• 제목/요약/키워드: foraging

검색결과 202건 처리시간 0.019초

Encryption-based Image Steganography Technique for Secure Medical Image Transmission During the COVID-19 Pandemic

  • Alkhliwi, Sultan
    • International Journal of Computer Science & Network Security
    • /
    • 제21권3호
    • /
    • pp.83-93
    • /
    • 2021
  • COVID-19 poses a major risk to global health, highlighting the importance of faster and proper diagnosis. To handle the rise in the number of patients and eliminate redundant tests, healthcare information exchange and medical data are transmitted between healthcare centres. Medical data sharing helps speed up patient treatment; consequently, exchanging healthcare data is the requirement of the present era. Since healthcare professionals share data through the internet, security remains a critical challenge, which needs to be addressed. During the COVID-19 pandemic, computed tomography (CT) and X-ray images play a vital part in the diagnosis process, constituting information that needs to be shared among hospitals. Encryption and image steganography techniques can be employed to achieve secure data transmission of COVID-19 images. This study presents a new encryption with the image steganography model for secure data transmission (EIS-SDT) for COVID-19 diagnosis. The EIS-SDT model uses a multilevel discrete wavelet transform for image decomposition and Manta Ray Foraging Optimization algorithm for optimal pixel selection. The EIS-SDT method uses a double logistic chaotic map (DLCM) is employed for secret image encryption. The application of the DLCM-based encryption procedure provides an additional level of security to the image steganography technique. An extensive simulation results analysis ensures the effective performance of the EIS-SDT model and the results are investigated under several evaluation parameters. The outcome indicates that the EIS-SDT model has outperformed the existing methods considerably.

Improved marine predators algorithm for feature selection and SVM optimization

  • Jia, Heming;Sun, Kangjian;Li, Yao;Cao, Ning
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제16권4호
    • /
    • pp.1128-1145
    • /
    • 2022
  • Owing to the rapid development of information science, data analysis based on machine learning has become an interdisciplinary and strategic area. Marine predators algorithm (MPA) is a novel metaheuristic algorithm inspired by the foraging strategies of marine organisms. Considering the randomness of these strategies, an improved algorithm called co-evolutionary cultural mechanism-based marine predators algorithm (CECMPA) is proposed. Through this mechanism, search agents in different spaces can share knowledge and experience to improve the performance of the native algorithm. More specifically, CECMPA has a higher probability of avoiding local optimum and can search the global optimum quickly. In this paper, it is the first to use CECMPA to perform feature subset selection and optimize hyperparameters in support vector machine (SVM) simultaneously. For performance evaluation the proposed method, it is tested on twelve datasets from the university of California Irvine (UCI) repository. Moreover, the coronavirus disease 2019 (COVID-19) can be a real-world application and is spreading in many countries. CECMPA is also applied to a COVID-19 dataset. The experimental results and statistical analysis demonstrate that CECMPA is superior to other compared methods in the literature in terms of several evaluation metrics. The proposed method has strong competitive abilities and promising prospects.

A Spiking Neural Network for Autonomous Search and Contour Tracking Inspired by C. elegans Chemotaxis and the Lévy Walk

  • Chen, Mohan;Feng, Dazheng;Su, Hongtao
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제16권9호
    • /
    • pp.2846-2866
    • /
    • 2022
  • Caenorhabditis elegans exhibits sophisticated chemotaxis behavior through two parallel strategies, klinokinesis and klinotaxis, executed entirely by a small nervous circuit. It is therefore suitable for inspiring fast and energy-efficient solutions for autonomous navigation. As a random search strategy, the Lévy walk is optimal for diverse animals when foraging without external chemical cues. In this study, by combining these biological strategies for the first time, we propose a spiking neural network model for search and contour tracking of specific concentrations of environmental variables. Specifically, we first design a klinotaxis module using spiking neurons. This module works in conjunction with a klinokinesis module, allowing rapid searches for the concentration setpoint and subsequent contour tracking with small deviations. Second, we build a random exploration module. It generates a Lévy walk in the absence of concentration gradients, increasing the chance of encountering gradients. Third, considering local extrema traps, we develop a termination module combined with an escape module to initiate or terminate the escape in a timely manner. Experimental results demonstrate that the proposed model integrating these modules can switch strategies autonomously according to the information from a single sensor and control steering through output spikes, enabling the model worm to efficiently navigate across various scenarios.

