Statistical approach for the estimation of watershed scale nitrate export : a case study from Melen watershed of Turkey

Nutrient pollution such as nitrate (NO3−) can cause water quality degradation in rivers used as a source of drinking water. This situation raises the question of how the nutrients have moved depending on many factors such as land use and anthropogenic sources. Researchers developed several nutrient export coefficient models depending on the aforementioned factors. To this purpose, statistical data including a number of factors such as historical water quality and land use data for the Melen Watershed were used. Nitrate export coefficients are estimates of the total load or mass of nitrate (NO3−) exported from a watershed standardized to unit area and unit time (e.g. kg/km2/day). In this study, nitrate export coefficients for the Melen Watershed were determined using the model that covers the Frequentist and Bayesian approaches. River retention coefficient was determined and introduced into the model as an important variable

Some constraints and tradeoffs in the design of network communications

A number of properties and features of interprocess communication systems are presented, with emphasis on those necessary or desirable in a network environment. The interactlonsbetween these features are examlned, and the consequences of thelr incluslon in a system are explored. Of special interest are the tlme-out feature which forces all system table entries to "die of old age " after they have remained unused for some period of time, and the insertion property which states that it is always possible to design a process which may be Invls~bly inserted into the communication path between any two processes. Though not fled_to any particular system, the discussion concentrates on distributed systems of sequential processes (no interrupts) with no system buffering