• The Journal of the Petrological Society of Korea
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• v.23 no.2
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• pp.119-138
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• 2014

There are various ways to monitor active volcanoes, such as the method of observing the activity of a volcano with the naked eye, the method of referring to the past eruptive history based on the historic records and the method of monitoring volcanoes by using observation equipment. The most basic method from the observation equipment-using methods to monitor volcanoes is seismic monitoring. In addition to this, the ways to monitor volcanoes are as follows: resonance observation which may be effective to remove artificial noises from the seismic activities that are recorded in the seismograph, ground deformation by using precision leveling, electronic distance measurement, tiltmeter, GPS, and InSAR observation method, volcanic gas monitoring, hydrologic and meteorological monitoring, and other geophysical monitoring methods. These monitoring methods can make volcanic activities effectively monitored, determine the behavior of magmas in magma chambers and help predict the future volcanic eruptions more accurately and early warning, thus, minimize and mitigate the damage of volcanic hazards.

• Journal of Korean Traditional Oncology
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• v.19 no.1
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• pp.53-59
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• 2014

Objectives : Thyroid cancer is one of the most common and rapid increases of malignancy worldwide. It is the aim of the present a case of papillary thyroid microcarcinoma (PTMC) treated with acupuncture alone to derive further studies of the determination of treatment options for PTMC, such as surgery, acupuncture and observation alone, etc. Method : A 51-year-old woman with malignancy of thyroid nodule ($0.89{\times}0.59cm$) was referred to our hospital on January 2010. We applied to the acupuncture alone three times weekly by the patient's decision from January 2010 to November 2014. Blood tests were conducted three times during the treatment period and ultrasonography was performed every 6 months. Results : Both laboratory data and tumor size results showed no deteriorations as compared with those of initial examination. The patients has been survived in healthy state without any metastasis or disease progression on November, 2014. Conclusion : This case presents a possibility that acupuncture or observation alone can be provided as an option in the treatment means for patients with PTMC. Further study will need to study more longer follow-up and a large number of patients for PTMC using acupuncture or observation alone.

• Ocean and Polar Research
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• v.27 no.2
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• pp.189-195
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• 2005

Several models predict large and potentially abrupt ocean circulation changes due to anthropogenic greenhouse-gas emissions. These circulation changes drive-in the models-considerable oceanic oxygen trend. A sound estimate of the observed oxygen trends can hence be a powerful tool to constrain predictions of future changes in oceanic deepwater formation, heat and carbon dioxide uptake. Estimating decadal scale oxygen trends is, however, a nontrivial task and previous studies have come to contradicting conclusions. One key potential problem is that changes in the historical observation network might introduce considerable errors. Here we estimate the likely magnitude of these errors for a subset of the available observations in the Southern Ocean. We test three common data analysis methods south of Australia and focus on the decadal-scale trends between the 1970's and the 1990's. Specifically, we estimate errors due to sparsely sampled observations using a known signal (the time invariant, temporally averaged, World Ocean Atlas 2001) as a negative control. The crossover analysis and the objective analysis methods are for less prone to spatial sampling location biases than the area averaging method. Subject to numerous caveats, we find that errors due to sparse sampling for the area averaging method are on the order of several micro-moles $kg^{-1}$. for the crossover and the objective analysis method, these errors are much smaller. For the analyzed example, the biases due to changes in the spatial design of the historical observation network are relatively small compared to the tends predicted by many model simulations. This raises the possibility to use historic oxygen trends to constrain model simulations, even in sparsely sampled ocean basins.

• The Korean Journal of Applied Statistics
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• v.29 no.1
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• pp.113-122
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• 2016

Longitudinal data often occur in prospective follow-up studies. Joint model for longitudinal data and failure time has been applied on several works. In this paper, we extend it to the case where longitudinal data involve informative observation time process as well as competing risks survival times. We use a likelihood approach and derive an EM algorithm to obtain maximum likelihood estimate of parameters. A suggested joint model allows us to make inferences for three components: longitudinal outcome, observation time process and competing risk failure time. In addition, we can test the association among these components. In this paper, liver cirrhosis patients' data is analyzed. The relationship between prothrombin times measured at irregular visiting times and drop outs is investigated with a joint model.

• Journal of the Korean Society of Earth Science Education
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• v.3 no.3
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• pp.184-190
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• 2010

This study is to verify the effects of classes at a finishing stage using cartoons depicting certain science textbook units on scientific attitudes and academic achievements of students, compared to those of classes using experiment and observation oriented textbooks. Participants of this study were 56 fifth graders at B Elementary School in Busan, and cartoon textbooks were developed based on 'Unit 1. Mirror & Lens' and 'Unit 3. Temperature & Wind' from a science textbook for the 1st semester, the year 5 to conduct cartoon led lessons just before ending a class till the 10th lesson, for the period of 4 weeks. The result of this study can be summarized as follows: Firstly, scientific attitudes improved better from the cartoon based lesson of a final stage than from the experiment and observation method, and especially more effective in lower groups among all other academic achievement levels as well as in male students. Secondly, academic achievements scored higher when cartoons were used in lessons than when the experiment and observation type was used, with higher groups of academic achievement levels working better, despite no significant gap existing between two genders. Thirdly, the memory transfer and sustenance of lessons were more effective in finishing class stage with cartoon studies than with experiment and observation one, and among all levels and both sexes, higher academic groups and male pupils exceeded. Fourthly, when questioned about their opinions on a cartoon led lesson for a final stage, 65% of those participants responded positively, while higher groups preferred more than lower groups. responded positively, while higher groups preferred more than lower groups.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.1
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• pp.27-33
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• 2012

