• Title/Summary/Keyword: aggregate selection

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Selection of Suitable Aggregates for Long-term Stability of Concrete (콘크리트 장기 안정성을 위한 골재의 선택)

  • Yang, Dong-Yoon;Lee, Dong-Young
    • Economic and Environmental Geology
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    • v.28 no.5
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    • pp.519-525
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    • 1995
  • Recently, there have been several cases of serious accidents on concrete structure resulting from rapid deterioration of concrete strength. On the view point of long term stability of concrete, deterioration of concrete strength is mostly due to chemical reaction between alkali and reactive aggregates (alkali-aggreagte reaction; AAR) in concrete rather than a problem of execution. For long-term stability of concrete, concrete aggregates must be carefully selected. Some of rocks used for concrete aggregates contain deleterious minerals reactive to alkali components in concrete. Most of AAR result from chemical reaction between alkali components and reactive silica minerals in aggregates (so called alkali-silica reaction; ASR). The silica minerals are as follows; quartz with seriously distorted lattice structure, volcanic glass, chalcedony, opal, cristobalite, tridymite, etc. ASR may cause expansion and cracks, further collapse in concrete structure, in a few years. In case of crushed aggregates, only a part of rock mass without reactive minerals must be produced in aggregates mine after thorough examination of the distribution of rocks with reactive minerals. In case of natural aggregates, the total content of reactive minerals must be calculated, if, the content is more than 20%, the rate should be lower by mixing other non-reactive crushed- or natural aggregates. If it is obliged to use concrete aggregates all containing deleterious minerals in a discrete area, they must be used with low alkali cement Even if it is low quality in the chemical properties, aggregates with suitable range in the physical properties can be utilized as the aggregate of other purposes.

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The Research Regarding the Visual Continuity of the Green in the Re-development Area by Using the Aerial Photograph

  • Lee Hyuk-Hae;Koshimiz Hajime
    • Journal of the Korean Institute of Landscape Architecture International Edition
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    • no.2
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    • pp.102-108
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    • 2004
  • In the city of Asia like Seoul and Tokyo, aggregate power is poured into the city making which is suitable in new age. Large-scale re-development is active in various places as the present condition, As for the various East Asian cities, high-level utilization conversion of the land and high conversion of the building are advanced. As for these realities, the re-development is advanced in the situation that has not been clarified enough though it is true that green of the city has decreased. This research was aimed at the clarifying the allocation of greenery when proceeding with town planning projects by quantifying the possibility of allocating greenery in the form of rooftop landscaping in redeveloped areas. Moreover, the distribution of the green in the re-development region was calculated and the coexistence level of green space was calculated, The realities of a desirable green were clarified in the spectacle by understanding a sight and spatial continuousness in the green. In order to clarify the potentiality of roof greenery revaluating, the research was conducted by analyzing from aerial photographs, in Tokyo and Seoul, And the flow of the research was conducted by selection of research object area, taking pictures, acquisition of the aerial photography, rearrangement the data and the analysis. As a result, I was able to prepare a land vegetation coverage classification chart and obtain data pertaining to the level of urban and green tract of land for the researched cities of Tokyo and Seoul. By analyzing this data, we were able to indicate patterns of greenery unable to be obtained through data from ratio of vegetation coverage and ascertain the effectiveness of rooftop landscaping.

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Multi-Criteria Group Decision Making under Imprecise Preference Judgments : Using Fuzzy Logic with Linguistic Quantifier (불명료한 선호정보 하의 다기준 그룹의사결정 : Linguistic Quantifier를 통한 퍼지논리 활용)

