• Title/Summary/Keyword: Lee Sam

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Development of electrochemical biosensor for determination of galactose (4갈락토오즈 측정을 위한 전기화학적 바이오센서 개발)

  • Park, Kap Soo;Cho, Soon Sam;Quan, De;Lee, Jae Seon;Cha, Geun Sig;Nam, Hakhyun
    • Analytical Science and Technology
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    • v.20 no.5
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    • pp.393-399
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    • 2007
  • In principle, the blood galactose level may be determined conveniently with a strip-type biosensor similar to that for glucose. In this study, we describe the development of a disposable galactose biosensor strip for point-of-care testing. The sensor strip is constructed with screen-printed carbon paste electrode (SPCE) and sample amount (< $100{\mu}L$). The developed strip the galactose level in less than 90 s using bienzymatic system of galactose oxidase (GAO) and horseradish peroxidase (HRP). The effects of pH, mediator (1,1-ferrocenedimethanol) concentration, ratio of enzymes, and applied potential were determined preliminarily with glassy carbon electrodes, and optimized further with the strip-type electrodes. The sensor exhibits linear response in the range of $0{\sim}400{\mu}M$ ($r^2$ = 0.997, S/N = 3). Since a low working potential, in principle, the fabricated disposable galactose biosensor has -100 mV (vs. Ag/AgCl), it is applied for the detection of galactose, interfering responses from common interferents such as ascorbic acid, uric acid and acetaminophen could be minimized. The sensor has been used to determine the total galactose level in standard samples with satisfactory reproducibility (CV = 5 %).

Chemical characteristics and sources of fine ambient particulate matter from the third and fourth industrial complex area of Daejeon city, Korea (대전 3, 4 공단지역의 미세분진에 대한 화학적 특성과 오염원 연구)

  • Lim, Jong-Myoung;Lee, Jin-Hong;Chung, Yong-Sam
    • Analytical Science and Technology
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    • v.20 no.1
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    • pp.33-40
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    • 2007
  • This study centered on the quantitative analysis of about 27 trace elements including toxic ones using instrumental neutron activation analysis of fine ambient particulate matter in the third and fourth industrial complex area of Daejeon city, Korea. For analytical quality control, the certified reference material (NIST, the National Institute of Standards and Technology, U.S.A., SRM 2783, air particulate on filter media) was used. The errors relative to SRM values of Sb, Mn, V, Mg, Na, K, Ti, Co, Zn, and Sm fell below 5%, while those of Cr, Fe, Ba, Th, Ce, Al, and Cu were less than 10%. From the results of the quantitative analysis, the concentration of toxic metals such as As, Mn, Se, V, and Zn were $3.26{\pm}2.72$, $9.86{\pm}4.71$, $2.18{\pm}1.25$, $4.91{\pm}2.41$, $158{\pm}78ng/m^3$, respectively. And the results of factor analysis indicated that there are no more than six factors of sources of fine ambient particulate with statistical significance in the study area.

Wave Control by Submerged Breakwater under the Solitary Wave(Tsunami) Action (고립파(지진해일) 작용하의 수중방파제에 의한 파랑제어)

  • Lee, Kwang Ho;Kim, Chang Hoon;Jeong, Seong Ho;Kim, Do Sam
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.3B
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    • pp.323-334
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    • 2008
  • Present study examined the functionality of the solitary wave (tsunami) control of the two-rowed porous submerged breakwater by numerical experiments, using a numerical wave tank which is based on the Navier-Stokes equation to explain fluid fields and uses a Volume of Fluid (VOF) method to capture the free water surface. Solitary wave was generated by the internal wave source installed within the computational zone in the numerical wave tank and its wave transformations by structure were compared with those in the previous study. Comparisons with the precious numerical results showed a good agreement. Based on these results, several tow-dimensional numerical modeling investigations of the water fields, including wave transformations, reflection, transmission and energy flux, by the one- and two-rowed permeable submerged breakwater under solitary waves were performed. Even if, it is a research of the limited scope, in case of two-rowed permeable submerged breakwater with $h_0/h=0.925$ ($h_0$ is height of submerged breakwater and h is water depth), the wave height damping in range of $l/L_{eff}>0.4$($L_{eff}$ is effective distance of solitary wave) can reach nearly 60% of the incident wave height. In addition, it is found that reflection coefficient increases nearly 47% and transmission coefficient decreases nearly 18% than one-rowed one. The numerical results revealed that the tow-rowed submerged breakwater can control the incident solitary wave economically and more efficiently than the one-rowed one.

