• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.5
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• pp.45-53
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• 2007

To recover transmitted signal perfectly at DTV receiver, we have to acquire carrier frequency synchronization to compensate pilot signal which located in wrong position and rotated phase. Also, we need a symbol timing synchronization to compensate sampling timing error. Conventionally, to synchronize symbol timing, we use Gardner's scheme which used in multi-level signal. Gardner's scheme is well known for its sampling the timing error signal from every symbol and it makes easy to detect and keep timing sync in multi-path channel. In this paper, to discuss the problem when the received power level is out of range and we cannot get synchronization information. With this problem, we use 2 step procedures. First, we put a received signal power compensation block before Garder's timing error detector. Second, adaptive loop filter to get a fast synchronization information and averaging loop filter's output value to reduce the amount of jitter after synchronization in PLL(Phased Locked Loop) circuit which is used to get a carrier frequency synchronization and symbol timing synchronization. Using the averaging value, we can estimate offset. Based on offset changing ratio, we can adapt adaptive loop filter to carrier frequency and symbol timing synchronization circuit.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.5
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• pp.43-51
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• 2008

In this paper, we are implemented low-power structure for Inter prediction, Intra prediction, Deblocking filter, Transform and Quantization blocks in H.264/AVC Encoder. The proposed Inter/Intra prediction blocks are shown 60.2% cell area reduction by adder reduction through Distributed Arithmetic, 44.3% add operation reduction using MUX for hardware share in Deblocking filter block. Furthermore we applied CSD and CSS process to reduce the cell area instead of multipliers that take a lot of area. The FPGA(Field Programmable Gate Array) and ARM Process based H.264/AVC encoder is implemented using proposed low power IPs. The proposed structure Platforms are implemented to interlock with FPGA and ARM processors. H.264/AVC Encoder implementation using Platforms shows that proposed low-power IPs can use H.264/AVC Encoder SoC effectively.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.12
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• pp.20-29
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• 2014

Recently, LTE is preparing to make a new leap forward LTE-A all over the world. As LTE privides high speed service, the role of mobile phones seems to change from voice to data service. According to Cisco, global mobile data traffic will increase nearly 11-fold between 2013 and 2018. Mobile video traffic will reach 75% by 2018 from 66% in 2013 in Korea. However, voice service is still the most important role of mobile phones. Thus, controllability of throughput and low BLER is indispensable for high-quality VoIP service among various type of traffic. Although the maximum AMR-WB, 23.85 Kbps is sufficient to a VoIP call, it is difficult for the LTE which can provide tens to hundreds of MB/s may not keep the certain level VoIP QoS especially in the cell-edge area. This paper proposes a new scheduling algorithm in order to improve VoIP performance after analyzing various scheduling algorithms. The proposal is the technology which applies more priority processing for VoIP than other applications in cell-edge area based on two-tier scheduling algorithm. The simulation result shows the improvement of VoIP performance in the view point of throughput and BLER.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.5
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• pp.165-172
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• 2013

Convergence is increasingly prevalent in the IT world which generally refers to the combination of two or more different technologies in a single device. Especially, the spectrum scarcity is becoming a big issue because there are exponential growth of broadcasting and communication systems in the spectrum demand. Cognitive radio (CR) is a convergence technology that is envisaged to solve the problems in wireless networks resulting from the limited available spectrum and the inefficiency in the spectrum usage by exploiting the existing wireless spectrum opportunistically. However, the very process of convergence is likely to expose significant security issues due to the merging of what have been separate services and technologies and also as a result of the introduction of new technologies. The main purpose of this research is focused on devising an adaptive security framework based on carousel for CR networks as a distinct telecommunication convergence application, which are still at the stage of being developed and standardized with the lack of security concerns. The framework uses a secure credential, named as carousel, initialized with the location related information from objects position, which is used to design security mechanisms for supporting privacy and various securities based on it. The proposed adaptive security framework could be used as a security building block for the CR network standards and various convergence applications.

