• Journal of Korea Water Resources Association
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• v.43 no.6
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• pp.583-595
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• 2010

Virtual water is defined as the volume of water to produce commodities and provide services, which has been developed by Tony Allan since the early 1990s. This research aims to evaluate a volume of virtual water trade in Korea from 1998 to 2007 by applying the evaluation method of unit virtual water volume to agricultural, live stock and industrial products, which is developed by Chapagain and Hoekstra (2004). Also, the concept of water footprint is deployed to quantify the volume of virtual water trade between countries. The study attempts to assess the appropriateness of the evaluation method of unit virtual water volume by employing the method to calculate the total amount of agricultural products in Korea and comparing this with the amount of agricultural water demand in the Korea Water Vision 2006. The research outcome shows that Korea has a net virtual water import of 32 billion $m^3$ on average in the form of agricultural, live stock and industrial commodities whose volume gradually increases. The gap between the volume of virtual water import of agricultural and live stock commodities and the total volume of agricultural water use reaches approximately 600 million $m^3$. This figure can be negligible considering the total volume of water demand in Korea, around 16 billion $m^3$, which demonstrates the validity of the evaluation method in terms of analyzing water balance.

• Membrane Journal
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• v.20 no.1
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• pp.29-39
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• 2010

This study focuses on the modeling of DMFC to predict the characteristics and to improve its performance. This modeling requires deep understanding of the design and operating parameters that influence on the cell potential. Furthermore, the knowledge with reference to electrochemistry, transport phenomena and fluid dynamics should be employed for the duration of mathematical description of the given process. Considering the fact that MEA is the nucleus of DMFC, special attention was made to the development of mathematical model of MEA. Multiscale modeling is comprised of process modeling as well as a computational fluid dynamics (CFD) modeling. The CFD packages and process simulation tools are used in simulating the steady-state process. The process simulation tool calculates theelectrochemical kinetics as well as the change of fractions, and at the same time, CFD calculates various balance equations. The integrated simulation with multiscal modeling explains experimental observations of transparent DMFC.

• Magazine of the Korean Society of Agricultural Engineers
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• v.13 no.3
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• pp.2349-2371
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• 1971

1. The historical development of the agriculture in Korea is observed and the future of Korean agriculture is suggested with present situation in order to recommend a direction of policy in agricultural mechanization. 2. A factor analysis of agricultural mechanization The needs of agricultural mechanization in the view of both national need and the armer's desire under the present situation are analyzed with data from the various sources. The researcher found that the agricultural mechanization is badly needed to develop prospective Korean agriculture to future. 3. The direction of agricultural mechanization. It can be said that the position of agriculture in the national economy plays a very important role. This importance should not be ignored by the Politicians in their process of developing long range economy plan. The agricultural mechanization for the modernized Korean agriculture should be directed to increase the most effective results with minimize the least sacrifice. The merry tiller is recommended to the main agricultural machinery in Korea in order to meet its small farming operation un-its(or farm size). Tractor is recommended in the plain area for the crop cultivation. The cooperative cultivation for rice and the upland crops will be developed in the plain area. Tractor, therefore, is recommended for the main agricultural machinery in these areas. Either tractor or merry tiller is recommended to the orchard area by its operating size of the orchard. The researcher also disoussed about the development of animal husbandry on the farm with increasing the farm size in order to develop meadow and pasture nuder the consideration of both the improvement of food consumption and the comprehensive development of national resources. 4. Relationship between the Performance of various agricultural machinery and the economic scale. Because of the agricultural machinery needs an expensive fixed expense(fixed cost) the total expense Per ha of the fixed expense and the operation expense should less than the traditional expense Per Dan Bo with in creased corpgiclds Per Dan Bo. Since the anual fixed expense of the agricultural machinery is figured out by the durability the more the farm size the less fixed expense of machinery is required. The formula of this principle is as follows; fixed expense for Dan Bo=Fixed expense of agricultural machinery farm size(or farming scale) The breaking-even point is the balance point between the expense of the using agricultural machinery and the traditional farming expenses. Labor cost of the Dan Bo is increasing when the management scale increases by the tradititional farming while the machanized management decrease the management cost Per Dan Bo. The reseracher found that the distribution of agricultural machinery will be the adeventeous after the year of 1981 by the result of frguring out the breaking-even point. 5. The Investigate and the conclusion. The purpose of this study is found out the direction of agricultural machanization and the breaking-even point of various agricultural machinery, there for is found out effective of the using various agricultural machinery for Collection cutter, Binder, Footing thresser, Semi-power thresser, Power thresser, Combine, Power rice-Trans-Planter, etc.

