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A Study on Facial Expression Acting in Genre Drama - with Focus on K-Drama Voice2 - (장르 드라마에서의 표정연기연구 - 드라마 '보이스2'를 중심으로 -)

  • Oh, Youn-Hong
    • Journal of Korea Entertainment Industry Association
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    • v.13 no.8
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    • pp.313-323
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    • 2019
  • For the actors on video, facial expression acting can easily become 'forced facial expression' or 'over-acting'. Also, if self-restraint is emphasized too much, then it becomes 'flat acting' with insufficient emotions. By bringing forth questions in regard to such facial expression acting methods, this study analyzed the facial expression acting of the actors in genre dramas with strong commercial aspects. In conclusion, the facial expression acting methods of the actors in genre dramas were being conducted in a typical way. This means that in visual conventions of video acting, the aesthetic standard has become the important standard in the facial expression acting of the actors. In genre dramas, the emotions of the characters are often revealed in close-up shots. Within the close-up shot, the most important expressive medium in a 'zoomed-in face' is the 'pupil of the eye', and emotions are mostly expressed through the movements of the eye and muscles around it. The second most important expressive medium is the 'mouth'. The differences in the degree of opening and closing the mouth convey diverse emotions along with the expression of the 'eye'. In addition, tensions in the facial muscles greatly hinder the expression of emotions, and the movement of facial muscles must be minimized to prevent excessive wrinkles from forming on the surface of the face. Facial expressions are not completed just with the movement of the muscles. Ultimately, the movement of the muscle is the result of emotions. Facial expression acting takes place after having emotional feelings. For this, the actor needs to go through the process of 'personalization' of a character, such as 'emotional memory', 'concentration' and 'relaxation' which are psychological acting techniques of Stanislavsky. Also, the characteristics of close-up shots that visually reveal the 'inner world' should be recognized. In addition, it was discovered that the facial expression acting is the reaction acting that provides the important point in the unfolding of narratives, and that the method of facial expression and the size of the shots required for the actors are different depending on the roles of main and supporting characters.

Problems of Each Category of Gyeongsanjain Dano Festival and Solutions (경산자인단오제 연행의 분야별 문제와 종합적 개선방안)

  • Lee, Byoung Ok
    • (The) Research of the performance art and culture
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    • no.19
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    • pp.88-123
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    • 2009
  • Gyeongsanjain Dano Festival is a local festival of Yeongnam that was initially designated as Intangible Cultural Heritage No. 44 "Hanjanggun Nori" in 1971 and finally became Gyeongsanjain Dano Festival in 2007. At first, few parts of it were designated for preservation and it was succeeded as a whole without connections between each part. Problems also rise from the fact that it has not been closely studied. Gyeongsanjain Dano Festival is mostly classified into five parts: Keungut, Yeowonmu, Hojanggut, Hanmyoje, and Jainpalgwangdae. This study has closely discussed each part as follows: 1. Keungut 1) Process and Contents of Keungut - Characteristics of Gut in Daegu and Gyeongsan 2) Presence of Performers that can Execute Traditional Gut of Local Area 3) Problems with the Name of Keungut - Ex: 'Hanjanggungut' or 'Keungut' 4) Problems of Dano Festival without Parts to Summon and Send off Spirits before and After Keungut and Restoration Measures 2. Yeowonmu 1) Essence of Yeowonmu and Yeowonhwa 2) Problems with the Mass Game of Hundreds of High School Girls 3) Origin and Succession of Yeowonmu 3. Hojanggut 1) Changes in Characters of Hojanggut 2) Composition and Characteristics of Hojanggut 3) Problems with the Name and Characteristics of Hojanggut 4. Jainpalgwangdae Nori 1) Similarity with Newly Created Shows 2) Problems with the Name of Palgwangdae 3) Difference with the Composition of Other Mask Dances 4) Dances and Movements Distinguished from Other Mask Dances in Yeongnam The following are the solutions suggested for Gyeongsan Jain Dano Festival. First, for the restoration of Gyeongsanjain Dano Festival, Dano festivals and Byeolsinje of nearby areas with clear traditions could be benchmarked. Second, the major content of Gyeongsanjain Dano Festival is 'Hanjanggungut,' and it has to be the leading content of the festival. Third, the structural principle of Korean festival must be adopted and the process and principle must correspond to those of other traditional shows. Fourth, as Gyeongsanjain Dano Festival is the comprehensive form of art, folk, and festival, each part must be closely related in a well-planned scenario. Fifth, Intangible talents and successful training must be widely acknowledged for successful transmission and responsible performances. Sixth, traditional festivals must be restored along with the discovery and development of various festival repertories and spectacles such as tour programs and experiential tours that contribute to local economy.

