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Medicininės įrangos gaminimo įmonių sujungimas ir kokybės sistemų evoliucija / Merger of Medical Device Manufacturers and Evolution of Quality Management SystemsPūras, Gediminas 19 June 2008 (has links)
ĮVADAS: Įmonių sujungimai ir įsigijimai yra brangus ir sudėtingas verslo pasaulio reiškinys, pastaruoju metu vis dažniau pasireiškiantis ir valstybiniame sektoriuje. Daug mokslinių tyrinėjimų atlikta šioje srityje nustatant esminius sėkmės faktorius, lemiančius efektyvią įmonės veiklą po integracijos. Kokybės vadyba integruojantis įmonėms deja nėra dominuojanti tema moksliniuose darbuose.
DARBO TIKSLAS IR UŽDAVINIAI: Šio darbo tikslas yra įvertinti kokybės valdymą integruojantis įmonėms darbuotojų ir vadovybės požiūriu. METODIKA: Tyrimo metodika rėmėsi literatūros apžvalgoje identifikuotais svarbiais strateginio valdymo, visuotinės kokybės vadybos ir verslo tobulumo principais kurie padėjo sudaryti šios srities teorines rekomendacijas bei klausimynus. Kiekybinis ir kokybinis tyrimai buvo suplanuoti ir atlikti tiriant Šveicarijos ir Danijos medicininės įrangos gamybos įmonių susijungimą ir praėjus 33 mėnesiams po oficialios datos. Tyrimo duomenys atskleidė darbuotojų (34 respondentai) ir vadovybės (3 respondentai) požiūrį į integracijos eigą, pointegracinę įmonės veiklą ir kokybės vadybą. Kiekybiniai duomenys buvo išanalizuoti naudojant Chi-kvadrat testą (požymių nepriklausomumo kriterijų) ir z-testą (tikimybių lygybių kriterijų).
REZULTATAI IR IŠVADOS: Tyrimas parodė, kad pagrindinė sujungimo motyvacija buvo strateginio pobūdžio – produktų portfelio plėtra. Tai labai sustiprino Šveicarijos padalinį, kuriam buvo sudarytos geresnės sąlygos siekti komercinių tikslų. Tačiau... [toliau žr. visą tekstą] / INTRODUCTION: Mergers and acquisitions are common and complex phenomenon in the world of business also moving to the public sector lately. Vast amounts of research have been made to look for the critical success factors for successful post-integration performance. Quality Management in M&As has not been dominating on the agenda though. Due to relevance to today’s business success and lacking presence on research agendas the topic was chosen to be explored more deeply.
AIM OF STUDY AND OBJECTIVES: The purpose of this master thesis is to evaluate the merger process and Quality Management role seen from a perspective of both employees and management. METHODS: Strategic Management, Total Quality Management and Business Excellence principles served as a framework in designing qualitative and quantitative surveys. The surveys were executed in Danish and Swiss medical device company’s affiliates merged 33 months before the research. The data demonstrates perception of employees (34 respondents) and managers (3 respondents) with regards to the merger’s course, impact on the new company’s performance and the Quality Management in the merger process. Quantitative data was analyzed using Chi-square test for association and two proportion z-test for independence of probabilities.
RESULTS AND CONCLUSIONS: The surveys revealed a strategic merger with product portfolio expansion as a main motive which substantially strengthened Swiss subsidiary with new capabilities and more business... [to full text]
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RFID technologijų panaudojimas gamybos kokybės valdyme / Applying RFID technology for manufacture quality managementKumža, Mantas 16 August 2007 (has links)
Gamybos pramonės sektorius apima viena iš didžiausių ir pelningiausią rinkos
sektorių pasaulyje. Norėdamos išlikti ir sėkmingai dirbti besikeičiančios konkurencinės rinkos
sąlygomis, įmonės neišvengiamai susiduria su konkurencinio pranašumo didinimo poreikiu.
