• Title/Summary/Keyword: 노출율

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Evaluating Impact Resistance of Externally Strengthened Steel Fiber Reinforced Concrete Slab with Fiber Reinforced Polymers (섬유 보강재로 외부 보강된 강섬유 보강 콘크리트 슬래브의 충격저항성능 평가)

  • Yoo, Doo-Yeol;Min, Kyung-Hwan;Lee, Jin-Young;Yoon, Young-Soo
    • Journal of the Korea Concrete Institute
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    • v.24 no.3
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    • pp.293-303
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    • 2012
  • Recently, as construction technology improved, concrete structures not only became larger, taller and longer but were able to perform various functions. However, if extreme loads such as impact, blast, and fire are applied to those structures, it would cause severe property damages and human casualties. Especially, the structural responses from extreme loading are totally different than that from quasi-static loading, because large pressure is applied to structures from mass acceleration effect of impact and blast loads. Therefore, the strain rate effect and damage levels should be considered when concrete structure is designed. In this study, the low velocity impact loading test of steel fiber reinforced concrete (SFRC) slabs including 0%~1.5% (by volume) of steel fibers, and strengthened with two types of FRP sheets was performed to develop an impact resistant structural member. From the test results, the maximum impact load, dissipated energy and the number of drop to failure increased, whereas the maximum displacement and support rotation were reduced by strengthening SFRC slab with FRP sheets in tensile zone. The test results showed that the impact resistance of concrete slab can be substantially improved by externally strengthening using FRP sheets. This result can be used in designing of primary facilities exposed to such extreme loads. The dynamic responses of SFRC slab strengthened with FRP sheets under low velocity impact load were also analyzed using LS-DYNA, a finite element analysis program with an explicit time integration scheme. The comparison of test and analytical results showed that they were within 5% of error with respect to maximum displacements.

Family Structure and Succession of the Late Chosun Seen through Male Adoption (양자제도를 통해 본 조선후기 가족구조와 가계계승: 의성김씨 호구단자 분석을 중심으로)

  • Park, Soo-Mi
    • Korea journal of population studies
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    • v.30 no.2
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    • pp.71-95
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    • 2007
  • This paper attempts to identify the principle of family succession and family patterns of yangban in the late Chosun period through an analysis of male adaptation cases found in family registration records. The primary source of analysis is the family registration documents of Uiseong Kim's from the late 17th century to the early 20th century. As a result, it is found that there is a substantial change in the patterns of family from the early and mid Chosun period to the late Chosun period. The change is the strengthening of the principle of patriarchy succession through male adoption. Looking at the data as a whole, the average number of household members is increased and the membership of kinship also expanded. In contrast to the family patterns of the early Chosun period, not only the patterns of Uiseong Kim's family are predominately immediate family or collateral family but also the majority is extended family in the 18th and 19th centuries. The male adoption cases recorded in Uiseong Kim's family registration documents take up 33.8% of the male adoption cases in the entire family registration documents. This goes to show that the strengthening of the principle of primogeniture succession at a time when child mortality rate is very high resulted in the increase of male adoption. In conclusion, the late Chosun society was a society where the seat of primogeniture was much more important than immediate hereditary members in the family succession.

A Study on Heavy Metal Contents in Processed Foods and Their Safety Evaluations (가공식품 중 중금속 함량 및 안전성 평가)

  • Lee, Hyo-Jung;Shim, Jee-Youn;Oh, Hyun-Suk;Jang, Mi-Ran;Lee, Yoon-Ae;Lee, Ryun-Kyung;Kim, Min-A;Lee, Sang-Min;Cho, Tae-Yong;Kang, Ho-Il
    • Korean Journal of Food Science and Technology
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    • v.44 no.1
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    • pp.21-27
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    • 2012
  • This research was carried out as a survey on the contents of lead, cadmium, and arsenic in processed foods (milk, vegetable oil, and margarine) in Korea. The limits of quantification (LOQs) were Pb 0.3 ${\mu}g/kg$, Cd 0.15 ${\mu}g/kg$, and As 0.45 ${\mu}g/kg$ for milk and Pb 0.61 ${\mu}g/kg$, Cd 0.31 ${\mu}g/kg$, and As 0.91 ${\mu}g/kg$ for vegetable oil and margarine. The recoveries were 92.6-98.0% for Pb, 91.2-98.9% for Cd, and 97.9-104.7% for As. The average levels of Pb were 2.395 ${\mu}g/kg$ for milk, and 7.656 ${\mu}g/kg$ for vegetable oil. The average levels of Cd were 0.483 ${\mu}g/kg$ for milk, and 0.380 ${\mu}g/kg$ for vegetable oil, and levels of As were 0.781 ${\mu}g/kg$ for milk, and 1.241 ${\mu}g/kg$ for vegetable oil. The results of this study showed that Pb, Cd, and As contents in the whole samples were less than the maximum residual levels in the processed foods that were specified by the Codex standard.

