• Journal of the Korea Concrete Institute
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• v.15 no.5
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• pp.726-736
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• 2003

Concrete columns confined with high-strength fiber composites can enhance its strength as well as maximum strain. In recent years, several equations have been developed to predict the behavior of the concrete columns confined with fiber composites. While the developed equations can predict the compressive strength of the confined columns with reasonable agreement, these equations are not successful in predicting the observed maximum strain of the columns. In this paper, a total of 61 test results is analysed to propose an equation to predict both compressive strength and maximum strain of concrete cylinders. The proposed equation takes into account the effects of confining pressure and cylinder size. Furthermore, in order to verify the proposed stress-strain curve for concrete cylinders, six cylindrical specimens were tested. Comparisons between the observed and calculated stress-strain curves of the tested cylinders showed reasonable agreement.

• Journal of the Microelectronics and Packaging Society
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• v.3 no.2
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• pp.39-50
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• 1996

본 연구에선 주어진 조성의 알루미나 green sheet에 대하여 텅스텐의 입경 및 산화 물의 조성을 변화시키므로써 수축률을 제어하여 camber를최소화하여 결합강도를 최대로 하 는 텅스텐 페스트조성을 찾아내는 것을 목적으로 하였다. 본 실험에서 사용한 텅스텐 분말 의 입경은 0.35$\mu$m, 0.6$\mu$m, 0.72$\mu$m, $1.5\mu$m, 1.9$\mu$m, 3.2$\mu$m이며 frit는 Al2O3, MgO, SiO2 와 Al2O3, CaO, SiO2를 사용하여 각각의 조성에 따라 함량을 변화시키며 실험하였다. 소성 은 154$0^{\circ}C$로 습윤 수소분위기에서 시행하였으며 사용된 알루미나 green sheet의 알루미나 중심 입경은 2.8$\mu$m이었다. 분석은 주사전자 현미경으로 미세구조를 관찰하였고 EPMA Line Profile로 원소 분석을 하였으며 잔류응력을 측정하기 위하여 XRD분석을 하였다. Frit 을 함유하지 않은 경우 텅스텐 분말의 입경이 1.9$\mu$mdlfEo 최대 접합 강도를 나타내었다. Frit을 함유한 경우 Mgo계 frit조성에서는 MgO/Al2O3/SiO3=1/1/1일 때 CaO계 frot 조성에 서는 CaO/Al2O3/SiO2=1/2/1일 때 최대 접합 강도를 나타내었다. Frit 함량을 변화시킨 경우 MgO계는 10wt%함유하였을 때 CaO 계는 5wt%함유하였을 때 최대 접합강도를 나타내었 다. Frit 함량을 변화시킨 경우 MgO계는 10wt%함유하였을 때, CaOr계는 5wt%함유하였을 때 최대 접합강도를 나타내었다.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1830-1834
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• 2006

본 연구에서는 강우의 수문학적 특성을 고려하여 도시지역에서의 시간분포를 분석하고, Huff의 무차원 누가곡선 및 Yen과 Chow의 무차원 특성변수를 제시하였으며, 강우의 수문학적 특성은 지속기간, 강우의 발생원인(장마, 태풍, 집중호우, 전선형 강우), 강우강도 등으로 분류하였다. 본 연구의 수행으로 인해 얻어진 결과를 요약하면 다음과 같다. 첫째, 국내 도시지역의 단시간 강우의 최대강우강도는 전방위구간에서 발생할 확률이 가장 높게 나타났으며, 둘째, 강우발생원인별 분류에서도 전반적으로 전방위구간에서, 태풍의 경우에는 후방위구간에서 최대강우강도가 발생하였다. 셋째, 평균강우강도이하의 경호우와 평균강우강도이상의 중 호우에서는 전방위구간에서 최대강우강도가 발생하였다. 넷째, 전기간 강우자료를 이용한 기존 연구들의 무차원 누가곡선 및 특성변수와의 비교를 실시하여, 수문학적 특성에 따라 무차원 누가곡선의 위치 및 특성변수의 값에서 차이가 발생한다는 것을 알 수 있었다.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1992.03a
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• pp.47-58
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• 1992

