• 디지털융복합연구
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• 제11권7호
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• pp.201-207
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• 2013

첩 신호는 그 양호한 코릴레이션 특성으로 인하여 전통적으로 레이더에서 주로 사용되어 왔으나, 최근에는 ISO/IEC 24730-5와 IEEE 802.15.4a 등에서 위치추적을 위한 표준규격으로 선정되어 여러 회사에서 이 방식을 구현하고 있다. 본 논문에서는 무선채널을 라이시안 채널로 모델링하고, 신호대 간섭 잡음비를 S/I = -30[dB], -20[dB], -10[dB]의 세가지 경우로 고려하고, 각 경우마다 라이시안 팩터 K=10과 K=20를 적용하여 성능을 시뮬레이션하여 평가하였다. 성능평가 결과, S/I = -30[dB]에서는 K=10에서 K=20으로 신호조건이 변화하면서 25%의 성능이 향상되었고, S/I = -20[dB]에서는 약 27%, S/I = -10[dB]에서는 약 50%의 성능이 향상되었다. 결과적으로 S/I=-20[dB] 미만인 경우 가시성분이 성능을 향상시킨다고 하더라도 신호의 전력은 필요한 최소값이 요구된다. 한편, 신호대 잡음비가 S/I=-20[dB] 이상으로 유지되는 경우 신호의 가시성분을 강화시킨다면 시스템의 성능을 크게 향상시킬 수 있다.

• 한국콘텐츠학회논문지
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• 제22권4호
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• pp.700-705
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• 2022

혈우병은 혈액 응고에 필요한 13개의 인자들 중 1개라도 결핍될 경우 혈액 응고에 장애가 발생하여 지혈 이상을 보이는 선천성 출혈성 질환이다. 13개의 인자들 중 결핍된 응고 인자에 따라 혈우병 A(제8번 인자, factor VIII), 혈우병 B(제9번 인자, factor IX), 혈우병 C(제10번 인자, factor X)로 분류된다. 혈우병 A 진단을 받은 40대 남성 환자가 전체적인 만성 치아 주위 염증으로 인한 치조골 흡수 및 치주농양을 문제를 주소로 을지대학교병원 치과에 내원하였고, 초진당시 전반적인 골흡수 및 염증상태를 보였다. 혈액응고인자의 농도를 적절히 유지하며 관혈적 및 비관혈적 치료를 시행한 바, 10년 동안의 정기적인 내원으로 #35, #36 부위를 제외한 나머지 부위에서 별다른 합병증이나 출혈성향은 관찰되지 않았고, 전반적으로 양호한 구강 상태를 보였으며 부작용이나 합병증은 보이지 않았다.

• 전기학회논문지
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• 제57권11호
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• pp.2041-2046
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• 2008

A frequency-dependent slow-wave factor (SWF) and equivalent circuit model of transmission line with defected ground structures (DGS) is described. Once S-parameters of a DGS transmission line are given, the conventional frequency -independent equivalent circuit elements are extracted using 3dB cutoff and resonant frequencies (Fc and Fo) as the first step. Using the initial equivalent elements and simple transmission line theories, a frequency-dependent equivalent transmission line model is established through an analytical method, and finally the frequency dependent SWF is calculated. The proposed equivalent circuit model and SWF are frequency-dependent and more reliable because even small insertion loss within available passband is considered, while they have been independent of frequency.

• Nutrition Research and Practice
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• 제5권1호
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• pp.34-39
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• 2011

