Papers by Jean Claude Kamgang
Future Internet, Aug 27, 2020
To keep its business reliable, Google is concerned to ensure the quality of apps on the store. On... more To keep its business reliable, Google is concerned to ensure the quality of apps on the store. One crucial aspect concerning quality is security. Security is achieved through Google Play protect and anti-malware solutions. However, they are not totally efficient since they rely on application features and application execution threads. Google provides additional elements to enable consumers to collectively evaluate applications providing their experiences via reviews or showing their satisfaction through rating. The latter is more informal and hides details of rating whereas the former is textually expressive but requires further processing to understand opinions behind it. Literature lacks approaches which mine reviews through sentiment analysis to extract useful information to improve the security aspects of provided applications. This work goes in this direction and in a fine-grained way, investigates in terms of confidentiality, integrity, availability, and authentication (CIAA). While assuming that reviews are reliable and not fake, the proposed approach determines review polarities based on CIAA-related keywords. We rely on the popular classifier Naive Bayes to classify reviews into positive, negative, and neutral sentiment. We then provide an aggregation model to fusion different polarities to obtain application global and CIAA reputations. Quantitative experiments have been conducted on 13 applications including e-banking, live messaging and anti-malware apps with a total of 1050 security-related reviews and 7,835,322 functionality-related reviews. Results show that 23% of applications (03 apps) have a reputation greater than 0.5 with an accent on integrity, authentication, and availability, while the remaining 77% has a polarity under 0.5. Developers should make a lot of effort in security while developing codes and that more efforts should be made to improve confidentiality reputation. Results also show that applications with good functionality-related reputation generally offer a bad security-related reputation. This situation means that even if the number of security reviews is low, it does not mean that the security aspect is not a consumer preoccupation. Unlike, developers put much more time to test whether applications work without errors even if they include possible security vulnerabilities. A quantitative comparison against well-known rating systems reveals the effectiveness and robustness of CIAA-RepDroid to repute apps in terms of security. CIAA-RepDroid can be associated with existing rating solutions to recommend developers exact CIAA aspects to improve within source codes.
Siam Journal on Applied Mathematics, 2006
In this paper we propose a malaria within-host model with k classes of age for the parasitized re... more In this paper we propose a malaria within-host model with k classes of age for the parasitized red blood cells and n strains for the parasite. We provide a global analysis for this model. A competitive exclusion principle holds. If R 0 , the basic reproduction number, satisfies R 0 ≤ 1, then the disease-free equilibrium is globally asymptotically stable. On the contrary if R 0 > 1, then generically there is a unique endemic equilibrium which corresponds to the endemic stabilization of the most virulent parasite strain and to the extinction of all the other parasites strains. We prove that this equilibrium is globally asymptotically stable on the positive orthant if a mild sufficient condition is satisfied.
EAI endorsed transactions on context-aware systems and applications, May 12, 2020
The low yield of the agricultural sector in Sub-Saharan Africa (SSA) is not solely due to the typ... more The low yield of the agricultural sector in Sub-Saharan Africa (SSA) is not solely due to the type of agriculture (mainly traditional), but also to the crop selection process which is typically based on impressions or past experience. This approach cannot always ensure an optimal crop selection even for subsistence farming. To improve farmers' net revenue, this work proposes a three-stage approach for crop selection in the context of traditional agriculture. Firstly, since crops' yields are influenced by several environmental parameters, an analytic hierarchy process is used to set the weights of those parameters. Secondly, an expert system using a rule-based inference engine is designed to determine the appropriateness of crops depending on environmental and time constraints. Finally, the net revenue of the farmer is formulated as a linear programming problem, considering the operating account of the various crops selected during the previous stages. In addition, a web interface has been developed to allow farmers to benefit from the whole system. Scenarios have been designed from a collection of crop technical itineraries, and they have been compared with the outputs of the expert system. The result shown that the system can effectively help farmers to improve their net revenues.
CRC Press eBooks, Mar 14, 2023
arXiv (Cornell University), Jun 24, 2023
We propose and analyze an epidemiological model for vector borne diseases that integrates a multi... more We propose and analyze an epidemiological model for vector borne diseases that integrates a multi-stage vector population and several host sub-populations which may be characterized by a variety of compartmental model types: subpopulations all include Susceptible and Infected compartments, but may or may not include Exposed and/or Recovered compartments. The model was originally designed to evaluate the effectiveness of various prophylactic measures in malaria-endemic areas, but can be applied as well to other vector-borne diseases. This model is expressed as a system of several differential equations, where the number of equations depends on the particular assumptions of the model. We compute the basic reproduction number R 0 , and show that if R 0 ⩽ 1, the disease free equilibrium (DFE) is globally asymptotically stable (GAS) on the nonnegative orthant. If R 0 > 1, the system admits a unique endemic equilibrium (EE) that is GAS. We analyze the sensitivity of R 0 and the EE to different system parameters, and based on this analysis we discuss the relative effectiveness of different control measures.
