• Title/Summary/Keyword: Factor of Safety

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Analysis of the Influence of Environmental Factors on the Density of Ecosystem-Disturbing Plant Sicyos angulatus - Centering on Miho Stream - (생태계교란 식물 가시박의 개체밀도에 대한 환경요인 영향 분석 - 금강수계 미호천을 중심으로 -)

  • Lee, Younggi;Kim, Hojoon;Kim, Leehyung
    • Journal of Wetlands Research
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    • v.22 no.4
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    • pp.295-301
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    • 2020
  • This research analyzed the relationship between environmental factors and the density of Sycios angulatus in the Miho Stream, Geum River water system in order to secure basic data for the control of the ecosystem-distrubing plant Sycios angulatus. As a result of the soil particle size analysis of Sycios angulatus habitat, it was found that the density of Sycios angulatus decreased as the silty and clay contents increased. Most of the Sycios angulatus habitats had high sandy and silt content, and low clay content of less than 2%. The increased flow rate reduced the density of Sicyos angulatus. This is because when the flow rate is increased, the Sicyos angulatus cannot grow due to the change in soil characteristics. Water quality plays a role in supplying nutrients when Sicyos angulatus are submerged. However, due to the change in soil characteristics during flooding, the density of Sicyos angulatus tended to decrease due to impaired growth. The Sicyos angulatus can be managed through artificial and natural techniques. The appropriate natural control technique is the creation of a natural waterway in the habitats to change the water contents.

A Study on the Operational Activation strategies of Gyeongin Port Using Fuzzy-IPA (Fuzzy-IPA분석을 활용한 경인항 운영 활성화에 대한 연구)

  • Park, Jong-Min;Yang, Tae-Hyeon;Park, Sung-Hoon;Yeo, Gi-Tae
    • Journal of Digital Convergence
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    • v.16 no.10
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    • pp.169-178
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    • 2018
  • Gyeongin Port has low awareness, insufficient hinterland infrastructures, and lower competitiveness. So, in this study, we conducted Fuzzy-IPA analysis reflecting the recognition of the consignor companies that are using Gyeongin port to suggest present practical improvement measures for the activation of the operation of Gyeongin port hereafter. As a result of the analysis, three factors, that is, cargo loading/unloading/storage costs, port facility fees, and incentive and support were derived as priority investment areas. Three factors, that is, cargo safety, infrastructure equipment, and inland transportation costs were derived as the areas for maintenance strengthening and factors related to cargo handling and service factors were derived as areas for maintenance of the status quo and areas for gradual improvement, respectively. This study is significant in that it analyzed the recognition of the consignor companies that are using Gyeongin port using a quantifying method and suggested realizable measures for activation based on the results of the analysis. In future studies, the frequency of ships' calling at the port and measures to diversify the sea routes should be additionally reflected on the analysis.

The Effects of Storytelling Family Classes Using Picture Books on the Resilience and Parent-Child Relationship of Adolescents: Focusing on the Core Concepts of 'Relationship' and 'Safety' in Middle School Technology·Home Economics (그림책을 활용한 스토리텔링 가족 수업이 청소년의 회복탄력성과 부모자녀관계에 미치는 효과: 중학교 기술·가정 '관계'와 '안전'의 핵심개념을 중심으로)

  • Joo, Hyunjung;Choi, Saeeun
    • Journal of Korean Home Economics Education Association
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    • v.32 no.1
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    • pp.167-184
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    • 2020
  • The purpose of this study was to examine the effects of storytelling lessons using picture books on the resilience of adolescents and the parent-child relationships in the family unit of home economics subject in middle school. For this purpose, I selected picture books of five themes on family type, family relationship, family conflict, sexual violence, domestic violence, and family loss, and developed a teaching-learning process plan for 'Family class with picture book' using storytelling elements and techniques. The teaching-learning plan was applied to 194 middle school students in technology·home economics classes, and the learning effet was evaluated by comparing pre- and post-tests. As a result, the resilience level perceived by adolescents increased significantly after class, but no significant effect was found on self-expansion, which is a sub-factor of sociality. In the parent-child relationship of adolescents, the effect of instruction was shown in all areas, and the affectional bonds felt in the relationship with mother than with father showed higher increase. In the family unit of home economics, storytelling lesson through picture book seems to have a positive influence on the adolescents in their relationship with the family by bringing up the potential power in them to stand against the adversities they may face.

