The 3rd International Conference on Digital Arts, Media and Technology (ICDAMT2018) A Labanotation based ontology for representing Vietnamese folk dances Ma Thi Chau Nguyen Thanh Thuy Human Machine Interaction Laboratory University of Engineering and Technology, Hanoi, Vietnam chaumt@vnu.edu.vn Computer Science Department University of Engineering and Technology, Hanoi, Vietnam Bui The Duy Human Machine Interaction Laboratory University of Engineering and Technology, Hanoi, Vietnam Abstract— This paper aims at designing and constructing an ontology, representing and allowing Vietnamese folk dances annotation An effective approach proposed is based on movement analysis It is possible to divide Vietnamese folk dances into basic units, then movement phrases, movement primitives and dance poses Studying deeply Vietnamese folk dances features and characteristics allows to find out different types of relationships between main dance components Typical relationships could be written in the form of logical predicates For enriching ontologies, a formal encoding of the ontology expertise knowledge in the domain is performed by DL-Lite The paper uses OWL-2 for building, organizing and visualizing ontologies A case study – Mo folk dance with a knowledge base, is structured simply but effectively, with reasoning in DL-Lite and answering queries in SPARQL Our objective is to build up an initial ontology for Vietnamese folk dances, covering main concepts and properties of folk dance movements This ontology, organizing messages and regional feature of dances, structuring movements and expressing relationships of related dance objects, will help storing, retrieving, classifying and analyzing folk dances, as well as training the folk-dance performance for the young generation It also can be used to model folk dances with advanced 3D-animation technology, hence to contribute to preserving and promoting the folk-dance heritage With the above objectives, we aim to use the dance ontology to develop multimedia solutions promoting the folk dance and its domain in museums, to develop tools supporting dance training in Hanoi Academy of Theatre and Cinema, and to build a 3D dance viewer to show folk dances in theater Keywords— semantic web, ontology, description logics lite DLlite, Labanotation, Vietnamese folk dance, Mua mo (Mo dance) In this paper, we present principal steps in building a Vietnamese folk dance ontology We determine main concepts along with properties, build up the concept map based on expert knowledge in the concerned domain Regional features and messages in Vietnamese folk dances are discussed Logical assertions, embedded in that ontology, will allow inferred results, enhancing the efficiency of searching dances Briefly, we have three main contributions: (i) to make taxonomy of movements in the folk dances based on analyzing Labanotation movements; (ii) to analyze relationship between dance movements and their historical, cultural message; and (iii) to build a dance ontology describing dance movements and their messages The paper is organized as follows Section II presents some related works Section III focuses on the analysis and ontology development on Vietnamese folk dance, whereas Section IV illustrates, in detail, process of building and formalizing the dance ontology and some typical folk dances in Vietnam with an embedded logical representation Experiment result is discussed in section V I INTRODUCTION Vietnam is known as a country having a very diverse, original and rich folk culture heritage, including folk songs, folk games, water puppetry and folk dances whose promoting and preserving are an urgent request Among Vietnamese folk art forms, folk dances are really valuable art sources Observing and studying folk dances, we can identify the attitude, awareness, and religion, aesthetic and daily labor of different ethnic communities In order to promote and preserve folk dances, we propagate not only the dance performance, but we have to understand also deeply the dance content and context and its related domain knowledge Ontologies – a formalism of describing entities with their properties and relationships, suggest a new approach to managing and sharing information using semantic metadata, hence allow preserving and promoting Intangible Cultural Heritage (ICH) in Vietnam Building ontologies for Vietnamese folk dances is thus one of the most important and specific issues that can be dealt with immediately to meet practical demands in Vietnam, because ontologies provide an effective method to understand deeply dances and their related issues [1] 978-1-5386-0572-1/18/$31.00 ©2018 IEEE II RELATED WORKS Preserving and promoting of the Intangible Cultural Heritage (ICH) have attracted lots of attention and are in urgent need Renzo et al [6] analyzed the usefulness of a 75 The 3rd International Conference on Digital Arts, Media and Technology (ICDAMT2018) semantic network, the benefits of wikis, and the expressive power of ontologies They are effective methods allowing the community to participate in building, storing, and sharing knowledge in order to preserve ICH In [10], authors showed and analyzed the impact of the choreographic language agent and the digital dance archive method on dance ontology