Montri Thongmoon

A new class of continuous multifunctions between an ideal topological space and a bitopological space,called upper (lower) weakly $\tau^\star\beta(\sigma_1,\sigma_2)$-continuous multifunctions, has been defined and studied. Furthermore, several characterizations and some properties concerning upper weakly$\tau^\star\beta(\sigma_1,\sigma_2)$-continuous multifunctions and lower weakly $\tau^\star\beta(\sigma_1,\sigma_2)$-continuous multifunctions are discussed.

This paper introduces four classes of continuous multifunctions defined from an ideal topological space into a bitopological space, namely upper almost quasi $\tau^\star(\sigma_1,\sigma_2)$-continuousmultifunctions, lower almost quasi $\tau^\star(\sigma_1,\sigma_2)$-continuous multifunctions, upper weakly quasi $\tau^\star(\sigma_1,\sigma_2)$-continuous multifunctions and lower weakly quasi $\tau^\star(\sigma_1,\sigma_2)$-continuous multifunctions. Moreover, several characterizations of upper almost quasi $\tau^\star(\sigma_1,\sigma_2)$-continuous multifunctions, lower almost quasi $\tau^\star(\sigma_1,\sigma_2)$-continuous multifunctions, upper weakly quasi $\tau^\star(\sigma_1,\sigma_2)$-continuous multifunctions and lower weakly quasi $\tau^\star(\sigma_1,\sigma_2)$-continuous multifunctions are established. Furthermore, the relationships between almost quasi $\tau^\star(\sigma_1,\sigma_2)$-continuity and weak quasi $\tau^\star(\sigma_1,\sigma_2)$-continuity are discussed.

This paper introduces a new class of functions between bitopological spaces, namely $\theta(\tau_1,\tau_2)$-continuous functions. Moreover, several characterizations and some properties concerning $\theta(\tau_1,\tau_2)$-continuous functions are investigated.

This paper presents new classes of multifunctions called upper nearly $(\tau_1,\tau_2)$-continuousmultifunctions and lower nearly $(\tau_1,\tau_2)$-continuous multifunctions. Furthermore, some characterizations of upper nearly $(\tau_1,\tau_2)$-continuous multifunctions and lower nearly $(\tau_1,\tau_2)$-continuous multifunctions are established.

Our main purpose is to introduce the concepts of upper and lower weakly $(\tau_1,\tau_2)$-continuous multifunctions.Moreover, some characterizations of upper and lower weakly $(\tau_1,\tau_2)$-continuous multifunctions are investigated.

This paper deals with the concepts of weakly β(Λ, p)-open functions and weakly β(Λ, p)-closed functions. Moreover, some properties of weakly β(Λ, p)-open functions and weakly β(Λ, p)-closed functions are investigated.

Our main purpose is to introduce the concepts of weakly p(Λ, p)-open functions and weakly p(Λ, p)-closed functions. Moreover, several characterizations of weakly p(Λ, p)-open functions and weakly p(Λ, p)-closed functions are investigated.

This paper is concerned with the concepts of some topological spaces. Firstly, we introduce the notions of δs(Λ, p)-open sets. Some properties concerning δs(Λ, p)-open sets are discussed. Secondly, the concept of s(Λ, p)-connected spaces is introduced. Moreover, we give several characterizations of s(Λ, p)-connected spaces by utilizing δs(Λ, p)-open sets. Thirdly, we apply the notion of s(Λ, p)-open sets to present and study new classes of spaces called s(Λ, p)-regular spaces and s(Λ, p)-normal spaces. Especially, some characterizations of s(Λ, p)-regular spaces and s(Λ, p)-normal spaces are established. Fourthly, we introduce and investigate the concepts of s(Λ, p)-T2 spaces and s(Λ, p)-Urysohn spaces. Finally, the notion of S(Λ, p)-closed spaces is studied. Basic properties and characterizations of S(Λ, p)-closed spaces are considered.