• Journal of Embryo Transfer
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• v.26 no.4
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• pp.271-276
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• 2011

This study was focused on improvement of milk production in Mongolian dairy industry by artificial insemination (AI) technology, supported by ODA of KOICA in Republic of Korea. This program was started in January 2009 and it is in $3^{rd}$ years. This manuscript summarized the data especially on estrus synchronization and pregnancy establishment in dairy cows (Holstein) this year. A total of 81 dairy cows from 4 private farms (38 from Undarmal milk and that of 30, 8 and 5 dairy cows from Onjin (Enkhbayer), Jargalant, and BRM School farms respectively) were synchronized with 5 ml Lutalyse (i.m.) in the dump of dairy cows and then estrus was detected 2 to 3 days after $PGF_{2{\alpha}}$ injection. The synchronized dairy cows were inseminated with 0.5 ml dairy frozen semen by conventional artificial insemination (AI) techniques. Pregnancy was diagnosed about 60 days after AI by palpation method. About 96.3% (78/81) of synchronized cows were responded to single $PGF_{2{\alpha}}$ injection. Total 75 over 78 dairy cows (90.1%) inseminated were diagnosed as pregnant. The estrus induction and pregnancy rates were very effective using Lutalyse injection and conventional AI techniques in Mongolian dairy cow. The present results indicated that AI after estrus induction in Mongolian dairy cows could be applied to dairy breeding technology for improving breeding efficiency and milk production of the country.

• Journal of Embryo Transfer
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• v.33 no.3
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• pp.129-137
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• 2018

Acute vascular rejection has been known as a main barrier occurring in a xenograted tissue of alpha 1,3-galactosyltransferase knock-out (GalT KO) pig into a non-human primate (NHP). Adenosine which is a final metabolite following sequential hydrolysis of nucleotide by ecto-nucleotidases such as CD39 and CD73, act as a regulator of coagulation, and inflammation. Thus xenotransplantation of CD39 and CD73 expressing pig under the GalT KO background could lead to enhanced survival of recipient NHP. We constructed a human CD39 and CD73 expression cassette designed for endothelial cell-specific expression using porcine Icam2 promoter (pIcam2-hCD39/hCD73). We performed isolation of endothelial cells (pAEC) from aorta of 4 week-old GalT KO and membrane cofactor protein expressing pig ($GalT^{-MCP/-MCP}$). We were able to verify that isolated cells were endothelial-like cells using immunofluorescence staining analysis with von Willebrand factor antibody, which is well known as an endothelial maker, and tubal formation assay. To find optimal condition for efficient transfection into pAEC, we performed transfection with GFP expression vector using four programs of nucleofection, M-003, U-023, W-023 and Y-022. We were able find that the program W-023 was optimal for pAEC with regard to viability and transfection efficiency by flow cytometry and fluorescent microscopy analyses. Finally, we were able to obtain $GalT^{-MCP/-MCP}/CD39/CD73$ pAEC expressing CD39 and CD73 at levels of 33.3% and 26.8%, respectively. We suggested that pACE isolated from $GalT^{-MCP/-MCP}$ pig might be provided as a basic resource to understand biochemical and molecular mechanisms of the rejections and as an alternative donor cells to generate $GalT^{-MCP/-MCP}/CD39/CD73$ pig expressing CD39 and CD73 at endothelial cells.

• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.409-415
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• 2017

The vegetation period of trees might be prolonged by the delay of the leaf senescence in autumn. Thus, we focused on the generation of senescence-delayed transgenic trees to enhance biomass production. The PagMYC2, a gene containing the basic helix-loop-helix domain, was selected as a candidate for a senescence-delayed transgenic tree. The PagMYC2 gene was specifically induced after treatment with phytohormone jasmonic acid, and upregulated by abiotic stresses such as salinity, osmotic pressure and a low temperature. The constitutive overexpression of the PagMYC2 delayed the leaf senescence and inhibited chlorophyll degradation in the transgenic poplars. Leaf senescence analysis was performed in the leaf tissues of the PagMYC2-over-expression transgenic poplars. The transgenic poplars exhibited higher photochemical efficiency than did a wild type plant under a short-day condition (6 hours light/18 hours darkness) or a low temperature condition ($15^{\circ}C$) that was similar to the weather conditions of autumn. These results suggest that the PagMYC2 is a useful genetic resource to improve biomass production, which is able to sustain growth with senescence-delayed leaves for a long time in autumn.

