• 한국축산식품학회지
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• 제32권5호
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• pp.618-626
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• 2012

Citrus (Citrus unshiu S. Marcoy) industry by-products were used as a source of dietary fiber, and the effects of dietary fiber extracted from citrus peel on the proximate composition, pH, color, protein solubility, cooking loss, emulsion stability, and apparent viscosity of a chicken emulsion in model systems were examined. Chicken emulsions were prepared by adding citrus peel fiber at four different concentrations (1, 2, 3, and 4%). The apparent viscosity, redness, and yellowness of the chicken emulsion with citrus peel fiber were higher than those of the control (p<0.05). The lightness values of the chicken emulsions were lower in treatments containing citrus peel fiber (p<0.05). Furthermore, moisture content, cooking loss, and emulsion stability of the chicken emulsion with 1-2% citrus peel fiber were higher than those of other treatments (p<0.05). Fat content was lower in the treatments with added citrus peel fiber than that in the control (p<0.05). Chicken emulsions with added citrus peel fiber had improved quality characteristics, and the best results were obtained for the chicken emulsion with 2% added citrus peel fiber.

• 동의생리병리학회지
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• 제37권2호
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• pp.25-29
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• 2023

This study was designed to establish an atopic dermatitis (AD) model using MC903 and was conducted to find out the optimal challenge concentration that can cause dermatitis symptoms enough to be experimentally verified while reducing adverse effects such as weight loss. MC903 was treated at concentrations of 2, 3, and 4 nmol/day, and evaluation of skin surface symptoms, water contents, histopathological changes, body weight changes, and spleen/body weight ratio was conducted. In addition, the expression level of thymic stromal lymphopoietin (TSLP) was also observed. In our results, MC903 induced AD skin lesions such as erythema, scab and fissure and lowered skin moisture level significantly. In addition, water holding capacities in the 3 or 4 nmol groups were diminished significantly compared to that in the control group. On the other hand, 4 nmol treatment induced a weight loss of up to 20% compared to control group. Finally, a higher level of TSLP expression was observed in the 3 nmol group than in the 2 nmol group or the 4 nmol group. Taken together, we propose a total 14-day protocol consisting of 3 days of sensitization (2 nmol/day) and 6 days of challenge (3 nmol/day).

• Geomechanics and Engineering
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• 제35권6호
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• pp.581-591
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• 2023

North Anatolian Fault Zone is tectonically active with recent earthquakes (Mw7.6 1999-Kocaeli and Mw7.2 1999-Düzce earthquakes) and it passes through Marmara region, which is highly industrialized, densely populated and economically important part of Turkey. Many power plants, located in Marmara region, are exposed to high seismic hazard. In this study, open source OpenQuake software has been used for the probabilistic earthquake hazard analysis of Marmara region and risk assessment for the specified energy facility. The SHARE project seismic zonation model has been used in the analysis with the regional sources, NGA GMPEs and site model logic trees. The earthquake hazard results have been compared with the former and existing earthquake resistant design regulations in Turkey, TSC 2007 and TBSCD 2018. In the scope of the study, the seismic hazard assessment for a typical natural gas combined cycle power plant located in Marmara region has been achieved. The seismic risk assessment has been accomplished for a typical control building located in the power plant using obtained seismic hazard results. The structural and non-structural fragility functions and a consequence model have been used in the seismic risk assessment. Based on the seismic hazard level with a 2% probability of exceedance in 50 years, considered for especially these type of critical structures, the ratios of structural and non-structural loss to the total building cost were obtained as 8.8% and 45.7%, respectively. The results of the study enable the practical seismic risk assessment of the critical facility located on different regions.

• 한국철도학회논문집
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• 제15권4호
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• pp.357-363
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• 2012

