• Journal of Internet Computing and Services
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• 제14권6호
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• pp.125-139
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• 2013

Distribution of malicious applications developed by attackers is increasing along with general normal applications due to the openness of the Android-based open market. Mechanism that allows more accurate ways to distinguish normal apps and malicious apps for common mobile devices should be developed in order to reduce the damage caused by the rampant malicious applications. This paper analysed the normal event pattern from the most highly used game apps in the Android open market to analyse the event pattern from normal apps and malicious apps of mobile devices that are based on the Android platform, and analysed the malicious event pattern from the malicious apps and the disguising malicious apps in the form of a game app among 1260 malware samples distributed by Android MalGenome Project. As described, experiment that extracts normal app and malicious app events was performed using Strace, the Linux-based system call extraction tool, targeting normal apps and malicious apps on Android-based mobile devices. Relevance analysis for each event set was performed on collected events that occurred when normal apps and malicious apps were running. This paper successfully extracted event similarity through this process of analyzing the event occurrence characteristics, pattern and distribution on each set of normal apps and malicious apps, and lastly suggested a mechanism that determines whether any given app is malicious.

• KIISE Transactions on Computing Practices
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• 제23권9호
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• pp.535-541
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• 2017

Today, the scale of the computer software market has increased, and massive sized software has been developed to satisfy diverse requirements. In this context, software complexity is increasing and the quality of software is becoming more difficult to manage. In particular, software reuse is important for the improvement of the environments of legacy systems and new system development. In this paper, we propose a method to reuse modules that are certified by quality. Reusable levels are divided into code area (method, class, and component), project domain, and business levels. Based on the coupling and cohesion of software complexity, we propose a reusable module extraction mechanism with reusability metrics, which constructs a visualization of the "reusable module's chunk" based on the method and class levels. By applying reverse engineering to legacy projects, it is possible to identify reusable modules/objects/chunks. If these modules/objects/chunks are to be reused to develop an extension system or similar new system, we need to ensure software reliability in order to reduce the time and cost of software development.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제27권5호
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• pp.463-470
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• 2016

In this paper, we introduce a method of scattering centers extraction using the polarimetric data. VIRAF software based on the PO (Physical Optics) and PTD(Physical Theory of Diffraction) were used to calculate the surface scattering and the edge or wedge scattering, respectively. In addition, by using the unitary transformation, 4-channel data based on the linear polarization basis were converted to 2-channel data based on the left/vertical-circular polarization basis, leading to data compression coherently. The scattering mechanism was analyzed in terms of the polarization states and different look angles by using the scattering center of a target extracted by the 2D RELAX algorithm.

• KIPS Transactions on Software and Data Engineering
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• 제3권7호
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• pp.255-262
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• 2014

Our previous research[1] suggested object extraction and modeling method based on Fillmore's case grammar. This approach had not considered of use case extraction and method. To solve this problem, we adopt Fillmore's semantic method as linguistic approach into requirement engineering, which refine fillmore's case grammar for extracting and modeling use cases from customer requirements. This Refined mechanism includes the definition of a structured procedure and the representation of visual notations for 'case' modeling. This paper also proposes the use case decision matrix to identify use case size from extracted use cases based on goal oriented requirement engineering(GoRE), which related with the complexity of use case, and also prioritizes the use cases with this matrix. It demonstrates our proposal with the bank ATM system.