Molecular Basis of Hexanoic Acid Taste in Drosophila melanogaster

  • Roshani Nhuchhen Pradhan;Bhanu Shrestha;Youngseok Lee
    • Molecules and Cells
    • /
    • 제46권7호
    • /
    • pp.451-460
    • /
    • 2023
  • Animals generally prefer nutrients and avoid toxic and harmful chemicals. Recent behavioral and physiological studies have identified that sweet-sensing gustatory receptor neurons (GRNs) in Drosophila melanogaster mediate appetitive behaviors toward fatty acids. Sweet-sensing GRN activation requires the function of the ionotropic receptors IR25a, IR56d, and IR76b, as well as the gustatory receptor GR64e. However, we reveal that hexanoic acid (HA) is toxic rather than nutritious to D. melanogaster. HA is one of the major components of the fruit Morinda citrifolia (noni). Thus, we analyzed the gustatory responses to one of major noni fatty acids, HA, via electrophysiology and proboscis extension response (PER) assay. Electrophysiological tests show this is reminiscent of arginine-mediated neuronal responses. Here, we determined that a low concentration of HA induced attraction, which was mediated by sweet-sensing GRNs, and a high concentration of HA induced aversion, which was mediated by bitter-sensing GRNs. We also demonstrated that a low concentration of HA elicits attraction mainly mediated by GR64d and IR56d expressed by sweet-sensing GRNs, but a high concentration of HA activates three gustatory receptors (GR32a, GR33a, and GR66a) expressed by bitter-sensing GRNs. The mechanism of sensing HA is biphasic in a dose dependent manner. Furthermore, HA inhibit sugar-mediated activation like other bitter compounds. Taken together, we discovered a binary HA-sensing mechanism that may be evolutionarily meaningful in the foraging niche of insects.

Comparison of Gayal (Bos frontalis) and Yunnan Yellow Cattle (Bos taurus): In vitro Dry Matter Digestibility and Gas Production for a Range of Forages

  • Xi, Dongmei;Wanapat, Metha;Deng, Weidong;He, Tianbao;Yang, Zhifang;Mao, Huaming
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제20권8호
    • /
    • pp.1208-1214
    • /
    • 2007
  • Three male Gayal, two years of age and with a mean live weight of $203{\pm}26$ kg, and three adult Yunnan Yellow Cattle, with a mean live weight of $338{\pm}18$ kg were fed a ration of pelleted lucerne hay and used to collect rumen fluid for in vitro measurements of digestibilities and gas production from fermentation of a range of forages. The forages were: bamboo stems, bamboo twigs, bamboo leaves, rice straw, barley straw, annual ryegrass hay, smooth vetch hay and pelleted lucerne hay. There were significant (p<0.05) effects of the source of rumen fluid on in vitro dry matter digestibility (IVDMD) and gas production during fermentation of forage. For the roughage of lowest quality (bamboo stems and rice straw), gas production during fermentation was higher (p<0.05) in the presence of rumen fluid from Gayal than Yunnan Yellow Cattle. Differences for these parameters were found for the better quality roughages with gas production being enhanced in the presence of rumen fluid from Yunnan Yellow Cattle. Moreover, the IVDMD of investigated roughages was significantly higher (p<0.05) in Gayal than Yunnan Yellow Cattle. The results offer an explanation for the positive live weight gains recorded for Gayal foraging in their natural environment where the normal diet consists of poor quality roughages.

