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ROC Analysis of Visual Assessments Made in Gated Blood Pool Scans of Patients with Coronary Artery Disease (관상동맥질환에서 심장풀 스캔의 육안적 평가에 대한 ROC 분석)

  • Lee, Kyun-Han;Choi, Yoon-Ho;Lee, Bum-Woo;Moon, Dae-Hyuk;Koong, Sung-Soo;Chung, June-Key;Lee, Myung-Chul;Koh, Chang-Soon
    • The Korean Journal of Nuclear Medicine
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    • v.23 no.2
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    • pp.175-181
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    • 1989
  • Visual assessment of regional wall motion abnormality (RWMA) by gated blood pol scan (GBPS) serves as an useful parameter in the diagnosis, functional evaluation, and follow up in various clinical settings, but are still subject to some inherent limitations. On important problem may be the interobserver as well as intraobsever variation that may well be present due to the subjective nature of the interpretations. This study was carried out to determine the reliability and reproducibility of visual assessments made in GBPSs, and to observe the degree to which the results would be influenced by observer variation. Fifty two patients with coronary heart disease had resting GBPS and contrast ventriculography within 4 days appall. Contrast ventriculography-showed normal wall motion in 6 patients and the remaining 46 had RWMA in one or more segments. The anterior and left anterolateral views of all 52 GBPSs were analyzed by three independent observers, who selected from 5 scales, their level of confidence that there was RWMA in that segment. Reciever operating characteristic (ROC) curves for each analysis was plotted and the area under the curve $(\theta)$ was used as a parameter representing each observer's performance in his interpretations. The findings of contrast ventriculographies were used as the standard for RWMA. The apical and inferoapical segments showed the best correlation with contrast ventriculography ($\theta=0.90-0.94$, 0.81-0.94, respectively), and the inferior wall showed the poorest correlation $(\theta=0.70-0.74)$. The interpretations of the inferior, septal, apical, and posteroinferior, segments showed no difference between the observers, but there was significantly better performance in assessment by observer A compared to that by B or C for the anterolateral segments ($\theta=0.87$, 0.78, 0.76, respectively. p<0.01 for A vs B, p<0.05 for A vs C), as well as when all segments were considered altogether ($\theta=0.88$, 0.83, 0.82, respectively. both p<0.05). This was also true for the infero-apical segment between A and C ($\theta=0.09$, 0.81, p<0.05). The intraobserver variation, however, did not appear significant, with only the inferior segment for observer B showing any significant difference when observer A and B repeated the analysis 10 days latter. There was no difference in assessing dyskinesia, with all observers showing a high performance ($\theta=0.98$, 0.87, 0.97, respectively). The visual assessment of left ventricular ejection fraction by all three observers correlated well with the calculated value from a semiautomated method (Spearman's r = 0.91, 0.83, 0.83. p<0.01, p<0.05, p < 0.05). The assessment of LV and RV size also correlated well between the three observers (Kendall's w = 0.80, 0.51, p<0.01 for both left and right ventricles). The above findings suggest that RWMA visually assessed by GBPS correlates well with that done by contrast ventriculography. And although the observer's experience or skill may influence the results in certain segments, visual analysis of GBPS may serve as a reliable and reproducible means for evaluating ventricular function.

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CEO's Political Independence, Board Chair Separation, Executive's Expertise, and Performance in State-Owned Enterprises (공기업 CEO의 정치적 독립성, 이사회 의장 분리, 임원의 전문성과 성과)

