• 한국정보통신학회논문지
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• 제12권8호
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• pp.1349-1355
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• 2008

최근에 ZigBee, Bluetooth, RFID(Radio Frequency Identification)와 같은 근거 리 무선통신 시스템에 대한 연구가 활발히 진행되고 있으며, 이와 같은 시스템들은 대부분 소출력무선기기들이다. 미래에는 개인을 중심으로 하는 WPAN(Wireless Personal Area Network)을 위해서 더 많은 소출력 무선기기들이 출현할 것이며, 간섭저감기술은 소출력무선기기들이 한정된 주파수 자원을 효율적으로 이용하기 위한 필수 기술이 될 것으로 예상된다. 본 논문에서는 두 가지의 주파수를 공유 방법을 고려하였다. 첫 번째는 이미 특정 시스템에 할당된 주파수를 공유하는 경우이고, 두 번째는 새로운 주파수대역을 할당하는 경우이며, 이 두 가지 경우에 대한 효율적인 주파수 공유 방법을 연구하였다. 첫 번째 방법으로 주파수출 공유하는 경우의 한 가지 예로서 ZigBee, RPID, DCP(Digital Cordless Phone) 및 Bluetooth가 특정 주파수대역을 공유하는 경우 주파수 공유 조건을 검토하였다. 그리고 두 번째 공유 방법에서는 서로 다른 간섭저감기술을 사용하는 통신시스템에 대해서 공평한 신호 방사조건을 유지하기 위한 balancing factor의 개념을 제안하였으며, FH(Frequency Hopping) 시스템을 기준으로 하는 경우 LBT(Listen Before Talk)는 0.9, DS (Direct Spreading)은 0.8의 balancing factor를 이 용하면, 이들 간섭저감기술들 사이의 방사조건을 비슷하게 유지 할 수 있기 때문에 전체적으로 더 많은 시스템이 주파수를 공유할 수 있음을 보였다.

• Pediatric Infection and Vaccine
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• 제18권2호
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• pp.135-142
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• 2011

목 적 : 집중 치료를 받고 있는 환자들에서 MDR-HAI이 전세계적으로 중요한 문제로 인식되고 있다. 그러나 이와 관련하여 소아 환자들을 대상으로 한 연구는 성인에 비해 상대적으로 부족하다. 본 연구에서는 단일 대학병원 중환자실에 입원한 소아환자를 대상으로 MDR-HAI의 발생률과 연관인자를 알아보고자 하였다. 방 법: 2009년 1월부터 2010년 12월까지 본원 환자실에서 3일 이상 입원치료 하였던 135명의 소아 환자를 대상으로 입원기록을 후향적으로 검토하였다. 원내감염을 MDR-HAI과 non-MDR-HAI의 두 군으로 나누어 각각 임상적 특징과 여러 연관인자들을 비교하였다. 결 과: 39명의 환자에서 45례의 중환자실내 원내감염이 발생하였다. 원내감염의 발생률은 중환자실 재원 1,000일당 47.7이었다. 45례 원내감염 중 36례(80.0%)가 다제 내성균에 의한 감염이었다. A. baumannii는 MDR-HAI군에서 더 흔하게 검출되었다(54.5% vs. 8.3%; P=0.007). 중환자실 입원 적응증 중 내과적 질환, 인공 호흡기 치료, 도뇨관 삽입, 이전 광범위 항생제 사용은 MDR-HAI군에서 통계적으로 유의하게 높았다. 회귀분석 결과 이전 광범위 항생제 사용만이 MDR-HAI의 독립적 위험인자였다. 결 론 : 중환자실내 원내감염의 발생률은 이전에 보고된 것보다 높았으며, 이전 광범위 항생제 사용이 MDR-HAI의 독립적 위험인자였다. 향후 중환자실에 입원한 소아 환자에게 발생한 MDR-HAI의 정확한 특징을 확인하기 위해 추가적인 연구가 필요할 것으로 생각된다.

