• The Korean Journal of Nuclear Medicine
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• v.29 no.3
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• pp.328-331
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• 1995

$^{99m}Tc$ labeled PnAO(propylene amine oxime) derivatives have been widely studied as brain perfusion agents. We synthesized and characterized a PnAO derivative, (RR/SS/ meso)-4,8-diaza-3,9-dimethylundecane-2, 10-dione bisoxime(PRODD). Proton-NMR spectroscopy and thin layer chromatography(silica gel) were performed for its characterization. PRODD was labeled with $^{99m}Tc$ using stannous chloride as reducing agent. The labeling efficiency was determined to be about 85%. Brain uptakes of $4.16{\pm}0.42$ %ID/g and $3.24{\pm}0.13$ %ID/g were found after 10min and 30min after intravenous injection. Brain-to-blood ratios were 1.17 and 0.75 at 10 and 30 minutes, which were lower than 1.3 and 1.9 of the ratios with commercial ${\pm}$-HMPAO. Autoradiographs of rat brain sections showed the gray matter to white matter ratios of $1.13{\pm}0.10$ at 30 min after intravenous injection, which was lower than $1.94{\pm}0.19$ of commercial $^{99m}Tc$-HMPAO. With the above findings, we concluded that the lipophilic $^{99m}Tc$-PRODD complex was able to cross the blood-brain barrier, however the complex showed lower uptake than $^{99m}Tc$-HMPAO in mouse or rat brains. We could suggest possibility that PRODD could be used as another $^{99m}Tc$ chelator.

• Radiation Oncology Journal
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• v.23 no.1
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• pp.17-21
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• 2005

Purpose : To evaluate the voices of irradiated patients with early glottic carcinoma and to compare these with the voices of healthy volunteers. Materials and Methods : The voice samples (sustained vowel) of seventeen male patients who had been irradiated for T1a glottic squamous carcinoma at least 1 year prior to the study were analyzed with objective voice analyzer (acoustic voice analysis, aerodynamic test, and videostroboscopic analysis) and compared with those of a normal group of twenty age- and sex-matched volunteers. Average fundamental frequency, jitter, shimmer, and noise-to-harmonic ratio were obtained for acoustic voice analysis. Maximal phonation time, mean flow rate, intensity, subglottic pressure, glottal resistance, glottal efficiency, and glottal power were obtained for aerodynamic test. Results : The irradiated group presented higher values of shimmer in acoustic voice analysis. There was no significant difference between two groups in other parameters. Conclusion : In this study all the objective voice parameters except shimmer were no4 significantly different between the irradiated group and the control group. These results suggest that the voice quality is minimally affected by radiation therapy for 71 a glottic carcinoma.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.7
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• pp.900-905
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• 2016

The field of power system harmonics has been receiving a great deal of attention recently. This is primarily due to the fact that non-linear (or harmonic-producing) loads comprise an ever-increasing portion of what is handled at a typical industrial plant. The incidence rate of harmonic-related problems is low, but awareness of harmonic issues can still help increase offshore power plant system reliability. On the rare occasion that harmonics become a problem, this is either due to the magnitude of harmonics produced or power system resonance. This harmonic study used an electrical configuration for the offloading scenario of a Floating LNG (FLNG) unit, considering power load. This electrical network configuration is visible in the electrical network load flow study part of the project. This study has been carried out to evaluate the performance of an electric power system, focusing on the harmonic efficiency of an electrically driven motor system to ensure offshore plant safety. In addition, the design part of this study analyzed the electric power system of an FLNG unit to improve the safety of operation and maintenance.

