• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1830-1835
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• 2003

A novel index representing burden distribution form in the blast furnace is developed and index estimation model is built with an empirical modeling method to monitor inner condition of the furnace without expensive sensors. To find the best combination of index and modeling method, two candidates for the index and four modeling methods have been examined. Results have shown that 3-D index have more resolution in describing the distribution form than 1-D index and ANN model produces smallest RMSE due to nonlinearity between the indices and charging mode. Although ANN has shown the best prediction accuracy in this study, PLS can be a good alternative due to its advantages in generalization capability, consistency, simplicity and training time. The second best result of PLS in the prediction results supports this fact.

• 대한수학회논문집
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• 제38권1호
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• pp.223-234
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• 2023

The main purpose of this paper is to study the lightlike hypersurface (M, $\overline{g}$) of cosymplectic space form $\overline{M}$(c). In this paper, we computed the Gauss and Codazzi formulae of (M, $\overline{g}$) of cosymplectic manifold ($\overline{M}$, g). We showed that we can't obtain screen semi-invariant lightlike hypersurface (SCI-LH) of $\overline{M}$(c) with parallel second fundamental form h, parallel screen distribution and c ≠ 0. We showed that if second fundamental form h and local second fundamental form B are parallel, then (M, $\overline{g}$) is totally geodesic. Finally we showed that if (M, $\overline{g}$) is umbilical, then cosymplectic manifold ($\overline{M}$, g) is flat.

• 생태와환경
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• 제41권2호
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• pp.166-173
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• 2008

오염물질을 제거하기 위한 방법 중 하나인 석회 처리를 통하여 청초호 표층 퇴적물에 함유된 중금속의 존재 형태 변화와 환경변화시 수층으로의 용출가능성을 알아보았다. 연속추출 방법을 사용하여 중금속의 화학적 형태를 분석하였고 수층으로의 용출 가능성은 흡착된 형태와 공침된 형태의 합으로 하였다. 석회 처리 전의 청초호 퇴적물에 함유된 Cd과 Cu 및 Zn의 존재형태는 호수 바닥과 같은 혐기성 상태에서 안정된 산화성 형태가 많았으나 석회 처리 시료에서는 이 부분의 비율이 줄어든 반면 용출되기 쉬운 부분인 흡착된 형태와 공침된 형태의 비율이 증가하였다. 이는 석회 첨가로 인한 공극수의 pH상승과 대기중에 노출로 인한 산화에 의한 것으로 판단된다. 수층으로 이동 가능한 부분의 비율은 Cd의 경우 석회함량 15%, Pb은 10%, Cu와 Zn은 20%에서 높게 나타나 중금속으로 오염된 퇴적물의 석회 처리는 퇴적물에 함유된 중금속의 용출을 증가시킬 가능성이 있는 것으로 사료된다.

• Bulletin of the Korean Chemical Society
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• 제20권10호
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• pp.1209-1212
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• 1999

The entropies and chemical potentials of hard-sphere solutes solvated in hard-sphere solids were calculated by Monte Carlo method using the radial free-space distribution function. This method is based on calculating the entropy by comparing the free volume of a molecule with that of an ideal gas, and is applicable even when the size of solute is very large and the solvent is a solid. When the diameter of hard-sphere solute is small the solute molecule behaves as like as a fluid in solid structures, but when the diameter of solute becomes large, a fluid-to-solid phase transition takes place. The fluid-to-solid phase transition occurs at the region of the smaller size of solute with the more increase of solvent density. The least square fit values of analytical form of the radial free-space distribution functions of solute molecules are presented for future uses.

• 대한화학회지
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• 제18권5호
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• pp.358-362
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• 1974

벤조산과 그 유도체들에 대한 음이온 교환분리를 여러 농도의 염화니켈-메탄올 용매 내에서 연구하였다. Amberlite CG-400, $Cl^-$ form에 대한 유기산들의 부피분배계수를 측정하고 이 분배계수로부터 제시된 적절한 농도의 $NiCl_2-MeOH$ 용액을 용리액으로 사용하여 몇 개의 혼합유기산을 정량적으로 분리하였다. 모든 유기산들의 농도는 자외선 분광광도계를 사용하여 정량하였다.

