• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3243-3248
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• 2013

The tissue inhibitor of metalloproteinase-2 (TIMP-2) inhibits matrix metalloproteinases activity and modulates cellular proliferation and apoptosis. The human serum albumin-TIMP-2 with folic acid conjugate (termed HT2-folate) was synthesized to promote uptake through folate receptors (FRs), and a corresponding radio-labeled compound was prepared for tumor diagnosis by positron emission tomography (PET). $^{68}Ga$-NOTA-HT2-folate was synthesized from $^{68}Ga$ and the NOTA chelator with HT2-folate. The fusion protein was identified using MALDI-TOF mass spectrometry. The radioligand was prepared with a high radiochemical yield. Cell-surface association of $^{68}Ga$-NOTA-HT2-folate significantly increased over time in FR-positive tumor cells. In animal PET and biodistribution studies, tumor uptake was very high as early as 1 h after radioligand injection. Folate conjugation enhanced the selective receptor-targeting efficacy of HT2 in FRexpressing tumors, and its radioligand will be useful as an in vitro tool and for in vivo tumor diagnosis by PET imaging.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.196-201
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• 2002

The SSB(Single Side Band) communication in the 27MHz band has mainly been using between fishiery station and small fishing ship less than 10tons, but the most of small fishing ship are depend on cellular system. When accident for small ship at sea happens, It's very important to communicate continuously for preventing the collision and taking action. At present it is hard to control small fishing ship and provide information properly by using 27MHz SSB channel. Therefore in this paper We present TRS communication system applied for small fishing ship to protect the safy and life at sea and to prepare for emmergency, and also validate it's application.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3A
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• pp.254-266
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• 2006

Recently, researches about downlink resource allocation algorithms applying SDMA to enhance the system throughput and cell coverage have begun. Most OFDM/SDMA based resource allocation algorithms have some limitations such that those only concentrate on maximizing the system throughput or can be applied in single cell environment. In this paper, we propose an OFDM/SDMA based downlink resource allocation algorithm which considers high layer QoS parameters suitable for the required data traffic and it also minimizes the system throughput loss and considers inter-cell interference from adjacent cells. so it can be adopted in multi-cell environment. We manifest the performance of the proposed algorithm in Ped A and SCME MIMO Channel Model.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.10A
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• pp.1461-1472
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• 2000

Recently, the mobile users seem to be rapidly increasing and then the capacity limit will be reached at close hand. In these situations, to provide them with good quality of service in the coming future, newly planned cell design is needed. In the next generation mobile communication systems, namely IMT-2000, good quality services will be possible only by designing the cell structure hierarchically with the help of appropriate cell planning. In the research process, the standardization reports on the future mobile cellular IMT-2000 system (3GPP) are investigated and the parameters, that are essential to cell planning, are also researched. Modeling of IMT-2000 radio link and the numerical analysis on that make it possible to calculate the forward/reverse link budget, system capacity call blocking probability Erlang capacity and cell coverage. In planning the cell of IMT-2000 system, various parameters are considered, such as hierarchical cell structure, number of users, data service forms and propagation area environments. From the results, efficient cell planning methods are proposed. Through this thesis efficient cell planning and maximum capacity will be achieved in the beginning of commercial IMT-2000 service.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.5C
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• pp.351-360
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• 2008

In cellular mobile radio systems with frequency reuse, the interference signals degrade the channel estimation and signal detection performance due to the low signal-to-interference ratio near coverage boundaries. When the preamble pilot sequences from different cells are orthogonal or located in disjointed positions, they can be used for multi-cell channel estimation and interference cancellation. In time-varying channels caused by Doppler spread, data pilot symbols are needed for channel estimations. However, data pilot symbols are usually located in identical positions for the overhead reduction, which degrades the channel estimation performance. In this paper, we demonstrate a significant amount of performance improvement is achieved by multiplying different pseudonoise(PN) sequences to the data pilot symbols from adjacent interference cells. In particular, for detection scheme using maximal ratio combining(MRC) and inter-cell spatial demultiplexing(ISD), quantitative performance gain of spectral efficiency for different values of Doppler frequency and interference power is presented.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.5
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• pp.534-540
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• 2013

Interest of the hand effect on the electromagnetic wave are internationally increasing with the increase of the use of the mobile phone. IEC TC106(International Electrotechnical Commission, Technical Committee 106) promotes international research exchange program in order to reflect the effect of human hands in the standard assessment method of human exposure dosimetry by the electromagnetic wave of mobile phones. Since current commercialized hand phantom is manufactured by taking into account the average size of westerners and provides only one grip posture, it imposes many restrictions on the accurate SAR measurement. Therefore, the development of proper hand phantom accounting for domestic situation and various grip posture capability is essential in order to analyze the accurate effect of human hand on the exposure estimation. In this paper, a jelly hand phantom suitable for Korean was manufactured with various grip posture capability at 835 MHz and 1,800 MHz bands. Although the tolerances of permittivity and conductivity of the manufactured hand phantom are with ${\pm}10%$ each, it was much less than CTIA(Cellular Telecommunication Industry Association) tolerance of ${\pm}20%$ at both bands. Its 3D CAD(3 Dimensional Computer Aided Design) file which was developed can be utilized for the simulation of human hand effect on SAR measurement of mobile phones. The findings in this study can be utilized for the analysis of human hand effect on SAR measurement of a mobile phone.

