• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.1
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• pp.32-38
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• 2005

The efficacy of bioresorbable fixation has recently been described in the osseosynthesis of the oral & maxillofacial region. However, a liitle data exist regarding the use of biodegradable plates and screws for the internal fixation of human mandible fractures. The purpose of this study is to analyze and compare the treatment of mandibular fractures by using a bioresorbable fixation system with conventional titanium system in human mandible fractures. eighteen patients constituted the bioresorbable fixation group and twenty-five patients constituted the titanium fixation group. Both groups underwent open reduction and internal fixation by use of a bioresorbable system or a titanium fixation system. Panoramic radiograph were obtained preoperatively, immediately postoperatively after reduction, at 6 months and at 12 months postoperatively. In the bioresorbable fixation group, complication(infection) occurred in 1 patient(5.6%) and was resolved by incision & drainage, plate removal and antibiotics without untoward sequelae. 2 patients(8.0%) experienced complications in the titanium fixation group and were treated using conservative treatment. There was no statistical difference in complication rates between two groups. Our data supported the use of bioresorbale plate fixation in mandibular fractures as a means of avoiding the potential and well documented problems with rigid titanium fixation systems. In conclusion, the bioresorbable fixation system provide a reliable and sufficient alternative to conventional titanium plate system.

• Journal of the Korea Concrete Institute
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• v.16 no.2 s.80
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• pp.229-240
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• 2004

Many experiments have been performed to investigate eccentric shear strength and unbalanced moment-carrying capacity of flat plate-column connections under combined gravity and lateral load. However, each existing experiment used different test setup, and the shear strength of the connection was different depending on the test setup. Current design methods which were based on the experimental results might not accurately explain the shear strength of the flat plate. In a companion study, based on results of nonlinear finite element analyses, an alternative design method for the plate-column connection was developed. However, in this method, eccentric shear strength of the connection which was required for assessing unbalanced moment-carrying capacity was evaluated by an empirical formula. In the present study, a theoratical approach using Rankine's failure criterion was attemped to investigate failure mechanism of the eccentric shear. Based on the results, an improved strength model of the eccentric shear was developed, and it was verified by comparison with the existing experimental results. By means of the strength model, the design method developed in the companion study was re-verified.

• The Journal of Fisheries Business Administration
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• v.32 no.2
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• pp.73-89
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• 2001

The market conditions of sea mustard is changing by overproduction, decreasing price, Import of blanched and salted sea mustard from China into Korea domestic market and increasing market share of sea mustard of China in Japan. In addition, the price support program in sea mustard aquaculture must be modified due to the restriction of domestic support by international organization such as WTO. There are two ways to solve those problems. First is that finding a way to solve the overproduction of sea mustard. One of possible ways is the production adjustment by Marketing Order. Second is that finding an alternative way to replace price support program. The possible way is Direct Payment instead of purchase stockpile system. To introduce marketing Order, outlook center, organization of self-management, production adjustment through output control measure, improvement of market structure, and education/publicity arc necessary. Also, to implement marketing order, setting a model business by government is required. There are two steps for implementation of marketing order. First step is to construct Order Committee including organization of producer, people related marketing. However, this committee must run by government for certain short-term. Second step is to improve quality of product and acceleration of demand. At visual point that enforcement of the first step is completed, government has process that government transfers Order Committees self-correcting. It is desirable that government only conduct the support acts such as quality improvement and acceleration of demand. Also, at early stage it is necessary to have aid system for marketing order For example, we can expect that income increase by production adjustment in long run. However, in short run the income of producer may decrease so, it is required to compensate his economic lose. For compensation, The useful means that can be utilized is direct payment. Direct payment is not continued policy. Also, when production adjustment policy such as Marketing Order has effective results, Direct Payment as an assistant measure must be reduced or abolished. Therefore, when production adjustment acts as an effective tool to control overproduction, Direct Payment system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.9 no.1
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• pp.63-70
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• 1989

The numerical model for the flood routing at the downstream of the Han river is established by using Preissmann's four-point linear implicit finite difference scheme. It is approved by the applications of this model to the selected four flood events that the released discharge hydrograph at Paldang dam which is used as upstream boundary condition of this model is better than the discharge hydrograph at Goan site. Such a result is due to the poor reliability of rating curve at Goan site. As its alternative, new rating curve at Goan site is proposed by means of applications of this numerical flood routing model. The variations of Manning's roughness coefficient may be negligible in view of the flood routing results.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1631-1638
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• 2013

Distress data, IRI, etc. are important factors in the evaluation of pavement condition. Recently, the need to consider tire-pavement noise in PMS (pavement management system) is raised. Generally, tire-pavement noise highly depends on the characteristics of pavement texture. Therefore, estimation of texture characteristics may give useful information to predict tire-pavement noise. Measurement of MPD (Mean Profile Depth) by using PLP (Portable Laser Profiler) provide very fast. The texture characteristics by means of MPD can be in a short time. hence, It can be a good alternative to give noise information, if MPD and tire-pavement noise have robust relationship. In this study, MPD and tire-pavement noise were simultaneously collected on the number of asphalt section to evaluate the tire-pavement noise due to the pavement texture characteristics. A set of statistical analysis was performed to propose relationship between tire-pavement noise and MPD for asphalt concrete pavement.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2005.11a
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• pp.31-43
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• 2005

