• Ocean and Polar Research
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• v.40 no.2
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• pp.77-85
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• 2018

We observed the concentrations of Dissolved Organic Carbon (DOC) and Colored Dissolved Organic Matter (CDOM) in coastal seawater and groundwater around a volcanic island, Jeju, Korea. The sampling of surface seawater and coastal groundwater was conducted in Woljeongri, Pyoseon, and Kwakgi beaches, in three sampling campaigns (June, July, and October 2016). The concentrations of DOC in groundwater were relatively higher in June and October than in July. Salinity and DOC concentrations in the coastal groundwater of Woljeongri and Pyoseon beaches did not show a marked relationship, whereas those in Kwakgi beach showed a good positive correlation (July: $R^2=0.64$, P < 0.01; October: $R^2=0.95$, P < 0.01). In addition, the concentrations of CDOM (C and M peaks) in the groundwater of Woljeongri and Pyoseon beaches, where saline groundwater discharge dominates, were relatively higher than those of Kwakgi beach, where fresh groundwater discharge dominates. The relatively higher DOC concentrations in the coastal groundwater of Woljeongri and Pyoseon, with higher CDOM concentrations, seem to be mainly from anthropogenic sources such as local pollution sources (i.e., aquaculture wastewater or domestic sewage). In order to understand the behavior of DOC in the coastal groundwater of a volcanic island, extensive studies are necessary in the future over a larger-area and greater time-scales using various isotopic tracers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.3
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• pp.209-213
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• 1976

Spinous loaches widely distributed in Korea, are of many color pattern types, but interestingly the crossband B and C-types of these coaches are collected only in the two rivers, the Yeongsan River and the Seomjin River, flowing through the south-western part of Korea. These two types have not only different color pattern, but also different geographical distribution: the B-type is found in the Yeongsan River and the C-typs, in the Seomjin River. But the both types have four common distinctive features, which easily distinguish them from other already known species of this genus: the B and C-types have the similar total length distribution, the same structure of lamina circularis and scales, and the black spots at the back of their opercula. These peculiarities may be explained by studing the history of these two rivers. The author considers that they are once rivers of the same origin located around the Noryeong and the Sobaeg Mountains, and then were eventually separated from each other as the water level or the crust of Korea peninsula changed. Thus, these two types, B and C, of spinous loaches should have been the same species living in the same river, but in the course of time, these two types have taken different color patterns since the separation of two rivers thus making them impossible to cross between these two populations.

• Korean journal of applied entomology
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• v.30 no.1
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• pp.86-93
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• 1991

Adult eclosion and emergence behavior of the black pine base scale, Matsucoccus thunbergianae Miller and Park, was studied in a laboratory. Adult eclosion in males did not appear to be limited to a specific time of the day. Newly molted male adults, at room temperatures, usually remained in the cocoons as pre-emergence adults for 0.5-20. days before emerging; most males emerged within one hour after the onset of photophase, and emergence was faster at higher light intensity. Most females molted into adults within three hours after the onset of photophase, and they were active immediately after molting. Quiescence in males appears to help the scales concentrate their sexual activity within a particular period of the day as well as to protect newly molted adults until sexual and locomotive maturity.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.1
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• pp.39-39
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• 2013

We present a study of correlations between the elemental abundances and galaxy morphologies of 91 blue compact galaxies (BCGs) at z=0.20-0.35 with Sloan Digital Sky Survey (SDSS) DR7 data. We classify the morphologies of the galaxies as either 'disturbed' or 'undisturbed', by visual inspection of the SDSS images, and using the Gini coefficient and M20. We derive oxygen and nitrogen abundances using the Te method. We find that a substantial fraction of BCGs with disturbed morphologies, indicative of merger remnants, show relatively high N/O and low O/H abundance ratios. The majority of the disturbed BCGs exhibit higher N/O values at a given O/H value compared to the morphologically undisturbed galaxies, implying more efficient nitrogen enrichment in disturbed BCGs. We detect Wolf-Rayet (WR) features in only a handful of the disturbed BCGs, which appears to contradict the idea that WR stars are responsible for high nitrogen abundance. Combining these results with Galaxy Evolution Explorer (GALEX) GR6 ultraviolet (UV) data, we find that the majority of the disturbed BCGs show systematically lower values of the $H{\alpha}$ to near-UV star formation rate ratio. The equivalent width of the $H{\beta}$ emission line is also systematically lower in the disturbed BCGs. Based on these results, we infer that disturbed BCGs have undergone star formation over relatively longer time scales, resulting in a more continuous enrichment of nitrogen. We suggest that this correlation between morphology and chemical abundances in BCGs is due to a difference in their recent star formation histories.

