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Soils are natural bodies which function as open systems within a landscape. A wide variety of processes contribute to, and are reflected in, the properties of individual soil profiles (pedons). Material and energy fluxes occur into, within, and through soils as a function of parent material, climate, topography, organisms, time, and a variety of possible other factors (Jenny, 1941). Ideally, the existing properties of an individual soil can provide information about the environment(s) in which it formed, and the processes that have acted upon it. The town of Los Alamos, and the Los Alamos National Laboratory (LANL), are located on the Pajarito Plateau in north-central New Mexico (Figure 1). Environmental concerns have recently focused attention on the numerous fractures in the Bandelier Tuff, the series of volcanic rock units that make up most of the plateau. These fractures have come into question as possible conduits for transport of contaminants downward through the tuff. This study arose out of a need to evaluate the potential for contaminant transport in the fractures. Because the fractures are typically filled, or partially filled, with soil-like material, and appear to be physically continuous with the soils on the surface of the Pajarito Plateau, it was decided to approach the question of the fractures from a soil genesis and morphology standpoint. Specifically, it was believed that soil characterization techniques, including soil micromorphological and mineralogical analyses, could provide information about the dominant processes (past and present) acting in the soils and fractures. The specific objectives of this research were to investigate: (1) the physical, mineralogical and chemical nature of fracture-filling materials in the Bandelier Tuff, as well as associated surface soils; (2) the relationships among fracture-fills, tuff bedrock, and surface soils of the Pajarito Plateau; (3) the processes responsible for the development of the fracture-fills; and (4) the likely sequence of events leading to the present morphology of the soils and fracture-fills.

Contents include: Soil Water Conservation; Plant-Water Status and Growth; and Other Investigations; Summary of Applied Investigations with Antitranspirants; Future Investigations; and Publications.

Antitranspirants conserve water and maintain favorable plant water balances by reducing stomatal apertures, by forming a thin film over the leaves, or by reflecting excessive radiation. Under normal conditions, reductions in both transpiration and photosynthesis are to be expected, but reduction in growth does not always occur, and need not always be disadvantageous when it does. Antitranspirants do not raise leaf temperature excessively, and are not likely to interfere greatly with mineral nutrition. They are likely to be most effective in reducing transpiration when other factors (boundary layer and stomatal resistances) are not large. The effectiveness of an antitranspirant also depends on plant factors such as stomatal distribution and amount of new foliar growth, and on spray factors such as degree of coverage, concentration and amount of spray, and phytotoxicity. Investigations on possible uses for antitranspirants included experiments on: 1) reducing irrigation frequency and growth of highway oleanders; 2) reducing water requirement turf grass; 3) growth, yield and water use of an annual field crop; 4) increasing survival of transplants; 5) increasing vase life of cut flowers and reducing water loss from bedding plants for shipment; 6) prolonging life of cut Christmas trees; 7) correcting plant disorders associated with water balance, e.g., lettuce tip burn, bean blossom drop, prune cracking, and cherry cracking; 8) increasing water potential and fruit growth of orchard trees, including olives, peaches and apricots.

The yield of rain-fed crops needs to increase to meet the requirements of a growing human population. One way to achieve this is to store more rain in the root zone of soils and increase its use by crops. This will be difficult where poorly structured, dense clay subsoils occur. These subsoils limit crop yields by reducing root growth, and the uptake of soil water and nutrients. Reduced root growth results from physical factors, such as low porosity restricting the movement of air and water, high soil strength and temporal water logging which impedes the roots. Chemical factors such as alkalinity, salinity, and sodicity may further restrict root growth in neutral pH and alkaline clay subsoils. This review will focus on the challenging task of improving structure in these dense clay subsoils and to overcome physicochemical constraints in the subsoil, in order to increase crop yields. Early attempts to ameliorate these subsoils using tillage practices, and amendments in some cases, were rarely successful. A more recent and successful approach has been to deep-band nutrient-rich organic amendments in the subsoil, and to follow with a field crop. This increased root growth in the subsoil, and was often associated with improved subsoil structure. It was able to produce substantial and prolonged increases in crop production. A key benefit was an increase in plant available water in the subsoil and the utilization of this water by the crop. The impact of the practice depends on the amount and distribution of rainfall, and this results in increased financial risk for the farm business. Specialized machinery will need to be developed to handle the amendments, while the form, rate of incorporation, and placement depth of amendments will need to be optimized to reduce high upfront costs of the practice. Refereed/Peer-reviewed

