• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.885-889
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• 2004

Fast and high-quality document clustering algorithms play an important role in providing data exploration by organizing large amounts of information into a small number of meaningful clusters. Hierarchical clustering improves the performance of retrieval and makes that users can understand easily. For outperforming of clustering, we implemented hierarchical structure with variety and readability, by careful selection of cluster topic words and deciding the number of clusters dynamically. It is important to select topic words because hierarchical clustering structure is summarizes result of searching. We made choice of noun word as a cluster topic word. The quality of topic words is increased $33\%$ as follows. As the topic word of each cluster, the only noun word is extracted for the top-level cluster and the used topic words for the children clusters were not reused.

• Journal of Korean Society for Quality Management
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• v.17 no.2
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• pp.121-141
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• 1989

This paper is concerned with a development and evaluation of heuristics for the multi-stage sequence dependent flowshop sequencing. Eighteen heuristics, CAM1, CAM2, and etc., are proposed. The performance measure is a makespan which is to be minimized. The experiment for each algorithm is designed for a 4*3*3 factorial design with 360 observations. The experimental factors are PS(ratio of processing times to setup times), M(number of machines), N(number of jobs). The makespan of the proposed heuristics is compared with the optimal makespan obtained by the complete enumeration of schedules. This yardstick of comparison is called a relative error. The mean relative errors of the eighteen heuristics are from 2.048% to 8.717%. The computational results are analysed using SPSS. The experimental results show that the three factors are statistically significant at 5% level. The simulation for the large size problems is conducted to show having the similar computational results like the small size problems.

• Journal of the Korean Society for Precision Engineering
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• v.9 no.1
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• pp.66-74
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• 1992

The joining processes of aluminum alloy tubes and polyurethane cores by electromagnetic impulsive compression are studied. The influences of various geometrical factors (the length of joined part, the thickness of tube, and the clearance between tube and core) and the process factors(the discharged energy and the number of discharge)are examined experimentally and discussed. And the magnetic pressure in metal/polymer joining is calculated and is compared to the pressure in metal/metal joining. The following results are obtained: (1) The joining strength is dependent upon the residual radial strain of the polyurethane cores. (2) The joining strength increases as discharged energy and the number of discharge increase, but decreases as the clearance, thickness and joining length of tube increases. (3) In the case of metal/polymer joining energy loss is increased and the value of magnetic pressure is less than that in the case of metal/metal joining.

• 열병합발전
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• s.36
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• pp.16-21
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• 2003

For many years, T/G Supplier has constructed a number of thermal power plants and researched to improve the performance and the reliability of steam turbine, which are achieved by advances in design and materials technology. In recent, interest is renewed in advance steam condition as means of improving economy of thermal power plant and reducing environmental pollution. Improvements in the maximum power have been driven by the development of advanced rotor and bucket material and longer last stage bucket. Improvements in efficiency have been brought through advance in mechanical efficiency and thermodynamic efficiency. This paper describes a number of new steam path design features introduced to the steam turbine product. And also this paper describes new design technologies' development, new technologies' trend and technologies' development for ultra-super critical steam turbine.

• Journal of Korea Foundry Society
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• v.9 no.3
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• pp.228-236
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• 1989

The relationships between nodularity, tensile property and ultrasonic velocity were studied in ductile iron castings having similar matrix structure. Also, the effects of heat treatment and the number of graphite nodules on the ultrasonic velocity were investigated. The results were as follows 1. The ultrasonic velocity increased proportionally with increassing nodularity and tensile strength. 2. The ultrasonic velocity in annealed and normalized state decreased average 1.7% and 3.4% respectively than that in as cast state. 3. The ultrasonic velocity increased with increasing the number of graphite nodules. Therefore, ductile iron castings can be evaluated in the only case of castings having the same manufacturing history by ultrasonic velocity.

