• Geomechanics and Engineering
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• 제28권6호
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• pp.599-611
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• 2022

Tendon reinforced cemented soil is applied extensively in foundation stabilisation and improvement, especially in areas with soft clay. To solve the deterioration problem led by steel corrosion, the glass fiber-reinforced polymer (GFRP) tendon is introduced to substitute the traditional steel tendon. The interface bond strength between the cemented soil matrix and GFRP tendon demonstrates the outstanding mechanical property of this composite. However, the lack of research between the influence factors and bond strength hinders the application. To evaluate these factors, back propagation neural network (BPNN) is applied to predict the relationship between them and bond strength. Since adjusting BPNN parameters is time-consuming and laborious, the particle swarm optimisation (PSO) algorithm is proposed. This study evaluated the influence of water content, cement content, curing time, and slip distance on the bond performance of GFRP tendon-reinforced cemented soils (GTRCS). The results showed that the ultimate and residual bond strengths were both in positive proportion to cement content and negative to water content. The sample cured for 28 days with 30% water content and 50% cement content had the largest ultimate strength (3879.40 kPa). The PSO-BPNN model was tuned with 3 neurons in the input layer, 10 in the hidden layer, and 1 in the output layer. It showed outstanding performance on a large database comprising 405 testing results. Its higher correlation coefficient (0.908) and lower root-mean-square error (239.11 kPa) were obtained compared to multiple linear regression (MLR) and logistic regression (LR). In addition, a sensitivity analysis was applied to acquire the ranking of the input variables. The results illustrated that the cement content performed the strongest influence on bond strength, followed by the water content and slip displacement.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.327-327
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• 2023

인간 활동의 영향으로 인한 기후변화는 지구의 물 순환을 변화시키며 결과적으로 수문학적 재해의 발생빈도와 강도를 변화시킬 것으로 전망한다. 파키스탄은 기후변화에 대한 기여도가 적음에도 불구하고 기후변화로 인한 피해가 큰 나라 중 하나이다. 파키스탄은 2022년 여름 국가의 30% 이상의 지역이 침수되며 3300만명이 피해를 받은 기록적인 홍수를 겪은 바 있다. 본 연구에서는 하천 물리 모델인 Catchment based Macro-scale Floodplain (CaMa-Flood)를 사용하여 2022년 파키스탄에서 발생한 홍수에 대하여 인간 활동에 의한 기후변화 영향을 평가했다. 결합모델간 상호비교 프로젝트 (Coupled Model Intercomparision Project Phase 6, CMIP6)에 참여한 모형들 중, 일 유출량을 제공하는 4개의 전구기후모델 (CanESM5, CNRM-CM6-1, HadGEM3-GC31-LL, IPSL-CM6A-LR)을 선정하였다. 본 연구는 선정된 모델을 기반으로 지난 1950-2014년의 총 65년간, 인간의 영향을 제외한 hist-nat과 인간의 영향이 포함된 historical 시뮬레이션 결과를 비교하여 홍수에 대한 인간 활동의 기여도를 평가하였다. 각 hist-nat과 historical 시뮬레이션에서 산출된 일 유출량을 CaMa-Flood의 입력 자료로 사용하여, 파키스탄 지역의 자연 변동성 및 인위적 강제력이 영향을 미치는 하천 유량, 저수량, 범람 면적 및 수위 등을 계산하였다. 연구 결과, 인간 활동이 2022년 파키스탄 홍수의 하천 범람 면적 및 총 하천 유량 증가에 영향을 미쳤으며, 이는 자연 변동성만을 고려한 hist-nat 시뮬레이션과의 비교를 통해 차이를 확인하였다. 이는 향후 파키스탄 지역에서 발생하는 홍수 사례 전망 및 유엔 기후변화협약당사국총회(COP27)에서 의제로 채택된 기후변화로 인한 손실과 피해의 보상에 대한 구체적인 근거에 도움이 될 것으로 보인다.

