This study compares and analyzes changes in users’ perceptions of industrial catering food service quality before and after COVID-19. The survey enrolled 226 subjects at five industrial catering establishments in Seoul and Gyeonggi Province; a total of 204 customers with complete data were included in the final analysis. Factor analysis was conducted to verify convergence validity and construct reliability; results pertaining to ‘service and environmental hygiene’ and ‘quality of food’ were extracted. Among the general variables of food service quality, differences were obtained in the user’s perceptions of food service qualities according to gender, education, and marital status. Our results revealed that women, low education, and married people perceived significant differences in all attributes before and after COVID-19. Additionally, varied altered perceptions were determined for service quality according to the occupations of the subjects. However, no differences were obtained for pleasant dining environment in the ‘service and environmental hygiene factor’ and variety of desserts in the ‘food quality factor’.

본 연구에서는 백혈구 친화 흡착 및 분리 가능한 기능성 필터를 개발하기 위해, 직경이 3μm이하를 가지는 부직포 표면에 전기 방사법을 이용하여 평막형태의 혈액분리용 필터를 제조하였다. 전기방사는 고분자 농도, 유량, 인가전압, 에어갭 등의 변수를 조절하여 나노/마이크로 구조를 최적화하였다. 분리막의 단면과 표면 모폴로지는 전계방출형주사현미경(FE-SEM)을 이용하여 관찰하였다. 화학적 표면처리를 통해 친수성을 증가시켰으며, 혈액적합성 평가결과 우수한 것을 확인 할 수 있었다.

PURPOSES : The purpose of this study is to analyze the requirements of the road traffic safety moderator robot when road repairing. The road traffic safety moderator robot is road traffic safety equipment and to conversions mechanical engineering and IT when road repairing. METHODS: The study used AHP based on the survey from road repair related expert that field engineers, design engineers, public officials and professors. The survey used paired comparison. The survey items were safety, convenience and economics. The safety is classified as visibility or efficiency, the convenience is classified as utility or mobility and the economics is classified as initial investment cost or maintenance $ management cost. The survey alternatives were the road traffic safety moderator robot, traffic regulation by human, traffic regulation by mannequin and traffic signs. The software for AHP is Expert Choice 2000. RESULTS : The results of AHP analyze, the weighted value of safety was analyzed with the highest at 0.488 of survey items. The weighted value of convenience was analyzed at 0.295, the weighted value of economics was analyzed at 0.218. The results of the road traffic safety moderator robot, the weight value of efficiency and utility were analyzed with the highest at 0.284 and 0.259 of alternatives. The weighted value of initial investment cost and maintenance & management cost were analyzed with the lowest at 0.203 and 0.211 of alternatives. The consistency test results of each items, null hypothesis is rejected because the CR values were 0.000 respectively. Therefore, the study results are consistency. CONCLUSIONS : The result of this study, overall value of the road traffic safety moderator robot came off second-best of other alternatives. The road traffic safety moderator robot has been received highest praise by the result of the study as good road traffic safety equipment when road repairing because the weighted values of efficiency and utility were analyzed with the highest of survey items. The efficiency mean securing safety and the utility mean practical assistance when road repairing. The results of this study showed that the road traffic safety moderator robot will effective for traffic safety when road repairing. economics and visibility are that supplementation of the road traffic safety moderator robot because the weighted values of economics and visibility were analyzed with the lowest of survey items. The consistency test results are consistency because the CR values were 0.000 respectively.

PURPOSES : This study is to analysis for benefit and construction cost in underpass for small vehicles. METHODS : The study was performed using the traffic software VISSIM 5.20 for analysis on a variety of traffic conditions and analysed of benefits of changes through analysis of travel speed and travel time after modeling of existing underpass and small vehicle underpass. RESULTS : Results of this study, the benefits will be reduced by the introduction underpass for small vehicles were analyzed because heavy vehicles use the intersection above the underpass. However, it was required economic analysis considering both the benefits reduction and the construction costs reduction because it has the effect of reducing the construction cost. Showed that the difference in benefit changes depending on the v/c and heavy vehicles ratio and construction cost was difference by types of underpass. As a result of performing economic analysis with total benefits and construction cost, it was analyzed to be economical in underpass over a certain size. CONCLUSIONS : The result of this study are expected to be able to contribute to reviewing for feasibility due to the small vehicles underpass introduction and economic analysis. The study is case study to the underpass in Daegu. Therefore, the future requires the calculation of benefits reflect a wider range of traffic conditions and the economic analysis to construction cost calculation for various types of grad separation facilities.