• Applied Biological Chemistry
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• 제40권6호
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• pp.519-524
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• 1997

As an investigation for utilization of ascidian tunic carotenoids as a food color additives, we attempted to collect the volatile thermal degradation compounds from ascidian tunic carotenoids. Oxygenate volatile compounds were extracted by simultaneous distillation and extraction/concentration apparatus and analyzed by gas chromatography and mass spectrometery. Total 63 compounds were identified and some of them were caused by thermal degradation. They included 1,3,5-trimethylbenzene, 3,5,5-trimethyl-3-cyclohexen-1-ol, 3,5,5-trimethyl-3-cyclohexen-1-one, 1,1,2,3-tetramethyl-2-cyclohexen-5-ol, 1,1,2,3-tetramethyl-2-cyclohexen-5-one, 2,3,4,4-tetramethyl-6-hydroxy-2-cyclohexene-1-one, 1,2,3,8-tetrahydro-3,3,6-trimethyl-1-naphtol, dihydroacetinidolide, ${\beta}-ionone$, 2-(1,1,5-trimethyl-3-hydroxy-5-cyclohexen-6-yl)-1-tolylethene, 2,6-dimethyl-8-(1,1,5-trimethyl-3-hydroxy-5-cyclohexen-6-yl)-1,3,5-octatriene-7-yne. Proposed mechanism of formation of some compounds as thermal degradation products of ascidian tunic carotenoids are provided.

• Applied Chemistry for Engineering
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• 제33권5호
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• pp.538-544
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• 2022

One of the most exciting areas for the development of alternative fuels is the production of biodiesel. To reduce the cost of biodiesel production, in situ trans-esterification has been introduced to simplify the production process by enabling extraction and trans-esterification to occur at a single stage in the presence of a catalyst. In this study, we investigated the feasibility of using non-corrosive and environmentally receptive flying jet plasma as an alternative catalytic route for in situ tran-sesterification of castor bean seeds (CBS). Upon optimizing the reaction conditions, it is elucidated that applying a low ratio of methanol to seeds (≤6:1) has resulted in hindering the in situ trans-esterification and leading to insignificant conversion. The yield of esters has increased from 80.5% to 91.7% as the molar ratio rose from 9:1 to 12:1. Excess alcohol beyond the ratio of 15:1 was shown to have a negative impact on the yield of the produced esters, attributed to an increase in the biodiesel portion prone to dissolving in the co-product (glycerol). An increase in the reaction bulk temperature from 40 to 55 ℃ led to a higher ester content by 50%. Further increases in the bulk temperature beyond 55 ℃ did not affect yields. Regarding the reaction period, the results have shown that 3 h of reaction is adequate for a higher biodiesel yield. The quality of the biodiesel obtained has demonstrated that all physicochemical properties meet the ASTM D6751 specifications.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권11호
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• pp.3991-4010
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• 2021

The Question Similarity Measurement of Chinese Crop Diseases and Insect Pests (QSM-CCD&IP) aims to judge the user's tendency to ask questions regarding input problems. The measurement is the basis of the Agricultural Knowledge Question and Answering (Q & A) system, information retrieval, and other tasks. However, the corpus and measurement methods available in this field have some deficiencies. In addition, error propagation may occur when the word boundary features and local context information are ignored when the general method embeds sentences. Hence, these factors make the task challenging. To solve the above problems and tackle the Question Similarity Measurement task in this work, a corpus on Chinese crop diseases and insect pests(CCDIP), which contains 13 categories, was established. Then, taking the CCDIP as the research object, this study proposes a Chinese agricultural text similarity matching model, namely, the AgrCQS. This model is based on mixed information extraction. Specifically, the hybrid embedding layer can enrich character information and improve the recognition ability of the model on the word boundary. The multi-scale local information can be extracted by multi-core convolutional neural network based on multi-weight (MM-CNN). The self-attention mechanism can enhance the fusion ability of the model on global information. In this research, the performance of the AgrCQS on the CCDIP is verified, and three benchmark datasets, namely, AFQMC, LCQMC, and BQ, are used. The accuracy rates are 93.92%, 74.42%, 86.35%, and 83.05%, respectively, which are higher than that of baseline systems without using any external knowledge. Additionally, the proposed method module can be extracted separately and applied to other models, thus providing reference for related research.

