20 research outputs found
Privacy of User Identities in Cellular Networks
This thesis looks into two privacy threats of cellular networks. For their operations, these networks have to deal with unique permanent user identities called International Mobile Subscriber Identity (IMSI). One of the privacy threats is posed by a device called IMSI catcher. An IMSI catcher can exploit various vulnerabilities. Some of these vulnerabilities are easier to exploit than others. This thesis looks into fixing the most easily exploitable vulnerability, which is in the procedure of identifying the subscriber. This vulnerability exists in all generations of cellular networks prior to 5G. The thesis discusses solutions to fix the vulnerability in several different contexts.
One of the solutions proposes a generic approach, which can be applied to any generation of cellular networks, to fix the vulnerability. The generic approach uses temporary user identities, which are called pseudonyms, instead of using the permanent identity IMSI. The thesis also discusses another solution to fix the vulnerability, specifically in the identification procedure of 5G. The solution uses Identity-Based Encryption (IBE), and it is different from the one that has been standardised in 5G. Our IBE-based solution has some additional advantages that can be useful in future works. The thesis also includes a solution to fix the vulnerability in the identification procedure in earlier generations of cellular networks. The solution fixes the vulnerability when a user of a 5G network connects to those earlier generation networks. The solution is a hybridisation of the pseudonym-based generic solution and the standardised solution in 5G.
The second of the two threats that this thesis deals with is related to the standards of a delegated authentication system, known as Authentication and Key Management for Applications (AKMA), which has been released in July 2020. The system enables application providers to authenticate their users by leveraging the authentication mechanism between the user and the user's cellular network. This thesis investigates what requirements AKMA should fulfil. The investigation puts a special focus on identifying privacy requirements. It finds two new privacy requirements, which are not yet considered in the standardisation process. The thesis also presents a privacy-preserving AKMA that can co-exist with a normal-mode AKMA.Väitöskirjassa tutkitaan kahta yksityisyyteen kohdistuvaa uhkaa mobiiliverkoissa. Näissä verkoissa käyttäjät tunnistetaan yksikäsitteisen pysyvän identiteetin perusteella. Hyökkääjä voi uhata käyttäjän yksityisyyttä sellaisen radiolähettimen avulla, joka naamioituu mobiiliverkon tukiasemaksi. Tällainen väärä tukiasema voi pyytää lähellä olevia mobiililaitteita kertomaan pysyvän identiteettinsä, jolloin hyökkääjä voi esimerkiksi selvittää, onko tietyn henkilön puhelin lähistöllä vai ei. Väitöskirjassa selvitetään, millaisilla ratkaisuilla tämän tyyppisiltä haavoittuvuuksilta voidaan välttyä.
Viidennen sukupolven mobiiliteknologian standardiin on sisällytetty julkisen avaimen salaukseen perustuva suojaus käyttäjän pysyvälle identiteetille. Tällä ratkaisulla voidaan suojautua väärän tukiaseman uhkaa vastaan, mutta se toimii vain 5G-verkoissa. Yksi väitöskirjassa esitetyistä vaihtoehtoisista ratkaisuista soveltuu käytettäväksi myös vanhempien mobiiliteknologian sukupolvien yhteydessä. Ratkaisu perustuu pysyvän identiteetin korvaamiseen pseudonyymillä. Toinen esitetty ratkaisu käyttää identiteettiin pohjautuvaa salausta, ja sillä olisi tiettyjä etuja 5G-standardiin valittuun, julkisen avaimen salaukseen perustuvaan menetelmään verrattuna. Lisäksi väitöskirjassa esitetään 5G-standardiin valitun menetelmän ja pseudonyymeihin perustuvan menetelmän hybridi, joka mahdollistaisi suojauksen laajentamisen myös aiempiin mobiiliteknologian sukupolviin.
