=Paper=
{{Paper
|id=Vol-1293/paper10
|storemode=property
|title=Tracking Hot Topics for the Monitoring of Open-World Processes
|pdfUrl=https://ceur-ws.org/Vol-1293/paper10.pdf
|volume=Vol-1293
|dblpUrl=https://dblp.org/rec/conf/simpda/PareschiRS14
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==Tracking Hot Topics for the Monitoring of Open-World Processes==
https://ceur-ws.org/Vol-1293/paper10.pdf
Tracking Hot Topics for the
Monitoring of Open-world Processes
Remo Pareschi¹, Marco Rossetti², Fabio Stella²
¹ Department of Bioscience and Territory, University of Molise, Pesche (IS), Italy
remo.pareschi@unimol.it
² Department of Informatics, Systems and Communication, University of Milano-Bicocca,
Milan, Italy
{rossetti,stella}@disco.unimib.it
Abstract. We introduce the notion of open-world process to refer to processes
that generally require flexible execution and are influenced by external factors.
Among such processes we focus on those that fit also with the notion of “busi-
ness process”. We then introduce “hot topics” to capture contextual information
flows that, by flowing into the context of execution of open-world business
processes, may affect their definitions. Hot topics are discovered using unsu-
pervised learning techniques based on Probabilistic Topic Modeling and by
tracking variations of the information flows into topics over time. We illustrate
an application of this methodology to the tracking of recent innovations in labor
laws that affect a variety of open-world business processes, from labor sourcing
to merge-and-acquisition. Finally, we define a number of future directions for
research.
Keywords: open-world, business process management, probabilistic topic
modeling, process monitoring
1 Introducing open-world processes
When talking about processes in computer science and in artificial intelligence we
generally refer to computational objects that, once defined, have clear-cut and pre-
dictable behaviors. The background from which such processes arise may be itself
characterized by formal clarity, as is the case of the goals of a robot that through the
verification offered by logical reasoning are synthesized into a process corresponding
to an executable plan. Conversely, it may be of an initially murkier kind, as is the case
of sequences of logs of actions or tasks performed by people with diverse roles within
an organization, which can be mined and combined into explicitly defined work pro-
cesses. However, in either case, the result is an object with fixed formal and computa-
tional properties, corresponding to a repeatable sequence of actions that may allow
diverse degrees of flexibility, which are however known and planned for in advance.
Compare this situation with the following quote from the book War, a best-selling
in-depth report on the current Afghan war (written by the journalist Sebastian Junger,
who witnessed first-hand all the dramatic episodes described there): “the war also
diverged from the textbooks because it was fought in such axle-breaking, helicopter-
crashing, spirit-killing, mind-bending terrain that few military plans survive intact
even for an hour.” Without reaching such extremes, even in far more peaceful and
less tragic states of affairs, there are lots of work and business processes that diverge
substantially upon execution from the way they were planned, and that consequently
redefine themselves dynamically according to circumstances. Such dynamic redefini-
tions may, more often than not, be quite radical, and hence go beyond the boundary of
mere adaptation.
Clearly, these processes include all those that require real-time interactions be-
tween the agents involved and are heavily entangled with the physical world, for in-
stance, in addition to military activities, those relating to geographical and geological
exploration, logistics, energy planning. However, they include also processes where
the role of the physical world is less immediate and the interaction among the partici-
pating agents is more asynchronous. This is the case with the execution of different
aspects of corporate strategy (like market expansion, go-to-market plans, technology
transfer, protection of intellectual property, merge-and-acquisition), the running of
electoral and advertisement campaigns and financial placements.
We shall refer to processes of this kind as “open-world” by borrowing a terminolo-
gy that was used in [1] to refer to the evolution of software development from a
“closed-world” process to an “open-world” one. A more general way to look at these
processes comes from observing that they are subject to flexible execution and are
strongly influenced by external factors [2]. It should be noticed that in no way we are
implying that “open-world” processes are to be considered better, or even just more
relevant, than “closed-world” ones. As a matter of fact, closed-world processes are
certainly easier to deal with both from the point of view of organizational models and
of methods of computer support. On the other hand, open-world processes do exist.
Furthermore, in a time when the traditional boundaries between organizations, institu-
tions and countries are getting more and more friable, they are likely to increase.
Hence there is room and need to increase also the support that can be derived for them
from information technology.
