• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.7
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• pp.841-855
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• 1999

In the present work, the effect of a flow maldistribution on the thermal and conversion response of 8 monolith catalytic converter is Investigated. To achieve this goal, a combined chemical reaction and multi-dimensional fluid dynamic mathematical model has been developed. The present results show that flow uniformity within the monolith brick has 8 great impact on light-off performance of the catalytic converter. In the case of lower flow uniformity, large portions of the monolith remain cold due to locally concentrated high velocities and CO, HC are unconverted during warm-up period, which loads to retardation of light-off. It has been also found that the heat-up pattern of the monolith ill similar to the flow distribution profile, In the early stage of the reaction. It may be concluded that flow maldistribution can cause a significant retardation of the light-off and hence can eventually worsen tho conversion efficiency of automotive catalytic converter.

• Polymer(Korea)
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• v.35 no.4
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• pp.337-341
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• 2011

To expand the viewing angle of vertical alignment liquid crystal display (VA-LCD), a wide-band compensation film has been newly developed. VA-LCD needs a retardation film with improved oblique viewing property. The retardation film for VA-LCD has been fabricated by solvent casting and subsequent drawing triacetylcellulose (TAC) containing optical additives. Here, optical birefringence and wavelength dispersion of the retardation film strongly depend on the chemical structures of optical additives. Utilizing quantum mechanical computation, the polarizing anisotropy of retardation film was calculated with respect to additives. It is also realized that the wavelength dispersion of polarizing anisotropy depends on the type and location of substituent to the selected main isomer. When two propionates are substituted to the meta position of the selected main isomer, the wavelength dispersion of polarizing anisotropy shows the most gentle slop, which is well matched with the experimental results. The most gentle slop of wavelength dispersion means that the viewing angle characteristics of LCD are less influenced according to the wavelength of light source of LCD, and it's possible to make better image quality than the present level.

• 재활복지
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• v.21 no.1
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• pp.141-171
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• 2017

The purpose of this study is to investigate the job experience of the life rehabilitation teacher who is working in the residence with mental retardations. The purpose of this study is to suggest the intervention plan that can enhance the capacity of the living rehabilitation teachers and seek improvement points of residence institution of mental retardation. The results of this study show the meaning of experience in the job performance of the welfare facility workers. Through in -depth interviews through the candid stories of the research participants during the research, meaningful results could be obtained. There are 7 workers who participated in the study who worked in the institute for more than a year. Four sections are categorized made of 15 sub-categories constituted by 60 subjects collected by significant worker's answers. Four categories are the beginning of life rehabilitation teacher, adaptation as a life rehabilitation teacher, the pain of life rehabilitation teacher, the growth and the wish. The results of this study are expected to contribute to the improvement of the professionalism of the life rehabilitation teacher. It will also contribute to the development of the operation of residential facilities for people with mental retardation.

• Proceedings of the Korean Society For Composite Materials Conference
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• 1999.11a
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• pp.198-203
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• 1999

2D carbon/carbon composites have been prepared with and without addition of 1, 3 and 5wt% of oxidation inhibitor boron and then heat teated up to 1700, 2000, 2300, 2600 each. This paper presents the effects of boron on the mechanical properties of 2D C/C composites in terms of the acceleration of graphitization and also discussed about the retardation of air oxidation.

• Journal of Genetic Medicine
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• v.7 no.1
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• pp.37-44
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• 2010

Purpose : Kabuki syndrome is a multiple congenital malformation syndrome with mental retardation. It was named after its characteristic appearance, a face resembling that of an actor in a Kabuki play. To date, six Korean cases of Kabuki syndrome have ever been reported. Here, we present the phenotypic and genetic characteristics of six patients with Kabuki syndrome. Materials and Methods : Between 2003 and 2009, six Korean girls have been diagnosed and followed up as Kabuki syndrome at Center for Genetic Diseases of Ajou University Hospital. Their clinical and laboratory data were collected and analyzed by the retrospective review of medical records. Results : All six patients showed the characteristic facial dysmorphism and developmental delay. Persistent fingertip pads were also found in all patients. Most patients showed postnatal growth retardation (83.3%) and hypotonia (83.3%). Opthalmologic problems were common, particularly for strabismus (83.3%). Congenital heart defects were present in three patients (50%). Skeletal abnormalities including 5th finger shortening (83.3%), clinodactyly (50%), joint hypermobility (50%) and hip dislocation (16.7%) were also observed. There was no patient who had positive family history for Kabuki syndrome. Cytogenetic and molecular cytogenetic analyses including karyotyping and array CGH could not reveal any underlying genetic cause of Kabuki syndrome. Conclusion : Korean patients with Kabuki syndrome showed a broad spectrum of clinical features affecting multiple organ systems. Although clinical manifestations of Kabuki syndrome have been well established, our results failed to detect recurrent chromosome aberrations which could cause Kabuki syndrome. Its natural history and genetic background remains to be further studied for providing appropriate management and genetic counseling.

