High Energy Physics Libraries Webzine |
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HEP
Libraries Webzine
Issue 5 / November 2001
http://webzine.web.cern.ch/webzine/5/papers/5
Davide Papotti, Alberto Salarelli
22/10/2001
Keywords
<landscape>; <digital library>; <digital
photography>.
1. Introduction
Landscape: a complex interdisciplinary object of study
The study of landscape requires an interdisciplinary approach.
In the field of landscape studies there are two levels of interdisciplinarity:
a "horizontal" and a "vertical" one. The horizontal dimension of interdisciplinarity
comes from the fact that different fields of study analyze landscape from
complementary points of view. Among other fields, geography, architecture,
and art history, each with its own conceptual and methodological background,
play a particular role in the tradition of landscape studies. Each discipline
develops its own conception of landscape, with emphasis on different elements
and different values. The "vertical" dimension of interdisciplinarity,
on the other hand, comes from the fact that a landscape is made up of different
layers whose interpretation requires a specific competency in a discipline.
The use of adjectives associated with the term is significant in understanding
the wealth of meanings of "landscape." One can speak, for instance, of
"botanical landscapes", "geological landscapes", "cultural landscapes",
etc. All these characteristics make landscape a complex object of study.
Specific techniques of survey and collection have to be developed in order
to grasp landscape in all its richness.
The revival of the scientific discussion of the concept of landscape
and even the term's popular "success" (its use in mass media, tourism marketing,
real estate publicity, etc.) have recently been accompanied by the promotion
of the concept at an institutional level. In the Italian context, for instance,
it is important to mention the first National Conference on Landscape
held in Rome in 1999; at the European level, one should refer to the European
Convention on Landscape signed in 2000 [1].
Landscapes as cultural heritage
The attention to landscape is well rooted in the western cultural tradition,
and the theoretical debate on the importance of landscape runs through
the twentieth century. The Italian geographer Filippo Porena wrote, in
an article published more than a century ago, of «the current fashion
of the term landscape» [1892: 72]. From an institutional point of
view, it is important to recall a law that dates back to 1939 (Law of June
29, n. 1947) entitled "Protection of Natural Heritage" focused on «panoramic
values», of a network of material «goods» characterized
by «specific aspects of esthetic and traditional value». This
law has recently been acknowledged in the set of laws concerning the protection
of cultural heritage (October 29, 1999, n. 490). The recent shift in conservation
policies from the attention given to single historic or natural monuments
to the value attributed to landscape as a whole marks an important change
of perspective [Veyret and Le Maître 1996]. Precisely because landscape
is considered a basic expression of a national, regional or local cultural
heritage, it is important to develop techniques that allow one to catalogue
and to archive it.
The importance of visual inquiry in landscape studies
Studies on the concept of landscape have particularly emphasized
its visual quality. A landscape exists where an eye is observing the territory
[Collot 1986]. Within the vast available bibliography on landscape, a strong
emphasis has been placed on its visual components and qualities, which
have a primary role in shaping the way it is perceived [Bailly, Raffestin
and Reymond 1980; Cosgrove 1996]. Among other attempts to classify and
archive landscapes, scholars have produced maps able to portray the visual
limits of an area, identifying panoramic points, ridges and obstacles [Raveneau
1977]. The result is a map of the "visibility" of a landscape. Other important
studies on visual components of a landscape come from the work of the Netherlands
Soil Survey Institute [De Veer and Burrough 1978] where a complex system
of classification of landscapes according to their visual potentiality
was developed. The concept of visibility lies at the basis of the very
idea of landscape [Zerbi 1993: 168]. For this reason it is important to
study and to critically examine the ways in which landscape can be observed
and recorded by technical means.
2. Archiving landscapes?
Given the prevailing visual component of the object, photography represents a privileged means to archive landscapes. The use of photographs in this field has had two main outcomes:
a) geometrically planned and complete surveys of the territory from
a zenithal point of view (satellite and aerial photographs)
b) selective archives of photographs focused on the aesthetic or cultural
value of specific elements within the landscape [2].
Aerial photographs
Most western countries have completed surveys of their territories
through aerial photographs. Series of surveys made at different times often
testify to the evolution of landscapes in the last decades. Many cartographic
products such as land use maps have been developed from the interpretation
of aerial photographs. This kind of documentation, however, does not provide
an immediately communicative image of the landscape, and the reading of
the data requires quite a sophisticated interpretive ability.