Interpretation of Microscale Behaviors and Precision Measurement Monitoring for the Five-story and Seven-story Stone Pagodas from Cheongnyangsaji Temple Site in Gongju, Korea (공주 청량사지 오층석탑 및 칠층석탑의 정밀 계측모니터링과 미세거동 해석)

  • LEE Jeongeun;PARK Seok Tae;LEE Chan Hee
    • Korean Journal of Heritage: History & Science
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    • v.56 no.4
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    • pp.132-158
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    • 2023
  • The five-story and seven-story stone pagodas at Cheongnyangsaji temple site in Gongju are located under the Sambulbong peak of Gyeryongsan mountain, and are known to have been built of the middle in Goryeo dynasty. As the two pagodas in which two types of Baekje stone pagoda coexist in one era, their historical and academic value are recognized. The seven-story pagoda was overturned by robbery in 1944, and as a result, the five-story pagoda was tilted. Although the two pagodas were restored in 1961, structural instability was continuously raised. In this study, measurement data accumulated from May 2021 to March 2022, and seasonal characteristics were reviewed, and the micro behavior of pagodas were analyzed according to temperature and precipitation during the same period. As a result, the micro thermoelastic behavior was repeated according to the daily temperature change in all sensors, and both the slope and the displacement showed microscale behavior. In the inclinometer, moisture containing the surface and inside of the stones repeated expansion and contraction due to temperature change, showing the micro movements. In particular, the upper part of the five-story pagoda moved up to 3.89° to the northwest, and the seven-story pagoda tilted up to 0.078° to the northeast. The maximum displacements were recorded as 0.127 and 0.149 mm in the five-story and the seven-story pagoda, respectively. These values tended to return to the original position at the end of the measurement, but did not recover completely, indicating a state requiring precise monitoring. The result obtained through the study can be used as basic data for the stable conservation of the two stone pagodas. Based on the behavioral characteristics considering various environmental factors should be analyzed, and the preventive conservation through the maintenance of measurement system built this time should be continued.

A Study on the Discourse Regarding the Lineage Transmission to Haewol in the Eastern Learning: Focused on Document Verification (해월의 동학 도통전수 담론 연구 - 문헌 고증을 중심으로 -)

