• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.7
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• pp.1048-1054
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• 2014

The purpose of this study was carried out to investigate the cause of sulfur dioxide occurrence, general element composition, sulfur compounds, heavy metals, macro- & micro-minerals, and oxidation-reduction potential (ORP) following baking time course of RS (RS1, RS2, RS3, and RS4) and mudflat solar salts (MSS). Sulfur dioxide ($SO_2$) and sulfite ($SO{_3}^{2-}$) were not detected in MSS or RS. However, sulfate ($SO{_4}^{2-}$) content significantly decreased in RS (29,878.15~36,097.45 ppm) compared to that in MSS (35,601.65 ppm). ORP was 181.15 mV in MSS, and 58.55 mV in RS1. Moisture content was 9.34% in MSS and 0.00% in RS with increased NaCl (94.77~95.77%). Moisture and NaCl contents showed no significant difference in RS. Insoluble and sandy residues were higher in RS than in MSS, whereas Ca and K showed no significant difference. Mg and Cl contents were higher in RS than in MSS. Br level was higher in MSS (628.1 ppm) than in RS (512.72~586.62 ppm), but there was no significant difference in $NO_3$. Heavy metals (Pb, As, and Hg) were more abundant in RS than in MSS, but levels were still safe. These results suggest that MSS and RS may increase protection against from $SO_2$ and $SO{_3}^{2-}$.

• Journal of the Korean association of regional geographers
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• v.13 no.6
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• pp.651-673
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• 2007

In the studies on residential move, there has been tendency of dichotomy where short distance moves are largely caused by housing to adjust to changes in households while long distance moves are induced by shift in labor market. However, some empirical studies have proven that residential move is so complex process that the simple dichotomy should be elaborated. In this sense, the present study seeks to identify compounded course of residential move in Korea. In determining migration history, families with younger householders, renters, householders with higher educational attainment and smaller households show a higher probability to move. In case of mobility, women were more prone to move compared to man. Women compared to man, older age augmented the probability to own a house after migration. Families with householders following an occupation of sales and technical service showed lowest tendency to own houses while it marked the highest in the group of professionals. Higher land price of a region was negatively related to owning houses after migration. The present study revealed that factors in macro level as well as micro level significantly affect the move of individuals with varying effects in accordance with migration history.

• Journal of Korea Technology Innovation Society
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• v.21 no.2
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• pp.767-787
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• 2018

Technology-driven innovation and job-creation has each been the subject of much scholarly attention, but have largely been considered separately rather than in conjunction with each other. While the previous literature on economics pinpointed the macro effects on industry-level, this study explores the micro-level comparisons on innovation sources over the employment and financial performances. The PSM (propensity-score matching) analysis presents that firms, involved in an inward technology, tend to have higher employees with dominant technology capabilities than in-house R&D firms. The in-house R&D firms, on the contrary, have superior financial performances, suggesting that external technology commercialized firms suffer from low transformative efficiency. The mediation test analysis corroborates that the external technology-driven innovation induces more human resources in internalizing the exogenous technology. The positive relationship between R&D innovation and employment allow verification of the government's intervention in the promotion of technology commercialization in public sector. On the other hand, it also signals that the policy needs to enhance the recipient firms' commercializing capacity rather than a 'one-hit' transaction.

• Journal of Korean Society of Forest Science
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• v.88 no.3
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• pp.379-388
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• 1999

As a first step for delineating the provenance regions of the forest trees in Korea, horizontal zones have been deduced primarily from the various climatic factors such as annual mean temperature, extremely low temperature, relative humidity, annual gum of possible growing days, duration of sunshine and dry index. The basic concept to the delineation of the provenance regions was based on the ecological regions, which was likely to be more practical than that on the basis of the typical provenance regions at the species level. Primary classification of the regions has been based on the forest zones(sub-tropical, warm-temperate, mid-temperate and cool-temperate) as a broad geographic region. Further classification has been carried out using cluster analyses among the basic regions within forest zone. On the basis of clustering, a total of 19 regions including 3 from sub-tropical, 6 from warm-temperate, 8 from mid-temperate and 2 from cool-temperate was horizontally delineated. Of the mean values of 6 climate factors at the broad geographic region level, three factors such as annual mean temperature, extremely low temperature, annual growing days showed directional tendencies from subtropical to cool-temperate, while the others didn't. The values of relative humidity, duration of sunshine and dry index varied among the provenance regions within forest zone. These three factors might he more sensitive by the micro-environment condition than by the macro-environment condition. Present study aimed to delineate the primary provenance regions for tentative application to forest practices. These will be stepwise revised through the supplement using accumulated information regard to genecological data.

