Investigating programming language support for fault-tolerance

Dataflow systems have become the norm for developing data-intensive computing applications. These systems provide transparent scalability and fault tolerance. For fault tolerance, many dataflow-system adopt a snapshotting approach which persists the state of an operator once it has received a snapshot marker on all its input channels. This approach requires channels to be blocked for potentially prolonged durations until all other input channels have received their markers to guarantee that no events from the future make it into the operator’s present state snapshot. Alignment can for this reason have a severe performance impact. In particular, for black-box user-defined operators, the system has no knowledge about how events from different channels affect the operator’s state. Thus, the system must conservatively assume that all events affect the same state and align all channels. In this thesis, we argue that alignment between two channels is unnecessary if messages from those channels are not written to the same output channel. We propose a snapshotting approach for the fault tolerance and call it partial approach. The partial approach does not require alignment when an operator’s input channels are independent. Two input channels are independent if their events do not affect the same state and are never written to the same output channel. We propose the use of static code analysis to identify such dependencies. To enable this analysis, we translate operators into finite state machines that make the operator’s state explicit. As a proof of concept, we extend the implementation of Arc-Lang, an existing dataflow language, so that applications written in it transparently execute with fault tolerance. We evaluate our approach by comparing it to a baseline eager approach that always requires alignment between the input channels. The conducted experiments’ results show that the partial approach performs about 47 % better than the eager approach when the streaming sources are producing data at different velocities.Dataflödessystem har blivit normen för utveckling av dataintensiva datorapplikationer. Dessa system erbjuder transparent skalbarhet och felhantering. För felhantering adopterar många dataflödessystem en snapshot-approach som sparar en operatörs tillstånd när den har fått en snapshot-markör på alla sina ingångskanaler. Denna metod kräver att kanalerna blockeras under möjligen förlängda tidsperioder tills alla andra ingångskanaler har fått sina markörer, vilket görs för att garantera att inga händelser från framtiden når operatörens nuvarande tillstånd. Synkronisering mellan kanaler kan därför ha en allvarlig prestandapåverkan. Särskilt för black-box användardefinierade operatörer där systemet inte har kunskap om hur händelser från olika kanaler påverkar operatörens tillstånd. Systemet måste därför konservativt anta att alla händelser påverkar samma tillstånd och synkronisera alla kanaler. I denna avhandling argumenterar vi för att synkroniseringen mellan två kanaler inte är nödvändig om meddelanden från de kanalerna inte skrivs till samma utgångskanal. Vi föreslår en snapshot-approach för felhantering och kallar den för partial-approach. Partial-approach kräver inte justering när en operatörs ingångskanaler är oberoende. Två ingångskanaler är oberoende om deras händelser inte påverkar samma tillstånd och aldrig skrivs till samma utgångskanal. Vi föreslår användning av statisk kodanalys för att identifiera sådana beroenden. För att möjliggöra denna analys översätter vi operatörer till finite state machines som gör operatörens tillstånd explicit. För att bevisa konceptet utökar vi implementeringen av Arc-Lang, vilket är en existerande dataflödesspråk, så att program skrivna i den transparent körs med felhantering. Vi utvärderar vår approach genom att jämföra den med en baseline eager-approach som alltid kräver justering mellan ingångskanalerna. Resultaten från de genomförda experimenten visar att partial-approach presterar cirka 47 % bättre än eager-approach när sourcestreams producerar data i otakt

Bursa Uludag University Hospital Newborn Hearing Screening Results

YÖK Tez No: 10479518Bu çalışmanın özeti; Yenidoğan işitme tarama programı (YİTP), yenidoğan bebeklerde işitme kayıplarının erken tanı ve müdahalesini amaçlamaktadır, bu nedenle ülkemizin önde gelen üniversitelerinde başlatılan ve Sağlık Bakanlığı protokolü ile geliştirilen tarama programı ile bu amaçlara ulaşılmaya çalışılmıştır.İşitme bozukluklarının en önemli ve en sık nedeni olan konjenital kaynaklı işitme kayıplarının erken tanılanmasında büyük öneme sahip olduğu görülen Yenidoğan İşitme Tarama Programları sonucunda ayrıca işitme kaybı tanısı almış bu çocukların erken müdahaleler ile dil gelişimleri, akademik becerileri üzerinde de olumlu etkileri olduğu görülmüştür.Bu araştırma, Bursa Uludağ Üniversitesi Hastanesi Yenidoğan İşitme Tarama birimine ve sonrasında referans bölümüne Ocak 2019 ile Aralık 2020 tarihleri arasında başvuran 1152 bebeğin işitme tarama testi sonuçları ve referans merkezi sonuçlarının geriye dönük arşiv dosyalarının taranarak değerlendirilmesiyle yapılmış tanımlayıcı çalışmadır.Çalışmanın sonucunda, değerlendirmenin yapıldığı tarihler arasındaki yenidoğan işitme tarama ve referans merkezi tanılanma zamanları, Ulusal Yenidoğan İşitme Tarama Programında belirlenen tanılanma zamanlarıyla uyumlu olarak bulunmuştur. İşitme kaybı sıklığı, çalışma kapsamında ki dönemler için, ülkemizde ve dünyada yenidoğanlarda işitme kaybı görülme sıklığı ile benzer nitelikte bulunmuştur

