• Journal of Soil and Groundwater Environment
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• v.23 no.3
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• pp.27-42
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• 2018

It is important to identify the contaminant sources and to evaluate the fate and transport of heavy metals to crops in agricultural lands. This study was conducted to evaluate metal sources and its transfer and accumulation to crop in agricultural soils. Pollution indices were calculated and multivariate analysis was performed to identify metal sources. To evaluate transfer and accumulation of metals to crops, the contents of phytoavailable metals were evaluated by using single extraction method and the correlation between metal content and soil properties was analyzed. Also the BCF was quantitatively evaluated for investigating the metal transition to each crop grown in the research area. As a result, Cr, Ni, and Co were expected to be mainly derived from geologic factors due to weathering of certain parent rocks. The content of nickel in soils of the research area was slightly higher than that of the concern level criteria based on total concentration, but the amount transferred and accumulated in the crops was actually low. Understanding the contamination characteristics by investigating the pollution sources of heavy metals and its transfer and accumulation to crops through various evaluation techniques could provide important information for proper management of the agricultural land.

• Development and Reproduction
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• v.25 no.4
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• pp.269-277
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• 2021

Effects of water temperature and hormones on ovarian development of conger eel in Korea were investigated. Ovarian development was analyzed by measuring gonadosomatic index (GSI) and oocyte diameter with histological methods. At rearing water temperatures of 12℃, 14℃, and 16℃, GSI value increased from 3.66 at the start of the experiment to 7.44, 8.82, and 7.34 at the end of the experiment, respectively. At rearing water temperatures of 12℃, 14℃, and 16℃, egg diameter increased from 245.11-300.25 ㎛ at the start of the experiment to 377.62-480.27 ㎛, 396.72-498.54 ㎛, and 382.29-475.69 ㎛ at the end of the experiment, respectively. Follicular oocyte development revealed that primary yolk globule stage observed from January to March. It entered to secondary yolk globule stage in April and remained at the same stage until July. As a result of examining effects of three hormones (human chorionic gonadotropin (HCG), luteinizing hormone releasing hormone analogue (LHRHa), and salmon pituitary extraction (SPE) on ovarian development, HCG was found to be the most effective one. The progress from diapause of the secondary yolk globule stage to migratory nucleus stage of oocytes could be induced by treating fish with HCG at 1,000 IU/kg. The effect of hormone treatment on ovarian development of conger eel in Korea was the most effective at water temperature of 14℃.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.10
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• pp.225-234
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• 2019

The purpose of this paper is to analyze the additional construction cost of G-SEED certification for domestic office building reflecting the latest standard(G-SEED 2016-2), and to derive cost impact by category and level. Therefore, it is intended to provide quantitave cost data according to G-SEED certification at the planning phase of the project, estimate the additional construction cost per level according to G-SEED Certification of similar project to be carried out in the future, and encourage G-SEED certification by supporting the decision of the owners. Method: The Process and method of this study are summarized in five steps, 1) Review of previous research, 2) Selection of target project, 3) Scenario setting by level, 4) Additional construction cost for each evaluation category, 5) Extraction of additional construction cost ratio by level. Result: This paper analyzed the cost impact by deriving the additional construction cost of detailed category for level improvement according to the revised G-SEED certification(G-SEED 2016-2). In conclusion, an additional construction cost(ratio) of G-SEED projects to the reference building is drawn as good level; 157,426,241 KWN(+0.43%), very good level; 321,907,802 KWN(+0.88%), excellent level; 999,371,478 KWN(+2.74%), and outstanding level; 1,467,047,718 KWN(+4.02%).

• The Plant Pathology Journal
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• v.37 no.6
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• pp.521-532
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• 2021

Knowledge and better understanding of functions of the microbial community are pivotal for crop management. This study was conducted to study bacterial structures including Acidovorax species community structures and diversity from the watermelon cultivated soils in different regions of South Korea. In this study, soil samples were collected from watermelon cultivation areas from various places of South Korea and microbiome analysis was performed to analyze bacterial communities including Acidovorax species community. Next generation sequencing (NGS) was performed by extracting genomic DNA from 92 soil samples from 8 different provinces using a fast genomic DNA extraction kit. NGS data analysis results revealed that, total, 39,367 operational taxonomic unit (OTU), were obtained. NGS data results revealed that, most dominant phylum in all the soil samples was Proteobacteria (37.3%). In addition, most abundant genus was Acidobacterium (1.8%) in all the samples. In order to analyze species diversity among the collected soil samples, OTUs, community diversity, and Shannon index were measured. Shannon (9.297) and inverse Simpson (0.996) were found to have the highest diversity scores in the greenhouse soil sample of Gyeonggi-do province (GG4). Results from NGS sequencing suggest that, most of the soil samples consists of similar trend of bacterial community and diversity. Environmental factors play a key role in shaping the bacterial community and diversity. In order to address this statement, further correlation analysis between soil physical and chemical parameters with dominant bacterial community will be carried out to observe their interactions.

• Geophysics and Geophysical Exploration
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• v.24 no.4
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• pp.164-170
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• 2021

Frequency-domain and time-domain induced polarization methods can provide spectral information about subsurface media. Analysis of spectral characteristics has been studied mainly in the frequency-domain, however, time-domain induced polarization research has recently become popular. In this study, assuming a homogeneous half-space model, an inversion method was developed to extract Cole-Cole parameters from the measured secondary potential or electrical resistivity. Since the Cole-Cole parameters of chargeability, time constant, and frequency index are not independent of each other, various problems, such as slow convergence rate, initial model problem, local minimum problem, and divergence, frequently occur when conventional nonlinear inversion is applied. In this study, we developed an effective inversion method using the initial model close to the true model by introducing a grid search method. Finally, the validity of the developed inversion method was verified using inversion experiments.