• Korean Security Journal
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• no.35
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• pp.37-62
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• 2013

One of the organizational characteristics in the modern society is the emphasis placed upon individual autonomy in an effort to promote and develop each member's morale as well as the efficiency in personnel management. Therefore, it can be understood that the importance of "Self" is recognized in work places and the leadership of supervisors and each member's self-management and control are also emphasized, leading to establishment of the "Self-leadership" concept. In this study, the effect of the Transformational Leadership of the supervisors on the subordinates' Self-leadership was analyzed and the causal factor of organizational support in the relationship between Transformational Leadership and Self-leadership was defined. A survey was conducted with 182 security officials at the National Assembly and the following results were obtained. First, Transformational Leadership had a positive effect on Self-leadership and the Transformational Leadership of the supervisors had a statistically significant impact on the organizational support awareness. Furthermore, organizational support showed a statistically significant mediator effect in the relationship between the Transformational Leadership of the supervisors and the Self-leadership of the subordinates. Finally, future directions in regard to the personnel management system were suggested.

• Journal of Korea Water Resources Association
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• v.32 no.5
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• pp.579-591
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• 1999

The operation of a reservoir system is necessary for establishing the operation rule as well as designing the reservoirs for water resources planning or management. Increasingly complex water resource systems require more advanced operation techniques. As a result, various techniques have been introduced and applied until now. In this study Linear Tracking model based on optimal control theory is applied to the operation of the largest scale multi-reservoir system in the Han river and its applicability proved. This system normally supplies the water resources required downstream for hydro-power and plays a role in satisfying the water demand of the Capital region. For the optimal use of the water resources the Linear Tracking model is designed with the objective to maximize the hydro-power energy subject to the water supply demand. The multi-reservoir system includes the seven main reservoirs in IIan river such as Hwachon, Soyanggang, Chunchon, Uiam, Cheongpyong, Chungju and Paldang. These reservoirs have been monthly operated for the past 21 years. Operation results are analyzed with respect to both hydro"power energy and water supply. Additionally the efficiency of the technique is assessed.sessed.

• The Korean Journal of Applied Statistics
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• v.23 no.6
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• pp.1157-1167
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• 2010

This paper details a method for establishing a wind energy map having($1Km{\times}1Km$) resolution. The map is essential for measurement and efficiency-testing of wind energy resources and wind site analysis. To this end, a statistical wind field model is estimated that covers 345,682 regions obtained by $1Km{\times}1Km$ lattices made over South Korea. The paper derives various characteristics of a regional wind energy resource under the statistical wind field model and estimates them to construct the wind energy map. Kolmogorov-Smirnov test, based on TMY(typical meteorological year) wind data of 76 weather station areas, shows that a Log-normal model is adequate for the statistical wind field model. The model is estimated by using the wind speed data of 345,682 regions provided by the National Institute of Meteorological Research(NIMR). Various wind energy statistics are studied under the Log-normal wind field model. As an application, the wind energy density(W$/m^2$) map of South Korea is constructed with a resolution of $1Km{\times}1Km$ and its utility for the wind site analysis is discussed.