지리산 지역에서 등산로에 의한 번식기 조류 군집의 영향 (Effect of Trails on Breeding Bird Communities in Chirisan National Park)

  • 이우신
    • 한국환경생태학회지
    • /
    • 제14권2호
    • /
    • pp.103-110
    • /
    • 2000
  • 본 연구는 1994년 4월에서 8월까지의 기간 동안 지리산국립공원내 임걸령 지역과 노고단 지역에서 등산로가 개설되어 있는 지역과 개설되어 있지 않은 지역을 대상으로 등산로가 번식기 조류 군집에 미치는 영향을 파악함으로써 등산로의 합리적인 관리방안을 모색하고가 실시하였다. 조사지역별 서식지 환경은 노고단 등산로 지역과 노고단 지역이 유사하였으며 임걸령 등산로 지역과 임걸령 지역이 각각 유사하였다. 4개 지역에서 조사를 실시 한 결과 총 25종의 조류가 관찰되었으며. 그 중 18종이 번식한 것으로 파악되었다. 번식기 조류 군집의 종 수 및 번식 쌍수와 길드구조에 있어서 산림 지역과 등산로 지역간에 큰 차이를 보이지 않아, 등산로가 조류 군집에 미치는 영향은 크지 않았던 것으로 판단된다. 이는 등산로의 상층식생이 울폐되어 상층수관이 연결되어 있었으며, 등산로 주변에 하층식생이 발달해 있는 지역이므로 조류 군집에 큰 영향을 주지 않았던 것으로 보여진다. 그러므로 등산로의 개설 혹은 현재 등산로의 유지 및 관리를 위해서 등산로 주변의 수관 울페율을 높게 유지할 수 있도록 등산로 주변의 대경목 및 상층임관이 보호 및 관리되도록 해야 하고, 또한 주변의 식생, 특히 관목층 및 하층식생의 보호 및 유지가 할 것으로 판단된다.

  • PDF

산림 지역의 조류 군집에 대한 도로의 영향 (Effects of Road on Bird Communities in Forest Areas)

  • 허위행;임신재;이우신
    • 한국환경생태학회지
    • /
    • 제17권1호
    • /
    • pp.1-8
    • /
    • 2003
  • 본 연구는 경남 남해군 금산 지역에서 도로가 조류 군집에 미치는 영향을 파악함으로서 산림 지역에 개설되는 도로의 합리적인 관리방안을 모색하고자 2000년 5월부터 2001년 1월까지의 기간 동안 실시되었다. 조류군집 조사 결과 도로 지역에서는 26종, 산림 지역에서는 23종의 조류가 각각 관찰되었다. 지역별로 호랑지빠귀, 할미새사촌 등은 산림 지역에서 만, 쇠유리새와 큰유리새 휘파람새, 상모솔새 등은 도로 지역에서만 관찰되었다. 번식기 조류 군집의 길드 분석 결과 도로 지역에서는 관목층 영소 길드와 채이 길드의 비율이 높게 나타났다. 대체로 도로는 야생동물의 서식에 부정적인 영향을 주는 것으로 보고 되었으나, 본 연구에서는 도로의 차량 통행량이 적고, 도로변에 다양한 서식환경이 존재하며, 상층임관의 단절이 소규모이고 연속적이지 않아 도로가 조류 군집에 부정적인 영향을 크게 미치지 않는 것으로 나타났다. 그러므로 산림 지역에서 도로의 영향을 최소화하기 위해서는 상층임관의 수관부가 연결될 수 있도록 도로변 교목의 유지 및 관리와 관목층의 조성이 필요할 것으로 판단된다.

대구 불로고분 자연마당 조류군집 및 서식지 이용 특성 (Characteristics of Bird Community and Habitat Use in Daegu Bulnogoboon Jayeon Madang)

