Text Categorization and Sorting of Web Search Results

With the Internet facing the growing problem of information overload, the large volumes, weak structure and noisiness of Web data make it amenable to the application of machine learning techniques. After providing an overview of several topics in text categorization, including document representation, feature selection, and a choice of classifiers, the paper presents experimental results concerning the performance and effects of different transformations of the bag-of-words document representation and feature selection, on texts extracted from the dmoz Open Directory of Web pages. Finally, the paper describes the primary motivation for the experiments: a new meta-search engine CatS which utilizes text categorization to enhance the presentation of search results obtained from a major Web search engine

Informaciono-bezbednosna kultura - imperativ savremenog društva

The importance of building information-security culture of each society has become a well-established idea. The aim of such a culture is the impact on different human behaviors that may affect the overall results of protection of information assets. The authors believe that culture is the 'key' of the information security. Extensive review and analysis of the information security literature have come to the conclusion that the collective consciousness about the use and protection in the field of contemporary forms of crime is very low. In this sense, the goal of this paper is that the examination of information security culture from the standpoint of best practices, support the view that knowledge and education play an important role in building a secure environment with a special emphasis on raising awareness of end-users about the need and importance of data protection, information and knowledge.Značaj izgradnje informaciono-bezbednosne kulture svakog društva postala je dobro utemeljena ideja. Cilj takve kulture je uticaj na različita ljudska ponašanja koja se mogu odraziti na ukupne rezultate zaštite informacione imovine. Autori rada smatraju da je kultura 'ključ' informacione bezbednosti. Obimnim pregledom i analizom literature o informacionoj bezbednosti došlo se do zaključka da je kolektivna svest o upotrebi informacionih tehnologija i zaštiti u domenu savremenih oblika kriminaliteta na veoma niskom nivou. U tom smislu, cilj rada je da se, razmatranjem informaciono- bezbednosne kulture sa stanovišta najbolje prakse, podrži stav da znanje i obrazovanje igraju važnu ulogu u izgradnji bezbednog ambijenta sa posebnim akcentom na podizanju svesti krajnjih korisnika o potrebi i važnosti zaštite podataka, informacija i znanja

Multifunctionalized Self-supported (Nano) Membranes as Integrated Platform for Plasmonic Metamaterials

We considered the possibility to fabricate multifunctional nanocomposite membranes as a platform for plasmonic metamaterials, simultaneously incorporating pores, built-in functional groups and active nanoparticles. To this purpose we combined lamination and inclusion of nanofillers into the membrane host. For the basic material we chose macroporous crosslinked copolymers based on glycidyl methacrylate (GMA). The epoxy group present in GMA molecule is readily transformed into various functional groups that further serve as affinity enhancers, ensuring the usability of the membranes as pre-concentrators of selected agents in plasmonic sensors. To form GMA-based membranes we used a recently proposed method combining the traditional immersion precipitation with photopolymerization and crosslinking of functional monomers. Further functionalization is obtained by in-situ formation of noble metal nanoparticles directly within the GMA host. In this way membranes with simultaneous plasmonic, adsorbent and catalytic functionality are obtained. We considered the use of the our structures for plasmonic chemical sensors where separator, pre-concentrator and binding agent are integrated with the plasmonic crystal, as well as for plasmonic enhancement of photocatalytic reactions in microreactors. Our approach gives a highly tailorable element compatible with microelectromechanical systems (MEMS) technologies and readily transferable across platforms

Usporedba torakalne epiduralne analgezije i intravenske analgezije koju kontrolira bolesnik nakon kolorektalnih onkoloških operacija

