• Journal of Biosystems Engineering
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• v.22 no.2
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• pp.199-209
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• 1997

A one-pass rice whitener with hard metal blades was developed to solve the problems of the existing one-pass rice whitener. The developed one-pass rice whitener was tested and improved through various milling experiments. It showed high performance such as the capacity of 3.5 t/h, the energy consumption of $1.0 kWh/100kg$, milled rice recovery of 91.6%, broken rice rate of 2.2%, the crack rate of 1.9% at the 750 rpm of the roller shaft, compared with those other domestic and foreign one-pass rice whiteners. Especially, it could whiten broun rice of high moisture (16～l7%) with water sprayed at low internal pressure of less than $0.2 kg/cm^2$ and low temperature due to the characteristics of the cutting part composed of 24 hard metal blades. The developed one-pass rice whitener was industrilized and distributed to some rice processing complexs in one fourth price compared with that of imported one-pass rice whiteners.

• Journal of Mechanical Science and Technology
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• v.16 no.9
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• pp.1033-1039
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• 2002

Partial penetration welding joint refers to the groove weld that applies to the one side welding which does not use steel backing and to both side welding without back gouging, that is, the partial penetration welding joint leaves an unwelded portion at the root of the welding area. In this study, we analyzed the residual stress and fracture on the thick metal plates that introduced the partial penetration welding method. According to the above-mentioned welding method, we could draw a conclusion that longitudinal stress and traverse stress occurred around the welding area are so minimal and do not affect any influence. We also performed the fracture behavior evaluation on the partial penetration multi pass welding with 25.4 mm thick plate by using the J-integral, which finally led us the conclusion that the partial penetration multi-pass welding method is more applicable and effective in handling the root face with less than 6.35 mm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.101-103
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• 2016

Recently, the target object can be represented as sparse coefficient vector in visual tracking. Due to this reason, exploitation of the compressibility in the transform domain by using L1 minimization is needed. Further, L1 minimization is proposed to handle the occlusion problem in visual tracking, since tracking failures mostly are caused by occlusion. Furthermore, there is a weighted parameter in L1 minimization that influences the result of this minimization. In this paper, this parameter is analyzed for occlusion problem in visual tracking. Several coefficients that derived from median value of the target object, mean value of the arget object, the standard deviation of the target object are, 0, 0.1, and 0.01 are used as weighted parameter of L1 minimization. Based on the experimental results, the value which is equal to 0.1 is suggested as weighted parameter of L1 minimization, due to achieved the best result of success rate and precision performance parameter. Both of these performance parameters are based on one pass evaluation (OPE).

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.1
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• pp.112-125
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• 2021

Marine spatial planning(MSP) designates the marine as nine kinds of use zones for the systematic and rational management of marine spaces. One of them is the fishery protection zone, which is necessary for the sustainable production of fishery products, including the protection and fosterage of fishing activities. This study intends to quantitatively identify the fishing activity space, one of the elements necessary for the designation of fisheries protection zones, by mapping of fishery activities using V-Pass data and deriving the fishery activity concentrated zone. To this end, pre-processing of V-Pass data was performed, such as constructing a dataset that combines static and dynamic information, calculating the speed of fishing vessels, extracting fishing activity points, and removing data in non-fishing activity zone. Finally, using the selected V-Pass point data, a fishery activity map was made by kernel density estimation, and the concentrated space of fishery activity was analyzed. In addition, it was confirmed that there is a difference in the spatial distribution of fishing activities according to the type of fishing vessel and the season. The pre-processing technique of large volume V-Pass data and the mapping method of fishing activities performed through this study are expected to contribute to the study of spatial characteristics evaluation of fishing activities in the future.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.2
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• pp.300-307
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• 2002

Partial penetration welding joint is defined as groove welds welded from one side, without steel backing or groove welds welded from both sides but without back gouging. So it has an unwelded portion at the root of the weld. Study of partial penetration weldment fracture behavior includes residual stress analysis and fracture analysis. The J-integral loses its path independency in residual stress field. Therefore, it is necessary to introduce a new J-integral, J, which is defined including the effect of plastic deformation and thermal strain. In this study, theoretical formulation and program were developed for the evaluation of J-integral for the crack tip located in the weldment. Evaluations of fracture behavior were performed for partial penetration multi-pass weldment of 25.4mm thick plate by J-integral. From a point of fracture in partial penetration multi-pass welding, it seemed to be better to control root face smaller than 6.35mm.

