• 제목/요약/키워드: GRS

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수치해석을 이용한 기존 피해 보강토 옹벽의 보강에 관한 사례 연구 (A Case Study on the Reinforcement of Existing Damaged Geogrid Reinforced Soil Wall Using Numerical Analyses)

  • 원명수;란쿠얀크리스틴;최정호;하양성
    • 한국지반신소재학회논문집
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    • 제19권1호
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    • pp.75-82
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    • 2020
  • 보강토 옹벽이 붕괴되는 사례가 종종 발생되면서, 붕괴된 옹벽의 보강 및 복구에 대한 사회적인 관심은 날로 커지고 있으나 이에 대한 연구는 미미한 경향이 있다. 이와 같은 배경 아래, 본 연구에서는 Plaxis 2D프로그램을 이용한 일련의 수치해석을 수행하여 설계부실로 전면블록의 전도와 배면 침하 피해가 발생된 기존 보강토 옹벽을 복구할 수 있는 방안에 대한 사례연구를 수행하였다. 복구방안으로는 기존 피해 보강토 옹벽에 쏘일네일링과 보강콘크리트(RC) 전면벽체를 보강하는 방안(Case 1)과 기존 피해 보강토 옹벽을 제거하고 재시공하는 방안(Case 2)으로 검토하였다. 보강토 옹벽의 내적안정검토결과는 파단에 대해서는 Case 1이 Case 2보다 크고 인발에 대해서는 Case 2가 Case 1보다 안전율이 크게 나타났다. 수치해석에 의한 외적거동과 전단강도감소법에 의한 전체사면안정 안전율은 Case 1이 Case 2보다 안정적으로 나타났다. 본 연구에서는 보다 안정적인 외적거동을 나타내는 Case 1로 기존 피해 보강토 옹벽을 보강하도록 하였다.

풍화잔류토의 생성모델의 제안 (A Proposal of a Model for the Generation of Weathered Residual Soils)

  • 민덕기;이완진
    • 한국지반공학회논문집
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    • 제20권9호
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    • pp.47-56
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    • 2004
  • 본 연구에서는 풍화잔류토의 생성을 특성화시키는 새로운 분열모델을 제안하였으며, GRS모델이라고 명명하였다. GRS 모델은 풍화가 많이 진행될수록 흙 입자의 크기가 작아지고 흙 속의 간극이 많아진다는 사실에 착안하였으며, 프랙탈 이론으로부터 도출된 $P_F$(분열가능성)로써 풍화잔류토의 생성과정을 표현할 수 있다. 암석이 분열됨으로써 흙 입자들이 생성되며 암석의 분열은 단계별로 진행되지만 각 단계별 분열가능성은 일정하지 않다는 것이 GRS모델의 기본개념이다. GRS모델의 적용성을 검증한 결과, 입자들의 잔류량이 많은 입경에서 $P_{Fi}$(분열단계별 분열가능성)가 작게 산출되었고, 입도분포가 양호할수록 크게 산출되었다. 일반적인 흙에서 나타나는 S자형상의 입도분포곡선은 $P_{Fi}$가 높은 오목형상에서 나타났으며, $P_{Fi}$의 변화형상이 볼록하면서 높은 값을 가질경우에는 빈입도의 입도분포특성을 나타내었다. 전반적으로 $P_{Fi}$가 작은 경우에는 $P_{Fi}$의 변화형상에 관계없이 큰 입자의 잔류량이 많은 오목한 형상의 입도분포곡선을 나타내었다. $P_{Fi}$의 평균값은 균등계수$(C_u)$와 분열프랙탈차원$(D_r)$에 비례하여 증가하였으나, 곡률계수$(C_C)$와는 무관하였다.

베셀타원체상에서의 한반도 지오이드 모델의 개발 (Development of the Geoid Model in Korean Peninsula referred to Bessel Ellipsoid)

  • 이석배
    • 한국측량학회지
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    • 제16권2호
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    • pp.213-223
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    • 1998
  • 본 논문은 베셀타원체상에서 한반도 일원의 지오이드모델을 개발하기 위한 연구이다. 여러가지의 유용한 데이터를 사용하여 remove and restore technique에 의하여 GRS80 타원체상에서 정밀지오이드고를 계산하였으며, FFT 기법에 의하여 Stokes 적분을 수행하였다. GTOPO30으로부터 표고값을 추출하여 모든 격자점의 위치를 3 매개변수 방법에 의하여 베셀타원체 좌표계로 환산하였으며, 기하학적 방법으로 베셀지오이드고를 계산하였다. 연구 결과 한반도 일원에서의 GRS80 기준의 정밀 중력지오이드모델(KOGGDM33)과 베셀타원체 기준의 지오이드모델 (KOBGDM33)을 얻을 수 있었으며, 베셀타원체상에서의 지오이드고는 용암포의 -91.8 m에서 대한해협의 -39.0 m 에 이르기까지의 점진적인 분포를 보이는 것을 알 수 있었다.