  • Park Sang-kyu
    • Journal of the Daesoon Academy of Sciences
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    • v.48
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    • pp.41-155
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    • 2024
  • Among the records that attest to the period from July to August of 1863, when Suwun was believed to have transmitted the orthodox lineage to Haewol, the oldest documents are The Collection of Suwun's Literary Works (水雲文集), The Collection of Great Master Lord's Literary Works (大先生主文集), and The Records of Dao Origin of Master Choe's Literary Collection (崔先生文集道源記書, hereafter referred to as The Records of Dao Origin). The records regarding Suwun in these three documents are considered to have originated from the same context. The variances embedded in the three documents have led to arguments about which documents accurately reflect the fact of orthodox lineage transmission. Additionally, these variances highlight the necessity of a review regarding the characteristics of early Eastern Learning, such as its faith and organizational systems. Accordingly, by thoroughly examining these three documents, it is possible to elucidate the chronological order, establishment-date, accuracy, descriptive direction, and characteristics of the faith system of early Eastern Learning as these are reflected in each document. If successful, this examination would provide a clearer description of the developmental process of Eastern Learning from 1860 to 1880, facilitating a more in-depth analysis of the significance embedded in various forms of discourse on the movement's orthodox lineage transmission. In comparing the three documents and contrasting them with related sources, the results of the textual examination assert that the documents within the lineage of The Collection of Suwun's Literary Works, given they lack a clear record of the event regarding Haewol's orthodox lineage succession, may be the first draft of The Collection of Great Master Lord's Literary Works and The Records of Dao Origin, as these texts distinctly include that record. This reflects that Haewol's succession was not precisely recognized within and outside of the Eastern Learning order until the time when The Collection of Great Master Lord's Literary Works and The Records of Dao Origin were published. This is further attested to by the fact that during the late 1870s, when various Yeonwon (fountainhead) factions of Eastern Learning began to converge around Haewol, and his Yeonwon became the largest organization within Eastern Learning. At that point, the order's doctrine was reinterpreted, and its organization was reestablished. In this regard, it is necessary to view Eastern Learning after Suwun-especially the orthodox lineage transmission to Haewol-from a perspective that considers it more as competing forms of discourse than as a historical fact. This view enables a new perspective on Haewol's Eastern Learning, which forms a distinct layer from Suwun's, shedding light on the relationship between Haewol and the new religious movements in modern-day Korea.

The Great Opening of the Later World in Daesoon Thought and the World of Pre-experientialism from the Reordering Works of Heaven and Earth as Understood in Yi-Jing Studies (천지개벽의 역학적 사유에서 본 대순사상의 후천개벽과 선험주의적 세계)

  • Kim Yon-jae
    • Journal of the Daesoon Academy of Sciences
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    • v.47
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    • pp.1-37
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    • 2023
  • This essay seeks to answer the question of how best to understand Korean new religious movements (KNRMs). KNRMs have the characteristics of folk religion, ethno-religion, or popular religion. KNRMs are products of the national consciousness promoted by Korean society during the Late Joseon Dynasty at the turning point of modern Yi-Jing Studies. From the perspective of social evolutionary theory of developmental history, during that period, Joseon (Korea), like China, was faced with a double-edged sword consisting of the strength of tradition and the upheaval of modernity. If the strength of tradition depended on the Yi-Jing Studies to promote national enlightenment toward anti-imperialist aims, then it was equally the case that modernity depended on the sense of urgency to guide the people to secure livelihoods and edification regarding anti-feudalism. In this essay, the KNRMs that appeared during this transition period of Yi-Jing Studies will be a significant focus, and the worldview of Daesoon Thought will be the main focus. As one of the central topics, intensive discussion will be dedicated to the issue of the nature of pre-experientialism (先驗主義) which characterized the Great Opening (開闢). The principles of Daesoon Thought have a religious dimension of realistic awareness that guides the people's lives and edifies them. The process of the Great Opening aims to secure an ontological clock that tracks the Great Itineration of the world toward Daesoon Truth. This in turn as a process establishes the epistemological world of the Reordering Works of Heaven and Earth (天地公事) and reaches the axiological boundary of the future world. The links among the Three Realms is characterized by a pre-experientialist line that experiences the space-time nature of the universe as the Great Opening of the Later World (後天) within the framework of Heaven and Earth. Throughout this course, humans look to enjoy the infinite vitality of the universe from within their own finite vitality. Therefore, Daesoon Thought can overcome perceived reality through pre-experientialist channels such as the Great Opening of the Later World and aim for a state of self-awareness such as the Earthly Paradise. This is an attempt to participate and practice in the actual world rather than pursuing a world of transcendental ideas, and therefore, it tends to be proactive in the world rather than exhibit a passive tendency to be worldliness. In conclusion, the truth of Daesoon Thought, which is characterized by the Great Opening of the Later World, contains a future-oriented outlook that longs for a Nextopia full of hope and promise rather than idealistic fancy towards a Utopia or well-founded dread and disdain towards Dystopia.

