• Title/Summary/Keyword: failure development

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Effect of Shear Rate on Strength of Non-cemented and Cemented Sand in Laboratory Testing (실내시험 시 재하속도가 미고결 및 고결 모래의 강도에 미치는 영향)

  • Moon, Hong Duk;Kim, Jeong Suk;Woo, Seung-Wook;Tran, Dong-Kiem-Lam;Park, Sung-Sik
    • Journal of the Korean Geotechnical Society
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    • v.37 no.11
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    • pp.23-36
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    • 2021
  • In this paper, the effect of shear rate on internal friction angle and unconfined compressive strength of non-cemented and cemented sand was investigated. A dry Jumunjin sand was prepared at loose, medium, and dense conditions with a relative density of 40, 60 and 80%. Then, series of direct shear tests were conducted at shear rates of 0.32, 0.64, and 2.54 mm/min. In addition, a cemented sand with cement ratio of 8% and 12% was compacted into a cylindrical specimen with 50 mm in diameter and 100 mm in height. Unconfined compression tests on the cemented sand were performed with various shear rates such as 0.1, 0.5, 1, 5 and 10%/min. Regardless of a degree of cementation, the unconfined compressive strength of the cemented sand and the angle of internal friction of the non-cemented sand tended to increase as the shear rate increased. For the non-cemented sand, the angle of internal friction increased by 4° at maximum as the shear rate increased. The unconfined compressive strength of the cemented sand also increased as the shear rate increased. However, its increasing pattern declined after the standard shear rate (1 mm/min). A discrete element method was also used to analyze the crack initiation and its development for the cemented sand with shear rate. Numerical results of unconfined compressive strength and failure pattern were similar to the experimental results.

Birth of artificial nature and the humanities of coexistence (인공자연의 탄생과 공존의 인문학 -90년대 사이버문학론을 중심으로)

  • Lee, yongwook
    • The Journal of the Convergence on Culture Technology
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    • v.7 no.4
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    • pp.449-460
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    • 2021
  • The development process of cyber literature theory in the 1990s clearly shows the duality of the pursuit of symbolic power and desire through the formation and conflict of literary fields, collective intelligence. All desires are bound to be power-oriented, and cyber literature is meaningful in that network-space critics developed while advocating the humanities of coexistence. The failure of cyber literature theory is due to the conflicting desire of critical power between real and virtual spaces. Cyber literature theory in the 1990s was the first literary response to the birth of artificial nature, although the contradiction of desires revealed in symbolic power and the limitations of barking are clear. Literature discourse has always explored the relationship between the social conditions of the time (including technological progress) and art texts. Producing a new critical discourse encompassing the whole within the literary field of artificial nature is an important task in literature in the era of technology compilation, and humanities and technology must coexist. Through this paper, we examined the impact of the birth of artificial nature on humanities. This study is an important achievement of humanities engineering that understands, interprets, and leads technology.

Modeling and Simulation for Effectiveness Analysis of Anti-Ballistic Warfare in Naval Vessels (함정의 대탄도탄전 효과도 분석을 위한 모델링 및 시뮬레이션)

  • Jang Won Bae;GuenHo Lee ;Hyungho Na ;Il-Chul Moon
    • Journal of the Korea Society for Simulation
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    • v.32 no.3
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    • pp.55-66
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    • 2023
  • In recent years, naval vessels have been developed to fulfill a variety of missions by being equipped with various cutting-edge equipment and ICT technologies. One of the main missions of Korean naval vessels is anti-ballistic missile warfare to defend key units and areas against the growing threat of ballistic missiles. Because the process of detection and interception is too complex and the cost of failure is much high, a lot of preparation is required to effectively conduct anti-ballistic missile warfare. This paper describes the development of a simulation model of anti-ballistic missile warfare with combat systems and equipment to be installed on future naval vessels. In particular, the DEVS formalism providing a modular and hierarchical modeling manner was applied to the simulation model, which can be utilized to efficiently represent various anti-ballistic missile warfare situations. In the simulation results presented, experiments were conducted to analyze the effectiveness of the model for effective detection resource management in anti-ballistic missile warfare. This study is expected to be utilized as a variety of analysis tools necessary to determine the optimal deployment and configuration of combat resources and operational tactics required for effective anti-ballistic missile warfare of ships in the future.

Evaluating Essential Aspects of Novel Architectural Products: An In-depth Application of Importance-Performance Analysis (중요도-성취도 분석을 통한 건축 신제품의 요구사항 분석 연구)

  • Lee, Ung-Kyun;Kim, Jae-Yeob
    • Journal of the Korea Institute of Building Construction
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    • v.23 no.3
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    • pp.305-313
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    • 2023
  • With an increasing interest in the commercialization of research results in the present societal climate, especially in the construction industry, preliminary product analysis plays a critical role when introducing a new product to the market. It significantly influences the product's success or failure. In this context, this study aims to investigate the utility of Importance-Performance Analysis (IPA) as a management strategy tool for preliminary analysis in the commercialization of new architectural technologies. The study specifically assesses a smart ball product engineered for pipeline inspection. The evaluation is carried out based on product quality, convenience, and usability categories. Seventeen factors are recognized as sub-items, and a survey is conducted among relevant experts and consumer groups. From the survey, four key items are chosen: "Keep up the good work," "Concentrate here," "Low priority," and "Possible overkill." Suitable strategic measures are derived for each item. By conducting a correlation analysis between product importance and performance, this study offers a method to establish priority directions for future development. This analysis assists in identifying areas that necessitate improvement or additional focus to increase the product's commercial potential. On the whole, this study contributes to understanding and applying Importance-Performance Analysis as a valuable tool in the preliminary analysis and commercialization of novel technologies in the field of architecture.

