• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.1
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• pp.1-10
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• 2012

Digital Forecast of the Korea Meteorological Administration (KMA) represents 5 km gridded weather forecast over the Korean Peninsula and the surrounding oceanic regions in Korean territory. Digital Forecast provides 12 weather forecast elements such as three-hour interval temperature, sky condition, wind direction, wind speed, relative humidity, wave height, probability of precipitation, 12 hour accumulated rain and snow, as well as daily minimum and maximum temperatures. These forecast elements are updated every three-hour for the next 48 hours regularly. The objective of this study was to construct Forest Fire Danger Rating Systems on the Korean Peninsula (FFDRS_KORP) based on the daily weather index (DWI) and to improve the accuracy using the digital forecast data. We produced the thematic maps of temperature, humidity, and wind speed over the Korean Peninsula to analyze DWI. To calculate DWI of the Korean Peninsula it was applied forest fire occurrence probability model by logistic regression analysis, i.e. $[1+{\exp}\{-(2.494+(0.004{\times}T_{max})-(0.008{\times}EF))\}]^{-1}$. The result of verification test among the real-time observatory data, digital forecast and RDAPS data showed that predicting values of the digital forecast advanced more than those of RDAPS data. The results of the comparison with the average forest fire danger rating index (sampled at 233 administrative districts) and those with the digital weather showed higher relative accuracy than those with the RDAPS data. The coefficient of determination of forest fire danger rating was shown as $R^2$=0.854. There was a difference of 0.5 between the national mean fire danger rating index (70) with the application of the real-time observatory data and that with the digital forecast (70.5).

• Tuberculosis and Respiratory Diseases
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• v.40 no.3
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• pp.259-266
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• 1993

Background: To evaluate the risk factor of pneumothorax (PNX) which is the most common complication of CT-guided needle aspiration of the lung, we have examined the frequency of PNX according to the presence of obstructive ventilatory impairment determined by pulmonary function tests. Methods: A comparative study of analysis of forecd expiratory volume and folw-volume curves, and determinations of diffusing capacity taken before procedure were made between each 16 cases with PNX and controls with no PNX. Each of the control group was matched for sex, age, height, and size and depth of lesion with the former. Results: 1) In comparison of vital capacity and parameters derived from forced expiratory volume curve between two groups, VC and FVC were not significantly different, whereas $FEV_1$, $FEV_1$/FVC%, and FEF25-75% showed a significant decrease in the PNX gorup. Also, in the PNX group, all the observed values of parameters analyzed from flow-volune curve were siginificantly reduced in the PNX group compared with those in the control group. 2) The diffusing capacity tended to decrease along with varying individual differences in the PNX group. 3) Patients who had obstructive ventilatory impairment according to the results of pulmonary function tests experienced a twofold increase in the frequency of PNX and a sixfold increase in the frequency of chest tube drainage for treatment of PNX compared with those whose results were normal. Conclusion: These findings suggest that the exact evaluation of obstructive lung disease determined by pulmonary function test be considered assessing a pastient's risk for PNX in the patients who will take the CT-guided needle aspiration of the lung.

• Asia pacific journal of information systems
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• v.18 no.2
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• pp.95-114
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• 2008