We take the following properties to be characteristic of an open-world process:
1. First of all, it is, indeed, a process: namely it is defined as a number of steps that
can be executed in a sequence in order to achieve a certain type of objective, with
possible choice points subject to pre-conditions determined by its context of execu-
tion; taking a business-oriented definition, it can also be viewed as “a set of linked
activities that take an input and transform it to create an output. Ideally, the trans-
formation that occurs in the process should add value to the input and create an
output that is more useful and effective to the recipient either upstream or down-
stream.” [3].
2. However, the process definition is open to the possibility of continuous revision,
refinement, and re-interpretation due to the interaction with external agents during
its execution; similarly, roles and resources in the process may need to be revised,
for instance in consequence of the encounter of hitherto unknown stakeholders, or
2
of the impossibility to access resources that turn out to be unavailable at execution
time.
3. Open-world processes of this kind are most often mission-critical for their originat-
ing organizations or institutions, that thus generally create explicit or implicit roles
for decision-makers of last resort, who have the powers to redefine the process and
reset roles and resources; hence the need of identifying clearly such decision mak-
ers and of extracting the decisions that they have made in order to get a grasp on
the status of definition of the process and on how much it has eventually stabilized.
Point 3 defines the scope of this article, and of the future developments that can fol-
low from it.
Our approach hinges on the tracking of increased information flows, what we call
hot topics, around the execution of open-world processes, thus detecting situations
where the current process execution is stressed by external factors, and an evolution-
ary change of its definition is therefore likely to take place. Hot topic tracking derives
from the application of Probabilistic Topic Modeling (PTM) [4], a framework for the
unsupervised learning of topics in collections of textual contents that has proved ro-
bust and effective in a variety of contexts. We shall illustrate an application of our
approach to a specific type of external factors. In fact, we shall show how the imple-
mentation of legislation, and in particular of labor law, may affect a number of busi-
ness processes where employees are among the key stakeholders, either directly, as in
the case of hiring and dismissal, or indirectly, as in the case of business transfers.
The remainder of this paper is therefore structured as follows:; in Section 2 we il-
lustrate the general principles underlying our application of PTM to the tracking of
hot topics; Section 3 is the core of the paper, where we apply hot topic tracking to the
monitoring of the evolution of open-world processes in the context of implementation
of labor law, a very dynamic and socially “hot” sector of civil law; Section 4 outlines
directions for future work and concludes the article.
2 Topic Modeling for Hot Topic Tracking
Text mining approaches based on Probabilistic Topic Modeling (PTM) are recently
gaining considerable value as they allow the discovery of high-level dependencies
between contents of a document corpus. Probabilistic Topic Models are statistical
methods capable to handle, through unsupervised learning techniques, large volumes
of unstructured data. The main purpose of these algorithms is the analysis of words in
natural language texts in order to discover themes represented by sorted lists of
words. For instance, Figure 1 shows 4 out of 300 topics extracted from the TASA
corpus [5]. It is easy to see that words in the four topics are related to each other and
can be considered as consistent themes. Furthermore, PTM is also able to provide
topic proportions for each document, which is very useful to understand which themes
a document is about. PTM-based text mining approaches aim to get the best of both
worlds, by providing richly structured representations of the knowledge derived from
the empirical validation of "Big Data" processing. Hence they improve both on tradi-
tional symbolic approaches, that lack data validation, and on connectionist approach-
es, that lack capability to represent knowledge [6].
Fig. 1. Example of topics extracted from the TASA corpus [5].
More technically, PTM, exploits LDA (Latent Dirichlet Allocation) [7] to automati-
cally extract topics (concepts) from document corpora. Each topic is associated with a
list of words and each document is associated with a mixture of topics. The process
of topic extraction returns the probability distribution of the words of the docu-
ment corpora for each topic and the probability distribution of the topics for each
document . By exploiting techniques of statistical inference and sampling, these
probability distributions are inferred by observing the frequency of words within doc-
uments. Figure 2 illustrates the probabilistic generative process and the statistical
inference process for topic extraction.
The idea behind the use of PTM for monitoring open-world processes is to exploit
the flow of information that accompanies the different steps of the process to identify
situations where topics that are most closely associated with contents exchanged dur-
ing process execution become densely populated. We take this as a signal that the
process is going through a critical phase and that the information that accumulates
around it during that period of time can contain key indicators of possible changes
and re-adaptations.