Evaluation and future of social welfare policy in Korea - Focusing on social inclusiveness - (한국사회복지정책의 평가와 미래 - 사회적 포용성을 중심으로 -)

  • Han, Chang-Keun
    • Korean Journal of Social Welfare
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    • v.69 no.4
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    • pp.9-33
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    • 2017
  • This study aims to emphasize the importance of social inclusiveness for evaluation and future development of social policy in Korea. In particular, this study emphasizes that the future of social policy in Korea depends on the level of social inclusiveness. Social inclusiveness can be measured by the extent to which social policy is inclusive and the level of citizens' perception of social inclusiveness. This study uses 4 frameworks (universality, progressiveness, life-long, and adequacy) of inclusive asset-based policy to evaluate the level of social inclusiveness of key laws and social policies. Key findings are as follows: First, Korea has established normative systems of laws and social policies. Second, however, Korean social policy has multiple problems in universality, progressiveness, life-long, and adequacy. To enhance social inclusiveness of social policy, this study emphasizes the 'socialness' of social problems. Korea has faced market failure, the high level of rate experiencing poverty during life, and inefficiency of social policy. If we accept the socialness of social problems, social policy should attempt to increase publicness of social policy. The increase in socialness as well as social inclusiveness may be fundamental for inclusive society in Korea.

A Case Study of New Franchise Brand Launching Through Proactive Market Response: BEERBARKET'S Successful Story of INTO FRANCHISE SYSTEMS (선행적 대응을 통한 프랜차이즈 뉴비즈니스 런칭 사례 : (주)인토외식산업의 맥주바켓 성공사례)

  • Seo, Min-Gyo
    • The Korean Journal of Franchise Management
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    • v.3 no.1
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    • pp.111-129
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    • 2012
  • Domestic franchise industry is a promising business to more than 10% per year growth rate and emerging as core of retail. In addition, due to the socio-cultural phenomena, including the retirement of the baby-boom generation, the growth of the franchise industry for some time expected to continue. But Domestic franchise reveals that limits to ensure for new franchisees because that few industries are concentrated to advance for franchisor and franchisees. Franchisors that within the industry came to a saturated, are for the growth and expansion of business into new industries to deploy as second, third brand. But reality is that the more success rather than failure. Therefore, in this study is a new brand development approach and case study results it focus on the BEERBARKET's successful story of INTO FRANCHISE SYSTEMS, INC. Case analysis results of this study, are reveled that franchise headquarters derived through research methods and research information, environmental survey and analysis should be continuously and objectively. Thus, based on the derived contents, the new brand Biz-Model should be established for recognition from the industry and customers. Ability to respond sensitively to changes in the environment and business activities can be associated with linking franchise headquarters belonging to the saturated competitive environment more is needed. Through proactively respond Franchise New business launching instance that BEERBARKET's successful story of INTO FRANCHISE SYSTEMS, INC. suggests the need to study about how to respond to environmental changes.

The gene expression programming method to generate an equation to estimate fracture toughness of reinforced concrete

  • Ahmadreza Khodayari;Danial Fakhri;Adil Hussein, Mohammed;Ibrahim Albaijan;Arsalan Mahmoodzadeh;Hawkar Hashim Ibrahim;Ahmed Babeker Elhag;Shima Rashidi
    • Steel and Composite Structures
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    • v.48 no.2
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    • pp.163-177
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    • 2023
  • Complex and intricate preparation techniques, the imperative for utmost precision and sensitivity in instrumentation, premature sample failure, and fragile specimens collectively contribute to the arduous task of measuring the fracture toughness of concrete in the laboratory. The objective of this research is to introduce and refine an equation based on the gene expression programming (GEP) method to calculate the fracture toughness of reinforced concrete, thereby minimizing the need for costly and time-consuming laboratory experiments. To accomplish this, various types of reinforced concrete, each incorporating distinct ratios of fibers and additives, were subjected to diverse loading angles relative to the initial crack (α) in order to ascertain the effective fracture toughness (Keff) of 660 samples utilizing the central straight notched Brazilian disc (CSNBD) test. Within the datasets, six pivotal input factors influencing the Keff of concrete, namely sample type (ST), diameter (D), thickness (t), length (L), force (F), and α, were taken into account. The ST and α parameters represent crucial inputs in the model presented in this study, marking the first instance that their influence has been examined via the CSNBD test. Of the 660 datasets, 460 were utilized for training purposes, while 100 each were allotted for testing and validation of the model. The GEP model was fine-tuned based on the training datasets, and its efficacy was evaluated using the separate test and validation datasets. In subsequent stages, the GEP model was optimized, yielding the most robust models. Ultimately, an equation was derived by averaging the most exemplary models, providing a means to predict the Keff parameter. This averaged equation exhibited exceptional proficiency in predicting the Keff of concrete. The significance of this work lies in the possibility of obtaining the Keff parameter without investing copious amounts of time and resources into the CSNBD test, simply by inputting the relevant parameters into the equation derived for diverse samples of reinforced concrete subject to varied loading angles.

