• Title/Summary/Keyword: Reinforcement Methods

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A Study on Efficient Deconstruction of Supporters with Response Ratio (응답비를 고려한 효율적인 버팀보 해체방안에 관한연구)

  • Choi, Jung-Youl;Park, Sang-Wook;Chung, Jee-Seung
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.5
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    • pp.469-475
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    • 2022
  • As the recent structure construction is constructed as a large-scale and deep underground excavation in close proximity to the building, the installation of retaining wall and supporters (Struts) has become complicated, and the number of supporters to avoid interference of the structural slab has increased. This construction process becomes a factor that causes an increase in construction joints of a structure, leakage and an increase in wall cracks. In addition, this reduced the durability and workability of the structure and led to an increase in the construction period. This study planned to dismantle the two struts simultaneously as a plan to reduce the construction joints, and corrected the earth pressure by assuming the reaction force value by the initial earth pressure and the measured data as the response ratio. After recalculating the corrected earth pressure through the iterative trial method, it was verified by numerical analysis that simultaneous disassembly of the two struts was possible. As a result of numerical analysis applying the final corrected earth pressure, the measured value for the design reaction force was found to be up to 197%. It was analyzed that this was due to the effect of grouting on the ground and some underestimation of the ground characteristics during design. Based on the result of calculating the corrected earth pressure in consideration of the response ratio performed in this study, it was proved analytically that the improvement of the brace dismantling process is possible. In addition, it was considered that the overall construction period could be shortened by reducing cracks due to leakage and improving workability by reducing construction joints. However, to apply the proposed method of this study, it is judged that sufficient estimations are necessary as there are differences in ground conditions, temporary facilities, and reinforcement methods for each site.

Transition of Rice Culture Practices during Chosun Dynasty through Old References. Ⅵ Fertilizing Practices (주요 고농서를 통한 조선시대의 도작기술 전개 과정 연구 Ⅵ. 시비기술)

  • Lee, Sung-Kyum;Guh, Ja-Ok;Lee, Eun-Woong;Lee, Hong-Suk
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.37 no.2
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    • pp.209-215
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    • 1992
  • Different from 'Seyokwiryang' (歲易爲良 : fallowing as the best method) which was an agricultural technique of ancient China, fertilization of rice fields was already practiced in the end of Koryo age in Korea. 'Bunjongbeob'(糞種法 : fertilizer applicating method on seed) or 'Bunkwabeob' (糞科法 : fertilizer applicating method on each plant) was practiced before green manure of bean crops and 'Bunjeonbeob'(糞田法 : fertilizer practicing method on fields) were done. In the 15th century 'Dojeonbunjeonbeob'(稻田糞田法 : fertilizer applicating method on paddy) in 'Jikseol' was divided the materials to be used into the soil brought from another place, trees, grasses, and the manure. Also, it discribed the fertilization between first plowing and the second, and proper fertilization for particular soil conditions. In case of transplanting techniques, the fertilization practices were specified into nursery and rice fields, and restoration of organic matter was systemized by plowing for cultivation in the reclaimed areas. In the 17th century, through 'Jikseolbo'($\ulcorner$直說補$\lrcorner$), the habitual practice of Kyungsang province was systemized and 'Bunyangsool'(糞壤術 : technique of fertilization) of 'Jodoangkicheo' (早稻秧基處 : rearing fields of early-ripening rice) was completed. Specific things was the manufacturing and utilizing techniques of 'Bunhoe'(糞灰 : mixture of manure and ash), 'Yohoe'(尿灰 : mixture of urine and ash), and additional fertilizers. In the 18 to 19th century, the materials of fertilization were greatly enlarged to recover the waste lands and to support the reinforcement of soil fertility for increasing the system of two cropping a year. Also, 'Jeobunbeob'(貯糞法 : method of manure storage) and additional fertilization were emphasized, and use of wagons for it was emphasized to improve the theory of fertilization and working efficiency. As mentioned above, limitation of fertilizing materials was conquered by 'Dojeonbunyang'(稻田糞壤 : techniques of practicing fertilizers in paddy) and the system of additional fertilization was established. The fertilization methods were improved with 'Jeobunbeob' due to the theory and recognition necessary for high rates of fertilizers.

