• Journal of Korea Water Resources Association
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• v.35 no.6
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• pp.797-805
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• 2002

The EV ROM, a joint reservoir operation model for flood control that accounts for the downstream flow condition, has been introduced in the preceding article (Shin et al, 2000). A joint reservoir operation model computer program for the Geum river basin, developed by FORTRAN Power Station 4.0 using the EV ROM, is hereby presented. Three case studies of flood control by joint operation of the Yongdam and Daechung Multipurpose Dams in the Geum river basin revealed that the performance of the EV ROM was superior to the existing Rigid ROM and Technical ROM. This is because the EV ROM can account for the downstream flow condition as well as the upstream inflow and the reservoir water level. In order to apply for various floods events in the future, consistent improvement of the developed EV ROM and efforts for more accurate rainfall prediction are required.

• Radiation Oncology Journal
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• v.16 no.4
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• pp.357-366
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• 1998

Brachytherapy is an essential part of radiotherapy for uterine cervical cancer. The low dose rate (LDR) regimen has been the major technique of intracavitary therapy for cervical cancer. However, there has been an expansion in the last 20 years of high dose rate (HDR) machines using Ir-192 sources. Since 1979, HDR brachytherapy has been used for the treatment of uterine cervical cancer in Korea. The number of institutions employing HDR has been increasing, while the number of low dose rate system has been constant. In 1995, there was a total 27 HDR brachytherapy units installed and 1258 cases of patients with cervical cancer were treated with HDR Most common regimens of HDR brachytherapy are total dose of 30-39 Gy at point A with 10-13 fractions in three fractions per week. 24-32 Gy with 6-8 fractions in two fractions per week, and 30-35 Gy with 6-7 fractions in two fractions per week. The average fractionation regimen of HDR brachytherapy is about 8 fractions of 4.1 Gy each to Point A. In Korea, treatment results for HDR brachytherapy are comparable with the LDR series and appears to be a safe and effective alternative to LDR therapy for the treatment of cervical carcinoma. Studies from the major centers report the five-year survival rate of cervical cancer as. 78-86$\%$ for Stage 1, 68-85$\%$ for stage 11, and 38-56$\%$ for Stage III. World-wide questionnaire study and Japanese questionnaire survey of multiple institutions showed no survival difference in any stages and dose-rate effect ratio (HDR/LDR) was calculated to be 0.54 to 0.58. However the optimum treatment doses and fractionation schemes appropriate to generate clinical results comparable to conventional LDR schemes have yet to be standardized. In conclusion, HDR intracavitary radiotherapy is increasingly practiced in Korea and an effective treatment modality for cervical cancer. To determine the optimum radiotherapy dose and fractionation schedule, a nation-wide prospective study is necessary in Korea. In addition, standardization of HDR application (clinical, computer algorithms, and dosimetric aspects) is necessary.

• Journal of KIISE:Information Networking
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• v.29 no.2
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• pp.141-155
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• 2002

A medium access control protocol is proposed for integrated voice and data services in the packet CDMA network with a small coverage. Uplink channels are composed of time slots and multiple spreading codes for each slot. This protocol gives higher access priority to the delay-sensitive voice traffic than to the data traffic. During a talkspurt, voice terminals reserve a spreading code to transmit multiple voice packets. On the other hand, whenever generating a data packet, data terminals transmit a packet based on the status information of spreading codes in the current slot, which is received from base station. In this protocol, voice packet does not come into collision with data packet. Therefore, this protocol can increase the maximum number of voice terminals.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.12
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• pp.463-478
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• 2014

Portal site is not only providing search engine and e-mail service but also various services including blog, news, shopping, and others. The fact that average number of daily login for Korean portal site Naver is reaching 300 million suggests that many people are using portal sites. With the increase in number of users followed by the diversity in types of services provided by portal sites, the attack is also increasing. Most of studies of password authentication is focused on threat and countermeasures, however, in this study, we analyse the security threats and security requirement of membership, login, password reset first phase, password reset second phase. Also, we measure security score with common criteria of attack potential. As a result, we compare password authentication system of domestic and abroad portal sites.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.12
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• pp.455-462
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• 2014

In recent years, various services in mobile environments due to the growth of mobile devices and related techniques like wireless networks. Furthermore, as the increasing communication traffic in cellular networks has become a new significant issue, many studies for device-to-device(D2D) communication and D2D-based cooperative services have been performed recently. In this paper, we design a smart agent system for D2D-based cooperative services and propose a dynamic service binding method based on service ontology. We classify roles of mobile devices for cooperative services by defining three types of smart agents, and construct a knowledge base in order to describe properties of 'service' unit. The proposed knowledge model, D2D cooperative service ontology, can enable a autonomous cooperative services between mobile devices by binding a requested service to the appropriate member device according to the real-time context in mobile environments.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.9
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• pp.229-236
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• 2016

