Sep 12, 2017

Uma pena...

A autora desse blog cantinhodamisty.blogspot.com.br decidiu parar de escrever…

Uma pena. Poucas vezes vi um texto tão fluído e bacana com tanta rapidez de raciocínio.

Aug 17, 2017

Um texto divertidíssimo

Go for it

cats.jpg

Jan 29, 2016

80 plus

Certificação 80 Plus

Uma boa forma de saber se sua fonte entrega ou não a capacidade prometida, é procurar uma PSU na lista da 80Plus. É mais ou menos como consultar um nutricionista de fontes para saber se a alimentação está ou não adequada a “dieta” do seu computador.

A certificação 80Plus é dada para fontes que possuem eficiência de 80% ou mais. Existem cinco certificações 80Plus que são dadas de acordo com a capacidade energética da fonte:

Certificação Potência entregue
Potencia usada 20% 50% 100%
80 PLUS 80% 80% 80%
80 PLUS Bronze 82% 85% 82%
80 PLUS Silver 85% 88% 85%
80 PLUS Gold 87% 90% 87%
80 PLUS Platinum 90% 92% 89%

Feb 11, 2015

Padrão brasileiro para o ATA Linksys PAP2

O ata da Linksys PAP2 é um dos melhores equipamentos disponívels no mercado atualmente. Porém, por ser um equipamento importado, todo o padrão de funcionamento dele vem ajustado para funcionar de acordo com os padrões norte americanos. Por este motivo é comum algumas centrais telefônicas não reconhecerem o tom de discagem gerada por ele.

Fizemos pesquisas e estudos em cima deste equipamento e reunimos os principais ajustes que deve ser feito para que este equipamento fique padronizado com o sistema telefonico brasileiro.

Supondo que você já esteja com acesso a área administrativa do equipamento, em modo avançado e com nível de usuário administrativo, siga os seguintes procedimentos:

1- Clique na opção “Regional” e substitua os valores padrões nas configurações, pelos valores citados abaixo:

* Dial Tone 1: 425@-16,425@-16,450@-16;10(*/0/1+2+3) ou 425@-19;15(*/0/1)
* Sinal de Controle de Chamada (Ring Back Tone) 425@-19;*(1/4/1)
* Sinal de Código Inacessível (Reorder Tone) 425@-19;10(.25/.25/1,.75/.25/1)
* Sinal de Ocupado (Busy Tone) 425@-19;10(.25/.25/1)
* Caller ID method: DTMF (Finland/Sweden)
* FXS Port Input Gain: 0 (zero)
* FXS Port Output Gain: 0 (zero)

Jan 26, 2015

Deutsch

A língua alemã é relativamente fácil. Todos aqueles que conhecem as línguas derivadas do latim e estão habituados a conjugar alguns verbos podem aprendê-la rapidamente. Isso dizem os professores de alemão logo na primeira lição.
Para ilustrar como é simples, vamos estudar um exemplo.

Primeiro, pegamos um livro em alemão, neste caso um magnífico volume, com capa dura, publicado em Dortmund, e que trata dos usos e costumes dos índios australianos Hotentotes (em alemão, “Hottentotten”).

Conta o livro que os cangurus (Beutelratten) são capturados e colocados em jaulas (Kotter) cobertas com uma tela (Lattengitter) para protegê-las das intempéries. Essas jaulas, em alemão, chamam-se jaulas cobertas com tela Lattengitterkotter) e, quando possuem em seu interior um canguru, chamamos ao conjunto de jaula coberta de tela com canguru (Lattengitterkotterbeutelratten).

Um dia, os hotentotes prenderam um assassino (Attentäter), acusado de haver matado a mãe (Mutter) hotentote (Hottentottermutter) de um garoto surdo e mudo (Stottertrottel). Essa mulher, em alemão, chama-se Hottentottenstottertrottelmutter e, a seu assassino, facilmente chamamos de Hottentottenstottertrottelmutterattentäter.

