• Structural Engineering and Mechanics
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• v.71 no.3
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• pp.271-282
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• 2019

The span record of cable-stayed bridges has exceeded 1,000 m, which makes research on the maximum possible span length of cable-stayed bridges an important topic in the engineering community. In this paper, span limit is discussed from two perspectives: the theoretical span limit determined by the strength-to-density ratio of the cable and girder, and the engineering span limit, which depends not only on the strength-to-density ratio of materials but also on the actual loading conditions. Closed form equations of both theoretical and engineering span limits of cable-stayed bridges determined by the cable and girder are derived and a detailed parametric analysis is conducted to assess the engineering span limit under current technical conditions. The results show that the engineering span limit of cable-stayed bridges is about 2,200 m based on materials used available today. The girder is the critical member restricting further increase in the span length; its compressive stress is the limiting factor. Approaches to increasing the engineering span limit are also presented based on the analysis results.

• Mycobiology
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• v.48 no.6
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• pp.528-531
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• 2020

Scopulariopsis brevicaulis is a widely distributed soil fungus known as a common saprotroph of biodegradation. It is also an opportunistic human pathogen that can produce various secondary metabolites. Here, we report the first complete mitochondrial genome sequence of S. brevicaulis isolated from air in South Korea. Total length of the mitochondrial genome is 28,829 bp and encoded 42 genes (15 protein-coding genes, 2 rRNAs, and 25 tRNAs). Nucleotide sequence of coding region takes over 26.2%, and overall GC content is 27.6%. Phylogenetic trees present that S. brevicaulis is clustered with Lomentospora prolificans with presenting various mitochondrial genome length.

• Journal of Species Research
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• v.12 no.4
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• pp.313-320
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• 2023

Diatoms are unicellular eukaryotic microalgae, and they are highly diversified in aquatic environments. We describe an unrecorded diatom species Fragilaria saxoplanctonica Lange-Bertalot & Ulrich (Bacillariophyceae) collected from Paldang Reservoir, Korea, on 4 April 2022. The valve was needle shaped and narrowly rectangular, its ends were rounded, and no spines were found on the outline of their valves. The valve was 67.2-70.2㎛ in length and 1.4-2.9㎛ in width. The ratio of width-to-length was 1 : 23.2-50.1. The pattern of striation was alternate or opposite, and the number of striae in 10㎛ was 24-26. Molecular comparisons of the 18S rDNA and rbcL sequences showed that it belonged to the genus Fragilaria. These morphological and phylogenetic results confirmed that our species was F. saxoplanctonica, and it was the first record in Korea.

• Journal of Korean Clinical Health Science
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• v.8 no.1
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• pp.1386-1397
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• 2020

Purpose: To examine the effectiveness of various treatments; bifocal spectacles, orthokeratology, atropine, and time spent in outdoors; in slowing down the myopia progression for Asian adolescents (6-18age). Methods: The research focused on examining the most effective treatment in controlling myopia based on the literature sources that have been published. Through meta-analysis of various research papers that already has been done in this field, a lot of data was collected. For each treatment, the difference in axial length and spherical equivalent over time was measured and recorded. To quantitatively record the difference, both axial length and spherical equivalent was determined by value of control group value of treatment group. The paper compared the effectiveness of each treatment based on the data that was measured. Results: Adolescents who chose to spend time outdoors in order to slow down myopia progression had axial length difference of 0.03 mm and spherical equivalent difference of 0.17 D. Adolescents that used atropine had axial length difference of 0.36 mm and spherical equivalent difference of 0.92 D. Bifocal spectacle resulted in axial length difference of 0.21 mm and spherical equivalent difference of 0.59 D, and for orthokeratology 0.23 mm and 0.04 D, respectively. Axial length wise, myopia was most controlled by the atropine since there was a greatest difference between the group that got the treatment and the group that did not have the treatment. According to the spherical equivalent difference data, myopia was most controlled by atropine. Conclusion: Atropine showed the most effective result in controlling myopia among the four treatment. Again, compared to other three treatment, using atropine appeared to have greatest ability in slowing down myopia progression since adolescents who were treated with atropine had greatest difference from adolescents in the control group that had the same condition but didn't get the treatment. However, every treatment was only used for 2 or 3 years which is quite short time period to measure the long term effect of the four treatments. Also, since atropine is a pharmaceutical method to control myopia, it may harm adolescents' eyes compared to optical or environmental treatment.

• Korean Journal of Ichthyology
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• v.32 no.1
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• pp.21-25
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• 2020

A single specimen of Strophidon sathete (1,302 mm in total length), belonging to the family Muraenidae, was collected in a danish seine off the southern coast of Jejudo Island in April, 2019 for the first time. It was characterized by having unpatterned coloration and thin body, snout slightly rounded, three superorbital pores, four infraobital pores, and six mandibular pores. This species is distinguishable from morphologically similar Gymnothorax albimarginatus inhabiting Korean waters by having all fins dark (vs. fins dark posteriorly with white margin for latter), body depth 1.8~3.1% in total length (vs. 3.2~5.7%), and no dark band on head in less than 50~70 cm (vs. exist). We add Strophidon sathete to the Korean fish fauna and propose a new Korean name, "Ga-neun-gom-chi" for the species because the body is relatively thinner than other similar moray species (G. albimarginatus) in Korea.