In the past, crime prediction methods utilized previous records to accurately predict crime occurrences. Yet these crime prediction models had difficulty in updating immense data. To enhance the crime prediction methods, some approaches used social network service (SNS) data in crime prediction studies, but the relationship between SNS data and crime records has not been studied thoroughly. Hence, in this paper, we analyze the relationship between SNS data and criminal occurrences in the perspective of crime prediction. Using Latent Dirichlet Allocation (LDA), we extract tweets that included any words regarding criminal occurrences and analyze the changes in tweet frequency according to the crime records. We then calculate the number of tweets including crime related words and investigate accordingly depending on crime occurrences. Our experimental results demonstrate that there is a difference in crime related tweet occurrences when criminal activity occurs. Moreover, our results show that SNS data analysis will be helpful in crime prediction model as there are certain patterns in tweet occurrences before and after the crime.

• Journal of Power Electronics
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• v.17 no.6
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• pp.1658-1671
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• 2017

To address the inaccurate load demand sharing problems among parallel inverter-interfaced voltage-controlled distributed generation (DG) units in islanded microgrids (MGs) with different DG power ratings and mismatched feeder impedances, an enhanced voltage control scheme based on the active compensation of circulating voltage drops is proposed in this paper. Using the proposed strategy, reactive power and harmonic currents are shared accurately and proportionally without knowledge of the feeder impedances. Since the proposed local controller consists of two well-separated fundamental and harmonic voltage control branches, the reactive power and harmonic currents can be independently shared without having a remarkable effect on the amplitude or quality of the DGs voltage, even if nonlinear (harmonic) loads are directly connected at the output terminals of the units. In addition, accurate load sharing can also be attained when the plug-and-play performance of DGs and various loading conditions are applied to MGs. The effects of communication failures and latency on the performance of the proposed strategy are also explored. The design process of the proposed control system is presented in detail and comprehensive simulation studies on a three-phase MG are provided to validate the effectiveness of the proposed control method.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.5
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• pp.648-653
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• 2007

Researches on artificial emotion which generates emotion artificially from various external excitations imitating human emotion has been initiated in recent years. But the conventional studies in which the emotion state is changed exponentially or linearly by external emotion excitation have a drawback that the variation of emotion state is changed rapidly and abruptly. In this paper, we propose an artificial emotion generation model which reflects not only strength and frequency of external emotion excitations but also period of it in the emotion state and represents the emotion state with a sigmoid curve w.r.t. time. And we propose an artificial emotion system which generates emotion at the situation of no external emotional excitations through recollection of past emotional excitations, and show its effectiveness through computer simulation results.

• Journal of International Academy of Physical Therapy Research
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• v.10 no.4
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• pp.1914-1920
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• 2019

Background: Mobilization and cranio-cervical flexion exercise has been reported in reducing pain from cervical part and improving its motor function; also, has been represented that alleviate of neck pain and recover of neck muscles improve the normal gait performance. However, few studies have identified the effects of mobilization and exercise on pain and gait parameters with preceding issues. Objective: To examine the effects or changes of pressure pain threshold (PPT) and gait parameters in patients with chronic neck pain. Design: Cross-Sectional Clinical Trials Methods: Twenty patients with the history of neck pain (>3 months) performed the cervical mobilization and cranio-cervical flexion exercise. Gait parameters were assessed with wireless device and collected data were transmitted to the personal computer via Bluetooth. The PPT was measured posteroanterior direction at the prone position and the mean of subsequent three PPT measurements was used for the final analysis. Results: Both cervical central posteroanterior mobilization (CCPAM) (p<.000) and sling-based cranio-cervical flexion exercise (SBCCFE) (p<.000) group showed a significant increase in the PPT and the gait parameters, cadence (p<.023), was significantly increased in the CCPAM group, however slightly increased in the SBCCFE group. The comparison between the CCPAM and the SBCCFE groups after treatment did not show significant differences for the score on the PPT and gait parameters. Conclusions: This study suggests that CCPAM and SBCCFE increase PPT, cadence, and gait speed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.2022-2030
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• 2008

System such as FA and breakup TC is applied by real time and need to manage. This paper studies data processing skill that can divide TC and data of much quantity with collection by real time. Modularize to several system, and use of computer communication network that interlink computers that can achieve control function of each systems to network is spreading. Develop that can take advantage of Ideonet communication method and transmit signal of channel because do multiplex all. Do data that have semi-conductor equipment or many input of LCD equipment and output node multiplex, and several units real time Ideonet communication that control is available use that all input of point of contact and output module develop.