군사용으로 먼저 개발되어 온 드론은 요소기술의 급격한 발전을 통해 민간 분야로 확대되면서 최근 다양한 산업분야에 활용되 고 있다. 이러한 시대적 흐름에 따라, 조선해양 산업계에서도 유지보수 및 점검용으로 드론의 활용이 유럽을 중심으로 본격화되고 있다. 이와 관련하여, 본 논문에서는 조선해양 분야에 적합한 드론의 기술개발을 위해 선박 및 해양플랜트의 유지보수 점검의 현상태를 진단함 으로써 드론 기술개발의 방향성을 제시한다. 즉, 조선해양용 드론이 이미 상용화 된 선진국의 기술력을 살펴보고, 조선해양 산업계에서 드론시대를 대비하여 해결해야 할 기술적 과제들을 소개한다. 또한, 이러한 드론의 시장성장 가능성을 전망함으로써 기술개발의 추진력 을 제공하고자 한다.
In the present study, sled analysis was conducted under the condition of 20g (20 times of gravitational acceleration) and 48 km/h of initial velocity, suggested by WC-19 to investigate the injuries of traffic minorities of tie-down type fixing inside a vehicle during crash. Also, four new parameters, which were related to angles between belts and wheelchair and their levels were limited by WC-19, were proposed and orthogonal array was prepared with different levels of each parameter. In the meantime, four parameters were optimised by minimising head injury criteria and chest acceleration of passengers in each case of the orthogonal array.
In this study, Fe-Cu-C alloy is sintered by spark plasma sintering (SPS). The sintering conditions are 60 MPa pressure with heating rates of 30, 60 and 9oC/min to determine the influence of heating rate on the mechanical and microstructure properties of the sintered alloys. The microstructure and mechanical properties of the sintered Fe-Cu-C alloy is investigated by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM). The temperature of shrinkage displacement is changed at 450oC with heating rates 30, 60, and 90oC/min. The temperature of the shrinkage displacement is finished at 650oC when heating rate 30oC/min, at 700oC when heating rate 60oC/min and at 800oC when heating rate 90oC/min. For the sintered alloy at heating rates of 30, 60, and 90oC/min, the apparent porosity is calculated to be 3.7%, 5.2%, and 7.7%, respectively. The hardness of the sintered alloys is investigated using Rockwell hardness measurements. The objective of this study is to investigate the densification behavior, porosity, and mechanical properties of the sintered Fe-Cu-C alloys depending on the heating rate.
국내 고속도로 콘크리트 중앙분리대는 SB5-B(270kJ)의 충돌등급에 저항하도록 설계되어 있다. 그러나 최근 대형 화물차 량의 충돌사고가 지속적으로 증가하는 경향을 보이고 있어 SB6(420kJ) 등급으로의 상향이 필요하다. 충돌등급 상향을 위한 새로운 중앙분리대 단면을 제시하기 위해서는 실제 충돌시험을 수행하여 기준 통과여부를 결정하며, 충돌시험 수행을 위한 적정 단면을 제시하기 위해서는 충돌해석을 통해 선정한다. 이러한 충돌해석의 정확도 향상을 위해서는 차량 모델, 콘크리트 단면 열화상태, 콘크리트 피복 두께 등 다양한 변수에 대한 정확한 변수 선정이 필요하다. 따라서 본 연구에서는 공차 중량, 단면 열화, 콘크리트 피복 두께에 대한 변수연구를 수행하여 충돌저항성능 저감을 확인하였다. 전체 중량뿐만 아닌 공차 중 량에 따라 중앙분리대의 충돌저항성능에 차이가 있는 것으로 확인되었으며, 10cm 이하의 콘크리트 피복 두께에서는 충돌저 항성능이 민감하게 증가 또는 감소한다. 단면 열화가 발생할 경우 중앙분리대의 충돌저항성능의 감소가 발생하여 열화정도 에 따른 보수 및 보강이 이루어져야 하는 것으로 판단된다. 따라서 콘크리트 구조물과 차량의 충돌해석을 수행할 경우 트럭 의 공차중량 비율, 콘크리트의 피복두께 및 열화에 대한 영향이 상세하게 고려될 필요가 있음을 확인하였다.
