• Steel and Composite Structures
• /
• v.28 no.1
• /
• pp.63-71
• /
• 2018

This paper reports an experimental study that was accomplished to assess the seismic behavior of steel tube reinforced concrete bridge columns (SBCs). The motivation of this study was to verify a supposition that the core steel tube may be terminated at a rational position in the column to minimize the material cost while maintaining the seismic behavior of this composite column. Four SBC specimens were tested under combined constant axial load and cyclic reversed lateral loads. The unique variable in the test matrix was the core steel tube embedment length, which ranged from 1/3 to 3/3 of the column effective height. It is observed that SBCs showed two distinctly different failure patterns, namely brittle shear failure and ductile flexural failure. Tests results indicate that the hysteretic responses of SBCs were susceptible to the core steel tube embedment length. With the increase of this structural parameter, the lateral strength of SBC was progressively improved; the deformability and ductility, however, exhibited a tendency of first increase and then decrease. It is also found that in addition to maintained the rate of stiffness degradation and cumulative energy dissipation basically unchanged, both the ductility and deformability of SBC were significantly improved when the core steel tube was terminated at the mid-height of the column, and these were the most unexpected benefits accompanied with material cost reduction.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.7 no.5
• /
• pp.73-78
• /
• 2007

It has been increasing that significant loss of life and property due to global wanning and extreme weather, and the climate and temperature changes in Korea Peninsula are now greater than the global averages. Climate information from regional climate models(RCM) at a finer resolution than that of global climate models(GCM) is required to predictclimate and weather variability, changes, and impacts. The new surface boundary conditions(SBCs) development is motivated by the limitations and inconsistencies of existing SBCs that have influence on model predictability. A critical prerequisite in constructing SBCs is that the raw data should be accurate with physical consistency across all relevant parameters and must be appropriately filled for missing data if any. The aim of this study is to construct appropriate SBCs for the RCM in Asia domain which will be used for the prevention of disasters due to climate changes. As all SBCs have constructed onto the 30km grid-mesh of the RCM suitable for Asia applications, they can be also used for other distributed models for climate and hydrologic studies.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.41 no.3
• /
• pp.145-148
• /
• 2015

In 1942 Stafne reported 35 asymptomatic, radiolucent cavities that were unilaterally located in the posterior region of the mandible between the mandibular angle and the third molar, and below the mandibular canal. The term Stafne bone cavity (SBC) is now used for such asymptomatic lingual bone depressions of the lower jaw. Since then there have been many reports of SBCs but very fews tudies have used cone-beam computed tomography (CBCT) for their diagnosis. The aim of this paper is to describe the clinical and radiological characteristics of two cases of SBCs and the importance of limited CBCT in confirming the diagnosis.

• International Commerce and Information Review
• /
• v.10 no.4
• /
• pp.373-393
• /
• 2008

The object of this thesis is to evaluate performance of Industry Complex of Rural Areas Policy and to suggest solutions to solve problems of the policy and development plans for Industry Complex of Rural Areas in Korea. The Industry Complex of Rural Areas Policy has contributed to increase of income and growth of industries in farming areas. Since business environment has been changing rapidly and competition has been getting fierce, Korean small business in rural are as need to develop new strategies to strengthen their competitiveness. Therefore, this thesis will suggest public programs to support for development of Korean small businesses in rural areas. The suggestions are as below 1) plans to form funds to provide financial aid to small business in rural areas. Specific plans to raise funds for public programs that would be executed by National Industry Complex of Rural Areas Association are included. 2) plans to improve abilities of SBCs to develop technologies 3) plans to establish marketing channels for SBCs in rural areas. 4) plans to create systems to promote restructuring in Industry Complex of Rural Area.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.11 no.9
• /
• pp.4301-4319
• /
• 2017

Adopting mobile chargers (MC) in rechargeable wireless sensors network (R-WSN) to recharge sensors can increase network efficiency (e.g., reduce MC travel distance per tour, reduce MC effort, and prolong WSN lifetime). In this study, we propose a mechanism to split the sensing field into partitions that may be equally spaced but differ in distance to the base station. Moreover, we focus on minimizing the MC effort by providing a new charging mechanism called the sector-based charging schedule (SBCS), which works to dispatch the MC in charging trips to the sector that sends many charging requests and suggesting an efficient sensor-charging algorithm. Specifically, we first utilize the high ability of the BS to divide the R-WSN field into sectors then it select the cluster head for each sector to reduce the intra-node communication. Second, we formulate the charging productivity as NP-hard problem and then conduct experimental simulations to evaluate the performance of the proposed mechanism. An extensive comparison is performed with other mechanisms. Experimental results demonstrate that the SBCS mechanism can prolong the lifetime of R-WSNs by increasing the charging productivity about 20% and reducing the MC effort by about 30%.

