• 한국환경보건학회지
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• 제23권3호
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• pp.102-108
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• 1997

It has been studied that SO$_2$ removal efficiency of anthracite-bituminous coal blend combustion in a fludized bed coal combustor. The objectives of this study were to investigate SO$_2$ removal characteristics of coal blend combustion with Ca/S, anthracite fraction, bed temperature, and limestone size. The experimental results were presented as follows First, the effect of the desulfurization by the dia size of limestone was great and SO$_2$ removal efficiency was highest in limestone dia 631 $\mu$m. Second, as air velocity increased, the desulfurization rate decreased a little. But the difference of the desulfurization rate according to air velocity was not too large. As the height of fluidized bed combustor increased regardless of air velocity, SO$_2$ concentration tends to increase largely. Third, as Ca/S mole ratio incresed, SO$_2$ desulfurization rate incresed rapidly up to Ca/S mole ratio 3 while the desulfurization rates did not increse too largely in the range of more than the level. Forth, the bed temperature had a great effect on the desulfurization rate and the desulfurization rate tended to increase slightly as anthracite fraction increased.

• 한국분무공학회지
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• 제22권2호
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• pp.96-102
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• 2017

In order to reduce the NOx, SCR technology is most suitable. In this study, we focused on studying the injector part of urea-SCR system. When stoichiometric 1 mole of urea is injected, 2 moles of $NH_3$ are created. $NH_3$ causes a SCR reaction by reacting with NOx. However, urea is decomposed by the side reaction of coming out HNCO, deposit formation is formed. In this study, it was to design a nozzle that can spray the optimal spray flow rate. Test nozzle used in this experiment is efferverscent type. The result of the experiment, liquid flow rate was confirmed to be that they are dominated by the exit orifice diameter. The area ratio is defined by ratio of the area of exit orifice hole and that of aerorator. The droplet size was measured by varying the area ratios. In addition, it was also confirmed that there is no change of the liquid flow rate and air flow rate to change the aerorator at the same exit orifice. Further, It was confirmed that the droplet size was relatively uniform even though the area ratio was different. Finally, there is little change in the SMD that air flow rate increases in 0.3 or more ALR.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.3120-3124
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• 2008

A three-dimensional computational fluid dynamics (CFD) analysis is performed to investigate flow characteristics in the anode channels and manifold of the internal reforming type molten carbonate fuel cell (MCFC). Considering the computational difficulties associated with the size and geometric complexity of the MCFC system, the polyhedral meshes that can reduce mesh connectivity problems at the intersection of the channel and the manifold are adopted and chemical reactions inside the MCFC system are not included. Through this study, the gas flow rate uniformity of the anode channels is mainly analyzed to provide basic insights into improved design parameters for anode flow channel design. Results indicate that the uniformity in flow-rate is in the range of ${\pm}1%$ between the anode channels. Also, the mal-distributed inlet flow-rate conditions and the change in the size of the manifold depth have no significant effect on the flow-rate uniformity of the anode channels.

• Asian Pacific Journal of Cancer Prevention
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• 제15권20호
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• pp.8793-8796
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• 2014

Objective: To explore the influence of serum vascular endothelial growth factor (VEGF) level on therapeutic outcome and diagnosis/prognostic value in patients with cervical cancer. Materials and Methods: A total of 37 patients diagnosed with cervical cancer by biopsy were selected and treated with concurrent chemoradiotherapy. Double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) was adopted before treatment to assess VEGF levels, and its relationships with clinicopathological features and short-term therapeutic effects were analyzed. Results: The median VEGF level in 37 patients before treatment was 647.15 (393.35~1125.16) pg/mL. Serum VEGF levels in patients aged <50 years, in International Federation of Gynecology and Obstetrics (FIGO) stage IIIa~IVa, with lymph node metastasis and tumor size >4 cm were significantly increased (P<0.05). The complete remission (CR) rate was 48.7% (18/37), partial remission (PR) rate was 35.1% (13/37), stable disease (SD) rate was 13.5% (5/37) and progressive disease (PD) rate was 2.70% (1/37), so the objective remission rate (ORR) after treatment was 83.8% (31/37). Logistic regression analysis showed that tumor size and serum VEGF level before treatment were independent risk factors affecting the therapeutic outcome, and the higher the level of serum VEGF, the worse the prognosis when tumor size>4 cm. Some 56.8% of patients manifested with myelosuppression, 37.8% with leucopenia, 24.3% with thrombocytopenia, 5.41% with diarrhea, 46.0% with nausea and vomiting, 21.6% with hair loss and 8.11% with hepatic and renal injury during the treatment. Conclusions: Serum VEGF level may reflect the degree of malignancy of cervical cancer and predict therapeutic effect, which is of great importance to cancer diagnosis and prognosis.

