• Journal of Acupuncture Research
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• 제22권6호
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• pp.229-239
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• 2005

목적: 알레르기비염은 이환율이 높은 질환이다. 비폐색은 알레르기비염의 주요 증상으로 수면장애, 우울, 주의력 저하, 기억력 감퇴 등을 유발한다. 비염에 대한 침치료는 문헌에 언급되어 있고 임상에서 많이 사용되지만 잘 디자인된 임상연구는 많지 않다. 본 연구는 알레르기비염환자의 비폐색에 대한 침치료의 효과에 대해 알아보고자 하였다. 방법: 본 연구는 단일맹검, 무작위배정, 대조군연구로 치료혈은 영향(Il20), 상성(GV23), 합곡(IL4)으로 하였고, 유효성 평가는 음향비 강통기도검사를 통한 총비강용적, 총비강최소단면적의 변화로 하였다. 결과: 101명의 피험자가 연구를 종료하였으며 연령, 성별, 체중, 신장, 맥박, 호흡수, 지속성 비염의 중증도, 양성반응을 보인 항원의 수에서 대조군과 침치료군에서 차이는 없었다. 침치료군과 대조군 모두에서 치료직후 총비강용적이 유의성(침치료군: p=0.0007, 대조: p=0.0175)있게 증가하였고, 치료15 분후 침치료군에서 대조군에 비하여 증가된 총비강용적이 경계수준의 유의성(p=0.0871)으로 유지되었다. 침치료군과 대조군 모두에서 치료직후 총비강최소단면적이 유의성(침치료군: p<0.0001, 대조군: p=0.0005)있게 증가하였고, 치료15분후 침치료군에서 대조군에 비하여 증가된 총비강최소단면적이 경계수준의 유의성(p=0.0929)으로 유지되었다. 결론: 지속성 알레르기비염의 비폐색에 대한 침치료는 비강용적과 비강단면적을 증가시켜 비폐색을 완화시키는 효과가 있었으나 지속적인 효과에 대하여는 추가적 연구가 필요하다.

• Journal of Yeungnam Medical Science
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• 제35권1호
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• pp.54-62
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• 2018

Background: The type and regimen of anesthesia may affect perioperative hyperglycemia following major surgical stress. This study compared the effects of sevoflurane and propofol on the incidence of hyperglycemia and clinical outcomes in diabetic patients undergoing lung surgery. Methods: This retrospective study included 176 patients with type 2 diabetes mellitus who had undergone lung surgery. Blood glucose levels and clinical outcomes from the preoperative period to the first 2 postoperative days (PODs) were retrospectively examined in patients who received sevoflurane (group S, n= 87) and propofol (group P, n=89) for maintenance of general anesthesia. The primary endpoint was the incidence of persistent hyperglycemia (2 consecutive blood glucose levels >180 mg/dL [10.0 mmol/L]) during the perioperative period. The secondary composite endpoint was the incidence of major postoperative complications and 30-day mortality rate after surgery. Results: Blood glucose levels similarly increased from the preoperative period to the second POD in both groups (p=0.857). Although blood glucose levels at 2 hours after surgery were significantly lower in group P than in group S (p=0.022; 95% confidence interval for mean difference, -27.154 to -2.090), there was no difference in the incidence of persistent hyperglycemia during the perioperative period (group S, 70%; group P, 69%; p=0.816). The composite of major postoperative complications and all-cause in-hospital and 30-day mortality rates were also comparable between the two groups. Conclusion: Sevoflurane and propofol were associated with a comparable incidence of perioperative hyperglycemia and clinical outcomes in diabetic patients undergoing lung surgery.

• 전자공학회논문지S
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• 제34S권9호
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• pp.1-12
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• 1997

The performance of Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) protocol adopted as a draft standard of IEEE 802.11 wireless LAN, is analyzed by using mathematical method based on renewal theory. We introdude three kinds of CSMA/CA protocols basic, stop-and-wait and 4-Way handshake CSMA/CA with their mathematical analysis. First, a network of finite population is considered and then expand to infinite population. We model the CSMA/CA protocol as a hybrid protocol of 1-persistent CSMA and p-persistent CSMA protocol, and verify analaytical results by computer simulation. We have found that 4-Way Handshake CAMA/CA shows better performance than those of other two types of CSMA/CA in case of high traffic load.