Recent interests in data mining result from the expansion of the amount of business data and the growing business needs for extracting valuable knowledge from the data and then utilizing it for decision making process. In particular, recent advances in association rule mining techniques enable us to acquire knowledge concerning sales patterns among individual items from the voluminous transactional data. Certainly, one of the major purposes of association rule mining is to utilize acquired knowledge in providing marketing strategies such as cross-selling, sales promotion, and shelf-space allocation. In spite of the potential applicability of association rule mining, unfortunately, it is not often the case that the marketing mix acquired from data mining leads to the realized profit. The main difficulty of mining-based profit realization can be found in the fact that tremendous numbers of patterns are discovered by the association rule mining. Due to the many patterns, data mining experts should perform additional mining of the results of initial mining in order to extract only actionable and profitable knowledge, which exhausts much time and costs. In the literature, a number of interestingness measures have been devised for estimating discovered patterns. Most of the measures can be directly calculated from what is known as a contingency table, which summarizes the sales frequencies of exclusive items or itemsets. A contingency table can provide brief insights into the relationship between two or more itemsets of concern. However, it is important to note that some useful information concerning sales transactions may be lost when a contingency table is constructed. For instance, information regarding the size of each market basket(i.e., the number of items in each transaction) cannot be described in a contingency table. It is natural that a larger basket has a tendency to consist of more sales patterns. Therefore, if two itemsets are sold together in a very large basket, it can be expected that the basket contains two or more patterns and that the two itemsets belong to mutually different patterns. Therefore, we should classify frequent itemset into two categories, inter-pattern co-occurrence and intra-pattern co-occurrence, and investigate the effect of the market basket size on the two categories. This notion implies that any interestingness measures for association rules should consider not only the total frequency of target itemsets but also the size of each basket. There have been many attempts on analyzing various interestingness measures in the literature. Most of them have conducted qualitative comparison among various measures. The studies proposed desirable properties of interestingness measures and then surveyed how many properties are obeyed by each measure. However, relatively few attentions have been made on evaluating how well the patterns discovered by each measure are regarded to be valuable in the real world. In this paper, attempts are made to propose two notions regarding association rule measures. First, a quantitative criterion for estimating accuracy of association rule measures is presented. According to this criterion, a measure can be considered to be accurate if it assigns high scores to meaningful patterns that actually exist and low scores to arbitrary patterns that co-occur by coincidence. Next, complementary measures are presented to improve the accuracy of traditional association rule measures. By adopting the factor of market basket size, the devised measures attempt to discriminate the co-occurrence of itemsets in a small basket from another co-occurrence in a large basket. Intensive computer simulations under various workloads were performed in order to analyze the accuracy of various interestingness measures including traditional measures and the proposed measures.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.2
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• pp.3-9
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• 2013

Purpose: Currently commercially available phantom can reproduce and evaluate only a static situation, the study is incomplete research on phantom and system which is can confirmed functional situation in the kidney by time through dynamic phantom and blood flow velocity, various difference according to the amount of radioactive. Therefore, through this study, it has produced the dynamic kidney phantom to reproduce images through the dynamic flow of the kidney, it desire to evaluate the usefulness of nuclear medicine imaging. Materials and Methods: The production of the kidney phantom was fabricated based on the normal adult kidney, in order to reproduce the dynamic situation based on the fabricated kidney phantom, in this study it was applied the volume pump that can adjust the speed of blood flow, so it can be integrated continuously radioactive isotopes in the kidney by using $^{99m}Tc-pertechnate$. Used the radioactive isotope was supplied through the two pump. It was confirmed the changes according to the infusion rate, radioactive isotopes and the different injection speeds on the left and right, analysis of the acquired images was done by drawn ten times ROI in order to check the reproducibility of each on the front and rear of the kidney and bladder. Results: Under the same conditions infusion rate 40 mL/min fixed to adjust the pressure of the pump when the radiopharmaceuticals between 2-3 minutes in the most integrated in the kidney phantom was excreted inthe bladder. Glomerular filtration rate (GFR), respectively, by each device SYMBIA 1,091 mL/min, FORTE 1,232 mL/min, ARGUS 1,264 mL/min, INFINIA 1,302 mL/min in that there isno statistically significant difference was found, Tmax values and T1/2 values stars from all equipment with no statistically significant difference was found. CV values of the coefficient of variation less than 5% was found to be repeatable, and to 2.67% of the lowest SYMBIA appeared, INFINIA was the highest in the 4.86%. Conclusion: Through this study, the results showed that the dynamic kidney phantom system is able to similarly reproduce renogram in the actual clinical. Especially, the depicted over time for the flow to be excreted through the kidney into the bladder was adequately reproduce, it is expected to be utilized as basic data to check the quality of the dynamic images. In addition, it is considered to help in the field of functional imaging and quality control.

