Detection of complex point targets with distributed assets in a MIMO radar system

The report explores the problem of detecting complex point target models in a MIMO radar system. A complex point target is a mathematical and statistical model for a radar target that is not resolved in space, but exhibits varying complex reflectivity across the different bistatic view angles. The complex reflectivity can be modeled as a complex stochastic process whose index set is the set of all the bistatic view angles, and the parameters of the stochastic process follow from an analysis of a target model comprising a number of ideal point scatterers randomly located within some radius of the targets center of mass. The proposed complex point targets may be applicable to statistical inference in multistatic or MIMO radar system. Six different target models are summarized here – three 2-dimensional (Gaussian, Uniform Square, and Uniform Circle) and three 3-dimensional (Gaussian, Uniform Cube, and Uniform Sphere). They are assumed to have different distributions on the location of the point scatterers within the target. We develop data models for the received signals from such targets in the MIMO radar system with distributed assets and partially correlated signals, and consider the resulting detection problem which reduces to the familiar Gauss-Gauss detection problem. We illustrate that the target parameter and transmit signal have an influence on the detector performance through target extent and the SNR respectively. A series of the receiver operator characteristic (ROC) curves are generated to notice the impact on the detector for varying SNR. Kullback–Leibler (KL) divergence is applied to obtain the approximate mean difference between density functions the scatterers assume inside the target models to show the change in the performance of the detector with target extent of the point scatterers.

Risk analysis of light-frame wood construction due to multiple hazards

Light-frame wood buildings are widely built in the United States (U.S.). Natural hazards cause huge losses to light-frame wood construction. This study proposes methodologies and a framework to evaluate the performance and risk of light-frame wood construction. Performance-based engineering (PBE) aims to ensure that a building achieves the desired performance objectives when subjected to hazard loads. In this study, the collapse risk of a typical one-story light-frame wood building is determined using the Incremental Dynamic Analysis method. The collapse risks of buildings at four sites in the Eastern, Western, and Central regions of U.S. are evaluated. Various sources of uncertainties are considered in the collapse risk assessment so that the influence of uncertainties on the collapse risk of lightframe wood construction is evaluated. The collapse risks of the same building subjected to maximum considered earthquakes at different seismic zones are found to be non-uniform. In certain areas in the U.S., the snow accumulation is significant and causes huge economic losses and threatens life safety. Limited study has been performed to investigate the snow hazard when combined with a seismic hazard. A Filtered Poisson Process (FPP) model is developed in this study, overcoming the shortcomings of the typically used Bernoulli model. The FPP model is validated by comparing the simulation results to weather records obtained from the National Climatic Data Center. The FPP model is applied in the proposed framework to assess the risk of a light-frame wood building subjected to combined snow and earthquake loads. The snow accumulation has a significant influence on the seismic losses of the building. The Bernoulli snow model underestimates the seismic loss of buildings in areas with snow accumulation. An object-oriented framework is proposed in this study to performrisk assessment for lightframe wood construction. For home owners and stake holders, risks in terms of economic losses is much easier to understand than engineering parameters (e.g., inter story drift). The proposed framework is used in two applications. One is to assess the loss of the building subjected to mainshock-aftershock sequences. Aftershock and downtime costs are found to be important factors in the assessment of seismic losses. The framework is also applied to a wood building in the state of Washington to assess the loss of the building subjected to combined earthquake and snow loads. The proposed framework is proven to be an appropriate tool for risk assessment of buildings subjected to multiple hazards. Limitations and future works are also identified.

Development of record-breaking statistics for climatological time-series analysis

The number of record-breaking events expected to occur in a strictly stationary time-series depends only on the number of values in the time-series, regardless of distribution. This holds whether the events are record-breaking highs or lows and whether we count from past to present or present to past. However, these symmetries are broken in distinct ways by trends in the mean and variance. We define indices that capture this information and use them to detect weak trends from multiple time-series. Here, we use these methods to answer the following questions: (1) Is there a variability trend among globally distributed surface temperature time-series? We find a significant decreasing variability over the past century for the Global Historical Climatology Network (GHCN). This corresponds to about a 10% change in the standard deviation of inter-annual monthly mean temperature distributions. (2) How are record-breaking high and low surface temperatures in the United States affected by time period? We investigate the United States Historical Climatology Network (USHCN) and find that the ratio of record-breaking highs to lows in 2006 increases as the time-series extend further into the past. When we consider the ratio as it evolves with respect to a fixed start year, we find it is strongly correlated with the ensemble mean. We also compare the ratios for USHCN and GHCN (minus USHCN stations). We find the ratios grow monotonically in the GHCN data set, but not in the USHCN data set. (3) Do we detect either mean or variance trends in annual precipitation within the United States? We find that the total annual and monthly precipitation in the United States (USHCN) has increased over the past century. Evidence for a trend in variance is inconclusive.

