• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권11호
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• pp.5179-5202
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• 2018

Transmission Control Protocol (TCP) is the most widely used protocol in the cloud data centers today. However, cloud data centers using TCP experience many issues as TCP was designed based on the assumption that it would primarily be used in Wide Area Networks (WANs). One of the major issues with TCP in the cloud data centers is the Incast issue. This issue arises because of the many-to-one communication pattern that commonly exists in the modern cloud data centers. In many-to-one communication pattern, multiple senders simultaneously send data to a single receiver. This causes packet loss at the switch buffer which results in TCP throughput collapse that leads to high Flow Completion Time (FCT). Recently, Software-Defined Networking (SDN) has been used by many researchers to mitigate the Incast issue. In this paper, a detailed survey of various SDN based solutions to the Incast issue is carried out. In this survey, various SDN based solutions are classified into four categories i.e. TCP Receive Window based solutions, Tuning TCP Parameters based solutions, Quick Recovery based solutions and Application Layer based solutions. All the solutions are critically evaluated in terms of their principles, advantages, and shortcomings. Another important feature of this survey is to compare various SDN based solutions with respect to different performance metrics e.g. maximum number of concurrent senders supported, calculation of delay at the controller etc. These performance metrics are important for deployment of any SDN based solution in modern cloud data centers. In addition, future research directions are also discussed in this survey that can be explored to design and develop better SDN based solutions to the Incast issue.

• Structural Engineering and Mechanics
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• 제70권4호
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• pp.479-497
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• 2019

In the current code design, the use of a uniform internal pressure coefficient of cooling towers as internal suction cannot reflect the 3D characteristics of flow field inside the tower body with different ventilation rate of shutters. Moreover, extreme weather such as heavy rain also has a direct impact on aerodynamic force on the internal surface and changes the turbulence effect of pulsating wind. In this study, the world's tallest cooling tower under construction, which stands 210m, is taken as the research object. The algorithm for two-way coupling between wind and rain is adopted. Simulation of wind field and raindrops is performed iteratively using continuous phase and discrete phase models, respectively, under the general principles of computational fluid dynamics (CFD). Firstly, the rule of influence of 9 combinations of wind speed and rainfall intensity on the volume of wind-driven rain, additional action force of raindrops and equivalent internal pressure coefficient of the tower body is analyzed. The combination of wind velocity and rainfall intensity that is most unfavorable to the cooling tower in terms of distribution of internal pressure coefficient is identified. On this basis, the wind/rain loads, distribution of aerodynamic force and working mechanism of internal pressures of the cooling tower under the most unfavorable working condition are compared between the four ventilation rates of shutters (0%, 15%, 30% and 100%). The results show that the amount of raindrops captured by the internal surface of the tower decreases as the wind velocity increases, and increases along with the rainfall intensity and ventilation rate of the shutters. The maximum value of rain-induced pressure coefficient is 0.013. The research findings lay the basis for determining the precise values of internal surface loads of cooling tower under extreme weather conditions.

• Korean journal of medical education
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• 제30권4호
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• pp.295-308
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• 2018

Purpose: Although medical curricula are now better structured for integration of biomedical sciences and clinical training, most teaching and learning activities still follow the older teacher-centric discipline-specific formats. A newer pedagogical approach, known as Collaborative Learning Cases (CLCs), was adopted in the medical school to facilitate integration and collaborative learning. Before incorporating CLCs into the curriculum of year 1 students, two pilot runs using the action research method was carried out to improve the design of CLCs. Methods: We employed the four-phase Kemmis and McTaggart's action research spiral in two cycles to improve the design of CLCs. A class of 300 first-year medical students (for both cycles), 11 tutors (first cycle), and 16 tutors (second cycle) were involved in this research. Data was collected using the 5-points Likert scale survey, open-ended questionnaire, and observation. Results: From the data collected, we learned that more effort was required to train the tutors to understand the principles of CLCs and their role in the CLCs sessions. Although action research enables the faculty to improve the design of CLCs, finding the right technology tools to support collaboration and enhance learning during the CLCs remains a challenge. Conclusion: The two cycles of action research was effective in helping us design a better learning environment during the CLCs by clarifying tutors' roles, improving group and time management, and meaningful use of technology.

