• Structural Engineering and Mechanics
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• 제50권4호
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• pp.419-439
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• 2014

In this study, the structural performance of a seven span masonry arch bridge was evaluated. Investigations were performed on Aspendos (Belkis) Masonry Arch Bridge which was located on road of Aspendos Acropolis City in Antalya, Turkey. The old bridge was constructed in the early of fourth century AD, but it was exposed to the earthquakes in this region and the overloading by the river water. The old bridge was severely damaged and collapsed by probably an earthquake many years ago and a new bridge was then reconstructed on the remains of this old bridge by Seljuk in the 13th century. The bridge has also been affected from overflowing especially in the spring of each year, so some protective measures should be taken for this monumental bridge. Therefore, the structural performance under these loading has to be known. For this purpose, an initial finite element model was developed for the bridge and it was calibrated according to ambient vibration test results. After that, it was analyzed for different load cases such as dead, live, earthquake and overflow. Three load combinations were taken into account by deriving from these load cases. The displacements and the stresses for these combination cases were attained and compared with each other. The structural performance of Aspendos Masonry Arch Bridge was determined by considering the demand-capacity ratio for the tensile stress of the mortar used in Aspendos Masonry Arch Bridge. After these investigations, some concluding remarks and offers were presented at the end of this study.

• Journal of Astronomy and Space Sciences
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• 제20권4호
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• pp.393-402
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• 2003

The Multi-Spectral Camera (MSC) is the payload of KOMPSAT-2 which is designed for earth imaging in optical and near-infrared region on a sun-synchronous orbit. The telescope in the MSC is a Ritchey-Chretien type with large aperture. The telescope structure should be well stabilized and the optical alignment should be kept steady so that best images can be achieved. However, the MSC is exposed to adverse thermal environment on the orbit which can give impacts on optical performance. Solar incidence can bring non-uniform temperature rise on the telescope tube which entails unfavorable thermal distortion. Three ways of preventing the solar radiation were proposed, which were installing external mechanical shield, internal shield, and maneuvering the spacecraft. After trade-off study, internal sun shield was selected as a practical and optimal solution to minimize the effect of the solar radiation. In addition, detailed designs of the structure and sunshield were produced and analyses have been performed. The results were assessed to verify their impacts to the image quality. It was confirmed that the internal sunshield complies with the requirements and would improve image quality.

• 폴리머
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• 제36권3호
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• pp.338-343
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• 2012

콘텍트렌즈용 하이드로젤의 계면 특성의 이해를 위해 단백질 흡착 현상을 열역학을 바탕으로 연구하였다. 다른 습윤성을 갖는 $1{\times}1mm^2$ 크기의 하이드로젤을 알부민(bovine serum albumin, BSA)용액에 1시간 동안 침지시킨 후 남아있는 BSA 용액의 농도를 Bradford assay로 정량하였다. 모든 하이드로젤로의 단백질 흡착량은 단백질 농도가 증가함에 따라 계면 흡착량이 증가하며 Langmuir 곡선의 형태를 보였다. 또한 계면과 용액내의 단백질 농도비($P$), 계산된 흡착 Gibbs free energy는 하이드로젤 재료의 친수성도가 증가함에 따라 증가하였다. 표면에너지와 단백질 흡착량 상관관계를 이해하여 콘택트렌즈 재질로의 단백질 흡착현상의 물리화학적 해석이 가능함을 알 수 있었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1594-1597
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• 2005

A rapid development and a wide use of the Internet have expanded a network environment. Further, the network environment has become more complex due to a simple and convenient network connection and various services of the Internet. However, the Internet has been constantly exposed to the danger of various network attacks such as a virus, a hacking, a system intrusion, a system manager authority acquisition, an intrusion cover-up and the like. As a result, a network security technology such as a virus vaccine, a firewall, an integrated security management, an intrusion detection system, and the like are required in order to handle the security problems of Internet. Accordingly, a router, which is a key component of the Internet, controls a data packet flow in a network and determines an optimal path thereof so as to reach an appropriate destination. An error of the router or an attack against the router can damage an entire network. This paper relates to a method for RSMS (router security management system) for secure networking based on a security policy. Security router provides functions of a packet filtering, an authentication, an access control, an intrusion analysis and an audit trail in a kernel region. Security policy has the definition of security function against a network intrusion.

• 대한의생명과학회지
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• 제15권3호
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• pp.233-239
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• 2009

The aim of this study was to evaluate the photodynamic effect of various photosensitizing agents against methicillin-resistant Staphylococcus aureus (MRSA). MRSA was exposed to light from a 632 urn diode laser (15 J/$cm^2$) in the presence of various photosensitizer, such as photofrin, photogem, radachlorine and ALA. In vivo study was performed using ICR mice. Twenty eight mice had a standard wound ($100\;mm^2$) created on the dorsum, and MRSA was inoculated into the wound region. The four groups were classified as follows: (1) the untreated control group (bacteria alone), (2) the bacteria plus light group (15 J/$cm^2$), (3) the bacteria plus photofrin group (kept in the dark), and (4) the photodynamic therapy (PDT) group (bacteria, photofrin, and light). After photofrin (dose 1 mg/kg) injection, the experimental group was irradiated with 632 urn diode laser (15 J/$cm^2$) for 30 minutes after In vitro results of PDT showed the complete killing of MRSA at the photofrin, radachlorine, and photogem However, ALA-PDT was ineffective on MRSA viability. In vivo results showed that photofrin has therapeutic effect on the wound infection. These results demonstrate that selective lethal photosensitization of MRSA can be achieved using phofrin, photogem and radachlorin. Thus, PDT can inactivate MRSA survival.