The Correction Effect of Motion Artifacts in PET/CT Image using System (PET/CT 검사 시 움직임 보정 기법의 유용성 평가)

  • Yeong-Hak Jo;Se-Jong Yoo;Seok-Hwan Bae;Jong-Ryul Seon;Seong-Ho Kim;Won-Jeong Lee
    • Journal of the Korean Society of Radiology
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    • v.18 no.1
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    • pp.45-52
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    • 2024
  • In this study, an AI-based algorithm was developed to prevent image quality deterioration and reading errors due to patient movement in PET/CT examinations that use radioisotopes in medical institutions to test cancer and other diseases. Using the Mothion Free software developed using, we checked the degree of correction of movement due to breathing, evaluated its usefulness, and conducted a study for clinical application. The experimental method was to use an RPM Phantom to inject the radioisotope 18F-FDG into a vacuum vial and a sphere of a NEMA IEC body Phantom of different sizes, and to produce images by directing the movement of the radioisotope into a moving lesion during respiration. The vacuum vial had different degrees of movement at different positions, and the spheres of the NEMA IEC body Phantom of different sizes produced different sizes of lesions. Through the acquired images, the lesion volume, maximum SUV, and average SUV were each measured to quantitatively evaluate the degree of motion correction by Motion Free. The average SUV of vacuum vial A, with a large degree of movement, was reduced by 23.36 %, and the error rate of vacuum vial B, with a small degree of movement, was reduced by 29.3 %. The average SUV error rate at the sphere 37mm and 22mm of the NEMA IEC body Phantom was reduced by 29.3 % and 26.51 %, respectively. The average error rate of the four measurements from which the error rate was calculated decreased by 30.03 %, indicating a more accurate average SUV value. In this study, only two-dimensional movements could be produced, so in order to obtain more accurate data, a Phantom that can embody the actual breathing movement of the human body was used, and if the diversity of the range of movement was configured, a more accurate evaluation of usability could be made.

Studies on the Functional Interrelation between the Vestibular Canals and the Extraocular Muscles (미로반규관(迷路半規管)과 외안근(外眼筋)의 기능적(機能的) 관계(關係)에 관(關)한 연구(硏究))

  • Kim, Jeh-Hyub
    • The Korean Journal of Physiology
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    • v.8 no.2
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    • pp.1-17
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    • 1974
  • This experiment was designed to explore the specific functional interrelations between the vestibular semicircular canals and the extraocular muscles which may disclose the neural organization, connecting the vestibular canals and each ocular motor nuclei in the brain system, for vestibuloocular reflex mechanism. In urethane anesthetized rabbits, a fine wire insulated except the cut cross section of its tip was inserted into the canals closely to the ampullary receptor organs through the minute holes provided on the osseous canal wall for monopolar stimulation of each canal nerve. All extraocular muscles of both eyes were ligated and cut at their insertio, and the isometric tension and EMG responses of the extraocular muscles to the vestibular canal nerve stimulation were recorded by means of a physiographic recorder. Upon stimulation of the semicircular canal nerve, direction if the eye movement was also observed. The experimental results were as follows. 1) Single canal nerve stimulation with high frequency square waves (240 cps, 0. 1 msec) caused excitation of three extraocular muscles and inhibition of remaining three muscles in the bilateral eyes; stimulation of any canal nerve of a unilateral labyrinth caused excitation (contraction) of the superior rectus, superior oblique and medial rectus muscles and inhibition (relaxation) of the inferior rectus, inferior oblique and lateral rectos muscles in the ipsilateral eye, and it caused the opposite events in the contralateral eye. 2) By the overlapped stimulation of triple canal nerves of a unilateral labyrinth, unidirectional (excitatory or inhibitory) summation of the individual canal effects on a given extraocular muscles was demonstrated, and this indicates that three different canals of a unilateral vestibular system exert similar effect on a given extraocular muscles. 3) Based on the above experimental evidences, a simple rule by which one can define the vestibular excitatory and inhibitory input sources to all the extraocular muscles is proposed; the superior rectus, superior oblique and medial rectus muscles receive excitatory impulses from the ipsilateral vestibular canals, and the inferior rectus, inferior oblique and lateral rectus muscles from the contralateral canals; the opposite relationship applies for vestibular inhibitory impulses to the extraocular muscles. 4) According to the specific direction of the eye movements induced by the individual canal nerve stimulation, an extraocutar muscle exerting major role (a muscle of primary contraction) and two muscles of synergistic contraction could be differentiated in both eyes. 5) When these experimental results were compared to the well known observations of Cohen et al. (1964) made in the cats, extraocular muscles of primary contraction were the same but those of synergistic contraction were partially different. Moreover, the oblique muscle responses to each canal nerve excitation appeared to be all identical. However, the responnes of horizontal (medial and lateral) and vertical (superior and inferior) rectus muscles showed considerable differences. By critical analysis of these data, the author was able to locate theoretical contradictions in the observations of Cohen et al. but not in the author's results. 6) An attempt was also made to compare the functional observation of this experiment to the morphological findings of Carpenter and his associates obtained by degeneration experiments in the monkeys, and it was able to find some significant coincidence between there two works of different approach. In summary, the author has demonstrated that the well known observations of Cohen et al. on the vestibulo-ocular interrelation contain important experimental errors which can he proved by theoretical evaluation and substantiated by a series of experiments. Based on such experimental evidences, a new rule is proposed to define the interrelation between the vestibular canals and the extraocular muscles.