Tuo tikslu yra kuriamos veiklos vystymo strategijos, taikoma naujų technologijų diegimas,
verslo valdymo procesų tobulinimas, produktų kokybės didinimas, valdymas, kokybės
reikalavimų ir standartų taikymas. Vienas iš gamybos kokybės proceso optimizavimo
sprendimas gali būti RFID technologijos pritaikymas gamybos veiklose. RFID yra viena
naujausių ir besivystančių technologijų, kuri pasaulyje yra pritaikoma ir naudojama įvairiose
srityse.
Įgyvendintas projektas ir jo pasakoje sukurta RFID sistemos modulis, bei priemonės
gali būti naudojamos, ne tik su užsakovo UAB „RTech“ plėtojama „QMS“ (Quality
Management Systems) programinę įrangą, bet ir kaip sąsaja tarp RFID įrangos ir vartotojo
veiklos taikomosios programos. Panaudojus RFID technologas ir sąsajas su RFID
technologijomis galima:
• dalinai automatizuoti gamybos kokybės valdymo procesą,
• padidinti efektyvumą gaminio atsekamume,
• sumažinti broko kontrolę tiekiant gaminius užsakovui.
Šio darbo vienas iš tikslų yra įvertinti sukurta sistemą ir ką būtu galima patobulinti,
kad būtų galima padaryti lankstesne pritaikant darbui su kitomis programinės įrangos
sistemomis. Darbo metu yra tiriami ir analizuojami ISO standartų RFID sistemų modeliai, bei
jų pritaikymo galimybės... [toliau žr. visą tekstą] / Manufactory industry is the most profitable sector of world’s market. Companies confronts with competitive market advantages to keep working successfully in continually changing market conditions. Therefore activities development strategies are created, new technologies are used in installation process, perfection of business control process, increasing quality of products, use of standards and quality requirements. The solution of these problems can be use of RFID (Radio Frequency Identification) technologies in manufacture management process. RFID is an automatic identification technology that relies on cheap tags (transponders) that can be attached to objects and storage information on it. The results of this project are RFID systems components witch can be used with other users applications such as „QMS“ (Quality Management Systems) of “RTech” company or other users applications. The successful integration of RFID technologies in manufacture quality management process can give effect in: • Automate and computerize manufacture quality management process; • Increase efficiency of product traceability system process; • Reduce rejects on product supply for consumer’s process. One of the master’s work goals is to evaluate the system, which was created in this work. The system can be improved by ISO standard models and made more flexible to use it for other works.
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DBVS praplėtimo nauju funkcionalumu galimybių tyrimas / The Research of Possibilities of Extending DBMS by New FunctionalityTolvaišis, Andrius 26 August 2010 (has links)
Duomenų bazių valdymo sistema (DBVS) yra pagrindas beveik visų šiuolaikinių informacinių sistemų (IS). Iš esmės kiekvienas verslo, mokslo arba valdžios valdymo procesas remiasi duomenų baze. Interneto plėtra tik paspartino šią tendenciją – šiandien duomenų bazių operacijos yra kiekvieno duomenų pakeitimo didesniuose tinklalapiuose, paieškos arba apsipirkimo internete variklis [1].
