• Clinical and Experimental Pediatrics
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• v.58 no.2
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• pp.64-68
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• 2015

Purpose: The purpose of this study was to investigate the importance of initial screening tests for depression and anxiety disorders in children with headache. In addition, this study evaluated whether the Children's Depression Inventory (CDI) and Revised Children's Manifest Anxiety Scale (RCMAS) are suitable for screening symptoms of depression and anxiety. Methods: A retrospective chart review was conducted of 720 children aged 7-17 years who had visited a pediatric neurology clinic for headaches and were referred to a pediatric psychiatric clinic for psychiatric symptoms from January 2010 to December 2011. All patients completed the CDI and RCMAS. Among them, charts of patients with clinically significant total scores (cutoff>15) for psychiatric symptoms, as defined by the CDI and RCMAS scoring scales, were reviewed. Results: Nineteen patients had headaches and clinically significant total scores for psychiatric symptoms. The mean age at headache diagnosis was 11.7 years, and 57% were male. Mean duration of headache was 11.5 months. Two point eight percent of the patients were diagnosed with psychiatric disorders including major depression (1.7%), generalized anxiety disorder (1.1%), and bipolar disorder (0.1%). Four patients (0.6%) were diagnosed with attention deficit/hyperactivity disorder (ADHD). Total mean CDI and RCMAS scores of patients referred to the psychiatric clinic were 18.8 and 22.2, respectively. There was no correlation between CDI or RCMAS total scores and headache frequency, duration, or severity. Conclusion: We recommend that all patients with headache should be screened for depression and anxiety by CDI and RCMAS scores.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.4
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• pp.9-17
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• 2012

This study was aimed to characterize non-point source (NPS) pollutant runoff and estimate event mean concentrations (EMCs) from a small rural watershed located at the headwater area of the Gyeongan stream. The study watershed consists of the two major landuse, forest (72 %) and paddy field (28 %). The nine rainfall events ranging from 18.5 to 192.6 mm in amount were monitored in this study. Stream flow was measured at the watershed outlet using a water level gauge, while a number of water samples for each event were collected and analysed for water quality. Event pollutant loads varied greatly depending on rainfall events varying from 22.6 to 3,134.2 mg/L, 0.32 to 24.56 mg/L, 0.090 to 1.320 mg/L, and 2.3 to 149.8 mg/L for SS, TN, TP, and COD, correspondently. The respective mean EMCs were estimated by 104.2, 1.00, 0.168, and 7.9 mg/L. The Pearson correlation analysis showed that COD EMC was significantly correlated with those of SS, TN, and TP. Rainfall runoff ratio appeared to be negatively correlated with EMCs of SS, TP, and COD, although not statistically significant. The event loads from the largest rainfall was greater than the sum of those from the remaining eight events. The study results suggest that the appropriate management of intensified storm events are of greater importance in curbing NPS loads, while the estimated EMCs provide base data for the unit pollutant loads determination for the forest-paddy composite upstream watershed.

• The Journal of the Korea Contents Association
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• v.6 no.10
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• pp.134-142
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• 2006

In this paper, we investigate a Hausdorff distance, which is used for the measurement of image similarity, to see whether it is also effective for document retrieval. The proposed method uses a local crowdedness and a Hausdorff distance to locate text images by determining whether a pair of images scanned at different time comes from the same text or not. To reduce the processing time, which is one of the disadvantages of a Hausdorff distance algorithm, we adopt a local crowdedness for feature point extraction. We apply the proposed method to 190 pairs of the same class and 190 pairs of the different class collected from postal envelop images. The results show that the modified Hausdorff distance proposed in this paper performed well in locating the tort region and calculating the degree of similarity between two images. An improvement of accuracy by 2.7% and 9.0% has been obtained, compared to a binary correlation method and the original Hausdorff distance method, respectively.

