• Title/Summary/Keyword: Logging

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Spatial and temporal dynamic of land-cover/land-use and carbon stocks in Eastern Cameroon: a case study of the teaching and research forest of the University of Dschang

  • Temgoua, Lucie Felicite;Solefack, Marie Caroline Momo;Voufo, Vianny Nguimdo;Belibi, Chretien Tagne;Tanougong, Armand
    • Forest Science and Technology
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    • v.14 no.4
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    • pp.181-191
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    • 2018
  • This study was carried out in the teaching and research forest of the University of Dschang in Belabo, with the aim of analysing land-cover and land-use changes as well as carbon stocks dynamic. The databases used are composed of three Landsat satellite images (5TM of 1984, 7ETM + of 2000 and 8OLI of 2016), enhanced by field missions. Satellite images were processed using ENVI and ArcGIS software. Interview, focus group discussion methods and participatory mapping were used to identify the activities carried out by the local population. An inventory design consisting of four transects was used to measure dendrometric parameters and to identify land-use types. An estimation of carbon stocks in aboveground and underground woody biomass was made using allometric models based on non-destructive method. Dynamic of land-cover showed that the average annual rate of deforestation is 0.48%. The main activities at the base of this change are agriculture, house built-up and logging. Seven types of land-use were identified; adult secondary forests (64.10%), young secondary forests (7.54%), wetlands (7.39%), fallows (3.63%), savannahs (9.59%), cocoa farms (4.28%) and mixed crop farms (3.47%). Adult secondary forests had the highest amount of carbon ($250.75\;t\;C\;ha^{-1}$). This value has decreased by more than 60% for mixed crop farms ($94.67\;t\;C\;ha^{-1}$), showing the impact of agricultural activities on both forest cover and carbon stocks. Agroforestry systems that allow conservation and introduction of woody species should be encouraged as part of a participatory management strategy of this forest.

Analysis of Security Vulnerability on Firewall Logging Mechanism against DDoS Attack (DDoS 공격에 대한 방화벽 로그 기록 취약점 분석)

  • Choun, Jun-Ho;Jang, Kun-Won;Jun, Moon-Seog;Shin, Dong-Gyu
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.17 no.6
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    • pp.143-148
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    • 2007
  • In the context of mass traffic, firewall system cannot record normal log files against DDoS attack. The loss of log record causes that a firewall system does not know whether a packet is normally filtered or not, and firewall log, which is an essential data for the counter measure of violation accident, cannot be verified as trusted. As a network speed increases, these problems happen more frequently and largely. Accordingly, the method to use simply additional hardware devices is not recommended for the popularization of firewall. This paper is devoted to verify the loss of iptable log that is the mother's womb of most domestic firewall systems and show that the log handling methods for conventional firewall systems are needed to improve.

Research on Efficient Live Evidence Analysis System Based on User Activity Using Android Logging System (안드로이드 로그 시스템을 이용한 효율적인 사용자 행위기반 라이브 증거수집 및 분석 시스템 연구)

  • Hong, Il-Young;Lee, Sang-Jin
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.22 no.1
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    • pp.67-80
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    • 2012
  • Recently as the number of smartphone user is growing rapidly, android is also getting more interest in digital forensic. However, there is not enough research on digital data acquisition and analysis based on android platform's unique characteristics so far. Android system stores all the related recent systemwide logs from the system components to applications in volatile memory, and therefore, the logs can potentially serve as important evidences. In this paper, we propose a digital data acquisition and analysis system for android which extracts meaningful information based on the correlation of android logs and user activities from a device at runtime. We also present an efficient search scheme to facilitate realtime analysis on site. Finally, we demonstrate how the proposed system can be used to reconstruct the sequence of user activities in a more intuitive manner, and show that the proposed search scheme can reduce overall search and analysis time approximately 10 times shorter than the normal regular search method.

Hydrochemical Investigation for Site Characterization: Focusing on the Application of Principal Component Analysis (부지특성화을 위한 지하수의 수리화학 특성 연구: 주성분 분석을 중심으로)

