• Neonatal Medicine
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• 제17권2호
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• pp.155-160
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• 2010

Metabolic acidosis is commonly encountered issues in the management of critically ill neonates and especially of preterm infants during early neonatal days. In extremely premature infants, low glomerular filtration rate and immaturity of renal tubules to produce new bicarbonate causes renal bicarbonate loss. Higher intake of amino acids, relatively greater contribution of protein to the energy metabolism and mineralization process in growing bones are also responsible for higher acid load in premature infant than in adult. Despite widespread use of sodium bicarbonate in the management of severe metabolic acidosis, use of sodium bicarbonate in premature infants should be restricted to a reasonable but unproven exception such as ongoing renal loss. Despite concern about the low pH value (<7.2) which can compromise cellular metabolic function, no treatment guideline has been established regarding the management of metabolic acidosis in premature infants. Appropriately powered randomized controlled trials of base therapy to treat metabolic acidosis in critically ill newborn infants are demanding.

• 펄프종이기술
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• 제39권5호
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• pp.32-38
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• 2007

The purpose of this study is to investigate the cause of fine wrinkles occurred in silky wallpaper and its solution. The characteristics of base papers, wallpapers and adhesives (conventional and modified) were evaluated to find the possibility for the occurrence of fine wrinkles. It was found that the base papers and wallpapers did not cause the occurrence of silky wallpaper. It was concluded that the fine wrinkles in silky wallpaper was caused by the nonuniform distribution of adhesive, the localized shrinkage of adhesive and the breaking the balance between the resistance of wallpaper and shrinkage of adhesive. Three possible solutions for the prevention of the occurrence of fine wrinkles in silky paper were recommended.

• 한국가금학회지
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• 제17권4호
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• pp.310-317
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• 1990

고온 stress를 받고 있는 산란계의 사료에 소금을 초과 첨가하였을 때 혈액의 산－입기 평형과 음수량 및 난질에 미치는 영향을 조사하기 위하여 실험을 실시하였다. 44주령된 갈색 실용 산란계(Dekalb Warren) 18수를 소금 025% 및 0.75% 처리구에 처리당 9반복, 반복당 1수씩 완전임의 배치하였다. 우선 상은(13~$16^{\circ}C$)에서 3일간의 예비실험을 거친 후 3일간의 본 실험을 수행하였다. 그 후 실온을 고온(33~$35^{\circ}C$)으로 올린 후 3일간의 본 실험 기간을 둠으로써 $2\times2$ 요인실험이 되게 하였다. ANOVA 검정은 5% 수준에서 실시하였으며 처리평균간의 유의성 검정도 역시 5% 수준에서 실시하였다. 얻어진 결과를 요약하면 다음과 같다. 1. 고온 stress에 의하여 사료 섭취량은 유의적으로 감소하였고 음수량과 배설물의 수분 함량은 증가하였으며, 소금의 추가 급여는 사료 섭취량과 음수량에는 영향을 주지 못하였으나 배설물의 수분 함량을 유의적으로 증가시켰다. 2. 고온 stress에 의하여 pH늘 유의적으로 증가하였고 $pCO_2$는 유의적으로 감소하였으며 ${HCO_3}^-$는 유의적인 차이를 나타내지 않았다. 또한 혈액의 산－염기변수는 소금의 추가 급여에 의하여 영향을 받지 않았다. 3. 고온 stress에 의하여 난중 및 난각의 질은 유의하게 감소하였고 Haugh unit는 유의하게 증가하였으며, 소금의 추가 급여는 난중, 난각 및 Haugh unit에 영향을 주지 못하였다. 결론적으로, 본 실험에서는 산란계에서 고온 stress 처리를 하였을 때 예상되는 호흡성 alkalosis와 난질 저하 현상 등을 관찰하였으며, 소금의 추가 급여는 고온 stress를 완화시키지 못하는 것으로 나타났다.

