• Journal of the Korea Concrete Institute
• /
• v.28 no.2
• /
• pp.129-139
• /
• 2016

Cast-in-place concrete-filled hollow PC (HPC) columns are used to reduce lifting load of heavy-weight PC columns and to improve the structural integrity of joints. In the present study, a new type of HPC column was proposed to improve the productivity and structural integrity of the concrete. To form the hollow PC columns, a permanent inner form was prefabricated using structural deck plates and penetrated lateral bars. Half-scale specimens of four HPC columns were tested under combined axial compression and lateral cyclic loading to evaluate the seismic resistance. In the design of test specimens, various parameters such as the spacing of lateral re-bars, the use of steel fiber, and the thickness of PC cover were considered. The test results showed that the proposed HPC columns generally exhibited satisfactory load-carrying capacity and deformation capacity without brittle failure of PC. If closely spaced hoops or fiber reinforcements are used for PC, the deformation capacity can be improved further by restraining PC spalling.

• Korean Journal of Ichthyology
• /
• v.20 no.3
• /
• pp.156-162
• /
• 2008

Five microsatellite DNA markers were used to investigate genetic diversity and population structure of olive flounder Paralichthys olivaceus collected from four locations (YD, SC, GJ, WD) where hatchery-based seeds of the flounder have been released. The average of observed (Ho) and expected heterozygosity (He) ranged from 0.833 to 0.871, and from 0.842 to 0.876, respectively. The average number of alleles per locus ranged from 12.4 to 17.8. The proportion of stocked flounder ranged from 20.0% to 95.8% for wild-caught populations with a decreasing tendency of alleles per locus following a higher proportion of stocked flounder. There is need to implement a more careful stock-enhancement program of hatchery-based seeds and to monitor its genetic effects on wild populations to ensure conservation of natural flounder resources.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.11 no.3
• /
• pp.138-145
• /
• 2012

The material used in this study is dielectric and ferrite. Because of the unique characteristics of the material, it is easily exposed to external shocks and pressure, which cause damage to the product. However, after being processed under high-temperature environment repeatedly, the mechanical strength of the product is greatly increased due to the change of the electrical properties. In this paper, dielectric and bonded ferrite material was tested for the material properties. The equipment for this experiment was produced and tested to allow Cylindrical and Three-dimensional geometry of the product for the vacuum deposition. For Cylindrical shape of the product, in order to obtain the equivalent film thickness, the device is constructed in a vacuum chamber which gives arbitrary revolving and rotating capability. The electrical performance of the product is obtained through this process as well. However, as mentioned above, with repeating processes under high temperature and exposure to external environment, the product is easy to be broken. This experiment has enabled us to find out a stable condition to apply the communication of the RF high frequency to each of the core elements, such as Ferrite and Dielectric which is then used for the mechanical strength of the Raw material, hetero-junction material, Hetero-junction Ag Coating material and hetero-junction Ag Coating SiO2 Coating material respectively.

• Korean Journal of Plant Tissue Culture
• /
• v.21 no.6
• /
• pp.347-351
• /
• 1994

To measure the time required for ginseng explants to become determined to form flower buds, we cultured zygotic embryos, seedlings, and cotyledonary nodes on MS medium supplemented with BA and GA$_3$of 5 ${\mu}$M each (flower inducing medium, FIM) for various periods and transferred to the basal medium. The explants required a minimum of 10 days on FIM to be determined. Histological observations revealed that the axillary meristem to be fated to develop into flower bud remained in a state of shoot meristem during the first 10 days of culture and differentiated into flower bud after 15 days of culture. We suggest that the in-vitro flowering system described in this study is useful in investigating (a) regulatory element(s) to cause the phase change from the vegetative to reproductive state by comparing predetermined explants with determined ones at the molecular level.

• Korean Journal of Plant Tissue Culture
• /
• v.28 no.1
• /
• pp.21-24
• /
• 2001

Peucedanum japonicum $T_{HUNB}$ used as a edible and medicinal plants was investigated for in uitro regeneration. Callus formation occurred on leaf and stem explant cultures and showed spontaneous embryogenic and organogenic capability on MS basal medium supplemented with 0.1~5 mg/L NAA and 0~10 mg/L BA in dark. The regeneration was highest on the condition supplemented with 2.5 mg/L NAA and 10 mg/L BA. Development of the somatic embryo progressed through the globular, heart-shaped, torpedo-shaped and cotyledonary stage, typical of zygotic embryos. When the first somatic embryos was cultured on the medium supplemented with 0.2 mg/L NAA, secondary somatic embryo were induced with higher frequency on the hypocotyl then on the cotyledon and root.t.