• 한국전자통신학회논문지
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• 제9권2호
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• pp.181-186
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• 2014

본 논문에서는 셀룰러 기반의 사물 간 통신 네트워크에서의 임의접근채널 과부하 문제를 해결하기 위한 부하제어 기법을 제안한다. 사물 간 통신 단말은 기존 이동통신 단말에 비해 매우 높은 밀도로 분포하며 주로 간헐적으로 짧은 데이터를 전송하는 특성을 가지고 있다. 이러한 특성으로 인해 임의접근 기반으로 기지국에 접속하게 되는데 이 때 다수의 사물 간 통신 단말이 기지국 임의접근 채널에 신호를 전송하는 경우 임의접근 채널에 과부하가 일어날 수 있다. 그러므로 본 논문에서는 이러한 문제를 해결하기 위해 기지국이 네트워크의 부하를 측정하고 이를 바탕으로 p-persistent 방식을 이용해 부하를 제어하는 기법을 제안한다.

• 한국멀티미디어학회논문지
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• 제4권4호
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• pp.349-355
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• 2001

본 논문에서는 대표적 근거리 통신망인 이더넷(Ethernet)에서 이용되는 CSMA/CD 프로토콜이 p-지속이나 비-지속의 고정 모드에서 동작하는 것이 아니라 통신망 상태에 따라 두 모드 사이에서 동적으로 변환하도록 하여 통신망 사용 효율을 높일 수 있는 새로운 프로토콜을 제안한다. 동적 모드 변환은 각 노드에서 독립적으로 발생하며, 연속적으로 패킷 전송에 성공한 횟수와 실패 한 횟수를 이용하게 된다. 시뮬레이션을 통한 성능 분석 결과 단일 모드에서 동작하는 것보다 통신망 사용 효율이 항상되며, 전송 지연 특성 또한 우수함을 알 수 있었다. 또한 새로이 제안한 프로토콜은 기존의 이더넷 전용칩을 그대로 이용하면서 간단한 제어 기능의 추가만으로 동작 모드의 제어가 가능하다.

• 대한전자공학회논문지TC
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• 제37권2호
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• pp.7-16
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• 2000

본 논문에서는 p-persistent CSMA 방식의 IEEE 802.11 MAC 계층 프로토콜을 모델링 하였다. 그리고 renewal 이론을 적용하여 수학적으로 분석한 Basic CSMA/CA 프로토콜, CTS/RTS 프로토콜 그리고 은닉 노드를 고려한 Basic CSMA/CA 등의 성능분석모델을 제안하였다. 제안한 분석 모델을 이용하여 throughput을 구한 결과, active 노드 수가 적거나 패킷의 길이가 짧을 때는 Basic CSMA/CA 프로토콜 방식이, active 노드 수가 많거나 패킷의 길이가 길 때는 CTS/RTS 프로토콜 방식이 우수하였다. 또한 active 노드 수가 적은 경우가 많은 경우 보다 은닉 노드의 영향을 적게 받았다.

• Ocean and Polar Research
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• 제38권3호
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• pp.171-184
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• 2016

In order to assess the level of contamination and identify the priority contaminants in the Busan coast, intensive sediment sampling was conducted and persistent organic pollutants and heavy metals were analyzed. The Sediment Quality Index (SQI) was derived based on the contaminant data by comparing with Sediment Quality Guidelines (SQGs) established in Korea, Canada, and Australia/New Zealand. Toxic contaminants were found to be widely distributed across the coast. Among organic contaminants, PAHs showed the highest concentration, followed by butyltins, nonylphenols, PBDEs, DDTs, PCBs, HCHs and CHLs. Heavy metals were also abundantly detected with the highest concentration of Zn followed by Cu > Cr > Pb > Ni > As > Cd > Hg. Compared to organic contaminants, most heavy metals, except for Cu and Hg, were homogeneously distributed along the coast in a good relationship with total organic carbon of sediment particles. In general, the concentrations of organic compounds and heavy metals were highest at the inner part of harbor areas with a tendency to decline from inside areas to the outside, indicating the high loading of pollutants from harbors. A high exceedance for low-SQGs and high-SQGs was found for TBT, p'-DDT, p,p'-DDD, Cu and Zn. The SQI scores calculated from low-SQGs and high-SQGs were in the range of 18-100 and 54-100, respectively. The inner part of Busan Harbor, Dadaepo Harbor, and Gamcheon Harbor were observed as being regions of concern. Overall, TBT, Cu, and p,p'-DDT were the chemicals most frequently exceeding SQGs and influencing SQI scores.

