Java Type Research Articles

Fragility of Indonesian houses: scenario damage analysis of the 2006 Yogyakarta and 2009 Padang earthquakes

Indonesia is located in one of the most seismically active regions in the world and often experiences damaging earthquakes. In the past the housing sector has sustained higher earthquake related damage and losses than other sectors. This is often attributed to the fact that the most common houses in Indonesia are non-engineered, built with poor quality workmanship, poor quality materials and without resilient seismic design features. However little effort has been made to quantify how fragile Indonesian houses are, or how their fragility may vary according to the population density or relative wealth of a region. It is not possible to derive empirical fragility functions for Indonesia due to insufficient damage data. The aim of this study is to determine whether existing earthquake fragility functions can be applied to common house types in Indonesia. Scenario damage analyses simulating the 2006 Yogyakarta and 2009 Padang events were undertaken several times testing different fragility functions. The simulated damage results were then compared to the damage observed post event to determine whether an accurate damage prediction could be achieved. It was found that the common house types in Yogyakarta and Central Java vary according to age of construction, location and relative wealth of a region and can be reasonably well represented by existing fragility functions. However, the houses in Padang and surrounding West Sumatra did not vary in a predictable manner and are more fragile than anticipated. Therefore, the fragility of the most common house types in Indonesia differs between Central Java and West Sumatra. This has important implications for seismic damage and risk assessment undertaken in Indonesia.

The persilan on agroforestry crops system in java production forest

Agroforestry is an agricultural system that integrates primary trees and alternative crops on the same land to provide economic, social, and ecological benefits. One of the agroforestry planting patterns is called Persilan. The purpose of this paper is to investigate the concept of persilan carried out by pesanggem (forest farmers) in several blood types in Java. Researchers observed agroforestry activities in three districts in Java, namely Rembang, Blora, and Tuban. To see agricultural patterns in several regions of Java, we used secondary data studies and Google Maps. In addition, we also collect data through stakeholder surveys to find out the philosophy, land plot, calendar, and ecological function of persilan patterns. The results showed interesting facts related to land parcels in the context of agroforestry which were widely developed in several regions, including Pati, Grobogan, Rembang, Blora, Tuban, to Bojonogoro. Persilan is a form of agriculture where people use Perum Perhutani production forests as their planting land. They plant in the empty parts between the trees by combining primary plants with interstitial plants for 5 years. The concept of Persilan plays a role in maintaining the ecological balance of forests, economic prosperity, and social welfare of local communities.

Determination of Catechin Content in Green and Black Tea (Camellia sinensis L.) by UV-Vis Spectrophotometric Method

Tea is one of the most commonly consumed beverages around the world. The chemical compounds contained in tea have a good effect on health because they contain polyphenolic compounds, catechins. This study examined the catechin compound content of black tea and green tea from Karanganyar (A) and Malang (B). This research aims to determine the differences in catechin levels in black and green tea types in Malang, East Java, and Karanganyar, Central Java plantations. The research method used was experimental. Identification of catechin content was done using UV-Vis Spectrophotometry method. Tea is extracted by brewing, 4 grams of green tea is brewed using distilled water for 6 minutes, while 5.6 grams of black tea is brewed using distilled water for 10 minutes with the comparison used is pure catechin solution. The results obtained for green tea Karanganyar (A) had a catechin content of 3.61±0.083%, green tea Malang (B) had a level of 2.97±0.037%, black tea Karanganyar (A) had a level of 3.14±0.065%, and black tea Malang (B) had a level of 1.60±0.009%. It is concluded that the catechin content of green tea is higher than black tea, and of the two samples, the high catechin content comes from Karanganyar (A). Keywords: catechins, green tea, black tea, malang, karanganyar

