• Economic and Environmental Geology
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• v.49 no.4
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• pp.249-267
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• 2016

The Hongseong area of the central-western Korean Peninsula is considered to be a part of collision zone that is tectonically correlated to the Qinling-Dabie-Sulu belt of China. The area includes the elliptical-shaped serpentinized ultramafic bodies, together with mafic rocks. The studied bodies are in contact with the surrounded Neoproterozoic alkali granites at the Baekdong and Wonnojeon bodies and the Paleoproterozoic Yugu gneiss at the Bibong body. The Baekdong body contains the blocks of the Neoproterozoic alkali granites and the Late Paleozoic metabasites. The Bibong body also includes the Neoproterozoic alkali granite blocks. The Mesozoic intrusive rocks are also recognized at the Baekdong, Wonnojeon and Bibong bodies. On the other hand, the Early Cretaceous volcanic rocks are occurred at the Bibong body. The detrital zircon SHRIMP U-Pb ages of the serpentinites at three bodies range variously from Neoarchean to Middle Paleozoic at the Baekdong body, and from Neoarchean to Early Cretaceous at the Wonnojeon and Bibong bodies. Although serpentinization does not generally produce minerals suitable for direct isotopic dating, the youngest Middle Paleozoic age at the Baekdong body and the Early Cretaceous age at the Wonnojeon and Bibong bodies indicate the possible upper age limit for the (re)serpentinization. Especially, the Early Cretaceous serpentinization ages may be related to the widespread Early Cretaceous igneous activity in the central-southern Korean Peninsula. Age results for the serpentinite bodies and the included blocks of the studied serpentinized ultramafic bodies in the Hongseong area, therefore, provide several possible interpretations for the serpentinization ages of the ultramafic rocks as well as the geotectonic implications of serpentinization, requiring more detailed study including other serpentinized ultramafic bodies in the Hongseong area.

• Economic and Environmental Geology
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• v.53 no.4
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• pp.383-395
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• 2020

The stratigraphical position of the Haengmae Formation can provide clues towards solving the hot issue on the Silurian formation, also known as Hoedongri Formation. Since the 2010s, there have been several reports denying the Haengmae Formation as a lithostratigraphic unit. This study aimed to clarify the lithostratigraphic and chronostratigraphic significance of the Haengmae Formation. The distribution and structural geometry of the Haengmae Formation were studied through geologic mapping, and the correlation of relative geologic age and the absolute age was performed through conodont biostratigraphy and zircon U-Pb dating respectively. The representative rock of the Haengmae Formation is massive and yellow-yellowish brown pebble-bearing carbonate rocks with a granular texture similar to sandstone. Its surface is rough with a considerable amount of pores. By studying the mineral composition, contents, and microstructure of the rocks, they have been classified as pebble-bearing clastic rocks composed of dolomite pebbles and matrix. They chiefly comprise of euhedral or subhedral dolomite, and rounded, well-sorted fine-grained quartz, which are continuously distributed in the study area from Biryong-dong to Pyeongan-ri. Bedding attitude and the thickness of the Haengmae Formation are similar to that of the Hoedongri Formation in the north-eastern area (Biryong-dong to Haengmae-dong). The dip-direction attitudes were maintained 340°/15° from Biryong-dong to Haengmae-dong with a thickness of ca. 200 m. However, around the southwest of the studied area, the attitude is suddenly changed and the stratigraphic sequence is in disorder because of fold and thrust. Consequently, the formation is exposed to a wide low-relief area of 1.5 km × 2.5 km. Zircon U-Pb age dating results ranged from 470 to 449 Ma, which indicates that the Haengmae Formation formed during the Upper Ordovician or later. The pebble-bearing carbonate rock consisted of clastic sediments, suggesting that the Middle Ordovician conodonts from the Haengmae Formation must be reworked. Therefore, the above-stated evidence supports that the geologic age of the Haengmae Formation should be Upper Ordovician or later. This study revealed that the Haengmae Formation is neither shear zone, nor an upper part of the Jeongseon Limestone, and is also not the same age as the Jeongseon Limestone. Furthermore, it was confirmed that the Haengmae Formation should be considered a unit of lithostratigraphy in accordance with the stratigraphic guide of the International Commission on Stratigraphy (ICS).