Development of Truck Axle Load Distribution Model using WIM Data (WIM 자료를 활용한 화물차 축하중 분포 모형 개발)

  • Lee, Dong Seok;Oh, Ju Sam
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.5D
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    • pp.821-829
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    • 2006
  • Traffic load comprise primary input to pavement design causing pavement damage. therefore it should be proceeded suitable traffic load distribution modeling for pavement design and analysis. Traffic load have been represented by equivalent single axle loads (ESALs) which convert mixed traffic stream into one value for design purposes. But there are some limit to apply ESALs to other roads because it is empirical value developed as part of the original AASHO(American Association of State Highway Officials) road test. There have been many efforts to solve these problems. Several leading country have implemented M-E(Mechanistic-Empirical) design procedures based on mechanical concept. As a result, they established traffic load quantification method using load distribution model known as Axle Load Spectra. This paper details Axle Load Spectra and presents axle load distribution model based on normal mixture distribution function using truck load data collected by WIM system installed in national highway. Axle load spectra and axle load distribution model presented in this paper could be useful for basic data when making traffic load quantification plan for pavement design, overweight vehicle permit plan and pavement maintenance cost plan.

Effectiveness of a Wave Resonator under Short-period Waves and Solitary Waves (공진장치를 이용한 단주기파랑과 고립파의 제어)

  • Lee, Kwang Ho;Jeong, Seong Ho;Jeong, Jin Woo;Kim, Do Sam
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.1B
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    • pp.89-100
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    • 2010
  • The performance evaluation of a conventional Wave Resonator at the entrance of harbors against solitary wave has been performed using 3D numerical wave flume. A wave resonator has been designed for the attenuation of the transmitted wave energy by trapping the short periodic incident waves only. In this study, however, the controlled performance of the wave resonator by its various widths has been numerically investigated for solitary waves. Source distribution method based on the Green function and the 3D one-field Model for immiscible TWO-Phase flows (TWOPM-3D) using 3D numerical wave flume were used for the short-periodic waves and the solitary waves, respectively, and these models were verified through the comparisons with the previous experimental and numerical results by other researchers. It was confirmed that the wave resonator is effective enough to control the solitary waves as well as the periodic waves when it compares with the case of no resonance system. Further, it was found that there is the optimal width of a wave resonator to attenuate the target solitary waves.

Numerical Analysis of Runup and Wave Force Acting on Coastal Revetment and Onshore Structure due to Tsunami (해안안벽과 육상구조물에서 지진해일파의 처오름 및 작용파력에 관한 수치해석)

  • Lee, Kwang Ho;Kim, Chang Hoon;Kim, Do Sam;Yeh, Harry;Hwang, Young Tae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.3B
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    • pp.289-301
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    • 2009
  • In this work, wave run-up heights and resultant wave forces on a vertical revetment due to tsunami (solitary wave) are investigated numerically using a numerical wave tank model called CADMAS-SURF (CDIT, 2001. Research and Development of Numerical Wave Channel (CADMAS-SURF). CDIT library, No. 12, Japan.), which is based on a 2-D Navier-Stokes solver, coupled to a volume of fluid (VOF) method. The third order approximate solution (Fenton, 1972. A ninth-order solution for the solitary wave. J. of Fluid Mech., Vol. 53, No.2, pp.257-271) is used to generate solitary waves and implemented in original CADMAS-SURF code. Numerical results of the wave profiles and forces are in good agreements with available experimental data. Using the numerical results, the regression curves determined from the least-square analysis are proposed, which can be used to determine the maximum wave run-up height and force on a vertical revetment due to tsunami. In addition, the capability of CADMAS-SURF is demonstrated for tsunami wave forces acting on an onshore structure using various configuration computations including the variations of the crown heights of the vertical wall and the position of the onshore structure. Based on the numerical results such as water level, velocity field and wave force, the direct effects of tsunami on an onshore structure are discussed.

Numerical Analysis of Wave Transformation of Bore in 2-Dimensional Water Channel and Resultant Wave Loads Acting on 2-Dimensional Vertical Structure (2차원수조내에서 단파의 변형과 구조물에 작용하는 단파파력에 관한 수치해석)

  • Lee, Kwang Ho;Kim, Chang Hoon;Kim, Do Sam;Hwang, Young Tae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.5B
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    • pp.473-482
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    • 2009
  • This study numerically discusses wave forces acting on a vertical wall such as breakwaters or revetments, subjected to incident undular or turbulent bores. Due to the complex hydrodynamics of bore, its wave forces have been predicted, mainly through laboratory experiments. Numerical simulations in this paper were carried out by CADMAS-SURF(CDIT, 2001), which is based on Navier-Stokes momentum equations and VOF method (Hirt and Nichols, 1981) for tracking free water surface. Its original source code was also partly revised to generate bore in the numerical water channel. Numerical raw data computed by CADMAS-SURF included great strong spike phenomena that show the abrupt jumps of wave loads. To resolve this undesired noise of raw data, the band-pass filter with the frequency of 5Hz was utilized. The filtered results showed reasonable agreements with the experimental results performed by Matsutomi (1991) and Ramsden (1996). It was confirmed that CADMASSURF can be applied to the design of coastal structures against tsunami bores. In addition, the transformation process and propagation speed of bores in the same 2-d water channel were discussed by the variations of water level for time and space. The numerical results indicated that the propagation speed of bore was changed due to the nonlinear interactions between negative and reflected waves.