Fluently specifying taint-flow queries with fluentTQL

Previous work has shown that taint analyses are only useful if correctly customized to the context in which they are used. Existing domain-specific languages (DSLs) allow such customization through the definition of deny-listing data-flow rules that describe potentially vulnerable or malicious taint-flows. These languages, however, are designed primarily for security experts who are expected to be knowledgeable in taint analysis. Software developers, however, consider these languages to be complex. This paper thus presents fluent TQL, a query specification language particularly for taint-flows. fluentTQL is internal Java DSL and uses a fluent-interface design. fluentTQL queries can express various taint-style vulnerability types, e.g. injections, cross-site scripting or path traversal. This paper describes fluentTQL’s abstract and concrete syntax and defines its runtime semantics. The semantics are independent of any underlying analysis and allows evaluation of fluent TQL queries by a variety of taint analyses. Instantiations of fluentTQL, on top of two taint analysis solvers, Boomerang and FlowDroid, show and validate fluent TQL expressiveness. Based on existing examples from the literature, we have used fluentTQL to implement queries for 11 popular security vulnerability types in Java. Using our SQL injection specification, the Boomerang-based taint analysis found all 17 known taint-flows in the OWASP WebGoat application, whereas with FlowDroid 13 taint-flows were found. Similarly, in a vulnerable version of the Java Spring PetClinic application, the Boomerang-based taint analysis found all seven expected taint-flows. In seven real-world Android apps with 25 expected malicious taint-flows, 18 taint-flows were detected. In a user study with 26 software developers, fluentTQL reached a high usability score. In comparison to CodeQL, the state-of-the-art DSL by Semmle/GitHub, participants found fluentTQL more usable and with it they were able to specify taint analysis queries in shorter time.

Anopheline Diversity in Indonesia: An Evaluation of Animal-Baited Sampling Techniques.

Indonesia has rich Anopheline (Diptera: Culicidae) mosquito species living in various types of ecosystems. The study was conducted to profile and compare Anopheles diversity, equitability, and dominance in various ecosystems using different animal-based sampling techniques. The present study analyzed a subset of data collected from a nation-wide vector and animal reservoirs survey in 2016. Analyses were restricted to three ecosystem types (forest, nonforest, and coastal areas) in Java and Sumatera Islands. A total of 5,477 Anopheles were collected by using animal-baited (n = 1,909) and animal-baited trap nets (n = 1,978), consisting of 23 Anopheline species. Overall, Anopheles vagus was the most abundant species, followed by An. subpictus and An. barbirostris. Among the three ecosystems, the forest had a higher diversity index (H' = 1.98), but each ecosystem has its specific predominant species. Compared with the animal-baited method, the Anopheles abundance collected by animal-baited trap nets was two-fold higher. Ecosystem, elevation, and sampling methods were associated with the abundance of female Anopheles (P-value < 0.001). Our findings revealed that Anopheles were found in a different ecosystem, indicating the potential of malaria transmission. This suggests that improved malaria vector surveillance is essential in all types of ecosystem. Furthermore, the study suggested that animal-baited trap nets could be used as the standard method of outdoor resting sampling in Indonesia in addition to the traditional human landing collection approach.

RELATION OF ANCIENT MATARAM TEMPLE BASED ON NORTH INDIA AND SOUTH INDIA’S CHARACTERISTICS: FROM THE FIGURE-TECTONICS, MASS-SPACE STUDY, AND ORNAMENTATION

Abstract- Hinduism is a religion that was born in India and has developed rapidly into the archipelago with evidence of Sanskrit inscriptions and Pallava. The religion had a significant influence on Java which changed the political, economic, social and cultural life which at that time was still a kingdom. The arrival of Indians to Indonesia affected by the reverse flow between Indonesia and India and India and Indonesia. This can be seen by the presence of Indonesian dormitories in Nalanda (North India) and Nagapattinam (South India). The influence of North and South India can be seen from the existence of Hindu-Buddhist temples in the Archipelago which was built in one of the Hindu kingdoms, namely the Kingdom of Ancient Mataram which had areas of authority from Central Java to East Java. The temples that were built are thought to have an identity with temples in North and South India in terms of figure, inner space tectonics, mass layout, spatial planning, and ornamentation. This identity is thought to be a close relationship between North India and South India with Indonesia, especially in the era of Ancient Mataram.&#x0D; The purpose of this study is to find out the relationship or relationship of Ancient Mataram era temple architecture to North and South Indian temple architecture. The analysis method used is the comparative – qualitative method. Work plans, plans, pieces, site plans, and block plans of 28 Hindu-Buddha tower types in Central Java will be compared in terms of similarities and differences and then analyzed regarding the position of the laying, and elements of the temple so that the relationship between the two countries is found. Data obtained from literature studies and field surveys. The conclusion drawn from this study is that there is a closer relationship with South India than North India. The influence of North India and South India is only limited to the external appearance in the study of figure and ornamentation, while in the study of mass and spatial planning and inner space tectonics is more developed by the people of Ancient Mataram which is adjusted to traditional values and natural influences.&#x0D; &#x0D; &#x0D; Key Words: figure, tectonics, mass layout, spatial planning, ornamentation, North and South India, Ancient Mataram

