• Journal of Korean Society of Forest Science
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• v.90 no.4
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• pp.505-512
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• 2001

This study examined the impacts of tariff reductions on timber products in the new round of WTO negotiations on domestic timber products markets and presented the measures to minimize their impacts. Scenarios on reductions in tariffs were developed based on result of UR negotiation and prospective issues on scope of tariffs bound, base rates for negotiation, degree of tariff cuts, etc. emerged during preparatory meetings held to launch the New Round of WTO Negotiation. Korea Timber Market Model(KORTIMM) developed by Korea Forest Research Institute was used to simulate the impacts on forest products markets by scenario. It was estimated that their impacts on net imports would be much larger than those on both consumption and production. The results showed that their impacts on plywood market and on net imports of processed forest products would be much larger relatively but that their impacts on log market and on consumption and production of processed forest products would be less than 1 percent. It was estimated that log consumption would be reduced due to reduction in domestic production of processed products and thus both production and imports of logs would be reduced as well. In oder to minimize the impacts, efforts should be made to start negotiations to reduce tariffs with bound rates for bounded products and with applied rates for non-bounded products, to expand the implementation period and to maintain the status of developing country. In addition, it might be one of countermeasures to use legitimate measures consistent with WTO rules such as anti-dumping, countervailing measures and safeguards.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.1
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• pp.5-14
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• 2017

Many web services which use OAuth Protocol offer users to log in using their personal profile information given by resource servers. This method reduces the inconvenience of the users to register for new membership. However, at the time a user finishes using OAuth client web service, even if he logs out of the client web service, the resource server remained in the login state may cause the problem of leaking personal information. In this paper, we propose a solution to mitigate the threat by providing an additional security behavior check: when a user requests to log out of the Web Client service, he or she can make decision whether or not to log out of the resource server via confirmation notification regarding the state of the resource server. By utilizing the proposed method, users who log in through the OAuth Protocol in the public PC environment like department stores, libraries, printing companies, etc. can prevent the leakage of personal information issues that may arise from forgetting to check the other OAuth related services. To verify our study, we implement a Client Web Service that uses OAuth 2.0 protocol and integrate it with our security behavior check. The result shows that with this additional function, users will have a better security when dealing with resource authorization in OAuth 2.0 implementation.

• The Journal of Engineering Geology
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• v.23 no.4
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• pp.457-465
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• 2013

We integrated and correlated datasets from surface and subsurface geophysics, drilling cores, and engineering geology to identify geological interfaces and characterize the joints and fracture zones within the rock mass. The regional geometry of a geologically weak zone was investigated via a fence projection of electrical resistivity data and a borehole image-processing system. Subsurface discontinuities and intensive fracture zones within the rock mass are delineated by cross-hole seismic tomography and analyses of dip directions in rose diagrams. The dynamic elastic modulus is studied in terms of the P-wave velocity and Poisson's ratio. Subsurface discontinuities, which are conventionally identified using the N value and from core samples, can now be identified from anomalous reflection coefficients (i.e., acoustic impedance contrast) calculated using a pair of well logs, comprising seismic velocity from suspension-PS logging and density from logging. Intensive fracture zones identified in the synthetic seismogram are matched to core loss zones in the drilling core data and to a high concentration of joints in the borehole imaging system. The upper boundaries of fracture zones are correlated to strongly negative amplitude in the synthetic trace, which is constructed by convolution of the optimal Ricker wavelet with a reflection coefficient. The standard deviations of dynamic elastic moduli are higher for fracture zones than for acompact rock mass, due to the wide range of velocities resulting from the large numbers of joints and fractures within the zone.

• Journal of the Korean Wood Science and Technology
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• v.10 no.3
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• pp.52-67
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• 1982

We have relatively heavy stocks of hardwood which consist of inferior and nonproductive natural hardwood species in Korea. As conception above to develope these forest resources, the study was carried out to obtain the basical data for the reasonable and efficient utilization of hardwoods. The sample trees were selected 11 natural hardwood species grown in Kangwon-do region and Kwangnoong Experimental Forest. We have investigated anatomical, physical and mechanical properties of them. Especially, Quercus species which is a major species in the forests was investigated on qualities of trees, logs and lumbers, recevery of bucking and lumber yield, etc.

