Abstract The evolution in the technology of automobiles has reached its peak. One of the most innovative features is the invention of driver less car or an autonomous car. An autonomous car controls the motion, sensor activation and action automatically without any human intervention. Such vehicles ensure high degree of safety, comfort and ease of driving. The project aims at designing a system to be used in such autonomous cars. The project is to develop an automatic headlight beam intensity switcher. Such a system will sense the beam status of opposing vehicle and switch the beam intensity of headlight. A sensor based mechanism is utilized to develop the system. The beam intensity switcher plays a very important role while driving. During night time, when two vehicles approach each other in opposite direction the high intensity headlight creates an effect called “Troxler effect”. This effect creates a temporary blindness for some seconds thus resulting in unfortunate accidents. Thus, the high beam of both the vehicles must be switched to low so as to have a comfortable driving. The use of such a device in cars can prevent accidents at night time due to driver inattentiveness and provides an ease of driving. We have used the Arduino UNO board as our micro-controller and application specific sensors. In our project we have designed a device which is a combination of software and hardware coding. The sensor used is a light intensity sensor named BH1750 which has a wide range of sensing capacity. The light sensor takes the “lux ” reading of the headlight rays from the opposing vehicle and checks for a threshold value assigned in the coding. Based on the threshold value the beam switches from high to low state and vice-versa when both the vehicles pass by each other. The same process takes place in opposite vehicle too. This device can be implanted on the front part of the car at an appropriate position and angle. Keywords: automatic, low cost, accurate, headlight beam intensity switcher, Troxler effect, sensor based mechanism and lux readings.
http://www.youtube.com/watch?v=-7FsX1XbtVw&list=UU2pioW2u9AyEpQofiYOIUHw&index=1
Bulgarian rock group "Poduene Blues Band" and their song "Day after Day"
Lyrics:
Храстът казал на дървото
Слез и ниско залегни
Виждаш, буря се задава
Тук до мен и ти се наведи
Ще преживеем дружно с тебе братко
Ще се скатаем от вятърът студен
Ще оцелеем сладко сладко
Ден след ден...
Дървото клоните разклати
Погледна тъжно старата гора
Обрасла от досадни храсталаци
Вещаят бури, а цял живот пълзят...
И преживяват си под чужда сянка
Така на завет от вятърът студен
И оцеляват сладко сладко...
Ден след ден...
Ден след ден...
И така - животът продължава
Вечният си мъдър кръговрат
Някой постоянно оцелява
Защото други срещу бурята, стърчат
Ден след ден...
Ден след ден...
Ден след ден...
Agile Australia 2016 - Rescuing Legacy Software from Impending DoomJacques De Vos
Dealing with an ageing code base is one of the hardest challenges that software development teams face. Legacy code bases can slow teams to a crawl, and therefore it is critical to solve this on the road to agility. Software rewrites fail at alarming rates! Refactoring – a safer approach – has emerged as the de-facto technique to tackle this challenge.
This session we will equip attendees with techniques and lessons to help them refactor more effectively. We will share our experience gained while working with various software teams, from startups to mid-sized organisations, that attempted to rescue their legacy from impending doom.
You will learn how to justify the investment in refactoring legacy code to product owners; when and how to apply different refactoring workflows on legacy code; and practical tips to avoid common pitfalls when refactoring code.
Abstract The evolution in the technology of automobiles has reached its peak. One of the most innovative features is the invention of driver less car or an autonomous car. An autonomous car controls the motion, sensor activation and action automatically without any human intervention. Such vehicles ensure high degree of safety, comfort and ease of driving. The project aims at designing a system to be used in such autonomous cars. The project is to develop an automatic headlight beam intensity switcher. Such a system will sense the beam status of opposing vehicle and switch the beam intensity of headlight. A sensor based mechanism is utilized to develop the system. The beam intensity switcher plays a very important role while driving. During night time, when two vehicles approach each other in opposite direction the high intensity headlight creates an effect called “Troxler effect”. This effect creates a temporary blindness for some seconds thus resulting in unfortunate accidents. Thus, the high beam of both the vehicles must be switched to low so as to have a comfortable driving. The use of such a device in cars can prevent accidents at night time due to driver inattentiveness and provides an ease of driving. We have used the Arduino UNO board as our micro-controller and application specific sensors. In our project we have designed a device which is a combination of software and hardware coding. The sensor used is a light intensity sensor named BH1750 which has a wide range of sensing capacity. The light sensor takes the “lux ” reading of the headlight rays from the opposing vehicle and checks for a threshold value assigned in the coding. Based on the threshold value the beam switches from high to low state and vice-versa when both the vehicles pass by each other. The same process takes place in opposite vehicle too. This device can be implanted on the front part of the car at an appropriate position and angle. Keywords: automatic, low cost, accurate, headlight beam intensity switcher, Troxler effect, sensor based mechanism and lux readings.
