• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.12
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• pp.2615-2621
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• 2010

The multi-band six-port phase correlator using metamaterial was designed and fabricated in this paper. The lumped metamaterial structure that can process the dual-band receiving signal was analyzed. Based on the analyzed results, the small-sized metamatrial six-port phase correlator for multi-band direct conversion method was proposed and fabricated. Also, the resistive power divider and $90^{\circ}$ hybrid coupler that comprises the six-port phase correlator were implemented based on the scattering parameters of metamatrial six-port phase correlator. The measured results of the proposed six-port phase correlator show the good agreement with simulation results. The performance of the six-port phase correlator shows the reflection loss below -20 dB in the dual-band. Also, the proposed six-port phase correlator got a good transmission characteristic within 1 dB gain difference and ${\pm}4.1^{\circ}$ phase imbalance, respectively.

• Korean Journal of Environment and Ecology
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• v.22 no.2
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• pp.83-97
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• 2008

This study was carried out to investigate the actual vegetation and Degree of Green Naturality(DGN) and distribution of exotic plants replanted in Bukhansan National Park. The actual vegetation of the surveyed site was classified into eight plant communities and crop land, etc. Substitutional forest were classified into five plant communities; Quercus mongolica community, Q. mongolica-Pinus densiflora community, Deciduous broadleaf forest, etc. Reforested lands were classified into three forest types: P. koraiensis forest, Robinia pseudoacacia forest, P. rigida forest, etc. The area of DGN 8 consisted of 92.80% in Bukhansan National Park. The replanted plants in Bukhansan National Park was enlisted as 212 taxa, 71 families. The indigenous native among the replanted species were enlisted as 67 taxa(31.6%), 37 families. The exotic plants were enlisted as 145 taxa(68.4%), 58 families. The exotic plants needs to management that for recovery of natural environment, improvement about maintenance of multiplicity and a site of scenery about natural plants in Bukhansan National Park.

• Journal of Digital Convergence
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• v.11 no.1
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• pp.225-236
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• 2013

The voice recognition has been made continuously. Now, this technology could support even natural language beyond recognition of isolated words. Interests for the voice recognition was boosting after the Siri, I-phone based voice recognition software, was presented in 2010. There are some occasions implemented voice enabled services using Korean voice recognition softwares, but their accuracy isn't accurate enough, because of background noise and lack of control on voice related features. In this paper, we propose a sort of multi-purpose preprocessor to improve this situation. This supports Keyword spotting in the continuous speech in addition to noise filtering function. This should be independent of any voice recognition software and it can extend its functionality to support continuous speech by additionally identifying the pre-predicate and the post-predicate in relative to the spotted keyword. We get validation about noise filter effectiveness, keyword recognition rate, continuous speech recognition rate by experiments.

• The Korean Journal of Quaternary Research
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• v.14 no.2
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• pp.101-107
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• 2000

Using the phytogram system, this study monitored hourly environmental factors(climate and soil), and radial growths and cambium activities of conifers in Worak mountain for 28 months from May 1996 to October 1998 to examine the influences of climatic factors on tree growths/carnbium activities of conifers in Worak Mountain, Korea. The phytogram system first puts a fine electrode into cambial zone. This device can automatically record environmental factors and cambium electrochemistry(hydration and proton levels). Dendrometers are attached to the phytogram for monitoring seasonal dynamics of cambial growth. We compared the results of radial growth by species and by diameter class. The growth decreased in order of Larix leptolepis, Pinus densiflora and Pinus rigida. Pre-monsoon growths were fast and May-June moisture regime was the most critical for all species. In the middle of September, radial growths were finished. The proton level and stem diameter reached the minimum at 4 p.m. On the other hand, the hydration level reached the maximum at 4 p.m. This diurnal change resulted from transpiration and the release of water from phloem storage to sapwood through xylem stream.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.10
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• pp.1000-1004
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• 2010

A large number of current language processing systems use a part-of-speech tagger for preprocessing. Most language processing systems required a tagger with the highest possible accuracy. Specially, the use of domain-specific advantages has become a hot issue in machine translation community to improve the translation quality. This paper addresses a method for customizing an HMM or LHMM based English tagger from general domain to specific domain. The proposed method is to semi-automatically customize the output and transition probabilities of HMM or LHMM using domain-specific raw corpus. Through the experiments customizing to Patent domain, our LHMM tagger adapted by the proposed method shows the word tagging accuracy of 98.87% and the sentence tagging accuracy of 78.5%. Also, compared with the general tagger, our tagger improved the word tagging accuracy of 2.24% (ERR: 66.4%) and the sentence tagging accuracy of 41.0% (ERR: 65.6%).

• Journal of the Korea Society of Computer and Information
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• v.25 no.4
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• pp.37-45
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• 2020

The development process of deep learning is an iterative task that requires a lot of manual work. Among the steps in the development process, pre-processing of learning data is a very costly task, and is a step that significantly affects the learning results. In the early days of AI's algorithm research, learning data in the form of public DB provided mainly by data scientists were used. The learning data collected in the real environment is mostly the operational data of the sensors and inevitably contains various noises. Accordingly, various data cleaning frameworks and methods for removing noises have been studied. In this paper, we proposed a method for detecting and removing noises from time-series data, such as sensor data, that can occur in the IoT environment. In this method, the linear regression method is used so that the system repeatedly finds noises and provides data that can replace them to clean the learning data. In order to verify the effectiveness of the proposed method, a simulation method was proposed, and a method of determining factors for obtaining optimal cleaning results was proposed.

