• Proceedings of the KOSOMBE Conference
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• v.1989 no.05
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• pp.39-43
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• 1989

In this paper, hierachical representation method with a 1-to-4 and 1-to-8 data structure is used to reconstruct the three-dimensional scene from two-dimensional cross sections provided by computed tomography with small memory computer system. To reduce the internal memory use, 2-D section is represented by quadtree, and 3-D scene is represented by octree. Octree is constructed by recursively merging consecutive quadtrees. This method uses 7/200 less memory than pointer type structure with all the case, and less memory up to 60.3% than linear octree with experimental data.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.2
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• pp.8-18
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• 1993

A multi-font, multi-size and high speed character recognition system is designed. The design principles are simpilcity of algorithm, adaptibility, learnability, hierachical data processing and attention by feed back. For the multi-size character recognition, the extracted character images are normalized. A hierachical classifier classifies the feature vectors. Feature is extracted by applying the directional receptive field after the directional dege filter processing. The hierachical classifier is consist of two pre-classifiers and one decision making classifier. The effect of two pre-classifiers is prediction to the final decision making classifier. With the pre-classifiers, the time to compute the distance of the final classifier is reduced. Recognition rate is 95% for the three documents printed in three kinds of fonts, total 1,700 characters. For high speed implemention, a multiprocessor system with the ring structure of four transputers is implemented, and the recognition speed of 30 characters per second is aquired.

• Magazine of the Korean Society of Agricultural Engineers
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• v.36 no.2
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• pp.31-43
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• 1994

General concepts and overall procedures of interactive graphical user interface, a preand post- processor, for building analysis are introduced. Attention is forcused on the data structures and the modeling operators which can ensure the intergrity of its database should have. An example of model building process is presented to illustrate its capability, its facilities for modifying, and for processing.

• Journal of the Korean Regional Science Association
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• v.6 no.1
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• pp.11-38
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• 1990

The purpose of this thesis is, first to present the spatial division of labor in Korea and its mechanism, and second, to elucidate the organic integral relation between local labor market and local community by studing the mechanism that the spatial division of labor is projected into the individual lacal labor marker, and reproduction of labor force process in this local labor market. According to this purpose, the theoretical frame of this analysis is done, the positive analysis is made and Kumi is choosed as its analysis case area. The main data is from 'Survey Report on Manufacturing Idustry Wage Conditions' published by Minimum Wage Council, Ministry of Labour and from the questionnaires and interview on textile industry and electric electronics industry firms in Kumi Export Industrial Estate. The following are the results of this study. 1. The mechanism of spatial division of labor in Korea, seen through the employment structure index, is accelerating the regional discrimination by fixing the regional hierarchisation between Seoul (or Seoul Metropolitan Area as expanded Seoul) and other areas. But it is also developing highly the regional employment structure at the level of technical division of labor, since the spatial division of labor in Korea is leaded by large firms and influenced by the policy for regional development. 2. Local labor market is formed in Kumi area and its delimitation is Kumi city. The employment structure of Kumi local labor market is occupying lower hierarchy division at management hierachical level and occupying upper hierarchy division at the level of technical division of labor, and brand plants of large firs are determinating and dominating this emplogment structure. These bdranch plants of large firs are forming more favorable and stabel labor marker than locally controlled ploants in Kumi local labor market. But the reproduction of labor force process in Kumi local labor market is not fully carried out and leaked into central city, therefore Kumi is now becoming an unstable local community, suffering from large movement of population. This is because Kumi local labor market is found not for itself, but by the state policy and externally controlled plants of large firms, and therefore no potentiality to control and to absorb the exterior influences is built in Kumi local labor market. 3. The case firms A, B have spatial division of labor between decision-making function and production function, and between upper management hierachical labor force and lower management hierachical labor force in internal labor market.