• Journal of the Korean Wood Science and Technology
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• v.4 no.1
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• pp.38-47
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• 1976

This study was carried out to exploit and utilize American sycamore (Platanus occidentalis) and poplar grown in Korea as veneer species for plywood manufacture. At this study to save the imported lauan logs and dollars, the effects affecting to the properties of plywood constructed by sycamore, poplar and lauan veneers were studied. Important items dealt with this study were dry and wet shear strength, moisture content, and specific gravities By the results and discussion it may be summarized as followings. 1) Sycamore core lauan plywood (A-II type) was shown best dry shear strength, and the next were all lauan veneer plywood (A-I type), poplar core lauan plywood (B-I type), lauan core sycamore plywood (A-III type) in order. There are no differences between dry shear strength of A-II type and A-I type, A-II type and B-I type plywood. 2) Wet shear strength showed the same order with dry shear strength. A-II type plywood showed best wet shear strength and it showed more difference than other plwoods. A-I type, B-I type and A-III type plywood were all very good without significant difference in wet shear strength. 3) B-I type plywood showed highest moisture content of all type plywood and the next were all sycamore(A-IV type) all poplar plywood (B-III type), A-III type, B-II type, A-II type pllywood in order. Generally high moisture content showed when two or three veneers were same species in the three layer plywood. 4) A-III type plywood showed highest specific gravity of all and the next was A-IV type plywood without a difference to A-I type plywood on the whole. plywoods constructed by lauan and sycamore were shown high specific gravities and the next was lauan, sycamore and poplar, lauan and poplar. It seemed to be that connected wi th the specific gravity of veneer itself in different species. 5) The plywood manufactured by extension of potato flour is not only superior but also profitable in the price aspect than the plywood manufactured by extension of wheat flour.

• The Korean Journal of Mycology
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• v.39 no.1
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• pp.44-47
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• 2011

A harmful fungus occurred seriously in bed-log of shiitake(Lentinula edodes) in Jangheung-Gun, Korea. The fungus was identified as Bjerkandera adusta by its morphology and ITS(Internal Transcribed Spacer) analysis. The fungus was reported as causal agent of stem-rot of Populus euramericana in Korea, but not reported in bed-log of shiitake until this notification. Thus, studies were made to investigate inside condition of bed-log of shiitake damaged by B. adusta, physiological characteristics of B. adusta and antagonism between these two fungi. First of all, B. adusta is white-rotting fungus like shiitake and wood-rotting condition is similar to that of shiitake. But, there are a lot of small spots in damaged wood tissue under bark which are not seen in case of shiitake. Optimal temperature for mycelial growth of B. adusta is ca. $30^{\circ}C$ while that of shiitake is ca. $25^{\circ}C$. When confrontation cultures were made between these two fungi under $15^{\circ}C$, $20^{\circ}C$, $25^{\circ}C$ and $30^{\circ}C$, B. adusta has antagonistic ability against shiitake in all the temperatures. From the results of experiments, if the bed-logs of shiitake are exposed to high temperature, there should be mass propagation of B. adusta, and shiitake mycelia will be seriously injured by the fungus. Therefore, to prevent the damage by B. adusta, it is needed to grow the mycelia of shiitake fast in the bed-log, and to avoid exposure of the bed-log to high temperature in summer.

• Journal of the Korean Wood Science and Technology
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• v.13 no.3
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• pp.41-48
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• 1985

In near future about 500,000 hectares of Japanese larch and pitch pine need thinning to improve crop-tree spacing and reasonable species composition in Korea. Although thinned trees show very little high quality wood, in fact, all the sawed products are suitable for construction and farming materials. Studies on the utilization of thinned small-diameter trees have been implemented in order to increase lumber yield and display the skeleton of farm buildings. The results obtained in this study were summarized as follows: 1. According to Korean Conifers Log Grading System, log grade 3 was 87.4 percent in Japanese larch bolts and 95.8 percent in pitch pine bolts from thinned trees. The ability to identify defects was essential for grading logs. 2. Cutting diagrams of sawing were developed for 1-sided sawing, 2-sided sawing and 3-sided sawing by small end diameter class of bolt and cutting sizes also were found to use effectively lumber with wane. 3. Lumber recovery of Pitch pine was a little higher than that of Japanese larch. The maximum lumber yields of pitch pine by sawing patterns were 87.2 percent for 1-sided sawing, 80.8 percent for 2-sided sawing an 64.1 percent for 3-sided sawing, up yield compared with 58.1 percent for 4-sided sawing. The lumber yield of 1, 2 and 3-sided sawing significantly was higher value than that of 4-sided sawing. 4. Lumber was inspected and graded. Lumber quality of diameter class 12cm was a little better than that of diameter class 8cm, but 90 percent of lumber in diameter c1ass 16cm fell into grade 3. The lumber grade was classified by Korean standard grades of confiers lumber. 5. Lumber from 1, 2 and 3-sided sawing was used to build the skeleton of a farm house ($53m^2$) and greenhouse ($60m^2$) in order to display more efficient use of small diameter trees from thinning 6. Total volume of timber for building a farm house was $8.1m^3$ of imported timber. Timber of $7m^3$, 70 percent of total volume would be substituted imported timber for domestic timber.