• Biomedical Science Letters
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• v.1 no.1
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• pp.45-54
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• 1995

The effect of different fatty acids supplementation on antobody production of Salmonella typhi was studied in ICR mice. Subjects supplemented their diets with $50\mu$g of extracted pig oil(as a saturated fatty acid) and fish oil (as a unsaturated fatty acid) / 2 days for 8 weeks. Blood was collected control and experimental groups of mice after 8 weeks of oil supplementation. The different fatty acids supplementation reduced unsaturated fatty acids composition in mice liver such as $C_{18:3}, \; C_{20:3}\; and\; C_{20:4}\; except\; C_{18:1}\; and\; C_{18:2}/C_{18:0}$ in fish oil and pig oil groups compared to control group. Also, the phagocytic activities of mice macrophages for Candida albicans was reduced by 6% in pig oil group and 9％ in fish oil group than control group. The antigen-stmulated lympocite proliferative response was significantly increased by fatty acid in pig oil group(48％) but 57％ in fish oil group. The different fatty acid supplementation increased antibody production in both experimental groups than control group ; this increase was only significant in pig oil group(1:$2^4$) on mice but not in fish oil group(1:$2^0$) compared to control group(1:$2^0$), however, increased antibody titer in both groups in vitro spleen cell culture supernatant(1:$2^3$ in fish oil group and 1:$2^2$ in pig oil group compared to control group 1:$2^0$). Thus, fish oil supplementation was immunosuppresive agent in macrophage phagocytosis, in-vivo antobody producibilities and lympocyte proliferation but pig oil supplementation was more effective than fish oil in antibody formation in-vivo. We find that antibody producibilities affected by fed on different fatty acids were considered by balance between saturated and unsaturated fatty acid, and $C_{20:3}/C_{20:4}$ ratio. Also, it affected to antigen-stimulated lymphocyte proliferation and macrophage phagocytic activities.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1244-1244
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• 2001

In linear discriminant analysis there are two important properties concerning the effectiveness of discriminant function modeling. The first is the separability of the discriminant function for different classes. The separability reaches its optimum by maximizing the ratio of between-class to within-class variance. The second is the stability of the discriminant function against noises present in the measurement variables. One can optimize the stability by exploring the discriminant variates in a principal variation subspace, i. e., the directions that account for a majority of the total variation of the data. An unstable discriminant function will exhibit inflated variance in the prediction of future unclassified objects, exposed to a significantly increased risk of erroneous prediction. Therefore, an ideal discriminant function should not only separate different classes with a minimum misclassification rate for the training set, but also possess a good stability such that the prediction variance for unclassified objects can be as small as possible. In other words, an optimal classifier should find a balance between the separability and the stability. This is of special significance for multivariate spectroscopy-based classification where multicollinearity always leads to discriminant directions located in low-spread subspaces. A new regularized discriminant analysis technique, the principal discriminant variate (PDV) method, has been developed for handling effectively multicollinear data commonly encountered in multivariate spectroscopy-based classification. The motivation behind this method is to seek a sequence of discriminant directions that not only optimize the separability between different classes, but also account for a maximized variation present in the data. Three different formulations for the PDV methods are suggested, and an effective computing procedure is proposed for a PDV method. Near-infrared (NIR) spectra of blood plasma samples from mastitic and healthy cows have been used to evaluate the behavior of the PDV method in comparison with principal component analysis (PCA), discriminant partial least squares (DPLS), soft independent modeling of class analogies (SIMCA) and Fisher linear discriminant analysis (FLDA). Results obtained demonstrate that the PDV method exhibits improved stability in prediction without significant loss of separability. The NIR spectra of blood plasma samples from mastitic and healthy cows are clearly discriminated between by the PDV method. Moreover, the proposed method provides superior performance to PCA, DPLS, SIMCA and FLDA, indicating that PDV is a promising tool in discriminant analysis of spectra-characterized samples with only small compositional difference, thereby providing a useful means for spectroscopy-based clinic applications.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1042-1042
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• 2001