  • Yu, Seungwon
    • KDI Journal of Economic Policy
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    • v.35 no.2
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    • pp.1-39
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    • 2013
  • Considering the relationship between state-owned enterprise (SOE) CEOs and political circles, this study examines the performance impacts of CEO's succession type, board chair separation, and industry expertise and finance expertise of CEOs and outside directors. I propose the definition of political independence in SOE CEOs based on the independence in appearance that might affect general people's perception. It means that there are no relationships or circumstances that might affect SOE CEO's judgment, activity, and report. The definition is able to overcome the limitations of the prior research that could not discover the CEOs who were affiliated to political circles because the research just distinguished the CEOs following their pre-jobs. This study focused on the performance impacts of political independence impaired CEO as well as the CEO's impacts on the relationship between the performance and other corporate governance variables. I selected as dependent variables the average return on asset as operating income divided by total assets and the average customer satisfaction rate evaluated by Korean government during the first three years following the year of the events of explanatory variables. My theory and evidence from the various CEO's personal background and financial information from SOEs in Lee Myung-bak Administration and Rho Moo-hyun Administration suggest the following important things. First, the analysis based on whether or not a SOE CEO keeps political independence shows that a political independence impaired CEO made a significantly negative impact on customer satisfaction rate. Second, the separation between a board chair and a CEO in SOEs introduced by Korean Act on Management of Public Institutions made a significantly positive impact on customer satisfaction rate. However, the positive impact of the board chair separation was removed in a political independence impaired CEO's SOE. Third, outside director's industry expertise made a significantly positive impact on return on asset. However, the positive impact of the outside director's industry expertise was removed in a political independence impaired CEO's SOE. Fourth, the comparison between Lee Myung-bak Administration and Roh Moo-hyun Administration on the corporate governance and performance of SOEs shows that the ratio of political independence impaired CEO was significantly higher in Lee Administration and the ratio of outside director's industry expertise and finance expertise were respectively significantly higher in Roh Administration. Based on these results, I suggested a few policy alternatives for CEO's improved political independence and requirements for executive's expertise in SOEs.

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Status of Brain-based Artistic Education Fusion Study - Basic Study for Animation Drawing Education (뇌기반 예술교육 융합연구의 현황 - 애니메이션 드로잉 교육을 위한 기초연구)

  • Lee, Sun Ju;Park, Sung Won
    • Cartoon and Animation Studies
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    • s.36
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    • pp.237-257
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    • 2014
  • This study is the process of performing the interdisciplinary fusion study between multiple fields by identifying the status on the previous artistic education considering the brain scientific mechanism of image creativity and brain-based learning principles. In recent years, producing the educational methods of each field as the fusion study activities are emerging as the trend and thanks to such, the results of brain-based educational fusion studies are being presented for each field. It includes artistic fields such as music, art and dance. In other words, the perspective is that by understanding the operating principles of the brain while creativity and learning is taking place, when applying various principles that can develop the corresponding functions as a teaching method, it can effectively increase the artistic performance ability and creativity. Since the animation drawing should be able to intuitively recognize the elements of movement and produce the communication with the target beyond the delineative perspective of simply drawing the objects to look the same, it requires the development of systematic educational method including the methods of communication, elements of higher cognitive senses as well as the cognitive perspective of form implementation. Therefore, this study proposes a literature study results on the artistic education applied with brain-based principles in order to design the educational model considering the professional characteristics of animation drawing. Therefore, the overseas and domestic trends of the cases of brain-based artistic education were extracted and analyzed. In addition, the cases of artistic education studies applied with brain-based principles and study results from cases of drawing related education were analyzed. According to the analyzed results, the brain-based learning related to the drawing has shown a common effect of promoting the creativity and changes of positive emotion related to the observation, concentration and image expression through the training of the right brain. In addition, there was a case of overseas educational application through the brain wave training where the timing ability and artistic expression have shown an enhancement effect through the HRV training, SMR, Beta 1 and neuro feedback training that strengthens the alpha/seta wave and it was proposing that slow brain wave neuro feedback training contributes significantly in overcoming the stress and enhancing the creative artistic performance ability. The meaning of this study result is significant in the fact that it was the case that have shown the successful application of neuro feedback training in the environment of artistic live education beyond the range of laboratory but the use of the machine was shown to have limitations for being applied to the teaching methods so its significance can be found in providing the analytical foundation for applying and designing the brain-based learning principles for future animation drawing teaching methods.

The Distribution and Characteristics of Use of Urban Farms - A Case Study of the Siji Region in Daegu Metropolitan City - (도시텃밭의 분포 및 이용 특성 - 대구광역시 시지지역을 사례로 -)