Qualitative archives
Archives of landscape photographs usually collect the results
of campaigns aimed at selecting "relevant" points of interests (a panoramic
view, a monument, a single element of the historical and/or natural heritage
of the area). The rendering of these analytic elements (single features
in the landscape) has normally been considered a sufficiently realistic
and adequate "portrait" of the territory [Cosgrove 1984] [3].
An example of this policy is, in the Italian context, the so-called "Archive
of Space" organized by the Province of Milan (Lombardy, Northern Italy),
a photographic collection of the most interesting elements of the cultural
heritage of the area. The survey campaigns allowed the photographers invited
to collaborate in the project a high degree of freedom in the choice of
how and what to portray [4]. From this perspective,
landscape is considered a system that is the sum of single noticeable elements
more than an autonomous entity. What is often missing in these archives
is a documentation of so-called "ordinary landscapes," spaces that do not
present any particular artistic or aesthetic value but nevertheless represent
the everyday theatre of common work and leisure activities (on the interpretative
metaphor of landscape as a theatre see Turri, 1998).
The renewed institutional interest in landscapes creates the
necessity to make a "census" of the landscape heritage both for preservation
purposes and for a better understanding of its complexity and richness.
The new possibilities offered by the digital techniques of data collection
also open up new perspectives in this field. As Zerbi states, «the
new instruments available to scholars seem to be able to renew in depth
this tradition of research. The limits of this tradition have been repeatedly
emphasized by contemporary researchers, while on the contrary its strengths
have not been adequately recognized: the integrated approach, the logic
structure of the classifying methods, certain analytic categories adopted»
[1993: 143]. It is therefore important to develop new techniques of landscape
archiving while at the same time keeping in mind the existing tradition
of studies in this field.
3. The LDL (Landscape Digital Library)
The goal of the LDL (Landscape Digital Library) project is the implementation
of a Web accessible database [5] able to present
a portion of a territory with documentary evidence in a new format and
from a new perspective. The case study presented here as a test is related
to a small area of the plain of the river Po valley (Northern Italy). In
the future we plan to apply the LDL research criteria in other geographical
contexts in order to test the method's validity in a variety of physical
and human environments.
Aerial photography (City of Forlì, Italy - by Aernova)
|
Qualitative photography (Gabriele Basilico - image from Cityscapes) |
LDL - Landscape Digital Library (screenshot of a database record - click on it to enlarge) |
Methods of data collection for the LDL
The LDL is based on a collection of photographs taken following
a systematic grid of survey points. This grid is identified through topographic
cartography. The encounter of two UTM (Universal Transverse Mercator; an
internationally adopted system of geographical reference) coordinates identifies
on the map the exact point where the pictures are to be taken. This system
being based on a kilometric base, each point is one kilometer distant from
the nearest other points (in the four cardinal points). Once the point
has been identified (with the help of GPS instruments) the surveyor takes
four photographs, directing the digital camera (with a 50 mm objective
focused for infinity) to the four cardinal points. The result will be four
pictures for each point, identified by both UTM and geographical coordinates
of the shooting point and by the direction (North, East, South, West).
The point of view is that of a human eye view, with a horizontal perspective
from a height variable from 1.5 to 2 meters. A tolerance of nearly 10 meters
is acceptable in the choice of the location from which to shoot the photographs
(one has also to keep in mind the margin of error related to the GPS system
in giving the coordinates). The goal of the database is to reproduce by
specimens, taken according to a systematic grid, the appearance of the
landscape in a given area, including possible obstacles and barriers.
Technical characteristics of the LDL
The files of the photographs are inserted in a database accessible
by way of different search criteria. A series of elements of indexing are
applied to the database. These elements are not taken into consideration
during the photographic campaign, but nevertheless they can be attached
in the subsequent process of assigned indexing. Photographs have a resolution
of 2048 X 1536 dpi (dots per inch), the image size is about 1.2 Mb. The
image format used in LDL is JPEG (Joint Photographic Experts Group): even
though this is a compressed format, the image resolution is adequate in
order to obtain prints for paper publications and also, of course, for
screen display. JPEG is the format that best fits LDL purposes, considering
that "JPEG is designed to exploit known limitations of the human eye, notably
the fact that small color changes are perceived less accurately than small
changes in brightness. Thus, JPEG is intended for compressing images that
will be looked at by humans"[6].