In this study, the electroless nickel plating method has been investigated for the coating of Ni nanoparticles onto fine Al powder as promising energetic materials. The adsorption of nickel nanoparticles onto the surface of Al powders has been studied by varying various process parameters, namely, the amounts of reducing agent, complexing agent, and pH-controller. The size of nickel nanoparticles synthesized in the process has been optimized to approximately 200 nm and they have been adsorbed on the Al powder. TGA results clearly show that the temperature at which oxidation of Al mainly occurs is lowered as the amount of Ni nanoparticles on the Al surface increases. Furthermore, the Ni-plated Al powders prepared for all conditions show improved exothermic reaction due to the selfpropagating high-temperature synthesis (SHS) between Ni and Al. Therefore, Al powders fully coated by Ni nanoparticles show the highest exothermic reactivity: this demonstrates the efficiency of Ni coating in improving the energetic properties of Al powders.
In this study, STS316L powders prepared by gas atomization are used to manufacture bulk structures with dimensions of 10 × 10 × 10 mm3 using selective laser melting (SLM). The microstructures and hardness of the fabricated 316L stainless steel has been investigated with the laser beam overlap varied from 10% to 70%. The microstructures of the fabricated STS316L samples show a decrease in the balling and satellite of powders introducing defect in the bulk samples and the porosity caused by the gap between the molten metal pools disappearing as the overlap ratio increases, whereas a low overlap ratio results in significant balling and a large amount of isolated powders due to the increased gap between the melt pools. Furthermore, the highest value in Vickers hardness is obtained for the sample fabricated by 30% overlapped laser beams. These results show that the overlap ratio of laser beams in the SLM process should be considered as an important process parameter.
조선조의 불교의례는 어렵고 힘든 시기를 견디어야 했던 불교계의 현실과 조선의 치국이념인 유교에서 얻지 못하는 내세관이 반영될 수밖에 없었다. 그렇게 형성된 불교의례는 현세 구복적이며 주술적인 성격이 강하였다.
개항 이후 불교에 대한 인식이 달라지고 한국불교의 모순을 타파하고 새 로운 이념을 제시한 개혁가들은 이런 의례에 대해 비판하기 시작하였다. 비 판과 함께 근대 불교의례의 방향으로 대중들이 쉽게 읽을 수 있고 이해할 수 있는 한글화와 대중화가 제시되었다.
이와 같은 한국불교의 자체적인 변화에도 불구하고 한국을 병합한 일제 는 사법을 제정하여 한국불교 의례를 크게 변질시키면서 통제정책에 활용 하였다.
그런 분위기를 인식한 한국불교인들은 1910년대 한국불교 의례 회복을 논의하였지만 실행되기 어려웠고, 1930년대 이르러 일제강점에 의해 훼손된 불교의례를 재정립하기 위한 노력이 대두되었다. 뜻있는 선지식들은 지난날 비판하고 버려두었던 불교의례 속에서 우리의 전통을 찾으려 하였다. 그런 배경에서 1931년 발간된 불자필람과 1935년 대중들을 위해 약본으로 발 간한 석문의범이다. 그런 의식에서 형성된 전통의례의 출판은 한국 불교 인의 많은 관심과 활용으로 이어졌다.
그러나 일제는 전시 체제에 맞도록 한국 1,500여 사찰에서 대동아전쟁의 연전연승을 위한 기도법회를 열어 절대적인 친일과 동원을 강요하면서 변질 된 의례를 지속시켰다.
이렇게 변질된 한국불교 의례는 광복 후에 회복될 수 있었다. 새로운 집 행부가 설립된 후 모범총림을 시설하여 옛날부터 전해지는 한국불교 범음전 통을 회복하였고, 성철과 청담의 주도하에 설립된 봉암사 결사운동에서 비 불교적인 요소들을 제거함으로써 현대 불교의례의 방향성이 제시되었다.
PURPOSES :This study was initiated to estimate the utilities of usage attributes of BRT and Bimodal Trams using a conjoint analysis method in order to identify the important features pertaining to the use of BRT and Bimodal Trams.METHODS :For this purpose, important attributes and those level in the use of BRT and Bimodal Trams in the city of Sejong were identified. Next, a profile questionnaire pertaining to BRT and Bimodal Trams was designed for the conjoint analysis, and a survey was conducted in the city of Sejong. Using SPSS software, conjoint analysis was performed to identify the important attributes vis`-a-vis the use of BRT and Bimodal Trams in the city of Sejong. Finally, the utilities for individual attributes were calculated based on the models estimated by the conjoint analysis.RESULTS :The results of the conjoint analysis were used to identify the important attributes. With regard to the usage of BRT, users indicated that fare was the most important attribute with the highest utility. In the case of Bimodal Trams, the users indicated that the number of seats and internal environment were the most important attributes with the highest utilities.CONCLUSIONS :Based on the results of the conjoint analysis, the important attributes pertaining to the use of BRT and Bimodal Trams in the city of Sejong were identified. Our study indicates that BRT in the city of Sejong needs to be upgraded to improve the utilities of the important attributes. Currently, Bimodal Trams has not been introduced completely in the city of Sejong. However, in the future, when the introduction of Bimodal Trams is completed, the important attributes should be emphasized in order to improve the quality of its service.