• The Journal of the Acoustical Society of Korea
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• v.37 no.4
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• pp.223-231
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• 2018

Recently, due to various environmental problems, blast tracks in tunnel are replaced with concrete tracks, but they have more adverse effects on noise than blast tracks so that additional noise measures are needed. Among these measures, sound-absorbing blocks start to be used due to its easy and quick installation. However, the performance of sound absorption blocks need to be verified under real environmental and operational conditions. In this paper, interior noise levels in KTX train cruising in Dalseong tunnel are measured before and after the installation of sound-absorbing blocks and the measured data are analyzed and compared. Additionally, noise reduction are estimated by modeling the high speed train, the tunnel and absorption blocks. Measurement devices and methods are used according to ISO 3381 and the equivalent sound pressure levels during the cruising time inside the tunnel are computed. In addition to overall SPLs(Sound Pressure Levels), 1/3-octave-band levels are also analyzed to account for the frequency characteristics of sound absorption and equipment noise in a cabin. In addition, to consider the effects of train cruising speeds and environmental conditions on the measurements, the measured data are corrected by using those measured during the train-passing through the tunnels located before and behind the Dalseong tunnel. Analysis of measured results showed that the maximum noise reduction of 6.8 dB (A) can be achieved for the local region where the sound-absorbing blocks are installed. Finally, through the comparison of predicted 1/3-octave band SPLs for the KTX interior noise with the measurements, the understanding of noise reduction mechanism due to sound-absorbing blocks is enhanced.

• Journal of Conservation Science
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• v.25 no.2
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• pp.207-217
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• 2009

After replicating 10 bronze types such as Gyemija, Gyeongjaja, Eulhaeja, etc. before the Imjin war, we studied the change of microstructure from each casting process, method, and alloy ratio by Gyechukja replicated from "Donggukyeojiseungnam". We selected the average of compositions of Eulhaeja in the National Museum of Korea as the standard(Cu 86.7%, Sn: 9.7%, Pb: 2.3%) of bronze types, so we decided on the alloy's composition of Cu 87%, Sn 15%, Pb 8% added to 5% Sn and Pb contents because of evaporating the Sn and the Pb. Before replicating major metal types, we made master-alloy first, melting it again, and then replicated metal types. The composition of the 1'st replicated Gyechukja showed the range of Cu 85.81~87.63%, Sn 9.27~10.51%, Pb 3.05~3.19%. The 2'nd replicated Gyechukja made using the branch metal left after casting the 1st replica. The 2nd replicated Gyechukja showed the composition range of Cu 87.21~88.09%, Sn 9.06~9.36%, Pb 2.80~3.05%. This result decreases a little contents of Sn and Pb as compared with metal types of the 1st replica. However, it's almost the same as the Eulhaeja's average composition ratio in the National Museum of Korea. As a result of observing the microstructure of restored Gyechukja, it showed the dendrite structure of the typical casting structure and the segregation of Pb. There is no big difference of microstructure between the 1st and the 2nd restored metal types, even though the 2nd restored types partially decreases the eutectoid region in comparison with the 1st types. The systematic and scientific restoration experiment of metal types using Joseon period will be showed the casting method and alloy ratio, and this will be of great help to the study of restoration metal types in the future.

• The Korean Journal of Nuclear Medicine
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• v.38 no.4
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• pp.306-310
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• 2004

Purpose: The aim was to assess how the background site affects the Gates' glomerular filtration rate(GFR) measurement using Tc-99m-DTPA in correlation with GFR by I-125-lothalamate method. Material and methods: The study populations were 63 adults with 39 men and 24 women aged from 20 to 59 yrs (mean=37.9 yrs). The fellowing five background regions of interest were used in measurement of GFR using Gates' method: 1) lower side of each kidney(subrenal), 2) around each kidney(circumferential), 3) upper side of each kidney(suprarenal), 4) lateral side of each kidney(lateral), 5) between the two kidneys(inter-renal). We also measured GFR using I-125-iothalamate in each subject. The two studies were separated by 1 to 3 weeks. The subjects were divided into two groups by renal depth. Group 1 with renal $depth{\geq}7cm$ and group 2 with renal depth<7cm. We calculated the means and standard deviations of the GFRs measured by two studies. And we statistically analyzed the correlation and differences among GFRs by Gates' method and the GFR by iothalamate method with correlation analysis. Results: The GFRs by Gates' method using suprarenal and inter-renal background correction showed better correlation with the GFR measured by I-125-iothalamate. And GFRs measured by Gates' method showed statistically significant correlation with the GFR measured by I-125-iothalamate in the group with renal depth<7cm. But GFRs measured by Gates' method did not show statistically significant correlation with the GFR measured by I-125-iothalamate in the group with renal $depth{\geq}7cm$. Conclusion: GFRs measured with Gates' method showed higher correlation with the GFR measured by I-125-iothalamate when the regions of interest were plated over the suprarenal and inter-renal backgrounds. And GFRs measured with Gates method showed statistically significant correlation with the GFR measured by I-125-iothalamate in the group with renal depth<7cm.

