School of Architecture and Spatial Planning

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On outlier identification in geodetic networks using principal component analysis
(1986) Aduol, Francis O.
Detection of outliers in geodetic networks using principal component analysis and bias parameter estimation.
(1987) Aduol, Francis O.
A static dynamic model for densification of geodetic networks.
(1993) Aduol, Francis O.
in the tradition of several joint papers by the honoree and myself, including E. Grafarend and B. Schaffrin (1974, 1976, 1988) and E. Grafarend, B. Schaffrin, and E. Knickmeyer (1982), I took up the subject again in B. Schaffrin (1984, 1989), N. Tamim and B. Schaffrin (1995) and B. Schaffrin and J. Cothren (1998), now with the emphasis on network densification methods which are rigorous, but which leave tie points unchanged along with their variances and covariances. Such a requirement led to the notion of “reproducing estimators” as first presented by B. Schaffrin (1997). It has been known for a long time that the so-called “dynamic adjustment” of geodetic networks can be interpreted as least-squares collocation, according to H. J. Buiten (1978), which would not yield estimates with the “reproducing property.” Also the “free net adjustment” followed by a Helmert transformation would not per se guarantee identical tie point coordinate estimates unless we “forget” about the deviations whose norm we had minimized, but usually not to zero. So the only “reprodu c - ing” alternative seemed to be given by the formulas of a classical least-squares adjustment with fixed constraint even though the tie points are “ fiducial” in their nature, having typically a full dispersion matrix. Therefore, in the formula for the corresponding variance-covariance matrix we find an add i - tional term which vanishes as soon as the “ fiducial” points become real “fixed” points; see, for i n - stance, B. Schaffrin (1984, 1989). This apparently has been the method, applied by JPL over the years, when they talked about “ fiducial network strategies” as in S. M. Lichten et al. (1989), for instance, without spelling out exactly what they did. In any case, as could have been expected, the latter one was shown not to be the optimal estimator with the “reproducing property” by B. Schaffrin (1997). Instead, the optimum turned out to be the “forgetful dynamic adjustment” where every densification point is found conventionally through least- squares collocation, but the tie points remain unchanged. Consequently, a free adjustment followed by a “forgetful Helmert transformation” must be considered inferior and may no longer be carried out routinely; see also K. R. Koch (1983) and F. W. O. Aduol (1993). Here we try to employ least-squares methodology to generate that “reproducing estimator” which, as we already know, will be optimal in this class
A model for the establishment of an integrated regional geodetic datum
(1993) Aduol, Francis O.
A model for the establishment of an integrated geodetic datum covering a region is treated. The integrated geodetic datum is understood here to comprise the geoid, the reference ellipsoid, and the positional coordinates. A comprehensive unified solution model including the three parameters comprising the datum is considered. The estimation model adopted rigorously incorporates determined prior information in the estimation of the datum parameters. Mathematical models together with the pertinent observation equations are presented, followed by a description of the procedure for the actual setting up of the datum. The observational scheme is based on a system of modular traverses anchored on a trilateration of GPS baselines.
Robust geodetic parameter estimation through iterative weighting
(1994) Aduol, Francis O.
A procedure for robust linear estimation of parameters on the basis of iterative weighting of observations is presented. The approach considers the weights of observations as not just functions of the observational variances, but as functions of both the observational variances and estimates of the observational residuals. However, as the residuals are themselves functions of the estimates of the unknown parameters, the entire estimation procedure is performed iteratively. Three test examples comprising a linear point estimation, a linear regression case, and a geodetic network have been adopted to demonstrate the procedure. The results indicate that the proposed approach is effective in the isolation and management of outliers, and further that the robust estimation is in general a more efficient estimation procedure than the ordinary least squares.
An evaluation of some robust estimation techniques in the estimation of geodetic parameters.
(1999) Aduol, Francis O.
In Part 1 of this study, we reported on an evaluation of the performances of four robust estimation techniques, namely: the modified residuals technique, the modified weights technique, the modified residuals-weights technique, and the iterative weighting technique. The methods were then tested on a simulated geodetic network. In this second part of the study, we carry out a further evaluation of the methods with a real geodetic network as the test network. In order that a set of gross-error contaminated observational may be available for the study, gross errors have been simulated into observational set. The results of the study largely corroborate the findings in Part 1 of the study
Establishing teaching staff requirements for university academic programmes
(1999-07) Aduol, Francis O.
