• KSBB Journal
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• v.17 no.1
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• pp.73-79
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• 2002

The method to optimize the microbial production of ethanol from CO using Clostridium ljungdahlii was developed. The kinetic parameter study on CO conversion with Clostridium ljungdahlii was carried out and maximum CO conversion rate of 37.14 mmol/L-hr-O.D. and $K_{m}$ / of 0.9516 atm were obtained. It was observed that method of two stage fermentation, which consists of cell growth stage and ethanol production stage, was effective to produce ethanol. When pH was shifted from 5.5 to 4.5 and ammonium solution was supplied to culture media as nitrogen source at ethanol production stage, the concentration of ethanol produced was increased 20 times higher than that without shift. Ethanol production from CO in a fermenter with Clostridium ljungdahlii was optimized and the concentration of ethanol produced was 45 g/L and maximun ethanol productivity was 0.75 g ethanol/L-hr.

• Korean Chemical Engineering Research
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• v.43 no.2
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• pp.206-214
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• 2005

Heterogeneously-catalyzed oxidation of aqueous phase trichloroethylene (TCE) over supported metal oxides has been conducted to establish an approach to eliminate ppm levels of organic compounds in water. A continuous flow reactor system was designed to effect predominant reaction parameters in determining catalytic activity of the catalysts for wet TCE decomposition as a model reaction. 5 wt.% $CoO_x/TiO_2$ catalyst exhibited a transient period in activity vs. on-stream time behavior, suggesting that the surface structure of the $CoO_x$ might be altered with on-stream hours; regardless, it is probable to be the most promising catalyst. Not only could the bare support be inactive for the wet decomposition reaction at $36^{\circ}C$, but no TCE removal also occurred by the process of adsorption on $TiO_2$ surface. The catalytic activity was independent of all particle sizes used, thereby representing no mass transfer limitation in intraparticle diffusion. Very low TCE conversion appeared for $TiO_2$-supported $NiO_x$ and $CrO_x$ catalysts. Wet oxidation performance of supported Cu and Fe catalysts, obtained through an incipient wetness and ion exchange technique, was dependent primarily on the kinds of the metal oxides, in addition to the acidic solid supports and the preparation routes. 5 wt.% $FeO_x/TiO_2$ catalyst gave no activity in the oxidation reaction at $36^{\circ}C$, while 1.2 wt.% Fe-MFI was active for the wet decomposition depending on time on-stream. The noticeable difference in activity of the both catalysts suggests that the Fe oxidation states involved to catalytic redox cycle during the course of reaction play a significant role in catalyzing the wet decomposition as well as in maintaining the time on-stream activity. Based on the results of different $CoO_x$ loadings and reaction temperatures for the decomposition reaction at $36^{\circ}C$ with $CoO_x/TiO_2$, the catalyst possessed an optimal $CoO_x$ amount at which higher reaction temperatures facilitated the catalytic TCE conversion. Small amounts of the active ingredient could be dissolved by acidic leaching but such a process gave no appreciable activity loss of the $CoO_x$ catalyst.

• Geophysics and Geophysical Exploration
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• v.11 no.2
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• pp.99-108
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• 2008

To extend our detailed knowledge for the Hwasan caldera, we carried out magnetotelluric (MT) survey, which is pretty sensitive to electrical property variation in both horizontal and vertical direction of subsurface, across the Hwasan caldera with the direction of EW. The 2-D inversion results of observed MT data lead to following conclusions. Firstly, the depth of the basin basement inferred by the MT inversion results matches well with that suggested by previous potential studies, but the basement resistivity seems fairly low when compared to that of general case. This feature might be related with the large-scaled, highly conductive layer beneath the Euisung Sub-basin suggested by the previous MT study. Secondly, the high resistivity zones reaching to 4000 $\Omega{\cdot}m$ are imaged around two external ring fault boundaries. These zones are thought of as the response of the rhyolitic dykes intruding along the ring fault, and in the previous gravity data correspond to relatively high density anomalies. Thirdly, low resistivity zone reaching to 200 $\Omega{\cdot}m$ is detected around a depth of 1km beneath the central part of the caldera, which has not been yet reported in korean geophysical literatures. If we take account of the evolution model of the Hwasan caldera, this zone is regarded as the past sedimentary layer that subsided during the period of forming external ring fault system. In addition, the relatively low density anomaly observed in the central part of the caldera may be attributed to this sedimentary layer.

