• Journal of Life Science
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• v.28 no.1
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• pp.99-104
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• 2018

Streptococcus pneumoniae is one of the major pathogens in community-acquired diseases, and it contains several factors that promote its pathogenesis, including pneumolysin (PLY). PLY is a member of the cholesterol-dependent cytolysin family, which attacks cholesterol-containing membranes, thereby forming ring-shaped pores. Thus, it is a major key target for vaccines against pneumococcal disease. We cloned the PLY gene from S. pneumoniae D39 and inserted it into the pQE-30 vector. Recombinant PLY (rPLY) was overexpressed in Escherichia coli M15 and purified by $Ni^{2+}$ affinity chromatography. Similarly, a PLY-EGFP fusion gene was produced by inserting the EGFP gene at the 3' end of the PLY gene in the same vector, and the recombinant protein was purified. Sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE) showed that both recombinant proteins were purified. rPLY exhibited significant hemolytic activity against 1% human red blood cells (RBCs). Complete hemolysis was obtained at 500 ng/ml, and 50% hemolysis was found with a 240 ng/ml concentration. In contrast, rPLY-EGFP did not show hemolytic activity. However, rPLY-EGFP did bind the RBC membrane, indicating that rPLY-EGFP lost hemolytic activity via EGFP fusion, while retaining its membrane-binding ability. These data suggest that PLY's C terminus is important for its hemolytic activity. Therefore, these two recombinant proteins can be extremely useful for investigating the toxin mechanism of PLY and cell damage during pneumonia.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.4
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• pp.259-263
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• 2010

We measured and compared the partition coefficients and absorption levels of preservative phenoxyethanol (PE), antimicrobial ethylhexylglycerin (EG) and UV-filters widely used in cosmetic products and more specifically evaluated the relative absorption level of PE depending on various packaging materials. The resulting partition coefficients of 11 UV filters in relation to PE and EG displayed EG with a relatively higher partition coefficients. The partition coefficients of Tinsorb M and Solaveil CT434 were also high. Among the UV-filter ingredients with EG absorption levels exceeding 40 % were Gransil PSQ, UV Titan M 160 and Micro $TiO_2$ MT 100 TV, whereas Gransil PSQ and Scadder showed PE absorption levels above 40 %. In addition, we confirmed that PE had displayed an absorption level of 7 ~ 8 % as a result of 1 month-long exposure to packaging material polyoxymethylene. This extensive research illustrates the possibility of producing the most potent preservative contents based on studying the relative compatibility between UV-filters and preservatives and selecting the adequate preservatives to be used. Furthermore, preservative level can also decline with passage of time depending on the type of packaging material used.

• Journal of the Korea Concrete Institute
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• v.22 no.1
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• pp.19-27
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• 2010

Aging and severe environments are major causes of damage in reinforced concrete (RC) structures such as buildings and bridges. Deterioration such as concrete cracks, corrosion of steel, and deformation of structural members can significantly degrade the structural performance and safety. Therefore, effective and easy-to-use methods are desired for repairing and strengthening such concrete structures. Various methods for strengthening and rehabilitation of RC structures have been developed in the past several decades. Recently, FRP composite materials have emerged as a cost-effective alternative to the conventional materials for repairing, strengthening, and retrofitting deteriorating/deficient concrete structures, by externally bonding FRP laminates to concrete structural members. The main purpose of this study is to investigate the effectiveness of adaptive neuro-fuzzy inference system (ANFIS) in predicting behavior of circular type concrete column retrofitted with FRP. To construct training and testing dataset, experiment results for the specimens which have different retrofit profile are used. Retrofit ratio, strength of existing concrete, thickness, number of layer, stiffness, ultimate strength of fiber and size of specimens are selected as input parameters to predict strength, strain, and stiffness of post-yielding modulus. These proposed ANFIS models show reliable increased accuracy in predicting constitutive properties of concrete retrofitted by FRP, compared to the constitutive models suggested by other researchers.

• Composites Research
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• v.34 no.5
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• pp.283-289
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• 2021

This paper derives numerically the buckling Knockdown factors using two different initial imperfection models, such as geometric and loading imperfection models, to investigate the unstiffened composite cylinder with an ellipse pre-buckling deformation pattern. Single Perturbation Load Approach (SPLA) is applied to represent the geometric initial imperfection of a thin-walled composite cylinder; while Single Boundary Perturbation Approach (SBPA) is used to represent the geometric and loading imperfections simultaneously. The buckling Knockdown factor derived using SPLA is higher than NASA's buckling design criteria by approximately 84%, and lower than buckling test result by 9%. The buckling Knockdown factor using SBPA is higher than NASA's buckling design criteria by about 75%, and 14% lower than the buckling test result. Therefore, it is shown that the buckling Knockdown factors derived in this study can provide a lightweight design compared to the previous buckling design criteria while they give reasonably a conservative design compared to the buckling test for both the initial imperfection models.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.1
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• pp.22-28
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• 2019

Cement is a basic material for the construction industry and it requires high temperature sintering when manufacturing cement. $CO_2$ emissions from raw materials and fuels are recognized as new environmental problems and efforts are underway to reduce them. Techniques for reducing $CO_2$ in concrete are also recommended to use blended cement such as blast furnace slag or fly ash. In addition, the construction waste generated in the dismantling of concrete structures is recognized as another environmental problem. Thus, various methods are being implemented to increase the recycling rate. The purpose of this study is to utilize the inorganic raw materials generated during the dismantling of the structure as a raw material for the low carbon type cement binder. Such as, waste concrete powder, waste cement block, waste clay brick and waste textile as raw materials for low carbon type cement binder. From the research results, low carbon type cement binder was manufactured from the raw material composition of waste concrete powder, waste cement block, waste clay brick and waste textile.