• 한국산학기술학회논문지
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• 제10권7호
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• pp.1549-1555
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• 2009

무선센서 네트워크에서 노드들의 데이터를 수집하고 기지국에 전달하는 중계노드의 위치(Relay Node Placement)를 구하는 문제는 전체 네트워크의 생존시간에 관련되어 있기 때문에 매우 중요하다. 중계노드 위치문제는 전체 네트워크의 센서노드에서 소비되는 에너지를 최소화시키는데 그 초점이 맞추어져 있다. 그러나 중계노드 위치와 센서노드와의 거리가 모두 다르므로 센서노드에서 소비되는 에너지의 불균형이 초래된다. 본 논문에서는 클러스터링 모델에서 에너지 균형비(Energy Balance Ratio)라는 개념을 제안하고 이 에너지 균형비를 최대화시키는 목적함수를 사용하여 중계노드의 위치를 구한다. 에너지 균형비를 최대화시키는 것은 클러스터에 할당된 센서노드들의 에너지 소비를 클러스터 간에 균형 잡히게 한다. 이것은 궁극적으로 대규모 센서 네트워크의 에너지 소비를 최소화시켜서 네트워크 생존기간을 최대화시키는 효과가 있다. 그러나 이 문제의 해를 구하는 것은 NP-hard 문제이므로 완전해(Exact Solution) 를 구하는 것은 현실적으로 힘들다. 따라서 제약프로그래밍 방법을 사용하여 에너지 균형비와 중계노드 위치를 함께 고려하는 EBR-RNP 문제로 모델링하여 근사해를 구한다.

• 한국산학기술학회논문지
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• 제12권11호
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• pp.5087-5093
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• 2011

본 연구는 30명의 치매환자를 대상으로 균형반응 특성을 알아보고자 다음과 같이 실시하였다. 인지기능이 중등도와 중도인 환자로 나누어 인지 기능에 따른 균형과 감각상호작용(CTSIB), 균형수행력(BBS), 일상생활동작(BI)의 상관관계를 각각 측정하였다. 그 결과 치매환자의 균형과 감각상호작용(CTSIB)은 두 그룹 간에 유의한 차이가 없었다. 중등도와 중도의 치매환자에서 균형수행력(BBS)은 중등도 $47.32{\pm}4.80$점, 중도 $43.09{\pm}4.18$점으로 통계학적으로 유의한 차이가 있었으며(p<0.05), 일상생활동작에서도 중등도 $92.89{\pm}9.33$점, 중도 $76.82{\pm}6.81$점으로 통계학적으로 유의한 차이가 있었다(p<0.05). 치매환자의 인지기능, 균형수행력, 일상생활동작도 통계학적으로 유의한 상관관계가 있었다(p<0.05, p<0.01). 따라서 향후 치매환자를 위한 재활프로그램 개발이나 치매환자의 보호관리 시 기초자료로 이용 될 수 있을 것으로 생각된다.

• Wind and Structures
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• 제18권4호
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• pp.443-456
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• 2014

A popular modern architectural form for tall buildings is two (or more) towers which are structurally linked through such features as a shared podium or sky-bridges. The fundamental features of the wind loading and the structural links of such buildings can be studied by measuring load components on the individual unlinked towers along with their correlations. This paper describes application of dual high frequency force balance (DHFFB) in a wind tunnel study of the base wind loading exerted on generic tall twin buildings in close proximity. Light models of two identical generic tall buildings of square plan were mounted on DHFFB and the base wind loading exerted on the buildings was simultaneously acquired. The effects of the relative positions of the buildings on the correlations and coherences involving loading components on each building and on the two buildings were investigated. For some relative positions, the effects of the building proximity on the wind loading were significant and the loading was markedly different from that exerted on single buildings. In addition, the correlations between the loadings on the two buildings were high. These effects have potential to significantly impact, for example, the modally-coupled resonant responses of the buildings to the aerodynamic excitations. The presented results were not meant to be recommended for direct application in wind resistant design of tall twin buildings. They were intended to show that wind loading on tall buildings in close proximity is significantly different from that on single buildings and that it can be conveniently mapped using DHFFB.