Photograph thumbnails are provided in order to make browsing easier
between the records retrieved.
The database is implemented using the DBMan package that is freely
distributed by Gossamer Threads for non-profit use [7].
It is installed on a Linux server that uses Red Hat 7.1 (Seawolf) distribution
with kernel 2.4.2-2, even if the database can run also on Windows or Mac
platforms. As stated in the homepage of the product, «DBMan is a
full-featured database manager that provides a Web interface to add, remove,
modify or view records in a flat file ASCII database. It supports an advanced
user management system, as well as powerful permission system. An SQL version
is also available for very large databases».
The LDL database is made up of several files:
ldl.cfg - this is the LDL config file that defines
the database.
ldl.db - this stores the textual information.
ldl.pass - this stores the user passwords and permissions.
ldl.count - this stores the counter for the next ID number to
use.
ldl.log - this stores a log of all activity to the
database.
ldl.pl - this is the
html for the LDL database.
Another file is required in order to run LDL:
db.cgi - the CGI interface between LDL and the Web.
Finally, images and thumbnails are stored in a directory that must be
accessible by Apache Web server.
Following is inserted a part of the LDL set-up file that contains the
database fields definition:
field_name => ['position', 'field_type', 'form-length', 'maxlength',
'not_null', 'default', 'valid_expr']
%db_def = (
'point' | => [ 0, 'alpha', | 20, | 20, 1, '', | ''], |
'IGM' | => [ 1, 'alpha', | 30, | 30, 1, '', | ''], |
'UTM' | => [ 2, 'alpha', | 20, | 20, 1, '', | ''], |
'GEO-coord' | => [ 3, 'alpha', | 45, | 45, 1, '', | ''], |
'date' | => [ 4, 'alpha', | 30, | 30, 1, '', | ''], |
'surveyor' | => [ 5, 'alpha', | 20, | 20, 1, '', | ''], |
'north' | => [ 6, 'alpha', | 20, | 20, 1, '', | ''], |
'geo-names-north' | => [ 7, 'alpha', | '40x3', | 1000, 0, '', | ''], |
'east' | => [ 8, 'alpha', | 20, | 20, 1, '', | ''], |
'geo-names-east' | => [ 9, 'alpha', | '40x3', | 1000, 0, '', | ''], |
'south' | => [10, 'alpha', | 20, | 20, 1, '', | ''], |
'geo-names-south' | => [11, 'alpha', | '40x3', | 1000, 0, '', | ''], |
'west' | => [12, 'alpha', | 20, | 20, 1, '', | ''], |
'geo-names-west' | => [13, 'alpha', | '40x3', | 1000, 0, '', | ''], |
);
Where:
field_name = the name of the column.
position = field's position in the delimited text file.
field_type = one of 'number', 'alpha', 'date' depending
on whether the information is numerical, alphabetical or a date.
form-length = the length the form field should be. Set to 0
for select, checkbox or radio buttons, and set to '40x3' to make a 40 col
by 3 row text area box. Set to -1 for hidden fields. Set -2 for admin only
fields. This is useful for the Userid field that will let an admin edit/view
it, without other users seeing it. All these fields only apply if you are
using auto_form_generation.
maxlength = maximum length of the field. The script will
kick out an error if a user tries to enter a data larger then the max.
not_null = set to 1 if this field can't be blank.
set to 0 if it can.
default = you can enter a value to use as
a default. For example call &get_date to insert today's date.
valid_expr = enter a regular expression to validate input.
Using the LDL
The database is accessible in two ways: from a cartographic image and
by keywords. In order to retrieve the image using the cartographic base one
starts from a clickable image map (see picture n.
1). It is then necessary to identify a precise point from which the
images were taken (the "shooting point," identified by an intersection
of the UTM grid lines). By clicking on it one accesses a card (see picture
n. 2) with the following information: UTM and geographical coordinates
of the shooting point, date of the shot, previews of the four photographs
taken from the point, and meaningful geographical information such as geographical
names. From this cross-reference document one can visualize the full-size
pictures or go back to the search screen.