On the Evaluation of Physical Distribution Service in Ports (항만물류서비스의 평가에 관하여)

    • Journal of Korean Port Research
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    • v.10 no.2
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    • pp.17-29
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    • 1996
  • It is required to consider pricing and non-pricing factors and external economy in order to achieve the objects of physical distribution system in a port. Recently, among the three factors, much attention has been paid to non-pricing factor in the system. Although physical distribution service in a port(PDSP)has been frequently mentioned in documents and literature related to port and shipping studies, few study on it has not been systematically and scientifically made due to the following problems; $\circ$ there are not proper criteria to evaluate level and quality of PDSP and as a result it is difficult to set up a unified standard for doing so. $\circ$ algorithms to evaluate problems with complex and ambiguous attributes and multiple levels in PDSP are not available. This thesis aims to establish a paradigm to evaluate PDSP and to abvance existing decision making methods to deal with complex and ambiguous problems in PDSP. To tackle the first purpose, extensive and thorough literature survey was carried out on general physical distribution service, which is a corner stone to handle PDSp. In addition, through interviews and questionnaire to the expert, it have extracted 82 factors of physical distribution service in a port. They have been classified into 6 groups by KJ method and each group defined by the expert's advice as follows; a. Potentiality b. Exactness c. safety d. Speediness e. Convenience f. Linkage Prior to the service evaluation, many kinds of its attributes must be identified on the basis of rational decision owing to complexity and ambiguity inherent in PDSP. An analytical hierarchy process (AHP) is a method to evaluate them but it is not applicable to PDSP that have property of non-additivity and overlapped attributes. Therefore, probablility measure can not be used to evaluate PDSP but fuzzy measure is required. Hierarchical fuzzy integral method, which is merged AHP with fuzzy measure, is also not effective method to evaluate attributes because it has vary complicated way to calculate fuzzy measure identification coefficient of attributes. A new evaluation algorithm has been introduced to solve problems with multi-attribute and multi-level hierarchy, which is called hierarchy fuzzy process(HFP).Analysis on ambiguous aspects of PDSP under study which is not easy to be defined is prerequisite to evaluate it. HFP is different from algorithm existed in that it clarified the relationship between fuzzy measure and probability measure adopted in AHP and that it directly calculates the family of fuzzy measure from overlapping coefficient and probability measure to treat and evaluate ambiguous and complex aspects of PDSP. A new evaluation algorithm HFP was applied to evaluate level of physical distribution service in the biggest twenty container port in the world. The ranks of the ports are as follows; 1. Rotterdam Port, 2. Hamburg Port, 3. Singapore Port, 4. Seattle Port, 5. Yokohama Port, 6. Long beach Port, 7. Oakland Port, 8. Tokyo Port, 9. Hongkong Port, 10. Kobe Port, 11. Los Angeles Port, 12. New york Port, 13. Antwerp Port, 14. Felixstowe Port, 15. Bremerhaven Port, 16. Le'Havre Port, 17. Kaoshung Port, 18. Killung Port, 19. Bangkok Port, 20. Pusan Port

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Study of the Factors Determining Life Satisfaction of Local Residents in Chungbuk Province (지역주민의 생활 만족도에 영향을 미치는 결정요인 연구 -충청북도를 대상으로-)

  • Cho, Taek-Hee;Bae, Min-Ki
    • The Journal of the Korea Contents Association
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    • v.17 no.5
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    • pp.591-601
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    • 2017
  • The purpose of this research was to identify the effects of factors determining life satisfaction (LS) of local residents in chungbuk province. After reviewing the literature, this research selected and developed the 9 categories and specific indicators of LS. This research had obtained data through a face to face investigation using questionnaire, which surveyed 1,619 residents at 11 local governments in chungbuk province. This research analyzed the data using descriptive statistical methods and multiple linear regression method. This research found that 1) the level of overall LS had 4.433 points out of 7, the level of residential environment satisfaction had highest point (4.911), but the level of leisure culture satisfaction had lowest point (4.155), 2) in multiple regression analysis, The effect of income and consumption level on LS was highest. The degree of labor and life-social services was important factor to increase LS. The results of this study were expected to provide many implications for implementing policies to improve LS in the country and local governments.

Factors Influencing Driving ability and Its Measurements in Older Driver: A Systematic Review (고령자의 운전능력 영향요인 및 측정도구에 대한 체계적 문헌고찰)

  • Woo, Ye-Shin;Shin, Ga-In;Park, Sang-Mi;Park, Hae Yean
    • 한국노년학
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    • v.38 no.1
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    • pp.225-241
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    • 2018
  • Self-driving is meaningful activity for older persons because it enlarges the range of activity and provides opportunities for social participation. Driving is a complex activity that requires integration of physical, cognitive and sensory functions and is influenced by human and psychological factors. Age related functional deterioration affects the driving ability of older drivers. The purpose of this study is to investigate the factors affecting the risk of accidents and driving cessation of elderly drivers through systematic literature review. MEDLINE, EMBASE, Cochrane Library, KoreaMed, Pubmed were used for searching articles published from 2007 to 2017. 'aged', 'aging', 'automobile driving', 'age factors' were used as search terms and 18 articles were finally selected for analysis among 1,458 articles. In result of the study, the most significant effect showed in the physical domain, the driving habit and the performance function. The most frequent used tools evaluated driving habit and the cognitive function. In demographic characteristics, there was a correlation with the driving discontinue according to sex and age. This study emphasizes the necessity of preparing measures for safety driving with elderly. In addition, it suggests the necessity of systematically services such as individual education programs based on various driving cessation related factors of the elderly.