Spatial and temporal analysis of land cover and landscape structure change in Zagros Forests

The Zagros oak forests in Western Iran are critically important to the sustainability of the region. These forests have undergone dramatic declines in recent decades. We evaluated the utility of the non-parametric Random Forest classification algorithm for land cover classification of Zagros landscapes, and selected the best spatial and spectral predictive variables. The algorithm resulted in high overall classification accuracies (>85%) and also equivalent classification accuracies for the datasets from the three different sensors. We evaluated the associations between trends in forest area and structure with trends in socioeconomic and climatic conditions, to identify the most likely driving forces creating deforestation and landscape structure change. We used available socioeconomic (urban and rural population, and rural income), and climatic (mean annual rainfall and mean annual temperature) data for two provinces in northern Zagros. The most correlated driving force of forest area loss was urban population, and climatic variables to a lesser extent. Landscape structure changes were more closely associated with rural population. We examined the effects of scale changes on the results from spatial pattern analysis. We assessed the impacts of eight years of protection in a protected area in northern Zagros at two different scales (both grain and extent). The effects of protection on the amount and structure of forests was scale dependent. We evaluated the nature and magnitude of changes in forest area and structure over the entire Zagros region from 1972 to 2009. We divided the Zagros region in 167 Landscape Units and developed two measures— Deforestation Sensitivity (DS) and Connectivity Sensitivity (CS) — for each landscape unit as the percent of the time steps that forest area and ECA experienced a decrease of greater than 10% in either measure. A considerable loss in forest area and connectivity was detected, but no sudden (nonlinear) changes were detected at the spatial and temporal scale of the study. Connectivity loss occurred more rapidly than forest loss due to the loss of connecting patches. More connectivity was lost in southern Zagros due to climatic differences and different forms of traditional land use.

Optimal game theoretic distributed control methodologies in small scale power systems

This dissertation presents the competitive control methodologies for small-scale power system (SSPS). A SSPS is a collection of sources and loads that shares a common network which can be isolated during terrestrial disturbances. Micro-grids, naval ship electric power systems (NSEPS), aircraft power systems and telecommunication system power systems are typical examples of SSPS. The analysis and development of control systems for small-scale power systems (SSPS) lacks a defined slack bus. In addition, a change of a load or source will influence the real time system parameters of the system. Therefore, the control system should provide the required flexibility, to ensure operation as a single aggregated system. In most of the cases of a SSPS the sources and loads must be equipped with power electronic interfaces which can be modeled as a dynamic controllable quantity. The mathematical formulation of the micro-grid is carried out with the help of game theory, optimal control and fundamental theory of electrical power systems. Then the micro-grid can be viewed as a dynamical multi-objective optimization problem with nonlinear objectives and variables. Basically detailed analysis was done with optimal solutions with regards to start up transient modeling, bus selection modeling and level of communication within the micro-grids. In each approach a detail mathematical model is formed to observe the system response. The differential game theoretic approach was also used for modeling and optimization of startup transients. The startup transient controller was implemented with open loop, PI and feedback control methodologies. Then the hardware implementation was carried out to validate the theoretical results. The proposed game theoretic controller shows higher performances over traditional the PI controller during startup. In addition, the optimal transient surface is necessary while implementing the feedback controller for startup transient. Further, the experimental results are in agreement with the theoretical simulation. The bus selection and team communication was modeled with discrete and continuous game theory models. Although players have multiple choices, this controller is capable of choosing the optimum bus. Next the team communication structures are able to optimize the players’ Nash equilibrium point. All mathematical models are based on the local information of the load or source. As a result, these models are the keys to developing accurate distributed controllers.

