• Journal of Broadcast Engineering
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• v.14 no.5
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• pp.573-588
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• 2009

In this paper, we propose a novel video quality degradation monitoring scheme titled VR-VQMS(Visual Rhythm based Video Quality Monitoring Scheme) over an IPTV service prone to packet losses during network transmission. Proposed scheme quantifies the amount of quality degradation due to packet losses, and can be classified into a RR(reduced-reference) based quality measurement scheme exploiting visual rhythm data of H.264-encoded video frames at a media server and reconstructed ones at an Set-top Box as feature information. Two scenarios, On-line and Off-line VR-VQMS, are proposed as the practical solutions. We define the NPSNR(Networked Peak-to-peak Signal-to-Noise Ratio) modified by the well-known PSNR as a new objective quality metric, and several additional objective and subjective metrics based on it to obtain the statistics on timing, duration, occurrence, and amount of quality degradation. Simulation results show that the proposed method closely approximates the results from 2D video frames and gives good estimation of subjective quality(i.e.,MOS(mean opinion score)) performed by 10 test observers. We expect that the proposed scheme can play a role as a practical solution to monitor the video quality experienced by individual customers in a commercial IPTV service, and be implemented as a small and light agent program running on a resource-limited set-top box.

• Korean Security Journal
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• no.41
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• pp.185-212
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• 2014

This research examines the decentralization of al-Qaida and other Salafi-jihadist terrorist groups, which is a subject of intense debate in the West. Especially, this study focused on investigating the status and evolution of al Qa'ida and other two Salafi-jihadist groups, Boko Haram and the Islamic States. These terrorist groups are currently considered as the most active Salafi-jihadist terrorist groups leading today's decentralization from Al-Qaida central terrorism network. This study also aims to examine the contemporary threats posed by the two extremely violent jihadist terrorist groups and these groups's terrorist networks. In order to achieve the purpose of this study, this study conducted content analyses with a wide range of documents reporting about Salafi-jihadist terrorists groups. Also this study utilized GTD data set drwan from START centner to provide descriptive analyses regarding IS and Boko Haram's activities and threats. On the basis of analyses, this study argues that recently the threats posed by core al Qaida has been severely weakened. Further, the broader Salafi-jihadist movement has become more decentralized among four tiers: first, core al Qaida in Pakistan; second, formal al Qa'ida affiliated groups that have sworn allegiance to core al Qaida; a number of Salafi-jihadist groups that have committed to establishing an extremist Islamic emirate without sworn allegiance to al Qaida; third, individual followers and networks inspired by al Qaida and other Salafi-jihadist groups. In concusion and discussion, this study highlights the need for a long-term engagement counter terrorism strategy against Salifi-jihadist terrorists groups on behalf of the peace and security of the world society.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.2
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• pp.64-70
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• 2011

Portable artificial electronic nose (E-nose) system suffers from noisy fluctuation in surroundings such as temperature, vapor concentration, and gas flow, because its measuring condition is not controled precisely as in the laboratory. It is important to develop a simple and robust vapor recognition technique applicable to this uncontrolled measurement, especially for the portable measuring and diagnostic system which are expanding its area with the improvements in micro bio sensor technology. This study used a PDA-based portable E-nose to collect the uncontrolled vapor measurement signals, and applied the image matching algorithm developed in the previous study on the measured signal to verify its robustness and improved accuracy in portable vapor recognition. The results showed not only its consistent performance under noisy fluctuation in the portable measurement signal, but also an advanced recognition accuracy for 2 similar vapor species which have been hard to discriminate with the conventional maximum sensitivity feature extraction method. The proposed method can be easily applied to the data processing of the ubiquitous sensor network (USN) which are usually exposed to various operating conditions. Furthermore, it will greatly help to realize portable medical diagnostic and environment monitoring system with its robust performance and high accuracy.