본 논문에서는 단상PWM컨버터 차량의 새로운 운전방식에 대해 기술하였다. 최근의 전기차량은 PWM 컨버터를 채택함으로써 그 이전의 차량들에 비하여 역률을 1.0에 가깝도록 유지할 수 있게 되었다. 그러나 이들 차량은 컨버터 제어방식의 비교적 간단한 수정을 통하여 진상 역률 영역에서의 운전이 가능한데, 이러한 특징은 차량 자체만으로는 큰 의미가 없을지 모르나 급전계통과 연계하여 검토하는 경우 선로의 무효전력 손실을 보상함으로써 급전선로의 유효전력 손실을 감소시키고 전압 분포를 개선하는 효과를 나타내게 된다. 이동형 보상장치가 될 수 있다는 특징으로 무효전력 보상을 위해 일반적으로 검토되는 SVC와 비교해도 장점을 가지게 된다. PWM컨버터차량의 진상운전 조건 및 관련식의 유도와 함께 이러한 방식을 적용하기 위한 새로운 역률 제어 알고리즘을 제시하였다. SIMULINK 모델을 사용한 모의를 통하여 제시된 방법의 실 적용 가능성을 검토하였으며 만족할 만한 결과를 얻을 수 있었다.

• 한국통신학회논문지
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• 제29권7B호
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• pp.667-674
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• 2004

TCP(transmission control protocol)의 성능은 손실 복구 과정의 성능에 크게 좌우되는데, 특히 패킷 손실이 발생했을 때 이를 RTO(retransmission timeout)을 유발하지 않고 재전송에 의해서 복구가 가능한가의 여부는 매우 중요한 문제라고 할 수 있다. TCP SACK(selective acknowledgement)은 다수 개의 패킷 손실이 발생하더라도 재전송에 의해서 효율적으로 복구할 수 있는 장점을 가지고 있지만, 재 전송한 패킷이 다시 손실되는 경우에는 언제나 RTO를 유발시키는 문제점이 있다. 본 논문에서는 이 문제를 해결하기 위한 알고리듬을 제안한다. 제안된 알고리듬을 사용하는 TCP SACK+는 기존의 TCP와의 호환성을 완벽하게 유지하는 동시에 재전송 패킷 손실을 감지할 수 있는 장점을 가지고 있다 TCP SACK+의 성능을 평가하기 위해서 모델링을 이용한 확률적 분석과 시뮬레이션을 도입한다. 결과를 통해서 TCP SACK+는 거의 모든 재전송 손실을 복구할 수 있기 때문에 TCP SACK보다 손실 복구 성능 차원에서 상당히 성능을 향상시킬 수 있음을 알 수 있다.

• 대한한의학회지
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• 제39권1호
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• pp.1-12
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• 2018

Objectives: Astragalus membranaceus has been reported to inhibit immune responses, but its effect on hair loss is not clear. In this study, the effect of A. membranaceus extract (AM) on hair regrowth in C57BL/6 mice with natural hair loss in the telogen phase was investigated. Methods: Mice with natural hair loss were topically treated with 1% AM on the dorsal skin for 2 weeks. Dorsal skin samples were stained with hematoxylin and eosin and probed with an anti-mouse CD8a IgG. The mRNA expression levels of tumor necrosis factor $(TNF)-{\alpha}$, interferon $(IFN)-{\gamma}$ and interleukin (IL)-4 were measured by reverse transcription polymerase chain reaction and quantitative real-time polymerase chain reaction. Results: AM treatment induced hair regrowth in hair loss mice, while control mice suffered continued hair loss. Tapering hair shafts and broken hair follicles were decreased as well as CD8+ T lymphocyte infiltration. In addition, the expressions of $TNF-{\alpha}$, $IFN-{\gamma}$ and IL-4 were reduced by AM treatment. Also, AM treatment significantly increased the KGF expressions in Hs68 fibroblast cells. Conclusion: These results suggest that topical application of A. membranaceus may be an alternative therapy for hair loss.

• Steel and Composite Structures
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• 제33권6호
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• pp.891-906
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• 2019

This study considers the instability behavior of sandwich plates considering magnetorheological (MR) fluid core and piezoelectric reinforced facesheets. As facesheets at the top and bottom of structure have piezoelectric properties they are subjected to 3D electric field therefore they can be used as actuator and sensor, respectively and in order to control the vibration responses and loss factor of the structure a proportional-derivative (PD) controller is applied. Furthermore, Halpin-Tsai model is used to determine the material properties of facesheets which are reinforced by graphene platelets (GPLs). Moreover, because the core has magnetic property, it is exposed to magnetic field. In addition, Kelvin-Voigt theory is applied to calculate the structural damping of the piezoelectric layers. In order to consider environmental forces applied to structure, the visco-Pasternak model is assumed. In order to consider the mechanical behavior of structure, sinusoidal shear deformation theory (SSDT) is assumed and Hamilton's principle according to piezoelasticity theory is employed to calculate motion equations and these equations are solved based on differential cubature method (DCM) to obtain the vibration and modal loss factor of the structure subsequently. The effect of different factors such as GPLs distribution, dimensions of structure, electro-magnetic field, damping of structure, viscoelastic environment and boundary conditions of the structure on the vibration and loss factor of the system are considered. In order to indicate the accuracy of the obtained results, the results are validated with other published work. It is concluded from results that exposing magnetic field to the MR fluid core has positive effect on the behavior of the system.