• Journal of the Korean Chemical Society
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• v.18 no.5
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• pp.329-340
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• 1974

Sulfadiazine, $C_{10}H_{10}N_4O_2S$, forms monoclinic crystals of space group $P21}c$ from a mixture of acetone and ethanol with $a=13.71{\pm}0.04,\;b=5.84{\pm}0.03,\;c=15.11{\pm}0.05{\AA},\;{\beta}=115.0{\pm}0.3^{\circ}$, and four molecules per cell. Three dimensional photographic data were collected with $CuK\alpha$ radiation. The structure was determined using Patterson and Fourier synthesis methods and refined by block diagonal least-squares methods with isotropic thermal parameter for all non-hydrogen atoms. The final R value was 0.15 for the 1517 observed independent reflections. The dihedral angle between the planes through the benzene ring and the pyrimidine ring is $76^{\circ}$. The conformational angle formed by the projection of the S-C(5) bond with that of N(1)-C(1) where the projection is taken along the S-N(1) bond is $77^{\circ}$. The imino nitrogen atom, N(1), and pyrimidine nitrogen atom, N(3), form intermolecular $N-H{\cdots}N$ hydrogen bond between the molecules related by center of symmetry. Amino nitrogen atom, N(4), forms two intermolecular $N-H{\cdots}O$ hydrogen bonds, with O(1) and O(2) atoms of different molecules separated by b. A two dimensional network of hydrogen bonds form infinite molecular sheets parallel to the (100) plane. Adjacent sheets are bound together by van der Waals forces.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.1
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• pp.39-46
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• 2000

Objective: A number of studies to improve in vitro culture conditions have been tried over past ten years by using co-culture system with helper somatic cells. However, the mechanism of coculture is poorly understood. This study was designed to understand the mechanism for the mode of actual action of co-culture using co-culture system of ICR strain's 1-cell embryos with human oviduct epithelial cells by examining the effect of conditioned medium and contactless coculture using a cell culture insert on the embryo development and by measuring the level of superoxide anion from conditioned medium after co-culture. Methods: ICR strain's zygote embryos were cultured in medium alone (control), coculture, conditioned medium, or contactless coculture system for 6 days. Conditioned media (CM) were prepared as following 5 groups. All CM were collected after culturing oviduct cells for 2 days. CM-1 was stored at $-20^{\circ}C$ until use, and CM-2 was prepared just before use as a culture medium. CM-3 was cocultured with embryos and retrieved just before use. CM-4 and CM-5 were derives from the microfilteration of CM-2 and CM-3, respectively, using Microcon-10 (10 kDa molecular weight cut-off). The percentage of the embryos developed to hatched blastocyst stage and the level of superoxide anion in supernatant from medium alone culture (control), coculture, and contactless coculture were measured. Results: The rates of embryo development to the hatched blastocyst stage were significantly higher in coculture (43%) than in control (0%) (p<0.05). The CM-1 group had no embryo development since 2-cell embryonic stage, whereas the CM-2, CM-3, CM-4 and CM-5 groups had the improved development to 4 or 8 cell embryo stage, but the similar rate of development to hatched blastocyst compared to control. The effect of coculture on embryo development was disappeared in the contactless coculture group. The level of superoxide anion was significantly reduced in coculture group compared to control. Conclusion: It is concluded that the present coculture system overcomes the 2-cell block in vitro and improves the embryo development. This beneficial effect may be due to the direct cell-cell contact between embryo and helper cells or the removal of deleterious components from medium rather than the embryotrophic factors.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.4
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• pp.729-738
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• 2017

With the signing of the Paris Agreement, which is the new climate change agreement at the end of 2015, it will have a great impact on Korea environmental policy. The construction industry, which accounts for 42% of Korea's total $CO_2$ emissions, has been implementing various policies to improve the environmental problems. However, it is only applying passively to other projects except eco-friendly building certification. This is because most of the eco-related systems are based on building facilities. Therefore, there is a need for a new eco - friendly design evaluation model that can be widely applied not only to architecture but also to civil engineering facilities. In this study, a new model is developed based on the existing VE model, which adds new factors to evaluate the environmental friendliness, potential environmental pollution concept and environmental risk of facilities. This model is an eco-friendly design evaluation model that enables decision makers to effectively select alternative environmental criteria at the design stage. As a result of the case analysis of the block retaining wall and the alternative retaining wall, the value of the eco - friendly value of the alternative was 1.026 times higher than the original one. If this model is used at the design stage, it is expected to contribute not only to the construction of environmentally friendly facilities but also to the reduction of carbon emissions.

