• Korean Journal of Environment and Ecology
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• v.36 no.2
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• pp.139-149
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• 2022

This study aimed to prepare basic data for protecting the habitat of Fairy Pitta Pitta nympha and coping with climate change by detecting songs with bio-acoustic recording technology and identifying phenological characteristics in protected areas in Korea. The study sites were 36 protected areas nationwide. Data were collected between January and December 2019, and the analysis period was from May 1 to August 31, 2019. The main results are described as follows. Firstly, songs were detected in 22 out of 36 study sites. Frequency analysis results of songs show that high frequency was observed in southern inland, including Jeju island, and the area with the highest latitude was Seoraksan National Park. Secondly, the first song was observed in Hallyeohaesang National Park Geumsan on May 14, 2019, and the last song was observed in Ungok wetland in Gochang on August 6, 2019. Thirdly, circadian rhythm analysis results of songs show that the frequency rapidly increased at five o'clock in the morning, peaked at six o'clock, and then decreased afterward. Fourthly, seasonal cycle analysis results of songs show that they were observed from May 14, 2019 to August 6, and the day with the highest accumulated frequency of songs was June 3, 2019 (Julian date: 154). The average temperature of the day the songs were detected was 17.4℃, the average precipitation was 0.02mm, and the average humidity was 82.6%. Fifthly, a correlation analysis result between Fairy Pitta's songs and meteorological factors shows that temperature indicated a negative correlation with Fairy Pitta's songs (p<0.001), but precipitation (p=0.053) and humidity (p=0.077) did not indicate a statistical significance (df=471). This study is significant in that it confirmed the distribution of Fairy Pitta's songs using bio-acoustic recording technology in protected areas nationwide and identified their ecological characteristics by precisely analyzing the relationship between the song period and meteorological factors.

• Journal of the Korean Geographical Society
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• v.42 no.4
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• pp.469-487
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• 2007

Grain-Size Trend Analysis is the methodology to identify net sediment transport pathways, based on the assumption that the movement of sediment from the source to deposit leaves the identifiable spatial pattern of mean, sorting, and skewness of grain size. It can easily be implemented with low cost, so it has great potentials to contribute to geomorphological research, whereas it can also be used inadequately without recognition of its limitations. This research aims to compare three established methods of grain-size trend analysis to search for the adequate way of application, and also suggest the research tasks needed in improving this methodology 1D pathway method can corporate the field experience into analyzing the pathway, provide the useful information of depositional environments through X-distribution, and identify the long-term trend effectively. However, it has disadvantage of the dependence on subjective interpretation, and a relatively coarse temporal scale. Gao-Collins's 2D transport vector method has the objective procedure, has the capability to visualize the transport pattern in 2D format, and to identify the pattern at a finer temporal scale, whereas characteristic distance and semiquantitative filtering are controversial. Le Roux's alternative 2D transport vector method has two improvement of Gao-Collins's in that it expands the empirical rules, considers the gradient of each parameters as well as the order, and has the ability to identify the pattern at a finer temporal scale, while the basic concepts are arbitrary and complicated. The application of grain sire trend analysis requires the selection of adequate method and the design of proper sampling scheme, based on the field knowledge of researcher, the temporal scale of sediment transport pattern targeted, and information needed. Besides, the relationship between the depth of sample and representative temporal scale should be systematically investigated in improving this methodology.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.7
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• pp.784-795
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• 2007