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A New Deoxyhexose Biosynthetic Gene Cluster in Streptomyces griseus ATCC10137: Heterologous Expression of dTDP-D-Glucose 4,6-Dehydratase Gene

  • Kim, Sang Suk;Bang, Jung-Hee;Hyun, Chang-Gu;Kim, Joo-Woo;Han, Jae-Jin;Suh, Joo-Won
    • Journal of Applied Biological Chemistry
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    • 제43권3호
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    • pp.136-140
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    • 2000
  • A novel 6-deoxyhexose biosynthetic gene cluster different from the one for the biosynthesis of streptomycin was isolated from Streptomyces griseus using specifically designed PCR primers to compare the sequence of known dTDP-glucose synthase genes. We cloned a 5.8-kb DNA from Streptomyces griseus ATCC10137, which contained the 4-ketoreductase homologue (grsB), dTDP-glucose synthase (grsD), and dTDP-glucose 4, 6-dehydratase (grsE) genes. Escherichia coli cultures containing plasmid of the PCR product which encoded the grsE region under the controUed T7 promoter were able to catalyze the formation of dTDP-4-keto-6-deoxy-D-glucose from TDP-glucose. The enzyme showed high substrate specificity, being specific to only dTDP-glucose that is known to be incorporated into secondary metabolites such as antibiotics.

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유리섬유강화슬래그(Glass-fiber Reinforced Slag)의 경관석 성능 적합성 평가 (The Suitability Assessment of Performance Standards on Landscaping Rocks of GRS(Glass Fiber Reinforced Slag) Panels)

  • 윤복모;이용복;구본학
    • 한국환경복원기술학회지
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    • 제16권2호
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    • pp.127-135
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    • 2013
  • This study was carried out to verify the suitability of GRS(Glass-fiber Reinforced Slag) as natural type landscape stone according to the material property and structural safety performance standards. The structural safety performance of the GRS panel showed 12.4MPa and 16.2MPa each in flexural strength at 2 and 3% content of glass fiber while the flexural strength at 4 and 5% of glass fiber content showed 26.9MPa, and 30.2MPa, respectively, all satisfying the standards. In addition, air-dried gravity was found to be 1.82~1.89 in measuring range at 2~5% level of glass fiber content, satisfy the existing standards 1.8~2.3. In structural safety performance, the range of flexural strength consequent on glass fiber content was surveyed to be 12.8~30.2MPa, all satisfying the performance standards, while 10MPa and more while the compressive strength range was found to be 41.5~53.3MPa, all satisfying the performance standards, 40~60MPa. This study judged the suitability of only the items for a property of matter of landscape stone GRS by applying the natural-form landscape stone GFRC material standard, but in case an installation constructed with GRS material comes into existence later, there should be comprehensive performance guidelines through the research on durability, landscape performance and environmental and ecological performance.

세계측지계상에서 천문측량데이터를 이용한 연직선편차 계산에 관한 연구 (A Study on the Computation of Deflection of the Vertical Referred to World Geodetic System by Astrogeodetic Data)

  • 이석배
    • 대한공간정보학회지
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    • 제15권1호통권39호
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    • pp.47-53
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    • 2007
  • 천문측량은 각 나라가 지역측지계를 사용하던 때 각 나라의 측지원점을 결정하는 중요한 수단으로 취급되어 왔다. 본 연구에서는 1970년 이후로 관측된 우리나라의 천문측량 데이터를 이용하여 지역측지계에서 사용해 오던 베셀타 원체를 기준으로 천문측지지오이드고를 계산하고 아울러 GRS80타원체를 기준으로 하는 세계측지계상에서 연직선 편차 성분과 천문측지지오이드고를 계산하였다. 연구결과 세계측지계상에서 연직선편차의 $\xi$성분은 $-5.725"{\sim}8.005"$의 분포를, $\eta$성분은 $-14.917"{\sim}6.2"$ 분포를 보였으며 천문측지지오이드고는 $23m{\sim}27m$에 이르는 분포를 보였다. 아울러 두 타원체의 이격량을 통하여 GRS80타원체가 베셀타원체에 비하여 우리나라에 더욱 적합한 타원체임을 알 수 있었다.

