• 전자공학회논문지 IE
• /
• v.45 no.2
• /
• pp.34-39
• /
• 2008

This study established the efficient system that retrieves the 3D model by using a statistical technique called the function of discriminant analysis. This method was suggested to search index, which was formed by the statistics of 128 feature vectors including those scope, minimum value, average, standard deviation, skewness and scale. All of these were sampled with Osada's D2 method and the statistics as a factor effecting a change turned the value of discriminant analytic function into that of index. Through the primary retrieval on the model of query, the class above the top 2% was drawn out by comparing the query with the index of previously saved class from the group of same models. This method was proved an efficient retrieval technique that saved its procedural time. It shortened the retrieval time for 3D model by 57% faster than the existing Osada's method, and the precision that similar models were found in the first place was recorded 0.362, which revealed it more efficient by 44.8%.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.30 no.2
• /
• pp.67-81
• /
• 1988

The purpose of the present study is to set up an efficient optimum design method for the large-scale reinforced concrete cylindrical shell structures like intake tower of reservoir and to establish a solid foundation for the automatic optimum structural design combined with finite element analysis. The major design variables are the dimensions and steel areas of each member of the structures. The construction cost which is composed of the concrete, steel, and form work costs, respectively, is taken as the objective function. The constraint equations for the design of intake-tower are derived on the basis of the working stress design method. The corresponding design guides including the standard specification for concrete structures have been also employed in deraving the constraint conditions. The present nonlinear optimization problem is solved by SUMT method. The reinforced concrete intake-tower is decomposed into three major substructures. The optimization is then conducted for both the whole structure and the substructures. The following conclusions can be drawn from the present study. 1. The basis of automatic optimum design of reinforced concrete cylindrical shell structures which is combined with finite element analysis was established. 2. The efficient optimization algorithms which can execute the automatic optimum desigh of reinforced concrete intake-tower based on the working stress design method were developed. 3. Since the objective function and design variables were converged to their optimum values within the first or second iteration, the optImization algorithms developed in this study seem to be efficient and stable. 4. The difference in construction cost between the optimum designs with the substructures and with the entire structure was found to be small and thus the optimum design with the substructures,rnay conveniently be used in practical design. 5. The major active constraints of each structural member were found to be the tensile stress insteel for salb, the minimum lonitudinal steel ratio constraints for tower body and the shearing stress in concrete, tensile stress in steel and maximum eccentricityconstraints for footing, respectively. 6. The computer program develope in the present study can be effectively used even by an unexperienced designer for the optimum design of reinforced concrete intake-tower.

• Wind and Structures
• /
• v.26 no.6
• /
• pp.397-413
• /
• 2018

Excitation mechanism of interference effect between two tall buildings is investigated with wind tunnel experiments. Synchronized building surface pressure and flow field measurements by particle image velocimetry (PIV) are conducted to explore the relationship between the disturbed wind flow field and the consequent wind load modification for twin buildings in tandem. This reveals evident excitation mechanisms for the fluctuating across-wind loads on the buildings. For small distance (X/D < 3) between two buildings, the disturbed flow pattern of impaired vortex shedding is observed and the fluctuating across-wind load on the downstream building decreases. For larger distance ($X/D{\geq}3$), strong correlation between the across-wind load of the downstream building and the oscillation of the wake of the upstream building is found. By further analysis with conditional sampling and phase-averaged techniques, the coherent flow structures in the building gap are clearly observed and the wake oscillation of the upstream building is confirmed to be the reason of the magnified across-wind force on the downstream building. For efficient PIV measurement, the experiments use a square-section high-rise building model with geometry scale smaller than the usual value. Interference factors for all three components of wind loads on the building models being surrounded by another identical building with various configurations are measured and compared with those from previous studies made at large geometry scale. The results support that for interference effect between buildings with sharp corners, the length scale effect plays a minor role provided that the minimum Reynolds number requirement is met.

• Journal of Korean Society for Atmospheric Environment
• /
• v.15 no.4
• /
• pp.475-483
• /
• 1999

A lab-scale test was carried out to study the reduction of electrical energy consumption in the pulsed corona discharge process for nitrogen oxides removal. The experiment was mainly focused on 1) the activation of pollution removal reactions by chemical additives and 2) the optimization of electrical circuit for the efficient energy transfer from the power supply to the corona reactor. Hydrocarbon chemical additives used in the experiment are thought to be responsible for the enhancement of the NO conversion through the chain reactions of free radicals such as, R, RCO, and RO. Electrical energy consumption per converted NO molecule has a minimum value of 17 eV when pentanol is injected. When ethylene and propylene are injected, 30 eV and 22 eV of electrical energy consumption is required for the conversion of NO molecule respectively. The ratio of the pulse forming capacitance$(C_e)$ to the reactor capacitance$(C_R)$ plays an important role in the energy transfer efficiency to the reactor. Maximum energy transfer efficiency of approximately 72% could be obtained by using the pulse forming capacitance which is 3.4 times larger than the reactor capacitance, and also the maximum NO conversion efficiency was observed with the same condition.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.11 no.4
• /
• pp.89-97
• /
• 2015

