• Journal of Electrochemical Science and Technology
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• 제12권1호
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• pp.159-165
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• 2021

YSZ based anode supported solid oxide fuel cells (SOFCs) were prepared, and two cells with different electrolyte thicknesses were connected in series for the simulation of a cell-imbalanced fuel cell stack. Pure YSZ cells in a series connection exhibited a rapid degradation when a thick electrolyte cell was operated under a negative voltage. On the other hand, ceria added-YSZ cells in a series connection were stable under similar operating conditions, and the power density and impedance were about the same as those before tests. The improved stability was due to the reduction of internal partial pressure in the electrolyte by locally increasing the electronic conduction. Thus, we propose a new protection method, i.e., the local addition of ceria in the YSZ electrolyte, to extend the lifetime of a cell-imbalanced SOFC stack.

• Radiation Oncology Journal
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• 제32권1호
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• pp.14-22
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• 2014

Purpose: To evaluate the safety and efficacy of transcatheter arterial chemoembolization (TACE) followed by radiotherapy (RT) in treatment-na$\ddot{i}$ve patients with locally advanced hepatocellular carcinoma (HCC). Materials and Methods: Eligibility criteria were as follows: newly diagnosed with HCC, the Barcelona Clinic Liver Cancer stage C, Child-Pugh class A or B, and no prior treatment for HCC. Patients with extrahepatic spread were excluded. A total of 59 patients were retrospectively enrolled. All patients were treated with TACE followed by RT. The time interval between TACE and RT was 2 weeks as per protocol. A median RT dose was 47.25 $Gy_{10}$ as the biologically effective dose using the ${\alpha}/{\beta}$ = 10 (range, 39 to 65.25 $Gy_{10}$). Results: At 1 month, complete response was obtained in 3 patients (5%), partial response in 27 patients (46%), stable disease in 13 patients (22%), and progressive disease in 16 patients (27%). The actuarial one- and two-year OS rates were 60.1% and 47.2%, respectively. The median OS was 17 months (95% confidence interval, 5.6 to 28.4 months). The median time to progression was 4 months (range, 1 to 35 months). Grade 3 or greater liver enzyme elevation occurred in only two patients (3%) after RT. Grade 3 gastroduodenal toxicity developed in two patients (3%). Conclusion: The combination treatment of TACE followed by RT with two-week interval was safe and it showed favorable outcomes in treatment-na$\ddot{i}$ve patients with locally advanced HCC. A prospective randomized trial is needed to validate these results.

• Tuberculosis and Respiratory Diseases
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• 제57권3호
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• pp.257-264
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• 2004

배 경 : 생존율이 아주 낮은 국소 진행성의 비소세포 폐암에서 생존율 증가 시키기 위한 여러가지 방법이 시도되고 있다. 그 중에서 화학-방사선 동시요법은 치료 반응율은 높아지지만 치료에 따른 부작용 또한 적지 않다. 화학-방사선치료를 병용할 경우에 있어서 항암제의 종류, 용량 및 투여방법과 방사선 조사의 적절한 시기에 관해서 아직 논란이 많은 상태이다. 본 연구는 docetaxel/cisplatin 병용화학요법의 초기에 방사선 치료를 동시에 실시한 환자들의 치료성적과 부작용 및 생존 기간을 알아보았다. 방 법 : 2000년 5월부터 2001년 9월까지 고신대학교 복음병원에 내원하여 비소세포 폐암으로 진단받은 병기 IIIA, IIIB의 환자들 중, 과거 항암치료력이 없고 수술이 불가능한 16명 환자를 분석하였다. 환자는 평균 연령은 58세이고 모두 남자이었다. ECOG 0-1이 14명, 2가 2명이었다. 병리조직학적으로 편평 상피세포암 10명(62.5%), 선암 6명(37.5%)이었다. 병기는 IIIA 2예, IIIB 14 예이었다. 방사선치료는 첫 번째 화학요법을 마친 다음날 1.15 Gy 씩 1일 2회 과분할조사를 시행하여 총 69 Gy를 6주간 조사하였고, 화학치료는 매 3주 주기로 6회 치료를 원칙으로 하였다. 화학요법 제1일에 docetaxel 75 $mg/m^2$를 주입한 후 이어서 cisplatin 60 $mg/m^2$를 정주하였다. 총 6차례 항암 화학 요법을 마친 후 치료반응 및 치료 동안의 부작용 및 생존기간을 조사하였다. 결 과 : 완전 관해는 4명(25.0%), 부분 관해는 12명(75%)으로 모든 환자에서 반응이 있었다. 치료 도중 독성의 빈도는 3도 이상의 백혈구 감소증이 87.5%, 3도 식도염이 68.8%이 발생하였다. 항암 화학 요법은 평균 5.6회(4-6회)실시하였고 백혈구의 감소로 인하여 16명 모두에서 약제 감량을 실시하였고 평균 2.9회에서 이루어졌다. 16명 중 13명이 사망하였고 중앙 생존 기간은 19.9개월(4.3-39.7개월)이고 1년 생존율은 68.7%, 2년 생존율은 43.7%, 3년 생존율은 29.1%이고 무질병 진행 기간은 중앙값이 9.3개월이었다. 추적 조사 중 국소재발은 11예 66.8%이었고, 원격 전이는 3예(18.8%)에서 관찰이 되었다. 원격 전이의 경우 골전이가 2예, 뇌전이가 1예에서 일어났다. 결 론 : 국소 진행성 폐암의 치료로 docetaxel/cisplatin을 3주마다 주사하면서 초기에 화학-방사선 요법을 동시에 실시할 경우에 반응율과 생존율은 우수하였으나 치료에 따른 부작용은 많이 발생하였다. 따라서 향후 부작용을 최소화시키고 치료효과를 최대화시키기 위해서는 약제의 용량, 투여방법 및 방사선치료 시기에 대한 연구가 더 필요할 것으로 생각된다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권4호
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• pp.51-62
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• 2012

