Earticle

We investigated radical scavenging effects and protective activities of fucoidan and alginic acid, active polysaccharide components from brown seaweeds, against peroxyl radical-induced oxidative stress under in vitro and cellular system. Fucoidan exerted strong radical scavenging effects against nitric oxide (NO) and superoxide anion $(O_2)$. On the other hand, alginic acid did not show inhibitory activity against NO and relatively weak $O_2{^-}$ scavenging effect. Additionally, alginic acid exhibited higher hydroxyl scavenging activity than fucoidan. Both fucoidan and alginic acid significantly enhanced cell viability against oxidative stress induced by 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH). At $1000{\mu}g/mL$ concentration of fucoidan and alginic acid, the viability was increased from 16.4% to 85.9% and 67.7%, respectively. In addition, fucoidan and alginic acid ameliorated the lipid peroxidation in LLC-PK1 cell induced by AAPH in a dose-dependent manner. In particular, fucoidan showed stronger inhibitory effect than alginic acid in the cellular system. The present study suggests that fucoidan and alginic acid may be promising antioxidants against oxidative stress induced by free radicals.

자연재해 및 급격한 트래픽 수요 문제 해결에 UAV(unmanned aerial vehicle) 셀룰러 무선망이 충족할 수 있는 대안으로 급부상하고 있지만, 통신용량(capacity), 커버리지(coverage) 및 에너지 효율성 문제가 가장 중요하다. 이를 해결하기 위해 셀 내 및 셀 간 간섭환경의 UAV 셀룰러 무선망에서 전력 도메인(domain) NOMA(non-orthogonal multiple access) 기술을 도입하여 SIC(successive interference cancellation)를 적용한다면, UAV 이동성의 자유도를 활용하여 OMA(orthogonal multiple access) 보다 스펙트럼 효율성과 에너지 효율성을 향상시킬 수 있을 것이다. 본 논문에서는 UAV 셀룰러 간섭 환경을 고려하여 다운링크 및 업링크에서 NOMA 유저 스루풋(rhroughput) 및 중단 확률(outage probability) 면에서 이득 개선 효과를 제시한다.

Uumanned aerial vehicle(UAV) cellular wireless networks are emerging as an alternative to solve the problems of natural disasters and sudden traffic demands, However, issues of capacity, coverage, and energy efficiency are considered of paramount importance. To address these issues, a new and promising power domain non-orthogonal multiple access(NOMA) technology with receiver successive interference cancellation(SIC) in intra- and inter-cell interference environment for UAV wireless networks can improve spectral and energy efficiency by utilizing the additional degree of freedom of UAV mobility compared to orthogonal multiple access(OMA). In this paper, the gain improvement effects through NOMA user throughput and outage probability performance have been discussed in UAV cellular downlink and uplink considering the interference envitronment.

본 논문은 매크로/펨토 셀룰러 망에서 모든 셀들 간의 서비스 공평성을 유지함으로써 시스템을 안정화하고 데이터 전송속도를 향상시키기 위한 채널 분배 기법을 제안한다. 특히 매크로셀과 펨토셀 간에 분배하는 채널의 비율이 시스템에 주는 구체적인 영향을 파악하기 위하여 IP 기반의 매크로/펨토 셀룰러 망에 대한 대기행렬 모형을 제시한다. 이를 바탕으로 실질적인 채널 분배 전략을 제안하고, 실험을 통하여 다양하게 변화하는 시스템 환경에 따라 제안 기법의 동작을 분석한다. 또한 그 결과를 통하여 효율적인 시스템 구조의 설계 방향에 대하여 논의한다.

In the macro/femto cellular networks, the portion of channels assigned to each cell is a critical factor which sets the stability and the performance of the whole system. To grasp the concrete influence that the channel split portion have on the system, we present the queueing model for IP based macro/femto cellular networks, and find the stability conditions. Additionally we provide the strategy to decide the portion of channels allocated to each cell. Through the experiments, we prove that the proposed strategies operate feasibly in various network environments, and on the basis of these results we discuss the efficient system structure plan.

인터넷 기술의 발달로 e-러닝 서비스가 활성화되었으며 최근에는 m-러닝의 수요가 증가하고 있다. 현재의 e-러닝은 획일적인 학습 서비스만 가능한 단점을 가지고 있으며, m-러닝의 경우 솔루션 부족으로 인해 제한적인 서비스만이 가능하다. 본 논문에서는 개방형 소프트웨어 플랫폼을 통한 개인 최적화된 학습 서비스 시스템의 제안한다. 제안 시스템은 휴대 단말기에 탑재 가능한 경량 LMS를 가지며, 이를 이용하여 인터넷에 접속 여부에 관계없이 사용자 개개인에 최적화된 학습 서비스를 제공하고 개인별 학습 서비스의 수준을 지속적으로 재조정하도록 설계되었다.