The Design Concept of Rotary Tray Dryer Machine to Dry Gepuk Beef Patties

Gepuk is a typical West Java Sundanese food made from cattle beef, tastes a little sweet and savory. Before being served, usually gepuk is fried first, so the effect of frying process can cause health problems due to the repeated use of cooking oil. This study aims to create a design concept for a rotary tray dryer for drying beef patties as an effort to replace the frying process. The research method used an engineering design approach which included design analysis, functional design and structural design of rotary tray dryer.

Reusing Static Analysis across Different Domain-Specific Languages using Reference Attribute Grammars

Context: Domain-specific languages (DSLs) enable domain experts to specify tasks and problems themselves, while enabling static analysis to elucidate issues in the modelled domain early. Although language workbenches have simplified the design of DSLs and extensions to general purpose languages, static analyses must still be implemented manually. Inquiry: Moreover, static analyses, e.g., complexity metrics, dependency analysis, and declaration-use analysis, are usually domain-dependent and cannot be easily reused. Therefore, transferring existing static analyses to another DSL incurs a huge implementation overhead. However, this overhead is not always intrinsically necessary: in many cases, while the concepts of the DSL on which a static analysis is performed are domain-specific, the underlying algorithm employed in the analysis is actually domain-independent and thus can be reused in principle, depending on how it is specified. While current approaches either implement static analyses internally or with an external Visitor, the implementation is tied to the language's grammar and cannot be reused easily. Thus far, a commonly used approach that achieves reusable static analysis relies on the transformation into an intermediate representation upon which the analysis is performed. This, however, entails a considerable additional implementation effort. Approach: To remedy this, it has been proposed to map the necessary domain-specific concepts to the algorithm's domain-independent data structures, yet without a practical implementation and the demonstration of reuse. Thus, to make static analysis reusable again, we employ relational Reference Attribute Grammars (RAGs) by creating such a mapping to a domain-independent overlay structure using higher-order attributes. Knowledge: We describe how static analysis can be specified on analysis-specific data structures, how relational RAGs can help with the specification, and how a mapping from the domain-specific language can be performed. Furthermore, we demonstrate how a static analysis for a DSL can be externalized and reused in another general purpose language. Grounding: The approach was evaluated using the RAG system JastAdd. To illustrate reusability, we implemented two analyses with two addressed languages each: a cycle detection analysis used in a small state machine DSL and for detecting circular dependencies in Java types and packages, and an analysis of variable shadowing, applied to both Java and the Modelica modelling language. Thereby, we demonstrate the reuse of two analysis algorithms in three completely different domains. Additionally, we use the cycle detection analysis to evaluate the efficiency by comparing our external analysis to an internal reference implementation analysing all Java programs in the Qualitas Corpus and thereby are able to show that an externalized analysis incurs only minimal overhead. Importance: We make static analysis reusable, again, showing the practicality and efficiency of externalizing static analysis for both DSLs and general purpose languages using relational RAGs.

Data type Modeling with DFA and NFA as a Lexical Analysis Generator

Lexical analysis helps the interactivity and visualization for active learning that can improve difficult concepts in automata. This study gives an implementation of two frequently used model, NFA for combination of Real and Integer data type and DFA for Double Data Type in Java this chosen model will be implemented using JFLAP. The model will also be tested using JFLAP that will accept at least FIVE (5) inputs and rejected FIVE (5) inputs. These two models are some of the different lexical analyzer generators that have been implemented for different purposes in finite automata.

