• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3074-3079
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• 2007

The conventional control valves have been used at the locations occurring high differential pressure and high temperature which causes cavitation, flashing, severe vibration due to abrupt flow change, and sudden pressure drop. Previous studies concerning control valves focused to prevent damage of valve trim due to the internal leak and low flow rate. The newly designed helical trim of control valve has been installed at the location of high pressure change and high temperature in a power plant, and operated for evaluation. It is confirmed that the new control valve developed in this study generates flow characteristics in comparison with previous helical trim of control valves.

• Korea Journal of Hospital Management
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• v.27 no.1
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• pp.43-57
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• 2022

Background: Avoidable mortality rate has been widely used as an indicator of the quality of health care and the degree of inequality in health levels. The purpose of this study was to identify the factors affecting the avoidable mortality rate in the region. Methods: The data was MDIS(Microdata Integrated Service) Causes of Death Statistics, and the analysis period was from 2010 to 2019. Panel analysis was performed to identify the influencing factors on the avoidable mortality rate. Findings: Result showed that the current smoking rate had a significant positive effects on the avoidable mortality rate of both men and women. And the smoking cessation trial rate, low salt diet rate, weight control trial rate, annual vaccination rate had a significant negative effect. In the social environment, the divorce rate had a significant positive effect. In the economy environment, financial independence and social welfare budget rate had a significant negative effect. In the physical environment, the factory area rate had a significant positive effect. Practical Implication: Practical implication in order to lower the local avoidable mortality rate, various social determinants of health as well as health care resources should be considered together.

• The Journal of the Korean bone and joint tumor society
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• v.15 no.2
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• pp.104-110
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• 2009

Purpose: Compared to soft tissue sarcoma, the relative risk of extraskeletal osteosarcoma is still not clear. The purpose of this study is to identify the difference in survival and local recurrence rate between two soft tissue sarcomas. Materials and Methods: Twelve patients with pathologically confirmed extraskeletal osteosarcoma were analysed. For retrospective matched case-control study, we selected 72 patients who were confirmed as high grade soft tissue sarcoma and had similar tumor location, tumor size and age to extraskeletal osteosarcoma. Results: Median age was 50 years old. Five cases were located in upper extremity, four in the buttocks, three in the lower extremity. Overall survival rate of extraskeletal osteosarcoma group and high grade soft tissue sarcoma group at 5 years were 52% and 55%. There is no significant difference (p=0.8). Local recurrence rate and metastasis rate were 58%, 67% in extraskeletal osteosarcoma group and 36%, 51% in soft tissue sarcoma group, which were not stastistically significant(p=0.2, p=0.4). Conclusion: Extraskeletal osteosarcoma have similar local recurrence, metastasis and survival rate compare to high grade soft tissue sarcoma. The number of patients of this study were too small to identify outcome of extraskeletal osteosarcoma. Further multi-institutional study should be attempted.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.7
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• pp.1-8
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• 2004

A simple AMC (Adaptive Modulation and Coding) technique using ARQ (Automatic Repeat Request) for a MIMO (Multiple Input Multiple Output) system is proposed which does not require the additional feedback. In addition, the proposed AMC technique is different from the conventional technique in the aspect of considering the MCS (Modulation and Coding Scheme) level from the previous packet. The proposed technique can discard fewer amounts of unsuitable packets than the conventional technique. In the proposed system not only same rate control method for transmit antennas but also individual rate control method can be applied. The performance of the proposed technique is verified under a MIMO-OFDM (Orthogonal Frequency Division Multiplexing) system based on WLAN (Wireless Local Area Network), IEEE 802.11a. The results of the computer simulation show that a MIMO system with the proposed technique achieves higher throughput than one with a fixed transmission rate.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.150.2-150
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• 2001

For pneumatic system control, we need a data transmission system with high speed and reliability for information interchange between main computer and I/O devices. This paper presents a set of design techniques for a data communication system that is mainly used for pneumatic system control. For this purpose, we first designed hardware modules for an interface between central control module and local node that handles the operation of solenoid valves. In addition, we developed a communication protocol for construction of RS-485 based multi-drop network, and this protocol is basically designed with a kind of polling technique. Finally we evaluated performance of the developed system. The field test results show that, even under high noise environment, the data transmission of 375Kbps rate is ...