Šiuo metu rinkoje yra didelis komercinių ir nemokamų (taip pat ir atviro kodo) duomenų bazių valdymo sistemų (DBVS) pasirinkimas, pavyzdžiui: Oracle, Microsoft SQL Server, IBM DB2, Microsoft Access, MySQL, PostgreSQL. Kiekviena jų turi savo privalumų ir trukumų. Tačiau informacinių sistemų projektavimo eiga, naudojant šias DBVS ir neatsižvelgiant į jų ypatumus, yra panaši: suprojektuojama duomenų bazė (sukuriamos lentelės, nustatomi jų tarpusavio ryšiai), rašomos užklausos, kuriamos (arba generuojamos) duomenų įvedimo/redagavimo formos bei kuriamos duomenų išrinkimo ataskaitos. Ši informacinių sistemų kūrimo tvarka yra nusistovėjusi per daugelį metų. Tačiau DB projektavimo procesas taptų lengvesnis, pakeitus IS projektavimo procesą taip, kad realizacijos metu iš pradžių būtų kuriamos formos, o tik po to iš sukurtų formų būtų generuojama duomenų bazė. Toks IS kūrimo procesas leistų iš dalies automatizuotų DB projektavimą. Be to, galutinai suderinus prototipus su užsakovu, užtektų tik sugeneruoti DB, t.y. nereikėtų iš naujo kurti formų, o sistema sugeneruotų DB bei automatiškai susietų formų laukus... [toliau žr. visą tekstą] / The Data Base Management System (DBMS) is the foundation of almost every modern business information system. Virtually every administrative process in business, science or government relies on a database. There are a lot of DBMS products in our days, such as Oracle, Microsoft SQL Server, IBM DB2, Microsoft Access, MySQL and PostgreSQL. Each of it has their advantages and disadvantages. But the database design process using these DBMS is the same – at the first stage we need to create a database (tables and relationships between them), then we need to create (or generate by using wizard) forms for data input/modification and reports for data selection. However, the database design process would become easier by changing database design process in such a way that at first we create forms and then database is generated from forms data and forms are automatically associated with database tables. The task of research is to extend chosen free open source DBMS by new functions which would enable to develop forms and DB using new methods – automated database generation from forms and automatic forms association with database tables. OpenOffice.org Base DBMS and Java programming language has been chosen for the task implementation. This thesis consists of analysis, design, user manual, experimental and conclusion parts.
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The potential of a learning management system to enhance self-directed learning / Chantelle TredouxTredoux, Chantelle January 2012 (has links)
The use of Learning Management Systems (LMSs) in higher education institutions is not a new tendency. Although this is an innovative way of implementing e-learning in the educational process, there are a few problems concerning these systems. Educators tend to apply traditional classroom ideas and pedagogy in computer-supported e-learning environments, assuming that because these environments allow the interaction that we see in the classroom, traditional pedagogy can be used. Although most of the pedagogical principles that apply to the traditional classroom-delivery method also apply to e-learning, the e-environment supports such interactions in a different manner. Traditional pedagogical principles should be adapted to accommodate the e-learning environment and should form the very basis for inclusion of features in LMSs. These principles should be integrated into the LMS where every feature included is accompanied by explicit guidelines on how to use the feature in such a way that it will effect pedagogically sound instruction.
The aim of this study is to determine how an LMS could be used in order to enhance self-directed learning. In order to reach this aim a brief history of SDL was given and a number of SDL models were discussed. These models were analyzed in order to compile a list of guidelines to foster SDL. The first set of guidelines didn’t focus on any specific learning environment and it was necessary to refine these guidelines for an online environment. To be able to refine the guidelines for an online environment, LMSs in general were discussed and a few models for SDL in an online environment were reviewed. The SDL guidelines were further refined for implementation in eFundiTM. eFundiTM is the LMS used at the North-West University, Potchefstroom campus, South Africa. The nature of the AGLE 121 module (a literacy module for all first year students) and the specific functionalities of eFundiTM were discussed and taken in consideration when the final set of guidelines was compiled.
