• Title/Summary/Keyword: variable foundation

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Evaluation Methods of Soil Resilience Related to Agricultural Environment (농업환경 분야에서 토양 리질리언스 분야별 평가 방법)

  • Kim, Min-Suk;Min, Hyun-Gi;Hyun, Seung-Hun;Kim, Jeong-Gyu
    • Ecology and Resilient Infrastructure
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    • v.7 no.2
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    • pp.97-113
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    • 2020
  • Soil is the foundation of human life and the basis for food security. Considering this it is prioritized in the UN's Sustainable Development Goals (SDG). Therefore, research on soil resilience in the agricultural environment is crucial for sound and sustainable soil management, especially in highly uncertain and unpredictable conditions. Soil resilience is defined in different ways by several researchers; however, its definition typically includes the concepts of recovery and resistance to stress. The physical, chemical, and biological characteristics of soils that are used to assess the soil resilience, i.e., the response of soil to various types of stress are summarized in this study. In addition, various statistical processing techniques and quantification methods are summarized considering the wide spatial and temporal scope of soil resilience research. Several soil resilience studies typically conduct the following five steps: (1) soil and site selection (2) stress (independent variable) setting (3) soil characteristics and indicator (dependent variable) setting (4) performing various spatiotemporal scale experiments (5) statistical analysis. The previous and present studies present a general introduction of soil resilience, based on which, further practical research considering domestic agricultural environment should be conducted. The extensive range of soil resilience measurements will require collaboration between researchers in various fields.

A Study on the Quantitative Risk Assessment of Bridge Construction Projects (교량 공사 프로젝트의 정량적 리스크 평가에 관한 연구)

  • Ahn, Sung-Jin
    • Journal of the Korea Institute of Building Construction
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    • v.20 no.1
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    • pp.83-91
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    • 2020
  • The recent bridge construction projects is demanded more sophisticated risk management measures and loss forecasts to brace for risk losses from an increase in the trend of bridge construction. This study aims to analyze the risk factors that caused the loss of material in actual bridge construction and to develop a quantified predictive loss model, based on the past record of insurance payment by major domestic insurance companies for bridge construction projects. For the development of quantitative bridge construction loss model, the dependent variable was selected as the loss ratio, i.e., the ratio of insurance payout divided by the total project cost, while the independent variable adopted 1) Technical factors: superstructure type, foundation type, construction method, and bridge length 2) Natural hazards: typhoon and flood 3) Project information: construction period and total project cost. Among the selected independent variables, superstructure type, construction method, and project period were shown to affect the ratio of bridge construction losses. The results of this study can provide government agencies, bridge construction design and construction and insurance companies with the quantitative damage prediction and risk assessment services, using risk indicators and loss prediction functions derived from the findings of this study and can be used as a guideline for future basic bridge risk assessment development research.

Creep Behaviours of 9% Ni Alloy (Ni 합금강의 크리프 거동)

  • Hwang, Kyung-Choong;Kim, Jong-Bae;Kang, Sung Soo
    • Journal of Korean Ophthalmic Optics Society
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    • v.13 no.4
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    • pp.89-94
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    • 2008
  • Purpose: To observe the high temperature creep test and the fracture surface of the samples of 9% Ni alloy steel generally used for all kinds of mahine parts and predict the durability of that by determining a constant of C with a Larson-Miller variable. Methods: The equipment of this test was made into lever-beam style designed by Andrade and F. Garofalo et al.. The condition of creep test was set under 16 kinds of conditions after fixing 4 kinds of temperature condition and 4 kinds of stress condition to check how it effects the samples. Results: The temperature of creep test was increased, the stress index (n) of creep deformation was gradually decreased from 3.97 to 3.55. The activation energy of creep deformation was decreased from 90.39 to 83.64 kcal/mol when the stress was increased. A constant of C value by calculation of larson-Miller variable was about 22 and if temperature for use is suggested, the durability could be calculated. Conclusions: By analyzing the fracture phenomenon and suggesting the observation result of the fracture surface of the samples and creep test of 9% Ni alloy steel, the basic design data for the practical use of accessories in the field of equipment could be constructed and used to predict the durability of the equipment.

