• Earthquakes and Structures
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• 제18권2호
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• pp.215-222
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• 2020

In this paper, slit steel rubber bearing is presented as an innovative seismic isolator device. In this type of isolator, slit steel damper is an energy dissipation device. Its advantages in comparison with that of the lead rubber bearing are its simplicity in manufacturing process and replacement of its yielding parts. Also, slit steel rubber bearing has the same ability to dissipate energy with smaller value of displacement. Using finite element method in ABAQUS software, a parametric study is done on the performance of this bearing. Three different kinds of isolator with three different values of strut width, 9, 12 and 15 mm, three values of thickness, 4, 6 and 8 mm and two steel types with different yield stress are assessed. Effects of these parameters on the performance characteristics of slit steel rubber bearing are studied. It is shown that by decreasing the thickness and strut width and by selecting the material with lower yield stress, values of effective stiffness, energy dissipation capacity and lateral force in the isolator reduce but equivalent viscous damping is not affected significantly. Thus, by choosing appropriate values for thickness, strut width and slit steel damper yield stress, an isolator with the desired behavior can be achieved. Finally, the performance of an 8-storey frame with the proposed isolator is compared with the same frame equipped with LRB. Results show that SSRB is successful in base shear reduction of structure in a different way from LRB.

• Structural Engineering and Mechanics
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• 제78권5호
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• pp.545-556
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• 2021

The present experimental study evaluated the seismic performance of six engineered cementitious composite (ECC) columns strengthened with carbon fiber reinforced polymer (CFRP) laminates under cyclic lateral loading. The ECC columns damaged and crushed in the first stage of cyclic tests were repaired using the ECC with a certain polyvinyl alcohol (PVA) fiber and strengthened with flexural and sheer CFRP laminates and then re-assessed under the cyclic loading. The effects of some variables were examined on lateral displacement, energy absorption and dissipation, failure modes, crack patterns, load bearing capacity and plasticity, and the obtained results were compared with those of the first stage of cyclic tests. The results showed that retrofitting the ECC columns can improve their performance, plasticity and load-bearing threshold, delayed the concrete failure, changed the failure modes and increased the energy absorbed by the strengthened columns element by over 50%.

• 생물환경조절학회지
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• 제16권3호
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• pp.264-268
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• 2007

국내 육성 품종인 3년생 '홍로'와 도입 품종인 4년생 '갤럭시갈라' 사과를 대상으로 정아 고사 시 장과지 및 액아의 활용 가치를 알아보고자 결과지 길이 및 꽃눈 위치 따른 개화 및 과실 특성을 조사하였다. '홍로'와 '갤럭시갈라' 모두 개화시, 만개기 및 낙화기는 20 cm 이상 결과지에서 5 cm 미만과 $10{\sim}15cm$ 결과지보다 다소 늦었다. 화총당 꽃수도 때 정도 적었다. 과중, 종자수, 당산비 등 대부분의 과실 특성은 5 cm 미만과 $10{\sim}15cm$ 20 cm 이상 결과지보다 높았지만, 당도와 산 함량은 반대의 경향이었다. 20 cm 이상 결과지의 정아와 액아 간 대부분의 과실 특성은 액아에서 좋은 경향을 나타내었지만, '홍로' 사과의 종자수, '갤럭시갈라'의 Hunter a값을 제외하고는 유의한 차이를 나타내지 않았다. 그리고 두 품종 모두 과중과 종자 간 높은 상관성을 나타내었다. 따라서 정아 고사 시 장과지로 대체 활용할 수 있고 '갤럭시갈라'의 경우 액화아의 이용도 가능하였다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1997년도 추계학술대회 논문집
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• pp.278-283
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• 1997

This paper proposes a systematic design method for axial(or thrust) magnetic bearings using optimal design methodology. The objective of the optimal design is to minimize bearing volume. The constraints include the bearing load capacity, linearized bearing stiffness and damping, the magnetic flux density, and geometric relations. In order to obtain design values which can be applied to fabrication of bearings, branch and bound method was introduced in the postprocessing procedure of optimal design results. Verification of the proposed design methodology was perfomed by an example.

• 한국산림과학회지
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• 제97권5호
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• pp.516-524
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• 2008

We investigated on the distribution of nutrient contents (N. P and K) in current and one-year old needles of Korean pine, Pinus koraiensis, to understand the physiological effects of alternate bearing. One experimental set was designed with three types of cone number (one, three and five) under natural state and cone number of another one was controlled by thinning. Test samples were separated to collect into three fractions; current needles on the shoot and one-year old needles above and under the cone. On the branch without cone, N, P and K concentrations in needles on the shoot were higher than those in needles of one-year old branch. At natural state, needle P concentration was the lowest in needles on the five-cone branch in August. Macronutrient concentrations were the lowest in needles above the cone, which was remarkably observed in needle K concentration. Under cone thinning, N. P and K concentrations were the highest in needles on one-cone branch and the lowest in needles on five-cone branch. Needle nutrient concentrations were the lowest in needles above the cone, which was remarkably observed in the needle on five-cone branch. In conclusion, the current needles of the shoot and cones are a strong sink of nutrient like N. P and K, and the increase of cone number influences nutrient removal from needles.

