• Journal of the Korean Data and Information Science Society
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• 제12권2호
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• pp.1-10
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• 2001

신경망은 점차 분류 및 함수추정을 위한 현대 통계적 방법론으로 부각되고 있다. 신경망은 특히 선형 회귀함수를 일반화시키는 유연한(flexible) 방법을 제공하며 일반적 비선형 함수를 모수화하는 방법으로 간주된다. 본 논문에서는 함수추정을 위한 신경망을 생각한다. 신경망이 훈련자료를 과대적합하는 것을 피할 수 있도록 하는 간단한 방법은 정칙화(regularization)이다. 신경망에서는 정칙화를 위해 주로 가중치 감소법(weight decay method)을 사용한다. 함수추정을 위해 가중치감소 신경망을 사용할 때 은닉노드수, 가중치모수, 학습률 및 학습반복회수가 중요한 모수이다. 본 논문에서는 유전자 알고리즘을 사용하여 가중치감소 신경망의 중요한 모수들을 자동으로 최적화하는 방법을 제안하고 결과적으로 가중치감소 신경망을 자동학습하는 방법을 설명한다. 그리고 다른 함수추정방법들과 자동학습된 가중치감소 신경망을 비교분석한다.

• Journal of the Korean Wood Science and Technology
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• 제36권5호
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• pp.1-10
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• 2008

Decay and mold resistance of zinc borate (ZB) and calcium borate (CB) modified oriented strandboard (OSB) from southern mixed hardwood and southern yellow pine was investigated in this study. Brown rot fungus Gloeophyllum trabeum and white-rot fungus Trametes versicolar were used to examine the decay resistance of the OSB. The OSB test specimens were colonized by brown and white rot fungal mycelium in both the brown and white-rot culture bottles after 8 and 12 weeks, respectively. The wood species and fungus type had the significant effects on the decay resistance. Brown rot decay was evident for all untreated southern pine and mixed hardwood controls. The white-rot decay, however, did not show significant weight loss at both species control samples. The incorporation of ZB and CB composites provides suitable protection against brown-and white-rot fungi. No significant weight loss was observed from the borate treated OSB.

• Journal of the Korean Wood Science and Technology
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• 제44권6호
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• pp.880-889
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• 2016

To evaluate the resistance of wood to decay caused by fungi, sapwood and heartwood of red pine (Pinus densiflora) and sapwood and heartwood of larch (Larix kaempferi) were conducted. Wood samples were immersed for 96 h in pyroligneous liquor. Then, the brown-rot fungus, Fomitopsis palustris, was used to examine the decay resistance of red pine and larch. Weight and density of wood from the all conditions increased after immersion treatment. Weight loss after decay resistance test was also dropped with a immersion treatment. The lowest weight loss indicated at immersion-treated heartwood of larch. Immersion treatment using pyroligneous liquor effectively increased the resistance of wood to decay caused by fungi.

• Journal of the Korean Wood Science and Technology
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• 제24권1호
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• pp.81-86
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• 1996

This study was performed to evaluate the reduction in bending properties of radiata pine sapwood associated with incipient brown-rot decay. Decayed bending specimens by Tyromyces palustris and Gloeophyllum trabeum for varoious periods were tested destructively. Brown-rot decay by T. palustris and G. trabeum caused serious reduction in bending properties at very early stages of decay, with about 30 percent decrease in bending strength observed for only 1~2 percent weight loss. In general, the reduction in bending properties caused by T. palustris was somewhat greater than that by G. trabeum. Work to maximum load was reduced most severely and rapidly from the onset of decay, while modulus of elasticity showed a much more moderate rate of reduction. Modulus of rupture was affected by decay to a greater extent than was modulus of elasticity. Since a relatively strong correlation between weight loss and bending strength was observed, the residual strength of decayed wood can be predicted by weight loss due to decay. The results of this study indicate that very early stages of brown-rot decay reduce the bending strength significantly. Thus, it is recommended that all load-bearing members in wooden structures, especially those that are periodically wetted, should be inspected regularly to prevent a sudden failure even though there are no definite signs of decay.

• Journal of the Korean Wood Science and Technology
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• 제45권2호
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• pp.195-201
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• 2017

This study was conducted to evaluate the resistance of heat-treated wood using the catalyst to decay caused by fungi for sapwood and heartwood of two tree species, Korean red pine (Pinus densiflora) and Japanese larch (Larix kaempferi), respectively. Wood samples were immersed for 10 min in sulfuric acid (7.5%) and then heat-treated at $130^{\circ}C$ for 90 min. Fomitopsis palustris, a brown-rot fungus, was used to examine the decay resistance of Korean red pine and Japanese larch wood. Weight and density of wood from the all conditions increased after heat treatment using the catalyst. Weight loss after decay resistance test was also dropped with a heat treatment. The lowest weight loss indicated at heat-treated heartwood of Japanese larch. Heat treatment using the catalyst effectively increased the resistance of wood to decay caused by fungi.