The purpose of this study was to assess vitamin $B_6$ intake and status in Korean patients with newly diagnosed type 2 diabetes. Sixty-four patients with newly diagnosed type 2 diabetes and 8-11% glycated hemoglobin (A1C), along with 28 age-matched non-diabetic subjects, participated. Dietary vitamin $B_6$ intake was estimated by the 24 hour recall method and plasma pyridoxal 5'-phosphate (PLP) was measured. There was a significant difference in daily total calorie intake between the diabetic and non-diabetic groups ($1,917{\pm}376$ vs $2,093{\pm}311\;kcal$). There were no differences in intake of total vitamin $B_6$ ($2.51{\pm}0.91$ vs $2.53{\pm}0.81\;mg/d$) or vitamin $B_6$/1,000 kcal ($1.31{\pm}0.42$ vs $1.20{\pm}0.32\;mg$) between the diabetic and non-diabetic groups, and I intakes of total vitamin $B_6$ were above the Korean RDA in both groups ($180.0{\pm}57.9$ vs $179.0{\pm}65.4$). There was a higher percentage of diabetic subjects whose plasma PLP concentration was < 30 nmol/L compared to non-diabetic group. Plasma PLP levels tended to be lower in the diabetic subjects than in the non-diabetic subjects, although the difference was not statistically significant due to a large standard deviation ($80.0{\pm}61.2\;nmol/L$ vs $68.2{\pm}38.5\;nmol/L$). Nevertheless, plasma PLP levels should be monitored in pre-diabetic patients with diabetic risk factors as well as in newly diagnosed diabetic patients for long-term management of diabetes, even though this factor is not a major risk factor that contributes to the development of degenerative complications in certain patients.

• 현장농수산연구지
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• 제23권1호
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• pp.67-80
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• 2021

단감 '부유'의 가을 동상해 발생과 과실생장에 미치는 식재위치의 표고와 농장의 온도환경의 영향과, 서리가 발생한 과수원의 과실 저장 특성을 알아보고자 경남 창원(과원 A)과 창녕(과원 B)의 경사지 과원에서 표고별(상, 중, 하)로 과실특성을 조사하고 서리가 발생한 후 수확한 과실을 MA저장 후 저장특성(품질, 저온장해)을 조사하였다. 수확기 전후(10월25일, 11월5일, 11월20일)에 조사된 두 과원의 과실의 생장 특성(과중, 당도, 경도)은 표고와 농장 요인의 유의미한 영향을 받지 않았다. 과실 착색은 표고 요인의 영향을 받았으며, 과실의 착색(hunter 'a')은 B 과원보다 A 과원에서 더 빨리 진행되었다. 수확기에 발생한 저온으로 인하여 과원 B의 하부에서만 약 2%의 과실에서 동상해 피해가 관찰되었다. 두 과원(A, B)에서 11월 5일과 11월 20일에 수확한 과실을 저밀도 폴리에틸렌 필름을 사용하여 MA저장 한 결과, 저온지 과원(B)보다 고온지 과원(A)의 과실 경도가 높게 유지되었다. 그리고 11월 5일에 수확한 과실은 약 80일 저장 후에도 건전과율이 과원 A에서 약 73%, 과원 B에서 약 85%로 높게 유지되었으나, 11월 20일(서리 발생 후) 수확한 과실은 A 과원의 과실은 약 80일 저장 후에도 76%의 높은 건전과율을 유지하였으나 B 과원의 과실 건전과율은 약 14%에 불과했다.

• 한국초전도ㆍ저온공학회논문지
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• 제16권2호
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• pp.24-28
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• 2014

Magnesium diboride superconductor is still of considerable interest because of its appealing characteristics towards application mainly at around 20 K. Unlike Nb-based superconductors, $MgB_2$ can be operated by cryogen-free cooler which provides a cost effective alternative at low field of around 2-5 T. To explore this operating field region considerable efforts are necessary to marginally improve the superconducting properties of $MgB_2$. Under this situation, even the heat treatment environment during the synthesis is considered as an important factor. The addition of $H_2$ gas in small amount with Ar as a mixed gas during annealing has an adverse effect on the superconducting properties of $MgB_2$. It is although interesting to find that the presence of Mg vapor along with hydrogen during heat treatment results in the appreciable improvement in the flux pinning and the overall response of the critical current density for the ex-situ $MgB_2$ samples.