Two figurations of the noble lie in dystopian literature: we and kallocain

The goal of this thesis is to scrutinize whether Plato’s noble lie, which one can find in the III Book of the Republic, is a recurring narrative framework in later utopian/dystopian works of literature. While criticizing the ideology that Greek mythological sources, most notably Hesiod and Homer, actualized, Plato adopted a similar method/theory to keep the state stable through concept noble lie that at the same time functions as a means of social control. I come to suggest that Plato develops an artificial/fictional ideological truth regarding the genealogy of the state by combining old mythic structures. Through a selective survey, I specify that there may exist a general outline regarding how the main political narrative is modeled in utopian works and I question the possibility of analogous ideological patterns among the books. Although one can rightly assert that many dystopian works utilize a founding/creation myth/narrative, I opted for Yevgeny Zamyatin’s We and Karin Boye’s Kallocain for the following reasons. Initially, when compared with books such as Brave New World, 1984, and Fahrenheit 451, one finds fewer studies that are limited in scope on both works, which are especially examined from a different ‘angle’. Secondly, both books not only meet the criteria for a successful dystopia but also better correspond to the primary narrative that Plato presented through the noble lie. For instance, while We appropriates the same class of guardians as one can come across in the Republic, possessing identical roles in the division of labour, the psychologist in Kallocain follows the steps of Platonic Socrates who delivers the method he is going to use for generating a falsehood, in stages

Investigating programming language support for fault-tolerance

Dataflow systems have become the norm for developing data-intensive computing applications. These systems provide transparent scalability and fault tolerance. For fault tolerance, many dataflow-system adopt a snapshotting approach which persists the state of an operator once it has received a snapshot marker on all its input channels. This approach requires channels to be blocked for potentially prolonged durations until all other input channels have received their markers to guarantee that no events from the future make it into the operator’s present state snapshot. Alignment can for this reason have a severe performance impact. In particular, for black-box user-defined operators, the system has no knowledge about how events from different channels affect the operator’s state. Thus, the system must conservatively assume that all events affect the same state and align all channels. In this thesis, we argue that alignment between two channels is unnecessary if messages from those channels are not written to the same output channel. We propose a snapshotting approach for the fault tolerance and call it partial approach. The partial approach does not require alignment when an operator’s input channels are independent. Two input channels are independent if their events do not affect the same state and are never written to the same output channel. We propose the use of static code analysis to identify such dependencies. To enable this analysis, we translate operators into finite state machines that make the operator’s state explicit. As a proof of concept, we extend the implementation of Arc-Lang, an existing dataflow language, so that applications written in it transparently execute with fault tolerance. We evaluate our approach by comparing it to a baseline eager approach that always requires alignment between the input channels. The conducted experiments’ results show that the partial approach performs about 47 % better than the eager approach when the streaming sources are producing data at different velocities.Dataflödessystem har blivit normen för utveckling av dataintensiva datorapplikationer. Dessa system erbjuder transparent skalbarhet och felhantering. För felhantering adopterar många dataflödessystem en snapshot-approach som sparar en operatörs tillstånd när den har fått en snapshot-markör på alla sina ingångskanaler. Denna metod kräver att kanalerna blockeras under möjligen förlängda tidsperioder tills alla andra ingångskanaler har fått sina markörer, vilket görs för att garantera att inga händelser från framtiden når operatörens nuvarande tillstånd. Synkronisering mellan kanaler kan därför ha en allvarlig prestandapåverkan. Särskilt för black-box användardefinierade operatörer där systemet inte har kunskap om hur händelser från olika kanaler påverkar operatörens tillstånd. Systemet måste därför konservativt anta att alla händelser påverkar samma tillstånd och synkronisera alla kanaler. I denna avhandling argumenterar vi för att synkroniseringen mellan två kanaler inte är nödvändig om meddelanden från de kanalerna inte skrivs till samma utgångskanal. Vi föreslår en snapshot-approach för felhantering och kallar den för partial-approach. Partial-approach kräver inte justering när en operatörs ingångskanaler är oberoende. Två ingångskanaler är oberoende om deras händelser inte påverkar samma tillstånd och aldrig skrivs till samma utgångskanal. Vi föreslår användning av statisk kodanalys för att identifiera sådana beroenden. För att möjliggöra denna analys översätter vi operatörer till finite state machines som gör operatörens tillstånd explicit. För att bevisa konceptet utökar vi implementeringen av Arc-Lang, vilket är en existerande dataflödesspråk, så att program skrivna i den transparent körs med felhantering. Vi utvärderar vår approach genom att jämföra den med en baseline eager-approach som alltid kräver justering mellan ingångskanalerna. Resultaten från de genomförda experimenten visar att partial-approach presterar cirka 47 % bättre än eager-approach när sourcestreams producerar data i otakt

