• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 추계학술대회 학술발표 논문집
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• pp.433-439
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• 1998

In this paper, we present an approach to the structure identification based on the input space partition methods and to the parameter identification by hybrid learning method in neuro-fuzzy system. The structure identification can automatically estimate the number of membership function and fuzzy rule using grid partition, tree partition, scatter partition from numerical input-output data. And then the parameter identification is carried out by the hybrid learning scheme using back-propagation and least squares estimate. Finally, we sill show its usefulness for neuro-fuzzy modeling to truck backer-upper control.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권1호
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• pp.227-247
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• 2018

For intermittently connected wireless sensor networks deployed in hash environments, sensor nodes may fail due to internal or external reasons at any time. In the process of data collection and recovery, we need to speed up as much as possible so that all the sensory data can be restored by accessing as few survivors as possible. In this paper a novel redundant data storage algorithm based on minimum spanning tree and quasi-randomized matrix-QRNCDS is proposed. QRNCDS disseminates k source data packets to n sensor nodes in the network (n>k) according to the minimum spanning tree traversal mechanism. Every node stores only one encoded data packet in its storage which is the XOR result of the received source data packets in accordance with the quasi-randomized matrix theory. The algorithm adopts the minimum spanning tree traversal rule to reduce the complexity of the traversal message of the source packets. In order to solve the problem that some source packets cannot be restored if the random matrix is not full column rank, the semi-randomized network coding method is used in QRNCDS. Each source node only needs to store its own source data packet, and the storage nodes choose to receive or not. In the decoding phase, Gaussian Elimination and Belief Propagation are combined to improve the probability and efficiency of data decoding. As a result, part of the source data can be recovered in the case of semi-random matrix without full column rank. The simulation results show that QRNCDS has lower energy consumption, higher data collection efficiency, higher decoding efficiency, smaller data storage redundancy and larger network fault tolerance.

• Journal of Plant Biotechnology
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• 제30권4호
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• pp.359-363
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• 2003

20년 이상된 백합나무의 성숙목에서 채취한 미숙구과의 배를 배양하여 체세포배를 유도하고 식물체를 생산하는 대량증식의 기초를 확립하였다. 미숙종자를 1/2LM (Litvay)배지에 식물생장조절물질인 2,4-D와 BA를 첨가한 반고체배지에 치상하여 배발생 조직을 유도하였다. 배발생 조직을 배발생 조직 유도와 같은 조건의 배지에서 생장조절물질을 제거하고 AgNO$_3$또는 활성탄을 첨가한 배지에 이식하였을 때 체세포배가 발달하고 정상적인 식물체로 발아되었다. 배발생 조직의 유도와 체세포배의 발아에서 식물체로 발달하는 데 영향을 끼치는 몇 가지 요인이 밝혀졌다. 여기에는 배발생 조직의 유도를 위한 미숙종자의 채취시기, 배지의 sucrose농도,AgNO$_3$와 활성탄의 농도 및 체세포배에서 식물체로 발달하기 위한 배의 성숙과 발아를 위하여 발아 배지에 체세포배의 치상밀도 등이 포함된다.

• Transactions on Electrical and Electronic Materials
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• 제13권5호
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• pp.252-255
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• 2012

In order to characterize insulation properties of epoxy/micro-silica/nano-silicate composite (EMNC), long-term and short-term AC treeing tests were carried out undr non-uniform electric field generated between needle-plate electrodes. In a long-term test, a 10 kV (60 Hz) electrical field was applied to the specimen positioned between the electrodes with a distance of 2.7 mm in an insulating oil bath at $30^{\circ}C$, and a typical branch type electrical tree was observed in the neat epoxy resin and breakdown took place at 1,042 min after applying the 10 kVelectrical field. Meanwhile, the spherical tree with the tree length of $237{\mu}m$ was seen in EMNC-65-0.3 at 52,380 min (36.4 day) and then the test was stopped because the tree propagation rate was too low. In the short-term test, an electrial field was applied to a 3.5 mm-thick specimen at an increasing voltage rate of 0.5 kV/s until breakdown in insulating oil bath at $30^{\circ}C$ and $130^{\circ}C$, and the data was estimated by Weibull statistical analysis. The electrical insulation breakdown strength for neat epoxy resin was 1,763 kV/mm at $30^{\circ}C$, while that for EMNC-65-0.3 was 2,604 kV/mm, which was a modified value of 47%. As was expected, the breakdown strength decreased at higher test temperatures.

• KSBB Journal
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• 제10권4호
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• pp.393-400
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• 1995

전통도료인 황칠의 재현을 위한 황칠나무의 다량 증식 및 이용에 관한 연구의 일환으로 황칠나무의 자생지 분포조사 및 황칠의 성분 분석을 실시하여 다음과 같은 결론을 얻였다. 1. 황칠나무의 자생지는 완도, 상황봉 등 8개 지역이었으며, 해남 두륜산은 처음으로 자생지로 확인되었다. 2. 황칠나무는 해발 lOO~450m 사이에셔 자생하고 있으며 해발 200m 부근에서 빈도가 가장 높게 냐다났다. 또한 자생지의 토양은 pH 4.9~5.8로 약 산성이며, 수분 함유량은 16.5~27.4%로 비교적 습 기가 많은 지역에서도 자생하는 것으로 나타났다. 3. 군락지 조새에서 보길도와 제주도가 우점도 및 군도가 교목층에셔 3.3으로 높게 나타났으며 완도는 아교목층에서 많이 나타났다. 4. 생육상황은 보길도에서 가장 높게 나타나 흉고 직경 1.O~20cm, 높이 O.2~9m 까지의 개체가 다수 확인되었다. 5. 황칠의 성분을 분석한 결과 대표적 인 성분이 ${\beta}$- selinene과 capnellane-8-one을 확인하였다.

