• 한국ITS학회 논문지
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• 제8권2호
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• pp.118-127
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• 2009

본 연구는 최근 사회적으로 이슈가 되고 있는 고령자 교통사고 인적요인을 평가할 수 있는 모형 개발을 목적으로 한다. 본 연구의 수행을 위해 교통안전공단의 운전자적성검사(Simulation, 설문조사) 자료를 수집하였으며, 교통사고영향 모형개발을 위해 포아송 및 음이항 회귀분석(Poisson Regression Analysis)을 실시하였다. 교통안전성 평가모형 분석결과, 고령운전자의 경우 선택적 주의능력, 속도예측능력, 주의배분능력이 교통사고에 유의한 정(+)의 영향을 미치는 것으로 분석되었다. 다음으로 비고령운전자의 경우 선택적 주의능력, 속도예측능력, 거리지각능력, 주의배분능력, 주의전환능력이 교통사고와 유의한 정(+)의 영향을 미치는 것으로 분석되었다. 이러한 분석결과를 바탕으로 고령운전자와 비고령운전자의 사고발생에 미치는 영향요인은 서로 다르게 나타났으며, 교통사고를 미연에 방지하기 위한 최소한의 방편으로 고령운전자와 비고령운전자를 구분하여 교통사고 예방교육을 실시해야 할 것으로 판단된다.

• Journal of Electrical Engineering and Technology
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• 제10권4호
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• pp.1734-1737
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• 2015

Insulating characteristics of Cl₂-He mixture gases in gas discharges were analysed to evaluate ability of these gases for using in medium voltage and many industries. These are electron transport coefficients, which are the electron drift velocity, density-normalized longitudinal diffusion coefficient, and density-normalized effective ionization coefficient, in Cl₂-He mixtures. A two-term approximation of the Boltzmann equation was used to calculate the electron transport coefficients for the first time over a wide range of E/N (ratio of the electric field E to the neutral number density N). The limiting field strength values of E/N, (E/N)_lim, for these binary gas mixtures were also derived and compared with those of the pure SF₆ gas.

• 한국해안해양공학회지
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• 제10권1호
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• pp.37-44
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• 1998

본 연구에서 제안하는 혼합 방법(hybrid method)은 흐름이 우세한 영역에서의 전송 문제를 정확하고 효과적으로 해결하기 위하여 개발된 것으로 오일러-라그란쥐적 방법과는 달리 전방추적에 의하여 이송 과정이 수행되므로 보간 기법이 불필요하고 무작위 행보에 의한 라그란쥐적 방법과 달리 유한 차분법에 의하여 확산 과정이 수행되므로 많은 입자가 요구되지도 않는다. 한 점에 순간적으로 부하되는 오염원과 연속적으로 부하되는 오염원에 대한 이론적인 해와 비교하여 확산 계수와 무관하게 상당히 만족할 만한 결과를 얻었다. 현 방법은 또한 2차원 상에서 주변 5격자로부터 보간하는 오일러-라그란쥐적 방법과 무작위 행보로 입자 추적하는 순수 라그란쥐적 방법과 비교하여 정확성은 물론 계산 시간에 있어서도 상당히 월등한 방법임이 입증되었다.

• Nuclear Engineering and Technology
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• 제55권2호
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• pp.769-779
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• 2023

This paper describes an hp-angular adaptivity algorithm in the discrete ordinates method for Boltzmann transport applications with strong angular effects. This adaptivity uses discontinuous finite element quadrature sets with different degrees, which updates both angular mesh and the degree of the underlying discontinuous finite element basis functions, allowing different angular local refinement to be applied in space. The regular and goal-based error metrics are considered in this algorithm to locate some regions to be refined. A mapping algorithm derived by moment conservation is developed to pass the angular solution between spatial regions with different quadrature sets. The proposed method is applied to some test problems that demonstrate the ability of this hp-angular adaptivity to resolve complex fluxes with relatively few angular unknowns. Results illustrate that a reduction to approximately 1/50 in quadrature ordinates for a given accuracy compared with uniform angular discretization. This method therefore offers a highly efficient angular adaptivity for investigating difficult particle transport problems.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.675-679
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• 2004

The existing conjugated blue emitting material polymer which has been used for the two-wavelength method white-emission has good stability and low operating voltage as merits, but the imbalanced carrier transport has been indicated as problem area. We have introduced a novel blue emitting material having perylene moiety unit with hole transporting ability and blue emitting property and triazine moiety unit with electron transporting ability into the same host chain. We have synthesized N-[p-(perylen-3-y1)pheny1]methacry1 amide (PPMA) monomer and [N-(2,4-dipheny1-1,3,5-triazine)pheny1 methacry1 amide] (DTPM) monomer having blue light-emitting unit and electron transport unit, respectively by three steps. A novel non-conjugated blue emitting material Poly[N -[p­(perylene-3-y1) pheny1] methacry1 amide-co-N-[P-(4,6-dipheny1-1,3,5-triazine-2-y1]pheny1]methacry1 amide] (PPPMA-co-DTPM) copolymer having electron transporting unit was synthesized by the solution polymerization of PPMA and DTPM monomers with an AIBN initiator and showed high yield of $75{\%}$. It was very soluble in common organic solvents, and the fabrication of the thin film using a spin coating method was very simple. The PPPMA exhibited a good thermal stability.

