On the finiteness and stability of certain sets of associated primes ideals of local cohomology modules

Let $(R,\frak{m})$ be a Noetherian local ring, $I$ an ideal of $R$ and $N$ a finitely generated $R$-module. Let $k{\ge}-1$ be an integer and r=\depth_k(I,N) the length of a maximal $N$-sequence in dimension $>k$ in $I$ defined by M. Brodmann and L. T. Nhan ({Comm. Algebra, 36 (2008), 1527-1536). For a subset S\subseteq \Spec R we set S_{{\ge}k}={\p\in S\mid\dim(R/\p){\ge}k}. We first prove in this paper that \Ass_R(H^j_I(N))_{\ge k} is a finite set for all $j{\le}r$}. Let \fN=\oplus_{n\ge 0}N_n be a finitely generated graded \fR-module, where \fR is a finitely generated standard graded algebra over $R_0=R$. Let $r$ be the eventual value of \depth_k(I,N_n). Then our second result says that for all $l{\le}r$ the sets \bigcup_{j{\le}l}\Ass_R(H^j_I(N_n))_{{\ge}k} are stable for large $n$.Comment: To appear in Communication in Algebr

On the cofiniteness of generalized local cohomology modules

Let $R$ be a commutative Noetherian ring, $I$ an ideal of $R$ and $M$, $N$ two finitely generated $R$-modules. The aim of this paper is to investigate the $I$-cofiniteness of generalized local cohomology modules \displaystyle H^j_I(M,N)=\dlim\Ext^j_R(M/I^nM,N) of $M$ and $N$ with respect to $I$. We first prove that if $I$ is a principal ideal then $H^j_I(M,N)$ is $I$-cofinite for all $M, N$ and all $j$. Secondly, let $t$ be a non-negative integer such that \dim\Supp(H^j_I(M,N))\le 1 \text{for all} j Then $H^j_I(M,N)$ is $I$-cofinite for all $j<t$ and \Hom(R/I,H^t_I(M,N)) is finitely generated. Finally, we show that if $\dim(M)\le 2$ or $\dim(N)\le 2$ then $H^j_I(M,N)$ is $I$-cofinite for all $j$.Comment: 16 page

Challenges, Opportunities, and Effective Solutions for the Enhancement of Sustainable Fisheries Development Planning Capacity in Vietnam

Planning is an important kind of policies making. Meanwhile it is considered as activities which specify general development strategies of a nation, sector or even a specific field; it also is the basis for developing and implementing development projects (Huong, 2005). Therefore, it is essential to recognize the challenges, opportunities and solutions in enhancing the planning capacity. Vietnamese Fisheries managers and other stakeholders have been facing a number of challenges. Being an efficient fishery planner requires a broad-spectrum knowledge and skills which have been changing and updating quickly in the modern dynamic world. The second issue is why and how to corporate in planning process. Other challenge is how to solve various conflicts (related to economics, social and environment value). Financial and other regulations are also major issues impacting on the quality of planning. Opportunities of innovations for planners, however, have been being more available and they need to be recognized and applied effectively. These opportunities occur since there has been development in Economy, Education, Technology, and the chances of joining the global market. To enhance the capacity of fisheries planning, a package of effective solutions should be considered. They mainly are of upgrading the regulation and awareness (related to supply of data, updating knowledge, evaluation and monitoring of planning process&); considering in more suitable way to organize, to develop and implement planning process. (Combination of top-down as well as bottom-top approach planning, corporation&); identify goals and strategies to educate or train planners at different levels.Keywords: Vietnam Institute for Fisheries Economics and Planning, Global Information System, Food and Agriculture Organization, Global market, Vietnam, Fisheries Economics, Sustainable fisheries, Research Institute for Aquaculture No

