• 제목/요약/키워드: Alternation

검색결과 386건 처리시간 0.03초

제지(製紙) 슬러지 소각재(燒却滓)를 활용(活用)한 섬유보강(纖維補强)콘크리트의 균열(龜裂) 억제(抑制) 효과(效果) (Effect on the Crack Resistance of Fiber Reinforced Concrete using Incinerated Paper Mill Sludge Ash)

  • 김남욱
    • 자원리싸이클링
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    • 제17권4호
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    • pp.10-20
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    • 2008
  • 본 연구는 아직까지 활용실적이 적은 제지슬러지소각재를 대량으로 활용할 수 있는 방법을 도출하기 위하여 제지슬러지소각재를 시멘트의 대체재로 사용하고자 하였다. 또한 제지슬러지소각재 대체 시 나타나는 단점인 수화열 및 흡수율의 증가로 인한 수축균열을 폴리프로필렌섬유 및 셀룰로오스섬유를 혼입하여 이에 대한 제어효과를 고찰하여 제지슬러지소각재의 시멘트 대체재로써의 활용가능성을 규명하였다.

칼코게나이드 박막에서 전계효과에 의한 편광 홀로그래피 회절효율 특성 (The properties of diffraction efficiency in polarization holography using the chalcogenide thin films by the electric field effects.)

  • 장선주;여철호;박정일;정홍배
    • 한국전기전자재료학회논문지
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    • 제13권9호
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    • pp.791-795
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    • 2000
  • Amorphous chalcogenide glasses have a wide variety of light-induced effects. In this study, we have investigated the diffraction efficiency of chalcogenide. As$_{40}$ Ge$_{10}$ Se$_{15}$ S$_{35}$ thin films by the various applied electric fields. The holographic grating in these thin films has been formed using a linearly polarized He-Ne laser light (633nm). The diffraction efficiency was investigated the two method of applied electric field in the perpendicular and parallel to the direction of inducing beam. We obtained that properties of diffraction efficiency in the two methods of applied electric field. The result is shown that the diffraction efficiency of parallel electric field is 285% increase, η=1.1$\times$10$^{-3}$ and the diffraction efficiency of perpendicular electric field is 80% decrease, η=9.83$\times$10$^{-5}$ . Also, we have investigated the anisotropy property on chalcogenide thin films by the electric field effects.

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SSL MITM 프록시 공격에 대한 효과적 방어방법 (An Effective Protection Mechanism for SSL Man-in-the-Middle Proxy Attacks)

  • 임차성;이우기;조태창
    • 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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    • 제16권6호
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    • pp.693-697
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    • 2010
  • 신용카드 정보나 공인 인증서들이 웹을 통해 전송되어지는 현재 전자상거래 시스템에서 사용자의 의도와 다르게 클라이언트가 웹 프록시 서버를 경유하게 되거나 프록시 서버의 경로가 변경될 경우가 종종 발생한다. 이때 전송되는 기밀 정보가 SSL(Secure Sockets Layer) 또는 TLS(Transport Layer Security)프로토콜을 통해 암호화 되어 전송 되어도 프록시 서버에서 인증서 변조를 통하여 계좌번호나 신용카드 비밀번호를 스니핑 당하는 위험에 노출된다. 본 논문에서는 현재 사용되고 프록시 정보 변조 해킹에 의해 무방비 상태의 신용카드 결제 보안 시스템에 대해서 분석하고 이를 방지하기 위한 인증 프록시 서버와 프록시 변조 MITM(Man-In-The-Middle) 공격 방지 방법에 대해서 제안한다.