• Bulletin of the Korean Chemical Society
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• 제24권2호
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• pp.209-218
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• 2003

Ecosystems in the Keweenaw Peninsula region of Lake Superior, USA, were disturbed by over 500 million tons of copper-rich mine tailings during the period 1850-1968. Metals leaching from these mine residues have had dramatic effects on the ecosystems. Vast acreages of exposed tailings that are over 100 years old remain unvegetated because of the combination of metal toxicity, absence of nutrients, and temperature and water stress. Therefore, it is important to characterize and fractionate solid copper phases for assessing labile forms of copper in soils and sediments contaminated by the mining wastes. X-ray diffraction analyses indicate that calcite, quartz, hematite, orthoclase, and sanidine minerals are present as major minerals, whereas cuprite,tenorite, malachite, and chalcopyrite might be present as copper minerals in the mining wastes. Sequential extraction technique revealed that carbonate and oxide fractions were the largest pools of copper (ca. 50-80%) in lakeshore and wetland stamp sands whereas the organic matter fraction was the largest reservoir (ca. 32%) in the lake sediments. The concentrations of iron and copper were inversely correlated in the oxide fraction suggesting that copper may occur as a surface coating on iron oxides. As particle size and water contents decrease, the percent of the copper bound to the labile carbonate fraction increases.

• Progress in Superconductivity
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• 제5권2호
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• pp.89-93
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• 2004

We have studied alternating transport current losses in the vertically stacked high temperature superconducting tapes(HTS) using numerical techniques. In the case of stacked conductors, HTS tapes are exposed to self-field generated by transport current itself and also experienced external magnetic field around adjacent tapes. It is well known that magnetic interactions between neighbored tapes have significant effect on their properties of superconducting tapes such as current distribution, AC loss, and critical current. In this paper, we investigated the transport current losses in stacked conductors consisting of a few of the HTS tapes using numerical analysis. Current distributions are calculated in HTS tape cross-section taking account of magnetic field dependencies, which are represented superconducting nonlinear properties. Dissipated losses in tape and stacked conductors were integrated with current distribution and electric field intensity in the whole conductor region. Finally estimated results were discussed and verified through the analytical theory.

• 대한두개안면성형외과학회지
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• 제19권1호
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• pp.68-71
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• 2018

Intraosseous hemangioma is an extremely rare tumor that accounts for 1% or fewer of all osseous tumors. The most common sites of its occurrence are the vertebral column and calvaria. Occurrence in a facial bone is very rare. The authors aim to report a case of the surgical treatment of intraosseous hemangioma occurring in the periorbital region, which is a very rare site of occurrence and to introduce our own experiences with the diagnosis and treatment of this condition along with a literature review. A 73-year-old male patient visited our hospital with the chief complaint of a mass touching the left orbital rim. A biopsy was performed by applying a direct incision after local anesthesia. Eventually, intraosseous hemangioma was diagnosed histologically. To fully resect the mass, the orbital floor and zygoma were exposed through a subciliary incision under general anesthesia, and then the tumor was completely eliminated. Bony defect was reconstructed by performing a seventh rib bone graft. Follow-up observation has so far been conducted for 10 months after surgery without recurrence or symptoms.

• BMB Reports
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• 제46권2호
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• pp.92-96
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• 2013

The breast cancer susceptibility gene BRCA1 encodes a nuclear protein, which functions as a tumor suppressor and is involved in gene transcription and DNA repair processes. Many families with inherited breast and ovarian cancers have mutations in the BRCA1 gene. However, only a few studies have reported on the mechanism underlying the regulation of BRCA1 expression in humans. In this study, we investigated the transcriptional regulation of BRCA1 in HeLa cells treated with etoposide. We found that three Egr-1-binding sequences (EBSs) were located at -1031, -1005, and -385 within the enhancer region of the BRCA1 gene. Forced expression of Egr-1 stimulated the BRCA1 promoter activity. EMSA data showed that Egr-1 bound directly to the EBS within the BRCA1 gene. Knockdown of Egr-1 through the expression of a small hairpin RNA (shRNA) attenuated etoposide-induced BRCA1 promoter activity. We conclude that Egr-1 targets the BRCA1 gene in HeLa cells exposed to etoposide.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.401-401
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• 2014

In this study, graphene, the most attractive material today, has been applied to the wavelength-modulated surface plasmon resonance (SPR) sensor. The optical fiber sensor technology is the most fascinating topic because of its several benefits. In addition to this, the SPR phenomenon enables the detection of biomaterials to be label-free, highly sensitive, and accurate. Therefore, the optical fiber SPR sensor has powerful advantages to detect biomaterials. Meanwhile, Graphene shows superior mechanical, electrical, and optical characteristics, so that it has tremendous potential to be applied to any applications. Especially, grapheme has tighter confinement plasmon and relatively long propagation distances, so that it can enhance the light-matter interactions (F. H. L. Koppens, et al., Nano Lett., 2011). Accordingly, we coated graphene on the optical fiber probe which we fabricated to compose the wavelength-modulated SPR sensor (Figure 1.). The graphene film was synthesized via thermal chemical vapor deposition (CVD) process. Synthesized graphene was transferred on the core exposed region of fiber optic by lift-off method. Detected analytes were biotinylated double cross-over DNA structure (DXB) and Streptavidin (SA) as the ligand-receptor binding model. The preliminary results showed the SPR signal shifts for the DXB and SA binding rather than the concentration change.