• International Commerce and Information Review
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• v.13 no.4
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• pp.485-516
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• 2011

Republic of Korea is small nation that is comprised of 0.7% of the world population and occupying just 0.07% of the world territory. Despite this, Republic of Korea once again proved herself to be as the world's major economic powerhouse by becoming the world's 7th largest exporter in 2010. However, the reality is that Republic of Korea is still significantly concerned about the volatile economic nature and anxiety that is spread across the globe since the global depression that began at the end of 2008 and the financial crisis that has been threatening the Euro-Zone recently. This has resulted in the nation reaching the limitation in significant economic growth and limited creation of jobs within the nation and due to such circumstances, the nation is becoming more aware of the fact that she needs to pay more attention on the service sector and service exports if she was to see a more positive economic outlook in the upcoming future. This research is aimed to analyse the cost that is associated with the service export sector, by examining a number of enterprises in relation to the MICE(Meeting Incentives Convention Exhibition) industry which certainly has both direct and indirect influences on the service exports of the nation Further, the prime goal of the research is to encourage the SMEs of Korea, who have substandard experience associated to foreign exports, to intensify and increase service exports and also the goal extends to the degree to suggest appropriate assistance measures to aid these enterprises to achieve such goals. This research is fundamentally designed and based on the literature research associated with the MICE industry and also, this research is premeditated through the analysis of the case of exports to Vietnam. As the result of research, it has been found out that SMEs in the MICE industry and those of in service export sector are reluctant or even feel insecure to attempt any kind of export of their services mainly due to; the lack of foreign market information and also the lack of experience associated with service exports. Furthermore, it has also been revealed that the difficulty to estimate the validity and profitability of service the export is a significant factor withholding those enterprises from attempting any service export to the foreign markets. Henceforth, in order to aid and stimulate service export to the foreign markets by these SMEs (including those in association with the MICE industry), it is imperative to prepare an one-stop service export assistance program which would provide the information associated with marketing, law and legislation, taxation system and financial area in regard to the global markets.

• Management & Information Systems Review
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• v.32 no.5
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• pp.69-88
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• 2013

This study aimed to analyze the effects that the exchange relationship among employees engaged in the wedding industry in Busan, Ulsan and Gyeongnam area exerted on job satisfaction and voluntary service intentions. For this purpose, a theoretical model was presented based on previous studies and the relationship among variables was analyzed based on the analysis results through a survey. There have recently been great difficulties in the whole wedding industry due to the global economic depression and the low birthrate. Moreover, it is hard to optimize the future business environment. In particular, the low birthrate has weakened the demand base of the wedding industry. As a result, it is expected that the competition among companies will be more fierce in the wedding industry. Employees' voluntary service intention become much more important to overcome difficulties in this industry. Employees' voluntary service intentions can be possible when their job satisfaction is achieved. Many studies report the result that this job satisfaction can naturally be achieved when the high quality exchange relationship among a leader, team members (co-workers) and customers is formed. It is viewed that employees' voluntary service intentions should be induced through job satisfaction to improve the profitability through the efficient operation and management of the system. A leader of the organization should make an effort to form the high-quality exchange relationship with members, support so that team members(coworkers) and other employees can get along together and the teamwork can be improved and induce them to improve a high level of service quality with friendly customer services. In spite of the significance of the study discussed above, there are the following limitations in this study. There is a limit to a certain extent in generalizing study conclusions because the study was limited to the Busan, Ulsan and Gyeongnam area. If practical surveys which full- and part-time employees are included in the composition of samples are conducted for wedding suppliers in the country in the future, the quality of study will be able to improve.

• Phonetics and Speech Sciences
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• v.12 no.2
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• pp.73-80
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• 2020

Breathing is the voice's driving force and also acts as a regulator of larynx function and efficiency. Respiratory distress is a side effect of general anesthesia in thyroid surgery. Therefore, this study's objective was to provide practical and complementary information for voice recovery after thyroid surgery, based on aerodynamic evaluation pre- and post-thyroidectomy. From May 2014 to July 2015, aerodynamic evaluations were performed on 34 female patients diagnosed with thyroid papillary cancer one week before surgery (PRE), one month after surgery (P1), and three months after surgery (P3). The Phonatory Aerodynamic System (model 6600, KayPENTAX, USA) was employed for this purpose, and a total of 29 analysis parameters were selected. The results showed statistically significant differences in peak expiratory airflow (p=0.004), mean pitch (p<0.01), expiration airflow duration (p=0.001), and expiratory volume (p=0.018), based on time factors. In the comparison of time factors, peak expiratory airflow and mean pitch parameters were different in PRE-P1 and PRE-P3. Expiration airflow duration and expiratory volume parameters were different in PRE-P3 and P1-P3. The interaction effect of time and surgical range was significant only for expiratory volume (p=0.024). Female patients who undergo thyroidectomy require post-operative breathing training, and exhalation improvement is considered to reflect a positive lifestyle after surgery.