The surveying profession beyond the Year 2000 and the Kenyan surveyor.
(2000) Aduol, Francis O.
An overview of geospatial information education and its development in Kenya in general and Jomo Kenyatta University of Agriculture and Technology (JKUAT) in particular is given. The gradual evolution and conception, design and establishment of Geomatic Engineering and Geospatial Information Systems (GIS) training programmes at Jomo Kenyatta University is discussed. The impetus of this growth, envisaged direction, expected impact on the practice of Geomatic Engineering, GIS and associated disciplines in Kenya and the Eastern Africa Region are explored. The anticipated challenges and strategies for meeting the same are discussed
A model for estimating student unit cost and staffing requirements for university programmes with reference to Kenyan public universities.
(2001) Aduol, Francis O.
A model for the estimation of student unit costs and the staffing requirements for university academic programmes is presented. The development of the model starts off with the specification of a staff distribution matrix, which sets out the proportions of the various staff levels in a given staff category that are needed to service at a particular degree level. The categories of staff considered are teaching (academic), senior administrative, technical, clerical, and semi-skilled. Within a given category of staff are considered various staff levels, e.g. Professor, Senior Lecturer and Lecturer in the case of the teaching staff category. The academic programmes are considered to be taken at the Bachelor's, Master's and the Doctorate degree levels. Ratios between numbers of staff in a given level within a category, as well as ratios of staff within the category needed to service at the various degree levels are specified a priori. Academic (teaching) student-staff ratios for the various programmes are also set out a priori. Student-staff ratios for the other categories of staff are then computationally derived from the academic student-staff ratios. For each staff category a staff distribution matrix is then worked out. With the staff distribution matrix thus specified, the student unit cost and staffing requirement for a given academic programme are computed through various manipulations on the matrix. As a test example, the model is used to estimate student unit cost and staffing requirements for the six public universities in Kenya
Financing public universities in Kenya: a model based on rationalised student unit costs and staffing
(2001) Aduol, Francis O.
Whitehead (1967:4) defines the term “Education is t he acquisition of the art of the utilization of knowledge.” The universities are those institutions that teach learners the art of the utilization of knowle dge. For this to be achieved, goals and objectives are set in such a way that at a certain time 3 or 4 years, an individual is said to acquire the basic art at u ndergraduate level. If still interested, the individual can continue to higher l evels. This basic level and other levels above it are referred as higher educa tion. In this paper, the term university will be used to refer higher education. The art of the teaching and learning process requir es the appropriate media to communicate the curriculum content in this paper, the term communication simply refers to the art of sending o r receiving messages. Development of any nations depends on the participa tion of its human resources. This need well qualified personnel to handle all matters pertaining to her specific needs. Education in deve loping countries has expanded tremendously from few secondary schools at independence to the vast numbers that we have today. Most of the Africa n countries had either one or two universities at independence or none at all. However, this trend has changed and the countries can be congratulated for making sure that their people/citizens have access to higher education
Robust Geodetic Parameter Estimation Under Least Squares Through Weighting on the Basis of the Mean Square Error
(2003) Aduol, Francis O.