building There are many different ways of media usage by choreographers, as a result, ontology builders have to face with enormous sources and their inconsistence We could not create different ontologies for distinct types of things because this would cause the dispute of the existence dances Instead, we should build a unified system about dance which reveals about the ontology of the form and existing concepts of movement, notation and embodiment Recently, many significant ontologies for representing folk song and dance have been developed In [8], ontology was built in OWL-2 to represent and archive dance choreographies of seven Greek folk dances Dances were described and stored taking advantage of the Description Logics expressivity and the semantics of the Labanotation SPARQL queries were used to search within the ontology based on the steps and movements of dances In [7], Basque folk song ontologies was reported The authors also described a representation for folk song metadata based on Ontology Web Language (OWL) He showed in the paper how complex queries could be expressed in OWL and solved using a description logic reasoner An Ontology for video human movement representation based on Benesh movement notation (BMN) [9] was proposed For ontology building, an approach for semantic annotation of movement and semantic concept classifiers in the videos was used by combination of OWL and the semantics of the Benesh Notation Then, the ontology concept was used to annotate with BMN the video human movements In addition, the proposed system allowed searching within the video movement ontology via SPARQL queries Fig 1. Proposal for building Vietnamese folk dance ontology B Gathering and analyzing expert knowledge Analyzing regional features and messages in the Vietnamese folk dance In Vietnam, 54 ethnic groups have their own folk dances, which express cultural knowledge, spiritual life, reflecting Vietnamese people’s creativity and talent Ethnic groups, geographically closing together, have similar customs Therefore, folk dances of Vietnam’s 54 ethnic groups can be classified regionally into main groups: Highland-Midland Northern, Red River Delta, North Central, Coastal South Central, Highlands, South East and South West regions [4, 5] In addition, Vietnamese folk dances express groups of messages [5]: (i) daily life activities, (ii) festival activities and, (iii) human spirituality Through dances, people want to pass on an experience of productive labor, hunting and show the behavior of human beings, such as sailing dance (mua cheo thuyen), weaving dance (mua det cui) Festivals of any village, reflected alive popularly in dances, are always composed of two parts: the ceremonial part, to give homage to the local genies and deities, and the festival one to entertain the whole village Drum dance (mua trong), Thai spreading dance (mua xoe Thai), for example, are performed in local festivals Chau dance (mua Chau), Hau Dong dance (mua Hau Dong) are typical examples of spiritual dances, which express praying for auspices and blessing by the gods, heaven, Buddha We identify regional features and messages transmitted in a dance, based on many aspects such as dance posture and movement, clothing, dance props, music In the first phase, we concentrate only on representing and analyzing movement aspects of folk dances III VIETNAMESE FOLK DANCE ONTOLOGY DEVELOPMENT A Proposed approach An initial ontology for Vietnamese folk dances is built up as proposed in Fig For dance annotation, the Labanotation [2] seems useful in analysis Labanotation is composed of two main parts: movement analysis and movement symbolic representation Movement analysis records the general idea behind movements and allows an improvement of basic movements The part also descripts specifically and precisely movement elements including body parts, time, direction and dynamics We apply movement analysis of Labanotation in the folkdance analysis We also study Vietnamese folk dance domain in order to perceive their messages Based on a hierarchy structure of dance movements and expertise knowledge of the folk-dance domain, OWL will be used to describe classes and properties Next, dance and its domain descriptions are represented formally in Description Logic, in which the reasoner supports answering different queries on Vietnamese folk dance 978-1-5386-0572-1/18/$31.00 ©2018 IEEE 76 The 3rd International Conference on Digital Arts, Media and Technology (ICDAMT2018) movement primitives include hand movements, upper/lower arm movements, feet movements, upper/lower leg movements, head movements, and arm-leg movements We use dance orientations, angles between arms/legs with the torso and angles between limbs inside arms/legs to describe basic body part poses In Vietnam folk dances, there are eight orientations, denoted by Orient1, Orient2, Orient3, Orient4, Orient5 Orient6, Orient7, Orient8 corresponding to forward, right front diagonal, right side, right back diagonal, backward, left back diagonal, left side and left front diagonal respectively As mentioned above, there are two types of movements related to body and body parts Hence, it is necessary to discriminate orientation of body or body parts For the first type, the dancer, for example, moves straight