• Journal of Music and Human Behavior
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• v.7 no.1
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• pp.37-59
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• 2010

The purpose of this study was to examine how a creative musical play program affected peer relational skills of children in a community child center. The creative musical play program was implemented with six children in K Community Child Center for twenty (20) sessions. To investigate quantitative change, the Peer Relational Skills Scale and the Revised Social Skills Scale (for teachers) were filled out by children and teachers before and after the program. Also, to investigate musical and behavior changes related with peer relational skills in the creative musical program, the responses of children were categorized from the data of the children's responses according to previously identified sub-factors of peer relational skills. The results show that the participants' average scores presented an improvement in peer relational skills. Qualitative analysis of session logs presented that negative factors which had appeared in early sessions changed to positive traits as the sessions went on. In conclusion, the creative musical play program was effective in increasing peer relational skills of children in the community child center.

• Journal of Mushroom
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• v.15 no.4
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• pp.269-272
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• 2017

We developed a log-burying cultivation technique for Grifola frondosa using oak logs and surveyed its annual yield characteristics. As a result of G. frondosa log cultivation, the harvesting period of the 'Yipsae1ho' cultivar was delayed by approximately 10-15 days compared to that of the Dabak cultivar, and the fruit color of the 'Yipsae1ho' cultivar was dark brown, while that of the 'Dabak' cultivar was grayish brown. Yield of the 'Yipsae1ho' cultivar was $16.0 kg/m^2$ in the first year, $15.4kg/m^2$ in the second year, $9.5 kg/m^2$ in the third year, $4.6 kg/m^2$ in the fourth year, and $4.6kg/m^2$ in the fifth year, while yield of the 'Dabak' cultivar was $12.3kg/m^2$ in the first year, $11.5kg/m^2$ in the second year, $12.7kg/m^2$ in the third year, $6.2 kg/m^2$ in the fourth year, and $8.2kg/m^2$ in the fifth year. Total yield of the 'Yipsae1ho' cultivar ($50.0 kg/m^2$) was slightly lower than that of the 'Dabak' cultivar ($50.8kg/m^2$). The optimum period for log-burying cultivation of Grifola frondosa is estimated to be 3 years.

• Research in Plant Disease
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• v.20 no.4
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• pp.270-274
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• 2014

Division of Forest Diseases & Insect Pests, Korea Forest Research Institute, Seoul 130-712, Korea The objective of this study was to evaluate the virulence of geographically different isolates of oak wilt pathogen, Raffaelea quercus-mongolicae and other Raffaelea species. In this study, mature trees of Quercus mongolica were inoculated with the various isolates of Raffaelea spp. and their virulence was evaluated by measuring the extent of sapwood discoloration resulting from the inoculation. The average length of discolored sapwood in a lateral direction was longest in the trees inoculated with the isolates from Korea (8.69 cm) followed by R. quercivora (7.51 cm) and the other Raffaelea spp. (3.35 cm). The lateral length of discolored sapwood caused by the inoculation with Korean strains varied from 4.71 to 14.90 cm indicating their differences in virulence. The area of discolored sapwood caused by the inoculation with Raffaelea spp. varied from 1.57 to $8.42cm^2$ indicating their differences in virulence. Based on the length and area of the discolored sapwoods, isolated YY and wj43 appeared to have the highest virulence among all the Raffaelea isolates tested. Each of the two isolates was obtained from Gangwon Province and Jeonbuk Province, respectively.