• Journal of Korean Medicine Rehabilitation
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• v.30 no.2
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• pp.105-123
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• 2020

Objectives This study was conducted to verify the effectiveness of east-west integrative rehabilitation therapy on activity of daily living and cognitive functional recovery in stroke patients by comparing with integrative rehabilitation therapy group and conventional rehabilitation therapy group in a single institution. Methods The medical records of 106 stroke patients hospitalized in Department of Rehabilitation Medicine, Dongguk University Bundang Oriental Hospital from January 1, 2017 to February 28, 2019 were reviewed. After screening and dividing it into conventional rehabilitation (CR) group and integrative rehabilitation (IR) group, Korean version of Modified Barthel Index (K-MBI), functional independence measure (FIM), clinical dementia rating-sum of boxes (CDR-SB) were statistically analyzed. Results IR group showed significant improvement in K-MBI, FIM, and CDR-SB after treatment (p<0.001) and there was a statistically significant difference in K-MBI and CDR-SB score changes than CR group (p<0.05). And chronic patient of IR group showed significant improvement in K-MBI, FIM, and CDR-SB after treatment (p<0.01) and there was a statistically significant difference in CDR-SB score changes than CR group (p<0.05). In particular, the earlier the treatment initiation time, the more the improvement in function and when the treatment started within 2 years from the onset and patients took acupuncture and pulsed electromagnetic therapy, all scales significantly improved (p<0.001). Conclusions IR showed more improvement on activities of daily life and cognitive functional recovery than CR in this study.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.65.1-65.1
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• 2016

We present results of long-term multi-wavelength polarization observations of the powerful blazar 3C 279 after its ${\gamma}$-ray flare on 2013 December 20. We followed up this flare by means of single-dish polarization observations with two 21-m telescopes of the Korean VLBI Network, carried out weekly from 2013 December 25 to January 11, and at 22, 43, and 86 GHz, simultaneously. These observations were part of the Monitoring Of GAmma-ray Bright AGNs (MOGABA) program. We Measured 3C 279 total flux densities at 22, 43, and 86 GHz, showing a mild variability of a factor of ${\leq}50%$ over the period of our observations. The spectral index ranged from -0.13 to -0.36 at between 22 and 86 GHz. The degree of linear polarization was in the range of 6 ~ 12 %, and slightly decreased with time at all frequencies. We found Faraday rotation measures (RM) of -300 to $-1200rad\;m^{-2}$ between 22 and 43 GHz, and -800 to $-5100rad\;m^{-2}$ between 43 and 86 GHz. The RM values follow a power law ${\mid}RM{\mid}{\propto}{\nu}^{\alpha}$, with a mean ${\alpha}$ of 2.2, implying that the polarized emission at these frequencies travels through a Faraday screen in or near the jet. We conclude that the regions emitting polarized radio emission may be different from the region responsible for the 2013 December ${\gamma}$-ray flare, and that these regions are maintained by the dominant magnetic field perpendicular to the direction of the radio jet at milliarcsecond scales.

• Journal of the Ergonomics Society of Korea
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• v.26 no.2
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• pp.45-59
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• 2007

The operating tasks of overhead crane have caused undue stress to the operators from physical, mental, and environmental workload. Existing workload assessment models for musculoskeletal disorders such as OWAS, RULA, and QEC have limited applicability to the crane operating tasks because they focus mainly on physical factors and do not consider the relative importance of each factor. The present study was to develop a workload assessment model customized to overhead crane operation, following a systematic process: (1) analyzing task characteristics, (2) selecting workload factors, (3) developing assessment methods, (4) establishing action levels, and (5) computerizing the assessment model. Based on literature review, worksite survey, and focus group interview, 4 physical factors (awkward posture, static posture, repetitive motion, and excessive force), 6 mental factors (visual demand, auditory demand, task complexity and difficulty, time urgency, work schedule related stress, and safety related stress), and 4 environmental factors (noise, vibration, dust, and temperature) were selected and their rating scales and relative weights were determined. Then, based on the workload assessment results of 8 overhead cranes operated at different workplaces, the action levels of each factor category were established. Finally, the crane operation assessment model was computerized for effective analysis and report preparation. The present approach is applicable to develop a customized workload assessment model for an operating task under consideration.

