Translation of user requirements into house designs: A multi-dimensional scaling analysis

An experiment was conducted to determine how user requirements for single-storey houses are translated into actual design layouts. Architectural students were asked to provide floorplans of houses for four quite different hypothetical users. The briefs contained information either about spatial requirements or about life-style characteristics. Another group of architectural students later evaluated the appropriateness of the designs for the intended user. An INDSCAL analysis of the data (inter-room distances) produced a 4-dimensional solution that accounted for 65% of the variance between house designs. The salience of the dimensions seemed to be more a function of the designer than of the requirements of the user.It was found that when users' requirements are expressed in spatial terms only, the designs produced are clearly a function of the user, not the designer. The more information supplied about the user, the greater the tendency for congruence in the designs. When the brief consisted of life-style characteristics only, the results remained equivocal. There appeared to be little consensus on what designs were appropriate for the hypothetical users.The experiment strongly suggested that (a) architecture students handle information about spatial requirements with ease and with a good deal of consensus on what they consider to be the appropriate design solution for each user; (b) information about life-style characteristics and activity profiles, on the other hand, is handled quite differently by different students. In the latter case, the house designs produced probably follow implicit design-behaviour theories that are quite idiosyncratic. A number of theoretical and methodological issues that require further investigation are raised in the discussion.     

A Daily Time Series Analysis of StreamWater Phosphorus Concentrations Along an Urban to Forest Gradient

During a 1-year period, we sampled stream water total phosphorus (TP) concentrations daily and soluble reactive phosphorus (SRP) concentrations weekly in four Seattle area streams spanning a gradient of forested to urban-dominated land cover. The objective of this study was to develop time series models describing stream water phosphorus concentration dependence on seasonal variation in stream base flows, short-term flow fluctuations, antecedent flow conditions, and rainfall. Stream water SRP concentrations varied on average by ±18% or ±5.7 μg/L from one week to another, whereas TP varied ±48% or ±32.5 μg/L from one week to another. On average, SRP constituted about 47% of TP. Stream water SRP concentrations followed a simple sine-wave annual cycle with high concentrations during the low-flow summer period and low concentrations during the high-flow winter period in three of the four study sites. These trends are probably due to seasonal variation in the relative contributions of groundwater and subsurface flows to stream flow. In forested Issaquah Creek, SRP concentrations were relatively constant throughout the year except during the fall, when a major salmon spawning run occurred in the stream and SRP concentrations increased markedly. Stream water SRP concentrations were statistically unrelated to short-term flow fluctuations, antecedent flow conditions, or rainfall in each of the study streams. Stream water TP concentrations are highly variable and strongly influenced by short-term flow fluctuations. Each of the processes assessed had statistically significant correlations with TP concentrations, with seasonal base flow being the strongest, followed by antecedent flow conditions, short-term flow fluctuations, and rainfall. Times series models for each individual stream were able to predict ∼70% of the variability in the SRP annual cycle in three of the four streams (r² = 0.57–0.81), whereas individual TP models explained ∼50% of the annual cycle in all streams (r² = 0.39–0.59). Overall, time series models for SRP and TP dynamics explained 82% and 76% of the variability for these variables, respectively. Our results indicate that SRP, the most biologically available and therefore most important phosphorus fraction, has simpler and easier-to-predict seasonal and weekly dynamics.     

Computer simulations of terrestrial carbon and atmospheric interactions

Terrestrial carbon modelling shows that the Goudriaan and Ketner and Esser simulations fit historical data well, but the results are sensitive to the decomposition rate coefficient of old sediment carbon. Modification of this rate constant over time, weighted by emission increases or linear increases, changes the model results to fit historic ice core data. Very old sediment carbon decomposition has an effect on the model postdictions only when the rate constant is 10 times greater than that predicted from sediment studies. Future estimates show that a maximum change from agriculture to forest has a small effect on abating emission increases. Controlling emission rates at 5.1 x 10(15) g C/a will result in almost a 50% increase in atmospheric CO(2) in 200 years, and reducing emission rates to 1960 levels (approximately 2.5 x 10(15) g C/a) immediately will still result in an increase in atmospheric CO(2).     

Advanced manufacturing technology and work simplification: An empirical study

This paper is concerned with the effects of advanced manufacturing technology on shopfloor operator jobs and work attitudes. A strong line of argument from labour process theory suggests that such technology will simplify and deskill jobs, and reduce the quality or working life. This proposition was explored within a large electronics company which assembles computer boards, where two different applications of information technology have been experienced. These were compared with two traditional manual assembly jobs. Assessment of job content, perceived job characteristics and operator work attitudes, showed no uniform deskilling effects of advanced manufacturing technologies. Much larger differences existed both between the different new technology applications and between the traditional jobs. This demonstrates that choice of technology is important to skill use and employees' attitudes, as are the choices for the organization of work around it. These are not uniform processes even within a single organization. Experience of operating advanced manufacturing technology was also accompanied by more positive views concerning its impact on the shopfloor.     

Conservation tillage: best management practice for nonpoint runoff

Decisionmakers are in the process of selecting remedial measures for controlling nonpoint pollution runoff. Conservation tillage (CT) is being looked to as one of the major recommended practices. Many different systems exist and vary in the amount of crop residue left and soil roughness produced. Therefore, varying results occur in terms of yield and potential water quality impacts. Differences vary with type of tillage system, soils, geographic region, and the farmer's management. The purpose of this review is to provide material to decisionmakers that points out the assets and liabilities of the various CT systems. Tillage effects on soil characteristics and plant growth are presented and include a discussion of soil moisture and temperature, weed and insect control, nutrient availability, and yields. Water quality aspects are addressed through a discussion of the effects CT systems have on sediment, water, pesticide, and phosphorus loss.This work was supported by the Soil Science Department, College of Agriculture and Life Sciences, University of Wisconsin-Madison, and the U.S. Environmental Protection Agency, Region V, Chicago, Illinois. (Grant No. G005139-01).