Abstract.  An ecodesign model focus on the ergonomic dimension as the evolving core of the architectural and urban design (anthropometry included).  Ergonomics or human factors is a body of knowledge about human characteristics that are relevant to design.  Basically it is concerned with the design of behaviour at a micro and macrolevels.  This it achieves by designing the environment in which behaviour occurs according to the intrinsic needs of the human beings in their relationships with themselves and with each other and with the environment.  These individual local needs trigger off an encompassing awareness of the homeostatic mechanisms of the human being and of the Mother Earth.  The link between the local and the global necessarily entails "dwell regionally".  The autopoietic and hermeneutic nature of the author's ecodesign model (MPSTW) reveal several levels of granularity enabling the design and planning of sustainable environments in different scales.  It is being advanced as a software implemented in a prototype based object oriented programming language Self.  Prototype based languages are the newest branch of the emerging hermeneutic computer science as opposed to the mainstream formal computer science.  They allow flexibility and malleability and cooperative work, thus mimicking the very nature of design.

Key words: ecodesign model, ergonomic dimension, externality space.

I The levels of ergonomics

The aim of this paper is to deal with the ergonomic dimension as a main pillar of an ecodesign model that is being implemented in the prototype based object oriented programming language Self.  Prototype based languages are the newest branch of the emerging hermeneutic computer science as opposed to the mainstream formalist computer science.  They add flexibility, malleability and cooperative work, thus mimicking the intrinsic nature of design.

Ergonomics or human factors is a body of knowledge about human abilities, human limitations and other human characteristics that are relevant to design (Alphonse Chapanis 1995:1625).  Ergonomic design or human factors engineering is the application of ergonomic information to the design of tools, household equipment, systems, tasks, jobs, artifacts, processes, activities and environments for safe, comfortable and effective human use.

If our aim is to apply what we know about or what we find out to the design of practical things or artifacts, we have to study people in special local circumstances. Ergonomics, in terms of its unique technology, can be defined as the development and application of human-system interface technology.  H.W. Hendrick adds further, at the microlevel this includes:

 human-machine, human-product, human-artifact interface technology or hardware

 ergonomics,

 human-environment interface technology or environmental ergonomics and

 user-system interface technology or software ergonomics.

Software ergonomics is referred to as cognitive ergonomics because it deals with how people conceptualize and process information.  Hence ergonomics must play a great role here since human beings are not endowed with biological functions corresponding to associative capacities fundamental to inter, multi and transdisciplinary studies.  Only in the last decade studies indicate the profuse ramification of dendrites would perform this function.  Nobody is born with it.  It is triggered off by brain storm techniques.

At the macro - or overall systems there is organization-machine, organization-product, organization-artifact interface technology or macroergonomics.  Bammer (1993) conducted an analysis on biomechanical factors.  This led her to conclude that (ergonomic) efforts to effect biomechanical improvements are important and should be encouraged; but, by themselves these improvements are insufficient to reduce work-related musculoskeletal disorders (WMSDs).  Bammer concluded that improvements in work organization to reduce pressure, and to increase task variety, control and the ability for employees to work together must be the main focus of prevention and intervention.  She further notes that ironically, such improvements in work organisation generally also lead to increased productivity (Bammer 1993:35).

II Homeostasis is common to the human being and to the planet

The continuing degradation of our physical environment as well as the anthropogenic environment has led to life cycle analysis, life cycle assessment, environmental assessment and other similar terms that are bandying around.  Jacqueta J. Lee, P.O'Callaghan and D. Allen define life cycle assessment (LCA) encompassing three well defined stages:

Life cycle inventory (LCI), an objective data-based process of quantifying energy and raw material requirements, air emissions, water borne effluents, solid waste, and other environmental releases incurred throughout the life cycle of a product, process or activity.

Life cycle impact analysis, a technical quantitative and/or qualitative process to characterise and assess the effects of the environmental loadings identified in the inventory component. The assessment should address both ecological and human health considerations as well as other effects such as habitat modification and noise pollution.

