• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.86-93
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• 2018

This study examines the differences in the determinants of dividend payout across advance disclosure firms and ordinary disclosure firms using firm-level data from firms listed on the Korea Exchange. Results are as follows: First, firm characteristics of advance disclosure firms significantly differ from those of ordinary disclosure firms in all variables except sales growth and operating risk variables. Second, regression results show that the determinants of dividend payout from ordinary disclosure firms are generally similar to results of previous studies. However, determinants of advance disclosure firms contain only few variables such as Tobin's Q, corporate bond yield, and operating cash flows from conventional factors. Third, logistic regression results show that factors affecting the probability of dividend payment substantially differ across advance disclosure firms and ordinary disclosure firms. These results suggest that the motivation and incentive of dividend payout from firms choosing advance disclosure are substantially and systematically different from those of ordinary disclosure firms.

• Journal of Animal Science and Technology
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• v.54 no.5
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• pp.341-347
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• 2012

The purpose of this study was to evaluate the effects of dietary Flammulina velutipes mycelium (FVM) on broiler chick performance, pathogenic bacterial (E. coli, Salmonella) counts in caecal contents and amount of $NH_3$ in excreta. Ninety-six broiler chicks (HanHyup No. 3, Korea) were divided into four groups: 1) Control (basal diet), 2) T1 (supplemented with 1% FVM), 3) T2 (3% FVM), and T3 (5% FVM), and rose for 7 weeks. In results, there were no significant differences among treatments in weight gain, feed intake, feed efficiency and carcass yield. However, giblets were significantly increased in FVM treatments compared with control group (p<0.05). The number of Salmonella in caecum was significantly decreased in FVM treatments compared with control group (p<0.05). The number of E. coli was decreased in T2 but increased in T1 and T3 compared with control group. The emission of fecal $NH_3$ gas was significantly decreased in accordance with increasing the feeding level of FVM (p<0.05). In conclusion, our data indicated that the supplementation of high level of FVM could inhibit the Salmonella in caecum and reduce the emission of fecal $NH_3$ gas. Therefore, FVM at 5% level could be added in the diet of broiler chicks.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.387-396
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• 2018

This study examined the instability factor of real income and net profits of Chung-yang Green Pepper Farm through an analysis of the operating costs. Furthermore, this paper suggests a plan for stabilizing the price by shipment adjustments resulting from an analysis of the price elasticity by A Linear Approximated Inverse Almost Ideal Demand System (LA/IAIDS). The income instability factor of the farm based on an analysis of the operating costs was attributed to the unexpected loading of utility expenses and collapse of the price due to oversupply at a specific point in time. On the other hand, this is insufficient to completely explain the income instability factor of Chung-yang Green Pepper Farm because a price collapse does not include the monthly price changes. An analysis of the price and scale flexibility of Chung-yang Green Pepper Farm by monthly data showed that annual farm net yield increases by 1.21% due to a 2.21% increase in price if the shipment quantity is reduced to 1% a year. In summary, a plan that supports the farm price received through declining shipments in winter is effective in stabilizing the income of farms. Because Chung-yang Green Pepper in Gyeongnam region has an especially high market share of 82.5%, the prices and income of Gyeongnam Chung-yang Green Pepper farms can be stabilized effectively if they form an association of producers around the Gyeongnam region and adjust the shipment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.484-492
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• 2017

This study assessed female occupational therapist job stress and musculoskeletal pain, and examines the problems caused by sexual harassment, family, and marriage policy. The results provide information to improve work environments, reduce job stress, yield data needed for sexual harassment prevention education, examine women occupational therapists' economic activities, and broadly improve the quality of life through participation. The study subjects were currently employed female occupational therapists. Initially 200 subjects were recruited, of whom 185 returned the study questionnaire. Questions addressing job stress included, 'There are times when one feels that the salary is worth less than the job effort', 'Feel tired due to work.', 'That it is time to pay attention to other therapy.', answered positively in that order. Musculoskeletal pain in the wrist and hand (90%), shoulder (86%), neck (69.7%) and waist (68.6%) were the order of the wrist and hand (63%), shoulder (62.2%) and waist (51.9%) pain resulted in interference with daily life. Verbal harassment was reported by 71.4% and 48.6% reported physical and visual harassment. The most common topics in workplace relations were 'Must choose whether to focus on the individual or work (61.1%).', 'Need for understanding and someone who can share their feelings (54.6%).', and 'Colleagues are willing to listen to my story (73%)'.