• Korean Journal of Ecology and Environment
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• v.50 no.1
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• pp.137-147
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• 2017

The identity of toxin producers remains only hypothesis unless there were identified by strain isolation and analytical confirmation of both the cyanotoxin production and the genetic identity of the monoculture. The purposes of this study were to identify a morphologic and phylogenetic classification in Aphanizomenon flos-aquae strains isolated from the Nakdong River and to investigate the potential ability of the strains to produce toxins such as saxitoxin and cylindrospermopsin using target genes. The 16S rRNA and sxtA, sxtI, cyrA, cyrJ genes were analyzed on two strains (DGUC001, DGUC003) isolated from the Nakdong River. Morphological features of the strains were observed a shape of aggregated trichomes in parallel fascicles which can reach up to macroscopic size and a hyaline terminal cell without aerotope. In addition, the 16S rRNA phylogenetic analyses showed that the strains were identified as the same species with high genetic similarity of 98.4% and grouped within a monospecific andsupported cluster I of Aphanizomenon flos-aquae selected from GenBank of the NCBI. The cyrA and cyrJ genes encoding for the cylindrospermopsin-biosynthesis were not detected in the present study. The sxtA gene was in detected both the two strains, whereas the sxtI gene which had been suggested as a suitable molecular marker to detect saxitoxin-producing cyanobacteria was not found both the strains. Thus, the two strains isolated from Nakdong River were identified as the same species of Aphanizomenon flos-aquae Ralfs ex Bornet et Flahault 1888, the two strains were confirmed as potential non-producing strains of the saxitoxin and cylindrospermopsin.

• Journal of Animal Science and Technology
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• v.45 no.5
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• pp.711-724
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• 2003

Some growth curve models were used to fit individual growth of 1,083 Hanwoo cows born from 1970 to 2001 in Daekwanryeong branch, National Livestock Research Institute(NLRI). The effects of year-season of birth and age of dam were analyzed. In analysis of variance for growth curve parameters, the effects of birth year-season were significant for mature weight(A), growth ratio(b) and maturing rate(k)(P〈.01). The effects of age of dam were significant for growth ratio(b) but not significant for mature weight(A) and maturing rate(k). The linear term of the covariate of age at the final weights was significant for the A(P〈.01) and k(P〈.01) of Gompertz model, von Bertalanffy model and Logistic model. For the growth curve parameters fitted on individual data using Gompertz model, von Bertalanffy model and Logistic model, resulting the linear contrasts(fall-spring), Least square means of A in three nonlinear models were higher cows born at fall and A of Logistic model was significant(P〈.05) between the seasons. According to the results of the least square means of growth curve parameters by age of dam, least square means of mature weight(A) in Gompertz model was largest in 6 year and smallest estimating for 3 and 8 years of age of dam. The growth ratio(b) was largest in 2 year of age of dam and smallest estimating in 8 year. The A and k were not different by age of dam(p〉.05), On the other hand, the b was different by age of dam(p〈.01). The estimate of A in von Bertalanffy model was largest in 6 year and smallest in 8 and 9 years of age of dam. The b was largest in 2 year and tend to decline as age of dam increased. The A and k were not different by age of dam(p〉.05), On the other hand, the b was highly significant by age of dam(p〈.01).

• Management & Information Systems Review
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• v.37 no.3
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• pp.83-113
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• 2018

