• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.10
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• pp.1986-1993
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• 2015

We investigate the optimal resource and power allocation for device-to-device (D2D) communications in a multicell environment. When D2D links reuse the cellular radio resources, each D2D user will interfere with a cellular link and other D2D links, in its own cell as well as in adjacent cells. Under such situation, we propose a coordinated resource allocation scheme that can handle the intercell interferences as well as the intracell interference. For a given resource allocation, we also formulate a power optimization problem and present an algorithm for finding the optimal solution. The resource and power allocation algorithms are designed to maximize the achievable rate of the D2D link, while limiting the generated interference to the cellular link. The performance of the proposed algorithms is evaluated through simulations in a multicell environment. Numerical results are presented to verify the coordination gain in the resource and power allocation.

• International Journal of Computer Science & Network Security
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• v.22 no.6
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• pp.275-287
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• 2022

As a result, for the increasing expansion by the university faculties in the field of postgraduate studies, The Deanship of Graduate Studies at the university has been established in 1430 AH/2009 CE to specifically address the needs of the current and prospective graduate population to supervise postgraduate studies programs in coordination with the concerned faculties. This comes as a result for the university being certain of the importance of providing postgraduate studies opportunities that follow the bachelor's degree to qualify our ambitious youth appropriately. The University offers 72 different Graduate programs, awarding doctoral and master's degrees along with fellowships and diplomas in various disciplines like health, engineering, science, literary, and educational. Currently, the financial model for admission and students' payment is manual and paper based. This paper proposes to provide a user interface for Financial Management in Deanship of Graduate studies The basic purpose of the system was to minimize human interference and reduce mistakes placed by human interference, also to have efficient and a fast performance, and perform Electronic Data Interchange (EDI) for various tasks such as billing and scheduling details.

• Journal of Communications and Networks
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• v.12 no.5
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• pp.449-458
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• 2010

In this paper, we present a distributed resource allocation algorithm for multi-cell uplink systems that increases the weighted sum of the average data rates over the entire network under the average transmit power constraint of each mobile station. For the distributed operation, we arrange each base station (BS) to allocate the resource such that its own utility gets maximized in a noncooperative way. We define the utility such that it incorporates both the weighted sum of the average rates in each cell and the induced interference to other cells, which helps to instigate implicit cooperation among the cells. Since the data rates of different cells are coupled through inter-cell interferences, the resource allocation taken by each BS evolves over iterations. We establish that the resource allocation converges to a unique fixed point under reasonable assumptions. We demonstrate through computer simulations that the proposed algorithm can improve the weighted sum of the average rates substantially without requiring any coordination among the base stations.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.4
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• pp.35-42
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• 2008

Since Bianchi's 2-D Markov Chain Model considers collision problem only in ideal channel condition, it does not reflect real channel impaired by fading, interference, and noise. Distributed Coordination Function(DCF) doubles its contention window(CW) when transmission fails regardless of collision or transmission error. Increase of CW caused by transmission error degrade throughput and increase the delay. In this paper, we present quantitative analysis of the impact of the parameters such as contention window size(CW), transmission probability for a given time slot(${\Im}$), transmission failure probability($p_f$), on the system performance and provide a method how to decrease the initial CW to achieve equivalent performance.

• Textile Coloration and Finishing
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• v.27 no.4
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• pp.261-269
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• 2015

Two new D-${\pi}$-A dyes were synthesized by the condensation reaction between active methyl and aromatic aldehyde and its biothiol sensing properties in DMSO/water were investigated by UV-vis spectroscopy. Upon addition of $Hg^{2+}$, the solution of D-${\pi}$-A dyes showed color change and the absorption band shows a formation of a dye-$Hg^{2+}$ coordination complex. These dyes exhibited high selectivity for $Hg^{2+}$ as compared with other cations. The dye-$Hg^{2+}$ could be recovered by adding glutathion(GSH). The absorption intensity of dye-$Hg^{2+}$ increased only by the addition of glutathione(GSH). The competition experiments revealed that no obvious interference was observed by performing the titration with the mixture of glutathione(GSH) and other amino acids. The results indicated that these D-${\pi}$-A dyes were highly selective for glutathione(GSH) detection.