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관절통환자의 통증정도와 통증연관 행위에 관한 연구 (The Pain Behavior of Patients with Joint Pain)

  • 이은옥;한윤복;김순자;이선옥;김달숙;김조자;김광주;김주희;박점희
    • 대한간호학회지
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    • 제18권2호
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    • pp.197-210
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    • 1988
  • The purposes of this study were : 1) to assess the level of pain and to identity the varieties and the degree of pain-related behavior, 2) to measure the level of correlation between the level of pain and the degree of pain- related behavior, 3) to test the correlation between the Korean Pain Rating Scale (KPRS) and Graphic Rating Scale(GRS), and 4) to gather data relevant to the Socio-demographic status of the subjects. The level of pain was measured by KPRS and GRS developed by the researchers. The KPRS consists of three dimensions ; the sensory, the affective and the miscellaneous and the GRS of two separate scales ; the intensity scale and the unpleasantness scale. Of the 2, 025 who had visited orthopedic and neurosurgical out-patients department of 11 university hospitals in various districts of Korea with the episode of Joint pain, 405 subjects were self-selected by responding to the data gathering tools and questionaires mailed. The results are summaried as follows : 1. Maale(217, 53.6%) exceeded female patients(188, 46.4%) in number and the onset of joint pain was more prevalent in the age groups of the 20s and the 30s. 160(39.5%) had been hospitalized for the treatment of, and 87(21.5%) had retired because of the joint pain. 2. Mean pain score measured by KPRS was 128.31 (range; 0-1.344.8) ; mean sensory score was 43.23(range ; 0-645.88%), mean affective score was 46.09(range ; 0- 356.72), and mean miscellaneous score was 39.99(range ; 0-341.68). Mean pain scores measured by GRS were ; sensory intensity score ; 109.1(range ; 0-200) and distress score ; 99.1 (range ; 0-200). 3. The prevalent sites of joint pain revealed to be the right knee joint(203; 50.1%), left knee joint(181(44.7%), left ilium(147, 36.3%), lumbar region (106; 26.2%), hip joint(92; 22.7%) and the ankle(84; 20.7%). 4. The average sleep hour was 6.8hours per day and the average rest hour during the day hours was 3.3hours (range 0-20). 5. The average duration of suffering from joint pain was 49.1 months. 6. Most of the subjects(298; 73.6%) used some sorts of pain relieving practices ; the most prevalent pain relieving practice was the compliance with the physician prescribed treatments(34.4%). 7. The level of discomfort in carrying out the ADL(activities of daily living was 101.16(38.83) and the level of needs for aid in carrying out the ADL was 76.62(31.79). 8. The interrelation between KPRS total score and GRS sensory intensity score(.4438), as well as that of GRS distress score(r=.4446) were not highly correlated, however, sensory and affective dimension within KPRS (.7547) and pain intensity and distress score of GRS(.6975) revealed moderate intercorrelation. 9. Pain-related behaviors such as discomfort in carrying out ADL, the need for aids in carrying out ADL, frequency of pain relieving practices, varieties of pain sites and length of rest hours during the day hours revealed to be highly correlated with the level of pain measured by KPRS, GRS sensory intensity scale and GRS distress scale. The following are recommended ; 1. Test for the correlation of KPRS total score and the summated score of GRS ; sensory intensity and distress scores. 2. Possibilities of utilization of the pain-related behaviors which revealed high correlation as indirect assessment tool for measuring the level of pain.

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Urban sprawl and its impact on the land cover-a geospatial study

  • Jayakumar, S.;Enkhbaatar, Lkhagva;Heo, Joon
    • 대한공간정보학회지
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    • 제16권4호
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    • pp.73-78
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    • 2008
  • The present study was aimed to estimate the urban sprawl in a historical city of India using series of satellite data between 1968 and 2005(37 years) and GIS. The total area of the Tiruchirappalli city was 1991.96 ha during 1968 and it was expanded into 4335.98 ha(117.67%) during 2005. The average growth rate per year was 63.35 ha. This 117.67% growth was at the cost of agriculture land(97.81%) and water body(2.19%). The satellite data used in this study were found to be good source of information for this kind of analysis and further studies are need to estimate the impact of this city expansion on agriculture yield and ground water.

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철도구조물 적용을 위한 보강토옹벽 벽체시스템과 단계시공의 효과에 관한 연구 (A Study on the Effect of Facing System and Staged Construction Procedures in GRS Walls for Application in Railroad Structures)

  • 원명수;권오현;김영신;방윤경
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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    • pp.359-366
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    • 2009
  • The present paper analyzes and discusses the effect of facing system and staged construction in GRS (geosynethetic reinforced soil) walls for railway structures throughout various case analyses. The result shows that postconstruction facing system by staged construction procedures is more advantageous for railway structure construction than preconstruction and simultaneous construction facing system with reinforced soil.

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