The purpose of this study to empirically examine a smart work investment and job performance by change resistance. Firstly, There investigates mediating role of the communication between the smart work investment and the job performance. Secondly, It will identify the job productivity differences through a level of organizational change resistance that reduced smart work investment. The smart work is to provide the flexibility of time and location and is a working method to improve a work productivity of organization members. The introduction of smart work means the adoption of new organizational culture, institution and technology and requires a novel change of a custom and pattern on existing organization culture and institution because of transformation form of communication and collaboration. The method of this study adopts a structural equation model to test a mediating effect of communication and a moderating effect of change resistance level. This model confirms whether smart work investments provide a positive impact on communication and organizational productivity. In addition, I will classify a change resistance level of smart work by cluster analysis and then check a critical path difference of job productivity between each group. As a result, The organizational IT, institution and culture on the smart work investment appeared to important influencers in communication and also had a direct influence of individual performance. Also, The three independent variables of smart work investment have an indirect influence of individual and organizational performance through communication mediating variables. However, the organizational IT and institution as independent variables do not provide direct influence of organization performance. Nevertheless, two independent variables of organizational IT and institution have an indirect influence the organization performance through communication mediating variables. As a result of confirming a productivity of three groups on organization resistance, there was a difference the individual and organizational performance among groups. The low-level group of organizational resistance showed high coefficient value of performance compared to other groups. The group analysis implications, The smart work investment appeared significantly to revise the institution first, build culture secondly and advanced technology lastly. The theoretical implication from this study contributes an extension of social science theory through socio-technical systems, institution, culture, change resistance and job performance based on smart work. The practical implications explain the smart work success in step-by-step investment rather than radical investment as level management of change resistance. In future research, the smart work performance between private and public firms will analyze a difference of the organizational culture, institution, technology and performance.

• Geophysics and Geophysical Exploration
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• v.12 no.1
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• pp.56-68
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• 2009

Ongoing and extensive urbanisation, which is frequently accompanied with careless construction works, may threaten important archaeological structures that are still buried in the urban areas. Ground Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT) methods are most promising alternatives for resolving buried archaeological structures in urban territories. In this work, three case studies are presented, each of which involves an integrated geophysical survey employing the surface three-dimensional (3D) ERT and GPR techniques, in order to archaeologically characterise the investigated areas. The test field sites are located at the historical centres of two of the most populated cities of the island of Crete, in Greece. The ERT and GPR data were collected along a dense network of parallel profiles. The subsurface resistivity structure was reconstructed by processing the apparent resistivity data with a 3D inversion algorithm. The GPR sections were processed with a systematic way, applying specific filters to the data in order to enhance their information content. Finally, horizontal depth slices representing the 3D variation of the physical properties were created. The GPR and ERT images significantly contributed in reconstructing the complex subsurface properties in these urban areas. Strong GPR reflections and highresistivity anomalies were correlated with possible archaeological structures. Subsequent excavations in specific places at both sites verified the geophysical results. The specific case studies demonstrated the applicability of ERT and GPR techniques during the design and construction stages of urban infrastructure works, indicating areas of archaeological significance and guiding archaeological excavations before construction work.

• Clinical and Experimental Pediatrics
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• v.53 no.3
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• pp.323-328
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• 2010

Purpose : To verify the effect of hyperglycemia on mortality rates in critically ill children and to identify the blood glucose level that influences prognosis. Methods : From July 2006 to June 2008, a total of 206 patients who were admitted to the pediatric intensive care unit (PICU) at Asan Medical Center and who survived for more than 7 days were retrospectively reviewed. We analyzed the maximum glucose value within 7 days in PICU, PRISM-III score and SOFA score within 24 hours, and mortality. We did not perform an adjustment analysis of drugs affecting glucose level. Results : The maximum glucose level within 7 days in PICU was higher in the nonsurvival group than in the survival group. Using 4 cutoff values (125, 150, 175, and 200 mg/dL), the mortality of patients with hyperglycemia was found to be 13.0 %, 14.4%, 19.8%, and 21.1%, respectively, and the cutoff values of 175 and 200 mg/dL revealed significant differences in mortalities between the hyperglycemic and normoglycemic groups. The PRISM-III score was not significantly different between the hyperglycemic and normoglycemic groups under a glucose cutoff value of 175 mg/dL, but the SOFA score was higher in the hyperglycemic group. Under a glucose cutoff value of 200 mg/dL, the PRISM-III score was higher in the hyperglycemic group, and the SOFA score did not differ between the 2 groups. Conclusion : Hyperglycemia with a maximal glucose value ${\geq}175\;mg/dL$ during the first 7 days after PICU admission was associated with increased mortality in critically ill children.