Construction cleared land impact on air quality deterioration: quantification of soil borne dustfall and suspended particulate generation

Impact of land clearing during construction that generate dustfall and suspended particulate in ambient air is awfully obvious to observe. According to Indonesian standard as stipulated in Government Regulation (PP) no. 41/1999 pertaining to Air Pollution Control, dustfall and suspended particulate are two important parameters of ambient air quality. However, it remains a problem on how to predict the quantity of dustfall and suspended particulate that is potentially generated during construction land clearing due to lack of prediction method. In this research, a simple way to predict this number has been developed by applying mathematical expressions that are based on a series of laboratory and field experiments covering 15 soil types in Java and Sumatra Islands of Indonesia in 2013-2017. The mathematical formulas can now be implemented directly as a part of an environmental impact assessment, especially in the part of impact prediction of land clearing on air quality change. The formula consists of four parameters, i.e. soil types, local wind velocity, soil moisture content, and percentage of land cover. By inputting these four parameters in the mathematical equation simultaneously, one could directly obtain the quantity of dustfall and suspended particulate generation due to any human activity, such as construction land clearing. The quantity of the generated dustfall is expressed in [ton/km2/month], whereas the suspended particulate generation is expressed in [ug/Nm3] in compliance with the national standard of air quality, i.e. PP No.41/1999. Currently, calculation of the generated dustfall and suspended particulate could be carried out faster and even simpler by using a programmed spreadsheet containing all equations, limitations and terms of conditions that have been compiled during the last five year research campaign.

A greedy particle swarm optimization (GPSO) algorithm for testing real-world smart card applications

Software testing continues to be regarded as a necessary and critical step in the software development life cycle. Among the multitudes of existing techniques, particle swarm optimization (PSO) algorithm, in particular, has shown superior merits for automatically generating software test cases for its easy implementation and for relying on fewer parameters that require tuning. Hence, several state-of-the-art PSO-based algorithms have been successfully used as a test data generator. On the other hand, greedy-based algorithms, which are commonly used to solve complex and multi-step combinatorial problems, are starting to gain momentum as a solution for the complexity problem of software testing. Greedy algorithms favored over other techniques when the solution of the problem is guaranteed to be near-optimal. As a result, the utilization of both greedy and PSO algorithms in a single solution for automatically generating test data represents a strong candidate if designed carefully. In this paper, we propose a novel hybrid greedy and PSO algorithm (GPSO) that jointly guarantees the effectiveness and close to optimality results for generating a minimum number of test data. Compared with the widely employed genetic algorithm (GA), our proposed GPSO outperforms the GA in terms of the average number of iterations, execution time, and coverage percentage. Experimental trials with six different typical Java card applications show that the use of the proposed GPSO as a test data generator results in an outstanding performance.

PENYULUHANPELATIHAN ORIENTASI KEWIRAUSAHAAN BAGI PENGRAJIN FIGURA BINGKAI KAYU JATI RIZKYMARTAPURA

Entrepreneurial activity is not the result of an inheritance or a derivative talent parents alone, entrepreneurship can be taught and nurtured. The ability to create and use new knowledge on an ongoing basis is strongly influenced by the degree of entrepreneurial person. Therefore, entrepreneurship is defined ability to create and build a vision of something that does not exist and meaningful to humans through creative action and innovative measures to create business opportunities. Entrepreneurial action is manifested as an entrepreneurial orientation is behavior that reflected the behavior of the owner or craftsman through keinovasian, dare to take risks and proactivity. Given the importance of entrepreneurial orientation training to succeed as a business then craftsmen figura teak frame Rifky in Martapura Banjar district needs to develop entrepreneurship orientation in its business activities. Motifs, colors and designs are less attractive and less innovative so that interest figura teak frame is very less. Unlike the typical Java figura in addition to easily be everywhere also available in various designs, patterns and colors. In addition to expression differences with Java figura. It is necessary for the training effort for the craftsmen in Martapura Banjar district cultivate the spirit more active and resilient in the face of all obstacles either comes from internal and external craftsmen craftsmen, so figura teak able to increase revenues for craftsmen figura teak. Internal aspects indicated the failure of the craftsman among others the quality of the resource, setting the selling price is relatively high, the motives are less developed, deterioration of working capital and the increase in debt as a result of low accumulation of capital and the inability to find sources of capital cost, network limited business, the ability to innovate are less able. This information indicates internal weaknesses that have the potential to make an effort figura teak can fail.

