• 대한환경공학회지
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• 제34권6호
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• pp.406-413
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• 2012

막오염을 감소시킬 수 있는 첨가제로서 chitosan, 염화제이철, MPE50의 막오염 저감 효과를 비교하여 연구하였다. 세가지 첨가제를 다양한 농도로 활성슬러지에 주입한 후 회분여과실험을 수행하여 막오염 특성의 변화를 평가하였다. Chitosan 20 mg/g-MLSS, 염화제이철 70 mg/g-MLSS, MPE50 20 mg/g-MLSS의 주입량에서 여과저항과 케이크 비저항이 모두 최소화되었는데, 케이크 여과저항 뿐 아니라 파울링 여과저항도 함께 감소하는 양상이 관찰되었다. 그러나 서로 다른 활성슬러지에 chitosan을 첨가하는 세 차례의 실험에서 최적 주입농도는 10, 20, 30 mg/g-MLSS로 서로 다르게 나타나, 최적 주입농도가 상수치가 아니라 활성슬러지의 특성에 영향을 받는 것으로 확인되었다. 세 첨가제 모두 최적 주입농도보다 더 많은 양을 주입한 경우 오히려 막여과 특성이 악화되었다. 첨가제의 주입에 따른 여과저항 감소의 기작을 분석하기 위하여 미생물 플록의 제타 전위, 소수성, 입도분포, 상징수 탁도, 용존성 EPS 등의 다양한 분석을 수행하였다. 최적 주입농도에서 제타전위는 0에 가깝게 그리고 입자크기는 가장 크게 나타났는데, 이러한 결과는 음전하를 띠는 슬러지 플록에 양전하의 첨가제가 주입되면서 미세입자의 불안정화 및 재안정화 메커니즘을 보이는 것으로 해석할 수 있다. 또한 최적 주입농도에서 용존성 EPS 농도와 상징수 탁도는 가장 작은 값이 관찰되었는데, 미생물 플록이 응집하며 성장하는 과정에서 고분자의 EPS와 미세 입자가 포집된 결과로 해석된다. 또한 이러한 효과는 고분자성 양이온물질인 chitosan과 MPE50에서 염화철보다 더 크게 나타났다.

• Tuberculosis and Respiratory Diseases
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• 제75권6호
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• pp.244-249
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• 2013

Background: Conventional biomarkers cannot always establish the cause of pleural effusions; thus, alternative tests permitting rapid and accurate diagnosis are required. The primary aim of this study is to assess the ability of pentraxin-3 (PTX3) in order to diagnose the cause of pleural effusion and compare its efficacy to that of other previously identified biomarkers. Methods: We studied 118 patients with pleural effusion, classified as transudates and exudates including malignant, tuberculous, and parapneumonic effusions (MPE, TPE, and PPE). The levels of PTX3, C-reactive protein (CRP), procalcitonin (PCT) and lactate in the pleural fluid were assessed. Results: The levels of pleural fluid PTX3 were significantly higher in patients with PPE than in those with MPE or TPE. PTX3 yielded the most favorable discriminating ability to predict PPE from MPE or TPE by providing the following: area under the curve, 0.74 (95% confidence interval, 0.63-0.84), sensitivity, 62.07%; and specificity, 81.08% with a cut-off point of 25.00 ng/mL. Conclusion: Our data suggests that PTX3 may allow improved differentiation of PPE from MPE or TPE compared to the previously identified biomarkers CRP and PCT.

• 한국항만경제학회지
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• 제40권2호
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• pp.191-204
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• 2024