• The Journal of Korean Obstetrics and Gynecology
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• v.33 no.1
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• pp.36-58
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• 2020

Objectives: We conducted a literature study on the treatment trends in China to find out the possibility of Oriental medicine treatment of atypical hyperplasia of breast (AHB). Methods: RCTs (randomized controlled trial) on AHB were collected from CNKI (China National Knowledge Infrastructure). The search words were "乳腺增生", "乳腺囊性增生", "乳癖", "中医", "中药" and "中西医结合". The search period was limited from July 2006 to May 2017. Finally, we selected 107 RCTs which were clinical studies to find out the effectiveness of Chinese herbal medicine in comparison with Western medicine. After reviewing, we investigated Chinese herbal medication guide, Chinese treatment method and prescriptions. And the correlation between the treatments and the medicinal herbs was investigated to be useful in the clinical practice. Results: 1. The administration of herbal medicine was 58.9 percent in 63 cases, followed by menstrual cycles, and 41.1 percent in 44 cases, regardless of menstrual cycles. 2. In the basic frequency analysis between the treatment and the medicinal herb, the frequency of dissipate binds (散結) was the highest. Next, there was a high frequency of therapies such as activating blood-activating (活血), relieve pain (止痛), soothe the liver (疏肝), regulate qi (理氣), resolve phlegm (化痰), soften hardness (軟堅), resolve depression (解鬱), move qi (行氣) of frequency was high. In herbal medicine, bupleuri radix (柴胡), cyperi rhizoma (香附子), angelicae gigantis radix (當歸), fritillaria thunbergii bulb (貝母), paeoniae radix alba (白芍藥), prunellae spica (夏枯草), corydalis rhizoma (玄胡索) showed high frequency. 3. We finded out the correlation between the frequent treatment methods and the medicinal herbs using Text Mining. Conclusions: These findings are thought to help implement Korean traditional medicine treatments for AHB.

• New & Renewable Energy
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• v.18 no.3
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• pp.23-31
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• 2022

This study evaluated the potential of coffee waste (CW) and used frying oil (UFO) as an additive in the production of pitch pine (PIP) and Mongolian oak (MOK) pellets. Ash contents obtained from CW and UFO were 0.5% and <0.1%, respectively. The calorific values of UFO (31.4 MJ/kg) and CW (26.3 MJ/kg) are higher than PIP (20.6 MJ/kg) and MOK (19.1 MJ/kg). For pellets fabricated using a pilot-scale flat-die pellet mill, regardless of fabricating conditions, moisture content (MC) and bulk density of PIP and MOK pellets satisfied the A1 wood pellet standard for residential and small-scale commercial uses, as designated by the National Institute of Forest Science (NIFOS) of the Republic of Korea. When CW was used as an additive, durability of PIP pellets made with 12%-MC sawdust and MOK pellets increased. The optimal conditions for producing PIP and MOK pellets could be by adding 20 mesh CW as an additive and the using of 12%-MC sawdust. However, durability of PIP pellets and ash content MOK pellets did not satisfy the A1 wood pellet standard of NIFOS. Thus, further research is needed to improve the properties of wood pellets with additives.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.2
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• pp.131-138
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• 2023

Globally, the eco-friendly industry is developing due to the climate crisis. Electric vehicles are an eco-friendly industry that is attracting attention as it is expected to reduce carbon emissions by 30~70% or more compared to internal combustion engine vehicles. As electric vehicles become more popular, charging stations have become an important factor for purchasing electric vehicles. Recent research is using artificial intelligence to identify local demand for charging stations and select locations that can maximize economic impact. In this study, in order to contribute to the improvement of the performance of the electric vehicle charging station demand prediction model, nationwide data that can be used in the artificial intelligence model was defined and a pre-processing technique was proposed. In addition, a preprocessor, artificial intelligence model, and service web were implemented for real charging station demand prediction, and the value of data as a location selection factor was verified.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.72-74
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• 2022

The National Science and Technology Knowledge Information Service (NTIS) provides information on national R&D projects. Project information consists of meta-information such as 'project name', 'project performance institution', 'research manager name', and text explaining projects such as 'research goal', 'research content', and 'expected effect'. There is a problem that it takes a lot of time to find the desired project information by checking all of the "research goals" or "research contents" in the list of results of searching for 1 million project information. To solve this problem, this paper proposes a project information summary system that summarizes the parts consisting of long texts within the national R&D project information. By analyzing the linguistic characteristics of the Korean language, a preprocessor was built and a project information summary model based on natural language processing technology was developed to process preprocessed text information. Through this, project information composed of long sentences is provided in a compressed and summarized form, which will help users to easily and quickly infer the overall content with the summary information alone.