The intensive development of the petrochemical industry globally reflects the necessity of an efficient approach for oily sludge and wastewater. Hence, for the first time, the current study utilized magnetic waxy diesel sludge (MWOPS) to synthesize activated carbon coated with TiO2 particles for the removal of total petroleum hydrocarbons (TPH) and COD from oily petroleum wastewater (OPW). The photocatalyst was characterized using CHNOS, elemental analysis was performed using X-ray fluorescence spectroscopy (XRF), field emission scanning electron microscope (FESEM), high-resolution transmission electron microscope (HR-TEM), X-ray diffraction analysis (XRD), Fourier transform infrared spectrometer (FTIR), Raman, energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), MAP thermo-gravimetric analysis/ differential thermo-gravimetric (TGA–DTG), Brunauer–Emmett–Teller (BET), diffuse reflectance spectroscopy (DRS), and vibrating sample magnetometer (VSM). The optimization of synthesized highly porous AC/Fe3O4/TiO2 photocatalyst was conducted considering the impacts of pH, temperature, photocatalyst dosage, and UVA6W exposure time. The results demonstrated the high capacity of the MWOPS with inherent magnetic potential and desired carbon content for the removal of 91% and 93% of TPH and COD, respectively. The optimum conditions for the OPW treatment were obtained at pH 6.5, photocatalyst dosage of 250 mg, temperature of 35 °C, and UVA6W exposure time of 67.5 min. Moreover, the isotherm/kinetic modeling illustrated simultaneous physisorption and chemisorption on heterogeneous and multilayer surfaces. Notably, the adsorption efficiency of the AC/Fe3O4/TiO2 decreased by 4% after five adsorption/desorption cycles. Accordingly, the application of a well-designed pioneering photocatalyst from the MWOPS provides a cost-effective approach for industry manufacturers for oily wastewater treatment.
The sub-frame is located on the lower body of a monocoque type vehicle and serves as an engine and suspension, and is an important object part that receives a lot of load. The existing press-type sub-frame has a large number of parts for assembling, which causes an increase in cost. Changing the machining form of this part from the existing press-type machining method to the hydro-forming machining method has the advantage of reducing the cost and weight at the same time due to the reduction of the process. Therefore, in this study, the purpose of this study is to change the design so that the sub-frame of the existing press type can be changed to the hydro-forming process method. To this end, we intend to present a design method by analyzing the effect on the rigidity of the sub-frame using the existing machining method through shape optimization analysis.
In this study, we studied the method of using general architectural glass instead of using the existing acrylic material for high luminance flat lighting. The flat panel lighting used the side illumination method to increase the ease of installation and aesthetic satisfaction. In general, glass has an amorphous structure with a lower angle of refraction than acrylic, so it is not suitable for use in flat panel lighting as a light guide, but in this study, the role of light distribution characteristics and diffusion patterns in the case of using such a glass light guide. Quantitative simulations were conducted to confirm new possibilities. In the simulation, the backlight estimation method was used, and about 10,000,000 rays were placed within a unit area in order to obtain a result similar to the real thing. As a result of the simulation, the geometry of the diffusion pattern could be specified, and the value of the geometry could be quantified using the ratio of the diameter and height of the pattern. As a result of the calculation, it was found that the maximum amount of light was generated around 75 degrees by quantitatively calculating the ratio and the outgoing light angle at which the maximum value of the outgoing light occurred between 05 and 1.0. As a result of these studies, it was confirmed that it is possible to use ordinary glass at the same time as a transparent window and light-emitting lighting at night.
본 연구는 전기자동차 충전시스템에서 전력변환장치의 경량화를 위한 최적화 분석프로세스에 대한 내용을 서술하였다. 최적화 설계는 재료 물성치에 대한 설계민감도와 수학적 최적화를 결합하여 주어진 재료량 제한조건 하에 최적의 재료분포를 찾는 설계기법으로 위상의 고정화, 자유도가 묶이는 문제 등을 해결할 수 있는 위상 최적화방법을 사용하였으며, 위상 최적화 방법 중 비교적 수식화가 간단하고 수렴성이 좋은 SIMP법(solid isotropic material with penalization)에 의해 경량화 설계를 수행하였다. 경량화 설계는 3단계의 절차로 구성하였으며, 첫 번째 단계로 전력변환장치의 기본 설계에 대한 유한요소모델을 구성하고, 하중에 대한 정적해석을 수행하였다. 두 번째 단계로 정적해석 결과에 대해 등방성 재료의 강성계수를 적용한 밀도법을 이용하여 위상 최적화를 수행하여 경량화를 위한 최적 형상을 도출하였다. 세 번째 단계로 최적 형상에 대해 차량 탑재 부품의 충격시험기준에 만족하는 반정현파 펄스형태 충격하중을 인가하여 충격해석을 수행하였다. 위상 최적화단계에서 사용 환경조건으로 설계영역 정의는 마운팅 브래킷 영역으로 제한하였으며, 마운팅 브래킷의 설계 최적화를 통해 최종적으로 기본설계대비 20%이상의 경량화가 가능한 설계기술을 확보하였다.