HAL (Le Centre pour la Communication Scientifique Directe), Jan 30, 2020
Dans ce travail nous avons utilise le concept de la modelisation et de la simulation multi-agent ... more Dans ce travail nous avons utilise le concept de la modelisation et de la simulation multi-agent pour developper un simulateur qui decrit la dynamique d'une epidemie de cholera. Nous l'avons developpe dans la plate-forme multi-agent GAMA 1 en y integrant le systeme d'information geographique de la ville de Ngaoundere comme environnement des agents. Ensuite quelques simulations y ont ete executees sur un ensemble de jeux de donnees relatif a la sensibilisation et l'assainissement. Les resultats obtenus a l'issu de ces simulations nous donne de suggerer une strategie de controle optimal axees sur trois points essentiels portant sur l'identification rapide des infectes, la sensibilisation immediate des populations et surtout de la basse classe et l'assainissement rapide des zones a risque.
EAI Endorsed Transactions on Context-aware Systems and Applications, 2020
The low yield of the agricultural sector in Sub-Saharan Africa (SSA) is not solely due to the typ... more The low yield of the agricultural sector in Sub-Saharan Africa (SSA) is not solely due to the type of agriculture (mainly traditional), but also to the crop selection process which is typically based on impressions or past experience. This approach cannot always ensure an optimal crop selection even for subsistence farming. To improve farmers' net revenue, this work proposes a three-stage approach for crop selection in the context of traditional agriculture. Firstly, since crops' yields are influenced by several environmental parameters, an analytic hierarchy process is used to set the weights of those parameters. Secondly, an expert system using a rule-based inference engine is designed to determine the appropriateness of crops depending on environmental and time constraints. Finally, the net revenue of the farmer is formulated as a linear programming problem, considering the operating account of the various crops selected during the previous stages. In addition, a web interface has been developed to allow farmers to benefit from the whole system. Scenarios have been designed from a collection of crop technical itineraries, and they have been compared with the outputs of the expert system. The result shown that the system can effectively help farmers to improve their net revenues.
Journal of Applied Analysis and Computation, 2015
In this paper, we propose and analyse a model of dynamics trans-mission of malaria, incorporating... more In this paper, we propose and analyse a model of dynamics trans-mission of malaria, incorporating varying degrees p of susceptible and ofinfectious that makes the dynamic of the overall host population integrateSEIRS, SEIS, SIRS and SIS at the same time. For this model we compute anew threshold number and establish the global asymptotic stability of thedisease-free equilibrium when R0 1 depending on case the systemadmits one or two endemic equilibrium. Numerical simulations are presentedfor dierent value of R0, based on data collected in the literature. Finally,the impact of parameters p and of system dynamics are investigated.
Informatics in Medicine Unlocked, 2022
Applications and Applied Mathematics: An International Journal (AAM), 2021
We construct a new model for the comprehension of the Covid-19 dynamics in Cameroon. We present t... more We construct a new model for the comprehension of the Covid-19 dynamics in Cameroon. We present the basic reproduction number and perform some numerical analysis on the possible outcomes of the epidemic. The major results are the possibilities to have several peaks before the end of the first outbreak for an uniform strategy, and the danger to have a severe peak after the adoption of a careless strategy of barrier anti-Covid-19 measures that follow a good containment period.
Background: In their behavior, Africans generally pour dirty water around their homes. This dirty... more Background: In their behavior, Africans generally pour dirty water around their homes. This dirty water becomes stagnant at a given moment, which hence constitutes aquatic habitats (AH). These AH are sought after by mosquitoes for egg-laying and larval development. Recent studies have shown the effectiveness of destroying AH around host habitats (humans and animals) in reducing the incidence of malaria. In this paper, an agent-based model (ABM) is proposed for controlling the incidence of malaria through population sensitizing campaigns on the harmful effects of aquatic habitats around houses.Methods: The environment is constituted of houses, AH, mosquitoes, humans, and a hospital that will allow humans to heal themselves when they have malaria. The dynamics of malaria’s spread is linked to the dynamics of individuals (humans and mosquitoes) populations. The dynamic of the mosquito is represented by two phases: egg-laying and a phase of seeking blood. The dynamic of human is animated ...
