• Title/Summary/Keyword: horizontal connection

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Curating the Korean Medical Classics Curriculum with a Focus on Its Introductory Role to Clinical Korean Medicine (임상한의학입문 역할을 반영한 원전학 수업 설계)

  • Jo, Na-young;Jo, Hak-jun
    • Journal of Korean Medical classics
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    • v.34 no.2
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    • pp.1-22
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    • 2021
  • Objectives : A transition course of 'Introduction to Clinical Korean Medicine' was developed to meet the demands for better preparation for clinical application of Korean Medicine within the curriculum. A Korean Medical Classics curriculum reflecting such demands was newly designed. Methods : Based on the 'Introduction to Clinical Medicine(ICM)' course of the Medical School curriculum that follows the medical education guideline, the 'Introduction to Clinical Korean Medicine(ICKM)' course was designed and developed. The role of Korean Medical Classics was suggested in the process. Results : In the following course, Korean Medical diagnosis, diagnostics, patient intake methods reflecting the Korean Medical diagnostic system, clinical skills, basic skills, treatment planning, patient education, etc. are included. Faculty members of the basic sectors of the Korean Medical school will participate in this curriculum, of which a head will be appointed to overlook the curriculum. In the case of Korean Medical Classics, previous learning outcomes need to be reorganized based on clinical expression while clinical case studies need to be added to course material. A more active approach utilizing new pedagogic strategies and teaching methods should be taken. Conclusions : The Korean Medical Classics curriculum could effectively take on the introductory role to clinical Korean Medicine, successfully strengthening the connection between the basic and clinical Korean Medicine to improve learners' satisfaction.

Progressive Collapse of Steel High-Rise Buildings Exposed to Fire: Current State of Research

  • Jiang, Jian;Li, Guo-Qiang
    • International Journal of High-Rise Buildings
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    • v.7 no.4
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    • pp.375-387
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    • 2018
  • This paper presents a review on progressive collapse mechanism of steel framed buildings exposed to fire. The influence of load ratios, strength of structural members (beam, column, slab, connection), fire scenarios, bracing systems, fire protections on the collapse mode and collapse time of structures is comprehensively reviewed. It is found that the key influencing factors include load ratio, fire scenario, bracing layout and fire protection. The application of strong beams, high load ratios, multi-compartment fires will lead to global downward collapse which is undesirable. The catenary action in beams and tensile membrane action in slabs contribute to the enhancement of structural collapse resistance, leading to a ductile collapse mechanism. It is recommended to increase the reinforcement ratio in the sagging and hogging region of slabs to not only enhance the tensile membrane action in the slab, but to prevent the failure of beam-to-column connections. It is also found that a frame may collapse in the cooling phase of compartment fires or under travelling fires. This is because that the steel members may experience maximum temperatures and maximum displacements under these two fire scenarios. An edge bay fire is more prone to induce the collapse of structures than a central bay fire. The progressive collapse of buildings can be effectively prevented by using bracing systems and fire protections. A combination of horizontal and vertical bracing systems as well as increasing the strength and stiffness of bracing members is recommended to enhance the collapse resistance. A protected frame dose not collapse immediately after the local failure but experiences a relatively long withstanding period of at least 60 mins. It is suggested to use three-dimensional models for accurate predictions of whether, when and how a structure collapses under various fire scenarios.

Erection Capability of Heavy Precast Frames with Metal Plates using Wet Concrete for Tolerance (톨러런스기반 플레이트 접합 장치를 사용한 고중량 RC보의 설치 성능)

  • Hong, Won-Kee;Nguyen, Van Tien;Nguyen, Manh Cuong;Nkundimana, Eric
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.05a
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    • pp.12-13
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    • 2021
  • Methods for the manufacture, erection, and assembly of heavy frame modules were proposed. Interferences among precast members were prevented by using bolted metal plates for dry precast beam-to-column joints during assembly with a clearance for tolerance implementing grouted concrete filler plates instead of metal filler plates. Clearances for tolerances were provided to avoid conflictions among components during erection phases. These gaps were, then, grouted by high-strength mortar. The constructability of new connections of a beam-to-column joint using bolted metal plates for precast structures was examined using a full-scale assembly test in which practical observations indicated that members could be aligned and placed accurately in both horizontal and vertical directions, leading to a fast and convenient assembling. Bolt holes of the endplate were properly aligned using couplers with 30 mm fastened length embedded in the columns. The assembly test demonstrated the erection safety and structural stability of the proposed joints that were without filler plates when they were subjected to heavy loads at the time of their erection. The facile and rapid assembly of precast beam-to-column connections with a 30 mm tolerance was observed. The proposed assembly method is rapid, sustainable, and resilient, replacing the conventional methods of concrete frame construction, offering a connection that can be used in constructing infrastructure, such as buildings and pipe-rack frames.