• The Korean Journal of Community Living Science
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• v.22 no.4
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• pp.689-704
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• 2011

Farm themed restaurants is an initiation by the Rural Development Administration (RDA) in order to perpetuate and develop Korean traditional food-culture. This food business model contributes to the increase of local food consumption and non-farm income for rural communities. Thus, the purpose of this study was to investigate the visitor's expectations, perception and satisfaction on the farm restaurant management type in order to assist activation of farm restaurants. Farm restaurants were categorized into two types; restaurant style and experience style. The majority of subjects(67.9%) were experiencing their first time to dine at farm restaurants. Regardless of farm restaurant style, the subjects perceived that farm restaurants use high quality food ingredients. The degree of subjects expectations prior to visiting a farm restaurant was estimated by 7 Likert scales. The results show that most subjects had high expectations for using good-quality food ingredients such as ‘fresh food (restaurant style 6.25, dietary education style 6.02)’ and ‘environment-friendly food (restaurant style 6.07, dietary education style 5.91)’. Overall satisfaction of the farm restaurants was also high. The satisfaction of food scored 4.1 and the satisfaction of experience program scored 3.8.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.21 no.1
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• pp.31-36
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• 2010

Objective ： We investigated the characteristics of cellular phone use and its association with psychological problems among adolescents. Methods ： A total of 332 adolescent students were recruited for this study. The participants' self-reported characteristics of cellular phone use and the psychological problems caused by this were tested by using the Excessive Cellular Phone Use Survey (ECPUS), the Children's Depression Inventory (CDI), Spielberger's State-Trait Anxiety Inventory for Children (STAIC) and the Korea-Youth Self Report (K-YSR). Results ： The excessive user group made more use of text messages and they spent more time and paid higher fees than the comparison group. They expressed severer depression and anxiety and they had more behavior problems and lower school performance than the comparison group. The ECPUS score was positively correlated with score of the CDI, STAIC and the behavior problem scales of the K-YSR, and the ECPUS score was negatively correlated with the school performance scale of the K-YSR. Conclusion ： Our findings suggest that excessive cellular phone use by adolescents may be related to psychological problems. Careful education about the use of cellular phones and intervention are recommended for adolescents who excessively use cellular phones.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1996.06b
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• pp.285-309
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• 1996

Non oxide ceramics such as nitrides of transition metals have shown significant potential for future economic impact, in diverse applications in ceramic, aerospace and electronic industries, as refractory products, abrasives and cutting tools, aircraft components, and semi-conductor substrates amid others. Combustion synthesis has become an attractive alternative to the conventional furnace technology to produce these materials cheaply, faster and at a higher level of purity. However he process os highly exothermic and manifests complex dynamics due to its strongly non-linear nature. In order to develop an understanding of this process and to study the effect of operational parameters on the final outcome, numerical modeling is necessary, which would generated essential knowledge to help scale-up the process. the model is based on a system of parabolic-hyperbolic partial differential equations representing the heat, mass and momentum conservation relations. The model also takes into account structural change due to sintering and volumetric expansion, and their effect on the transport properties of the system. The solutions of these equations exhibit steep moving spatial gradients in the form of reaction fronts, propagating in space with variable velocity, which gives rise to varying time scales. To cope with the possibility of extremely abrupt changes in the values of the solution over very short distances, adaptive mesh techniques can be applied to resolve the high activity regions by ordering grid points in appropriate places. To avoid a control volume formulation of the solution of partial differential equations, a simple orthogonal, adaptive-mesh technique is employed. This involves separate adaptation in the x and y directions. Through simple analysis and numerical examples, the adaptive mesh is shown to give significant increase in accuracy in the computations.