• Interdisciplinary Bio Central
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• 제3권1호
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• pp.5.1-5.5
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• 2011

Introduction: Many signal transduction pathways mediate cell's behavior by regulating expression level of involved genes. Abnormal behavior indicates loss of regulatory potential of pathways, and this can be attributed to loss of expression regulation of downstream genes. Therefore, function of pathways should be assessed by activity of a pathway itself and relative activity between a pathway and downstream genes, simultaneously. Results and Discussion: In this study, we suggested a new method to assess pathway's function by introducing concept of 'responsiveness'. The responsiveness was defined as a relative activity between a pathway itself and its downstream genes. The expression level of a downstream gene as a function of an upstream pathway activation characterizes disease status. In this aspect, by using the responsiveness we predicted potential progress in cancer development. We applied our method to predict primary and metastatic status of melanoma cancer. The result shows that the responsiveness-based approach achieves better performance than using gene or pathway information alone. The mean of ROC scores in the responsiveness-based approach was 0.90 for GSE7553 data set, increased more than 40% compared to a gene-based method. Moreover, identifying the abnormal regulatory patterns between pathway and its downstream genes provided more biologically interpretable information compared to gene or pathway based approaches.

• International Journal of Aeronautical and Space Sciences
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• 제18권4호
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• pp.719-728
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• 2017

This paper proposes a synthesis of new guidance law to generate an evasive maneuver against enemy's missile interception while considering its impact angle, acceleration, and field-of-view constraints. The first component of the synthesis is a new function of repulsive Artificial Potential Field to generate the evasive maneuver as a real-time dynamic obstacle avoidance. The terminal impact angle and terminal acceleration constraints compliance are based on Time-to-Go Polynomial Guidance as the second component. The last component is the Logarithmic Barrier Function to satisfy the field-of-view limitation constraint by compensating the excessive total acceleration command. These three components are synthesized into a new guidance law, which involves three design parameter gains. Parameter study and numerical simulations are delivered to demonstrate the performance of the proposed repulsive function and guidance law. Finally, the guidance law simulations effectively achieve the zero terminal miss distance, while satisfying an evasive maneuver against intercept missile, considering impact angle, acceleration, and field-of-view limitation constraints simultaneously.

• 한국항행학회논문지
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• 제7권2호
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• pp.180-190
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• 2003

실수축 상의 적분 방법에 의한 정확한 closed-form 그린함수를 이용하여 코플래너 도파로의 불연속에 대한 공간영역 full-wave 해석을 하였다. MPIE(Mixed Potential Integral Equation)를 풀기 위한 수치계산 방법으로는 삼각형 요소를 이용한 갤러킨 방법을 사용하였다. 경계면에서 삼각형 요소상의 기저함수로는 선형함수를 사용하였으며, 관측점과 전원점이 일치하는 특이점 근방의 적분 계산을 위해 면적분을 선적분 형태로 바꾸어 피적분 함수의 특이점이 사라지도록 하는 해석적인 방법을 사용하였다. 실수축 적분방법에 의한 그린함수를 이용함으로써 불연속에 대한 정확한 특성을 구하였다.

• 한국광물학회지
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• 제9권1호
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• pp.17-25
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• 1996

Usual experimental adsorption isotherms as a function of relative humidity were constructed from adsorbed water contents in soils, which were kept more than 2 days in vacuum desiccators with constant humidities controlled by sulfuric acids of various concentrations. From the experimental data, the adsorption surface areas were calculated on the basis of the existing adsorption theory, such as Langmuir, BET, and Aranovich. Based on the Gibbs function describing chemical potential of perfect gas, the relative humidities in the desiccators were transformed into their chemical potentials, which were assumed to be the same as the potentials of equilibratedly adsorbed water in soils. Moreover, the water potentials were again transformed into the equivalent capillary pressures, heads of capillary rise, and equivalent radius of capillary pores, on the basis of Laplace equation for surface tension pressure of spherical bubbles in water. Adsorption quantity distributions were calculated on the profile of chemical potentials of the adsorbed water, equivalent adsorption and/or capillary pressures, and equivalent capillary radius. The suggested theories were proved through its application for the prediction of temperature rise of sulfuric acid due to hydration heat. Adsorption heat calculated on the basis of the potential difference was dependant on various factors, such as surface area, equilibrium constants in Langumuir, BET, etc.

• 한국식품영양과학회지
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• 제28권5호
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• pp.1180-1186
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• 1999

A wide ranges of chemicals released into the environment have potential to interfere with physiological and development process by disrupting endocrine pathways. Endocrine system embraces a multitude of mechanisms of action, including effect on growth, behavior, reproduction and immune function. These environmental endocrine disruptors are present in environment and pose potential health consequences to human and wildlife. The best known form in endocrine distruptors involves substances which mimic or block the action of natural hormone in the body. Endocrine disruptor have been variously defined as exogenous agents that interfere with the synthesis, secretion, transport, metabolism, binding action or elimination of the natural hormones in the body which are responsible for the maintenance of homeostasis, reproduction developmental and/or behavior. Many compounds polluted into the environment by human activity are capable of disrupting the endocrine system of animals, including fish, wildlife, and humans. Among these chemicals are pesticides, industrial chemicals, and other anthropogenic products. It has been alleged that several adverse effects on human health are linked with exposure to chemicals which are claimed to be endocrine disrupters, that is, increased incidence of testicular, prostate and female breast cancer, time dependent reductions in sperm quality and quantity, increased incidence of cryptorchidism (undescended testicles) and hypospadias(malformation of the penis), altered physical and mental de velopment in children. This observation is currently the only example of chemically mediated endocrine disruption which has resulted in a clear effect at the population level.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.69.2-69.2
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• 2012