In linear discriminant analysis there are two important properties concerning the effectiveness of discriminant function modeling. The first is the separability of the discriminant function for different classes. The separability reaches its optimum by maximizing the ratio of between-class to within-class variance. The second is the stability of the discriminant function against noises present in the measurement variables. One can optimize the stability by exploring the discriminant variates in a principal variation subspace, i. e., the directions that account for a majority of the total variation of the data. An unstable discriminant function will exhibit inflated variance in the prediction of future unclassified objects, exposed to a significantly increased risk of erroneous prediction. Therefore, an ideal discriminant function should not only separate different classes with a minimum misclassification rate for the training set, but also possess a good stability such that the prediction variance for unclassified objects can be as small as possible. In other words, an optimal classifier should find a balance between the separability and the stability. This is of special significance for multivariate spectroscopy-based classification where multicollinearity always leads to discriminant directions located in low-spread subspaces. A new regularized discriminant analysis technique, the principal discriminant variate (PDV) method, has been developed for handling effectively multicollinear data commonly encountered in multivariate spectroscopy-based classification. The motivation behind this method is to seek a sequence of discriminant directions that not only optimize the separability between different classes, but also account for a maximized variation present in the data. Three different formulations for the PDV methods are suggested, and an effective computing procedure is proposed for a PDV method. Near-infrared (NIR) spectra of blood plasma samples from daily monitoring of two Japanese cows have been used to evaluate the behavior of the PDV method in comparison with principal component analysis (PCA), discriminant partial least squares (DPLS), soft independent modeling of class analogies (SIMCA) and Fisher linear discriminant analysis (FLDA). Results obtained demonstrate that the PDV method exhibits improved stability in prediction without significant loss of separability. The NIR spectra of blood plasma samples from two cows are clearly discriminated between by the PDV method. Moreover, the proposed method provides superior performance to PCA, DPLS, SIMCA md FLDA, indicating that PDV is a promising tool in discriminant analysis of spectra-characterized samples with only small compositional difference.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.11
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• pp.1455-1461
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• 2010

Three rumen-cannulated Holstein steers were fed three diets, each with a different synchrony index (SI) (LS: 0.77, MS: 0.81, and HS: 0.83), in order to examine the effect of diet on rumen fermentation, nitrogen balance, and microbial protein synthesis. Synchrony index was calculated based on the carbohydrate and crude protein fractions of each ingredient and their degradation rates. Feeding the steers diets with different SIs did not influence dry matter, crude protein, NDF, or ADF digestibility. The concentrations of total and individual VFA in the rumens of steers that were fed the two higher-SI diets were higher than in those fed the low-SI diet (p<0.05), but there was no significant difference between the two higher-SI diets. One hour after feeding, steers on the LS diet had lower ruminal pHs than did those fed the MS or HS diets (p<0.05), and animals on the LS diet generally showed higher ruminal $NH_3$-N levels than did animals on the other diets, with the 4-h post-feeding difference being significant (p<0.05). Steers receiving the LS diet excreted more nitrogen (N) in their urine than did those on the two higher-SI diets (p<0.05), and the total N excretion of those on the LS diet was also higher (p<0.05). Microbial N levels calculated from the concentration of urinary purine derivatives were generally higher when the SI was higher, with the highest microbial protein synthesis being produced by steers on the HS diet (p<0.05). In conclusion, in the current study, ingestion of a synchronous diet by Holstein steers improved microbial protein synthesis and VFA production and decreased total N output.

