• Applied Microscopy
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• v.35 no.3
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• pp.121-128
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• 2005

It has been known that ras signaling transduction leads to cell proliferation and migration including various adaptor molecules. Dynamin protein has been implicated in the formation of nascent vesicles in both the endocytic and secretory pathways. Dynamin was classified into three isoforms: dynamin I is only expressed in neuronal tissue, dynamin II is expressed ubiquitously in all tissue but that of dynamin III is confined to testis. We have reported in previous study that Grb2, binding to ras, was associated with dynamin II in NIH3T3 cells. Therefore we have tried to identify the relative expression of dynamin II according to overexpressed ras protein in ras oncogene transfected cells (NIH3T3 (ras)). For the detection of differential expression of dynamin II, we have used immunofluorescent staining and western blot methods in NIH3T3 and NIH3T3 (ras) cells. Next we have described the morphological differences between NIH3T3 and NIH3T3 (ras) cells using SEM and TEM. From these experiments dynamin II was highly expressed in NIH3T3 (ras) cells. NIH3T3 cells was transformed to more spindle shape with many cell process by transfection of ras oncogene. Moreover dynamin II was more concentrated in endocytotic membrane of the NIH3T3 (ras) cells compared to that of NIH3T3 cells. The present results suggested that dynamin II may involve the intermediate messenger in Ras signaling transduction pathway.

• Journal of Food Hygiene and Safety
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• v.27 no.1
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• pp.103-107
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• 2012

We compared between an automated most-probable-number technique $TEMPO^{(R)}$TVC and traditional plating methods $Petrifilm^{TM}$ for estimating populations of total aerobic bacteria in various livestock products. 257 samples randomly selected in local retail stores and 87 samples inoculated with $E.$ $coli$ ATCC 25922, $Staphylococcus$ $aureus$ ATCC 12868 were tested in this study. The degree of agreement was estimated according to the CCFRA (Campden and Chorleywood Food Research Association Group) Guideline 29 and the agreement indicates the difference of two kinds methods is lower than 1 log base 10($log_{10}$). The samples of hams, jerky products, ground meat products, milks, ice creams, infant formulas, and egg heat formed products were showed above 95% in the agreement of methods. In contrast, proportion of agreement on meat extract products, cheeses and sausages were 93.1%, 92.1%, 89.1%, respectively. One press ham and five sausages containing spice and seasoning, two pork cutlets containing spice and bread crumbs, two meat extract product and two natural cheeses and one processing cheese with a high fat content, and one ice cream containing chocolate of all samples showed the discrepancy. Our result suggest that $TEMPO^{(R)}$TVC system is efficient to analyses total aerobic bacteria to compare manual method in time-consuming and laborious process except livestock products having limit of detection.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3340-3353
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• 2009

This paper aims to study the effect of academia-industrial cooperation on the technical innovation of small and medium-sized companies. A survey was conducted on about 1,100 businesses located in the Sihwa-Banwol industrial estate to analyze the consequence of three factors of academia-industrial cooperation. the joint use of equipments, technological support of universities to businesses, and cooperative technological development through technical guidance-on entrepreneurial capability and their knowledge-absorption ability, and ultimately on their technological innovation,. The validity of the survey result was tested through the Structural Equation Model. On the basis of the comparison between companies which have participated in academy-industry cooperation and companies which have not, this paper suggests that venture businesses should take advantage of the cooperation with universities to boost their competitiveness. The analysis of the three individual factors of the academy-industry cooperation based on the Structural Equation Model shows that all of them have remarkable influence on entrepreneurial capability, but that they don't have as much impact on businesses' knowledge absorption ability. However, the outcome of technological innovation of businesses is primarily influenced by entrepreneurial capability rather than their knowledge absorption ability. The survey also shows that the three factors of the cooperation have an equal impact on the competitiveness of companies regardless of their business type or their products' growth stages. As the companies involved in academy industry cooperation outweigh other businesses, in terms of technological innovation, the numbers of new product development, and the numbers of their process improvement cases, this paper argues that new strategies should be taken for the businesses to fully take advantage of academy-industry cooperation.