Proliferation of the Internet has made e-learning services become popular, and demand for m-learning has also been increased. However, the weakness of current e-learning or m-learning service is such that the service is not adaptable to individual user’s performance. In this paper, a personalized and optimized learning service system using open software platform is proposed. The design of the proposed system is mainly based on a Lightweight LMS which is installed onto a portable device. It provides individually optimized learning services and operates even in an Internet-inaccessible environment. The system also periodically re-adjusts level of learning content using feedback information from the user.

최근 전 세계적으로 전자가격 표시기 시스템이 매장 및 유통업체에서 활성화됨에 따라 2.4GHz의 동일 대역을 사용하는 무선단말기 의 Wi-Fi 통신과 간섭현상이 발생하게 되었다. 무선단말기에 의한 전자가격표시기 시스템의 간섭영향을 분석하기 위해 간섭시나리 오와 확장된 하타 전파모델을 설정하였다. 심캣을 적용하여 시뮬레이션을 수행하여 무선단말기 간섭으로부터 전자가격표시기 시스 템의 태그를 보호하기 위한 이격거리를 도출하였다.

As ESL(Electronic Shelf Label) system is increased at the market in the world, the interference between ESL system and Wi-Fi(Wireless Fidelity) Cellular Phone at 2.4GHz becomes issue. The interference scenario and propagation of the Extended HATA Model were established to analyze the interference from Wi-Fi Cellular Phone into ESL system. Through simulation results based on SEAMCAT(Spectrum Engineering Advanced Monte Carlo Analysis Tool), separation distance was obtained to protect ESL system from Wi-Fi Cellular Phone interference.

The efficient management and sharing of the radio spectrum among numerous users become an important issue. The frequency channels are a scarce resource in a cellular mobile system. Thus, many schemes have been proposed to assign frequencies to the cells such that the available spectrum is efficiently used. In this paper, we propose a channel allocation mechanism including migration concept using genetic algorithm in cellular mobile computing environments. Our simulation results indicate that the proposed algorithm could reduce a search time for an available channel.

This paper presents new mmWave-based cellular system as one of means to achieve the capacity requirement of 5G mobile communications. The base station of new system covers its service area with spot beams formed by many beamforming antennas, and one beam can be composed of multiple frequency allocation beam component carriers in which one broadband bandwidth is divided into multiple sub-bands at the millimeter frequency. The best feature of new cellular architecture is the multi-layered FA dynamic cell configuration and it means that one or more beam component carrier(s) can be grouped and then operated as one cell. The effect of this dynamic cell configuration is to avoid interference among cells via the association among multi-layered FAs and to imitate pseudo-small cells and pseudo-macro cell like 3GPP small cell enhancement architecture (user equipment in small cell enhancement architecture can use coverage layer (macro cell(s)) for mobility robustness and capacity layer (small cells) for capacity offering). In this paper, we design new system, its basic operation and evaluate its capacity to confirm the possibility as an alternative of 5G mobile communications.

Antioxidant activity of viticis fructus, fruits of Vitex rotundifolia was investigated. The samples of viticis fructus were extracted twice with CH2Cl2 and methanol (MeOH), respectively and then combined crude extracts were partitioned between H2O and CH2Cl2. The aqueous layer was re-partitioned between n-butanol (n-BuOH) and H2O and then the organic layer, between 85% aq. MeOH and n-hexane. Antioxidant activity of crude extract and its solvent-partitioned fractions was evaluated by using DPPH radical and intracellular reactive oxygen species (ROS) generated in HT 1080 cells, respectively. Degree of occurrence of intracellular reactive oxygen species (ROS) was measured using 2',7'-dichlorofluorescin diacetate as fluorescence probe.

This study examined the antioxidative activity of delphinidin, a kind of anthocyanidin from eggplant. Cellularprotective potential from oxidative damage by nitric oxide (NO), superoxide anion (O2−), and peroxynitrite (ONOO−) usingepithelial cell line LLC-PK1 cell as well as in vitro radical scavenging effects were investigated. Delphinidin showed strong invitro radical scavenging effects against NO, O2−, and hydroxyl radical (·OH) in dose-dependent manners. In addition,delphinidin increased cell viability in LLC-PK1 cells in a concentration-dependent manner when viability was reduced byONOO−-induced oxidative damage. To elucidate the protective mechanisms of delphinidin from ONOO−, sodiumnitroprusside (SNP), and pyrogallol were also employed to generate NO and O2−, respectively. The treatment of delphinidinrecovered reductions in cell viability caused by SNP and pyrogallol, indicating that delphinidin can attenuate oxidative stressinduced by NO and O2−. The present study suggests that delphinidin is a promising antioxidative agent.