탄소성 재료의 파괴에서 최대하중을 계산할 수 있는 방법이 제시되었다. 사용된 재 료상수는 파괴개시인성, 항복강도, 진행된 균열선단에서 열림 변위 증분에 대한 균열성장의 비이고, 계산을 실험결과에 맞추어 재료상수를 결정한다. 이들 상수로 다른 시편의 최대하 중을 계산하는 간단한 방법을 평면변형하의 A572 강(상온)과 4533(B)강(-10C)에 적용하여 기존의 실험결과와 비교하였다. 또한 균열 선단 열림 변위와 J-적분값에 기초한 다른 방법 과 비교·논의되었다.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1156-1160
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• 2006

본 연구는 빈도별 수문조건하의 2차원 수리해석모형(FLUMEN) 결과를 제공받아 빈도별 침수범람 등을 분석하고, 이로부터 도출되는 침수면적, 최대침수심, 최대유속 등의 특성정보를 이용하여 침수심보다 상대적으로 홍수 위험에 대한 척도를 나타내어 줄 수 있는 홍수 강도(Flood Intensity) 개념을 도입하여 대상유역에 적합한 홍수 위험지표(Flood Hazard Value) 및 홍수 위험도(Flood Risk Map)를 작성하고자 하였다. 본 연구의 대상지역은 안성천 중류부의 평택시 6개동을 포함하는 약 $12.6km^2$의 대상지역으로 2차원 수리해석모형(FLUMEN)의 분석한 시간별 침수심(Flow Depth), 최대침수심과 최대 유속 등의 결과를 ASCII파일의 XYZ값 형태로 제공받아 ArcGis 등을 이용하여 Point Coverage를 만들고, 이로부터 TIN (Triangulated Irregular Network)작업을 수행한 후 대상지역의 최대 침수심도 및 최대 유속분포도 등을 작성하였다. 그리고, 침수예상도 등으로부터 얻어진 침수면적, 최대 침수심, 최대유속 등을 분석하여 침수심과 유속의 함수로 홍수강도를 정의하고 홍수강도와 홍수발생확률의 곱으로 위험지표를 산정하였고, 산정된 홍수 위험지표를 적용하여 홍수 위험도를 작성하였다. 본 연구로부터 도출되는 홍수 위험지표 및 홍수 위험도는 홍수범람에 의한 인명피해 및 재산손실과 이에 대한 복구 및 구호활동에 소요되는 노력 등의 여러 가지 사회..경제적 역기능을 방지하고자 홍수에 의한 침수특성을 이해하고 홍수에 대비한 적절한 홍수방어대책 수립시의 지원 정보로 제공되어 활용될 수 있다.

• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.4
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• pp.292-301
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• 2012

The rise in sea surface temperature (SST) as a global warming enhance overall typhoon activity. We assumed that there exist thermodynamic limits to intensity that apply in the absence of significant interaction between storms and their environment. The limit calculations depend on SST and atmospheric profiles of temperature and moisture. This approach do appear to provide resonable upper bounds on the intensities of observed storms and may even be useful for predicting the change in intensity over a long period time. The maximum storm intensities was estimated through the global warming scenarios from IPCC-AR4 report over the North-East Asia. The result shows stronger intensities according to scenarios for increase of carbon dioxide levels. And storm surge simulations was performed with the typhoons which were combined route of the typhoon Maemi (2003) and intensity as climate change scenarios. The maximum increase of storm surge heights was shown about 29~110 cm (36~65%) regionally. Especially at Masan, the result of simulated maximum surge height exceed the 200 years return period surge.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.3
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• pp.579-588
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• 2018