King oyster mushroom (Pleurotus eryngii), an improved species of oyster mushroom, is a popular ingredient in Asian cuisine. Spleen cells were treated with various concentrations (0, 5, 10, 50, 100, 250, 500, and 1,000 μg/mL) of king oyster water extracts (KOWE); then, the proliferation of the cells was measured 24, 48, and 72 h after each treatment. Also, type 1 T helper cytokine productions (TNF-α, IFN-γ, and IL-2) were measured in activated macrophage by KOWE in seven concentrations. Under the condition of its 50, 100, 250, and 1,000 μg/mL for 48 h, the proliferation of cells was increased. However, there was no significant fluctuation in the spleen cells proliferation for 24 and 72 h-long KOWE exposure. To determine cytokine (TNF-α, IFN-γ, IL-2) productions of type 1 T helper cells, macrophage was stimulated by KOWE for 48 h. Treatment of KOWE gave a rise to the levels of TNF-α and IFN-γ, but not in that of IL-2 productions. These results suggest that king oyster mushroom water extracts may be beneficial for enhancing immune functions in its high concentration.
This study presents a sustainable design method to optimize the embodied energy and CO2 emission complying with the design code for reinforced concrete column. The sustainable design method effectively achieves the minimization of the environmental load and energy consumption whereas the conventional design method has been mostly focused on the cost saving. Failure of reinforced concrete column exhibits compressive or tensile failure mode against an external force such as flexure and compression; thus, optimization analyses are conducted for both failure modes. For the given sections and reinforcement ratios, the optimized sections are determined by optimizing cost, embodied energy, and CO2 emission and various aspects of the sections are thoroughly investigated. The optimization analysis results show that 25% embodied energy and 55% CO2 emission can be approximately reduced by 10% increase in cost. In particular, the embodied energy and CO2 emission were more effectively reduced in the tensile failure mode rather than in the compressive failure mode. Consequently, it was proved that the sustainable design method effectively implements the concept of sustainable development in the design of reinforced concrete structure by optimizing embodied energy consumption and CO2 emission.
본 연구에서는 경기도 내 유통되고 있는 다소비 생선류 100건을 대상으로 납, 수은(메틸수은 포함), 카드뮴의 오염도 및 셀레늄의 함량을 알아보았다. 금아말감법의 수은 분석기, ICP-MS, GC-ECD를 사용하여 측정하였으며 각 항목별 평균함량은 Pb 0.0915(0.0021-0.4490) mg/kg, Cd 0.0084(ND-0.1773) mg/kg, Hg 0.0412(0.0013-0.3032) mg/kg 으로 모두 기준규격 이하로 나타났다. 셀레늄은 수은과 결 합하여 수은의 독성을 감소시키는 것으로 알려져 있는데 본 연구에서 조사된 생선류에서는 셀레늄의 평균함량이 0.4044(0.1981-1.0227) mg/kg이었다. 규격 외 항목인 메틸 수은은 100건 중 갈치와 대구 2개 시료에서 각각 0.0677 mg/ kg, 0.2941 mg/kg로 나타났다. 이러한 결과를 바탕으로 다소비 생선류를 통한 납, 수은 및 카드뮴의 총 섭취량은 JECFA에서 설정한 PTWI 및 PTMI의 0.97%, 3.42% 및 0.45%로 조사되었다. 따라서 도내에서 유통되는 생선류의 섭취는 납, 수은, 카드뮴 등의 위해에서 안전하다고 판단된다.
