• Journal of Dental Rehabilitation and Applied Science
• /
• v.24 no.2
• /
• pp.169-181
• /
• 2008

The aim of this study was to compare the retention and stability of implant overdenture according to the shape and the number of magnetic attachment. The experimental groups were designed for the number of implants(1, 2, 4) and shape of magnetic attachments(flat, cushion, dome type) resulting in 9 subgroups. 45 attachments were tested attached to $Br{\aa}nemark$ system implants which were planted on a mandibular model. Each attachment was composed of the magnet assembly embedded in a overdenture sample and the abutment keeper screwed into the implants. Dislodging tensile forces were applied to the overdenture samples using an Instron(cross-head speed 50.80mm/min) in 3 directions simulating function: vertical, oblique, and anterior-posterior. The loading was repeated 10 times in each direction for 45 samples. The values of maximum dislodging force of each subgroup were processed statistically using SPSS V. 12.0 at the 0.05 level of significance. The results of this study were as follows: 1. Flat type magnetic overdenture was the most retentive when subjected to vertically directed forces and dome type was the lest retentive when subjected to obliquely directed forces(p<0.05). 2. In case of planting one implant, flat type had a higher vertically retentive force than anterior-posteriorly retentive force. In case of planting two implants, flat type and dome type had a higher vertically retentive force and in case of planting four implants, flat type and cushion type had a higher vertically retentive force than anterior-posteriorly retentive force(p<0.05). 3. The incremental number of dental implant, without regards to the three types of magnetic attachment shapes, showed higher retention of overdenture(p<0.05). From the results, if a patient need much more retention of implant overdenture, flat type magnetic overdenture would be a good treatment. In case of the bruxism where excessive lateral forces are already present, dome type could be expected to produce better results. In case of planting one implant, flat type is more stable than the other shape of magnet and in case of two implant, flat type and dome type are more stable and in case of four implants, flat type and cushion type are more stable. Planting more than two implants and using flat type magnetic attachment would provide better retention and stability of implant overdenture

• The Korean Journal of Air & Space Law and Policy
• /
• v.20 no.2
• /
• pp.59-158
• /
• 2005

When a military aircraft suffers damages due to the defects in its design, manufacturing or notification, all of which are generally understood as products liability defects, the obvious compensation is sought as it would in other consumer good case. However, there exist clear yet unappreciated difference between general consumer goods and military aircraft, as far as products liability law is concerned - some sort of recovery should be obtained even when there exist only defects, not damages, to the aircraft because of the implication of defective parts is much grave than what can be expected in a consumer goods case. While certain anticipatory measures do exist in manual or at negotiation stages for the safety of military aircraft, such measures are ineffective, if not ambiguous, in recovery effort in the post-accident stage In another word, the standardized military procurement contract manuals and boilerplate forms do not appreciate the unique and dangerous military nature of military aircraft. There are many unique legal issues which can arise when trying to prevent defective aircraft or parts, or to recover compensations for accident due to such defects. At two-level, the government should establish legal system (or countermeasures if you'd like) for purchasing safer military aircraft. First, one should be able to work with legal ground and policy that allows selecting and purchasing safer goods - the purpose of such contract is not litigious, but rather in acquiring what are most reliable. Second, in case the defects do arise and lead to damages, solid legal principles and instructions should be established for effectively pursuing appropriate company, (usually a aerospace industry giant with much experience) for products liability - the purpose of such pursuit is inevitable for a public official, since he or she is no private business man with much flexibilities, even to the point of waiving such compensatory right for future business purposes. This article tries to identify problems in methods of procuring military aircraft or parts - after reviewing on how the military can improve on legal and policy grounds for procuring what will be the focus of future military strength, it will offer some of the ways to effectively handling and resolving a liability issues.

• The Journal of Korean Academy of Prosthodontics
• /
• v.49 no.1
• /
• pp.57-64
• /
• 2011

Purpose: The purpose of this study was to compare the cleansing performance of a distilled water, a diluted solution of sodium hypochlorite as a household bleaching cleanser and three alkaline peroxide cleansers in vivo plaque deposits by using scanning electron microscope. Materials and methods: Five individuals were selected from department of the prosthodontics in Pusan National University Hospital, and each of them was inserted with specimens for plaque accumulation in their temporary dentures for 48 hours. The specimens were removed and cleaned by each cleansing agents for 8 hours. Scanning electron micrographs were made from the specimens at a magnification of ${\times}2,000$. A panel of ten persons with a dental or paradental background, but not directly involved in the study, was selected to analyze the photomicrographs to determine which denture cleanser was more effective in removing plaque. Results: Diluted solution of sodium hypochlorite was the most effective at removing plaque following $Polident^{(R)}$, $Cleadent^{(R)}e$, $Bonyplus^{(R)}$ and distilled water in order. But there was no significant difference of cleansing efficacy between diluted solution of sodium hypochlorite and $Polident^{(R)}$, $Polident^{(R)}$ and $Cleadent^{(R)}e$, $Cleadent^{(R)}e$ and $Bonyplus^{(R)}$, respectively (P > .05). Alkaline peroxide cleansers by themselves cannot adequately remove accumulated plaque deposits, especially if the deposits are heavy. Corrosion could be seen on the surface of non-precious alloy specimens immersed in diluted solution of sodium hypochlorite. Conclusion: It is recommended to use of alkaline peroxide type cleansers with brushing whenever possible, since denture cleanliness is often poor due to the relative inefficiency of these cleansers.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.36 no.3
• /
• pp.404-411
• /
• 2009