• Resources Recycling
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• 제31권2호
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• pp.49-55
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• 2022

In the present study, the thermodynamic evaluation of the sulfate-roasting process was conducted to extract vanadium from the Korean vanadium titano-magnetite ore. The leaching efficiency of vanadium and other impurities was analyzed for varying roasting temperatures and addition of Na₂SO₄. In the case of sulfate roasting, the roasting temperature was 200 ℃ higher than that previously observed Na₂CO₃ roasting. However, the higher leaching efficiency of vanadium and lower leaching efficiency of other impurities, such as aluminum and silicon, were observed. The high selectivity for the extraction of vanadium in sulfate roasting would result from the reaction mechanism between SO₂ gas and vanadium concentrate.

• KSCE Journal of Civil and Environmental Engineering Research
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• 제28권1B호
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• pp.137-147
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• 2008

Soil Vapor Extraction (SVE) has been extensively used to remove volatile organic compounds (VOCs) from the vadoze zone. In order to investigate the removal mechanism during SVE operation, laboratory modeling experiments were carried out and tailing effect could be observed in later stage of the experiment. Tailing effect means that removal rate of contaminants gets significantly to decrease in later stage of SVE operation. Also, mathematical model simulating the tailing effect was used, which considers rate-limited diffusion in a water film during mass transfer among gas, liquid, and solid phases. Measurement data obtained through the experiment was used as input data of the numerical analyses. Sensitivity analysis was performed to examine the effect of each parameter on required time to reach final target concentration. Finally, it was found that the concentration in the soil phase decreased significantly with a liquid and gas diffusion coefficient larger, actual path length shorter, and water saturation smaller.

• Journal of Haehwa Medicine
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• 제25권1호
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• pp.71-86
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• 2016

Objective : Hongyi (Formica yessensis) is the dried insect of fomicidae. In previous studies, it appeared possibilities on anti-thrombosis, preventing atherosclerosis, treating rheumatoid disease, and inhibiting hela cell. In this study, we investigated anti-inflammatory effects and mechanism of Hongyi. Methods : Hongyi A was extracted by water and made dried powder. Hongyi B was extracted by ethanol and made dried powder. We measured Nitric Oxide (NO) production on the mouse macrophages (RAW 264.7), mouse vascular endothelial cell (MOVAS) and human vascular endothelial cell (HUVEC) for anti-inflammatory effect. In addition, we conducted reverse transcription reaction (RT-PCR) for investigating the mechanism. Results : In RAW 264.7 macrophages stimulated by LPS, Hongyi A ($100{\mu}g/m{\ell}$) decreased NO production compared with LPS $2{\mu}g/ml$ control group with statistical significance (p<0.05). Hongyi A (50, $100{\mu}g/m{\ell}$) also decreased NO production compared with LPS $4{\mu}g/ml$ control group with statistical significance (p<0.01). Hongyi B (50, $100{\mu}g/m{\ell}$) decreased NO production compared with LPS $2{\mu}g/ml$ control group with statistical significance (p<0.01). Hongyi B (10, 50, $100{\mu}g/m{\ell}$) also decreased NO production compared with LPS $4{\mu}g/ml$ control group with statistical significance (p<0.01, p<0.001, p<0.001). In the MOVAS, Hongyi A and B increased NO production compared with control group. In the HUVEC, Hongyi B increased NO production compared with control group. The expression of NF-${\kappa}B$ in 12-hours MOVAS culture was decreased by Hongyi A and B (10, $50{\mu}g/ml$) compared with control group, but expression of $I{\kappa}B$ was increased. In the 24-hours MOVAS culture, expression of $I{\kappa}B$ was significantly increased. The expression of NF-${\kappa}B$ in 12-hours HUVEC culture was decreased by Hongyi A and B compared with control group, but expression of $I{\kappa}B$ was increased. Hongyi B also increased eNOS mRNA gene expression. Conclusions : Hongyi A and B showed anti-inflammatory effect in mouse macrophages with the activation of vascular endothelial cell through NO production in MOVAS and HUVEC repectively. Honyi B showed superior effect than Hongyi A, but additonal mechanism study should be conducted.