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Sequence Stratigraphy of the Yeongweol Group (Cambrian-Ordovician), Taebaeksan Basin, Korea: Paleogeographic Implications (전기고생대 태백산분지 영월층군의 순차층서 연구를 통한 고지리적 추론)

  • Kwon, Y.K.
    • Economic and Environmental Geology
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    • v.45 no.3
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    • pp.317-333
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    • 2012
  • The Yeongweol Group is a Lower Paleozoic mixed carbonate-siliciclastic sequence in the Taebaeksan Basin of Korea, and consists of five lithologic formations: Sambangsan, Machari, Wagok, Mungok, and Yeongheung in ascending order. Sequence stratigraphic interpretation of the group indicates that initial flooding in the Yeongweol area of the Taebaeksan Basin resulted in basal siliciclastic-dominated sequences of the Sambangsan Formation during the Middle Cambrian. The accelerated sea-level rise in the late Middle to early Late Cambrian generated a mixed carbonate-siliciclastic slope or deep ramp sequence of shale, grainstone and breccia intercalations, representing the lower part of the Machari Formation. The continued rise of sea level in the Late Cambrian made substantial accommodation space and activated subtidal carbonate factory, forming carbonate-dominated subtidal platform sequence in the middle and upper parts of the Machari Formation. The overlying Wagok Formation might originally be a ramp carbonate sequence of subtidal ribbon carbonates and marls with conglomerates, deposited during the normal rise of relative sea level in the late Late Cambrian. The formation was affected by unstable dolomitization shortly after the deposition during the relative sea-level fall in the latest Cambrian or earliest Ordovician. Subsequently, it was extensively dolomitized under the deep burial diagenetic condition. During the Early Ordovician (Tremadocian), global transgression (viz. Sauk) was continued, and subtidal ramp deposition was sustained in the Yeongweol platform, forming the Mungok Formation. The formation is overlain by the peritidal carbonates of the Yeongheung Formation, and is stacked by cyclic sedimentation during the Early to Middle Ordovician (Arenigian to Caradocian). The lithologic change from subtidal ramp to peritidal facies is preserved at the uppermost part of the Mungok Formation. The transition between Sauk and Tippecanoe sequences is recognized within the middle part of the Yeongheung Formation as a minimum accommodation zone. The global eustatic fall in the earliest Middle Ordovician and the ensuing rise of relative sea level during the Darrwillian to Caradocian produced broadly-prograding peritidal carbonates of shallowing-upward cyclic successions within the Yeongheung Formation. The reconstructed relative sea-level curve of the Yeongweol platform is very similar to that of the Taebaek platform. This reveals that the Yeongweol platform experienced same tectonic movements with the Taebaek platform, and consequently that both platform sequences might be located in a body or somewhere separately in the margin of the North China platform. The significant differences in lithologic and stratigraphic successions imply that the Yeongweol platform was much far from the Taebaek platform and not associated with the Taebaek platform as a single depositional system. The Yeongweol platform was probably located in relatively open shallow marine environments, whereas the Taebaek platform was a part of the restricted embayments. During the late Paleozoic to early Mesozoic amalgamations of the Korean massifs, the Yeongweol platform was probably pushed against the Taebaek platform by the complex movement, forming fragmented platform sequences of the Taebaeksan Basin.