• Child Health Nursing Research
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• v.2 no.2
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• pp.45-57
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• 1996

A serious disease in a family influences the entire family member given the fact that the members closely interact with each other. Especially in terms of pediatric nursing, study on family gains importance as the need to care of families whose children with developmental disabilities and chronic disease This study was done based on The Resiliency Model of Family Adjustment and Adaptation(McCubbin, 1991) is intended to examine the stress of parents whose children suffer from cleft lip or /and cleft palate. It also helps them to cope with the stress and analyze the relationship between the stress and coping This study used Family Inventory of Life Events and Changes (FILE) and Coping Health Inventory for Parents(CHIP) for measuring family stress and coping. The two instruments are revised to fit the social and cultural environment of Korean culture. Data collection was done from April 18, 1996 to May 18, 1996 at 8 University medical centers located in Seoul. Those who answered questionnaires were 84 parents whose children have cleft lip or /and cleft palate. SPSS PC+ was used to analyze the data collotted. Programs used for data analysis were t-test, ANOVA, Pearson correlation coefficient. The study is summarized as follows .1. The average score of family stress is 10.46(percentage of the full score 24.90) and 'finance and business strains'(3.25), and 'intrafamily strains'(2.65) ranked the highest. The average score of family's coping is 1.93, which is close to the answer of' moderately helpful' and they are measured to put their utmost efforts to' intergration and cooperation of family and optimistic definition on the situation'. 2. There is no significant statistical correlation between the family stress and coping. 3. Mothers show more stress than fathers in the parts of 'illness and family care strains' and 'losses'(t〓-2.34, t〓-2.32, p<.05). 4. Fathers show more willingness to cope with the stress than mothers do in the parts of' seeking social support','self-esteem','emotional comfort' 5. Mothers are more stress than fathers in the parts of family stress and its coping with it by usual traits(t〓-2.78, p<.05). Parents with religion are measured to cope more willingly than those who are not 6. Income of a family shows positive correlationship with family coping (r〓.28, p<.05). The study shows that gender difference is significant variable in studying on family stress and coping. Mothers get more stress than fathers, which has much to do with the fact that they are in charge of raising children and keeping houseworks. Accordingly, managing family crisis and its survival can be induced by giving support for the mothers, studying fathers including the rest of the family members and giving nursing care and arbitration ; religious background is also considered to be one of the important factors in family stress , judging from the relationship between family income and family's coping, caring given to suffering children is needed on societal levels. The above considerations bring up the need to have a longitudinal study of children with congenital anomaly including cleft lip or /and cleft palate and their families about family stress and coping. Resiliency programs on family system and their effectiveness and the relationship between the enlarged families with social and cultural values reflecting Korean tradition are also needed to be studied.

• Asian Journal of Turfgrass Science
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• v.11 no.2
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• pp.105-115
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• 1997

Responses of 'Penncross' creeping bentgrass turf to various fairway cultural practices are not well-established or supported by research results. This study was initiated to evaluate the effects of irrigation frequency, clipping return or removal, and nitrogen rate on leaf and soil nitrogen con-tent in the 'Penncross' creeping bentgrass (Agrostis palustris Huds.) turf. A 'Penncross' creeping bentgrass turf was established in 1988 on a Sharpsburg silty-clay loam (Typic Argiudoll). The experiment was conducted from 1989 to 1991 under nontraffic conditions. A split-split-plot experimental design was used. Daily or biweekly irrigation, clipping return or removal, and 5, 15, or 25 g N $m-^2$ $yr-^1$ were the main-, sub-, and sub-sub-plot treatments, respectively. Treatments were replicated 3 times in a randomized complete block design. The turf was mowed 4 times weekly at a l3 mm height of cut. Leaf tissue nitrogen content was analyzed twice in 1989 and three times in both 1990 and 1991. Leaf samples were collected from turfgrass plants in the treatment plots, dried immediately at 70˚C for 48 hours, and evaluated for total-N content, using the Kjeldahl method. Concurrently, six soil cores (18mm diam. by 200 mm depth) were collected, air dried, and analyzed for total-N content. Nitrogen analysis on the soil and leaf samples were made in the Soil and Plant Analyical Laboratory, at the University of Nebraska, Lincoln, USA. Data were analyzed as a split-split-plot with analysis of variance (ANOVA), using the General Linear Model procedures of the Statistical Analysis System. The nitrogen content of the leaf tissue is variable in creeping bentgrass fairway turf with clip-ping recycles, nitrogen application rate and time after establishment. Leaf tissue nitrogen content increased with clipping return and nitrogen rate. Plots treated with clipping return had 8% and 5% more nitrogen content in the leaf tissue in 1989 and 1990, respectively, as compared to plots treated with clipping removal. Plots applied with high-N level (25g N $m-^2$ $yr-^1$)had 10%, 17%, and 13% more nitrogen content in leaf tissue in 1989, 1990, and 1991, respectively, when compared with plots applied with low-N level (5g N $m-^2$ $yr-^1$). Overall observations during the study indicated that leaf tissue nitrogen content increased at any nitrogen rate with time after establishment. At the low-N level treatment (5g N $m-^2$ $yr-^1$ ), plots sampled in 1991 had 15% more leaf nitrogen content, as compared to plots sampled in 1989. Similar responses were also found from the high-N level treatment (25g N $m-^2$ $yr-^1$ ).Plots analyzed in 1991 were 18% higher than that of plots analyzed in 1989. No significant treatment effects were observed for soil nitrogen content over the first 3 years after establishment. Strategic management application is necessary for the golf course turf, depending on whether clippings return or not. Different approaches should be addressed to turf fertilization program from a standpoint of clipping recycles. It is recommended that regular analysis of the soil and leaf tissue of golf course turf must be made and fertilization program should be developed through the interpretation of its analytic data result. In golf courses where clippings are recycled, the fertilization program need to be adjusted, being 20% to 30% less nitrogen input over the clipping-removed areas. Key words: Agrostis palustris Huds., 'Penncross' creeping bentgrass fairway, Irrigation frequency, Clipping return, Nitrogen rate, Leaf nitrogen content, Soil nitrogen content.