Ecological Characteristics of Korean Red Pine (Pinus densiflora S. et Z.) Forest on Mt. Nam as a Long Term Ecological Research (LTER) Site (국가장기생태연구 장소로서 구축된 남산 소나무림의 생태적 특성)

  • Lee, Chang-Seok;Cho, Yong-Chan;Shin, Hyun-Cheol;Lee, Choong-Hwa;Lee, Seon-Mi;Seol, Eun-Sil;Oh, Woo-Seok;Park, Sung-Ae
    • Journal of Ecology and Environment
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    • v.29 no.6
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    • pp.593-602
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    • 2006
  • Species composition, spatial distribution of major species, diameter and height classes distribution, and species diversity were .analyzed in the Korean red pine (Pinus densiflora, hereafter referred as pine) forest in the permanent quadrats, which were designed for Long Term Ecological Research (LTER). Collected data were compared with those from the other areas including urban center (Mt. Inwang and Hongneung) and boundary areas (Mts. Acha, Bukhan, Bulam, Cheonggye, Daemo, and Surak), and natural areas (Mts. Seolak, Songni, and Wolak) to clarify the ecological characteristics of pine forest on Mt. Nam. Species composition of pine forest on Mt. Nam showed a similarity with those of urban center but did a little and big differences with those on urban boundary and natural areas, respectively. Such differences that pine forest on Mt. Nam showed, were usually due to Styrax japonicus, Sorbus alnifolia, Oplismenus undulatifolius, Ailanthus altissima, Ageratina altissima and so on, which showed higher coverage there. Predicted from diameter and height classes distribution of tree species, pine forest on Mt. Nam showed a possibility to be replaced by a S. japonica. Considered that this replacer species is not only a sub-tree but also shade intolerant, such successional trend could be interpreted as a sort of retrogressive succession. Those on urban boundary and natural areas showed a difference by displaying probabilities to be maintained as themselves as an edaphic climax or succeeded to oak forests. Species diversity of pine forest on Mt. Nam was lower than those in urban boundary and natural areas due to excessive dominance of several species, which led to different species composition from the other areas. Plants, which produced the differences, were species that flourishes in the polluted industrial area (S. japonica and S. alnifolia), favors the disturbed site (O. undulatifolius), and exotic species (A. altissima and Eupatorium rugosum). Those results reflects that pine forest of Mt. Nam was exposed on severe environmental pollution and excessive human interferences.

Smartphone Security Using Fingerprint Password (다중 지문 시퀀스를 이용한 스마트폰 보안)

