• Journal of the Korean GEO-environmental Society
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• v.23 no.12
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• pp.17-23
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• 2022

This paper analyze the precast panel retaining wall's safety factor changes based on the numerical analysis using PLAXIS 2D software. Numerical analysis conditions include construction method, nail and panel fixing method, backfill material compaction conditions, rainfall conditions. The classification according to the construction method of the precast panel retaining wall includes the top-down and bottom-up methods. The difference between the top-down and bottom-up methods is the presence or absence backfill material and the ground excavation method. The top-down method involves vertically excavating the ground and attaching the panel using mortar, but in the bottom-up method, the ground is vertically excavated and harden the backfill material. As a result of numerical analysis, the top-down method secured a higher safety factor in all cases except the rainfall conditions.

• Korean Journal of Cognitive Science
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• v.6 no.3
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• pp.41-63
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• 1995

We present a LR,bottom-up parsing algorithms for TAG. We will introduce the adjoining rules system to handle the formal properties of TAG and to describe the parsing process more effectively. We will consider the context-free behavior of TAG at the adjoining instant. Then we will present the LR bottom up parsing algorithm for TAG by using this property. The basic idea behind a LR bottom up parsing algorithm can be applied to parsing TAG with other conventional algorithms.

• Journal of Digital Convergence
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• v.15 no.6
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• pp.107-119
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• 2017

This article explores early childhood teachers' practices from bottom-up perspectives on the relationship between theory and practice. Results of the review of literature are as follows: 1) From top-down perspectives early childhood teachers' practices and their classroom behaviors have been traditionally defined within the framework of theories of child development, the notion of developmentally appropriate practice, and designed program models; 2) From bottom-up perspectives researchers have a focus on how teachers' practices lead theories and how they construct the act of teaching through reflective thinking; 3) empirical research on preservice and inservice teachers demonstrates that preservice teachers develop their own theories of teaching from their previously held assumptions, gained knowledge from preparation programs, and their individual experiences. It also shows that inservice teachers construct teaching through their implicit knowledge and the use of strategies to negotiate problems. Implications for future studies on teachers's practices are discussed.

• The Journal of Engineering Geology
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• v.29 no.3
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• pp.201-209
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• 2019

Bottom-up multi-stage pressure grouting is widely applied to domestic slopes and tunnels. It involves injecting earth from the ground to the surface after drilling. Various reports of construction performance have demonstrated its wide applicability. However, little research has studied top-down multi-step pressure grouting in Korea, which involves injection from the surface. This paper compares the grouting effect of both the established bottom-up method and the top-down method in soil box and field tests. The soil box test showed that the bulb volume of the top-down method is ~24% less than that of the bottom-up method. The field test confirmed that the top-down method has a wider grouting range and a higher injection density per area than the bottom-up method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.758-764
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• 2018

Digital documents such as patents, scholarly papers and research reports have author keywords which summarize the topics of documents. Different documents are likely to describe the same topic if they share the same keywords. Document clustering aims at clustering documents to similar topics with an unsupervised learning method. However, it is difficult to apply to a large amount of documents event though the document clustering is utilized to in various data analysis due to computational complexity. In this case, we can cluster and connect massive documents using keywords efficiently. Existing bottom-up hierarchical clustering requires huge computation and time complexity for clustering a large number of keywords. This paper proposes an inverted index based bottom-up clustering for keywords and analyzes the results of clustering with massive keywords extracted from scholarly papers and research reports.

• Journal of the Korean Solar Energy Society
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• v.30 no.6
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• pp.34-43
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• 2010

Recently environmental regulations like the Kyoto Protocol, adopted in 1997, required the reduction of the greenhouse gas of 5.2% up to 1990 regulations. and 13th General Assembly in 2007, held in Bali of India, have agreed to duty reduction even in developing countries in 2013. Because of the lack of information about real process in small or middle size industries, most recent research omitted to calculate green house gas emissions from the industrial process. Bottom-up methodology will be applied for calculation of green house gasemission from industry sector to solve these problems in this research. Total amount from industry sector of Shicheung-City in 2007 was about 1,797,305 tons of greenhouse gas $CO_2$ and 3,049,403 tons of the greenhouse gas $CO_2$ calculated from industry sector of Ansan-City in 2007.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.11-11
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• 2004

