• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.11B
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• pp.750-757
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• 2005

This paper reports on the study of P2P traffic behaviors in a high-speed campus network under a simple firewall which drops packets with default port numbers for the well-blown P2P applications. Among several ways of detecting P2P traffic, the easiest method is to filter out packets with the default port number of each P2P application. After deploying the port-based firewall against P2P-traffic, it is expected that the amount of P2P traffic will be decreased. However, during the eight-month measurement period, three new commercial P2P applications have been identified and their traffic usages have reached up to $30/5.6\%$ of the total outbound/inbound traffic volumes at the end of the measurement period. In addition, the most famous P2P application, eDonkey, has adapted and has escaped detection through port hopping. The measurement result shows that the amount of eDonkey traffic is around $6.7/4.0\%$ of the total outbound/inbound traffic volume. From the measurement results, it is observed that the port-based firewall is not effective to limit the usage of P2P applications and that the P2P traffic is steadily growing due to not only the evolution of existing P2P applications such as port hopping but also appearances of new P2P applications.

• The KIPS Transactions:PartC
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• v.15C no.2
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• pp.87-92
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• 2008

This paper proposes a session control model for the P2P(Peer to Peer) IPTV(Internet Protocol Television) services and presents the IPTV session control procedures based on the proposed model. Since, while public IPTV traffic is usually processed via a separate network, P2P IPTV traffic is processed together with the conventional Internet access traffic, the P2P IPTV control mechanism needs to provide multi-stream processing for the constituent TPS(Triple Play Service) traffic and corresponding QoS(Quality of Service) control functions. Besides, P2P IPTV session control mechanism should provide appropriate multicast control functions in order to support effective transmission of video traffic generated by personal IPTV broadcasters. The P2P IPTV session control model proposed in this paper is designed to be based on the standard SIP(Session Initiation Protocol), IGMP(Internet Group Management Protocol), and COPS(Common Open Policy Service) protocol so that it can contribute to the easy and prompt deployment of inter-operable P2P IPTV platform.

• 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 Internet Computing and Services
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• v.8 no.2
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• pp.77-87
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• 2007

A typical VOD service allows that a number of remote clients playback a desired video from a large collection of videos stored in one or more video servers. The main bottleneck for a VOD service is the network bandwidth connecting to the VOD server to the client due to the high bandwidth requirements. Many previous researches have shown that VOD server can be greatly improved through the use of multicast, broadcast, or P2P scheme. Broadcast is one of the most efficient techniques because it can transmit a stream to many users without additional network bandwidth. But the broadcast has long latency time. In order to overcome the drawback, in this paper, we propose P2Prefix broadcast scheme that can solve the service latency time, which is the problem of broadcast scheme, by using P2P caching as well as minimizing the client buffer requirement.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.2
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• pp.57-62
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• 2014

In order to provide real-time multimedia streaming service, a lot of system resources and network bandwidth required. Thus each computer is any computer other equivalent has the ability to act as a client and a server Peer-to-Peer(P2P) architecture with much interest. In this paper, techniques of P2P content that requires a user to efficiently retrieve the desired time in the streaming service have placed the focus of the research techniques. In a number present in the P2P contents, the user requests to find out the desired amount of time the content streaming services in order to provide seamless lookup latency contents search algorithm to minimize the study. P2P based smart network system and the structure of the super-node and the peer node is composed of super-gateway. Smart network system architecture proposed by performing a content search algorithm. The user requests a desired content, the service can be retrieved within the provided the flexibility.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.386-391
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• 2001

A finite element code based on P2P1 tetra element has been developed for the large eddy simulation (LES) of turbulent flows around a complex geometry. Fractional 4-step algorithm is employed to obtain time accurate solution since it is less expensive than the integrated formulation, in which the velocity and pressure fields are solved at the same time. Crank-Nicolson method is used for second order temporal discretization and Galerkin method is adopted for spatial discretization. For very high Reynolds number flows, which would require a formidable number of nodes to resolve the flow field, SUPG (Streamline Upwind Petrov-Galerkin) method is applied to the quadratic interpolation function for velocity variables, Noting that the calculation of intrinsic time scale is very complicated when using SUPG for quadratic tetra element of velocity variables, the present study uses a unique intrinsic time scale proposed by Codina et al. since it makes the present three-dimensional unstructured code much simpler in terms of implementing SUPG. In order to see the effect of numerical diffusion caused by using an upwind scheme (SUPG), those obtained from P2P1 Galerkin method and P2P1 Petrov-Galerkin approach are compared for the flow around a sphere at some Reynolds number. Smagorinsky model is adopted as subgrid scale models in the context of P2P1 finite element method. As a benchmark problem for code validation, turbulent flows around a sphere and a MIRA model have been studied at various Reynolds numbers.