To give an example on which we will return with further details later on, an inter-
company process of the highest relevance is the one that governs the transfer of a
business from one ownership to another. Clearly, this is an open-world business pro-
cess in the sense meant in Section 1, in fact:
1. It is a set of linked activities that take an input and transform it to create an output.
In this case the input is the existing ownership of a business or of a business unit,
and the output is a new ownership, with a downstream recipient corresponding to
the new owner, to whom the business is transferred, and an upstream recipient cor-
responding to the former owner, who gets the proceeds of the transaction;
4
2. It is open-world, since its control does not reside within the boundary of a single
organization and its execution is contextually influenced by a number of factors
and stakeholders which may vary and change over time.
Fig. 2. From the generative process to the statistical inference [5].
For companies that operate in countries that adhere to the European Union such con-
textual factors and stakeholders include, respectively, the "Transfers of Undertakings
Directive" of the European Union, that protects the contracts of employment of peo-
ple working in transferred businesses, and the decision-makers with powers on the
interpretation and application of this law. Each member state is responsible for the
implementation of the Directive with respect to transfer operations of its pertinence
and the rules of implementation have been generally clarified through the intervention
of decision-makers of last resort, who have arbitrated conflicting interpretations dur-
ing the run-in period and thus have defined the standards of implementation from then
on. Considering the time generally required for a European law to stabilize within the
legislative framework of the member states, and the fact that this legislation replaces
since the beginning of the 2000s a previous European law in force during the last 25
years of the previous century, we can say that the Directive is reaching just now the
final stage of its running-in. As we shall see, this situation is clearly reflected by the
high heat of the topic most directly associated with the Directive in relatively recent
times, when the Italian Court of Cassation, which is the decision-maker of last resort
on this subject in Italy, made a number of judgments that interpret and define the
criteria for its implementation. These documents are clustered within the topic during
that interval of time, causing its heating up. After that the process of business transfer
in Italy appears, as regards the Directive of Undertakings, to have reached a stable
state, and this is reflected in the corresponding cooling down of the topic, as shown by
the fact that in the successive time intervals the amount of content clustered within it
drops very sharply.
Thus, spotting when a topic becomes “hot” and, conversely, when it “cools down”,
requires plotting the content carried by the topic through time. This will be illustrated
in the next section.
3 Methodology
In order to substantiate the relationship between open-world business processes and
hot topics we have employed LDA to classify 20.600 rulings issued by the Italian
Court of Cassation in matters pertaining labor law between 2009 and 2014. This peri-
od saw several innovations of the Italian labor law, some of which attributable to the
implementation of European directives in the field. In the Italian civil law system the
Court of Cassation is called upon to address and validate the work of the lower courts
as well as to fix the interpretation of the legislation. We can therefore expect that
processes, which typically involve businesses, trade unions and workers as stakehold-
ers, made possible by these innovations have gone through a period of adjustment
solved through the deliberating activity of the Court of Cassation; such activity can in
turn be reconstructed by tracking hot topics within the corpus. To achieve this, we
need to plot the evolution of the measured probability of each topic against time. Let
us define as the time frame considered, | as the probability of topic given the
judgment , | as the probability of judgment given the time frame and as a
function that associates the judgment with the corresponding time frame. The empir-
ical probability that an arbitrary judgment issued at time period was about topic
is indicated with | and it is defined in Equation 1:
1
| = | | = | 1
: :
Since | is the probability that the judgment is assigned to the time frame , that
term can be substituted with , where is the number of judgments in the time frame
. The function T can be parameterized to yield time intervals corresponding to one
month, two months, four months, six months and one year periods.
We ran LDA setting the number of topics to extract equal to 10, 20, 50, 100 and 200
in order to find the best granularity of topics. The standard LDA model assumes that
the topic structure is flat, and tries to assign a unique theme to each topic. However, if
the number of topics is too big themes are split across many topics, while if the num-
ber is too little more themes can be aggregated in a single topic. While selecting the
correct number of topics is still an open issue [8], an empirical analysis can be con-
ducted to assess the topic quality. In our case domain experts, namely labor lawyers,
chose the 50 topics experiment as the best candidate and specifically reviewed and
graded the 50 topics set. In all 18 topics turned out to be good performers, 14 were
considered noise with remaining ones being somewhat uncertain. Of the 18 good
performers a further selection can be made by taking out 4 topics that are so close to
other ones to correspond substantially to clones. Best performing topics have been
manually labelled on the basis of the domain specific sense of topic words (Table 1).