Effects of climate change on groundwater system requires understanding the groundwater system in temporal and spatial scales through the long-term monitoring. In this study, the spatio-temporal variations of groundwater were analyzed through the continuous observation of water level, electrical conductivity (EC) and water temperature with automatic data-loggers and sampling in a Gwangneung catchment, Korea, for the four years from 2008 to 2011. Groundwater monitoring were performed at the nest-type wells, MW1 and MW2, located in upsteam and downstream of the catchment, respectively. During the survey period, both the total amount of annual precipitation and the frequency of concentrated rainfall have increased resulting in the elevation of runoff. Water level of MW1 showed no significant fluctuations even during the rainy season, indicating the confined groundwater system. In contrast, that of MW2 showed clear seasonal changes, indicating the unconfined system. The lag-time of temperature at both wells ranged from one to three months depending on the screened depths. Results of chemical analyses indicated that major water compositions were maintained constantly, except for the EC decreases due to the dilution effect. Values of the stable-isotope ratios for oxygen and deuterium were higher at MW2 than MW1, implying the confined system at the upstream area could be locally developed.

• 대한기계학회논문집B
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• 제26권9호
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• pp.1201-1208
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• 2002

A numerical flow-field analysis is performed to investigate flow configurations in the anode, cathode and cooling channels on the bipolar plates of a proton exchange membrane fuel cell (PEMFC). Continuous open-faced flow channels are formed on the bipolar plate surface to supply hydrogen, air and water. In this analysis, two types of channel pattern are considered: serpentine and spiral. The averaged pressure distribution and velocity profiles of the hydrogen, air and water channels are calculated by two-dimensional flow-field analysis. The equations for the conservation of mass and momentum in the two-dimensional fluid flow analysis are slightly modified to include the characteristics of the PEMFC. The analysis results indicate that the serpentine flow-fields are locally unstable (because two channels are cross at right angles). The spiral flow-fields has more stable than the serpentine, due to rotational fluid-flow inertia forces. From this study, the spiral channel pattern is suggested for a channel pattern of the bipolar plate of the PEMFC to obtain better performance.

• 제어로봇시스템학회논문지
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• 제10권12호
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• pp.1148-1154
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• 2004

The goal of this paper is to verity that the gradual reduction of drug dose (GRDD), which has already been shown by authors to be effective for a simplified HIV infection model, still works for a more realistic model. While the simplified HIV infection model does not take into account an helper-independent CTL, the five state nonlinear model proposed by Wodarz describes the dynamics of both helper-dependent and helper-independent CTL in HIV infection. In this paper, it is shown that, by applying GRDD to Wodarz's five state HIV infection model, the state of HIV infected patient converges to that of non-progressor whose immune response is excited so that his symptom would not be developed into AIDS. Roughly speaking, GRDD is 'slow reduction of dose after the maximum dose for a certain period.' It turns out that an equilibrium representing non-progressor is locally asymptotically stable for the most values of drug dosage, which is required to hold in order to apply GRDD. Simulation results establish that GRDD is still considerably effective both for an AIDS patient and a patient who has been on HAART for a long time.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권10호
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• pp.3361-3377
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• 2014