http://www.youtube.com/watch?v=-7FsX1XbtVw&list=UU2pioW2u9AyEpQofiYOIUHw&index=1
Bulgarian rock group "Poduene Blues Band" and their song "Day after Day"
Lyrics:
Храстът казал на дървото
Слез и ниско залегни
Виждаш, буря се задава
Тук до мен и ти се наведи
Ще преживеем дружно с тебе братко
Ще се скатаем от вятърът студен
Ще оцелеем сладко сладко
Ден след ден...
Дървото клоните разклати
Погледна тъжно старата гора
Обрасла от досадни храсталаци
Вещаят бури, а цял живот пълзят...
И преживяват си под чужда сянка
Така на завет от вятърът студен
И оцеляват сладко сладко...
Ден след ден...
Ден след ден...
И така - животът продължава
Вечният си мъдър кръговрат
Някой постоянно оцелява
Защото други срещу бурята, стърчат
Ден след ден...
Ден след ден...
Ден след ден...
Agile Australia 2016 - Rescuing Legacy Software from Impending DoomJacques De Vos
Dealing with an ageing code base is one of the hardest challenges that software development teams face. Legacy code bases can slow teams to a crawl, and therefore it is critical to solve this on the road to agility. Software rewrites fail at alarming rates! Refactoring – a safer approach – has emerged as the de-facto technique to tackle this challenge.
This session we will equip attendees with techniques and lessons to help them refactor more effectively. We will share our experience gained while working with various software teams, from startups to mid-sized organisations, that attempted to rescue their legacy from impending doom.
You will learn how to justify the investment in refactoring legacy code to product owners; when and how to apply different refactoring workflows on legacy code; and practical tips to avoid common pitfalls when refactoring code.
A guest lecture delivered to International Marketing students at the Fashion Institute of Technology February 28, 2012.
Topics include the state of SoMoLo shopping, how businesses are responding, and examples of winning attempts to leverage these new technologies to engage the new breed of shopper.
14. Èäåÿ áàéåñîâñêèõ ñåòåé Ìîòèâàöèÿ
Ïðîïàãàöèÿ â ñåòÿõ áåç öèêëîâ d -ðàçäåëèìîñòü
Âûâîä â áàéåñîâñêîé ñåòè ñ öèêëàìè Òåîðåìà î äåêîìïîçèöèè è ñâèäåòåëüñòâà
d -ðàçäåëèìîñòü
Îïðåäåëåíèå
Äâà óçëà íàïðàâëåííîãî ãðàôà x è y íàçûâàþòñÿ
d-ðàçäåë¼ííûìè, åñëè äëÿ âñÿêîãî ïóòè èç x â y (çäåñü íå
ó÷èòûâàåòñÿ íàïðàâëåíèå ð¼áåð) ñóùåñòâóåò òàêîé
ïðîìåæóòî÷íûé óçåë z (íå ñîâïàäàþùèé íè ñ x, íè ñ y), ÷òî
ëèáî ñâÿçü â ïóòè â ýòîì óçëå ïîñëåäîâàòåëüíàÿ èëè
ðàñõîäÿùàÿñÿ, è óçåë z ïîëó÷èë îçíà÷èâàíèå, ëèáî ñâÿçü
ñõîäÿùàÿñÿ, è íè óçåë z, íè êàêîé-ëèáî èç åãî ïîòîìêîâ
îçíà÷èâàíèÿ íå ïîëó÷èë.
 ïðîòèâíîì ñëó÷àå óçëû íàçûâàþòñÿ d-ñâÿçàííûìè.
Ñåðãåé Íèêîëåíêî Áàéåñîâñêèå ñåòè äîâåðèÿ
15. Èäåÿ áàéåñîâñêèõ ñåòåé Ìîòèâàöèÿ
Ïðîïàãàöèÿ â ñåòÿõ áåç öèêëîâ d -ðàçäåëèìîñòü
Âûâîä â áàéåñîâñêîé ñåòè ñ öèêëàìè Òåîðåìà î äåêîìïîçèöèè è ñâèäåòåëüñòâà
Âåðîÿòíîñòè
Äî ñèõ ïîð áûëè òîëüêî ãðàôû è ðàññóæäåíèÿ ¾íà
ïàëüöàõ¿.