• Korean journal of communication and information
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• v.48
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• pp.46-62
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• 2009

The current study attempted to review the standards of retransmisison consent and arbitration for the terrestrial broadcasting signal. The standards are based upon the principles encouraged by the MIAC(Ministry of Internal Affairs and Communications). It has been criticized that the standards of judgement for the retransimission consent and arbitration are ambiguous and arbitrary in Japan. In 2009, MIAC announced five decisions regarding the retransmission of over-the-air. The result of the current study found that the regulations of compulsory over-the-air signal retransmission have been sustained until now. The retransmission policy of the Japan government based upon three principles; localism, proper cause and copyright act. The judgment is dependent on the intrepretation of MIAC's standard about these three principles.

• Journal of the Korea Institute of Building Construction
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• v.16 no.2
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• pp.97-105
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• 2016

Recently, application case of the ultra rapid hardening concrete-polymer composite(URHCPC) are increasing to repair for the deterioration of pavement. But it is a major disadvantage that the main material is expensive and has environmental load. For these reasons, the development of the economic, eco-friendly materials is needed. Calcium Aluminate Composite (CAC), produced by rapid cooling of atomizing method with molten ladle furnace slag, is a material capable of improving the economic feasibility and reducing the environmental load of URHCPC. In this paper, the properties of CAC and gypsum mixed CAC (GC) as alternative materials of RSC according to the types of polymer dispersion were studied. The results were as follows; compressive strength, tensile strength, flexural strength, bonding strength and modulus of elasticity of the composites using CAC or GC showed higher values than those of plain proportion in 3 hour. In later age, they were at the same level as the general proportions. URHCPC using BPD as polymer dispersion had superior strength properties generally. But modulus of elasticity was the same level as the case of using a SBR latex. According to these results, CAC or GC can partially substituted for RSC to product the URHCPC. When URHCPC uses the BPD as the polymer dispersion, it can be improved performance.

• Journal of the Korean Society of Radiology
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• v.15 no.5
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• pp.749-754
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• 2021

In order to maximize the matching ratio between the scintillation pixel and the photosensor of the PET detector using a small number of photosensor, various arrays of scintillation pixels and four photosensors were used. The array of scintillation pixels consisted of six cases from 6 × 6 to 11 × 11. The distance between the photosensors was applied equally to all scintillation pixels, and the arrangement was expanded by reducing the size of scintillation pixel. DETECT2000 capable of light simulation was used to acquire flood images of the designed PET detectors. At the center of each scintillation pixel array, light generated through the interaction between extinction radiation and scintillation pixels was generated, and the light was detected through for four photosensors, and then a flood image was reconstructed. Through the reconstructed flood image, we found the largest arrangement in which all the scintillation pixels can be distinguished. As a result, it was possible to distinguish all the scintillation pixels in the flood image of 8 × 8 scintillation pixel array, and from the 9 × 9 scintillation pixel flood image, the two edge scintillation pixels overlapped and appeared in the image. At this time, the matching ratio between the scintillation pixel and the photosensor was 16:1. When a PET system is constructed using this detector, the number of photosensors used is reduced and the cost of the oveall system is expected to be reduced through the simplification of the signal processing circuit.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.3
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• pp.23-32
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• 2013

As the mobile communication technology is developed, the services for communication between the mobile devices are provided, and the amount of usage is increasing tremendously. For the device-to-device communication, the device should be verified if it is a service member. The existing verification schemes include interactions with the third party, while this may cause the problems that the bandwidth is dissipated and the devices which are out of the communication range of the base station cannot communicate with other devices. To solve such problems, we propose a new scheme for verification between mobile devices without interaction of third party. For the proposed scheme, we develop and employ a new zero-knowledge proof protocol, which verifies the device's membership and its expiration time. Furthermore, the scheme guarantees privacy of the mobile device since it checks the encrypted verification message without decrypting, and protects replaying attack since it uses challenge-response method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.11C
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• pp.1152-1157
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• 2002

In this paper, a detailed procedure of development for an AAL2 processor widely used in voice gateway application is introduced. The processor supports CPS and SSCS with voice service and framed mode data service. It provides 4 ATM virtual connections, which include 1020 AAL2 channels. The processor has one UTOPIA Level 1 interface for an ATM cell interface and 4 TDM ports for a voice channel interface. The TDM ports carry PCM/ADPCM voice streams. Most AAL2 processors are implemented as software, or hardware and software, so its latency is large. But this processor has very low latency as to CPS and SSCS because all of them are implemented in hardware. Also, it allows not only loopback and switching of CPS packets, but loopback and switching of TDM channels. The key feature is that the internal structure of the CPS and SSCS in this processor seems like as each software function, so they are called whenever they are required. In addition, they are reusable for another design and are scalable for more channels.