• Analytical Science and Technology
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• v.24 no.4
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• pp.256-265
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• 2011

Ambers have been used as a gemstone and a religious object since the ancient times and found in several archaeological sites in Korea. To prepare an enhanced conservation measures, we surveyed the chemical and spectroscopic properties of the ambers according to the provenance. Total 14 amber samples were collected from 6 different provenances including Baltic, Chiapas, Colombian, Dominican, Fushun and Madagascar amber. Infrared (IR) spectroscopic analysis was conducted for the non-destructive examination of the amber samples. They were also analyzed with pyrolysis/GC/MS (py/GC/MS) at the pyrolysis temperature of $300^{\circ}C$ with the on-line derivatization to trimethylsilyl ester. Baltic shoulder corresponding to the absorption at $1250cm^{-1}{\sim}1150cm^{-1}$ appeared in the IR spectrum of Baltic amber. IR spectra of the other ambers also showed somewhat distinctive characteristic peaks. In py/GC/MS analysis peaks assignable to succinic acid, dehydroabietic acid and pimaric acid were detected, which are known to be the components of the amber. In the meanwhile, the presence of compounds appearing in certain amber will be applied to differentiate the provenances of amber relics if their fragments are available for the analysis. These results are expected to help the confirmation of archaeological amber relics and archaeometric interpretation of provenances and manufacturing techniques.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.2
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• pp.237-243
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• 2020

Listeria sp. is one of the pathogenic bacteria causes the infection listeriosis, through mainly raw food such as fishery food, dairy food and vegetables. Listeria sp. is a Gram-positive, non-spore-forming, motile, and facultative anaerobic bacterium. Because of the tolerance of Listeria sp. to low temperature and high salt concentration, it is very difficult to prevent them contaminated in the food, which do not require heating, especially, such as raw fishery products. So prevention and removal of bacterial contamination at the food manufacturing stage is the best method. In this study, therefore, several natural products including Psidium guajava and Geranium thunbergii were screened to investigate the antibacterial activity against Listeria sp., with expectation of fewer side effects and fewer resistance problems. Significant effects of two extracts were confirmed by well diffusion assay, MIC assay, and growth inhibition assay. P. guajava and G. thunbergii showed MIC values at 64-256 ㎍/mL meaning strong antibacterial activities against 6 kind of Listeria sp. tested. And the growth of Listeria sp. in the liquid media was actually inhibited by the addition of these two extracts.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.63-71
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• 2018

A flower support was developed for real flower decoration automation production system using an ultrasonic wave sealer to automatically produce a system. Because a flower support for real flower decoration that was produced manually could not meet the needs of the consumers, this study developed an automated manufacturing system to increase productivity. A flower support for real flower decoration was constructed using a cap consisting of plastic and plate made from non-woven fabric. The guide was designed to transport the cap to the ultrasonic wave sealer and optimal guide was developed from the test according to the material and shape. To produce the entire system, the guides and accessories were weighed and appropriate motors and pulleys were calculated. Control of the automation production system was based on a PCB board, which increased the reliability and security, and a remote controller with manual and automatic modes was prepared. After development, tests of the transfer precision and repetition accuracy revealed an X-axis of 2.7mm, a Y-axis of 1 mm, and a repetition of 0 mm. The productivity was also checked. The automated machine worked 8 hours/day to make 35 supports and 70 Therefore, the automatic system produces 200% more output than manual work

• Applied Biological Chemistry
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• v.42 no.4
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• pp.277-282
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• 1999

