• Journal of the Korean Wood Science and Technology
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• v.43 no.6
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• pp.838-850
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• 2015

In this study, dilute acid pretreatment was operated using small-diameter Quercus mongolica for evaluating the yield change of furfural and levulinic acid depending on pretreatment factors. The dilute acid pretreatment was conducted depending on reaction temperature ($140-180^{\circ}C$), reaction time (10-30 min), and sulfuric acid concentration (0-2%, w/w). Then, glucose, XMG (xylose + mannose + galactose), furfural, and levulinic acid contents in the liquid hydrolyzate were measured and analyzed after pretreatment. Glucose content increased to 16.02% as reaction temperature, reaction time, and sulfuric acid concentration increased, but it decreased at the sulfuric acid concentration of 2% (reaction temperature: > $170^{\circ}C$, reaction time: > 20 min). On the other hand, reaction temperature had a strong influenced on XMG content, and XMG content decreased to 1.63% through increasing of reaction temperature and sulfuric acid concentration, but XMG content was less affected by changes of reaction time. Furfural content increased with the increase of reaction temperature, reaction time, and sulfuric acid concentration, and maximum furfural content was 7.61% (reaction temperature: $180^{\circ}C$, reaction time: 20 min, sulfuric acid concentration: 1%) based on a weight of raw material, while furfural content was dropped in more severe condition than in maximum furfural content condition. Levulinic acid content also increased with higher reaction temperature, reaction time, and sulfuric acid concentration. Especially, the sharp increase of levulinic acid content was observed above $170^{\circ}C$, and maximum levulinic acid content was 10.98% (reaction temperature: $180^{\circ}C$, reaction time: 30 min, sulfuric acid concentration: 2%). However, less than 1% of furfural and levulinic acid content was obtained in non-acidic catalyst condition that in whole conditions of reaction temperature and reaction time.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.2
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• pp.53-62
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• 2013

Land-use/cover changes not only amplify or alleviate influence of climate changes but also they are representative factors to affect environmental change along with climate changes. Thus, the use of land-use/cover changes scenario, consistent climate change scenario is very important to evaluate reliable influences by climate change. The purpose for this study is to predict and analyze the future urban growth considering social and economic scenario from RCP scenario suggested by the 5th evaluation report of IPCC. This study sets land-use/cover changes scenario based on storyline from RCP 4.5 and 8.5 scenario. Urban growth rate for each scenario is calculated by urban area per person and GDP for the last 25 years and regression formula based on double logarithmic model. In addition, the urban demand is predicted by the future population and GDP suggested by the government. This predicted demand is spatially distributed by the urban growth probability map made by logistic regression. As a result, the accuracy of urban growth probability map is appeared to be 89.3~90.3% high and the prediction accuracy for RCP 4.5 showed higher value than that of RCP 8.5. Urban areas from 2020 to 2050 showed consistent growth while the rate of increasing urban areas for RCP 8.5 scenario showed higher value than that of RCP 4.5 scenario. Increase of urban areas is predicted by the fact that famlands are damaged. Especially RCP 8.5 scenario indicated more increase not only farmland but also forest than RCP 4.5 scenario. In addition, the decrease of farmland and forest showed higher level from metropolitan cities than province cities. The results of this study is believed to be used for basic data to clarify complex two-way effects quantitatively for future climate change, land-use/cover changes.

• Journal of Korean Society of Forest Science
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• v.87 no.3
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• pp.466-474
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• 1998

This study was conducted to evaluate heavy metal concentrations(Cd, Cu, Z, and Pb) in the soil of two zinc mines and to correlate heavy metal contents between the soils and trees growing near the mines. Soils and leaves, stems, and roots of five tree species(Corylus heterophylla, Pinus rigida. Populus alba${\times}$glandulosa, Rhododendron mucronulatum, and Robinia pseudoacacia) were collected from Sambo Zinc Mine located in Hwasung and Gahak Zinc Mine in Kwangmyung city in Kyonggido. Soils near two zinc mines were not seriously contaminated by heavy metals, but Zn and Pb concentrations were at toxic level. The heavy metal concentration in soils decreased in the order of Zn, Pb, Cu, and Cd, and decreased with increasing distance from zinc mining sites. Among the five tree species, Populus alba ${\times}$ glandulosa showed the highest heavy metal concentrations in the tissue except for Pb. Particulars, leaves of the species contained the high concentrations of heavy metals to reach the maximum of 91ppm Zn. The roots of Corylus heterophylla contained high concentrations of Cu and Pb. The order of heavy metal concentrations in the tree species was Zn, Cu, Pb and Cd. The concentration of heavy metals in the tree tissues showed a positive correlation with that in soil in which trees are growing. The ratio of heavy metal concentration of trees to that of soils(concentration factor : CF) was highest in Zn and lowest in Pb. Populus alba${\times}$glandulosa had the highest CF value among the five tree species. It was concluded that Populus alba${\times}$glandulosa, based on the high metal uptake ability, could be used for decontaminating of heavy metals from contaminated soils, and Pinus rigida could be used to reflect the level of contamination in soils.