THE DIVERSITY OF YELLOW CAMELLIAS IN THE CENTRAL HIGHLANDS, VIETNAM

The Central Highlands (Tây Nguyên) is a center of yellow camellia diversity in Vietnam and the world. The Central Highlands contains 18 of Vietnam’s yellow camellia species, accounting for 37% of yellow camellia species in Vietnam and 28% of yellow camellia species worldwide. Moreover, all 18 yellow camellia species in the Central Highlands are endemic to Vietnam. The camellias of the Central Highlands belong to nine sections, accounting for 75% of the world. The yellow colors occur in three groups: pale yellow, yellow, and yellow with compound colors. The yellow camellia distribution is dispersed at 500–1600 m elevation in evergreen broadleaf forests and mixed wood-bamboo forests

A propensity score matching analysis of the relationship between forest resources and household welfare in Vietnam

Using secondary data from a socio-economic quantitative household survey in of the North Central region of Vietnam, the main aim of our study is to analyze the causal effect of forest resources on household income and poverty. Based on the observed characteristics of a forest-based livelihood and forest-related activities, we use a propensity score matching (PSM) method to control for potential bias arising from self-selection. The PSM results indicate that households with a forest livelihood had a higher level of income and lower level of poverty than did those without. Interestingly, our findings confirm that a forest-based livelihood offers much higher income than any other type of livelihood adopted by local households. Also, the poverty rate among households with a forest livelihood is lower than those earning non-labor income or engaged in wage/crop and crop livelihoods. Moreover, households whose livelihoods depend on timber forest products (TFPs) and animals (non-TFPs) also had higher income and lower levels of poverty than did those lacking these resources. Among households and provinces, we find differing opportunities deriving from forest resources, suggesting that there are potential barriers hindering local households from pursuing a forest livelihood or participating in some forest activities. Therefore, government policy and regulations on forest management should focus on improving the access of households to forest resources, at the same time enhancing the sustainability of these resources

A propensity score matching analysis of the relationship between forest resources and household welfare in Vietnam

Using secondary data from a socio-economic quantitative household survey in of the North Central region of Vietnam, the main aim of our study is to analyze the causal effect of forest resources on household income and poverty. Based on the observed characteristics of a forest-based livelihood and forest-related activities, we use a propensity score matching (PSM) method to control for potential bias arising from self-selection. The PSM results indicate that households with a forest livelihood had a higher level of income and lower level of poverty than did those without. Interestingly, our findings confirm that a forest-based livelihood offers much higher income than any other type of livelihood adopted by local households. Also, the poverty rate among households with a forest livelihood is lower than those earning non-labor income or engaged in wage/crop and crop livelihoods. Moreover, households whose livelihoods depend on timber forest products (TFPs) and animals (non-TFPs) also had higher income and lower levels of poverty than did those lacking these resources. Among households and provinces, we find differing opportunities deriving from forest resources, suggesting that there are potential barriers hindering local households from pursuing a forest livelihood or participating in some forest activities. Therefore, government policy and regulations on forest management should focus on improving the access of households to forest resources, at the same time enhancing the sustainability of these resources

Calculation of nonlinear vibrations of piecewise-linear systems using the shooting method

In this paper, an explicit formulation of the shooting scheme for computation of multiple periodic attractors of a harmonically excited oscillator which is asymmetric with both stiffness and viscous damping piecewise linearities is derived. The numerical simulation by the shooting method is compared with that by the incremental harmonic balance method (IHB method), which shows that the shooting method is in many respects distinctively advantageous over the incremental harmonic balance method

Influence of damping coefficient into engine rubber mounting system on vehicle ride comfort

This study presents a method to improve vehicle ride comfort using additional damping coefficient values for an internal combustion engine (ICE) rubber mounting system. To analyze the effect of the adding damping coefficient values into the rubber mounting system on vehicle ride comfort, a full-vehicle vibration model with 10 degrees of freedom is established under the combination of road surface roughness and ICE excitations. The damping coefficient values are added into ICE rubber mounting system which are respectively analyzed and evaluated according to the international standard ISO 2631-1 (1997). The study results do not only evaluate the influence of the adding damping coefficients on vehicle ride comfort but also suggest the optimal design solution for ICE mounting system to improve vehicle ride comfort