• Title/Summary/Keyword: 이중차이모델

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Flow Dimensional Analysis for Constant Pressure Injection Test (정압주입시험을 이용한 지하수유동차원 해석)

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    • The Journal of Engineering Geology
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    • v.3 no.2
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    • pp.149-165
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    • 1993
  • Nowadays, the field hydraulic test is still an only method to evaluate groundwater characteristics in subsurface. The results of hydraulic test are very important for the concept model of fracture hydrogeology as well as the geometric pattern of fractures. The hydraulic tests performed in Korea are generally analysed under such assumption as steady radial flow in homogeneous aquifer or along simple geometry of fractures. Also the transmissivity measured in a fixed interval length is equivalent to a sum of individual fracture transmissivities in test legth. The boundary effects of weH hydraulics and the geometry of flow paths are hardly obtained from the test results analysed by a steady flow method. To circumvent this problem, the flow dimensional analysis was attempted from the results of constant pressure injection test carried out in a fractured granite area. A comparison of the hydraulic conductivity values from the transient and steady analysis shows that the latter is about a factor of 2~3 higher than the former. However, it was possible to analyse a flow dimension of each test interval from flow rate variation with time. The upper part of the bedrock(<10m deep) indicates an open boundary and the flow dimension shows nearly steady states, while the lower part of the bedrock(>25m deep) is characterized as sublinear flow dimension with a dosed boundary. In one of the test sections(15m deep), the flow dimension was changed from linear flow to spherical flow. From the experience of this study, one of the immediate problems to be solved is to enhance the field testing equipments, i.e., an accurate flowmeter with autorecording and a pressure detecting device to be able to install in the test section.

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The Effects of the National Basic Livelihood Security System on labor supply (국민기초생활보장제도의 노동공급 효과)

  • Lee, Sang-Eun
    • Korean Journal of Social Welfare
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    • v.56 no.2
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    • pp.71-91
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    • 2004
  • The National Basic Livelihood Security System implemented from October 2000 has expanded cash assistance to cover the poor households that have work ability. The cash assistance for the households with work ability has positive aspects of providing basic livelihood security for all people, but many people have worried about its negative aspects such as the decrease of labor supply among the low-income people with work ability. However, there has been few study that evaluated the effects of the NBLS implementation on labor supply. One of the reason for this may be related with the difficulty of research methodology that there were neither program group nor control group, because NBLS was implemented for all the people at the same time. This study suggests alternative program groups and control groups based on work ability and education. Using wave1 to wave5 data of the Korean Labor and Income Survey, this study estimated the effects of the NBLS implementation on employment and work hours. A difference-in-difference approach was applied to these alternative program and control groups. I found that the implementation of NBLS did not have any statistically significant effects on employment an work hours. It is too early to conclude from this result that cash assistance for the poor households with work ability does not induce any labor supply decrease in Korea. Rather, I interpret this result as reflecting that the NBLS system was too limited to induce any sizable decrease of labor supply or that the work requirement imposed on the recipients with work ability was effective in deterring work disincentive among the low-income population. Future research need to explore better program and control groups and investigate long-term effects.

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Influence of Hypoxic Exercise at Head Down Tilt on Cardiovascular Responses (머리하향기울기 자세에서 운동 중 저산소호흡이 심혈관계반응에 미치는 영향)

  • Kim, Kyong-Tae;Lee, Dae-Taek
    • Aerospace Engineering and Technology
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    • v.8 no.1
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    • pp.207-214
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    • 2009
  • The purpose of this study was to examine the influence of hypoxic exercise at head down tilt (HDT) on cardiovascular responses. Eight men ($23{\pm}2$ yrs, $176{\pm}4$ cm, and $75{\pm}8$ kg) underwent four separate exercise testing sessions; seated normoxia (SN), seated hypoxia (SH), HDT normoxia (HN), and HDT hypoxia (HH). Each participant performed the leg cycling at predetermined 40% of maximal aerobic capacity relevant to each posture for 15 min. Heart rate was higher in SH than SN and higher also in HH than SH (p<0.05). Blood oxygen saturation was lower in SH than SN (p<0.05). During resting, diastolic blood pressure and mean arterial pressure was significantly lower in HDT than seated posture (p<0.05). No differences were found between conditions in hemoglobin and hematocrit and electrolytes including, sodium, potassium, and chloride. Lactate was higher in SH than SN. In conclusion, there was no effect for cardiovascular responses to duplicate stimuli both hypoxia and posture.

