• Journal of Korean Society of Forest Science
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• v.98 no.2
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• pp.148-155
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• 2009

The objective of this study is to know market structures of softwood logs being imported to South Korea from log producing countries. Import demand of softwood logs imported to South Korea from America, New Zealand and Chile is fixed as a function of log prices, the lagged dependent variable and output. On the basis of the adaptive expectations model, linear regression models that the explanatory variables included and the lagged dependent variable were estimated by Seemingly Unrelated Regression Equations (SURE). The short-run and long-run own price elasticity of America's softwood log import demand is -1.738 and -4.250 respectively. Then long-run elasticity is much higher than short-run elasticity. Short-run and long-run crosselasticity of New Zealand's softwood log import demand with respect to American's softwood log import price are inelastic at 0.505 and 0.883 respectively. Short-run and long-run cross-elasticity of Chile's softwood log import demands with respect to American's softwood log import prices were highly elastic at 2.442 and 4.462 respectively. Long-run elasticity was almost twice as high as short-run elasticity.

• Journal of the Korean Graphic Arts Communication Society
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• v.30 no.3
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• pp.35-43
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• 2012

Internal bonding strength of printing paper was increased with sea-algae pulp treatment. Spacially, 9% contents sea-algae pulp treatment in the hardwood pulp are more effective than in the softwood pulp. Most effective mixture ratio of the raw matrials for improvement of the internal bonding strength are softwood pulp 30%, hardwood pulp 70%, sea-algae pulp 9%. Internal bonding strength is effective in more sea-algae pulp contents and softwood pulp contents and wetness.

• Journal of Sericultural and Entomological Science
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• v.39 no.2
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• pp.203-204
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• 1997

The authors studied on mulberry cutting of soft wood. It had been known that the rootability of softwood cuttings was formed after 25 days after winter bud sprouting. But, the result showed that the formation of rootability of soft wood was 9 days earlier than the conventional time.

• Journal of the Korean Wood Science and Technology
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• v.19 no.4
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• pp.34-42
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• 1991

Protection of tropical forest affects on significant reduce of tropical hardwood supply, and softwood resources will be increasingly important for the timber security in Korea. U.S. softwood log was most favorite species for Korean softwood log importers in overall import conditions except price stablization and consistency of export policy. Reduced export volume from Pacific Northwest to Korean market has been immediately replenished by rediata pine from New Zealand and Chilean plantation. Siberian timber will hardly play major roles in Korean timber market unless budding structure. softwood plywood and softwood furniture uses are enhanced. Recent rapid rise of labor cost and reducing tariff rrate in Korea provided better opportunities for import lumber in building materials market. Dry dimension lumber was relatively profitable when processed from import U.S. soft-wood log while green lumber was favorable products processed from radiata pine log in Korean lumber market. This means U.S. softwood lumber would have better opportunity to market for '2${\times}$'4 studs when wood frame housing is introduced. On the other hand while radiata pine is competitive on temporary construction lumber such as supporter and concrete forming frame in Korea. Shortage of raw material for the new capacity of board plants in Korea will be it bottle neck. Major log export countries to Korea as U.S. New Zealand and Chile showed high trade intensity indices of composite hoard produces for Korean market. As Korea efforts to diversify import sources, and tariffs are reduced to 8% as scheduled by 1994. countries of scoring higher comparative advantages as Portugal. Brazil, Austria as well as New Zealand will have better opportunity to penetrate into promised Korean composites hoard market.

• Journal of Korea Foresty Energy
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• v.25 no.2
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• pp.49-54
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• 2006

This study was carried out to provide basic data for using domestic structural softwood lumber efficiently and ensuring structural safety of timber structures. The ratios (k-factor) between static and dynamic MOE measured by ultrasonic device for $2{\times}6$ domestic softwood structural lumber are 1.0602 for Korean red pine, 1.0013 for Korean white pine and 1.2320 for Japanese larch. In machine grade using nondestructive method, 76% of Korean red pine was classified into higher than E9 grade, 85% of Korean white pine was sorted into higher than E7 grade and 68% of Japanese larch was classified into higher than E11 grade. Correlation between MOE and MOR by static bending with k-factor from nondestructive method provide a possibility to predict bending strength and allowable stress of domestic softwood structural lumber.

• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.166-174
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• 2007

To know the effect of enzymatic pre-treatment on softwood Kraft pulp, two xylanse-encoding genes, named xynl and xynll were isolated from Thrichoderma ressei. Structural genes of xylanase (XYNI, XYNII) and cellulase (EGIV-CBDII) were isolated from T. ressei and Rumicoccus albus respectively, and expressed in E. coli. bacterial culture. The specific activity of purified recombinant XYNI is higher than XYNII. The brightness of XYNI treated softwood Kraft pulp increased to 29.9%. On further sequential treatment with EGIV-CBDII and XYNI the brightness of softwood Kraft pulp were improved to 9.1 and 73% respectively. As expected the Kappa number of softwood Kraft pulp also decreased 8.1, 4.6 and 3.2% respectively. Results further indicate that this sequential combination of enzyme treatment has synergic effect for improving bleaching of softwood Kraft pulp.

• Journal of Korean Society of Forest Science
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• v.95 no.2
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• pp.203-208
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• 2006

This study compared the roundwood demand prediction accuracy of econometric and time-series models using Korean data. The roundwood was divided into softwood and hardwood by species. The econometric model of roundwood demand was specified with four explanatory variables; own price, substitute price, gross domestic product, dummy. The time-series model was specified with lagged endogenous variable. The dummy variable reflected the abrupt decrease in roundwood demand in the late 1990's in the case of softwood roundwood, and the boom of plywood export in the late 1970's in the case of hardwood roundwood. On the other hand, the prediction accuracy was estimated on the basis of Residual Mean Square Errors(RMSE). The results showed that the softwood roundwood demand prediction can be performed more accurately by econometric model than by time-series model. However, the hardwood roundwood demand prediction accuracy was similar in the case of using econometric and time-series model.

• Korean Journal of Plant Resources
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• v.13 no.2
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• pp.140-146
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• 2000

This study was conducted to determine the effect of cutting type, growth regulators and propagation media on the rooting and root growth of Roea davurica $P_{ALL}$. Three type of cutting, hardwood, half-softwood, softwood cutting and root cutting of Rosa davurica $P_{ALL}$, were used to study the rooting ability. There was no rooting in hardwood cutting while root cutting was appeared 100% of callus formation and rooting. The optimum conditions of softwood cutting for rooting were IAA 100ppm and rooton-F at vermiculite+perlite. The rate of rooting in treatment of rooton-F ranged from 10 to 60%, but such a good effect was not appeared in other growth regulators, IAA, NAA and IBA.

• Journal of the Korean Graphic Arts Communication Society
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• v.29 no.1
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• pp.89-99
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• 2011

The making of high leveled smoothness for the printed electronics base paper, wood pulp and sea algal pulp were mixed. If sea algal pulp contents is increased to 9%, the smoothness was moderately increased, and more effective in Softwood mixture than Hardwood, low freeness(high wetness) than high freeness(low wetness).

• Journal of Korean Society of Forest Science
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• v.97 no.1
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• pp.45-52
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• 2008

The objectives of this study are to explain a supply plan of domestic softwood log by long-term prospect of MDF production to stably promote industry of MDF. For it, we developed the long supply function as Ordinary Least Squares Method. Between 2005 and 2050, it was estimated that quantity of domestic production of MDF increased from 1,653 thousand $m^3$ to 2,041 thousand $m^3$. In 2050, quantities of domestic softwood log used by raw materials to product MDF of 2,041 thousand $m^3$ were estimated to be used about 1,355 thousand $m^3$. Exampling Pinus rigida used presently by raw materials to product MDF, cutting area of it is estimated to be 10,828 ha per year. And larch is cutted about 9,160 ha per year. This study estimated annual softwood log cutting amount and total afforestation area at 2050 year by 3 scenarios which are 35%, 45% and 55% about use of domestic softwood log for MDF production. If we do a criterion of cutting area, we advantage to plant larch. But the species of trees are use and growth property. We think that the afforestation policy must be performed on the base of those to supply raw materials of MDF. Although government plans hardwood afforestation policy after cutting Pinus rigida, it needs to support and manage certainly afforestation area of softwoods to need to supply raw materials of MDF to stably promote industry of MDF.