• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.4
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• pp.2002-2019
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• 2017

RPL routing protocol for low-power and lossy networks is an Internet Engineering Task Force (IETF) recommended IPv6 based protocol for routing over Low power Lossy Networks (LLNs). RPL is proposed for networks with characteristics like small packet size, low bandwidth, low data rate, lossy wireless links and low power. RPL is a proactive routing protocol that creates a Directed Acyclic Graph (DAG) of the network topology. RPL is increasingly used for Internet of Things (IoT) which comprises of heterogeneous networks and applications. RPL proposes a single path routing strategy. The forwarding technique of RPL does not support multiple paths between source and destination. Multipath routing is an important strategy used in both sensor and ad-hoc network for performance enhancement. Multipath routing is also used to achieve multi-fold objectives including higher reliability, increase in throughput, fault tolerance, congestion mitigation and hole avoidance. In this paper, M-RPL (Multi-path extension of RPL) is proposed, which aims to provide temporary multiple paths during congestion over a single routing path. Congestion is primarily detected using buffer size and packet delivery ratio at forwarding nodes. Congestion is mitigated by creating partially disjoint multiple paths and by avoiding forwarding of packets through the congested node. Detailed simulation analysis of M-RPL against RPL in both grid and random topologies shows that M-RPL successfully mitigates congestion and it enhances overall network throughput.

• Korean Journal of Biological Psychiatry
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• v.18 no.2
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• pp.101-108
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• 2011

Objectives The aim of this study is to explore the association among DRD4 polymorphism, temperament and alcohol drinking behavior of Koreans in their early adulthood. Method Participants were 172 healthy Korean adults (mean age $28.1{\pm}0.8$). Their temperament was assessed with the Temperament and Character Inventory (TCI) and their alcohol drinking behavior were evaluated with a self-reported questionnaire including the CAGE and the Korean version of Alcohol Use Disorder Identification Test (AUDIT-K). DRD4 exon III 48 base pair variable number of tandem repeats (VNTR) was genotyped by PCR. Results No significant association was found between DRD4 polymorphism and TCI temperament dimension (novelty seeking, harm avoidance, reward dependence, and persistence) as well as alcohol drinking behavior scales. However, novelty seeking was significantly associated with alcohol drinking behavior. The higher level of novelty seeking was associated with the higher severity index of drinking (B = -0.225, p < 0.001) and problematic alcohol use on the CAGE and AUDIT-K [Odds Ratio (OR) = 1.111, 95% Confidence Interval (CI) 1.021-1.209, p = 0.015, OR = 1.087, 95% CI 1.009-1.170, p = 0.028]. Conclusion In our study, while there is no significant association of DRD4 polymorphism with temperament and alcohol drinking behavior, novelty seeking affects problematic alcohol use. Results suggest that novelty seeking may play an important role in problematic alcohol use in young Korean adults.

• Journal of Internet Computing and Services
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• v.3 no.6
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• pp.43-51
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• 2002

In this paper, we study the new packet dropping scheme using an active queue management algorithm. Active queue management mechanisms differ from the traditional drop tail mechanism in that in a drop tail queue packets are dropped when the buffer overflows, while in active queue management mechanisms, packets may be dropped early before congestion occurs, However, it still incurs high packet loss ratio when the buffer size is not large enough, By detecting congestion and notifying only a randomly selected fraction of connection, RED causes to the global synchronization and fairness problem. And also, it is the biggest problem that the network traffic characteristics need to be known in order to find the optimum average queue length, We propose a new efficient packet dropping method based on the active queue management for congestion control. The proposed scheme uses the per-flow rate and fair share rate estimates. To this end, we present the estimation algorithm to compute the flow arrival rate and the link fair rate, We shows the proposed method improves the network performance because the traffic generated can not cause rapid fluctuations in queue lengths which result in packet loss

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.12
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• pp.4819-4834
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• 2015