How Okun’s law was affected by the global financial crisis in three different countries : - An empirical analysis of the USA, Italy and Sweden in the timespan of 1985-2019

The global financial crisis that started in the USA affected several countries around the world. This study focuses on only three countries; the USA, Sweden, and Italy, which are examples of economies with three different labor market models. The purpose of this study is to investigate if and in that case how Okun's law was affected by the global financial crisis in the three countries’ labor market models and if there are any differences in the correlations before and after the global financial crisis. Okun’s difference version was used in this study. Quarterly time series data was used in this study during the time period 1985-2019. The Chow test was used to test the hypothesis. The results show that the global financial crisis affected Okun’s law after the crisis in all three countries. The USA, Sweden, and Italy were affected differentl

Postmodernizm açısından pazarlama iletişimi

Büyük anlatılara olan güvensizliğin artması, doğrusal gelişime olan inancın sarsılması, üstgerçekliğin oluşumuyla zaman ve mekan sınırının silikleşmesi ve imgelemin ön plana çıkmasıyla temel olarak tanımlanabilen postmodern koşullar, günümüz tüketicisinin zihnini biçimlendirerek tüketim anlayışları ve alışkanlıklarını değiştirmektedir. Söz konusu değişimlere, küreselleşmenin etkisiyle oluşan tek dünya pazarının yarattığı keskin rekabetin eklemlenmesi, kısa bir zaman öncesine kadar geçerliliğini koruyan pazarlama anlayışlarının etkisinin zayıflamasına ve avantajlarını yitirmesine sebep olmuştur. Modern pazarlama yaklaşımı içerisinde filizlenmiş olmasına rağmen, uygulama yapısını, postmodern koşulların zorunlu kıldığı zeminde biçimlendiren bütünleşik pazarlama iletişimi, tüm pazarlama iletişimi enstrümanlarının pazarlama karmasıyla koordinasyon içerisinde kullanılmasını, kitlesel olarak üretilen her türlü ürün veya hizmetin mümkün olan her şekilde bireyselleştirilmesini, bu süreçte teknolojinin içselleştirilmesini ve bu yolla müşterilere odaklanılmasını ve hedef kitle ile sürdürülebilir interaktif bir iletişim süreci kurulmasını içermektedir. Pazarlama iletişiminin temel yapısında meydana gelen söz konusu değişimler, işletmelere, postmodern koşullar içerisinde biçimlenen tüketici zihinlerine nüfuz edebilme, hedef kitle ile kurulan iletişimi sürdürülebilir kılmak, kısacası mevcut pazar yapısında kaybedilen rekabet avantajını yeniden kazanmak adına işletmelere ışık tutmaktadır

How Okun’s law was affected by the global financial crisis in three different countries : - An empirical analysis of the USA, Italy and Sweden in the timespan of 1985-2019

The global financial crisis that started in the USA affected several countries around the world. This study focuses on only three countries; the USA, Sweden, and Italy, which are examples of economies with three different labor market models. The purpose of this study is to investigate if and in that case how Okun's law was affected by the global financial crisis in the three countries’ labor market models and if there are any differences in the correlations before and after the global financial crisis. Okun’s difference version was used in this study. Quarterly time series data was used in this study during the time period 1985-2019. The Chow test was used to test the hypothesis. The results show that the global financial crisis affected Okun’s law after the crisis in all three countries. The USA, Sweden, and Italy were affected differentl

Förutsättningar för styrning, kontroll och uppföljning inom offentlig upphandling