• 보존과학회지
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• 제37권4호
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• pp.362-369
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• 2021

In museums, exhibition content focuses mostly on cultural heritage's historical values and functions, but doing so tends to limit visitors' interest and immersion. To counter this limitation, the study developed an experiential media art exhibition fusing bronze mirrors' traditional production technology and modern conservation science. First, for the exhibition system, scientific cultural heritage contents were projected on the three-dimensional (3D) printed bronze mirror through interactions between motion recognition digital information display (DID) and the projector. Then, a scenario of 17 missions in four stages (production process, corrosion mechanism, scientific analysis and diagnosis, and conservation treatment and restoration) was prepared according to the temporal spectrum. Additionally, various media art effects and interaction technologies were developed, so visitors could understand and become immersed in bronze mirrors' scientific content. A user test was evaluated through the living lab, reflecting generally high levels of satisfaction (90.2 points). Qualitative evaluation was generally positive, with comments such as "easy to understand and useful as the esoteric science exhibition was combined with media art" (16.7%), "wonderful and interesting" (11.7%), and "firsthand experience was good" (9.2%). By combining an esoteric science exhibition centered on principles and theories with visual media art and by developing an immersive directing method to provide high-level exhibition technology, the exhibition induced visitors' active participation. This exhibition's content can become an important platform for expanding universal museum exhibitions on archaeology, history, and art into conservation science.

• 한국환경복원기술학회지
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• 제22권5호
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• pp.13-25
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• 2019

The Baekdudaegan protected area is a regulatory-oriented policy that does not consider the residents, and has been affected by the shrinking of local economy and the reduction of community activities. In order to minimize the damages, Baekdudaegan resident support programs has been implemented but various problems have been pointed out failing to lead to local revitalization. In addition, the zoning districts consists only of the core district and buffer district, which makes it more difficult to improve the lives and satisfy the needs of residents due to the stricter regulations. This study suggests the revitalization of Baekdu-daegan protected area by reforming the zoning system of Baekdu-daegan protected area. Considering related plans and systems, legal validity, residents' repulsion, area, etc., four reorganization plans were drawn according to each strength and weakness. Principles, additional permissible activities, example of amendment to 'Baekdudaegan Protection Act' according to each plan were also presented. The results of this study can contribute to the improvement of income and welfare of the residents in Baekdudaegan protected area. However, further research is needed because it is a limitation that the specific scope of the proposed plans could not be set.

• 한국중재학회지:중재연구
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• 제32권2호
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• pp.135-157
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• 2022

Religion has a very close relationship with our everyday lives. In particular, religion maintains an absolute and ultimate value system and is deeply associated with all sectors of society such as politics, economy, thought, arts, culture, and science. The original meaning of religion in Buddhism means the teachings that become fundamentals. There are numerous religions around the world, and each religion has its own object of faith, different system, and unique rites and lifestyles. Therefore, evaluating or denouncing other regions based on the doctrines or conventions of a specific religion can lead to conflicts and disputes. The Buddhist Vinaya Pitaka related to alternative dispute resolution (ADR) is a method regarding the operation of a community. Vinaya Pitaka contains Buddha's teachings about individual and organizational ethics and on community life and activities. It is the Buddhist dispute resolution (BDR) of the Vinayata Pitaka that contains knowledge on howto remedy disputes among the four types of disputes that can occur. Vinaya Pitaka contains the principles and systems of BDR, and it is sufficient background for succeeding in the development of harmony today. The messages of laws, ethics, and Buddhist teachings are clear in these characteristics. The systems, progress, and procedures for various rites, events, and disputes as well as for everyday life, etc. display a rational operating system through karma. In particular, when disputes occur, the cause of the dispute is resolved as much as possible through transparent fairness and being unanimous using the seven remedies for disputes. Buddhist priests pursue private autonomy of ADR through karma, repentance, acceptance, etc. to maintain and continue the integrated functions of Buddhist priest harmony.

• 대한한의학원전학회지
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• 제34권2호
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• pp.45-62
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• 2021

Objectives : To study the characteristics and meaning of the division pharmaceutical method in the Donguibogam through analysis of formulas that apply such method. Methods : Each formula applying the division method within the Donguibogam was analyzed Results & Conclusions : In the Donguibogam, medicinals to which the division pharmaceutical method was applied were baizhu[白朮], cangzhu[蒼朮], zhiqiao[枳殼], wuzhuyu[吳茱萸], xiangfuzi[香附子], chuanlianzi[川練子], huangbo[黃柏], etc. Formulas where this method was used were few, while the four methods that were used, together with the Center represents the principle of the five phases. The formulas that applied the division method usually did not adopt the tablet or decoction form, which means they were meant to treat slowly, treating deficiency or stagnation diseases due to problems in the middle-lower body such as the Spleen, Liver and Kidney. It could be said that compared to other more common formulas, this was a unique method. The division pharmaceutical method allows for usage of a wider variety of processing methods compared to single ingredient formulas, while there is lower chance of interference among the different types of processing. Another benefit is that the properties of the main medicinal ingredient could be preserved as much as possible. In addition, the division method allows for the main ingredient and the processed ingredient to interact exclusively, after which the processed medicinal is eliminated leaving only the main ingredient. This allows for maximum improvement of the main ingredient. The division method includes the principles of formula composition as well, whose concept could be positioned between single ingredient formulas and common formulas.