The researcher did an empirical study to gather valid and reliable data. A mixed methods inquiry approach was used to obtain reliable evidence. The population consisted of all the students that were enrolled for the AGLE modules over 2 years. These students were divided into 2 groups, the AGLE 121 in 2010 (237 students) and the AGLE 121 (287 students) in 2011. The questionnaire that was used for the quantitative research in this study was based on the Fisher, King and Taque (2001) SDL readiness scale for nursing education. Semi-structured interviews were conducted with seven participants from each group in order get a better understanding of the data collected from the quantitative research, and to elaborate further on the students’ development of SDL. Findings indicated that the students from the second year of the study did not necessarily improve their SDL-skills. Most of the results from the quantitative data showed small practical significant differences. However, the qualitative data indicated that the SDL skills of the students improved in two of the three factors after they used the newly developed eFundiTM site, in the second year of the study and therefore the researcher is of opinion that the intervention had a positive impact on the students’ SDL skills. / Thesis (MEd (Computer Science Education))--North-West University, Potchefstroom Campus, 2012
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The potential of a learning management system to enhance self-directed learning / Chantelle TredouxTredoux, Chantelle January 2012 (has links)
The use of Learning Management Systems (LMSs) in higher education institutions is not a new tendency. Although this is an innovative way of implementing e-learning in the educational process, there are a few problems concerning these systems. Educators tend to apply traditional classroom ideas and pedagogy in computer-supported e-learning environments, assuming that because these environments allow the interaction that we see in the classroom, traditional pedagogy can be used. Although most of the pedagogical principles that apply to the traditional classroom-delivery method also apply to e-learning, the e-environment supports such interactions in a different manner. Traditional pedagogical principles should be adapted to accommodate the e-learning environment and should form the very basis for inclusion of features in LMSs. These principles should be integrated into the LMS where every feature included is accompanied by explicit guidelines on how to use the feature in such a way that it will effect pedagogically sound instruction.
The aim of this study is to determine how an LMS could be used in order to enhance self-directed learning. In order to reach this aim a brief history of SDL was given and a number of SDL models were discussed. These models were analyzed in order to compile a list of guidelines to foster SDL. The first set of guidelines didn’t focus on any specific learning environment and it was necessary to refine these guidelines for an online environment. To be able to refine the guidelines for an online environment, LMSs in general were discussed and a few models for SDL in an online environment were reviewed. The SDL guidelines were further refined for implementation in eFundiTM. eFundiTM is the LMS used at the North-West University, Potchefstroom campus, South Africa. The nature of the AGLE 121 module (a literacy module for all first year students) and the specific functionalities of eFundiTM were discussed and taken in consideration when the final set of guidelines was compiled.
The researcher did an empirical study to gather valid and reliable data. A mixed methods inquiry approach was used to obtain reliable evidence. The population consisted of all the students that were enrolled for the AGLE modules over 2 years. These students were divided into 2 groups, the AGLE 121 in 2010 (237 students) and the AGLE 121 (287 students) in 2011. The questionnaire that was used for the quantitative research in this study was based on the Fisher, King and Taque (2001) SDL readiness scale for nursing education. Semi-structured interviews were conducted with seven participants from each group in order get a better understanding of the data collected from the quantitative research, and to elaborate further on the students’ development of SDL. Findings indicated that the students from the second year of the study did not necessarily improve their SDL-skills. Most of the results from the quantitative data showed small practical significant differences. However, the qualitative data indicated that the SDL skills of the students improved in two of the three factors after they used the newly developed eFundiTM site, in the second year of the study and therefore the researcher is of opinion that the intervention had a positive impact on the students’ SDL skills. / Thesis (MEd (Computer Science Education))--North-West University, Potchefstroom Campus, 2012
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Kokybės vadybos sistemos įgyvendinimas sveikatos priežiūros įstaigose personalo požiūriu / Personnel opinion on implementation of quality management system at health care institutionsAugulevičienė, Diana 18 June 2014 (has links)
Darbo tikslas - ištirti privačios ir VŠĮ (viešoji įstaiga) pirminės sveikatos priežiūros paslaugas teikiančios įstaigos personalo požiūrį į kokybės vadybos sistemos įgyvendinimą.
Uždaviniai: išsiaiškinti sveikatos priežiūros įstaigos darbuotojų dalyvavimą įgyvendinant kokybės vadybos principus; nustatyti nepageidaujamų įvykių valdymą ir registravimą sveikatos priežiūros įstaigoje personalo požiūriu; ištirti medicinos personalo požiūrį į pokyčius sveikatos priežiūros įstaigoje kokybės vadybos sistemos įdiegimo laikotarpiu.