• Journal of Korean Society of Archives and Records Management
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• v.18 no.1
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• pp.129-154
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• 2018

It is time to prepare for the imminent development from the field of records management through decentralization to the records management of the new age in accordance with the flow of decentralization. To overcome a centralized record management system, more archives should be established to realize autonomous and decentralized records management. In accordance with the shift to a full-scale electronic record management environment, the appropriateness and effectiveness of the three-phase system of processing-archival-permanent record management based on physical transfer should be reviewed in terms of transfer cost and work efficiency. The archives should function as institutional archives to carry out the continuous volume record management and the autonomous record management at the institution level. This study examined the possibilities and implications of the archives to expand their functions as archives of institutions for the decentralization of record management and information governance orientation. In addition, the study diversified the types of records management institutions as a way to accomplish this and determined a way to design the functions of archives that integrate the current-end-end-end records management. At each level, institutions should set up archives based on their circumstances and aim at information governance at the level of each archive. Moreover, each archive level should establish a horizontal network to govern record information management.

• Solar Energy
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• v.15 no.3
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• pp.3-14
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• 1995

The Direct Contact heat Exchanger(DCHX) has been widely studied in the chemical industry for many years due to its inherent simplicity as a counter-current divice for heat and mass transfer. In many solar systems, the DCHX unit can be combined with the thermal storage unit, or alternatively, it can be used separately from the storage unit, much like an external(to storage) closed heat exchanger system. In the present work, the spray column type of direct contact heat exchangers are studied extensively to harness the solar energy for hot water and spaced heating. Some of the major considerations that are involved in the design of heat exchangers in this study are that : working fluid is a hydrocaabon(such as Texaterm) or water which is either lighter or heavier than storage medium. The experimental data have revealed some interesting characteristics concerning the application of DCHXs for solar energy utilization. These experiments are carried out in the line of solar heating system, major results are as follows : 1) the flow and aspect of working fluid drop for maxium heat transfer 2) efficiency and volumetric heat transfer coefficient of D.C.H.X with a heavier working fluid are higher than those of D.C.H.X with a lighter working fluid.

• Journal of Korean Society on Water Environment
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• v.28 no.5
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• pp.743-753
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• 2012

The hydrologic models, capable of simulating groundwater recharge for long-term period and effects on it of crops management in the agricultural areas, have been used to compute groundwater recharge in the agricultural fields. Among these models, the Soil and Water Assessment Tool (SWAT) has been widely used because it could interpret hydrologic conditions for the long time considering effects of weather condition, land uses, and soil. However the SWAT model couldn't represent the spatial information of Hydrologic Response Unit (HRU), the SWAT HRU mapping module was developed in 2010. With this capability, it is possible to assume and analyze spatio-temporal groundwater recharge. In this study, groundwater recharge of rate for various crops in the Mandae stream watershed was estimated using SWAT HRU Mapping module, which can simulate spato-temporal recharge rate. As a result of this study, Coefficient of determination ($R^2$) and Nash-Sutcliffe model efficiency (NSE) for flow calibration were 0.80 and 0.72, respectively, and monthly groundwater recharge of Mandae watershed in Haean-myeon was 381.24 mm/year. It was 28% of total precipitation in 2009. Groundwater recharge rate was 73.54 mm/month and 73.58 mm/month for July and August 2009, which is approximately 18 times of groundwater recharge rate for December 2009. The groundwater recharges for each month through the year were varying. The groundwater recharge was smaller in the spring and winter seasons, relatively. So, it is necessary to enforce proper management of groundwater recharge during droughty season. Also, the SWAT HRU Mapping module could show the result of groundwater recharge as a GIS map and analyze spatio-temporal groundwater recharge. So, this method, proposed in this study, would be quite useful to make groundwater management plans at agriculture-dominant watershed.