This study was carried out to clarify the microorganisms which participated in the fermentation of kanjang. The changes in the viable cell counts of total aerobic bacteria, lactic acid bacteria and yeasts for raw soybean, soybean during cooking, meju during cultivation, and kanjang mash during maturing were investigated along with the changes in components during those periods. Lactic acid bacteria that were found to be $6{\times}10^2\;CFU/g$ in raw soybean were disappeared after cooking process, but total aerobic bacteria were diminished from $1.9{\times}10^6\;CFU/g$ to $10^2\;CFU/g$. Aerobic bacteria of inner and outer parts of meju increased to more than $10^9\;CFU/g$. The higher viable cell counts of lactic acid bacteria in the inner parts of meju were observed than those in outer ones. On the contrary, significantly higher viable cell counts of yeasts in the outer parts of meju were found. Total nitrogen content and color density of kanjang increased by using meju with extended cultivation periods. No significant differences were observed in microbial counts between kanjang mash with aeration and non-aeration during kanajng mash maturing.

• Journal of Korea Technology Innovation Society
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• v.17 no.1
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• pp.146-173
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• 2014

Extant studies have explained that firm's innovations including technological product and process innovations contribute to its competitive advantage and growth, thereby supporting competitiveness and growth of industry. These studies, however, have focused mainly on the role and effect of technological change that is primarily measured by the patent numbers and R&D intensity. Aside from these traditional streams, there has been growing interest on the impact by various dimensions of innovation including non-technological innovations. Apart from the discussions on the dimensions and scope of innovation, stages or processes of innovation also have been studied. Extant studies on innovation process model, however, has limited its interests in the structure of the transformation of knowledge. This study have established a comprehensive model embracing operational and financial performance to investigate the causal paths between innovation and firm performance. Using multi-level generalized linear model with path analysis, this study have found results as follows: First, the processes from innovative activities to innovation output and outcomes including operational and financial performance at firm level were verified. Secondly, the influence of innovation decreases gradually as the distance away from the direct outputs of the innovation increase in the direction of financial outcomes. Third, the effect of innovation on the sales growth rate is higher for small businesses than for medium-sized businesses. The effect of innovation on the profit rate, however, is significant only for medium-sized businesses. For large businesses, innovation has no positive significant impact on any financial performance at all. Fourth, Fourth, the appropriability of innovation has positive impacts on innovative performance, patent applications, and operational performance.

• Journal of Korea Technology Innovation Society
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• v.20 no.1
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• pp.239-270
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• 2017

This paper examines the relationship between ownership structure and the intensity of R&D expenditures of a firm by analyzing the panel data composed of 553 manufacturing firms in KSE(Korea Stock Exchange) and KOSDAQ listed firms for the period of 2007-2014. The major findings are as follows; (1) Regarding the relationship between CEO stockholding and R&D intensity, we find the inverted-U shape relationship in KOSDAQ firms, consistent with the theoretical discussion and empirical studies on U.S. firms. The result suggests that management stockholding reduces agency problem at the R&D margin. On the contrary, the insignificant result in KSE firms seems to be due to the scant stockholding of most 'non-owner' CEOs. (2) Regarding the relationship between the largest shareholder's portion and R&D intensity, KSE firms exhibit negatively significant relationship, suggesting the existence of serious agency problem between the largest shareholder and the minor shareholders. This agency problem seems to be alleviated in KOSDAQ firms mainly because the founders with technology expertise are still in charge of the business. (3) Foreign investors seem to fail in effectively encouraging R&D expenditures in either KSE or KOSDAQ listed firms. This study contributes to the existing literature by showing for the first time that ownership structure affects R&D activities in different ways between KSE and KOSDAQ firms.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1585-1593
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• 2015

3D-structured (embossed) aluminum sheets have been used in the heat insulation purpose for automative exhaust parts because of increasing their surface areas and stiffness reinforcement imposed in making the embossing pattern. However, there are many restrictions in press forming of the embossed sheet compared with the flat sheet (non-embossed one) because of its difference in the mechanical properties and the geometrical 3-dimensional shape. In this paper we investigated the deformation characteristic of embossed aluminum sheet in the incremental sheet forming process which has frequently used in the design verification and the trial manufacturing of sheet products. The single point incremental forming (SPIF) experiments for the rectangular cone forming using the CNC machine with a chemical wood-machined die and a circular tool shape showed that the formability of the embossed sheet are better than that of the flat sheet in view of the maximum angle of cone forming. This comes from the fact that the embossed sheet between the tool and the elastic die wall is plastically compressed and the flatted area contributes to increase the plastic deformation. Also the tool path along the outward movement from the center showed a better formability than that of the inward movement from the edge. However the surface quality for the tool path along the outward movement evaluated from the surface deflection is inferior than that of the tool path along the inward movement.

