• Title/Summary/Keyword: 공통현상

Search Result 408, Processing Time 0.028 seconds

Analysis on the Rainfall Driven Slope Failure Adjacent to a Railway : Flume Tests (강우로 인한 철도 연변사면의 활동분석 : 실내모형실험)

  • SaGong Myung;Kim Min-Seok;Kim Soo-Sam;Lee In-Yong
    • Journal of the Korean Geotechnical Society
    • /
    • v.22 no.5
    • /
    • pp.83-91
    • /
    • 2006
  • Recently, the intensive rainstorm possibly induced by global warming plays a key role on the instability of railway adjacent slopes. The instability of slopes results as covering and loss of railway lines induced by slided soil mass. According to the site investigation on the failed slopes triggered by rainfall, low types of slope failure were observed: shallow, intermediate, gully erosion, and soil-rock interface failures. The observation reveals the different characteristics of slope failure depending on the thickness of soil layer, morphological features of slope, etc. Based upon the observations, flume tests were conducted to analyze the sliding mechanism of each failure. The variables of flume test are soil layer thickness, rainfall intensity, and morphology of slope under the constant condition of the percentage of fine, initial soil moisture content, slope angle and compaction energy. Test results show that shallow failure was mostly observed from the surface of the slope and caused by the soil erosion; in addition, compared to the other types of failure, the occurrence of initial erosion is late, however, the development of erosion is fast. In gully erosion failure, the collected water from the water catchment area helps erosion of the upper soil layer and transfer of residual corestone, which impedes the erosion process once the upper soil layers are eroded and corestone are exposed. The soil-rock interface failure shows the most fast initial erosion process among the failure types. Interestingly, the common feature observed from the different types of failure was the occurrence of the initial deformation near the toe of slopes which implies the existence of surbsurface flow along the downslope direction.

Factor Analysis on Psychological Cause of Speed Reduction in Expressway Tunnel Section Utilizing Importance-Performance Analysis (IPA) (고속도로 터널부 속도 감소에 관한 심리적 요인분석)

  • Lee, Ki Young;Kim, Tae Ho
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.30 no.2D
    • /
    • pp.127-134
    • /
    • 2010
  • Tunnel sections on the highway are different from rest of sections on the highway in terms of velocity, the number of passing cars, and vehicle density which, in particular, affect drivers' behavior before and after drivers pass through the tunnel. However, literature review reveals that former studies are too focused on quantitative indicator to consider qualitative aspects. Therefore, this paper conducts survey questionnaire and IPA (Importance Performance Analysis) to find out qualitative improvements on velocity drop on the tunnel sections. The results show as follows: First, drivers require improvements of tunnel form (length and curved form inside tunnel) which is derived from long distance tunnel. Second, experts primarily ask for amendment of geometric characteristics. With comparison of requirements of both drivers and experts, there are many differences in length of tunnel and form of curved tunnel. This also presents that drivers don't satisfy with both length of tunnel and form of curved tunnel that are provided as a part of highway design factors.

A Servicism Model of the New Financial System (서비스주의 금융시스템 연구)

  • Hyunsoo Kim
    • Journal of Service Research and Studies
    • /
    • v.12 no.1
    • /
    • pp.49-68
    • /
    • 2022
  • This study was conducted to design a financial system for the sustainable life of mankind. Human society faces a constant crisis and leads a life while overcoming it. The polarization is intensifying in the process of overcoming the economic crisis or crisis caused by the virus. In a society adopting the capitalist economic system, it is a common phenomenon that polarization intensifies with the passage of time, but since the intensification of polarization can destroy human society as a community, active countermeasures are required. The purpose of this study was to prevent the deepening of polarization by redesigning important financial-related systems from the perspective of human life and maintenance of human society. Through the history of mankind, monetary and financial systems related to sustainable society have been analyzed, and a financial system model that is ideal for the modern and future society and is sustainable in the long term has been derived. The conditions for a long-term sustainable financial system should be a model that can solve the problems of the current system, such as deepening polarization, and a model that is faithful to the characteristics of the modern economic society and the essence of sustainable life. And it can be sustainable only if it is based on the common principles of human society. It should be a model that guarantees core values such as growth and equality that human society demands. After analyzing the problems of the current economic system and analyzing the conditions required for the new system, the basic axioms that the new financial system should be based on were presented, and a desirable model was derived based on this. The structure of the derived model and the specific operation model were presented. In the future, follow-up studies are needed to concrete this model.