As a part of search for antioxidants from marine organisms, antioxidant activities of two seagrasses Zostera japonica and Z. asiatica were investigated. Each of them was extracted two times with acetone-CH2Cl2(1:1) and MeOH in turn. Crude extracts were combined for each sample. Each of the combined crude extracts was partitioned between CH2Cl2 and water. The organic layer was further partitioned between 85% aq MeOH and n-hexane, and the aqueous layer was fractionated with n-BuOH and H2O, successively. The protective effect of each fraction from Z. japonica and Z. asiatica on H2O2-induced oxidative stress was examined in Raw 264.7 cells. The levels of intracellular ROS and GSH were measured using 2',7'-dichlorofluorescin diacetate and monobromobimane as fluorescence probe, respectively. All solvent fractions including their crude extracts not only significantly decreased levels of intracellular ROS in a dose-dependent manner but also increased intracellular GSH level. Moreover, they exhibited a significant protective effect on membrane lipid peroxidation in TBARS assay system. These results suggest that potential natural antioxidants related to oxidative stress could be isolated from Z. japonica and Z. asiatica

The tradeoff between energy efficiency (EE) and spectral efficiency (SE) under the smart grid with joint energy harvesting and grid power supply is considered. The price factor in economics is used to propose the economic EE and SE. Then a new EE-SE tradeoff metric called the EE-SE adaptive tradeoff (ESAT) is built under the fluctuating harvesting energy. Furthermore, the offline optimization problem is put forward and the solution is discussed. The offline solutions based on the branch-and-bound algorithm and the Lagrange dual decomposition method are discussed to analyze the influence of renewable energy quantity on the proposed structure. Numerical results indicate that the proposed ESAT framework is efficient to the tradeoff between EE and SE.

Vehicle License Plate Images Segmentation is a substantial stage for developing an Automatic License Plate Recognition (ALPR) system. In this paper, it is considered an efficient segmentation algorithm for extracting vehicle license plate images using Cellular Neural Networks (CNN). The learning CNN templates values are formulated as an optimization problem to achieve the desired performances which can be found by means of Adaptive Fuzzy (AF) algorithm and Neuro-Fuzzy (NF) algorithm techniques. The main objective of the paper is to compare the performances of standard CNN, Adaptive Fuzzy (AF), and Neuro-Fuzzy (NF) on real data of several vehicle license plate images of standard Indonesia License Plates. The results are then compared with ideal vehicle license plate images. Quantitative analysis between ideal vehicle license plate images and segmented vehicle license plate images is presented in terms of Peak signal-to-noise ratio (PSNR), Mean Squared Error (MSE) and Root Mean Squared Error (RMSE). From the performance analysis, the CNN template optimized by ANFIS algorithm is more recommended than the standard CNN edge detector or the CNN template optimized by Adaptive Fuzzy algorithm in vehicle license plate image segmentation. It is shown from the calculation that PSNR is 80% better than the standard CNN, and the resulted MSE and RMSE are 70% better than the standard CNN. Whereas the CNN template optimized by Adaptive Fuzzy algorithm achieves the PSNR 90% better than the standard CNN, but it yields the MSE and RMSE 40% worse than the standard CNN.

Cell edge effect has been recently paid much attention in the development of new mobile communication systems because it can cause serious performance degradation in the cell edge. The cell edge problem is essentially due to non-uniform distribution of the radio power of cellular systems. It can be softened to a certain extent by using new radio architecture called distributed antenna system (DAS). In traditional collocated antenna system (CAS), multiple antennas are centrally located at the BSs, while in the DAS, multiple antennas of BS called remote antenna unit (RAUs) are separately and remotely located in a cell and connected to a baseband processing unit (BPU) via high speed backbone links. Since the distance between the mobile terminals (MTs) and the antenna of the BS is greatly reduced by introducing RAUs, the large path loss of the radio signals can be avoided. The objective is to tackle the shortcomings due to the cell edge effects in a cellular system by suitably changing the existing collocated antenna system (CAS) to a distributed antenna system (DAS) and to compare its performance. The performance analysis namely bit error rate (BER) and capacity were performed and the results are shown. It is inferred from the results that the proposed DAS scheme outperforms the existing CAS scheme.

A Location Register(LR) system manages each subscriber’s location information, which continuously changes in mobile cellular network. For this purpose, the LR database system provides backup management facilities. The objectives of this paper are to identify the problems of the current LR system through rigorous analysis, to suggest solutions to them. I proposed efficient backup methods that takes into account the characteristics of LR database transactions. In the proposed backup method, I use two kinds of dirty flags in order to solve the performance degradation problem caused by frequent registration- location operations.