• 한국건축시공학회지
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• 제13권6호
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• pp.522-529
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• 2013

As concrete forms, panel forms made of plywood used to be widely used, but recently a system form made of aluminum has been broadly adopted because of the advantages it offers in terms of constructability and economy. However, an aluminum form reacts with concrete, which is alkali, and creates hydrogen gas. As a result, air pockets occur on the concrete's surface, and its finishability deteriorates. Therefore, this research analyzed the relationship between the distribution of voids and surface roughness and the damage degree and number of uses of the aluminum form. The analysis of the distribution of voids shows that the number of voids of 0.1~1 mm, which are considered to have occurred because of chemical reaction, was 200~500 on the coating plywood, but was 1 500~2 000 on the aluminum form after 3 uses, and impossible to count after a higher number of uses. Surface roughness was $1.7{\sim}3.2{\mu}m$ on the coating plywood form, but was about $2.6{\mu}m$ after the first use and about $6.8{\mu}m$ after 10 uses, a 2.6-fold increase. Distribution of voids did not show a particular tendency depending upon the degree of damage to the concrete form, but surface roughness showed an increasing tendency as the degree of damage grows. Therefore, when using aluminum forms, surface maintenance should be carried out completely, such as prevention of damages to the form surface coating materials and spreading of separating materials on forms.

• Nuclear Engineering and Technology
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• 제30권3호
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• pp.235-244
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• 1998

The parametric model method determines the accident source term which is Presented by a set of source term parameters. In this method, the cumulative distribution of each source term parameter should be derived for its uncertainty analysis. This paper introduces a method of generating the parameters in the form of cumulative distribution using MAAP version 4.0. In MAAP, there are model parameters which could incorporate uncertain physical and/or chemical phenomena. In general, the model parameters do not have a point value but a range. In this paper, considering that, the input values of model parameters influencing each parameter are sampled using LHS. Then, the computation results are shown in cumulative distribution form. For a case study, the CDFs of FCOR and WES of Kori Unit 1 are derived. The target scenarios for the computation are the ones whose initial events are large LOCA, small LOCA and transient, respectively. It is found that the computed CDF's in this study are consistent to those of NUREG-1150 and the use of MAAP is proven to be adequate in assessing the parameters of the severe accident source term.

• Bulletin of the Korean Chemical Society
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• 제32권10호
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• pp.3687-3691
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• 2011

Ion exchange experiments of molybdenum(VI) from strong HCl and $H_2SO_4$ solution have been done to investigate the existence of anionic complexes. The concentration of HCl and $H_2SO_4$was changed from 1 to 9 M. From the data on the complex formation of molybdenum in aqueous solution, a new distribution diagram of Mo(VI) was constructed in the pH range from zero to 10. AG 1 X-8, an anion exchange resin, and Diphonix, a cation exchange resin were used in the loading experiments. Ion exchange results indicate that anionic complexes of Mo(VI) begins to form from 3 M HCl and 1 M $H_2SO_4$ solution and the tendency to form anionic complexes is stronger in HCl than in $H_2SO_4$ solution. Our results can be utilized in the analysis of Mo(VI) in strong acid solution and in the design of a process to separate Mo(VI).

• Bulletin of the Korean Chemical Society
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• 제23권6호
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• pp.872-879
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• 2002

One of the improtant characteristics of core-shell type nanoparticles is the long-term storage and reuse as an aqueous injection solution when required. For this reason, reconstruction of lyophilized core-shell type nanoparticles is considered to be essential . BAB type triblock copolymers differ from AB type diblock copolymers, which contain the A block as a hydrophilic part and the B block as a hydrophobic part. by not being easily redistributed into phosphate-buffered saline (PBS, pH 7.4, 0.1 M). Therefore, lyophilized core-shell type nanoparticles of CEC triblock copolymer were reconstituted using a somication process with a bar-type sonicator in combination with a freezing-thawing process. Soncation for 30s only resuspended CEC nanoparticles in PBS; their particle size distribution showed a monomodal pattern with narrow size distribution. The bimodal size distribution pattern and the aggregates were reduced by further sonication for 120 s but these nanoparticles showed a wide size distribution. The initial burst of drug release was increased by reconstitution process. The reconstitution of CEC core-shell type nanoparticles by freezing-thawing resulted in trimodal distribution pattern and formed aggregates, although freezing-thawing process was easier than sonication . Drug release form CEC nanoparticles prepared by freezing-thawing was slower than from the original dialysis solution. Although core-shell typenanoparticles of CEC triblock copolymers were not easily performed. Cytotoxicity testing of core-shell type nanoparticles of CEC-2 triblock copolymers containing clonazepam (CNZ) was performed using L929 cells. Cytotoxicity of CNZ was decreased by incorporation into nanoparticles.

• 소성∙가공
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• 제13권3호
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• pp.279-284
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• 2004

Electroforming is the highly specialized use of electrodeposition for the manufacture of metal parts and basically a specialized form of electroplating. So, we can apply electrochemical system analysis for electroforming process. Electrochemical systems are concerned with the interplay between electricity and chemistry, namely the measurements of electrical quantities, such as current density, potential, and charge, and their relationship to chemical parameters. This paper based on the basic equations of electrics and electrochemical kinetics, was employed for a theoretical explanation of the current density distribution on electroforming process. We calculated current density distribution and potential distribution on cathode. Also, calculated current density distribution of vertical direction. It was shown that current density is related with distance of between anode and cathode and mass transfer process.