본 연구에서는 항공물류산업의 소부장 전문기업을 대상으로 AHP 기반의 생산관리 직무교육을 개발하였다. AHP 모형은 1계층과 2계층으로 설계하였다. 생산관리 직무교육의 1계층의 요인으로는 구매관리역량, 자재관리역량, 공정관리역량, SCM역량이 선정되었다. 각 1계층에 2계층 평가요인을 선정하였다. AHP 분석결과, 1계층 평가요인의 상대적 중요도는 SCM 역량(0.322), 공정관리역량(0.314), 자재관리역량(0.201), 구매관리역량(0.163)의 순으로 나타났다. 1계층 중에는 SCM역량과 공정관리역량의 중요도가 높게 나타난 것으로 분석되었다. 항공물류산업의 소부장 기업의 생산관리 교육과정 개발을 위한 평가요인의 우선 순위는 다음과 같이 분석되었다. 먼저, SCM역량의 2계층인 공급망 성과관리가 최우선 요인으로 분석되었고, 공정관리 역량의 2계층인 설비보전관리, SCM 역량의 2계층인 공급망 생산운영, 공정관리 역량의 2계층인 공정픔질관리, SCM 역량의 2계층인 공급망 운송관리와 공급망 공급계획 등으로 평가요인의 우선순위가 도출되었다

• Journal of Electrical Engineering and Technology
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• 제13권2호
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• pp.800-811
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• 2018

This paper presents a regenerative braking control scheme for Switched Reluctance Machine (SRM) drive in Electric Vehicles (EVs). The main purpose is to maximize the recovered energy during battery charging by taking into account the nonlinear physical characteristics of the Switched Reluctance Machine. The proposed regenerative braking method employs the back-EMF in the generation process as a complicated position-dependent voltage source. The proposed maximum power recovery (MPR) operation of the regenerative braking is first based on the maximization of the extracted power from the machine and then the maximization of the power transferred to the battery. The maximum power extraction (MPE) from SRM is based on maximizing the energy conversion ratio by the calculation of the optimum PWM switching duty cycle, turn-on, and turn-off angles. By using the impedance matching theorem that allows the maximum power transfer (MPT) of the MPE, the proposed MPR is achieved. The parametric averaged value modeling of the machine phase currents in the chopping control mode is used for MPR realization. By following this model, a nonlinear equivalent input resistance is derived for the battery internal resistance matching. The effectiveness of the proposed regenerative braking method is demonstrated through simulation results and experimental implementation.

• 대한약침학회지
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• 제26권1호
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• pp.10-17
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• 2023

Objectives: Murraya paniculata (family-Rutaceae), popularly known as orange jasmine, is the most important evergreen plant. The Rutaceae family is economically significant due to its diverse edible fruits and essential oils. Methods: Murraya paniculata extracts (MPE) of leaf have been shown to include phenolic compounds, highly oxygenated flavonoids, flavanones, sesquiterpenoids, polymethoxy glycosides, and coumarins. Cyclocitral, methyl salicylate, trans-nerolidol, cubenol, isogermacrene, -cadinol, and cubeb-11-ene are all abundant in MPE. The usages of various parts of this plant, such as bark, leaves and flower, as a remedy for a variety of ailments as widely recorded in the traditional literature. The plant has anti-diabetic, anti-obesity, antibacterial, anti-implantation, anti-oxidative, cytotoxic, anti-diarrheal, antidepressant and anti-anxiety properties and many others. Results: The goal of the review is to reignite interest in this potential plant, encouraging researchers to continue their research in order to uncover novel therapeutic compounds for the treatment and management of a range of infections. The current review provided a comprehensive overview of this traditional unique plant. Conclusion: The review paves a way for exploring its active chemical elements with substantial pharmacological values further for potential benefits of mankind.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2009년도 춘계학술발표대회
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• pp.1296-1299
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• 2009

본 논문은 이동체에 대한 위성방송 및 인터넷 서비스를 지속적으로 제공하기 위해 기존의 DVB-S2 표준화에 DVB-H 와 DVB-T 를 결합한 새로운 DVB-SSP 표준화에 대한 연구를 하고 있다. 이동형 DVB-S2의 표준화는 DVB-SSP 라 불리며 최근에는 DVB-SH로 불리고 있다. 이는 이동체에 대해서 위성을 이용한 통신 방식을 규정하고 있으며, physical layer 와 upper layer 의 두 단계로 부호화 및 복호화하는 방식인 cross layer 부호화 방식을 적용하고 있다. 기존의 방식 경우, LDPC 복호후 CRC 검사를 수행하여 수신된 데이터에서 1 bit 의 오류에도 IP 패킷 모두를 삭제함으로써 복호시 비효율성을 나타낼 수 있다. 따라서 본 논문에서는 LDPC 복호기에 출력되는 LLR 값을 이용하여 IP 패킷 전체를 삭제하는 것이 아니라 LLR 값이 낮은 비트만 선택적으로 삭제하는 방식을 제안하며, 이를 시뮬레이션하여 기존의 CRC 방식과 비교하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권7호
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• pp.3495-3499
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• 2012

