• Journal of Animal Science and Technology
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• v.47 no.4
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• pp.547-554
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• 2005

An experiment was conducted to investigate the dietary effects of a transgenic Aspergillus oryzae(AO) culture on the performance, egg quality and intestinal microflora of layers. A total of 840 Hy-line Brown layers of 39wks old were assigned to one of the following 7 dietary treatments: control(C), C+0.2% AO culture, C+0.5% AO culture, C+0.2% transgenic AO culture, C+0.5% transgenic AO culture, C+0.2% transgenic mutant AO culture, and C+0.5% transgenic mutant AO culture. The transgenic AO was made by inserting Salmonella gallinarum gene to AO. And the transgenic mutant AO was made by inserting Salmonella gallinarum gene to mutant AO which was mutated by UV irradiation. Each treatment was replicated six times with 20 birds housed in 2 bird cage. Twenty birds units were arranged according to completely randomized block design. Feeding trial lasted for 8wks under 16 hour lighting regimen. Laying performance and egg quality were significantly(P<0.05) affected by the treatments. Transgenic AO culture supplementation at the level of 0.2% significantly increased egg production, while its egg weight was significantly decreased compared to that of the control. Feed intake and feed conversion ratio(FCR) were not significantly different among the AO treatments and the control. The eggshell strength of the AO treatments was significantly higher than that of the control. Transgenic mutant AO culture supplemented at the level of 0.5% significantly increased egg yolk color. Intestinal microflora were significantly(P<0.05) affected by the treatments. The cfu of Lactobacilli spp. significantly increased and those of Salmonella species and E. coli decreased in the AO treatments. The transgenic AO and transgenic mutant AO culture were more effective than the AO culture in reducing the cfu of Salmonella species and E. coli. It is concluded that supplementation of the transgenic AO culture at the level of 0.2% could be recommended for the improvement of egg production. Supplementation of transgenic AO or transgenic mutant AO culture at 0.2% level effectively controlled intestinal Salmonella species population.

• 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.

• Restorative Dentistry and Endodontics
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• v.32 no.1
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• pp.37-46
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• 2007

The C-shaped canal system is an anatomical variation mostly seen in mandibular second molars, although it can also occur in maxillary and other mandibular molars. The main anatomical feature of C-shaped canals is the presence of fins or web connecting the individual root canals. The complexity of C-shaped canals prevents these canals from being cleaned, shaped, and obturated effectively during root canal therapy, and sometimes it leads to an iatrogenic perforation from the extravagant preparation. The purpose of this study was to provide further knowledge of the anatomical configuration and the minimal thickness of dentinal wall according to the level of the root. Thirty extracted mandibular second molars with fused roots and longitudinal grooves on lingual or buccal surface of the root were collected from a native Korean population. The photo images and radiographs from buccal, lingual, apical direction were taken. After access cavity was prepared, teeth were placed in 5.25% sodium hypochlorite solution for 2 hours to dissolve the organic tissue of the root surface and from the root canal system. After bench dried and all the teeth were embedded in a self-curing resin. Each block was sectioned using a microtome (Accutom-50, Struers, Denmark) at interval of 1 mm. The sectioned surface photograph was taken using a digital camera (Coolpix 995, Nikon, Japan) connected to the microscope. 197 images were evaluated for canal configurations and the minimal thickness of dentinal wall between canal and external wall using 'Root Thickness Gauge Program' designed with Visual Basic. The results were as follows : 1. At the orifice level of all teeth, the most frequent observed configuration was Melton's Type C I (73%), however the patterns were changed to type C II and C III when the sections were observed at the apical third. On the other hand, the type C III was observed at the orifice level of only 2 teeth but this type could be seen at apical region of the rest of the teeth. 2. The C-shaped canal showed continuous and semi-colon shape at the orifice level, but at the apical portion of the canal there was high possibility of having 2 or 3 canals 3. Lingual wall was thinner than buccal wall at coronal, middle, apical thirds of root but there was no statistical differences.