A technique for the robust estimation of geodetic parameters under the least squares method when weights are specified through the use of the mean square error is presented. The mean square error is considered in the specification of observational weights instead of the conventional approach based on the observational variance. The practical application of the proposed approach is demonstrated through computational examples based on a geodetic network. The results indicate that the least squares estimation with observational weights based on the mean square error is relatively robust against outliers in the observational set, provided the network (or the system) under consideration has a good level of reliability, as to make the network (or system) stable under estimation
A networks approach to understanding the role of the market and the State in housing: the cases of Nairobi, Kenya and Johannesburg South Africa
(2005) Omenya, A
This paper outlines the concept of 'housing networks' to reveal housing problems in the context of Johannesburg, South Africa, and Nairobi, Kenya. It first defines housing networks and outlines areas of knowledge where the 'networks concept' has been used. The paper then develops a case for the application of 'networks' in understanding urban housing problems, focusing on the roles of the State, the market and civil society. It explores resource origins, allocation, flows and destination in low-income housing in Nairobi and Johannesburg. It argues that the networks for land delivery make land inaccessible for low-income households in both cities. The means of accessing finance for housing available to the poor tend to be exploitative despite government regulation in the case of Johannesburg. Provision of infrastructure, services and social amenities ignore the collective resources of low-income households. Labour and sweat equity concepts are misplaced in light of cheap labour and unemployment, particularly in Nairobi. Building standards, materials and technology favour the upper-income groups despite allowance in both cities for lower building standards. Key lessons and conclusions are drawn in conclusion
Agent-based modelling of urban sanitation: informal settlements in Nairobi
(2006) Obonyo, Esther; Omenya, Alfred
During the last two decades, Nairobi in Kenya has experienced a rapid increase in its urban population. With the number of houses failing to match the increase in urban population, a number of informal settlements (slums) have mushroomed. As the population of these areas continues to increase, the inability of the local authorities to provide basic sanitation services for the urban dwellers is becoming a serious problem. The unprocessed soil water being discarded into the environment is not only adversely affecting the ecosystem; it is also creating unhygienic conditions that are conducive for the transmission of diseases in the densely populated informal settlements. A number of community-based organisations (CBOs) have undertaken various initiatives to mitigate against such problems. These organizations operate largely independently and there is no evidence of an evaluation being undertaken across the board to model the social, economical and environmental impact of the existing sanitation initiatives. This paper describes a proposed agent-based model that is aimed at doing just that. The proposed system will increase the comparative efficacy in the selected domain by modeling the values and incentives for the different organisations in various scenarios.
A Networks Approach to Understanding the Role of the Market and the State in Housing: The Cases of Nairobi, Kenya and Johannesburg, South Africa
(2008) Omenya, A
This paper presents an outline case for use of ‘housing networks concept’ to unpack housing problems in the context of Johannesburg, South Africa and Nairobi, Kenya. It begins by defining housing networks and outlining areas of knowledge where the ‘networks concept’ has been used. The paper then develops a case for application of ‘networks’ in understanding urban housing problems, focusing on the roles of the state, the market and civil society. It explores resource origins, allocation, flows and destination in low-income housing in Nairobi, Kenya and Johannesburg, South Africa. The paper argues that the networks for land delivery make land inaccessible for the low-income in both cities. The means of accessing finance for housing available to the poor tend to be exploitative despite government regulation in the case of Johannesburg. Provision of infrastructure, services and social amenities ignore the collective resources of the low-income. Labour and sweat equity concepts are misplaced in light of cheap labour and unemployment, particularly in Nairobi. Building standards, materials and technology favour the upper- income despite allowance in both cities for lower building standards. Key lessons and conclusions are drawn at the end.
Evolution of urban housing strategies and dweller-initiated transformations in Nairobi
(Elsevier, 2011) Makachia, Peter A
In her century of existence, Nairobi has served as a laboratory of various housing strategies targeting the indigenous Africans and the poor. Discriminated based on racial segregation during colonisation, the poor have also been the object of post-colonial economic marginalisation. Consequently informal settlements and dweller-initiated transformations of formal housing has become their only mode of urban domicile. The paper looks at the later model and isolates the strategic policy and design choices that have guided the dwellers’ drive to transform the provided houses. The investigation uses an historical review of related literature in existing housing estates in city’s Eastlands’ District. Further, a case study of Kaloleni Rental Estate from the district was undertaken. The resultant dwellings point to informalisation leading to deterioration through use of ‘temporary’ materials and unplanned space uses in these formal schemes. The strategies based on modernist templates which ignored consultation, local cultural spatial paradigms and basic functional needs are faulted for the proliferation of these undue transformations that compromise the living environments. Further, the continued lack of tenant security in transforming dwellings has aided in the continual physical and social deterioration of neighbourhoods. The recommendations include a phased design guided densification model, socially inclusive through the incorporation of the existing dwellership and their participation.