The aim of this study was to evaluate the diagnostic value of interleukin 21(IL-21) and carcinoembryonic antigen (CEA) in tuberculous pleural effusions (TPEs) and malignant pleural effusions (MPEs). Pleural effusion samples from 103 patients were classified on the basis of diagnosis as TPE (n=51) and MPE (n=52). The concentration of IL-21 was determined by ELISA. Lactate dehydrogenase (LDH), adenosine dehydrogenase (ADA) and CEA levels were also determined in all patients. A significant difference was observed in the levels of ADA and CEA (P<0.01), but not in the levels of LDH (P>0.05) between TPE and MPE. The concentration of IL-21 in MPE was significantly higher compared to TPE (P<0.01). With a threshold value of 4.32 pg/ml, IL-21 had a sensitivity of 76.9% (40/52) and a specificity of 80.4% (41/51). Combined detection of IL-21 and CEA had a sensitivity of 69.2% (36/52) and a specificity of 92.2% (47/51). These two markers can contribute to the differential diagnosis of MPEs.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.282-284
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• 2003

Multi-phase extraction of LNAPLs not only floating on groundwater but also captured in soil pores was studied in a simulated soil system. The extraction rate of LNAPL under the MPE conditions was much higher than the rate under usual hydraulic gradient conditions. The WE might be especially useful for recovery of oils in fine-textured soils such as clay-dominant soils. The vacuum-enhanced transport of LNAPL in soils also depended on the properties of LNAPL such as viscosity and density as well as soil textures.

• 한국멀티미디어학회논문지
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• 제9권12호
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• pp.1669-1680
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• 2006

This paper explains that the RF systems for hi-directional wireless capsule endoscopes were designed and implemented. The designed RF systems for a capsule endoscope can transmit the images of intestines from the inside to the outside of a body and the behavior of the capsules can be controlled by an external controller simultaneously. The hi-directional wireless capsule endoscope consists of a CMOS image sensor, FPGA, LED, battery, DC to DC Converter, transmitter, receiver, and antennas. The transmitter and receiver which were used in the hi-directional capsule endoscope, were designed and fabricated with $10mm(diameter){\times}3.2mm(thickness)$ dimensions taking into the MPE, power consumption, system size, signal to noise ratio and modulation method. The RF systems designed and implemented for the hi-directional wireless capsule endoscopes system were verified by in-vivo experiments. As a result, the RF systems for the hi-directional wireless capsule endoscopes satisfied the design specifications.

• 천문학회보
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• 제37권1호
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• pp.32.2-32.2
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• 2012

Gamma Ray Bursts (GRBs) are the most energetic events in the universe, and are known to arise from the death of massive stars in many cases. Their extreme brightness makes it possible to detect them at very high redshift (z > 6.5), well into the epoch of re-ionization, providing us with an opportunity to investigate the deaths of the first stars when the universe was much younger than 1 Gyr. Here, we report the discovery of GRB 100905A, a GRB at $z$ - 7.5 (age of the universe at 700 Myr). Our observation revealed a strong spectral break between z and J band, allowing us to estimate its photometric redshift. Its gamma-ray light curve shows a very short duration of about 0.7 sec, the shortest duration event at z > 5. Investigation of this and three other known GRBs at z > 6.5 reveals that they are all short duration bursts. This is puzzling, considering that GRBs from death of massive stars do not show short duration. We suggest two possible explanations for this: (i) the BAT light curves of the high redshift GRBs suffered from observational selection effect where we are only observing the very tip of the light curve; (ii) the stars in the early universe had a peculiar nature that are different from ordinary stars at lower redshifts.