• Journal of the HCI Society of Korea
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• v.2 no.1
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• pp.33-39
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• 2007

Because of the cognitive overload which is caused by the complicated information structure, Digital Convergence product interferes with the effective retrieval of the information from the menu. Two methods have been used to alleviate that cognitive overload by making an effective menu structure; physical menu structure method which is related with the width and depth of the menu, semantic menu structure method which is related with the menu title. In this research, we tried to demonstrate the effectiveness of the menu structure designing method by suggesting a new semantic methodology which uses the Fixation and Fixation duration which are accompanied by the visual search. Because the Fixation is automatically processed by the human cognitive model, we could easily recognize whether the information structure is correspond to the cognitive model or not. From this fact we established the hypothesis that the number of cognitively well established menu structures are fewer than that of the wrongly designed menu structures in terms of the Fixation number and Duration. To verify this hypothesis, we compared the Fixation number and Duration of the modified menu structures with those of the original menu structures by using the Eye-Tracking experiment. As a result, we could find the significant decrease of the Fixation number and Duration after modification. Therefore we could recognize that the modified menu structure was more effective than the original menu structure. In sum, the newly suggested menu structure designing methodology which uses the Fixation and Fixation Duration accompanied by the visual search was proved to be a very effective method.

• The Journal of the Korea Contents Association
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• v.8 no.10
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• pp.20-26
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• 2008

The quality of stream remaking is decided the load of a server and Jitter through the traffic of the transmission path between end to end. In order to improve these problems in this paper, I propose tree construction method of low-delay-level-multicast. In this case which the network congestion will be occurred by streaming quality, I also propose the technique which dynamically changes the transmission path. This technique first constructs the overlay structure for relaxing the overload of server. Secondly, in order to decrease Jitter of client, it makes upload bandwidth and low latency balanced. In the evaluation of the performance, this paper showed better enhancement of about $15%{\sim}24%$ than P2CAST[4] in the simulation about node average join count, average bandwidth, service request refusal ratio, RTT measurement of nodes, and node average join count by defect ratio.

• Journal of KIISE:Computer Systems and Theory
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• v.37 no.6
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• pp.339-347
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• 2010

Inter-process communication (IPC), which is a technique that enables exchanging data among multiple processes, is commonly used not only in user applications but also in system processes. For this reason, the performance of IPC highly influences the performance of whole computer system. Especially, heavy overload on a single server process caused by IPC requests from multiple client processes, easily results overall slowdown of IPC response time. Here, to deal with the problem stated above, the time-slice donation technique which is adapted in L4 microkernel is analyzed and enhanced for reducing latency of IPC response time and implemented on linux kernel for actual performance evaluation. While trying to maintain the additional overhead as least as possible, the experiment shows that the use of this technique enhances the performance of IPC multiple times of existing technique under certain circumstances.

• Journal of Korean Society of Steel Construction
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• v.11 no.2 s.39
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• pp.213-222
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• 1999

Elastic-plastic methods have been used for the better prediction of the actual behavior of continuous-composite plate girder bridges in the overload and maximum load analysis. The structural evaluation using ALFD(Alternate Load Factor Design) uses the elastic-plastic analysis. The plastic rotations that remain after the load is removed can be occurred by the yielding locations of the maximum moment section. This situation can occur due to the residual stresses even if the moment is below the theoretical yield moment. The local yielding causes positive automoments that assure elastic behavior under subsequent overloads. In this study, the automoments at the piers occurred due to the unit plastic rotations and other locations were calculated by the conjugate-beam method and three-moment equation, using the nine design span with progressively smaller pier sections. The automoments were determined by the developed computer programs in this study in which the moments and plastic rotations from the continuity and moment-inelastic rotation relationships must be equal. And also the ratings of 3-span continuous composite plate girder bridges with non-compact section were carried out according to the Korean Highway Bridge Specification.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.6
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• pp.75-84
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• 2014

In order to solve the problems such as overload, single point of failure, non-optimized data path, and network scalability in conventional central mobility management protocols, distributed mobility management schemes have been continually studied in and around the IETF. In this paper, a network-based partially-distributed mobility management mechanism, pDMMv6, is suggested and the performance comparison with traditional protocols such as PMIPv6 and MIPv6 is made through simulation under the various user traffic environment. The simulation results include UDP packet delivery ratio, end-to-end packet delay, binding delay for registration signaling, CPU utilization in each node, and response delays in several server-client TCP applications such as web browsing, e-mail, telnet remote login, FTP file up/down-load, and database access.