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Study of the Theatrical History in Chungnam Yesan (충남 예산 연극사 연구)

  • Do, Jung-Nim;Lee, Seung-Won
    • Journal of Korea Entertainment Industry Association
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    • v.13 no.4
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    • pp.107-117
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    • 2019
  • This paper establishes and propagates the value of the play through the study of the transition process of the yesan play from 1920 to the present, presents an alternative through the unique theatricality of the region and aims to activate it. The theater divided the theater into Yecheon, Chungnam Theater Festival, and Youth Theater Festival, which are currently active, and focused on Yedang International Performing Arts Festival, which is the only one in Yesan. The details of the performance due to the loss of data were not specified as much as possible, but the contents of the yesan play before 1990 were reviewed using the eupji and Myeonji. It also starts with a lack of diversity in plays in the developing direction of Yesan. Children's plays should be dismissed for simple commercial purposes, or the value of traditional Korean plays should be compared to Western ones, to promote the development of local plays through the natural characteristics and the basis of traditional culture, and to sustain the continuity of extreme economic performance and performances through the development of repertoires. Infrastructure deployment can be cited. The in flow of specialized actors and the use of art administrators creates a stable theater environment and activates the reeducation of local actors to promote theatrical imagination. It is also an urgent task to develop a new theatrical form by introducing experimental theatrical methods of young artists in the overseas performance business of theater troupe Yechon. Finally, Yedang International Performing Arts Festival should be characterized and differentiated from other festivals.

Characteristics of Collapsed Retaining Walls Using Elasto-plastic Method and Finite Element Method (탄소성 방법과 유한요소법에 의한 붕괴 토류벽의 거동차이 분석)

  • Jeong, Sang-Seom;Kim, Young-Ho
    • Journal of the Korean Geotechnical Society
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    • v.25 no.4
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    • pp.19-29
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    • 2009
  • In this study, a numerical analysis was performed to predict the sequential behavior of anchored retaining wall where the failure accident took place, and verified accuracy of prediction through the comparisons between prediction and field measurement. The emphasis was given to the wall behaviors and the variation of sliding surface based on the two different methods of elasto-plastic and finite element (shear strength reduction technique). Through the comparison study, it is shown that the bending moment and the soil pressure at construction stages produce quite similar results in both the elasto-plastic and finite element method. However, predicted wall deflections using elasto-plastic method show underestimate results compared with measured deflections. This demonstrates that the elasto-plastic method does not clearly consider the influence of soil-wall-reinforcement interaction, so that the tension force (anchor force and earth pressure) on the wall is overestimated. Based on the results obtained, it is found that finite element method using shear strength reduction method can be effectively used to perform the back calculation analysis in the anchored retaining wall, whereas elasto-plastic method can be applicable to the preliminary design of retaining wall with suitable safety factor.

Evaluation of Human Demonstration Augmented Deep Reinforcement Learning Policy Optimization Methods Using Object Manipulation with an Anthropomorphic Robot Hand (휴먼형 로봇 손의 사물 조작 수행을 이용한 인간 행동 복제 강화학습 정책 최적화 방법 성능 평가)

  • Park, Na Hyeon;Oh, Ji Heon;Ryu, Ga Hyun;Anazco, Edwin Valarezo;Lopez, Patricio Rivera;Won, Da Seul;Jeong, Jin Gyun;Chang, Yun Jung;Kim, Tae-Seong
    • Proceedings of the Korea Information Processing Society Conference
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    • 2020.11a
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    • pp.858-861
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    • 2020
  • 로봇이 사람과 같이 다양하고 복잡한 사물 조작을 하기 위해서 휴먼형 로봇손의 사물 파지 작업이 필수적이다. 자유도 (Degree of Freedom, DoF)가 높은 휴먼형(anthropomorphic) 로봇손을 학습시키기 위하여 사람 데모(human demonstration)가 결합된 강화학습 최적화 방법이 제안되었다. 본 연구에서는 강화학습 최적화 방법에 사람 데모가 결합된 Demonstration Augmented Natural Policy Gradient(DA-NPG)와 NPG 의 성능 비교를 통하여 행동 복제의 효율성을 확인하고, DA-NPG, DA-Trust Region Policy Optimization (DA-TRPO), DA-Proximal Policy Optimization (DA-PPO)의 최적화 방법의 성능 평가를 위하여 6 종의 물체에 대한 휴먼형 로봇손의 사물 조작 작업을 수행한다. 그 결과, DA-NPG 와 NPG를 비교한 결과를 통해 휴먼형 로봇손의 사물 조작 강화학습에 행동 복제가 효율적임을 증명하였다. 또한, DA-NPG 는 DA-TRPO 와 유사한 성능을 보이면서 모든 물체에 대한 사물 파지에 성공하여 가장 안정적이었다. 반면, DA-TRPO 와 DA-PPO 는 사물 조작에 실패한 물체가 존재하여 불안정한 성능을 보였다. 본 연구에서 제안하는 방법은 향후 실제 휴먼형 로봇에 적용하여 휴먼형 로봇 손의 사물조작 지능 개발에 유용할 것으로 전망된다.

