• 멤브레인
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• 제23권5호
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• pp.367-374
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• 2013

본 논문에서는 Pebax-2533 판형 분리막을 1-프로판올과 n-부탄올 혼합용매를 이용하여 용해, 건조하여 제조하였고 time-lag 장치를 이용하여 $CO_2$, $N_2$ 투과특성을 평가하였다. 제조된 분리막은 평가조건에 따라서 130-288 barrer의 $CO_2$ 투과율을 가졌으며, $CO_2/N_2$ 투과선택도는 5-8이었다. Time-lag 장치의 주입부 압력이 증가함에 따라서, 투과온도가 낮아짐에 따라서, 그리고 혼합용매의 n-부탄올 양이 증가함에 따라서 $CO_2$ 투과도는 감소하였다. 이러한 실험 자료는 Pebax-2533 분리막의 $CO_2$ 투과율이 $CO_2$ 용해에 매우 의존할 것이라 예측과 달리, $CO_2$ 용해뿐만 아니라 $CO_2$ 확산도 매우 중요한 단계임을 의미하였다.

• 한국융합학회논문지
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• 제12권10호
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• pp.353-363
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• 2021

본 연구는 입원환자 섬망의 아형별 위험요인, 증상 및 중재를 조사하기 위해 시행되었다. 상급종합병원에 입원한 뒤 섬망을 진단받은 환자 108명의 전자의무기록을 SPSS WIN 26.0 프로그램을 이용해 분석하였다. 분석결과, 대상자는 고령, 남성, 정형외과, 골절이나 절단 환자의 비율이 높았다. 섬망의 아형은 과활동형 51.9%, 저활동형 6.5%, 혼재형 41.7%이었다. 위험요인 중 우울과 향정신성 약물 복용은 저활동형 섬망군에게 더 많이 선행되었다. 섬망의 중재 중 행동문제 관리와 공격적 행동 중재는 과활동형, 혼재형 섬망군에게 주로 시행되었고 정서적 지지는 저활동형, 혼재형 섬망군에게 주로 시행되었다. 공격적 행동을 동반할 경우 즉각적으로 중재를 제공받을 가능성이 높았다. 따라서, 추후 입원환자의 섬망을 조기발견하고 중재할 수 있도록 중재전략과 프로토콜을 개발하기 위한 연구가 요구된다.

• Journal of Radiation Protection and Research
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• 제46권3호
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• pp.83-97
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• 2021

Background: The lifetime risk of lung cancer incidence due to radiation for nonsmokers is overestimated because of the use of the average cancer baseline risk among a mixed population, including smokers. In recent years, the generalized multiplicative (GM)-excess relative risk (ERR) model has been developed in the life span study of atomic bomb survivors to consider the joint effect of radiation and smoking. Based on this background, this paper discusses the issues of radiation risk assessment considering smoking in two parts. Materials and Methods: In Part 1, we proposed a simple method of estimating the baseline risk for nonsmokers using current smoking data. We performed sensitivity analysis on baseline risk estimation to discuss the birth cohort effects. In Part 2, we applied the GM-ERR model for Japanese smokers to calculate lifetime attributable risk (LAR). We also performed a sensitivity analysis using other ERR models (e.g., simple additive (SA)-ERR model). Results and Discussion: In Part 1, the lifetime baseline risk from mixed population including smokers to nonsmokers decreased by 54% (44%-60%) for males and 24% (18%-29%) for females. In Part 2, comparison of LAR between SA- and GM-ERR models showed that if the radiation dose was ≤200 mGy or less, the difference between these ERR models was within the standard deviation of LAR due to the uncertainty of smoking information. Conclusion: The use of mixed population for baseline risk assessment overestimates the risk for lung cancer due to low-dose radiation exposure in Japanese males.