In this study, We studied design method to reduce scattering reflection by adding a three - dimensional structure to light guide plate of LED backlight widely used in small and portable devices. In order to improve the efficiency of the light-incident part, a three-dimensional structure is used in which a repetitive structure of a prism shape and a semi-cylindrical shape is repeatedly added to the light-entering face in light-guide plate. As a result of the study, it was found that uniform luminance values were obtained in the light-incident portion and the backlight when a repetitive pattern of a semi-cylindrical shape was added as compared with a case in which a prism shape was added. Particularly, when a rectangular lens with a semi-cylindrical shape is added, the average value of the total luminance is increased by about 15% from 7278 lm to 8324 lm as compared with a general light guide plate.
As a preparation of a design standard regarding road facilities in terms of reliability based optimum design examples, such as cantilever columns for traffic lights, optimum design in deterministic and probabilistic ways for the foundation of traffic lights poles are proposed. Most of the previous study have focused on the foundation surrounded by cohesionless soil. However, the design would be governed by risky condition. Therefore the resistance by clay-soil is investigated compared with other design specifications. In deterministic optimization, GRG method is applied. It is found that both geometries of deep and shallow foundation provides optimum values. The resistance of cohesive soil is selected to represent the ultimate limit states, in terms of sliding, overturning and bearing pressures from super structures to the foundation under external loads. Example foundations with varying height of columns for traffic lights are optimized about 30% decreased embedded depth of foundation. The optimum coefficients of resistant and load factors may need to be developed with design load combinations in order to prepare design specifications as the next step.
In order to obtain the goal of the weight reduction of automobile components, the researches about lighter and stronger wheel carriers have been studied without sacrificing the safety of them. In this study, the weight reduction design process of wheel carrier could be proposed based on the variation of von-Mises stress contour by substituting an AA6061 (aluminum 6061 alloy) having tensile strength of 310 MPa grade instead of FCD600 Irons. From the stress analysis results before and after design modification, the stress relaxation was done at every given loading conditions. Therefore, it could be reached that this approach method could be well established and be contributed for light-weight design guide and the optimum design conditions of the automotive wheel carrier development.
Modern systems development becomes more and more complicated due to the need on the ever-increasing capability of the systems. In addition to the complexity issue, safety concern is also increasing since the malfunctions of the systems under development may result in the accidents in both the test and evaluation phase and the operation phase. Light rail transit(LRT) with passenger capacity between bus and subway is driven by an unmanned control, so safety issues of LRT in emergency shall be considered more carefully than other rolling stock. Modern railway system is a complex system and many actions in emergency are required. In this view, interoperability approach is effective to identify the related elements in emergency. In this paper, we propose the method to generate the fire response scenario of unmann ed LRT based on the outputs of systems engineering architecture design methodology. The proposed method is could be contributed to establish more reliable and applicable fire response scenario.
The study will design the structural optimization of 30W LED heat sink using the thermal conductive plastic materials. The advantages of thermal conductive plastic heat sink are having formability and being able to lighten products. A heat sink was optimized in terms of the number, and the thickness of fins and the base thickness of the heat sink, using the Heatsinkdesigner software. Also by using SolidWorks Flow simulation and thermal analysis software, the thermal characteristics of the heat sink were analyzed. As the result, the optimized heat sink has 22 fins, which are 1.5mm thick and a 3.8mm-thick base. The weight of the heat sink was 310g, and the highest and the lowest temperature were 64.93℃ and 45.96℃ respectively. Because of the low thermal conductivity of the thermal conductive plastic, the highest and the lowest temperature of the thermal conductive plastic heat sink were 14.3℃ higher and 2.19℃ lower respectively than an aluminum heat sink
본 연구는 인공광 이용형 common ice plant 식물공장 설계를 위한 기초자료를 확보하고자 수행되었다. 인공광 이용형 식물공장에서 작물의 광합성을 위해 필요한 광도는 120~200μmol·m−2·s−1, 탄소 고정률은 0.84nmolCO2·cm−2·s−1 이었다. 1주의 점유 면적 0.0225m2(15×15cm), 광도 200μmol·m−2·s−1, 하루 1,000주 생산을 가정할 경우, 식재 주수는 25,000주, 563m2의 재배면적이 필요하며, 전체 광도는 140,625μmol·s−1가 필요하게 된다. 하루 전력 약 153.2kW 기준으로 약 2,785개의 55W 형광등이 필요하며, 1개월 전기요금은 246만원(농업용 전력(을))이 된다. 또한 조명 설비 비용 2,785만원, 설비 비용 8,356만원과 전체 생산 비용 10,027만원이 소요된다. 재배기간 25일(325일 생산), 상품화율 80%에 따른 1주 당 생산 비용은 인건비 포함하여 약 370원이 된다. 경비 총합, 감가 상각비와 연간 판매수입을 고려해볼 때, 1주당 판매 비 용은 970원 이상으로 판단되었다.