HIGH PERFORMANCE, LOW COST SUBSPACE DECOMPOSITION AND POLYNOMIAL ROOTING FOR REAL TIME DIRECTION OF ARRIVAL ESTIMATION: ANALYSIS AND IMPLEMENTATION

This thesis develops high performance real-time signal processing modules for direction of arrival (DOA) estimation for localization systems. It proposes highly parallel algorithms for performing subspace decomposition and polynomial rooting, which are otherwise traditionally implemented using sequential algorithms. The proposed algorithms address the emerging need for real-time localization for a wide range of applications. As the antenna array size increases, the complexity of signal processing algorithms increases, making it increasingly difficult to satisfy the real-time constraints. This thesis addresses real-time implementation by proposing parallel algorithms, that maintain considerable improvement over traditional algorithms, especially for systems with larger number of antenna array elements. Singular value decomposition (SVD) and polynomial rooting are two computationally complex steps and act as the bottleneck to achieving real-time performance. The proposed algorithms are suitable for implementation on field programmable gated arrays (FPGAs), single instruction multiple data (SIMD) hardware or application specific integrated chips (ASICs), which offer large number of processing elements that can be exploited for parallel processing. The designs proposed in this thesis are modular, easily expandable and easy to implement. Firstly, this thesis proposes a fast converging SVD algorithm. The proposed method reduces the number of iterations it takes to converge to correct singular values, thus achieving closer to real-time performance. A general algorithm and a modular system design are provided making it easy for designers to replicate and extend the design to larger matrix sizes. Moreover, the method is highly parallel, which can be exploited in various hardware platforms mentioned earlier. A fixed point implementation of proposed SVD algorithm is presented. The FPGA design is pipelined to the maximum extent to increase the maximum achievable frequency of operation. The system was developed with the objective of achieving high throughput. Various modern cores available in FPGAs were used to maximize the performance and details of these modules are presented in detail. Finally, a parallel polynomial rooting technique based on Newton’s method applicable exclusively to root-MUSIC polynomials is proposed. Unique characteristics of root-MUSIC polynomial’s complex dynamics were exploited to derive this polynomial rooting method. The technique exhibits parallelism and converges to the desired root within fixed number of iterations, making this suitable for polynomial rooting of large degree polynomials. We believe this is the first time that complex dynamics of root-MUSIC polynomial were analyzed to propose an algorithm. In all, the thesis addresses two major bottlenecks in a direction of arrival estimation system, by providing simple, high throughput, parallel algorithms.

EXAMINING POLICY CAPACITY INITIATIVES WITHIN CLIMATE CHANGE FRAMEWORKS IN THREE US AND CANADIAN SECTORS USING NVIVO CONTENT ANALYSIS

The climate change narrative has changed from one of mitigation to one of adaptation. Governments around the world have created climate change frameworks which address how the country can better cope with the expected and unexpected changes due to global climate change. In an effort to do so, federal governments of Canada and the United States, as well as some provinces and states within these countries, have created detailed documents which outline what steps must be taken to adapt to these changes. However, not much is mentioned about how these steps will be translated in to policy, and how that policy will eventually be implemented. To examine the ability of governments to acknowledge and incorporate the plethora of scientific information to policy, consideration must be made for policy capacity. This report focuses on three sectors: water supply and demand; drought and flood planning; and forest and grassland ecosystems, and the word ‘capacity’ as related to nine different forms of policy capacity acknowledged in these frameworks. Qualitative content analysis using NVivo was carried out on fifty four frameworks and the results obtained show that there is a greater consideration for managerial capacity compared to analytical or political capacity. The data also indicated that although there were more Canadian frameworks which referred to policy capacity, the frameworks from the United States actually considered policy capacity to a greater degree.