Self-Healing Property of Hardened Cement Paste (시멘트 페이스트 경화체의 self healing 특성)

  • Kim, Jae Young;Byun, Seung Ho
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.28 no.2A
    • /
    • pp.297-304
    • /
    • 2008
  • It is well known that cracks in concrete decrease permeability and durability of concrete because cracks enhance the penetration of water or corrosive chemicals like as chlorides, carbon dioxides, sulfates and some others. But some of cracks in hardened cements may be sealed in case of contacting water. This phenomenon is called "self healing" and it has a close relation to hydration products newly formed on surfaces of cracks. Many studies on self healing in concretes commonly showed that CSH gel has been observed on crack surfaces. And some studies have reported that calcium hydroxides and ettringite were observed as well as CSH gel on crack surfaces. This study was carried out to investigate hydration products formed by self healing process and also examine the influence of waterproof admixture for concretes on self healing of cement. As a result of XRD, DSC, SEM and EDX analysis of crack surfaces, it was found that self healing of cement was related to CSH gel, calcium hydroxides and ettringite. And waterproof admixture increased fibrous (needle-like) hydration products which were in network form. It is estimated that such fibrous products are effective for self healing process of cement system.

A Comparative Analysis of Qualitative Research on Experience of Grandchild Rearing between Grandfamily and Custodial Grandparents in Korean Journal since 2000 (조손가족과 공동양육 조부모의 양육에 관한 질적 연구 내용 비교분석: 2000년 이후 국내 학술지 게재 논문을 중심으로)

  • Youngae Lee;Eunryoung Bang
    • Korean Journal of Culture and Social Issue
    • /
    • v.24 no.3
    • /
    • pp.491-518
    • /
    • 2018
  • The purpose of this study was to compare with qualitative research articles on the grandparents' parenting experiences of grandchildren between those with primary responsibility and those with partial responsibility in Korean Journals since 2000. For the purpose of the study, this study analyzed research of 43 qualitative research articles(19 grandfamilies, 24 custodial grandparents), with respect to their objectives, basic annual trends, methodology, subject, category of content. The major findings are as follows. Firstly, the annual number of articles of grandfamilies are on an decreasing trend, while those of custodial grandparents are on an increasing trend. Secondly, the phenomenology and interview are frequently used in research of the two types of family. Thirdly, 6~10 participants were the most frequent number of participation in all of the family. However, demographics, caring circumstances, physical circumstances were significantly different in two types of family. Fourthly, caring categories of contents(the meaning, positive factor, conflict factor and resolution of conflicts) were also similar, while these were significant diffent in specific psychological experiences in all of the family. Based on the findings of this comparative study, suggestions for pratical services and implication for future study were proposed.

Climatic Yield Potential Changes Under Climate Change over Korean Peninsula Using 1-km High Resolution SSP-RCP Scenarios (고해상도(1km) SSP-RCP시나리오 기반 한반도의 벼 기후생산력지수 변화 전망)

  • Sera Jo;Yong-Seok Kim;Jina Hur;Joonlee Lee;Eung-Sup Kim;Kyo-Moon Shim;Mingu Kang
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.25 no.4
    • /
    • pp.284-301
    • /
    • 2023
  • The changes in rice climatic yield potential (CYP) across the Korean Peninsula are evaluated based on the new climate change scenario produced by the National Institute of Agricultural Sciences with 18 ensemble members at 1 km resolution under a Shared Socioeconomic Pathway (SSP) and Representative Concentration Pathways (RCP) emission scenarios. To overcome the data availability, we utilize solar radiation f or CYP instead of sunshine duration which is relatively uncommon in the climate prediction f ield. The result show that maximum CYP(CYPmax) decreased, and the optimal heading date is progressively delayed under warmer temperature conditions compared to the current climate. This trend is particularly pronounced in the SSP5-85 scenario, indicating faster warming, except for the northeastern mountainous regions of North Korea. This shows the benef its of lower emission scenarios and pursuing more efforts to limit greenhouse gas emissions. On the other hand, the CYPmax shows a wide range of feasible futures, which shows inherent uncertainties in f uture climate projections and the risks when analyzing a single model or a small number of model results, highlighting the importance of the ensemble approach. The f indings of this study on changes in rice productivity and uncertainties in temperature and solar radiation during the 21st century, based on climate change scenarios, hold value as f undamental information for climate change adaptation efforts.

How Market Reacts on the Metaverse Initiatives? An Event Study (메타버스 투자 추진이 기업 가치에 미치는 영향 분석: 이벤트 연구 방법론)

  • Mina Baek;Jeongha Kim;Dongwon Lee
    • Information Systems Review
    • /
    • v.25 no.4
    • /
    • pp.183-204
    • /
    • 2023
  • Due to the COVID-19 pandemic, lots of occasions need to be held in online environment. This is the reason why "Metaverse" gets lots of attention in 2021. A number of companies made announcements on Metaverse, and this situation also boomed stock market. This paper investigates the relationship between Metaverse initiatives and business value of the firm (i.e., stock prices). We examine this relationship by using event study method with Lexis-Nexis News data from 2019 to 2021. The results indicate that Metaverse initiatives significantly impact positive influence on firm's value. In the technological perspective, technical factors affect more positive market returns, including Metaverse enablers (e.g., NFT, VR devices, digital twin) and common infrastructure (e.g., semiconductor, AI, cloud), and especially virtual environment was emphasized. Additionally, in the strategical perspective, radical innovation (e.g., pivoting, acquisition) impact more positive market return rather than incremental innovation (e.g., partnership, investment). Also, firms from non-service industries can achieve benefits from Metaverse initiatives rather than service industry in some degree.