• 대한한의진단학회지
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• 제11권1호
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• pp.48-60
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• 2007

Palpation of the pulse has been used in Korean traditional medicine since ancient times to assess physical health. Pulse wave contour may be obtained by measuring arterial pressure or blood volume change of skin. The latter is called as Photoplethysmography(PPG) or digital volume pulse(DVP). The PPG signal is measured by a device comprising an infrared light sourece and a photodetector. Although less widely used, this technique deserves further consideration because of its simplicity and ease of use. The contour of the PPG is formed as a result of a complex interaction between the left ventricle and the systemic circulation. It usually exhibits an early systolic peak and an early diastolic peak. the first peak is formed mainly by pressure trasmitted along a direct path from the left ventricle to the finger. The second peak is formed in part by pressure transmitted along the aorta and large arteries to sites of impedance mismatch in the lower body. The contour of the PPG is sensitive to changes in arterial tone and is influenced by ageing and large artery stiffness. Measurements taken directly from the PPG or from its second derivative can be used to assess these properties. In some mathematical approaches, the extraction of periodic components using frequency analysis was tried to analysis of the PPG. But we don't understand yet what kind of factor in the cardiovascular system or human body is related with the respective specific Fourier components of PPG. This review describes the background to measurement principles, representative contour, contour analysis and frequency domain analysis of PPG, and current and future.

• 대한임상검사과학회지
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• 제41권1호
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• pp.1-5
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• 2009

The Platelet Function Analyzer (PFA)$^{(R)}$-100 measures the ability of platelets activated in a high-shear environment to occlude an aperture in a membrane treated with collagen and epinephrine (CEPI) or collagen and ADP (CADP). The time taken for the flow across the membrane to stop (closure time, CT) is recorded. The aim of this study was to assess the potential of the PFA$^{(R)}$-100 as a primary clinical screening tool using the wide spectrum of clinical samples assessed for platelet function as well as to perform the optimal algorithm for the use of PFA$^{(R)}$-100. We established the reference interval in 460 hospital inpatients defined as having normal platelet function based on classical laboratory tests. The reference interval by using the range $5^{th}$ and $95^{th}$ percentile was 84~251 seconds for males CEPI-CT and 85~249 seconds for females CEPI-CT. A total of 1,200 inpatients were enrolled to identify impaired hemostasis before surgical interventions. The abnormal group showing prolonged CEPI-CT was 303 cases (18.9%). Only 3 cases had both abnormal CEPI-CT and CADP-CT. Several factors including sample errors, drugs, hematologic abnoralities were contributed to unexpected prolonged CEPI-CT for screening test. The von Willebrand factor (vWF:Ag) assay was performed only in one patient to verify the algorithm for the use of PFA$^{(R)}$-100. The PFA$^{(R)}$-100 was sensitive and rapid method for primary screening test of platelet dysfunction, so we can substitute it for the bleeding time in routine clinical practice.

• 한국지진공학회논문집
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• 제24권6호
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• pp.267-275
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• 2020

In the event of an earthquake, non-structural components require seismic performance to ensure evacuation routes and to protect lives from falling non-structural components. Accordingly, the seismic design code proposes horizontal force for the design and evaluation of non-structural components. Ground motion observed on each floor is affected by a building's eigen vibration mode. Therefore, the earthquake damage of non-structural components is determined by the characteristics of the non-structural component system and the vibration characteristics of the building. Floor response spectra in the seismic design code are estimated through time history analysis using seismic waves. However, it is difficult to use floor response spectra as a design criterion because of user-specific uncertainties of time history analysis. In addition, considering the response characteristics of high-rise buildings to long-period ground motions, the safety factor of the proposed horizontal force may be low. Therefore, this study carried out the horizontal force review proposed in the seismic design code through dynamic analysis and evaluated the floor response of seismic waves considering buildings and predominant periods of seismic waves.

• 한국소음진동공학회논문집
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• 제17권12호
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• pp.1254-1261
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• 2007

The structure has several types of noise and booming noise of a vehicle is usually caused by the vibration of the vehicle's body transmitted from the engine through the mounting system. Vector synthesis analysis is performed to predict the booming noise when the characteristic of the engine mounting system is changed., i.e., when magnitudes and phases of vibratory forces after the mounts are altered. To use this method effectively, the concept of Multi-dimensional-analysis and Experimental Design are introduced to identify the contributions of each vibration sources and transmission paths to interior noise. It was used 3inputs/1output system and found the magnitudes and phases of the forces for minimizing the noise. Finally, the synthesized interior booming noise level is predicted by the vector synthesis diagram. It is shown that the vector synthesis method can be used to obtain the optimum design characteristic of the mounting system to control the interior booming noise of a vehicle.