Life cycle improvement analysis.  The systematic evaluation of the needs and opportunities to reduce the environmental burden associated with energy and raw materials use throughout the whole life cycle of a product, artifact, process or activity. The analysis may include quantitative and qualitative measures of improvement, such as changes in product design, raw material use, industrial processing, consumer use and waste management.  For example, the cement production process emits 38% of the total amount of CO₂ emission in the USA.  This is LCI.  Its effect on global warming is dealt by the life cycle impact analysis.  Definitely 1% of the total amount of gases producing global warming is due to the cement production around the world (Ecodecision).

Being a green designer, the author is especially concerned with creating an environment to improve the physical, mental, psychical health of the human beings.  Sure this will have a tremendous impact in the cognitive abilities of the human beings.  Due to the overwhelming growth of human population, there is not a single human being that may be considered sound, if the health of Gaia is in jeopardy.  How can man stop this entropic behaviour towards the site and hence the planet?  The response is obviously through understanding of the nature of nature's behaviour.  To understand that the triad of temperature, potential evapotranspiration ratio and average total annual precipitation in mm determines a range of natural life zones or ecosystems in terms of world plant formations and their associated local biodiversity.

James Lovelock in his theory of Gaia has taken this possibility to the level of the entire globe: the Earth's living matter, air, oceans and land surface form a complex system which can be seen as a single organism and which has the capacity to keep our planet a fit place to live.  Gaia is...a cybernetic or feedback system which seeks an optimal physical and chemical environment for life on this planet (S.E. Joergensen 1992).

Hence ecosystems are capable of homeostasis.  They maintain a healthy steady state over a wide range of conditions.  However, there are limits beyond which they cannot assimilate change.  Once forced beyond these limits, homeostasis breaks down and major damage occurs.

Likewise, the ergonomist or the human factor engineer is well aware that the general thermal state of the body both in comfort and in heat or cold stress is dependent on an analysis of the heat balance for the human body:

S = M - W - C - R - E_sk - C_res - E_res - K

where S = heat storage in the body; M = metabolic heat production; W = external work; C = heat loss by convection; R = heat loss by radiation; E_sk = evaporative heat loss from skin; C_res = convective heat loss from respiration; E_res = evaporative heat loss from respiration; and K = heat loss by conduction.

The factors influencing this heat balance are: activity level (metabolic rate, met or Wm^-2); thermal resistance of clothing I_cl (clo or m²CW^-1); evaporative resistance of clothing R_e (m²PaW^-1); air temperature t_a(C); mean radiant temperature t_r (C); air speed _ar (ms^-1); partial water vapour pressure p_a(Pa).

These parameters must be combined so that the thermal storage is 0, or else the working time has to be limited to avoid too much strain on the body.  To provide comfort, the mean skin temperature also has to be inside certain limits, and the evaporative heat loss must be low. In existing standards, guidelines or handbooks, different methods are used to evaluate the general thermal state of the body in moderate environments, cold environments and hot environments; but all are based on the above heat balance and the listed factors (Bjarne W. Olesen 1995).

Moreover this is a fundamental law of life.  Eric D. Schneider and James J. Kay state that as systems are moved away from equilibrium, they will utilize all the means available to them to dissipate externally applied gradients (thermal equilibrium = inorganic soup at the onset of the universe).  When highly ordered complex systems emerge, they develop and grow at the expense of increasing the disorder at other hierachical levels in the system.. This suggests that as an ecosystem develops it becomes more effective at removing the exergy (it is a measure of the potential of energy to perform useful work) in the energy it captures and this exergy is utilized to build and support organization and structure.  The more exergy that the ecosystem can utilize the greater its ability to support organizational processes.  Hence how to deal with the "forgotten country" which lies "in between" local and global spheres of action and that is causing so much distress?  If Gaia is well designed macro and microergonomically (of course the author is using a metaphor because primarily ergonomics is concerned with human beings) why shouldn't we mimic it?  The fourth law of thermodynamics or the Ecological law of thermodynamics revealed by S.E. Joergensen states: If a system has a through-flow of exergy, it will attempt to utilize the flow to increase its exergy, i.e., to move farther away from thermodynamic equilibrium; if more combinations and processes are offered to utilize the exergy flow, the organization that is able to give the system the highest exergy under the prevailing conditions and perturbations will be selected.

