Index Tree Research Articles

Vegetation analysis, physico-chemical properties and economic potential of damar (Agathis dammara) in Mount Halimun Salak National Park,West Java, Indonesia

Abstract. Adalina Y, Sawitri R. 2020. Vegetation analysis, physico-chemical properties and economic potential of damar (Agathis dammara) in Mount Halimun Salak National Park,West Java, Indonesia. Biodiversitas 21: 1122-1129. Analysing the potential of non-timber forest product (NTFP) plants in Mount Halimun Salak National Park (MHSNP) is one of the important aspects in supporting conservation and improving the economic status of communities around the forest. This study aims to determine the economic potential and benefits of damar plants (Agathis dammara) in MHSNP area of Kawah Ratu Resort, Sukabumi District, West Java, Indonesia along with analysis of damar plant forest and physico-chemical analysis of the copal/resin. The selection of research village was by purposive sampling and the selection of respondents was by random sampling. Forest vegetation in the Kawah Ratu Resort is entirely dominated by damar plants. The Important Value Index (IVI) of damar plant trees is 300% and the density is 582 trees/ha. The quality of copal from Kawah Ratu Resort meets SNI standards in parameters like ash content, soft point and melting point, while the saponification number is above SNI standard. Level of dung in copal chunks meet SNI standards and has better quality than copal in the form of powder. The present average income of farmers from resin tapping is Rp 624,000/person /month, which makes an average contribution of 63.08% to the total household income of farmers. But the actual economic potential of gum resin in Kawah Ratu Resort was estimated to be around Rp 596,920,000/month.

Extremal trees for the Randić index with given domination number

The Randić index is the topological index most widely used in applications for chemistry and pharmacology. It is defined for a graph G with vertex set V(G) and edge set E(G) asR(G)=∑uv∈E(G)1deg(u)deg(v),where deg(u) and deg(v) denote the degrees of the vertices u, v ∈ V(G). In this paper we find upper and lower bounds of the Randić index of trees in terms of the order and the domination number. The extremal trees are characterized.

Pbsx: A practical private boolean search using Intel SGX

Searchable encryption enables private keyword search over encrypted data held on an untrusted cloud. However, existing searchable encryption schemes promise search efficiency at the expense of additional privacy leakage or expensive storage overhead. Intel SGX is a promising tool to allow efficient and private keyword search. However, since the size of enclave created by SGX is limited, frequent sensitive-page swaps between the enclave and the untrusted memory cause severe performance degradation for large datasets. Moreover, SGX does not protect against access pattern leakages which are vulnerable to statistical inference attacks.To overcome the above problems, we present Pbsx, an efficient private boolean searchable encryption scheme using Intel SGX. Pbsx firstly analyzes and chooses the suitable index data structures (e.g. bitmap and bloom filter tree) for private boolean search in the context of Intel SGX. Pbsx then combines these index data structures with oblivious random access machine (ORAM) schemes to design oblivious index data structures (e.g. oblivious bitmap and oblivious bloom filter tree), such that it could provide storage efficiency without suffering from access pattern leakages. Since the direct composition of the index data structures and the ORAM schemes is extremely costly for search operations, we design auxiliary data structures (e.g. map table and id index tree) to mitigate the efficiency barrier. Based on these oblivious index data structures, we propose oblivious search algorithms which can achieve a worst-case sub-linear search time. We implement Pbsx and evaluate the performance of our constructions with various metrics. Comparing with previous schemes, the results indicate that Pbsx can achieve a 5~12x speed-up for the million-level dataset and a 13~51x speed-up for the small dataset. In addition, Pbsx also achieves less access pattern leakages.