in orientation Orient1 means he moves straight forward Or, he performs Phrase Movement Trans_O1 The second type of orientation (also included values) is associated with body parts (considered as a local coordinate) In this type, Orient1 coincides with the forward of the dancer LegPose1, for instance, is described as follows: both legs are straight, left foot is in Orient8 and right foot is in Orient2 (fig b, top) LegPose4 has right knee bent, left foot is in Orient8 and right foot is in Orient1 with the right toes are at the left heel (fig b, bottom) The orientations in LegPose1 and LegPose4 is the second type Analyzing movements in Vietnamese folk dances Fig 2. Laban symbol hierachy For a dance, Labanotation analyzes some aspects as travelling and travelling time of dancers, the relationship between dancers, between dancers and stage, and dancers themselves [2] (Fig 2) Labanotation system analyzes the body of dancer as symmetry objects and divide the body in to different parts based on joints of bones Laban symbol system is used to represent movements of body parts, movement trajectory of dancer and positon of dancer in the stage by the time We take advantage of analyzing movement techniques into analyzing Vietnamese folk dance A Vietnamese folk dance includes basic units [3] Each basic unit is defined as the smallest movement with a complete meaning There are two main types of movements, corresponding to basic actions: actions of the whole body and actions of some body parts as in Labanotation [2] (i) Body movements, making the position of the whole body of dancer changed in space and (ii) Body part movements, making the position of different parts of dancer’s body changed For body movements, dancers move on stage On the other hand, dancers change their position on a plane The Vietnam traditional folk dance is different from modern dances in body movement There are no body movements, which lift dancers on the air So, body movements in the Vietnamese folk dance are not too complicate We define movement phrases as follows Each movement phrase is a simple body movement, which has a trajectory in the form of a line: an acre, a dot on a plane as a straight pathway, a curved pathway and stillness as in the Labanotation [2] Body movements are composed of movement phrases As said above, movement phrases include moving spot (a dot), translation (a line), and rotation (an arc) A translation can be done in one of eight orientations There are two types of rotation: clockwise and counter clockwise Moving spot phrase can be also in the turn (with different degrees) or no-turn Along with the implementation of the body phrases, dancers perform body part movements, called as movement primitives Movement primitives are quick movements which change the position of body parts On the other hand, a movement primitive is a movement between two main dance poses A dance pose is a particular position of dancer’ body There are basic head poses, basic hand poses, basic arm poses, basic leg poses and basic combined arm-leg poses (fig a) So, Fig 3. a, dance poses b, legposes C Concepts and properties We start building a Vietnamese folk dance ontology by defining dance components based on movement analysis and dance domain knowledge As mentioned above, we segment a dance into basic units Most visual and meaningful dance features will be used to associate a description to basic units A basic unit consists of one or several movement phrases Each movement phrase contains several movement primitives A primitive has at least basic poses with a duration, changing from the first pose to the last one In order to provide rich movement descriptions, we organize a taxonomy of dance movement classes as represented in Fig Some of the more prominent classes of the ontology are the following: • 77 Movement: This class can be considered as the “root” of the movement aspect (related to body and body The 3rd International Conference on Digital Arts, Media and Technology (ICDAMT2018) Beside properties and values of dance movement classes, we add a meaning of the basic unit with detailed descriptions to make metadata (Table II) part) of dance It encodes the information about phrase movements, primitives and poses • Dancer: this class represents dancers in a dance • Group, Groupshape, LineRelation, CircleRelation: these classes encode information of dancer groups in dance • • TABLE II N o Description MO away cm in front of torso, Inviting A Region and Message: these classes represent regional and content information of dance BelongToRegion(a,b) MemberOf(a,b) any Dancer a/Group a has Position b delta ahead along the orient, backward or Start with leg pose1 MO toe Repeat: touching straight, left/right knees bend with toe touch the ground, right/left legs Joy Red River delta arms clap up in orient 8/2, head lean in orient 8/2 Repeat: MO Foot (1) move right leg 40cm in Joy; scope Red Dragging orient2, (2) drag left leg next to right change River delta leg, with left feet in orient8 (3) clap hand in front of right shoulder Dancer a is member of Group b HasPosition(a,b) Red River forward Region b Invitation are ground, right/left arms also Dance a/BasicUnit a belong to Dance a /BasicUnit a has Message b forearm orientation of the leg with opened hand Body