• Korean journal of applied entomology
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• v.10 no.1
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• pp.49-53
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• 1971

The only record of spider's from Cholla Namdo was made by T. Kambe in 1953. They were collected from Mokpo area which is located south-west coast of Cholla Namdo and included 24 species belonging to 8 families. In this paper are given for the first time a iist of spiders from Kwangju City, inland of Cholla Namdo. wis located at the center of Cholla Namdo. More than 5,000 individual spiders were collected by one of the junior author, J.K. Yoon during autumn in 1570. In spite ef rather large number of spiders were collected, collecting season and the locality are restricted, number of species was reiatit·ely small and many young spiders were undeterminable, A total of 50 species belong to 15 families, including 5 unrecorded species from Korea, were identified. Unrecorded species were as follows: Uloborus yesoensis $(S_{AITO},\;1934)$ Pirate piraticus $(C_{LERCK},\;, 1757)$ Stemmops sp. Trochosa ruricola$(D_E\; G_{EER},\; 1778)$ Erigone koshiensis $O_r$, 1960

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2003.11a
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• pp.289-294
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• 2003

Purpose of this study is to supply data that need in qualitative improvement and plan for middle class through a post occupancy evaluation by the tenants in the rental apartment of national housing size. The results of this study are as follows; 1) Characteristic of household differ as the size tenants live in at present. But, usually characteristic of household was family life cycle was from child-rearing time to secondary education time, a family's number was 3${\sim}$4 person, and income per month was 1${\sim}$3 million won. 2) The satisfaction of whole and physical environment were satisfied more than average 3 points. However, the satisfaction of economic performance and administration environment were dissatisfied by average 3 points low. 3) Factors that affect in housing satisfaction were administration environment, the housing size, a family's number.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.788-791
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• 2003

Optimal loudspeaker positions are important as much as the control algorithms and hardware performance in the active noise control system. This study is similar to the past researches on the optimal transducer locations but with a far field noise source having a plane wave characteristic and the noise coming through an opening such as a window in the enclosure. An optimization technique called simulated annealing algorithm is used to find a set of optimal loudspeaker positions from a larger possible loudspeaker positions. Loudspeakers are placed on the surface of opening at the wail. Using the measured acoustic transfer impedances and numerical simulations with the optimization technique, optimal positions we identified and compared. When a small number of loudspeakers are used, loudspeaker positions on the opening near the center seems to be the best place, but when a larger number of loudspeakers are used it was difficult to find simple patterns Un the optimal positions.

• Journal of Korean Society for Quality Management
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• v.17 no.1
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• pp.35-47
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• 1989

This paper is concerned with a development and evaluation of heuristic algorithms for the n-job, M-stage flowshop with sequence dependent setup times. Three heuristic algorithms, CAIDAN, DANNEN and PETROV, are proposed. The makespan is taken as a performance measure for the algorithms. The experiment for each algorithm is designed for a $4{\times}3{\times}3$ factorial design with 360 observations. The experimental factors are PS (ratio of processing times to setup times), M (number of machines), and N (number of jobs). The makespan of the proposed heuristic algorithms is compared with the optimal makespan obtained by the complete enumeration method. The result of comparision of performance measure is called a relative error. The mean relative errors of CAIDAN, DANNEN and PETROV algorithms are 4.488%. 6.712% and 7.282%, respectively. The computational results are analysed using SPSS. The experimental results show that the three factors are statistically signiticant at 5% level.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2006.02a
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• pp.125-126
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• 2006

NimbleGen has developed strategies to use its high-density oligonucleotide microarray platform (385,000 probes per array) to map both promoter binding sites and copy number variation at very high-resolution in the human genome. Here we describe a genome-wide map of active promoters determined by experimentally locating the sites of transcription imitation complex binding throughout the human genome using microarrays combined with chromatin immunoprecipitation. This map defines 10,567 active promoters corresponding to 6,763 known genes and at least 1,196 un-annotated transcriptional units. Microarray-based comparative genomic hybridisation (CGH) is animportant research tool for investigating chromosomal aberrations frequently associated with complex diseases such as cancer, neuropsychiatric disorders, and congenital developmental disorders. NimbleGen array CGH is an ultra-high resolution (0.5-50 Kb) oligo array platform that can be used to detect amplifications and deletions and map the associated breakpoints on the whole-genome level or with custom fine-tiling arrays. For whole-genome array CGH, probes are tiled through genic and intergenic regions with a median probe spacing of 6 Kb, which provides a comprehensive, unbiased analysis of the genome.