• Journal of Powder Materials
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• v.9 no.6
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• pp.394-408
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• 2002

Nanostructured high strength metastable Al-, Mg- and Ti-based alloys containing different amorphous, quasicrystalline and nanocrystalline phases are synthesized by non-equilibrium processing techniques. Such alloys can be prepared by quenching from the melt or by powder metallurgy techniques. This paper focuses on one hand on mechanically alloyed and ball milled powders containing different volume fractions of amorphous or nano-(quasi)crystalline phases, consolidated bulk specimens and, on the other hand. on cast specimens containing different constituent phases with different length-scale. As one example. $Mg_{55}Y_{15}Cu_{30}$- based metallic glass matrix composites are produced by mechanical alloying of elemental powder mixtures containing up to 30 vol.% $Y_2O_3$ particles. The comparison with the particle-free metallic glass reveals that the nanosized second phase oxide particles do not significantly affect the glass-forming ability upon mechanical alloying despite some limited particle dissolution. A supercooled liquid region with an extension of about 50 K can be maintained in the presence of the oxides. The distinct viscosity decrease in the supercooled liquid regime allows to consolidate the powders into bulk samples by uniaxial hot pressing. The $Y_2O_3$ additions increase the mechanical strength of the composites compared to the $Mg_{55}Y_{15}Cu_{30}$ metallic glass. The second example deals with Al-Mn-Ce and Al-Cu-Fe composites with quasicrystalline particles as reinforcements, which are prepared by quenching from the melt and by powder metallurgy. $Al_{98-x}Mn_xCe_2$ (x =5,6,7) melt-spun ribbons containing a major quasicrystalline phase coexisting with an Al-matrix on a nanometer scale are pulverized by ball milling. The powders are consolidated by hot extrusion. Grain growth during consolidation causes the formation of a micrometer-scale microstructure. Mechanical alloying of $Al_{63}Cu_{25}Fe_{12}$ leads to single-phase quasicrystalline powders. which are blended with different volume fractions of pure Al-powder and hot extruded forming $Al_{100-x}$$(Al_{0.63}Cu_{0.25}Fe_{0.12})_x$ (x = 40,50,60,80) micrometer-scale composites. Compression test data reveal a high yield strength of ${\sigma}_y{\geq}$700 MPa and a ductility of ${\varepsilon}_{pl}{\geq}$5% for than the Al-Mn-Ce bulk samples. The strength level of the Al-Cu-Fe alloys is ${\sigma}_y{\leq}$550 MPa significantly lower. By the addition of different amounts of aluminum, the mechanical properties can be tuned to a wide range. Finally, a bulk metallic glass-forming Ti-Cu-Ni-Sn alloy with in situ formed composite microstructure prepared by both centrifugal and injection casting presents more than 6% plastic strain under compressive stress at room temperature. The in situ formed composite contains dendritic hcp Ti solid solution precipitates and a few $Ti_3Sn,\;{\beta}$-(Cu, Sn) grains dispersed in a glassy matrix. The composite micro- structure can avoid the development of the highly localized shear bands typical for the room temperature defor-mation of monolithic glasses. Instead, widely developed shear bands with evident protuberance are observed. resulting in significant yielding and homogeneous plastic deformation over the entire sample.

• Journal of the Korean Society for information Management
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• v.35 no.1
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• pp.183-203
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• 2018

As the users' information use environment changes to the Web, the archives are providing more services on the Web than before. This study analyzes the users' recent inflow route and the highly ranked 100 search terms of each month for 10 and half years in the Web site of National Archives of Korea, and suggests suitable information services. As a result of the analysis, it was found out that the inflow route could be divided into access from portal site, by country, from related institutions, and via mobile platform. As a result of analyzing the search terms of users for the last 10 and half years, the most frequently searched term turned out to be 'Land Survey Register', which was also the search term that was searched for with steady interests for 10 and half years. Also, other government documents or official gazettes were of great interests to users. As results of identifying the most frequently searched and steadily searched terms, we were able to categorize the search terms largely in terms of land, Japanese colonial period, the Korean war and relationship of North Korea and South Korea, and records management and use. Based on the results of the analysis, we suggested strengthening connection of the National Archives Web site with portal sites and mobile, and upgrading and improving search services of the National Archives. This study confirmed that the analysis of Web log and user search terms would yield meaningful results that could enhance the user services in archives.

• Journal of Microbiology and Biotechnology
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• v.24 no.12
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• pp.1664-1672
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• 2014

In this study, a fibrous bed bioreactor (FBB) was used for $\small{D}$-lactic acid ($\small{D}$-LA) production by Sporolactobacillus inulinus Y2-8. Corn flour hydrolyzed with ${\alpha}$-amylase and saccharifying enzyme was used as a cost-efficient and nutrient-rich substrate for $\small{D}$-LA production. A maximal starch conversion rate of 93.78% was obtained. The optimum pH for $\small{D}$-LA production was determined to be 6.5. Ammonia water was determined to be an ideal neutralizing agent, which improved the $\small{D}$-LA production and purification processes. Batch fermentation and fed-batch fermentation, with both free cells and immobilized cells, were compared to highlight the advantages of FBB fermentation. In batch mode, the $\small{D}$-LA production rate of FBB fermentation was 1.62 g/l/h, which was 37.29% higher than that of free-cell fermentation, and the $\small{D}$-LA optical purities of the two fermentation methods were above 99.00%. In fe$\small{D}$-batch mode, the maximum $\small{D}$-LA concentration attained by FBB fermentation was 218.8 g/l, which was 37.67% higher than that of free-cell fermentation. Repeate$\small{D}$-batch fermentation was performed to determine the long-term performance of the FBB system, and the data indicated that the average $\small{D}$-LA production rate was 1.62 g/l/h and the average yield was 0.98 g/g. Thus, hydrolyzed corn flour fermented by S. inulinus Y2-8 in a FBB may be used for improving $\small{D}$-LA fermentation by using ammonia water as the neutralizing agent.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.7
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• pp.1319-1330
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• 2000