can rotate Explanations HasMessage(a,b) bicep and orthogonal, straight SOME PREDICATES Region s ahead with heel touching the There are some types of relationships among classes presented in the form of predicates First ones relate to performing different poses and movements Second ones are about the spatial relationship with the stage for dancers and dancer groups Third ones concern dancer groups Fourth ones deal with the relationship between the content of a folk dance and its region Table I shows typical predicates and their explanation Predicates Messages Repeat: right/left legs straight Based on the movement dance analysis in III.B, we completely determine objects in dance Group(A), Groupshape(“Circle”), and CircleRelation(“FaceToTheCenter”), for instance, represent A is a group of dancers, the dancers make a circle and they face to center of the circle respectively No Basic units Start with legpose1, arms CKeyTime: this class encodes the connection between all different objects related to a step in a dance or relations between pairs of all objects at a time TABLE I SOME BASIC UNITS Repeat: MO (1) lift right knee where right Jump and Red rotation calf orthogonal to body, arms clap under the calf; rotation River (2) lift left knee where left combinati on delta jumping calf orthogonal to body, arms clap under the calf; (3) lift right knee where right calf orthogonal to body, arms clap above the head; (4) lift left knee where left calf orthogonal to body, arms clap behind the back; IV FORMALIZATION OF MO DANCE IN DL-LITE In this section, we present a logical representation in DLLite [1] of Vietnamese folk dances We shall investigate in details a specific folk dance, called “MO dance under the moon” which is very well known in the Red River Delta region of Vietnam Fig 4. Some ance movement classes and their instances 78 The 3rd International Conference on Digital Arts, Media and Technology (ICDAMT2018) A Vietnamese folk dance representation The classes (Dance, BasicUnit, Region, Message, etc, as mentioned in section 3) are now converted into corresponding atomic concepts Inclusion assertions of the form B⊆C, expressing constraints, relationships between concepts (in section 3.3), are encoded in TBox For example, the assertion, ∃BelongToRegion⊆ Dance, indicates that if there exists an individual belonging to a certain region, this individual is a dance or a basic unit in a dance When we recognize a dance or a basic unit, we will know also its regional feature ABox contains a set of assertions of folk Vietnamese folk dance domain Tbox ∃BelongToRegion⊆ Dance ∃BelongToRegion - ⊆ Region ∃HasMessage⊆ BasicUnit ∃HasMessage - ⊆ Message ∃MemberOf⊆Dancer ∃MemberOf-⊆Group Abox PhraseMovement("Trans_O2") OrientOfTurn("CCW") BasicUnit(“MoInviting”) CircleRelation(“FaceToTheCenter”) belongToRegion(“MoDanceUnderTheMoon”,”Red river delta”) B Time problem solving representation of dance C Mo dance under the moon After having solution for time problem, specific dances are added to enrich the ontology MO is a very popular folk musical instrument, used usually by a very special messenger in old villages, when go through the village for announcing an important notice to villagers Mo dances, combinations of Mo Dance Basic units, are actually existing only in the Red River Delta These dances are usually performed in village’s festivals The following gives the logical representation of “Mo Dance Under the Moon” – a specific MO dance in DL-Lite The dance having 20 steps is performed by groups of dancers Firstly, there is some description of whole dance Group(A) Group(B) Group(C) Group(D) memberOf(Ai,A) %i=1-3 memberOf(Bi,B) %i=1-3 memberOf(Ci,C) %i=1-3 memberOf(Di,D) %i=1-3 Dance(“MoDanceUnderTheMoon”) hasStep(Sti) %i=1-19 nextStep(Sti+1,Sti) i=1-18 Then, each step is descripted in detail combinesGroup(D2,D3) %make group D2 step(st1) CKeyTime(t11) CKeyTime(t12) CKeyTime(t13) CKeyTime(t14) CKeyTime(t15) hasPositionCKT(t11,”rightfront”) GroupCKT(t11,A) isInOrientationKDT(t11,Orient6) isInShapeCKT(t11,”line”) isInRelationCKT(t11,”behind each other”) belongToStep(t11,st1) … Step has identity st1 In this step, two dancer D2 and D3 make a group t11, t12, t13, t14, t15 are keys At the key time t11, all dancers in group A make a line in direction Orient6 and in relation behind to each other in A dance which is a series of movements over time includes different steps So, class Step is necessary in the ontology A movement in each step is a relationship of at least three related objects, while predicates in DL-Lite is binary one For instance, dancer A1 performs basic unit “MoInviting” and group of dancer B simultaneously performs phrase movement Trans_O1 in side by side relation at step S To solve the problem, we add class CKeyTime to express the key connecting one of the related objects On the other hand, the fifth group of relationships is the one in which one of classes is CKeyTime Hens, each predicate between two objects is divided into two predicates which are the relationships between the key and one of two objects Step(S) Dancer(A1) Group(B) CKeyTime(T1) %for dancer A1’s movement CKeyTime(T2) %for group B’smovement dancerCKT(T1,A1) groupCKT(T2,B) performsBasicunitCKT(T1,”MoIniviting”) isInShapeCKT(T2,”Line”) isInLineRelationCKT(T2,SideBySide”) performsPhraseMovementCKT(T2,”Trans_O”) belongToStep(T1,S) belongToStep(T2,S) V