• Journal of Korean Society of Forest Science
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• v.87 no.2
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• pp.308-315
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• 1998

This study was conducted to evaluate the availability of the forest topsoil as a source of the "Native-soil(seed-fertilizer-soil materials)" for the hydroseeding measures which are environmentally and ecologically stable revegetation measures on rock cut-slopes. Soil sampling and factorial experiments were used with a split plot design(main plot : forest soil type and soil spraying thickness, subplot : seeding rate) in 1996. Results obtained in this study were summarized as follows : Because of the competition between the seeded(introduced) species and the native species, the number of naturally emerged species in the non-seeded plot and that of in the seeded plot were $5{\sim}9species/0.07m^2$ and $2{\sim}6species/0.07m^2$, respectively. As increasing the seeding rate(introduced species), the appearance ratio of naturally emerged species was decreased. The total number of individuals was high in the plot which used coniferous forest soil as a seed source, however the ratio of the individuals of naturally emerged species was high(30%) in the plot which used deciduous forest soil. The usage of the forest topsoil as seed bank source onto the "Native-soil" materials for hydroseeding could be reduce the seeding rate to $1,000seedlings/m^2$. According to the several factors which are competition between seeded species and naturally emerged species, dryness of soil materials, and seed burial, spraying thickness with more than 5cm was suitable for the growth of plants in variety.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.13 no.5
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• pp.41-54
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• 2018

In recent years, as interest in youth startup has increased, the Korean government has established various policies to support young entrepreneurs and actively implements such policies. Especially, as a way to promote youth startup, the development of startup clubs in universities is being suggested, and the importance of startup clubs is growing day by day. As reflected in these points, the Korean government is increasing its budget every year to support the startup clubs of universities, and actively supports the funds and space required for the startup clubs of universities. Unfortunately, however, despite the growing importance of startup clubs and the active support of the government for the startup clubs, academic attempts to see how effectively the startup clubs are operating are not enough. For this reason, this study analyzes the effect of entrepreneurship of university start-up club members on the effectiveness of start-up club. More specifically, in this study, entrepreneurship of club members is classified as risk-taking propensity, proactiveness, and innovativeness, as emphasized in previous researches. We empirically analyzed the effects of these independent variables on the effectiveness of the start-up clubs, focusing on the moderating effect of club members' diversity. We conducted empirical analyses on 1112 start-up club members from 12 universities located in Jeollanam-do and Jeollabuk-do, and the analysis results are as follows. First, the entrepreneurship of the start-up club members, namely risk taking propensity, proactiveness and innovativeness, all have a positive effect on the effectiveness of the start-up club. These results are consistent with the emphasis of many previous studies. The higher the tendency to take risks, the more inclined to move forward through difficulties, and the higher the tendency to break out of the existing framework and pursue new things, suggesting that the effectiveness of the club is enhanced. Second, as a result of verifying the moderating effect of the club members' diversity, it was found that club members' diversity moderates the relationship between the proactiveness of club members and club effectiveness in the negative (-) direction. In other words, the positive effect of the entrepreneurship of club members on the effectiveness of the start-up club means that the proactiveness is weakened in the case of a club having members from different major backgrounds. The results of this study are expected to provide meaningful theoretical and practical implications by identifying the influencing factors of the start-up club's effectiveness, which has not received much attention so far.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.3
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• pp.159-174
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• 2020