  • Nam, Tae-Ho;Jung, Tae-Yeol
    • Journal of the Korean Institute of Landscape Architecture
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    • v.42 no.6
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    • pp.1-9
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    • 2014
  • Within the urban area, over the past decades unused land and public land such as streams and road sides have given urban residents a space for farming (urban farms). However, because this use is illegal, farming in unused and public lands could cause conflicts between urban farm users and land owners, degrade the quality of the urban landscape and contaminate the environment. Therefore, the purpose of this study is to provide a way of legalizing these farming practices that have been cultivated in unused urban areas and public lands. This study analyzed the status of distribution and use of the urban farms that have been scattered around urban areas in many different forms. The survey was conducted through on-the-spot investigation and in-person interviews with farm users and those who were operating weekend farms in the Siji region of Daegu Metropolitan City. According to the results of this study, urban farms were mainly found in green areas that were easily accessible from residential districts and prohibited from development. It was also revealed that the nearer to the border of the residential districts the sites of urban farms were, the larger the number of urban farms was. When it comes to the type of land use, although the proportion of urban farms located in farmlands was very high, the proportion of those located on state-owned lands such as roads, railroads and streams was also high, over 1/3 of that of the former sites. Among the users of urban farms, the percentage of users who were farming private-owned land for free was highest and that of state-owned land without permission ranked second. Most people who were farming unused lands or state-owned lands without permission, such as streams, roads, railroads, were the elderly. This shows the potential of farms in urban area as leisure activities spaces for the elderly. Even though this study has limitations in that the survey target area was selected in a certain area and the sizes of all urban farms were not measured by surveying apparatus and instruments, it helps to determine the characteristics of use and distribution associated with the spaces of urban farming, and to raise the importance and necessity of legalizing urban farms cultivated illegally in public land.

The Development of Education Model for CA-RP(Cognitive Apprenticeship-Based Research Paper) to Improve the Research Capabilities for Majors Students of Radiological Technology (방사선 전공학생의 연구역량 증진을 위한 인지적 도제기반 논문작성 교육 모형 개발)

  • Park, Hoon-Hee;Chung, Hyun-Suk;Lee, Yun-Hee;Kim, Hyun-Soo;Kang, Byung-Sam;Son, Jin-Hyun;Min, Jung-Hwan;Lyu, Kwang-Yeul
    • Journal of radiological science and technology
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    • v.36 no.2
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    • pp.99-110
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    • 2013
  • In the medical field, the necessity of education growth for the professional Radiation Technologists has been emphasized to become experts on radiation and the radiation field is important of the society. Also, in hospitals and companies, important on thesis is getting higher in order to active and cope with rapidly changing internal and external environment and a more in-depth expert training, the necessity of new teaching and learning model that can cope with changes in a more proactive has become. Thesis writing classes brought limits to the in-depth learning as to start a semester and rely on only specific programs besides, inevitable on passive participation. In addition, it does not have a variety opportunity to present, an actual opportunity that can be written and discussed does not provide much caused by instructor-led classes. As well as, it has had a direct impact on the quality of the thesis, furthermore, having the opportunity to participate in various conferences showed the limitations. In order to solve these problems, in this study, writing thesis has organized training operations as a consistent gradual deepening of learning, at the same time, the operational idea was proposed based on the connectivity integrated operating and effective training program & instructional tool for improving the ability to perform the written actual thesis. The development of teaching and learning model consisted of 4 system modeling, scaffolding, articulation, exploration. Depending on the nature of the course, consisting team following the personal interest and the topic allow for connection subject, based on this, promote research capacity through a step-by-step evaluation and feedback and, fundamentally strengthen problem-solving skills through the journal studies, help not only solving the real-time problem by taking wiki-space but also efficient use of time, increase the quality of the thesis by activating cooperation through mentoring, as a result, it was to promote a positive partnership with the academic. Support system in three stages planning subject, progress & writing, writing thesis & presentation and based on cognitive apprenticeship. The ongoing Coaching and Reflection of professor and expert was applied in order to maintain these activities smoothly. The results of this study will introduce actively, voluntarily and substantially join to learners, by doing so, culture the enhancement of creativity, originality and the ability to co-work and by enhance the expertise of based-knowledge, it is considered to be help to improve the comprehensive ability.

A Study of a Non-commercial 3D Planning System, Plunc for Clinical Applicability (비 상업용 3차원 치료계획시스템인 Plunc의 임상적용 가능성에 대한 연구)