• Journal of Welding and Joining
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• v.19 no.6
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• pp.636-642
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• 2001

Partial penetration welding joint defines the groove welds that applies the one side welding which does not use steel backing and both side welding without back gouging, that is, the partial penetration welding joint leaves an unwelded portion at the root of the welding area. In this study, we analyzed the residual stress and fracture on the thick metal plates that introduced the partial penetration welding method. As results of using above mentioned welding method, we could draw a conclusion that longitudinal stress and traverse stress occurred around the welding area was so minimal and did not affect any influence. We also performed the fracture behavior evaluation on the partial penetration multi-pass welding with 25.4mm thick plate by using theJ-integral, which finally led us the conclusion that the partial penetration multi -pass welding method is more applicable and effective in handling the root face with less than 6.35mm.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.365-366
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• 2002

The sliding wear behavior of ultra high molecular weight polyethylene (UHMWPE) was examined on a novel low temperature degradation-free zirconia/alumina composite material and conventional alumina and zirconia ceramics used for femoral head in total hip joint replacement. The wear of UHMWPE pins against these ceramic disks was evaluated by performing linear reciprocal sliding and repeat pass rotational sliding tests for one million cycles in bovine serum. The weight loss of polyethylene against the novel low temperature degradation-free zirconia/alumina composite disks was much less than those against conventional ceramics for all tests. The mean weight loss of the polyethylene pins was more io the linear reciprocal sliding test than in the repeal pass rotational sliding lest for all kinds of disk materials. Neither the coherent transfer film nor the surface damage was observed on the surface of the novel zirconia/alumina composite disks during the test. The observed r,'stilts indicated that the wear of the polyethylene was closely related to contacting materials and kinematic motions. In conclusion, the novel zirconia/alumina composite leads the least wear of polyethylene among the tested ceramics and demonstrates the potential as lhe alternative materials for femoral head in total hip joint replacement.

• Journal of the Institute of Convergence Signal Processing
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• v.4 no.4
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• pp.30-39
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• 2003

In this paper, we carried out the performance evaluation of HM-Net(Hidden Markov Network) speech recognition system for Korean speech databases. We adopted to construct acoustic models using the HM-Nets modified by HMMs(Hidden Markov Models), which are widely used as the statistical modeling methods. HM-Nets are carried out the state splitting for contextual and temporal domain by PDT-SSS(Phonetic Decision Tree-based Successive State Splitting) algorithm, which is modified the original SSS algorithm. Especially it adopted the phonetic decision tree to effectively express the context information not appear in training speech data on contextual domain state splitting. In case of temporal domain state splitting, to effectively represent information of each phoneme maintenance in the state splitting is carried out, and then the optimal model network of triphone types are constructed by in the parameter. Speech recognition was performed using the one-pass Viterbi beam search algorithm with phone-pair/word-pair grammar for phoneme/word recognition, respectively and using the multi-pass search algorithm with n-gram language models for sentence recognition. The tree-structured lexicon was used in order to decrease the number of nodes by sharing the same prefixes among words. In this paper, the performance evaluation of HM-Net speech recognition system is carried out for various recognition conditions. Through the experiments, we verified that it has very superior recognition performance compared with the previous introduced recognition system.

• The Journal of the Acoustical Society of Korea
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• v.18 no.2
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• pp.3-10
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• 1999

This paper describes the development and evaluation of a Korean address input system employing automatic speech recognition technique as user interface for input Korean address. Address consists of cities, provinces and counties. The system works on a window 95 environment of personal computer with built-in soundcard. In the speech recognition part, the Continuous density Hidden Markov Model(CHMM) for making phoneme like units(PLUs) and One Pass Dynamic Programming(OPDP) algorithm is used for recognition. For address recognition, Finite State Automata(FSA) suitable for Korean address structure is constructed. To achieve an acceptable performance against the variation of speakers, microphones, and environmental noises, Maximum a posteriori(MAP) estimation is implemented in adaptation. And to improve the recognition speed, fast search method using variable pruning threshold is newly proposed. In the evaluation tests conducted for the 100 connected words uttered by 3 males the system showed above average 96.0% of recognition accuracy for connected words after adaption and recognition speed within 2 seconds, showing the effectiveness of the system.

• Journal of Power Electronics
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• v.10 no.5
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• pp.563-571
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• 2010

A model of an advanced aircraft electric power system is developed and studied under variable-speed constant-frequency (VSCF) operation. The frequency of the generator's output voltage is varied from 400-Hz to 800-Hz for different loading scenarios. Power conversions are obtained using 12-pulse power converters. To reduce the harmonic contents of the generator output waveforms, two high-pass passive filters are designed and installed one at a time at the generator terminals. The performance of the two passive filters is compared according to their losses and effectiveness. The power quality characteristics of the studied VSCF aircraft electric power system are presented and the effectiveness of the proposed filter is demonstrated through compliance with the newly published aircraft electrical standards MIL-STD-704F.