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A Study of the Factors Influencing the Staff Members' Recognition of the Level of Ethical Management in the Elderly Welfare Institutions (노인복지기관 종사자의 윤리경영수준 인식에 대한 영향 요인 연구)

  • Lim, HyoSoon;Kim, HyeWook;Joo, HyeonAah;Kim, SungHyun;MENG, XIANGQI
    • 한국노년학
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    • v.38 no.3
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    • pp.395-408
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    • 2018
  • The purpose of this study is to investigate the effects of staffs' general characteristics and institutional characteristics on the staff members' recognition of the level of ethical management in the elderly welfare institutions and to provide basic materials for raising standard of ethical management in the elderly welfare institutions. For this purpose, we conducted a questionnaire survey using structured self-filling-type questionnaires for 245 staffs of elderly welfare institutions in Seoul and Gyeonggi-do. This study sets general characteristics of staffs and institutional characteristics as the independent variables and the staff members' recognition of the level of ethical management as the dependent variable. The variables are investigated through the descriptive statistics such as frequency, percentage and average analysis, and the difference of effect on the staff members' recognition of ethical management in the elderly welfare institutions by each independent variable was analysed by t-test, ANOVA and multiple regression analysis. The results of the study shows that in terms of general characteristics of staffs, the higher male to female ratio and the higher educational level; and in institutional characteristics, the less experience in basic ethics education and the better ethical working environment of the institution are the positive factors for that the staff members estimate the level of ethical management of their workplace high. Based on these results, for making staff members recognize the level of ethical management in the elderly welfare institutions higher, we should create actual atmosphere of the ethical working environment in the institution and implement not formal but step-by-step intensive ethics education that make employees can apply it in the real situations. In conclusion, this study gives the practical suggestions for improving the staff members' recognition of ethical management level in the practice field of elderly welfare on the fast-changing trends including downsizing and privatization.

Development of Fashion Design Depending on the Modern Woman's Contra-sexual Trend (현대 여성의 콘트라섹슈얼 성향에 따른 패션 디자인 개발)

  • Yang, Eun-Jin;Lee, In-Seong
    • The Research Journal of the Costume Culture
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    • v.17 no.5
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    • pp.733-745
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    • 2009
  • The contra-sexual phenomenon that is recently focused is one of the new factors, which is focused when explaining the life style of progressive woman's image and it is creating cultural category. Moreover, the contra sexual people that are rising as new consuming subjects are not simple primary consumers but their shopping culture and cultural tastes are giving effects to many people. Because of the tendency, marketer of consuming industry are making efforts to predict the changes of contra-sexual people's shopping habits and tastes. Therefore, it is necessary to grasp contra-sexual phenomenon and research the fashion design aiming at that in order to predict woman's fashion image in the future. Therefore, the study considered concept and characteristic of contra-sexual phenomenon and surveyed its example in the popular culture. And, the study analyzed the formative characteristic of contra-sexual fashion shown in the public cultures such as drama and movie. On the basis of the result, design was suggested by reflecting contra-sexual fashion characteristic under the concept of 'Urban Splendor'. From the results above, it was possible to grasp the concept and characteristic of contra-sexual phenomenon, which appeared as a trend and understand new woman's image and the fashion that has changed because of it. It is considered that the establishment of the foundation of contra-sexual phenomenon, which plays as an important variable in woman's fashion, fashion accessory, cosmetic and advertisement field but it is hard to clarify, by analyzing the work aiming at contra-sexual phenomenon will be helpful for predicting the change of woman's fashion in the future.

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A Essay on International Development Cooperation and ODA of Science and Technology (과학기술의 국제개발협력과 ODA에 대한 시론적 고찰)

  • Kim, Duk-Jin
    • Korea and Global Affairs
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    • v.1 no.2
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    • pp.149-170
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    • 2017
  • This paper aim to find activities related to science and technology in the field of Official Development Assistance in Korea and to research its meaning. In order for Korea to achieve greater results through international cooperation in science and technology and ODA, it seems to be the primary task to establish a foundation for collecting social opinions. In other words, when civil society and the private sector are not willing to participate, international cooperation has many limitations in achieving substantial benefits because it embodies the problem of domestic politics. And the science and technology ODA will be a factor considered to be more important variable in the international political order in which multiple actors such as supranational organizations and social organizations play a role in the multi-layer.

The Correlation Analysis through the Contact Stress and the Curvature Radius according to Flexion Angle for the Design of Unicompartment Knee Replacement (반치환 슬관절의 설계 평가를 위한 굴곡각도에 따른 곡률반경과 접촉응력의 상관도 분석)

