• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2001.06a
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• pp.15-19
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• 2001

Creating an artificial strain with a minimal gene set for a specific purpose is every biologist's dream. With the complete genome sequencing of more than 50 microorganisms and extensive functional analyses of their genes, it is possible to design a genetic blueprint for a simple custom-designed microbe with the minimal gene set. Two different approaches are being considered. The first 'top-down' approach is trimming the genome to a minimal gene set by selectively removing genes of an organism thought to be unnecessary based on microbial genomics. The second 'bottom-up' approach is to synthesize the proposed minimal genome from basic chemical building blocks. The 'top-down' approach starting with the genome of a well known microorganism is more technically feasible, whereas the bottom-up approach may not be attainable in the nearest future because of the lack of the complete functional analysis of the genes needed for a life. Here in this study, we used the top-down approach to minimize the E. coli genome to create an artificial organism with 'core' elements for self-sustaining and self-replicating cells by eliminating unnecessary genes. Using several different kinds of sophisticated deletion techniques combined with a p:1age and transposons, we deleted about 19％ of the E. coli genome without causing any damages to cellular growth. This smaller E. coli genome will be further reduced to a genome with a minimal gene l;et essential for cell life. This minimized E. coli genome can lead to the construction of many custom-designed strains with myriad practical and commercial applications.

• Journal of the Korean Wood Science and Technology
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• v.36 no.4
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• pp.26-36
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• 2008

As the height of the light-framed building increases, the lateral load and overturn-moment are increased and the possibility of the building overturn becomes larger. Because the shear wall resists lateral load in light-framed building, the reinforcement of shear wall is required. In order to reinforce the light-framed shear wall, using lag screw fastener type (B-HD) and using bolt type (S-HD) hold-down connectors were applied for test. And domestic larch lumbers, $38{\times}140mm$ and $89{\times}140mm$, KS 2nd grade, were used for the stud. The North American OSB panels were used for sheathing panel. Static loads, load speed 6 mm/min, were applied on top of the wall. As a result, shear strength of the wall that using hold-down connector was improved sufficiently. And when applying the S-HD type hold-down connector, stud should be reinforced against weakening by drilled hole. As increasing the number of lag screw, the number of bolt and the product allowable strength, the strength of shear wall that using hold-down connector was also increased. When applying hold-down connector to light-framed building using 38 mm stud, it must be reinforced by enlarging the thickness of stud like as 38 mm doubled column.

• Korean Journal of Remote Sensing
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• v.37 no.1
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• pp.111-122
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• 2021

Building footprint extraction is an active topic in the domain of remote sensing, since buildings are a fundamental unit of urban areas. Deep convolutional neural networks successfully perform footprint extraction from optical satellite images. However, semantic segmentation produces coarse results in the output, such as blurred and rounded boundaries, which are caused by the use of convolutional layers with large receptive fields and pooling layers. The objective of this study is to generate visually enhanced building objects by directly extracting the vertices of individual buildings by combining instance segmentation and keypoint detection. The target keypoints in building extraction are defined as points of interest based on the local image gradient direction, that is, the vertices of a building polygon. The proposed framework follows a two-stage, top-down approach that is divided into object detection and keypoint estimation. Keypoints between instances are distinguished by merging the rough segmentation masks and the local features of regions of interest. A building polygon is created by grouping the predicted keypoints through a simple geometric method. Our model achieved an F1-score of 0.650 with an mIoU of 62.6 for building footprint extraction using the OpenCitesAI dataset. The results demonstrated that the proposed framework using keypoint estimation exhibited better segmentation performance when compared with Mask R-CNN in terms of both qualitative and quantitative results.

• Journal of Korean Institute of Industrial Engineers
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• v.18 no.2
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• pp.31-42
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• 1992

This paper introduces a distuibuted simulation scheme that is useful in the top-down FMS building approach. In the scheme, we first introduce "FMS Shell" that contains basic functions and structure of FMS's. To test a proposed FMS, appropriate features of the proposed FMS are added to the shell, then distributed simulation is performed with the resulting software. This runs like a real system only without hardware devices. An real application case is stated at later part of this paper.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.559-562
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• 2004

The methodologies to develop land use plans are divided into two different ways, top-down and bottom-up planning. The bottom-up method is more efficient and effective to detailed land use planning. However, it requires considerable amount of information about the present status of land use. Cadastral information system is one of the best information provider for the planning. Building Register Database shows the type, area, use and location of a building. Both cadastral and Building Register systems apparently contain useful information needed to the physical planning. The study focuses on developing a prototype to provide real time information for detailed physical planning by a federated database system using the two databases.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.199-202
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• 2014

In recent years the downtown, Top-down method has been applied in a major method to solve the complaints due to noise, vibration, dust and safety issues such as cracking due to settlement when the excavation close to the building. Until it is installed underground permanent foundation, the Pre-founded Column is a pile foundation as well as a column to bear the upper construction load. The Pre-founded Column is constructed by PRD method generally. The EnP(Enlarging Pile) method can be expanded locally boring diameter of the embedment zone as compared to the PRD method existing general. Since the bearing capacity is increased by the boring diameter is expanded, the embedment length is reduced, the construction cost is reduced.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.4
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• pp.68-74
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• 2002

The FD process is analogous to the direct piston extrusion process where the cold feed filament acts as a piston extruding the molten filament from the heated liquefier through a nozzle. The extruded filament is deposited on top of futureless platform, where the liquefier and the nozzle move in X and Y direction control by computer based on the part geometry. After the first layer, the Z platform indexes down and the next layer get deposited on top of the first layer. the layer by layer building process introduces surface problem. This paper describes effect of slice interval of the parts built by fused deposition modelling rapid prototyping system.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.7-12
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• 2008

We constructed Seal type waterproofing with adhesive and swelling properties in the field of construction work as yet. But we have many problems of seal type waterproofing with adhesive and swelling properties for construction. Because it has high viscosity, so wokers are too adhered for the work. So, we developed and applied about the high temperature and spray equipments of piston type better than before. We able to be expect that cost reduction and increase construction ability by high temperature and spray equipments of piston type.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.279-280
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• 2018

The waterproofing material can be roughly divided into a coating material and a sheet waterproofing material. In the case of coating waterproofing materials, sheet waterproofing materials, which are easy to use in terms of workability and quality control, have been recently used because of their incomplete use of coating thickness, long curing time and poor blending due to in situ blending. However, in the case of the sheet waterproofing material, since the sheet overlapping portion is inevitably generated, various defects (breakage due to the behavior) are frequently observed. Therefore, it is imperative to establish fundamental measures to minimize this.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.162-163
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• 2016

This paper presents a mathematical model for optimizing earthwork allocation plan that minimizes earthwork cost. The model takes into account operational constraints in the real-world earthwork such as material-type (i.e., quality level of material) and quantities excavated from cut-sections, required quality of material and quantities for each embankment layer, top-down cutting and bottom-up filling constraints, and allocation orders. These constraints are successfully handled by assuming the rock-earth material as the three dimensional (3D) blocks. The study is of value to project scheduler because the model identifies the optimal earth allocation plan (i.e., haul direction (cut and fill pairs), quantities of soil, type of material, and order of allocations) expeditiously and is developed as an automated system for usability. It is also relevant to estimator in that it computes more realistic earthworks costs estimation. The economic impact and validity of the mathematical model was confirmed by performing test cases.