• Clinical and Experimental Pediatrics
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• 제64권5호
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• pp.229-238
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• 2021

Background: Bronchial hyperresponsiveness (BHR), an important physiological feature of asthma, is a prognostic marker of childhood asthma. Purpose: We aimed to investigate the factors associated with BHR in adolescents with childhood asthma. Methods: Two hundred and fifteen adolescents (≥13 years of age; 149 males, 66 females) who were diagnosed with asthma during childhood were enrolled, underwent methacholine challenge tests, and were divided into the BHR group (<25 mg/mL of provocation concentration causing a 20% fall in forced expiratory volume in 1 second [FEV₁] [PC₂₀], n=113) or non-BHR group (≥25 mg/mL of PC₂₀, n=102). We examined longitudinal changes in BHR and the risk factors for its persistence in the 108 adolescents for whom baseline data, including methacholine PC₂₀ at age 6 years, were available. Multivariate logistic regression analyses were performed to assess the factors associated with BHR in adolescents. Results: Mold sensitization (adjusted odds ratio [aOR], 5.569; P=0.005) and increased blood eosinophil count (aOR, 1.002; P=0.026) were independently associated with BHR in boys but not girls. The odds of BHR decreased by 32% with each 1-year increase in age in boys (aOR, 0.683; P=0.010) but not girls. A reduced FEV₁/forced vital capacity ratio (<90%) was independently related with BHR in female patients only (aOR, 7.500; P=0.007). BHR decreased with age throughout childhood. A low methacholine PC₂₀ at age 6 years was independently associated with persistent BHR throughout childhood in male and female patients, whereas early mold sensitization was a risk factor for persistent BHR in male patients only (aOR, 7.718; P=0.028). Conclusion: Our study revealed sex-specific differences in the factors associated with BHR in adolescents with childhood asthma. Our findings suggest the risk factors that might affect asthma transition from childhood to adolescence and adulthood.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제15권1호
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• pp.29-37
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• 2012

Purpose: To examine the prevalence of $Clostridium$ $difficile$ ($C.$ $difficile$) colonization (CDC) and potential neonatal determinants of CDC in hospitalized preterm infants. Methods: Fecal samples were serially collected within 72 h after birth and at 1, 2, and 4-6 weeks of age from preterm infants in the neonatal intensive care units (NICUs) of two different university hospitals. Total bacterial DNA was extracted from each fecal sample from 49 infants, and polymerase chain reaction (PCR) was performed with primers for the 16S gene of $C.$ $difficile$ and the toxin A and toxin B genes. The correlation between the results of $C.$ $difficile$ PCR assays and the clinical characteristics of the infants was analyzed. Results: The prevalence rates of CDC were 34.7, 37.2, 41.3, and 53.1% within 72 h after birth and at 1, 2, and 4.6 weeks of age, respectively. The toxin positivity rate was significantly higher in the infants with persistent CDC than in those with transient CDC (8/12 [66.7%] vs. 6/25 [24.5%] ($p$=0.001). Among the various neonatal factors, only the feeding method during the first week after birth was significantly associated with persistent CDC. Exclusive breast-milk feeding (EBMF) significantly decreased the risk of persistent CDC compared to formula or mixed feeding (adjusted odds ratio: 0.133, 95% confidence interval: 0.02-0.898, $p$=0.038). Conclusion: The prevalence of CDC increased with the duration of hospitalization in preterm infants in the NICU. EBMF during the first week after birth in hospitalized preterm infants may protect against persistent CDC.

• 한국환경농학회지
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• 제1권1호
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• pp.1-13
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• 1982

전국의 논, 밭, 과수원 및 plastic film house 토양시료 236점을 1981년(年) 4월(月)부터 5월(月)사이에 채취(採取), 유기염소계 잔류농약을 GLC로 분석하였다. 실험결과(實驗結果)는 다음과 같이 요약(要約)하였다. 1) ${\alpha}-BHC$, ${\gamma}-BHC$, PCNB, heptachlor, aldrin, heptachlor epoxide, ${\alpha}-endosulfan$, dieldrin, p,p'-DDD 및 p,p'-DDT 등의 잔류농약성분이 국내 농경지에서 검출되었다. 2) 과수원토양에 잔류성 유기염소계농약이 가장 많았고 논 및 밭토양의 잔류수준은 이에 비해 훨씬 낮았다. 3) 논 및 밭토양에 비해 과수원토양에는 aldrin, ${\alpha}-endosulfan$, dieldrin, p,p'-DDD 및 p,p'-DOT의 검출빈도(檢出頻度)와 잔류수준이 높았다. 4) ${\alpha}-BHC$와 ${\gamma}-BHC$는 모든 공시토양(供試土壤)에서 검출되었으나 농경지별 차이가 없었고, 평균잔류량은 $0.008{\sim}0.014$ ppm였다 . 5) 과수원토양의 높은 p,p'-DDT의 잔류량에 관해 토론(討論)하였고 현용(現用) 또는 사용(使用)이 금지(禁止)된 농약에 대한 잔류연구의 필요성을 강조하였다.