• Journal of Korea Water Resources Association
• /
• v.38 no.11
• /
• pp.955-962
• /
• 2005

Even though the runoff volume is very sensitive to the antecedent soil moisture condition (AMC), the general rainfall-runoff analysis in Korea has accepted, without careful consideration of its applicability, the AMC classification of the Soil Conservation Service (SCS, 1972). In this study, by following the development procedure of SCS Curve Number (CN), the rainfall-runoff characteristics of the Jangpyung subbasin of the Pyungchang River Basin were analyzed to estimate the CN and evaluate the AMC classification of currently being used. As results, CN(I), CN(II), and CN(III) were estimated to be 72.1, 79.3, and 76.7, respectively. Among them CN(II) was found to be similar to the other reports but the other two were totally different from those of theoretically estimated. However, it is difficult to evaluate the AMC with CN, rather the frequency of each AMC could be a better indicator for its validity. This study developed the histogram of AMC and compared the frequency of each AMC. hs results we found that the criterion for AMC-III should be increased, Hut that for AMC-I decreased.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.8 no.1
• /
• pp.97-102
• /
• 2008

The Natural Resource Conservation Service Curve Number(NRCS-CN) method is one of the widely used methods for computation of runoff from a basin. However, NRCS-CN method has a weak point in that the spatial land use distribution characteristics are ignored by using area-weighted CN value. This study developed a runoff estimation algorithm which can reflect the spatial land-use distribution. The algorithm consists of Moglen's theory and a developed flow accumulation estimation program in FORTRAN. Comparisons between the results from area-weighted CN method and this study showed reasonably good agreement with measured data of experimental watersheds. The developed program predicted lower runoff than the conventional NRCS-CN method. As a conclusion, this study proposes a new design direction which can simulate real runoff phenomena. And the developed program could be applied into runoff minimization design for a basin development.

• Journal of Korea Water Resources Association
• /
• v.41 no.12
• /
• pp.1231-1244
• /
• 2008

The objective of this study is to present a methodology for estimating runoff curve number(CN) using SWAT model which is capable of reflecting watershed heterogeneity such as climate condition, land use, soil type. The proposed CN estimation method is based on the asymptotic CN method and particularly, it uses surface flow data simulated by SWAT. This method has advantages to estimate spatial CN values according to subbasin division and to reflect watershed characteristics because the calibration process has been made by matching the measured and simulated streamflows. Furthermore, the method is not sensitive to rainfall-runoff data since CN estimation is on a daily basis. The SWAT based CN estimation method is applied to Chungju dam watershed. The regression equation of the estimated CN that exponentially decays with the increase of rainfall is presented.

• Journal of Environmental Science International
• /
• v.29 no.1
• /
• pp.95-108
• /
• 2020

Silver nanoparticles were loaded onto g-C₃N₄ (CN) with a nanoroll-type morphology (Ag/CN) synthesized using a co-polymerization method for highly selective conversion of toxic nitrobenzene to industrially-valuable aminobenzene. Scanning electron microscopy and high-resolution transmission electron microscopy (HRTEM) images of Ag/CN revealed the generation of the nanoroll-type morphology of CN. Additionally, HRTEM analysis provided direct evidence of the generation of a Schottky barrier between Ag and CN in the Ag/CN nanohybrid. Photoluminescence analysis and photocurrent measurements suggested that the introduction of Ag into CN could minimize charge recombination rates, enhancing the mobility of electrons and holes to the surface of the photocatalyst. Compared to pristine CN, Ag/CN displayed much higher ability in the photocatalytic reduction of nitrobenzene to aminobenzene, underscoring the importance of Ag deposition on CN. The enhanced photocatalytic performance and photocurrent generation were primarily ascribed to the Schottky junction formed at the Ag/CN interface, greater visible-light absorption efficiency, and improved charge separation associated with the nanoroll morphology of CN. Ag would act as an electron sink/trapping center, enhancing the charge separation, and also serve as a good co-catalyst. Overall, the synergistic effects of these features of Ag/CN improved the photocatalytic conversion of nitrobenzene to aminobenzene.

