• Title/Summary/Keyword: Virtual presence

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Evaluation of Teachers and Students on VR/AR Contents in the Science Digital Textbook: Focus on the Earth and Universe Area for the 8th Grade (과학 디지털 교과서 실감형 콘텐츠에 대한 교사와 학생의 평가 -중학교 2학년 지구와 우주 영역 콘텐츠를 중심으로-)

  • Hyun-Jung Cha;Seok-Hyun Ga;Hye-Gyoung Yoon
    • Journal of The Korean Association For Science Education
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    • v.43 no.2
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    • pp.59-72
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    • 2023
  • This study analyzed a group interview with six earth science teachers and eight middle school students to find out the evaluations and criteria they use to evaluate VR/AR contents (two virtual reality content and two augmented reality contents) in middle school science digital textbook. The study found the VR/AR contents were evaluated on four criteria as follows: VR/AR media characteristics; technical operation; user interface; and teaching-learning design. The evaluations can be summarized by each criterion. First, regarding VR/AR media characteristics, interesting features of VR/AR contents were considered relatively advantageous compared to other media like videos. However, its shortage of visual presence and inconvenience of using markers were mentioned as shortcomings. Second, in the technical operation criteria, teachers and students found the following conditions as technically challenging: failing to properly operate on a particular OS; huge volumes of contents in the application; and frequent freezing when using the application. Third, poor intuitiveness and lack of flexibility were found as negative aspects in user interface. Fourth, regarding teaching-learning design, the teachers evaluated whether the VR/AR contents delivered scientifically accurate information; whether they incorporated class goals set by teachers; and whether they can help students' inquiry. It turned out teachers gave negative feedbacks on VR/AR contents. The students evaluated VR/AR contents by assessing whether they help them with learning science but concluded they did not regard them necessary in science learning at school. Based on the findings, this study discusses which development direction VR/AR contents should take to be useful in teaching and learning science.

Comparison of Metal Artifact Reduction Algorithms in Patients with Hip Prostheses: Virtual Monoenergetic Images vs. Orthopedic Metal Artifact Reduction (고관절 인공치환술 환자에서 금속 인공물 감소 방법의 비교: 가상 단일에너지영상 대 금속 인공물 감소기법)

  • Hye Jin Yoo;Sung Hwan Hong;Ja-Young Choi;Hee Dong Chae
    • Journal of the Korean Society of Radiology
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    • v.83 no.6
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    • pp.1286-1297
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    • 2022
  • Purpose To assess the usefulness of various metal artifact reduction (MAR) methods in patients with hip prostheses. Materials and Methods This retrospective study included 47 consecutive patients who underwent hip arthroplasty and dual-energy CT. Conventional polyenergetic image (CI), orthopedic-MAR (OMAR), and virtual monoenergetic image (VMI, 50-200 keV) were tested for MAR. Quantitative analysis was performed in seven regions around the prostheses. Qualitative assessments included evaluation of the degree of artifacts and the presence of secondary artifacts. Results The lowest amount of image noise was observed in the O-MAR, followed by the VMI. O-MAR also showed the lowest artifact index, followed by high-keV VMI in the range of 120-200 keV (soft tissue) or 200 keV (bone). O-MAR had the highest contrast-to-noise ratio (CNR) in regions with severe hypodense artifacts, while VMI had the highest CNR in other regions, including the periprosthetic bone. On assessment of the CI of pelvic soft tissues, VMI showed a higher structural similarity than O-MAR. Upon qualitative analysis, metal artifacts were significantly reduced in O-MAR, followed by that in VMI, while secondary artifacts were the most frequently found in the O-MAR (p < 0.001). Conclusion O-MAR is the best technique for severe MAR, but it can generate secondary artifacts. VMI at high keV can be advantageous for evaluating periprosthetic bone.