• Environmental Engineering Research
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• v.15 no.2
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• pp.123-126
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• 2010

Modeling non-point pollution across multiple scales has become an important environmental issue. As a more representative and practical approach in quantifying and qualifying surface water, a modular neural network (MNN) was implemented in this study. Two different site-scales ($1.5\;{\times}\;10^5$ and $1.62\;{\times}\;10^6\;m^2$) with the same plants, soils, and paddy field management practices, were selected. Hydrologic data (rainfall, irrigation and surface discharge) and water quality data (time-series nutrient loadings) were continuously monitored and then used for the verification of MNN performance. Correlation coefficients (R) for the results predicted from the networks versus measured values were within the range of 0.41 to 0.95. The small block could be extrapolated to the large field for the rainfall-surface drainage process. Nutrient prediction produced less favorable results due to the complex phenomena of nutrients in the drainage water. However, the feasibility of using MNN to generate improved prediction accuracy was demonstrated if more hydrologic and environmental data are provided. The study findings confirmed the estimation accuracy of the upscaling from a small-segment block to large-scale paddy field, thereby contributing to the establishment of water quality management for sustainable agriculture.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.6A
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• pp.614-622
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• 2004

In this paper, we propose the frequency diversity scheme for performance improvement of a OFDM system without decreasing the spectral efficiency. In the proposed scheme, information bit is encoded to symbol by a simple procedure, and the encoded symbol is transmitted through the two lowest correlated sub-channels with the particular phase difference. At the receiver, a frequency diversity gain is obtained by a simple signal processing. We also suggest optimum phase difference value to minimize the performance degradation which resulted from a phase difference estimation error and bit/symbol mapping method to minimize BER. As results, at the point of performance improvement, the proposed scheme is excellent even though it requires a little increase of system complexity because of an additional encoding and decoding. In particular, we confirmed through computer simulation that on the same channel environment and bandwidth efficiency, the 27x/1Rx STBC-OFDM system adopting the proposed frequency diversity scheme outperforms the conventional 27x/1Rx STBC-OFDM system performance

• International Journal of Highway Engineering
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• v.13 no.1
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• pp.49-57
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• 2011

This study deals with the traffic accident of arterial link sections in the case of Cheongju. The purpose of the study is to develop the traffic accident model by the function of arterial links. In pursuing the above, this study gives particular attentions to developing the appropriate models using the accident data of main and minor arterial roads divided by 472 small link sections. The main results analyzed are as follows. First, as the t test on the accident characteristics of main and minor arterial roads shows that there are differences in the number of accident and EPDO(equivalent property damage only) between two roads, the development of models by function is analyzed to be appropriate. Second, it is analyzed that ZINB models are all statistically suitable to the number of accident and EPDO of main arterial roads. Third, the analysis shows that EPDOs of minor arterial roads fit to ZINB, and the number of the accident fit to ZIP model. Finally, the common variables of main arterial roads are evaluated to be the traffic volume and the number of inflection point, and those of minor be the average grade.

• Journal of the Mineralogical Society of Korea
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• v.9 no.1
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• pp.1-6
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• 1996

Woolastonite from Susan occurs as intercalations in limestone beds of Lower Paleozoic Joseon Supergroup. It is a thermal metamorphic product of impure limestone. Electron microprobe analysis shows that it is considerably pure wollastonite. It has triclinic cell with a=7.932$\AA$, b=7.328$\AA$, c=7.069$\AA$, $\alpha$=89.995$^{\circ}$, $\beta$=$95.255^{\circ}$, and $ \Upsilon=103.367^{\circ}$.Dissolution behaviors of wollastonite have been studied conducting three different dissolution experiments; two different reactions with HC1 (one batch and one re-initialization experiment) and one traction with distilled water. In the batch type powder wollastonite-HCl reaction, pH of solution rapidly increases in the early stage and then its rate of increase slows down to reach plateau resulting in parabolic relationship with time. It is represented by the early rapid rise and fall in pH giving a sharp pH-edge and succeeding slow rise in the re-initialization experiment. The early rapid rise in pH is due to the rapid sorption of H- in solution to oxygens on the reactive surface of wollastonite and the fall in pH means that all reactive surface sites are occupied by H- ions and no more H- adsorption occurs. The slow rise in pH following the pH- edge is due to the dissolution of wollastonite as evidenced by the correlation of pH variation and cation concentration. Dissolution of powder wollastonite in HCl shows linear trend with time. Si is dissolved predominantly over Ca at a constant rate. Ca is dissolved predominantly in the very early stage. Dissolution rate of coarse-grained wollastonite fragments in distilled water is parabolic with times howing a rapid reaction in the early stage and a slow reaction in the advanced stage. The Ca/Si ratio in solution is high in the case of coarse-grained wollastonite fragment as compared with powder wollastonite. The coarse-grained wollastonite fragment-water (acid) reaction resulted in the solution with an elevated constant pH value (alkaline) giving an important significance on the environmental view point.