The characteristics of a good performer, in the eyes of domain experts, can be
summarily characterized in the ability to identify concepts specifically attributable to
a particular legislative and / or decision-making context, e.g. “collective dismissal /
6
union agreement / selection criteria” or “rotation / redundancy funds / Fiat agree-
ment”.
Table 1. Best performing topics from the 50 topics extracted.
Best performing topics Relevant words
Transfer of business judge (giudice), convinction (convincimento), evidence (prova), irre-
gularity (irregolarità), company (azienda)
Collective contract collective (collettivo), contract (contratto), agreement (accordo)
Collective dismissal employees (dipendenti), union (sindacali), criteria (criteri), mobility
(mobilità), collective (collettivo)
Work injury injury (infortunio), liability (responsabilità), damage (danno), insuran-
ce (assicurazione)
Dismissal for just cause contestation (contestazione), sanction (sanzione), just_cause (giusta
causa), conduct (condotta), justified (giustificato)
Overtime work compensatory_rest (riposo compensativo), damage (danno), availabi-
lity (reperibilità)
Journalistic job provision provision (prestazione), activities (attività), journalists (giornalisti),
nature (natura), guarantee (garanzia)
Nature of the enterprise cooperative (cooperativa), family (familiare), tax (tributario), admin-
istration (gestione), protection (tutela), shareholder (socio)
Fixed-term employment contract (contratto), fixed-term (termine), Italian Post (Poste Ital-
contracts at the Italian Post iane), damage (danno)
Impact on severance indem- overtime_work (lavoro_straordinario), indemnities (trattamento),
nities of overtime work compensation (compenso), national_collective_labor_contract
(CCNL)
Notice and indemnity in the contract (contratto), agent (agente), indemnity (indennità), notice
agency contracts (preavviso)
Criteria of rotation in the extraodinary_wages_guarantee_fund (CIGS), criteria (criteri), rota-
extraordinary wages guaran- tion (rotazione), agreement (accordo), Fiat
tee fund
European directive on trans- transferee (cessionario), European (europea), court_of_justice (corte
fer of undertakings di giustizia), directive (direttiva), transfer (trasferimento), seniority
(anzianità)
Duties and qualifications of national_collective_labor_contract (CCNL), qualifications (mansioni),
company directors category (categoria), speriore (higher), director (dirigente)
Conversely, the characteristics of a bad performers may be multiple, some of which
amendable through an improved morpho-syntactic analysis of the text, but the most
frequent and endemic one resides in a composition of the topic in terms of elements
too general to lead to significant identification, such as “law”, “burden”, “responsibil-
ity” and so on.We have then applied Formula [1] to monitor the trends in the topics.
Topic Dismissal for just cause (the fifth from the top of Table 1) makes for an inter-
esting and a relevant case. The theme of the topic has been in fact substantially re-
vised by the most recent labor reform in Italy, which entered in force in June 2012,
among other things by introducing relevant modifications in the open-world process
related to the retaining of workers by businesses, in particular regarding so called
small and medium enterprises (SMEs). We can therefore expect that immediately
after that the topic would heat up. This could not be related much to the possibility to
open and finalize new legal procedures on the basis of the recent legislation, which
would not be possible in such a short period of time, but rather on the ability to make
decisions on extant procedures by also taking into account the new norms. So it turns
out to be the case: the graphic in Figure 3 shows a peak in the topic trend (probability
evolution) during the second half of 2012, that on a bimonthly split can be exactly
located in September 2012. After this peaking the topic progressively cools down, an
indicator that the corresponding process has for the time being readjusted and stabi-
lized.
Fig. 3. “Dismissal for just cause” topic evolution.
As representative of the typical development of a hot topic, and an associated open
world process, as Dismissal for just cause is, it is far from being the hottest topic
among those that we have identified. In fact at the top of the “hit parade” of hot topics
we find the second last item from Table 1, namely European directive on undertak-
ings. We can compare how far hotter it is with respect to Dismissal for just cause by
plotting the trends of the two topics one against the other as in the graphic in Figure 4,
where we can also notice that the latter topic peaks up at its highest probability value
during the second half of 2011 and then resurges sharply yet again, even if without
reaching the previous heights, for a longer period encompassing most of the second
half of 2012 and of the first half of 2013. Indeed, it is in this period that the Italian
8
Court of Cassation issues a number of rulings that have become fundamental bench-
marks for the implementation in the Italian context of the European directive on trans-
fer of a business (or of a business unit). We can also ask ourselves why European
directive on undertakings is so much hotter as a topic than Dismissal for just cause.