  • Yu, Soonyoung;Kim, Han-Suk;Jun, Seong-Chun;Yi, Jong Hwa;Yun, Seong-Taek;Kwon, Man Jae;Jo, Ho Young
    • Journal of Soil and Groundwater Environment
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    • v.27 no.spc
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    • pp.34-50
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    • 2022
  • Principal component analysis (PCA) was conducted using hydrochemical data in four testbeds (A to D) built for the development of site characterization technologies to assess the hydrochemical processes controlling the hydrochemistry in each site. The PCA results indicated the nitrogen loading to deep bedrock aquifers through permeable fractures in Testbed A, the chemical weathering enhanced with the biodegradation of petroleum hydrocarbons in Testbed B, the reductive dechlorination in Testbed C, and the different hydrochemistry depending on the depth to bedrock in Testbed D, consistent with the characteristics of each site. In Testbeds B and D, outliers seemed to affect the PCA result probably due to the small number of samples, whereas the PCA result was still consistent with site characteristics. This study result indicates that the PCA is widely applicable to hydrochemical data for the assessment of major hydrochemical processes in contamination sites, which is useful for site characterization when combined with other site characterization technologies, e.g., geological survey, geophysical investigation, borehole logging. It is suggested that PCA is applied in contaminated sites to interpret hydrochemical data not only for the distribution of contamination levels but also for the assessment of major hydrochemical processes and contamination sources.

A Study on the Consumer Perception of Metaverse Before and After COVID-19 through Big Data Analysis (빅데이터 분석을 통한 코로나 이전과 이후 메타버스에 대한 소비자의 인식에 관한 연구)

  • Park, Sung-Woo;Park, Jun-Ho;Ryu, Ki-Hwan
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.6
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    • pp.287-294
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    • 2022
  • The purpose of this study is to find out consumers' perceptions of "metaverse," a newly spotlighted technology, through big data analysis as a non-face-to-face society continues after the outbreak of COVID-19. This study conducted a big data analysis using text mining to analyze consumers' perceptions of metaverse before and after COVID-19. The top 30 keywords were extracted through word purification, and visualization was performed through network analysis and concor analysis between each keyword based on this. As a result of the analysis, it was confirmed that the non-face-to-face society continued and metaverse emerged as a trend. Previously, metaverse was focused on textual data such as SNS as a part of life logging, but after that, it began to pay attention to virtual reality space, creating many platforms and expanding industries. The limitation of this study is that since data was collected through the search frequency of portal sites, anonymity was guaranteed, so demographic characteristics were not reflected when data was collected.

Smart monitoring system using electromagnetic waves to evaluate the integrity of reinforced concrete structural elements

  • Jong-Sub Lee;Dongsoo Lee;Youngdae Kim;Goangseup Zi;Jung-Doung Yu
    • Computers and Concrete
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    • v.31 no.4
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    • pp.293-306
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    • 2023
  • This study proposes and demonstrates a smart monitoring system that uses transmission lines embedded in a reinforced concrete structure to detect the presence of defects through changes in the electromagnetic waves generated and measured by a time-domain reflectometer. Laboratory experiments were first conducted to identify the presence of voids in steel-concrete composite columns. The results indicated that voids in the concrete caused a positive signal reflection, and the amplitude of this signal decreased as the water content of the soil in the void increased. Multiple voids resulted in a decrease in the amplitude of the signal reflected at each void, effectively identifying their presence despite amplitude reduction. Furthermore, the electromagnetic wave velocity increased when voids were present, decreased as the water content of the soil in the voids increased, and increased with the water-cement ratio and curing time. Field experiments were then conducted using bored piles with on-center (sound) and off-center (defective) steel-reinforcement cage alignments. The results indicated that the signal amplitude in the defective pile section, where the off-center cage was poorly covered with concrete, was greater than that in the pile sections where the cage was completely covered with concrete. The crosshole sonic logging results for the same defective bored pile failed to identify an off-center cage alignment defect. Therefore, this study demonstrates that electromagnetic waves can be a useful tool for monitoring the health and integrity of reinforced concrete structures.

Software Formal Verification Methodology using Aspect DEVS Verification Framework (Aspect DEVS 검증 틀을 이용한 소프트웨어 정형 검증 방법론)

  • Choi, Chang-Beom;Kim, Tag-Gon
    • Journal of the Korea Society for Simulation
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    • v.18 no.3
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    • pp.113-122
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    • 2009
  • Software is getting more complex due to a variety of requirements that include desired functions and properties. Therefore, verifying and testing the software are complicated problems. Moreover, if the software is already implemented, inserting and deleting tracing/logging code into the source code may cause several problems, such as the code tangling and the code scattering problems. This paper proposes the Aspect DEVS Verification Framework which supports the verification and testing process. The Aspect DEVS Verification Framework utilizes Aspect Oriented Programming features to handle the code tangling and the code scattering problems. By applying aspect oriented features, a user can find and fix the inconsistency between requirement and implementation of a software without suffering the problems. The first step of the verification process is the building aspect code to make a software act as a generator. The second step is developing a requirement specification using DEVS diagrams and implementing it using the DEVSIM++. The final step is comparing the event traces from the software with the possible execution sequences from DEVS model.