Òåïåðü ïîðà ïåðåéòè ê çàäàíèþ âåðîÿòíîñòåé è ïðî÷èì
÷èñëåííûì ïðèìåðàì.
 âåðøèíàõ çàäàíû óñëîâíûå âåðîÿòíîñòè ïðè óñëîâèè
âñåãî ìíîæåñòâà ïðåäêîâ. Åñëè ïðåäêîâ íåò, âåðîÿòíîñòè
íå óñëîâíûå (à ìàðãèíàëüíûå).
Ñåðãåé Íèêîëåíêî Áàéåñîâñêèå ñåòè äîâåðèÿ
16. Èäåÿ áàéåñîâñêèõ ñåòåé Ìîòèâàöèÿ
Ïðîïàãàöèÿ â ñåòÿõ áåç öèêëîâ d -ðàçäåëèìîñòü
Âûâîä â áàéåñîâñêîé ñåòè ñ öèêëàìè Òåîðåìà î äåêîìïîçèöèè è ñâèäåòåëüñòâà
Ïðèìåð
Ñåðãåé Íèêîëåíêî Áàéåñîâñêèå ñåòè äîâåðèÿ
17. Èäåÿ áàéåñîâñêèõ ñåòåé Ìîòèâàöèÿ
Ïðîïàãàöèÿ â ñåòÿõ áåç öèêëîâ d -ðàçäåëèìîñòü
Âûâîä â áàéåñîâñêîé ñåòè ñ öèêëàìè Òåîðåìà î äåêîìïîçèöèè è ñâèäåòåëüñòâà
×èñëåííûé ïðèìåð
Âû÷èñëèì ñîâìåñòíûå âåðîÿòíîñòè öåïî÷êè uv w: ~~ ~
p(uvw ) = p(w |uv ) ~ p(u|~)p(v |~)p(~) = 0.000199025,
t t t t
p(uv w ) = p(w |uv ) ~ p(u|~)p(v |~)p(~) = 0.000010475,
t t t t
p(uv w ) = p(w |uv ) ~ p(u|~)p(v |~)p(~) = 0.012722625,
t t t t
p(uv w ) = p(w |uv ) ~ p(u|~)p(v |~)p(~) = 0.038167875,
t t t t
p(uvw ) = p(w |uv ) ~ p(u|~)p(v |~)p(~) = 0.00160245,
t t t t
p(uv w ) = p(w |uv ) ~ p(u|t t t
t ~)p (v |~)p (~) = 0.00017805,
p(uv w ) = p(w |uv ) ~ p(u|~)p(v |~)p(~) = 0.01894239,
t t t t
p(uv w ) = p(w |uv ) ~ p(u|~)p(v |~)p(~) = 0.92817711.
t t t t
Ñåðãåé Íèêîëåíêî Áàéåñîâñêèå ñåòè äîâåðèÿ
18. Èäåÿ áàéåñîâñêèõ ñåòåé Ìîòèâàöèÿ
Ïðîïàãàöèÿ â ñåòÿõ áåç öèêëîâ d -ðàçäåëèìîñòü
Âûâîä â áàéåñîâñêîé ñåòè ñ öèêëàìè Òåîðåìà î äåêîìïîçèöèè è ñâèäåòåëüñòâà
Âàæíûå çàìå÷àíèÿ
Åñëè ó óçëà n ïðåäêîâ, íóæíî çàäàâàòü 2n óñëîâíûõ
âåðîÿòíîñòåé.
Åñëè ïðåäêîâ ó óçëà x íåò, íóæíî çàäàâàòü ìàðãèíàëüíûå
âåðîÿòíîñòè p(x ).
 ãðàôå çàïðåùåíû íàïðàâëåííûå öèêëû.
Âñÿ ýòà èíôîðìàöèÿ â ñóììå äàñò âîçìîæíîñòü âû÷èñëÿòü
ëþáóþ âåðîÿòíîñòü â ñåòè, ò.å. åäèíñòâåííûì îáðàçîì
çàäàñò ðàñïðåäåëåíèå.