• Restorative Dentistry and Endodontics
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• v.34 no.1
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• pp.51-60
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• 2009

The purpose of this study was to perform quantitative comparisons of water permeable zones in both the adhesive and the hybrid layer before and after thermo cycling in order to assess the integrity of the bonding interface. Twenty eight flat dentin surfaces were bonded with a light-cured composite resin using one of four commercial adhesives [OptiBond FL (OP), AdheSE (AD), Clearfil SE Bond (CL). and Xeno III (XE)]. These were sectioned into halves and subsequently cut to yield 2-mm thick specimens; one specimen for control and the other subjected to thermocycling for 10,000 cycles. After specimens were immersed in ammoniacal silver nitrate for 24 h and exposed to a photo developing solution for 8 h, the bonded interface was analyzed by scanning electron microscopy (SEM) and wavelength dispersive spectrometry (WDS) at five locations per specimen. Immediately after bonding. the adhesive layer of OP showed the lowest silver uptake, followed by CL, AD. and XE in ascending order (p < 0.0001); the hybrid layer of CL had the lowest silver content among the groups (p = 0.0039). After thermocycling, none of the adhesives manifested a significant increase of silver in either the adhesive or the hybrid layer. SEM demonstrated the characteristic silver penetrated patterns within the interface. It was observed that integrity of bonding was well maintained in OP and CL throughout the thermocycling process. Adhesive-tooth interfaces are vulnerable to hydrolytic degradation and its permeability varies in different adhesive systems, which may be clinically related to the restoration longevity.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.3
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• pp.165-173
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• 2010

A cloud detection method is introduced to improve the reliability of NOAA/AVHRR Sea Surface Temperature (SST) data processed during the daytime and nighttime in the TeraScan System. In daytime, the channels 2 and 4 are used to detect a cloud using the three tests, which are spatial uniformity tests of brightness temperature (infrared channel 4) and channel 2 albedo, and reflectivity threshold test for visible channel 2. Meanwhile, the nighttime cloud detection tests are performed by using the channels 3 and 4, because the channel 2 data are not available in nighttime. This process include the dual channel brightness temperature difference (ch3 - ch4) and infrared channel brightness temperature threshold tests. For a comparison of daytime and nighttime SST images, two data used here are obtained at 0:28 (UTC) and 21:00 (UTC) on May 13, 2009. 6 parameters was tested to understand the factors that affect a cloud masking in and around Korean Peninsula. In daytime, the thresholds for ch2_max cover a range 3 through 8, and ch4_delta and ch2_delta are fixed on 5 and 2, respectively. In nighttime, the threshold range of ch3_minus_ch4 is from -1 to 0, and ch4_delta and min_ch4_temp have the fixed thresholds with 3.5 and 0, respectively. It is acceptable that the resulted images represent a reliability of SST according to the change of cloud masking area by each level. In the future, the accuracy of SST will be verified, and an assimilation method for SST data should be tested for a reliability improvement considering an atmospheric characteristic of research area around Korean Peninsula.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.2
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• pp.139-154
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• 2008

