanadi. Bu o‘z navbatida axborot kanallarining o‘tkazish qobilyatini anglatadi.
Oliy ta’lim muassasalari kasb hunar kollejlari va akademik litseylarning hamda maktablarning kompyuter tarmoqlari, ular asosida yechiladigan masalalar.
Oliy ta’lim muassasalari, kasb-hunar kollejlari va akademik litseylar va maktablarning kompyuter tarmoqlari hamda ular asosida yechiladigan masalalar quyidagilardan iborat:
axborotni tashkil qilish va izlab topish;
zamonaviy axborot texnologiyalari yordamida axborot va bilimlarni almashishga imkoniyatini yaratish;
fanlardan bilimlarini chuqurlashtirish uchun qo‘shimcha ma’lumotlarni tarmoqdan qidirish;
talabalrning fanlardan mustaqil ishlarni bajarish;
elektron kutubxonadagi manbalardan foydalanish;
masofaviy ta’lim olish;
hisobotlar tayyorlash va uzatish;
elektron hujjat almashishni tashkil qilish;
talabalar ota-onalari farzandlarining o‘zlashtirishi va davomatini kuzatib borish.
Bundan tashqari hozirgi kunda Respublikamizda ta’lim muassasalarining ta’lim tarmog‘i yaratilgan. Ziyonet axborot-ta’lim tarmog‘i barcha ta’lim muassasalarining axborot resurslarini o‘zida jamlagan. Hozirgi kunda barcha o‘qituvchilar, o‘quvchilar va talabalar ushbu tarmoqdan foydalanish imkoniyatiga ega. Ziyonet axborot-ta’lim tarmog‘i axborotlarni joylashtirish, toifalash, guruhlash hamda ularni qidirib topish imkoniyatini taqdim etadi.
Xozirgi kunda kompyuterlarni yagona tarmoqka ulab ular Ыrtasidagi ma’lumot almashishni tashkil etish mumkin. Kompyuterdan turli masalalarni xal kilishda foydalanish mumkin. Axborot almashish uchun magnit va kompakt disklardan foydalanish yoki boshka kompyuterlar bilan umumiy tarmoqka ulanish kerak buladi.
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