Activated carbons prepared by chemical activation of organic waste sludges with $ZnCl_2$ and $K_2S$ have been studied in terms of their pore development and adsorptivity. Pore development of the carbons prepared from organic waste sludges was characterized by the nitrogen adsorption at 77K. The $ZnCl_2$-activated carbon produced by chemical activation with zinc chloride exhibited type I isotherm characteristics according to the BDDT classification, suggesting the presence of micropores formed by activation process. The isotherms of the commercial powdered activated carbon and $K_2S$-activated carbon reveal a hysteresis similar to that of type IV in BDDT classification, indicating the formation of mesopores. This result implies that the major pores of $K_2S$-activated carbon are composed of meso and micropores, and a macropores are minor. The adsorptive capacities of metal on the $K_2S$-activated carbon prepared from organic waste sludges were found to be superior to those on a commercial granular activated carbon. The Langmuir and Freundlich isotherms yield a fairly good fit to the adsorption data, indicating a monolayer adsorption of metals onto $K_2S$-activated carbon. The adsorptive capacity of the $K_2S$-activated carbon was superior to $ZnCl_2$-activated carbon for $PO_4$-P, and vice versa for $NO_3$-N. From the results of the studies reported here, it can be concluded that activated carbons with adsorptivity superior to commercial granular activated carbons can be produced from organic waste sludge using a two-step carbonization/activation procedure with zinc chloride or potassium sulfide as the activating agents.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2005.10a
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• pp.34-46
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• 2005

For treating a huge amount of plastic waste with the environment problem, pyrolysis of plastic waste into alternative fuel oil is one of important issue in recycling methods. This study was introduced over the trend of generation of plastic waste, pyrolysis technology in domestic and foreign countries, basic technology in pyrolysis process and new technology of pyrolysis developed in KIER (Korea Institute of Energy Research). The characteristics of process developed in KIER are the continuous loading treatment of mixed plastic waste with an automatic control system, the minimization of wax production by circulation pyrolysis system in non-catalytic reactor, the reuse of gas produced and the oil recovery from sludge generated in pyrolysis plant, which have greatly the advantage economically and environmetally. The experiment result data in 300 ton/yr pilot plant showed about 81 wt% liquid yield for 3 days continuous reaction time, and also the boiling point distribution of light oil (LO) and heavy oil (HO) produced in distillation tower was a little higher than that of commercial gasoline and diesel, respectively.

• Journal of Wetlands Research
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• v.9 no.1
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• pp.69-78
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• 2007

Constructed wetlands and other aquatic systems have been successfully used for waste and wastewater treatment in either temperate or tropical regions. To treat waste or wastewater in a sustainable manner, the integrated eco-engineering designs are explained in this paper with 2 case studies: (i) a combination of vertical-flow constructed wetland (CW) with plant irrigation systemfor fecal sludge management and (ii) integrated CW units with landscaping at full-scale application for domestic wastewater treatment. The pilot-scale study of fecal sludge management employed 3 vertical-flow CW units, each with a dimension of $5{\times}5{\times}0.65m$ (width ${\times}$ length ${\times}$ media depth) and planted with cattails (Typha augustifolia). At the solid loading rate of 250 kg total solids (TS)/$m^2.yr$ and a 6-day percolate impoundment, the CW system could achieve chemical oxygen demand (COD), TS and total Kjeldahl nitrogen (TKN) removal efficiencies in the range of 80 - 96%. The accumulated sludge layers of about 80 - 90 cm was found at the CW bed surface after operating the CW units for 7 years, but no clogging problem has been observed. The CW percolate was applied to 16 irrigation Sunflower plant (Helianthus annuus) plots, each with a dimension of $4.5{\times}4.5m$ ($width{\times}length$). In the study, the CW percolate were fed to the treatment plots at the application rate of 7.5 mm/day but the percolate was mixed with tap water at different ratio of 20%, 80% and 100%. Based on a 1-year data of 3-crop plantation were experimented, the contents of Zn, Mn and Cu in soil of the experimental plots were found to increase with increasing in CW percolate ratios. The highest plant biomass yield and oil content of 1,000 kg/ha and 35%, respectively, were obtained from the plots fed with 20% or 50% of the CW percolate, whereas no accumulation of heavy metals in the plant tissues (i.e. leaves, stems and flowers) of the sunflower is found. In addition to the pilot-scale and field experiments, a case study of the integrated CW systems for wastewater treatment at Phi Phi Island (a Tsunami-hit area), Krabi province, Thailand is illustrated. The $5,200-m^2$ CW systems on Phi Phi Island are not only for treatment of $400m^3/day$ wastewater from hotels, households or other domestic activities, but also incorporating public consultation in the design processes, resulting in introducing the aesthetic landscaping as well as reusing of the treated effluent for irrigating green areas on the Island.