En offentlig organisation befinner sig in en miljö som präglas av i huvudsak tre olika logiker, samhällsvärde, effektivitet och laglighet. Den offentliga organisationen är tvingad till att beakta upphandlingslagstiftningen i alla sina anskaffningar. Denna lagstiftning kritiseras ofta, både avforskare och praktiker, för att vara ett hinder mot att kunna styra verksamheten på ett ekonomiskt effektivt sätt. Denna studie har genom kvalitativa intervjuer undersökt hur förutsättningarna ser ut för att styra, kontrollera och följa upp inköpen i organisationer som omfattas av lagen om offentlig upphandling. Syftet har varit att kunna bidra med insikter om hur ekonomistyrning kan tillämpas praktiskt trots normativa motsättningar mellan de olika logikerna som präglar organisationen. Den teoretiska utgångspunkten har varit klassiska teorier för interna organisatoriska förutsättningar i kombination med de konkreta aktiviteter som bygger upp tillämpad ekonomistyrning och därtill relaterade verktyg. Studiens slutsatser och bidrag innefattar att i den praktiska tillämpningen ses inte lagen om offentlig upphandling somett hinder mot ekonomistyrningsaktiviteter utan de avgörande problemen ur ett ekonomistyrningsperspektiv är bristande möjligheter att styra, kontrollera och följa upp organisationens inköpsaktiviteter på grund av undermåliga tekniska system eller dålig kommunikation mellan system. Praktiskt bidrar studien med insikten om att den undersökta organisationen kan bli mer ekonomiskt effektiv genom att involvera inköpsfunktionen tidigare i inköpsprocessen och genom att investera i bättre systemstöd för kontroll och uppföljning.The context of a public organisation is one that is affected mainly by three different logics, public value, efficiency and legalities. The public organisation has to comply with the law of public procurement in all its procuring activities. The aforementioned law is often criticised, by both researchers and practitioners, for being a hindrance to efficient governance. Through qualitative interviews, this study has investigated how the conditions affecting management control activities regarding governance, control and follow-up of procurement in organisations abiding by the law of public procurement. The purpose of the study was to contribute with insights regarding how management control activities can be applied in practice despite the normative conflicts between the underlying logics that characterise the context of the organisation. The theoretical starting point is classical theories for internal organisational conditions in combination with practical activities that constructs applied management control and associated activities. The study concludes that, in practical application the law of public procurement itself is not seen as a hindrance to management control activities, instead the crucial problems from a management control perspective is the lacking possibilities to govern, control and follow-up procurement activities caused by poor technical systems or lacking communication between existing systems. The practical contributions of the study includes theinsight that the studied organisation could increase its economic efficiency by involving the procurement function earlier in the procurement process and by investing in better systems for control and follow-up

Förutsättningar för styrning, kontroll och uppföljning inom offentlig upphandling

En offentlig organisation befinner sig in en miljö som präglas av i huvudsak tre olika logiker, samhällsvärde, effektivitet och laglighet. Den offentliga organisationen är tvingad till att beakta upphandlingslagstiftningen i alla sina anskaffningar. Denna lagstiftning kritiseras ofta, både avforskare och praktiker, för att vara ett hinder mot att kunna styra verksamheten på ett ekonomiskt effektivt sätt. Denna studie har genom kvalitativa intervjuer undersökt hur förutsättningarna ser ut för att styra, kontrollera och följa upp inköpen i organisationer som omfattas av lagen om offentlig upphandling. Syftet har varit att kunna bidra med insikter om hur ekonomistyrning kan tillämpas praktiskt trots normativa motsättningar mellan de olika logikerna som präglar organisationen. Den teoretiska utgångspunkten har varit klassiska teorier för interna organisatoriska förutsättningar i kombination med de konkreta aktiviteter som bygger upp tillämpad ekonomistyrning och därtill relaterade verktyg. Studiens slutsatser och bidrag innefattar att i den praktiska tillämpningen ses inte lagen om offentlig upphandling somett hinder mot ekonomistyrningsaktiviteter utan de avgörande problemen ur ett ekonomistyrningsperspektiv är bristande möjligheter att styra, kontrollera och följa upp organisationens inköpsaktiviteter på grund av undermåliga tekniska system eller dålig kommunikation mellan system. Praktiskt bidrar studien med insikten om att den undersökta organisationen kan bli mer ekonomiskt effektiv genom att involvera inköpsfunktionen tidigare i inköpsprocessen och genom att investera i bättre systemstöd för kontroll och uppföljning.The context of a public organisation is one that is affected mainly by three different logics, public value, efficiency and legalities. The public organisation has to comply with the law of public procurement in all its procuring activities. The aforementioned law is often criticised, by both researchers and practitioners, for being a hindrance to efficient governance. Through qualitative interviews, this study has investigated how the conditions affecting management control activities regarding governance, control and follow-up of procurement in organisations abiding by the law of public procurement. The purpose of the study was to contribute with insights regarding how management control activities can be applied in practice despite the normative conflicts between the underlying logics that characterise the context of the organisation. The theoretical starting point is classical theories for internal organisational conditions in combination with practical activities that constructs applied management control and associated activities. The study concludes that, in practical application the law of public procurement itself is not seen as a hindrance to management control activities, instead the crucial problems from a management control perspective is the lacking possibilities to govern, control and follow-up procurement activities caused by poor technical systems or lacking communication between existing systems. The practical contributions of the study includes theinsight that the studied organisation could increase its economic efficiency by involving the procurement function earlier in the procurement process and by investing in better systems for control and follow-up