Soil profile amelioration practices are gaining momentum to improve productivity on sandy soils in the Southern region. Diagnosing the underlying soil constraints and understanding the yield gap are important factors in supporting cost-effective management decisions. Drawing on findings from nine multi-year trials,we present the impact of different deep tillage practice (ripping, topsoil slotting, spading) with/without amendments on crop production in a range of sandy soils with different soil constraints. In sands with physical and nutritional constraints, yield responses to ripping alone ranged from nil responses in very dry seasons (decile 1) to 1.1 t/ha (average ~0.5 t/ha). Further yield gains, of 0.5 t/ha or more over-and-above the ripped treatment were commonly achieved through the addition of chicken manure, and sometimes with fertilisers. In water repellent sands, spading led to annual gains of between nil and 1.4 t/ha. However nil responses are also observed on acidic sands and/or under dry seasonal conditions. In water repellent sands, additional gains achieved from incorporation of N-rich hays lead to further gains, largely in the first 2-3 years, with 5-year cumulative gains of around 2.3 t/ha. Further trials will be undertaken to optimise the timing of nutrient release through managing the form of nutrition and the depth of placement, and to improve the understanding of thetiming of nutrient availability, mineralisation/immobilisation dynamics and the contribution of micronutrients. Refereed/Peer-reviewed

Know the water limited yield potential and target the soil constraints to crop water-use: Assessing the yield gap relative to expected gains and seasonal risks, alongside identifying the key soil constraints, are important in developing an amelioration plan with cost effective outcomes. Yield responses to physical disruption are common but not guaranteed: Considering the depth and severity of compaction, any co-occurring constraints, and machinery specific impacts on soil strength offer an opportunity to optimise decisions for cost effective outcomes. Yield responses to increasing fertility at depth (i.e. deep placement/incorporation) are highly dependent on seasonal conditions with risks of neutral or negative yield responses in dry years. Depth of placement and form of nutrition (fertiliser, chicken litter, plant biomass) offer potential to manage nutrient carryover and crop growth responses over multiple years. Long term effects are essential for cost effective amelioration outcomes. Economic analysis of long-term trials (five years) has highlighted the importance of seasonal and crop sequence response effects on the cost benefit outcomes. Refereed/Peer-reviewed