The second possibility is a keyword search of the entire database
(see picture n. 3). Thanks to the search options
provided by DBMan, it is possible to make searches within all the cards
using one or more keywords appropriately connected by Boolean operators.
The LDL characteristics and values
The LDL follows the tradition of studies mentioned above and tries
to add a new technique in landscape archiving by introducing four significant
innovative elements:
1) The criterion on which the photographic data collection is based
is systematic and not selective. It records the "state of the art" of a
landscape independently from its single features, following a predetermined
pattern of frequency and orientation of the shots. In this way the LDL
helps to overcome the problems created by an uneven distribution of attention:
«The richest documentation is generally related to highly valued
landscapes or to landscapes that are under the menace of substantial changes.
On the other hand what is normally lacking is - in the great majority of
cases - the study and knowledge of ordinary landscapes» [Zerbi 1993:
173]. The use of four shooting points (which means sixteen pictures) every
square kilometer provides a detailed coverage of the territory. To make
a comparison, the system proposed by K. D. Fines proposed two points for
each square kilometer [1968].
2) The reference system is based on cartography, and specifically on
one of the most abstract elements of cartography (the UTM coordinates),
which is not directly recognizable on the ground. This impartial distribution
of shooting points guarantees a complete "coverage" of the territory [8].
By choosing such an abstract grid of reference, the documentation of the
landscape, as repeatedly emphasized above, avoids the dangers of a subjective
selection criterion, but also encourages possible interactions between
cartographic archives and photographic collections. Since the point where
the pictures have been taken is easily identifiable on the maps, it is
possible to give a new and easily accessible "visibility" - not mediated
by symbols and by geometric scales of reproduction - to cartographic representation,
a sort of parallel text to the cartographic perspective. The reading of
the maps can be systematically accompanied by samples of the landscape
appearance as portrayed by photographs. The fact that the UTM grid of reference
is universally adopted makes the system potentially adoptable everywhere
in the world. The fact that UTM coordinates can be identified on most kinds
of topographic cartography (in the Italian context both on the State cartography
produced by the Geographical Military Institute (IGMI) and on the
cartography produced by regional agencies) makes the LDL system a flexible
tool applicable to different cartographic supports. The contemporary reference
to geographical coordinates (latitude and longitude) constantly allows
shifting from one system to the other when necessary. The GPS instrument
used during the survey campaigns gives the possibility to mark the coordinates
in both the systems.
3) The point of view of the photographs is a horizontal one, similar
to the one perceived by the human eye, and not zenithal, like that of aerial
photographs. The human perceptive component is therefore guided and "limited"
by technical constraints, but not erased by the artificial point of view
typical of an aerial photograph. The LDL provides samples of a perspective
of visual perception that is "ordinary". Many scholars consider the
camera lens itself (50 mm) to be close to the field of vision on which a human eye concentrates
(not counting peripheral vision) [Miossec, 1977].
4) The specific characteristics of the documentation in digital format
(flexibility in use, possibility to simulate different alternative scenarios
through programs of landscape modeling, possibility to send the images
and data through Internet) guarantee the specific "added value" of this
system when compared to a traditional survey made by analogical means ("traditional"
photography).
Limits of the LDL
Like any other articulated set of choices, inevitably, the LDL has
some limits of its own:
1) It does not go beyond the visual inspection of the landscape. Like
all the other visual records, it does not include the global sensorial
perception of the landscape experienced in the field (a mix of visual,
olfactory, and auditive data).
2) It records a horizontal perspective whose extension can be limited
by random obstacles. It can happen that from the selected shooting point
some natural or artificial obstacle blocks the perspective. It has to be
remembered, however, that the LDL does not look for specific panoramic
perspectives or visually privileged points. The presence of visual obstacles
(such as walls, fences, hedges) is as meaningful to the data collection
as a pleasant scenic view from a hill. Like aerial photographs, the LDL
survey system needs a predetermined set of meteorological conditions that
provide a standard of homogeneity to the shoots (atmospheric visibility,
light conditions, absence of fog, snow, rain, etc.). To overcome this limit,
in some cases and for specific purposes, one could think of making available
in the database different shots taken from the same point of view in different
seasons and with different meteorological conditions.
3) It represents a static record of the situation at a precise time
and does not provide documentation on the dynamic aspects of the landscape.