Network analysis as an alternative tool for understanding and intervening in informal housing: case studies from Nairobi, Kenya
(2011) Omenya, Alfred
This paper highlights possible areas of application of network analysis to analyse aspects of informal housing. It illustrates three network concepts: ego-centric networks (ties of individuals); networks towards collaborative action (ties that groups involved in various aspects of housing use to access resources); and networks of exchange (general ties defined by the resources they are used to access). Using examples from two low income settlements in Nairobi, the paper illustrates how each of the three concepts may be used to analyse empirical data. There are few previous studies of how these networks function in housing. However, there is a link between the network patterns and quality of informal housing. Analysing the networks shows how resources are actually accessed in informal settlements, providing useful insights for enhancement of various ‘soft’ and ‘hard’ outcomes of informal housing initiatives; helping give ‘new lenses’ through which informality can be better understood.
Effects of globalization in training architectural design
(2011) Omenya, Alfred
African architect unable to solve context-specific design challenges or explore context-specific design opportunities that Africa offers. This paper analyses some of the basis of western training that have had structural impacts on architectural design training in Africa. It also explains how the design studio at the University of Nairobi is trying to deal with this dilemma through a studio experiment.The paper further explores how the position of the human is being expanded beyond the object oriented traditional approaches to an approach that takes cognizance of the human as an emotional being and also considers the emotional context of the design. Further, the paper puts a case for African constructionism to compliment western abstract representation a case for design principles based on nature, arguing that organic architecture can also help refine the locally trained architect who will also be relevant globally. The paper finally argues that these approaches among others would help reconnect the trained African architect with his / her context and his / her client
Research on Suitable Low Income Housing Models for Urban Settlements
(2012) Anyamba, Tom JC; Omenya, Alfred
Innovative Housing Financing for Sustainable Growth Modeling Incremental Financing Strategies.
(Kenya Bankers Association, 2015) Makachia, Peter A
The Centre for Research on Financial Markets and Policy was established by the Kenya Bankers Association in 2012 to oﬀer an array of research, commentary, and dialogue regarding critical policy matters that impact on ﬁnancial markets in Kenya. The Centre sponsors original research, provides thoughtful commentary, and hosts dialogues and conferences involving scholars and practitioners on key ﬁnancial market issues. Through these activities, the Centre acts as a platform for intellectual engagement and dialogue between ﬁnancial market experts, the banking sector and the policy makers in Kenya. It therefore contributes to an informed discussion that inﬂuences critical ﬁnancial market debates and policies. The Kenya Bankers Association (KBA) Working Papers Series disseminates research ﬁndings of studies conducted by the KBA Centre for Research on Financial Markets and Policy. The Working Papers constitute “work in progress” and are published to stimulate discussion and contribute to the advancement of the banking industry’s knowledge of matters of markets, economic outcomes and policy. Constructive feedback on the Working Papers is welcome. The Working Papers are published in the names of the author(s). Therefore their views do not necessarily represent those of the KBA.
Development Of A New Cadastral Model For Kenya
(2017-09-25) Wayumba, Gordon
The Cadastral system in Kenya was established in 1903 to support land alienation for the white settlers who had come into the country in latter part of the 20th Century. In the last hundred years, the system has remained more or less the same, where land records are kept in paper format and majority of operations are carried out on a manual basis. The lack of a modern cadastral system has contributed to problems in land planning, access and administration. The Government has expressed the need to modernize the system in order to facilitate better land administration, support the development of an integrated Land Information Management System and a National Spatial Data Infrastructure. However, one persistent denominator to these efforts has been the lack of a modern cadastral model. This paper discusses a recent study carried out in Kenya to provide solution to the problem by developing a new cadastral model, based on an Object-Relational Model. In carrying out the study, user needs assessment was carried out to support conceptual and logical design of the new cadastral database. In implementing the model, a conceptual/logical model was developed based on Multi-Value Vector Maps and Smiths Normalization procedures. The resulting Functional Dependency Diagrams were used to design tables for subsequent querying with Microsoft SQL Language. Results from the study indicated that Smiths Normalization and Functional Dependency Diagrams are suitable for the automatic generation of fully Normalized Tables and a successful query of and displayed of multi-parcel ownership. On the other hand, it has been observed by various authors that typical Cod Normalization procedures do not support the display of multi-parcel ownership and automatic production of fully Normalized tables.

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