• Journal of Multimedia Information System
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• 제2권3호
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• pp.263-274
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• 2015

The subject of this work is the complex discrete systems simulation special features with the aid of dynamic graph models. The proposed simulation technique allows to determine the ways for tasks solutions in terms of discrete systems analysis and synthesis of various complication: one-dimensional and multidimensional, steady and unstable, with the pulse elements abnormal operating mode and others. Often complex control systems analysis and synthesis task solutions, via classical approach comes out to be insolvent, because of the computational problems. The application of graph models allows to perform clear and strict characterization and computer procedures automation. The optimal controls synthesis algorithm presented in this paper, transferring the discrete system from target initial state to target final state within the minimum time, allows to consider the zero initial conditions systems, with the initial potential energy, with the control actions limitations and complex pulse elements operating mode.

• Toxicological Research
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• 제28권3호
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• pp.173-178
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• 2012

This study investigated the human health risks of trichloroethylene from Industrial Complex A. The excessive carcinogenic risks for central tendency exposure were $1.40{\times}10^{-5}$ for male and female residents in the vicinity of Industrial Complex A. The excessive cancers risk for reasonable maximum exposure were $2.88{\times}10^{-5}$ and $1.97{\times}10^{-5}$ for males and females, respectively. These values indicate that there are potential cancer risks for exposure to these concentrations. The hazard index for central tendency exposure to trichloroethylene was 1.71 for male and female residents. The hazard indexes for reasonable maximum exposure were 3.27 and 2.41 for males and females, respectively. These values were over one, which is equivalent to the threshold value. This result showed that adverse cancer and non-cancer health effects may occur and that some risk management of trichloroethylene from Industrial Complex A was needed.

• Bulletin of the Korean Chemical Society
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• 제29권4호
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• pp.795-798
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• 2008

The formation of complex $XeHCl^+$ in the collision-induced reaction of $Xe^+$ with HCl has been studied by use of classical dynamics procedures using the London-Eyring-Polanyi-Sato empirical potential energy surfaces. A small fraction of trajectories on the $Xe^+$ + HCl and Xe + $HCl^+$ surfaces lead to the formation of complex $XeHCl^+$ with life-times of 1-2 ps which is long enough to survive many rotations before redissociating back to the reactant state. The formation of complex $XeHCl^+$ occurs mainly from collision angle of $\Theta$ = ${45^{\circ}}$.

• 전기화학회지
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• 제6권4호
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• pp.255-260
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• 2003

다공성 탄소전극의 전위에 짜른 EDLC(e)ectric double-layer capacitor)특성을 조사하기 위해 복소캐패시턴스분석(complex capacitance analysis)을 수행하였다. 하나의 원통형 기공에 대해 복소캐패시턴스를 이론적으로 유도하였고, 기공의 분포를 고려하여 다공성 전극에 대하여서도 계산하였다. 복소캐패시턴스의 허수부를 주파수에 대해 도시하면 피크 형태의 곡선이 얻어지는데, 이때 피크의 면적은 캐패시턴스 값의 크기와, 피크의 위치는 다공성전극의 전기화학 파라매터와 기공구조에 의해 결정되는 $\alpha_0$와 상관관계가 있음을 알 수 있었다. 이를 이용하면, 동일한 기공구조를 갖는 전극에 대해, 전위에 따른 캐패시턴스와 기공 내 이온전도도의 변화를 측정할 수 있다. 메조포러스 탄소전극에 대하여 전위를 변화시키며 electrochemical impedance spectroscopy를 측정하고 이를 복소캐패시턴스법에 의해 분석하였다. 피크 면적으로부터 구한 전위에 따른 캐패시턴스는 0.3V부근에서 최대값을 가졌는데, 이는 cyclic voltammetry 실험결과와도 일치하였다. 한편, 피크 위치로부터 구한 기공 내 이온전도도는 0.2V에서 최대 값을 가지고 전위가 증가할 수록 서서히 감소하였다. 이를 탄소 표면전하의 증가로 인해 이온/표면의 전기적 작용력이 커졌기 때문으로 해석하였다.

• 한국산림과학회지
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• 제112권4호
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• pp.523-529
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• 2023

본 연구에서는 홍천 가리산 국유림 선도산림경영단지를 대상으로 목재생산 가능면적과 목재생산 잠재량을 분석하고, 지속가능한 목재수확을 위한 최적 목표수확량을 제시하고자 하였다. 목재생산 가능면적을 분석하기 위해서 공간분석을 통해 경사도 40° 이상인 지역(지형적 제약조건), 수계 양안 30 m 이내 지역(환경적 제약조건), 임도로부터 300 m 이상 떨어진 지역(기술적 제약조건)을 제외하여 분석한 결과, 전체 단지 면적 6,679 ha 가운데 3,298 ha (49%)가 목재생산 가능 면적으로 분석되었다. 목재생산 가능면적을 대상으로 목재생산 잠재량을 분석한 결과 608,613 m³으로 나타났으며, 특히 침엽수 인공림의 목재생산 잠재량이 409,721 m³으로 67.3%를 차지하여 매우 높았다. 향후 50년간 일정한 목재수확량을 유지하면서 영급 간 면적의 편차를 최소화할 수 있도록 최적화 분석을 실시한 결과, 연 평균 41.9 ha, 7,988 m³가 최적의 목재 수확량으로 나타났으며, 이 경우 50년 후의 영급구조가 보다 안정적인 형태로 전환이 가능한 것으로 나타났다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1140-1143
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• 1996