In this thesis, the Multi element antenna with wideband and enhanced gain characteristic is proposed to operate at both frequency range from 824 MHz to 896 11Hz for the CDMA and frequency range from 908.5 MHz to 914 MHz for the RFID band. The proposed antenna has tile size of $35{\times}15{\times}5mm^3$ in order to put it in the A model of S company and each element of the proposed antenna is folded to obtain the minimum size. To obtain the antenna with wideband and high gain characteristic, the radiator of the antenna is divided into 4 elements. As a result, bandwidth of the proposed antenna become broader and lower center frequency is appeared due to increased and lengthened current path. Moreover, the enhanced gain characteristic is verified because divided element structure that induct uniform current distribution can get increased antenna efficiency. To attain more uniform current distribution, modified structure of the feeding point that can deliver currents directly is designed. The antenna that alters the feeding structure has higher gain value. Each element is folded to increase the current paths considering the current directions to attain the miniaturization of the antenna. To measure the handset antenna, the handset case must be considered. Even though antenna is designed for predicted characteristic, the resonance frequency is shifted and antenna gain is deteriorated at predicted frequency while antenna is set in the handset case. 1.08 GHz of the resonant frequency is determined after frequency shift from 150 MHz to 200 MHz is confirmed and the maximum gain is measured as 3.1 dBi while antenna is not set in the handset. In case handset case is considered, the experimental results show that the impedance bandwidth for VSWR<2 is from 0.824 GHz to 0.936 GHz(110 MHz). This result appears that the proposed antenna can cover both CDMA and RFID band at once. The measured gain is from -3.4 dBi to -0.5 dBi and it has omni-directional pattern practically.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.161-167
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• 2011

The soil moisture has an important effect on growth and development of highbush blueberry (HB), mainly because the root system, devoid of root hairs, is superficial. Moreover, the texture and organic matter content of Korean soil is different from the main producing counties, such as USA and Canada. To facilitate the growth and development of HB and long-term maintenance of productivity, the research related to soil moisture condition in Korea should be the priority. This study was performed to investigate the growth properties of the HB in various soil moisture conditions in order to determine the irrigation trigger point and optimum soil water potential. The texture of soil used in this experiment was loam. For the experiments, the soil was mixed with peatmoss at a rates 30% (v/v). Irrigation was scheduled at -3, -4, -5, -8, -15 and -22 kPa soil water potential then investigated leaf macronutrient, bush growth, and fruit properties. The leaf K content of HB showed the same trend in the soil water potential, but Leaf P and Mg content was highest in -5 and -22 kPa, respectively. The productivity and growth amount of HB showed the peak at the range of -4~-8 kPa as normal distribution pattern, and greatly decreased at above -15 kPa. Total dry weight and Cane diameter were highest at -4 kPa, plant width, fruit weight and yield were highest at -5 kPa, and plant height, cane number and shoot tension were highest at -8 kPa. Soluble solids content showed same trend in the soil water potential, but titratable acidity, anthocyanins and total polyphenols were not significantly different. Therefore, the optimal soil water potential for the development and a maximum production of HB were a range of -4~-8 kPa, and the recommended ideal irrigation trigger point was within -15 kPa.

• Radiation Oncology Journal
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• v.19 no.3
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• pp.275-286
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• 2001

Purpose : To setup procedures of quality assurance (OA) for implementing intensity modulated radiation therapy (IMRT) clinically, report OA procedures peformed for one patient with prostate cancer. Materials and methods : $P^3IMRT$ (ADAC) and linear accelerator (Siemens) with multileaf collimator are used to implement IMRT. At first, the positional accuracy, reproducibility of MLC, and leaf transmission factor were evaluated. RTP commissioning was peformed again to consider small field effect. After RTP recommissioning, a test plan of a C-shaped PTV was made using 9 intensity modulated beams, and the calculated isocenter dose was compared with the measured one in solid water phantom. As a patient-specific IMRT QA, one patient with prostate cancer was planned using 6 beams of total 74 segmented fields. The same beams were used to recalculate dose in a solid water phantom. Dose of these beams were measured with a 0.015 cc micro-ionization chamber, a diode detector, films, and an array detector and compared with calculated one. Results : The positioning accuracy of MLC was about 1 mm, and the reproducibility was around 0.5 mm. For leaf transmission factor for 10 MV photon beams, interleaf leakage was measured $1.9\%$ and midleaf leakage $0.9\%$ relative to $10\times\;cm^2$ open filed. Penumbra measured with film, diode detector, microionization chamber, and conventional 0.125 cc chamber showed that $80\~20\%$ penumbra width measured with a 0.125 cc chamber was 2 mm larger than that of film, which means a 0.125 cc ionization chamber was unacceptable for measuring small field such like 0.5 cm beamlet. After RTP recommissioning, the discrepancy between the measured and calculated dose profile for a small field of $1\times1\;cm^2$ size was less than $2\%$. The isocenter dose of the test plan of C-shaped PTV was measured two times with micro-ionization chamber in solid phantom showed that the errors upto $12\%$ for individual beam, but total dose delivered were agreed with the calculated within $2\%$. The transverse dose distribution measured with EC-L film was agreed with the calculated one in general. The isocenter dose for the patient measured in solid phantom was agreed within $1.5\%$. On-axis dose profiles of each individual beam at the position of the central leaf measured with film and array detector were found that at out-of-the-field region, the calculated dose underestimates about $2\%$, at inside-the-field the measured one was agreed within $3\%$, except some position. Conclusion : It is necessary more tight quality control of MLC for IMRT relative to conventional large field treatment and to develop QA procedures to check intensity pattern more efficiently. At the conclusion, we did setup an appropriate QA procedures for IMRT by a series of verifications including the measurement of absolute dose at the isocenter with a micro-ionization chamber, film dosimetry for verifying intensity pattern, and another measurement with an array detector for comparing off-axis dose profile.