The nearly 75% of animal feed materials used for livestock production are imported every year in Korea. Most of imported feed ingredients are concentrated feeds such as com, wheat, soybean, soybean meal, etc. and they are used as the source materials for the production of assorted feed. The imported concentrated feeds are high in nitrogen and phosphorus. Therefore, the consistent import of feed ingredients may cause an increase of nutrient deposit in our agricultural ecosystem. In the current review, it was discussed with the situation of the feed importation and its nutritional composition to evaluate the nutrient load by the imported feeds onto agricultural ecosystem. The nutrient load caused by imported feeds in agricultural environment was compared with the nutrient demand for crop production. The amounts of N, $P_2O_5\;and\;K_2O$ introduced by the imported fteds in Korea were 371, 140 and 143 Ktons. And, the N, $P_2O_5\;and\;K_2O$ loads excreted from imported feeds in livestock were 148, 84 and 86 Ktons of N, $P_2O_5\;and\;K_2O$ and These nutrient loads by the imported feeds are at the percentage of N 52%, $P_2O_5$ 52% and $K_2O$ 42% in the comparison of total nutrient amounts excreted from livestock animals in Korea. The 82.3% of nutrients excreted from livestock was recycled to crop land as compost and liquid fertilizer, and the others were discharged to river after water treatment processing or disposed to ocean. Also, passing through the recycling process far the production of compost and liquid fertilizer, the amount of nutrients was reduced by the ammonia vaporization of livestock feces and urine. Accordingly, N 81, $P_2O_5$ 74 and $K_2O$ 76 Ktons in the nutrients excreted from livestock were estimated to be utilized in the crop land. Consequently, it was estimated that 44, 48 and 69 Ktons of N, $P_2O_5\;and\;K_2O$ were taken up with crops in the consideration of the ratio of mineralization, and the amounts of leached or deposited N, $P_2O_5\;and\;K_2O$ in crop land were estimated to be 37, 27 and 7 Ktons, respectively. It is estimated that 12%, 34% and 48% of N, $P_2O_5\;and\;K_2O$ introduced by the imported feeds were used by crops, and 10%, 34% and 5% of N, $P_2O_5\;and\;K_2O$ were leached or deposited in agricultural ecosystem. Therefore, considering the leached and deposited amounts of N, $P_2O_5\;and\;K_2O$ originated from the imported feed ingredients, the consistent import of feeds may gradually increase the nutrient load onto agricultural ecosystem.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.20 no.1
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• pp.49-59
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• 1984

Optimizing investigation of characteristics of underwater welding by a gravity type arc welding process was experimentally carried out by using six types of domestic coated welding electrodes for welding of domestic marine structural steel plates (KR Grade A-1, SWS41A, SWS41B,) in order to develop the underwater welding techniques in practical use. Main results obtained are summarized as follows: 1. The absorption speed of the coating of domestic coated lime titania type welding-electrode became constant at about 60 minutes in water and it was about 0.18%/min during initial 8 minutes of absorption time. 2. Thus, the immediate welding electrode could be used in underwater welding for such a short time in comparison with the joint strength of in-atmosphere-and on-water-welding by dry-, wet-or immediate-welding-electrode. 3. By bead appearance and X-ray inspection, ilmenite, limetitania and high titanium oxide types of electrodes were found better for underwater-welding of 10 mm KR Grade A-1 steel plates, while proper welding angle, current and electrode diameter were 6$0^{\circ}C$, above 160A and 4mm respectively under 28cm/min of welding speed. 4. The weld metal tensile strength or proof stress of underwater-welded-joints has a quadratic relationship with the heat input, and the optimal heat input zone is about 13 to 15KJ/cm for 10mm SWS41A steel plates, resulting from consideration upon both joint efficiency of above-100% and recovery of impact strength and strain. Meanwhile, the optimal heat input zone resulting from tension-tension fatigue limit above the base metal's of SWS41A plates is 16 to 19KJ/cm. Reliability of all the empirical equations reveals 95% confidence level. 6. The microstructure of the underwater welds of SES41A welded in such a zone has no weld defects such as hydrogen brittleness with supreme high hardness, since the HAZ-bond boundary area adjacent to both surface and base metal has only Hv400 max with the microstructure of fine martensite, bainite, pearlite and small amount of ferrite.

• KSBB Journal
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• v.20 no.5 s.94
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• pp.376-382
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• 2005

