• Structural Engineering and Mechanics
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• 제64권4호
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• pp.449-459
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• 2017

High-rise buildings are generally sensitive to strong winds. The evaluation of wind loads for the structural design, structural health monitoring (SHM), and vibration control of high-rise buildings is of primary importance. Nevertheless, it is difficult or even infeasible to measure the wind loads on an existing building directly. In this regard, a new inverse method for evaluating wind loads on high-rise buildings is developed in this study based on a discrete-time Kalman filter. The unknown structural responses are identified in conjunction with the wind loads on the basis of limited structural response measurements. The algorithm is applicable for estimating wind loads using different types of wind-induced response. The performance of the method is comprehensively investigated based on wind tunnel testing results of two high-rise buildings with typical external shapes. The stability of the proposed algorithm is evaluated. Furthermore, the effects of crucial factors such as cross-section shapes of building, the wind-induced response type, errors of structural modal parameters, covariance matrix of noise, noise levels in the response measurements and number of vibration modes on the identification accuracy are examined through a detailed parametric study. The research outputs of the proposed study will provide valuable information to enhance our understanding of the effects of wind on high-rise buildings and improve codes of practice.

• 한국조경학회지
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• 제35권6호
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• pp.74-83
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• 2008

As urban residents' standard of living has recently risen, efforts to improve urban landscapes have increased. It is very important to manage streetscapes to improve the urban landscape because they are one of the essential elements in city construction and urban landscaping. This study focuses on the indicators that manage streetscapes more accurately and realistically. To achieve this purpose, this study used dynamic simulations considering shape and layout of buildings, the primary factors in streetscapes. This study can be summarized as follows: 1. Two indicators to manage streetscape were investigated in previous studies: one to increase visual openness and the other to reduce visual overstimulation. These indicators had high correlation with scenic beauty. Therefore, increasing openness and reducing overstimulation are essential to improve streetscapes. 2. Two household tower type buildings should be arranged along roadsides to increase openness and scenic beauty. However, low tower buildings with two household are not suitable along roadsides because they create monotony and intervals are needed between buildings. 3. To increase openness, the angled arrangement of buildings is suggested $75^{\circ}{\sim}90^{\circ}(105^{\circ}{\sim}135^{\circ})$ for low buildings, $30^{\circ}{\sim}45^{\circ}(135^{\circ}{\sim}150^{\circ})$ for mid-sized buildings, and $75^{\circ}{\sim}90^{\circ}(105^{\circ}{\sim}135^{\circ})$ for high buildings. 4. To reduce overstimulation, the height and setback control regulations should be at an angle of less than $45^{\circ}$. This study suggests more accurate management guidelines by organizing the indicators that could effectively manage streetscapes and by overcoming limitations of reality shown in a static simulation.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.412-412
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• 2014

Zinc oxide (ZnO) is one of the most powerful materials for purifying organic pollutants using photocatalytic activity. In this study, we have introduced a novel method to design highly photoreactive flexible 3 dimensional (3D) ZnO nanocomposite [F-ZnO-m (m: reaction time, min)] by electrospinning and simple-step ZnO growth processing (one-step ZnO seed coating/growth processing). Significantly, the F-ZnO-m could be a new platform (or candidate) as a photocatalytic technology for both morphology control and large-area production. The highest photocatalytic degradation rate ([k]) was observed for F-ZnO-m at 2.552 h-1, which was 8.1 times higher than that of ZnO nanoparticles (NPs; [k] = 0.316 h-1). The enhanced photocatalytic activity of F-ZnO-m may be attributed to factors such as large surface area. The F-ZnO-m is highly recyclable and retained 98.6% of the initial decolorization rate after fifteen cycles. Interestingly, the F-ZnO-m samples show very strong antibacterial properties against both Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) after exposure to UV-light for 30 min. The antibacterial properties of F-ZnO-m samples are more effective than those of ZnO NPs. More than 96.6% of the E. coli is sterilized after ten cycles. These results indicate that F-ZnO-m samples might have utility in several promising applications such as highly efficient water/air treatment and inactivation of pathogenic microorganisms.

