• Title/Summary/Keyword: Neutralization characteristics

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Replay Attack based Neutralization Method for DJI UAV Detection/Identification Systems (DJI UAV 탐지·식별 시스템 대상 재전송 공격 기반 무력화 방식)

  • Seungoh Seo;Yonggu Lee;Sehoon Lee;Seongyeol Oh;Junyoung Son
    • Journal of Aerospace System Engineering
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    • v.17 no.4
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    • pp.133-143
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    • 2023
  • As drones (also known as UAV) become popular with advanced information and communication technology (ICT), they have been utilized for various fields (agriculture, architecture, and so on). However, malicious attackers with advanced drones may pose a threat to critical national infrastructures. Thus, anti-drone systems have been developed to respond to drone threats. In particular, remote identification data (R-ID)-based UAV detection and identification systems that detect and identify illegal drones with R-ID broadcasted by drones have been developed, and are widely employed worldwide. However, this R-ID-based UAV detection/identification system is vulnerable to security due to wireless broadcast characteristics. In this paper, we analyze the security vulnerabilities of DJI Aeroscope, a representative example of the R-ID-based UAV detection and identification system, and propose a replay-attack-based neutralization method using the analyzed vulnerabilities. To validate the proposed method, it is implemented as a software program, and verified against four types of attacks in real test environments. The results demonstrate that the proposed neutralization method is an effective neutralization method for R-ID-based UAV detection and identification systems.

Characteristics of Sulfuric Acid Neutralization by Geomedia from Korea with Relevance to Chemical Spill Accidents (사고 누출 황산의 국내 지질매체 반응 특성)

  • Lee, Yoonho;Hyun, Sung Pil;Moon, Hee Sun;Shin, Doyun;Lee, Eunhee;Yoo, Jae-Young
    • Journal of the Mineralogical Society of Korea
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    • v.32 no.4
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    • pp.249-258
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    • 2019
  • Acid spill accidents are frequently occurring in Korea with increasing production, use, storage, and transport of acids, accompanying industrialization and economic growth. The acids introduced to the subsurface environments would eventually be neutralized by reactions with geomedia. However, the spatial and temporal extent to which the spilled acids would affect will be dependent on the characteristics of the geomedia exposed to the acids. In this work, sulfuric acid, the most used acid in Korea, was reacted with a set of model geomedia representative of the geology of Korea. The buffering capacity of the model geomedia was determined through batch-type experiments using pH changes as an indicator. X-ray diffraction was used to identify the mineral phases contributing to the acid neutralization. The results showed that sandstone had the largest acid neutralization capacity among the tested geomedia, while kaolinite had the smallest. The findings of this study would contribute to quantitatively assessing the impact of spilled acids on geomedia and hence to predicting the vulnerability of geomedia to the spilled acid.

Removal Characteristics of Heavy Metals by Continuous Neutralization of Plating Wastewater with Waste-Oyster Shells (폐굴껍질에 의한 산성도금폐수의 연속 중화시 중금속제거 특성)

  • 김형석;송동근;성낙창
    • Resources Recycling
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    • v.7 no.3
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    • pp.36-41
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    • 1998
  • Objective of the research is to deteonine the praeLic따 running parameters for neutralization and removal of heavy metals from plating wastewater with waste-oyster shells by the Bohart$.$Adams equation. Waste-oyster shells discharged from the d domestic oyster cultnring fields cause a serious ocean environmental pollution. However, it is expected that those are able to b be recycled for removal of heavy metals through neutralization of plating wastewater because the shells contain approximate 93% $CaCO_3$, and have multi-pore voids. By applying the results of the continuous experiments to Bohart-Adams equation, s service time decreases in the order of Cr>Fe>Cu while removal efficiencies of metals become less in the order of Fe>Cr>Cu.

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Chemical Composition Characteristics of Size-fractionated Particles during Heavy Asian Dust Event in Spring, 2010 (2010년 봄철 고농도 황사의 입경별 화학조성 특성)