No livro, os índios o capturaram e, sem ter onde colocá-lo, puseram-no numa jaula de canguru (Beutelrattenlattengitterkotter). Mas, incidentalmente, o preso escapou.

Após iniciarem a busca, rapidamente veio um guerreiro hotentote gritando:

- Capturamos o assassino (Attentäter)!

- Qual?? – perguntou o chefe.

- O Lattengitterkotterbeutelratterattentäter – respondeu o guerreiro.

- Como? O assassino que estava na jaula de cangurus coberta de tela? -disse o chefe dos hotentotes.

- Sim – responde a duras penas o indígena – o Hottentottenstottertrottelmutteratentäter (assassino da mãe do garoto surdoe mudo).

- Ah – diz o chefe – você poderia ter dito desde o início que havia capturado o Hottentotterstottertrottelmutterlattengitterkotterbeutelrattenattentäter!

Assim, através desse exemplo, podemos ver que o alemão é facílimo e simplifica muito as coisas. Basta um pouco de interesse.

Nov 28, 2014

mplayer wizardry

Como extrair um frame de um vídeo usando linux de comando em Linux e mplayer:

mplayer -vo jpeg -ss 0:23:45 -frames 1 foobar.mkv

Jun 21, 2014

Projeto de férias

One day backyard projects

Build a micro-sized first-person-view quadcopter

Jun 6, 2014

Gerador de chavão de esquerdas

Gerador de chavão de esquerdas

May 11, 2014

Cheap digital microscope

click

Apr 15, 2014

Bookmark it

Why clever and lazy people become leaders?

Declare suas perdas ao leão para reduzir o imposto no futuro

Feb 1, 2014

Multi-AP Roaming Network Background

There is no magic to making multiple-AP (roaming) 802.11 networks work. Wireless clients just assume that all APs with the same SSID are configured similarly and are all just different points of access to the same underlying wired network. A client will scan all channels looking for APs publishing the SSID it wants, and will pick whichever one suits its needs best (usually that means whichever one shows the highest signal strength).

Once on the network, clients stay with the same AP as long as it is meeting the client’s needs (i.e. as long as its signal strength is above a “good enough” threshold). If the client later thinks it could be better off with another AP on that network, it will do periodic scans of all channels looking for other APs publishing that SSID. If a scan turns up a candidate AP that is enough better than the AP it is currently on, it will automatically roam to the other AP, usually without so much as a missed frame.

One roaming caveat: As another commenter pointed out, there are definitely poorly engineered clients out there with poor roaming algorithms or thresholds, which don’t actually roam when they should, and thus end up being too “sticky”, staying on the first AP they joined well after they could have been getting better performance and reliability with another AP that they are now closer to. Sometimes it helps to force the client’s Wi-Fi interface to rejoin the network when you notice that a client has stuck to the wrong AP. If you have a lot of these buggy clients, then using the same SSID for multiple APs might not work well for you; you might want to use different SSIDs so you can more easily monitor and control which AP your client is associated to.*

Assuming both APs are configured similarly and are connected to the same underlying network, roaming is seamless and invisible to the user (except nerds like me who run tools to watch for these things). Roaming events are invisible to applications using the network, although some low-level parts of the network stack might be notified of the event, so that, for example, your DHCP client can double-check that this new AP really is connected to the same network, so it can be sure your DHCP lease is still valid on this network.

Some other users’ Answers and Comments on this question erroneously suggested that wireless protocols or features like wireless relay or WDS might be needed for roaming, but that is absolutely incorrect. Those features are just ways to replace a wired Ethernet backhaul with a wireless one.

For the sake of completeness, I should mention that there is a set of technologies, some proprietary, some standardized in IEEE 802.11F, known generally as Inter-Access Point Protocol. IAPP is a method by which generally enterprise-class APs can communicate with each other over the backhaul to optimize client roaming. But that’s just an optimization, not a prerequisite for roaming. Roaming works “well enough” on networks both small and large without any IAPP going on.