  • Cho, Byung-Chul;Oh, Do-Hoon;Bae, Hoon-Sik
    • Radiation Oncology Journal
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    • v.16 no.1
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    • pp.71-79
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    • 1998
  • Purpose : The objective of this study is to introduce our installation of a non-commercial 3D Planning system, Plunc and confirm it's clinical applicability in various treatment situations. Materials and Methods : We obtained source codes of Plunc, offered by University of North Carolina and installed them on a Pentium Pro 200MHz (128MB RAM, Millenium VGA) with Linux operating system. To examine accuracy of dose distributions calculated by Plunc, we input beam data of 6MV Photon of our linear accelerator(Siemens MXE 6740) including tissue-maximum ratio, scatter-maximum ratio, attenuation coefficients and shapes of wedge filters. After then, we compared values of dose distributions(Percent depth dose; PDD, dose profiles with and without wedge filters, oblique incident beam, and dose distributions under air-gap) calculated by Plunc with measured values. Results : Plunc operated in almost real time except spending about 10 seconds in full volume dose distribution and dose-volume histogram(DVH) on the PC described above. As compared with measurements for irradiations of 90-cm 550 and 10-cm depth isocenter, the PDD curves calculated by Plunc did not exceed $1\%$ of inaccuracies except buildup region. For dose profiles with and without wedge filter, the calculated ones are accurate within $2\%$ except low-dose region outside irradiations where Plunc showed $5\%$ of dose reduction. For the oblique incident beam, it showed a good agreement except low dose region below $30\%$ of isocenter dose. In the case of dose distribution under air-gap, there was $5\%$ errors of the central-axis dose. Conclusion : By comparing photon dose calculations using the Plunc with measurements, we confirmed that Plunc showed acceptable accuracies about $2-5\%$ in typical treatment situations which was comparable to commercial planning systems using correction-based a1gorithms. Plunc does not have a function for electron beam planning up to the present. However, it is possible to implement electron dose calculation modules or more accurate photon dose calculation into the Plunc system. Plunc is shown to be useful to clear many limitations of 2D planning systems in clinics where a commercial 3D planning system is not available.

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The Definition and Regulations of Drone in Korea (韓国におけるドロ?ンの定義と法規制)

  • Kim, Young-Ju
    • The Korean Journal of Air & Space Law and Policy
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    • v.34 no.1
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    • pp.235-268
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    • 2019
  • Under the Aviation Safety Act of Korea, any person who intends to operate a drone is required to follow the operational conditions listed below, unless approved by the Minister of Land, Infrastructure, Transport and Tourism; (i) Operation of drones in the daytime, (ii) Operation of drones within Visual Line of Sight, (iii) Maintenance of a certain operating distance between drones and persons or properties on the ground/ water surface, (iv) Do not operate drones over event sites where many people gather, (v) Do not transport hazardous materials such as explosives by drone, (vi) Do not drop any objects from drones. Requirements stated in "Airspace in which Flights are Prohibited" and "Operational Limitations" are not applied to flights for search and rescue operations by public organizations in case of accidents and disasters. This paper analyzes legal issues as to definition and regulations of drones in Korean Aviation Safety Act. This paper, also, offers some implications and suggestions for regulations of drones under Korean Aviation Safety Act by comparing the regulations of drones in Japanese Civil Aeronautics Act.

A Study of the Application of 'Digital Heritage ODA' - Focusing on the Myanmar cultural heritage management system - (디지털 문화유산 ODA 적용에 관한 시론적 연구 -미얀마 문화유산 관리시스템을 중심으로-)

  • Jeong, Seongmi
    • Korean Journal of Heritage: History & Science
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    • v.53 no.4
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    • pp.198-215
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    • 2020
  • Official development assistance refers to assistance provided by governments and other public institutions in donor countries, aimed at promoting economic development and social welfare in developing countries. The purpose of this research is to examine the construction process of the "Myanmar Cultural Heritage Management System" that is underway as part of the ODA project to strengthen cultural and artistic capabilities and analyze the achievements and challenges of the Digital Cultural Heritage ODA. The digital cultural heritage management system is intended to achieve the permanent preservation and sustainable utilization of tangible and intangible cultural heritage materials. Cultural heritage can be stored in digital archives, newly approached using computer analysis technology, and information can be used in multiple dimensions. First, the Digital Cultural Heritage ODA was able to permanently preserve cultural heritage content that urgently needed digitalization by overcoming and documenting the "risk" associated with cultural heritage under threat of being extinguished, damaged, degraded, or distorted in Myanmar. Second, information on Myanmar's cultural heritage can be systematically managed and used in many ways through linkages between materials. Third, cultural maps can be implemented that are based on accurate geographical location information as to where cultural heritage is located or inherited. Various items of cultural heritage were collectively and intensively visualized to maximize utility and convenience for academic, policy, and practical purposes. Fourth, we were able to overcome the one-sided limitations of cultural ODA in relations between donor and recipient countries. Fifth, the capacity building program run by officials in charge of the beneficiary country, which could be the most important form of sustainable development in the cultural ODA, was operated together. Sixth, there is an implication that it is an ODA that can be relatively smooth and non-face-to-face in nature, without requiring the movement of manpower between countries during the current global pandemic. However, the following tasks remain to be solved through active discussion and deliberation in the future. First, the content of the data uploaded to the system should be verified. Second, to preserve digital cultural heritage, it must be protected from various threats. For example, it is necessary to train local experts to prepare for errors caused by computer viruses, stored data, or operating systems. Third, due to the nature of the rapidly changing environment of computer technology, measures should also be discussed to address the problems that tend to follow when new versions and programs are developed after the end of the ODA project, or when developers have not continued to manage their programs. Fourth, since the classification system criteria and decisions regarding whether the data will be disclosed or not are set according to Myanmar's political judgment, it is necessary to let the beneficiary country understand the ultimate purpose of the cultural ODA project.