Otomobiller için GPS cihazları ve havayolu şirketlerinin ağ siteleri gibi bir çok sistem, mekanlar arasında rota bilgileri sunmaktadır. Bu tip sistemler yaygın olarak kullanılmalarına ve rota bilgilerini doğru bir şekilde sunmalarına rağmen, kullanıcıların veri girişine izin vermemektedir. Bu tip sistemlerde tüm veri, sistem yöneticileri tarafından girilmekte ve sistemler kullanıcılarının rota tecrübelerinden faydalanamamaktadır.Bu çalışmada, kullanıcı sorguları karşılığında mekanlar arasında rotalar sunan katılımcı bir sistem sunulmuştur. Sistemdeki veriler kullanıcılar tarafından girilmektedir. Verilerin saklanması için, mekanların, mekanlar arasındaki bağlantıların ve mekanlar arasındaki ilişkilerin (kapsama, komşuluk, kesişme) tanımlandığı bir model sunulmuştur. Rotaları bulabilmek için, A* arama algoritmasının özelleştirilmiş bir uyarlaması sunulmuştur. A*CD (A* for Collaborative Data) olarak adlandırdığımız bu uyarlama, arama esnasında mekanları işlerken, hedef mekana kalan tahmini bedeli hesaplamak için buluşsal yöntemler kullanmaktadır. Ayrıca alternatif rotalar sunmak, belli bağlantı tiplerini hariç tutmak ve çok sayıda durağa sahip taşım araçları ile ilgili sorunlara çözüm getirmek için A* arama algoritması üzerinden yapılmış değişiklikler sunulmuştur. Bedel modeli olarak seyahat süresi ve seyahat maliyeti (finansal) kullanılmaktadır.Çalışmamızda, sezgisel bağlantılar kavramı da sunulmuştur. Seçilen mekanlar arasında bir rota bulunamaması durumunda bile, sistem eksik bağlantılara sahip bir rota dönebilmektedir. Eksik bağlantılar, mekanlar arasındaki ilişkiler yardımıyla doldurulabilmektedir.A*CD algoritmasının performansını değerlendirmek amacıyla otomatik testler sunulmuştur. Bu testler A*CD algoritması ile bulunan rotaların bedellerinin en düşük bedelli rotaya çok yakın olduğunu göstermektedir. Sezgisel bağlantılar kavramını örneklemek için otomatik olmayan testler sunulmuştur. Many systems, such as in-car GPS devices and airline company web sites, provide route information between locations. Although such systems are used widely and can provide route information successfully, users of these systems cannot contribute to the data entry process. In these systems, data is entered by the administrators and these systems cannot take advantage of the route expertise of their users.In this work, we present a collaborative system, which provides routes between locations upon user queries. The data in the system is entered by the users of the system. We present a model which is containing locations, links between locations and relationships between locations (containment, neighborhood and intersection) in order to store the data. For the route finding purpose, we present a customized version of the A* search algorithm. This customized version, named A*CD (A* for Collaborative Data), uses heuristics for estimating the cost remaining to the target location while processing the nodes. A*CD can also provide alternative routes, exclude certain link types in the searches according to user preferences and handle the problems associated with multiple stop transportation lines. As the cost models, we use duration and financial cost.We also present the intuitive connections concept. Even if a route does not exist between the selected locations, the system can provide a route with missing links. The gap(s) between the disconnected locations are filled by the help of the relationships between locations.In order to evaluate the performance of the A*CD algorithm, we present automated tests. These tests show that the costs of the routes that are provided by the A*CD algorithm are close to the actual shortest routes. In order to demonstrate the intuitive connections concept, we also present manual test queries. 97

Cataloged from PDF version of article. The AI field is currently dominated by domain-specific approaches to intelligence and cognition instead of being driven by the aim of modeling general human intelligence and cognition. This is despite the fact that the work widely regarded as marking the birth of AI was the project of creating a general cognitive architecture by Newell and Simon 1959. This thesis aims to examine recently designed models and their various cognitive features and limitations in preparation for building our own comprehensive model that would aim to address their limitations and give a better account for human cognition. The models differ in the kind of cognitive capabilities they view as the most important. They also differ in whether their foundation is built on symbolic or sub-symbolic atomic structures. Furthermore, we will look at studies in the philosophy and cognitive psychology domain in order to better understand the requirements that need to be met in order for a system to emulate general human cognition. Bozyiğit, Öge M.S.