The author wants to convey the idea the whole is much more than the simple sum of its parts despite the second law of thermodynamics if we manage to create a link between the local and the global keeping the homeostasis of the organisms and of the planet (the greatest organism).  So we will reach the perfect internal physiological functioning of the body in a broad scale.

III Ergonomics and the global problems

What role can ergonomics play in the solution of the problems that are menacing mankind and the planet's integrity?  Neville Moray says ergonomics is concerned with the design of behaviour.  This it achieves by designing the environment in which behaviour occurs (including particular devices such as tools) by designing tasks and methods and by shaping behaviour directly through selection and training.  It encompasses all the environments from domestic, industrial to agricultural, medical, military, etc.

Ergonomics alone will not solve the problem but within an interdisciplinary approach, what ergonomics has to contribute to the problems that mankind and the planet are facing is essentially a technology for changing behaviour to that which offsets the problems.  Basically people must change their behaviour.  They must conserve resources; they must refrain from polluting the environment; they must minimize their consumption of energy, water and products; they must recycle waste; they must adopt healthy lifestyles.  So ergonomics must help to ensure such behaviour. Neville Moray adds further that systems design are needed that will elicit the desired behaviour whether or not people voluntarily undertake to perform it.  The increasing growth of environmental nongovernmental organizations (ENGOs) from 176 in 1909 to 4, 518 in 1988 (Greenpeace members increased from 1,400,000 members in 1985 to 6, 750, 000 in 1990) (M. Finger 1994) shall play a great role in this aspect.  ENGOs attempt to link local needs with the challenges of the global ecological crisis.  They do this by transcending national boundaries where states and international organizations are reluctant to do so.  So ENGOs seek rather to develop solutions to global and local environmental problems.  So time is ripe to support vast participation of the citizen to shape the environment.

IV The ergonomic dimension of an ecodesign model

The author contributes to the solution of these problems through the development of a software based on the domain dependent knowledge designed as the Model of Primary, Secondary and Tertiary Wave (MPSTW) for the design and planning of sustainable cities.  It is the outcome of the application of catastrophe, semiotics and graph theories to the realm of architectural design and urban design.  Here planning (the tertiary waves) are born out of the primary waves that deal with the interaction processes of the architectonic object with the environment and the secondary waves that deal with the design processes (basically a geometric modeling carried out through rosette, frieze and crystallographic groups, tilings, splines and in a further stage fractals)  The ecosystem is partitioned into eco-systems with hyphen.

Here the author wants to focus on the ergonomic level of the MPSTW.  The primary and secondary waves are applied to each element of the design process namely environmental comfort (thermal comfort, acoustics, daylighting), activities, structural systems, hydraulic installations, constructive systems and so on.  The primary waves are described by the four hypotheses homeostasis, continuity, differentiation and repeatability.  Homeostasis will deal respectively to the corresponding elements with the comfort zone, the audibility range with inferior and superior thresholds of approximately 20 Hz and 20kHz respectively characterizing the audibility threshold and pain threshold; the eye has a great ability to adapt to a wide range of illumination ranging from 100,000 lux at open air to a 300 lux in the interior of a home; an activity needs a space that is limited by adequate measures and by anthropometric measures and ergonomic concerns of the equipment (household, industrial equipment, etc); the site must be examined from the viewpoint of excavation, erosion and bearing capacity of the earth to determine the soil nature and the requisites of the foundations to be implanted in it; the need for water conservation manifested as design for toilets in which the tank is refilled by a pipe which provides water for washing hands, the dirty water then being collected for use in flushing, moreover two flush handles, one of which uses half tank of water after urinating and one a full tank after defecating, special design to control the amount of water (2 liters in Japan), the need for not polluting the rivers and aquifers through building of special reservoirs and recycling of sewage as well as a sound policy of geotechnical mapping for not building around the margins of rivers and the application of life cycle assessment for architectural artifacts.

The hypothesis continuity deals with the climate, the sound, the daylighting graphics of the lighting environment (illumination under sunny, cloudy and rainy days along the year); the sequence of actions bound to different settings and depicted as functional structure; the geology of the site; hidrogeology and the assets of renewable and nonrenewable resources.  Obviously uniting life cycle assessment techniques and the interaction with the environment may be leading to another level of concern in ergonomics that may well define another emerging field of building.