Avermectin (AVM) $B_{1a}$ produced by Streptomyces avermitilis via polyketide pathway is a secondary metabolite with powerful anthelmintic and insecticidal activities, thus being used as an efficient agent in the field of agriculture and animal health. It has been reported that a precursor for AVM $B_{1a}$ biosynthesis was isoleucine and the biosynthetic pathway of AVM $B_{1a}$ was closely similar to that of fatty acid. Based on understanding of the biosynthetic pathway of AVM $B_{1a}$, we intended to screen various mutants resistant against O-methyl threonine (OMT), an isoleucine-anti metabolite, and/or mutants resistant against p-fluoro phenoxy acetic acid (pFAC), an inhibitor of fatty acid biosynthesis. It was inferred that these mutants could produce AVM $B_{1a}$ more efficiently, due to the acquired capability of not only overproducing isoleucine intracellularly but also channelling metabolized carbon-sources into the polyketide pathway, thus leading to enhanced biosynthesis of AVM $B_{1a}$. The resulting mutant (PFA-1 strain) resistant against 100 ppm of pFAC was able to produce approximately 42 fold higher amount of AVM $B_{1a}$ compared to the parallel mother strain (4,200 vs. 100 units/l). In addition, through the process of continuous strain improvement program carried out by gradually increasing the OMT concentration, it was possible to obtain a more attractive mutant with greater AVM $B_{1a}$ production capacity (9,000 units/l). Notable was that significantly higher producer (12,000 units/l) could be selected through further screening of the resistant mutants, this time, to even higher concentration of PFAC. Meanwhile, through the analysis of AVM Bla production histograms (i.e., number of strains according to their AVM $B_{1a}$ biosynthetic ability) for the earlier strains in comparison with the high producers having the characteristics of resistance to OMT and pFAC, it was found that production stability of the high-yielding producers were remarkably improved, as demonstrated by the fact that larger proportion of the mutated strains had greater capability of AVM $B_{1a}$ biosynthesis ($71\%$ in the range between 5,000 and 7,000 units/L; $47\%$ in the range between 6,000 and 7,000 units/l). Based on these consequences, it was concluded that the rational screening strategy based on the understanding of the biosynthetic pathway of AVM $B_{1a}$ was very effective in obtaining high-yielding mutants with the features of enhanced production stability.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.3 s.118
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• pp.248-256
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• 2007

In this paper, we propose a selective DFT spreading method to solve a high PAPR problem in uplink OFDMA system. A selective characteristic is added to the DFT spreading, so the DFT spreading method is mixed with SLM method. However, to minimize increment of computational complexity, differently with common SLM method, our proposed method uses only one DFT spreading block. After DFT, several copy branches are generated by multiplying with each different matrix. This matrix is obtained by linear transforming the each phase rotation in front of DFT block. And it has very lower computational complexity than one DFT process. For simulation, we suppose that the 512 point IFFT is used, the number of effective sub-carrier is 300, the number of allowed sub-carrier to each user's is 1/4 and 1/3 and QPSK modulation is used. From the simulation result, when the number of copy branch is 4, our proposed method has more than about 5.2 dB PAPR reduction effect. It is about 1.8 dB better than common DFT spreading method and 0.95 dB better than common SLM which uses 32 copy branches. And also, when the number of copy branch is 2, it is better than SLM using 32 copy branches. From the comparison, the proposed method has 91.79 % lower complexity than SLM using 32 copy branches in similar PAPR reduction performance. So, we can find a very good performance of our proposed method. Also, we can expect the similar performance when all number of sub-carrier is allocated to one user like the OFDM.

• Journal of Korea Port Economic Association
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• v.32 no.4
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• pp.73-87
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• 2016

The purpose of this study is to investigate the empirical results of Analytic Hierarchy Process/Data Envelopment Analysis-Assurance Region(AHP/DEA-AR) by using multiple regression analysis during the period of 2009-2012 with 5 inputs (number of gantry cranes, number of berth, berth length, terminal yard, and mean depth) and 2 outputs (container TEU, and number of direct calling shipping companies). Assurance Region(AR) is the most important tool to measure the efficiency of seaports, because individual seaports are characterized in terms of inputs and outputs. Traditional AHP and multiple regression analysis techniques have been used for measuring the AR. However, few previous studies exist in the field of seaport efficiency measurement. The main empirical results of this study are as follows. First, the efficiency ranking comparison between the two models (AHP/DEA-AR and multiple regression) using the Wilcoxon signed-rank test and Mann-Whitney signed-rank sum test were matched with the average level of 84.5 % and 96.3% respectively. When data for four years are used, the ratios of the significant probability are decreased to 61.4% and 92.5%. The policy implication of this study is that the policy planners of Korean port should introduce AHP/DEA-AR and multiple regression analysis when they measure the seaport efficiency and consider the port investment for enhancing the efficiency of inputs and outputs. The next study will deal with the subjects introducing the Fuzzy method, non-radial DEA, and the mixed analysis between AHP/DEA-AR and multiple regression analysis.