Comparative Analysis of Entrepreneurship Education and Entrepreneurship Programs in American Universities: Focusing on Major Entrepreneurship Centers in 7 Universities in the United States (미국 대학의 창업교육 및 창업프로그램 비교분석: 미국 7개 대학 주요 기업가정신센터를 중심으로)

  • Lee, Sung Ho;Nam, Jung Min
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.15 no.6
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    • pp.67-79
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    • 2020
  • This study analyzed the start-up education curriculum and start-up education programs of seven universities in the U.S. to find out what courses are provided, what various programs exist, and what the characteristics of start-up education in each university are. California State University, San Bernardino / University of California, Irvine / Drexel University / Oklahoma State University / Florida State University / San Diego State University / University of Southern California where entrepreneurship education based on the Entrepreneurship Degree Course is being established based on the Entrepreneurship Center of seven universities in the United States, which is not well introduced in Korea. This study examined how the start-up education courses and start-up support systems at seven universities in the U.S. are progressing at the undergraduate, MBA, master's and doctoral levels, and comparative levels. Through the case studies of the universities presented, the primary analysis was carried out to explore the various characteristics of American university start-up education. The implications of start-up education at American universities in this study are as follows. First, in order for universities to take the initiative in providing start-up education, they should be organized to suit the course of start-up education suitable for the characteristics of universities and introduce support programs. Second, it is necessary to establish an independent center within domestic universities to be operated autonomously. Third, the start-up education of universities should include building university-industry partnerships, operating entrepreneurship degree courses and collaboration between departments of universities. Fourth, the independent center should lead the active participation of alumni and local start-ups and start-up-related programs should be operated based on this. Fifth, Differentiated programs for each university's characteristics should be introduced and applied to universities. Although case studies have limitations that cannot be generalized, they can provide a useful framework. Therefore, it is necessary to design a systematic start-up education that reflects the correct design direction and characteristics of each university.

Development of Electret to Improve Output and Stability of Triboelectric Nanogenerator (마찰대전 나노발전기의 출력 및 안정성 향상을 위한 일렉트렛 개발)

  • Kam, Dongik;Jang, Sunmin;Yun, Yeongcheol;Bae, Hongeun;Lee, Youngjin;Ra, Yoonsang;Cho, Sumin;Seo, Kyoung Duck;Cha, Kyoung Je;Choi, Dongwhi
    • Korean Chemical Engineering Research
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    • v.60 no.1
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    • pp.93-99
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    • 2022
  • With the rapid development of ultra-small and wearable device technology, continuous electricity supply without spatiotemporal limitations for driving electronic devices is required. Accordingly, Triboelectric nanogenerator (TENG), which utilizes static electricity generated by the contact and separation of two different materials, is being used as a means of effectively harvesting various types of energy dispersed without complex processes and designs due to its simple principle. However, to apply the TENG to real life, it is necessary to increase the electrical output. In addition, stable generation of electrical output, as well as increase in electrical output, is a task to be solved for the commercialization of TENG. In this study, we proposed a method to not only improve the output of TENG but also to stably represent the improved output. This was solved by using the contact layer, which is one of the components of TENG, as an electret for improved output and stability. The utilized electret was manufactured by sequentially performing corona charging-thermal annealing-corona charging on the Fluorinated ethylene propylene (FEP) film. Electric charges artificially injected due to corona charging enter a deep trap through the thermal annealing, so an electret that minimizes charge escape was fabricated and used in TENG. The output performance of the manufactured electret was verified by measuring the voltage output of the TENG in vertical contact separation mode, and the electret treated to the corona charging showed an output voltage 12 times higher than that of the pristine FEP film. The time and humidity stability of the electret was confirmed by measuring the output voltage of the TENG after exposing the electret to a general external environment and extreme humidity environment. In addition, it was shown that it can be applied to real-life by operating the LED by applying an electret to the clap-TENG with the motif of clap.