• 소성∙가공
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• 제11권3호
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• pp.255-261
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• 2002

The grain size of 7010 Al alloy was refined to submicrometer level by using equal channel angular pressing (ECAP) and additional warm rolling. The mechanisms of grain refinement in ECAP process were fragmentation of coarse grain to ultra fine subgrains after a few passes and continuous recrystallization of the subgrains with the increase o( passes. Because of ultrafine grain size, essentially low temperature and high strain rate superplasticity was observed after ECAP process and warm rolling to form a sheet metal. The maximum elongation of 700% was obtained for an ECA pressed specimen after IS passes without warm rolling at $450^{\circ}C$ with strain rate of 5x$10^{-3}$/sec.

• 한국해양공학회지
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• 제16권3호
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• pp.59-64
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• 2002

In the present study, we examined the influence of prestrain on creep strength of Class M alloy(STS310S) and Class A(STS310J1TB) alloys containing precipitates. Prestrain was given by prior creep at a higher stress than the following creep stresses. Creep behaviour before and after stress change and creep rate of pre-strained specimens were compared with that of virgin specimens. Pre-straining produced the strain region where the strain rate was lower than that of a virgin specimen both for STS310J1TB and STS310S steels. The reason for this phenomenon was ascribable to the viscous motion of dislocations, the interaction between dislocations and precipitates in a STS310J1TB steel, and the interaction of dislocations with sub-boundaries in a STS310S steen which has the higher dislocation density and smaller subgrain size resulted from pre-straining at higher stress.

• 한국전자거래학회:학술대회논문집
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• 한국전자거래학회 2005년도 e-Biz World Conference 2005
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• pp.299-304
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• 2005

This paper is a research on the dynamic signature verification of error rate which are false rejection rate and false acceptance rate, the size of signature verification engine, the size of the characteristic vectors of a signature, the ability to distinguish similar signatures, and so on. We suggest feature extraction and comparison method of the signature verification. Also, we have implemented our system with Java technology for more efficient user interfaces and various OS Platforms.

• 한국전자거래학회지
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• 제10권3호
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• pp.49-65
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• 2005

본 논문은 동적(온라인) 서명인증 기술에 관한 것으로 서명의 특징 벡터, 유사 서명에 대한 변별력, 오류율 등에 대해서 살펴보고, 고성능 서명 인증시스템을 위한 특징 추출과 매칭 방법을 제안하고, 보다 효율적인 사용자 인터페이스를 설계하였고, 다양한 OS플랫폼 지원을 위하여 Java 기술을 이용한 웹 인증 서버를 구현하였다.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.219-220
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• 2006

To understand the effect of powder characteristics on the thermal debinding behavior, PIM parts produced with powders with different particle sizes and particle shapes were examined to determine their weight losses during thermal debinding. The results show that the average diameter of the pore channel in the compact increased when the temperature increased and when coarse powders were used. However, the weight loss rates did not increase proportionally with the pore size. This suggests that the different powders that are frequently used in PIM parts do not affect the thermal debinding rate significantly. This is because the pore size is much larger than the mean free path of the decomposed gas molecules. Thus, the diffusion rates of the gases are not rate-controlling in thermal debinding. The controlling mechanism of the thermal debinding rate is the decomposition of the backbone binder in the PIM parts.

• Journal of Information Processing Systems
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• 제16권4호
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• pp.959-974
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• 2020

High efficiency video coding (HEVC) employs quadtree coding tree unit (CTU) structure to improve its coding efficiency, but at the same time, it also requires a very high computational complexity due to its exhaustive search processes for an optimal coding unit (CU) partition. With the aim of solving the problem, a fast CU size decision optimal algorithm based on neighborhood prediction is presented for HEVC in this paper. The contribution of this paper lies in the fact that we successfully use the partition information of neighborhood CUs in different depth to quickly determine the optimal partition mode for the current CU by neighborhood prediction technology, which can save much computational complexity for HEVC with negligible RD-rate (rate-distortion rate) performance loss. Specifically, in our scheme, we use the partition information of left, up, and left-up CUs to quickly predict the optimal partition mode for the current CU by neighborhood prediction technology, as a result, our proposed algorithm can effectively solve the problem above by reducing many unnecessary prediction and partition operations for HEVC. The simulation results show that our proposed fast CU size decision algorithm based on neighborhood prediction in this paper can reduce about 19.0% coding time, and only increase 0.102% BD-rate (Bjontegaard delta rate) compared with the standard reference software of HM16.1, thus improving the coding performance of HEVC.