Low temperature desorption of the used activated carbons that contain VOCs (Volatile Organic Compounds) produced from Shiwha/Banwal industrial complex were investigated. Iodine number and BET specific surface area of the activated carbons manufactured by N company in China were measured to see their characteristics prior to use in the experiment. Activated carbons were used to adsorb VOCs in a company of Shiwha/Banwal complex. Used activated carbons were collected and desorbed by the desorbing facility. After 1st adsorption and 1st desorption samples were taken for analysis. Desorbed activated carbons were reused in the same company. After 2nd adsorption and 2nd desorption samples were taken again for analysis. 4 samples were analyzed by TGA (Thermogravimetric Analyzer) at 170℃ with a heating rate of 10℃/min. Also, activation energies and reaction orders of desorption reaction were assessed by employing Friedman method and Freeman-Carroll method. The activation energies were 16.86kJ/mol by Friedman method and reaction orders were 0.36∼5.16 by Freeman-Carroll method.

In Shiwha/Banwal industrial complex, activated carbons are widely used to remove VOCs. General method of regenerating activated carbons is proceeded at high temperature (800℃). But it causes loss of activated carbons and high cost. In this study, activated carbons were treated at a low temperature of 170℃ to avoid these. Desorption reactions were analyzed based on the data obtained from a thermogravimetric analyzer. THC(Total Hydro Carbon) analyzer was used to analyze desorption reaction of activated carbons.

Highly textured Ag, Al and Al:Si back reflectors for flexible n-i-p silicon thin-film solar cells were prepared on 100-μm-thick stainless steel substrates by DC magnetron sputtering and the influence of their surface textures on the light-scattering properties were investigated. The surface texture of the metal back reflectors was influenced by the increased grain size and by the bimodal distribution that arose due to the abnormal grain growth at elevated deposition temperatures. This can be explained by the structure zone model (SZM). With an increase in the deposition temperatures from room temperature to 500˚C, the surface roughness of the Al:Si films increased from 11 nm to 95 nm, whereas that of the pure Ag films increased from 6 nm to 47 nm at the same deposition temperature. Although Al:Si back reflectors with larger surface feature dimensions than pure Ag can be fabricated at lower deposition temperatures due to the lower melting point and the Si impurity drag effect, they show poor total and diffuse reflectance, resulting from the low reflectivity and reflection loss on the textured surface. For a further improvement of the light-trapping efficiency in solar cells, a new type of back reflector consisting of Ag/Al:Si bilayer is suggested. The surface morphology and reflectance of this reflector are closely dependent on the Al:Si bottom layer and the Ag top layer. The relationship between the surface topography and the light-scattering properties of the bilayer back reflectors is also reported in this paper.

근래의 폭발적인 차량의 증가와 지가 상승, 도시부 시가지 내에서의 지상공간의 공급한계, 자연환경 및 경관에 대한 사용자 요구수준의 증대 등 여러 이유로 지하공간 개발의 필요성이 증대되고 있다. 지하공간의 개발은 필연적으로 건설비의 증가로 이어지며 대형 구조물의 설치는 도시 미관을 저해하는 요인으로 작용하기 때문에 최근에 가능하면 도심 구조물의 경우 경량화, 소형화 하려는 경향이 있다. 따라서 본 연구에서는 효율적인 지하공간의 개발을 위해 대구광역시의 도시부 도로에 설치되어 운영 중인 지하차도 구조물을 대상으로 미시적 소프트웨어인 VISSIM 5.20을 이용하여 소형차 전용 지하차도 도입에 따른 지체시간의 변화를 분석하였다. 소형차 전용 지하차도 도입 시 운영 방식의 변화를 반영하기 위해 대형차량을 지하차도를 통해 통행시키지 않고 지하차도 상부 평면교차로를 이용해 통행하도록 하였으며, 교통특성에 따른 영향을 분석하기 위해 접근로의 포화도(v/c)와 대형차량 혼입률을 순차적으로 증가시켜 통행시간의 변화를 알아보고 기존 지하차도와 비교 분석하였다. 본 연구의 결과로 미루어 볼 때 소형차 전용 지하차도의 도입은 토지매입에 따른 경제적 손실, 구조물의 대형화에 따른 환경훼손 및 친환경적 녹색교통 측면에서도 유리할 것으로 판단된다.