• 한국산림과학회지
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• 제100권3호
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• pp.432-440
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• 2011

밤나무의 수고와 근원경은 액비처리구와 화학비료처리구에서 가장 많은 생장량을 나타냈으며 수관폭 생장량은 동-서방향과 남-북방향에서 각각 액비처리구와 화학비료처리구에서 우수하였다. 결과지의 총 길이와 착구부~정단부의 길이생장은 액비처리구에서 가장 우수하였으며 기부~착구부의 길이는 액비처리구와 화학비료처리구에서 동일하게 가장 길게 생장하였다. 결과지의 기부직경과 착구부의 상하부직경은 모두 액비처리구에서 가장 두껍게 생장하였다. 본 연구의 5개의 생장지수(결과지발생지수, 길이생장지수, 착구부상하직경비율, 직경생장지수, 굵기지수)에서 길이생장지수만이 액비처리구에서 가장 높고 나머지 모든 지수는 화학비료처리구에서 가장 높았다. 결과모지당 가지발생수와 소약지 개수는 무처리구와 액비처리구에서 많았으며 처리간 유사한 경향을 보였다. 결과모지당 결과지수는 화학비료처리구와 유기질비료처리구에서 많았으며, 결과지당 착구수는 유기질비료처리구와 액비처리구에서 많았다. 과실의 중량과 수량을 기준으로 한 상품화 비율은 무처리구(87.5%)와 화학비료처리구(84.6%)에서 높았으나 액비처리구의 상품화 비율은 각각 84.3%와 82.7%로 평균 수준이었다. 평균입중과 총착구수는 각각 액비처리구와 화학비료처리구로 가장 우수하였다. 함과수는 처리 간 차이는 없었으며 본당수확량은 화학비료처리구(8.2 kg)와 액비처리구(8.0 kg)에서 다수확성을 보였으나 처리간 통계적으로 유의한 차이는 없었다. 과실의 중량과 수량을 기준으로 등급을 구분한 결과, 액비처리구에서 대립 이상의 비율이 각각 43.5%와 34.3%로 가장 높아 액비처리에서 고부가가치의 고품질 밤이 가장 많이 생산되었다.

• 한국패류학회지
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• 제25권1호
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• pp.71-79
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• 2009

Based on investigation of archive collections of A.V. Zhirmunsky Institute of Marine Biology of the Far-Eastern Branch of the Russian Academy of Sciences (Vladivostok) and O.A. Scarlato Zoological Institute of the Russian Academy of Sciences (Saint Petersburg), as well as on the analysis of published data, the species composition of shell-bearing gastropod mollusks of the Russian waters of the East Sea (Sea of Japan), consisting of 331 species and subspecies, has been identified. The fourth part of the Review includes 46 species of Heterobranchia (Allogastropoda, Opistobranchia, and Pulmonata). Each species is assigned to a biogeographic grouping in the study area. Its type locality and habitat (depth and substrate) are also documented.

• 한국패류학회지
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• 제25권1호
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• pp.51-70
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• 2009

Based on investigation of collections at the A.V. Zhirmunsky Institute of Marine Biology of the Far-Eastern Branch of the Russian Academy of Sciences (Vladivostok) and Zoological Institute of the Russian Academy of Sciences (Saint Petersburg), as well as on the analysis of published data, the species composition of shell-bearing gastropod mollusks of the Russian waters of the East Sea (Sea of Japan), consisting of 331 species and subspecies, has been identified. Each species is assigned to a biogeographic grouping in the study area. Its type locality and habitat (depth and substrate) are also documented. The third part of this review includes 129 species in Neogastropoda (Caenogastropoda).

• 한국패류학회지
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• 제26권2호
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• pp.127-143
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• 2010

Based on investigation of collections at the A.V.Zhirmunsky Institute of Marine Biology of the Far-Eastern Branch of the Russian Academy of Sciences (Vladivostok) and Zoological Institute of the Russian Academy of Sciences (Saint-Petersburg), as well as on the analysis of published data, the species composition of shell-bearing gastropod mollusks of the Russian waters of the East Sea, consisting of 331 species and subspecies, has been identified. Eachspecies is assigned to a biogeographic grouping in the study area. Its type locality and habitat (depth and substrate) are also documented. The second part of this review includes 101 species from Sorbeoconcha and Hypsogastropoda (Caenogastropoda).

• 한국패류학회지
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• 제26권2호
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• pp.115-126
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• 2010

Based on investigation of collections at the A. V. Zhirmunsky Institute of Marine Biology of the Far-Eastern Branch of the Russian Academy of Sciences (Vladivostok) and Zoological Institute of the Russian Academy of Sciences (Saint-Petersburg), as well as on the analysis of published data, the species composition of shell-bearing gastropod mollusks of the Russian waters of the East Sea, consisting of 331 species and subspecies, has been identified. Each species is assigned to a biogeographic grouping in the study area. Its type locality and habitat (depth and substrate) are also documented. The first part of this review includes 55 species from Patellogastropoda, Vetigastropoda and Cocculiniformia.