• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.08a
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• pp.103-106
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• 2003

In this study, an ultrasonic transducer is fabricated with 1-3 type composite resonators. Pulse-echo responses of an ultrasonic transducer are investigated in underwater dependent on the variable designated water-level. LED Output signals of a level limit with changing a water level is obtained by the 1-3 type self-made composite transducer and electric measuring unit. LED is turned on at above the up-limit level with increasing a water level, and LED is turned on at less than the down-limit level with decreasing a water level. There was good agreement between the virtual water level and output LED signal by using the self-made water-detecting system.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.771-773
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• 2007

미국의 텍사스 A&M 대학의 Damon Holzer교수가 개발한 Elevation buffbyrise 프로그램을 이용하여 여주대교부근의 가상홍수범람지역을 산정하였다. 하도 buffering기법을 이용하여 얻어진 가상홍수범람지역은 제방의 홍수범람제어 기능과 물의 흐름특성을 고려하기 어렵기 때문에 홍수범람지역이 과도하게 산정되었을 것으로 판단되지만 단시간에 홍수범람피해지역을 추정할 수 있으므로 침수예상지역에 대한 주민대피계획을 수립하고 대처할 수 있을 것으로 판단된다.

• Radiation Oncology Journal
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• v.22 no.3
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• pp.225-233
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• 2004

Purpose: The Ideal breast irradiation method should provide an optimal dose distribution In the treated breast volume and a minimum scatter dose to the nearby normal tissue. Physical wedges have been used to Improve the dose distribution In the treated breast, but unfortunately Introduce an Increased scatter dose outside the treatment yield, pavllculariy to the contralateral breast. The typical physical wedge (FW) was compared with 4he virtual wedge (VW) to do)ermine the difference In the dose distribution affecting on the treated breast and the contralateral breast, lung, heart and surrounding perlpheral soft tissue. Methods and Materials: The data collected consisted of a measurement taken with solid water, a Humanoid Alderson Rando phantom and patients. The radiation doses at the ipsllateral breast and skin, contralateral breast and skin, surrounding peripheral soft tissue, and Ipsllateral lung and heart were compared using the physical wedge and virtual wedge and the radiation dose distribution and DVH of the treated breast were compared. The beam-on time of each treatment technique was also compared Furthermore, the doses at treated breast skin, contralateral breast skin and skin 1.5 cm away from 4he field margin were also measured using TLD in 7 patients of tangential breast Irradiation and compared the results with phantom measurements. Results: The virtual wedge showed a decreased peripheral dose than those of a typical physical wedge at 15$^{\circ}$, 30$^{\circ}$, 45$^{\circ}$, and 60$^{\circ}$. According to the TLD measurements with 15$^{\circ}$ and 30$^{\circ}$ virtual wedge, the Irradiation dose decreased by 1.35$\%$ and 2.55$\%$ In the contralateral breast and by 0.87$\%$ and 1.9$\%$ In the skin of the contralateral breast respectively. Furthermore, the Irradiation dose decreased by 2.7$\%$ and 6.0$\%$ in the Ipsllateral lung and by 0.96$\%$ and 2.5$\%$ in the heart. The VW fields had lower peripheral doses than those of the PW fields by 1.8$\%$ and 2.33$\%$. However the skin dose Increased by 2.4$\%$ and 4.58$\%$ In the Ipsliateral breast. VW fields, In general, use less monitor units than PW fields and shoriened beam-on time about half of PW. The DVH analysis showed that each delivery technique results In comparable dose distribution in treated breast. Conclusion: A modest dose reduction to the surrounding normal tissue and uniform target homogeneity were observed using the VW technique compare to the PW beam in tangential breast Irradiation The VW field is dosmetrically superlor to the PW beam and can be an efficient method for minimizing acute, late radiation morbidity and reduce 4he linear accelerator loading bV decreasing the radiation delivery time.

• The Korean Journal of Food And Nutrition
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• v.36 no.1
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• pp.69-85
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• 2023

Sustainable and healthy diet is a challenge in recent world. Despite the global depletion of water resources, Korea has no system for controlling its water footprint. This study established the water footprint tables of Korean food using the Water Footprint Network databases, and applied them into two meal plans for 19~64 year-old adults recommended in the Dietary Reference Intakes for Koreans 2020. Nut, oil, and meat's water footprints were higher and those of fruit and vegetable were lower. Sesame oil had the highest water footprint of 21,793 L/kg and pineapple had the lowest domestic water footprint of 102 L/kg. Water footprint of one serving size of beef was 925 L, that of chicken was 260 L, and those of soybean were 43 L in global and 81 L in domestic. The water footprint of the recommended 2,400 kcal meal plan was 2,882 L, and that of 1,900 kcal meal plan was 1,915 L. The water resources can be saved by choosing food with lower water footprint. The results of this study can be used in the further researches for more sustainable and healthier Korean diet.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.770-771
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• 2011