• Korean Journal of Medicinal Crop Science
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• v.28 no.5
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• pp.339-346
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• 2020

Background: Cnidium officinale Makino have been used in traditional medicine in Northeast Asia. Although gamma-ray mutagenesis has been used to develop breeding resources with novel characteristics, research on the radiation sensitivity of C. officinale Makino is limited. Hence, the optimal gamma-ray dosage for mutation breeding in C. officinale Makino was investigated. Methods and Results: Seedstocks were exposed to doses of gamma rays (5 Gy - 50 Gy), and subsequently planted in a greenhouse. After 30 days of sowing, the survival rates and growth decreased rapidly at doses above 20 Gy, while all individuals died at 50 Gy. The median lethal dose (LD₅₀) was 25.65 Gy, and the median reduction doses (RD₅₀) for plant height, number of stems, and fresh weight were 12.81, 9.32, and 23.26 Gy, respectively. Post-irradiation levels of malondialdehyde (MDA), peroxidase (POD), and chlorophyll in the aerial parts of the plant were quantified using spectrophotometry. Relative to the controls, the levels of MDA and POD increased, while the level of chlorophyll decreased at doses ≥ 10 Gy, indicating cellular damage. Conclusions: A dose of 20 Gy was found to be optimal for mutation breeding in C. officinale Makino.

• The Journal of Advanced Prosthodontics
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• v.5 no.4
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• pp.402-408
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• 2013

PURPOSE. The aim of this study was to evaluate the surface properties and in vitro bioactivity to osteoblasts of magnesium and magnesium-hydroxyapatite coated titanium. MATERIALS AND METHODS. Themagnesium (Mg) and magnesium-hydroxyapatite (Mg-HA) coatings on titanium (Ti) substrates were prepared by radio frequency (RF) and direct current (DC) magnetron sputtering.The samples were divided into non-coated smooth Ti (Ti-S group), Mg coatinggroup (Ti-Mg group), and Mg-HA coating group (Ti-MgHA group).The surface properties were evaluated using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The surface roughness was evaluated by atomic force microscopy (AFM). Cell adhesion, cell proliferation and alkaline phosphatase (ALP) activity were evaluated using MC3T3-E1 cells. Reverse transcription polymerase chain reaction (RT-PCR) analysis was performed. RESULTS. Cross-sectional SEM images showed that Mg and Mg-HA depositionson titanium substrates were performed successfully. The surface roughness appeared to be similaramong the three groups. Ti-MgHA and Ti-Mg group had improved cellular responses with regard to the proliferation, alkaline phosphatase (ALP) activity, and bone-associated markers, such as bone sialoprotein (BSP) and osteocalcin (OCN) mRNA compared to those of Ti-S group. However, the differences between Ti-Mg group and Ti-MgHA group were not significant, in spite of the tendency of higher proliferation, ALP activity and BSP expression in Ti-MgHA group. CONCLUSION. Mg and Mg-HAcoatings could stimulate the differentiation into osteoblastic MC3T3-E1 cells, potentially contributing to rapid osseointegration.

• The KIPS Transactions:PartC
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• v.9C no.3
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• pp.385-398
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• 2002

To accommodate the increasing number of mobile terminals in the limited radio spectrum, wireless systems have been designed as micro/picocellular architectures for a higher capacity. This reduced coverage area of a cell has caused a higher rate of hand-off events, and the hand-off technology for efficient process becomes a necessity to provide a stable service. Population-based Bandwidth Reservation(PBR) Scheme is proposed to provide prioritized handling for hand-off calls by dynamically adjusting the amount of reserved bandwidth of a cell according to the amount of cellular traffic in its neighboring cells. We analyze the performance of the PBR scheme according to the changes of a fractional parameter, f, which is the ratio of request reservation to the total amount of bandwidth units required for hand-off calls that will occur for the next period. The vague of this parameter, f should be determined based on QoS(Quality of Service) requirement. To meet the requirement the value of Parameter(f) must be able to be adjusted dynamically according to the changing traffic conditions. The best value of f can be determined by a function of the average speed of mobile stations, average call duration, cell size, and so on. This paper considers the average call duration and the cell size according to the speed of mobile stations. Although some difference exists as per speed, in the range of 0.4 $\leq$ f $\leq$ 0.6, Blocking Probability, Dropping Probability and Utilization show the best values.

• Journal of KIISE:Information Networking
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• v.33 no.4
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• pp.333-342
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• 2006

The cdma2000 lxEV - DO mobile communication system provides broadcast and multicast services (BCMCS) to meet an increasing demand from multimedia data services. The servicing of video streams over a BCMCS network must, however, face a challenge from the unreliable and error-prone nature of the radio channel. The BCMCS network uses Reed-Solomon coding integrated with the MAC protocol for error recovery. We analyze this coding technique and show that it is not effective in the case of slowly moving mobiles. To improve the playback quality of an MPEG-4 FGS video stream, we propose the Hybrid error recovery scheme, which combines Reed-Solomon with ARQ, using slots which are saved by reducing the Reed-Solomon coding overhead. The target packets to be retransmitted are prioritized by a utility function to reduce the packet error rate in the application layer within a fixed retransmission budget. This is achieved by considering of the map of the error control block at each mobile node. The proposed Hybrid error recovery scheme also uses the characteristics of MPEG-4 FGS (fine granularity scalability) to improve the video quality even when conditions are adverse: slow-moving nodes and a high error rate in the physical channel.