• Spatial Information Research
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• v.20 no.1
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• pp.59-69
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• 2012

For the USN(Ubiquitous Sensor Network) environment which generally uses spatial sensor data as well as aspatial sensor data, a sensor database system to manage these sensor data is essential. In this reason, some sensor database systems such as TinyDB, Cougar are being developed by many researchers. However, since most of them do not support spatial data types and spatial operators to manage spatial sensor data, they have difficulty in processing spatial sensor data. Therefore, this paper developed a spatial sensor database system by extending TinyDB. Especially, the system supports spatial data types and spatial operators to TinyDB in order to manage spatial sensor data efficiently and provides the memory management function and the filtering function to reduce the system overload caused by sensor data streams. Lastly, we compared the processing time, accuracy, and memory usage of the spatial sensor database system with those of TinyDB and proved its superiority through the performance evaluation.

• Journal of IKEEE
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• v.18 no.4
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• pp.442-446
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• 2014

A method for applying emergency ratings to improve the reliability of power supply in ACSR overhead transmission lines is described in this paper. Due to re-regulate power industry, most power companies worldwide as well KEPCO have been searching for only economical strategies without new investment. Power demand was rapidly increasing, however, generation amount did not follow sufficiently. Hence in order to increase the transmission capacity for the existing transmission lines in case of peak load, or contingency in transmission lines, an application method of emergency ratings such as short or long term rating is proposed. If applying long term emergency rating instead of static line rating for the period of a peak load, power transmission can be increased to 10 % or more. Furthermore, it was shown that emergency rating can be effectively used in the contingency of double-circuit transmission lines and/or overload cases.

• Journal of IKEEE
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• v.22 no.3
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• pp.733-737
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• 2018

In this paper, we describe the effects on the power system by adding renewable generator. In order to examine the stability of the system, the system analysis was performed using the PSS/E software. We confirmed whether occur the line overload of system through the load flow analysis and contingency analysis. and confirmed whether exceed of fault current using the fault current analysis. Dynamic stability of the system is analyzed through dynamic simulation. The analysis of the system according to the addition of the renewable generator was carried out according to the power system reliability and electricity quality maintenance standard.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.5967-5970
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• 2015

Background: The prevalence of prostate cancer is considered high in many countries, and screening tests are very important in order to detect prostate cancer in its early stages; however false positivity with these screening tests means that a lot of patients undergo unnecessary biopsy, which is an invasive procedure, for the confirmatory test. The purpose of this study was to estimate the frequency of unnecessary biopsy cases in patients referred for prostate biopsy in one of the most important and overload cancer centers in Syria. Materials and Methods: Retrospective data for a period of four years between January 2009 and December 2012 were collected in Al-Bayrouni University Medical hospital in Damascus, Syria. The patients from whom data were collected were referred to our histopathological department because of elevated prostate specific antigen (PSA) serum or an abnormal digital rectal examination (DRE). All patients underwent prostatic TRUS-guided biopsies. Diagnosis of prostate cancer (PCa) or benign prostatic hyperplasia (BPH) was based on histopathological examination and prostate cancers cases were graded and scored according to the Gleason score system. Results: For the 406 patients referred to biopsy, the $mean{\pm}SD$ age was $58.4{\pm}23.3$ years. The $mean{\pm}SD$ PSA level was $49.2{\pm}21.5ng/ml$. Of the total we found 237 patients diagnosed with PCa (58. 4%), 166 patients with BPH (40.9%) and 3 cases were unable to be diagnosed (0.7%) because of biopsy collection errors. Conclusions: Our study shows that a high percentage of patients are undergoing unnecessary biopsy, which suggests that the performed screening tests had a high level of false positive and may need re-evaluation.

• The Transactions of the Korea Information Processing Society
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• v.6 no.6
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• pp.1581-1589
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• 1999

In B-ISDN(Broadband Integrated Services Digital Networks), the efficient implementation of multicast function is very important since the demand for distributed type of service such as VOD(Video On Demand) system is expected to grow. In this paper, the multicast performance characteristics of fully-interconnected switch fabric used for our research is the proper architecture for a small-sized switch element, and it uses bit addressing method for addressing scheme and thus it is easy to implement multicast function without adding a function block. To incorporate the bursty nature of traffic in ATM networks, we used IBP(Interrupted Bernoulli Process) model as an input traffic model. We presented and analyzed the simulation results in terms of the multicast operation of the switch. Based. on this study, it its analyzed that congestion avoidance may be feasible if we use a proper traffic control scheme by finding an overload point due to multicast.