• Journal of Chest Surgery
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• v.27 no.2
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• pp.99-113
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• 1994

Pentastarch is a new synthetic hydroxyethyl starch similar to hetastarch. We report on the clinical comparisons the clinical efficacy and safety of 10% pentastarch in prime solutions for CPB in cardiac operations with that of 20% serum albumin. During CPB, group P [n = 20] received 500ml of 10% pentastarch and group A [n = 20] received 100ml of 20% albumin in prime solutions The postoperative time of ICU stay in group P and the day and amount of chest drain, hospital stay in group A were longer [p<0.05]. Fresh whole blood and PRBC were added only in group A and a higher amount of hartman solution was added in group A during CPB [p<0.05]. Prothrombin time was prolonged preoperatively and 2 days postoperatively in group A and 7 days postoperatively in group P [p<0.05] but there were no significant differences in bleeding time or fibrinogen level. Platelet count was higher immediately postoperatively in group A and preoperatively and 1, 2, and 7 days postoperatively in group P [p<0.05].Total protein and albumin level were higher 1 day postoperatively in group A and 2 and 7 days postoperatively in group P [p<0.05]. BUN was increased 2 days postoperatively in group A and Cr was increased 1 day postoperatively in group P [p<0.05]. CPK was higher preoperatively and 1, 2, and 7 days postoperatively in group A and plasma hemoglobin level was also higher 2 and 7 days postoperatively in group A [p<0.05]. There were no significant differences in arterial blood gas analysis but higher pO2 and lower pCO2 levels were maintained in group P and ejection fraction was higher 7 days postoperatively in group P [p<0.05]. Both groups were improved postoperatively in NYHA class and the hemodynamic parameters such as MAP, CO, CI, SV, LVSWI were well maintained in group P [p<0.05]. The amount of blood products used was higher in group A and urine output was higher immediately postoperatively in group A and 1, 2 days postoperatively in group P and the chest output was higher in group A. The complications were developed in 7 patients in group A and 5 patients in group P and mortality was not present in both groups.In conclusion, 10% pentastarch is as safe and effective as 20% albumin in prime solutions for cardiopulmonary bypass in cardiac operations.

• Bulletin of the Korean Mathematical Society
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• v.56 no.2
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• pp.333-349
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• 2019

We give explicitly an average value formula under the multiplication-by-2 map for the x-coordinates of the 2-division points D on the Jacobian variety J(C) of a hyperelliptic curve C with genus g if $2D{\equiv}2P-2{\infty}$ (mod Pic(C)) for $P=(x_P,y_P){\in}C$ with $y_P{\neq}0$. Moreover, if g = 2, we give a more explicit formula for D such that $2D{\equiv}P-{\infty}$ (mod Pic(C)).

• Kyungpook Mathematical Journal
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• v.59 no.1
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• pp.23-34
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• 2019

In this paper, we first define generalizations of Pell and Pell-Lucas sequences by the recurrence relations $$p_n=2ap_{n-1}+(b-a^2)p_{n-2}\;and\;q_n=2aq_{n-1}+(b-a^2)q_{n-2}$$ with initial conditions $p_0=0$, $p_1=1$, and $p_0=2$, $p_1=2a$, respectively. We give generating functions and Binet's formulas for these sequences. Also, we obtain some identities of these sequences.

• Journal of Genetic Medicine
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• v.19 no.2
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• pp.105-110
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• 2022

The microdeletion syndrome of chromosome 2p15p16.1 (MIM: 612513) is an extremely rare contiguous gene deletion syndrome. Microdeletions of varying sizes in the 2p15-16.1 region are associated with developmental delay, intellectual disability, autism spectrum disorder, hypotonia, and craniofacial dysmorphism. Previous studies have identified two critical regions: the proximal 2p15 and distal 2p16.1 regions. BCL11A, PAPOLG, and REL genes play crucial roles in patients with 2p16.1 microdeletion. To our knowledge, only 39 patients have been reported as having 2p15p16.1 microdeletion syndrome. Here, we present another patient with 2p15p16.1 microdeletion syndrome. A nine-month-old boy was referred to our clinic for the psychomotor delay, facial dysmorphism, and congenital hypothyroidism. During his follow-up visits, he was diagnosed with global developmental delay, intellectual disability, abnormal behavior, hypotonia, microcephaly, and abnormal electroencephalography. Using a chromosomal microarray for genetic analysis, a novel, de novo, 622 kb microdeletion of 2p16.1 was identified as one of the critical regions of the 2p15p16.1 microdeletion syndrome. This is the first case of its kind in Korea. We have discussed our case and literature reviews to clarify the relationship between the genes involved and clinical phenotypes in 2p15p16.1 microdeletion syndrome.