  • Bae, Kyoung-Yul
    • Journal of Intelligence and Information Systems
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    • v.19 no.3
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    • pp.45-55
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    • 2013
  • Thereby using smartphone and mobile device be more popular the more people utilize mobile device in many area such as education, news, financial. In January, 2007 Apple release i-phone it touch off rapid increasing in user of smartphone and it create new market and these broaden its utilization area. Smartphone use WiFi or 3G mobile radio communication network and it has a feature that can access to internet whenever and anywhere. Also using smartphone application people can search arrival time of public transportation in real time and application is used in mobile banking and stock trading. Computer's function is replaced by smartphone so it involves important user's information such as financial and personal pictures, videos. Present smartphone security systems are not only too simple but the unlocking methods are spreading out covertly. I-phone is secured by using combination of number and character but USA's IT magazine Engadget reveal that it is easily unlocked by using combination with some part of number pad and buttons Android operation system is using pattern system and it is known as using 9 point dot so user can utilize various variable but according to Jonathan smith professor of University of Pennsylvania Android security system is easily unlocked by tracing fingerprint which remains on the smartphone screen. So both of Android and I-phone OS are vulnerable at security threat. Compared with problem of password and pattern finger recognition has advantage in security and possibility of loss. The reason why current using finger recognition smart phone, and device are not so popular is that there are many problem: not providing reasonable price, breaching human rights. In addition, finger recognition sensor is not providing reasonable price to customers but through continuous development of the smartphone and device, it will be more miniaturized and its price will fall. So once utilization of finger recognition is actively used in smartphone and if its utilization area broaden to financial transaction. Utilization of biometrics in smart device will be debated briskly. So in this thesis we will propose fingerprint numbering system which is combined fingerprint and password to fortify existing fingerprint recognition. Consisted by 4 number of password has this kind of problem so we will replace existing 4number password and pattern system and consolidate with fingerprint recognition and password reinforce security. In original fingerprint recognition system there is only 10 numbers of cases but if numbering to fingerprint we can consist of a password as a new method. Using proposed method user enter fingerprint as invested number to the finger. So attacker will have difficulty to collect all kind of fingerprint to forge and infer user's password. After fingerprint numbering, system can use the method of recognization of entering several fingerprint at the same time or enter fingerprint in regular sequence. In this thesis we adapt entering fingerprint in regular sequence and if in this system allow duplication when entering fingerprint. In case of allowing duplication a number of possible combinations is $\sum_{I=1}^{10}\;{_{10}P_i}$ and its total cases of number is 9,864,100. So by this method user retain security the other hand attacker will have a number of difficulties to conjecture and it is needed to obtain user's fingerprint thus this system will enhance user's security. This system is method not accept only one fingerprint but accept multiple finger in regular sequence. In this thesis we introduce the method in the environment of smartphone by using multiple numbered fingerprint enter to authorize user. Present smartphone authorization using pattern and password and fingerprint are exposed to high risk so if proposed system overcome delay time when user enter their finger to recognition device and relate to other biometric method it will have more concrete security. The problem should be solved after this research is reducing fingerprint's numbering time and hardware development should be preceded. If in the future using fingerprint public certification becomes popular. The fingerprint recognition in the smartphone will become important security issue so this thesis will utilize to fortify fingerprint recognition research.

Expression of Growth Factors and Secretory Leukocyte Protease Inhibitor (SLPI) in RAW264.7 Cells after Lipopolysaccharide (LPS) Stimulation (대식세포주 (RAW264.7)에서 박테리아성 지질다당류 (LPS) 자극에 의한 분비백혈구단백분해효소억제제 (SLPI)와 성장인자들의 발현)

  • Son, Wook-Hee;Choi, Baik-Dong;Jeong, Soon-Jeong;Wang, Guan-Lin;Hwang, Ho-Keel;Jeong, Moon-Jin
    • Applied Microscopy
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    • v.37 no.2
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    • pp.93-102
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    • 2007
  • Secretory leukocyte protease inhibitor (SLPI) was known as one of bacterial lipopolysaccharide (LPS)-induced products of macrophage. Macrophages play an important role in the development of inflammatory responses by secreting an array of cytokines and chemokines in a tissue microenvironment. To identify the function and relationship between potent growth factors and SLPI after LPS stimulation, we conducted reverse transcriptase polymerase chain reaction (RT-PCR) and Western blots for the detection of mRNA and protein expression of SLPI and growth factors such as VEGF, PDGF, bFGF after 100 ng LPS stimulation on the RAW264.7 cells. The result of RT-PCR was showed SLPI mRNA expression was increased from 60 min to 48h in RAW 264.7 cells after incubation with LPS. VEGF and PDGF mRNA was expressed highly at initial stage by LPS stimulation. The mRNA of bFGF and type I collagen was very weakly expressed after LPS stimulation. SLPI protein level was increased likely the mRNA levels in RAW 267.7 cells. Additionally, phase contrast and scanning electron microscopic observation demonstrated that the LPS induce the change of morphology of the RAW264.7 cells. From these results, it suggest that expression of SLPI by LPS treatment may associate with VEGF and PDGF expression in RAW264.7 cells.