Toinen väitöskirjassa tutkittu yksityisyyteen kohdistuva uhka liittyy 5G-standardin mukaiseen delegoidun tunnistautumisen järjestelmään. Tämä järjestelmä mahdollistaa käyttäjän vahvan tunnistautumisen automaattisesti mobiiliverkon avulla. Väitöskirjassa tutkitaan järjestelmälle asetettuja tietoturvavaatimuksia erityisesti yksityisyyden suojan näkökulmasta. Työssä on löydetty kaksi vaatimusta, joita ei ole toistaiseksi otettu huomioon standardeja kehitettäessä. Lisäksi työssä esitetään ratkaisu, jolla delegoidun tunnistautumisen järjestelmää voidaan laajentaa paremmin yksityisyyttä suojaavaksi
Computer Vision-Based Gender Detection from Facial Image
face detection, object detection, image processing Abstract � Computer vision-based gender detection from facial images is a challenging and important task for computer vision-based researchers. The automatic gender detection from face images has potential applications in visual surveillance and human-computer interaction systems (HCI). Human faces provide important visual information for gender perception. This research presents a novel approach for gender detection from facial images. The system can automatically detect face from input images and the detected facial area is taken as region of interest (ROI). Discrete Cosine Transformation (DCT) of that ROI plays an important role in gender detection. A gender knowledgebase of the processed DCT is created utilizing supervised learning. To detect gender, input image is passed through a classifier which is based on that knowledgebase. To improve the matching accuracy Local Binary Pattern (LBP) of the ROI is done before converting it into DCT. This research has experimented on a database of more than 4000 facial images which are mainly of this subcontinent in order to evaluate the performance of the proposed system. The average accuracy rate achieved by the system is more than 78%. 1
Optimization of Hormone for Artificial Breeding and Seed Production of Clarias batrachus (Linnaeus, 1758) Under Captive Condition
Aims: The study aimed to develop brood stock of Magur (Clarias batrachus), artificial breeding and seed production under captive condition using growth hormones in north-eastern Bangladesh.
Study Design: Fifteen pairs of brood Clarias batrachus were used in this experiment. Brood fishes were reared up to maturation for spawning operation in the farm by providing artificial diet for 4-5 months before onset of breeding season. In the present experiment, the brood fishes were induced with three growth hormones viz., Ovupin (100 mg dompridone and 0.2 mg S-GnRHa) at the rate of 1 ml.kg-1 body weight, Flash (20 mg S-GnRHa, 10 mg dompridone IP and propylene glycol) at the rate of 1 ml.kg-1 body weight and Human Chorionic Gonadotropin (HCG) hormone at the rate of 2272 IU.kg-1 body weight; respectively. The broods were injected with single injection in all treatments.
Place and Duration of Study: The present study was conducted on induced spawning of Magur (Clarias batrachus) at the Reliance Aqua Farm, Boilor, Trisal of Mymensingh district from March to August, 2016.
Methodology: Sexually mature healthy, uninjured male and female fishes were collected from the broodstock ponds for induced breeding. The fishes were transferred in the clean and germ free conditioning tanks for about 6-7 hours. During conditioning, continuous splash of water was given by keeping the male and female separate. The fishes were then weighed individually and injected intramuscularly with Ovupin, Flash and HCG hormone respectively. Only females were injected at 45° angle of the caudal peduncle. About 23-24 hours of post-injection the testes from males were dissected and mixed with stripping eggs for fertilization.
Results: The incubation period for fertilized eggs were 23-24 hours for all the treatments. Fertilization rates were 78.20±0.52, 93.09±0.61 and 81.60±0.97 % and hatching rates were 54.93±0.61, 75.77±0.47 and 64.41±0.71 % in Ovupin, Flash and HCG treatments, respectively.