Sure the hypothesis differentiation is the realm of macroergonomics.  The different activities may be characterized as generating light (L), heat (H) and sound (S) and needing L, H and S and being insensitive to L, H and S; generating L, H and S, sensitive to L, H and S needing L, H and S; not generating L, H and S, insensitive to L, H and S and not needing L, H and S and finally not generating L, H and S, sensitive to L, H and S and not needing L, H and sound like sleeping for example. In designing for housing groups, it may be necessary to lay out plans for families wrt their needs of communication and privacy.  A wide variety of plans would be the outcome.  A family with small children should live in a setting that allows the free movement of the child as well as communication with other children and exploitation of the space in terms of the touch, smell, seeing, hearing and tasting.  But parents may be extremely introspective and not at all willing to get rid of their privacy and the design must cope up with these needs for differentiation.  It must foster diversity in unity.

In the hypothesis repeatability one truly links the local with the global hence generating the third waves responsible for planning.  Here a finer granularity manifests.  Each eco-system with hyphen is indeed an application of the sum of the processes of each element, which is seen as a subeco-system with hyphen.  It works as the figure of a language.  A sign is composed of figures, i.e., the prefixes, suffixes and radicals that shape a word.  Hence the eco-system with hyphen defines the ecossystem and is defined by the ecossystem.  Christopher Alexander fails in his A Pattern language because the granularity is too coarse.  Although it is a breakthrough when it blends design and planning through the discretization of planning as design patterns, by its turns the design patterns are wholes whose intrinsic nature is not revealed.  An eco-system with hyphen in the MPSTW is seen as a summation of interaction processes of the architectonic object with the environment(sort of genotype) and design processes (sort of phenotype).  The author has already introduced the finer granularity of the primary waves.  The finer granularity of the design processes consists first of all in showing that the architectural design may be considered as a language with its planes function and form and its respective stratas substance of the function, form of the function, substance of the form and form of the form.  Of course graph theory enables one to reveal them.  It is exactly the hypothesis repeatability that calls attention to what is common to a set of artifacts and may be quantified.

For example, George C. Galster puts forward that the neighborhood can be seen in terms of an externality space.  It is defined as an area where environmental changes initiated by others are perceived as altering the well being (psychological or financial) that a given individual expects from a given place.  It is characterized by:

a) congruence - the degree to which the externality space of an individual corresponds to

predefined geographic boundaries.

b) generality - the degree to which externality spaces of an individual for different types of

externality correspond.

c) accordance - the degree to which externality spaces for different individuals in the same

area correspond.

Galster unfolds his theories in terms of mathematical algorithms through the set theory.

The author hopes to convince the reader that hermeneutic and autopoietic nature of the MPSTW reveals the ergonomic dimension as central to the shaping of the artifacts ranging from single units to their grouping as housing groups, neighborhoods, boroughs, cities, etc.  We may well talk about an ecoergonomics approach to depict this new mode of designing.

V Conclusion

Being aware about the homeostatic mechanisms of the individuals and of the planet will cause one to feel as pulsating in the rythm of the Mother Earth.  Indeed certain environments help man to keep its cellular oscillations.  For example, patients submitted to surgery experience considerable stress.  Data of recovery for pairs of patients with the same surgery, sex, weight, age, tobacco use and previous hospitalization booked in identic rooms with exception of the view through the window were compared.  A member of each pair looked into a grove, while the other looked to a wall of brown bricks.  Individuals with view for trees recovered sooner and left the hospital earlier.  The wall patients received more analgesics, narcotics while the tree patients needed only aspirin.  Sure this awareness shall trigger off a love for the region.  Instead of thinking globally , act locally, we might also say "dwell regionally", for then our actions consciously ressonate on every other level in a way appropriate to it.(David Closkey 1995). At the end of the 20th century, the world faces three major interlinked crises: a crisis in the relationship between humans and their environment; a crisis in the relationship between human themselves and a crisis in the relationship between societies. These crises are rooted in modern Western thought which has turned the market and science into ends in themselves to which everyone if required to submit regardless of the consequences (Pierre Calame 1996).

We do hope more awareness about the homeostatic mechanisms of the planet and of the human beings will improve human cognitive capacities and enable mankind to overcome the actual crisis.

V Bibliography

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