• Journal of the Korean Data and Information Science Society
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• v.27 no.2
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• pp.409-417
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• 2016

The purpose of this study was to demonstrate the effect on the degree of fatigue and accuracy of cardiopulmonary resuscitation according to the different time delays (3 minutes, 4 minutes). Carrying out repeated measures of variance (repeated ANOVA), we have shown that time effect (F = 7.835, p <.01) and group effect (F = 8.695, p<.01) and the interaction effect between time and group (F = 12.582, p<.001) were all statistically significant. It means, in the test of the main effect of group and time (3 minutes, 4 minutes) using the Bonferroni method, it turned out that the amount of lactic acid of the experimental group was larger than that of the control group (p<.01), and there was no difference until 3 minutes, but the difference of the amount of lactic acid was shown between before the experiment and after 4 minutes, and between 3 minutes and 4 minutes (p <.05), respectively. Then, in the result of the corresponding sample t-test, for comparing the according to the measurement time, the accuracy after 3 minutes became higher than the case of 4 minutes (t = 4.584, p <.001). Therefore, before 119 arrives performing cardiopulmonary resuscitation for emergency, rescuers need to perform cardiopulmonary resuscitation alternating with others before 3 minutes.

• Korean Journal of Construction Engineering and Management
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• v.17 no.2
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• pp.12-20
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• 2016

Along with the change of national accounting, the importance of systematic management of assets is emphasized and the awareness that the concept termed Asset Management should be introduced to the construction field too to manage facilities. The present study is a basic study for the introduction of the concept Asset Management and proposed accounting guidelines(proposal) for public building maintenance cost that can clarify maintenance cost accounting. Existing literatures and current accounting standards were examined and the actual states of maintenance cost accounting of public buildings in A metropolitan city were examined to draw problems. For the practice guidelines(proposal), the types and contents of government office building maintenance expenditures were analyzed and items that must be treated as OPEX and CAPEX were presented. Expert interviews were conducted to verify the reliability of the items presented. The practice guidelines(proposal) were applied to the public buildings in A metropolitan city to identify situations of changes in asset values and review the effects of the practice guidelines(proposal) on increases in asset values. When applied to practices, the practice guidelines(proposal) suggested in the present study are considered to increase building asset values and provide consistent financial information to help stakeholders' decision making.

• Journal of Korean Society of Forest Science
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• v.102 no.4
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• pp.515-521
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• 2013

The objective of this study was to estimate the changes of stand structure before and after applying the three different silvicultural treatments such as selection cutting system, two-storied system, and shelterwood system. This study has been conducted in the natural deciduous forests in Pyeongchang of Gangwon Province, Korea. Nine permanent sampling plots of 0.09 ha were established in the forests and each of the three silvicultural treatments was applied to three sampling points. Some tree variables were measured in each stand before and after the silvicultural treatments were applied. With these data, stand attributes were estimated in each stand before and after applying the silvicultural treatments. In this study, a competition index was used to analyze the differences among structures of stands managed by three different silvicultural treatments. Hegyi's distance-dependent competition index was estimated and compared to analyze the differences of stand structures among the stands before and after silvicultural treatments. A method using a height angle $50^{\circ}$ from the base of the subject tree was adopted as the selection method of competitor trees. Duncan's multiple range test and t-test were then employed to statistically analyze the difference of stand structure among the stands. The results revealed that competition status among trees in the stand seems to be improved after applying the silvicultural treatments. There are significant differences in the competition index between before and after silvicultural treatments for each stand. According to the evaluation of competition index, it was confirmed that spatial structure of the stands was improved by applying the silvicultural treatments.