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Determination of Design Parameters with SWAN Model at Southwest Coast (SWAN모형을 이용한 남서 도서해역에서의 설계 파라메타 추출)

  • Kim, Kang-Min;Kang, Suk-Hyung;Lee, Joong-Woo;Lee, Hoon;Kwon, So-Hyun
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.29 no.1
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    • pp.253-260
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    • 2005
  • Recently, the storms which hit Korean Peninsula are getting bigger, and the damages from the storms are wide spreaded. Thus, and approach with disaster prebention to offshore area and/or opened island area is neccessary. The existing wave design parameter was calculated with linear regular wave models inputting deep water design wave or wind sources. so it wasn't able to deal with wind-induced waves, interactions with waves, and redistribution of wave energy simultaneously. In this study, we made numerical simulation with SWAN(Simulation Waves Nearshore) Model which can consider development of waves and winds and their interference. The result from this model shows much different with those from existing model's. so the result from this study, especially in this modeling area, could be used for harbor design and coastal disaster prevention field in the future.

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Meaning of the Expression a:b=c:d and Implications for Teaching (비례식 a:b=c:d의 의미 분석과 학습 지도에의 시사점)

  • Yim, Jaehoon
    • Journal of Elementary Mathematics Education in Korea
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    • v.23 no.3
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    • pp.273-288
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    • 2019
  • This study focuses on understanding proportionality, in particular, what constitutes relational understanding of a:b=c:d, which is called proportional expression. The meanings of a:b=c:d are analyzed and some suggestions are offered for improving the teaching and learning of it. The equation a:b=c:d has three different meanings. First, it represents two different structures in one proportional situation. Second, it represents a common structure in two different proportional situations. Finally, it represents a number or a quantity underlying in different proportional situations. It is important to choose and use a unit flexibly to understand the first and the second meanings of a:b=c:d, Double strip diagram and double number line are useful to visualize the meanings of a:b=c:d. In addition, what a number or a quantity in the third meaning of a:b=c:d refers to in proportional situations should be emphasized in teaching and learning of a:b=c:d.

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The Relative Influence of Political Ad Attitude and Candidate Cognition On the Candidate Attitude - Focused On Direct Comparative, Indirect Comparative, and Noncomparative Ad - (정치광고에서 광고 태도와 후보자 인지가 후보자 태도에 미치는 상대적 영향력에 관한 연구 -직접비교 광고, 간접비교 광고와 일반광고의 비교-)

  • Moon, Jae-Hak
    • Management & Information Systems Review
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    • v.32 no.5
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    • pp.101-117
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    • 2013
  • This study compares the relative effectiveness of affective factor(Ad attitude) and cognitive factor(candidate cognition) on candidate attitude among three ad types - direct comparative, indirect comparative, and noncomparative ads. The results showed that in direct comparative advertising context the candidate cognition is dominant in determining candidate attitude. In indirect comparative advertising context candidate cognition is also dominant in determining candidate attitude, but the difference is less than direct comparative advertising. In noncomparative advertising context the ads attitude is dominant in determining candidate attitude. According to research outcomes, it could be said that direct comparative advertising is more effective than indirect comparative advertising in political advertising area.

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An Empirical Study on Prediction of the Art Price using Multivariate Long Short Term Memory Recurrent Neural Network Deep Learning Model (다변수 LSTM 순환신경망 딥러닝 모형을 이용한 미술품 가격 예측에 관한 실증연구)

  • Lee, Jiin;Song, Jeongseok
    • The Journal of the Korea Contents Association
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    • v.21 no.6
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    • pp.552-560
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    • 2021
  • With the recent development of the art distribution system, interest in art investment is increasing rather than seeing art as an object of aesthetic utility. Unlike stocks and bonds, the price of artworks has a heterogeneous characteristic that is determined by reflecting both objective and subjective factors, so the uncertainty in price prediction is high. In this study, we used LSTM Recurrent Neural Network deep learning model to predict the auction winning price by inputting the artist, physical and sales charateristics of the Korean artist. According to the result, the RMSE value, which explains the difference between the predicted and actual price by model, was 0.064. Painter Lee Dae Won had the highest predictive power, and Lee Joong Seop had the lowest. The results suggest the art market becomes more active as investment goods and demand for auction winning price increases.