• Journal of Adhesion and Interface
• /
• v.14 no.2
• /
• pp.95-100
• /
• 2013

In this study, a series of hot-melt pressure sensitive adhesives (HMPSAs) based on metallocene polyolefin (me-PO) were prepared to investigate their possibility of replacing the HMPSAs based on styrenic block copolymers (SBCs). In addition, to optimize the performance of HMPSAs based on me-PO, several tackifiers having different softening point and molecular weight were evaluated. To achieve the HMPSAs which can satisfy the Dahlquist Criterion, hot melts required over 10% of process oil. To obtain the HMPSAs having low viscosity which can be applied by a spraying type applicator, secondary polymer having relatively low crystallinity was required. And, tackifier having high molecular weight attributed to increasing the cohesive strength of me-PO based HMPSAs.

• Korean Journal of Veterinary Research
• /
• v.45 no.1
• /
• pp.1-6
• /
• 2005

In this study we assessed the influences of ultraviolet (UV) light B radiation on epidermal cells by apoptotic sunburn cell (SBC) and the effect of green tea treatment on the inhibition of SBC formation in SKH1-hr mouse. The extent of changes following $200mJ/cm^2$ (0.5 mW/sec) was studied at 0, 3, 6, 12, 18, 24, 30 or 36 hours after exposure. SBCs were recognized by 3 hours after irradiation. There was tendency to increase from 3 hours to 24 hours and decrease from then to 36 hours after irradiation. The mice that received 0, 25, 50, 100, 200, 400 or $800mJ/cm^2$ of UVB were examined 24 hours after irradiation. The SBCs were induced as the radiation dose increases from 0 to $200mJ/cm^2$. A further increase of radiation dose has little further effect. The frequency of UVB ($200mJ/cm^2$)-induced SBC formation was reduced by intraperitoneal injection of green tea extract (p<0.01).

• Toxicological Research
• /
• v.20 no.4
• /
• pp.315-320
• /
• 2004

In this study we assessed the influences of ultraviolet (UV) light B radiation on epidermal ATPase-positive dendritic cell (DC) and the effect of green tea treatment in ICR mouse. The extent of changes following 200 mJ/$cm^2$ (0.5 mW/sec) was studied at 0, 6, 12, 18, 24, 30 or 36 hours after exposure. SBCs were decreased by 6 hours after irradiation. There was tendency to decrease from 6 hours to 24 hours and had little further change from then to 36 hours after irradiation. The mice that received 0, 50, 100, 200, 300 or 400 mJ/$cm^2$ of UVB were examined 24 hours after irradiation. The DCs were decreased as the radiation dose increases from 100 to 400 mJ/$cm^2$. The frequency of UVB (200 mJ/$cm^2$)-induced DC decrease was reduced by treatment of green tea (i.p. and topical application, p<0.01).

• Journal of Adhesion and Interface
• /
• v.15 no.4
• /
• pp.145-150
• /
• 2014

Dicyclopentadiene (DCPD)-based hydrocarbon resins are widely used as tackifiers in many applications. In particular, hydrogenated DCPD-based hydrocarbon resins are widely used in premium hot-melt-type adhesives such as hot melt adhesives (HMAs) and/or hot melt pressure-sensitive adhesives (HMPSAs), because are water-white in color and possess excellent stability to light and heat. This article discusses the adhesive performance of various hydrogenated DCPD resins when they are used as tackifiers in styrene-block-copolymer (SBC)-based HMPSAs. This article shows the correlation between the characteristics of tackifiers and the adhesive performance of SBC-based HMPSAs. The higher the softening point of the tackifier, the higher is the $T_g$, softening point, and crossover temperature of the PSAs. High aromatic H wt% content reduces the high-temperature resistance of PSAs, as suggested by the decrease in the crossover temperature and softening point of the PSAs.

• Korean Journal of Veterinary Research
• /
• v.49 no.1
• /
• pp.17-22
• /
• 2009

The effect of Bu-Zhong-Yi-Qi-Tang (BZYQT) on the changes of ultraviolet (UV) light B radiation-induced apoptotic sunburn cell (SBC) and epidermal ATPase-positive dendritic cell (DC) in SKH1- hr or ICR mouse were investigated. The mice were treated with UVB (200 mJ/$cm^2$) and were sacrificed 24 h later. BZYQT (50 mg/kg of body weight) or vehicle (saline) was given i.p. at 36 and 12 h before irradiation, and 30 min after irradiation or BZYQT cream (0.2%) or cream base (vehicle) was topically treated at 24 h and 15 min before irradiation, and immediately after irradiation. The skin of SKH1-hr mouse prepared from the back of untreated mice exhibited about 0.3 SBC/cm length of epidermis, and 24 h after UV irradiation, the applied areas show an increased number of SBCs. But the frequency of UVB-induced SBC formation was reduced by intraperitoneal injection of BZYQT extract (p < 0.01). The numbers of DC in normal ICR mouse were 628.00 ${\pm}$ 51.56 or 663.20 ${\pm}$ 62.58 per $mm^2$ of ear epidermis. By 1 day after UVB treatment, the number of ATPase-positive cells/$mm^2$ were decreased by 39.0% or 27.1% in i.p. or topical application group with vehicle. Treatment of BZYQT was associated with increase of 33.9% in i.p. group (p < 0.05) or 2.7% in topical application group in the number of ATPase positive cells compared with the irradiation control group. The results presented herein that BZYQT administration could reduce the extent of skin damages produced by UVB.