There are the plastic resin, fiber and the single metal among materials. There is also the inhomogeneous material whose durability is improved as the composite material with the property of light weight. This study notices the composite material with light weight of CFRP. The strength properties of stainless steel and aluminum which have been used generally are compared and analyzed each other with CFRP. The compact tension specimen of the same standard by each material were designed and the simulation tensile analyses were carried out. As the study result, the maximum deformation, maximum stress and maxium strain energy are shown to be about 0.0148mm, 59.104MPa and 0.00529mJ respectively in case of CFRP specimen model. The maximum deformation, maximum stress and maxium strain energy were shown to be about 0.0106mm, 42.22MPa and 0.002699mJ respectively at stainless steel. It could be checked that the maximum deformation, maximum stress and maxium strain energy of aluminum specimen model were shown to be about 0.023mm, 33.29MPa and 0.00464mJ respectively at stainless steel. Therefore, the results at this study are thought to be applied with the basic data on the strength property of CFRP composite material.

• Journal of the Korea Concrete Institute
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• v.22 no.5
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• pp.711-718
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• 2010

The requirement of the maximum yield strength of shear reinforcement in the KCI-07 code is quite different to those in the ACI-08 code, EC2-02, CSA-04, and JSCE-04 codes. Eighteen RC beams having high strength shear reinforcement were tested. Test results indicated that even if the yield strength of shear reinforcement in beams was much greater than the maximum yield strength required by the KCI-07 design code, the shear reinforcement of these beams reached their yield strains. Furthermore, the shear strengths of tested beams increased almost linearly with the increase of the amount of shear reinforcement. In addition, larger numbers of diagonal cracks developed in the web of the beam having greater yield strength than the beams having lower yield strength of shear reinforcement. The maximum crack width of the beam having high strength shear reinforcement was approximately the same to the crack with of the beam having normal strength shear reinforcement.

• The korean journal of orthodontics
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• v.33 no.6 s.101
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• pp.437-451
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• 2003

The purpose of this study was to measure maximum bite force and to investigate its relationship with anteroposterior, vertical, and transverse facial skeletal measurements. From among the dental students at the College of Dentistry, forty subjects (26 male and 14 female) were selected. With two sets of strain gauge, maximum bite force at the right and left first molars and anterior teeth was measured in the morning and afternoon. After taking lateral and posteroanterior cephalograms, fifty and nineteen variables were evaluated, respectively Paired t-tests and an independent t-test were done and correlation coefficients were obtained. 1. The maximum bite force at the first molars was $68.0\pm13.9kg$. in males and $55.6\pm10.5kg$ in females (p<0.05) while the force at the anterior teeth was $8.4\pm4.9kg\;and\;1.1\pm3.4kg$ respectively (p<0.05). 2. Some tendency for a greater value of maximum bite force at the preferred side was observed but not statistically significant (p>0.05). 3. Significant difference was observed between the strong bite force group and the weak bite force group in some cephalometric and other measurements (p<0.05). N-S-Ar, S-Ar-Go, FH-Hl, IMPA and MMO showed a significant difference in posterior maximum bite force (P). N-S-Ar and FH-H1 also showed a significant difference in anterior maximum bite force (A). 4. Several cephalometric variables showed some correlation with maximum bite force (p<0.05). N-S-Ar, S-Ar-Go, UGA, FH-H6, FH-H1, body weight and MMO were significantly correlated with posterior maximum bite force (P). Go-Me, P-1 and IMPA were significantly correlated with anterior maximum bite force (A).

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.4 s.19
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• pp.29-36
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• 2005

In this study, relations among unconfined compressive strength, strain at maximum strength and depth were compared with each other. Test specimen is marine clay originated from the place near Ga-duck island in Busan city. In addition, influence of impure material contained in specimen and that of total core recovery(TCR) on unconfined compressive strength and degree of disturbance were investigated. As a result of tests, unconfined compressive strength decreases as strain corresponding to maximum strength increases. Also, the deeper the sampling depth and the bigger the TCR, the unconfined compressive strength increases. Especially, as the TCR increases, the unconfined compressive strength Increases and quality of specimen is enhanced.