The synthesis behavior of nanoporous silica aerogel in the macroporous ceramic structure was observed using TEOS as a source material and glycerol as a dry control chemical additive (DCCA). Silica aerogel in the macroporous ceramic structure was synthesized via sono-gel process using hexamethyldiazane (HMDS) as a modification agent and n-hexane as a main solvent. The wet gel with a modified surface was dried at under ambient pressure. The addition of glycerol appears to give the wet gel a more homogeneous microstructure. However, glycerol also retarded the rate of surface modification and solvent exchange. Silica aerogel completely filled the macroporous ceramic structure without defect in the condition of surface modification (20% HMDS/nhexane at 36hr).

본 연구에서는 도시부도로의 곡선구간에서 주행차량의 횡방향 이격량을 분석하여 차량 주행에 필요한 최소 소요차로폭을 산정하였으며 본 연구결과와 선행연구에서 제시된 직선구간에서의 최소 소요차로폭을 비교 분석하였다. 이를 바탕으로 도로의 선형과 차종에 따라 곡선구간에서의 최소 소요차로폭을 제시하였다. 조사대상 곡선구간 도로의 차로폭은 2.79m~3.40m이다. 주행차량의 횡방향 이격량의 분포 및 조사대상 차량의 85%를 기준으로 누적분포를 분석하였다. 분석결과 곡선구간에서의 최소 소요차로폭이 소형차량의 경우 2.31m~2.58m, 대형차량의 경우 2.80m~3.27m로 산정되었다. 본 연구결과는 녹색교통 도입을 위한 공간, 도로공사 중, 소형차 전용도로의 건설 등에 활용될 수 있을 것이다. 또한 설계자의 목적에 따라 유연한 차로폭 설계기준의 적용에 필요한 기초적인 연구로 활용될 수 있을 것으로 기대된다.

Desorption reaction characteristics of the used activated carbons collected from manufacture of rubber and plastics products in Shiwha/Banwal industrial complex were investigated. Desorption reactions were analyzed based on the data obtained from a thermogravimetric analyzer. Activation energies and reaction orders for desorption reaction characteristics of the used activated carbons were estimated by employing the Friedman method and the Freeman-Carroll method. It was found that the activation energies were 24.7∼41.3 kJ/㏖ in the Friedman method and 13.9∼24.4 kJ/㏖ in the Freeman-carroll method, and reaction orders were 0.3∼1.4.

급격한 도시화는 교통지체를 포함하여 다양한 교통문제를 유발하였다. 따라서 도로건설, 교통소통 위주의 정책을 통해 교통지체 문제를 해결하기 위해 노력하였다. 그러나 차량중심의 교통소통 정책의 한계를 인식하고 최근에는 인간중심의 녹색교통 정책으로 전환 되고 있다. 도로다이어트는 이러한 녹색교통의 하나로 추진되고 있는 개념이다. 도로다이어트는 차로수, 차로폭 등을 줄여서 확보된 공간에 자전거도로, 보행자를 위한 쾌적한 보행로 등 녹색교통을 위한 공간으로 활용하고자 하는 방법이다. 도로다이어트는 최근에 도이된 개념으로 아직 구체적이고 실증적인 연구가 많이 수행되지 못하고 있는 실정이다. 따라서 본 연구에서는 도로다이어트를 위한 차로폭 축소 방안에 대한 기초적이고 실증적인 연구를 수행하였다. 현장조사를 통해 차로를 주행하는 차량의 차로중심선에서 이격량을 분석하여 차량이 주행시에 필요로 하는 최소한의 차로폭을 분석하였다. 분석결과 소형차의 경우 조사지점별로 2.34~2.70m, 대형차의 경우에는 2.62~2.89m의 차로폭이 필요한 것으로 나타나 도로다이어트 등 설계자의 목적에 따라 차로폭을 다소 축소할 수 있도록 설계기준을 완벽할 필요가 있을 것으로 판단된다. 본 연구결과는 도로다이어트, 도로공사 등으로 인해 동행이 가능한 도록폭이 축소되었을 때 차로폭 축소를 위한 설계기준으로 활용될 수 있을 것이다.

