• The Journal of Korean Academy of Prosthodontics
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• v.57 no.3
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• pp.219-224
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• 2019

Purpose: The image registration of radiographic image and digital surface data is essential in the computer-guided implant guide system. The purpose of this study was to examine the effects of using micro-screw on the working time and convenience of operators in the process of image matching for guided implant surgery. Materials and methods: A mandibular dental model was prepared in partial edentulism for Kennedy class I classification. Two micro-screws were placed on the each side of retromolar area. Radiographic and scan images were taken using computed-tomography and digital scanning. The images were superimposed by 12 operators in software in two different conditions: using remaining teeth image alone and using teeth and micro-screws images. Working time, operator convenience and satisfaction were obtained, and analyzed using the Mann-Whitney U test (${\alpha}=.05$). Results: The working time was not statistically different between image registration conditions (P>.05); however, operator convenience and satisfaction were higher in the teeth and micro-screw assisted condition than in the teeth-alone assisted condition (P<.001). Conclusion: The use of micro-screw for the image registration has no effect in working time reduction, but improves operator convenience and satisfaction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.451-458
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• 2019

Reliability in the course of weapons system development and operation is a key measure of the ability of a system to perform the required functions under specified conditions over a specified period of time, and the mission confidence for the assessment of mission fulfillment is an important indicator of victory or defeat in a battle. Mission reliability indicates the probability that a given task will succeed or fail in an event or environmental situation over a given period of time. The existing mission reliability was calculated after creating a confidence blow map with only physical connections based on the mission. However, as modern weapons systems evolve and advance, the related equipment structure becomes increasingly complex, making it impossible to express mission relevance when mission classification is required based on functional or physical connections. In this study, the mission reliability was calculated for a gun control system, which is part of a ship's combat system, by expressing the association between the physical and functional structures using the design structure matrix technique and the interface matrix technique. We expect the study results to be used as verification data for mission reliability.

• Journal of Korean Society of Forest Science
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• v.108 no.2
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• pp.189-199
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• 2019

The forest management paradigm has recently shifted from focusing on commercial production to focusing on ecosystem management. Accordingly, a natural seedling regeneration method that has a naturally high affinity has attracted much attention in recent years. The aim of this study was to determine the relationship among various environmental factors, lower stratum vegetation, and seedling regeneration in Pinus densiflora forests. The survey site comprised 50 sectors divided using the line transect method, and the survey data were divided into those from wet habitat (19 sites) and dry habitat (31 sites), depending on the soil humidity, and were analyzed separately to show the close relationship between soil humidity and natural seedling regeneration. As a result, the dry habitat exhibited high seedling density (157,419 trees/ha), with the main species being Quercus serrata, Zanthoxylum piperitum, Smilax china, and Pueraria lobata, while wet habitat exhibited low seedling density (57,895 trees/ha), with the main species being Stephanandra incisa, Castanea crenata, Lespedeza maximowiczii, Lysimachia barystachys, Aralia elata, and Styrax japonicus. The height and root-collar diameter under wet conditions exhibited faster growth than those under dry conditions. Height growth by the root-collar diameter in dry habitat increased faster than that in wet habitat. It was also confirmed that seedling regeneration in wet habitat exhibited a rapid growth pattern 5 years after germination. These results suggest that the seedlings begin to grow more rapidly after a period of suppression by competition with surrounding plants. Considering an ecosystem or ecological management approach, specific practices, such as bush control and vine clearing in wet habitats, should be more intensively conducted, especially at the beginning of the management operations.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.5
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• pp.493-498
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• 2019

This study deals with the analysis of the technology association rules between CPC codes of the Internet of Things(IoT) patent, the core of the Fourth Industrial Revolution ICT-based technology. The association rules between CPC codes were extracted using R, an open source for data mining. To this end, we analyzed 369 of the 605 patents related to the Internet of Things filed with the Patent Office until July 2019, with a complex CPC code, up to the subclass-level. As a result of the technology association rules, CPC codes with high support were [H04W ${\rightarrow}$ H04L](18.2%), [H04L ${\rightarrow}$ H04W](18.2%), [G06Q ${\rightarrow}$ H04L](17.3%), [H04L ${\rightarrow}$ G06Q](17.3%), [H04W ${\rightarrow}$ G06Q](9.8%), [G06Q ${\rightarrow}$ H04W](9.8%), [G06F ${\rightarrow}$ H04L](7.9%), [H04L ${\rightarrow}$ G06F](7.9%), [G06F ${\rightarrow}$ G06Q](6.2%), [G06Q ${\rightarrow}$ G06F](6.2%). After analyzing the technology interconnection network, the core CPC codes related to technology association rules are G06Q and H04L. The results of this study can be used to predict future patent trends.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.252-266
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• 2019