겨울철 온실의 기본적인 열에너지원인 일사를 최대한 확보하도록 하는 은실의 지붕형상을 결정하기 위해 유전알고리즘 및 광투과율 전산모델을 이용한 최적화기법을 이용하여 설치지역, 피복재료특성, 온실의 기본치수등이 주어졌을 때 지붕경사각, 경간폭비의 최적조합을 결정할 수 있도록 하는 최적설계를 수행하였다. 수원지방에 위치한 경간폭 6m의 2연동 동서동 온실 및 단동 온실을 가정하여 최적화를 수행한 결과 경사각, 폭비 순으로 2연동, 단동 온실에 대해 각각 40.861≒40 。 / , 0.4806≒0.5, 37.490≒37 。 / , 0.7748≒0.78의 결과를 얻을 수 있었다. 광투과율 문제를 예로 적용해 본 결과 직접 전산모델을 호출하여 최적화를 수행하는 유전알고리즘의 기법은 온실환경의 해석을 위해 연구되어온 다양한 분야의 전산모델들을 종합적인 온실의 최적설계에 활용하도록 하는데 유용한 기법이 될 것으로 판단되었다.판단되었다.
Unilateral neglect has been the most considerable problem that affects the functional prognosis of CVA patients. The approaches to this symptom are both remedial and compensatory approach. Remedial approach is more valuable method than compensatory approach in terms of reducing the unilateral neglect originally. One of the method of remedial approach is controlled sensory stimulation. The purpose of this study was to investigate the effects of left visual stimuli for reducing the severity of unilateral neglect. The subject was a 40-year-old male patient who had left unilateral neglect. We have put blinking light in the left space of the patient while he performed the line bisection test before and after the stimulation. As a result, the stimulation was not
distinctively effective to release the neglect. For further study. it is considered that the environment when stimulating, the strength and duration of stimulation must be controlled.
블록형 섬광체와 픽셀형 섬광체를 이용한 반응 깊이 측정 검출기를 설계하였으며, 층 구분 능력을 DETECT2000을 사용하여 측정하였다. 블록형 섬광체를 사용하여 민감도를 향상했으며, 반응 깊이를 측정함으로써 공간분해능을 향상했다. 위층은 블록형으로 아래층은 픽셀형 섬광체를 위치시켜 감마선과 반응한 섬광체에서 발생한 빛의 분포를 변화시켰으며, 변화된 빛의 분포의 채널별 신호 특성 분석을 통해 반응 깊이를 측정하였다. 아래층을 픽셀형 섬광체로 구성하여 평면 영상 획득 시 위층의 블록형 섬광체에서도 픽셀형 섬광체의 위치와 비슷한 곳에서 영상을 획득할 수 있었다. 앵거 알고리듬을 사용하여 16채널의 신호를 4개의 채널로 감소시켜, 신호 특성 분석을 용이하게 하였으며, 층 구분은 간단한 알고리듬을 사용하여 측정하였고 층별 약 84%의 측정 정확도를 보였다. 본 검출기를 전임상용 PET에서 사용할 경우 반응 깊이 측정을 통해 검출 시야 외곽에서의 공간분해능을 향상할 수 있을 것이다.
The effect of fine dust on indoor and outdoor atmospheric environment in Korea is getting larger and it is tried to solve this problem by incorporating photocatalyst. Conventional light transparent concrete (LEFC) arranges plastic rods to ensure light transmittance. However, it is difficult to secure sufficient fluidity due to the heterogeneity and spacing of the materials. In addition to the flow test, J-ring test and L-box test, which are ASTM standards or EN standards, are used to evaluate the fluidity and to find out the optimum mix design of light transparent concrete with self-consolidating performance.
국내 디자인경영은 약 30년의 노력을 통하여 원론적인 연구 기반을 구축하였다고 볼 수 있다. 디자인경영 정책 및 기반 구축, 대기업 사례, 중소기업의 가이드라인 그리고 인력과 조직, 체계 중심에서 전략 중심으로 연구를 말한다. 이제 중소기업의 실질적인 디자인경영 도입을 위한 사례별 연구가 절실하다. 이런 다양한 사례 연구를 통하여 기업의 경영목표 달성을 위한 특성별로 구체적이고 책임감 있는 대안을 제시할 수 있을 것이다. 제조업 중소기업인 드림라이트는 대기업과 유사한 최고경영자를 중심으로 하는 경영, 브랜드, 마케팅, 소비자, 기술, 스타일 6가지 요소를 모두 가지고 있는 독특한 종합형 디자인경영체계를 가지고 있다. 하지만 일반적 대기업과 다른 내부 외부의 전문가 집단을 통한 최고경영자에게 조언이 가능하게 하면서, 내부 과정과 조직을 소기업에 맞게 효과적으로 가지고 있음을 확인하였다. 그러므로 국내 제조업 기반의 소기업의 최고경영자를 조언하는 전문가 집단을 통하여 디자인을 중심으로 하나의 비전을 만들어 가는 사례를 제시하고자 한다.