Integrative analysis of RUNX1 downstream pathways and target genes

BACKGROUND: The RUNX1 transcription factor gene is frequently mutated in sporadic myeloid and lymphoid leukemia through translocation, point mutation or amplification. It is also responsible for a familial platelet disorder with predisposition to acute myeloid leukemia (FPD-AML). The disruption of the largely unknown biological pathways controlled by RUNX1 is likely to be responsible for the development of leukemia. We have used multiple microarray platforms and bioinformatic techniques to help identify these biological pathways to aid in the understanding of why RUNX1 mutations lead to leukemia. RESULTS: Here we report genes regulated either directly or indirectly by RUNX1 based on the study of gene expression profiles generated from 3 different human and mouse platforms. The platforms used were global gene expression profiling of: 1) cell lines with RUNX1 mutations from FPD-AML patients, 2) over-expression of RUNX1 and CBFbeta, and 3) Runx1 knockout mouse embryos using either cDNA or Affymetrix microarrays. We observe that our datasets (lists of differentially expressed genes) significantly correlate with published microarray data from sporadic AML patients with mutations in either RUNX1 or its cofactor, CBFbeta. A number of biological processes were identified among the differentially expressed genes and functional assays suggest that heterozygous RUNX1 point mutations in patients with FPD-AML impair cell proliferation, microtubule dynamics and possibly genetic stability. In addition, analysis of the regulatory regions of the differentially expressed genes has for the first time systematically identified numerous potential novel RUNX1 target genes. CONCLUSION: This work is the first large-scale study attempting to identify the genetic networks regulated by RUNX1, a master regulator in the development of the hematopoietic system and leukemia. The biological pathways and target genes controlled by RUNX1 will have considerable importance in disease progression in both familial and sporadic leukemia as well as therapeutic implications.

RESILIENT WOMEN, METISTIC SCIENTISTS: A MULTIPLE CASE STUDY OF HOW WOMEN NEGOTIATE THEIR SITUATEDNESS IN SCIENCE FIELDS

The concept of feminist metistic resilience postulates that the voiceless, the marginalized and the minority in societies employ strategies in order to turn tables in their favor. This study presents a qualitative analysis of how women, considered to be the minority, negotiate their situatedness in science fields in order to effect change in their lives or that of the society and why they become successful. By “situatedness,” I refer to the everyday life of women as they live and encounter people, society and culture, especially, the life of women who have transcended the culturally stipulated role of women and are excelling in a male dominated field. The study, in different dimensions, conceptualizes the reason for the fewer number of women in science; looks at how scientific methods and practices inhibit the development of women in science; and, finally, interrogates the question of objectivity in science. It becomes apparent, through feminist metistic resilience, that women become successful when they accept conventional practices in scientific arrangements and structures. They accept the practices by embracing and not questioning structures and arrangements that have shaped the field of science and by shifting shapes and assuming different forms in order to adapt to conditions they encounter. Apart from adapting and shape shifting, the women also become successful through environmental and social influences. My analysis suggests that more women can be encouraged to pursue science when women practicing science begin to question structures and arrangements that have shaped the practice of science over the centuries. The overall findings of the research provide implications for policy makers, educators and feminist researchers.

Past is Prologue: Montana’s Historic Women’s Movement Re-emerges in the Progressive 1970s -- Dorothy Bradley, Marilyn Wessel & Jane Jelinski “In the Crucible of Change”