• Journal of Korea Water Resources Association
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• v.40 no.8
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• pp.629-641
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• 2007

This study estimated the urbanization effect of Seoul, the largest city in Korea, on its rainfall. For a comparative analysis, two different data sets are used: One is the precipitation data at the Jeonju rain gauge station, which has a relatively long record length but least urbanization effect, and the other at the Ichon rain gauge station, which has a short record length but located very near to Seoul with least urbanization effect. Also, the difference of the rainfall between Seoul and Jeonju rain gauge stations, as an indicator of urbanization effect, is quantified by use of the intervention model. As a result, it was found that the maximum rainfall intensity of the annual maximum rainfall events shows the increasing trend, its duration the decreasing trend, and the mean intensity the decreasing trend especially after 1960. Also, the quantification of urbanization effect using the intervention model shows that the increasing trend of rainfall intensity and total volume is still on going.

• Korean Journal of Ichthyology
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• v.32 no.3
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• pp.191-196
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• 2020

A single specimen of Strophidon dorsalis (1,254 mm in total length), belonging to the family Muraenidae, was firstly collected in a fish trap off the coastal waters of Jindo Island in July 2018. It was characterized by having unpatterned body coloration, thin body, slightly rounded snout, two superorbital pores, three infraorbital pores, and six mandibular pores. This species is distinguishable from a morphologically similar species, S. sathete inhabiting the Korean waters by having three infraorbital pores (vs. four in S. sathete), last infraorbital pore below an anterior part of the eye (vs. below a posterior part of the eye), body depth 3.2~4.1% in total length (vs. 1.8~3.1%), and total vertebrae 154~167 (vs. 188~200). We add S. dorsalis to the Korean fish fauna and propose a new Korean name, "Seo-mang-gom-chi" for the species.

• Journal of Acupuncture Research
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• v.21 no.1
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• pp.99-110
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• 2004

Objective: The purpose of this study was to examine the different effects on labor pain, length of delivery time, and hemoglobin for primipara women treated by San-Yin-Jiao(SP-6) acupressure of 15 minutes or 30 minutes. Methods: The design of this study was a randomized clinical trial with two experimental groups and one control group, the participants included primiparas who underwent vaginal delivery. Data were collected using a structured questionnaire consisting of general characteristics with a subjective labor pain scale with VA.S, and length of delivery time and hemoglobin were collected in the medical record. Data was analyzed using descriptive statistics, x2- test, t-test, and ANCOVA. Results: There was statistically significant lower labor pain in the group of 30 minutes SP6 acupressure than the control group(t=7.733, p=.007), and there was statistically significant short length of delivery time in the group of 15 minutes SP6 acupressure than the control group(t=-2.230, p=.030). Conclusions: Even though we could not found a consistent effect with the SP6 acupressure, It was found that there was effect on shortening length of delivery time by 15 minutes of SP6 acupressure or lessening labor pain by 30 minutes of SP6 acupressure without risk of blood loss. It is necessary to replicate the study with a larger number of participants to find a consistent result.

• Journal of the Korea Convergence Society
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• v.8 no.5
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• pp.87-96
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• 2017

This study was carried out to provide basic data for prevention of death from injuries and traumas by analyzing the characteristics of length of hospital stay of patients with injuries and traumas, utilizing in-depth investigation data of discharged injuries. The study subjects were 233 patients discharged from January 1 to December 31 in 2014 whom the final treatment result was 'death' and the main diagnosis were injuries and accidental external causes(S00-T98). According to the research findings, the length of hospital stay of females was longer than that of males. Based on the main diagnosis, the longest length of hospital stay had complication of other internal prosthetic devices, implants and grafts(T85). In conclusion, it is necessary to develop a policy to identify the factors affecting the length of hospital stays of patients and to manage them intensively.

• Wind and Structures
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• v.19 no.5
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• pp.505-522
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• 2014

While effects of the atmospheric boundary layer flow on engineering infrastructure are more or less known, some local transient winds create difficulties for structures, traffic and human activities. Hence, further research is required to fully elucidate flow characteristics of some of those very unique local winds. In this study, important characteristics of observed vertical velocity profiles along the main wind direction for the gusty Bora wind blowing along the eastern Adriatic coast are presented. Commonly used empirical power-law and the logarithmic-law profiles are compared against unique 3-level high-frequency Bora measurements. The experimental data agree well with the power-law and logarithmic-law approximations. An interesting feature observed is a decrease in the power-law exponent and aerodynamic surface roughness length, and an increase in friction velocity with increasing Bora wind velocity. This indicates an urban-like velocity profile for smaller wind velocities and rural-like velocity profile for larger wind velocities, which is due to a stronger increase in absolute velocity at each of the heights observed as compared to the respective velocity gradient (difference in average velocity among two different heights). The trends observed are similar during both the day and night. The thermal stratification is near neutral due to a strong mechanical mixing. The differences in aerodynamic surface roughness length are negligible for different time averaging periods when using the median. For the friction velocity, the arithmetic mean proved to be independent of the time record length, while for the power-law exponent both the arithmetic mean and the median are not influenced by the time averaging period. Another issue is a large difference in aerodynamic surface roughness length when calculating using the arithmetic mean and the median. This indicates that the more robust median is a more suitable parameter to determine the aerodynamic surface roughness length than the arithmetic mean value. Variations in velocity profiles at the same site during different wind periods are interesting because, in the engineering community, it has been commonly accepted that the aerodynamic characteristics at a particular site remain the same during various wind regimes.