Desorption characteristics of waste activated carbons collected from chemicals manufacturing industries in Shiwha/Banwal industrial complex were investigated. Activated carbons were decomposed in a thermogravimetric analyzer (TGA) at 513K with heating rate of 10 ℃/min under nitrogen atmosphere. Activation energies and reaction orders for desorption, from the waste activated carbon were estimated by employing Friedman method and Freeman-Carroll method. It was found that the reaction orders of desorption in waste activated carbons were 0.27-1.69, and activation energies were 15.2-45.7 kJ/mol in Friedman method and 13.7-17.1 kJ/mol in Freeman-Carroll method.

본 연구에서는 현재 실존하는 제방을 대상으로 제방겸용도로 건설에 따른 안정성의 변화를 살펴보기 위해 건설단계별로 도로건설을 위한 성토 후, 겸용도로 건설 후 도로를 주행하는 차량에 의한 교통하중이 재하될 경우로 구분하여 안정성 변화를 분석하였다. 연구결과 겸용도로 건설을 위한 성토 후와 교통하중(DB-24)을 적용하였을 경우 모두 일반적인 안전율 기준인 1.3을 상회하고 있어 겸용도로 건설에 따른 제방의 안전은 확보되는 것으로 분석되어 제방겸용도로의 건설은 부지 확보 비용 절감을 위해 건설이 가능할 것으로 판단된다. 그러나 겸용도로의 건설로 인해 제방의 안전율 감소 현상이 발생하기 때문에 안정성에 대한 사전 검토가 충분히 이루어져야 할 것이다. 특히 안전율 감소가 가장 큰 경우는 비정상류 상태의 수위상승의 경우로 분석되어 하천제방과 같이 수위변화가 빈번한 경우에는 비정상류 해석으로 설계하는 것이 바람직하며 제내지의 사면경사는 기존제방과 동일한 1:2의 경사를 유지하도록 설계하는 것이 필요할 것으로 판단된다. 또한, 교통하중에 의한 안전율 감소현상도 발생하는 것으로 분석되어 겸용도로 건설 후 주행차량의 하중제한 등 유지 관리에도 지속적인 관심을 기울여야 할 것으로 판단된다.

In order to investigate a nitriding process of spent oxide fuel and the subsequent change in thermal properties after nitriding, simulated spent fuel powder was converted into a nitride pellet with simulated fission product elements through a carbothermic reduction process. Nitriding rate of simulated spent fuel was decreased with increasing of the amount of fission products. Contents of Ba and Sr in simulated spent fuel were decreased after the carbothermic reduction process. The thermal conductivity of the nitride pellet was decreased by an addition of fission product element but was higher than that of the oxide fuel containing fission product elements.

본 연구에서는 히알루론산나트륨/카르복시메틸셀룰로오스나트륨(HA/CMC)으로 구성된 유착방지 막을 제조하였고, 쥐에서 유착방지용에 대한 효과를 평가하였다. 유착방지 막은 HA/CMC 용액을 동결건조한 후 1-에틸-3-(3-디메틸아미노프로필)카보디이미드 (EDAC)로 가교하여 제조하였다. Sprague-Dawley쥐의 맹장/복벽 찰과상 모델에서 복부 중앙선 절개 후 장막과 복벽을 bone burr로 1×2;(cm2) 크기로 찰과상을 만들고, 상처 면 주위의 3곳을 봉합사로 고정시켰다. 상처난 장을 실험군의 경우 HA/CMC 막으로 덮어주었으며, 대조군은 아무처치도 하지 않은 상태로 복벽을 마주보게 하였다. 대조군의 대부분은 수술 후 7, 14, 21, 28일에 유착정도 3 이상을 나타내었고, 반면 실험군의 60~70%는 수술 후 14, 21, 28일에 유착정도 2 이하를 나타내었다. 이는 유착세기에서도 유사하였다. 일반적으로 유착정도와 유착세기는 수술 후 14일까지 점차 증가하였고, 수술 후 21일에는 거의 동일하거나 약간 증가하였으며, 28일째에는 감소하였다. 대조군은 유착정도와 유착세기, 유착면적에서 높은 수치를 나타내었다. 이 유착방지막은 수술 후 유착방지에서 좋은 임상결과를 나타낼 수 있을 것으로 기대된다.