One of the challenges facing precision manufacturers is the increasing feature complexity of tight tolerance parts. All engineering drawings must account for the size, form, orientation, and location of all features to ensure manufacturability, measurability, and design intent. Geometric controls per ASME Y14.5 are typically applied to specify dimensional tolerances on engineering drawings and define size, form, orientation, and location of features. Many engineering drawings lack the necessary geometric dimensioning and tolerancing to allow for timely and accurate inspection and verification. Plus-minus tolerancing is typically ambiguous and requires extra time by engineering, programming, machining, and inspection functions to debate and agree on a single conclusion. Complex geometry can result in long inspection and verification times and put even the most sophisticated measurement equipment and processes to the test. In addition, design, manufacturing and quality engineers are often frustrated by communication errors over these features. However, an approach called profile tolerancing offers optimal definition of design intent by explicitly defining uniform boundaries around the physical geometry. It is an efficient and effective method for measurement and quality control. There are several advantages for product designers who use position and profile tolerancing instead of linear dimensioning. When design intent is conveyed unambiguously, manufacturers don’t have to field multiple question from suppliers as they design and build a process for manufacturing and inspection. Profile tolerancing, when it is applied correctly, provides manufacturing and inspection functions with unambiguously defined tolerancing. Those data are manufacturable and measurable. Customers can see cost and lead time reductions with parts that consistently meet the design intent. Components can function properly-eliminating costly rework, redesign, and missed market opportunities. However a supplier that is poised to embrace profile tolerancing will no doubt run into resistance from those who would prefer the way things have always been done. It is not just internal naysayers, but also suppliers that might fight the change. In addition, the investment for suppliers can be steep in terms of training, equipment, and software.
This study was aimed to find yield prediction model of Italian ryegrass using climate big data and geographic information. After that, mapping the predicted yield results using Geographic Information System (GIS) as follows; First, forage data were collected; second, the climate information, which was matched with forage data according to year and location, was gathered from the Korean Metrology Administration (KMA) as big data; third, the climate layers used for GIS were constructed; fourth, the yield prediction equation was estimated for the climate layers. Finally, the prediction model was evaluated in aspect of fitness and accuracy. As a result, the fitness of the model (R2) was between 27% to 95% in relation to cultivated locations. In Suwon (n=321), the model was; DMY = 158.63AGD –8.82AAT +169.09SGD - 8.03SAT +184.59SRD -13,352.24 (DMY: Dry Matter Yield, AGD: Autumnal Growing Days, SGD: Spring Growing Days, SAT: Spring Accumulated Temperature, SRD: Spring Rainfall Days). Furthermore, DMY was predicted as 9,790±120 (kg/ha) for the mean DMY(9,790 kg/ha). During mapping, the yield of inland areas were relatively greater than that of coastal areas except of Jeju Island, furthermore, northeastern areas, which was mountainous, had lain no cultivations due to weak cold tolerance. In this study, even though the yield prediction modeling and mapping were only performed in several particular locations limited to the data situation as a startup research in the Republic of Korea.
This study illustrates changes in the epilithic diatom assemblages in response to urban climatic conditions. We further assess the impact of abnormal urban climate to the urban stream environment. Epilithic diatoms, water chemical and physical variables were sampled every quarter, and assessed at 3 Oncheon stream sites, for a period of two years (from 2013~2014). The variation of physiochemical properties such as BOD, COD, T-N and T-P, show that the water quality was strongly influenced with long periods of drought and flood disturbance. Epilithic diatom assemblages were separated along the stream sites; however, the physical disturbance from urban drought and stormwater changed the composition of diatom assemblages instead of decreasing the taxonomic richness. Thus, our results suggest that epilithic diatom assemblages are altered in response to urban climatic changes, resulting in variations of stream conditions. Hence, strategies of climate change adaptation are required when considering urban stream environments.
배경/목적: 바터팽대부에서 발생하는 선암종은 드문 질환으로 항암화학요법에 대한 연구가 부족하다. 본 연구에서 진 행성 바터팽대부 선암종 환자에서 XELOX 병합요법의 효능 및 안전성을 분석하고자 한다. 방법: 2006년 10월부터 2014년 1월까지 국립암센터에서 XELOX 병합요법으로 치료한 바터팽대부 선암종 환자 28명 을 대상으로 후향적으로 분석하였다. 모든 환자는 진단 당시 전이성 또는 재발한 바터팽대부 선암종 환자이었다. XELOX 병합요법은 외래에서 3주마다 다음과 같은 프로토콜에 따라 투여되었다. 치료 시작 1-14일에 하루 2회 카페시타빈 750 mg/m2를 경구 투여하고, 1일에 옥살리플라틴 130 mg/m2을 정맥 주사하였다. 결과: 24.6개월(범위 4.8-78개월)의 중앙 추적관찰 기간에서 중앙 무진행 생존 기간은 4.8개월(범위 0.7-18.0개월)이었고, 중앙 생존 기간은 11.9개월(범위 2.0–26.1개월)이었다. 1명의 환자(4%)가 완전 관해를 얻었고, 5명의 환자(18%)는 부분 관 해를 보였다. 무진행 생존 기간와 전체 생존 기간에서 항암화 학요법 반응 여부에 따른 차이는 없었다. 환자에서 가장 흔한 3등급의 이상 반응은 메스꺼움과 구토였다(10.7%). 치료와 관 련된 사망은 관찰되지 않았다. 결론: XELOX 요법은 전이 혹은 재발 바터팽대부 선암종에서 비교적 낮은 독성의 발현과 중등도 효과를 보이는 치료법이다.