• 한국지구물리탐사학회:학술대회논문집
• /
• 2006.06a
• /
• pp.155-160
• /
• 2006

In this paper, we propose a spatial filtering scheme using factorial kriging, one of geostatistical filtering methodin order to separate regional and residual gravity anomaly. This scheme is based on the assumption that regional anomalies have longer distance relation and residual anomalies have effected on smaller range. We decomposed gravity anomalies intotwo variogram models with long and short effectiveranges by means of factorial kriging. And decomposed variogram models produced the regional and residual anomalies. This algorithm was examined using by a synthetic gravity data, and applied to a real microgravity data to figure out abandoned mineshaft.

• Journal of Veterinary Clinics
• /
• v.30 no.5
• /
• pp.359-362
• /
• 2013

A 6-year-old castrated male Maltese weighing 4.16 kg presented with a history of bleeding from the mouth after scaling and dental extraction 2 days prior. The von Willebrand factor antigen (vWf:Ag) level was 54% (reference range, 70-180%), indicating that the dog was homozygous for an inherited von Willebrand disease (vWD). The dog received whole-blood transfusion as initial treatment, consequently showing markedly improved clinical signs, and is currently in good condition. To our knowledge, this is the first reported case of type 1 vWD in a Maltese in Korea.

• Journal of the Korea Concrete Institute
• /
• v.21 no.5
• /
• pp.599-609
• /
• 2009

This paper discusses generalized modeling schemes for both reinforced concrete (RC) and post-tensioned (PT) flat plate buildings. In this modeling approach, nonlinear behavior due to slab flexure, moment and shear transfer at slab-column connections, and punching shear was included along with linear secant stiffness of each member or connection that accounts for concrete cracking. This generalized model was capable of simulating all different scenarios of slab-column connection failures such as brittle punching, flexure-shear interactive failure, and flexural failure followed by drift-induced punching. Furthermore, automatic detection of drift-induced punching shear and subsequent backbone curve modifications were realistically modelled by incorporating the limit state model, in which gravity shear versus drift capacity relations were adopted. The validation of the model was conducted using one-third scale two-story by two-bay RC and PT flat plate frames. The comparisons revealed that the model was robust and effective.

• Journal of Korean Society of Steel Construction
• /
• v.14 no.4
• /
• pp.481-487
• /
• 2002

Currently, the load transfer's mechanism from a beam to a column has yet to ve clarified in a concrete filled steel tubular (CFT) structure with a connection type of an exterior diaphragm. The loads for each floor are transferred to the concrete core from a steel beam through ha contacted face between an in-filled concrete and the interior surface of a steel tube. Thus, a Push-Out test was performed to investigate the load transfer mechanism. A total of 30 samples were tested to confirm the bond stress and/or axial load distribution between a steel tube and in-filled concrete for CFT column. The main parameters considered for this study included concrete type, steel tube-shape/length, and the effect of a weld joint wit ha backing strip for a column splice. Test results were summarized to confirm load transfer behavior between a concrete and steel tube for each experimental parameter, using the analytical approach to verify experimental results.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.02a
• /
• pp.387-387
• /
• 2012

결정 Si 및 비정질 Si 태양전지는 환경친화적이며 안정적인 물질로 전력변환 및 에너지 저장 장치에 중요하기 때문에 연구가 활발하게 진행되고 있다. 고효율 Si 태양전지를 제작하여 상용화하기에는 여러 가지 문제점이 있다. 공기와 비교하여 높은 굴절률을 갖고 있기 때문에 발생하는 반사를 줄이기 위해서 필요한 무반사 코팅층(Anti-reflective coating; ARC)은 주로 SiO2 와 SiNx 와 같은 유전체를 이용하여 사용하지만 이들 ARC 증착은 PECVD와 같은 진공장비를 사용하므로 제작 비용이 높아지는 단점이 있다. 나노선 또는 나노 팁과 같은 sub-wavelength 구조를 표면에 만들어 반사율을 줄이는 작업을 통해 ARC 공정비용을 감소하고 효율을 증진하는 연구가 활발히 진행되고 있다. CdS 양자점을 태양전지 표면에 형성함으로 ARC로 해결할 수 없는 단파장영역에 해당하는 부분을 줄이는 연구가 진행되었으며, 비정질의 경우 원기둥 형태의 태양전지 형태와 더불어 지름 방향으로의 PN 접합 나노로드 배열을 만들어 흡수면을 증가하여 효율을 증가한 연구도 진행되었다. 태양전지 표면의 형태를 V-groove 형태로 형성하여 입사하는 태양전지의 광밀도를 증가하는 이론적 결과도 발표되었다. 본 연구에서는 Si 태양전지의 표면변형에 따른 태양전지의 전력변환효율의 변화를 관찰하기 위하여 태양전지 표면의 texture 지름을 $3{\sim}15{\mu}m$, 간격을 $5{\sim}20{\mu}m$로 변화하고, 태양전지 표면의 나노 패턴을 2~10 nm 로 변화하여 반사율과 전력변환효율을 비교하였다. 나노와 마이크로 패턴은 각각 polystyrene nanosphere 와 photo mask를 이용하여 제작하였으며 PN junction Si 태양전지는 spin on dopant 방식으로 제작하여 성능을 조사하였다.