• Journal of Korean Ophthalmic Optics Society
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• v.11 no.2
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• pp.121-129
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• 2006

Prevalence of refractive error have revealed variation in relation to ethnicity, educational level, age, gender, and social economic status. Especially prevalence of refractive error varies by country, estimation of prevalence of refractive error have shown increase in Asia than in Western world. The present report aimed to investigate the prevalence of refractive errors by the age and gender in Korean population without eye disease. A total of 960 subjects were sampled and their refractive error was determined using Auto refractometer. Prevalence of emmetropia was 29% and that for myopia and hyperopia was 67%, 4%, respectively. Astigmatism was 22%, and the simple astigmatism was 1%. However the compound astigmatism was 99%. Prevalence of refractive errors differed significantly among age and gender group in our results. The percentages of with-the-rule, against-the-rule and oblique astigmatism among people with astigmatism were 36.6%, 20.7% and 42.7% for right eye and 31.8%, 10% and 58.1% for left eye.

• Korean Journal of Plant Taxonomy
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• v.35 no.4
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• pp.273-285
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• 2005

Genetic variation of notorious invasive plants, common ragweed (Ambrosia artemisiifolia L.) and giant ragweed (Ambrosia trifida L.) were examined using the internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA. A total of 18 different ITS types were detected from 156 individuals of common ragweed sampled mainly from the southern part of Korean peninsula whereas four types were identified from 46 individuals of giant ragweed. High sequence diversity observed from common ragweed in Korean populations was interpreted as multiple introduction. Genetic recombination was suggested as possible method for the production of some of the ITS types while point mutation was mainly responsible for the origin of the sequence diversity. This study provided some of basic genetic information needed for understanding of the evolutionary process in ragweed during invasion.

• The korean journal of orthodontics
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• v.26 no.2 s.55
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• pp.141-151
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• 1996

This study was undertaken to assess the effect of growth on the lips. Not only does lip growth influence the stability of such orthodontic treatment; it also directly influence facial profile, in which the lips have an important part. An understanding of the growth of lips is thus central to a consideration of profile change in orthodontics. By analyzing the serial lateral cephalograms of 15 male and 15 female of 8 years old to 16 yaers old who have normal occlusion. The result of this study were summerized as follows; 1. The largest growth increments in the length of the lips was mod age of 14 in both sexes. 2. The thickness of lips showed lager value for the male than that of the female in the most age group. The lagest growth increments at A point was occured age of 14, while Ls, Li, B point decreased after the age of 10-11. 3. The largest increase in the interval between crest of lower lip and edge of upper incisors was occured between ages 9 and 11 in males. The interval decreased slightly from 8 to 16 years in females. 4. The nasolabial angle decreased slightly from 8 to 16 years in both sexes. 5. The mentolabial angle showed large variation.

• Journal of the Korean GEO-environmental Society
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• v.16 no.5
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• pp.35-42
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• 2015

This is conducted to observe underground temperature and to analyze its change affected by climate condition and soil infiltration in the mountainous area, Yesan region, Chungcheong-namdo province. Additionally, underground temperature change is also simulated using air temperature and soil thermal properties with a numerical model. Soil temperature monitoring data acquired from each depth, 20 cm, 50 cm, and 100 cm, indicates that the data within 50 cm in depth shows peak-shaped big fluctuation directly affected by air temperature and it at 100 cm has open-shaped small fluctuation. Underground temperature variation, a difference between high and low values, during monitoring period is weakly proportional to hydraulic conductivity of the sediment and it is assumed that water plays a part in delivering air temperature in soil. The underground temperature estimated by a numerical model is very similar to the observed data with an average value of 0.99 cross-correlation coefficient. From the result of this study, the aquifer unsaturated hydraulic conductivity of the soil and the groundwater recharge is likely to be able to estimate with underground temperature profile calculated using a numerical model.