One-hundred years ago, in 1914, male voters in Montana (MT) extended suffrage (voting rights) to women six years before the 19th Amendment to the US Constitution was ratified and provided that right to women in all states. The long struggle for women’s suffrage was energized in the progressive era and Jeanette Rankin of Missoula emerged as a leader of the campaign; in 1912 both major MT political party platforms supported women suffrage. In the 1914 election, 41,000 male voters supported woman suffrage while nearly 38,000 opposed it. MT was not only ahead of the curve on women suffrage, but just two years later in 1916 elected Jeanette Rankin as the first woman ever elected to the United States Congress. Rankin became a national leader for women's equality. In her commitment to equality, she opposed US entry into World War I, partially because she said she could not support men being made to go to war if women were not allowed to serve alongside them. During MT’s initial progressive era, women in MT not only pursued equality for themselves (the MT Legislature passed an equal pay act in 1919), but pursued other social improvements, such as temperance/prohibition. Well-known national women leaders such as Carrie Nation and others found a welcome in MT during the period. Women's role in the trade union movement was evidenced in MT by the creation of the Women's Protective Union in Butte, the first union in America dedicated solely to women workers. But Rankin’s defeat following her vote against World War I was used as a way for opponents to advocate a conservative, traditionalist perspective on women's rights in MT. Just as we then entered a period in MT where the “copper collar” was tightened around MT economically and politically by the Anaconda Company and its allies, we also found a different kind of conservative, traditionalist collar tightened around the necks of MT women. The recognition of women's role during World War II, represented by “Rosie the Riveter,” made it more difficult for that conservative, traditionalist approach to be forever maintained. In addition, women's role in MT agriculture – family farms and ranches -- spoke strongly to the concept of equality, as farm wives were clearly active partners in the agricultural enterprises. But rural MT was, by and large, the bastion of conservative values relative to the position of women in society. As the period of “In the Crucible of Change” began, the 1965 MT Legislature included only three women. In 1967 and 1969 only one woman legislator served. In 1971 the number went up to two, including one of our guests, Dorothy Bradley. It was only after the Constitutional Convention, which featured 19 women delegates, that the barrier was broken. The 1973 Legislature saw 9 women elected. The 1975 and 1977 sessions had 14 women legislators; 15 were elected for the 1979 session. At that time progressive women and men in the Legislature helped implement the equality provisions of the new MT Constitution, ratified the federal Equal Rights Amendment in 1974, and held back national and local conservatives forces which sought in later Legislatures to repeal that ratification. As with the national movement at the time, MT women sought and often succeeded in adopting legal mechanisms that protected women’s equality, while full equality in the external world remained (and remains) a treasured objective. The story of the re-emergence of Montana’s women’s movement in the 1970s is discussed in this chapter by three very successful and prominent women who were directly involved in the effort: Dorothy Bradley, Marilyn Wessel, and Jane Jelinski. Their recollections of the political, sociological and cultural path Montana women pursued in the 1970s and the challenges and opposition they faced provide an insider’s perspective of the battle for equality for women under the Big Sky “In the Crucible of Change.” Dorothy Bradley grew up in Bozeman, Montana; received her Bachelor of Arts Phi Beta Kappa from Colorado College, Colorado Springs, in 1969 with a Distinction in Anthropology; and her Juris Doctor from American University in Washington, D.C., in 1983. In 1970, at the age of 22, following the first Earth Day and running on an environmental platform, Ms. Bradley won a seat in the 1971 Montana House of Representatives where she served as the youngest member and only woman. Bradley established a record of achievement on environmental & progressive legislation for four terms, before giving up the seat to run a strong second to Pat Williams for the Democratic nomination for an open seat in Montana’s Western Congressional District. After becoming an attorney and an expert on water law, she returned to the Legislature for 4 more terms in the mid-to-late 1980s. Serving a total of eight terms, Dorothy was known for her leadership on natural resources, tax reform, economic development, and other difficult issues during which time she gained recognition for her consensus-building approach. Campaigning by riding her horse across the state, Dorothy was the Democratic nominee for Governor in 1992, losing the race by less than a percentage point. In 1993 she briefly taught at a small rural school next to the Northern Cheyenne Indian Reservation. She