• Earthquakes and Structures
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• 제9권3호
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• pp.455-480
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• 2015

In the last decade, displacement-based (DB) methods have become established design procedures for reinforced concrete (RC) structures. They use strain and displacement measures as seismic performance control parameters. As for other simplified seismic design methods, it is of great interest to prove if they are usually conservative in respect to more refined, nonlinear, time history analyses, and can estimate design parameters with acceptable accuracy. In this paper, the current Direct Displacement-Based Design (DDBD) procedure is evaluated for designing simple single degree of freedom (SDOF) systems with specific reference to simply supported RC bridge piers. Using different formulations proposed in literature for the equivalent viscous damping and spectrum reduction factor, a parametric study is carried out on a comprehensive set of SDOF systems, and an average error chart of the method is derived allowing prediction of the expected error for an ample range of design cases. Following the chart, it can be observed that, for the design of actual RC bridge piers, underestimation errors of the DDBD method are very low, while the overestimation range of the simplified displacement-based procedure is strongly dependent on design ductility.

• 대한수의학회지
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• 제59권2호
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• pp.75-80
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• 2019

Enrofloxacin, a fluoroquinolone, is a broad-spectrum antibiotic widely used in veterinary medicine that inhibits the action of bacterial DNA gyrase, resulting in anti-bacterial effects. This study was performed to examine whether enrofloxacin has modulatory and anti-inflammatory activity on immune cells. A few studies have reported the anti-inflammatory effects of enrofloxacin. In this study, we used mouse spleen cells treated with lipopolysaccharide (LPS) and examined the effects of enrofloxacin. Several assays were performed in LPS-treated spleen cells after the enrofloxacin treatment. Enrofloxacin inhibited the metabolic activity and mitochondrial membrane potential of LPS-treated spleen cells significantly. On the other hand, enrofloxacin did not alter the proportion of the subsets in spleen cells, and did not induce cell death. The production of tumor necrosis factor-alpha in LPS-treated spleen cells was inhibited by enrofloxacin. Overall, enrofloxacin had modulatory activity in spleen cells treated with LPS. These data may broaden the use of enrofloxacin as an antibiotic with anti-inflammatory activity in veterinary clinics.

• 한국의류학회지
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• 제46권1호
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• pp.132-146
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• 2022

To explore the potential use of Ecklonia cava as a natural dye for textiles, silk fabric was dyed with Ecklonia cava extracted by hot water under varied conditions, including temperature, duration, dye concentration, mordanting, and pH adjustment. The fabric was also evaluated for fastness, sun-protective property, and deodorization. Ecklonia cava extract was estimated by FT-IR to have polyphenol as a main functional colorant in plants, while the existence of phlorotannins through the UV-spectrum method was also confirmed. The fabric was optimized for maximum dye uptake at a temperature of 80℃ for a duration of 50 minutes along all dye concentrations. The dyed fabric showed a hue of Yellow Red under all dyeing conditions while additional color tones, such as grayish and dark, were generated through mordanting and pH adjustment. Both good sun-protective properties and a positive deodorization rate were also recorded, with more than 20% (owf) Ecklonia cava extract on silk fabric. These results imply that Ecklonia cava has great potential to be used as an eco-friendly natural dye and in fashion goods with skin-health functions made of silk.

• 한국의사학회지
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• 제34권1호
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• pp.11-22
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• 2021

In this study, we examine Cho Heon-yeong's medical theory in obstetrics and gynecology by looking at the contents and prescriptions of 『Buinbyeongchiryobeob (婦人病治療法)』. This book is a clinical text on obstetrics and gynecology written in the 1940's. This book consists of an Introduction, Jeungchi (證治), Yangjinhanchi (洋診漢治), Cheobangnonhae (處方論解) and refers to 『Donguibogam(東醫寶鑑)』, 『Keongakjeonseo (景岳全書)』, 『Junguihaksajeon (中醫學辭典)』, 『Jejungsinpyeon (濟衆新編)』, 『Uihakipmun (醫學入門)』 and 『UijongKeumkam (醫宗金鑑)』. Cho Heon-yeong's theory in this book has the following characteristics. First, his medical eclecticism is centered on Korean Medicine, with incidental use of Western medicine. Second, he regarded weakness (虛證) as a vital factor in obstetrics and gynecology. Third, he added "mental state" to the list of basic physiological characteristics of women. Fourth, he presented a new diagnostic standard based on a spectrum of fire (火) and cold (冷). There are 363 prescriptions in this book, and 171 of them are from 『Donguibogam (東醫寶鑑)』. The books frequently used prescriptions are all designed to supplement (補藥). There are 48 prescriptions that original to Cho Heon-yeong. Additionally, this book contains eopsaeng (攝生) and pretended stimulation therapies and exercise methods.