ÖZETSAĞLAMLIK VE ESNEKLIK: BILIŞSEL AJANLAR YARATMAKÖge BozyiğitBilgisayar Mühendisliğ Yüksek Lisansi,şDanıman: Yrd. Doç. Dr. David DavenportEylül, 20061959'da Newell ve Simon'nin geliştirdiğ genel insan zeka kabiliyeti modelleme projesiişyapay zeka ile ilgili çalımalarıbaş çın langı olarak biliniyor. Buna rağmen, günümüzdeyapay zeka alaninda genel beyin kabiliyeti modelleme yöntemleri değ dar biril,alanda spesifik zeka problemleri için özel cözüm üreten yöntemler hakim. Bu tezin amacıgenel biliş fonksiyonlar için yeni tasarlanmişmodellerin özeliklerini analiz edip,selonları sı rların nı nıhedef alan bir modelin araşrma zeminini oluştı turmak. Modelleribirbirinden ayı özellik temel biliş kapasitelerinin hangisinin daha üstün veya yayginran selsayı ğ Temel farklarin bir diğ ise, bazı nı sembolik altyapidan oluşıldı . eri ları n turulmuş,bazı nı ise daha ilksel mekanizmalardan kurulmuşları n olmalarıBunlarin yaninda, genel.biliş kapasitelerinin gerekçelerini daha da somutlaşrmak için bu alanda yapilansel tıfelsefik ve psikolojik araşrmalar da tezin konusu dahilinde.tıAnahtar Sözcükler: beyin fonksiyon modelleme, biliş dizge, mantik modelleme, genelselyapay zeka, tahmin kabiliyeti ABSTRACTSTABILITY AND PLASTICITY: CONSTRUCTING COGNITIVE AGENTSÖge BozyiğitM.S. in Computer EngineeringSupervisor: Asst. Professor Dr. David DavenportSeptember, 2006The AI field is currently dominated by domain-specific approaches to intelligence andcognition instead of being driven by the aim of modeling general human intelligence andcognition. This is despite the fact that the work widely regarded as marking the birth ofAI was the project of creating a general cognitive architecture by Newell and Simon1959. This thesis aims to examine recently designed models and their various cognitivefeatures and limitations in preparation for building our own comprehensive model thatwould aim to address their limitations and give a better account for human cognition. Themodels differ in the kind of cognitive capabilities they view as the most important. Theyalso differ in whether their foundation is built on symbolic or sub-symbolic atomicstructures. Furthermore, we will look at studies in the philosophy and cognitivepsychology domain in order to better understand the requirements that need to be met inorder for a system to emulate general human cognition.Keywords: Cognitive architecture, human-level intelligence, knowledge representation,prediction, spreading activation. 112

ÖZET CONTEXTPROXY: AĞ TABANLI BAĞLAMDAN- HABERD AR HİZMETLERİ VE UYGULAMALARI DESTEKLEMEK İÇİN YERDEN-HABERDAR HTTP PROXY SUNUCUSU Alper R. Uluçmar Bilgisayar Mühendisliği, Yüksek Lisans Tez Yöneticisi: Asst. Prof. Dr. David Davenport Ocak, 2005 Gündelik yaşamımıza hızla giren bilgi işleme ve haberleşme yeteneğine sahip taşınabilir cihazlar, bizlere sadece her an her yerde hesaplama yapabilme ve haberleşebilmeden daha fazlasını vaat etmektedirler. Hızla gelişen ve gün geçtikçe yaşamımıza daha derinden nüfuz eden bu altyapı bileşenleri tamamen yeni etkileşim yöntemlerini ve uygulamaları mümkün hale getirmişlerdir. Bu yeni uygulama ve hizmet sağlama yaklaşımlarından bir tanesi de bağlamdan-haberdar uygulamalardır. Bağlamdan- haberdar uygulamalar, kullanıcılarına sağladıkları hizmetleri ve bilgiyi kullanıcılarının içlerinde bulundukları bağlama göre devingen olarak uyarlayabilen uygulamalardır. Bağlamdan-haberdar uygulamaları desteklemek için gerekli altyapısal bileşenlerin hızla yaygınlaşmalarına karşın bu uygulamalarda rol alacak çeşitli bileşenlerin birbirleriyle etkileşimlerinde kullanılacak kabul görmüş yaklaşımlar ve standartlar henüz mevcut değildir. Bu çalışmamızda ContextProxy adını verdiğimiz yaygın olarak kullanılan Symbian düzleminde çalışan yerden-haberdar bir HTTP proxy sunucusu geliştirdik. ContextProxy' nin istemci uygulama tarafından standart bir HTTP proxy sunucusu olarak algılanmasına karşın esas işlevi, istemciye ait istekleri hizmet sağlayıcıya aktarırken kullanıcının bağlamından çıkardığı yer bilgisiyle zenginleştirmesidir. Böylelikle halihazırda kullanılmakta olan uygulamalar veya yeni geliştirilecek olanlar standart bir HTTP proxy sunucusu kullanmaya ayarlanabilir oldukları sürece yerden-haberdar hale gelebilmektedirler. Anahtar sözcükler. Bağlamdan-haberdar programlama, Symbian, Bluetooth, GSM iv ABSTRACT CONTEXTPROXY: A LOCATION-AWARE HTTP PROXY SERVER TO SUPPORT WEB BASED CONTEXT-AWARE SERVICES AND APPLICATIONS Alper R. Uluçınar M.S. in Computer Engineering Supervisor: Asst Prof. Dr. David Davenport January, 2005 The pervasion of computing in our physical world promises more than the ubiquitous availability of computing resources; totally new and exciting interaction schemes are to be explored. Context-awareness, one of the most important aspects of ubiquitous computing, enables applications that make use of their users' context to provide dynamically adapting information and services to their users or to other applications. Although the technological infrastructure to support ubiquitous and context-aware applications is being deployed rapidly, the standards and the best practices for the interactions of various components in a context-aware application are still missing. In our work we have developed a location-aware HTTP proxy server, called ContextProxy that runs on the popular Symbian platform. ContextProxy acts as a standard HTTP proxy server from the client application's perspective but it augments the service request of the client with the available location information while submitting the request to the service provider. This allows the existing nomadic applications to immediately become location- aware if they can be configured to make use of a standard HTTP proxy which is a common scheme for web based applications. And also it is possible to write new nomadic applications without considering the context-awareness aspect at the service requestor level. The contextual information added by ContextProxy can then be utilized by the service provider to dynamically adapt its services according to the service requestor's context. Keywords: Context- Aware/Nomadic Computing, Symbian, Bluetooth, GSM m 62