• 대한한의학회지
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• 제43권4호
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• pp.131-144
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• 2022

Objectives: This study aimed to review clinical studies on thread embedding acupuncture (TEA) for the treatment of patients with post-stroke spasticity (PSS) Methods: Clinical studies related to TEA treatment for PSS were searched for in several electronic databases, including PubMed, Cochrane Library, MEDLINE, OASIS, and CNKI. After the selection/exclusion process, information on study design, disease, experimental/control group, intervention, outcome measurement, between-group differences, and adverse events was extracted. Results: A total of 13 randomized controlled trials were included in this review. The usual frequency of TEA treatment was once every 1-2 weeks, and the treatment most commonly included 4 sessions. In the dorsal area, EX-B2 and the acupoints in governing vessel meridian were commonly used. Acupoints in the meridian of the large intestine were most frequently used in the treatment of upper limb spasticity. Except for HT1, PC6, and PC8, all TEA points for treating PSS of the upper limb were on the Yang meridians. For the lower limb spasticity, the most frequently used acupoints were ST36, GB34, GB30, BL60, and BL57 on Yang meridians, and LR3, SP6, SP9, and SP10 on Yin meridians. TEA treatment showed better effects than conventional treatment for PSS in terms of spasticity, motor dysfunction, and activities of daily livings. Nevertheless, the absence of the follow-up observation, lack of sham TEA treatment, and low quality of the included studies necessitated caution in interpreting the results. Conclusions: The results of this review are expected to provide basic data on the modalities of TEA treatment for PSS and provide insights to facilitate well-designed studies in the future.

• 대한예방한의학회지
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• 제28권1호
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• pp.109-118
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• 2024

Objectives : This study aimed to investigate the relationship between cold feet and sleep quality using polysomnography (PSG) and Pittsburgh Sleep Quality Index (PSQI). Methods : We divided 11 adults (6 females, 5 males) with Insomnia Severity Index score below 21 into cold feet (CF) and a non-cold feet (NCF) group based on the median feet temperature (Taichong, LR3). PSG and PSQI were administered to assess sleep characteristics and subjective sleep quality. Results : CF group exhibited significantly lower time in bed, sleep period time, and total sleep time compared to NCF group. While there were no significant group differences in sleep latency, wakefulness after sleep onset, or total arousal index, NCF group had significantly lower minimum oxygen saturation and apnea-hypopnea index in REM (rapid eye movement) sleep compared to CF group. Although the PSQI score and the proportion of poor sleepers were both higher in the CF group (7.40 and 80%) compared to the NCF group (5.50 and 50%), these differences did not reach statistical significance. Conclusions : This study showed that foot temperature affects sleep characteristics and suggests the need to utilize PSG in sleep research in Korean medicine.

• 대한한방내과학회지
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• 제45권1호
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• pp.111-118
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• 2024

목적: 본 연구는 임상에서 종종 마주치는 만성적이고 낫지 않는 항문거근증후군 환자의 한의학적 치료 유용성을 공유하고자 한다. 방법: 14년 전에 치질수술 후에 발생한 항문통증이 개선되지 않고 지속되어 고통스러웠던 47세 남자 환자의 병력과 한의학적 치료 후의 임상적 개선과정을 자세히 제시하였다. 결과: 환자는 평소 건강하였는데, 치질수술 후에 대변을 보면 시작되는 항문통이 발생하였으며, 경우에 따라서는 오전 내내 불편함이 지속되었다. 14년 동안 종종 줄어들기도 하였지만 점진적으로 심해지는 경과를 보였고, 특히 1년 전부터는 더욱 심해졌으나 다양한 치료에도 호전이 없었다. 외국에 거주하는 이유로 한국에 방문하는 기회에 본원에서 한의학적 변증 하에 한약치료 및 약침을 포함하는 침치료와 뜸 치료 후 빠르게 호전되었다. 8주 정도의 치료 후에 NRS 2로 개선되어 만족한 상태로 출국하였다. 결론: 본 증례는 특별한 치료법이 부재하는 만성적이거나 혹은 난치성 항문거근증후군에 대하여 한의학적 치료법이 하나의 훌륭한 치료법일 수 있음을 보여주는 임상 예로서 의미가 있다고 하겠다.

• Advances in aircraft and spacecraft science
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• 제11권2호
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• pp.153-175
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• 2024

In jet engines, turbine blade cooling has an extremely important role. The pin-fin array, which is situated close to the trailing edge of the blade, aids in internal cooling of the gas turbine blades and preserves the structural integrity of the blade. Previous studies often focused on pin-fin configurations, but the current research focuses on improving the geometry at the endwalls to reduce wake vortices behind the pin-fins and enhance heat transfer at the endwalls location. Using the k-ω turbulence model, a numerical study was conducted on a ribbed shape situated on the walls between pin-fin arrays, spanning a Reynolds number range of 7400 to 36000, in order to determine the heat transport characteristics. The heat transfer efficiency coefficient and Nusselt number increase dramatically with the revised wall configuration, according to the numerical data. The channel's heat transfer efficiency is increased by enlarging the heat transfer areas near the pin-fins and by the interaction of the flow with the endwalls. The addition of ribs causes the Nusselt number of the new model to climb from 78% to 96% at the previously given Reynolds numbers, and the heat transfer efficiency index to rise from 60% to 73%. The height (Hr), position (Lr), forward width (Wf), and backward width (Wb) of the ribs are among the geometric elements that were looked at in order to determine how they affected the performance of heat transmission. In comparison to the reference design, the parametric study results demonstrate that the best forward width (Wf/R=18.75%) and backward width (Wb/R=31.25%) increase the heat transfer efficiency index by 0.4% and 1.3%, respectively.