An Improved Retrieval Method for Multi-Transaction Mode Consortium Blockchain

The traditional method of blockchain retrieval is to search the “Block File” in sequence from the “tail” to the “head” of the blockchain, which always takes a lot of time. How to reduce the retrieval time has been a hot issue in blockchain research. This paper proposes a fast retrieval method for the Multi-Transaction Mode Consortium Blockchain (MTMCB). Firstly, we create a “User Set” and “Block Name Set” cached in Redis. Then, according to the transaction participants and “Block Name Set”, we can get the relevant “Block Name List”, and quickly obtain the corresponding block files. On this basis, in order to meet the needs of rapid retrieval in large-scale systems, an improved retrieval algorithm based on a B+-tree data structure is proposed. Firstly, the block file information is put into different ordered sets according to the transaction participants, and the B+-tree index is established to quickly get the information of relevant block files by participants. Experimental results show that the improved method of Redis cache retrieval in this paper can greatly increase the efficiency of blockchain retrieval, and can settle some crucial problem in the blockchain application and popularization.

Tree Species Composition and Diversity in Forest Ecosystem of Ranchi, Jharkhand, India

Tropical deciduous forests are rich in diversity and needs continuous conservation due to recent threats. The present study was done in these types of forests. A total of 30 tree species belonging to 14 families were recorded. Fabaceae was the dominant family having 12 species. Total stem density in the present study was found to be 1359.75 individual ha -1 . Tree species density varied from 1.25-513.5 individual ha -1 . Stem density was found to be maximum (545 ha -1 ) in the girth class 25-30 cm, which accounts for 40.08% of the total stem density. Basal area varies from 0.053–31.44 m 2 ha -1 for different species. Shorea robusta exhibited the highest IVI (48.59) which indicates that the forest is dominated by Shorea robusta trees. Forest showed rich diversity as Shannon-Wiener's index and Simpson's index for trees was found to be 2.46 and 0.83 respectively.

A Multibranch Search Tree-Based Multi-Keyword Ranked Search Scheme over Encrypted Cloud Data

In the interest of privacy concerns, cloud service users choose to encrypt their personal data before outsourcing them to cloud. However, it is difficult to achieve efficient search over encrypted cloud data. Therefore, how to design an efficient and accurate search scheme over large-scale encrypted cloud data is a challenge. In this paper, we integrate bisecting k-means algorithm and multibranch tree structure and propose the α-filtering tree search scheme based on bisecting k-means clusters. The novel index tree is built from bottom-up, and a greedy depth first algorithm is used for filtering the nonrelevant document cluster by calculating the relevance score between the filtering vector and the query vector. The α-filtering tree can improve the efficiency without the loss of search accuracy. The experiment on a real-world dataset demonstrates the effectiveness of our scheme.

Tree-Ring Analysis Reveals Density-Dependent Vulnerability to Drought in Planted Mongolian Pines

Population density influences tree responses to environmental stresses, such as drought and high temperature. Prolonged drought negatively affects the health of Mongolian pines in forests planted by the Three-North Shelter Forest Program in North China. To understand the relationship between stand density and drought-induced forest decline, and to generate information regarding the development of future management strategies, we analyzed the vulnerability to drought of planted Mongolian pines at three stand densities. A tree-ring width index for trees from each density was established from tree-ring data covering the period 1988–2018 and was compared for differences in radial growth. Resistance (Rt), recovery (Rc), resilience (Rs), and relative resilience (RRs) in response to drought events were calculated from the smoothed basal area increment (BAI) curves. The high-density (HDT) group showed a consistently lower tree-ring width than the border trees (BT) and low-density (LDT) groups. The BAI curve of the HDT group started to decrease five years earlier than the LDT and BT groups. Pearson correlation analysis revealed that the radial growth of all of the groups was related to precipitation, relative humidity (RH), potential evapotranspiration (ET0), and standardized precipitation evapotranspiration index (SPEI) in the previous October and the most recent July, indicating that Mongolian pine trees of different densities had similar growth–climate relationships. Over the three decades, the trees experienced three severe drought events, each causing reduced tree-ring width and BAI. All of the groups showed similar Rc to each drought event, but the HDT group exhibited significantly lower Rt, Rs, and RRs than the BT group, suggesting that the HDT trees were more vulnerable to repeated drought stress. The RRs of the HDT group decreased progressively after each drought event and attained <0 after the third event. All of the groups showed similar trends regarding water consumption under varying weather conditions, but the HDT group showed significantly reduced whole-tree hydraulic capability compared with the other two groups. From these results, HDT trees exhibit ecophysiological memory effects from successive droughts, including sap flux dysfunction and higher competition index, which may prevent recovery of pre-drought growth rates. HDT trees may be at greater risk of mortality under future drought disturbance.