Basic dyes such as malachite green and methylene blue have been used as disinfectants to control water fungal infections since the 1930s. However, after succeeding reports of carcinogenicity and bioaccumulation of the dye, their use was forbidden in lieu of public health. This study undertook to evaluate the therapeutic effect of sulfur solution processed by effective microorganisms (EM-PSS) against Saprolegnia parasitica infection, and its safety in fish. In vitro antifungal evaluation of EM-PSS inhibited the growth of S. parasitica mycelia at concentrations of 50 ppm or higher. The acute toxicity test of EM-PSS to the mud fish (Misgurnus mizolepis) measured a no effect concentration (NOEC) at 100 ppm, the lowest effect concentration (LOEC) at 125 ppm, and the half-lethal concentration (LC50) at 125 ppm in juvenile and 250 ppm in the immature stage. In addition, the ecotoxicity test of EM-PSS using Daphnia magna inhibited swimming of D. magna at concentrations of 100 ppm or less. Lastly, the EM-PSS prevented infection of S. parasitica to mud fish, at concentrations of 50 ppm. Furthermore, at 100 ppm concentration, the EM-PSS showed no acute toxicity on mud fish, nor any eco-toxic effects on D. magnano. Therefore, we conclude that carcinogenic disinfectants such as malachite green and methylene blue could be replaced by EM-PSS to remove S. parasitica in mud fish farming, and might be a potential eco-friendly disinfectant in aquaculture.
목적 :본 연구 목적은 장애인들의 지역사회참여를 객관적, 주관적으로 측정하기 위한 평가도구인 지역사회참 여지표(Community Participation Indicators; CPI)의 한국어판을 개발하고 신뢰도를 검증하는 것이다. 연구방법 :CPI의 번안과정을 통해 한국어판을 완성하고 신뢰도 검증을 하였다. 번역, 역번역, 전문검토위원 회의 검토를 거쳐 문항이해도를 확인하기 위한 사전검사를 거쳐 번역본을 완성하였고 전문가집단의 번 역 적합성 설문을 통해 최종본을 확정하였다. 또한 완성된 한국어판은 검사-재검사를 실시하고 참여권 문항의 내적 일치도를 구하여 신뢰도를 검증하였다.결과 :완성된 한국어판 지역사회참여지표(Korean-Community Participation Indicators; K-CPI)를 통해 일반인을 대상으로 한 검사-재검사 신뢰도는 .763∼.901였고 참여권 문항의 내적일치도는 장애인 410 명을 대상으로 .949로 나타났다.결론 :본 연구에서는 CPI의 번안과정을 통해 K-CPI를 완성하고 신뢰도를 검증하여 장애인의 참여에 대한 객관적, 주관적 측면을 측정하는 한국어판 참여 평가도구를 개발하고자 하였다. 본 연구를 토대로 K-CPI가 임상 현장에서 참여를 측정하는 도구로 활용되기를 기대한다.
The number of children who use day-care centers is increasing. Most indoor air quality (IAQ) management has been based on daily average pollutant concentrations measured once a year. A more comprehensive management of IAQ is needed to protect children’s health from air pollutants in day-care centers. In this study, we investigated the weekly variation of air pollutant concentrations in a nursing room of a day-care center located at the roadside for a week in June of 2014. Average concentrations of CO2, PM10, black carbon, and total surface area of lungdeposited particles during nursing time of the day-care center were 510 ppm, 27.8 μg/m3, 1.87 μg/m3, and 30.6 μm2/cm3, respectively, with a similar diurnal pattern shown on weekdays.