• Ocean and Polar Research
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• 제33권3호
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• pp.211-221
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• 2011

Contents of biogenic components [opal, $CaCO_3$, TOC (total organic carbon)] were measured in Core LHB-3PC sediments collected off Lutzow-Holm Bay, in order to understand glacial-interglacial cyclic variation of the high-latitude surface-water paleoproductivity, in the Indian Sector of the Southern Ocean. An age model was established from the correlation of ARM/IRM ratios of Core LHB-3PC with LR04 stack benthic ${\delta}^{18}O$ records, in complement with radiocarbon isotope ages and biostratigraphic Last Appearance Datum (LAD). The core-bottom age was estimated to be about 700 ka. Although the $CaCO_3$ content is very low less than 1.0% throughout the core, the opal and TOC contents show clear glacial-interglacial cyclic variation such that they are high during the interglacial periods (7.2-50.3% and 0.05-1.00%, respectively) and low during the glacial periods (5.2-25.2% and 0.01-0.68%, respectively). According to the spectral analysis, the variation of opal content is controlled mainly by eccentricity forcing and subsequently by obliquity forcing during the last 700 kyrs. The opal contents of Core LHB-3PC also represent the apparent Mid-Pleistocene Transition (MPT)-related climatic variation in the glacial-interglacial cycles. In particular, the orbital variation of the opal contents shows increasing amplitudes since marine isotope stage (MIS) 11, which defines one of the important paleoclimatic events during the late Quaternary, called the "Mid-Brunhes Event". Based on the variation of the opal contents in Core LHB-3PC, we suggest that the surface-water paleoproductivity in the Indian Sector of the Southern Ocean followed the orbital (glacial-interglacial) cycles, and was controlled mainly by the extent of sea ice distribution during the last 700 kyrs.

• 한국의학물리학회지:의학물리
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• 제18권2호
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• pp.98-106
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• 2007

2005년 6월 연세의료원 세브란스병원에서는 진단목적으로 20대의 5 mesa 화소 Totoku ME511L 평판 LCD 표시장치를 추가하여 PACS를 확장하였다. 20대의 Totoku ME511L 표시장치를 대상으로 반사, 휘도 반응, 휘도 공간 의존, 분해능, 잡음, 베일링 그레어, 그리고 색도 항목에 대하여 AAPM TG 18보고서에 기준하여 정량적인(또는 시각적인) 인수검사를 실시하였다. 측정에 사용된 장치는 색도를 측정할 수 있는 만원경식 휘도계, 조도계, 반사 측정에 필요한 빛 선원, 빛 차단 장치, 그리고 TG18 테스트 패턴들이었다. 선택된 8대의 표시장치에 대한 평균 확산 반사계수($R_d$)는 $0.019{\pm}0.02sr^{-1}$이었다. 휘도 반응 검사에서, 휘도비(LR), 최대 휘도 변이($L_{max}$), 그리고 최대 대조도 반응 변이는 각각 $550{\pm}100,\;2.0{\pm}1.9%$, 그리고 $5.8{\pm}1.8%$이었다. 휘도 균일도 검사에서, 최대 휘도 변이는 TG18-UNL10 테스트 패턴의 10% 휘도에 대하여 $14.3{\pm}5.5%$이었다. 분해능 측정은 휘도 측정법으로 수행하였으며 중심에서 퍼센트 휘도(${\Dalta}L$)는 $0.94{\pm}0.64%$이었다. 시각적인 방법의 잡음측정의 모든 경우에서, 중앙 및 주위 4사분면에서 가장 작은 것을 제외하고 15개의 모든 정사각형의 표적을 인식할 수 있었다. 글레어 비(GR)은 $12,346{\pm}1,995$이었다. 최대 색도 균일도 지표(D)는 $0.0025{\pm}0.0008$이었다. 또한 국내 실정에 적합한 진단용 표시장치의 정도관리 가이드라인 연구 결과를 제시하였다. 모든 인수검사 결과는 AAPM TG18 보고서 기준에 포함되어 진단 목적으로 사용하기에 적합하였다. 결론으로 인수검사는 표시장치가 진단에 사용하기에 적합한 성능임을 알려줄 뿐만 아니라 정도관리의 가이드라인, 최적 판독 환경, 그리고 표시장치의 교체시기를 결정하여주는 중요한 역할을 할 수 있다.