• The Korean Journal of Air & Space Law and Policy
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• v.28 no.2
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• pp.145-181
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• 2013

General aviation is an integral part of civil aviation and involves the widest range of aviation segments except commercial aviation. Featured with different operational procedures and practices to satisfy the economic needs and safety requirements of a sovereign state, general aviation tends to be regulated by an individual state. The last three decades have seen exponential growth of commercial air transport in China, but its general aviation sector has remained disproportionally underdeveloped. With the deepening of the reform of low-altitude airspace, the sector is poised for a radical change and rapid growth. However, legislation governing general aviation activities in China is distorted causing inconsistency and confusions in their application and implementation. This paper aims to analyse China's prevailing legislation regulating general aviation activities. It first discusses the various definitions adopted by ICAO and its member states and reviews the development of general aviation in the US, EU, Australia and China. It then examines the sources of China's general aviation laws, e.g. Chicago Convention and its annexes, and Chinese domestic legislature which covers legislation, laws, directives, rules and procedures. The paper continues to analyse and establish the deficiencies of its prevailing legal framework by pointing out the following: variation of definitions in different regulations, inconsistency of principles in existing laws and regulations, legal vacuum concerning government subsidy, environment protection, safety and security, and other operational areas such as aerial club, sightseeing, and search and rescue. In this process, the paper argues that a coherent, consistent and systematic legal framework is required in order to ensure fair competition and safety for a healthy, progressive and sustainable general aviation growth. Suggestions for rectification and improvement are proposed.

• Journal of Korean Society of Forest Science
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• v.71 no.1
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• pp.82-89
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• 1985

Morphological characteristics of leaves of 10 natural populations of Quercus mongolica and 9 natural populations of Q. serrata were investigated to study inter-population and intra-population variability as well as interspecies variability. Five leaf form indices, blade length/max. blade width, blade length/petiole length, blade length/vein number, upper 1/3 blade width/max.blade width, upper 1/3 blade width/lower 1/3 blade width, as well as petiole length and vein number were included in the present study of Leaf variabilities of the Quercus population. All of the investigated leaf variabilities except for the case of blade length/petiole length, in Q. serrata indicated highly significant differences among the populations and among the individual trees within population. Both of Q. mongolica and Q. serrata represented different leaf forms between southern populations and northern populations in the indices of blade length/max. blade width, blade length/petiole length and blade length/vein number, and so the leaf forms of northern populations were more similar to the unique characters of Q. mongolica and those of southern populations were more similar to the unique characters of Q. serrata. The variability among individual trees within population was more notable in blade length/petiole length, and petiole length than in other leaf form indices, and also it was more obvious for Mt. Kyeryrong population located in middle part of the country than for other population.

• The KIPS Transactions:PartD
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• v.11D no.3
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• pp.495-508
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• 2004

Recently, in content-based music information retrieval systems, to enhance the response time of retrieving music data from large music database, some researches have adopted the indexing mechanism that extracts and indexes the representative melodies. The representative melody of music data must stand for the music itself and have strong possibility to use as users' input queries. However, since the previous researches have not considered the musical composition forms, they are not able to correctly catch the contrast, repetition and variation of motif in musical forms. In this paper, we use an index automatically constructed from representative melodies such like first melody, climax melodies and similarly repeated theme melodies. At first, we expand the clustering algorithm in order to extract similarly repeated theme melodies based on the musical composition forms. If the first melody and climax melodies are not included into the representative melodies of music by the clustering algorithm, we add them into representative melodies. We implemented a prototype system and did experiments on comparison the representative melody index with other melody indexes. Since, we are able to construct the representative melody index with the lower storage by 34％ than whole melody index, the response time can be decreased. Also, since we include first melody and climax melody which have the strong possibility to use as users' input query into representative melodies, we are able to get the more correct results against the various users' input queries than theme melody index with the cost of storage overhead of 20％.