Cataloged from PDF version of article. The pervasion of computing in our physical world promises more than the ubiquitous availability of computing resources; totally new and exciting interaction schemes are to be explored. Context-awareness, one of the most important aspects of ubiquitous computing, enables applications that make use of their users’ context to provide dynamically adapting information and services to their users or to other applications. Although the technological infrastructure to support ubiquitous and context-aware applications is being deployed rapidly, the standards and the best practices for the interactions of various components in a context-aware application are still missing. In our work we have developed a location-aware HTTP proxy server, called ContextProxy that runs on the popular Symbian platform. ContextProxy acts as a standard HTTP proxy server from the client application’s perspective but it augments the service request of the client with the available location information while submitting the request to the service provider. This allows the existing nomadic applications to immediately become locationaware if they can be configured to make use of a standard HTTP proxy which is a common scheme for web based applications. And also it is possible to write new nomadic applications without considering the context-awareness aspect at the service requestor level. The contextual information added by ContextProxy can then be utilized by the service provider to dynamically adapt its services according to the service requestor’s context. Uluçınar, Alper Rifat M.S.

Cataloged from PDF version of article. This thesis presents Comet-KO, a software tool for knowledge construction and organization, which takes its basis from instructivist and constructivist learning theories. Comet-KO aids users to collect, create and represent information, visualize relationships between concepts, and collaborate during the knowledge construction process. The representation of knowledge in Comet-KO is based on semantic networking techniques, which proved to be more powerful than conventional text based note-taking methodologies. In addition to formal semantic networking language, grouping and hypergraph drawing is also supported by Comet-KO, which brings a new perspective on visualization of knowledge construction. Küçükyılmaz, Tayfun M.S.