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3D Printing in Modular Construction: Opportunities and Challenges

  • Li, Mingkai;Li, Dezhi;Zhang, Jiansong;Cheng, Jack C.P.;Gan, Vincent J.L.
    • International conference on construction engineering and project management
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    • 2020.12a
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    • pp.75-84
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    • 2020
  • Modular construction is a construction method whereby prefabricated volumetric units are produced in a factory and are installed on site to form a building block. The construction productivity can be substantially improved by the manufacturing and assembly of standardized modular units. 3D printing is a computer-controlled fabrication method first adopted in the manufacturing industry and was utilized for the automated construction of small-scale houses in recent years. Implementing 3D printing in the fabrication of modular units brings huge benefits to modular construction, including increased customization, lower material waste, and reduced labor work. Such implementation also benefits the large-scale and wider adoption of 3D printing in engineering practice. However, a critical issue for 3D printed modules is the loading capacity, particularly in response to horizontal forces like wind load, which requires a deeper understanding of the building structure behavior and the design of load-bearing modules. Therefore, this paper presents the state-of-the-art literature concerning recent achievement in 3D printing for buildings, followed by discussion on the opportunities and challenges for examining 3D printing in modular construction. Promising 3D printing techniques are critically reviewed and discussed with regard to their advantages and limitations in construction. The appropriate structural form needs to be determined at the design stage, taking into consideration the overall building structural behavior, site environmental conditions (e.g., wind), and load-carrying capacity of the 3D printed modules. Detailed finite element modelling of the entire modular buildings needs to be conducted to verify the structural performance, considering the code-stipulated lateral drift, strength criteria, and other design requirements. Moreover, integration of building information modelling (BIM) method is beneficial for generating the material and geometric details of the 3D printed modules, which can then be utilized for the fabrication.

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A Passport Recognition and face Verification Using Enhanced fuzzy ART Based RBF Network and PCA Algorithm (개선된 퍼지 ART 기반 RBF 네트워크와 PCA 알고리즘을 이용한 여권 인식 및 얼굴 인증)

  • Kim Kwang-Baek
    • Journal of Intelligence and Information Systems
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    • v.12 no.1
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    • pp.17-31
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    • 2006
  • In this paper, passport recognition and face verification methods which can automatically recognize passport codes and discriminate forgery passports to improve efficiency and systematic control of immigration management are proposed. Adjusting the slant is very important for recognition of characters and face verification since slanted passport images can bring various unwanted effects to the recognition of individual codes and faces. Therefore, after smearing the passport image, the longest extracted string of characters is selected. The angle adjustment can be conducted by using the slant of the straight and horizontal line that connects the center of thickness between left and right parts of the string. Extracting passport codes is done by Sobel operator, horizontal smearing, and 8-neighborhood contour tracking algorithm. The string of codes can be transformed into binary format by applying repeating binary method to the area of the extracted passport code strings. The string codes are restored by applying CDM mask to the binary string area and individual codes are extracted by 8-neighborhood contour tracking algerian. The proposed RBF network is applied to the middle layer of RBF network by using the fuzzy logic connection operator and proposing the enhanced fuzzy ART algorithm that dynamically controls the vigilance parameter. The face is authenticated by measuring the similarity between the feature vector of the facial image from the passport and feature vector of the facial image from the database that is constructed with PCA algorithm. After several tests using a forged passport and the passport with slanted images, the proposed method was proven to be effective in recognizing passport codes and verifying facial images.

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Seismic Performance Evaluation of Concrete-filled U-shaped Mega Composite Beams (콘크리트 채움 U형 메가 합성보의 내진성능 평가)

  • Lee, Cheol Ho;Ahn, Jae Kwon;Kim, Dae Kyung;Park, Ji-Hun;Lee, Seung Hwan
    • Journal of Korean Society of Steel Construction
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    • v.29 no.2
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    • pp.111-122
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    • 2017
  • In this paper, the applicability of a 1900mm-deep concrete-filled U-shaped composite beam to composite ordinary moment frames (C-OMFs) was investigated based on existing test results from smaller-sized specimens and supplemental numerical studies since full-scale seismic testing of such a huge sized beam is practically impossible. The key issue was the web local buckling of concrete-filled U section under negative bending. Based on 13 existing test results compiled, the relationship between web slenderness and story drift capacity was obtained. From this relationship, a 1900mm-deep mega beam, fabricated with 25mm-thick plate was expected to experience the web local buckling at 2% story drift and eventually reach a story drift over 3%, thus much exceeding the requirements of C-OMFs. The limiting width to thickness ratio according to the 2010 AISC Specification was shown to be conservative for U section webs of this study. The test-validated supplemental nonlinear finite element analysis was also conducted to further investigate the effects of the horizontal stiffeners (used to tie two webs of a U section) on web local buckling and flexural strength. First, it is shown that the nominal plastic moment under negative bending can be developed without using the horizontal stiffeners, although the presence of the stiffeners can delay the occurrence of web local buckling and restrain its propagation. Considering all these, it is concluded that the 1900mm-deep concrete-filled U-shaped composite beam investigated can be conservatively applied to C-OMFs. Finally, some useful recommendations for the arrangement and design of the horizontal stiffeners are also recommended based on the numerical results.