• The Journal of Engineering Geology
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• v.23 no.4
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• pp.457-465
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• 2013

We integrated and correlated datasets from surface and subsurface geophysics, drilling cores, and engineering geology to identify geological interfaces and characterize the joints and fracture zones within the rock mass. The regional geometry of a geologically weak zone was investigated via a fence projection of electrical resistivity data and a borehole image-processing system. Subsurface discontinuities and intensive fracture zones within the rock mass are delineated by cross-hole seismic tomography and analyses of dip directions in rose diagrams. The dynamic elastic modulus is studied in terms of the P-wave velocity and Poisson's ratio. Subsurface discontinuities, which are conventionally identified using the N value and from core samples, can now be identified from anomalous reflection coefficients (i.e., acoustic impedance contrast) calculated using a pair of well logs, comprising seismic velocity from suspension-PS logging and density from logging. Intensive fracture zones identified in the synthetic seismogram are matched to core loss zones in the drilling core data and to a high concentration of joints in the borehole imaging system. The upper boundaries of fracture zones are correlated to strongly negative amplitude in the synthetic trace, which is constructed by convolution of the optimal Ricker wavelet with a reflection coefficient. The standard deviations of dynamic elastic moduli are higher for fracture zones than for acompact rock mass, due to the wide range of velocities resulting from the large numbers of joints and fractures within the zone.

• Korean Journal of Food Science and Technology
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• v.52 no.5
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• pp.546-554
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• 2020

Natural food additives have recently attracted attention as alternatives to synthetic additives. However, little information is available regarding their potential toxicity. In this study, we evaluated ten different natural food additives that are widely used in commercial foods in South Korea based on their actual usage level and daily intake. The results showed that none of the tested natural additives exhibited cytotoxicity in terms of inhibition of cell proliferation/viability and lactate dehydrogenase leakage. Additionally, the tested natural food additives did not generate intracellular reactive oxygen species (ROS), whereas they significantly decreased intracellular ROS levels produced by hydrogen peroxide. Moreover, none of the tested natural additives affected cell proliferation and viability in 2D and 3D intestinal epithelium models. Taken together, the ten natural food additives did not exhibit cytotoxicity in their actual usage levels. These findings can be used to further assess the toxicity of natural food additives.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.6
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• pp.522-527
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• 2004

Barley growing in paddy fields often suffers from wet-injury due to oxygen deficiency in rhizospere caused by excessive water in the soil. This study was conducted to investigate responsiveness of growth, development and anaerobic glycolysis enzymes to acute hypoxia in barley seedlings. Barley seedlings at the third leaf stage were subjected to hypoxia (1 ppm dissolved oxygen) by sparging the culture solution with nitrogen gas for up to seven days. Length and fresh weights of the shoot and root were affected little by hypoxia for up to 5 days. But root dry weight was slightly decreased by hypoxia for 7 days. In the root, alcohol dehydrogenase and lactate dehydrogenase activities increased drastically under hypoxia, reaching at their maximum levels in 3 to 5 days of hypoxia and decreasing slightly thereafter. However, the activities of both enzymes changed little in the shoot. Increases of their activities in the root were contributed by all the isozymes found in barley. These results suggest that barley seedlings first adapt to hypoxia by rapidly activating fermentative glycolysis to stabilize cellular pH and to increase energy production for the following morphological adaptative changes.

• The Journal of the Korea Contents Association
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• v.17 no.6
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• pp.650-660
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• 2017

This study aims to research the indication way and contents description of grammar presented in Korean textbooks. Therefore we examine the common elements of grammar in four Korean textbooks and the transcription, notation methods and meaning descriptions the books use to present grammar items. After analyzing Korean textbooks for the beginner level, we found just 20 similar items among a total of 100-150 grammar items. Advanced researches required to examine the selection and classification of grammatical items in Korean education. The results show that it used as the same name "grammar" expressed in Korean textbooks compared to using different names in the past. We consider that just 20 grammar items are the same because the range of grammar items in every textbook is different including vocabulary, sentences etc. The study found that grammar items are expressed differently in the type of indication way, order of arrangement, and marks. We suggest that it is better to indicate the style of representation used in grammar items because an additional problem such as type of indication way, order of arrangement is removed by doing so. The study also found grammar items are expressed differently in the meaning description and grammar range of explanation of Korean textbooks. This study suggests that morphological information, restriction information and meaning should be described at a basic level. This study allows us to consider the indication way and contents description of grammar are presented in Korean textbooks.