• 생약학회지
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• 제24권4호
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• pp.304-308
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• 1993

A platelet activating factor(PAF) antagonist ginkgolides produced from Ginkgo biloba are well known for their potential usage in septic shock and other PAF related diseases. Even though they are extracted from the leaves and on occasion the root bark, the exact biosynthetic site and pathway have not proved yet. In order to locate the enzymes involved and elucidate the biosynthetic site of the compounds, embryo-derived aseptic intact plantlet and plantlet without root have been cultured on 0.3% active carbon-containing solid Murashige and Skoog's medium. The leaves from the six-week-old normal plantlet contained similar amount of ginkgolide B to that of outdoor plant leaves, while the plantlets without root had less than 30% of the ginkgolide B compared to the in vitro intact plantlets. The results suggest that the ginkgolides may be synthesized in the root and transported to the aerial part.

• 한방재활의학과학회지
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• 제30권3호
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• pp.71-87
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• 2020

Objectives Even though the various alternative herbal medicine has applied for osteoarthritis (OA) treatment, its scientific proof remains uncertain. The aim of the present study evaluates the effects of Chulbu-tang on inflammatory responses in a monosodium iodoacetate (MIA)-induced osteoarthritis rat model. Methods OA rat model was established by MIA injection in intra-joint of rats. 7 days after, OA rats except OA control rats were administrated Chulbu-tang (100 or 200 mg/kg) or Indomathacin (5 mg/kg) once a day for 14 days. The weight-bearing ability of hind paws were measured when group isolation 0, 7, and 14 days. Western blotting was performed to examine the knockdown/overexpressing efficiency of Chulbu-tang. In addition, cartilage destruction was measured histologically. Results Chulbu-tang treatment significantly reduced the protein expressions of inflammatory mediators such as inducible nitric oxide synthase and cyclooxygenase 2, and inhibited inflammatory cytokines including tumor necrosis factor alpha, interleukin (IL)-1β, and IL-6 through nuclear factor-kappa B (NF-κB) inactivation. Moreover, anti-oxidant enzymes such as superoxide dismutase and glutathione peroxidase-1/2 through nuclear factor-erythroid 2-related factor 2 (Nrf2) pathway significantly increased. Our findings indicate that Chulbu-tang has the potential therapeutic effect on OA through inhibiting the inflammatory responses via inactivating NF-κB signaling pathway. In addition, upregulation of Nrf2 led to anti-oxidant effects. Conclusions Taken together, Chulbu-tang is believed to have antioxidant, anti-inflammatory effects, and cartilage protection for arthritis-causing rats.

• 동아시아식생활학회지
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• 제20권2호
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• pp.307-312
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• 2010

Sugar snap cookies were prepared with the addition of carrot powder (2~12%) as a source of dietary fiber. Analyses of physiochemical properties, rheology and sensory evaluation of the cookies were conducted. Increasing carrot powder content weakened the flour, as evidenced by decreased diameter and increased thickness, which resulted in decreased spread factor. The water content of the carrot powder-amended cookies and unamended flour was not significantly different. The pH and L values progressively decreased and a and b values progressively increased with increasing addition of carrot powder. Textural analysis revealed no significant differences in brittleness with carrot powder addition, even though brittleness did decrease with the addition of more carrot powder. Sensory evaluation revealed a preference for cookies prepared with 2~4% carrot powder, with decreased preference at powder concentrations exceeding 6%. Addition of a dried vegetable with high fiber content caused the dietary fiber to absorb much water content, resulting in decreased diameter, increased thickness and decreased spread factor. Therefore, it is deemed desirable to increase the spread factor by controlling the water content and adding emulsifiers so as to enhance the functionality and maintain the quality of cookies.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권1호
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• pp.47-54
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• 2004

A new high voltage DC power supply is proposed. The proposed power supply is constructed with several power converters connected in series. It is easy to obtain high DC voltage for the same structure of each power converter. The output DC power of the proposed power supply can be disconnected from the load within several hundred microseconds at the instant of a load short-circuit fault. The rising time of the output DC voltage is also as small as several hundred microseconds, and there is no overshoot of the voltage because all of the output filter capacitors keep undischarged state even in load short-circuit condition. Therefore, the proposed scheme is suitable for the protection of frequent output short-circuit and fast on/off switching of output DC voltage. The proposed power supply has improved features such as simple structure, high power factor, and reduced size and volume compared with the conventional schemes. The operating principle is described and the validity of the proposed scheme is proved through simulations and experiments.