Theoretical Study of Thiazole Adsorption on the (6,0) zigzag Single-Walled Boron Nitride Nanotube

  • Moradi, Ali Varasteh;Peyghan, Ali Ahmadi;Hashemian, Saeede;Baei, Mohammad T.
    • Bulletin of the Korean Chemical Society
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    • v.33 no.10
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    • pp.3285-3292
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    • 2012
  • The interaction of thiazole drug with (6,0) zigzag single-walled boron nitride nanotube of finite length in gas and solvent phases was studied by means of density functional theory (DFT) calculations. In both phases, the binding energy is negative and presenting characterizes an exothermic process. Also, the binding energy in solvent phase is more than that the gas phase. Binding energy corresponding to adsorption of thiazole on the BNNT model in the gas and solvent phases was calculated to be -0.34 and -0.56 eV, and about 0.04 and 0.06 electrons is transferred from the thiazole to the nanotube in the phases. The significantly changes in binding energies and energy gap values by the thiazole adsorption, shows the high sensitivity of the electronic properties of BNNT towards the adsorption of the thiazole molecule. Frontier molecular orbital theory (FMO) and structural analyses show that the low energy level of LUMO, electron density, and length of the surrounding bonds of adsorbing atoms help to the thiazole adsorption on the nanotube. Decrease in global hardness, energy gap and ionization potential is due to the adsorption of the thiazole, and consequently, in the both phases, stability of the thiazole-attached (6,0) BNNT model is decreased and its reactivity increased. Presence of polar solvent increases the electron donor of the thiazole and the electrophilicity of the complex. This study may provide new insight to the development of functionalized boron nitride nanotubes as drug delivery systems for virtual applications.

Analysis on Pataphysics of the Metamorphosis in Film 'X-Men' (영화 '엑스맨(X-Men)'의 변신모티브에 나타난 파타피직스 분석)

  • Chang, Seyoung;Chung, Jeanhun
    • Journal of Digital Convergence
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    • v.14 no.10
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    • pp.407-414
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    • 2016
  • The movie, X-men, develops the narrative with metamorphosis as the main motif making visual effects of characters and background. The objective of this study is to suggest that the metamorphosis motif can be materialized based on the virtuality of "pataphysics" as one of the genre characteristics of superhero movies and the newly materialized virtuality can be aesthetic characteristics of metamorphosis motif movies. With the virtuality that has its own characteristics with metaphorical symbols such as satire on an absurd society out of existing traditions, pataphysics started in mid-twentieth century and has had an impact on art movements of dadaism, surrealism, pop art, and postmodernism. Analyzing the characteristics of pataphysics which were shown in these artworks, we applied it to metamorphosis scenes of the movie. As a result, we found out that it visualized the shape and aspect of inner and outer strength of a superhero with aesthetic characteristics of metamorphosis scenes and it realized the presence, hybridity, and ex-formal properties of pataphysics consisting of overlapped virtual and physical reality, with technical virtuality.

A Study on the Design Tendency of Contemporary Architecture Introducing New Media Art Concept - Focusing on the change for way of information transmission change and media development - (뉴 미디어 아트의 개념을 도입한 현대 건축의 디자인 경향에관한 연구 - 미디어 발전과 정보 전달 방식의 변화를 중심으로 -)

  • Cho, Kyoung-Soo;Woo, Ji-Chang
    • Korean Institute of Interior Design Journal
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    • v.19 no.2
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    • pp.66-72
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    • 2010
  • The purpose of this study is to pronounce design trends in contemporary architecture collaborated with new media art concept. Currently, the prevalence of media presence has evolved perspectives on contemporary aesthetics today. To make clear demonstration on the issue, this study categorized new media art's expressional characteristics applied in the contemporary architectural design in conjunction with analytical researches on typologies and expressional characteristics appear in new media art. More specifically, the study selected architects who adopted new media art's expressional characteristics into their works from the year 2000 and performed analytical case studies with regard to the effect of the new media art into their architectural practices. By following methodologies mentioned above, conclusively the study categorized distinct expressional characteristics appears in contemporary architecture as a result of merging with new media art. The characteristics of the new media art appeared in contemporary architecture are categorized into three groups such as the design controlling external environment, the design utilizing web environment and the design participated by users. These observation could be translated that architects could present interactive design between users and building as a result from architect's capability of designing protocols which generate variable forms, colors and patterns in architecture. In particular, architecture utilizing web environment has characteristic capability of configurating user's program in virtual space. Also it is anticipated to suggest new patterns in generating architectural programs and forms. These patterns would not recognize the city merely as an incident or fragmented image but would configurate forms and images constructed by individual notional character. In conclusion, the architecture itself is expected to perform as media to open up opportunities that enables to contribute in expediting interactions among environment, users, and buildings by deviating from perspectives of representation as an object expressed in modernism architecture or as a classical decoration in post-modernism architecture in the past era.