  • Choi, Duke Hyun;Ahn, Byeong Seok;Kim, Soung Hie
    • Journal of Intelligence and Information Systems
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    • v.12 no.3
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    • pp.15-32
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    • 2006
  • The increasing complexity of the socio-economic environments makes it less and less possible for single decision-maker to consider all relevant aspects of problem. Therefore, many organizations employ groups in decision making. In this paper, we present a multiperson decision making method using fuzzy logic with linguistic quantifier when each of group members specifies imprecise judgments possibly both on performance evaluations of alternatives with respect to the multiple criteria and on the criteria. Inexact or vague preferences have appeared in the decision making literatures with a view to relaxing the burdens of preference specifications imposed to the decision-makers and thus taking into account the vagueness of human judgments. Allowing for the types of imprecise judgments in the model, however, makes more difficult a clear selection of alternative(s) that a group wants to make. So, further interactions with the decision-makers may proceed to the extent to compensate for the initial comforts of preference specifications. These interactions may not however guarantee the selection of the best alternative to implement. To circumvent this deadlock situation, we present a procedure for obtaining a satisfying solution by the use of linguistic quantifier guided aggregation which implies fuzzy majority. This is an approach to combine a prescriptive decision method via a mathematical programming and a well-established approximate solution method to aggregate multiple objects.

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A study on the cultural ideology of narrative in 3D C.G. Animation (3D C.G. 애니메이션에 반영된 문화적 이데올로기 - <슈렉>을 중심으로)

  • Koh, Eun-Young
    • Cartoon and Animation Studies
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    • s.6
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    • pp.7-22
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    • 2002
  • Animation constitutes the core of the media industry, which in turn lies at the center of the cultural industry. It is considered one of the industries where South Korea has the competitive edge over other countries. With the pool of customers getting wider, the genre of animation has become more and more diverse, forming a great market for it. Aware of this trend, this study focused on animation as a part of the pop culture, and on providing corresponding various viewpoints for future cultural studies. This researcher measured the practicality and persuasiveness of this study through Shreck, a three-dimensional C.G. animation which is acclaimed for its success in dismantling the old grammar of animation movies that represent the anti-Disney ideas. This researcher felt it imperative to heed the unique language of Shreck, which contains discourses on various cultural ideologies such as paradoxical structure that pits entertainment that is shown through dismantling of the canon, feminism and antifeminism against each other. This study analyzed the entertaining element of the animation genre by means of the Semiotics of Keith Moxey, thereby attempting to establish a legitimate social status of the genre, whose artfulness has been depreciated in the art society. In chapter II, this researcher examines the chronological development of three-dimensional C.G. animation that has shown a rapid advancement. Chapter III defines the cultural ideology of Shreck by exploring basic theories and texts employed in analysis of art works. This study started with the assumption that defines, from the viewpoint of symbology, the animation text as an aggregate of discourses on entertainment, and competitive and paradoxical ideologies. Then, this researcher analyzed the text and the generation process of meanings in Shreck. Consequently, this study has come to the following conclusions: First, Shreck induces changes of concepts about the canon by means of distorting and reversing the existing animation movies, which seems to reflect in the contemporary tendency of seeking new interpretations of entertainment. Second, Shreck shows up the cognitive changes of our age as to feminism by competing feminism against antifeminism. Although Shreck serves as a venue of competition between the two opposing ideas, it stops short of brushing off women as outsiders in society. Rather, it represents the resistance to the male chauvinism existing in the structures of animation and culture. As shown in the text analysis, Shreck presents an advent of a new ideology critical of the previous animation films. In addition, it reflects in the struggle between the pro-feminism on the part of the viewers and the anti-feminism that lies in the social and culture structure. This study, however, is limited in its scope and selection of subject. First, although this researcher has stressed the importance of understanding the animation as part of the pop culture and conducting researches within the historic paradigm, this study fails to provide an in-depth insight in the impacts that the changes in the C.G. industry and the systematic conditions may have on the three-dimensional C.G. animation genre. Furthermore, this study runs the risk of being understood as pro-American due to its selection of Shreck as its research subject.