• Journal of the Korean Chemical Society
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• v.44 no.6
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• pp.611-624
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• 2000

In this study we analysed 3-12 grade science textbooks, many literatures and internet sites related to diffusion and dissolution concepts. From these data, we discovered that the explanations of diffusion that used in textbooks are not considered the site of collision with mediums, and confused with dissolution, state transition and effusion. In the case of dissolution, almost analysis data were short of the explanations of interaction effect. Most of all, the focus of dissolution explanations was to solve the calculation problems rather than to understand the concept. Every internet site was poor, just as the level of showing textbook contents with computer, so the only effect of using computer was the sense of sight and hearing. Chemistry must be understood nature phenomena with a view point of particle theory, but many textbooks and Internet sites didn't represent it sufficiently. We set up the correct scientific concept and linked micro world of particle theory with macro world of nature phenomena. With a use of computer which have the advantage of representing moving things, we developed the computer-assisted instruction programs related to diffusion and dissolution with the viewpoint of particle movement.

• Journal of the Korean Ceramic Society
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• v.38 no.12
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• pp.1097-1103
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• 2001

TiO$_2$anchored on a porous clay ceramic support (PCS) for use in lightweight photocatalyst were synthesized by the dropping precipitant method. A PCS of macro and micro pore size of around several mm~${\mu}{\textrm}{m}$ in diameter were prepared by the rapid heat treatment at, 1,15$0^{\circ}C$ for 10 min from low grade of clay. The change in pH of reaction solution due to the different addition rate of NH$_4$HCO$_3$as a precipitant, the reaction temperature and the concentration of TiCl$_4$had a pronounced effect on the nature of precipitated TiO$_2$particles on the surface of a PCS and the crystal structure of precipitated TiO$_2$particles. At an addition rate of 0.8 ml/min of NH$_4$HCO$_3$and pH=6 of reaction solution, homogeneous precipitation of TiO$_2$particles on a PCS was achieved. TiO$_2$particles with anatase phase was precipitated on the surface of a PCS at the low concentration of TiCl$_4$, the high addition rate of NH$_4$HCO$_3$and the high reaction temperature.

• Korean Journal of Social Welfare
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• v.52
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• pp.33-61
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• 2003

This study aims to identify early retirement and the subsequent career ending patterns and explain the phenomena in terms of social security policies and labor market perspectives. Although many older workers retire early, there are very few studies to examine how the retirees end their careers after quitting the long-time jobs. The paper investigates individual work experiences 55 through 61, identifies the career ending patterns, constitutes the micro and macro analytical models to estimate the impacts of labor market and work-related variables. The findings show that many older workers have diverse career ending patterns after long-time career jobs, that is, still working at age-55 job, exiting and reentering, sporadic work, retired permanently from age-55 job, a repeat of labor force entry. Also the estimation results indicate that pension, social security, labor market condition, work structure variables better explain the career ending behaviors than social psychological factors of health, education, attitudes toward retirement and job, ethnicity. Finally, this paper discusses theoretical importances of labor market perspectives and policy implications at the end of thesis.