• Korean Journal of Poultry Science
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• v.36 no.2
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• pp.125-131
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• 2009

This study was conducted to investigate the effects of dietary supplementation of mannan-oligosaccharides (MOS) and fructo-oligosaccharides (FOS) on the performance, immune response and small intestinal microflora in laying hens. A total of 960 Hy-Line $Brown^{(R)}$ laying hens of 27 wks old, housed in 2 bird cages, were assigned in a completely randomized block design into one of the following 6 dietary treatments: control, antibiotic (6 ppm avilamycine), 0.025% MOS, 0.05% MOS, 0.25% FOS, and 0.5% FOS. Each treatment had 4 replicates of 40 birds and was fed ad libitum for 6 wks under 16 h lighting regimen. There were significant differences among treatments in hen-day and hen-housed egg production. Hen-day egg production in 0.025% MOS was significantly higher than that of control. Hen-housed egg production in antibiotic-treated group was significantly higher compared with control. Egg weight, feed intake and feed conversion were not significantly different among treatments. Egg shell thickness was highest in 0.25% FOS, but was not significantly different among the rest of treatments. There were no significant differences among treatments in egg shell strength, egg shell color, egg yolk color and Haugh unit. IgG concentrations in serum were not significantly different among treatments. On the other hand, IgA concentrations of the treated birds tended to be increased compared with control. Dietary treatments tended to decrease Cl. perfringens and E. coli, and to increase Lactobacillus spp. The result of this experiment showed that dietary supplementation of MOS and FOS in laying hens tended to improve egg production comparable to the supplementation of antibiotics. The level of serum IgA and small intestinal microflora were also significantly affected by the treatments.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.69
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• pp.261-301
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• 2016

Recently the abusive calls on on-demand bonds have been a critical issue among many engineering and construction companies in Korea. On-demand bond is referred to as an independent guarantee in the sense that the guarantee is independent from its underlying contract although it was issued based on such underlying contract. For this reason, the issuing bank is not required to and/or entitled to look into whether there really is a breach of underlying contract in relation to the call on demand-bonds. Due to this kind of principle of independence, the applicant has to run the risk of the on demand bond being called by the beneficiary without due grounds. Only where the call proves to be fraudulent or abusive in a very clear way, the issuing bank would not be obligated to pay the bond proceeds for the call on on-demand bonds. In order to prevent the issuing bank from paying the proceeds under the on-demand bond, the applicant usually files with its competent court an application for injunction prohibiting the beneficiary from calling against the issuing bank. However, it is in practice difficult for the applicant to prove the beneficiary's call on the bond to be fraudulent since the courts in almost all the jurisdictions of advanced countries require very strict and objective evidences such as the documents which were signed by the owner (beneficiary) or any other third party like the engineer. There is another way of preventing the beneficiary from calling on the bond, which is often utilized especially in the United Kingdom or Western European countries such as Germany. Based upon the underlying contract, the contractor which is at the same time the applicant of on-demand bond requests the court to order the owner (the beneficiary) not to call on the bond. In this case, there apparently seems to be no reason why the court should apply the strict fraud rule to determine whether to grant an injunction in that the underlying legal relationship was created based on a construction contract rather than a bond. However, in most jurisdictions except for United Kingdom and Singapore, the court also applies the strict fraud rule on the ground that the parties promised to make the on-demand bond issued under the construction contract. This kind of injunction is highly unlikely to be utilized on the international level because it is very difficult in normal situations to establish the international jurisdiction towards the beneficiary which will be usually located outside the jurisdiction of the relevant court. This kind of injunction ordering the owner not to call on the bond can be rendered by the arbitrator as well even though the arbitrator has no coercive power for the owner to follow it. Normally there would be no arbitral tribunal existing at the time of the bond being called. In this case, the emergency arbitrator which most of the international arbitration rules such as ICC, LCIA and SIAC, etc. adopt can be utilized. Finally, the contractor can block the issuing bank from paying the bond proceeds by way of a provisional attachment in case where it also has rights to claim some unpaid interim payments or damages. This is the preservative measure under civil law system, which the lawyers from common law system are not familiar with. As explained in this article, it is very difficult to block the issuing bank from paying in response to the bond call by the beneficiary even if the call has no valid ground under the underlying construction contract. Therefore, it is necessary for the applicants who are normally engineering and construction companies to be prudent to make on-demand bonds issued. They need to take into account the creditability of the project owner as well as trustworthiness of the judiciary system of the country where the owner is domiciled.