Factors Impacting the Work Efficiency and Stress of Case Managers with the Korea Worker's Compensation & Welfare Service (근로복지공단 사례관리자의 업무 효율 및 스트레스에 영향을 미치는 요인)

  • Lee, Su-jin;Kim, Seung Won
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.32 no.1
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    • pp.64-77
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    • 2022
  • Objectives: The purpose of this study is to objectify the level of case management performance and the factors influencing performance, to improve the case management performance at the Korea Worker's Compensation & Welfare Service (KWCWS) on the basis of the recognition of the objective realities of case management by job coordinators at the KWCWS, to develop a model of case management fit for the KWCWS, and to provide a basis for establishing guidelines for standardized case management. Methods: A total of 156 questionnaires were distributed to job coordinators at the KWCWS's headquarters, six regional headquarters, and 55 branches. One hundred forty-one questionnaires were collected and 126 were analyzed statistically using SPSS 21.0. Factor analysis and reliability analysis were conducted to verify the validity and reliability of the main measurement items in the research model. Frequency analysis was conducted for general characteristics of survey subjects. Frequency analysis or descriptive statistics were conducted to identify the level of independent variables (case manager's individual variables, job variables, institutional and organizational variables). Dependent variables (case management performance) and the degree of correlation were analyzed through correlation analysis between research variables. Multiple regression analysis and hierarchical regression analysis were conducted to examine the effect of independent variables on case management performance. Results: The results of the study showed that the level of overall performance in the five stages of case management was ordinary, with an average level of 3.45 on a 5-point scale. Levels of performance by step were institutional approach and intake (3.69), assessment (3.63), goal setting and intervention planning (3.46), implementation of intervention plan (3.32), and evaluation and termination (3.20), in that order. The explanatory power of case management performance (overall) by case managers with the KWCWS was case manager's institutional and organizational variables, job variables, and individual variables, in that order. At each stage of case management, the explanatory power of a case manager's institutional and organizational variables was found to be the greatest. The model changes at each stage of case management assume similar aspects statistically. In hierarchical regression analysis, it was institutional support that had a significant effect on case management performance (overall), and institutional support had the greatest effect. The results of multiple regression analysis in which all variables are input simultaneously showed that institutional support and expertise as well as self-efficacy had a positive effect. However, case management work experience, expertise (technology), and autonomy were found to have a negative effect during the stage of case management performance. Conclusions: As a result of the study, it was confirmed that raising the case manager's expertise and support from the institution and organization are important factors to improve the level of case management performance. The research also derived practical ways of reinforcement of case manager capacity, institutional and organizational support, operation of rehabilitation-case management teams, and occupational health-related aspects.

A Study on the Strategic and Competitive Analysis of Public Libraries: Focusing on a Case of C Public Library (공공도서관의 전략경쟁분석에 관한 연구 - C도서관의 사례를 중심으로 -)

  • Noh, Dong-Jo
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.17 no.2
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    • pp.223-238
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    • 2006
  • For a public library. which is a regional information service agency. to acquire high competitiveness, preparation for uncertainties of future through understanding its own internal strengths and weaknesses. and external opportunities and threats based on assessments regarding knowledge information environment and characteristics of regional community. current status of the library, etc. Therefore. in this study, through SWOT analysis. one of competitive strategy analysis methods, the status of competitive strategy of C library was analyzed. In order to carry out the study interview and survey were performed with professional librarians, then through final consultations from management consulting experts, a plan to strengthen competitiveness for C library was devised. Conclusions from this study were as below. In order to strengthen competitiveness of C library offering distinguished high quality services through active cooperations with external institutions, efforts to improve library's position and stand following being selected as a library to visit for 2006 World Library and Information Congress, and revitalization of library usage through providing user oriented differentiated services are needed.

Hybrid Offloading Technique Based on Auction Theory and Reinforcement Learning in MEC Industrial IoT Environment (MEC 산업용 IoT 환경에서 경매 이론과 강화 학습 기반의 하이브리드 오프로딩 기법)