Comparison of marginal and internal fit of zirconia abutments with titanium abutments in internal hexagonal implants (내부육각 연결형 임플란트에서 지르코니아 지대주와 티타늄 지대주의 변연 및 내면 적합도의 비교)

  • Kim, Young-Ho;Cho, Hye-Won
    • The Journal of Korean Academy of Prosthodontics
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    • v.54 no.2
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    • pp.93-102
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    • 2016
  • Purpose: The aim of this study was to evaluate the fit accuracy of two zirconia and titanium abutments in internal hexagonal implants. Materials and methods: One titanium abutment and two zirconia abutments were tested in internal hexagonal implants (TSV, Zimmer). Prefabricated zirconia abutments (ZirAce, Acucera) and customized zirconia abutments milled by the Zirkonzahn system (Zirkonzahn Max, Zirkonzahn) were selected and prefabricated titanium abutments (Hex-Lock, Zimmer) were used as a control. Eight abutments per group were connected to implants with 30 Ncm torque. The marginal gaps at abutment-implant interface, the internal gaps at internal hex, vertical and horizontal gaps between screws and screw seats in abutments were measured after sectioning the embedded specimens using a scanning electron microscope. Data analysis included one-way analysis of variance and the Scheffe test (n=16, ${\alpha}=0.05$). Results: The mean marginal gap of customized zirconia abutment was higher than those of two prefabricated zirconia and titanium abutments. The internal gaps at internal hex showed no significant differences between customized and prefabricated abutments and were higher than those of prefabricated titanium abutments. The mean vertical and horizontal gaps at screw in prefabricated zirconia abutment were higher than those of prefabricated titanium abutment. In the case of customized zirconia abutment, the mean horizontal gap at screw was higher than those of both the prefabricated zirconia and the titanium abutment but the mean vertical gap was not even measureable. The screw seats were clearly formed but did not match with abutment screws in prefabricated zirconia abutments. They were not, however, precisely formed in the case of customized zirconia abutments. Conclusion: Within the limitations of this study, the prefabricated titanium abutments showed better fit than the zirconia abutments, regardless of customized or prefabricated. Also, the customized zirconia abutments showed significantly higher marginal gaps and the fit was less accurate between screws and screw seats than the prefabricated abutments, titanium and zirconia.

Studies on Changes in the Hydrography and Circulation of the Deep East Sea (Japan Sea) in a Changing Climate: Status and Prospectus (기후변화에 따른 동해 심층 해수의 물리적 특성 및 순환 변화 연구 : 현황과 전망)

  • HOJUN LEE;SUNGHYUN NAM
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.28 no.1
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    • pp.1-18
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    • 2023
  • The East Sea, one of the regions where the most rapid warming is occurring, is known to have important implications for the response of the ocean to future climate changes because it not only reacts sensitively to climate change but also has a much shorter turnover time (hundreds of years) than the ocean (thousands of years). However, the processes underlying changes in seawater characteristics at the sea's deep and abyssal layers, and meridional overturning circulation have recently been examined only after international cooperative observation programs for the entire sea allowed in-situ data in a necessary resolution and accuracy along with recent improvement in numerical modeling. In this review, previous studies on the physical characteristics of seawater at deeper parts of the East Sea, and meridional overturning circulation are summarized to identify any remaining issues. The seawater below a depth of several hundreds of meters in the East Sea has been identified as the Japan Sea Proper Water (East Sea Proper Water) due to its homogeneous physical properties of a water temperature below 1℃ and practical salinity values ranging from 34.0 to 34.1. However, vertically high-resolution salinity and dissolved oxygen observations since the 1990s enabled us to separate the water into at least three different water masses (central water, CW; deep water, DW; bottom water, BW). Recent studies have shown that the physical characteristics and boundaries between the three water masses are not constant over time, but have significantly varied over the last few decades in association with time-varying water formation processes, such as convection processes (deep slope convection and open-ocean deep convection) that are linked to the re-circulation of the Tsushima Warm Current, ocean-atmosphere heat and freshwater exchanges, and sea-ice formation in the northern part of the East Sea. The CW, DW, and BW were found to be transported horizontally from the Japan Basin to the Ulleung Basin, from the Ulleung Basin to the Yamato Basin, and from the Yamato Basin to the Japan Basin, respectively, rotating counterclockwise with a shallow depth on the right of its path (consistent with the bottom topographic control of fluid in a rotating Earth). This horizontal deep circulation is a part of the sea's meridional overturning circulation that has undergone changes in the path and intensity. Yet, the linkages between upper and deeper circulation and between the horizontal and meridional overturning circulation are not well understood. Through this review, the remaining issues to be addressed in the future were identified. These issues included a connection between the changing properties of CW, DW, and BW, and their horizontal and overturning circulations; the linkage of deep and abyssal circulations to the upper circulation, including upper water transport from and into the Western Pacific Ocean; and processes underlying the temporal variability in the path and intensity of CW, DW, and BW.