This study is an empirical study analyzing the effects of positive psychological capital on job burnout. In addition, positive psychological capital played a role in organizational citizenship behavior, and tried to verify the role of organizational citizenship behavior as a black box, or parameter, between job burnout. And then, the sub-factors of organizational citizenship behavior were divided into two: individual-oriented organizational citizenship behavior and organization-oriented organizational citizenship behavior. To this end, a questionnaire survey was conducted for members of small and medium-sized enterprises to compare and analyze the relationship between variables. Positive psychological capital is increasing interest in that it can reduce the job burnout of members and embrace the propensity of young generations represented by millennials because it can improve the effectiveness by developing positive mental states and strengths of the organization. There is a need for research as a keyword. As a result of this study, first, it was found that positive psychological capital of SME(small and medium-sized enterprises) members had a positive effect on organizational citizenship behavior. Second, positive psychological capital was found to have a significant negative effect on job burnout. Third, it was a verification of how positive psychological capital and organizational citizenship behavior affect job burnout. In the relationship between positive psychological capital and job burnout, organization-oriented organizational citizenship behavior was found to play a mediating role. However, it was found that individual-oriented organizational citizenship behaviors among the organizational citizenship behaviors are not valid. In this study, positive psychological capital and job burnout, which have been mainly studied in service workers' emotional workers(crew, nurses, counselors, etc.), nursery teachers, and social workers, were applied to SME members by using the parameters of organizational citizenship behavior. You can put that implication on things. The positive psychological capital and organizational citizenship behavior can be further enhanced through SME members' love for the company, improvement of consideration among employees and resulting organizational commitment and work performance. It could also provide momentum for sustainable management for small and medium-sized enterprises that are relatively short of capital and resources.

• Korean Journal of Heritage: History & Science
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• v.53 no.1
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• pp.126-149
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• 2020

Considering significant words that stand for the history of Paleolithic in North Korea, these can be summarized for each decade since the 1960s. The 1960s ought to be when the earliest discovery of a Paleolithic site was made by Korean hands. The 1970s might be the earliest period for textbooks being published that were geared towards increasing general understanding of the Paleolithic era in the Korean peninsula. The 1980s can be summarized as a period of reissued Paleolithic articles from a newly introduced archaeological journal. The 1990s witnessed efforts to formulate nationalistic interpretations about the Paleolithic period in Korea. The 2000s then synthesized several of these aspects of Paleolithic studies. Gulpori, the Paleolithic site that was discovered in the 1960s, holds significance not just because of the discovery itself, but because of its prompt acceptance by North Korean academic authorities. The publications that covered general understanding of Paleolithic archaeology such as Joseon Gogohag Gaeyo, Joseon-ui Guseoggisidae, and Joseonjeonsa: Wonsipyeon in the 1970s hold immense significance themselves, as they demonstrate contemporary achievements. Reintroduction of the archaeological Journal, Joseongogoyeongu in 1986, is the beacon of alleviation of conspicuous effect to the academic sector. During the 1990s, a new emphasis on nationalism influenced Paleolithic studies. In the 2000s, the formally constructed elements of Paleolithic research such as Paleolithic chronology, social evolution, lithic assemblage, Quaternary studies, and human evolution were consistently refined. Metaphorically speaking, these parts are like a polygonal structure. As is the case with a polygonal structure, these research aspects are united and work together. Each part affects the others. Although the content of each research aspect has been altered by either academic growth or sociopolitical agenda, the fundamental part of the polygonal structure is not likely to be changed. The structure is solid enough to continue to serve the purposes of North Korean Paleolithic studies. North Korean Paleolithic archaeology seems to be a juxtaposition; some parts are easily changed while others are not. In order to ascertain these, not only the academic but also the sociopolitical context should be followed.

• Journal of the Mineralogical Society of Korea
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• v.28 no.3
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• pp.255-263
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• 2015

To investigate the effect of the weathering process of biotite on Cs sorption, sorption experiment of Cs with $10^{-3}M$ solution was carried out on the biotite reacted at different reaction times at pH 2 and 4, and 1 M solutions of Na, K, Ca, Mg, Rb, and Cs. Peak changes were observed for some samples by XRD, indicating that new mineral phase formed by biotite weathering. Among several factors, cations in solutions have the most significant influence on the mineralogical changes. The samples reacted with Na showed the most outstanding change with increasing peak width and appearance of $12{\AA}$ peak and $14{\AA}$ peak. This new peaks indicate the formation of hydrobiotite and vermiculite. The new peaks had stronger peak intensity for the sample reacted at pH 4 than that at pH 2, probably due to the fast dissolution of small particles and edges and resultant decrease in the formation of expandable layers. The biotite reacted at Mg solution showed small intensity at $14{\AA}$. Based on XRD results, the degree of biotite weathering was in the order of Na, Mg, and Ca. The samples reacted with K, Rb, Cs solutions did not show noticeable mineralogical changes caused by weathering. The amount of sorbed Cs on weathered biotite showed close relationship with the degree of weathering indicated by XRD. At both pH 2 and 4, the biotite reacted with Na solution showed the highest Cs sorption, and those with Mg and Ca solutions showed the next highest ones. The sorbed amounts of Cs on the bitote reacted with K, Rb, Cs solutions were relatively low. This indicates that at the Cs concentration ($10^{-3}M$) which we used for this experiment and which was much higher than the maximum Cs concentration sorbed on the frayed edge site, expandable layer plays more important role than frayed edge. In the cases of K, Rb, and Cs solutions, Cs sorption was decreased because K is the same cations as the one in the interlayer or the sorption of Rb and Cs on the frayed edge prevents the formation of expandable layers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.4
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• pp.557-566
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• 2005