• 한국산림과학회지
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• 제99권4호
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• pp.568-572
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• 2010

희귀수종 시로미(Empetrum nigrum var. japonicum K. Koch.)의 기내증식 방법을 구명하기 위해 당년생 신초를 재료로 증식에 미치는 배지염류, 싸이토키닌 효과와 기내발근에 미치는 배지 및 오옥신의 효과를 시험하였다. 액아 마디로부터의 줄기 유도는 WPM 배지가 MS 배지보다 양호한 반응을 나타냈다. WPM 배지의 염류농도에 따른 줄기유도는 뚜렷한 차이가 없었으나 기본배지에서 비교적 건전한 줄기가 유도되었다. 다경 유도에는 zeatin이 BA보다 효과적인 반면에 줄기 생장은 BA가 더 양호한 것으로 나타났다. 증식된 줄기로부터 기내 발근은 1/2MS 배지보다는 WPM 배지가 효과적인 것으로 나타났으며 5.0 mg/L IBA 처리 시 가장 높은 발근율을 보였다. 발근묘는 인공 배양토에서 4 주후 93% 이상이 활착되었다. 이상의 결과는 희귀종 시로미의 기내배양을 통한 증식 가능성을 보여주었다.

• Journal of Plant Biotechnology
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• 제41권4호
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• pp.236-241
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• 2014

An efficient regeneration protocol for stem disc culture of Populus euramericana, which is important species for bioenergy resource in agroforestry, was established. The number of explants that were obtained and the number of explants that regenerated varied with the genotypes. However, in all the genotypes, stem disc culture produced more regenerated shoots than did in axillary bud culture. A comparison of the effects of cytokinin type and concentration on shoot regeneration in different explants (i.e., petiole, leaf, and root segments of P. euramericana) revealed that a concentration of $0.002mg\;l^{-1}$ thidiazuron (TDZ) used on petiole segments resulted in the greatest shoot regeneration (95.83%). The hormonal requirements for the greatest shoot regeneration in the three explant types varied. Different concentrations of $AgNO_3$ and $CoCl_2$ were added separately to the medium to stop the yellowing and subsequent necrosis of the regenerated shoots. Lower concentrations (3 and $5mg\;l^{-1}$) of these compounds improved shoot regeneration and elongation, compared with the control. The in vitro-regenerated shoots were transferred to rooting medium and subsequently acclimatized. The highly efficient regeneration system of P. euramericana reported here can be used for mass propagation of this recalcitrant for regeneration, economically important tree species.

• Computers and Concrete
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• 제6권3호
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• pp.203-223
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• 2009

Regression analysis (RA) can establish an explicit formula to predict the strength of High-Performance Concrete (HPC); however, the accuracy of the formula is poor. Back-Propagation Networks (BPNs) can establish a highly accurate model to predict the strength of HPC, but cannot generate an explicit formula. Genetic Operation Trees (GOTs) can establish an explicit formula to predict the strength of HPC that achieves a level of accuracy in between the two aforementioned approaches. Although GOT can produce an explicit formula but the formula is often too complicated so that unable to explain the substantial meaning of the formula. This study developed a Backward Pruning Technique (BPT) to simplify the complexity of GOT formula by replacing each variable of the tip node of operation tree with the median of the variable in the training dataset belonging to the node, and then pruning the node with the most accurate test dataset. Such pruning reduces formula complexity while maintaining the accuracy. 404 experimental datasets were used to compare accuracy and complexity of three model building techniques, RA, BPN and GOT. Results show that the pruned GOT can generate simple and accurate formula for predicting the strength of HPC.

• Journal of Forest and Environmental Science
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• 제36권4호
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• pp.267-273
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• 2020

Diospyros mespiliformis is a highly valued and threatened tree species within the Sahelo-Sudanian zone of Africa, but its seed germination requirements under cultivation are not well researched. In a first experiment which aimed at determining germination response of seeds to dehydration, fresh seeds were dried at room temperature for 26 days during which their moisture content, their germinability, and their viability were monitored at two-day intervals. In the second experiment, 14 pre-germination treatments were tested for their effect on the germination of dried seeds. Results showed that fresh seeds had 52.7% moisture and achieved 97.7% germination. As seeds were dried, percentage germination gradually decreased with decreasing moisture content and reached 0% when moisture content had dropped to 18%. Meanwhile, seed viability remained at 100% over drying duration. Seeds that were not germinated after air dry also recorded 100% viability. The most effective treatment for inducing germination of dried seeds was scarification using 98% sulfuric acid for 30 min which resulted in 96.6% germination. This study reports for the first time in D. mespiliformis seeds a desiccation-induced dormancy which can be efficiently alleviated by acid scarification. This study provides useful information that will contribute to efficient management of D. mespiliformis seed resources for propagation.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.886-890
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• 2007

Machine fault prognosis techniques have been considered profoundly in the recent time due to their profit for reducing unexpected faults or unscheduled maintenance. With those techniques, the working conditions of components, the trending of fault propagation, and the time-to-failure are forecasted precisely before they reach the failure thresholds. In this work, we propose an approach of Least Square Regression Tree (LSRT), which is an extension of the Classification and Regression Tree (CART), in association with one-step-ahead prediction of time-series forecasting technique to predict the future conditions of machines. In this technique, the number of available observations is firstly determined by using Cao's method and LSRT is employed as prognosis system in the next step. The proposed approach is evaluated by real data of low methane compressor. Furthermore, the comparison between the predicted results of CART and LSRT are carried out to prove the accuracy. The predicted results show that LSRT offers a potential for machine condition prognosis.