Ñåðãåé Íèêîëåíêî Áàéåñîâñêèå ñåòè äîâåðèÿ
19. Èäåÿ áàéåñîâñêèõ ñåòåé Ìîòèâàöèÿ
Ïðîïàãàöèÿ â ñåòÿõ áåç öèêëîâ d -ðàçäåëèìîñòü
Âûâîä â áàéåñîâñêîé ñåòè ñ öèêëàìè Òåîðåìà î äåêîìïîçèöèè è ñâèäåòåëüñòâà
Òåîðåìà î äåêîìïîçèöèè
Òåîðåìà
Äëÿ ÁÑÄ, ïîñòðîåííîé íà ìíîæåñòâå ïåðåìåííûõ
S = {x1 , x2 , . . . , xn }, îáùåå ðàñïðåäåëåíèå âåðîÿòíîñòåé
p(x1x2 . . . xn ), èíäóöèðóþùåå çàäàííûå óñëîâíûå è
~~ ~
ìàðãèíàëüíûå âåðîÿòíîñòè è ñîãëàñîâàííîå ñ óñëîâíîé
íåçàâèñèìîñòüþ, âûòåêàþùåé èç d-ðàçäåëèìîñòè óçëîâ,
ñóùåñòâóåò, åäèíñòâåííî è ïðåäñòàâëÿåò ñîáîé ïðîèçâåäåíèå
âñåõ òåíçîðîâ, çàäàííûõ â áàéåñîâñêîé ñåòè äîâåðèÿ:
p(S) = p(x |pa(x )),
~ ~
x ∈S
ãäå pa(x ) ìíîæåñòâî ðîäèòåëåé óçëà x â áàçîâîì ãðàôå ñåòè.
Ñåðãåé Íèêîëåíêî Áàéåñîâñêèå ñåòè äîâåðèÿ
20. Èäåÿ áàéåñîâñêèõ ñåòåé Ìîòèâàöèÿ
Ïðîïàãàöèÿ â ñåòÿõ áåç öèêëîâ d -ðàçäåëèìîñòü
Âûâîä â áàéåñîâñêîé ñåòè ñ öèêëàìè Òåîðåìà î äåêîìïîçèöèè è ñâèäåòåëüñòâà
Ïðèìåð
Ïîïðîáóåì â íàøåì ïðèìåðå
âû÷èñëèòü p(z ). Äëÿ ýòîãî
íàäî ïðîñóììèðîâàòü ïî âñåì
îñòàëüíûì âåðîÿòíîñòÿì:
p(z ) = p(~ u v w x y z ).
t~~ ~ ~~
~u v w x y
t ~~ ~ ~~
Òóò áåçóìíîå êîëè÷åñòâî
âû÷èñëåíèé.
Ñåðãåé Íèêîëåíêî Áàéåñîâñêèå ñåòè äîâåðèÿ
21. Èäåÿ áàéåñîâñêèõ ñåòåé Ìîòèâàöèÿ
Ïðîïàãàöèÿ â ñåòÿõ áåç öèêëîâ d -ðàçäåëèìîñòü
Âûâîä â áàéåñîâñêîé ñåòè ñ öèêëàìè Òåîðåìà î äåêîìïîçèöèè è ñâèäåòåëüñòâà
Ïðèìåð
Ïîñëå ïðèìåíåíèÿ ïðàâèëà
äåêîìïîçèöèè ïîëó÷àåòñÿ:
p(z ) =
~ p(~)
t p(v |~)p(z |v )
~t ~~
t
~ v
~
p(u|~)
~t p(x |u)
~~
u
~ x
~
p(w |uv )
~ ~~ p(y |w ),
~~
w
~ y
~
è âû÷èñëåíèé óæå ãîðàçäî
ìåíüøå.
Ñåðãåé Íèêîëåíêî Áàéåñîâñêèå ñåòè äîâåðèÿ
22. Èäåÿ áàéåñîâñêèõ ñåòåé Ìîòèâàöèÿ
Ïðîïàãàöèÿ â ñåòÿõ áåç öèêëîâ d -ðàçäåëèìîñòü
Âûâîä â áàéåñîâñêîé ñåòè ñ öèêëàìè Òåîðåìà î äåêîìïîçèöèè è ñâèäåòåëüñòâà
Ïðèìåð
 ýòîì è çàêëþ÷àåòñÿ ñìûñë
áàéåñîâñêèõ ñåòåé äîâåðèÿ
ðàçëîæèòü áîëüøîå
ðàñïðåäåëåíèå íà ïðîèçâåäåíèå
ìàëåíüêèõ. Ýòî ñìûñë íå
òîëüêî ÁÑÄ, íî è âîîáùå âñåãî
áàéåñîâñêîãî âûâîäà.
