u_course

4. GRAMMAR IN USE

4.1.Now look through the text again and find all passive forms of verbs (See Grammar Reference 1).

4.2.Complete the gaps in this summary of the text using passive forms of the

verbs:

The problem of operating systems unreliability and insecurity _______ in the text. Current operating systems ______ unreliable and insecure due to two characteristics: they are huge and they have very poor fault isolation. Fortunately, the situation is not hopeless. More reliable operating systems ______ by researchers. There are four different approaches to the problem solving. In the Nooks approach, each driver ______ in a software jacket to carefully control its interactions with the rest of the operating system, but it leaves all the drivers in the kernel. In the paravirtual machine approach the drivers ______ to one or more machines distinct from the main one. Both of these approaches _______ to

12

improve the reliability of existing operating systems. In two other approaches legacy operating systems ______ with more reliable and secure ones. The multiserver approach runs each driver and operating system component in a separate user process. Finally, in the most radical approach, a type-safe language, a single address space, and formal contracts ______ to carefully limit what each module can do. Thus, microkernels _____ in three of the four research projects, but it __ not _____ which of these approaches ____ widely ______.

4.3. Study the table of borrowings from Greek and Latin origin.

Table 1

Borrowings of Greek and Latin origin

4.4.Put the sentences into the plural.

1.This phenomenon is very interesting from its origin point of view.

2.The professor asks to explain this thesis.

3.An alumnus of our University is well known in the world.

4.Is a crisis in computing possible?

5.I have not a stimulus to do this research.

6.The index of this matrix is unknown.

7.You can find an appendix at the end of the book.

8.Is there any medium to enhance this development?

9.Any student can derive this formula.

10.They offered a hypothesis that can’t be disproved.

4.5.Translate the sentences into English.

1.Это явление сейчас изучают.

2.Причины поломки еще не установлены.

3.Анализ показал, что операционная система является ненадежной и незащищенной.

4.Я считаю, что гипотеза о возможном возвращении к микроядрам в операционных системах вполне оправданна.

5.Эти формулы были выведены еще в прошлом веке.

6.Каковы критерии надежности операционной системы?

7.Эти данные были получены до того, как их запросили.

8.Меморандум подписали неделю назад.

9.Это средство не может быть применимо в данной ситуации.

10.Тезисы по данному научному труду напишут к концу месяца?

5. LISTENING

Study the material about interviewing (See Supplement 2)

14

Paul is 24. He has a Higher National Certificate in Computing and a Higher National Diploma in Computing Support which he completed two years ago. He has been working for a company providing support services for the last eighteen months.

5.1.Listen to Part 1 of the recording to find the answers to these questions:

1.What subject areas does Paul mention?

2.Why did he choose to do his Diploma in support?

3.What practical work was included in the course?

4.Which subject did he particularly enjoy?

5.2.Listen to Part 2 of the recording to answer these questions:

1.What suggestions does Paul have for improving the course? Note

a)his suggestions for improvement

b)the reasons he gives.

2.Which of the subjects he studied has he found useful in his work? Note

a)the subjects

b)examples in work situation.

5.3.Listen to Part 2 of the recording to answer these questions:

1.In which situations does Paul have to learn fast?

2.What sources does he use for help?

3.What advice did the college provide on source of information?

4.What was the problem with the set book?

5.How does he feel about going back to college?

6. WRITING

Study the C.V. of Paul who was interviewed in Task 1.6. Then write your own C.V. in the same way. For the purpose of this task, you can invent experience and assume you have passed all your examination! (See Supplement 1)

15

16

Unit 2

What are the most acute information management challenges today? Where do they steam from?

1. PRE-READING ASSIGNMENT

1.1. Translate the vocabulary used in the text below:

1.2. Match the terms from the text below in table A with their equivalents in table B.

17

1.3. Study the title of the text below. Mark the following statements as True or False, according to your prediction of what the author will say.

1.Databases are more efficient in data management in comparison with dataspace.

2.DSSPs deal with data in variety of formats accessible through many systems with different interfaces.

3.Like a DBMS, a DSSP is in full control of its data.

4.A dataspace should be able to model any kind of relationship between two participants.

5.Dataspaces can be inserted into each other.

2.READING

2.1. Now study the text and the diagram of dataspace system and say what its components are responsible for?

From Databases to Dataspaces:

A New Abstraction for Information Management

In this article we introduce dataspaces as a new abstraction for data management and we propose the design and development of DataSpace Support Platforms (DSSPs) as a key agenda item for the data management field. In a nutshell, a DSSP offers a suite of interrelated services and guarantees that enables developers to focus on the specific challenges of their applications, rather than on the recurring challenges involved in dealing consistently and efficiently with large amounts of interrelated but disparately managed data. We begin our discussion of dataspaces and DSSPs by placing them in the context of existing systems.

