Joint-point method is one of the distance sampling methods for forest inventory. For estimation of tree density with joint-point sampling method two estimator suggested by Batcheler and also Engeman et al. that biased in nonrandom spatial pattern. Aim of this study was presentation a new unbiased and most efficiency estimator for this method. Forty-four sample size for each of six sampling methods: Circle plot (10ar as true value), Nearest individual method, nearest neighbor method, Compound method, second nearest neighbor method and Joint-point method in forests of Sorkheh dizeh Dalahoo of Kermanshah province with systematic random design (100m*100m) carried out. After that trees density of forest stand calculated with 10 estimators of above methods and new estimator. Then calculated density with new estimator compared with Batcheler and Engeman et al. estimators and other estimators in different spatial patterns (regular, random and aggregate) by precision and accuracy criteria. The results showed that this new estimator was not only most efficient than Batcheler and Engeman et al. estimators but also was best than other estimators.

Point-center Quarter method is one of the distance sampling methods for estimating the plant density and canopy cover. For plant density measurements, two formulas, one by Pollard (1982) and the other one by the author (2006) have been developed. In this study, applicability of these formulas with regard to accuracy to estimate the density and canopy cover of Zagross Oak (Quercus persica) forestes in research and educational Forest of Higher Education Center  of Qasr-e Shirin (Kermanshah province) were examined. Firstly, 50 hectars of these forest areas was selected and the inventory of the population was carried out. Then, 50 systematic random sampling points for Point-center Quarter method in this area were measured and recorded. The results show that none of the formulas could provide an acceptable estimate based on ±10% accepted accuracy; even though, the our formula has more accuracy level for density and crown coverage for this kind of forests and it could provide an acceptable estimate for management works based on ±25% acceptable accuracy.

Background and Objectives:Studying the structure of the landscape based on the principles of ecology and the spatial indicators of the landscape as its components is considered a suitable tool for mapping and quantifying the spatial characteristics of each land use. Ecological functions, the structure of the landscape, and landscape patterns have undergone unwelcome changes due to the increasing expansion of human activities. Therefore, to monitor and control these changes, quantifying and studying the landscape is important. This study aims to quantify the landscape pattern of regions with different development levels using the line intersect sampling (LIS) method to estimate the metrics of the total length of the forest edge, and the point sampling method was conducted to estimate the metric of contagion. In this regard, the preserved region of Sefidkuh and the manipulated region of Qaleh Gol in Lorestan province were considered.Materials and Methods:For this purpose, we selected two 200-hectare areas from the two mentioned regions on Google Earth images and in a GIS environment. To perform the line intersect method, 16 transects with lengths of 100 and 200 m were fitted on the study area using systematically randomized directions. For the paired point sampling method, paired points with 100 and 200 m were systematically and randomly implemented on the selected images, and then metrics were calculated. The outcomes show that in both measured transects, the total length of the forest edge in the Qaleh Gol region is greater than in the Sefidkuh region, and the numerical value of the contagion metric in the Qaleh Gol region is less than in Sefidkuh. Also, the t-student method was applied to compare the regions with different line intersect lengths and paired point lengths. Then, spatial indices were calculated. The paired t-test was also used to compare the different distances in the two regions.Results:The findings show that there is more disturbance and fragmentation in Qaleh Gol. Moreover, the results indicate that the sampling methods used in this study are a suitable alternative for more detailed vegetation cover maps. The landscape patterns can be quantified by spending less cost and time and with higher accuracy. The obtained results can be used in planning and management at different levels (local, regional, and national), especially in areas with a high rate of change. Also, in this study, it was found that sampling methods are a suitable alternative for vegetation maps with many details. The results of the total length of the forest edge are also consistent with the results of the contagion estimation, and the Qaleh Gol area, which has less contagion, has a longer total length of the forest edge, indicating more destruction and fragmentation of this area compared to the less disturbed Sefidkuh area. Among the reasons for the disturbances in the Qaleh Gol area, we canmention the presence of artificial and man-made disturbances such as numerous villages, agricultural activities, horticulture, livestock grazing, and other rural activities. These have caused the thinning of the forest cover in the area. Conclusion:Linear intercept sampling (LIS) can be used to estimate the total edge length of forests, while paired-point sampling can be used to estimate the spatial coverage index. These methods can be effective alternatives to detailed vegetation cover maps for downsizing the pattern of land cover in different regions with varying degrees of development. They can also provide a more accurate comparison of land cover patterns with lower costs and in less time.

This paper investigates repetitive acceptance sampling inspection plans of lots based on type I censoring when the lifetime has a Tsallis q-exponential distribution. A repetitive acceptance sampling inspection plan is introduced, and its components, along with the optimal average sample number and the operating characteristic value of the plan, are calculated under the specified values for the parameter of distribution and consumer's and producer's risks using a nonlinear programming optimization problem. Comparing the results of the proposed repetitive acceptance sampling plan with the optimal single sampling inspection plan demonstrates the efficiency of the repetitive acceptance sampling plan over the single sampling plan. Moreover, repetitive sampling plans with a limited linear combination of risks are introduced and compared with the existing plan. Results of the introduced plan in tables and figures show that this plan has a lower ASN and, therefore, more efficiency than the existing design. A practical example in the textile industry is used to apply the proposed schemes.

Non-cooperative intelligent control agents (ICAs) with dedicated cost functions, can lead the system to poor performance and in some cases, closed-loop instability. A robust solution to this challenge is to place the ICAs at the feedback Nash equilibrium point (FNEP) of the differential game between them. This paper introduces the designation of a robust decentralized infinite horizon LQR control system based on the FNEP for a linear time-invariant system. For this purpose, two control strategies are defined. The first one is a centralized infinite horizon LQR (CIHLQR) problem (i.e. a supervisory problem), and the second one is a decentralized control problem (i.e. an infinite horizon linear-quadratic differential game). Then, while examining the optimal solution of each of the above strategies on the performance of the other, the necessary and sufficient conditions for the equivalence of the two problems are presented. In the absence of the conditions, by using the least-squares error criterion, an approximated CIHLQR controller is presented. It is shown that the theorems could be extended from a two-agent control system to a multi-agent system. Finally, the results are evaluated using the simulation results of a Two-Area non-reheat power system.