• 한국컴퓨터정보학회논문지
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• 제26권11호
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• pp.75-84
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• 2021

본 논문에서는 혼합현실에서 다수의 사용자들이 공유객체를 조작하는 과정에서 충돌을 줄이고 충돌로 인한 작업 시간을 줄일 수 있는 적응형 동시성 제어 방법을 제안한다. 혼합현실에서 사용되는 공동 작업에 대해서 세부적인 골들과 이들에 대응되는 태스크들로 분류한 뒤 각 태스크에 알맞은 동시성 제어 방법을 매핑 하여 골-태스크-소유권에 대한 모델링을 수행하고 이에 대한 동시성 제어를 수행한다. 본 논문에서 제안된 시스템은 공동 작업이 진행되어 감에 따라서 같은 태스크이더라도 다른 동시성 제어 방법을 적용하여 사용자들이 동시에 공유 객체들 들고 같이 이동하고 회전을 하는 공동 작업 과정에서 사용자들의 동시적인 작업에 대한 충돌을 제어하여 사용자들에게 현실의 산업 현장과 유사한 혼합협실 공동작업 환경을 제공해 해준다. 본 논문에서 제안한 시스템을 혼합협실 환경에서 실제 동작처럼 작업을 지원하기 위해서 사용자는 MS 홀로렌즈와 마이오 센서를 착용하고 태스크 작업들을 수행한다. 실험 결과 공동 작업 과정에서 충돌 발생과 공동 작업의 완료 시간을 기존의 동시성 제어 방법보다 효과적으로 줄일 수 있었다.

• Membrane and Water Treatment
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• 제10권2호
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• pp.165-178
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• 2019

Mixed matrix membranes (MMMs) of poly (vinyl alcohol) (PVA) containing certain amounts of H-${\beta}$ zeolite for pervaporation were manufactured by using a solution casting protocol. These zeolite-embedded membranes were then characterized with scanning electron microscope (SEM), X-ray diffraction (XRD) and swelling tests. The membrane separation performance has been examined by means of isopropanol (IPA) dewatering from its highly concentrated aqueous solutions via response surface methodology (RSM). The results have demonstrated that the influences of feed IPA composition (85-95 wt.%), feed temperature ($50-70^{\circ}C$), zeolite loading (15-25 wt.%) and their interactive influences are all statistically significant on both pervaporation flux ($398-1228g/m^2{\cdot}h$) and water/isopropanol separation factor (617-2001). The quadratic models based on the RSM analysis have performed excellently to correlate experimental data with very high determination coefficients and very low relative standard deviations. The optimal pervaporation predictions given by using the RSM models demonstrate a total flux of $953g/m^2{\cdot}h$ and separation factor of 1458, and are excellently verified by experimental results. As reflected by these results, PVA MMMs embedded with hydrophilic $H-{\beta}$ zeolite entities have performed considerably better than its pure counterpart and indicated great potential for isopropanol dehydration applications.

• 융합정보논문지
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• 제9권8호
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• pp.155-163
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• 2019

수평원형관에서 나노입자인 산화알미늄과 기본유체인 물의 혼합인 나노유체에 대한 층류 혼합대류열전달현상을 유한체적법의 수치적 방법으로 규명하였다. 나노유체에 대하여 2상 혼합모델을 적용하였으며, 나노입자의 물성은 온도와 체적농도의 함수를 사용하였다. 수치해석에 적용한 모든 모델의 타당성 검증을 위하여 Kim등의 실험결과와 비교하였으며 좋은 결과를 얻었다. 벽면을 일정한 열유속으로 가열하므로 나노유체는 벽면부근에서 형성된 부력에 의하여 2차유동이 생성된다. Richardson수와 나노입자의 농도가 증가할수록 강한 2차유동이 형성되어 열전달을 향상시키게 된다. 또한 Richardson수와 나노입자의 농도가 증가하면 대류열전달계수와 전단응력도 증가한다. 이런 연구들은 열교환기의 성능향상을 위하여 나노유체를 적용하는데 기본자료로 활용이 가능하다. 이번 연구를 기반으로 향후 2중관형열교환기등 다양한 열교환기에 적용할 예정이다.

• 한국동물위생학회지
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• 제42권2호
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• pp.67-71
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• 2019