The distinguishing properties of dataspace systems are the following:

∙A DSSP must deal with data and applications in a wide variety of formats accessible through many systems with different interfaces. A DSSP is

18

required to support all the data in the dataspace rather than leaving some out, as with a Database Management System (DBMS).

∙Although a DSSP offers an integrated means of searching, querying, updating, and administering the dataspace, often the same data may also be accessible and modifiable through an interface native to the system hosting the data. Thus, unlike a DBMS, a DSSP is not in full control of its data.

∙Queries to a DSSP may offer varying levels of service, and in some cases may return best-effort or approximate answers. For example, when individual data sources are unavailable, a DSSP may be capable of producing the best results it can, using the data accessible to it at the time of the query.

∙A DSSP must offer the tools to create tighter integration of data in the space as necessary.

Logical Components of Dataspaces

A dataspace (see Figure 5) should contain all of the information relevant to a particular organization regardless of its format and location, and model a rich collection of relationships between data repositories. Hence, we model a dataspace as a set of participants and relationships.

Fig. 5. An example dataspace and the components of a dataspace system.

The participants in a dataspace are the individual data sources: they can be relational databases, XML repositories, text databases, web services and software packages. They can be stored or streamed (managed locally by data stream systems), or even sensor deployments.

19

Some participants may support expressive query languages, while others are opaque and offer only limited interfaces for posing queries (e.g., structured files, web services, or other software packages). Participants vary from being very structured (e.g., relational databases) to semi-structured (XML, code collections) to completely unstructured. Some sources will support traditional updates, while others may be append-only (for archiving purposes), and still others may be immutable.

A dataspace should be able to model any kind of relationship between two (or more) participants.

Dataspaces can be nested within each other (e.g., the dataspace of the Computer Science department is nested within the dataspace of the university), and they may overlap (e.g., the dataspace of the Computer Science department may share some participants with the Electrical Engineering department). Hence, a dataspace must include access rules between disparate dataspaces. In general, there will be cases where the boundaries of a dataspace may be fluid, but we expect that in most of the cases the boundaries will be natural to define.

Dataspace Systems

We now outline one possible set of components and architecture for a dataspace system. As depicted in Figure 5, a DSSP offers several interrelated services on the dataspace, some of which are generalizations of components provided by a traditional DBMS. It is important to keep in mind that unlike a DBMS, a DSSP does not assume complete control over the data in the dataspace. Instead, a DSSP allows the data to be managed by the participant systems, but provides a new set of services over the aggregate of these systems, while remaining sensitive to the autonomy needs of the systems. Furthermore, we may have several DSSPs serving the same dataspace – in a sense, a DSSP can be a personal view on a particular dataspace.

∙Catalog and Browse: The catalog contains information about all the participants in the dataspace and the relationships among them. The catalog must be able to accommodate a large variety of sources and support differing levels of information about their structure and capabilities. Wherever possible, the catalog should contain a basic inventory of the data elements at each participant: identifier, type, creation date and so forth.

∙Search and Query: The component should offer the following capabilities: query everything, structured query, meta-data queries, monitoring.

20

∙Local store and index: A DSSP will have a storage and indexing component for the following goals: (1) to create efficiently queryable associations between data objects in different participants, (2) to improve accesses to data sources that have limited access patterns, (3) to enable answering certain queries without accessing the actual data source, and (4) to support high availability and recovery.

∙The Discovery Component: The goal of this component is to locate participants in a dataspace, create relationships between them, and help administrators to refine and tighten these relationships.

∙The Source Extension Component: Certain participants may lack significant data management functions. A DSSP should be able to imbue such a participant with additional capabilities, such as a schema, a catalog, keyword search and update monitoring.

3. POST-READING

3.1. Copy out:

a)key words from every paragraph of the text

b)sentences that convey the main idea of every paragraph.

3.2. Retell the text in your own words using the key words and sentences.

4. GRAMMAR IN USE

4.1.Convert each of these statements to the Passive Voice.

1.We propose the development of DataSpace Support Platforms for the data management field.

2.The researchers place dataspaces and DSSPs in the context of existing systems.

3.We can distinguish some properties of dataspace systems.

4.Our desktops typically contain some structured data (e.g., spreadsheets).

5.A scientific research group may be monitoring a coastal ecosystem through weather stations, shore and buoy-mounted sensors and remote imagery.

6.Two of the main services that a DSSP will support are search and query.

7.A DSSP will also support updating data.