Limit distribution of the quartet balance index for Aldous’s $(\beta \ge 0)$-model

This paper builds up on T. Martinez-Coronado, A. Mir, F. Rossello and G. Valiente's work "A balance index for phylogenetic trees based on quartets", introducing a new balance index for trees. We show here that this balance index, in the case of Aldous's b>=0-model, convergences weakly to a distribution that can be characterized as the fixed point of a contraction operator on a class of distributions.

Productivity indices of sweet cherry trees under intercropping with medicinal plants

Productivity indices of sweet cherry trees under intercropping with medicinal plants

Second Zagreb index of trees with fixed diameter

Let G be a simple graph with vertex set V = V(G) = {v1, v2,..., vn} and edge set E = E(G). For vi ∈ V(G), by di = di(G) we denote the degree (number of neighbors) of the vertex vi. The second Zagreb index is defined as M2(G) = ∑ vivj∈E(G) didj. In this paper, we study the minimal and maximal second Zagreb index of trees with fixed diameter.

A homomorphic range searching scheme for sensitive data in internet of things

With the popularisation and development of the internet of things, big data and cloud computing, the search of data in cloud-based internet of things becomes a hot research topic. However, the sensitive data, such as the medical data collected by wearable devices, is inevitable to be stored in the cloud server. Homomorphic encryption has the ability to calculate the ciphertext without decryption. We separate the calculating and the decryption into different security domains to preserve the privacy of sensitive data, so the original plaintext would not be exposed in the cloud. Hence, we can compare two ciphertexts to get the difference of them in a privacy preserving way. In order to accelerate the search process of range query, we build an encrypted self-balancing binary index tree. Based on oblivious RAM, the searching scheme can hide the access patterns of the node of tree. The actual nodes and logic relation of tree are stored on different servers. A sample implementation of the proposed scheme is given, and the experimental results and analysis are presented to illustrate the scheme's effectiveness and security.

A homomorphic range-searching scheme for sensitive data in the internet of things

With the popularisation and development of the internet of things, big data and cloud computing, the search of data in cloud-based internet of things becomes a hot research topic. However, the sensitive data, such as the medical data collected by wearable devices, is inevitable to be stored in the cloud server. Homomorphic encryption has the ability to calculate the ciphertext without decryption. We separate the calculating and the decryption into different security domains to preserve the privacy of sensitive data, so the original plaintext would not be exposed in the cloud. Hence, we can compare two ciphertexts to get the difference of them in a privacy preserving way. In order to accelerate the search process of range query, we build an encrypted self-balancing binary index tree. Based on oblivious RAM, the searching scheme can hide the access patterns of the node of tree. The actual nodes and logic relation of tree are stored on different servers. A sample implementation of the proposed scheme is given, and the experimental results and analysis are presented to illustrate the scheme's effectiveness and security.

Local Feature Descriptor Indexing for Image Matching and Object Detection in Real-Time Applications

Local feature extraction and description algorithms can be used to address a large variety of computer vision problems, including pattern recognition, frame stitching and 3D reconstruction. One of the most computationally expensive and time-consuming stages of any method based on local features is keypoint matching. This paper discusses possible ways to optimize matching for frame alignment and object detection applications using Vantage-Point tree indexing to optimize pairwise keypoint matching, and image keypoint graph indexing to optimize pose estimation.