Configuration Suggestions

Give both APs the same network name (SSID), the same security type (WPA2-PSK recommended), and the same wireless security passphrase. Many clients assume that these kinds of settings will be the same across all APs with the same SSID.

Since you already have the cabling in place, use wired Ethernet as your backhaul. This saves your wireless bandwidth for your portable/mobile devices that actually need it, instead of wasting in on stationary devices like APs that could reasonably be cabled up.

If you have another device on the network, such as a broadband home gateway, providing NAT and DHCP service, then put both APs in bridge mode (turn off NAT and DHCP service). You generally only want one box on your network acting as a NAT gateway or serving DHCP. If you don’t already have another device on your network doing NAT and DHCP, and you need those services, then you can have one of your APs do it. Have the more “upstream” AP (the one that’s closer, topologically, to your broadband modem) do NAT and DHCP, and make sure that the wired Ethernet connection to the other AP comes from the first AP’s LAN port. Also make sure that the “downstream” AP is in bridge mode. I call this out because I have seen people make the mistake of leaving NAT and DHCP enabled on both of their APs, and I have seen clients that are not smart enough to realize that, say, the 192.168.1.x/24 network they are on now is not the same 192.168.1.x/24 network they were on a moment ago in the other room. I have also seen users get confused in this situation where two laptops in the same house had 192.168.1.x addresses, but could not ping each other because they were really on two separate IP networks behind two separate NATs.

Channel is one key setting you do want to vary from AP to AP in a roaming (multiple AP) 802.11 network. To maximize bandwidth, leave your APs to automatically select the channel to use, or you can manually pick different, non-overlapping, and hopefully unoccupied channels to use. You don’t want transmissions to/from one AP to compete for bandwidth with transmissions to/from the other AP.

Additional Considerations

The rest of this answer is just a bunch of general “how to maximize your home 802.11 network bandwidth” tips, not specific to your question of two APs with the same SSID.

Consider taking this opportunity to fully modernize

If you are already buying a new AP and taking the time to reconfigure things, I recommend using this opportunity to replace your existing AP as well, by buying two of the latest APs that support simultaneous dual-band 802.11ac technology. That way you can support both the 2.4GHz band for older clients that are 2.4GHz only, as well as the less busy 5GHz band for more bandwidth. It is becoming a “best practice” to set your 2.4GHz 802.11n radio to 20MHz (HT20) channels so that it leaves some of the band free for things like Bluetooth to use. This limits your 802.11n transmission rates in the 2.4GHz band to ~130mbps instead of 300mbps, but allows other non-802.11 2.4GHz devices to still work okay. In 5GHz, where there are many more channels available and they are all generally much less busy, you are encouraged to use 80MHz (VHT80) channels to get maximum throughput.

Apple’s latest 2013 AirPort Extreme and Time Capsule are simultaneous dual-band 802.11ac, and they also support 3 spatial stream (a.k.a. “3×3”, “3SS”) 802.11ac, for transmission rates up to 1300 megabits/sec if you have 3-stream 802.11ac clients that can do it. All of Apple’s Mac products introduced in 2013 or later have 802.11ac. The MacBook Airs are only 2SS (867 megabits/sec max signaling rate), the iMacs are 2SS on transmit and 3SS on receive, but I believe the Retina MacBook Pros and Mac Pro are 3SS on both transmit and receive.

Note that the industry has been slow to roll out good 802.11ac APs and clients. A lot of the stuff that came out in 2012 or even early 2013 was often buggy bleeding-edge first-generation junk. Starting in June 2013 the much more reliable second-generation 802.11ac stuff started coming out. Besides the Apple products, the ASUS RT-AC66U is a decent simultaneous dual-band, 3SS 802.11ac AP.

If you’re stuck with older single-band-at-a-time APs

If you don’t need to support any older 2.4GHz-only devices, use the 5GHz band since it is generally less busy, and you can use HT40 without starving Bluetooth and other uses.