A Comprehensive Review of the Foreign Literature regarding Protest Crowd Counting (집회시위 참가인원 집계방식에 대한 선행연구 고찰 - 국외연구 분석 중심으로 -)

  • Kim, Hak-kyong
    • Korean Security Journal
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    • no.58
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    • pp.9-34
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    • 2019
  • The Korean Police Force is equipped with the dual responsibility to not only protect the constitutional right to protest, but also prevent potential disorder and misconduct might be caused by the abuse of such a right. To this end, the Korean national police employ the crowd counting methodology, termed 'Maximum Figure at Any One Time' with a view to dispatching the proportionate number of police officers to protest scenes for safety management. However, protest organizers rather take advantage of 'Cumulative Figure' methodology, the purpose of which being to publicize the wide recognition of success, noticeably by demonstrating that as many people as possible support for their cause or voice. Hence, different estimates generated by different methods have raised serious political issues in Korean society. Nevertheless, it is found out that there are only three existing academic studies in Korea regarding crowd counting methods, and they are mainly geared towards comparing the two methods, unfortunately without any attempt to analyze the foreign literature in details. Keeping the research gap in mind, the research conducts a comprehensive review of the foreign literature with relation to protest crowd counting methods. Derived from the review and analysis, the counting methods can be broadly categorized into the three models such as: 1) Grid/Density Model, 2) Moving Crowds Model, and 3) Electronic & Non-Image Model. In the end, the research provides brief explanations regarding specific research findings per each model, and further, suggests some policy implications for the development of more accurate crowd counting methodology at protests in Korea.

.A Study on Parents' Transnational Educational Passion in the Tendency of Globalization : The Potential and Limitations of Educational Nomadism (세계화의 흐름에서 학부모의 초국가적 교육열 - 교육노마디즘의 가능성과 한계를 중심으로 -)

  • Kim, So-Hee
    • Korean Journal of Culture and Arts Education Studies
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    • v.5 no.1
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    • pp.97-147
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    • 2010
  • Under the recent trend of globalization, a new proposal on education has not been able to avoid the request for multi-cultural trend. Furthermore, education has been exposed to circumstances which are far different from the previous situations in which global cooperation and intercultural understanding have been more emphasized. 'Educational Nomadism'is a metaphor of creating new value and significance of education. In fact, transnational education which could be a crisis and opportunity at the same time has recently been the mainstream throughout the world. In terms of education, Korea has encountered base hollowing-out in which excessive dependence on the US education and autonomous education coexist. In fact, the world has spent a lot of time and money to have better educational background on a resume through redundant expense by the government and parents. Under this critical situation, it's urgent to change Korea's modern education into a creative educational system in connection with an advanced foreign educational system and further develop the advantage of Korea's education. A parent's investment in his/her child is a support to create new culture as well as an assistance for hope and better future of Korean education. A new direction of parents' education fever that has opened a door to global communitas can stir up infinite potential through which the flow of education fever can be changed to the resources of new civilization. The global cooperation and efforts for communitas means the communication with this world. Through this communication, the culture in which people are forced to zero-sum competition can leap into the education for change of civilization which creates pleasure of self sufficiency and donation.

A Study on the Ultimate Strength Behavior according to Modeling Range of the Stiffened Plate (선체보강판의 모델링범위에 따른 최종강도거동에 관한 연구)

  • Park, Joo-Shin;Ko, Jae-Yong;Park, Sung-Hyeon
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.10 no.2 s.21
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    • pp.35-39
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    • 2004
  • Ship structures are basically an assembly of plate elements and the load-carrying capacity or the ultimate strength is one of the most important criteria for safety assessment and economic design. Also, Structural elements making up ship plated structures do not work separately, resulting in high degree of redundancy and complexity, in contrast to those of steel framed structures. To enable the behavior of such structures to be analyzed simplifications or idealizations must essentially be made considering the accuracy needed and the degree of complexity of the analysis to be used On this study, to investigate effect of modeling range, the finite element method are used and their results are compared varying the analysis ranges. The model has been selected from bottom panels of merchant ship structures. For FHA, three types of structural modeling are adopted in terms of the extent of the analysis. The purpose of the present study is to numerically calculate the characteristics of ultimate strength behavior according to the analysis ranges of stiffened panels subject to uniaxial compressive loads.

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