A new approach based on artificial potential function is proposed for the obstacle avoidance of redundant manipulators. Unlike the so-called "global" path planning method, which requires expensive computation for the path search before the manipulator starts to move, this new approach, "local" path planning, researches the path in real-time using the local distance information. Previous use of artificial potential function has exhibited local minima in some complex environments. This thesis proposes a potential function that has no local minima even for a cluttered environment. This potential function has been implemented for the collision avoidance of a redundant robot in Simulation. The simulation also employ an algorithm that eliminates collisions with obstacles by calculating the repulsive potential exerted on links, based on the shortest distance to object.

• 상하수도학회지
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• 제21권1호
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• pp.113-122
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• 2007

Experimental studies were performed to investigate speciation and leaching potential of heavy metals(Cu, Cd, Pb Zn, Ni) in ten sediment samples collected from Nakdong River. Acid Volatile Sulfide (AVS) and Simultaneously Extractable Metals (SEM) measurements were used to estimate heavy metals that can be leached under anaerobic conditions. Sequential Extraction Procedure (SEP) and Toxicity Characteristic Leaching Procedure (TCLP) were used to characterize speciation and leaching potential of heavy metals under aerobic conditions. The results show that total concentrations of Cu, Zn and Ni were relatively high in the sediments from points Seongseo industrial complex stream (upper stream) (D), Seongseo industrial complex stream (midstream) (E), Dalseo stream (F), and Nakdong river estuary (J), and that Cd concentrations were higher in all sampling points except for Goriung Bridge (G) and Soosan Bridge (H). SEM and AVS analyses reveal that samples from points Ilsun Bridge (A), Namgumi Bridge (C), and Soosan Bridge (H) have potential of heavy metals leaching, although leachable concentrations are relatively low. The leaching potential of heavy metals in other points was low because of higher concentrations of AVS than SEM. SEP results show that more than 50% of Cu, Zn and Ni were present in residual fraction, which means these metals are less amenable to leaching in anaerobic conditions. On the other hand, more than 50% of Pb and Cd were extracted during the first through third step of the SEP, which means substantial fraction of these metals can be leached upon changing of redox conditions. TCLP tests predict that leaching potential of heavy metals was generally low, which is consistent with the results obtained by AVS and SEM measurements.

• Journal of Electrochemical Science and Technology
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• 제6권4호
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• pp.146-151
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• 2015

Here I report an electrochemical simulation work that compares voltammetric current and resistance of a complex electrochemical reaction over a potential scan. For this work, the finite element method is employed which are frequently used for voltammetry but rarely for impedance spectroscopy. Specifically, this method is used for simulation of a complex reaction where a heterogeneous faradaic reaction is followed by a homogeneous chemical reaction. By tracing the current and its polarization resistance, I learn that their relationship can be explained in terms of rate constants of charge transfer and chemical change. An unexpected observation is that even though the resistance is increased by the rate of the following chemical reaction, the current can be increased due to the potential shift of the resistance made by the proceeding faradaic reaction. This report envisions a possibility of the FEM-based resistance simulation to be applied to understand a complex electrochemical reaction. Until now, resistance simulations are mostly based on equivalent circuits or complete mathematical equations and have limitations to find proper models. However, this method is based on the first-principles, and is expected to be complementary to the other simulation methods.

• 산업식품공학
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• 제21권3호
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• pp.215-224
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• 2017

Resveratrol was incorporated into various combinations of single- and double-layer nanoemulsions, prepared by self-assembly emulsification and complex coacervation with chitosan, alginate, and ${\beta}$-cyclodextrin, respectively. Resveratrol nanoemulsions were composed of medium-chain trigacylglycerols (MCTs), $Tween^{(R)}$ 80, water, chitosan, alginate, and ${\beta}$-cyclodextrin. The corresponding mixtures were formulated for the purpose of being used as a nutraceutical delivery system. Resveratrol nanoemulsions were obtained with particle sizes of 10-800 nm, with the size variation dependent on the emulsification parameters including the ratio of aqueous phase and surfactant ratio. Resveratrol nanoemulsions were characterized by evaluating particle size, zeta-potential value, stability, and release rate. There were no significant changes in particle size and zeta-potential value of resveratrol nanoemulsions during storage for 28 days at $25^{\circ}C$. The stability of resveratrol in the double-layer nanoemulsions complexed with chitosan or ${\beta}$-cyclodextrin was higher, compared with the single-layer nanoemulsions.

• 한국태양에너지학회 논문집
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• 제33권2호
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• pp.18-27
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• 2013

This paper presents a method for assessing the wind energy potential at complex terrain using probability distribution. And the proper probability models of the parameters estimating the wind energy are presented. Finally a mixture-Weibull determined by numerical methods procedure are proposed to assess the probability distribution of the energy potential at a site. The developed method is applied to the Kwanjungchun Bridge and compared with wind records which the neighboring weather station.