Attack Detection Technology through Log4J Vulnerability Analysis in Cloud Environments (클라우드 환경에서 Log4J 취약점 분석을 통한 공격 탐지 기술)

  • Byeon, Jungyeon;Lee, Sanghee;Yoo, Chaeyeon;Park, Wonhyung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2022.05a
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    • pp.557-559
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    • 2022
  • The use of open source has the advantage that the development environment is convenient and maintenance is easier, but there is a limitation in that it is easy to be exposed to vulnerabilities from a security point of view. In this regard, the LOG4J vulnerability, which is an open source logging library widely used in Apache, was recently discovered. Currently, the risk of this vulnerability is at the 'highest' level, and developers are using it in many systems without being aware of such a problem, so there is a risk that hacking accidents due to the LOG4J vulnerability will continue to occur in the future. In this paper, we analyze the LOG4J vulnerability in detail and propose a SNORT detection policy technology that can detect vulnerabilities more quickly and accurately in the security control system. Through this, it is expected that in the future, security-related beginners, security officers, and companies will be able to efficiently monitor and respond quickly and proactively in preparation for the LOG4J vulnerability.

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A Long Term Characteristics of Hydraulic Conductivity and Tensile Strength of Natural Fiber Drain with respect to Installation Conditions (천연섬유배수재의 타설 조건에 따른 장기 투수계수 및 인장강도의 특성)

  • Jang, Jin-Young;Jang, Yeon-Soo;Cho, Sam-Duck
    • Journal of the Korean Geotechnical Society
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    • v.24 no.4
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    • pp.15-21
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    • 2008
  • Long term changes of hydraulic properties and tensile strength of natural fiber drain (NFD) are analyzed and compared with those of intact NFD's. NFD was buried in distilled water, two types of seawater and clay soils obtained in southern and western parts of Korea, Kwang-Yang and Si-hwa. Specimens are taken out in 0, 3, 9 and 18 month intervals, and durability tests of the NFD are performed. Hydraulic conductivity of the NFD samples decreased compared with that of intact NFD samples, because clay particles easily passed to coarsened mesh of filters and clogged the porous stone below and reduced hydraulic conductivity. Tensile strength of drains from the soil bucket is reduced larger than those in the seawater and the distilled water. Strength reduction was higher in summer than winter.

English Predicate Inversion: Towards Data-driven Learning

  • Kim, Jong-Bok;Kim, Jin-Young
    • Journal of English Language & Literature
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    • v.56 no.6
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    • pp.1047-1065
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    • 2010
  • English inversion constructions are not only hard for non-native speakers to learn but also difficult to teach mainly because of their intriguing grammatical and discourse properties. This paper addresses grammatical issues in learning or teaching the so-called 'predicate inversion (PI)' construction (e.g., Equally important in terms of forest depletion is the continuous logging of the forests). In particular, we chart the grammatical (distributional, syntactic, semantic, pragmatic) properties of the PI construction, and argue for adata-driven teaching for English grammar. To depart from the arm-chaired style of grammar teaching (relying on author-made simple sentences), our teaching method introduces a datadriven teaching. With total 25 university students in a grammar-related class, students together have analyzed the British Component of the International Corpus of English (ICE-GB), containing about one million words distributed across a variety of textual categories. We have identified total 290 PI sentences (206 from spoken and 87 from written texts). The preposed syntactic categories of the PI involve five main types: AdvP, PP, VP(ed/ing), NP, AP, and so, all of which function as the complement of the copula. In terms of discourse, we have observed, supporting Birner and Ward's (1998) observation that these preposed phrases represent more familiar information than the postposed subject. The corpus examples gave us the three possible types: The preposed element is discourse-old whereas the postposed one is discourse-new as in Putting wire mesh over a few bricks is a good idea. Both preposed and postposed elements can also be discourse new as in But a fly in the ointment is inflation. These two elements can also be discourse old as in Racing with him on the near-side is Rinus. The dominant occurrence of the PI in the spoken texts also supports the view that the balance (or scene-setting) in information structure is the main trigger for the use of the PI construction. After being exposed to the real data and in-depth syntactic as well as informationstructure analysis of the PI construction, it is proved that the class students have had a farmore clear understanding of the construction in question and have realized that grammar does not mean to live on by itself but tightly interacts with other important grammatical components such as information structure. The study directs us toward both a datadriven and interactive grammar teaching.