• The Journal of Korean Medicine
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• v.30 no.5
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• pp.88-101
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• 2009

Objectives: Since Korean traditional medicine has an integrative perspective by its nature, the patients' psychological and physical problems in a Korean traditional clinic may be resolved through a more integrative approach. The purpose of this study was to describe the latent characteristics of psychological health of child outpatients and their parents visiting Korean traditional clinic with physical complaints and was to propose an alternative curriculum to meet their needs based on their psychological and physical aspects. Methods: Subjects studied consisted of 100 outpatients (59 boys, 41 girls, mean age 55 months, age range 18 to 83 months) and their parents. Behavior characteristics for children were measured by Korean version of Child Behavior Checklist for Ages 1.5-5 (CBCL1.5-5) while parenting stress, depression, and anxiety for parent were measured by Korean-Parenting Stress Index-Short Form (K-PSI-SF), Center for Epidemiologic Studies Depression Scale (CES-D) and State-Trait Anxiety Inventory (STAI), respectively. The data of subjects were compared to those of standardized groups and then were compared according to child's gender within sample. Results: Child participants were reported to have significantly higher scores of all CBCL 1.5-5 subscales than the standardized group. When compared, no differences of K-PSI-SF, CES-D, and STAI was found between parents of participants and the standardized groups. However, parents of child participants with at-risk psychological problems showed significantly higher scores of all parenting stress subscales than those of all child participants. In addition, the mothers of boy participants demonstrated significantly higher anxiety, depression and parenting stress than those of girl participants irrespective of psychological severity. Conclusions: We discussed the implication of these results in clinical situation and make recommendations for curriculum of psychiatry and pediatrics with the aim of improving proper diagnosis, consulting and treatment.

• Korean Journal of Cognitive Science
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• v.28 no.1
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• pp.65-90
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• 2017

Rewards or penalties become informative only when contingent on an immediately preceding response. Our goal was to determine if the brain responds differently to motivational events depending on whether they provide feedback with the contingencies effective for learning. Event-related fMRI data were obtained from 22 volunteers performing a visuomotor categorical task. In learning-condition trials, participants learned by trial and error to make left or right responses to letter cues (16 consonants). Monetary rewards (+500) or penalties (-500) were given as feedback (learning feedback). In random-condition trials, cues (4 vowels) appeared right or left of the display center, and participants were instructed to respond with the appropriate hand. However, rewards or penalties (random feedback) were given randomly (50/50%) regardless of the correctness of response. Feedback-associated BOLD responses were analyzed with ANOVA [trial type (learning vs. random) x feedback type (reward vs. penalty)] using SPM8 (voxel-wise FWE p < .001). The right caudate nucleus and right cerebellum showed activation, whereas the left parahippocampus and other regions as the default mode network showed deactivation, both greater for learning trials than random trials. Activations associated with reward feedback did not differ between the two trial types for any brain region. For penalty, both learning-penalty and random-penalty enhanced activity in the left insular cortex, but not the right. The left insula, however, as well as the left dorsolateral prefrontal cortex and dorsomedial prefrontal cortex/dorsal anterior cingulate cortex, showed much greater responses for learning-penalty than for random-penalty. These findings suggest that learning-penalty plays a critical role in learning, unlike rewards or random-penalty, probably not only due to its evoking of aversive emotional responses, but also because of error-detection processing, either of which might lead to changes in planning or strategy.

• Journal of Korea Water Resources Association
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• v.43 no.11
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• pp.995-1009
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• 2010