As Giuseppe Papagno suggests, «landscape - with this word we mean
everything that is existing as well as perceived in a territory - becomes
a quadri-dimensional archive, a true "time archive", in which, beyond the
three classical dimensions, one has to add the fourth, time, that is inscribed
in its materials in a durable way [?]» [2000: 297]. The possibility
to repeat the photographic campaigns at pre-determined time intervals,
though, gives the LDL the possibility to follow the evolution of a landscape
through time.
4) It does not grasp directly the invisible values of landscape that,
as Simon Schama states, «is constructed as an excavation below our
conventional sight-level to recover the veins of myth and memory that lie
beneath the surface» [1995: 14]. The LDL, in this perspective, could
be used as a supporting database for the organization of related archives
of paintings, literary quotations, scientific descriptions, travel diaries
to which it could provide a cartographic and at the same time visual support
and reference.
In keeping in mind these limits, it should be remembered that
a global inquiry on the nature of landscape goes beyond the goals of the
LDL. Its systematic documentation pattern, which is more similar to a quantitative
"census" of landscape appearances than to a qualitative selection, aims
to provide a basic iconographic survey of the landscape. This visual archive
has a value in itself as a documentation of the aspects of a territory,
and also aims to support other forms of documentation already available
both to scholars and to professionals, such as cartography. The LDL, while
on the one hand providing a complete survey, can also represent a starting
point for further analyses and inquiries that will interpret and study
its data.
4. Possible uses of the LDL
There are many potential users of the digital documentation of
the LDL, belonging to different fields of research: geographers who study
the forms of the territory, technicians and engineers who are specialists
in the evaluation of environmental impact, historians interested in architecture
or in agricultural systems, landscape architects. Tourist agencies and
local tourist promotion offices could also benefit from the LDL by making
available to prospective visitors an "impartial" documentation of a specific
region that one could browse through as in a virtual tour of the territory.
Last but not least, the LDL could assume an important didactic role if
used in schools: it provides an archive of pictures that can be used to
study the students' area of residence, to prepare field trips, to study
other regions. As mentioned above, a specific value would be added to the
LDL through the repetition of the survey at pre-determined time intervals
(five or more years, for example). The comparison of the images belonging
to the different photographic campaigns would make an accurate portrait
of the evolution of the landscape available.
We plan to propose to public administrations in Italy the adoption
of the LDL system of survey. The setting up of a LDL database would provide
local governments with updated photographic archives of their territories
and would constitute the basis of an international standard of data related
to landscape: «we have also conducted an inquiry into the potential
users of landscape information (State offices and local authorities, public
and private consultants, agencies and institutes that are at different
levels interested in landscape) and their needs. During this research we
encountered a vast demand for a great variety of data at different scales
and for their possible uses (indexes of landscape vulnerability, their
suitability for specific uses, preferences expressed by users, evaluations
for preservation and planning goals)» [Zerbi 1993: 158]. The LDL
could help in satisfying part of this shared "need for landscape".
Footnotes
[1] European Landscape Convention,
EU
URL: <http://www.nature.coe.int/english/main/landscape/conv.htm>.
[2] Zerbi distinguishes two main kinds of
methods of research: "those using a real observer (with a precise position
in time and space) and those referring to an abstract observer, out of
a normal field of vision. The first ones adopt a "terrestrial" point of
view - oblique or even horizontal - while the others adopt a "vertical"
point of view" (1993: 151). This and the following translations from quotations
in Italian are ours.
[3] As summarized in Zerbi: "From an analysis
of the landscape as a resource the perspective was narrowed to an analysis
of the resources 'in' the landscape" (1993: 152).
[4] Archivio dello Spazio, Museo Fotografia
Contemporanea - Provincia di Milano
URL: <http://www.museofotografiacontemporanea.com/lcp_archiviodellospazio.php>.
[5] URL: <http://www.aldus.unipr.it/LDL>.
[6] JPEG image compression FAQ, resource
homepage
URL: <http://www.faqs.org/faqs/jpeg-faq/part1/preamble.html>.
[7] Gossamer Threads - DBMan, product
homepage
URL: <http://www.gossamer-threads.com/scripts/dbman>.