Ñåðãåé Íèêîëåíêî Áàéåñîâñêèå ñåòè äîâåðèÿ
23. Èäåÿ áàéåñîâñêèõ ñåòåé Ìîòèâàöèÿ
Ïðîïàãàöèÿ â ñåòÿõ áåç öèêëîâ d -ðàçäåëèìîñòü
Âûâîä â áàéåñîâñêîé ñåòè ñ öèêëàìè Òåîðåìà î äåêîìïîçèöèè è ñâèäåòåëüñòâà
Ñâèäåòåëüñòâà
Ñâèäåòåëüñòâà óòâåðæäåíèÿ âèäà ¾ñîáûòèå â óçëå x
ïðîèçîøëî¿. Íàïðèìåð: ¾Ó ïàöèåíòà äåôåêò çðåíèÿ¿, ò.å.
w.
Ãëàâíàÿ íàøà çàäà÷à: íàó÷èòüñÿ ïåðåñ÷èòûâàòü
âåðîÿòíîñòè ïðè ïîñòóïëåíèè ñâèäåòåëüñòâ.
Ñåðãåé Íèêîëåíêî Áàéåñîâñêèå ñåòè äîâåðèÿ
24. Èäåÿ áàéåñîâñêèõ ñåòåé Ìîòèâàöèÿ
Ïðîïàãàöèÿ â ñåòÿõ áåç öèêëîâ d -ðàçäåëèìîñòü
Âûâîä â áàéåñîâñêîé ñåòè ñ öèêëàìè Òåîðåìà î äåêîìïîçèöèè è ñâèäåòåëüñòâà
Ïåðåñ÷¼ò âåðîÿòíîñòåé â îäíîì óçëå
Ïóñòü ïîñòóïèëî ñâèäåòåëüñòâî ¾Äåôåêò çðåíèÿ¿. Äàâàéòå
ðàññ÷èòàåì àïîñòåðèîðíóþ âåðîÿòíîñòü p(u|w ).
Ñíà÷àëà íóæíî ïðèðàâíÿòü íóëþ íåñîâìåñòèìûå ñî
ñâèäåòåëüñòâîì ñëó÷àè â òàáëèöå ñîâìåñòíûõ âåðîÿòíîñòåé:
p(uvw ∧ w ) = 0.000199025, p(uv w ∧ w ) = 0,
p(uv w ∧ w ) = 0.012722625, p(uv w ∧ w ) = 0,
p(uvw ∧ w ) = 0.00160245, p(uv w ∧ w ) = 0,
p(uv w ∧ w ) = 0.01894239, p(uv w ∧ w ) = 0.
Ñåðãåé Íèêîëåíêî Áàéåñîâñêèå ñåòè äîâåðèÿ
25. Èäåÿ áàéåñîâñêèõ ñåòåé Ìîòèâàöèÿ
Ïðîïàãàöèÿ â ñåòÿõ áåç öèêëîâ d -ðàçäåëèìîñòü
Âûâîä â áàéåñîâñêîé ñåòè ñ öèêëàìè Òåîðåìà î äåêîìïîçèöèè è ñâèäåòåëüñòâà
Ïåðåñ÷¼ò âåðîÿòíîñòåé â îäíîì óçëå
È íîðìèðîâàòü òî, ÷òî ïîëó÷èëîñü:
p(u|w ) = v~w pp((uwv)w ∧w ) = 0.386107 . . . ,
~ ~~
p(u|w ) = v~w pp((uwv)w ∧w ) = 0.61389288 . . . .
~ ~ ~
Ñåðãåé Íèêîëåíêî Áàéåñîâñêèå ñåòè äîâåðèÿ
26. Èäåÿ áàéåñîâñêèõ ñåòåé Ìîòèâàöèÿ
Ïðîïàãàöèÿ â ñåòÿõ áåç öèêëîâ d -ðàçäåëèìîñòü
Âûâîä â áàéåñîâñêîé ñåòè ñ öèêëàìè Òåîðåìà î äåêîìïîçèöèè è ñâèäåòåëüñòâà
Ïåðåñ÷¼ò âåðîÿòíîñòåé â îäíîì óçëå
Âîïðîñ: êàêèì ïðåäïîëîæåíèåì ìû íåÿâíî ïîëüçîâàëèñü? ×òî
äåëàòü, åñëè îíî íå âûïîëíåíî?
Ñåðãåé Íèêîëåíêî Áàéåñîâñêèå ñåòè äîâåðèÿ
27. Èäåÿ áàéåñîâñêèõ ñåòåé Èäåÿ
Ïðîïàãàöèÿ â ñåòÿõ áåç öèêëîâ Âûâîä àëãîðèòìà
Âûâîä â áàéåñîâñêîé ñåòè ñ öèêëàìè Àëãîðèòì
Outline
1 Èäåÿ áàéåñîâñêèõ ñåòåé
Ìîòèâàöèÿ
d-ðàçäåëèìîñòü
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