• Journal of Power Electronics
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• v.17 no.6
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• pp.1650-1657
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• 2017

In this study, the distributed secondary voltage control of islanded microgrids with multi-agent consensus algorithm is investigated. As an alternative to a time-triggered approach, an event-triggered scheme is proposed to reduce the communication load among inverter-based distributed generators (DGs). The proposed aperiodic control scheme reduced unnecessary utilization of limited network bandwidth without degrading control performance. By properly establishing a distributed triggering condition in DG local controller, each inverter is only required to send voltage information when its own event occurs. The compensation of voltage amplitude deviation can be realized, and redundant data exchange related to fixed high sampling rate can be avoided. Therefore, an efficient use of communication infrastructure can be realized, particularly when the system is operating in steady state. The effectiveness of the proposed scheme is verified by simulations on a microgrid test system.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.20
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• pp.8987-8992
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• 2014

Background: The efficacy of concurrent chemoradiotherapy in the treatment of locally advanced cervical cancer is well established. We aimed to investigate the long-term efficacy of definitive concurrent chemoradiotherapy for cervical cancer in the University of Malaya Medical Centre. Materials and Methods: A cohort of 60 patients with FIGO stage IB2-IVA cervical cancer who were treated with definitive concurrent chemoradiotherapy with cisplatin followed by intracavitary brachytherapy or external beam radiotherapy (EBRT) boost between November 2001 and May 2008 were analysed. Patients were initially treated with weekly intravenous cisplatin ($40mg/m^2$) concurrent with daily EBRT to pelvis of 45-50Gy followed by low dose rate brachytherapy or EBRT boost to tumour. Local control rate, progression free survival, overall survival and treatment related toxicities graded by the RTOG criteria were evaluated. Results: The mean age was 56. At the median follow-up of 72 months, the estimated 5-year progression-free survival (PFS) (median PFS 39 months) and the 5-year overall survival (OS) (median OS 51 months) were 48% and 50% respectively. The 5-year local control rate was 67.3%. Grade 3-4 late gastrointestinal and genitourinary toxicity occurred in 9.3% of patients. Conclusions: The 5-year PFS and the 5-year OS in this cohort were lower than in other institutions. More advanced stage at presentation, longer overall treatment time (OTT) of more than fifty-six days and lower total dose to point A were the potential factors contributing to a lower survival.

• Radiation Oncology Journal
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• v.11 no.1
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• pp.127-132
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• 1993

Total of 53 patients of unresectable and recurrent rectal cancer treated with neutron beam during the period from Oct.1987 to Apr.1992 were analyzed. Dose fractionation for the neutron only group was 1.5 Gy per fraction,3 fraction per week,21 Gy/41/2 wks for 42 patients out of 53 ($76{\%}$). Neutron only but modified fractionation schedule ($10{\%}$ more or less of total dose) was applied for 9 patients, and mixed beam (neutron boost) was for 4 patients, Complete tumor response was obtained in 40 patients ($76{\%}$, response rate). Local control rate was 28 out of 53 ($53{\%}$). Statistically significant better prognostic factors for local control were age below 49 years old (15/22, $68{\%}$) than above 50 years old (13/31, $42{\%}$), male (20/32, $63{\%}$) than female (8/21, $38{\%}$), tumor size less than 5 cm and non-metastatic (16/24, $67{\%}$) than size more than 5 cm or metastatic (12/29, $41{\%}$). Major complication had developed in 7 patients ($13{\%}$). Two year overall survival rate by Kaplan-Meier method was $30{\%}$, but it was rised to, $47{\%}$ when the turner was less than 5 cm non-metastatic.

• Korean Journal of Head & Neck Oncology
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• v.4 no.1
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• pp.29-34
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• 1988

Radiation therapy is generally considered to be the treatment of choice in $T_1$ glottic cancer, maninly because of preservation of voice function and its local control rate is comparable to that of surgery. Failures from radiation therapy can be ultimately salvaged by surgery. A retrospective analysis of the treatment of 25 patients with $T_1$ glottic cancer seen at the Yonsei Cancer Center from 1980 to 1984 is presented. Radiation dose to the target volume varied from 6400 to 7000 cGy in 6-7 weeks. The local control rate is 84%. Four patients had primary failure and three of these patients had salvage surgery. Of the 3 patients who had salvage surgery, 2 were cured and aonther one was died with progression of the disease. 5-year acturial and disease free survival rate are 91.1%,78.0% respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3644-3653
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• 2011

This study proposes the automation of disinfection process in water treat plant to reach target effluent chlorine concentration rate according to chlorine consumption rate by varying travel time. Hydraulic analysis about the process and local facility was surveyed first and the program for automatic operation was developed to solve current problem, whose applied result was presented and proved to be better than present controller. Especially using multi variable process algorithm, the correlation coefficient is analyzed between environment factor and reaction time, and process control prove to be stable through model estimation with optimal control input.