A Novel Range Search Scheme Based on Frequent Computing for Edge-Cloud Collaborative Computing in CPSS

Due to the rapid advances of Information and Communication Technologies (ICT), especially 5G and Artificial Intelligence (AI), the Internet of Everything is gradually becoming a reality, and human beings living environments are becoming smarter and smarter. Every day there will be generated large amounts of data in Humans-Machines-Things hybrid space, which is also called Cyber-Physical-Social Systems (CPSSs). Today, the city we live in has become a data-driven society. However, how to effectively mine valuable information from these massive data to provide proactive and personalized services for human beings is a challenging problem. Thus, top-k search remains an important topic of ongoing research. In this paper, we focus on a basic problem of geo-tagged data: find the top-k frequent terms among the geo-tagged data in a specific region from the cloud. We first construct a Region Tree Index (RTI) for geo-tagged data. Then the list storage structure is proposed to Store Sorted Terms and Weights (SSTW) in RTI. And then an efficient kTermsSearch algorithm is presented to compute top-k frequent terms in a given region. Finally, extensive experiments verify the validity of the proposed scheme.

The Third Leap Zagreb Index for Trees

The third leap Zagreb index is the sum of the products of vertex degrees and second degrees. In this paper, a lower bound on the third leap Zagreb index is established, and the extremal trees achieving this bound are characterized.

Pinus sylvestris Breeding for Resistance against Natural Infection of the Fungus Heterobasidion annosum

Increasing resistance against biotic and abiotic factors is an important goal of forest tree breeding. The aim of the present study was to develop a root rot resistance index for Scots pine breeding and evaluate its effectiveness. The productivity, branch diameter, branchiness, stem straightness, spike knots, and damage from natural infection of root rot in 154 Scots pine open-pollinated families from Latvia were evaluated through a progeny field trial at the age of 38 years. Trees with decline symptoms were sampled for fungal isolations. Based on this information and kriging estimates of root rot, 35 affected areas (average size: 108 m2; total 28% from the 1.5 ha trial) were delineated. Resistance index of a single tree was formed based on family adjusted proportion of live to infected trees and distance to the center of affected area. Heritability for resistance to root rot based on the value of this index, was high (0.37) and comparable to indices of growth traits. Correlations of family breeding estimates between resistance to root rot and the other traits were not significant, except for a weak, yet significant, positive correlation with diameter at breast height and branch diameter. Selection index including only growth traits (height and stem volume) had a negligible effect on damage by root rot. We detected a maximum genetic gain in resistance index of 33.7% when incorporating it into the selection index with positive gains for growth traits (6.5–11.0%). Two-stage selection with prior selection of the most resistant families was not superior to the use of selection index with only rot resistance included. Overall; rot resistance index appeared to be an effective tool in tree breeding for the selection of more resistant families, using the existing trials with natural (uncontrolled) infection

Secure and privacy‐preserving keyword search retrieval over hashed encrypted cloud data

SummaryCloud computing (CC) is the universal area in which the data owners will contract out their pertinent data to the untrusted public cloud that permits the data users to retrieve the data with complete integrity. To give data privacy along with integrity, majority of the research works were concentrated on single data owner for secure searching of encrypted data via the cloud. Also, searchable encryption supports data user to retrieve the particular encrypted document from encrypted cloud data via keyword search (KS). However, these researches are not efficient for keyword search retrieval. To trounce such drawbacks, this paper proposes efficient secure and privacy‐preserving keyword search retrieval (SPKSR) system, in which the user retrieves the hashed encrypted documents over hashed encrypted cloud data. The proposed system includes three entities explicitly, (a) data owner (DO), (b) cloud server (CS), and (c) data users (DU). The owner outsources hashed encrypted documents set, along with generated searchable index tree to the CS. The CS hoards the hashed encrypted document collection and index tree structure. DU performs the “search” over the hashed encrypted data. Experimental results of the proposed system are analyzed and contrasted with the other existent system to show the dominance of the proposed system.