Graphene films have a strong potential to replace indium tin oxide anodes in organic light-emitting diodes (OLEDs), to date. However, the luminous efficiency of OLEDs with graphene anodes has been limited by a lack of efficient methods to improve the low work function and reduce the sheet resistance of graphene films to the levels required for electrodes. Here, we fabricate flexible OLEDs by modifying the graphene anode to have a high work function and low sheet resistance, and thus achieve extremely high luminous power efficiencies (37.2 lm/W in fluorescent OLEDs, 102.7 lm/W in phosphorescent OLEDs), which are significantly higher than those of optimized devices with an indium tin oxide anode (24.1 lm/W in fluorescent OLEDs, 85.6 lm/W in phosphorescent OLEDs). We also fabricate flexible white OLED lighting devices using the graphene anode. These results demonstrate the great potential of graphene anodes for use in a wide variety of high-performance flexible organic optoelectronics.

• 한국환경과학회지
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• 제29권11호
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• pp.1089-1098
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• 2020

To assess the trophic function of an artificial macroalgal habitat, we compared the stable carbon and nitrogen isotope ratios of two amphipods (Caprella sp. and Ampithoe sp.) and their potential food sources in a transplanted macroalgal habitat (Grateloupia asiatica) with those in a natural habitat. There were no significant differences in the isotopic values of both consumers and their potential food sources between the transplanted and natural habitats. Such isotopic similarities between the two sites indicate a comparable resource consumer relationship. Additionally, our results showed similar isotopic niche areas and high dietary overlap (>65%) of the two amphipods between the transplanted and natural sites, suggesting that the transplanted habitat plays ecological roles similar to the natural habitat. Overall, isotopic assessment can provide information on the trophic function of diverse transplanted macroalgal habitats and improve post-monitoring efforts in the management of artificial ecosystems.

• 한국동물위생학회지
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• 제46권3호
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• pp.181-192
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• 2023

Cystatin C, a low-molecular-weight protein synthesized by cells, is being explored as a valuable biomarker for assessing renal function in veterinary medicine. Although the relationship between cystatin C and heart disease remains unclear, some studies suggest a possible association. This retrospective case-control study aimed to investigate the role of cystatin C as a biomarker for heart disease and its correlation with diuretic use in veterinary clinical practice. A total of 39 dogs were included in this study, comprising 9 control dogs without a predisposition to heart disease and 30 dogs in the study group diagnosed with heart disease. Among the 30 dogs with heart disease, 18 exhibited symptoms indicative of heart failure. Results showed significantly higher cystatin C levels in the heart disease group compared to the control group (P<0.05). However, no significant differences were observed among different stages of heart disease severity in the control group. Furthermore, cystatin-C showed statistically positive correlations with BUN (r=0.478, P<0.01), creatinine (r=0.506, P<0.01), and furosemide (r=0.338, P<0.05). Diuretics are essential for managing congestive heart failure, and the observed associations between cystatin C and furosemide suggest potential impacts of diuretic use on renal function in dogs with heart failure. Monitoring renal function markers, such as cystatin C, can aid in predicting and managing potential renal complications, ultimately improving the overall health and quality of life of dogs with heart disease.

• Journal of Audiology & Otology
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• 제23권1호
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• pp.49-52
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• 2019

Background and Objectives: Considering important role of vitamin D in many physiological processes including vestibular system in the ear, aim of present study is to evaluate saccule function via cervical vestibular evoked myogenic potential (cVEMP), in patients with vitamin D deficiency. Subjects and Methods: After routine audiological tests, cVEMP were recorded in 15 patients with vitamin D deficiency and 16 normal subjects. The short tone burst (95 dB nHL, 500 Hz) was presented to ears. cVEMP was recorded with surface electromyography over the contracted ipsilateral sternocleidomastoid muscle. Results: Mean of p13, n13, interpeak latencies and amplitude ratios were measured in both groups. Statistical analysis did not show differences between two groups. Conclusions: Maybe serum 25-hydroxyvitamin D concentration was not low enough to have effect on saccule in the patients in present study or saccule have had low susceptibility to effects of vitamin D deficiency. For better judgment about effect of vitamin D deficiency on saccular function planning studies with high sample size is recommended.

• 대한청각학회지
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• 제23권1호
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• pp.49-52
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• 2019

Background and Objectives: Considering important role of vitamin D in many physiological processes including vestibular system in the ear, aim of present study is to evaluate saccule function via cervical vestibular evoked myogenic potential (cVEMP), in patients with vitamin D deficiency. Subjects and Methods: After routine audiological tests, cVEMP were recorded in 15 patients with vitamin D deficiency and 16 normal subjects. The short tone burst (95 dB nHL, 500 Hz) was presented to ears. cVEMP was recorded with surface electromyography over the contracted ipsilateral sternocleidomastoid muscle. Results: Mean of p13, n13, interpeak latencies and amplitude ratios were measured in both groups. Statistical analysis did not show differences between two groups. Conclusions: Maybe serum 25-hydroxyvitamin D concentration was not low enough to have effect on saccule in the patients in present study or saccule have had low susceptibility to effects of vitamin D deficiency. For better judgment about effect of vitamin D deficiency on saccular function planning studies with high sample size is recommended.