The spectral efficiency of cellular networks can be improved when proximate users engage in device-to-device (D2D) communications to communicate directly without going through a base station. However, D2D communications that are not properly designed may generate interference with existing cellular networks. In this paper, we study resource allocation and power control to minimize the probability of an outage and maximize the overall network throughput. We investigate three power control-based schemes: the Partial Co-channel based Overlap Resource Power Control (PC.OVER), Fractional Frequency Reuse based Overlap Resource Power Control (FFR.OVER) and Fractional Frequency Reuse based Adaptive Power Control (FFR.APC) and also compare their performance. In PC.OVER, a certain portion of the total bandwidth is dedicated to the D2D. The FFR.OVER and FFR.APC schemes combine the FFR techniques and the power control mechanism. In FFR, the entire frequency band is partitioned into two parts, including a central and edge sub-bands. Macrocell users (mUEs) transmit using uniform power in the inner and outer regions of the cell, and in all three schemes, the D2D receivers (D2DRs) transmit with low power when more than one D2DRs share a resource block (RB) with the macrocells. For PC.OVER and FFR.OVER, the power of the D2DRs is reduced to its minimum, and for the FFR.APC scheme, the transmission power of the D2DRs is iteratively adjusted to satisfy the signal to interference ratio (SIR) threshold. The three schemes exhibit a significant improvement in the overall system capacity as well as in the probability of a user outage when compared to a conventional scheme.

• Molecules and Cells
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• v.40 no.10
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• pp.714-730
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• 2017

Pre-mRNA splicing further increases protein diversity acquired through evolution. The underlying driving forces for this phenomenon are unknown, especially in terms of gene expression. A rice alternatively spliced transcript detection microarray (ASDM) and RNA sequencing (RNA-Seq) were applied to differentiate the transcriptome of 4 representative organs of Oryza sativa L. cv. Ilmi: leaves, roots, 1-cm-stage panicles and young seeds at 21 days after pollination. Comparison of data obtained by microarray and RNA-Seq showed a bell-shaped distribution and a co-lineation for highly expressed genes. Transcripts were classified according to the degree of organ enrichment using a coefficient value (CV, the ratio of the standard deviation to the mean values): highly variable (CVI), variable (CVII), and constitutive (CVIII) groups. A higher index of the portion of loci with alternatively spliced transcripts in a group (IAST) value was observed for the constitutive group. Genes of the highly variable group showed the characteristics of the examined organs, and alternatively spliced transcripts tended to exhibit the same organ specificity or less organ preferences, with avoidance of 'organ distinctness'. In addition, within a locus, a tendency of higher expression was found for transcripts with a longer coding sequence (CDS), and a spliced intron was the most commonly found type of alternative splicing for an extended CDS. Thus, pre-mRNA splicing might have evolved to retain maximum functionality in terms of organ preference and multiplicity.

• Journal of Korean Society of Steel Construction
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• v.28 no.2
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• pp.75-83
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• 2016

Existing tubes for concrete filled tubular structure are made through welding of four plates irrespective, but the production performance is poor and special welding technique is needed to weld the internal or through diaphragm. Accordingly, We developed a welded built-up square steel tube having a welding lines and a stiffeners at location out of stress concentration. The welded built-up square steel tube occurred a interference with stiffeners at the internal or through diaphragm, therefore researches of a external diaphragm for welded built-up square CFT column connections are needed for the purpose of avoidance of a interfere with stiffeners. In this study we suggest a design formulation for external diaphragm of the welded built-up square CFT external diaphragm connections. Four specimens were manufactured for a experimental test, then we analyzed the behaviors of the specimens.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.9
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• pp.848-857
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• 2011

Vision-based collision avoidance system for air traffic management requires a excellent multiple target detection algorithm under low signal-to-noise ratio (SNR) levels. The track-before-detect (TBD) approaches have significant applications such as detection of small and dim targets from an image sequence. In this paper, two detection algorithms with the TBD approaches are proposed to satisfy the multiple target detection requirements. The first algorithm, based on a dynamic programming approach, is designed to classify multiple targets by using a k-means clustering algorithm. In the second approach, a hidden Markov model (HMM) is slightly modified for detecting multiple targets sequentially. Both of the proposed approaches are used in numerical simulations with variations in target appearance properties to provide satisfactory performance as multiple target detection methods.