ÖZET Comet-KO: BİLGİ DÜZENLEMESİ İÇİN BİR ANLAMSAL AĞ ORTAMI Tayfun Küçükyılmaz Bilgisayar Mühendisliği Yüksek Lisans Tez Yöneticisi: Yard. Doç. Dr. David Davenport Eylül, 2003 Bu tez temellerini instrüktivist ve konstrüktivist eğitim teorilerinden alan bir bilgi inşaa ve düzenleme olan Comet-KO' u sunmaktadır. Comet-KO, bilgi inşaası ve düzenlemesi sürecinde kullanıcıya bilgiyi toplama, yaratma ve sunmada, bu bilgileri ilşkilendirmede ve bu süreçte diğer kullanıcılarla etkileşmede yardımcı olmayı amaçlamaktadır. Comet- KO bilginin ifadesini yazıya dayalı klasik bilgi sunum methodları yerine, bilgi inşaasında bu tekniklerden çok daha üstün olan mantıksal ağ teknikleri ile yapmaktadır. Bilinen anlamsal ağ tekniklerini gruplama ve hipergraf çizim gücü ile geliştiren Comet-Ko, bilginin sunumu konusunda en kapsamlı anlamsal ağ geliştirme araçlarından biri olmaya adaydır. Anahtar sözcükler: İnstrüktivizm, Konstrüktivizm, Anlamsal Ağlar, Bilgi Düzenlemesi iv ABSTRACT Comet-KO: A CONCEPT MAPPING ENVIRONMENT FOR KNOWLEDGE ORGANIZATION Tayfun Küçükyılmaz M.S. in Computer Engineering Supervisor: Asst. Prof. David Davenport September 2002 This thesis presents Comet-KO, a software tool for knowledge construction and organization, which takes its basis from instructivist and constructivist learning theories. Comet-KO aids users to collect, create and represent information, visualize relationships between concepts, and collaborate during the knowledge construction process. The representation of knowledge in Comet-KO is based on semantic networking techniques, which proved to be more powerful than conventional text based note-taking methodologies. In addition to formal semantic networking language, grouping and hypergraph drawing is also supported by Comet-KO, which brings a new perspective on visualization of knowledge construction. Keywords: Instructivism, Constructivism, Concept Maps, Semantic Networking, Knowledge Organization, 78

ÖZET ReMemex: BİLGİ İNŞAASI ve DÜZENLEMESİ İÇİN BİR YAZILIM ARACI Özden Emek Erarslan Bilgisayar ve Enformatik Mühendisliği, Yüksek Lisans Tez Yöneticisi: Yard. Doç. Dr. David Davenport Kasım, 1999 Bilgi Çağı insanları, bilginin inşaasmda; toplamada, çözümlemede, sentezleme- de ve düzenlemede vasıflı olmalıdır. Bu vasfa sahip olmaya yönelik talepler eğitimsel teknoloji araştırmalarını yeni teoriler ve uygulamalar bulmaya yönlen dirmektedir. Gelişen bir öğrenme teorisi olarak Konstrüktivizm (construc tivism), yeni bakış açıları önermekte ve bunun yakın gelecekte eğitim üzerinde büyük etkisi olması beklenmektedir. Bugün, artan çabalara rağmen, kon- strüktivist fikirlerin eğitim yazılımlarına en iyi ne şekilde uygulanacağına karar vermek ve etkisinin olup olmadığını ispatlamak için yeterince araştırmaya ihtiyaç hala vardır. Bu tez, bilgi işçilerinin bilgiyi toplama ve düzenlemesine yardım eden ve konstrüktivist öğrenme teorisinin eğitimsel yazılımlara uygulanması konusunda araştırmalar için bir taban teşkil eden ReMemex sistemini, bir yazılım aracını sunmaktadır. ReMemex, öğrenen konumundaki kişilerin kavram lar ve/ veya nesneler arasındaki ilişkileri görselleştirmek için bilgi peyzajı oluştur dukları bilgi inşaa ve düzenleme ortamları için bir çatıdır. Diğer uygula malardan aktarılan kütük ve verilerin düğümler şeklinde gösterilmesi, detay ların gruplama yoluyla soyutlanması, haritalar ve düğümler için çoklu-görünüş desteği ve biçem desteği gibi özelliklerin tamamı ReMemex sistemini geleneksel araçlardan daha güçlü kılmaktadır. ReMemex sisteminin temel gerçekleşti rimi Java kullanılarak, esnek ve geliştirmeye açık, Nesneye Yönelik Uygulama. Pro gramı Arayüzü (API) olarak yapılmıştır. Anahtar sözcükler: Konstrüktivizm, Bilgi Düzenleme, Eğitimsel Yazılım, An lamsal Ağlar, Bilişsel Araçlar iv ABSTRACT ReMemex: A SOFTWARE TOOL FOR KNOWLEDGE CONSTRUCTION and ORGANIZATION Özden Emek Erarslan M.S. in Computer Engineering and Information Science Supervisor: Asst. Prof. David Davenport November, 1999 Citizens of the Knowledge Age have to be skilled in the construction of mean ingful knowledge; in the collecting, analyzing, synthesizing, and organizing of information. These demands are driving educational technology research to find new theory and practices. Constructivism, an emerging theory of learning, offers new perspectives and is expected to have a major influence on education in the near future. Yet today, despite increasing efforts, considerable research is still needed to determine how best to apply constructivist ideas to educational software and to prove or disprove its effectiveness. This thesis presents the Re Memex system, a software tool, which both aids knowledge workers to collect and organize information, and provides a basis for research into the applica tion of constructivist learning theory in educational software. ReMemex is a framework for a knowledge construction and organization environment, where learners create information landscapes to visualize the inter-relationships be tween the concepts and/or objects the domain is composed of. Features such as importing files and data from other applications as nodes, abstraction of the details by grouping, multiple view support for maps and nodes, and style support make ReMemex more powerful than traditional tools. The base imple mentation of ReMemex has been developed in Java, as a flexible and extensible Object Oriented API. Keywords: Constructivism, Knowledge Organization, Educational Software, Cognitive Tools, Semantic Networks m 76