• Progress in Medical Physics
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• v.14 no.1
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• pp.15-19
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• 2003

High dose rate (HDR) brachytherapy for treating a cervix carcinoma has become popular, because it eliminates many of the problems associated with conventional brachytherapy. In order to improve the clinical effectiveness with HDR brachytherapy, a dose calculation algorithm, optimization procedures, and image registrations need to be verified by comparing the dose distributions from a planning computer and those from a phantom. In this study, the phantom was fabricated in order to verify the absolute doses and the relative dose distributions. The measured doses from the phantom were then compared with the treatment planning system for the dose verification. The phantom needs to be designed such that the dose distributions can be quantitatively evaluated by utilizing the dosimeters with a high spatial resolution. Therefore, the small size of the thermoluminescent dosimeter (TLD) chips with a dimension of <1/8"and film dosimetry with a spatial resolution of <1mm used to measure the radiation dosages in the phantom. The phantom called a pelvic phantom was made from water and the tissue-equivalent acrylic plates. In order to firmly hold the HDR applicators in the water phantom, the applicators were inserted into the grooves of the applicator holder. The dose distributions around the applicators, such as Point A and B, were measured by placing a series of TLD chips (TLD-to-TLD distance: 5mm) in the three TLD holders, and placing three verification films in the orthogonal planes. This study used a Nucletron Plato treatment planning system and a Microselectron Ir-192 source unit. The results showed good agreement between the treatment plan and measurement. The comparisons of the absolute dose showed agreement within $\pm$4.0 % of the dose at point A and B, and the bladder and rectum point. In addition, the relative dose distributions by film dosimetry and those calculated by the planning computer show good agreement. This pelvic phantom could be a useful to verify the dose calculation algorithm and the accuracy of the image localization algorithm in the high dose rate (HDR) planning computer. The dose verification with film dosimetry and TLD as quality assurance (QA) tools are currently being undertaken in the Catholic University, Seoul, Korea.

• Economic and Environmental Geology
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• v.39 no.5 s.180
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• pp.555-566
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• 2006

Major, trace and rare earth elements data of the Cretaceous Jindong granitic rocks were investigated in order to constrain the magma source characteristics and to establish the paleotectonic environment of the southwestern part of the Gyeongsang Basin. Geochemical signatures of the granitic rocks from the study area indicate that all of the rocks have characteristics of calc-alkaline series in the subalkaline field, and progressively shift from metaluminous to peraluminous with differentiation. In the variation diagrams, the overall geochemical features of the granites show systematic variations in major and trace elements. Chondrite normalized REE patterns show generally enriched LREE((La/Yb)c=4.2-12.8) and slight negative to flat Eu anomalies. Rb-Sr isotope data of the Jindong granites show that the whole rock age and Sr initial ratio are $114.6{\pm}9.1Ma$ and 0.70457, respectively. The Sr initial ratio of the Jindong granites is very similar to those of the Creataceous granites from Masan, Kimhae and Busan area($^{87}Sr/^{86}Sr=0.7049-0.707$). These results suggest that the magma have the mantle signature and intruded into the area during the early Cretaceous age. The Jindong granites have higher $Al_{2}O_{3},\;Na_{2}O$, Sr and lower $K_{2}O$, Y concentrations compared with typical calc-alkaline granitic rocks. These adakitic signatures are similar to those of adakitic pluton on Kyushu Island, southwest Japan arc. On the ANK vs. ACNK and tectonic discrimination diagrams, parental magma type of the granites corresponds to I-type, VAG granite. Interpretations of the geochemical characteristics of the granitic rocks favor their emplacement at continental margin during the subduction of Izanagi plate.