• Journal of Sasang Constitutional Medicine
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• v.11 no.2
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• pp.185-194
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• 1999

Recently some report has been published on the classification of Sasang constitution by analysis of genetic polymorphism. In this study, to present the ideas in the study on the classification of Sasang constitution based on the genetic variation of individuals, we reviewed the previous studies dealing with relationship between genetic polymorphism and Sasang constitution and suggested new molecular biological methodologies applicable to the classification of Sasang constitution. The results were as follow; 1. In the studies on the classification of constitution by analysis of genetic polymorphism, the special genes were desirable as subjects rather than the non-functional part of genome such as inter-gene and intron. Since microsatellite is usually located in inter-gene or intron, representation of constitutions may not associated with the polymorphism of certain microsatellite. 2. It may possible that polymorphism patterns of the genes related to the expression of individuality is associated with the types of Sasang constitutions. Therefore, angiotensin converting enzyme (ACE) which known have some role in the determination the human performance is one of the candidate genes can use for the classification of Sasang constitutions. 3. It is well known that HLA types are very variable in human and closely associated with the determination of susceptibility for certain disease. The studies on the polymorphism of HLA types may applicable to the classification of Sasang constitutions. 4. DNA chip technique which developed recently for the analysis of the expression of human genes may powerful tools in the study of Sasang medicine.

• Journal of Digital Convergence
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• v.11 no.1
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• pp.315-320
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• 2013

We have investigated the variation of spherical aberration of the anterior and posterior surface in a Korean sample population with various age between 20 to 71 years old. We used Pentacam (Oculus Inc., Germany) to measure the corneal radius, asphericity, and spherical aberration of 290 patients with normal cornea. There were negative correlation between corneal anterior radius and spherical aberration(r = -0.22, p<0.0001), and, there were negative correlation between corneal posterior radius and spherical aberration(r=-0.27, p < 0.0001). There were positive correlation between anterior asphericity and spherical aberration(r = 0.24, p < 0.0001), however there were negative correlation between posterior asphericity and spherical aberration(r = -0.17, p=0.00288).The average of anterior spherical aberration and posterior spherical aberration was $0.482{\pm}0.099{\mu}m$ and $-0.098{\pm}0.029{\mu}m$. The average of spherical aberration was $0.385{\pm}0.097{\mu}m$. There were significant positive correlations between anterior spherical aberration and age(r = 0.227, p<0.0001), and there were positive correlations between posterior aberration and age(r = 0.349, p<0.0001). It is considered that this data can be used as basic information for furture studies for improving the quality of vision of modern human and, through the analysis of the spherical aberration of cornea was to provide a better understanding of the optical part of the Korean's eye.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.6
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• pp.34-51
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• 2008

Today, the Internet is a part of our life. For that reason, we regard revealing characteristics of Internet traffic as an important research theme. However, Internet traffic cannot be easily manipulated because it usually occupy huge capacity. This problem is a serious obstacle to analyze Internet traffic. Many researchers use various sampling techniques to reduce capacity of Internet traffic. In this paper, we compare several famous sampling techniques, and propose efficient sampling scheme. We chose some sampling techniques such as Systematic Sampling, Simple Random Sampling and Stratified Sampling with some sampling intensities such as 1/10, 1/100 and 1/1000. Our observation focused on Traffic Volume, Entropy Analysis and Packet Size Analysis. Both the simple random sampling and the count-based systematic sampling is proper to general case. On the other hand, time-based systematic sampling exhibits relatively bad results. The stratified sampling on Transport Layer Protocols, e.g.. TCP, UDP and so on, shows superior results. Our analysis results suggest that efficient sampling techniques satisfactorily maintain variation of traffic stream according to time change. The entropy analysis endures various sampling techniques well and fits detecting anomalous traffic. We found that a traffic volume diminishment caused by bottleneck could induce wrong results on the entropy analysis. We discovered that Packet Size Distribution perfectly tolerate any packet sampling techniques and intensities.