Genetic polymorphisms of IGF1, GH, and OPN genes in crosses Peranakan Ongole cattle based on birth type in Central Java

&lt;p class="MsoNormal" style="text-align: justify; line-height: 150%;"&gt;Genetic Polymorphisms of IGF1, GH, and OPN Genes in Crossbred of Peranakan Ongole Cattle Based on Birth Type in Central Java. Improved productivity by crossing Peranakan Ongole (PO) cattle to exotic beef cattle through AI mating is preferred by many farmers in Central Java. Fertility determines the ability of a cow to give birth. IGF1 gene is predicted to affect either twin or multiple births in cattle, whereas GH and OPN genes determine reproductive fertility. Genetic polymorphisms of these three genes were studied in the crossbred of PO cattle for single birth (S) as well as twin and multiple (M) births or their historical (M) ones from two districts in Central Java, from Sragen (S = 7 hd and M = 13 hd.) and from Kendal (S = 9 hd, and M = 16 hd.). Genetic polymorphisms were identified by PCR-RFLP (polymerase chain reaction - restriction fragment length polymorphism) method using restriction enzymes of &lt;em&gt;Sna&lt;/em&gt;BI (IGF1 gene), &lt;em&gt;MSp&lt;/em&gt;I (GH gene), and &lt;em&gt;Bsr&lt;/em&gt;I (OPN gene). IGF1|&lt;em&gt;Sna&lt;/em&gt;BI locus in the observed crossbred PO did not have SNP polymorphism or monomorphic for single and twins or multiple births. In contrast, GH|&lt;em&gt;MSp&lt;/em&gt;I and OPN|&lt;em&gt;Bsr&lt;/em&gt;I loci were polymorphic with quite a high degree of diversity. In conclusion, the IGF1|&lt;em&gt;Sna&lt;/em&gt;BI&lt;em&gt; &lt;/em&gt;locus cannot be used to investigate possible genetic control of twins and multiple births, whilst GH|&lt;em&gt;MSp&lt;/em&gt;I and OPN|&lt;em&gt;Bsr&lt;/em&gt;I polymorphisms can be considered as initial information for selection on fertility traits in beef cattle.&lt;/p&gt;

An empirical study on the impact of AspectJ on software evolvability

Since its inception in 1996, aspect-oriented programming (AOP) has been believed to reduce the effort required to maintain software systems by replacing cross-cutting code with aspects. However, little convincing empirical evidence exists to support this claim, while several studies suggest that AOP brings new obstacles to maintainability. This paper discusses two controlled experiments conducted to evaluate the impact of AspectJ (the most mature and popular aspect-oriented programming language) versus Java on software evolvability. We consider evolvability as the ease with which a software system can be updated to fulfill new requirements. Since a minor language was compared to the mainstream, the experiments were designed so as to anticipate that the participants were much more experienced in one of the treatments. The first experiment was performed on 35 student subjects who were asked to comprehend either Java or AspectJ implementation of the same system, and perform the corresponding comprehension tasks. Participants of both groups achieved a high rate of correct answers without a statistically significant difference between the groups. Nevertheless, the Java group significantly outperformed the AspectJ group with respect to the average completion time. In the second experiment, 24 student subjects were asked to implement (in a non-invasive way) two extension scenarios to the system that they had already known. Each subject evolved either the Java version using Java or the AspectJ version using AspectJ. We found out that a typical AspectJ programmer needs significantly fewer atomic changes to implement the change scenarios than a typical Java programmer, but we did not observe a significant difference in completion time. The overall result indicates that AspectJ has a different effect on two sub-characteristics of the evolvability: understandability and changeability. While AspectJ decreases the former, it improves one aspect of the latter.