The aim of the study was to compare thoracic epidural analgesia (TEA) and intravenous patient-controlled analgesia (IV-PCA) after open colorectal cancer surgery. This prospective study included sixty patients scheduled for elective open colorectal surgery and randomized to either postoperative IV-PCA with morphine (n=30) or TEA with a mixture of levobupivacaine, fentanyl and adrenaline (n=30). Th e primary outcome was return of bowel function. The secondary outcome was quality of postoperative analgesia at rest, on coughing and during mobilization. Intermediate outcomes included patient satisfaction, time out of bed, rate of side effects and postoperative complications, and time of discharge. Recovery of postoperative ileus occurred sooner (p<0.001) and resumption of dietary intake was achieved earlier (p<0.001) in TEA group. Intensity of pain during the first 3 postoperative days was significantly lower at rest, on coughing and during mobilization (p<0.001), and mobilization was much more effi cient (p<0.005) in TEA than in IV-PCA group. Satisfaction scores were better in TEA group (p<0.001). Nausea, sedation and postoperative delirium occurred less frequently in TEA group (p<0.05, p<0.001 and p<0.05, respectively). TEA demonstrated significantly better effectiveness than IV-PCA after open colorectal cancer surgery and had a positive impact on bowel function, dietary intake, patient satisfaction and early mobilization. The results of this study demonstrated the importance of implementation of TEA as a preferred method for postoperative pain control after major open colorectal surgery.Cilj istraživanja bio je usporediti torakalnu epiduralnu analgeziju (TEA) i intravensku analgeziju koju kontrolira bolesnik (intravenous patient-controlled analgesia, IV-PCA) nakon otvorenih kolorektalnih onkoloških operacija. Prospektivnim istra-živanjem je obuhvaćeno šezdesetoro bolesnika podijeljenih u dvije skupine. U skupini IV-PCA (n=30) poslijeoperacijska analgezija je osigurana morfinom primijenjenim preko IV-PCA crpki, a u skupini TEA epiduralno primijenjenom smjesom levobupivakaina, fentanila i adrenalina (n=30). Kao primarni ishod analiziran je oporavak crijevne peristaltike, a kao sekundarni kvaliteta poslijeoperacijske analgezije u mirovanju, kod kašlja i pri mobilizaciji. Analizirani su i zadovoljstvo bolesnika analgezijom, vrijeme provedeno izvan postelje, učestalost neželjenih učinaka i poslijeoperacijskih komplikacija te dužina lije-čenja u bolnici. Crijevna peristaltika je brže uspostavljena (p<0,001) i tekuća-kašasta prehrana ranije uvedena kod bolesnika u skupini TEA (p<0,001). Poslijeoperacijska bol koju su tijekom 3 poslijeoperacijska dana bolesnici osjećali u mirovanju, kod kašlja i pri mobilizaciji (p<0,001) bila je značajno manjeg intenziteta u skupini TEA u usporedbi sa skupinom IV-PCA. TEA je omogućila bržu ranu mobilizaciju (p<0,005) i zadovoljstvo bolesnika poslijeoperacijskom analgezijom (p<0,001). Mučnina, sedacija i poslijeoperacijski delirij bili su rjeđi u skupini TEA (p<0,05, p<0.001 i p<0,05). TEA osigurava značajno bolju učinkovitost u usporedbi s IV-PCA nakon otvorenih kolorektalnih onkoloških operacija i ima pozitivan učinak na uspostavljanje crijevne peristaltike, početak peroralnog unosa, zadovoljstvo bolesnika i ranu mobilizaciju. Rezultati ovoga istraživanja dokazuju važnost primjene TEA kao prioritetne tehnike za analgeziju nakon opsežnih otvorenih kolorektalnih operacija

Silver nanoparticles within functionalized hydrogels for plasmonic (bio)chemical sensors

Plasmonics is the basis for a novel generation of adsorption-based ultrasensitive (bio) chemical sensors. In nanoplasmonic sensors one utilizes nanocomposites typically in the form of thin films, comprising metal nanoparticles or ordered metal-dielectrics (plasmonic crystals). In this work we investigated thin functionalized hydrogel films with embedded silver nanoparticles. These films were prepared by copolymerizing glycidyl methacrylate with mono and multifunctional methacrylates using UV irradiation. The epoxy group in glycidyl methacrylate can then be converted by chemical means into a desired functionality to capture the targeted analyte. Silver nanoparticles were either photochemically generated in situ, or were introduced into hydrogels by chemical reduction. Differences in morphology and performance of these nanocomposites were investigated and will be discussed