KEOP-2007 라디오존데 관측자료를 이용한 장마 특성 분석 : Part Ⅱ. 2007년 장마의 역학적 및 열역학적 특성에 관한 사례연구 (The Analysis of Changma Structure Using Radiosonde Observational Data from KEOP-2007: Part II. The Dynamic and Thermodynamic Characteristics of Changma in 2007)

  • 김기훈;김연희;장동언
    • 대기
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    • 제19권4호
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    • pp.297-307
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    • 2009
  • The synoptic structures and the dynamic and thermodynamic characteristics of Changma in 2007 are investigated using the ECMWF analysis data and the radiosonde data from KEOP-2007 IOP. The enhancement of the North-Pacific High into the Korean peninsula and the retreat of the Okhotsk High are shown during the onset of Changma and the change of wind component from southwesterly to northwesterly is appeared during the end of Changma. The baroclinic atmosphere is dominant during Changma at most regions over the Korean peninsula except at Gosan and Sokcho. The quasi-barotropic atmosphere is induced at Gosan by warm air mass and Sokcho by cold air mass. Precipitation in the Korean peninsula occurs when dynamic instability is strengthened as the baroclinic and qusi-barotropic structure is weakened. An empirical orthogonal function (EOF) analysis is performed to find the dominant modes of variability in Changma. The first EOF explains the onset of Changma. The second EOF is related to the discrimination for existence and nonexistence of precipitation during Changma period according to the alternation of equivalent potential temperature between middle and lower atmosphere.

WBAN 환경에서 응급 정보의 안정적 전송을 위한 프로토콜 설계 및 구현 (Design and Implementation of a protocol for stable transmission of emergency information in WBAN environment)

  • 이동호;왕종수
    • 디지털산업정보학회논문지
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    • 제6권4호
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    • pp.57-65
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    • 2010
  • Application of WBAN technology in medical field facilitates the prevention of diseases by collecting the vital signs remotely. It also enables to prevent the accidental emergency situation in advance plus long-tem monitoring of patients with chronic diseases such as heart diseases, hypertension, or the elderly and infirm. For emergency patients, major vital signal information collected by the 'Sensing' should have the top priority and such information should be transferred as promptly as possible without competition. In addition, when an emergency occurs to a patient, a priority mechanism is necessitated for a urgent message to get through to the final destination. However, LR-WPAN IEEE 802.15.4 technology does not consider such emergency message handling features. To deal with aforementioned issues, the IEEE 802.15.4 super frame protocol structure has been designed for stable transfer of emergency information in WBAN environment in this study, and alternation to super frame structures have been made, allowing GTS(Guaranteed Time Slot) can be used first at CFP (Contention Free Period) by reserving the resources in advance and prioritize the emergency signals. NS-2 has been utilized for the performance test and analysis.

전기회로 모델을 이용한 동맥 협착 후부의 소지맥 현상 해석 (What causes the Pulsus - Tardus and Parvus effect at the Arterial Post-stenosis region?)

  • 김수정;이동혁;김종효;박재형;민병구
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1997년도 추계학술대회
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    • pp.471-474
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    • 1997
  • Recently, many studies have shown clinically the detection of proximal arterial stenosis through evaluation of a Doppler waveform alternation, the so-called pulsus tardus and parvus, that often occurs distal to the stenosis. However the cause of the tardus-parvus phenomenon remains obscure. To analyze its cause, we modeled the blood-flow circuit as simple electrical circuit. This shows that pulsus tardus-parvus effect is caused as a result of high-frequency waveform component attenuation from low-pass filtering by capacitance(complience of the poststenotic vessel wall) and resistance(stenosis). As a result, the degree of pulsus tardus-parvus increased as the complience of the poststenotic segment of vessel increased, as well as increasing stenosis.

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행동 실험을 통한 총아100의 기억력 및 집중력 향상 효과 (Effects of ChongA 100 on Memory and Attentional Ability by Behavioral Test)

  • 경혁수;임강현;김이화;송효남;민성희;김정범
    • 동의생리병리학회지
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    • 제25권3호
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    • pp.431-437
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    • 2011
  • Recently, there are so many studies that herbal composition has the effect on enhancing the memorial ability. But there are few studies whether it has effect on enhancing attentional ability. The purpose of present study is to prove the effects of a herbal composition(ChongA 100) on enhancing not only memorial but also attentional ability. The memorial ability interfered by amyloid-${\beta}$ was evaluated with passive avoidance test Y-maze task. The attentional ability was studied with attentional set-shifting task(ASST). The 200mg/kg of ChongA100 could significantly recover the shortened latency of passive avoidance test and the interfered alternation of Y-maze task. The number of trials in ASST was significantly reduced as well. Our study suggests that it has effects on enhancing both memorial and attentional ability.