If you’re stuck supporting 2.4GHz-only devices with single-band-at-a-time APs, be careful of your channel selection. In the 2.4GHz band, the channels overlap to a great degree. However, channels 1, 6, and 11 don’t overlap at all, so those are good choices to pick manually. You could use a Wi-Fi network scanner like inSSIDer, NetStumbler, iStumbler, many “war driving” tools, etc. to see which channels are in use by other APs visible from where you are. If you suspect you have non-802.11 2.4GHz interferers in your area, such as Bluetooth, microwave ovens, and many (but not all) cordless phones, baby monitors, wireless webcams, and wireless room-to-room A/V senders, you could go all-out and get a spectrum analyzer like a Metageek Wi-Spy to find which channels are the least noisy where you are.

Extracted from here

SodaStream

Refrigerante caseiro

Jan 5, 2014

Para quando a reforma chegar

31 Insanely Clever Remodeling Ideas For Your New Home

Dec 30, 2014

T-Rex Illusion

T-Rex Illusion

Dec 18, 2013

Is compiz consuming too much CPU? Here's the solution

Is compiz consuming too much CPU? Here’s the solution

Nov 21, 2013

O almocreve

Vai então, empacou o jumento em que eu vinha montado; fustiguei-o, ele deu dous corcovos, depois mais três, enfim mais um, que me sacudiu fora da sela, e com tal desastre, que o pé esquerdo me ficou preso no estribo; tento agarrar-me ao ventre do animal, mas já então, espantado, disparou pela estrada afora. Digo mal: tentou disparar, e efectivamente deu dous saltos, mas um almocreve, que ali estava, acudiu a tempo de lhe pegar na rédea e detê-lo, não sem esforço nem perigo. Dominado o bruto, desvencilhei-me do estribo e pus-me de pé.

— Olhe do que vosmecê escapou, disse o almocreve.

E era verdade; se o jumento corre por ali fora, contundia-me deveras, e não sei se a morte não estaria no fim do desastre; cabeça partida, uma congestão, qualquer transtorno cá dentro, lá se me ia a ciência em flor. O almocreve salvara-me talvez a vida; era positivo; eu sentia-o no sangue que me agitava o coração. Bom almocreve! enquanto eu tornava à consciência de mim mesmo, ele cuidava de consertar os arreios do jumento, com muito zelo e arte. Resolvi dar-lhe três moedas de ouro das cinco que trazia comigo; não porque tal fosse o preço da minha vida, — essa era inestimável; mas porque era uma recompensa digna da dedicação com que ele me salvou. Está dito, dou-lhe as três moedas.

— Pronto, disse ele, apresentando-me a rédea da cavalgadura.

— Daqui a nada, respondi; deixa-me, que ainda não estou em mim…

— Ora qual!

— Pois não é certo que ia morrendo?

— Se o jumento corre por aí fora, é possível; mas, com a ajuda do Senhor, viu vosmecê que não aconteceu nada.

Fui aos alforjes, tirei um colete velho, em cujo bolso trazia as cinco moedas de ouro, e durante esse tempo cogitei se não era excessiva a gratificação, se não bastavam duas moedas. Talvez uma. Com efeito, uma moeda era bastante para lhe dar estremeções de alegria. Examinei-lhe a roupa; era um pobre diabo, que nunca jamais vira uma moeda de ouro. Portanto, uma moeda. Tirei-a, via-a reluzir à luz do sol; não a viu o almocreve, porque eu tinha-lhe voltado as costas; mas suspeitou-o talvez, entrou a falar ao jumento de um modo significativo; dava-lhe conselhos, dizia-lhe que tomasse juízo, que o «senhor doutor» podia castigá-lo; um monólogo paternal. Valha-me Deus! até ouvi estalar um beijo: era o almocreve que lhe beijava a testa.

— Olé! exclamei.