Digitalna forenzika u kontekstu zaštite informacionih sistema

Although a lot has been said and written about the protection of information systems and users of the Internet, only a small number of managers and users of information technologies are aware of the significance of this problem. This can lead to occurrence of risky situations in which business information systems may be threatened. Their inadequate protection may have disastrous effects on the business process itself. The purpose of the paper is to clearly and transparently establish relations between methods and techniques of information system protection and digital forensic investigation, as well as to raise the security awareness and promote security culture as essential elements of the cycle of risk management and protection.Iako se o zaštiti informacionih sistema i korisnika interneta često govori i piše, mali broj menadžera i korisnika informacionih tehnologija su svesni značaja ovog problema. To može dovesti do pojave rizičnih incidentnih situacija u kojima su ugroženi poslovni informacioni sistemi. Njihova neadekvatna zaštita može imati katastrofalne posledice na sam poslovni proces. Cilj rada je da se na jasan i transparentan način uspostave i dovedu u vezu metode i tehnike zaštite informacionih sistema sa digitalnom forenzičkom istragom, kao i da se skrene pažnja na bezbednosnu svest i kulturu kao esencijalne elemente ciklusa upravljanja rizikom i zaštitom

Нови родијум(iii)-ed3ap комплекс: кристална структура, карактеризација и компјутациона хемија

Only one (trans(O5)-Na[Rh(ED3AP)]∙3H2O) of possible two isomers was synthesized and characterized by single crystal X-ray analysis, IR and UV–Vis spectroscopy. Computational analysis of both isomers was performed with three levels of theory (B3LYP/TZV, BP86/TZV, OPBE/TZV), which gave consistent results. The more stable isomer by total energy and ligand field stabilization energy (LFSE) was trans(O5) which appeared in synthesis. The calculation of excited state energies complied with UV–Vis spectra, especially with OPBE functional. The results of excited state energy pointed out the dif­ferences among isomers in means of a splitting pattern of 1T2g excited state term. Both isomers have a strongly delocalized structure, according to the nat­ural bonding orbital (NBO) analysis. NBO analysis shows that the trans(O5) isomer is more stable than trans(O5O6) for approx. 87 kJ/mol. Therefore, only the trans(O5) isomer is present in the reaction mixture.Један (trans(O5)-Na[Rh(ED3AP)]∙3H2O) од могућа два изомера синтетисан je и окарактерисан применом дифракције X-зрака на монокристалу, IR и UV–Vis спектроскопијом. Компјутерска анализа оба изомера обављена је помоћу три теоријска модела која су дала конзистентне резултате. Стабилнији изомер по укупној енергији и енергији стабилизације лигандног поља (LFSE) јеt rans(O5) који је и изолован у синтези. Прорачун енергија ексцитованих стања дао је добру усаглашеност са UV–Vis спектром, посебно у случају прорачуна са OPBE функционалом. На основу резултата енергија ексцитованих стања уочене су разлике између изомера у начину цепања 1T2g терма. Оба изомера дају снажно-делокализовану структуру судећи по NBO анализи. Наоснову NBO анализе, trans(O5) изомер је стабилнији за 87 kJ/mol и једини је присутан у реакционој смеши.Supplementary material: [https://cer.ihtm.bg.ac.rs/handle/123456789/5108

Towards automated design of quantum cascade lasers

We present an advanced technique for the design and optimization of GaAs/AlGaAs quantum cascade laser structures. It is based on the implementation of the simulated annealing algorithm with the purpose of determining a set of design parameters that satisfy predefined conditions, leading to an enhancement of the device output characteristics. Two important design aspects have been addressed: improved thermal behavior, achieved by the use of higher conduction band offset materials, and a more efficient extraction mechanism, realized via a ladder of three lower laser states, with subsequent pairs separated by the optical phonon energy. A detailed analysis of performance of the obtained structures is carried out within a full self-consistent rate equations model of the carrier dynamics. The latter uses wave functions calculated by the transfer matrix method, and evaluates all relevant carrier–phonon and carrier–carrier scattering rates from each quantized state to all others within the same and neighboring periods of the cascade. These values are then used to form a set of rate equations for the carrier density in each state, enabling further calculation of the current density and gain as a function of the applied field and temperature. This paper addresses the application of the described procedure to the design of lambda~9 µm GaAs-based mid-infrared quantum cascade lasers and presents the output characteristics of some of the designed optimized structures. © 2005 American Institute of Physic

Functionalized Polymer Membranes for Plasmonic Sensing with Enhanced Selectivity

We investigate theoretically and experimentally the concept of enhancing the selectivity of chemical, biochemical and biological (nano)plasmonic sensors utilizing multifunctionalized polymer membranes. Membrane nanocompositing is done by lamination and surface/pore immobilization. A separator/filter and an affinity-based adsorption enhancer are integrated into a single multifunctional membrane structure. Functionalized membrane may be transferred across platforms and even used for different types of sensing devices