  • 김정수;남궁형;남상준;남은희
    • 한국환경복원기술학회지
    • /
    • 제23권5호
    • /
    • pp.15-27
    • /
    • 2020
  • This study was carried out four times on 2005 and 2006, respectively May and October to understand the bird community and habitat using condition in the Daegu Bulnogoboon Jayeon Madang (DBJM). In this study, 34 species and 332 individuals were observed. The dominant species were Passer montanus 22.0%, Pica pica 18.1%, Hypsipetes amaurotis 6.02% and Sinosuthora webbiana 5.72%, and the species diversity was 2.797. With migration, the highest number and percentage to the lowest was residents 61.7%, summer visitors 26.5% and winter visitors 11.8%. Among 24 species which bred(check or possibility) in the DBJM, canopy was 50.0%, hole was 37.5% and bush was 12.5% in their nesting guilds. In foraging guilds in breeding season was canopy was 58.1%, water was 19.3% and bush was 16.1%, and in non-breeding season, canopy was 54.8%, water 22.6% and bush 19.3%. For the habitats of the birds in the DBJM, wetlands including reservoir area were used by herons, ducks and Hirundo rustica, grassland area was used by Sinosuthora webbiana, buntings and Passer montanus, and forest area was used by Streptopelia orientalis, woodpeckers, Hypsipetes amaurotis and tits. The number of species and individuals of birds observed in the DBJM was higher than other urban parks. We suggest that this was attributed to various man-made habitats such as wetland with reservoir, grassland and forest area constructed in the DBJM.

Feeding Behaviour and Forage Nutrient Utilization by Goats on a Semi-Arid Reconstituted Silvipasture

  • Sharma, K.;Saini, A.L.;Singh, Nawab;Ogra, J.L.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제11권4호
    • /
    • pp.344-350
    • /
    • 1998
  • Seasonal variations in the feeding behaviour of Jamunapari and Barbari goat breeds and their utilization of browse and grass nutrients was evaluated in a promising 3-tier (Leucaena leucocephala- Dichro-stachys nutan-Cenchrus ciliaris) reconstituted pasture during summer, rainy and winter season of the years 1987 and 1988. Distinct diurnal pattern of feeding was observed with both the breeds. Jamunapari goats spent significantly more time foraging during winter season (352.0 min) followed by summer (306.0 min) and least in rainy season (277.0 min). Though no significant difference was observed in the relative time spent by Barbari goats on grazing activities during summer and winter season, they spent significantly more (p < 0.05) time during rainy season as compared to other two seasons. The preference of grazing goats for certain plant species in relation to others was evident with distinct seasonal and breed variations. DM intake (g/kg $BW^{075}$) varied significantly (p < 0.05) from season to season. Among the browse. L. leucocephala was prefered over D. nutan irrespective of breed over the seasons. There was no breed difference in DM intake, or proximate composition and nutrient digestibility of ingested herbage. The available nutrient content of ingested forage was found sufficient to meet the nutrient requirements of adult goats for maintenance (NRC, 1981). The reconstituted 3-tier pasture dominated by plant species like L. leucocephala and Cenchrus species appear to have great potential to sustain the nutrient requirement of goats without adverse seasonal fluctuations in pasture quality.

Environmental factors affecting the composition and diversity of the avian community in igune, a traditional agricultural landscape in northern Japan

  • Imai, Haruka;Nakashizuka, Tohru;Oguro, Michio
    • Journal of Ecology and Environment
    • /
    • 제41권3호
    • /
    • pp.54-65
    • /
    • 2017
  • Background: "Igune," a traditional agricultural landscape in the Tohoku region of Japan, is characterized by small-scale artificial woodlots surrounding a farmer's house that are interspersed with paddy fields. During the rapid economic growth of Japan over recent decades, some igune woodlots have been abandoned or logged. Biodiversity conservation is an important issue worldwide, and traditional agricultural landscapes are of particular interest. To elucidate the role of igune landscapes in conserving biodiversity, we examined the effects of environmental factors on avian communities. Results: The study was conducted in the suburban areas of Oshu and Hanamaki cities, Iwate Prefecture, Japan, at eight sites that varied in the density and area of igune woodlots within the landscape. Bird surveys were conducted from the middle to late breeding season, and several environmental factors of the igune landscape were also measured. The results of canonical correspondence analysis indicated that the characteristics of avian communities were mainly determined by the total forested area in the landscape. Increased total forested area and shrubs layer of igune woodlots did not cause a reduction in number of bird species of any habitat and foraging types, while increased both in species number and abundance of insectivores and forest species. The number of raptor species increased in igune sites without shrubs. Conclusions: Our results suggest that maintaining igune landscapes may enhance avian diversity within this landscape, although the effects of shrubs within igune varied; developed bush communities increased the evenness of the avian community, whereas some raptor species preferred an open forest understory.