• Journal of Korea Water Resources Association
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• v.49 no.2
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• pp.133-144
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• 2016

In this study, Frequency Domain Reflectometry (FDR) and COSMIC-ray soil moisture (SM) stations were installed at Sungkyunkwan University in Suwon, South Korea. To provide reliable information about SM, soil property test, time series analysis of measured soil moisture, and comparison of measured SM with satellite-based SM product are conducted. In 2014, six FDR stations were set up for obtaining SM. Each of the stations had four FDR sensors with soil depth from 5 cm to 40 cm at 5~10 cm different intervals. The result showed that study region had heterogeneous soil layer properties such as sand and loamy sand. The measured SM data showed strong coupling with precipitation. Furthermore, they had a high correlation coefficient and a low root mean square deviation (RMSD) as compared to the satellite-based SM products. After verifying the accuracy of the data in 2014, four FDR stations and one COSMIC-ray station were additionally installed to establish the Soil Moisture site with FDR and COSMIC-ray, called SM-FC. COSMIC-ray-based SM had a high correlation coefficient of 0.95 compared with mean SM of FDR stations. From these results, the SM-FC will give a valuable insight for researchers into investigate satellite- and model-based SM validation study in South Korea.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.12C
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• pp.1288-1298
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• 2002

To implement elliptic curve cryptosystem in GF(2$\^$m/) at high speed, a fast divider is required. Although bit-parallel architecture is well suited for high speed division operations, elliptic curve cryptosystem requires large m(at least 163) to support a sufficient security. In other words, since the bit-parallel architecture has an area complexity of 0(m$\^$m/), it is not suited for this application. In this paper, we propose a new serial-in serial-out systolic array for computing division operations in GF(2$\^$m/) using the standard basis representation. Based on a modified version of tile binary extended greatest common divisor algorithm, we obtain a new data dependence graph and design an efficient bit-serial systolic divider. The proposed divider has 0(m) time complexity and 0(m) area complexity. If input data come in continuously, the proposed divider can produce division results at a rate of one per m clock cycles, after an initial delay of 5m-2 cycles. Analysis shows that the proposed divider provides a significant reduction in both chip area and computational delay time compared to previously proposed systolic dividers with the same I/O format. Since the proposed divider can perform division operations at high speed with the reduced chip area, it is well suited for division circuit of elliptic curve cryptosystem. Furthermore, since the proposed architecture does not restrict the choice of irreducible polynomial, and has a unidirectional data flow and regularity, it provides a high flexibility and scalability with respect to the field size m.

• Restorative Dentistry and Endodontics
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• v.31 no.6
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• pp.477-484
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• 2006

The purposes of this study were to compare the apical terminus width of simulated curved root canal prepared with three NiTi file systems used by undergraduates for evaluation the effects of flute angle and pitch or radial land on reducing screw-in effect and to determine more safe NiTi file system for inexperienced operators. Fifty inexperienced undergraduate students prepared 150 simulated curved root canals in resin blocks with three NiTi file systems ; ProFile$^{(R)}$, Hero Shaper$^{(R)}$, K3$^{TM}$. The electric motor set at a speed of 300 rpm and torque of 30 in a 16 : 1 reduction handpiece was used. The simulated root canal was prepared to ISO #25 sizes with each file system. The scanned images of pre- and post-instrumented canal of resin block were superimposed. To evaluate the screw-in effect of three NiTi file systems, apical terminus width of root canal was measured from superimposed images and statistical analysis was performed. There were significant differences in three NiTi flle systems. ProFile$^{(R)}$ had significantly smaller width than Hero Shaper$^{(R)}$ and K3$^{TM}$"" (P < 0.05), but no significant difference was observed between K3$^{TM}$ and Hero Shaper$^{(R)}$. Under the condition of this study, active file system (Hero SHaper$^{(R)}$, K3$^{TM}$) with variable pitch and helical angle had more screw-in effect than passive file system (ProFile$^{(R)}$) with constant pitch and helical angle. It seems that the radial lands play more important role in reducing screw-in effect.