Conclusion: This study revealed higher fertilization (93.09 %) and hatching (75.77 %) rate was achieved with Flash hormone. Therefore, Flash hormone could be effective for the artificial breeding and seed production of Magur (Clarias batrachus)
Factors Affecting the Milk Production Traits and Lactation Curve of the Indigenous River Buffalo Populations in Bangladesh
Household buffalo dairy farming is gaining popularity nowadays in Bangladesh because of the outstanding food value of buffalo milk as well as the lower production cost of buffalo compared to cattle. An initiative has recently been taken for the genetic improvement of indigenous dairy buffaloes. The present study was carried out to determine the influence of some environmental factors like age, parity, season of calving, calving interval, dry period on the lactation yield, and lactation curve of indigenous dairy buffaloes of Bangladesh. A total of 384 indigenous dairy buffaloes from the 3rd and 4th parity of seven herds under two different agroecological zones covering four seasons were selected and ear tagged for individual buffalo milk recording. A milk yield of 300 days (MY300d) was calculated following the International Committee for Animal Recording (ICAR) and the data were evaluated using the generalized linear model (GLM). In production traits, the mean of calculated lactation period (CLP), calculated lactation yield (CLY), and milk yield of 300 days (MY300d) of the overall population were 267.28 days, 749.36 kg, and 766.92 kg, respectively, whereas calving interval (CI) and dry period (DP) as reproductive traits were 453.06 days and 185.78 days, respectively. The season of calving, age of buffalo cows, population or herd, agroecological zone, calving interval, and dry period had significant effects on production traits (p p p p p p < 0.001). Positive and high correlation was found within milk traits and reproduction traits, but correlation was negative between milk traits and reproduction traits. Therefore, these non-genetic factors should be considered in the future for any genetic improvement program for indigenous dairy buffaloes in Bangladesh
Traditional Islamic Herbal Medicine and Complementary Therapies
Herbal products found abundantly in several plants are the rich source of phytochemicals with a wide range of pharmacological activities and few adverse effects. Medicinal plants contain active ingredients that assist the body in reestablishing its natural balance and healing itself. Various herbs, which are commonly used in traditional Islamic medicine, can have an impact on human body systems. Natural products are primary sources of effective drugs with novel structures and distinct mechanisms of action for the treatment of various types of complications as well as the drug discovery process. The various pharmacological properties such as antimicrobial, anticancer, antioxidant, antihypertensive, immunomodulatory, anti-inflammatory and anti-diabetic properties of several natural products are well documented in the Ayurveda and Unani system of medicine. Some of the natural products’ active ingredients have been documented, but the majority are still being researched as complementary medicine. As a result, more research is required to investigate their complementary medicine system. The present chapter provides a comprehensive update on selected traditional Islamic medicinal plants and their bioactive products mentioned in Islamic scriptures as complementary therapies to various diseases. The chapter also provides an in-depth update of pharmacological and clinical studies of natural products with special emphasis on cancer and diabetes
Investigating the self-assembling of nicotinic hydrazide-based amphiphile into nano-range vesicles and its amphotericin B loading applications
AbstractMost of the drugs are hydrophobic and have low water solubility, therefore posing issues in their absorption and bioavailability. Nonionic surfactants improve the solubility of hydrophobic drugs by entrapping them in their lipid bilayers. Two nonionic surfactants NODNH-16 and NODNH-18 are synthesized and characterized using different techniques i.e. EI-MS, 1H NMR, and FTIR. These newly synthesized surfactants were screened for blood hemolysis assay and cell toxicity studies using the NIH/3T3 cell line to assess their biocompatibility. Then amphotericin B was loaded into niosomal vesicles, and the drug entrapment efficiency of these surfactants was measured using UV–visible spectroscopy. The morphology of drug-loaded niosomes of synthesized surfactants was investigated using AFM, and their size, polydispersity, and zeta potential were measured with the Zetasizer instrument. Finally, a simulation study was performed to determine the pattern of self-assembly of the synthesized amphiphiles. Both synthesized nonionic surfactants showed good entrapment efficiency of 60.65 ± 2.12% and 68.45 ± 2.12%, respectively. It was also confirmed that both these synthesized nonionic surfactants were safe and biocompatible and showed less blood hemolysis (i.e. 21.13 ± 2.11% and 23.32 ± 2.45%) and higher 3T3 cells’ viability at 150 µg/mL concentration as compared to Tween®-80. The antifungal potential of amphotericin B-loaded niosomes has been evaluated against unicellular multi-fungal species, which showed a promising potential for fungicidal activity. These results are substantiated by constructing a safe vehicle system for drug delivery