• Publications of The Korean Astronomical Society
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• v.31 no.2
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• pp.11-19
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• 2016

This paper presents the results of test observations toward a point source, 4C39.25, for observation modes with various bandwidths and numbers of IF streams in order to examine a reliability of the Daejeon hardware correlator performance for correlating VLBI (Very Long Baseline Interferometry) data obtained with the several observation modes of the KVN (Korean VLBI Network). We used a DiFX software correlator (DiFX) as a reference, for investigating the output visibilities from the Daejeon corelator. It is found that the band shapes of the output visibilities from two correlators are similar to each other and the correlated flux density for each baseline obtained from the Daejeon hardware correlator is lower by 3 - 7% than that from the DiFX. The flux difference is attributed to the limitation of FPGA resources and the difference of fringe rotation algorithm of the Daejeon hardware correlator. The conversion factor, 0.93 ~ 0.97, is proposed for future correlation with the Daejeon hardware correlator.

• Archives of Plastic Surgery
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• v.47 no.6
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• pp.590-596
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• 2020

Background The introduction of the partial second toe pulp free flap has enabled superior aesthetic and functional results for fingertip reconstruction in adults. Children undergoing fingertip amputation for various reasons have limited options for reconstruction. Conventional treatment could shorten the finger, leading to poor cosmesis and function. We report 18 years of our experiences with fingertip reconstruction using partial second toe pulp free flaps in patients in early childhood. Methods Medical charts of children who had undergone fingertip reconstruction using partial second toe pulp free flaps from 2001 to 2018 were retrospectively reviewed. The surgical procedures were identical to those for adults, except for the usage of 11-0 nylon sutures. Patients' demographic data, vessel size, flap dimensions, length of the distal phalanx, and functional outcomes over the course of long-term follow-up were documented. The statistical analysis was performed with the Student t-test, the Mann-Whitney U test, and Pearson correlation analysis. Results Eighteen toe pulp flaps in 17 patients (mean age, 3.0 years) were identified. All the flaps survived without any major complications. In long-term follow-up, the flap-covered distal phalanges showed growth in line with regular development. There was no donor-site morbidity, and all children adapted to daily life without any problems. In two-point discrimination tests, the fingertip sensation recovered to almost the same level as that in the contralateral finger. Conclusions Partial second toe pulp free flaps are an excellent option for fingertip reconstruction in young children, as well as in adults.

• The Journal of Society for e-Business Studies
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• v.24 no.4
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• pp.109-118
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• 2019

As a result of the United States (U.S) -China trade conflict, the recent instability of the stock market has led many people to invest in Bitcoin, a commodity that many previous studies have interpreted as a safe asset. However, recent Bitcoin market price fluctuations suggest that the asset's stability stems from speculative purchasing trends. Therefore, classifying the characteristics of Bitcoin assets can be an important reference point in analyzing relevant accounting information. To determine whether Bitcoin is a safe asset, this study analyzed the correlation between Bitcoin and economic indicators to verify whether gold and Bitcoin responded similarly in time series analyses. These show that the regression explanatory power between the price of gold and bitcoin is low, thus no relation between the two assets could be drawn. Additionally, the Granger causality analyses of six individual economic variables and Bitcoin did not establish any notable causality. This can be interpreted that short-term price fluctuations have a significant impact on the nature of Bitcoin as an asset.