A three-dimensional finite-element analysis of influence of splinting in mandibular posterior implants (스프린팅이 하악 구치부 임플랜트 보철물의 응력분산에 미치는 영향에 관한 삼차원 유한요소분석 연구)

  • Baik, Sang-Hyun;Jang, Ik-Tae;Kim, Sung-Kyun;Koak, Jai-Young;Heo, Seong-Joo
    • The Journal of Korean Academy of Prosthodontics
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    • v.46 no.2
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    • pp.157-168
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    • 2008
  • Statement of problem: Over the past two decades, implant supported fixed prosthesis have been widely used. However, there are few studies conducted systematically and intensively on the splinting effect of implant systems in mandible. Purpose: The purpose of this study was to investigate the changes in stress distributions in the mandibular implants with splinting or non-splinting crowns by performing finite element analysis. Materials and methods: Cortical and cancellous bone were modeled as homogeneous, transversely isotropic, linearly elastic. Perfect bonding was assumed at all interfaces. Implant models were classified as follows. Group 1: $Br{{\aa}}nemark$ length 8.5mm 13mm splinting type Group 2: $Br{{\aa}}nemark$ length 8.5mm 13mm Non-splinting type Group 3: ITI length 8.5mm 13mm splinting type Group 4: ITI length 8.5mm 13mm Non-splinting type An load of 100N was applied vertically and horizontally. Stress levels were calculated using von Mises stresses values. Results: 1. The stress distribution and maximum von Mises stress of two-length implants (8.5mm, 13mm) was similar. 2. The stress of vertical load concentrated on mesial side of implant while the stress of horizontal load was distributed on both side of implant. 3. Stress of internal connection type was spreading through abutment screw but the stress of external connection type was concentrated on cortical bone level. 4. Degree of stress reduction was higher in the external connection type than in the internal connection type.

Expressional Characteristics of Interior Design Presented in Exhibition Spaces of Jean-Michel Wilmotte (장 미쉘 빌모트의 전시공간에 나타난 실내디자인 표현특성)

  • Song, Ga-Hyun;Kim, Moon-Duck
    • Korean Institute of Interior Design Journal
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    • v.23 no.6
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    • pp.87-94
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    • 2014
  • Today, the growing number of international architects enters the open market of South Korean architecture and interior from exhibition spaces such as art galleries to buildings of major companies. Establishing new local landmarks, their works have a considerable influence on the development of architecture. Among many, French architect Jean-Michel Wilmotte has worked consistently in South Korea. The purpose of this study is to analyze and put together the expression characteristic of the interior design in his exhibition spaces including Gana Art Gallery. Jean-Michel Wilmotte has designed based on the history, culture, society, and arts in France and other European countries, and is influenced by architects like Charles Rennie Mackintosh, Josef Hoffmann, and Carlo Scarpa. Such an influence is shown in the form of contrast between verticality and horizontality as well as the fortification in his modern classical characteristic, which is one of his expression characters. In his work of improving the ancient architecture, Wilmotte is good at creating a modern space through contextual expression, and the textural contrast between materials of the past and the present. Thus I performed an analysis of the expression characteristic of the interior design in National Museum of Contemporary Art of Chiado in Lisbon, Cognac Hennessy Museum in France, Gana Art Gallery in Korea, Mus$\acute{e}$e du Pr$\acute{e}$sident Jacques Chirac in Sarran, France, Ullens Center for Contemporary Art (UCCA) in Beijing, and lastly Mus$\acute{e}$e d'Orsay in Paris. The results show that he maintains the spatial context by applying contemporary design to the preserved existing structure, continues the flow of exhibition through the lightings in the corridors and on the ceiling, and seeks for a balance by adding vertical or horizontal elements to the elevation. In the interior, the staircase and exhibition structure are turned into objects, and the contrasting texture of the wall vitalizes the space. Wilmotte redesigns the space of the past and the present by using indirect joint that allows an organic connection of the old and new structures, and by minimizing the conflict between the two elements through prefabrication. The expression character of his interior design will be potential resources for architects and interior designers to develop their own design languages.