  • Lee, Dong-Eun;Kim, Won-Hyung;Ko, Hee-Jung;Oh, Yong-Soo;Kang, Chang-Hee
    • Journal of Korean Society for Atmospheric Environment
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    • v.29 no.3
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    • pp.325-337
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    • 2013
  • The size-fractionated aerosol samples have been collected at Gosan Site of Jeju Island during the spring season of 2010, in order to examine the chemical composition characteristics of the Asian Dust and Non-Asian Dust particles. The concentrations of ${HCO_3}^-$, Al, and nss-$Ca^{2+}$ in $PM_{10}$ had tremendously increased during the heavy Asian Dust (March 20, 2010). The concentration ratios of Asian Dust to Non-Asian Dust for the soil species (nss-$Ca^{2+}$, ${HCO_3}^-$, Al, Fe, Ti, Mn) were 12.2~30.7, meanwhile those for the anthropogenic species (nss-${SO_4}^{2-}$, ${NH_4}^+$, ${NO_3}^-$, $K^+$, Zn, Pb, and Cu) were 2.9~7.8. During the heavy Asian Dust event, the concentration increase of ${NO_3}^-$ in $PM_{2.5}$ were much more apparent than those of nss-${SO_4}^{2-}$ and ${NH_4}^+$, and the soil species (nss-$Ca^{2+}$ and ${HCO_3}^-$) showed much higher concentration increase. The neutralization factor of $NH_3$ was higher than that of $CaCO_3$. However, the neutralization factor of $CaCO_3$ in $PM_{10}$ was exceptionally high during the heavy Asian Dust, showing the evidence of heavy migration of soil particles. From the study for size fractionated particles, it was found that nss-${SO_4}^{2-}$ and ${NH_4}^+$ were mostly distributed in fine particle mode, on the other hand, ${NO_3}^-$ existed evenly in both fine and coarse particle modes, and the soil species (nss-$Ca^{2+}$, Al, Fe, etc.) were mainly in the latter mode. During the heavy Asian Dust, in particular, the concentrations of ${NH_4}^+$, nss-${SO_4}^{2-}$, $K^+$, Zn, and Pb had increased in coarse particle mode as well.

Characteristics of Ionic Composition of Rainwater in Suwon (수원지역 빗물의 이온 조성)

  • Lee, Jong-Sik;Jung, Goo-Bok;Kim, Jin-Ho;Kim, Won-Il;Lee, Jeong-Taek
    • Korean Journal of Soil Science and Fertilizer
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    • v.40 no.2
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    • pp.151-155
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    • 2007
  • The issue of acid precipitation and related environmental problems in East Asia have been emerging. To evaluate the acidity and chemical characteristics of rainwater in Korea, its chemical properties during crop cultivation season from April to October were investigated at Suwon, Korea. Also, to estimate the contribution of ions on its acidity, ion composition characteristics and neutralization effects by cation ions were determined. Ion balance and electrical conductivity balance between the measured and estimated values showed high correlation. Rainwater had distributed highly in the range of pH 4.5~5.6. The pH of rainwater was relatively high at June as compared with other monitoring periods. $Na^+$ was the main cation followed by $NH_4{^+}$, $Ca^{2+}$, $H^+$ > $K^+$ > $Mg^{2+}$. Among these, $Na^+$, $NH_4{^+}$, $Ca^{2+}$ and $H^+$ covered over 93% of total cations. About 86% of anion in rainwater was composed of $SO{_4}^{2-}$ and $NO_3{^-}$. In rainwater samples, $NH_4{^+}$ and $Ca^{2+}$ contributed greatly to neutralization of the rain acidity. Also, 88% of soluble sulfate in rainwater was nss-$SO{_4}^{2-}$(non-sea salt sulfate).

Pollutant Removal and Characteristic of Floc by PACI Coagulation (PACI을 이용한 오염물질 제거 및 입자 특성에 관한 연구)

  • Moon, Byung-Hyun;Kim, Seung-Hyun;Lee, Hyang-In
    • Journal of Korean Society on Water Environment
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    • v.16 no.4
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    • pp.459-468
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    • 2000
  • This study is to investigate the floc structure and removal of turbidity and organic matter by PACI coagulation. The turbidity removal by PACI coagulation was obtained at larger pH range than alum coagulation. And the removal of organic matter was obtained at smaller pH range than that of turbidity. The organic matter was removed by the adsorption of $Al(OH)_3$ precipitates. Floc structure was characterized by measuring fractal dimension and volume diameter using AIA and SALLS. Fractal dimension measured by AIA did not show the different characteristics of floc produced in sweep floe and charge neutralization region. Using SALLS, floes in sweep floc region were found to be larger size and fractal dimension than flocs in charge neutralization region. As pollutant removal increased. larger fractal dimension and size of floc were measured. SALLS method was found to be more useful method to characterize flocs in coagulation than AIA method.