  • Bae Hyeon Ji;Kim Sung Wook
    • KIPS Transactions on Computer and Communication Systems
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    • v.12 no.9
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    • pp.263-272
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    • 2023
  • Industrial Internet of Things (IIoT) is an important factor in increasing production efficiency in industrial sectors, along with data collection, exchange and analysis through large-scale connectivity. However, as traffic increases explosively due to the recent spread of IIoT, an allocation method that can efficiently process traffic is required. In this thesis, I propose a two-stage task offloading decision method to increase successful task throughput in an IIoT environment. In addition, I consider a hybrid offloading system that can offload compute-intensive tasks to a mobile edge computing server via a cellular link or to a nearby IIoT device via a Device to Device (D2D) link. The first stage is to design an incentive mechanism to prevent devices participating in task offloading from acting selfishly and giving difficulties in improving task throughput. Among the mechanism design, McAfee's mechanism is used to control the selfish behavior of the devices that process the task and to increase the overall system throughput. After that, in stage 2, I propose a multi-armed bandit (MAB)-based task offloading decision method in a non-stationary environment by considering the irregular movement of the IIoT device. Experimental results show that the proposed method can obtain better performance in terms of overall system throughput, communication failure rate and regret compared to other existing methods.

Comparative analysis of the in vivo kinetic properties of various bone substitutes filled into a peri-implant canine defect model

  • Jingyang Kang;Masaki Shibasaki;Masahiko Terauchi;Narumi Oshibe;Katsuya Hyodo;Eriko Marukawa
    • Journal of Periodontal and Implant Science
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    • v.54 no.2
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    • pp.96-107
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    • 2024
  • Purpose: Deproteinized bovine bone or synthetic hydroxyapatite are 2 prevalent bone grafting materials used in the clinical treatment of peri-implant bone defects. However, the differences in bone formation among these materials remain unclear. This study evaluated osteogenesis kinetics in peri-implant defects using 2 types of deproteinized bovine bone (Bio-Oss® and Bio-Oss/Collagen®) and 2 types of synthetic hydroxyapatite (Apaceram-AX® and Refit®). We considered factors including newly generated bone volume; bone, osteoid, and material occupancy; and bone-to-implant contact. Methods: A beagle model with a mandibular defect was created by extracting the bilateral mandibular third and fourth premolars. Simultaneously, an implant was inserted into the defect, and the space between the implant and the surrounding bone walls was filled with Bio-Oss, Bio-Oss/Collagen, Apaceram-AX, Refit, or autologous bone. Micro-computed tomography and histological analyses were conducted at 3 and 6 months postoperatively (Refit and autologous bone were not included at the 6-month time point due to their rapid absorption). Results: All materials demonstrated excellent biocompatibility and osteoconductivity. At 3 months, Bio-Oss and Apaceram-AX exhibited significantly greater volumes of formation than the other materials, with Bio-Oss having a marginally higher amount. However, this outcome was reversed at 6 months, with no significant difference between the 2 materials at either time point. Apaceram-AX displayed notably slower bioresorption and the largest quantity of residual material at both time points. In contrast, Refit had significantly greater bioresorption, with complete resorption and rapid maturation involving cortical bone formation at the crest at 3 months, Refit demonstrated the highest mineralized tissue and osteoid occupancy after 3 months, albeit without statistical significance. Conclusions: Overall, the materials demonstrated varying post-implantation behaviors in vivo. Thus, in a clinical setting, both the properties of these materials and the specific conditions of the defects needing reinforcement should be considered to identify the most suitable material.

Field Applicability Evaluation Experiment for Ultra-high Strength (130MPa) Concrete (초고강도(130MPa) 콘크리트의 현장적용성 평가에 관한 실험)

  • Choonhwan Cho
    • Journal of the Society of Disaster Information
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    • v.20 no.1
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    • pp.20-31
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    • 2024
  • Purpose: Research and development of high-strength concrete enables high-rise buildings and reduces the self-weight of the structure by reducing the cross-section, thereby reducing the thickness of beams and slabs to build more floors. A large effective space can be secured and the amount of reinforcement and concrete used to designate the base surface can be reduced. Method: In terms of field construction and quality, the effect of reducing the occurrence of drying shrinkage can be confirmed by studying the combination of low water bonding ratio and minimizing bleeding on the concrete surface. Result: The ease of site construction was confirmed due to the high self-charging property due to the increased fluidity by using high-performance water reducing agents, and the advantage of shortening the time to remove the formwork by expressing the early strength of concrete was confirmed. These experimental results show that the field application of ultra-high-strength concrete with a design standard strength of 100 MPa or higher can be expanded in high-rise buildings. Through this study, we experimented and evaluated whether ultra-high-strength concrete with a strength of 130 MPa or higher, considering the applicability of high-rise buildings with more than 120 floors in Korea, could be applied in the field. Conclusion: This study found the optimal mixing ratio studied by various methods of indoor basic experiments to confirm the applicability of ultra-high strength, produced 130MPa ultra-high strength concrete at a ready-mixed concrete factory similar to the real size, and tested the applicability of concrete to the fluidity and strength expression and hydration heat.