Informatics in Medicine Unlocked, 2022
Engineering Applications of Artificial Intelligence, 2022
Mathematical Modelling and Control, 2021
A deterministic multi-stage malaria model with a non-therapeutic control measure and the effect o... more A deterministic multi-stage malaria model with a non-therapeutic control measure and the effect of loss of immunity due to the use of the Long-Lasting bednets with a control perspective is formulated and analyzed both theoretically and numerically. The model basic reproduction number is derived, and analytical results show that the model's equilibria are locally and globally asymptotically stable when certain threshold conditions are satisfied. Pontryagin's Maximum Principle with respect to a time dependent constant is used to derive the necessary conditions for the optimal usage of the Long-Lasting Insecticide-treated bednets (LLINs) to mitigate the malaria transmission dynamics. This is accomplished by introducing biologically admissible controls and $ \epsilon\% $-approximate sub-optimal controls. Forward-backward fourth-order Runge-Kutta method is used to numerically solve the optimal control problem. We observe that the disadvantage (loss of immunity, even at its maximu...
BIOMATH, 2021
We develop a new model of integro-differential equations coupled with a partial differential equa... more We develop a new model of integro-differential equations coupled with a partial differential equation that focuses on the study of the? naturally acquiring immunity to malaria induced by exposure to infection. We analyze a continuous acquisition of immunity after infected individuals are treated. It exhibits complex and realistic mechanisms precised mathematically in both disease free or endemic context and in several numerical simulations showing the interplay between infection through the bite of mosquitoes. The model confirms the (partial) premunition of the human population in the regions where malaria is endemic. As common in literature, we indicate an equivalence of the basic reproduction rate as the spectral radius of a next generation operator.
arXiv (Cornell University), Jan 11, 2016
In this paper, we derive and analyse a model for the control of arboviral diseases which takes in... more In this paper, we derive and analyse a model for the control of arboviral diseases which takes into account an imperfect vaccine combined with some other mechanisms of control already studied in the literature. We begin by analyse the basic model without controls. We prove the existence of two disease-free equilibrium points and the possible existence of up to two endemic equilibrium points (where the disease persists in the population). We show the existence of a transcritical bifurcation and a possible saddle-node bifurcation and explicitly derive threshold conditions for both, including defining the basic reproduction number, R 0 , which determines whether the disease can persist in the population or not. The epidemiological consequence of saddle-node bifurcation (backward bifurcation) is that the classical requirement of having the reproduction number less than unity, while necessary, is no longer sufficient for disease elimination from the population. It is further shown that in the absence of disease-induced death, the model does not exhibit this phenomenon. We perform the sensitivity analysis to determine the model robustness to parameter values. That is to help us to know the parameters that are most influential in determining disease dynamics. The model is extended by reformulating the model as an optimal control problem, with the use of five time dependent controls, to assess the impact of vaccination combined with treatment, individual protection and vector control strategies (killing adult vectors, reduction of eggs and larvae). By using optimal control theory, we establish optimal conditions under which the disease can be eradicated and we examine the impact of a possible combined control tools on the disease transmission. The Pontryagin's maximum principle is used to characterize the optimal control. Numerical simulations, efficiency analysis and cost effectiveness analysis show that, vaccination combined with other control mechanisms, would reduce the spread of the disease appreciably, and this at low cost.
Open journal of modelling and simulation, 2017
The lack of treatment for poliomyelitis doing that only means of preventing is immunization with ... more The lack of treatment for poliomyelitis doing that only means of preventing is immunization with live oral polio vaccine (OPV) or/and inactivated polio vaccine (IPV). Poliomyelitis is a very contagious viral infection caused by poliovirus. Children are principally attacked. In this paper, we assess the impact of vaccination in the control of spread of poliomyelitis via a deterministic SVEIR (Susceptible-Vaccinated-Latent-Infectious-Removed) model of infectious disease transmission, where vaccinated individuals are also susceptible, although to a lesser degree. Using Lyapunov-Lasalle methods, we prove the global asymptotic stability of the unique endemic equilibrium whenever vac 1 > . Numerical simulations, using poliomyelitis data from Cameroon, are conducted to approve analytic results and to show the importance of vaccinate coverage in the control of disease spread.
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Papers by Jean Claude Kamgang