Java generics are turing complete

This paper describes a reduction from the halting problem of Turing machines to subtype checking in Java. It follows that subtype checking in Java is undecidable, which answers a question posed by Kennedy and Pierce in 2007. It also follows that Java's type checker can recognize any recursive language, which improves a result of Gill and Levy from 2016. The latter point is illustrated by a parser generator for fluent interfaces.

Plantes aromatiques du Plateau des Cataractes (Bassin du Congo). Caractérisation du chémotype de l’huile essentielle de Cymbopogon nardus (L.) Rendle acclimaté au Congo-Brazzaville

Description. Les huiles essentielles de Cymbopogon nardus (L.) Rendle, Cymbopogon winterianus Jowitt, Cymbopogon flexuosus (Nees ex Steud.) Wats et Cymbopogon citratus L. (DC.) Stapf (lemongrass) sont constituées à plus de 80 % de citronellal, géraniol, citral, citronellol, acétate de géranyle et limonène. Elles ne se distinguent les unes des autres que par les proportions relatives de ces différents constituants. Il est donc important de connaitre la composition chimique exacte des huiles essentielles produites. Objectifs. Évaluer le chémotype de C. nardus acclimaté sur le Plateau des Cataractes. Méthode. Les huiles essentielles de C. nardus acclimatées sur le Plateau des Cataractes ont été extraites par hydrodistillation et analysées par chromatographie (GC et CG/MS) pendant plus d’une décennie. Résultats. Avec un profil caractérisé par la composition suivante : citronellal (40-48 %), géraniol (10-22 %), citronellol (10-12 %), limonène (2-3 %), acétate de géranyle (1-2 %), linalol (1 %), cette espèce produit une huile essentielle de citronella type Java. Ceci tient au fait que la différence entre les types Java et Ceylan de citronella repose uniquement sur les teneurs individuelles de leurs trois principaux constituants : citronellal, géraniol et citronellol. Cymbopogon nardus est connu pour sa variabilité élevée, avec deux variétés et sept sous-variétés. Conclusions. Le citronella diffusé en Afrique de l’Ouest et du Centre sous le nom de Cymbopogon nardus type Java serait plutôt proche de Cymbopogon winterianus Jowitt par sa composition chimique.

Five Years Facts of Bladder Cancer at West Java’s Top Referral Hospital, in Indonesia

Background : Bladder cancer is the second most common genitourinary cancer and its incidence is rising 15% annually in Indonesia. Smoking is the leading risk factor of bladder cancer and two thirds of men in Indonesia smokes. This study was conducted to describe the characteristics of bladder cancer based on sex, age and histopathology type in West Java’s Top Referral Hospital, Indonesia. Methods : This study was a descriptive study conducted during theperiod of September to November 2015 using 372 histopathological medical records of patients who had primary and secondary bladder cancer at the Pathology Department, Dr. Hasan Sadikin General Hospital Bandung from January 2010 to December 2014. Data were collected using total sampling method based on the characteristics of age, sex histopathology type, and staging of bladder cancer. Results : Out of the 372 cases, 298 cases were male and 38 cases were female with a male to female ratio of 7.8:1. The age group with the highest incidence was the 50–59 years old group. Infiltrating urothelial carcinoma was the most common histopathology type (71.1%) in primary cancers, 66.1% of cases was muscle invasive while 33.9% was non muscle invasive. Staging pT1 had the most number of cases. The most common site of origin for secondary neoplasm was cervix with adenocarcinoma as the most common histopathology type. Conclusions : Bladder cancer is more common in male than female and peaks at the sixth decade of life. Infiltrating urothelial carcinoma is the most common histopathology type. [AMJ.2017;4(1):94–9] DOI: 10.15850/amj.v4n1.1028