Assessment of spatial stand structure of hemiboreal conifer dominated forests according to different levels of naturalness

Abstract Ecosystem legacies, reflecting the management history traits, are visible in structural indicators of a forest stand. We assessed patterns of spatial forest structure by using individual tree indices based on the nearest-neighbourhood approach. Five different indices were quantified – species mingling, deadwood mingling, deadwood distribution, diameter differentiation and the uniform angle indices characterising the patterns that show the complexity and diversity of forests: the arrangement of tree dimensions, species and deadwood as well as tree positioning regularities. Managed Norway spruce (Picea abies) stands are remarkably more homogeneous in terms of occurrence and positioning of different tree species and dimensions when compared to unmanaged forests. Managed Scots pine (Pinus sylvestris) stands rarely show co-occurrence of living and dead trees and demonstrate lower dimensional variability than unmanaged stands. Trees are often quite randomly positioned; slightly regular positionings became evident in managed Norway spruce stands. Structural analysis confirm that large trees are particularly important in maintaining the structural diversity of forests. Forest management needs to integrate maintenance of important structural components and patterns into timber production for biodiversity conservation and sustainable forestry. Natural forests are indispensable source for reference structures in forest ecosystems.

Prediction of Competition Indices in a Norway Spruce and Silver Fir-Dominated Forest Using Lidar Data

Competitive interactions are important predictors of tree growth. Spatial and temporal changes in resource availability, and variation in species and spatial patterning of trees alter competitive interactions, thus affecting tree growth and, hence, biomass. Competition indices are used to quantify the level of competition among trees. As these indices are normally computed only over small areas, where field measurements are done, it would be useful to have a tool to predict them over large areas. On this regard, remote sensing, and in particular light detection and ranging (lidar) data, could be the perfect tool. The objective of this study was to use lidar metrics to predict competition (on the basis of distance-dependent competition indices) of individual trees and to relate them with tree aboveground biomass (AGB). The selected study area was a mountain forest area located in the Italian Alps. The analyses focused on the two dominant species of the area: Silver fir (Abies alba Mill.) and Norway spruce (Picea abies (L.) H. Karst). The results showed that lidar metrics could be used to predict competition indices of individual trees (R2 above 0.66). Moreover, AGB decreased as competition increased, suggesting that variations in the availability of resources in the soil, and the ability of plants to withstand competition for light may influence the partitioning of biomass.

Tree diversity, biomass and carbon storage in sacred groves of Central India

Sacred groves are small or large patches of forest and are rich in biodiversity, store carbon (C) in biomass and soil, besides providing important ecosystem services. However, the information on tree species diversity, biomass, and C storage in sacred groves of Central India, Madhya Pradesh is elusive and fragmented. In the present study, 41 sacred groves were inventoried for tree species diversity, biomass, and C storage in vegetation and soil. A total of 103 tree species from 81 genera belonging to 37 families were recorded. Shannon's diversity, Dominance, Fisher's alpha, and species evenness indices for trees varied: 0.77-2.53, 0.07-0.64, 1.58-20.37, and 0.28-0.90 respectively. Tree density ranged 75-675 no. of stems ha-1 with a mean of 271 no. of stems ha-1, while basal area ranged 6.8-47 m2 ha-1 with a mean value of 27 m2 ha-1. Tree biomass ranged 34.9-409.8 Mg ha-1 with a mean value of 194.01 Mg ha-1, while, tree C ranged between 17.5 and 204.9 Mg C ha-1 with a mean value of 97.0 Mg C ha-1. The total soil organic carbon stock (0-30 cm) ranged from 22.4 to 112.5 Mg C ha-1 with the mean value of 62 Mg C ha-1. Biomass C and SOC contributed 61% and 39% of the total C stocks, respectively. Tree C stock showed a significant positive relationship with tree basal area (R2 = 0.968). A total of five tree species belonging to four families were found to be vulnerable inCentral India. The present study reveals that the sacred groves of Central India are species rich, have higher C stocks and sequestration potential in both vegetation and soil, and calls for an immediate attention for conservation and planning for long-term C sequestration.