• Journal of Plant Biology
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• v.28 no.2
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• pp.165-175
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• 1985

The natural forest vegetation of the Piagol, Mt. Chiri, was classified into five major communities, i.e. Quercus mongolica, Carpinus laxiflora, C. tschonoskii, Q. serrata and Fraxinus mandshurica community. C. tschonoskii, C. laxiflora and Q. mongolica characteristically were dominated in the range of 500∼700 m, 700∼900 m and 900∼1,400 m in altitude, respectively. Abies nephrolepis and Rhododendron schlippenbachii in the ridge of Nogodan-Nalnaribong, and F. mandshurica and Q. serrata in the Yongsuam ravine were found as the dominant species. The transition between C. tschonoskii and C. laxiflora communities was relatively wide. The boundary between F. mandshurica, in the conglomerated zone, and the other communities surrounding its community was fairly abrupt. In Q. mongolica community, the canopy was relatively opened and the oak young tree of undergrowth was fairly dense. In the community of C. laxiflora and C. tschonoskii, the species composed of their understory was rich while their coverage was lower than that of Q. mongolica community. Shannon's diversity index was decreased in order of C. tschonoskii, C. laxiflora and Q. mongolica community, while their Simpson's dominance index increased conversely. Judging by the DBH-class distribution showing the negative exponential curve, these communities were considered as the climax forest. In Polar Ordination used samples (quadrats), the vegetation of the Piagol was divided into five groups, which was coincided with five communities classified by Braun-Blanquet system. In the ordination, the first axis and the second axis may be considered soil conditions and thermal conditions, respectively. It seems that two different methods, phytosociological method in macro level and ordination techniques in micro level, are useful for the vegetation classification.

• Korean Journal of Acupuncture
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• v.24 no.3
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• pp.149-164
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• 2007

Objectives : Inflammatory bowel disease (IBD) is a chronic relapsing inflammatory disease in the gastrointestinal tract. The sources and pathologic mechanisms of IBD are still unknown. Moreover conventional therapies for IBD are not always effective, and they often have serious side effects. The purpose of this study is to examine the effect of Moxi-tar herbal acupuncture in IBD affected mice. Methods : Mice were treated with 5 % 2, 4, 6 - trinitrobenzenesulfonic acid (TNBS) on day 1 and day 7. To assume the preemptive effect and therapeutic effect, herbal acupuncture was practiced with Moxi-tar at BL25 (Daejangsu) on day 0, day 3, and day 6. The end of day in treatment with Moxi-tar herbal acupuncture, the mortality and the inflammatory factors of the colon were measured by the various methods. Results TNBS induced high mortality but herbal acupuncture with Moxi-tar at BL25 sup-pressed the mortality caused by TNBS. TNBS induced infiltration of immune cells in all layers of the colon and increased myeloperoxygenase (MPO) activity, while the treatment with Moxi-tar herbal acupuncture at BL25 suppressed the infiltration of immune cells and the increase of MPO activity caused by TNBS to normal levels, Herbal acupuncture with Moxi-tar regulated $NF-{\kappa}B$ activity, which is an important factor for the pathogenesis of chronic colitis, and reduced the expressions of $TNF-{\alpha}$, $IL-1{\beta}$, and ICAM-1 in the colons of TNBS treated mice. Furthermore herbal acupuncture suppressed macro- and micro- colonic damages caused by TNBS. Conclusions : This study demonstrates that herbal acupuncture with Moxi-tar at BL25 isa potential preemptive and/or therapeutic method targeting the chronic IBD.

• Journal of the Korea Concrete Institute
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• v.17 no.4 s.88
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• pp.581-586
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• 2005

High-performance concrete (HPC), which is particularly sensitive to self-desiccation, is required to be durable even in severe environmental conditions, i.e. costal area, cold district, etc. However, in recent years, some attention was particularly given to cracking sensitivity of high performance concrete at early age. It has been argued and demonstrated experimentally that such concrete undergoes autogenous shrinkage due to self-desiccation at early age under restrained condition, nd, as a result, internal tensile stress may develop, leading to micro cracking and macro cracking. This shrinkage-introduced crack produces a major serviceability problem for concrete structures. One possible method to reduce cracking due to autogenous shrinkage is the addition of expansive additive. Tests conducted by many researches have shown the beneficial effects of addition of expansive additive for reducing the risk of autogenous shrinkage-introduced cracking. However, the research on hydration model of expansion additive has been hardly researched up to now. This paper presents a study of the hydration model of Ettringite-Gypsum type expansive additive. As a result of comparing forecast values with experiment value, proposed model is shown to expressible of hydration of expansive additive.