This study was performed in the Tropical Plant Resources Research Center of Korea National Arboretum to assess the effects of natural enemy attack on aphid population feeding on tropical plants. We measured the density of leaf-feeding aphids, Myzus persicae and Aphis gossypii, cohabiting with 5 types of tropical plants at intervals of approximately 2 weeks after introducing their natural enemy, Aphidius colemani. The density of aphids cohabiting with 4 types of tropical plants-Sanchezia parvibracteata, Hibiscus rosa-chinensis, Ficus kurzii, and Aloysia triphylla-started decreasing after 2 weeks of observation and was completely in control after 4 weeks of observation; however, the density of aphids cohabiting with the tropical plant, Hamelia patens, increased during 22 weeks of observation but decreased after the $23^{rd}$ week of observation. We suggest that a banker plant is necessary for the maintenance of A. colemani in tropical greenhouses, and monitoring studies on H. patens, which was weakest against the aphids, should be performed. Our results indicate that biological pest management strategies using their natural enemies were formulated for the construction of new tropical greenhouses.

• Atmosphere
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• v.31 no.4
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• pp.461-472
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• 2021

Yeongdong has frequently suffered from severe snowstorms, which generally give rise to societal and economic damages to the region in winter. In order to understand its mechanism, there has been a long-term measurement campaign, based on the rawinsonde measurements for every snowfall event at Gangneung since 2014. The previous observations showed that a typical heavy snowfall is generally accompanied with northerly or northeasterly flow below the snow clouds, generated by cold air outbreak over the relatively warmer East Sea. An intensive and multi-institutional measurement campaign has been launched in 2019 mainly in collaboration with Gangwon Regional Office of Meteorology and National Institute of Meteorological Studies of Korean Meteorological Administration, with a special emphasis on winter snowfall and spring windstorm altogether. The experiment spanned largely from February to April with comprehensive measurements of frequent rawinsonde measurements at a super site (Gangneung) with continuous remote sensings of wind profiler, microwave radiometers and weather radar etc. Additional measurements were added to the campaign, such as aircraft dropsonde measurements and shipboard rawinsonde soundings. One of the fruitful outcomes is, so far, to identify a couple of cold air damming occurrences, featuring lowest temperature below 1 km, which hamper the convergence zone and snow clouds from penetrating inland, and eventually make it harder to forecast snowfall in terms of its location and timing. This kind of comprehensive observation campaign with continuous remote sensings and intensive additional measurement platforms should be conducted to understand various orographic precipitation in the complex terrain like Yeongdong.

• Journal of Advanced Navigation Technology
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• v.26 no.6
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• pp.393-403
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• 2022

Various studies suggest that the initial operating form of UAM, which is being presented as a solution to the urban traffic problem, will be similar to VTOL aircraft among current aircraft. In a form similar to determining the direction of the runway where fixed-wing aircraft take off and land, the vertiport where take-off and landing of VTOL aircraft takes place determines the flight direction of departure and arrival in consideration of the direction of the wind. Unlike areas where airports are generally built, in the case of downtown areas, it is expected that the characteristics of wind may continuously change depending on the environment of changing terrain or obstacles such as the construction of new buildings. In this study, long-term actual observation data for reviewing the take-off and landing directions at the city center where the location of the vertiport is expected are compared using a wind speed map, and the characteristics of the ground wind and the possibility of change in the direction of the predominant wind depending on the observation period and observation location confirmed.

• Journal of Astronomy and Space Sciences
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• v.40 no.3
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• pp.113-122
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• 2023

Although the Relative Global Navigation Satellite System (GNSS) positioning technique provides high accuracy, it has several drawbacks. The scarcity of control points, the long baselines, and using of ultra-rabid and rabid products increased position errors. This study has designed a New MATLAB Program that helps users automatically select suitable IGS stations related to the baseline lengths and the azimuth between GNSS points and IGS stations. This study presented criteria for the length of the baselines used in Egypt and an advanced estimated accuracy before starting the project. The experimental test studies the performance of the position accuracy related to the relation between three factors: observation session, final, rabid, and ultrarabid products, and the baseline lengths. Ground control point mediates Egypt was selected as a test point. Nine surrounding IGS stations were selected as reference stations, and the coordinates of the tested point were calculated based on them. Baselines between the tested point and the IGS stations were classified regarding proposal criteria. The coordinates of the tested point were obtained in different observation sessions (0.5, 1, 2, 4, 5, 6, 7, 7.5 h). The results indicated that the lengths of the baseline in Egypt were classified short (less than 600 km), medium (600-1,200 km), and long (greater than 1,200 km) and required a minimum observation time of 4, 5, and 7 h to obtain accuracy 10, 19, 48 mm sequentially. The position accuracy was superior for the rapid and the final than the ultra-rapid products by 16%. A short baseline was at the best case; there was a performance in position accuracy with a 57% deduction in observation time compared with the long baseline.

• Journal of the Society of Disaster Information
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• v.13 no.1
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• pp.89-95
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• 2017

The cases of animals unusual behavior have been reported occasionally before a major disaster occurs. Could animals unusual behavior associated with a major disaster occurrence, if so, could we foreknow a disaster occurrence? The purpose of study is to quest an answer through literature reviews on the relation between animals unusual behavior and premonitory symptoms of an earthquake. These empirical studies are classified three parts according as methodological framework; statistical analysis, experimental analysis, observation analysis. The results are simply divided as two, 'animals unusual behavior may be seen as a precursor of pre-disaster phenomena' and 'difficult to see.' A number of studies have been performed abroad, however there is no one in Korea. Most of the studies point out common limitations-difficult to verify the reliability of data, accidentally get and fewer samples of data, difficulty of ensuring appropriate data, etc. That is why more related research with animals unusual behavior and disaster occurrence is needed to validate cause-and-effect relation of animal unusual behavior and pre-disaster phenomena.