was then hired as the Director of the Montana University System Water Center, an education and research arm of Montana State University. From 2000 - 2008 she served as the first Gallatin County Court Administrator with the task of collaboratively redesigning the criminal justice system. She currently serves on One Montana’s Board, is a National Advisor for the American Prairie Foundation, and is on NorthWestern Energy’s Board of Directors. Dorothy was recognized with an Honorary Doctorate from her alma mater, Colorado College, was named Business Woman of the Year by the Bozeman Chamber of Commerce and MSU Alumni Association, and was Montana Business and Professional Women’s Montana Woman of Achievement. Marilyn Wessel was born in Iowa, lived and worked in Los Angeles, California, and Washington, D.C. before moving to Bozeman in 1972. She has an undergraduate degree in journalism from Iowa State University, graduate degree in public administration from Montana State University, certification from the Harvard University Institute for Education Management, and served a senior internship with the U.S. Congress, Montana delegation. In Montana Marilyn has served in a number of professional positions, including part-time editor for the Montana Cooperative Extension Service, News Director for KBMN Radio, Special Assistant to the President and Director of Communications at Montana State University, Director of University Relations at Montana State University and Dean and Director of the Museum of the Rockies at MSU. Marilyn retired from MSU as Dean Emeritus in 2003. Her past Board Service includes Montana State Merit System Council, Montana Ambassadors, Vigilante Theater Company, Montana State Commission on Practice, Museum of the Rockies, Helena Branch of the Ninth District Federal Reserve Bank, Burton K. Wheeler Center for Public Policy, Bozeman Chamber of Commerce, and Friends of KUSM Public Television. Marilyn’s past publications and productions include several articles on communications and public administration issues as well as research, script preparation and presentation of several radio documentaries and several public television programs. She is co-author of one book, 4-H An American Idea: A History of 4-H. Marilyn’s other past volunteer activities and organizations include Business and Professional Women, Women's Political Caucus, League of Women Voters, and numerous political campaigns. She is currently engaged professionally in museum-related consulting and part-time teaching at Montana State University as well as serving on the Editorial Board of the Bozeman Daily Chronicle and a member of Pilgrim Congregational Church and Family Promise. Marilyn and her husband Tom, a retired MSU professor, live in Bozeman. She enjoys time with her children and grandchildren, hiking, golf, Italian studies, cooking, gardening and travel. Jane Jelinski is a Wisconsin native, with a BA from Fontbonne College in St. Louis, MO who taught fifth and seventh grades prior to moving to Bozeman in 1973. A stay-at-home mom with a five year old daughter and an infant son, she was promptly recruited by the Gallatin Women’s Political Caucus to conduct a study of Sex-Role Stereotyping in K Through 6 Reading Text Books in the Bozeman School District. Sociologist Dr. Louise Hale designed the study and did the statistical analysis and Jane read all the texts, entered the data and wrote the report. It was widely disseminated across Montana and received attention of the press. Her next venture into community activism was to lead the successful effort to downzone her neighborhood which was under threat of encroaching business development. Today the neighborhood enjoys the protections of a Historic Preservation District. During this time she earned her MPA from Montana State University. Subsequently Jane founded the Gallatin Advocacy Program for Developmentally Disabled Adults in 1978 and served as its Executive Director until her appointment to the Gallatin County Commission in 1984, a controversial appointment which she chronicled in the Fall issue of the Gallatin History Museum Quarterly. Copies of the issue can be ordered through: http://gallatinhistorymuseum.org/the-museum-bookstore/shop/. Jane was re-elected three times as County Commissioner, serving fourteen years. She was active in the Montana Association of Counties (MACO) and was elected its President in 1994. She was also active in the National Association of Counties, serving on numerous policy committees. In 1998 Jane resigned from the County Commission 6 months before the end of her final term to accept the position of Assistant Director of MACO, from where she lobbied for counties, provided training and research for county officials, and published a monthly newsletter. In 2001 she became Director of the MSU Local Government Center where she continued to provide training and research for county and municipal officials across MT. There she initiated the Montana Mayors Academy in partnership with MMIA. She taught State and Local Government, Montana Politics and Public Administration in the MSU Political Science Department before retiring in 2008. Jane has been married to Jack for 46 years, has two grown children and three grandchildren.