• 한국산학기술학회논문지
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• 제16권10호
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• pp.6483-6494
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• 2015

본 연구는 혈액투석환자에서 나타나는 증상들의 빈도, 심각성, 영향 등을 조사하고, 이런 증상과 자기효능감 및 가족지지와의 연관성을 분석하여, 어떤 요인이 환자의 증상에 영향을 미치는 지를 확인할 목적으로 시행되었다. 지역 병원에서 혈액투석을 받는 243명의 환자들을 증상의 발현과 심각성을 측정하는 질문지로 투석 증상 지표(DSI)를 이용했다. 자료는 서술적 통계, 독립 t-test, Pearson 상관계수, 다중 회귀분석 등을 이용해 분석했다. 증상 점수는 가족지지(r=-.35, p<.001) 및 자기효능감(r=-.16, p=.006)과 눈에 띄는 부적 상관관계를 보여주었다. 연령과 혈액투석 기간의 영향을 통제했을 때, 가족지지가 증상을 예측하는 가장 큰 변수였다. 또한 가족지지는 증상 점수 변화량의 16%를 차지했다. 혈액투석환자들은 수많은 고통스러운 증상들을 경험하는데, 이런 증상들은 그들 삶의 질에 부정적인 영향을 주는데 가족지지를 고취시킨다면 혈액투석환자들이 경험하는 고통스러운 증상들을 줄이고 억제하는 데에 도움이 될 수 있을 것이다.

• Asian-Australasian Journal of Animal Sciences
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• 제4권2호
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• pp.169-176
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• 1991

Four fibrous feedstuffs from alfalfa meal (AFM), cassava leaf meal (CLM), rubber seed meal (RSM) and leucaena meal (LM) were included in semi-purified diets for growing pig (45 kg body wt.) at 20%, to investigate the effects of these fiber sources and fractions on amino acid digestibility. Cellulose (C), a purified fiber source was included in another diet at 5% level for comparison. The barrows fitted with ileal T-cannula were used in the digestion trials with latin square design. The digestibilities of amino acids were measured at both terminal ileum and fecal level. NDF and hemicellulose content were the highest in AFM-diet whereas LM-diet had the highest ADF and lignin content. RSM-diet contained the highest crude fiber and cellulose content. The digestibilities of amino acids at ileal level were found the highest with CLM-diet, while LM-diet was the least. At fecal level, control diet and CLM-diet were the highest in amino acid digestibility while AFM-diet was the least. The digestibility of amino acids was higher at ileal than fecal level. The digestibility of arginine was not affected with fiber fractions but was found to be the most disestible across all diets. The most depressed amino acid was methionine at both levels; praline and glycine, in the dispensable amino acid group, were depressed at ileal and fecal level, respectively. Lignin did not depress amino acid digestibility in general but specifically depressed methionine, histidine, isoleucine and threonine digestibility. Cellulose content did not affect amino acid digestibility but undesirable factors might be responsible.

• 지질공학
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• 제17권3호
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• pp.339-350
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• 2007

암반에 발달하고 있는 단층이나 절리와 같은 불연속면뿐만 아니라 점토의 함량비, 팽창성 점토물질의 협재, 배수특성(drainage) 등은 암반의 붕괴여부를 결정하는 중요한 인자들이다. 특히 점토광물의 성분은 강우에 의한 암반붕괴를 예측할 수 있는 중요한 지표가 될 수 있다. 최근 사면이나 터널의 설계에서도 그 중요성이 점차 증가하는 추세이다. 본 연구는 니질천매암과 사질천매암이 호층을 이루고 있는 OO 터널의 선진시추코어(horizontal boring core)를 이용하여 단층발달에 따른 광물성분의 변화 및 이들이 불연속면의 역학성에 미치는 영향을 파악하고, 암석 구성물질과 파생된 점토광물을 비교하여 암반의 불안정성을 추정하기 위해 수행되었다. 연구방법은 시추코어 중에서 단층의 영향을 받은 구간과 비교적 신선한 구간에서 시료를 채취하여 박편을 제작하여 관찰하였고, 점토광물의 성분 및 함량을 분석하였다. 그리고 야외조사와 실내 시험으로 단층물질의 강도정수를 구하였다.

• 한국간호교육학회지
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• 제17권1호
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• pp.90-99
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• 2011

Purpose: To investigate the impacts of individualized versus group prenatal breast-feeding education on postnatal breast-feeding knowledge, this study addressed techniques and rates of first-time mothers as part of data collection for developing breast-feeding education programs. Methods: A quasi-experimental nonequivalent control group design was applied to compare the effects of prenatal breast-feeding individual vs. group education among first-time mothers. Collected data was analyzed using $x^2$-test, t-test, paired t-test, and ANOVA. Results: There was no difference on the knowledge of prenatal breast-feeding between individual and group education. However, individual education was a more effective method than group education on post-natal knowledge. In the 4th and 8th weeks of breast-feeding, individual education was more effective than group education. However, there was no difference between the two education methods at Week 12. Conclusion: This study indicates that many outpatient mothers should be given various individual approaches and prenatal breast-feeding education programs to provide them with opportunities for education to improve breast-feeding rates. However, there was no statistically significant difference in the breast-feeding rates at Week 12, which may be attributed not to education methods but to changes in external environmental factors. Further research is needed to address the changes.