• Journal of the Korean Society for Library and Information Science
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• v.47 no.2
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• pp.247-264
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• 2013

Wikipedia represents a revolutionary experiment in the sense that it allows anonymous Internet users to contribute, change, and edit Encyclopedia contents used by tens of millions of people. While a very popular information source on the Internet, because of its questionable information credibility and accuracy, citing Wikipedia articles is being regarded as a risky behavior for scholars. The present study identified 282 scholarly articles from Thomson Reuters' Web of Science citation database that cite Wikipedia at least once. Out of the millions of articles indexed in Web of Science, the proportion of articles citing Wikipedia is extremely small. On the other hand, the numbers are showing a marked increase since 2011. Wikipedia citing articles are distributed in subject areas, such as library and information science, business, psychology, education, and communication more often than in other areas. The distribution of a total of 577 citations from 267 articles for which we were able to obtain full texts shows that Wikipedia is being cited mainly in studies of Wikipedia (139 citations, 24.1%) or as a ready reference source (331 citations, 57.4%). At the same time, about 15% of total citations turned out to be cases of potentially risky behaviors in which Wikipedia is being cited as a crucial basis or data source for study.

• Korean Journal of Microbiology
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• v.41 no.3
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• pp.208-215
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• 2005

This study was accomplished in order to collect fundamental data on microbial roles in recycling process of reed rhizosphere. Sunchon bay, which is considered as one of the marsh and mud environments severely affected by human activities such agriculture and fisheries, was selected as a model place. In our initial efforts, two bacterial consortia were obtained by enrichment culture using PAH mixtures containing anthracene, naphthalene, phenanthrene and pyrene as the sources of carbon and energy, and four pure bacteria capable of rapid degradation of PAH were isolated from them. Four strains designated as SCB1, SCB2, SCB6, and SCB7 revealed by morphological, physiological and molecular analyses were identified as Burkholderia anthina, Alcaligenes sp., Achromobacter xylosoxidans., and Pseudomonas putida, respectively with over $99{\%}$ confidence. Notably, Burkholderia anthina SCB1 and Alcaligenes sp. SCB2 were found to utilize anthracene and pyrene more quickly than naphthalene and phenanthrene, whereas Achromobacter xylosoxidans SCB6 and Pseudomonas putida SCB7 exhibited similar growth and degradation patterns except for pyrene. These facts suggest that the rhizosphere microorganisms capable of PAH degradation might be used to clean up the contamination sites with polycyclic aromatic hydrocarbons.

• Journal of KIISE:Software and Applications
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• v.29 no.3
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• pp.167-179
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• 2002

In this paper, we propose a new acoustic model for characterizing segmental features and an algorithm based upon a general framework of hidden Markov models (HMMs) in order to compensate the weakness of HMM assumptions. The segmental features are represented as a trajectory of observed vector sequences by a polynomial regression function because the single frame feature cannot represent the temporal dynamics of speech signals effectively. To apply the segmental features to pattern classification, we adopted segmental HMM(SHMM) which is known as the effective method to represent the trend of speech signals. SHMM separates observation probability of the given state into extra- and intra-segmental variations that show the long-term and short-term variabilities, respectively. To consider the segmental characteristics in acoustic model, we present segmental-feature HMM(SFHMM) by modifying the SHMM. The SFHMM therefore represents the external- and internal-variation as the observation probability of the trajectory in a given state and trajectory estimation error for the given segment, respectively. We conducted several experiments on the TIMIT database to establish the effectiveness of the proposed method and the characteristics of the segmental features. From the experimental results, we conclude that the proposed method is valuable, if its number of parameters is greater than that of conventional HMM, in the flexible and informative feature representation and the performance improvement.