• The KIPS Transactions:PartC
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• v.9C no.5
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• pp.733-742
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• 2002

It has been known that the host mobility feature has very significant impact on the QoS (Quality of Service), which is usually required to a real-time multimedia application. The existing QoS support mechanisms to provide the real-time services to fixed network environment, like as RSVP, are inadequate to accommodate the mobile hosts which can frequently change their point of attachments to the fixed network. So, MRSVP (Mobile RSVP) protocol has been proposed to reduce the impacts of host mobility on QoS guarantees, in which a mobile host needs to make advance resource reservations at multiple locations it may possibly visit during the lifetime of the connection. This paper proposes a dynamic dual anchor node (DDAN) architecture which integrates the MRSVP and RSVP tunnel, in addition to the Mobile IP Regional Registration protocol. By limiting the resource reserved in local area, it preserves the lower level of resource reservation, but provides approximately the same degree of QoS support as the existing MRSVP.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3532-3536
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• 2012

Understanding of the maternal transcriptome increased to elucidate the underlying molecular mechanism of normal oocyte maturation, which depends on a precise sequence of changes in maternal genes expression. Previous reports that the translational potential of a maternal mRNA is generally determined by the length of the poly(A) tail, and deadenylation is usually the first sign of mRNA degradation. However, in vitro cultured system has the underlying molecular mechanisms remain unclear. We determined whether the role of molecular basis, four important maternal genes, C-mos, cyclin-B1 (regulatory subunit of MPF), BMP15 and GDF9, were selected for detection of their precise mRNA expression patterns by real-time PCR and for determination of their polyadenylation status by poly(A) tail PCR during oocyte maturation. In the present study. the abnormal expression of maternal mRNAs prior to zygotic genome activation, which results in suppression of the corresponding protein level, may be responsible for, at least in part, a profound defect in further embryonic development. Reasonable expression of maternal gene is crucial for proper oocyte maturation and further embryonic development.

• Smart Structures and Systems
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• v.23 no.6
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• pp.589-613
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• 2019

Cables are prone to vibration due to their low inherent damping characteristics. Recently, negative stiffness dampers have gained attentions, because of their promising energy dissipation ability. The viscous inertial mass damper (termed as VIMD hereinafter) can be viewed as one realization of the inerter. It is formed by paralleling an inertial mass part with a common energy dissipation element (e.g., viscous element) and able to provide pseudo-negative stiffness properties to flexible systems such as cables. A previous study examined the potential of IMD to enhance the damping of stay cables. Because there are already models for common energy dissipation elements, the key to establish a general model for IMD is to propose an analytical model of the rotary mass component. In this paper, the characteristics of the rotary mass and the proposed analytical model have been evaluated by the numerical and experimental tests. First, a series of harmonic tests are conducted to show the performance and properties of the IMD only having the rotary mass. Then, the mechanism of nonlinearities is analyzed, and an analytical model is introduced and validated by comparing with the experimental data. Finally, a real-time hybrid simulation test is conducted with a physical IMD specimen and cable numerical substructure under distributed sinusoidal excitation. The results show that the chosen model of the rotary mass part can provide better estimation on the damper's performance, and it is better to use it to form a general analytical model of IMD. On the other hand, the simplified damper model is accurate for the preliminary simulation of the cable responses.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.6
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• pp.33-42
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• 2010

With the emergence of increasingly complex networks and diverse user terminals, demand for the next generation IPTV service is rapidly growing. It enables any content to seamlessly be reused on the diverse terminals as well as be broadcasted in real-time through the complex networks. In this paper, a novel security framework is proposed for the real-time and reusable IPTV services. The proposed framework is advantageous over the conventional content protection techniques in easily producing the scalable content with lightweight, perceptual, transcodable, and adjustable security features. It does not only ensure end-to-end security over the entire service range based on a single security mechanism, but also can control a level of security while dynamically transcoding the original content. This approach basically performs selective encryption during and after the compression using scalable video coding. The suitability of the proposed approach is demonstrated through experiments with a practical service scenario. Therefore, it is expected that security technology alone could practically contribute to creating new business opportunities for IPTV services.

• Biomedical Science Letters
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• v.28 no.1
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• pp.42-49
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• 2022

Tetrodotoxin (TTX) is a natural neurotoxin found in several species of puffer fish belonging to Tetraodon fugu genus and has been reported to affect processes such as proliferation, metastasis and invasion of various cancer cells. However, it was not revealed which genes were influenced by these reactions. In this experiment, it was examined in human SW620 colorectal cancer cells. The proliferation of SW620 cells was significantly reduced when treated with 0, 1, 10 and 100 μM TTX for 48 h. It was confirmed using Annexin V-propidium iodide staining that some apoptosis was induced. Differentially expressed genes (DEGs) affecting cell proliferation through RNA sequencing (RNA-seq) were selected. The expression change of DEGs was confirmed by conducting quantitative real-time polymerase chain reaction (qRT-PCR). As a result, the mRNA expression of FOS and WDR48 genes was found to be increased in the 100 μM TTX treatment group compared to the control group. On the other hand, the mRNA expression of ALKBH7, NDUFA13, RIPPLY3 and SELENOM genes was found to be reduced, and in the case of the ALKBH7 gene was identified to show significant differences. This experiment suggests that TTX can be used as an important fundamental data to elucidate the mechanism that inhibits the proliferation of SW620 cells.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.6
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• pp.1073-1080
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• 2023