• 디지털융복합연구
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• 제12권11호
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• pp.141-157
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• 2014

이 연구에서는 대학생들 대상으로 하는 경험적 연구를 통해 그들의 창업의지를 살펴보고, 창업의지에 영향을 미치는 다양한 변수들을 살펴보았다. 창업의지에 대한 각 독립변수들의 영향요인을 검증한 결과, 개인적 특성에서는 개인역량이, 경력지향에서는 안전지향, 자율지향, 기술지향, 사업지향이 각각 유의미한 관계로 나타났다. 창업환경이 창업의지에 미치는 영향을 분석한 결과에서는 개인적 네트워크와 창업정책이 유의한 관계가 있는 것으로 확인되었고, 통제변수의 하나로 살펴본 창업교육 유무에서는 창업교육을 받았던 학생이 그렇지 않은 학생에 비해 창업의지가 높아지는 것을 확인할 수 있었다. 특히, 다수 변인의 유의성에도 불구하고 창업의지에 가장 유의미한 요인으로 나타난 것은 사업지향성이다. 따라서 대학생들 스스로 사업에 대한 아이디어를 구상하고 이와 관련된 설계 및 자기역량을 강화할 수 있는 다양한 창업 교육 프로그램을 개발, 보급해야 할 것이다.

• Nuclear Engineering and Technology
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• 제47권1호
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• pp.47-58
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• 2015

Four recycling scenarios involving pyroprocessing of spent fuel (SF) have been investigated for a 600-MWe transmutation sodium-cooled fast reactor (SFR), KALIMER. Performance evaluation was done with code system REBUS connected with TRANSX and TWODANT. Scenario Number 1 is the pyroprocessing of Canada deuterium uranium (CANDU) SF. Because the recycling of CANDU SF does not have any safety problems, the CANDU-Pyro-SFR system will be possible if the pyroprocessing capacity is large enough. Scenario Number 2 is a feasibility test of feed SF from a pressurized water reactor PWR. Thefsensitivity of cooling time before prior to pyro-processing was studied. As the cooling time sensitivity of cooling time before prior to pyro-processing was studied. As the cooling time increases, excess reactivity at the beginning of the equilibrium cycle (BOEC) decreases, thereby creating advantageous reactivity control and improving the transmutation performance of minor actinides. Scenario Number 3 is a case study for various levels of recovery factors of transuranic isotopes (TRUs). If long-lived fission products can be separated during pyroprocessing, the waste that is not recovered is classified as low- and intermediate-level waste, and it is sufficient to be disposed of in an underground site due to very low-heat-generation rate when the waste cooling time becomes >300 years at a TRU recovery factor of 99.9%. Scenario Number 4 is a case study for the recovery factor of rare earth (RE) isotopes. The RE isotope recovery factor should be lowered to ${\leq}20%$ in order to make sodium void reactivity less than <7$, which is the design limit of a metal fuel.

• 건축역사연구
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• 제14권4호
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• pp.177-195
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• 2005

Tough Korean architecture and urban environment has been developed for almost 100 years, it still remains various kinds of problems. Many attempts was carried out by every new plan to reduce the problems, it result in requiring more investment than before. It means all the investment for the development has been inefficient and immature to protect economic problems compared with the developed country. For the reason of economic problems it must be studied in historical cases which influenced the economic impacts, before the proposal of index with the economic theory. Searching typical architecture or urban development that brought about economic impacts can be classified into 3 cases. First case is the impact that caused the economic growth, increase, boom like the Westminster & others and the american architectures after the economic crisis. Second case is the impacts that was the origin of decline, shrink in economic as the Palace of Versailles, the skyscrape buildings in america before the economic crisis. Third case is the impact that was the both role of increase and decline in economic as the modern architecture in industrial revolution which led to the national economic growth and the gap between the rich and the poor, and as the american architecture that was the root of crisis and the revival in economic. From the case study, it is clear that architecture has relation with economics in various factors as mass production, labour, and another industries all over the history & the world. Now, architecture strongly needed not only to raise functional, cultural effect and value, but to predict and control the economic impacts with theory from further research of historical cases to policy and practise.