• The Journal of the Acoustical Society of Korea
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• v.37 no.4
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• pp.223-231
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• 2018

Recently, due to various environmental problems, blast tracks in tunnel are replaced with concrete tracks, but they have more adverse effects on noise than blast tracks so that additional noise measures are needed. Among these measures, sound-absorbing blocks start to be used due to its easy and quick installation. However, the performance of sound absorption blocks need to be verified under real environmental and operational conditions. In this paper, interior noise levels in KTX train cruising in Dalseong tunnel are measured before and after the installation of sound-absorbing blocks and the measured data are analyzed and compared. Additionally, noise reduction are estimated by modeling the high speed train, the tunnel and absorption blocks. Measurement devices and methods are used according to ISO 3381 and the equivalent sound pressure levels during the cruising time inside the tunnel are computed. In addition to overall SPLs(Sound Pressure Levels), 1/3-octave-band levels are also analyzed to account for the frequency characteristics of sound absorption and equipment noise in a cabin. In addition, to consider the effects of train cruising speeds and environmental conditions on the measurements, the measured data are corrected by using those measured during the train-passing through the tunnels located before and behind the Dalseong tunnel. Analysis of measured results showed that the maximum noise reduction of 6.8 dB (A) can be achieved for the local region where the sound-absorbing blocks are installed. Finally, through the comparison of predicted 1/3-octave band SPLs for the KTX interior noise with the measurements, the understanding of noise reduction mechanism due to sound-absorbing blocks is enhanced.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.9
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• pp.14-23
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• 2010

This paper reports the fabrication of a DVB-T/H System in Package (SiP) that is able to receive and process the DVB-T/H signal. The DVB-T/H is the European telecommunication standard for Digital Video Broadcasting (DVB). An IC-embedded Printed Circuit Board (PCB) process, interpose a chip between PCB layers, has applied to the DVB-T/H SiP. The chip inserted in DVB-T/H SiP is the System on Chip (SoC) for mobile TV. It is comprised of a RF block for DVB-T/H RF signal and a digital block to convert received signal to digital signal for an application processor. To operate the DVB-T/H IC, a 3MHz DC-DC converter and LDO are on the DVB-T/H SiP. And a 38.4MHz crystal is used as a clock source. The fabricated DVB-T/H SiP form 4 layers which size is $8mm{\times}8mm$. The DVB-T/H IC is located between 2nd and 3rd layer. According to the result of simulation, the RF signal sensitivity is improved since the layout modification of the ground plane and via. And we confirmed the adjustment of LC value on power transmission is necessary to turn down the noise level in a SiP. Although the size of a DVB-T/H SiP is decreased over 70% than reference module, the power consumption and efficiency is on a par with reference module. The average power consumption is 297mW and the efficiency is 87%. But, the RF signal sensitivity is declined by average 3.8dB. This is caused by the decrease of the RF signal sensitivity which is 2.8dB, because of the noise from the DC-DC converter.

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.2
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• pp.92-98
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• 1988

With a purpose of finding out the effects of magnesium and boron enriched organic-compound fertilizer application on the dry matter yield, yield components and changes in the botanical composition on the hilly pasture, a field experiment was arranged with five different treatments as a randomized block desigh and lasted from September, 1984 to the end of growing season in 1986. The results obtained are summarized as follows: 1. As a early plant growth and development, winter hardiness, growth vigour and coverate of grasses at the plots with organic-compound fertilizer application were better comparing to single dressing. 2. Average dry matter yields for two years were shown significantly high due to increasing amount of fertilizer. This trend was same both single and organic-compound fertilizer. And dry matter yields with organic-compound fertilizer application of low (8,693.1 kg/ha) and conventional level (12,758.7 kg/ha) were appeared to increase by 10 and 15% than those of single dressing of Low (7,930.6 kg/ha) and conventional level (11,122.6 kg/ha), respectively. But it was not significant difference. 3. Dry matter yield of grasses was significantly gained by increasing amount of fertilizer. The yield of legumes at the plots with organic-compound fertilizer application the yields of grasses were a litle more increased by 8-14%, and legumes were much more gained by 26-29% than those of the same species groups with single dressing, but it was not significant between the differnet kinds of fertilizer in the same fertilizing level. 4. At the grassland management, the rate of legumes tended to dominate at the plot without fertilization gradually. On the other hand, the botanical compositions and the rates of grasses were much better maintained at the plots with fertilization. But the rates of legumes with organic-compound fertilizer application tended to increase a little more than those of single dressing gradually. 5. All of the soil chemical properties after the experiment were much more improved comparing to before the experiment. But the average contents of soil organic matter and available $P_2O_5$ were slightly higher at the plot with organic-compound fertilization, on the other hand, pH and exchangeable cations tended to a little less than those of single dressing.