[8] The idea of using a mathematic grid was
already suggested by Zerbi: "The opposite choice may be open to criticism
from a conceptual point of view, but certainly it is more difficult to
criticize it as an operative tool. This choice founds the analysis on dimensionally
similar units or even on rigorously equal units such as the kilometric
grids. The map's division into squares may also be a solution that could
offer arrangements in interdisciplinary perspective. The advantages are
immediately evident, primarily the possibility of exchanging primary information
and secondary data coming from the work of various professionals" (1993:
174).
Bibliographic references
Bailly, Antoine; Raffestin, Claude and Reymond Henri, "Les concepts
du paysage: problématique et représentations", L'Espace
Géographique, 4, 1980, 277-286.
Collot, Michel, "Points de vue sur la perception des paysages", L'Espace
Géographique, 3, 1986, pp. 211-217.
Cosgrove, Denis E., Social Formation and Symbolic Landscape,
London, Croom Helm, 1984.
---, Geography and Vision, London, Royal Holloway - University
of London, 1996.
De Veer, A. A. and Burrough, Peter A., "Physiognomic Landscape Mapping
in the Netherlands", Landscape Planning, 5, 1978, pp. 45-62.
Fines, K. D. "Landscape Evaluation: a Research Project in East Sussex",
Regional
Studies, 2, 1968, pp. 41-55.
Miossec, Jean Marie, "L'image touristique comme introduction a la géographie
du tourisme", Annales de géographie, 86, 1977, pp. 55-70.
Papagno, Giuseppe, "L'archivio del paesaggio. Problemi e tecniche d'analisi",
in Id., Un modello per la storia. Materiale, Attività, Funzione,
Reggio Emilia (Italy), Diabasis, 2000, pp. 285-301.
Porena, Filippo, "Il paesaggio nella geografia", Bollettino della
Società Geografica Italiana, XXIX, 1892, pp. 72-91.
Raveneau, Jean, "Analyses morphologique, classification et protection
des paysages: Le cas de Charlevoix", Cahiers de Géographie de
Québec, XXI, 53-54, 1977, pp. 135-186.
Schama, Simon, Landscape and memory, New York, A.A. Knopf, 1995.
Turri, Eugenio, Il paesaggio come teatro, Venice, Marsilio,
1998.
Veyret, Yvette and Le Maître, Anne, "Réflexions sur le
paysage: paysage et patrimoine historique. Quelques fonctions du paysage",
L'information
Géographique, 1996, 60, pp. 177-183.
Zerbi, Maria Chiara, Paesaggi della geografia, Turin, Giappichelli,
1993.
Zunica, Marcello, "Dal mito del paesaggio al pragmatismo dell'ambiente",
in Il paesaggio tra ricerca e progetto, edited by Maria Chiara Zerbi,
Turin, Giappichelli, 1994, pp. 149-165.
Alberto Salarelli
Istituto di Biblioteconomia
e Paleografia, Università di Parma
Via D'Azeglio 85, 43100 Parma, Italy
Tel: +39 0521 902272
E-mail: alberto.salarelli@unipr.it
URL: http://www.unipr.it/~labbibl/ashome.html
Davide PAPOTTI is a Ph.D. candidate in the Department of Geography at the University of Padova (Italy). He previously studied at the University of Virginia (Charlottesville, VA, USA), where he received his M.A., and at the University of Chicago (IL, USA). Areas of research interest include geography of tourism, relations between geography and literature, landscape studies.
Alberto SALARELLI is assistant professor in the Institute
of Library Science and Paleography at the University of Parma (Italy)
where he currently teaches Information Systems. Areas of research interest
include digital libraries, Internet services for libraries and knowledge
management.
[*] A previous and abridged version of this
paper was presented at RCDL 2001, Third All-Russian Scientific Conference
"Digital Libraries: Advanced Methods And Technologies, Digital Collections",
Petrozavodsk, Russia, September 11-13, 2001.
URL: <http://rcdl2001.krc.karelia.ru/index.html>.
For citation purposes:
Davide Papotti, Alberto Salarelli, "LDL (Landscape Digital Library): A Digital
Photographic Database of a Case Study Area in the River Po Valley, Northern Italy",
High Energy Physics Libraries
Webzine, issue 5, November 2001
URL: <http://webzine.web.cern.ch/webzine/5/papers/5/>
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