ÖZET BİLİŞSEL DİZGENİN ALT DÜZEY ÖĞELERİNİN TAHMİN ETME TEMELİNDE ORGANİZASYONU Armağan Yavuz Bilgisayar ve Enformatik Mühendisliği, Yüksek Lisans Danışman: Yrd. Doç. Dr. David Davenport Ocak 1998 Bu tezde beyinin alt düzey duyusal-motor işlevlerinin tahmin etme temelinde organize olduğu öne sürülmektedir. Bu öneri duyusal-motor sistemler hakkındaki varolan kuramlardan oldukça farklıdır ve şu şekilde özetlenebilir: Beyindeki birtakım basit mekanizmalar diğerlerinin o anki ya da gelecekteki durumlarını tahmin ederler. Bu mekanizmalar dinamik olarak.oluşabilir ya da yok olabilirler. Tahminlerdeki doğruluk derecesi bu süreçte seçim kriteri olarak rol oynar. Basit mekanizmalar bu şekilde birbirlerine bağlanır ve hiyerarşik kompleksler oluştururlar. Bu kompleksler, ilginç olayları tanıma, yüksek düzey gösterimler oluşturma, ve bir hedefe yönelik etkinliklere yardımcı olma gibi bir dizi işlevi yerine getirirler. Dikkat ve bellek gibi diğer dizgeler bu işlemlere yardımcı olur ve bu sistemden yararlanırlar. Tahmin temelinde gerçekleşen böyle bir organizasyon alt-düzey bilişsel etkinliklerin temelini oluşturur. Bu tezde, tahmin temelinde çalışan bir duyusal-motor sistem modeli verilmekte ve bu modelin algıya ilişkin bazı ilginç problemleri nasıl çözümlediği ve diğer bilişsel etkinliklerle nasıl ilişkili olabileceği tartışılmaktadır. Anahtar Sözcükler: tahmin mekanizması, gösterimlerin oluşumları, konstrük- tivizm, algı, biliş, bilişsel bilim. iv ABSTRACT PREDICTION AS THE BASIS OF LOW LEVEL COGNITIVE ORGANIZATION Armağan Yavuz M.S. in Computer Engineering and Information Science Advisor: Asst. Prof. David Davenport January, 1998 I suggest that the brain's low-level sensory-motor systems are organized on the basis of prediction. This suggestion differs radically from existing theories of sensory-motor systems, and can be summarized as follows. Certain simple mechanisms in the brain predict the current or future states of other brain mecha nisms. These mechanisms can be established and disposed dynamically. Success ful prediction acts as a kind of selection criteria.and new structures are formed and others are disposed according to their predictive powers. Simple mechanisms become connected to each other on the basis of their predictive power, possibly establishing hierarchical structures, and forming large complexes. The complexes so formed, can implement a number of functionalities including detecting inter esting events, creating high-level representations, and helping with goal-directed activity. Faculties such as attention and memory contribute to such processes of internal predictions and they can be studied and understood within this setting. All of this does not rule out the existence of other mechanisms, but an organiza tion driven by prediction serves as the backbone of low-level cognitive activity. I develop a computational model of a sensory-motor system that works on this basis. I also show how this model explains certain interesting aspects of human perception and how it can be related to general cognitive capabilities. Keywords: prediction mechanism, emergent representations, constructivism, per ception, cognition, cognitive science. m 71