In this paper, a repeater system is studied which is basically used for the relay in the cellular communication. The LDPC (Low Density Parity Check) code is introduced into DFE (decision feedback equalizer) in the receiver for the BER (bit error rate) performance. For the better quality of service (QoS) and the higher convenience, the wireless repeater was considered for the relay system. In this paper, we propose an efficient equalizer algorithm for the cellular relay system, which uses the DFE combining the LDPC code. The proposed equalizer helps to compensate RF impairments and improve better performance than used independently. In addition, proposed equalizer has less iterative number of LDPC code. So, the proposed equalizer system has low complexity. Therefore, in this paper, BER performance of DFE combining the LDPC code for cellular relay system is satisfied with 4.3dB at 10-4.

For the purpose of efficiency and safety in marine traffic, and considering that ships have to change lane to move on in case of waterway partial closure caused by a marine work zone or an accidence, a new NaSch ship traffic model considering Integrated Bridge System (IBS) is presented, and then a cellular automata model considering IBS for partial reduction waterway is proposed. By numerical simulation, fundamental diagram and time-space spot diagrams of ship traffic flow and that when accidence happens and recovers are given. At last, a numerical example is forwarded to analyze the effect to waterway transit capacity by precautionary area length and ship arrival rate. The model may be applied in decision-making simulation and increase the transit capacity of waterway.

Wi-Fi positioning system is widely being studied in many fields of smartphones. In an open air environment a GPS receiver is able to determine its position with a high level accuracy. But in inside a building, where the GPS signal is bad or unavailable or unappreciated. The position estimation from the GPS receiver is very erroneous and has no practical use. Wi-Fi triangulation system is applied in indoor location but faced signal coverage error. Therefore, we propose a method of indoor positioning that determines the user's current position with the nearby Wi-Fi routers and cellular network signal strength RSSI values. This Signal strength RSSI estimates the location fingerprints based on at least two wireless Access Points and an alternative Cellular network or three access points. The cellular network is an alternative backup of unreached Wi-Fi Access point where this Access point’s coverage is unknown or sparse. Predefined points are used to measure distance from a user could also generate advance level accuracy. Referring to the floor map, our method adjusts the real-time user's current location. Gravity sensor works on the back end to control Wi-Fi scanning enable or disable considering user movement for energy efficiency. We have implemented the proposed method on Android smart phones and our test results are discussed in this paper.

To reveal how the ancient kiln has evolved along DongHe River Basin in Jingdezhen –Jiangxi Province of China, and further reflect the interaction of the political situation, the institutions and the natural environment, we create ancient virtual maps of study area and propose such constructs to unambiguously denote a integration system by combining the advantages of multi-agents, PSO and CA in time and space. We apply the system to model a dynamic interaction environment and conduct a series of spatial analyses of the land-use pattern from 1271 to 1554. Compared with model PSO-CA, the simulation result of this new model is of richer changing hierarchy and can better reflect the whole process from the first to the last firing. Meantime, the index Moran's I of simulation using the hybrid method is much closer to the actual Moran's I, which can better reflect the interaction between political environment and natural environment of different dynasties with the lack of ancient GIS spatial data.

본 연구에서는 차세대 CDMA 셀룰러 네트워크의 성능향상을 위한 멀티 데이터 전송 레이트 조절과 전력제어 문제를 결합한 문제를 제시하고 유전 알고리즘 접근에 기반한 새로운 해법을 제안하였다. 본 연구에서 제안한 알고리즘으로 많은 사용자를 보다 빨리 서비스 할 수 있고 SIR 제한값을 고려하면서 최적의 해를 얻을 수 있었다. 이 연구에서는 CDMA 셀룰러 네트워크의 데이터 전송 레이트를 최대화하는 적합도 문제와 가능한 모바일의 수를 최대화하는 적합도 문제 두 개를 고려하였으나 이 들을 결합한 문제나 다른 것 들에 대한 적합도 함수도 충분히 장착이 가능하다. 시뮬레이션 결과는 접근 방식의 유효성과 타당성을 보여준다.

In this work, we present a novel genetic approach to solve the problem of combining power control and data rate transmission adjustment for the performance enhancement of the next generation CDMA system. We obtained the optimal solution of multi rate and power control problem by compromising slightly on SIR limit values. The proposed algorithm was able to handle many more users with comparable or faster convergent service. While this paper considered two kinds of fitness function such as maximizing the total transmission data rate and maximizing the acceptable mobiles of CDMA cellular network, the evaluation function combining these two cases or others can be also easily implemented. The simulation results showed the effectiveness and validity of our approach.