• 대한방사선치료학회지
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• 제26권2호
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• pp.247-256
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• 2014

목 적 : 췌장 환자 방사선 치료 중 기점(Fiducial) 대상 내부 및 외부 종양 움직임의 오차를 정량화 하고자 한다. 또한 cone beam computed tomography (CBCT) 를 기반으로 호흡 시 췌장의 움직임 분석하고자 한다. 대상 및 방법 : 용적 세기변조 회전조사 (V-MAT)를 적용, 정위적 방사선 치료를 국소 진행성 췌장암 환자 11명을 대상으로 하였다. CBCT 및 직교 투시이미지를 적용하여 기점(Fiducial Marker)의 Inter, intra-fraction 움직임 변화를 치료 전, 치료 진행 시 분석하였다. 결 과 : 치료 후 프로토콜을 오프라인 교정 프로토콜을 사용하여, CBCT 와 직교투시 간의 평균 오차(범위)는 0.0(-1.7~4.0), 0.3(-0.5~3.0) and 0.0(-4.1~6.6)mm 측방 (LR), 세로 (AP) 및 종 방향 (SI) 이였다. 무작위 Inter-fraction Setup 오차 결과는 -0.1, -2.3 and -1.1 mm: 95% Fiducial포함 마진은 각 9.9, 7.8, 12.5mm로 수식되었다. 결 론 : 위 분석으로 뼈 일치 정렬 후 잔류 불확실성이 있으며, SI 방향에 큰 임의의 움직임은 적합한 여백이 필요하다. 주변 내부 장기를 보호, 내부 장기 문제점을 최소화, 호흡편차를 고려, 치료 시 정기적으로 측정하여야 한다.

• 대한한방소아과학회지
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• 제31권1호
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• pp.25-42
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• 2017

Objectives The goal of this review was to investigate clinical, experimental and literature studies of Korean medicine on atopic dermatitis (AD) of Korean children in Korean medicine literature, seeking for the better research methods for more effective treatments. Methods Electronic investigations were practiced on AKOP (The Association of Korean Oriental Pediatrics, http://www.akop.or.kr) to collect theses which were published by J Pediatr Korean Med. The key word 'Atopy' was used for searching to ensure that every related thesis was collected. The publication date was limited from 1996 to 2016. The selected literatures were assessed mainly according to distributions of study type, publication year, scale, treatment and its efficacy. Results 55 papers were selected from 59 studies. In these collected 55 related theses, there were 29 experimental studies (52.73%), 18 clinical studies (32.73%), 8 review studies (14.55%). In the 29 experimental studies, there were 20 studies (68.97%) using NC/Nga mouse as subjects. The mite antigen was used to trigger AD by 8 studies (27.59%). The studies have been utilizing DNCB and DNFB instead of mite antigen since 2011. All the experimental studies showed that the Korean medicine was effective in AD. In total 18 clinical studies, 3 studies (16.67%) were case reports, only 1 thesis (5.56%) was conducted by case control study and the rest were case series studies. 7 studies (38.89%) of 18 studies diagnosed AD according to Hanifin and Rajka's diagnostic criteria (1980), only 1 study (5.56%) according to the Korean standard and the rest 10 studies (55.56%) didn't mention diagnostic criteria. 12 clinical studies (66.67%) showed efficacy in treating AD. There were 10 studies (55.56%) only employing internal treatments and 1 thesis (5.56%) didn't mention the exact prescription. Naesowhajungtang-kamibang, Saenghyeoryunbue-um were used 3 times (16.67%) as the internal medicine respectively. 5 theses (27.78%) were combined with acupuncture therapy. Hegu (LI4), Sanyinjiao (SP6) were used in 4 theses, and Taichong (LR3), Quchi (LI11), Zusanli (ST36) in 3 theses. The number of acupoints chosen from The Spleen meridian of Foot-Taiyin was the largest. There were 8 review theses. 2 were about the foreign oriental medicine, 3 were about the external medicine or external treatment methods, and 3 other studies were about severity scoring systems, the methodological study in the latest clinical study, overview for pattern and results of herbal medicine-derived AD clinical researches. Conclusions The experimental studies and clinical studies showed the effectiveness of Korean medicine treatments. However, this study still needs improving by conducting more comparative studies and using better research methods, in order to find more effective treatments to improve clinical efficacy.