• The Journal of Korean Medicine
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• v.24 no.1
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• pp.1-8
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• 2003

Purpose : Nowadays, there are many studies of growth retardation treatment by oriental medical therapy. This study was performed to evaluate the effect of Hwalhyulsungjang-san (Huoxuechengzhang-san) and KC101 on physical development in growth, Methods : 60 young (3 weeks old) male rats, whose mean weight was $46.8{\pm}0,7g$, were divided into 5 groups : groups A, B, C, and D were fed an experimental diet containing respectively Hwalhyulsungjang-san 2.5%, Hwalhyulsungjang-san 7.5%, KC101 5.0%, and KC101 10.0%, and the other group were fed an AIN-diet containing neither Hwalhyulsungjang-san nor KC101 as a control. Study of each group used 2 rats and was repeated in 6 times. Body weight, daily weight gain, dietary intake, body length, femur length, backbone length and serum concentration of IGF-I and hemoglobin were measured. Result : 1. Body weight and daily weight gain of group D (KC101 10%) were highest; dietary intake of group D was also increased by 13% over the control group. 2. Average body length of group D was increased to 1.69cm, which was 3.2% over the control group. Backbone length of group D was also increased 4% compared to control group. 3. Serum concentration of IGF-I of group D increased 17% compared to control group. 4. Serum concentration of hemoglobin of group B (Hwalhyulsungjang-san 7.5%) increased 8% compared to control group. Conclusion : This study showed that Hwalhyulsungjang-san and KC101 composed of oriental medicinal stuffs have effect on physical development in growing rats. There were not any statistical meaning compared to control group, but this study suggests that intake of these compounds from a young age may lead to increase physical development in growth.

• The Journal of Pediatrics of Korean Medicine
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• v.18 no.2
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• pp.119-126
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• 2004

Objective : We used herbal medicine to treat various disease and also to keep good general condition of children. We aimed to evaluate the effect of herbal medicine on the growth of children treated with herbal medicine. Method: We studied 187 children who visited the department of Pediatrics, KyungHee Oriental Medical Hospital from March 2004 to August 2004. They meet condition as follows; they were treated for more than 6 months and they visited our clinic more than 3 times. Whenever patients visited our hospital, we measured their height, body weight and obesity degree using DS-102(dszenix, Seoul). We measured height percentile of first time visit, and that of last time visit. And we compared them using the Growth Statistics Curve made by the Korean Association of Pediatrics, 1998. Results : The mean growth of total children showed 4.04 percentile upwardly; the growth- up percentile of boys was 4.52 and that of girls was 3.26. Analysis according to disease resulted as follows; children with respiratory disease showed 10.29 percentile growth-up, digestive disease 4.21percentile, urinary disease 4 percentile, allergic disease 2.65 percentile, weak children 2.52 percentile and other disease 3.19 percentile. Conclusion : Herbal medical treatment helped growth not only in children who took medicine for growth retardation problem but children with various disease. Moreover herbal medical treatment applied to keep good general condition of children also gave positive effect on the growth of children.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.4
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• pp.224-231
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• 2013

The concept of the natural frequency is useful for understanding the characters of oscillating systems. However, when a circular cylinder floating horizontally on the water surface is heaving, due to the hydrodynamic forces, the system is not governed by the equation like that of the harmonic one. In this paper, in order to shed some lights on the more correct use of the concept of the natural frequency, a problem of the heaving circular cylinder is analyzed in the time domain. The equation of motion, an integro-differential equation, was derived following the fashion of Cummins (1962), and its coefficients including the retardation function were obtained using the numerical solution of Lee (2012). The equation was solved numerically, and the experiment was also carried out in the CNU flume. Using our numerical and experimental results, the natural frequency was defined as its average value given by the motion data excluding those of the initial stage. Our results were then compared with those of the existing investigations such as Maskell and Ursell (1970), Ito (1977) and Yeung (1982) as well as the newly obtained results of Lee (2012). Comparison showed that the natural frequency obtained here agrees well with that of Lee (2012), which was found through the frequency domain analysis. It was also shown that the approximation of heaving motion by a damped harmonic oscillation, which was regarded as suitable by most previous investigators, is not physically suitable for the reason that can be clearly shown through comparing the shape of MCFRs(Modulus of Complex Frequency Response). Furthermore, we found that although the previous approximations yield the damping ratio significantly different from our result the magnitude of natural frequency is not much different from our result.

• Food Engineering Progress
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• v.14 no.2
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• pp.173-182
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• 2010

A fiber fraction (Aloe cellulose), the by-product obtained from Aloe vera gel processing was freeze dried and investigated for in vitro glucose/ bile acid retarding effects of powdered sample (100 mesh) comparing with commercial $\alpha$-cellulose as a reference sample. We also examined the effectiveness of physiological functionality such as the antiobesity and anti-constipation on Sprague-Dawley (SD) rat. The Aloe cellulose powders during in vitro dialysis experiment for 2 hours exhibited the glucose and bile acid retarding index of 20.32-35.2% and 53.13-28.30%, respectively. Especially, freeze dried aloe cellulose showed the 2.5 and 1.2-6 times higher effect on in vitro glucose and bile acid retardation than those of $\alpha$-cellulose. These relatively good retarding effects on glucose and bile acid diffusion suggest a potential of preventing from diabetes and arteriosclerosis of some extent. Also, the results from animal experiments on SD rats fed a high-fat diet for 4 weeks suggested that Aloe cellulose might be used as a novel dietary fiber showing an effective anti-obesity and anti-constipation effect.

• Journal of Auto-vehicle Safety Association
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• v.7 no.4
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• pp.31-38
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• 2015

In the United States, when NHTSA initiates the vehicle defect investigation, the most of automotive manufactures voluntary start their vehicle's recall campaign immediately. However, in the domestic market, NGOs, medias and even the National Assembly complaint the attitude of domestic and foreign makers tendencies of retardation of recall campaign. Also there were criticism for the manufacturer's concealing or downsize of their vehicle defects to the publics. In general, the manufactures may wait until MLIT's decision to recall orders. Therefore, in this study, from the survey of foreign countries legal recall systems and it is recommended reinforcement of the current vehicle management law to promote more frequent voluntary recall campaign from makers. In this study, it is also includes summarize all previous recall related research works and proposes the more stringent regulations to punish of concealing or downsize their vehicle safety defects.