Efficiacy of CT Colonography in the Detection of Colorectal Polypoid Lesions (대장의 폴립양 병변의 발견에 있어 CT 대장조영술의 유용성)

  • Kim, Yun-Gyeong;Lee, Ji-Eun;Lee, Jeong-Gyeong;Baek, Seung-Yeon;Song, Hyeon-Ju;Jeong, Seong-Ae
    • Journal of Korea Association of Health Promotion
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    • v.4 no.1
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    • pp.49-59
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    • 2006
  • "본 논문은 대한영상의학회지 2005년 제52권 제1호에 실렸던 논문으로 대한영상의학회의 승인을 득하고 본 협회지에 게재함. Purpose: We wished to compare CT colonography with conventional colonoscopy for the detection of colorectal poiypoid lesions, and we wanted to evaluate the role of IV contrast-enhanced CT colonography for the differentiation between benign polypoid lesions and malignant polypoid lesions. Materials and Methods: Thirty-four consecutive patients underwent CT colonography prior to conventional colonoscopy, Precontrast prone-position CT images and post contrast supine position CT images were obtained and the virtual colonoscopic images were reconstructed, Axial, sagittal and presence, size and morphologic features of colorectal polypoid lesions, and thor these findings were compared with the colonoscopic findings. The degree of enhancement of colorecralpolypoid lesions was measured by subtracting the attenuation valves obtained with precontrastand postcontrast CT images for the differentiation of benignity and malignancy of the colorectal polypoid lesions. Results. Among 75 colorectal polypoid lesions identified on conventional colonoscopy, 49neoplasms were found on CT coloaographv, and the overall detection rate was 65,3%.Detection rate of lesions smaller than l0mm was 52.1%(24/46), and the detection rate for lesions equal to or larger than 10mm was 86.2%(25/29), Morphologic features of the sessile type lesions on CT colonography were well correlated with those noted on colonoscopy, but the stalks were not identified in 6 of 13 polyps on CT colonography. There was no statistical correlation between benignity and malignancy and the degree of contrast enhancement on CT colonography, Conclusion CT colonography is a useful modality for the detection of colorectal polypoid lesionsequal to or polyps. However, CT colonography cannot differentiate benignity from malignancy.

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Development of Sportainment Realistic Bike Simulator (스포테인먼트 실감 자전거 시뮬레이터 개발)

  • Youn, Jae-Hong;Choi, Hyo-Seung
    • The Journal of the Korea Contents Association
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    • v.14 no.2
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    • pp.10-18
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    • 2014
  • As the standard of living and leisure time of contemporary people is increasing, people who have interest not only in physical health activities but also in mental health activities are increasing. Also, people who have interest in sports activities, which include entertaining factors are gradually increasing. SporTainment is a compound of the words 'Sports' and 'Entertainment' and it possesses the meaning of doing sports and entertainment simultaneously. In addition, in the immersive media technology field, researches, which increase the feeling of existence and immersion through the stimulation of the consumer's emotional feedback technology, have been actively conducted. Such, emotional feedback technologies are based on fun and excitement and are activities, in which learning effects are included such as games, education, national defense etc. In addition, the emotional feedback technology is expanding in applied services, which maximize the feeling of existence and immersion of the consumers by adding reality effects in the virtual environment. In this research, the presence of the user was increased by developing a realistic bike simulation for the use of SporTainment, which combine emotional effects and reappearance devices in the bike simulation.

Numerical assessment of step-by-step integration methods in the paradigm of real-time hybrid testing

  • Verma, Mohit;Rajasankar, J.;Iyer, Nagesh R.
    • Earthquakes and Structures
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    • v.8 no.6
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    • pp.1325-1348
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    • 2015
  • Real-time hybrid testing (RTHT) involves virtual splitting of the structure into two parts: physical substructure that contains the key region of interest which is tested in a laboratory and numerical substructure that contains the remaining part of the structure in the form of a numerical model. This paper numerically assesses four step-by-step integration methods (Central difference method (CDM), Operator splitting method (OSM), Rosenbrock based method (RBM) and CR-integration method (CR)) which are widely used in RTHT. The methods have been assessed in terms of stability and accuracy for various realistic damping ratios of the physical substructure. The stability is assessed in terms of the spectral radii of the amplification matrix while the accuracy in terms of numerical damping and period distortion. In order to evaluate the performance of the methods, five carefully chosen examples have been studied - undamped SDOF, damped SDOF, instantaneous softening, instantaneous hardening and hysteretic system. The performance of the methods is measured in terms of a non-dimensional error index for displacement and velocity. Based on the error indices, it is observed that OSM and RBM are robust and performs fairly well in all the cases. CDM performed well for undamped SDOF system. CR method can be used for the system showing softening behaviour. The error indices indicate that accuracy of OSM is more than other method in case of hysteretic system. The accuracy of the results obtained through time integration methods for different damping ratios of the physical substructure is addressed in the present study. In the presence of a number of integration methods, it is preferable to have criteria for the selection of the time integration scheme. As such criteria are not available presently, this paper attempts to fill this gap by numerically assessing the four commonly used step-by-step methods.