• Acta Via Serica
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• 제7권2호
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• pp.109-132
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• 2022

Two of the main elements of Persian tangible heritage are rugs and gardens, which have evolved together from the dawn of Iranian history. Emerging from the same system of thought and geographical location, together they represent the Persians' world views, desires, dreams, and design paradigms. In this study, the Persian Garden's patterns, elements, typology, and meanings are introduced and compared with the same aspects of Persian rugs. This paper uses a qualitative comparative methodology to analyze rugs' designs and patterns in relation to Persian Gardens' design principles. Data is collected primarily through library study and observation. The author uses two categories for comparison: meanings and forms. First, the author identifies underlying meanings common to the two art forms and then introduces form, function, and general principal patterns into the analysis. There is a type of rug pattern, known as Chahar-Bagh (literally, "four gardens"), that mirrors a garden design, down to the details, which is the focus of this paper. Additionally, other representations of Persian Gardens in rug design, such as Shekargah ("hunting pattern"), are discussed, as are other rug patterns with fewer elements borrowed from garden design. The paper also considers several motifs that represent flora common in gardening on the Iranian plateau, some of which have symbolic meanings dating to the Zoroastrian era. By comparing these two mediums of art (garden and rug) in the context of Persian history and geography, it becomes clear that the Persian rug design, in its roots, is an attempt to bring a garden into interior space. The study shows that the forms, patterns, and meanings reflected in Persian rugs render the study of their designs incomplete without considering the history of gardens.

• 비교교육연구
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• 제19권2호
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• pp.147-173
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• 2009

이 연구는 개방형 공립학교 모델로서 프랑스의 프레네 학교에 대한 운영 철학, 운영 내용과 특징, 교육실천 사례, 우리나라 공교육 개혁에의 시사점을 다루고자 하였다. 프레네 학교는 프랑스의 교육실천가 셀레스탱 프레네(Célestin Freinet, 1896~1966)의 교육철학에 근거하고 있다. 연구자는 프레네 학교가 우리나라 공립학교의 변화와 개혁에 어떠한 영향을 줄 수 있는지 살펴보고자 하였으며 시사점은 다음과 같다. 첫째, 학생 자치회 운영을 통해 민주적인 의사결정에 기초한 개방형 공립학교를 구축할 수 있을 것이다. 둘째, 다양한 교육방법과 기술을 토대로 학생의 욕구를 반영한 프레네 교수학습 모형을 개발할 수 있을 것이다. 셋째, 프레네 학교에서는 교사협력팀을 구성하여 교육과정의 탄력적 운영을 통해 교과의 통합적 공동 운영을 실시할 수 있을 것이다. 이는 우선적으로 학급 또는 학년 간의 개방을 전제로 한다. 넷째, 프레네 교사들의 다양한 교재 개발 노력은 교과서 중심의 수업을 벗어나 여러 매체와 자료를 활용하는 수업 실천사례를 공유하여 교실수업의 질 개선에 기여할 수 있을 것으로 보인다.

• 한국치위생학회지
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• 제22권6호
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• pp.467-475
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• 2022

Objectives: This study aimed to understand the definitions, types, and principles of computer-aided design/computer-aided manufacturing (CAD/CAM) and scanners due to the introduction of digital workflows. Methods: This study was based on information from the government's law and articles published in academic journals. Results: CAD/CAM is a technology that measures the shape three-dimensionally, saves it as data, designs it into the desired shape, and processes the product. Scanners, which are classified as intraoral and extraoral scanners, measure teeth and the intraoral environment three-dimensionally and convert them into three-dimensional (3D). A 3D printer is a machine that creates a 3D object by layering materials based on a 3D drawing. It can be classified into four types according to the method: extrusion, powder bonding, lamination, and photopolymerization methods. The most used 3D printer methods in dentistry are stereolithograhpy and digital light processing, and they are widely used in prosthetic, surgical, and orthodontic fields. Conclusions: As the dental system is digitized, it is expected that the government will classify the dental hygienist scope of work and the universities will reflect the curriculum; it is necessary to develop excellent dental hygienists, diversify the educational pathways, and establish policies to meet the needs of the increasing number of patients.