The purpose of this study was to identify the type of health behaviors in Korean adults and to identify related factors. The data used in the analysis was the Korea Health and Nutrition Examination Survey 2014., which was representative of the Korean population. Cluster analysis was used to find the pattern of clustering of smoking, drinking, exercising and nutrition. Differences in the pattern of clustering was examined, first by bivariate chi-square test, and then by multinomial logit regression. Lastly, the association between the clusters of health behaviors and other behavioral risk factors was tested by chi-square test and logistic regression. The distribution of the clusters varied not only across socioeconomic characteristics and local size, but also between individuals with certain chronic diseases and those without. The results of this study can be used as a basis for the usefulness of approaching the cluster rather than individually approaching the health behavior.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.1
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• pp.161-170
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• 2019

Multi-product mass production small and medium enterprise factories have a wide variety of products and a large number of products, wasting manpower and expenses for inventory management. In addition, there is no way to check the status of inventory in real time, and it is suffering economic damage due to excess inventory and shortage of stock. There are many ways to build a real-time data collection environment, but most of them are difficult to afford for small and medium-sized companies. Therefore, smart factories of small and medium enterprises are faced with difficult reality and it is hard to find appropriate countermeasures. In this paper, we implemented the contents of extension of existing inventory management method through character extraction on label with barcode and QR code, which are widely adopted as current product management technology, and evaluated the effect. Technically, through preprocessing using OpenCV for automatic recognition and classification of stock labels and barcodes, which is a method for managing input and output of existing products through computer image processing, and OCR (Optical Character Recognition) function of Google vision API. And it is designed to recognize the barcode through Zbar. We propose a method to manage inventory by real-time image recognition through Raspberry Pi without using expensive equipment.

• Journal of the Korea Convergence Society
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• v.10 no.4
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• pp.1-6
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• 2019

Neural networks have been used to predict the direction of stock index movement from past data. The conventional research that predicts the upward or downward movement of the stock index predicts a rise or fall even with small changes in the index. It is highly likely that losses will occur when trading ETFs by use of the prediction. In this paper, a neural network model that predicts the movement direction of the daily KOrea composite Stock Price Index (KOSPI) to reduce ETF trading losses and earn more than a certain amount per trading is presented. The proposed model has outputs that represent rising (change rate in index ${\geq}{\alpha}$), falling (change rate ${\leq}-{\alpha}$) and neutral ($-{\alpha}$ change rate < ${\alpha}$). If the forecast is rising, buy the Leveraged Exchange Traded Fund (ETF); if it is falling, buy the inverse ETF. The hit ratio (HR) of PNN1 implemented in this paper is 0.720 and 0.616 in the learning and the evaluation respectively. ETF trading yields a yield of 8.386 to 16.324 %. The proposed models show the better ETF trading success rate and yield than the neural network models predicting KOSPI.

• Journal of the Korean neurological association
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• v.36 no.4
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• pp.294-301
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• 2018