• Smart Structures and Systems
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• v.30 no.1
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• pp.75-88
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• 2022

Engineering structures in operation essentially belong to time-varying or nonlinear structures and the resultant response signals are usually non-stationary. For such time-varying structures, it is of great importance to extract time-dependent dynamic parameters from non-stationary response signals, which benefits structural health monitoring, safety assessment and vibration control. However, various traditional signal processing methods are unable to extract the embedded meaningful information. As a newly developed technique, variational mode decomposition (VMD) shows its superiority on signal decomposition, however, it still suffers two main problems. The foremost problem is that the number of modal components is required to be defined in advance. Another problem needs to be addressed is that VMD cannot effectively separate non-stationary signals composed of closely spaced or overlapped modes. As such, a new method named generalized adaptive variational modal decomposition (GAVMD) is proposed. In this new method, the number of component signals is adaptively estimated by an index of mean frequency, while the generalized demodulation algorithm is introduced to yield a generalized VMD that can decompose mode overlapped signals successfully. After that, synchrosqueezing wavelet transform (SWT) is applied to extract instantaneous frequencies (IFs) of the decomposed mono-component signals. To verify the validity and accuracy of the proposed method, three numerical examples and a steel cable with time-varying tension force are investigated. The results demonstrate that the proposed GAVMD method can decompose the multi-component signal with overlapped modes well and its combination with SWT enables a successful IF extraction of each individual component.

• The Journal of Korean Medicine
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• v.43 no.2
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• pp.75-91
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• 2022

Objectives: The purpose of this overview was to summarize the evidence regarding the effectiveness of Cognitive Behavioral Therapy (CBT) for sleep disorders through systematic reviews (SRs) and meta-analyses (MAs). Methods: An overview of systematic review was conducted according to the study protocol (reviewregistry1320). A comprehensive literature search was performed using three databases (Pubmed, Cochrane Central Register of Controlled Trials, and Web of Science) and three Korean databases (KoreaMed, KMbase, and ScienceON). Final studies were selected by three authors according to inclusion and exclusion criteria, and data needed for analysis were extracted by a pre-planned extraction framework. Methodological quality of systematic review was assessed using the 'Assessment of multiple systematic reviews 2 (AMSTAR2)'. Results: Fourteen SRs and MAs were included, of which eleven SRs were performed MAs. Twelve studies studied insomnia among sleep disorders, and the rest are nightmares and sleep disturbances with PTSD. Ten studies reported the effect of CBT on sleep disorders measured by insomnia severity index (ISI) and sleep onset latency (SOL), and all reported a significant improvement effect. Eight studies reported the effect of CBT on sleep disorders measured by wake time after sleep onset (WASO), and seven studies reported a significant improvement effect. The methodological quality of the studies evaluated with AMSTAR 2 was mainly low or very low because of omission of protocol registration and excluded study list. Conclusions: Practical guidelines and studies show that CBT is effective for sleep disorders, but access to CBT needs to be improved.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.689-697
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• 2023

Purpose: The purpose of this study is to automatically extract information on underground facilities using a general-purpose smartphone in the process of applying the mini-trenching method. Method: Data sets for image learning were collected under various conditions such as day and night, height, and angle, and the object detection algorithm used the R-CNN algorithm. Result: As a result of the study, F1-Score was applied as a performance evaluation index that can consider the average of accurate predictions and reproduction rates at the same time, and F1-Score was 0.76. Conclusion: The results of this study showed that it was possible to extract information on underground buried materials based on smartphones, but it is necessary to improve the precision and accuracy of the algorithm through additional securing of learning data and on-site demonstration.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.12
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• pp.1872-1879
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• 2022

Recently, with the development of artificial intelligence technology, research to use artificial intelligence to detect hacking attacks is being actively conducted. However, the fact that security data is a representative imbalanced data is recognized as a major obstacle in composing the learning data, which is the key to the development of artificial intelligence models. Therefore, in this paper, we propose a W-VAE oversampling technique that applies VAE, a deep learning generation model, to data extraction for oversampling, and sets the number of oversampling for each class through weight calculation using K-NN for sampling. In this paper, a total of five oversampling techniques such as ROS, SMOTE, and ADASYN were applied through NSL-KDD, an open network security dataset. The oversampling method proposed in this paper proved to be the most effective sampling method compared to the existing oversampling method through the F1-Score evaluation index.

• Current Optics and Photonics
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• v.8 no.1
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• pp.38-44
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• 2024

Under the influence of atmospheric turbulence, a star's point image will shake back and forth erratically, and after exposure the originally small star point will spread into a huge spot, which will affect the ground calibration of the star sensor. To analyze the impact of atmospheric turbulence on the positioning accuracy of the star's center of mass, this paper simulates the atmospheric turbulence phase screen using a method based on a sparse spectrum. It is added to the static-star-simulation device to study the transmission characteristics of atmospheric turbulence in star-point simulation, and to analyze the changes in star points under different atmospheric refractive-index structural constants. The simulation results show that the structure function of the atmospheric turbulence phase screen simulated by the sparse spectral method has an average error of 6.8% compared to the theoretical value, while the classical Fourier-transform method can have an error of up to 23% at low frequencies. By including a simulation in which the phase screen would cause errors in the center-of-mass position of the star point, 100 consecutive images are selected and the average drift variance is obtained for each turbulence scenario; The stronger the turbulence, the larger the drift variance. This study can provide a basis for subsequent improvement of the ground-calibration accuracy of a star sensitizer, and for analyzing and evaluating the effect of atmospheric turbulence on the beam.