Drinking water has lots of minerals, especially calcium, sodium, kalium, magnesium, and fluoride must be labelled on the bottle about their contents. Minerals like calcium, magnesium, and fluoride have influence to the tooth development. Appropriately taking some minerals, dental caries can be prevented somewhat degree. There is no guide line about innoxious minerals like calcium and magnesium, however, noxious mineral like fluoride, should be contained less than 2 mgF/L according to the current drinking water standard. Hereupon, it is necessary to recognize the concentration of fluoride in drinking water, so I studied 15 samples of domestic drinking water on sale about the concentration of calcium and magnesium, fluoride. The results obtained were as follows ; 1. 14 drinking waters in 15 samples showed various Ca concentration. The average Ca concentration is 34.68${\pm}$31.84 mg/L, the highest is 128.91${\pm}$1.85 mg/L and the lowest is 2.0${\pm}$0.02 mg/L. 2. 13 drinking waters in 15 samples indicate the Mg concentration. The average concentration is 9.22${\pm}$11.06 mg/L, the highest is 30.43${\pm}$0.75 mg/L and the lowest is 0.0 mg/L. 3. 11 drinking waters in 15 samples indicate the F concentration. The average concentration is 0.25${\pm}$0.33 mg/L, the highest is 1.13${\pm}$0.04 mg/L and the lowest is 0.01${\pm}$0.03 mg/L. All samples are satisfied the current drinking water standard, 2 mg F/L.

• Journal of Bio-Environment Control
• /
• v.17 no.2
• /
• pp.150-156
• /
• 2008

The influences of night break by costly artificial light sources were investigated on the photo-morphogenesis and growth of leafy perilla (Perilla ocymoides L.). The irradiation of red, blue, and three-colored light for night break significantly increased the stem length and stem diameter compared to dark. Three-colored light gave the highest fresh and dry weight of stem, followed by red and blue light. Floral induction was suppressed up to 100 days after the night break, by red and three-colored light, but the plants grown under the dark or treated with blue light showed 85% and 31% flowering rate, respectively. The time needed for floral induction after night break was 60 days in dark and 80 days in blue light. The number of leaf, leaf area, and fresh weight per plant were the highest in red and three-colored light night break, followed by blue light and dark. The photosynthetic rate observed 80 days after night break was the highest in red light, followed by blue and three-colored light. A low light compensation point of $20\;{\mu}mol\;m^{-2}{\cdot}s^{-1}$ was observed in three-colored light, while red and blue light tended to show higher measurements.

• Journal of Bio-Environment Control
• /
• v.25 no.4
• /
• pp.343-350
• /
• 2016

The aim of this study was to evaluate effects of immature compost on the amount of nutrient content, heavy metal concentration, and application rate that were used for lettuce cultivation. The characteristics of the two composts (Compost A (CA) was immature compost and Compost B (CB) was mature compost) were evaluated upon mixing with commercial soil at 0%, 25%, 50%, and 75% (w/w). The poor chemical characteristics were appeared by use of immature compost as soil amendment; the 50% and 75% rates were weakly acidic at pH 5.39 and 5.50, respectively. The total carbon content at using of 75% of the immature compost and mature compost increased the most to 14.5 and 6.5% and it significantly increased concentrations of the total nitrogen and phosphorus compared to control. As for 75% mature compost rate increased significantly the concentrations of Cu ($128mg\;kg^{-1}$), Zn ($260mg\;kg^{-1}$), Pb ($0.32mg\;kg^{-1}$) and, Cd ($0.48mg\;kg^{-1}$) compared to control, and the highest As concentration increased significantly at 75% and 50% (6.69 and $6.28mg\;kg^{-1}$) including in 25% immature compost as $6.48mg\;kg^{-1}$. However, all of the high compost rates significantly decreased the shoot biomass of lettuce. The immature compost was potentially amended at an application rate of 25% due to a slight salinity and low risk to heavy metal uptake on lettuce growth. This use may be available if the rate is lower than that used in this trial.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.7 no.3
• /
• pp.45-53
• /
• 2012

This study is about the impact of a technology-based start-ups' patent-related activities on early stage company performance. Technology-based start-ups are closely related to the intellectual property rights, particularly patents that they aim the pursuit of new products or production methods and pioneer the introduction of market based on innovative technology, and that is a key role in such companies established and operating, hence the research of patent-related activities in technology-based start-ups has important implications. In most previous studies, the impact of the company's patent related activities on the performance of corporate management is determined by using quantitative patent indicators. Therefore, through this study, causal relationships leading to business performance through the development of new products, which includes technology performance and product performance, and the patent-related activities including the company's patented technology support activities, creating the right activities, infringement response activities, base activities validated as follows. First, the patent-related activities have a positive impact on technological and products achievements. In other words, the various activities involved in the acquisition and utilization of the patent have a positive impact on the performance of company's new product development, particularly developing new technologies or patent acquisition rate. Second, the technology have a positive impact on the performance of the products, not on the business performance. However, the empirical results shows that it has indirectly impacts on business performance through the product performance. Third, product performance have a positive impact on business performance. In conclusion, patent-related activities affects the performance of the company's management, and the maintenance of the company's business performance depends on the developing and selling product based on the customers needs, besides the technology performance such as the patents and the development of technology.