Unidirectional Photo-induced Charge Separation and Thermal Charge Recombination of Cofacially Aligned Donor-Acceptor System Probed by Ultrafast Visible-Pump/Mid-IR-Probe Spectroscopy

  • Kim, Hyeong-Mook;Park, Jaeheung;Noh, Hee Chang;Lim, Manho;Chung, Young Keun;Kang, Youn K.
    • Bulletin of the Korean Chemical Society
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    • v.35 no.2
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    • pp.587-596
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    • 2014
  • A new ${\pi}$-stacked donor-acceptor (D-A) system, [Ru(1-([2,2'-bipyridine]-6-yl-methyl)-3-(2-cyclohexa-2',5'-diene-1,4-dionyl)-1H-imidazole)(2,2':6',2"-terpyridine)]$[PF_6]_2$ (ImQ_T), has been synthesized and characterized. Similar to its precedent, [Ru(6-(2-cyclohexa-2',5'-diene-1,4-dione)-2,2':6',2"-terpyridine)(2,2':6',2"-terpyridine)]$[PF_6]_2$ (TQ_T), this system has a cofacial alignment of terpyridine (tpy) ligand and quinonyl (Q) group, which facilitates an electron transfer through ${\pi}$-stacked manifold. Despite the presence of lowest-energy charge transfer transition from the Ru-based-HOMO-to-Q-based-LUMO (MQCT) predicted by theoretical calculations by using time-dependent density functional theory (TD-DFT), the experimental steady-state absorption spectrum does not exhibit such a band. The selective excitation to the Ru-based occupied orbitals-to-tpy-based virtual orbital MLCT state was thus possible, from which charge separation (CS) reaction occurred. The photo-induced CS and thermal charge recombination (CR) reactions were probed by using ultrafast visible-pump/mid-IR-probe (TrIR) spectroscopic method. Analysis of decay kinetics of Q and $Q^-$ state CO stretching modes as well as aromatic C=C stretching mode of tpy ligand gave time constants of <1 ps for CS, 1-3 ps for CR, and 10-20 ps for vibrational cooling processes. The electron transfer pathway was revealed to be Ru-tpy-Q rather than Ru-bpy-imidazol-Q.

A Study on the Interactive Architecture in Nature Environment

  • Baek, Seung-Man
    • Journal of the Regional Association of Architectural Institute of Korea
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    • v.20 no.6
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    • pp.41-46
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    • 2018
  • The context of innovation in which we evolve today, subtracts us in a spacial reality and virtuality (digital) that aimed less and less to interact with natural processes which could converge to new possible relationships in the world. We constantly live in presence of fluctuations and imperceptible natural energies (wind, solar radiation, etc.) defined by flows, their own physicality, which remains without being virtual, elusive. This study first outlines how these energies already exploited within the framework of production, could be thought as interactive of our habitat's space dimension, as a prolongation of a physical and material environment built by men and for men, giving rise to new social, cultural dynamics, and making natural complexity of our space vivid, comprehensible with new visual and physical clues. In recent days, where lifestyles are changing, architecture no longer needs to limit its scope of creation to only built structures. Based on a deeper understanding of human and through new potential advanced technologies (kinetic system, etc), it is time to fundamentally diagnose what environments or devices contribute to our lives. Architecture becomes ${\ll}interface{\gg}$, step up its fundamental role, and newly defines the sturdy image and tectonics of existing environment, establishing a stance to search for a new typology. In the end, building will show two simultaneous and distinctive connections related to its physical existence: reality in its function and irreductibility, in its ability to forge new dynamic connections with its environment, hybridizing the spatial dimension to a new form of physicality, adaptive and incessantly flexible in the dimension time, becoming a vessel for ever changing contemporary lifestyles.