Isoflavones are naturally occurring plant chemicals belonging to the 'phytoestrogen' class. The isoflavones are strikingly similar in chemical structure to natural estrogens. The phenolic ring is a key structural element of most compounds that bind to estrogen receptors. Dietary components that recently have received attention for their action as phytoestrogens are soy isoflavones. Soy products are the most significant dietary sources of isoflavones. Recently It is concerned clinical nutrition of isoflavone that is driven by reason of alternative sources of exogenous estrogen are constantly being needed. Estrogen therapy after the menopause offers protection from cardiovascular disease, reduces the extent of osteoporosis and relieves menopausal symptoms. Exogenous estrogen treatment is a fear of possible increased risk of developing breast cancer and because of side effects. Daily intake of soybean or soy food can affirmative effect to disease occurrence, that is based on mechanical investigation, experimental results of animals and human. Research into isoflavone is going on various field to relieve hormone - dependent disease such as cancer, menopausal symptom, cardiovascular disease and osteoporosis. Isoflavone is plenty in soybean meal, soy by-product, but only limited information is available on isoflavone efficacy into animal husbandry. Thus we conducted three experiments to investigate the effects of dietary isoflavone on productivities, antioxidative responses and bone metabolism in poultry. Dietary supplementation of isoflavone resulted in preventing the lipid oxidation of plasma and egg yolk. Dietary isoflavone improved bone development in egg-type growing chicks and broilers in terms of tibial strength. It was suggested that the proper use of feed additives such as isoflavone might provide means of improving antioxidative effect, skeletal strength, egg and eggshell quality.

• Journal of the Korean School Mathematics Society
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• v.19 no.1
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• pp.63-82
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• 2016

Mathematical notation is the main means to realize the power of mathematics. Under this perspective, this study analyzed the difficulties of learning an irrational number concept in terms of notation. I tried to find ways to overcome the difficulties arising from the notation. There are two primary ideas in the notation of irrational number using root. The first is that an irrational number should be represented by letter because it can not be expressed by decimal or fraction. The second is that $\sqrt{2}$ is a notation added the number in order to highlight the features that it can be 2 when it is squared. However it is difficult for learner to notice the reasons for using the root because the textbook does not provide the opportunity to discover. Furthermore, the reduction of the transparency for the letter in the development of history is more difficult to access from the conceptual aspects. Thus 'epistemological obstacles resulting from the double context' and 'epistemological obstacles originated by strengthening the transparency of the number' is expected. To overcome such epistemological obstacles, it is necessary to premise 'providing opportunities for development of notation' and 'an experience using the notation enhanced the transparency of the letter that the existing'. Based on these principles, this study proposed a plan consisting of six steps.

• Applied Chemistry for Engineering
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• v.27 no.3
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• pp.252-258
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• 2016

The weight reduction and improved mechanical property are one of the prime factors to develop new materials for the aerospace industry. Composite materials have thus become the most attractive candidate for aircraft and other means of transportations due to their excellent property and light weight. In particular, fiber reinforced polymer (FRP) composite materials have been used as an alternative to metals in the aircraft. The composite materials have shown improved properties compared to those of metal and polymeric materials, which made the composites being used as the skin structure of the airplane. This review introduces different types of materials which have been developed from the FRP composite material and also one of the most advantageous ways to employ the composites in aircraft.

• Korean journal of food and cookery science
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• v.4 no.1
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• pp.27-32
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• 1988

The almost similar degumming effect was obtained by using oxalic acid instead of phosphoric acid, which also improves waste-water treatment. At this point, solution of Phosphoric, Acetic, Citric, Oxalic, and Nitric acid were used for degumming of rapeseed and soybean oil. Compared with Phosphoric(PA) and Oxalic acid(OA) were showed a simillar degumming effect in these vegetable oils. In rapeseed oil of 85% PA treating group and 5,10% OA fretting group, residual soap and phosphorus content in neutralized oil, color in bleached oil, and peroxide value and fatty acid content in deodrized oil were showed to simillar result. Soybean oil as well as rapeseed oil were showed to similar result. As a result, we could comfirmed substitutive possibility, which change PA into OA as a degumming agent. In the other hand, waste waters were obtained from 55% PA treating group and 10% OA treating group. Analytical result for this waste waters has showed a wide difference, especially in the BOD and COD. The amount of treating agents and time required in the precipitation seperation and chemical treatment each 3 and 1.7 times, which is PA treating group than OA treating group. We have investigated both the simillar degumming effect by OA solution and an alternative the pollution program means of a chemical treatment process is not possible.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.11
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• pp.1634-1638
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• 2002

Quantification of endogenous amino acid loss at the terminal ileum is an essential means for calculation of the true amino acid digestibility of a feedstuff. Since nitrogen appeared in the determined diet or not could shift the results very much, also, none of digestibility markers could be recovered with 100% rate at the terminal ileum, the objectives of the present study were: (1) to determine endogenous amino acid losses when fed either a casein diet or a protein-free diet and (2) to examine the reliability of chromic oxide or acid insoluble ash in the protein-free diet. Six ileal-cannulated pigs ($65{\pm}1.85 kg$ BW) with a simple T-cannula in the terminal ileum were used in a replicated $3{\times}3$ Latin square designed trial, after allowed a 14 d recuperation period. Each test period ran for 12 days comprised of a 10 d adjustment period and a 2 d collection period. The endogenous AA losses of His, Ile, Lys, Cys, Thr, Val, Trp, Asp, Glu, and Ser from pigs fed the casein diet were significantly higher than those of the protein-free diet (p<0.05). No significant difference was found in the amount of endogenous amino acid loss when determined with the different markers in the protein-free diet (p>0.05). These data suggest that endogenous amino acid loss could be underestimated when a protein-free diet is used. A direct effect of dietary peptides on the endogenous amino acid loss was found when the casein diet was fed. Our results also indicate that acid insoluble ash can be used as an inert marker as an alternative to chromic oxide when measuring endogenous amino acid loss.