Kinemetic analysis of a thumping security motion with an expandable barton (경호원의 삼단봉 머리치기 동작의 운동학적 분석)

  • Kim, Yong-Hak;Kim, Sin-Hye;Jung, Sung-Bae
    • Korean Security Journal
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    • no.36
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    • pp.93-109
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    • 2013
  • This research is mainly based on the experimental result due to seek different outcomes whena certain security motion with a paticular gear is applied in a plausible confrontational situation. For the purpose of this research an Expandable Baton, which is one of the most commonsecurity equipments, was chosen to be applied in a situation of hitting a person's head. Alsothe results will be studied in the view of Kinematic theory. To demonstrate, 10 students who were majeored in Escort Crane studies at 'H' university werechosen as testees. The participants were grouped into two-one is practiced with the 'expanadable baton use program' and the other is pre-practiced. In this report two groups abovewill be reffered as 'group A' and 'group B' for conveniency. There were a number of differences and changes between two groups. Group B took more timethan the other group did. Group A spent about 0.428sec in section 'e2' and 0.230sec in section'e3' while Group B took 0.435sec, 0.232sec in each sections.To add on, more distinctive results were out when it was more focused on physical movements. Two gropus presented considerable changes- in an 'left-right' moving displacement-Group A;$2.16{\pm}0.9cm$ (left side), $3.78{\pm}1.42cm$ (right side), total $5.94{\pm}2.03cm$. Group B; $2.97{\pm}1.01cm$ (left side),$4.56{\pm}1.57cm$ (right side), total $7.53{\pm}2.13cm$.Continuously, different outcomeswere shown between two groups in a 'back and forth' moving displacement-Group A;$32.48{\pm}3.86cm$, $35.21{\pm}4.64cm$, total $69.36{\pm}5.72$. Group B; $34.50{\pm}6.12cm$, $37.04{\pm}3.70cm$, total $71.46{\pm}7.17cm$. Furthermore, changes in an 'up and down' moving displacement were - GroupA; $5.62{\pm}2.41cm$, $4.54{\pm}1.87cm$, total $10.11{\pm}1.57cm$. Group B; $6.33{\pm}1.78cm$, $4.86{\pm}1.85cm$,total $10.68{\pm}1.81cm$. To continue, there were few modifications of degree on participants' joints, espcially on 'Wristjoint', 'Elbow joint' and 'Shoulder joint', depend on different sections -Wrist joint;Group A; e1 $114.62{\pm}7.13$, e2 $68.27{\pm}6.37$, e3 $131.64{\pm}6.27$. Group B; e1 $112.62{\pm}6.13$, e2 $66.28{\pm}7.38$, e3$137.42{\pm}4.28$ and Elbow joint ; Group A e1 $132.31{\pm}6.55$, e2 $117.92{\pm}8.42$, e3 $144.41{\pm}6.32$. Group B; e1 $133.58{\pm}8.56$, e2 $114.45{\pm}8.21$, e3 $139.89{\pm}4.38$. Lastly, degree changes ofshoulder joint were; Group A; e1 $13.55{\pm}3.85$, e2 $131.42{\pm}11.24$, e3 $78.32{\pm}6.28$. Group B; e1$9.45{\pm}1.23$, e2 $136.74{\pm}13.21$, e3 $79.75{\pm}4.24$.