• Journal of Industrial Technology
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• v.10
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• pp.15-20
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• 1990

A parallel processing algorithm for discrete Kalman filter, which is one of the most commonly used filtering technique in modern control, signal processing, and communication, is proposed. Previously proposed parallel algorithms to decrease the number of computations needed in the Kalman filter are the hierachical structures by distributed processing of measurements, or the systolic structures to disperse the computational burden. In this paper, a new parallel Kalman filter employing a structure similar to recursive doubling is proposed. Estimated values of state variables by the new algorithm converge with two times faster data processing speed than that of the conventional Kalman filter. Moreover it maintains the optimality of the conventional Kalman filter.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.64-67
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• 1990

A parallel processing algorithm for discrete Kalman filter, which is one of the most commonly used filtering technique in modern control, signal processing, and communication. is proposed. Previously proposed parallel algorithms to decrease the number of computations needed in the Kalman filter are the hierachical structures by distributed processing of measurements, or the systolic structures to disperse the computational burden. In this paper, a new parallel Kalman filter employing a structure similar to recursive doubling is proposed. Estimated values of state variables by the new algorithm converge with two times faster data processing speed than that of the conventional Kalman filter. Moreover it maintains the optimality of the conventional Kalman filter.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.871-873
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• 1995

The purpose of this paper is to design and construct the compact type joint driver and controller of the biped robot. This biped robot will be designed to be suitable for the practical usages and applications in the work environment, which is not plat floor, like a stairs by taking the stand-alone style that equipped all the parts except power sources. Generally, highly nonlinear motion dynamics of the biped robot is realized to linear approximations by installing a high-ratio speed reducer at each joint and dividing motions into a several piecewise linear motions, which is realized by the digital controller design techniques. This biped robot has symmetrical structure to get the stable walking ability and also the hierachical structure to control each joint as well. That is, all of the joint controllers are connected to the main controller in the composition of overall controllers. The driver and controller of each joint uses PI controller that compensate the velocity and position errors by the data of the encoder. And the signal characteristics of each joint controller forms a trapezoid speed profile which is predefined by the values of direction, maximum velocity and position.

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.4
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• pp.285-292
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• 2000

In general, exploratory data analysis consists of three processes: i) assessment of clustering tendency, ii) cluster analysis, and iii) cluster validation. This analysis method requiring a number of iterations of step ii) and iii) to converge is computationally inefficient. In this paper, we propose a density function-based approximate fuzzy clustering method with a hierachical structure which consosts of two phases: Phase I is a features(i.e., number of clusters and cluster centers) extraction process based on the tendency assessment of a given data and Phase II is a standard FCM with the cluster centers intialized by the results of the Phase I. Numerical examples are presented to show the validity of the proposed clustering method.

• Journal of the Korean Data and Information Science Society
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• v.27 no.2
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• pp.363-372
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• 2016

Two-stage sample designs are commonly used for household surveys in Korea using as clusters the enumeration districts (EDs). Since clustering decomposes the population variation into within- and between-cluster variations, the sample sizes allocated in stages can affect the overall precision. Alternative clusters are often considered due to diverse reasons such as the EDs' limitation in size, being out-of-date, and in-assessibility to their household lists. In addition, the EDs are currently under development by the Statistics Korea as an joint effort toward their transition from the traditional practice to the register census from 2015. We present an approach for evaluating the difference in the precision of the mean estimators of the sets of the cluster units in between a hierachical and nested form, where the design effect is used to reflect the effect of the clustering and the sample allocation. We also demonstrate our approach using the U.S. Census counts from the year 2000 for Anne Arundel County in Maryland. Our research shows that the within-cluster variance can be significantly different for survey variables and thus the choice of cluster units and the associated sample allocation scheme should reflect the corresponding variance decomposition due to clustering.

• Journal of the Korean Society for information Management
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• v.6 no.2
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• pp.87-103
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• 1989

In this study, A DDC online system was developed which provides subject access and browsing function for class numbers or subject terms. A knowledgebase of the DDC Schedules and Relative Index was designed for this purpose using IBM-PC. From the DDC 20th edition, subjects from 004 to 006, covering‘data processing’,‘computer science’‘programming and progrms’, and etc., were selected for this experiment. DDC schedules are represented as a frame structure which is apt to describe hierachical structures. This experiment, joining the DDC to the information retrieval environment of an online catalog, will contribute to the future of the online DDC system by providing possiblities for search strategies not feasible through the alphabetical approach of subject headings and keywords presently supported by online catalogs.