Accelerated soil erosion due to extreme climate change, such as increased rainfall intensity, and human-induced environmental changes, is a widely recognized problem. Existing soil erosion models are generally based on the gross erosion concept to compute annual upland soil loss in tons per acre per year. However, such models are not suitable for event-based simulations of erosion and deposition in time and space. Recent advances in computer geographic information system (GIS) technologies have allowed hydrologists to develop physically based models, and the trend in erosion prediction is towards process-based models, instead of conceptually lumped models. This study aims to propose an effective and robust distributed rainfall-sediment yield-runoff model consisting of basic element modules: a rainfall-runoff module based on the kinematic wave method for subsurface and surface flow, and a runoff-sediment yield-runoff model based on the unit stream power method. The model was tested on the Cheoncheon catchment, upstream of the Yongdam dam using hydrological data for three extreme flood events due to typhoons. The model provided acceptable simulation results with respect to both discharge and sediment discharge even though the simulated sedigraphs were underestimated, compared to observations. The spatial distribution of erosion and deposition demonstrated that eroded sediment loads were deposited in the cells along the channel network, which have a short overland flow length and a gentle local slope while the erosion rate increased as rainfall became larger. Additionally, spatially heterogeneous rainfall intensity, dependant on Thiessen polygons, led to spatially-distinct erosion and deposition patterns.

• Journal of Korean Society for Geospatial Information Science
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• v.9 no.2 s.18
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• pp.29-36
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• 2001

The purpose of this paper is to describe the Disaster Management System Development of Enterprise GIS at the Kangwon Province in Korea. This project is included into 'the Kangwon Enterprise GIS 21 plan'. The Division of Disaster Management is in the middle of the 2-year project of the Disaster Management System development, appropriate for business performed at the Departments of Forestry, Culture, Environment, Tourism, etc. At the 1st phase of CIS implementation, for more than half a year we focused on the necessity of management of disasters. In the planning process, we needed long-term information on the whole area of Kangwon. In the assessment and response processes, we needed real-time data from Korean Meteorological Administration and other agencies. All the above information was carefully studied and referred to. ESRI's new GIS technologies solve the natural hazard/disaster problems. For example, hazardous materials routing often needs to be found the least expensive path through a roadway network. In the circumstances given, we can choose the departure point and destination of the vehicle, which carries the materials. It's also possible to minimize overall risk and costs of disaster problems by making a plan of people and possessions evacuation from the disaster area in short time limits. We can meet all the above goals using the latest ESRI's technologies.

• 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.

• Journal of IKEEE
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• v.5 no.1 s.8
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• pp.100-110
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• 2001

In this paper, we investigated several buffer management schemes for the design of shared-memory type ATM switches, which can enhance the utilization of switch resources and can support quality-of-service (QoS) functionalities. Our results show that dynamic threshold (DT) scheme demonstrate a moderate degree of robustness close to pushout(PO) scheme, which is known to be impractical in the perspective of hardware implementation, under various traffic conditions such as traffic loads, burstyness of incoming traffic, and load non-uniformity across output ports. Next, we considered buffer management strategies to support QoS functions, which utilize parameter values obtained via connection admission control (CAC) procedures to set tile threshold values. Through simulations, we showed that the buffer management schemes adopted behave well in the sense that they can protect regulated traffic from unregulated cell traffic in allocating buffer space. In particular, it was observed that dynamic partitioning is superior in terms of QoS support than virtual partitioning.

• 한국노년학
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• v.38 no.3
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• pp.627-643
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• 2018

This study aims to analyze gender differences in the prevalence of and risk factors for self-neglect among the elderly in South Korea. In order to investigate the differences between male and female elderly group, we compared 793 elderly men and 1,089 women from the data "Research on the Healthy Aging and Well-being of the Elderly" conducted in 2018. First, t-test and ${\chi}^2$-test and multiple regression analysis identified that gender differences in the prevalence of elder self-neglect was not statistically significant. Second, There are differences in risk factors affecting self-neglect between genders. age and class(perception) are the factors only affecting men. Income(monthly), having-religion, living-alone, satisfaction with life, social network are the ones only affecting women. Third, the risk factors for both men and women are depression and social support(public support). It is notable that we verify the empirical evidence supporting the hypothesis that risk factors for elder self-neglect may exist differently according to gender. In particular, gender characteristics revealed in this study can be reasonably explained through exchange theory and feminist theory. Therefore, we emphasize that the policy approach should be done depending on the gender of the elderly, and that the social safety net more paying attention to the depression of the elderly should be strengthened.