Statistical analysis of multichannel scalp field data

High density spatial and temporal sampling of EEG data enhances the quality of results of electrophysiological experiments. Because EEG sources typically produce widespread electric fields (see Chapter 3) and operate at frequencies well below the sampling rate, increasing the number of electrodes and time samples will not necessarily increase the number of observed processes, but mainly increase the accuracy of the representation of these processes. This is namely the case when inverse solutions are computed. As a consequence, increasing the sampling in space and time increases the redundancy of the data (in space, because electrodes are correlated due to volume conduction, and time, because neighboring time points are correlated), while the degrees of freedom of the data change only little. This has to be taken into account when statistical inferences are to be made from the data. However, in many ERP studies, the intrinsic correlation structure of the data has been disregarded. Often, some electrodes or groups of electrodes are a priori selected as the analysis entity and considered as repeated (within subject) measures that are analyzed using standard univariate statistics. The increased spatial resolution obtained with more electrodes is thus poorly represented by the resulting statistics. In addition, the assumptions made (e.g. in terms of what constitutes a repeated measure) are not supported by what we know about the properties of EEG data. From the point of view of physics (see Chapter 3), the natural “atomic” analysis entity of EEG and ERP data is the scalp electric field

Semiotic Analysis in the Study of Social Work

Research and professional practices have the joint aim of re-structuring the preconceived notions of reality. They both want to gain the understanding about social reality. Social workers use their professional competence in order to grasp the reality of their clients, while researchers’ pursuit is to open the secrecies of the research material. Development and research are now so intertwined and inherent in almost all professional practices that making distinctions between practising, developing and researching has become difficult and in many aspects irrelevant. Moving towards research-based practices is possible and it is easily applied within the framework of the qualitative research approach (Dominelli 2005, 235; Humphries 2005, 280). Social work can be understood as acts and speech acts crisscrossing between social workers and clients. When trying to catch the verbal and non-verbal hints of each others’ behaviour, the actors have to do a lot of interpretations in a more or less uncertain mental landscape. Our point of departure is the idea that the study of social work practices requires tools which effectively reveal the internal complexity of social work (see, for example, Adams & Dominelli & Payne 2005, 294 – 295). The boom of qualitative research methodologies in recent decades is associated with much profound the rupture in humanities, which is called the linguistic turn (Rorty 1967). The idea that language is not transparently mediating our perceptions and thoughts about reality, but on the contrary it constitutes it was new and even confusing to many social scientists. Nowadays we have got used to read research reports which have applied different branches of discursive analyses or narratologic or semiotic approaches. Although differences are sophisticated between those orientations they share the idea of the predominance of language. Despite the lively research work of today’s social work and the research-minded atmosphere of social work practice, semiotics has rarely applied in social work research. However, social work as a communicative practice concerns symbols, metaphors and all kinds of the representative structures of language. Those items are at the core of semiotics, the science of signs, and the science which examines people using signs in their mutual interaction and their endeavours to make the sense of the world they live in, their semiosis. When thinking of the practice of social work and doing the research of it, a number of interpretational levels ought to be passed before reaching the research phase in social work. First of all, social workers have to interpret their clients’ situations, which will be recorded in the files. In some very rare cases those past situations will be reflected in discussions or perhaps interviews or put under the scrutiny of some researcher in the future. Each and every new observation adds its own flavour to the mixture of meanings. Social workers have combined their observations with previous experience and professional knowledge, furthermore, the situation on hand also influences the reactions. In addition, the interpretations made by social workers over the course of their daily working routines are never limited to being part of the personal process of the social worker, but are also always inherently cultural. The work aiming at social change is defined by the presence of an initial situation, a specific goal, and the means and ways of achieving it, which are – or which should be – agreed upon by the social worker and the client in situation which is unique and at the same time socially-driven. Because of the inherent plot-based nature of social work, the practices related to it can be analysed as stories (see Dominelli 2005, 234), given, of course, that they are signifying and told by someone. The research of the practices is concentrating on impressions, perceptions, judgements, accounts, documents etc. All these multifarious elements can be scrutinized as textual corpora, but not whatever textual material. In semiotic analysis, the material studied is characterised as verbal or textual and loaded with meanings. We present a contribution of research methodology, semiotic analysis, which has to our mind at least implicitly references to the social work practices. Our examples of semiotic interpretation have been picked up from our dissertations (Laine 2005; Saurama 2002). The data are official documents from the archives of a child welfare agency and transcriptions of the interviews of shelter employees. These data can be defined as stories told by the social workers of what they have seen and felt. The official documents present only fragmentations and they are often written in passive form. (Saurama 2002, 70.) The interviews carried out in the shelters can be described as stories where the narrators are more familiar and known. The material is characterised by the interaction between the interviewer and interviewee. The levels of the story and the telling of the story become apparent when interviews or documents are examined with the use of semiotic tools. The roots of semiotic interpretation can be found in three different branches; the American pragmatism, Saussurean linguistics in Paris and the so called formalism in Moscow and Tartu; however in this paper we are engaged with the so called Parisian School of semiology which prominent figure was A. J. Greimas. The Finnish sociologists Pekka Sulkunen and Jukka Törrönen (1997a; 1997b) have further developed the ideas of Greimas in their studies on socio-semiotics, and we lean on their ideas. In semiotics social reality is conceived as a relationship between subjects, observations, and interpretations and it is seen mediated by natural language which is the most common sign system among human beings (Mounin 1985; de Saussure 2006; Sebeok 1986). Signification is an act of associating an abstract context (signified) to some physical instrument (signifier). These two elements together form the basic concept, the “sign”, which never constitutes any kind of meaning alone. The meaning will be comprised in a distinction process where signs are being related to other signs. In this chain of signs, the meaning becomes diverged from reality. (Greimas 1980, 28; Potter 1996, 70; de Saussure 2006, 46-48.) One interpretative tool is to think of speech as a surface under which deep structures – i.e. values and norms – exist (Greimas & Courtes 1982; Greimas 1987). To our mind semiotics is very much about playing with two different levels of text: the syntagmatic surface which is more or less faithful to the grammar, and the paradigmatic, semantic structure of values and norms hidden in the deeper meanings of interpretations. Semiotic analysis deals precisely with the level of meaning which exists under the surface, but the only way to reach those meanings is through the textual level, the written or spoken text. That is why the tools are needed. In our studies, we have used the semiotic square and the actant analysis. The former is based on the distinctions and the categorisations of meanings, and the latter on opening the plotting of narratives in order to reach the value structures.