• International Commerce and Information Review
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• v.13 no.3
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• pp.119-142
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• 2011

Competitions for secure oil are intense around the world due to the limited oil reserves. The situations are becoming more serious as China has participated in the competition. This paper aims to investigate China's offshore oil development strategies to balance the supply and demand of oil and then suggest its policy implications. A surging increase of oil demand due to the rapid economic growth as well as the stagnation in domestic oil output has turned China into a net oil importer since 1993. Therefore, China has placed a significant priority on securing long-term stability of its offshore oil to cope with the rapid growing demand. It has taken a variety of strategies to secure stable oil resource such as development of offshore oil resource, increasing the number of oil importing countries. China with the highest foreign exchange reserve of approximately $3 trillion as of 2010, has considered to employ foreign exchange reserves while making a huge amount of investment to secure oil resource. China has pursued several policies such as loan to oil production country for securing oil, foreign direct investment on offshore oil development, M&A of oil exploration and production companies and geographical diversification of oil importing countries. China has promoted offensive strategies for securing oil resource rather than cooperation with other countries. Thus, China should find a trade-off point for recovering relationship with international society while developing and investing renewable energy for long-term future. It will also address some implications for Korea, which has to prepare new strategies of overseas oil development.

• International Commerce and Information Review
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• v.13 no.3
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• pp.377-401
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• 2011

Under the WTO system, direct export support system that provides financial and tax related support is altogether prohibited. This presented an obstacle in strengthening competitiveness of Korean export business and in increasing exports continuously. One of the methods used to solve this problem was to actively leverage export insurance. In Korea, export insurance services have been conducted by the Korea Trade Insurance Corporation (k-sure) to promote export. Korea has been among the world's active users of the export insurance system. Given this situation, this paper examines the effectiveness of the Korea export insurance system in the promotion of export. In particular, this study analyzed about discriminating effects of the export insurance on the export of big and small-medium business. In order to analyze, We introduce a Export Supply Function model. In this paper, We construct two model. The one is about big business, the other is small-medium business. For empirical analysis, unit-root test was conducted to understand the safety of time series. The results show that all variables are not I(0) time series. Instead, they are I(1) time series. To this, cointegration verification was conducted based on the use of Johansen verification method to define the existence (or non-existence) of long-term balance relationship among variables. The results come out as follows. The export insurance of big business has a stronger effect on export than that of small-medium business. The cause of these results is due to the distinct structure of Korea industries. In view of the fact that the insurance can make the risk decreased. We can say that the export insurance affects the export of a high-risk country.

• International Commerce and Information Review
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• v.13 no.3
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• pp.403-431
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• 2011

The environmental issues including domestic measures to protect public life or health are generally easy to bring the tension between the WTO and its member countries. The standard of review, whether de novo review, total deference, or somewhere in between, is largely important in the WTO's adjudicating mechanism because it is closely related to the appropriate balance of power between sovereign nations and the WTO: The multilateral trading regime, through the proper standard of review, could harmoniously operated without interest conflicts among the member countries and at the same time between the WTO and the member countries. Irrespective the important function of the standard of review in the WTO judicial system, applicable standard of review has not been established in the current SPS Agreement. Furthermore, the nature of the SPS Agreement related in scientific factors, such as scientific experiment, data and assessment prevents the WTO's panel from applying consistent standard of review. Considering the judicial demand for the moderate treatment of the case under the SPS Agreement, this paper explores appropriate standard of review applicable the SPS-related environmental measures, particularly, by analysing the recent SPS-related dispute, US-Hormones Suspension.