A variety of livestock feed resources were used in Korean dairy farm due to a lack of the endemic feed. However, there is inadequate real farm data to support farmers' decisions on the choice of options. The main objective of this study was to evaluate the nutritional value of total mixed ration (TMR) as well as the metabolic diseases status in Korean dairy farms. TMR samples were collected from nine feed companies and eight selected self-formulated by the dairy farms. The nutrient contents were examined by AOAC methods. The frequency of metabolic diseases such as ketosis and hypocalcemia were surveyed. The average moisture content was 36.2% although the min. and max. value were varied from 21.7% and 50.6% among farms. The mean${\pm}$standard deviation of crude fiber (CF), crude ash (CA), ether extract (EE), and crude protein (CP) were $21.4{\pm}2.5$, $4.6{\pm}0.4$, $3.2{\pm}0.5$ and $9.8{\pm}1.7$, respectively. However, the average ADF and NDF was $17.3{\pm}3.7$ and $31.0{\pm}5.7$, respectively. The compositions of TMR were varied significantly among the dairy farms. The frequency of clinical Ketosis (CK), subclinical ketosis (SCK) and hypocalcemia were higher in early lactation period with 4.5%, 11.0% and 3.0%, respectively. Also, the frequency of SCK was higher than CK and hypocalcemia throughout the lactation. Periodic TMR nutrient analysis based on herd production or physiology change would maximize the effects of TMR feeding. Furthermore, the study results would be useful to the farm practitioner and producer for their farm management.

• 대한건축학회논문집:계획계
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• 제35권6호
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• pp.21-26
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• 2019

This study is to investigate the possibility of legislation that is the foundation of school complexation project and the architectural planning for the target facility as stipulated by related law. Since 2000, many schools have been established and operated in the whole of Korea, mainly in Seoul. However, on the frontline, there is still a lot of difficulty in carrying out the project due to the legal possibility related to the school complexation and the lack of understanding about the facility for school complexation as stipulated by the law. The purpose of this study is to present the possibility of the school complexation project based on related laws and to clarify the classifications of school complexation facilities which are stipulated by the related law, and to propose the foundation for the future school complexation project. The contents of this study were investigated through the literature survey on the theoretical review and related laws of school complexation, and various laws related to school complexation were classified based on this, and the possibility of school complexification prescribed by each law was analyzed. In addition, by classifying facilities subject to school complexation prescribed by the Act and analyzing the detailed standards stipulated in relevant laws for each facility, we propose the facilities that can be combined with school facilities, and utilize the data of this study.

• 한국농촌건축학회논문집
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• 제23권1호
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• pp.1-8
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• 2021

In this study, a real-sized experimental equipment (pilot plant) was built at the site based on the preliminary research data to develop a movable separator for the mixed construction waste that can be implemented in agricultural areas to review its feasibility through the evaluation of its separation efficiency by waste types. The final construction of the movable separator and experimental results of the separation efficiency are summarized as follows. 1) The separation performance according to the blade type was the best for the combustible wastes either with 26 numbers of L-type blades and 32 numbers of pin type blades. As far as combination of blade types, when the L-type and pin-type were combined, the best separation efficiency was achieved. 2) The separation efficiency for waste wood by the conveyor type and angle of inclination (slope) of the trommel was the best when the conveyor had ribs of seagull shape with the angle of inclination 45°. 3) The separation efficiencies by process showed that 65.9% was separated as inorganic demolition wastes, 18.2% as waste woods, and 16.0% as combustible wastes at conveyor speed of 2-3 rpm, and the error rate was the least from the waste types generated in the dismantle site.

• 한국의상디자인학회지
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• 제23권4호
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• pp.133-148
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• 2021

Due to the COVID-19 pandemic, many people started working from home while avoiding unnecessary going-outs. As the 'stay-at-home life' becomes standard daily life, the pajamas market is absorbing young consumers, especially targeting Generation MZ, by using one-mile fashion that breaks down the boundary with everyday clothes. Also, owing to the demand for environmentally-friendly textiles, based on the strengthened environmental regulations, the development of textiles considering the environment is expanding. Thus, the purpose of this study is to develop fashion pajamas using environmentally-friendly textiles targeting Generation MZ. After theoretically considering the current status of recycled PETs and the pajama market by referring to preceding research, relevant books, and Internet data, this study performed the process setting up the design concepts, developing textiles, developing textile designs, and developing pajamas designs. As a result, this study wove two kinds of mixed textiles using recycled PETs and silk with the concept of 'Going out pajamas', and designed a total four patterns to be applied to those textiles, then digitally printed them. Using the developed textiles, this study produced a total four kinds of pajamas that were practical, trendy, and also good to be used as clothes for going-out. The consumers who are exhausted from the limited environment of the COVID-19 pandemic, are requesting comfortable and trendy in & out door fashion. For this reason, the results of this study are significant in the aspect of suggesting the new-normal fashion trend for pajamas designs.