Effects of Permeable Cryoprotectants on Viability of Mammalian Embryo Model (침투성 동결보호제가 포유류 초기배자의 생존성에 미치는 영향)

  • Kim, Hyun;Cho, Sang-Rae;Kim, Dong Kyo;Choe, Changyong;Seong, Hwan-Hoo
    • Journal of Embryo Transfer
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    • v.30 no.3
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    • pp.195-200
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    • 2015
  • The objective of this study was to evaluate the toxicities of permeable cryoprotectants and finally to establish the cryopreservation method of surplus embryos obtained during assisted reproductive technology (ART). Toxicities of permeable cryoprotectants, dimethyl sulfoxide (DMSO), ethylene glycol (EG), Glycerol, and 1,2-PROH were investigated using a murine embryo model. Female $F-{_1}$ mice were stimulated with gonadotropin, induced ovulation with hCG and mated. Two cell embryos were collected and cultured after exposure to among DMSO, EG, Glycerol, and 1,2-PROH. Embryo development was evaluated up to the blastocyst stage. The total cell count of blastocysts that were treated with DMSO and Glycerol at the 2-cell stage was significantly lower than that were treated with EG ($81.1{\pm}15.1$), 1,2-PROH ($88.0{\pm}21.1$) or the control ($99.9{\pm}21.3$) (p<0.001). On comparison of four cryoprotectant treated groups, the DMSO and Glycerol treated group showed a decreased cell count compared with the EG and 1,2-PROH treated group (p<0.05). Both DMSO ($14.7{\pm}1.3$), EG ($12.1{\pm}1.1$), Glycerol ($15.2{\pm}1.8$), and 1,2-PROH ($11.5{\pm}1.3$) treated groups showed higher apoptosis rates of cells in the blastocyst compared with the control ($6.5{\pm}0.7$, p<0.0001). In addition, the DMSO or Glycerol treated group showed more apoptotic cells than the EG or 1,2-PROH treated group (p<0.001). The potential toxicity of cryoprotectants was uncovered by prolonged exposure of murine embryos to among DMSO, EG, Glycerol, and 1,2-PROH at room temperature. When comparing four permeable cryoprotective agents, EG and 1,2-PROH appeared to be less toxic than DMSO and Glycerol at least in a murine embryo model.

Method Development for Determination of Multi-Mycotoxins in Chicken Liver and Kidney Tissues by LC-MS/MS (LC-MS/MS를 이용한 닭 간과 신장 중 곰팡이 독소 6종 동시분석법 개발)

  • Kim, Soohee;Kim, Kwang-Nam;Kim, Hyobi;Song, Jae-Young;Park, Sung-Won
    • Korean Journal of Poultry Science
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    • v.43 no.2
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    • pp.111-118
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    • 2016
  • Mycotoxins are secondary metabolites produced by molds, such as Aspergillus, Fusarium and Penicillium, that have adverse effects on animals and humans. Aflatoxin, ochratoxin, zearalenone, fumonisin and deoxynivalenol are the mycotoxins of greatest agro-economic importance and cause acute disease called mycotoxicoses. Mycotoxicosis in poultry birds results in decreased meat/egg production, immunosuppressant, and hepatotoxicosis. Some of toxins or their metabolites may be retained in animal or human tissues and induce health problems. This study was designed to develop a sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the simultaneous detection and quantification of mycotoxins, such as aflatoxin $B_1$, aflatoxin $M_1$, ochratoxin A, zearalenone, fumonisin B and deoxynivalenol, in chicken liver and kidney tissues. The mycotoxins were extracted and purified using modified QUECHERS methods, separated by LC and detected by an electrospray ionisation interface (ESI) and tandem MS. Good precision and linearity were observed for most of six mycotoxins. The recovery test for each mycotoxin in liver and kidney tissues mostly indicated good average recovery rates between 80.94% and 98.10% and the coefficient of variation mostly under 13.78%, except for aflatoxin $M_1$ and fumonisin $B_1$. The limit of detection (LOD) for six mycotoxins was $7.6{\sim}145.79{\mu}g/kg$ in liver tissues and $6.07{\sim}197.20{\mu}g/kg$ in kidney tissues. The quantification limits (LOQ) for 6 mycotoxins were in the range $23.04{\sim}441.78{\mu}g/kg$ in liver tissues and $18.40{\sim}597.59{\mu}g/kg$ in kidney tissues, respectively. The developed multi-mycotoxin method in this study permits simultaneous, simple, and rapid determination of several co-existing mycotoxins in chicken liver and kidney tissues.