• Journal of Korea Water Resources Association
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• v.53 no.9
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• pp.661-670
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• 2020

The water supply system has a wider installation range and various components of it than other infrastructure, making it difficult to secure stability against earthquakes. Therefore, it is necessary to develop methods for evaluating the seismic performance of water supply systems. Ground Motion Prediction Equation (GMPE) is used to evaluate the seismic performance (e.g, failure probability) for water supply facilities such as pump, water tank, and pipes. GMPE is calculated considering the independent variables such as the magnitude of the earthquake and the ground motion such as PGV (Peak Ground Velocity) and PGA (Peak Ground Acceleration). Since the large magnitude earthquake data has not accumulated much to date in Korea, this study tried to select a suitable GMPE for the domestic earthquake simulation by using the earthquake data measured in Korea. To this end, GMPE formula is calculated based on the existing domestic earthquake and presented the results. In the future, it is expected that the evaluation will be more appropriate if the determined GMPE is used when evaluating the seismic performance of domestic waterworks. Appropriate GMPE can be directly used to evaluate hydraulic seismic performance of water supply networks. In other words, it is possible to quantify the damage rate of a pipeline during an earthquake through linkage with the pipe failure probability model, and it is possible to derive more reasonable results when estimating the water outage or low-pressure area due to pipe damages. Finally, the quantifying result of the seismic performance can be used as a design criteria for preparing an optimal restoration plan and proactive seismic design of pipe networks to minimize the damage in the event of an earthquake.

• The Korean Journal of Ecology
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• v.26 no.3
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• pp.143-150
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• 2003

Korea has plentiful precipitation but rainfall events concentrate on several months of rainy season in her weather condition. Korea, therefore, experiences drought for a given period every year. Moreover the soil has usually low water holding capacity, as it is composed coarse particles originated from the granite. Response of several oaks and the Korean red pine (Pinus densiflora) on water stress showed that water budget was significant factor determining vegetation distribution. In addition, dehydration level due to cold resistance mechanism of several evergreen plants during the winter season was closely related to their distribution in natural condition. Experimental result under water stress showed that the Korean red pine was very tolerant to desiccation but the seedlings showed high mortality during the dry season. The mortality tended to proportionate to soil moisture content of each site. A comparison between soil moisture content during June when it is severe dry season and moisture content of the culture soil when the pine seedlings reached the permanent wilting point due to water withheld proved that high mortality during the dry season was due to water deficit. Water potential of sample plants measured during the exposure experiment to the air pollutant showed a probability that water related factors would dominate the occurrence of visible damage and the tolerance level of sample plants. In both field survey and laboratory experiment, plants exposed to air pollution showed more rapid transpiration than those grown in the unpolluted condition. The result would due to injury of leaf surface by air pollutants. Aluminum (Al/sup 3+/) increased in the acid soil not only inhibits root growth but also leads to abnormal distribution of root system and thereby caused water stress. The water stresses due to air pollution and soil acidification showed a possibility that they play dominating roles in inducing forest decline additionally to the existing water deficit due to weather and soil conditions in Korea. Sludge, which can contribute to improve field capacity, as it is almost composed of organic matter, showed an effect ameliorating the retarded growth of plant in the acidified soil. The effect was not less than that of dolomite known in widely as such a soil ameliorator. Litter extract contributed also to mitigate the water stress due to toxic Al/sup 3+/. We prepared a model showing the potential interaction of multiple stresses, which can cause forest decline in Korea by synthesizing those results. Furthermore, we suggested restoration plans, which can mitigate such forest decline in terms of soil amelioration and vegetation restoration.