• Elastomers and Composites
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• v.49 no.3
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• pp.181-190
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• 2014

Melt grafting of itaconic acid (IA) onto an ethylene-propylene-diene terpolymer (EPDM) with various organic peroxide initiators was performed. Finding the optimum mixing conditions and concentration of ingredients is critical for effective grafting and optimum properties of grafted materials. This study focused on the effects of mixing conditions (temperature and time), initiator type/concentration and monomer concentration on the grafting degree and efficiency, melt flow index, and gel content of EPDM-g-IA. The initiator, 2,5-dimethyl-2,5-di(tert-butyl peroxy)-hexane (T-101), appeared to meet for the best grafting degree (1.91%). The grafting degree increased markedly by increasing the amounts of monomer IA and initiator T-101. The grafting degree also increased by increasing mixing temperature and time. The optimum monomer and initiator concentrations and reaction temperature and time were found to be about 5wt%/0.05wt% and $160^{\circ}C$/15min, respectively. It was found that the physical properties of EPDM-g-IA were higher than those of the pristine EPDM.

• Journal of Korea Water Resources Association
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• v.53 no.spc1
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• pp.813-826
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• 2020

This study analyzes the effects of the Smart Water City (SWC) project that was introduced from 2014 to 2016 in Paju City, Gyeonggi Province, Korea, focusing on the achievement of the business goals. The SWC is referred to as a city that embraces a healthy water supply system based on Smart Water Management (SWM) that promotes the efficiency of water management by combining Information and Communication Technologies (ICTs) with water and sewerage facilities. In order to evaluate the effectiveness of the SWC project, this study deploys evaluation criteria corresponding to the project objectives, and analyzes the outputs before and after the project. The results show that the SWC has contributed to enhancing water supply services and the reliability and drinking rate of tap water. Specific improvement areas include the rise of average water flow rate and water leakage reduction, the diffusion of water quality monitoring system, and the reduction of floating particle concentration and turbidity in drainage pipes was achieved. These were possible because of specific implementation plans for clear goal setting and achievement and active services for citizens. The data related to water quantity and quality showed improved performance compared to before the introduction of SWMS, which is a positive effect. However, a quantitative analysis of the outputs has limitations in identifying other external factors that have led to the changes. In the future, guidelines for spreading SWC and more comprehensive and specific evaluation indicators for SWC should be prepared, and SWMS should be developed in consideration of the needs of users.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.733-737
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• 2008

Construction supply chain management focused on materials in construction industry plays a critical role which controls the success and failure of a project. For the efficiency of construction supply chain management, the framework which provides project participants with the information originated from whole construction logistics steps without the omission and discontinuation of information flow is required. The new management framework that can support this environment is necessary because of setting up the complicated and distributed environment including logistics information management by intelligent equipment, co-working management with pre-framework legacy system and various devices(UMPC and PDA etc.) as the information confirmation and electrical transmission tool between the project participants different from former construction supply chain management environment while recently developing ubiquitous technologies such as RFID/USN and intelligent equipment to support logistics process. Therefore, the objective of this study is to introduce the concept of SOA (Service Oriented Architecture) as an alternative of effective information integration under the complex and distributed environment and to propose the SOA-based application model for building intelligent construction supply chain management framework.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.2
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• pp.121-131
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• 2007

Despite the close linkage in changes between the ecological and hydrological processes in forest ecosystems, an integrative approach has not been incorporated successfully. In this study, based on the vegetation and hydrologic data of the Gwangneung headwater catchment with the Geographic Information System, we attempted such an integrated approach by employing the Regional Hydro-Ecologic Simulation System (RHESSys). To accomplish this, we have (1) constructed the input data for RHESSys, (2) developed an integrated calibration system that enables to consider both ecological and hydrological processes simultaneously, and (3) performed sensitivity analysis to estimate the optimum parameters. Our sensitivity analyses on six soil parameters that affect streamflow patterns and peak flow show that the decay parameter of horizontal saturated hydraulic conductivity $(s_1)$ and porosity decay by depth (PD) had the highest sensitivity. The optimization of these two parameters to estimate the optimum streamflow variation resulted in a prediction accuracy of 0.75 in terms of Nash-Sutcliffe efficiency (NSec). These results provide an important basis for future evaluation and mapping of the watershed-scale soil moisture and evapotranspiration in forest ecosystems of Korea.