• 사상체질의학회지
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• 제9권2호
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• pp.187-201
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• 1997

An experimental study was done to examine the effects of Dokwhaljiwhang-tang on gastro-intestinal track and central nervous system and were undertaken by being carried out with rat. The following results have been obtained ; 1. Dokwhaljiwhang-tang showed to have an inhibitory effect on the smooth muscle contraction of the isolated ileum by acetylcholene chloride and barium chloride. 2. Dokwhaljiwhang-tang showed to have an inhibitory effect on the contraction of the gastric fundus-strip by acetylcholine chloride and barium chloride. 3. The preventive effect was recognized on the pylorus-ligated ulcer, by administration of Dokwhaljiwhang-tang. 4. The preventive effect was not recognized on the indomethacine -induced ulcer, by administration of Dokwhaljiwhang-tang. 5. The inhibitory effects on the secretion gastric juice, free acidity were recognized, by administration of Dokwhaljiwhang-tang 6. The transport ability in the small intestine was increased, by administration of Dokwhaljiwhang-tang. 7. The transport ability in the large intestine was increased, by administration of Dokwhaljiwhang-tang. 8. The analgesic effect was recognized, by administration of Dokwhaljiwhang-tang. 9. The effect of sleeping time was not recognized, by administration of Dokwhaljiwhang-tang. according to the results, it is considered that Dokwhaljiwhang-tang has effects of gastric ulcer, chronic gastritis,hyper-acidity, gastroptosis such as abdominal discomfort, gastric acid, indigestion and anorexia.

• 한국ITS학회 논문지
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• 제5권3호
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• pp.24-28
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• 2006

본 논문에서는 메인 제어 보드에 연결되는 디바이스 모듈 보드들을 자동하는 인식하는 새로운 자동화 시스템을 설계 및 구현하였다. 본 논문의 시스템은 메인보드와 디바이스 모듈 보드로 나누어 설계하였으며, 메인보드에는 모듈보드와 연결할 수 있도록 슬롯 구조에 의해 설계되었다. 제안된 슬롯구조는 장착이 편리하고 기능의 추가 및 확장이 가능하도록 하였다. 또한 장치 보드들을 자동으로 인식함으로 통해 새로운 기존의 시스템을 업그레이드하거나 새로운 디바이스의 추가하는 등의 기능변경이 용이하도록 시스템을 설계 및 개발하였다. 본 논문에서 제안 된 시스템은 K10S1 PLC를 가지고 실험 및 검증하였다. 실험 분석 결과 제품의 기능향상에 드는 간 및 비용의 단축 효과가 나타났다.

• 환경위생공학
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• 제19권4호
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• pp.19-24
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• 2004

The objective of this study was to develop a mechanistically based mathematical model that would consider the interdependence of VOCs transport, microbial activity, and sorptive interactions in a moist, unsaturated soil. Because the focus of the model was on description of natural attenuation, the advective VOCs transport that is induced in engineered remediation processes such as vapor extraction was not considered. The utility of the model was assessed through its ability to describe experimental observations from diffusion experiments using toluene as a representative VOCs in well-defined soil columns that contained a toluene degrading bacterium, Pseudomonas putida G7 md Fl, as the sole active microbial species. The gas-liquid mass-transfer was found to be a key parameter controlling the ability of bacteria to degrade VOCs. This finding indicates that soil size and geometry are likely to be important parameters in assessing the possible success of natural attenuation of VOCs in contaminated unsaturated soils. Therefore we found that Pseudomonas putida G7 and Fl were very effective to remove of refractory pollutants such as toluene in soil by Bio-filter

• 대한한의학회지
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• 제18권2호
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• pp.82-96
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• 1997

In order to investigate the effect of Daewhajungeum on the isolated organs, gastrointestinal tract and C.N.S., some kinds of experiments using mice and rats were done. The results were as follows; 1. Daewhajungeum showed the inhibitory effect on the smooth muscle contraction of the isolated ileum and colon induced by acethylchorine chloride and barium chloride in mice. 2. Daewhajungeum showed inhibitory effect on the contraction of the fundus-strip induced by acethylchorine chloride and barium chloride in rats. 3. The preventive effect on pyloric ulcer, indomethacin induced ulcer and ethanol-HCl induced ulcer of mice was recognized. 4. The effect on the acidity of gastric juice was suppressed, but the effect on the pepsin output was not recognized. 5. The transport ability of small and large intestine was significantly decressed. 6. The analgesic effect and the sedative effect were recognized so that the effect of the C.N.S was suggested.

• 대한조선학회논문집
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• 제60권2호
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• pp.86-94
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• 2023

Tonnage taxation has contributed to developing the Korean maritime industry through tax relief for shipping companies. The current tonnage taxation relies on the net tonnage as an earning-capacity indicator in a merchant ship. Although the tonnage tax accords with horizontal equity, it does not match vertical equity because of the different taxable capacities of an individual company. Nowadays, maritime transport uses a dedicated vessel, and each shipping freight embeds a different value of time. It means the tonnage taxation regime should consider the added value of each shipping freight. Meanwhile, as the environmental regulations led by the International Maritime Organization are being strengthened, the Korean merchant fleet must be eco-friendly soon after. This study explores the alternative to renewing tonnage taxation by utilizing the Greenship certification and considering the ability-to-pay principle. Because the Greenship certification scheme encourages shipping decarbonization, maritime transport by a certified ocean-going vessel comes to be treated as an activity for the green economy. Special taxation for the green economy may contribute to shipping sustainability and market competitiveness.