This may find a plausible answer in the fact that the scope of European directive on
undertakings, that concerns companies of all sizes, and touches an issue of foremost
importance (sometimes decisive for the fate of thousands of workers), is so much
wider than the changes affecting the scope of Dismissal for just cause, where the ac-
tors mostly concerned are SMEs and the dealt cases are about individual workers. As
an example of a mid-flyer we can find topic Overtime work, dealing with theme of
compensation for overtime work, a subjects that is well-known and established, but
given its numerous interpretations and social relevance, is bound to heat up from time
to time, with the Court of Cassation acting an actor of arbitration and regulation for
the diverse options open in the execution of the processes.
Finally, we can see in Figure 4 these three topics against two topics that have been
deemed as non-performing by the domain experts. As can be expected, the topics
develop in a very flat way, by spreading evenly among all processes, and thus lack the
capability of highlighting major turning points in their definition and implementation.
As a note on related work, a somewhat similar equation has been applied in [9]
with a different purpose, namely the statistical and quantitative reconstruction of the
history of ideas in a variety of scientific areas. Indeed, the focus of [9] is a case study
on the evolution of research directions in computational linguistics through the topic-
based analysis of 12,500 articles published in major international conferences in the
field between 1980 and 2005. It is interesting to note that the trends reported in this
work show characteristics significantly different from those reported here. In fact, the
graphics contain mostly gentle slopes as opposed to the abrupt peaks with steep as-
cents and descents characterizing, albeit with varying levels of abruptness, our
graphics. This difference has a variety of reasons, the most obvious and paramount of
which is that the analyzed documents are, in this case, typically relevant for the ad-
vancement of a scientific discipline, a phenomenon that is indeed distributed over
time, but with none of the characteristics of processes aimed at attaining specific
goals, with which the documents analyzed in our case are associated. Thus, the gradu-
al emerging and waning of ideas, caught by such softer uphills and downhills, is pre-
cisely what we expect, in contrast to the sharp phases of adjustment, as required by
the practical needs of the moment, that characterize our topics. [10] do address the
notion of hot topic in a vein very similar to ours, but their formal and computational
treatment falls completely outside PTM and LDA, and in fact is term-oriented rather
than topic-oriented. Thus, it does not appear suitable for the spotting of hot topics
from large content corpora which is our purpose here, while it may be particularly
suitable for their identification in the context of short texts, such as the twits or the
threads of social networks.
Fig. 4. Topic evolution of significant topics compared to non-performing topics (NP).
4 Conclusions
We have introduced the notion of open-world process in order to capture large pro-
cesses that involve multiple organizations, and are influenced by a number of contex-
tual factors and stakeholders. Furthermore, we have introduced the notion of hot topic
so as to provide a computationally effective way to track context evolution around
open-world processes in terms of the information that flows into such processes at
various degrees of density over time. Hot topics are themselves an application of sta-
tistical inference in the form of PTM, and thus are firmly rooted into empirical evi-
dence, without sacrificing high level representations of the inferred meanings. Hence
they show promise to be effectively combined with existing high-level representations
of business processes. There are a number of research directions that can and, in order
to obtain useful and concrete results, must be pursued to evolve this initial contribu-
tion. A most immediate one is to carve out a framework for Open-world Business
Process Management within the wider field of Business Process Management [11],
the discipline that encompasses the established computational framework for the
10
management of closed-world processes, namely Workflow Management. One clear
direction to achieve this is to combine our statistical approach to the monitoring of
information flows in open-world processes with a general framework for the monitor-
ing of events over time in global systems, like, for instance, the reactive version of the
Event Calculus proposed in [12]. Once verified the heating up of a topic over a de-
fined interval of time such a calculus may then trigger the inspection of the pertinent
contents, and the consequent retuning of the closed-world processes in the participat-
ing organizations that are synchronized around the relevant open-world process,
through adaptive technologies like adaptive workflow management [13], [14] and
case handling management [15].