• Journal of Korean Neurosurgical Society
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• v.47 no.3
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• pp.191-198
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• 2010

Objective : This study is planned to determine the neurocognitive difficulties of hydrocephalic adults. Methods : The research group contained healthy adults (control group, n : 15), and hydrocephalic adults (n : 15). Hydrocephalic group consisted of patients with idiopathic aquaduct stenosis and post-meningitis hydrocephalus. All patients were followed with shunted hydrocephalus and not gone to shunt revision during last two years. They were chosen from either asymptomatic or had only minor symptoms without motor and sensorineural deficit. A neuropsychological test battery (Raven Standart Progressive Matrices, Bender-Gestalt Test, Cancellation Test, Clock Drawing Test, Facial Recognition Test, Line Orientation Test, Serial Digit Learning Test, Stroop Color Word Interference Test-TBAG Form, Verbal Fluency Test, Verbal Fluency Test, Visual-Aural Digit Span Test-B) was applied to all groups. Results : Neuropsychological assessment of hydrocephalic patients demonstrated that they had poor performance on visual, semantic and working memory, visuoconstructive and frontal functions, reading, attention, motor coordination and executive function of parietal lobe which related with complex and perseverative behaviour. Eventually, these patients had significant impairment on the neurocognitive functions of their frontal, parietal and temporal lobes. On the other hand, the statistical analyses performed on demographic data showed that the aetiology of the hydrocephalus, age, sex and localization of the shunt (frontal or posterior parietal) did not affect the test results. Conclusion : This prospective study showed that adult patients with hydrocephalus have serious neuropsychological problems which might be directly caused by the hydrocephalus; and these problems may cause serious adaptive difficulties in their social, cultural, behavioral and academic life.

• Journal of Korea Multimedia Society
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• v.24 no.8
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• pp.1138-1148
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• 2021

In this study, we developed a 'shared-use mobility'-mounted local particulate matter monitoring terminal technology to measure the actual particulate matter concentration around me. As a mobile terminal device in the form of an IoT sensor platform, it is designed to be separated into a control module and a sensor module to minimize interference between sensors and to consider the optimal observation position of each sensor. As a result of the field test, it was confirmed that particulate matter was locally different depending on time and space even within the same area. In addition, it was confirmed that the concentration of particulate matter in the relevant section differed by up to 100 times compared to the surrounding area due to specific sources of particulate matter such as unpaved roads. In addition, we positively reviewed the applicability of the service in the real-time metaverse environment using this result. Through technological advancement and application of multiple shared-use mobilities, we expect to be able to provide new services for practical smart city air environment monitoring, such as localized particulate matter information, air pollution event information, and identification of causes of particulate matter.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.10 s.352
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• pp.79-89
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• 2006

TCP is the most widely used transport protocol in Internet applications that guarantees a reliable data transfer. But, in the wireless multi-hop networks, TCP performance is degraded because it is designed for wired networks. The main reasons of TCP performance degradation are contention for wireless medium at the MAC layer, hidden terminal problem, exposed terminal problem, packet losses in the link layer, unfairness problem, reordering problem caused by path disconnection, bandwidth waste caused by exponential backoff of retransmission timer due to node's mobility and so on. Specially, in the mobile ad-hoc networks, discrepancy between a station's transmission range and interference range produces hidden terminal problem that decreases TCP performance greatly by limiting simultaneous transmission at a time. In this paper, we propose a new MAC algorithm for mobile ad-hoc networks to solve the problem that a node can not transmit and just increase CW by hidden terminal. In the IEEE 802.11 MAC DCF, a node increases CW exponentially when it fails to transmit, but the proposed algorithm, changes CW adaptively according to the reason of failure so we get a TCP performance enhancement. We show by ns-2 simulation that the proposed algorithm enhances the TCP performance by fairly distributing the transmission opportunity to the failed nodes by hidden terminal problems.