• Korean Business Review
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• v.11
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• pp.241-253
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• 1998

One form of the anomalies of stock price changes as reaction to earnings information is believed to be caused by the so-called earnings fixation, which is the overreaction of stock prices to earnings. According to the Sloan (1996) study, stock price changes are positively associated with earnings at the time of earnings releases, but the association becomes negative after that, as the early overreaction is corrected. However, the problem in his study is to use cash flows computed by adjusting earnings with appropriate income statement and balance sheet items. As Bahnson et al. (1996) show, these cash flows substantially deviate from SFAS No. 95 cash flows and the sample used in this study is found to be subject to this substantial measurement error. Therefore, the result of Sloan might be driven by this error and the reexamination of earnings fixation is warranted. The results are generally consistent with those in Sloan. First, earnings is positively associated with stock price changes at the time of earnings releases, but the association becomes negative after that. Second, cash flows show a weak association with stock price changes at the time of earnings releases, but the association become stronger thereafter. Third, when seperated from cash flows, accruals have an incremental explanation about stock price changes beyond that of cash flows, accruals have a negative association later on. This finding is consistent with stock price overreaction to accruals, even when more cleaner cash flow data are used.

• The Korean Journal of Financial Management
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• v.25 no.4
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• pp.25-51
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• 2008

In this paper, we analyse empirically the fixed asset investment smoothing of working capital of firms listed on Korea Securities Market. The main results of this study can be summarized as follows. Firms will seek to lower long-term cost by smoothing fixed asset investment and maintaining stationary investment with working capital. Working capital is not only an important use of fund, but also a source of liquidity that should be used to smooth fixed asset investment relative to cash flow shocks if firms face financial constraints. Working capital investment is more sensitive than fixed asset investment to cash flow fluctuations. If firms face financial constraints, working capital investment will compete with fixed asset investment for the limited pool of available cash flows. So, fixed asset investment will have negative relationship with working capital investment. However, criticism that the positive correlation between cash flows and fixed asset investment could arise simply because cash flows is proxy variable for investment demand. Finally, controlling for the fixed asset investment smoothing effects of working capital results in a much larger estimate of the long run impact of financial constraints. Financial constraints is measured by dividend payout ratio and market access level. Fazzari et al. (1988), Fazzari and Petersen (1993), and Faulkender et al. (2008) emphasize that low dividend firms or market unaccessible firms are more likely to face financial constraints, and rarely make use of new equity issuing. The results from empirical analysis show that financial constraints can be better explained using 'adjustment cost' concept. Specifically, the results show that financial constraints exist and that in order to measure financial constraint effects more succinctly, fixed asset investment smoothing effects with working capital should be considered.

• Journal of The Korean Association For Science Education
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• v.33 no.2
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• pp.478-485
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• 2013

"GukMinSoHakDokBon", published in 1895, is the first national textbook designated by the Education Institute. Ten of the 41 chapters consist of scientific contents. In this thesis, some the contents are reviewed in detail and studied to see what significance it has in view of science education. The scientific contents described in "GukMinSoHakDokBon" include Plants Change, Clock, Camels, Wind, Hive, Respiration, Crocodiles, Nature of Animals, and Chemical Elements. For that kind of diversity, it was told that "GukMinSoHakDokBon" was not considered for normal students, and there were many ambiguities due to in sufficient explanations. Some of the contents were even technically wrong. So it has been noted that the scientific contents of "GukMinSoHakDokBon" have more significance in providing new information at that time but not in understanding newly-organized scientific knowledge. However, it is obvious that the early science education in Korea is composed of the methods of reading "GukMinSoHakDokBon". This is a common figure, which can be found in "Willson's Reader", the elementary reading textbook in the U.S. in the 1860's or "小學讀本" by the Ministry of Education in Japan. One thing remarkable is "GukMinSoHakDokBon" induced students' interests through the use of storytelling method for introducing some unfamiliar scientific knowledge. There is no doubt that "GukMinSoHakDokBon" has a very positive role in increasing students interest and intelligence. These advantages are being actively applied in the present model of storytelling education these days. Therefore, "GukMinSoHakDokBon" can be regarded as both a language textbook and an early figure in science education, and it can be also considered that "GukMinSoHakDokBon" has a significance not only in approaching scientific substances theoretically but in using storytelling methods to deliver unfamiliar and strange knowledges to students.