• The Korean Journal of Applied Statistics
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• v.21 no.1
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• pp.81-94
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• 2008

Family-based tests such as the transmission and disequilibrium tests(TDT) have proved to be powerful tools in the search for disease genes. Unlike case-control studies, the tests are not affected by population admixture, which can lead to spurious association of multiple highly linked makers with disease-susceptible genes. Those tests have largely required knowledge of parental marker genotypes. However, parental data are often not available for late-onset diseases. In this article we propose sib-TDTs that overcome this problem by use of marker data from unaffected sib(s) instead of parents. To do this end, we fist defined a Mantel-Haenszel-type statistic for each haplotype and then proposed two tests based on this statistic. Simulation studies suggest that the proposed tests are robust to population admixture and are monotone increasing as a relative risk increases irrespective of mode of inheritance. We also illustrated the proposed tests with data adopted from Yonsei Cardiovascular Genome Center.

• Management & Information Systems Review
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• v.28 no.4
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• pp.109-129
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• 2009

This study aims at investigating the effectiveness of SME's R&D system empirically. Specifically, this study analyze the relationships among R&D inputs(R&D investment, R&D human resource management), process(R&D planning, external network, internal cooperation), and output(technological innovation). A questionnaire was developed to measure the above variables. To test these relations, data were collected from the small and medium-sized IT firms located in Daegu-Kyungbuk region. The survey data of 154 firms were integrated as the empirical base for testing the relations. Most respondents were from the managers. Structural equation modeling analyses were used to examine the relations. Major results are as follows: Firstly, R&D HRM was positively and significantly influenced on the R&D planning. Secondly, R&D planning was positively and significantly affected on the external network, internal cooperation, and technological innovation. Thirdly, the both relations between R&D investment and R&D planning, and external network and technological innovation were not significant statistically. These results suggest the following implications. First, R&D human resource management is very important for IT SMEs. Secondly, internal cooperation mediates R&D inputs and technological innovation by approaching the other department's unique resources and by sharing the cost of new resource development. Several future researches need to overcome the limitations of this research. First, this study's sample was based on the small and medium-sized IT firms just located in Daegu-Kyungbuk region. This limitation may imply that empirical results can not represent overall small and medium-sized firm's situations. Therefore, future research needs to include different samples. Secondly, this study depends on the latitudinal study.

• Journal of the Korea Computer Industry Society
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• v.5 no.9
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• pp.1101-1110
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• 2004

In the first quarter of 2004, there were about 1 billion 348 million mobile phone users worldwide with a penetration rate of only 29%. Korea ranks among the highest in the use of mobile communication, having over 36 million mobile phone subscribers with a mobile phone penetration rate of 75% as of May 2004. Since the introduction of wireless Internet service in May 1999, the number of subscribers rose to 34.5 million with 95.3% of the total mobile phone subscribers using wireless Internet services in May 2004, largely due to continued investments by telecommunication service providers, improvement of mobile handsets (color and digital camera phones) and implementation of policies on mobile number portability. In the Korean wireless Internet market, there are many user complaints since the service providers are competing with each other through TV commercial sales and phone discounts rather than improving their call quality, services and billing systems. therefore there is a growing need to improve the billing systems through means such as the implementation of reasonable payment plans according to consumer use, development of a wireless Internet billing system that can predict the number of users and establishment of pricing standards for controlled data (head, tail, etc...) as well as menu information by testing the texts. multimedia, video and other types of content provided by the three major mobile communication companies. The purpose of this study is to promote wireless Internet services and protect user rights by proposing a reasonable way to improve the billing systems for wireless Internet services after conducting a comparative analysis of file size and billing data of each of the service providers through a verification test on a packet billing system for wireless Internet services.