IV ÖZET WIZ - dinamik A? TABANLI DERS SUNUM SİSTEMİ Ozan Özhan Bilgisayar ve Enformatik Mühendisliği, Yüksek Lisans Tez Yöneticisi: Yrd. Doç. Dr. David Davenport Ağustos, 1997 Dünya Çapındaki Bilgisayar Ağı (WWW) eğitim açısından büyük bir potansiyele sahiptir. Bu ağ sadece haberleşme imkanı sağlamakla kalmayıp, bilgilerin saklanması ve arzu edildiğinde bunlara kolayca erişilmesine de imkan vermektedir. Bu özellikleri, Dünya Çapındaki Bilgisayar Ağı'nı uzaktan eğitim için ideal hale getirmektedir. Mevcut sorunlar bilgisayar ağının sabit doğasından kaynaklanmaktadır. Bu sabit yapı kişiye uygun bireysel sunumu çok zor hale getirmektedir. Bu tez bu sorunun üstesinden gelmek için geliştirilmiş bir projeyi; WIZ sistemini sunmaktadır. WIZ sistemi Internet üzerinde etkileşimli ders sunan bir dinamik hipermedya sistemidir. Bu sistem bireye en uygun ders sunumu sağlayabilmek için her bir öğrencinin dersteki durumunu sürekli olarak takip etmektedir. Öğrenciler ders materyali içerisinde istedikleri şekilde dolaşma özgürlüğüne sahip olmakla beraber, bir tuşa basmaları tekrar birey sel (kılavuzlu) sunuma dönüşü sağlamaktadır. Bununla birlikte, WIZ sistemi, derslerde, birlikte çalışma ve tartışma ortamı sağlamak için Internet 'in iletişim olanaklarını sonuna kadar kullanmaktadır. WIZ sistemi yer ve zamandan bağımsız, hesaplı, bireysel, etkileşimli uzaktan eğitimi sağlamak için somut eğitimsel tasarım ve yazılım mühendisliği prensiplerini kullanmaktadır. Anahtar kelimeler: Uzaktan Eğitim, Internet, WWW, Akıllı Eğitim Sistemleri, Dinamik Hipermetin, Hipermedya, Kullanıcı Modelleme III ABSTRACT WIZ - DYNAMIC WEB-BASED COURSE PRESENTATION SYSTEM Ozan Ozhan M.S. in Computer Engineering and Information Science Supervisor: Asst. Prof. Dr. David Davenport August, 1997 The educational potential of the World- Wide- Web is clear. It provides not only a means of communication, but, just as importantly, a means for storing and conveniently accessing a massive amount of information. Such character istics make it an ideal platform for distance education. One limitation however is the fixed nature of the web itself, making guidance and individualized pre sentation difficult. This thesis presents a project, the WIZ system, aimed at overcoming this problem. The WIZ system is a dynamic hypermedia system that presents interactive courses over the Internet. It monitors the progress of each student in order to provide a presentation that best matches the individ ual. Students have the freedom to browse the course material but can return back to the guided presentation by simply clicking on a button. In addition, the WIZ system exploits the communication (newsgroup and email) facilities of the Internet in order to provide a collaborative discussion environment for courses. WIZ employs sound educational design and software engineering principles to generate affordable, individualized, interactive distance education, indepen dent of time and location. Key words: Distance Education, Internet, WWW, Intelligent Tutoring Sys tems, Dynamic Hypertext, Hypermedia, User Modeling 107