475 research outputs found
Näytteenotto ympäristörikoksissa : näytteenotto-opas poliiseille
Opinnäytetyön tarkoitus oli kerätä ja valmistella materiaalia uudistettavaan Keskusrikospoliisin rikosteknisen laboratorion ympäristörikoksiin liittyvään näytteenotto-oppaaseen, joka on tarkoitettu poliisille. Materiaalin hankinta uuteen oppaaseen oli tarpeellista ja ajankohtaista juuri nyt, koska rikostekninen laboratorio on suunnitellut oppaan uusimista vuoden 2016 aikana. Lisäpontta oppaan laadintaan oli antanut ympäristö- ja sisäministeriön yhteistyöryhmän laatima ympäristörikostorjunnan strategia ja toimenpideohjelma, joka kannustaa viranomaisia yhteistyöhön ympäristörikosten tutkinnassa ja ennaltaehkäisyssä sekä lisäämään koulutusta ympäristörikosasioissa. Opinnäytetyössä keskityttiin biologisten näytteiden ottamiseen ja käsittelyyn, koska rikosteknisellä laboratoriolla ei ole omakohtaista osaamista näiden näytteiden osalta. Lisäksi opinnäytetyössä kerättiin tietoa vesi- ja maaperänäytteiden ottamiseen ja näytteiden säilyttämiseen sekä yleistä tietoa näytteenotosta ja sen valmistelusta sekä dokumentoinnista. Rikostekninen laboratorio käyttää kerättyä materiaalia uuden näytteenotto-oppaan valmistamiseen poliisin käyttöön.
Materiaalia tulevaan näytteenotto-oppaaseen kerättiin ensisijaisesti keskusrikospoliisin rikosteknisen laboratorion aikaisemmasta näytteenotto-oppaasta, muiden maiden rikoslaboratorioiden sekä Interpolin näytteenotto-oppaista. Lisäksi tietoa kerättiin haastattelemalla asiantuntijoita rikosteknisessä laboratoriossa ja muissa yhteystyölaboratorioissa. Opinnäytetyöhön taustatietoa kerättiin myös aihetta käsittelevistä kirjoista ja artikkeleista sekä tilastoista ja lainsäädännöstä.
Uutta tietoa ympäristönäytteenotosta saatiin kerättyä varsinkin biologiseen näytteenottoon liittyen sekä näytteiden säilytysolojen tärkeydestä. Tärkeänä havaintona biologisesta näytteenotosta ilmeni lähes jokaisesta lähteestä, että biologiseen näytteenottoon suositeltiin käytettävän asiaan perehtynyttä, sertifioitua näytteenottajaa. Aikaisempaan näytteenotto-oppaaseen verrattuna uutta materiaalia saatiin kerättyä myös ympäristönäytteenoton valmistelusta. Materiaaliin liitettiin Interpolin käyttämä tarkistuslista ympäristörikosnäytteenoton valmistelusta, näytteenotosta ja näytteiden käsittelystä sekä säilyttämisestä.Purpose of this thesis was to collect and prepare material for the new sampling guide in environmental crimes by the Forensic Laboratory of the National Bureau of Investigations to be used by the police. The collection for the new sampling guide was necessary and timely right now, because the forensic laboratory has been planning on renewing the current sampling guide during the year 2016. Also a collaboration of the Finnish ministry of the environment and the home office have compiled a strategy and operation program for preventing environmental crimes, which encourages authoritatives to work together to investigate and prevent environmental crimes and to increase education in environmental crime issues. The focus in this thesis was in biological sampling and handling of these samples, because the forensic laboratory does not investigate biological samples themselves and have the expertise in this matter. Also knowledge of water and ground sampling and storing these kind of samples as well as general information of environmental sampling, preparing of sampling and documenting the sampling event was gathered for the thesis. The forensic laboratory will use the gathered material to produce a new sampling guide for the police.
The material for new sampling guide was mainly collected from the earlier environmental crime sampling guide by the Forensic Laboratory of the National Bureau of Investigation, from sampling guides by other countries forensic laboratories and Interpol’s sampling guide. In addition, information was collected by interviewing specialists in Finnish forensic laboratory and other co-operating laboratories. Background material for the thesis was also gathered from topic concerning books, articles, statistics and legislation.
New information about environmental sampling was abled to be collected specially concerning biological sampling and the importance of the correct storing of biological samples. An important observation about biological sampling was, that almost every source stated that biological sampling should be conducted by a specialized and certified sampler. Compared to the earlier sampling guide, new material about preparing environmental sampling was collected. A checklist of preparing, sampling, handling and storing environmental samples used by the Interpol was also included to the new materia
Data exploration with learning metrics
A crucial problem in exploratory analysis of data is that it is difficult for computational methods to focus on interesting aspects of data. Traditional methods of unsupervised learning cannot differentiate between interesting and noninteresting variation, and hence may model, visualize, or cluster parts of data that are not interesting to the analyst. This wastes the computational power of the methods and may mislead the analyst.
In this thesis, a principle called "learning metrics" is used to develop visualization and clustering methods that automatically focus on the interesting aspects, based on auxiliary labels supplied with the data samples. The principle yields non-Euclidean (Riemannian) metrics that are data-driven, widely applicable, versatile, invariant to many transformations, and in part invariant to noise.
Learning metric methods are introduced for five tasks: nonlinear visualization by Self-Organizing Maps and Multidimensional Scaling, linear projection, and clustering of discrete data and multinomial distributions. The resulting methods either explicitly estimate distances in the Riemannian metric, or optimize a tailored cost function which is implicitly related to such a metric. The methods have rigorous theoretical relationships to information geometry and probabilistic modeling, and are empirically shown to yield good practical results in exploratory and information retrieval tasks.reviewe
Directing and Combining Multiple Queries for Exploratory Search by Visual Interactive Intent Modeling
In interactive information-seeking, a user often performs many interrelated queries and interactions covering multiple aspects of a broad topic of interest. Especially in difficult information-seeking tasks the user may need to find what is in common among such multiple aspects. Therefore, the user may need to compare and combine results across queries. While methods to combine queries or rankings have been proposed, little attention has been paid to interactive support for combining multiple queries in exploratory search. We introduce an interactive information retrieval system for exploratory search with multiple simultaneous search queries that can be combined. The user is able to direct search in the multiple queries, and combine queries by two operations: intersection and difference, which reveal what is relevant to the user intent of two queries, and what is relevant to one but not the other. Search is directed by relevance feedback on visualized user intent models of each query. Operations on queries act directly on the intent models inferring a combined user intent model. Each combination yields a new result (ranking) and acts as a new search that can be interactively directed and further combined. User experiments on difficult information-seeking tasks show that our novel system with query operations yields more relevant top-ranked documents in a shorter time than a baseline multiple-query system.Peer reviewe
Academic teaching: Local university policies for generative AI and students’ use of generative AI as a personalized tutor
Lects in Helsinki Finnish - a probabilistic component modeling approach
This article examines Finnish lects spoken in Helsinki from the 1970s to the 2010s with a probabilistic model called Latent Dirichlet Allocation. The model searches for underlying components based on the linguistic features used in the interviews. Several coherent lects were discovered as components in the data, which counters the results of previous studies that report only weak co-variation between features that are assumed to present the same lect. The speakers, however, are not categorical in their linguistic behavior and tend to use more than one lect in their speech. This implies that the lects should not be considered in parallel with seemingly uniform linguistic systems such as languages, but as partial systems that constitute a network.Peer reviewe
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