Background: Neuroimaging can play a crucial role in discovering potential abnormalities to cause secondary headache. There has been a progress in the fields of headache diagnosis and neuroimaging in the past two decades. We sought to investigate neuroimaging findings according to headache disorders, age, sex, and imaging modalities in first-visit headache patients. Methods: We used data of consecutive first-visit headache patients from 9 university and 2 general referral hospitals. The International Classification of Headache Disorders, third edition, beta version was used in headache diagnosis. We finally enrolled 1,080 patients undertook neuroimaging in this study. Results: Among 1,080 patients (mean age: $47.7{\pm}14.3$, female: 60.8%), proportions of headache diagnosis were as follows: primary headaches, n=926 (85.7%); secondary headaches, n=110 (10.2%); and cranial neuropathies and other headaches, n=43 (4.1%). Of them, 591 patients (54.7%) received magnetic resonance imaging (MRI). Neuroimaging abnormalities were found in 232 patients (21.5%), and their proportions were higher in older age groups and male sex. Chronic cerebral ischemia was the most common finding (n=88, 8.1%), whereas 76 patients (7.0%) were found to have clinically significant abnormalities such as primary brain tumor, cancer metastasis, and headache-relevant cerebrovascular disease. Patients underwent MRI were four times more likely to have neuroimaging abnormalities than those underwent computed tomography (33.3% vs. 7.2%, p<0.001). Conclusions: In this study, the findings of neuroimaging differed according to headache disorders, age, sex, and imaging modalities. MRI can be a preferable neuroimaging modality to identify potential causes of headache.

• Brain Tumor Research and Treatment
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• v.6 no.2
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• pp.60-67
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• 2018

Background Recently, modern technology such as diffusion tensor imaging (DTI), neuro-navigation and intraoperative neurophysiological monitoring (IOM) have been actively adopted for the treatment of thalamic tumors. We evaluated surgical outcomes and efficacy of the aforementioned technologies for the treatment of pediatric thalamic tumors. Methods We retrospectively reviewed clinical data from 37 children with thalamic tumors between 2004 and 2017. There were 44 operations (27 tumor resections, 17 biopsies). DTI was employed in 17 cases, neuro-navigation in 23 cases and IOM in 14 cases. All diagnoses were revised according to the 2016 World Health Organization Classification of Tumors of the Central Nervous System. Progression-free survival (PFS) and overall survival (OS) rates were calculated, and relevant prognostic factors were analyzed. The median follow-up duration was 19 months. Results Fifteen cases were gross total resections (GTR), 6 subtotal resections (STR), and 6 partial resections (PR). Neurological status did not worsen after 22 tumor resections. There were statistically significant differences in terms of the extent of resection between the groups with DTI, neuro-navigation and IOM (n=12, GTR or STR=12) and the group without at least one of the three techniques (n= 15, GTR or STR=9, p=0.020). The mean PFS was $87.2{\pm}38.0$ months, and the mean OS $90.7{\pm}36.1$ months. The 5-year PFS was 37%, and the 5-year OS 47%. The histological grade ($p{\leq}0.001$) and adjuvant therapy (done vs. not done, p=0.016) were significantly related to longer PFS. The histological grade (p=0.002) and the extent of removal (GTR/STR vs. PR/biopsy, p=0.047) were significantly related to longer OS. Conclusion Maximal surgical resection was achieved with acceptable morbidity in children with thalamic tumors by employing DTI, neuro-navigation and IOM. Maximal tumor resection was a relevant clinical factor affecting OS; therefore, it should be considered the initial therapeutic option for pediatric thalamic tumors.

• The Journal of the Korea Contents Association
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• v.21 no.10
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• pp.774-787
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• 2021

This thesis is a follow-up study on HwangJeNaeGyeogSoMun(SoMun). Its purpose is the usage of '心' letter used in HwangjenaegyeogYoungChu(YoungChu). The original manuscript of this study was the Hu's Gulin Sanctum of YoungChu. It was conducted by a literature review. Typically, the word '心' means a tangible heart and an intangible mind in the same form. Therefore, in order to understand the contents of the YoungChu, which provides the basis for the basic ideology related to health care, meditation, GiGong training, yoga, practice and oriental medicine, it is necessary to understand the meaning of the word '心' letter. The results of this study are as follows. First, it means human heart. Second, it means the human chest. Third, it means mind such as angry, joy sad, fear and so on. Fourth, it means the transcendent concept like spiritual enlightenment. Fifth, it means the pericardium. Sixth, it means logical thinking. Seventh, it means center or core, Eighth, it means the name of the constellation in the eastern sky of ancient Asia. Ninth, it can be classified into the inside. It can be used as a basic data to understand the contents of YoungChu related to various categories. The limitation of it is that the classification of the '心' letter may be different from the researchers' perspective.