Synchronous computing models provided by real-time synchrony protocols, such as TTA [1] and PALS [2], greatly simplify the design, implementation, and verification of real-time distributed systems. However, their application to real systems has been limited since their assumptions on underlying systems are hard to satisfy. In particular, most previous real-time synchrony protocols hypothesize the existence of underlying fault tolerant real-time networks. This, however, might not be true in most soft real-time applications. In this paper, we propose a practical approach to a synchrony protocol, called Quality-Aware PALS (qPALS), which provides the benefits of a synchronous computing model in environments where no fault-tolerant real-time network is available. qPALS supports two flexible global synchronization protocols: one tailored for the performance and the other for the correctness of synchronization. Hence, applications can make a negotiation flexibly between performance and correctness. In qPALS, the Quality-of-Service (QoS) on synchronization and consistency is specified in a probabilistic manner, and the specified QoS is supported under dynamic and unpredictable network environments via a control-theoretic approach. Our simulation results show that qPALS supports highly reliable synchronization for critical events while still supporting the efficiency and performance even when the underlying network is not stable.

• Interaction and multiscale mechanics
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• 제2권4호
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• pp.375-396
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• 2009

In the present work, the elasto-viscoplastic behavior, interactions between grains, and the texture evolution in polycrystalline materials subjected to finite deformations are modeled using a multiscale analysis procedure within a finite element framework. Computational homogenization is used to relate the grain (meso) scale to the macroscale. Specifically, a polycrystal is modeled by a material representative volume element (RVE) consisting of an aggregate of grains, and a periodic distribution of such unit cells is considered to describe material behavior locally on the macroscale. The elastic behavior is defined by a hyperelastic potential, and the viscoplastic response is modeled by a simple power law complemented by a work hardening equation. The finite element framework is based on a Lagrangian formulation, where a kinematic split of the deformation gradient into volume preserving and volumetric parts together with a three-field form of the Hu-Washizu variational principle is adopted to create a stable finite element method. Examples involving simple deformations of an aluminum alloy are modeled to predict inhomogeneous fields on the grain scale, and the macroscopic effective stress-strain curve and texture evolution are compared to those obtained using both upper and lower bound models.

• The Plant Pathology Journal
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• 제21권3호
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• pp.288-292
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• 2005

Pathogenesis-related protein-1a (PR-1a) is strongly induced in tobacco plants by pathogen attack, exogenous salicylic acid (SA) application and by other developmental processes. In order to develop a rapid screening system for the selection of plant defense-inducing compounds originated from various sources, we have transformed tobacco Samsun NN plants with a chimeric construct consisting of GUS $(\beta-glucuronidase)$. In the $T_1$ generation, three transgenic lines having stable GUS expression were selected for further promoter analysis. Using GUS histochemical assay, we observed strong GUS induction driven by PR-1a promoter in PR1a-GUS transgenic tobacco leaves in response to the exogenous application of SA or benzol (1,2,3) thiadiazole-7-carbothioic acid S-methyl ester (BTH), a SA­derivative compound. In addition, GUS expression was maintained locally or systemically in PR1a-GUS transgenic line $\#5\;T_2$ generation) until after 3 days when they were treated with same chemicals. Our results suggested that the PR1a-GUS reporter gene system in tobacco plants may be applicable for the large-scale screening of defense-inducing substances.

• 패션비즈니스
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• 제24권2호
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• pp.17-31
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• 2020

The concept of municipal police is in contrast to the national police, which is in charge of the overall people. With increased localization, the need for a municipal police system is emphasized in each region. This study is intended to analyze the role of municipal police uniform considering the change in security from the national to the local level based on the introduction of municipal police system. The study investigators developed the concept of centralized national police system and decentralized self-governing municipal police system based on a literature review and Internet research. The investigators analyzed the design of municipal police uniform by reviewing the systems in several other countries. The results revealed specific formative features of municipal police uniform such as representative ambivalence, expression of visual language, manifest visibility, and reflection of regional characteristics. The municipal police uniform is adapted to changes in local government requiring a shift of awareness on to municipal police compared with the existing national police. The creation of a municipal police uniform enhances the efficiency of work by projecting a resident-friendly image, social support and cooperation, which play a huge role in illustrating the exemplary service to promote a stable and peaceful society locally.