— Queira vosmecê perdoar, mas o diabo do bicho está a olhar para a gente com tanta graça…

Ri-me, hesitei, meti-lhe na mão um cruzado em prata, cavalguei o jumento, e segui a trote largo, um pouco vexado, melhor direi um pouco incerto do efeito da pratinha. Mas a algumas braças de distância, olhei para trás, o almocreve fazia-me grandes cortesias, com evidentes mostras de contentamento. Adverti que devia ser assim mesmo; eu pagara-lhe bem, pagara-lhe talvez demais. Meti os dedos no bolso do colete que trazia no corpo e senti umas moedas de cobre; eram os vinténs que eu devera ter dado ao almocreve, em logar do cruzado em prata. Porque, enfim, ele não levou em mira nenhuma recompensa ou virtude, cedeu a um impulso natural, ao temperamento, aos hábitos do ofício; acresce que a circunstância de estar, não mais adeante nem mais atrás, mas justamente no ponto do desastre, parecia constituí-lo simples instrumento de Providência; e de um ou de outro modo, o mérito do ato era positivamente nenhum. Fiquei desconsolado com esta reflexão, chamei-me pródigo, lancei o cruzado à conta das minhas dissipações antigas; tive (por que não direi tudo?), tive remorsos.

A Daddy’s Letter to his Little Girl About Her Future Husband

Dr. Kelly Flanigan is a therapist who has seen women who needs a good man in their life time and time again. He wanted to write a letter to not only his little girl, but to every woman out there. It’s a fantastic reminder of what a man needs to be to his wife.


Dear Cutie-Pie,

Recently, your mother and I were searching for an answer on Google. Halfway through entering the question, Google returned a list of the most popular searches in the world. Perched at the top of the list was “How to keep him interested.”

It startled me. I scanned several of the countless articles about how to be sexy and sexual, when to bring him a beer versus a sandwich, and the ways to make him feel smart and superior.

And I got angry.

Little One, it is not, has never been, and never will be your job to “keep him interested.”

Little One, your only task is to know deeply in your soul—in that unshakeable place that isn’t rattled by rejection and loss and ego—that you are worthy of interest. (If you can remember that everyone else is worthy of interest also, the battle of your life will be mostly won. But that is a letter for another day.)

If you can trust your worth in this way, you will be attractive in the most important sense of the word: you will attract a boy who is both capable of interest and who wants to spend his one life investing all of his interest in you.

Little One, I want to tell you about the boy who doesn’t need to be keptinterested, because he knows you are interesting:

I don’t care if he puts his elbows on the dinner table—as long as he puts his eyes on the way your nose scrunches when you smile. And then can’t stop looking.

I don’t care if he can’t play a bit of golf with me—as long as he can play with the children you give him and revel in all the glorious and frustrating ways they are just like you.

I don’t care if he doesn’t follow his wallet—as long as he follows his heart and it always leads him back to you.

I don’t care if he is strong—as long as he gives you the space to exercise the strength that is in your heart.

I couldn’t care less how he votes—as long as he wakes up every morning and daily elects you to a place of honor in your home and a place of reverence in his heart.

I don’t care about the color of his skin—as long as he paints the canvas of your lives with brushstrokes of patience, and sacrifice, and vulnerability, and tenderness.

I don’t care if he was raised in this religion or that religion or no religion—as long as he was raised to value the sacred and to know every moment of life, and every moment of life with you, is deeply sacred.

In the end, Little One, if you stumble across a man like that and he and I have nothing else in common, we will have the most important thing in common:

You.

Because in the end, Little One, the only thing you should have to do to “keep him interested” is to be you.

Your eternally interested guy,

Daddy

Original here

Nov 12, 2013

ffmpeg wizardry

Flip video vertically for ffmpeg version 0.8.8-4:

ffmpeg -i in.mp4 -strict experimental -r 23.967 -vf vflip out.mp4

Nov 5, 2013

Scrum, Agile e Burocracia

Click!

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