Tyrimo metodika. 2014 m. vasario - balandžio mėn. atlikta anketinė apklausa. Apklausti 248 darbuotojai, dirbantys VŠĮ ir privačioje pirminės sveikatos priežiūros įstaigoje. Anketinių duomenų analizei naudota statistinė programa SPSS 17.0. Rezultatai. 95,8 proc. apklaustųjų žino, jog jų įstaigoje yra įdiegta kokybės vadybos sistema, o 59,1 proc. yra ja visiškai patenkinti. 87,9 proc. apklaustųjų vykdo dokumentuotas procedūras ir laikosi patvirtintos tvarkos, o 9,8 proc. tyrimo dalyvių kokybės vadybos sistemos tobulinime nedalyvauja. 45,5 proc. respondentų nori dalyvauti įstaigos kokybės valdyme. Didžioji dauguma nurodo, kad nepageidaujamų įvykių (NĮ) registravimas, priežasčių analizavimas padeda nustatyti problemas (94,9 proc.) ir mažina galimų neatitikčių skaičių (94,7 proc.). 87,2 proc. teigia, kad NĮ registracija gerina teikiamų paslaugų kokybę ir didina pacientų saugumą (88,2 proc.), tačiau nedaug įtakoja gerinant darbo aplinką darbuotojams (67,3 proc... [toliau žr. visą tekstą] / Aim of the study - to explore the attitude of private and PI (Public Institution) of Primary Health Care Institution‘s personnel towards the implementation of Quality management system.
Objectives: to determine the participation of Health Care Institution‘s personnel in the implementation of Quality management principles; to determine the management and registration of Adverse Events at Health Care Institution according to its personnel, to explore medical personnel‘s attitude towards the changes at Health Care Institution during the implementaiotn of Quality management system.
Methods. A questionnaire survey was conducted in February – April 2014. 248 public and private Primary Health Care Institution employees were interviewed. Questionnaire data analysis was performed using SPSS 17.0 statistical software. Results. 95.8 % of respondents know that a Quality management system has been implemented at their Institution, while 59.1 % are completely satisfied with it. 87.9 % of the respondents exercise documented procedures and follow the approved order and 9.8 % of study participants do not take part in the improvement of Quality management system. 45.5 % are willing to participate in the management of Institution‘s quality. The vast majority states that the recording of Adverse Events as well as reason analysis help to identify the problems (94.9 %) and reduce the number of potential discrepancies (94.7 %). 87.2 % affirm that Adverse Event registration improves service... [to full text]
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Adaptive fuzzy systems for traffic responsive and coordinated ramp meteringBogenberger, Klaus. January 1900 (has links)
Originally presented as the author's Thesis (doctoral)--Technische Universität München. / "FGV-TUM." Includes bibliographical references (p. 147-156).
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Enforcing Business Rules in E-Business Systems : A Survey of Business Rule EnginesOhlsson, Jesper January 2006 (has links)
<p>E-business provides important opportunities of trade for businesses, and the supporting business system must handle this environment efficiently. One current trend in business systems is to move business logic, such as business processes and business rules, out from the application logic and into separate support systems. The reason to make this separation is to increase the agility of the business, to make the system able to change more rapidly when the business situation changes.</p><p>This report focus on business rules enforced in business rule engines. Specific interest is on how such rule engines meet the requirements of the e-business domain. The report presents an overview of business rule engines. Five general categories of characteristics are proposed. The proposed characteristics are then used in a comparison of three business rule engines.</p>
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Συγκριτική μελέτη εφαρμογών που αξιοποιούν τεχνολογίες κινητών συσκευών & αξιολόγησή τους ως προς τις εκπαιδευτικές τους δυνατότητες (Κινητή ηλεκτρονική μάθηση - Mobile e-learning)Κόρδας, Παναγιώτης 13 May 2012 (has links)
Η εισαγωγή των νέων Τεχνολογιών της Πληροφορίας και των Επικοινωνιών (ΤΠΕ) στην εκπαίδευση αποτελεί πλέον γεγονός παγκοσμίως συμβάλλοντας ουσιαστικά στη βελτίωση των διαδικασιών διδασκαλίας , μάθησης και απόκτησης γνώσεων αλλά και δημιουργώντας περιβάλλοντα για την ανάπτυξη ιδιαίτερων δεξιοτήτων . Καθοριστικό ρόλο στην πραγματικότητα αυτή έχει διαδραματίσει η ραγδαία ανάπτυξη του διαδικτύου και οι επιμέρους εφαρμογές του .