• Journal of Life Science
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• v.6 no.2
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• pp.142-148
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• 1996

Aloe(Aloe arborescens M$_{ILL}$) has been used as a home medicine for the past several thousand in the world, and has been studied on anti-bacterial and anti-fungal activities, hypotension, atherosclerosis, myocardiac infartion, apoplexy, diabetes as a chronic digenerative disease, tumors, gastrointestinal tract, liver and pancreas' diseases, and genitourinary tract etc. SAMP8 as a learing and memory impairment animal model were fed basic and/or experimental diets with 1.0% freezing dried(FD)-aloe for 8 months. The passive avoidance tests such as acqusition trial and retention test were significantly higher in aloe group than in control group. Grading score of senescence resulted in a marked decreases in aloe group compared with control group. Acetylcholinesterase(AChE) activity was remarkably increased in aloe group compared with control group. Neurotransmitters such as dopamine(DA) and serotonin(5-HT) almost did not change by the feeding of aloe-added diet, but their metabolites such as homovanillic acid(HVA) and 5-hydroxy-indole acetic acid(5-HIAA) in aloe group were significantly increased compared with control group. Therefore, the ratios of HVA/DA and 5-HIAA/5-HT as a ratio of metabolite on neurotransmitter were significantly increased by the feeding of aloe-added diet. These results suggest that aloe vara may be activated acetylcholinesterase, the metabolite of neurotransmitter, and ratios of metabolite on neurotransmitter, resulting ina greater prevention of learning and memory impairments such as Alzheimertype dementia.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.1
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• pp.64-76
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• 2017

Routing in mobile ad hoc networks (MANETs) is highly challenging because of the dynamic nature of network topology. AntHocNet is a bio-inspired routing protocol for MANETs that mimics the foraging behavior of ants. However, unlike many other MANET routing protocols, the paths constructed in AntHocNet are unidirectional, which requires a separate path setup if a route in the reverse direction is also required. Because most communication sessions are bidirectional, this unidirectional path setup approach is often inefficient. Moreover, AntHocNet suffers from looping problems because of its property of multiple paths and stochastic data routing. In this paper, we propose a modified path setup procedure that constructs bidirectional paths. We also propose solutions to some of the looping problems in AntHocNet. Simulation results show that performance is significantly enhanced in terms of overhead, end-to-end delay, and delivery ratio when loops are prevented. Performance is further improved, in terms of overhead, when bidirectional paths setup is employed.

• The Journal of Korean Medicine
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• v.28 no.1 s.69
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• pp.25-34
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• 2007

Objectives : The present study was carried out to provide basic information necessary for the prevention and efficient treatment of stroke through a comparison between thr patients of the first attack and those of recurrence. Methods : The observation f3r the current study was made on 210 cases of stroke that were confirmed through brain CT-scan. The patients were hospitalized at one of two oriental medical hospitals in Seoul during 2006. Result : The main results were as follows. First, the male-to-female ratio of stroke patients were 1:1.26, with more primary stroke far females and more recurrent stroke for males. Second, in the age distribution, seventies was the top, and sixties, fifties, and forties were next in the order of frequency. A large city was the most frequent residential site and unemployment was the most frequent occupation to have stroke. The incidence of stroke became higher as patients had a taste for spicy and salty food. Third, the most common preceding disease was hypertension. In the relationship of diastolic blood pressure with recurrence, there was significance in the test of independence. Fourth, the most important precipitating conditions at the onset of stroke were rest and steeping. The most common precedent symptoms were verbal disturbance, numbness, and dizziness. In the stroke patients with hemiparesis, male and female patients usually showed It. hemiparesis. Fifth, as a result of brain CT-scan, cerebral hemorrhage was inclined to reduce but cerebral infarction was inclined to increase due to senility and change of lifestyle. Finally, total cholesterol findings disclosed that 22.4% were hypercholesteremia, 18.6 % were hyperlipemia in triglyceride findings, and 19.0% were glycosemia in glucose findings. Conclusions : The above results suggested avoidance of meat and salty fDod and positive control of hypertension and diabetes mellitus in order to prevent stroke.