Experimental Studies on Lead Toxicity in Domestic Cats 1. Symptomatology and Diagnostic Laboratory Parameters (고양이의 납중독에 관한 실험적 연구 1. 임상증상 및 실험실적 평가)

  • Hong Soon-Ho;Han Hong-Ryul
    • Journal of Veterinary Clinics
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    • v.10 no.1
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    • pp.111-130
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    • 1993
  • Lead toxicity was evaluated in forty-five cats on a balanced diet, Treated with 0(control), 10, 100(low), 1, 000, 2, 000, and 4, 000(high) ppm of lead acetate orally on a body weight basis. The objectives were to establish toxic dosage level of leaf in cats, to characterize changes in behavior and clinical pathology, and to demonstrate what blood lead concentrations correlate with the known dosages of lead. Some high dose cats showed projectile vomiting, hyperactivity, and seizures. The growth rates did not appear to be altered in any of the dosed groups. Normal blood lead concentration in cats were lower than that of humans, dogs, and cattle. Blood lead concentrations of 3 to 20$\mu\textrm{g}$/100$m\ell$ could be termed a 'subclinical' range in the cat. Clinical lead toxicity in cats may have blood lead concentrations ranging 20 to 120$\mu\textrm{g}$/100$m\ell$. Zinc protoporphyrin concentrations were proportional to lead dosages and a significant ZPP elevation, greater than 50$\mu\textrm{g}$/100$m\ell$, may be indicative of clinical lead toxicity. The enzyme aminolevulinic acid dehydratase showed an inverss dose response relationship for all lead dosages and a significant ZPP elevation, greater than 50$\mu\textrm{g}$/100$m\ell$, may be indicative of clinical lead toxicity. The enzyme aminolevulinic acid dehydratase showed an inverse dose response relationship for all lead dosages and appears to be a good indicator of lead exposure in cats. Urinary aminolevuliruc acid concentrations generally increased with lead dosage, but individual values varied. Hair lead concentrations rose proportionately to lead dosages. Lead at least in high doses appears to inhibit chemotactic activity of polymorphonuclear cells and monocytes. No consistent dose response relationships were observed in hemoglobin, RBC, WBC, neutrophil, lymphocyte, monocyte, and eosinophil counts. There were no consistent dose related changes in total protein, plasma protein, BUN, and ALT values. Reticulocyte counts did not increase significantly in most lead dosage levels, and are probably of little value in diagnosing lead toxicity in cats. The fact that no significant changes were found in nerve conduction velocities may support that there was no segmental demyelination resulting from lead ingestion. The lethal dose in cats appear to range from 60 to 150mg/kg body weight. A reliable diagnosis of lead poisoning can be made utilizing blood lead, ZPP, and ALAD, and hair lead.

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Effects of Pseudomonas fluorescens on Production of Several Inflammatory Mediators in the Human Alveolar Epithelial Cells. (재조합 단백질 생산에 이용되는 Pseudomonas fluorescens의 인체 폐포 상피세포의 염증성 인자들의 발현에 미치는 영향)

  • Yang, Hyun;Ryoo, Jung-Min;Park, Seung-Hwan;Choi, Hye-Jin;Kim, Na-Yeon;Cho, Hyung-Hoon;Ahn, Jung-Hoon;Moon, Yu-Seok
    • Journal of Life Science
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    • v.18 no.4
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    • pp.530-536
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    • 2008
  • To investigate the molecular mechanism of the airway inflammation by Pseudomonas fluorescens, effects on the inflammatory mediators such as interleukin-8 (IL-8), cyclooxygenase-2 (COX-2), macophage inhibitory cytokine 1 (MIC-1) were assessed in the human alveolar epithelial cells. Exposure to P. fluorescens and its recombinant bacteria suppressed cellular viability in the A549 epithelial cells and pro-inflammatory cytokine interleukin-8 production. However, pro-inflammatory prostaglandin-producing COX-2 protein was not altered by P. fluorescens though its mRNA was slightly elevated. As the inhibitory cytokine for the pro-inflammatory mediators, MIC-1 expression was monitored in A549 cells. MIC-1 gene induction was not significantly enhanced but the protein processing was changed by exposure to P. fluorescens. Pro-protein form of MIC-1 (${\sim}40\;kD$) was cleaved into active form mature MIC-1 (${\sim}15\;kD$) and propeptide (${\sim}28\;kD$) by the bacteria exposure. MIC-1 activation can contribute to the suppression of cellular viability by P. fluorescens and can retard IL-8-induced monocyte recruitment. However, sustained activation of MIC-1 can mediate the tissue injury by P. fluorescens exposure.