Another crucial step is to survey and consequently map the existing open-world
processes from the informal sources through which they are currently documented
into a more rigorous notation. Given the inherent definitional fluidity of open-world
processes, in place of the formal notations commonly used for closed-world process-
es, like Petri Nets and Workflow Nets, it may be preferable to use one aimed at han-
dling incomplete information and soft constraints, such as the Generalized Process
Structure Grammars (GPSGs) presented in [16]. GPSGs that encode open-world pro-
cesses could in fact include rules containing symbols as names for topics generated
through LDA/PTM, thus acting as interfaces between process definitions and contex-
tual information flows. Another approach that could be similarly adopted, being itself
based on a declarative formalism for the definition of flexible processes, is the one
presented in [2].
As far as the topics are concerned, there are further possible constructions that can
help us to gain insight about the processes they are associated with. In particular, one
possibility we plan to explore is the generation of links among semantically related
content objects clustered within the topics, following the methodology presented in
[17]. In the context of the specific case study presented here, based on the implemen-
tation of labor law, this would allow us to rate the relevance of judgments on the basis
of how many other judgments make reference to it, this being a clear case of semantic
proximity. However, given that semantic proximity between content objects is itself
probabilistically computed, other less obvious relationships would emerge. In this
way, we could gain access not just to hot topics, but also to hot objects.
5 Bibliography
1. L. Baresi, E. Di Nitto e C. Ghezzi, «Toward Open-World Software: Issues and Challeng-
es,» IEEE Computer 39(10), pp. 36-43, 2006.
2. M. Pesic e W. M. van der Aalst, «A Declarative Approach for Flexible Business Processes
Management,» in Business Process Management Workshops, 2006.
3. H. J. Johansson, P. McHugh, J. Pendlebury e W. A. Wheeler, Business Process Reengi-
neering: Breakpoint Strategies for Market Dominance, John Wiley & Sons, 1993.
4. D. M. Blei, «Probabilistic Topic Models,» Commun. ACM 55(4), pp. 77-84, 2012.
5. M. Steyvers e T. Griffiths, «Probabilistic Topic Models,» in Handbook of Latent Semantic
Analysis, 2007, pp. 424--440.
6. J. B. Tenenbaum, C. Kemp, T. L. Griffiths e N. D. Goodman, «How to grow a mind: sta-
tistics, structure, and abstraction,» Science 331 (6022), pp. 1279-1285, 2011.
7. D. M. Blei, A. Y. Ng e M. Jordan, «Latent Dirichlet Allocation,» The Journal of Machine
Learning Research, pp. 993--1022, 2003.
8. E. H. Ramirez, R. Brena, D. Magatti e F. Stella, «Topic Model Validation,» Neurocompu-
ting, pp. 125-133, 2012.
9. D. Hall, D. Jurafsky e C. D. Manning, «Studying the History of Ideas Using Topic Mod-
els,» in EMNLP, 2008.
10. K.-Y. Chen, L. Luesukprasert e S.-c. T. Chou, «Hot Topic Extraction Based on Timeline
Analysis and Multidimensional Sentence Modeling,» IEEE Trans. Knowl. Data Eng.
19(8), pp. 1016-1025, 2007.
11. W. M. P. van der Aalst, A. H. M. ter Hofstede e M. Weske, «Business Process Manage-
ment: A Survey.,» in Business Process Management, 2003.
12. S. Bragaglia, F. Chesani, P. Mello, M. Montali e P. Torroni, «Reactive Event Calculus for
Monitoring Global Computing Applications,» in Logic Programs, Norms and Action,
2012.
13. U. Borghoff, P. Bottoni, P. Mussio e R. Pareschi, «Reflective Agents for Adaptive Work-
flows,» in Second International Conference on the Practical Application of Intelligent
Agents and Multiagent Technology, London, 1997.
14. M. Leitner, S. Rinderle-Ma e J. Mangler, «AW-RBAC: Access Control in Adaptive Work-
flow Systems,» in ARES, 2011.
15. W. M. P. van der Aalst, M. Weske e D. Grünbauer, «Case handling: a new paradigm for
business process support,» Data & Knowledge Engineering 53 , pp. 129-162, 2005.
16. N. S. Glance, D. Pagani e R. Pareschi, «Generalized Process Structure Grammars for Flex-
ible Representations of Work,» in CSCW, 1996.
17. M. Rossetti, R. Pareschi, F. Stella e F. Arcelli , «Integrating Concepts and Knowledge in
Large Content Networks,» New Generation Comput. 32(3-4), pp. 309-330, 2014.
18. T. L. Griffiths e M. Steyvers, «Finding scientific topics,» Proceedings of the National
academy of Sciences of the United States of America, pp. 5228-5235, 2004.
12