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Histopathoiogical Findings and Antibody Titers of the Experimental Animals Infected with Aujeszky′s Disease Virus(Korea Isolates) (ADV 국내 분리주를 접종한 실험 동물의 조직 병리 소견과 항체가 연구)

  • 최준식;육동현;김성삼;박석기
    • Korean Journal of Veterinary Service
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    • v.14 no.2
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    • pp.134-142
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    • 1991
  • We surveyed the antibody titers in the slaughtered pigs by enzyme immunodiffusion method for the epidemiological distribution of Aujeszky's disease in Korea. And also we observed the clinical symptoms, histopathological findings and antibody titers by serologic neutralization test in experimental animals infected with Aujeszky's disease virus(ADV) isolated from Korea. The results of the experiments were summarized as follows. 1. We detected 2 pigs infected with ADV of 1000 in 1990 and 1 of 600 in 1991 by enzyme immunodiffusion method. 2. In histopathological findings of experimental animals inoculated ADV, the typical characteristics of Aujeszky's disease were not observed in pig, but edema and degeneration in the epidermis were observed in rats, vasculoendotheriosis, perivascular cuffing and cellular infiltration in the cerebrum were appeared in rabbits and perivascular cuffing and forcal infiltration of glial cells in the cerebrum were appeared in mice. 3. The increasing antibody titers(1 : 64) in the serological neutralization test were ascertained in 2 carrier pigs inoculated ADV. 4. Rabbits, mice and rats died all about 5 days after inoculation, but pigs and chickens didn't die. 5. In 1 cat and 2 rabbits inoculated with the Aujeszky's disease virus(ADV), the typical clinical findings of Aujeszky's disease were observed in rabbit, but not in cat and so we slaughtered without any signs of Aujeszky's disease.

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The Study of Ideal Body Images based on the Product Types in Fashion Magazine Advertisement (패션잡지 광고상품의 유형에 따른 이상적인 신체미에 대한 연구)

  • Kwon, Gi-Young;Helvenston Sally I.
    • Journal of the Korean Society of Clothing and Textiles
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    • v.30 no.12 s.159
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    • pp.1672-1682
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    • 2006
  • Attitudes about the ideal body are influenced by media, including fashion magazine advertisements. The purpose of our study was to analyze the ideal body image for males and females in contemporary society. We analyzed the contemporary ideal gender image through the examination of physical characteristics(body type, age), and fashion styles(hair, make up, supplements, clothing styles, body exposure) in fashion advertisements published in Gentlemen's Quarterly(GQ) and Vogue issued during 2002. The results indicate some blurring in masculinity and femininity resulting in gender neutralization and naturalness pursuing natural appearances. But, some previous beauty norms related to masculinity and femininity remained.

Influence of Different Mixing Types on the Removal of Natural Organic Matter in Water Treatment (정수처리시 천연유기물질의 제거에 대한 급속혼화유형의 영향)

  • Kim, Hyun-Chul;Yu, Myong-Jin;Lee, Seock-Heon
    • Journal of Korean Society of Water and Wastewater
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    • v.19 no.3
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    • pp.370-377
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    • 2005
  • Dispersion of coagulant should be completed in a fraction of a second before the metal hydroxide precipitate has form. For the reason so-called pump diffusion flash mixing (PDFM) have been proposed, and PDFM is one of reasonable methods to quickly disperse the hydrolyzing metal salts. In this study, therefore, we attempt to understand the difference of removal characteristics of natural organic matter (NOM) between pump diffusion flash mixing (PDFM) and conventional rapid mixing (CRM) for coagulation in a water treatment system, and to enhance the removal of NOM through the improved mixing process. DOC and turbidity removal by PDFM higher than those by CRM, while SUVA value of water treated by PDFM was high as compared with that by CRM. Hydrophilic NOM was more effectively removed by PDFM than CRM, since charge neutralization effect increased by quick dispersion of coagulant. The DBP formation potentials due to NOM was effectively reduced by the improved mixing (i.e., PDFM) for coagulation and could be controlled through decrease in concentration of precursor rather than reduction of activity with disinfectant.

Efficiency Characteristics by Mixed Absorbents for the Removal of Odor Compounds in the Wet Scrubber (습식세정탑 내 악취가스 제거를 위한 복합흡수제의 효율 특성)

  • Park, Young G.;Kim, Jeong-in
    • Applied Chemistry for Engineering
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    • v.22 no.1
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    • pp.48-55
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    • 2011
  • It was found that the absorbent mixed with 2-aminoethanol and others has been applied to remove them via chemical neutralization. The absorbent of natural second metabolites was achieved by a removal efficiency of 20~30% by itself depending on treatment conditions, but the complex absorbent mixed with 0.2% amine chemical provides the removal efficiency of over 98%. Optimal removal efficiencies have been examined against two major parameters of the temperature and pH to remove ammonia and hydrogen sulfide gases. The chemical analysis was also performed to analyze the composition of an essential oil by GC-MS. The monoterpenes in an essential oil reacted with odorous compounds by neutralization and their reaction mechanism was partially elucidated.