경주지방의 무미 또는 단미 형태의 개(경주개 동경이)의 혈청 단백질의 분획에 대환 실태조사 (Investigation of serum protein electrophoresis fractions analysis in Gyeongju DongGyeong dogs)

  • 박창은;이은우;성기창;최석규
    • 한국동물위생학회지
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    • 제33권3호
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    • pp.293-297
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    • 2010
  • Serum proteins of Korean native dogs (Gyeongju DongGyeong dogs) was analyzed by capillary electrophoresis system. Electrophoretic patterns showed six fractions. Total serum protein and ratio of albumin to globulin were $5.99{\pm}0.83$ (g/dl) and $1.41{\pm}0.29$ (g/dl) in DongGyeong dogs. Relative percentages of total serum albumin and $\alpha-1$, $\alpha-2$, $\beta-1$, $\beta-2$, $\gamma$-globulin fraction were $57.94{\pm}5.43$, $3.15{\pm}2.30$, $7.49{\pm}4.09$, $9.43{\pm}3.50$, $7.63{\pm}5.70$, and $14.36{\pm}7.63$, respectively. It was observed that $\beta$-globulin was higher than other fractions. The most striking alternation with age was founded in the $\gamma$-fractions. Also, it was observed that ratios of albumin to globulin in DongGyeong dogs were higher than on other dogs.

Gray Leaf Spot in Peppers Caused by Stemphylium solani and S. lycopersici

  • Kim, Byung-Soo;Yu, Seung-Hun;Cho, Hyun-Jung;Hwang, Hee-Suk
    • The Plant Pathology Journal
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    • 제20권2호
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    • pp.85-91
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    • 2004
  • A disease causing severe leaf spots in pepper plants has been observed in northern Gyeongbuk and Gangwon provinces in Korea since 1994. The current study diagnosed the disease as gray leaf spot caused by Stemphylium solani Weber and S. lycopersici (Enjoji) Yamamoto, both of which are pathogenic in pepper and tomato plants. Although the disease has been found in almost all areas where peppers are grown, it is more severe in mountain terrains where the nights are cool. Both species of pathogenic fungi were found to sporu-late profusely on V-8 juice agar in plastic or Pyrex glass Petri dishes, although not in domestically-produced glass Petri dishes, when cultured at $20^{\circ}C$ under irradi-ation from a daylight fluorescent lamp with a 12-hour light and dark alternation. The domestically-produced glass Petri dishes, which are made of window glass, were found to block near ultraviolet wavelengths, around and below 300 nm, which explained why the fungi did not sporulate. However, sporulation decreased at above $25^{\circ}C$ and most isolates failed to sporulate above $27^{\circ}C$. The worst level of disease was obtained when the inoculated plants were incubated with a $15^{\circ}C$ night and $20^{\circ}C$ day temperature regime relative to 4 night/day temperature combinations (15/20, 20/25, 25/30, and 30/35$^{\circ}C$).

초음파 전처리에 의한 슬러지 생분해성 영향 평가 (Effects of Ultrasonic Pretreatment on Sludge Biodegradability)

  • 김주현;이강훈;;염익태
    • 상하수도학회지
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    • 제25권4호
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    • pp.611-616
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    • 2011
  • The impacts of ultrasonic pretreatment on the biodegradability of domestic sewage sludge were evaluated through a series of anaerobic digestion experiments in batch system. The gas and methane production from the sludge samples pretreated by an ultrasonic tool with different durations were measured with time. Although the biogas production increased with the extent of sludge solubilization and the period of ultrasonic pretreatment, the enhancement of sludge biodegradability was much more sensitive to the pretreatment for the relatively short periods. Most of the enhanced biodegradability by the pretreatment was appeared in the early stage of anaerobic digestion, less than 6 days. The maximum biogas production per day was observed between 4 to 6 days when the sludge was pretreated less than 10 minutes while it was obtained in the beginning for the sludge pretreated longer periods. The results suggest that the repeated alternation of low strength ultrasonic pretreatment and anaerobic digestion may be more effective than the combination of one time pretreatment for a relatively long period and following anaerobic digestion.