• The Journal of Korean society of community based occupational therapy
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• v.3 no.1
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• pp.55-66
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• 2013

Objective : The purpose of present study was to determine effects of task oriented action observation training on dexterity of upper limb function after stroke. Training was progressed to imitation and intensive training after observation to required action in ADL. Method : 15 stroke patients were selected and one group pretest-posttest design was applied. Targets observed performance actions of task orientated task through a video and limitated action repeatedly, Training was performed 3 times a week and 20~30 minutes for each round for 3 weeks. Manual function test and 10-second test and Box and block test were performed for a dexterity of upper extremity motor function, Modified Barthel index and Motor activity log were performed for ADL. Result : After the training, a dexterity of affected upper extremity motor function of the target showed significant difference between before and after intervention, ADL showed significant improvement between before and after intervention. Conclusion : Task orientated Action observation lead a positive effect of recovering a dexterity of upper extremity motor function and ADL. Therefore, this study suggest a action observation training as one strategy of an intervention type of th e occupational therapy.

• Journal of Environmental Science International
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• v.19 no.7
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• pp.871-877
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• 2010

The objectives of this study were to compare growth of Pllioblastus pygmaed and soil characteristics as affected by difference of soil thickness and mixture ratio in shallow-extensive green roof module system, and to identify the level of soil thickness and mixture as suitable growing condition to achieve the desired plants in green roof. Different soil thickness levels were achieved under 15cm and 25cm of shallow-extensive green roof module system that was made by woody materials for $500{\times}500{\times}300mm$. Soil mixture ratio were three types for perlit: peatmoss: leafmold=6:2:2(v/v/v, $P_6P_2L_2$), perlit: peatmoss: leafmold=5:3:2(v/v/v, $P_5P_3L_2$) and perlit: peatmoss: leafmold=4:4:2(v/v/v, $P_4P_4L_2$). On June 2006, Pllioblastus pygmaed were planted directly in a green roof module system in rows. All treatment were arranged in a randomized complete block design with three replication. The results are summarized below. In term of soil characteristics, Soil acidity and electric conductivity was measured in pH 6.0~6.6 and 0.12dS/m~0.19dS/m, respectively. Organic matter and exchangeable cations desorption fell in the order: $P_4P_4L_2$ > $P_5P_3L_2$ > $P_6P_2L_2$. $P_6P_2L_2$ had higher levels of the total solid phase and liquid phase, and $P_4P_4L_2$ had gas phase for three phases of soil in the 15cm and 25cm soil thickness. Although Pllioblastus pygmaed was possibled soil thickness 15cm, there was a trend towards increased soil thickness with increased leaf length, number of leaves and chlorophyll contents in 25cm. The growth response of Pllioblastus pygmaed had fine and sustain condition in order to $P_6P_2L_2$ = $P_5P_3L_2$ > $P_4P_4L_2$. However, The results of this study suggested that plants grown under $P_4P_4L_2$ appear a higher density ground covering than plants grown under $P_6P_2L_2$. Collectively, our data emphasize that soil thickness for growth of Pllioblastus pygmaed were greater than soil mixture ratio in shallow-extensive green roof module system.

• Journal of the Korean Institute of Intelligent Systems
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• v.12 no.1
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• pp.52-60
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• 2002

According as many people use a computer newly, damage of computer virus and hacking is rapidly increasing by the crucial users. A computer virus is one of program in computer and has abilities of self reproduction and destruction like a virus of biology. And hacking is to rob a person's data in a intruded computer and to delete data in a Person s computer from the outside. To block hacking that is intrusion of a person's computer and the computer virus that destroys data, a study for intrusion detection of system and virus detection using a biological immune system is in progress. In this paper, we make a model of positive and negative selection for self recognition which have a similar function like T-cytotoxic cell that plays an important role in biological immune system. We embody a self-nonself distinction algorithm in computer, which is an important part when we detect an infected data by computer virus and a modified data by intrusion from the outside. And we showed the validity and effectiveness of the proposed self recognition algorithm by computer simulation about various infected data obtained from the cell change and string change in the self file.