• Journal of the Korean Wood Science and Technology
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• 제32권4호
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• pp.74-81
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• 2004

비파괴 시험 방법 중 초음파 방법을 이용하여, 목재의 열화상태를 진단하였다. 기초 자료로서, 목재 내 온도변화에 따른 초음파 전송속도의 변화, 목재 내 함수율변화에 따른 초음파 전송속도 변화, 목재 강제부후에 의한 중량감소와 초음파 전송속도 변화를 검토하였다. 또한 원목의 비파괴 시험 등을 수행하고, 초음파 전송속도에 근거한 부후분포도를 작성하여 고목재의 열화 진단을 하였다. 일련의 시험들을 통하여 비파괴 방법에 의한 목재 열화진단을 위한 데이터를 축적하고, 이를 고목재에 적용하여 목재 내부의 부후분포도를 작성함으로써 금후 고목재의 비파괴 방법에 의한 부후탐지의 가능성을 검토하였다.

• Journal of the Korean Wood Science and Technology
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• 제32권6호
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• pp.7-13
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• 2004

In this study, the Korean pine wood (Pinus densiflora Sieb. et Zucc) and Italian poplar wood (Populus euramericana Guinier) was treated with a mixture of monoammonium phosphate (MAP) and boric acid. Their usability as fire retardant and as decay-resistant construction and interior materials were evaluated by testing of chemicals, corrosion rate and absorption rate, weight loss and chemical contents. An experiment was performed to compare treated pine wood and Italian poplar wood. According to the results, Italian poplar wood had higher specific gravity and retention of chemicals than pine wood, and treated wood showed higher decay-resistance than untreated one. Weight loss was less in treated wood than untreated one because the degree of decay was lower in the former than the latter. Corrosion rate and absorption rate met the KS standard for wood preservative performance. The chemical contents analysis was carried out to determine the degree of decay and it was found that the preservative effect of chemical treatment was lower in Italian poplar wood than in pine wood.

• International Journal of Computer Science & Network Security
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• 제23권11호
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• pp.133-141
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• 2023

This work take deeper analysis of Adaptive Moment Estimation (Adam) and Adam with Weight Decay (AdamW) implementation in real world text classification problem (DGA Malware Detection). AdamW is introduced by decoupling weight decay from L2 regularization and implemented as improved optimizer. This work introduces a novel implementation of AdamW variant as AdamW+ by further simplifying weight decay implementation in AdamW. DGA malware detection LSTM models results for Adam, AdamW and AdamW+ are evaluated on various DGA families/ groups as multiclass text classification. Proposed AdamW+ optimizer results has shown improvement in all standard performance metrics over Adam and AdamW. Analysis of outcome has shown that novel optimizer has outperformed both Adam and AdamW text classification based problems.

• Journal of Forest and Environmental Science
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• 제37권1호
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• pp.52-61
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• 2021

Decay fungi can decompose plant debris to recycle carbon in the ecosystem. Still, they can also be fungal pathogens, which can damage living trees and/or wood material and cause a large amount of timber loss. We isolated and identified basidiomycetous fungi from the decayed bark of Mongolian oak wrapped with sticky roll traps. The degrading enzyme activities were then tested for all fungal isolates. The decay ability of selected isolates was assessed based on the weight loss of wood discs after inoculating with culture suspension of decay fungi under the different humidity levels. A total of 46 basidiomycetous fungal isolates belonged to 12 species, and 10 genera were obtained from Jong Myo (16 isolates), Chang Kyung palace (7 isolates), Cheong Gye (10 isolates), and Gun Po (13 isolates). Gymnopus luxurians was the most dominant fungus in the present study, and this species distributed in all survey sites with 9 isolates in Jong Myo, followed by 3 isolates in Chang Kyung palace, while Cheong Gye and Gun Po had only 1 isolate each. Among 46 isolates, 44 isolates secreted at least one enzyme, while 25 isolates produced both cellulase and phenol oxidase enzymes, and 2 isolates produced neither. The assessment of decay ability by artificial inoculation indicated that the weight loss of wood discs was significantly influenced by humidity conditions when inoculated with bark decay fungi. The percent weight losses by G. luxurians inoculation in RH of 90-100% and RH of 65-75% were 4.61% and 2.45%, respectively. The weight loss caused by Abortiporus biennis were 6.67% and 0.46% in RH of 90-100% and RH of 45-55%, respectively. The humidity reduction approach should be applied for further studies to control the growth and spread of bark decay fungi on the trunks wrapped with sticky roll traps.

• Journal of the Korean Wood Science and Technology
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• 제24권2호
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• pp.1-6
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• 1996

This study was performed to investigate the feasibility of using sonic stress-wave technique in the longitudinal direction for the assessment of incipient decay of radiata pine wood. Decayed bending specimens by Tyromyces palustris and Gloeophyllum trabeum for varoious periods were tested nondestructively using stress-wave technique in the longitudinal direction and destructively. Decay detection, quantitative assessment of decay, and the prediction of residual strength of decayed wood with less than five percent weight loss can be feasible using stress-wave parameters (wave velocity, wave impedance, stress-wave elasticity) measured by stress-wave technique in the longitudinal direction and their percent reduction due to decay.