The development and speed improvement of the Internet network, and the development of many platforms based on it, have brought about a rapid expansion of production and consumption of various contents. However, the existing IP-based Internet system cannot efficiently cope with such an urgent increase in data. Accordingly, an alternative called the CCN(Contents Centric Network) has emerged, enabling more efficient data transmission and reception centered on content rather than host. In this paper, we will deal with the mobility of intermediate nodes in CCN real-time streaming service, which is one of the major research fields of CCN, and minimize network overload through more efficient path switching through RSSI detection. In other words, by improving the method of selecting and switching a spare path when an intermediate node located between the requester(consumer) and the provider moves, a mechanism for managing data transmission is not interrupted and unnecessary load due to route switching does not occur in the network.

• Journal of Ocean Engineering and Technology
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• v.13 no.3 s.33
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• pp.77-82
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• 1999

The compleete joining method for dissimilar hot die punch materials and its real-time evaluation method are not available at present. Brazing method has been used for joining them, but it is known that the welded joint by the brazing has the lower bonding efficiency and reliability than the diffusion welding. The friction wleding with a diffusion mechanism in bonding was applied in this study. So, this work was carried out to determine the optimal friction welding conditions and to analyze mechanical properties of friction welded joints of hot die punch materials (STD61 for the blade part of hot die punch) to alloy steel (SCM440 for the shank park of hot die punch) such as plunger. In addition, acoustic emission test was carried out during friction welding to evaluate the weld quality.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.05a
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• pp.34-39
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• 2002

The surfaces of machine components in sliding contact such as bearing, gears and pistons etc. frequently operate under the condition of mixed lubrication due to high load, high speed and slip. These machine components often undergo the inception of scuffing in practical application. The scuffing failure is a critical problem in modern machine components, especially for the requirement of high efficiency and small size. However, it is difficult to find a universal mechanism to explain all scuffing phenomena because there are so many factors affecting the onset of scuffing. In this study, scuffing experiments are conducted using Acoustic Emission(AE) measurement by an indirect sensing approach to detect scuffing failure. Acoustic Emission(AE) signal has been widely utilized to monitor the interaction at the friction interface. Using AE signals we can get an indication about the state of the friction processes, about the quality of solid and liquid layers eon the contacting surfaces in real time. The FFT(Fast Fourier Transform)analyses of the AE signal are used to understand the interfacial interaction and the relationship between the AE signal and the state of contact is presented

• Biomedical Science Letters
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• v.22 no.4
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• pp.215-219
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• 2016

The problems of tuberculosis and its drug resistance are very severe. Therefore, rapid and accurate drug susceptibility assay is required. Recently, there has been an increased understanding of the genetic mechanism of Mycobacterium tuberculosis (MTB) drug resistance as well as advancement of molecular technologies. While many gene mutations correlate well with drug resistance, many genes do not show a strong correlation with drug resistance. For this reason, the current study assessed the utility of rpoB mRNA as a target to detect live mycobacteria. In this study, RT-PCR targeting of rpoB mRNA in BCG treated with rifampin was performed. Conventional RT-PCR and real-time PCR targeting rpoB mRNA as well as 85B mRNA was performed to determine whether these two methods could distinguish between viable and non-viable MTB. The levels of rpoB and 85B mRNA detected by RT- PCR were compared in parallel with colony forming unit counts of BCG that were treated with rifampin for different periods of time. The data suggests that that even though both mRNA levels of rpoB and 85B decreased gradually when rifampin-treatment increased, the rpoB mRNA seemed to represent live bacteria better than 85B mRNA. This study clearly indicates that RT-PCR is a good method to monitor viable cell counts in the liquid culture treated with the anti-tuberculosis drug.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.2
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• pp.92-97
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• 2011

Vehicle lightings are very important for safe driving during night time. Since the eye recovery time after an exposure to oncoming headlights would take after several seconds, the aiming point of vehicle head lamps have to pass safety requirements. Despite the fact that vehicle inclination is variable with vehicle load conditions, the head lamps aiming point is usually fixed at a constant position which is set by car manufacturer. Consequently, vehicle head lamps under varying load conditions often make people in the opposing vehicle uncomfortable, and even worse, can cause an accident. This paper presents an active vehicle lighting mechanism to automatically adjust its aiming point, or cut-off line, in order to compensate the change in vehicle inclination resulting from load variations. The effectiveness of the proposed method is demonstrated through a set of simulations and experiments with a real vehicle.