• Water for future
• /
• v.24 no.2
• /
• pp.97-108
• /
• 1991

A number of different curve numbers are estimated, and three of them are the basin or composite curve numbers (CN-II and CN-III) evaluated from hydrologic soil cover complex, the observed curve numbers computed from rainfal1-runoff observations and the basin median curve numbers as a median of the observed curve numbers. Based on the observed runoff, CM-II underestimates the effective rainfall meanwhile CN-III overestimates. Hence, for the improvement in estimating effective rainfall, a modulating curve number may be defined as a value in between CN-II and CN-III. Basin median curve numbers produces the closest result to the observed runoff and therefore it can be adopted as a representative curve number for gaged basin.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.2
• /
• pp.485-499
• /
• 2021

Although non-binary low-density parity-check (NB-LDPC) codes have better error-correction capability than that of binary LDPC codes, their decoding complexity is significantly higher. Therefore, it is crucial to reduce the decoding complexity of NB-LDPC while maintaining their error-correction capability to adopt them for various applications. The extended min-sum (EMS) algorithm is widely used for decoding NB-LDPC codes, and it reduces the complexity of check node (CN) operations via message truncation. Herein, we propose a low-cost CN processing method to reduce the complexity of CN operations, which take most of the decoding time. Unlike existing studies on low complexity CN operations, the proposed method employs quick selection algorithm, thereby reducing the hardware complexity and CN operation time. The experimental results show that the proposed selection-based CN operation is more than three times faster and achieves better error-correction performance than the conventional EMS algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.8 no.6
• /
• pp.1194-1203
• /
• 2004

The RR protocole, proposed in IETF mip6 WG and standardized by RFC 3775 at lune 2004, send a message 'Binding Update' that express MN's location information to CN safety and update location information. Standard RR protocole has some problems with initiating the protocol by the MN; it causes to increases in communication load in the home network, to increases communication delay between MN and CN. Also, is connoting vulnerability to against attacker who are on the path between CN and HA in security aspect. This paper proposes doing to delegate MN's location information update rights by HA new location information update method. That is, When update MN's location information to HA, Using MN's private key signed location information certificate use and this certificate using method that HA uses MN's location information at update to CN be. It decreases the route optimization overhead by reducing the number of messages as well as the using location information update time. Also, remove security weakness about against attacker who are on the path between CN and HA.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.21 no.7
• /
• pp.805-814
• /
• 2010

The Crank-Nicolson isotropic-dispersion finite difference time domain(CN ID-FDTD) scheme is proposed based on isotropic-dispersion finite difference(ID-FD) $equation^{[1],[2]}$. The dispersion relation of CN ID-FDTD is derived for lossy media by solving the eigenvalue problem of iteration matrix in spatial spectral domain, in addition, the weighting factors and scaling factors of the CN ID-FDTD scheme are presented for low dispersion error. The CN ID-FDTD scheme makes the dispersion error drastically reduced and shows accurate numerical results compared to the conventional Crank-Nicolson FDTD method.

• Korean Journal of Microbiology
• /
• v.35 no.2
• /
• pp.169-172
• /
• 1999

Small-seeded legumes can be cultured enclosed in slant agar tubes if dlese plants are to he used for authenicaiing rhizobia or for enumerating 1-hizobia by the plant-inlection technique. An improved method has been developed with substiluting agar slant lor Korean paper(Har7ji). This method was panicularly useful for legumes with rigid radicle such as Cn.xsin 1mnmame. With this method Bmr!,~li1rzobin,17 sp. stram CN9135 on C nonmne induced root nodules biginning at day 7 of the nodulation period in 6% of the l ~ l a ~ l s , and all of ihe plants nodulated 14 days after inoculation by strain CN9135.

• Journal of Mechanical Science and Technology
• /
• v.16 no.7
• /
• pp.927-934
• /
• 2002

The HANARO ( High-flux Advanced Neutron Application Reactor) has been operated since 1995. The Cold Neutron (CN) hole was implanted in the reflector tank from the design stage. Before a vacuum chamber and a moderator cell for the cold neutron source are installed into the CN hole, it is necessary to measure exactly the size of the inside diameter and thickness of the CN hole to prevent the interference problem. Due to inaccessibility and high radiation field in the CN hole, a mechanical measurement method is not permitted. The immersed ultrasonic technique is considered as the best way to measure the thickness and the diameter of the CN hole. The 4-Axis manipulator was designed and fabricated for locating the ultrasonic sensors. The transducer of an ultrasonic sensor having 10 MHz frequency leads to high resolution as much as 0.03mm. The inside diameter and thickness of 550 points of the CN hole were measured using 2 channel ultrasonic sensors. The results show that the thickness and inside diameter of the CN hole is in the range of 3.3∼6.7mm and 156∼ 165mm, respectively. This data will be a good reference for the design of the cold neutron source facility.