In this paper, a method of color image segmentation based on DBSCAN(Density Based Spatial Clustering of Applications with Noise) using compactness of superpixels and texture information is presented. The DBSCAN algorithm can generate clusters in large data sets by looking at the local density of data samples, using only two input parameters which called minimum number of data and distance of neighborhood data. Superpixel algorithms group pixels into perceptually meaningful atomic regions, which can be used to replace the rigid structure of the pixel grid. Each superpixel is consist of pixels with similar features such as luminance, color, textures etc. Superpixels are more efficient than pixels in case of large scale image processing. In this paper, superpixels are generated by SLIC(simple linear iterative clustering) as known popular. Superpixel characteristics are described by compactness, uniformity, boundary precision and recall. The compactness is important features to depict superpixel characteristics. Each superpixel is represented by Lab color spaces, compactness and texture information. DBSCAN clustering method applied to these feature spaces to segment a color image. To evaluate the performance of the proposed method, computer simulation is carried out to several outdoor images. The experimental results show that the proposed algorithm can provide good segmentation results on various images.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.25 no.2
• /
• pp.92-101
• /
• 2002

The Job Shop Scheduling Problem(JSSP) is concerned with schedule of m different machines and n jobs where each job consists of a chain of operations, each of which needs to be processed during an uninterrupted time period of a given length on a given machine. The purpose of this paper is to develop the efficient heuristic method for solving the minimum makespan problem of the large scale job shop scheduling. The proposed heuristic method is based on a Tabu Search(TS) and on a Constraint Satisfaction Technique(CST). In this paper, ILOG libraries is used to embody the job shop model, and a CST is developed for this model to generate the increased solution. Then, TS is employed to overcome the increased search time of CST on the increased problem size md to refine the next-current solution. Also, this paper presents the new way of finding neighbourhood solution using TS. On applying TS, a new way of finding neighbourhood solution is presented. Computational experiments on well known sets of MT and LA problem instances show that, in several cases, our approach yields better results than the other heuristic procedures discussed In literature.

• The KIPS Transactions:PartA
• /
• v.13A no.1 s.98
• /
• pp.79-86
• /
• 2006

Recently the tagSNP selection problem has been researched for reducing the cost of association studies between human's diversities and SNPs. General approach for this problem is that all of SNPs are separated into appropriate blocks and then tagSNPs are chosen in each block. Marsel in this paper is the system that involved the concept of linkage disequilibrium for overcoming the problem that the existing block partitioning approaches have short of biological meanings. In most approaches, the contiguous regions, which recombinations have LD coefficient |D'| and then tagSNP selection step is performed. And MarSel guarantees the minimum tagSNP selection using entropy-based optimal selection algorithm when tagSNPs are chosen in each block, and enables chromosome-level association studies using efficient memory management technique when input is very large-scale dataset that is impossible to be processed in the existing systems.

• Journal of KIISE:Computer Systems and Theory
• /
• v.27 no.3
• /
• pp.255-263
• /
• 2000

A multistage interconnection network is a suitable class of interconnection architecture for constructing large-scale multicomputers. Broadcast and multicast communication are fundamental in supporting collective communication operations such as reduction and barrier synchronization. In this paper, we propose a new multicast technique in wormhole-switched bidirectional multistage banyan networks for constructing large-scale multicomputers. To efficiently support broadcast and multicast with simple additional hardware without deadlock, we propose a two-phase multicast algorithm which takes only two transmissions to perform a broadcast and a multicast to an arbitrary number of desired destinations. We encode a header as a cube and adopt the most upper input link first scheme with periodic priority rotation as arbitration mechanism on contented output links. We coalesce the desired destination addresses into multiple number of cubes. And then, we evaluate the performance of the proposed algorithm by simulation. The proposed two-phase multicast algorithm makes a significant improvement in terms of latency. It is noticeable that the two-phase algorithm keeps broadcast latency as efficient as the multicast latency of fanout 2^m where m is the minimum integer satisfying $2^m{\geq} {\sqrt{N}}$ ( N is a network size).

• Journal of the Korea Society of Computer and Information
• /
• v.15 no.10
• /
• pp.201-207
• /
• 2010

This paper covers a series of activities including initial proposal and actual development for the performance improvement of large-scale public facility management system under the application of green IT concept, which finally produced various excellent results in the administration of expense control, human resources, and general affairs. Actual development procedure starts from the analysis required by system users with the purpose of finding cost reduction opportunities under the application of green IT concept, which is followed by a series of activities including making a proposal for performance improvement, the development of trial system and the actual application into real system. As an example of large-scale public facility management system, national qualification management system was taken in order to convert the existing individual test storage unit into on-line storage space equipped with reinforced security function, resulting in acquisition of efficient productivity and greater savings in human resources as well as general expenses. A comparison with existing system and newly developed system was made in the area of number of operators, abnormal processing, system maintenances. It proved that efficiency increased to the minimum of 2 times and to the maximum 12 times with the 5 million savings of personal storage unit.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.1 no.1
• /
• pp.39-51
• /
• 1998

The purpose of this study is to find out the ways to supplement the Census, the digital maps, and their integration in comparison with the U.S. Census and the TIGER file and in light of their usefulness for urban and environmental analysis in Korea. Recommendations in this study are: (1) to include questions on household income and housing price in the Census, (2) to implement a 1~5% sampling survey similar to PUMS in the U.S. Census, (3) to make the Census Tract as a minimum size unit of analysis through subdivision of current Eup, Myon, and Dong into 5~10 smaller units, and (4) to utilize the 1:5,000 scale digital maps completed by the Korea National Geographic Institute for the fast and efficient activation of digital maps instead of producing 1:1,000 or 1:1,200 scale digital maps through each city's effort.