Single Cross Maize Hybrid 'Hwangdaok' for High Grain Yield (다수성 종실용 옥수수 단교잡 신품종 '황다옥')

  • Son, Beom-Young;Baek, Seong-Bum;Kim, Jung-Tae;Lee, Jin-Seok;Bae, Hwan-Hee;Go, Young-Sam;Kim, Sun-Lim
    • Korean Journal of Breeding Science
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    • v.51 no.2
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    • pp.105-109
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    • 2019
  • 'Hwangdaok', a new maize F1 hybrid (Zea mays L.), was developed by the maize breeding team at the National Institute of Crop Science (NICS), RDA in 2016. The high-yielding yellow dent hybrid named 'Hwangdaok' was obtained by crossing between two inbred lines, 'KS203' and 'KS190'. After advanced yield trial in Suwon in 2012, regional yield trial was subsequently carried out to evaluate the growth and yield of 'Hwangdaok' at three different locations from 2014 to 2016. The number of days to silking of 'Hwangdaok' is 76. The plant height is 262 cm and ear height ratio is 51%, which are similar to those of 'Jangdaok'. It has resistance to lodging. The number of ears per 100 plants is 95. The ear length is 21.3 cm and weight of 100 seeds is 34.7 g, similar to those of 'Jangdaok'. It has moderate resistance to southern leaf blight (Bipolaris maydis) and European corn borer (Ostrinia nubilalis). The grain yield (10 ton/ha) of 'Hwangdaok' is 6% higher than that of 'Jangdaok'. The seed production rate of 'Hwangdaok' is acceptable due to good synchronization of flowering period during crossing between the seed parent, KS203, and the pollen parent, KS190, in Yeongwol. F1 seed yield was 1.68 ton/ha. 'Hwangdaok' can be a suitable cultivar to plain areas in Korea. (Variety registration No. 7502).

A Study on Appropriate Nurse Staffing Levels in Intensive Care Units and Improvement of the Critical Care Nursing Fee Schedules (중환자실 적정 간호사 배치수준과 간호관리료 차등제 개선 연구)

  • Lee, Hyo Jin;Cho, Sung-Hyun;Shim, Mi Young;Kim, Jung Yeon;Song, Yu Gil;Kim, Jin;Kim, Young Sam
    • Journal of Korean Clinical Nursing Research
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    • v.29 no.3
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    • pp.312-326
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    • 2023
  • Purpose: This study attempted to analyze the staffing level and critical care nursing fees of intensive care units at tertiary and general hospitals and to provide a professional judgment-based recommendation on staffing level and critical care nursing fee schedules. Methods: Staffing grades and critical care nursing fee schedules for the first quarter of 2017~2020 and the fourth quarter of 2020~2022 were analyzed. A survey was conducted on nursing managers and nurses about the current and appropriate staffing levels. A total of 77 nurse managers and 708 nurses working in Intensive Care Unit(ICU)s at tertiary and general hospitals participated in the study. Results: Grade 1 staffing increased from 25.6% in 2017 to 92.1% in 2022 at tertiary hospitals and from 0.8% in 2017 to 28.4% in 2022 at general hospitals. The current staffing ratios of tertiary and general hospitals were 1:2.21 and 1:2.77, respectively. The appropriate staffing ratio according to nurse managers and nurses was 1:1.00 in patients with more than a ventilator application and 1:2.00 in patients without any ventilator application in tertiary hospitals, and it was 1:1.25 in patients with more than a ventilator application and 1:2.00 in patients without any ventilator application in general hospitals, respectively. Conclusion: The appropriate staffing level was suggested from 1:1.0 to 1:2.0. The new nursing fee schedules were suggested from 1:1.0 (Grade 1) to 1:3.0 (Grade 5) and recommended to be paid based on the staffing grade, minimum number of nurses, and standard annual working days. It is expected to increase staffing levels and provide a better nursing work environment.

Study on Improving the Facilities of Power-Driven Water Leisure Crafts for the Deaf (청각장애인을 위한 동력수상레저기구 운영 개선방안에 관한 연구)

  • Won-Sam Choi;Bong-Kyu Jung;Cheor-Hong Park;Nam-U Lee
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.7
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    • pp.836-842
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    • 2023
  • Under the Welfare of Disabled Persons Act, the national qualification test allows disabled and non-disabled people to appear for the same test, and the deaf do not fall under the reason for disqualification from obtaining a license for power-driven water leisure crafts; therefore, even the deaf can obtain a license. During a risk of collision at sea, ships and power-driven water leisure crafts notify the other party of dangerous signals such as maneuvering and warning signals through sound signals to prevent accidents that may occur because surrounding ships are not visible. However, a method is required to prevent marine accidents that may occur when the deaf cannot hear danger signals through sounds from nearby ships or power-driven water leisure crafts during leisure activities owing to hearing impairment. A sound reception system is a device installed on a ship where missionary work is completely deposed to display the amplification of external sounds and the direction of sound reception on the screen. Through visual display of sound signals such as dangerous signals that cannot be heard owing to hearing impairment, improvement measures were proposed to prevent marine accidents that can occur owing to the inability of the deaf to check sound signals during leisure activities.