• Journal of Labour Economics
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• v.29 no.3
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• pp.75-112
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• 2006

We found following evidences from our empirical analysis with the Workplace Panel Survey data of the Korea Labor Institute with reference to 'discord hypothesis' which insists that employee participatory high performance work practices would strengthen not only an enterprise focus in labor-management relations but also the enterprise unionism in the labor union system or collective bargaining structures, so they would probably come into conflict with the superenterprise-oriented industrial solidarity spirit in labor unionism. First, even though there are significant positive management performance effects of high performance work practices, especially in case of mining and manufacturing industries, the positive performance effects of employee participatory work practices such as job rotation ratio of workers and 6-sigma activities were much strengthened relatively in case of non-unionized establishments. Second, the superenterprise-oriented collective bargaining system is also found to give very strong and statistically significant negative performance effects to the introduction and implementation of work teams and performance-related payment systems such as profit sharing, group incentive pay system and so on. Although there are some careful reservations in interpreting the results of our analysis because of data insufficiency, they may have important implications that the industrial labor unionism or the superenterprise-oriented collective bargaining practices exercise the bargaining power to make individual firms be negative or feel it nearly impossible to introduce the employee participatory work practices which can be very favorable to improving those management performance.

• Journal of the Korean Wood Science and Technology
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• v.33 no.3 s.131
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• pp.22-29
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• 2005

This research was carried out not only to examine the proper manufacturing condition for white charcoal board in relation to charcoal particle size and final mat moisture content (FMC), but also to maintain the advantageous properties of white charcoal as a well being building material against the sick house problem. Excellent functional white charcoal board was produced with two groups of FMC 20~25% and FMC 36~60%. The latter showed best results among tested samples in two types which are #40-60type-P15%, M5%, FMC 60% and mixed type-P15%, M5%, FMC36% with non formaldehyde adhesives [MDI (M), poly vinyl acetate emulsion (P)] and three stage pressing cycle of 30-10-$30kgf/cm^2$ (1 min.-1.5 min.-6 min.). The former gave highly acceptable results in two types which are #6 over-M15%FMC25% and mixed type-M25%FMC20%. White charcoal board gave excellent in dimensional stability, gas adsorption and far-infrared emission.

• Journal of the Mineralogical Society of Korea
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• v.32 no.4
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• pp.287-301
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• 2019

Preservation of the original form is the principle for conservation, management and utilization of cultural heritages. Thus, non-destructive analysis of these samples are important field of the conservation science. In this study, examined the applicability of nondestructive surface X-ray diffraction analysis (ND-XRD) for cultural heritage by materials (rock specimen, jade stone, pigment painted specimen, earthen artifact, metal artifact). In result, all type of sample is recorded suitable X-ray diffraction patterns for identifying mineral composition in case of surface condition with adequate particle size and arrangement. And diffraction pattern is reflected surface information than matrix. Therefore, ND-XRD is thought to be applicable not only mineral identification but also interpretation of manufacturing technique and alteration trend about layered sample (in horizontally or vertically). Whereas some exceptional diffraction patterns were recorded due to overlapping information on specific crystal planes. It caused by skip the sample treatment (powdering and randomly orientation). It could be advantageously used for mineral identification, such as preferred orientation of clay minerals. In contrast, irregular diffraction pattern caused by single crystalline effect is required careful evaluation.