발전사업자는 한국전력거래소(KPX)의 급전지령을 원활히 수행하기 위해 EMS(Energy Management System) RTU를 설치하고 있다. 한국수자원공사는 수력발전소에 전기판넬 형식의 EMS RTU 대신 컴퓨터 기반의 가상(Virtual) EMS RTU를 설치하여 기존의 RTU방식에 비하여 설비 면적을 대폭 줄였으며, 설비 변동에 따른 감시제어 데이터의 수정시 하드웨어적인 작업을 소프트웨어적으로 간단하게 처리할 수 있다. 그래서 가상 EMS RTU는 발전통합운영시스템(GIOS)을 실시간으로 운영, 감시하여 장애를 신속히 복구함으로써 중앙급전소 발전기 원격운전 응답 특성을 향상시켜 전력계통의 안정적인 운영에 크게 기여하고 있다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.292-295
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• 2003

In this study, an ultrasonic transducer is fabricated with 1-3 type composite resonators. Pulse-echo responses of an ultrasonic transducer are investigated in underwater dependent on the variable designated water-level. LED Output signals of a level limit with changing a water level is obtained by the 1-3 type self-made composite transducer and electric measuring unit. LED is turned on at above the up-limit level with increasing a water level, and LED is turned on at less than the down-limit level with decreasing a water level. There was good agreement between the virtual level and output LED signal by using the self-made water-detecting system.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.5
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• pp.555-560
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• 2013

A cost analysis method for pretreament processes of a large scale seawater desalination plant was considered using a cost estimation model, WaTER (Water Treatment Estimation Routine). This model is based on cost functions of U.S. EPA to conduct economic analysis of water treatment facilities. A virtual seawater desalination plant which has pretreatment production capacity of $100,000m^3$ per day was chosen as a model plant. Dual media filtration and microfiltration systems were compared as pretreatment process, and the following reverse osmosis process was modeled. As a result, microfiltration showed a price competitiveness in condition of operating with reverse osmosis process by reducing the loads of water treatment and membrane cleaning despite it's high annual cost.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.4
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• pp.125-130
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• 2011

This paper investigates the possibility of exploiting haptic force-feedback technology for interacting with Nanta music. We use VR technologies including touch processing technologies and haptic devices to offer touch of cylinder objects and cup object to users. Haptic device is used to implement touch model in VR space. Matlab/Simulink and proSENCE Virtual Touch Toolbox of Handshake Inc. for experiment, are used as programing tools. Function needed to describe the movement of x, y, and z axis respectively are applied to delineate the natural movement of water in cup object modeled with 3D. A certain amount of water in cup object has the difference of sounds. In experiment, to perceive the appearance of 3D object by touch and to feel the tactile by touch are conducted with the effect of sound on Haptic perception. We also verify that it is possible to develop games or contents in VR space by using point.

• Journal of the Korean Geotechnical Society
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• v.16 no.4
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• pp.191-199
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• 2000

In this research, the finite element analysis of piezocone penetration and dissipation tests has been conducted using the anisotropic elastoplastic-viscoplastic bounding surface model, virtual work equation, and theory of mixtures formulated in the Up[dated Lagrangian reference frame for the large deformation and finite strain nature of piezocone penetration. The formulated equations have been implemented into a finite element program. The cone resistance, excess pore water pressure, and dissipation of excess pore water pressure from the finite element analysis have been compared and investigated. An effective simulation could be performed with the use of the anisotropic and viscous soil model. The finite element formulations and the results are described in part 'I' and part 'II' respectively.

• Water for future
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• v.14 no.4
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• pp.27-34
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• 1981

The design flow of the urban strom drainage systems has been assessed largely on a basis of empirical relations between rainfall and runoff, and the rational formula has been widely used for the cities in our country. In order to estimate it more accurately, the urban runoff simulation model based on the RRl method has been developed and applied to the sample basin in this study. The rainfall hyetograph of the design stromfor the design flow has been obtained by the determination of the total rainfall and the temporal distributions of that rainfall. The total rainfall has been assessed from the empirical formula of rainfall intensity and the temporal distribution of that rainfall determined on the basis of Huff's method from the historical rainfall data of the basin. The virtual inflow hydrograph to each inlet of the basin has been constructed by computing the series of discharges in each time increment, using design strom hyetograph and time-area diagram. The actual runoff hydrograph at the basin outlet has been computed from the virtual inflow hydrographs by developing a relations between discharge and storage for the watershed. The discharge data for verification of the simulated runoff hydrograph are not available in the sample basin and so the sensitivity analysis of the simulation model has not been possible. The peak discharge for the design of drainage systems has been estimated from the computed runoff hydrograph at the basin outlet and compared to thatl obtained form the rational formula.