• 대한전자공학회논문지TC
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• 제48권9호
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• pp.47-53
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• 2011

본 논문에서는 커넥터의 특성임피던스 추출, 분석 방법 및 설계 변경 방법을 제안하고 임피던스를 정합하여 신호 전달 특성을 개선한다. 3차원 FEM(Finite Element Method) 전자기장(Electro-Magnetic Field) 시뮬레이터를 이용하여 커넥터의 S-파라미터를 계산하고 반사손실 및 삽입손실을 추출한다. 커넥터의 신호 전달 특성은 반사손실이 0.9 GHz 이후부터 -20 dB 이상의 값으로 높게 나타났다. 신호 전달 특성이 낮은 원인을 파악하기 위해서 회로 해석 시뮬레이터를 이용하여 커넥터의 등가 회로 모델을 추출하고 특성임피던스를 계산하였다. 커넥터의 특성임피던스는 $90.3{\Omega}$으로 임피던스 부정합이 발생하여 신호 전달 특성이 저하되었다. 따라서 신호 전달 특성을 개선할 목적으로 임피던스를 정합하기 위해서 커넥터의 커패시턴스를 증가시켰다. 이러한 설계 방안으로 커넥터 신호선의 유효 면적을 확장하고, 커넥터의 몸체 소재로 고유전체를 사용하였다. 설계 변경된 커넥터의 특성임피던스는 $58.6{\Omega}$으로 임피던스 정합에 보다 근접하여 커넥터의 반사손실이 대략 10 dB 향상되었다. 신호선의 유효 면적 증가에 의한 반사손실 개선과 고유전체의 적용으로 전자기파의 신호선 주변 집중에 의해서 삽입손실 또한 개선되었다.

• 사물인터넷융복합논문지
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• 제6권3호
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• pp.1-6
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• 2020

본 논문은 평균 객체 전송 지연 시간에 대한 기존의 모델들을 하나의 프레임워크로 통합하고 실제 계산 경험을 통해 결과를 분석하는 것을 목표로 한다. 해석적 객체 전송 지연 시간 모델은 다중 패킷 손실과 작은 혼잡제어 윈도우로 인해 빠른 재전송이 불가능한 멀티홉 무선 네트워크를 위시한 사물 인터넷(IoT) 환경을 가정한다. 이 모델은 또한 초기 혼잡 윈도우 크기와 하나의 혼잡 윈도우에서의 다중 패킷 손실을 고려한다. 성능평가에 의하면, 전송 객체 크기와 패킷 손실률이 작은 경우 평균 객체 전송 지연의 하한값과 상한값은 거의 동일하다. 그러나 패킷 손실률이 커지면 초기 혼잡 윈도우의 크기와 왕복 시간이 평균 객체 전송 지연의 상·하한값에 영향을 미치는 것으로 나타났다.

• 대한기계학회논문집A
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• 제26권8호
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• pp.1552-1564
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• 2002

Meter-in, meter-out and bleed-off circuits are widely utilized in order to adjust the speed of a hydraulic actuator by using a flow control valve and in order to regulate the pressure of a hydraulic volume by using a simple on-off valve. In these circuits, a relief valve serves either to maintain constant system pressure or to protect the system from over-pressure loading. The relief valve of a bleed-off circuit is the second case frequently undergoing on-off action during operation. It makes the analysis of the pressure control characteristics of the circuit highly difficult. In this paper, steady-state flow rate, pressure, heat loss and efficiency of the three circuits are reexamined and basic experiments far obtaining the characteristics of a pump and relief valve are conducted. Finally, simple empirical first-order dynamic models of decreasing and increasing pressure were separately proposed and verified by comparison with experiment. As the result, the basis for the theoretical analysis of the pressure control characteristics of a bleed-off circuit using a simple on-off valve is established.