나노기술은 크게 2가지 접근방법을 가진다. 하나는 위에서 아래로(Top-Down)라는 관점으로 벌크물질로부터 이온빔 등을 이용해 이를 작게 잘라가는 방식이며, 다른 하나는 아래에서 위로(Bottom-Up) 방식으로 재질을 구성하는 분자를 재구성해 원하는 물성 및 특성을 가지도록 만드는 방법이다. 이 두 가지 접근 방법은 원하는 결과를 얻기 위해 상호 보완적으로 사용되기도 한다. Top-Down방식의 대표적인 기기로는 접속이온빔 장치(FIB, Focused Ion Beam)를 등 수 있으며, Bottom-Up방식의 대표적인 기기로는 SPM(Scanning Probe Microscope)을 들 수 있다.(중략)

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.10
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• pp.1358-1363
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• 1995

This paper presents a new learning method for a noise tolerant Fuzzy ART. In the conventional Fuzzy ART, the top-down and bottom-up weight vectors have the same value. They are updated by a fuzzy AND operation between the input vector and the current value of the top-down or bottom- up weight vectors. However, it can not prevent the abrupt change of the weight vector and can not achieve good performance for a noisy input vector. To solve the problems, we updated using the weighted sum of the input vector and the current value of the top-down vector. To achieve stability, the bottom-up weight vector is updated using the fuzzy AND operation between the newly learned top-down vector and the current value of the bottom-up vector. Computer simulations show that the proposed method prominently resolves the category proliferation problem without increasing the training epoch for stabilization in noisy environments.

• Journal of Cadastre & Land InformatiX
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• v.47 no.2
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• pp.185-199
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• 2017

This study is on a recombination method for the construction of spatial information products which demands are unpredictably various. The present production method of digital maps is not flexible enough for their reusability because it is not object-oriented but top-down. Each spatial object needs to have particular attributes to be recombined. The demand changes the production method through the reclassification of data and changing the properties. In a user perspective, the bottom-up method can produce on-demand spatial information products including existing digital maps. The method is derived from case studies and theoretical reviews and compared with the existing production method. In the method spatial information products are reclassified by their geometry objects such as point, line, and polygon, with basic attributes, and other related domain attributes. The geometry objects and domain attributes are connected by adding new attributes for their later relationship and management, which make the recombination possible. To prove its usability of the method it is tested for current and future user demands including the national base map, thematic maps and the future spatial information products.

• Spatial Information Research
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• v.17 no.1
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• pp.131-144
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• 2009

Recently, a lot of local autonomous entities are promoting Ubiquitous City(U-City) Construction by integrating Information Communication Technology(ICT) with city development, and also internationally, a lot of cities are making efforts to develop U-City to intensify a city's competitive strength and improve life quality of city dwellers. In keeping with such a stream of the times, each local autonomous entity and project developer are developing a lot of methodologies to establish optimal U-City in corresponding cities and also inquiring into a variety of development procedures, such as connecting existing urban development methods with information establishment methods. The method used usually is to establish Information strategy Plan(ISP) for a city which will be developed through consulting in the stage of city development planning. ISP is to establish vision & strategy for building the ubiquitous city and is a methodology including city vision, strategy, goal, and implementation method, etc. However, due to a lot of variables, such as a variety of city environment, establishment period, budget, information technology, and etc., it is difficult to contain establishment plans for every occasion in a similar method, in reality. Therefore, it is naturally necessary to suggest plans for city vision & strategy, and selection of element technology/service. Thus, this paper suggests models for vision & strategy establishment of U-City and suggests Top-Down Approach and Bottom-Up Approach method as a plan for U-City establishment. In addition, this paper analyzes general promotion methodologies for constructing U-City and analyzes how these two strategic methods [Top-Down Approach and Bottom-Up Approach] for city vision establishment are composed in such a methodology, to define and analyze its constituent plan.