EX PERIMENTS AND DISCUSSIONS Related materials of the folk dance are supported by Hanoi Academy of Theatre and Cinema The materials include videos, dance curriculum [3] cultural book [4], master thesis [5] With the materials, we build the initial experimental ontology including 37 classes, 198 individuals, and 35 properties, being built in Protege 5.0 alpha with hundreds of instances and axioms These classes, individuals, and properties descript hierarchy of movement, relationship among pair of dancers, dancer groups, time, messages, features, stages in the folk dance and two case studies of specific folk dances The two folk dances – “Mo dance in the moon” and “Sap dance” - are typical The version of Protege supports OWL-2 with SPARQL, OWLViz and many other useful plugins We analyzed Basic Units and some typical Vietnamese folk dances in different regions 79 The 3rd International Conference on Digital Arts, Media and Technology (ICDAMT2018) This ontology of Vietnamese folk dances is useful and could be used in different contexts Firstly, it supplies a kind of complementary knowledge to spectators who are enjoying a dance performance In order to understand dance contents and contexts, questions can be encoded in the form of queries The exploitation of information from the ontology is the platform to develop multimedia applications in the museum Secondly, this built-up ontology (organized in a hierarchical structure of Folk dances and specific dances) is a systematic document, which could be used as tutorial in dance teaching and training Finally, the ontology allows different analyses in dance movements Therefore, this supports choreographers in designing good dance performances and IT developers in building suitable 3D dance models These applications and tools are being developed in parallel with the ontology development same time, we will complete applications and tools in the museum and the academy of theatre and cinema ACKNOWLEDGMENT This work was supported by project named “Multimedia application tools for intangible cultural heritage conservation and promotion”, project number DTDL.CN-34/16 REFERENCES [1] A Artale, D Calvanese, R Kontchakov, and M Zakharyaschev The dllite family and relations J Artif Intell Res (JAIR), vol 36, pp 1-69, 2009 [Online] Available: http://dx.doi.org/10.1613/jair.2820 [2] Ann Kipling Brown, Monica Parker Dance notation for beginners Dance Books Ltd, Cecil Court, London WC2N 4EZ, first edition 1984 [3] Nguyen Tam Kien, Nguyen Thu Nga Classical dance curriculum Vietnam Ethnic Culture Publisher, Vietnam 2014 [4] Ngo Duc Thinh Regional Culture & culture zoning in Vietnam Young Publisher, Vietnam 2004 [5] Phung Quang Minh Folk dance - Origin of professional dance Master thesis, Hanoi Academy of Theatre and Cinema, 2010 [6] S Renzo and A Hernan Ontology and semantic wiki for an intangible cultural heritage inventory, In Proceeding of Computing Conference (CLEI), 2013 [7] S Debastian Ontologies for representation of folk song metadata, in Technical report, EHUKZAATR201201, 2012 [8] E R Katerina and I Yannis, A labanotation based ontology for representing dance movement, in Proceedings of the 9th International Gesture Workshop, 2011 [9] S Sawsan, D B Dominique, M Sald, and M Pierre, An ontology for video human movement representation based on Benesh notation, in Proceedings of International Conference on Multimedia Computing and Systems (ICMCS), 2012 [10] H Blades, Creative computing and the re-configuration of dance ontology, in Proceeding of Electronics Visualization in the Arts, 2012 VI CONCLUSION This paper presented an initial experimental ontology to represent and structure Vietnamese folk dances Our approach applies dancers’ body part movement analysis to investigate Vietnamese folk dances This adaptation shows classes and semantic relationships in the Vietnamese folk dance domain They are different relationships among (i) different body parts, (ii) different dancers in a group, (iii) dancers and stage, (iv) dances and their transmitted messages/ regional feature, and (v) time and other concepts OWL is a powerful language in building, organizing and visualizing ontologies The formal encoding of the ontology information is performed by DL-Lite The knowledge base of the Vietnamese folk dances, structured simply but effectively, together with encoding and reasoning, meets the demand of a wide range queries Future works with the ontology development, we will implement the representation of diverse dances and consider other aspects of dance such as clothing, related objects At the 80 ... Each movement phrase is a simple body movement, which has a trajectory in the form of a line: an acre, a dot on a plane as a straight pathway, a curved pathway and stillness as in the Labanotation. .. 2. Laban symbol hierachy For a dance, Labanotation analyzes some aspects as travelling and travelling time of dancers, the relationship between dancers, between dancers and stage, and dancers... structure Vietnamese folk dances Our approach applies dancers’ body part movement analysis to investigate Vietnamese folk dances This adaptation shows classes and semantic relationships in the Vietnamese