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A Review on Improvements of Climate Change Vulnerability Analysis Methods : Focusing on Sea Level Rise Disasters (도시 기후변화 재해취약성분석 방법의 개선방안 검토 : 해수면상승 재해를 중심으로)

  • Kim, Ji-Sook;Kim, Ho-Yong;Lee, Sung-Ho
    • Journal of the Korean Association of Geographic Information Studies
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    • v.17 no.1
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    • pp.50-60
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    • 2014
  • The purpose of this study is to identify characteristics and improvements of the climate change vulnerability analysis methods to build a safe city from disasters. For this, an empirical analysis on sea level rise disasters was performed focusing on Heaundae-gu in Busan. For the analysis, Census output areas and Dongs were set as analysis unit and their disaster vulnerability was analyzed. Improvements were reviewed through the comparison and review of analysis process and results. According to analysis results, Modifiable Areal Unit Problem(MAUP) which gives different results according to aggregate unit occurs. Improvements were induced by analysis process, and it was found that in spatial unit setting stage that becomes the base of analysis, analysis unit adjustment, score computation method adjustment, and clearer analysis method for each disaster type would be needed. In analysis execution stage, it was thought that weighting according to variables, diversification of variables, and exclusion of subjective analysis selection method would be needed. It is expected that accurate the total disaster vulnerability analysis will be the base for the improvement of efficiency in urban resilience responding to future weather changes.

Energy-Efficient Data Aggregation and Dissemination based on Events in Wireless Sensor Networks (무선 센서 네트워크에서 이벤트 기반의 에너지 효율적 데이터 취합 및 전송)

  • Nam, Choon-Sung;Jang, Kyung-Soo;Shin, Dong-Ryeol
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.11 no.1
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    • pp.35-40
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    • 2011
  • In this paper, we compare and analyze data aggregation methods based on event area in wireless sensor networks. Data aggregation methods consist of two methods: the direct transmission method and the aggregation node method. The direct aggregation method has some problems that are data redundancy and increasing network traffic as all nodes transmit own data to neighbor nodes regardless of same data. On the other hand the aggregation node method which aggregate neighbor's data can prevent the data redundancy and reduce the data. This method is based on location of nodes. This means that the aggregation node can be selected the nearest node from a sink or the centered node of event area. So, we describe the benefits of data aggregation methods that make up for the weak points of direct data dissemination of sensor nodes. We measure energy consumption of the existing ways on data aggregation selection by increasing event area. To achieve this, we calculated the distance between an event node and the aggregation node and the distance between the aggregation node and a sink node. And we defined the equations for distance. Using these equations with energy model for sensor networks, we could find the energy consumption of each method.

A Study Regarding Measurements of Bacterial Contamination Levels in Radiology Room Equipment (방사선과 촬영실 장비의 세균오염도 측정)

  • Choi, Eun-Jin;Song, Hyeon-Je;Dong, Kyung-Rae;Kim, Chang-Bok;Ryu, Jae-Kwang;Kwak, Jong-Gil
    • Journal of Radiation Industry
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    • v.11 no.1
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    • pp.1-6
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    • 2017
  • Reported some level of bacteria in areas that are well made contact in Radiology imaging room evaluate the importance of cleanliness in the hospital management of equipment to check for the presence of pathogenic bacteria. Gwang-ju and Jeol-la city and medium-sized hospitals in the material with a cotton swab and rub evenly Radiology selection cassette, a handle, Apron of the imaging apparatus having the most contact with patients from July 2016 to August 2016 as a target in place and special studios 6, and saline solution will placed in a test tube containing. The swab sample was diluted 1,000 times, you can see the bacteria and the intestinal bacterial selective medium Trypticase Soy Agar (TSA), Muller-Hinton Agar (MHA), Eosin-Methylene Blue (EMB), ENDO(BD, NJ, USA) then incubated smear to. In the incubator (incubator, SANYO, Japan) was observed after incubation of bacteria and counting the total number of bacteria also Colonies (colony) suspected intestinal bacteria were isolated and cultured on KIA medium (BD, NJ, USA). As a result, it was found that this came Gram positive Coccus A hospital handle the F hospital, from the C Gram positive Coccus cassette and handle the F hospital. The striking yellow coloring Staphylococcus aureus 110 agar (STA 110) in the medium sample, but it is suspected staphylococcal Coccus to the final identification in the laboratory is not a single specimen of the two samples from Gram positive Coccus biochemical identification Identification Kit is an API could not, it was thought to be non-Staphylococcus aureus was cultured on blood agar suggesting that (BAP) blood of dance. Dynamic tests were conducted biochemical API kit of the two samples were identified from Gram positive Coccus bacteria Escherichia coli (E. coli) is F hospital cassette was confirmed Eenterobacter cloaca in A hospital possession. Did not aggregate O-26, O-111, O-157 and the serum test was conducted in the laboratory from the E. coli F cassette hospital.