• Progress in Medical Physics
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• v.19 no.1
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• pp.73-79
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• 2008

Retinal prosthesis is regarded as the most feasible method for the blind caused by retinal diseases such as retinitis pigmentosa (RP) or age related macular degeneration (AMD). Recently Korean consortium launched for developing retinal prosthesis. One of the prerequisites for the success of retinal prosthesis is the optimization of the electrical stimuli applied through the prosthesis. Since electrical characteristics of degenerate retina are expected to differ from those of normal retina, we performed voltage stimulation experiment both in normal and degenerate retina to provide a guideline for the optimization of electrical stimulation for the upcoming prosthesis. After isolation of retina, retinal patch was attached with the ganglion cell side facing the surface of microelectrode arrays (MEA). $8{\times}8$ grid layout MEA (electrode diameter: $30{\mu}m$, electrode spacing: $200{\mu}m$, and impedance: $50k{\Omega}$ at 1 kHz) was used to record in-vitro retinal ganglion cell activity. Mono-polar electrical stimulation was applied through one of the 60 MEA channel, and the remaining channels were used for recording. The electrical stimulus was a constant voltage, charge-balanced biphasic, anodic-first square wave pulse without interphase delay, and 50 trains of pulse was applied with a period of 2 sec. Different electrical stimuli were applied. First, pulse amplitude was varied (voltage: $0.5{\sim}3.0V$). Second, pulse duration was varied $(100{\sim}1,200{\mu}s)$. Evoked responses were analyzed by PSTH from averaged data with 50 trials. Charge density was calculated with Ohm's and Coulomb's law. In normal retina, by varying the pulse amplitude from 0.5 to 3V with fixed duration of $500{\mu}s$, the threshold level for reliable ganglion cell response was found at 1.5V. The calculated threshold of charge density was $2.123mC/cm^2$. By varying the pulse duration from 100 to $1,200{\mu}s$ with fixed amplitude of 2V, the threshold level was found at $300{\mu}s$. The calculated threhold of charge density was $1.698mC/cm^2$. Even after the block of ON-pathway with L-(1)-2-amino-4-phosphonobutyric acid (APB), electrical stimulus evoked ganglion cell activities. In this APB-induced degenerate retina, by varying the pulse duration from 100 to $1200{\mu}s$ with fixed voltage of 2 V, the threshold level was found at $300{\mu}s$, which is the same with normal retina. More experiment with APB-induced degenerate retina is needed to make a clear comparison of threshold of charge density between normal and degenerate retina.

• Journal of Navigation and Port Research
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• v.28 no.1
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• pp.59-67
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• 2004

As the environment for international logistics varies according to the globalization in world economy, world-class seaports are struggling for the position as strongholds in their own block. As a new government begins its own era in Korea, they are positively implementing their strategies at the level of government for making the Korean Peninsula the logistics centre in North-eastern Asia, marking the most of its geographic advantage. As one of those strategies, it plans to foster a specific area as an international logistics base camp in Northeast Asia by activating its logistics industry through inducing multinational logistics enterprises. In reality, however, in order for Busan seaport, the late-comer, to induce investment from the world-class multinational companies, a considerably large volume of investment should be given from both central and local governments. Accordingly, the objective of this study is to assess its competitiveness and to suggest an activation plan for BSDFA(Busan Seaport Duty-Free Area), based upon the results of on-the-spot interviews in China and Japan. The survey for the respondent's preference by way of Conjoint Analysis indicated that Investment procedures and limitations get the highest 36.2％ preference, so the most critical strategy to be considered for attracting enterprises into DFA(Duty-Free Area) is to solve the problems related to the investment procedures and limitations. The simulation analysis results for market share showed that UAE has the highest preference and BSDFA the lowest preference among the five countries. However, when the levels of investment procedures and limitations and production costare upgraded, the competitiveness of BSDFA was elevated next to that of UAE among the 5 countries. Thus, in order for BSDFA to obtain competitiveness, it is implied that production cost level as well as investment procedures and limitations level, should be lowered so that it could meet companies' demand.