Τα τελευταία χρόνια η πρόσβαση στον παγκόσμιο ιστό δεν περιορίζεται στους επιτραπέζιους υπολογιστές αλλά πλέον περιλαμβάνει τα κινητά τηλέφωνα , τα PDAs και γενικότερα κάθε είδους κινητή συσκευή . Μάλιστα στις αναπτυσσόμενες χώρες ο αριθμός των χρηστών που πλοηγούνται στον παγκόσμιο ιστό είναι μεγαλύτερος από τον αντίστοιχο αυτών που πλοηγούνται μέσω επιτραπέζιων υπολογιστών .
Τα παραπάνω γεγονότα έχουν ως φυσικό επακόλουθο την δημιουργία και συνεχή ανάπτυξη ενός νέου είδους εκπαίδευσης : την κινητή ηλεκτρονική μάθηση (mobile e-learning) , η οποία βασίζεται στην ιδέα της μάθησης μέσω κινητών συσκευών οπουδήποτε οποιαδήποτε στιγμή θα χαρακτηρίσει τις νέες στρατηγικές, τις πρακτικές , τα εργαλεία , τις εφαρμογές , και τους πόρους για να εκπληρώσει την υπόσχεση της πανταχού παρούσας, προσωπικής, και συνδεδεμένης εκμάθησης,
Στόχος της διπλωματικής εργασίας είναι να μελετήσει και να συγκρίνει τις διαθέσιμες εφαρμογές , εργαλεία , Συστήματα Διαχείρισης Μάθησης (ΣΔΜ) & Λειτουργικά Συστήματα κινητών συσκευών ώστε να αξιολογήσει τις εκπαιδευτικές δυνατότητες τους και να καθορίσει αν μπορούν να συμβάλλουν στην παροχή αποτελεσματικής κινητής ηλεκτρονικής μάθησης στους χρήστες τους . / The integration of the Information and Communication Technologies (ICT) in the field of education is nowadays a fact worldwide contributing in improving the teaching methods , learning and knowledge gaining as well as creating environments which facilitate the development of special skills . The vast development of the Web and its applications have played a key role establishing the current reality.
During the last years the access to the Web , not only from desktop PCs but from mobile devices too , such as mobile phones and PDAs , is a fact. Furthermore , in developing countries the number of users that browse the Web through mobile devices is larger than the number of users that browse the web from desktop PCs .
As a natural consequence of the above facts a new kind learning has emerged and constantly been developed ever since : Mobile e-learning , based on the idea of learning with mobile devices anywhere at any time , which will feature new strategies , practices , tools, applications and resources to fulfill the promise of ubiquitous , personal and connected learning .
The aim of this thesis is to study and compare the available applications, tools, Learning Management Systems and mobile Operating Systems in order to evaluate their educational potentials and to determine whether they are capable of contributing to providing effective mobile e-learning to their users .