An Evaluation of Crack Resistance for Slag Asphalt Concrete Mixture Using Steel Slag Aggregates (제강슬래그 골재를 사용한 슬래그 아스팔트 혼합물의 균열저항성 평가)

  • Kim, Nakseok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.43 no.1
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    • pp.71-77
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    • 2023
  • With the continuous industrial development, not only natural resource depletion, waste generation, but also various weather conditions are becoming more frequent. Efforts are continuing to recycle industrial by-products to overcome the climate crisis and save resources. Slag is a representative by-product generated in the steel industry, and it is characterized by improving rutting resistance and moisture sensitivity by increasing strength and reducing deformation when used as a material for asphalt concrete. On the other hand, slag has expansion properties so it is used as a relatively low-value-added material such as embankment and refilling materials. In order to expand the application of slag, an experiment was conducted to evaluate the crack resistance of slag asphalt concrete pavement. As a result of the indirect tensile strength test, it was found that the asphalt mixture using slag aggregate showed a value 1.13 times higher than that of the general HMA with the same particle size, and the toughness was 1.17 units, improving crack resistance. In addition, it was found that the failure number of the 4-point beam fatigue experiment and the slag asphalt mixture was 20,409, which was more than doubled compared to the general HMA. Furthermore, Overlay Test showed a tensile load residual rate of 4 times or more, improving crack resistance to repeated fatigue. Accordingly, the use of slag aggregate will likely have various advantages in improving the performance of asphalt concrete pavement.

Rainfall Forecasting Using Satellite Information and Integrated Flood Runoff and Inundation Analysis (I): Theory and Development of Model (위성정보에 의한 강우예측과 홍수유출 및 범람 연계 해석 (I): 이론 및 모형의 개발)

  • Choi, Hyuk Joon;Han, Kun Yeun;Kim, Gwangseob
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.6B
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    • pp.597-603
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    • 2006
  • The purpose of this study is to improve the short term rainfall forecast skill using neural network model that can deal with the non-linear behavior between satellite data and ground observation, and minimize the flood damage. To overcome the geographical limitation of Korean peninsula and get the long forecast lead time of 3 to 6 hour, the developed rainfall forecast model took satellite imageries and wide range AWS data. The architecture of neural network model is a multi-layer neural network which consists of one input layer, one hidden layer, and one output layer. Neural network is trained using a momentum back propagation algorithm. Flood was estimated using rainfall forecasts. We developed a dynamic flood inundation model which is associated with 1-dimensional flood routing model. Therefore the model can forecast flood aspect in a protected lowland by levee failure of river. In the case of multiple levee breaks at main stream and tributaries, the developed flood inundation model can estimate flood level in a river and inundation level and area in a protected lowland simultaneously.

A Study on Non-financial Factors Affecting the Insolvency of Social Enterprises (사회적기업의 부실에 영향을 미치는 비재무요인에 관한 연구 )

  • Yong-Chan, Chun;Hyeok, Kim;Dong-Myung, Lee
    • Journal of Industrial Convergence
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    • v.21 no.11
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    • pp.13-27
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    • 2023
  • This study aims to contribute to the reduction of the failure rate and social costs resulting from business failures by analyzing factors that affect the insolvency of social enterprises, as the role of social enterprises is increasing in our economy. The data used in this study were classified as normal and insolvent companies among social enterprises (including prospective social enterprises) that were established between 2009 and 2018 and received credit guarantees from credit guarantee institutions as of the end of June 2022. Among the collected data, 439 social enterprises with available financial information were targeted; 406 (92.5%) were normal enterprises, and 33 (7.5%) were insolvent enterprises. Through a literature review, eight non-financial factors commonly used for insolvency prediction were selected. The cross-analysis results showed that four of these factors were significant. Logistic regression analysis revealed that two variables, including corporate credit rating and the personal credit rating of the representative, were significant. Financial factors such as debt ratio, sales operating profit rate, and total asset turnover were used as control variables. The empirical analysis confirmed that the two independent variables maintained their influence even after controlling for financial factors. Given that government-led support and development policies have limitations, there is a need to shift policy direction so that various companies aspiring to create social value can enter the social enterprise sector through private and regional initiatives. This would enable the social economy to create an environment where local residents can collaborate to realize social value, and the government should actively support this.