A Study on the Acceptance Factors of the Introduction of a Smart IoT Technology for Well-being Companion Animal (반려동물 웰빙을 위한 스마트 IoT 기술 도입 수용요인에 관한 연구)

  • Kang, Sung Kwang;Kim, Hoontae;Ji, Yong Gu;Lee, Jeongyoung
    • The Journal of Society for e-Business Studies
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    • v.24 no.2
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    • pp.143-163
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    • 2019
  • The purpose of this study is to identify acceptance factors and influencing factors of respondents' adoption of smart IoT technology to companion animal health based on the integrated technology acceptance model. Based on the previous studies, we constructed the hypotheses by defining the technical factors, social factors, control variables, and mediating variables (UTAUT), and set the hypotheses between the independent variables of each factor and the dependent intention. A research model was designed to verify the relationship between variables. We developed questionnaires on the items and verified them through data collected from 494 people. As a result, product design, quality of service, product performance, and quality service of technological factors had a significant effects on performance expectancy and effort expectancy. However, product safety, product function awareness, and product price did not significantly affect performance expectancy and effort expectancy. Social influence had significant effects on cognitive effect, welfare system, and welfare facilities. In conclusion, the comparative analysis of technical factors and social factors showed that social factors have more significant effects on welfare systems and facilities.

Major Factors Influencing Landslide Occurrence along a Forest Road Determined Using Structural Equation Model Analysis and Logistic Regression Analysis (구조방정식과 로지스틱 회귀분석을 이용한 임도비탈면 산사태의 주요 영향인자 선정)

  • Kim, Hyeong-Sin;Moon, Seong-Woo;Seo, Yong-Seok
    • The Journal of Engineering Geology
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    • v.32 no.4
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    • pp.585-596
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    • 2022
  • This study determined major factors influencing landslide occurrence along a forest road near Sangsan village, Sancheok-myeon, Chungju-si, Chungcheongbuk-do, South Korea. Within a 2 km radius of the study area, landslides occur intensively during periods of heavy rainfall (August 2020). This makes study of the area advantageous, as it allows examination of the influence of only geological and tomographic factors while excluding the effects of rainfall and vegetation. Data for 82 locations (37 experiencing landslides and 45 not) were obtained from geological surveys, laboratory tests, and geo-spatial analysis. After some data preprocessing (e.g., error filtering, minimum-maximum normalization, and multicollinearity), structural equation model (SEM) and logistic regression (LR) analyses were conducted. These showed the regolith thickness, porosity, and saturated unit weight to be the factors most influential of landslide risk in the study area. The sums of the influence magnitudes of these factors are 71% in SEM and 83% in LR.

Analysis of Failure Behavior of Piles Embedded in Liquefied Soil Deposits (액상화 지반에 근입된 말뚝의 파괴거동 분석)

  • Cho, Chong-Suck;Han, Jin-Tae;Hwang, Jae-Ik;Park, Young-Ho;Kim, Myoung-Mo
    • Journal of the Korean Geotechnical Society
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    • v.22 no.11
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    • pp.123-131
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    • 2006
  • Liquefaction-induced lateral spreading has been the most extensive damage to pile foundations during earthquakes. Several cases of pile failures were reported despite the fact that a large margin of safety factor was employed in their design. In this study, 1-g shaking table tests were performed in order to analyze the failure behavior of piles embedded in liquefied soil deposits by buckling instability. As a result, it can be concluded that the pile subjected to excessive axial loads $(near\;P_{cr})$ can fail easily by buckling instability during liquefaction. When lateral spreading took place in sloping grounds, it was found that lateral loading due to lateral spreading increased lateral deflection of pile and reduced the buckling load. In addition, from the buckling shape of pile, difference between Euler's buckling and pile buckling vat observed. In the case of pile buckling, hinge formed at the middle point of the pile, not at the bottom. And in sloping grounds, location of hinge formation got lower compared with level ground because of the soil movements.

Analysis of Stability and Behavior of Slope with Solar Power Facilities Considering Seepage of Rainfall (태양광 발전시설이 설치된 사면의 강우시 침투를 고려한 안정성 및 거동 분석)

  • Yu, Jeong-Yeon;Lee, Dong-Gun;Song, Ki-Il
    • Journal of the Korean Geotechnical Society
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    • v.39 no.7
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    • pp.57-67
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    • 2023
  • Slope failures during rainfall have been observed in mountainous areas of South Korea as a result of the presence of solar power facilities. The seepage behavior and pore pressure distribution differ from typical slopes due to the presence of impermeable solar panels, and the load imposed by the solar power structures also affects the slope behavior. This study aims to develop a method for evaluating the stability of slopes with solar power facilities and to analyze vulnerable points by considering the maximum slope displacement. To assess the slope stability and predict behavior while considering rainfall seepage, a combined seepage analysis and finite difference method numerical analysis were employed. For the selected site, various variables were assumed, including parameters related to the Soil Water Characteristic Curve, strength parameters that satisfy the Mohr-Coulomb failure criterion, soil properties, and topographic factors such as slope angle and bedrock depth. The factors with the most significant influence on the factor of safety (FOS) were identified. The presence of solar power facilities was found to affect the seepage distribution and FOS, resulting in a decreasing trend due to rainfall seepage. The maximum displacement points were concentrated near the upper (crest) and lower (toe) sections of the slope.