A Study on the Forecasting Model on Market Share of a Retail Facility -Focusing on Extension of Interaction Model- (유통시설의 시장점유율 예측 모델에 관한 연구 -상호작용 모델의 확장을 중심으로)

  • 최민성
    • Journal of Distribution Research
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    • v.5 no.2
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    • pp.49-68
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    • 2001
  • In this chapter, we summarize the results on the optimal location selection and present limitation and direction of research. In order to reach the objective, this study selected and tested the interaction model which obtains the value of co-ordinates on location selection through the optimization technique. This study used the original variables in the model, but the results indicated that there is difference in reality. In order to overcome this difference, this study peformed market survey and found the new variables (first data such as price, quality and assortment of goods, and the second data such as aggregate area, and area of shop, and the number of cars in the parking lot). Then this study determined an optimal variable by empirical analysis which compares an actual value of market share in 1988 with the market share yielded in the model. However, this study found the market share in each variables does not reflect a reality due to an assumption of λ-value in the model. In order to improve this, this study performed a sensitivity analysis which adds the λ value from 1.0 to 2.9 marginally. The analyzed result indicated the highest significance with the market share ratio in 1998 at λ of 1.0. Applying the weighted value to a variable from each of the first data and second data yielded the results that more variables from the first data coincided with the realistic rank on sales. Although this study have some limits and improvements, if a marketer uses this extended model, more significant results will be produced.

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A Study on the Resource Recovery of Fe-Clinker generated in the Recycling Process of Electric Arc Furnace Dust (전기로 제강분진의 재활용과정에서 발생되는 Fe-Clinker의 자원화에 관한 연구)

  • Jae-hong Yoon;Chi-hyun Yoon;Hirofumi Sugimoto;Akio Honjo
    • Resources Recycling
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    • v.32 no.1
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    • pp.50-59
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    • 2023
  • The amount of dust generated during the dissolution of scrap in an electric arc furnace is approximately 1.5% of the scrap metal input, and it is primarily collected in a bag filter. Electric arc furnace dust primarily consists of zinc and ion. The processing of zinc starts with its conversion into pellet form by the addition of a carbon-based reducing agent(coke, anthracite) and limestone (C/S control). These pellets then undergo reduction, volatilization, and re-oxidation in rotary kiln or RHF reactor to recover crude zinc oxide (60%w/w). Next, iron is discharged from the electric arc furnace dust as a solid called Fe clinker (secondary by-product of the Fe-base). Several methods are then used to treat the Fe clinker, which vary depending on the country, including landfilling and recycling (e.g., subbase course material, aggregate for concrete, Fe-source for cement manufacturing). However, landfilling has several drawbacks, including environmental pollution due to leaching, high landfill costs, and wastage of iron resources. To improve Fe recovery in the clinker, we pulverized it into optimal -sized particles and employed specific gravity and magnetic force selection methods to isolate this metal. A carbon-based reducing agent and a binding material were added to the separated coarse powder (>10㎛) to prepare briquette clinker. A small amount (1-3%w/w) of the briquette clinker was charged with the scrap in an electric arc furnace to evaluate its feasibility as an additives (carbonaceous material, heat-generating material, and Fe source).