• Earthquakes and Structures
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• 제4권5호
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• pp.471-487
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• 2013

Performance of a prototype base isolated building located at Indian Institute of Technology, Guwahati (IITG) has been studied here. Two numbers of three storeyed single bay RCC framed prototype buildings were constructed for experimental purpose at IITG, one supported on conventional isolated footings and the other on a seismic isolation system, consisting of lead plug bearings. Force balance accelerometers and a 12 channel strong motion recorder have been used for recording building response during seismic events. Floor responses from these buildings show amplification for the conventional building while 60 to 70% reduction has been observed for the isolated building. Numerical models of both the buildings have been created in SAP2000 Nonlinear. Infill walls have been modeled as compression struts and have been incorporated into the 3D models using Gap elements. System identification of the recorded data has been carried out using Parametric State Space Modeling (N4SID) and the numerical models have been updated accordingly. The study demonstrates the effectiveness of base isolation systems in controlling seismic response of isolated buildings thereby leading to increased levels of seismic protection. The numerical models calibrated by relatively low level of earthquake shaking provides the starting point for modeling the non-linear response of the building when subjected to strong shaking.

• ETRI Journal
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• 제45권5호
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• pp.887-898
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• 2023

Aerial base stations (ABSs) seem promising to enhance the coverage and capacity of fifth-generation and upcoming networks. With the flexible mobility of ABSs, they can be positioned in air to maximize the number of users served with a guaranteed quality of service (QoS). However, ABSs may be overloaded or underutilized given inefficient placement, and user association has not been well addressed. Hence, we propose a three-dimensional ABS placement scheme with a delay-QoS-driven user association to balance loading among ABSs. First, a load balancing utility function is designed based on proportional fairness. Then, an optimization problem for joint ABS placement and user association is formulated to maximize the utility function subject to statistical delay QoS requirements and ABS collision avoidance constraints. To solve this problem, we introduce an efficient modified gray wolf optimizer for ABS placement with a greedy user association strategy. Simulation results demonstrate that the proposed scheme outperforms baselines in terms of load balancing and delay QoS provisioning.

• 한국전문물리치료학회지
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• 제22권3호
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• pp.41-49
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• 2015

This study aimed to evaluate the surface area and velocity of center of pressure (COP) during one leg standing by stimulating the sensory system in normal adults. Thirty subjects were enrolled in this study. Subjects were asked to stand on one leg during testing conditions. Testing conditions included 6 different sensory stimulations as follows: eyes opened, eyes closed, eyes opened with vibrator, eyes opened with head-mounted display (HMD), eyes opened with vibrator and HMD, and eyes closed with vibrator. During each testing condition, the surface area and velocity of center of pressure were measured. There were significant differences in the mean surface area and the mean velocity of COP between the "eyes opened" condition and the other five testing conditions (p<.05). However, in the comparison between the "eyes closed" and "eyes opened with HMD" conditions, there were no significant differences in the tested parameters. This study shows that closing eyes or keeping eyes opened while using HMD to experience virtual reality has the same effect on one leg standing balance. This finding should be considered in the evaluation or intervention of balance, especially one leg standing balance and balance while standing with a small base of support.

• 한국전문물리치료학회지
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• 제23권2호
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• pp.35-43
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• 2016

Background: The Functional Gait Assessment (FGA) was developed to measure of gait-related activities. The FGA was translated in Korean but only a few psychometric characteristics had been studied. Objects: The purpose of this study was to evaluate the validity and reliability of the Korean version of FGA scale using Rasch analysis. Methods: The study included 120 patients with stroke (age range=30~83 years; mean${\pm}$standard deviation=$58.3{\pm}11.1$). The FGA and Berg Balance Scale were performed, and were analysed for dimensionality of the scale, item difficulty, scale reliability and separation, and item-person map using Rasch analysis. Results: The 4 rating scale categories of FGA were satisfied with optimal rating scale criteria. The most items of the FGA showed sound item psychometric properties except 2 items ('gait with the horizontal head turns', and 'gait with narrow base of support'), and the 2 misfit items were excluded for all further analyses. The 8 items were arranged in order of difficulty. The most difficult item was 'gait with eyes closed', the middle difficult item was 'gait level surface', and the easiest item was 'gait with vertical head turns.' A person separation reliability was .93 and the person separation index was 3.57. Conclusion: This study suggests that the 8-item Korean FGA are valid measure of assess the gait-related balance performance, and to set the goal of rehabilitation plan in patient with stroke.