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Accelerometer-based Gesture Recognition for Robot Interface (로봇 인터페이스 활용을 위한 가속도 센서 기반 제스처 인식)

  • Jang, Min-Su;Cho, Yong-Suk;Kim, Jae-Hong;Sohn, Joo-Chan
    • Journal of Intelligence and Information Systems
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    • v.17 no.1
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    • pp.53-69
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    • 2011
  • Vision and voice-based technologies are commonly utilized for human-robot interaction. But it is widely recognized that the performance of vision and voice-based interaction systems is deteriorated by a large margin in the real-world situations due to environmental and user variances. Human users need to be very cooperative to get reasonable performance, which significantly limits the usability of the vision and voice-based human-robot interaction technologies. As a result, touch screens are still the major medium of human-robot interaction for the real-world applications. To empower the usability of robots for various services, alternative interaction technologies should be developed to complement the problems of vision and voice-based technologies. In this paper, we propose the use of accelerometer-based gesture interface as one of the alternative technologies, because accelerometers are effective in detecting the movements of human body, while their performance is not limited by environmental contexts such as lighting conditions or camera's field-of-view. Moreover, accelerometers are widely available nowadays in many mobile devices. We tackle the problem of classifying acceleration signal patterns of 26 English alphabets, which is one of the essential repertoires for the realization of education services based on robots. Recognizing 26 English handwriting patterns based on accelerometers is a very difficult task to take over because of its large scale of pattern classes and the complexity of each pattern. The most difficult problem that has been undertaken which is similar to our problem was recognizing acceleration signal patterns of 10 handwritten digits. Most previous studies dealt with pattern sets of 8~10 simple and easily distinguishable gestures that are useful for controlling home appliances, computer applications, robots etc. Good features are essential for the success of pattern recognition. To promote the discriminative power upon complex English alphabet patterns, we extracted 'motion trajectories' out of input acceleration signal and used them as the main feature. Investigative experiments showed that classifiers based on trajectory performed 3%~5% better than those with raw features e.g. acceleration signal itself or statistical figures. To minimize the distortion of trajectories, we applied a simple but effective set of smoothing filters and band-pass filters. It is well known that acceleration patterns for the same gesture is very different among different performers. To tackle the problem, online incremental learning is applied for our system to make it adaptive to the users' distinctive motion properties. Our system is based on instance-based learning (IBL) where each training sample is memorized as a reference pattern. Brute-force incremental learning in IBL continuously accumulates reference patterns, which is a problem because it not only slows down the classification but also downgrades the recall performance. Regarding the latter phenomenon, we observed a tendency that as the number of reference patterns grows, some reference patterns contribute more to the false positive classification. Thus, we devised an algorithm for optimizing the reference pattern set based on the positive and negative contribution of each reference pattern. The algorithm is performed periodically to remove reference patterns that have a very low positive contribution or a high negative contribution. Experiments were performed on 6500 gesture patterns collected from 50 adults of 30~50 years old. Each alphabet was performed 5 times per participant using $Nintendo{(R)}$ $Wii^{TM}$ remote. Acceleration signal was sampled in 100hz on 3 axes. Mean recall rate for all the alphabets was 95.48%. Some alphabets recorded very low recall rate and exhibited very high pairwise confusion rate. Major confusion pairs are D(88%) and P(74%), I(81%) and U(75%), N(88%) and W(100%). Though W was recalled perfectly, it contributed much to the false positive classification of N. By comparison with major previous results from VTT (96% for 8 control gestures), CMU (97% for 10 control gestures) and Samsung Electronics(97% for 10 digits and a control gesture), we could find that the performance of our system is superior regarding the number of pattern classes and the complexity of patterns. Using our gesture interaction system, we conducted 2 case studies of robot-based edutainment services. The services were implemented on various robot platforms and mobile devices including $iPhone^{TM}$. The participating children exhibited improved concentration and active reaction on the service with our gesture interface. To prove the effectiveness of our gesture interface, a test was taken by the children after experiencing an English teaching service. The test result showed that those who played with the gesture interface-based robot content marked 10% better score than those with conventional teaching. We conclude that the accelerometer-based gesture interface is a promising technology for flourishing real-world robot-based services and content by complementing the limits of today's conventional interfaces e.g. touch screen, vision and voice.