In preparation of steamed foam-cakes, effects of whipping time, amount of wheat flour, and amounts of emulsifier on physical properties of the steamed foam cakes were investigated using RSM (response surface methodology). The three independent variables selected for the RSM experiment were whipping time $(X_1)$, amount of wheat flour $(X_2)$, and amounts of wheat flour $(X_2)$, and concentration of emulsifier $(X_3)$ were set for single-stage mixing, respectively. A rotatable central composite design was used for treatment arrangement. The responses from the product for loaf volume, color values and textural properties were analysed. In the analysis of variance for the foam cakes prepared by single-stage method, significant interactions were observed between independent variables (experimental factors) and physical property like loaf volume (p<0.05); textural properties like hardness, gumminess, and chewiness (p<0.05). Among independent variables, concentration of emulsifier had the most effects on physical properties while whipping time. The ordinary points in surface response showed maximal points with physical property like colorimetric b value while other properties revealed saddle points. The 3-dimensional response surface graphs of the predicted regression models displayed decreasing loaf volumes with increasing whipping times and emulsifier concentrations beyond optimum levels. The optimum conditions for best loaf volume and textural property (hardness, gummimess and chewiness) of the products selected by extracting intersectional areas of the contour maps that commonly overlapped all characteristics were; $11\~13$ min whipping time, $470\~486\;g$ amount of wheat flour, and $19\~20\;g$ emulsifier concentration, in case of single-stage method. The median values extracted from the RSM experimental results for optimum manufacturing conditions for single-stage method, i.e., 12 min whipping time, 478 g amount of wheat flour, and 20 g emulsifier concentration were empirically proven to fit the predicted levels of physical properties from the final foam cakes.

• Journal of Korean Society of Forest Science
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• v.40 no.1
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• pp.75-81
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• 1978

Elder-berries are economical plants and grown commercially in the United States. Most of the crop is sold to processors and made into natural colour, jellies, jam, port wine or elder berry wine, elder berry juice or used to manufacture of pie mixes. Processors are showing increasing interest in cultivation elder berries. In the present study was wish to find the effect of various factors and practical methods on the processing for the true fruit colour made from fresh elder berries juice as the clearing by the treated pectinase, added sugar, vaccum concentration, extraction of anthocyanosid powder and its property with used prospects. In this study obtained results can be summarized as follows. 1. Pectinase is useful and effected to make clear juice from fresh elder berry juice treated on the $34{\sim}45^{\circ}C$. 2. P.V.C. drum is most useful stored without unfading for clearing elderberry juice and its exposed redish dark purple colour. 3. Clearing elderberry juice stored in the stainless steel drum, changed colour from redish dark purple to dark violets during the stored at the room temperature. 4. Added sugar (Brix $48{\sim}53^{\circ}C$) to the fresh elderberry juice is useful and suitable prospects for to make home juice and wine. 5. The elderberry juice of vaccum concentration is change colour from dark purple to black brown colour during the stored at the room temperature. 6. Its possible to make anthocyanosid powder extracted made from fresh elderberry juice 7. Property of anthocyanosid is an follows. 1) The spectrum of elderberries juice is $523{\sim}530m{\mu}$ 2) The colouring stability is less than $pH_4$ 3) The colouring stability by the heating is less than $pH_4$, and then the more than $pH_4$ is changed colour from redish dark purple to dark brown. 4) By the light colouring stability is less than $pH_4$ 5) The colouring most stability in the pH is $pH_3$ 8. In the future, natural colour made from elderberry juice on the useful prospects is suitable used to make natural fruit juice, ice cream, candy, commercial and home wine, gum, and manufacture of jelly jam, pie maxes, ect.