Assessing Techniques for Advancing Land Cover Classification Accuracy through CNN and Transformer Model Integration (CNN 모델과 Transformer 조합을 통한 토지피복 분류 정확도 개선방안 검토)

  • Woo-Dam SIM;Jung-Soo LEE
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.27 no.1
    • /
    • pp.115-127
    • /
    • 2024
  • This research aimed to construct models with various structures based on the Transformer module and to perform land cover classification, thereby examining the applicability of the Transformer module. For the classification of land cover, the Unet model, which has a CNN structure, was selected as the base model, and a total of four deep learning models were constructed by combining both the encoder and decoder parts with the Transformer module. During the training process of the deep learning models, the training was repeated 10 times under the same conditions to evaluate the generalization performance. The evaluation of the classification accuracy of the deep learning models showed that the Model D, which utilized the Transformer module in both the encoder and decoder structures, achieved the highest overall accuracy with an average of approximately 89.4% and a Kappa coefficient average of about 73.2%. In terms of training time, models based on CNN were the most efficient. however, the use of Transformer-based models resulted in an average improvement of 0.5% in classification accuracy based on the Kappa coefficient. It is considered necessary to refine the model by considering various variables such as adjusting hyperparameters and image patch sizes during the integration process with CNN models. A common issue identified in all models during the land cover classification process was the difficulty in detecting small-scale objects. To improve this misclassification phenomenon, it is deemed necessary to explore the use of high-resolution input data and integrate multidimensional data that includes terrain and texture information.

The Dragon Symbol and its Meaning in the Painting Poetry (제화시에 나타난 용(龍)의 표상과 그 의미)

  • Park Hae-young
    • Journal of the Daesoon Academy of Sciences
    • /
    • v.49
    • /
    • pp.157-186
    • /
    • 2024
  • This study aims to understand the symbolic meanings of dragons in the contemporary period through the painting featuring poetry based on the Hwaryong (paintings of dragons) and to analyze the literary representations and characteristics of dragons. First, the shape and aura of the dragon in the paintings should be confirmed. In dragon Painting Poetry (Paintings Featuring Poetry), the shape of the dragon is embodied in the aura of 'spirit.' However, people in previous eras customarily believed that dragons were real. In addition, the main spirit of the Hwaryong was in the representation of the dragon's aura, or "Jeonsin (transmission of spirit)," such as the creature's dragonly virtue or Heavenly Perfection. Next, the rhetorical representation of the dragon in the painting is to be examined. In the actual Painting Poetry, dragon images were relatively common in descriptions of pines, bamboo, and plum trees. The pine-bamboo-plum motif is known as Sehan Samwu (the three friends of the cold season), and since the Northern Song Dynasty, it has become a symbol of literary incision. Manifested as a dragon, the pine-bamboo-plum motif has a common denominator of winding branches, tangled stems, and bluish jade coloration, and like the dragon, it is used as a backdrop for weather phenomena such as rain, wind, and lightning. In the schematic that connects the Hwaryong, dragon Painting Poetry, the original meaning of the dragon is transformed into shapes and language. This is the meaning conveyed by the dragon, and this symbolic meaning was shared among the writers of the period who viewed the poems and paintings.

Development of Theme-Based Integrated Unit in the Middle School Science and Analysis of it's Effects (중학교 과학수업을 위한 주제중심 통합단원의 개발 및 효과 분석)

  • Park, Soo-Kyong;Kim, Sang-Dal;Ju, Gook-Yong;Nam, Youn-Kyong
    • Journal of the Korean earth science society
    • /
    • v.22 no.5
    • /
    • pp.350-359
    • /
    • 2001
  • The purpose of this study is to develop theme-based integrated science unit by the interdisciplinary approach and to analyze it's effects on the science achievement and the attitude towards science learning. 'Interaction' and 'Stability' were selected as the integrated themes, and the main concept and subconcept in relation to the themes were extracted from the four areas of science, and the learning contents were constructed in the integrated ways. While the main concept have relevance to subconcept in the interaction, the main concept have little relevance to subconcept in the stability. Therefore, the stability was to fit with middle school integrated science theme, but the interaction was not. The theme-based integrated science units developed was implemented in middle school, and the results are follows. First, the science achievement of group of theme-based integrated science teaching is significantly higher than those of group of traditional teaching. Second, the scores of the test of attitude toward science learning of the group of theme-based integrated science teaching is significantly higher than those of group of traditional teaching. Third, the students' perception of theme-based integrated science teaching was positive. The students have participation, interest, motivation in theme-based integrated science teaching, and students have difficulty in learning theme-based integrated science teaching.

  • PDF