• The KIPS Transactions:PartC
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• v.15C no.5
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• pp.399-408
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• 2008

Mobile WiMAX provides wireless broadband services for data communication based on IP protocol. The limitation of physical bandwidth in the radio links may cause performance degradation in providing wireless broadband services in WIMAX. To enhance the efficiency of the radio link utilization, Payload Header Suppression (PHS) is defined as an optional header compression mechanism for mobile WiMAX. It has, however, a very limited compression capability since it has very restrictive compression fields. In this paper, hence, we assumed the application of Robust Header Compression (ROHC), a header compression scheme proposed for links characterized by high bit error ratios, long round-trip times (RTT), and scarce resource, to Mobile WiMAX, and studied its performance. Previous studies on ROHC performance merely focused on the impact of high bit error rate. However, bit error is virtually transparent to ROHC in the wireless systems like WiMAX, since the MAC provides the bit error checking function. In order to evaluate the performance of ROHC in the Mobile WiMAX environments, therefore, we evaluated the performance of ROHC with respect to the packet losses instead of bit error. We investigated the impact of the ROHC parameters that are recommended for the implementation in the ROHC and compared the performance of ROHC with PHS.

• Journal of KIISE
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• v.44 no.10
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• pp.1112-1123
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• 2017

As content providers further offload content-centric services to the cloud, data retrieval over the cloud typically results in many redundant items because there is a prevalent near-duplication of content on the Internet. Simply fetching all data from the cloud severely degrades efficiency in terms of resource utilization and bandwidth, and data can be encrypted by multiple content providers under different keys to preserve privacy. Thus, locating near-duplicate data in a privacy-preserving way is highly dependent on the ability to deduplicate redundant search results and returns best matches without decrypting data. To this end, we propose an efficient near-duplicate detection scheme for encrypted data in the cloud. Our scheme has the following benefits. First, a single query is enough to locate near-duplicate data even if they are encrypted under different keys of multiple content providers. Second, storage, computation and communication costs are alleviated compared to existing schemes, while achieving the same level of search accuracy. Third, scalability is significantly improved as a result of a novel and efficient two-round detection to locate near-duplicate candidates over large quantities of data in the cloud. An experimental analysis with real-world data demonstrates the applicability of the proposed scheme to a practical cloud system. Last, the proposed scheme is an average of 70.6% faster than an existing scheme.

• Journal of Bio-Environment Control
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• v.13 no.4
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• pp.258-265
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• 2004

The experiment was conducted to investigate the effect of EC and pH of nutrient solution on the growth and quality of the single-stemmed rose grown in a rose factory installed with hydroponic system. The growth and quality of the single-stemmed rose were not significantly different from each other with the EC of the nutrient solutions $1.0\~3.5dS{\cdot}m^{-1}$, which resulted in concluding high concentration of the nutrient solution was not necessary. The optimum range of the EC for single-stemmed rose was $1.5\~2.0dS{\cdot}m^{-1}$ considering plant growth, photosynthetic and transpiration rates. The optimum range of the pH for good plant growth without any visible physiological disorder was $4.0\~6.0$. Therefore, to keep the pH of the nutrient solution for rose low compared to other plants was beneficial for plant growth and uptake of the mineral ions.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.861-866
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• 2012

Water is the most important resource for the potato cultivation, especially to get the maximum water use efficiency and yield of potato, Water has to be applied moderately based on the water requirement of the potato. Crop water requirement (WR) is a function of the Potential evapo-transpiration(PET) and Crop coefficient (Kc). PET can be estimated by the climate data measured at the weather station in the production region. Kc was measured by the NIAST (RDA) through Lysimeter experiments. In this study, the growth stage of potato was divided as four (G-1 : Apr. 1~Apr. 15, G-2 : Apr. 16~May. 10, G-3 : May. 11~May. 31, G4 : Jun. 1~Jun. 15). The average PET during potato growing season of the 45 areas was $2.95mm\;day^{-1}$. The most water requirement was the G-3 stage among the potato growth stage. The MWR (Mean water requirement) according to growth stage was 1.0~1.2 (average 1.1), 1.5~1.8 (average 1.6), 1.9~2.2 (average 2.0) and 1.7~2.1 (average 1.8) mm $day^{-1}$, in the G-1, G-2, G-3 and G-4 stage, respectively. The TWR (Total water requirement) according to growth stage was 18.0~22.1 (average 19.3), 50.6~66.6 (average 56.3), 63.5~88.2 (average 72.4) and 38.3~54.5 (average 44) mm, in the G-1, G-2, G-3 and G-4 stage, respectively.