• Journal of Plant Biotechnology
• /
• v.36 no.1
• /
• pp.30-37
• /
• 2009

Tissue-type plasminogen activator (t-PA) is a thrombolytic agent important in fibirn clot lysis. T-PA causes fibirn-specific plasminogen activation. Six binary vectors harboring t-PA and its derivative genes were cloned and expressed in transgenic alfalfa plants. The insertion of the t-PA and its derivative genes in genomic DNA of alfalfa plants was confirmed by PCR. The presence of the t-PA and its derivative transcripts in total RNAs of the transgenic alfalfa leaves was verified by RT-PCR. ELISA experiments demonstrated that the highest level of recombinant t-PA expression was $75.1{\mu}g$/ total soluble protein (mg) in alfalfa plants. The amount of recombinant t-PA and its derivative proteins in transgenic plants was estimated to range from 9.7 to $39.5{\mu}g$/ total soluble proteins (mg). Western blot analysis of the transformed alfalfa leaves revealed bands of approximately 68-kDa recombinant t-PA and its derivative proteins. The fibrinolysis of recombinant t-PA and its derivative proteins was confirmed by a fibrin plate assay (range from 3.2 to 8.1 cm). The results presented provide information for the development of an additional production of recombinant human proteins having pharmaceutical applications using transgenic plants.

• Korean Journal of Poultry Science
• /
• v.44 no.1
• /
• pp.51-57
• /
• 2017

Subsequent to the introduction of the "Laws on Consumption Promotion of Livestock Products" in 2002, a mandatory check-off system for the egg industry was introduced in June 2009. Unlike other livestock products, the check-off on eggs is financed not from the sale of the egg-the end product-but from the spent hen. Variables such as the falling price of spent hens lead to a low financing rate; The present farm allotment rate of 14%, introduced in 2015, is much higher than the 0.2% to 0.3% check-off rate in other types of business, thus placing a huge burden on farms. When check-off is financed from the egg, it is expected that 6.5 billion won will be raised using a rate of 0.3% of sale proceeds, Therefore, it is urgent for the government to establish infrastructure to enable producers and merchants to do business through Grade & Packing centers. This can be achieved by the staged construction of local Grade & Packing centers. Check-off should continue to be financed from the present spent hen until this infrastructure is established, and an institutional strategy should be provided by the government to raise the financing rate accurately and transparently using statistical treatment of supply data for spent hens as a short-term alternative.

• Korean Journal of Poultry Science
• /
• v.44 no.1
• /
• pp.11-18
• /
• 2017

The purpose of this survey was to collect basic data on breeding systems of animal welfare-approved laying hen farms in Korea. Questionnaires were mailed to 64 animal welfare-approved farms, and 20 questionnaires (31.3%) were returned. The housing systems were fabric coverlet (4 farms, representing 20%), naturally farmed (Yamagisi, 7 farms, 35%), and steel panel-framed housing (9 farms, 45%). The 20 farms had stocking densities of $2{\sim}3birds/m^2$ (2 farms; 10%), $4{\sim}5birds/m^2$ (10 farms; 50%), and $6{\sim}7birds/m^2$ (8 farms; 40%). Breeding methods were floor-housed (14 farms; 70%), free-range (3 farms; 15%), and floor plus free-range (3 farms; 15%). Stocking density was $4{\sim}6birds/m^2$ at most of the farms with fabric coverlet and naturally farmed housing and $6{\sim}7birds/m^2$ at seven farms (of 9 farms) with a steel panel-framed housing. The daily feed intake of 11 farms (55%) was between 120 and 130 g, which included 3 farms (15%) with fabric coverlet, 3 farms (15%) with naturally farmed housing, and 5 farms (25%) with steel panel-framed housing. The age of peak production was 24~28 weeks overall 20 farms. Over 80% of production on fabric coverlet, naturally farmed, and steel panel-framed house farms was on 3, 4 and 6 farms, respectively. Respiratory disease on the 20 farms represented 55% of total disease incidence, and of each housing type represented 75% (fabric coverlet), 70% (naturally farmed) and 33% (steel panel-framed). E. coli disease was only found in the steel panel-framed housing. Most of the animal welfare-approved eggs were sold at large markets or a real sale markets. Egg price was 200~250 won per egg. These results indicate the current situation of animal welfare-approved farms and could be caused that windowless poultry house was applied to animal welfare approved farms.