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Análise e desenvolvimento de um novo algoritmo de junção espacial para SGBD geográficos / Analysis and design of a new algorithm to perform spatial join in geographic DBMSFornari, Miguel Rodrigues January 2006 (has links)
Um Sistema de Informação Geográfica armazena e mantém dados geográficos, combinando-os, para obter novas representações do espaço geográfico. A junção espacial combina duas relações de geometrias geo-referenciadas de acordo com algum predicado espacial, como intersecção e distância entre objetos. Trata-se de uma operação essencial, pois é constantemente utilizada e possui um alto custo de realização devido a realização de grande número de operações de Entrada/Saída e a complexidade do algoritmo. Este trabalho estuda o desempenho de algoritmos de junção espacial. Inicialmente, apresenta a análise dos algoritmos já publicados na literatura, obtendo expressões de custo para número de operações de disco e processamento. Após, descreve-se a implementação de alguns algoritmos em um ambiente de testes. Este ambiente permite ao usuário variar diversos parâmetros de entrada: cardinalidade dos conjuntos, memória disponível e predicado de junção, envolvendo dados reais e sintéticos. O ambiente de testes inclui os algoritmos de Laços Aninhados, Partition Based Spatial Join Method (PBSM), Synchronized Tree Transversal (STT) para árvores R* e Iterative Spatial Stripped Join (ISSJ). Os testes demonstraram que o STT é adequado para conjuntos pequenos de dados; o ISSJ se houver memória suficiente para ordenar os conjuntos internamente; e o PBSM se houver pouca memória disponível para buffer de dados. A partir da análise um novo algoritmo, chamado Histogram-based Hash Stripped Join (HHSJ) é apresentado. O HSSJ utiliza histogramas da distribuição dos objetos no espaço para definir o particionamento, armazena os objetos em arquivos organizados em hash e subdivide o espaço em faixas (strips) para reduzir o processamento. Os testes indicam que o HHSJ é mais rápido na maioria dos cenários, sendo ainda mais vantajoso quanto maior o número de objetos envolvidos na junção. Um módulo de otimização de consultas baseado em custos, capaz de escolher o melhor algoritmo para realizar a etapa de filtragem é descrito. O módulo utiliza informações estatísticas mantidas no dicionário de dados para estimar o tempo de resposta de cada algoritmo, e indicar o mais rápido para realizar uma operação específica. Este otimizador de consultas acertou a indicação em 88,9% dos casos, errando apenas na junção de conjuntos pequenos, quando o impacto é menor. / A Geographic Information System (GIS) stores geographic data, combining them to obtain new representations of the geographic space. The spatial join operation combines two sets of spatial features, A and B, based on a spatial predicate. It is a fundamental as well as one of the most expensive operations in GIS. Combining pairs of spatial, georreferenced data objects of two different, and probably large data sets implies the execution of a significant number of Input/Output (I/O) operations as well as a large number of CPU operations. This work presents a study about the performance of spatial join algorithms. Firstly, an analysis of the algorithms is realized. As a result, mathematical expressions are identified to predict the number of I/O operations and the algorithm complexity. After this, some of the algorithms (e.g.; Nested Loops, Partition Based Spatial Join Method (PBSM), Synchronized Tree Transversal (STT) to R-Trees and Iterative Spatial Stripped Join (ISSJ)) are implemented, allowing the execution of a series of tests in different spatial join scenarios. The tests were performed using both synthetic and real data sets. Based on the results, a new algorithm, called Histogram-based Hash Stripped Join (HHSJ), is proposed. The partitioning of the space is carried out according to the spatial distribution of the objects, maintained in histograms. In addition, a hash file is created for each input data set and used to enhance both the storage of and the access to the minimum bounding rectangles (MBR) of the respective set elements. Furthermore, the space is divided in strips, to reduce the processing time. The results showed that the new algorithm is faster in almost all scenarios, specially when bigger data sets are processed. Finally, a query optimizer based on costs, capable to choose the best algorithm to perform the filter step of a spatial join operation, is presented. The query optimizer uses statistical information stored in the data dictionary to estimate the response time for each algorithm and chooses the faster to realize the operation. This query optimizer choose the right one on 88.9% of cases, mistaken just in spatial join envolving small data sets, when the impact is small.
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