  • Lee, YongKyung;Yoo, OuiSik;Kim, JaeWon;Lim, Dohyung;Jung, TaeGon;Kim, JungSung
    • Journal of Biomedical Engineering Research
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    • v.37 no.6
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    • pp.215-221
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    • 2016
  • Conformity between the femoral component and tibial insert within the knee replacement may be measured in frontal or sagittal view, and shows differences in the curvature radius of the femoral component depending on the flexion angle, i.e., curvature radius has a complex effect on contact stress. Therefore, it is essential to confirm how the curvature radius effects contact stress, and provide an important variable to reduce contact stress. This study correlated contact stress with curvature radius measured in frontal and the sagittal views and confirmed the effect of curvature radius for assessment of the Newly Designed Unicompartment Knee Replacement (NDUKR). Finite element models were constructed for NDUKR and $Zimmer^{(R)}$ Unicompartment High Flex Knee Replacement system (ZUKR), incorporating the curvature radius as measured in either frontal or sagittal view. The femoral component had 1200N of compressive load applied approximately 1.65xbody weight. Contact stress was predicted at flexion angles $0^{\circ}C$, $30^{\circ}C$, $60^{\circ}C$, $90^{\circ}C$ and $120^{\circ}C$, for NDUKR: 42, 47.7, 47.7, 51.2, and 54.1 MPa, and ZUKR: 41.2, 49.5, 53.2, 54.3, and 57.4 MPa, respectively. Correlation analysis showed the influence of curvature radius measured from the sagittal view was larger than for frontal view.

Damage constitutive model of brittle rock considering the compaction of crack

  • Gu, Qingheng;Ning, Jianguo;Tan, Yunliang;Liu, Xuesheng;Ma, Qing;Xu, Qiang
    • Geomechanics and Engineering
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    • v.15 no.5
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    • pp.1081-1089
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    • 2018
  • The deformation and strength of brittle rocks are significantly influenced by the crack closure behavior. The relationship between the strength and deformation of rocks under uniaxial loading is the foundation for design and assessment of such scenarios. The concept of relative crack closure strain was proposed to describe the influence of the crack closure behavior on the deformation and strength of rocks. Considering the crack compaction effect, a new damage constitutive model was developed based on accumulated AE counts. First, a damage variable based on the accumulated AE counts was introduced, and the damage evolution equations for the four types of brittle rocks were then derived. Second, a compaction coefficient was proposed to describe the compaction degree and a correction factor was proposed to correct the error in the effective elastic modulus instead of the elastic modulus of the rock without new damage. Finally, the compaction coefficient and correction factor were used to modify the damage constitutive model obtained using the Lemaitre strain equivalence hypothesis. The fitted results of the models were then compared with the experimental data. The results showed that the uniaxial compressive strength and effective elastic modulus decrease with an increase in the relative crack closure strain. The values of the damage variables increase exponentially with strains. The modified damage constitutive equation can be used to more accurately describe the compressive deformation (particularly the compaction stage) of the four types of brittle rocks, with a coefficient of determination greater than 0.9.

The determinants of vertical overbite and overbite depth indicator(ODI) (수직피개의 결정요인과 수직피개 심도지수(ODI)의 상호관계)

  • Yang, Sang-Duk
    • The korean journal of orthodontics
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    • v.29 no.3 s.74
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    • pp.349-360
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    • 1999
  • The concept of denture frame, both the vertical and horizontal relationship of the dentitions are ultimately related to a skeletal configuration, leads to postulate that the vertical overbite will be determined by the jaw rotations and anteroposterior jaw relationship. Also, ODI is analyzed to be composed of the determinant factors of overbite such as FMA PPA and FABA. From the geometric analyses of an interrelationship between the ODT and the overbite determinants, the following formula can be induced. ODI norm=$85^{\circ} - 0.5 PMA-(1.08 - 0.01 FMA)(FABA - 81^{\circ})$. This formula indicates that the norm of ODI is not constant value but variable one according to the individual skeletal frames. Through the application of the formula to the various clinical cases, it is proved that the new concept, relativity of the ODI norm, is very diagnostically useful.

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Application of Regression Tree Model for the Estimation of Groundwater Use at the Agricultural (Dry-field Farming and Rice Farming) Purpose Wells (농업용(전작 및 답작용) 지하수 이용량 추정을 위한 회귀나무 모형의 적용)

  • Kim, yoo-Bum;Hwang, Chan-Ik
    • The Journal of Engineering Geology
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    • v.29 no.4
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    • pp.417-425
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    • 2019
  • Agricultural groundwater use accounts for 51.8% of total groundwater use, so accurate estimation of groundwater use is important for efficient groundwater management. The purpose of this study is to develop a method for estimating the groundwater use of agricultural (rice farming and dry-field farming) wells using regression tree model based on the measured data of 370 wells. Three input variables of the model were evaluated as being significant: well depth, pipe diameter, and pump capacity, and the importance of each variable was 75% for well depth, 17% for pipe diameter, and 8% for pumping capacity. The daily usage of agricultural (rice farming and dry-field farming) wells by the regression tree model was estimated to be very similar to the actual usage, compared to the previous estimation method proposed by the Ministry of Construction and Transportation. In the future, it is expected that the reliability of the usage statistics will be improved if additional observed data is secured and this classification method is modified.