Automated refactoring of legacy Java software to enumerated types

Modern Java languages introduce several new features that offer significant improvements over older Java technology. In this article we consider the new enum construct, which provides language support for enumerated types. Prior to recent Java languages, programmers needed to employ various patterns (e.g., the weak enum pattern) to compensate for the absence of enumerated types in Java. Unfortunately, these compensation patterns lack several highly-desirable properties of the enum construct, most notably, type safety. We present a novel fully-automated approach for transforming legacy Java code to use the new enumeration construct. This semantics-preserving approach increases type safety, produces code that is easier to comprehend, removes unnecessary complexity, and eliminates brittleness problems due to separate compilation. At the core of the proposed approach is an interprocedural type inferencing algorithm which tracks the flow of enumerated values. The algorithm was implemented as an open source, publicly available Eclipse plug-in and evaluated experimentally on 17 large Java benchmarks. Our results indicate that analysis cost is practical and the algorithm can successfully refactor a substantial number of fields to enumerated types. This work is a significant step towards providing automated tool support for migrating legacy Java software to modern Java technologies.

Native and introduced land snail species as ecological indicators in different land use types in Java

We investigated the effects of different land use types and environmental parameters on the number and abundance of native and introduced land snail species in East Java. 2919 specimens were sampled and assigned to 55 species of which 8 are introduced. Whereas species richness was highest in primary forest, the highest number of introduced species was found in agroforest. The snail assemblages in different habitat types differ much clearer in composition than in total species richness. Plantations and agroforest are dominated by introduced pulmonates with regard to number of individuals, while primary forest is dominated by native prosobranchs. The habitat requirements of the introduced pulmonates differ from those of the native species. In the study area, the abundance of native as well as introduced pulmonate species increased with increasing human impact. However, the abundance of introduced pulmonate species decreased with increasing density of the canopy cover, whereas the abundance of native pulmonate species increased with increasing canopy cover. The abundance of native prosobranch land snails also tends to increase with increasing canopy cover and with the availability of deadwood, but decreased with increasing human impact. Improving the canopy cover and retaining deadwood in plantations and agroforests might help to control the populations of introduced species or even prevent their establishment in these habitats. Land snails are good indicators for the long-term stability of natural habitats, because several species are restricted to undisturbed natural habitats and because of their low dispersal abilities. However, complete inventories of land snail species are costly. Therefore we propose two indices that can be scored with much less effort, namely the percentage of prosobranch individuals and the percentage of individuals of introduced species. Both indices are significantly correlated with the number of native species. Dense plantations and agroforests bordering primary forests may protect the latter from introduced species and help to conserve the native fauna by reducing desiccation and buffering the human impact on the primary forests.

SociaLite: An Efficient Graph Query Language Based on Datalog

With the rise of social networks, large-scale graph analysis becomes increasingly important. Because SQL lacks the expressiveness and performance needed for graph algorithms, lower-level, general-purpose languages are often used instead. For greater ease of use and efficiency, we propose SociaLite, a high-level graph query language based on Datalog. As a logic programming language, Datalog allows many graph algorithms to be expressed succinctly. However, its performance has not been competitive when compared to low-level languages. With SociaLite, users can provide high-level hints on the data layout and evaluation order; they can also define recursive aggregate functions which, as long as they are meet operations, can be evaluated incrementally and efficiently. Moreover, recursive aggregate functions make it possible to implement more graph algorithms that cannot be implemented in Datalog. We evaluated SociaLite by running nine graph algorithms in total; eight for social network analysis (shortest paths, PageRank, hubs and authorities, mutual neighbors, connected components, triangles, clustering coefficients, and betweenness centrality) and one for biological network analysis (Eulerian cycles). We use two real-life social graphs, LiveJournal and Last.fm, for the evaluation as well as one synthetic graph. The optimizations proposed in this paper speed up almost all the algorithms by 3 to 22 times. SociaLite even outperforms typical Java implementations by an average of 50 percent for the graph algorithms tested. When compared to highly optimized Java implementations, SociaLite programs are an order of magnitude more succinct and easier to write. Its performance is competitive, with only 16 percent overhead for the largest benchmark, and 25 percent overhead for the worst case benchmark. Most importantly, being a query language, SociaLite enables many more users who are not proficient in software engineering to perform network analysis easily and efficiently.