• Journal of Oral Medicine and Pain
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• v.13 no.1
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• pp.23-33
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• 1988

The purpose of this study was to standardized and classify the coordination pattern among the chewing side and non-chewing side masseter and anterior muscles, in terms of EMG values on lateral excursion, clenching, and mastication in presence of the non-chewing side. In this study, 25 subjects were selected for experiment of lateral excursion, clenching and mastication and EMG value of the masseter and anterior temporal muscle on both sides were recored 2 times respectively. The bioelectric processor model EM2(Myo-tonic research, INC. U.S.A.) with the surface electrodes were used to record the EMG activity during all experimental procedures. The results were as follows : 1. During lateral excursion on intereference of non-chewing side, the EMG values of the temporal muscle were significantly more prominent than those of the temporal muscle on the non-chewing side. The EMG values of non-chewing side were significantly more prominent than those of chewing side on the both side masseter muscle and those of chewing side were significantly more prominent than those of non-chewing side on the both side temporal muscle. 2. During clenching on the occlusal interferance, the EMG values of non-chewing side masseter muscle were most prominent. 3. During mastication on the occlusal interferance, the EMG values of the chewing side temporal muscle were most prominent and those of non-chewing side temporal muscle were the lowest. 4. The EMG values of temporal muscle of non-chewing side on interferance were significantly more prominent than those of canine guidance during lateral excursion. 5. During clenching on the occlusal interferance, the EMG values of the masseter and the temporal muscles of the non-chewing side were significantly more prominent than canine guidance, but those of chewing side temporal muscle on canine guidance were significantly more prominent than those of interferance. 6. During mastication on canine guidance, the EMG Values of the temporal muscle on the chewing side, the masseter muscle on the chewing side and the temporal muscle on the non-chewing side were more prominent than those of interferance, but temporal muscle of non-chewing side was not different between canine guidance and occlusal interferance on non-chewing side.

• Proceedings of the KOR-KST Conference
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• 1995.05a
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• pp.239-250
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• 1995

With speeding up the process of being international municipality, the gravity of lacking parking lots in Shanghai urban area, which directly blocks the traffic in the city, has been revealed. This thesis analyses present automobiles parking capability and forecasts the future's needs for the city. To solve the problem, the concept could be to expand parking areas in city center recently to relax the tention and to do thoughtful planning in the near future on the foundation of fully consideration the trend. The municipal government has to set up policy properly, amplify regulations, strenthern the administration and open up a path to raise founds. Berween road system administration which is dynamic and parking lot system administration which is static, there are a knot on macroscopic meaning and an interference as well. The coordination of these two systems would be reflested on the effects of whole municipal traffic adminisration. Basically, public parking lots are city's foundal facilities, just like roads, bridges, etc. The main problems now in Shanghai are large parking space demands, insufficient facilities, cheap parking expenses comparing with the cost of parking lots construcion and poor administration. According to the forecast on social economy development, there will be 580 thousand automobiles in Shanghai by the year 2000, and the amount of private cars will increase greatly. The frequency of automobiles going out will be 1.45 million per day. Public parking lots being able to afford 105 thousand units are needed. To satisfy the demands, the recent aim of planning should be speed up the parking lots construction, the planning objective in next period should be developing reasonably and exceed the demands properly. In order to realize the planning objective, the government has to formulate correct policy and amplify administration regulations. The government has to adopt both administration and economy means, including charging parking people reasonably, collect necessary taxes, bringing the parking lots planning into general municipality planning, opening up an effective path to raise founds, such as set up founds for parking lots construction, issue bonds and stocks, get loans at home and abroad, etc.