• 한국기후변화학회지
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• 제7권2호
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• pp.177-184
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• 2016

Recently, the need for technology development of commercial vehicle fuel consumption has emerged. Fuel economy improvement of transport equipment and transportation efficiency, and increasing attention to the logistics cost reduction measures. Increasing attention to the logistics cost reduction measures by fuel economy improvement of transport equipment and transportation efficiency. In this study, we have installed aerodynamic reduction device (side skirt, boat tail) to 14.5 ton cargo trucks and 45 ft tractor-trailers. And the fuel consumption was compared installed before and after. Fuel economy assessment for the aerodynamic reduction value device was tested by modifying the SAE J1321 Joint TMC/SAE Fuel Consumption Test Procedure - Type II test in according domestic situation. Greenhouse gas reductions were calculated in accordance with the scenario, including fuel consumption test results. When the 14.5 ton cargo trucks has been equipped with side skirts and boat tail, it confirmed the improvement in fuel efficiency of 4.72%. One Heavy-duty truck's the annual greenhouse gas reductions value are $6.86ton\;CO_2\;eq$. And if applying the technology to more than 50% of registered 15 ton trucks, greenhouse gas reductions are calculated as $686,826ton\;CO_2\;eq./yr$.

• 한국건축시공학회지
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• 제9권6호
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• pp.105-111
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• 2009

건설기계는 건설사업의 성공적인 수행의 중요한 요인이며, 건설기계에 소요되는 비용이 건설공사비에서 차지하는 비중은 점차 증가하고 있다. 우리나라는 표준품셈에 제시된 건설기계 시공능력 산정식을 이용하여 건설기계의 시간당 작업량을 계산하고 있다. 건설기계 성능은 개선되고 있으나 시공능력 산정식에서 활용되고 있는 요소들은 이를 반영하지 못하고 있는 실정이며 극히 부분적으로만 재 개정되었다. 본 연구에서는 건설기계 시공능력 산정식 요소 중 사이클타임에 대해서 조사하였다. 이를 위해 먼저 관련 선행연구를 분석하였고, 건설공사에 주로 사용되는 건설기계인 굴삭기와 로우더의 사이클타임을 실사하였다. 수집된 자료와 현행 표준품셈의 시공능력 산정식에 적용되는 수치를 바탕으로 시뮬레이션 프로그램인 크리스탈볼을 활용하여 건설기계의 시공능력을 산정하였다.

• Corrosion Science and Technology
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• 제13권1호
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• pp.28-35
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• 2014

Recently, the fuel oil of diesel engines of marine ships has been increasingly changed to heavy oil of low quality as the oil price is getting higher and higher. Therefore, the spiral gear attached at the motor of the oil purifier which plays an important role to purify the heavy oil is also easy to expose at severe environmental condition due to the purification of the heavy oil in higher temperature. Thus, the material of the spiral gear requires a better mechanical strength, wear and corrosion resistance. In this study, the heat treatment(tempering) with various holding time at temperature of $500^{\circ}C$ was carried out to the alloy of Cu-7Al-2.5Si as centrifugal casting, and the properties of both hardness and corrosion resistance with and without heat treatment were investigated with observation of the microstructure and with electrochemical methods, such as measurement of corrosion potential, cathodic and anodic polarization curves, cyclic voltammogram, and a.c. impedance. in natural seawater solution. The ${\alpha}$, ${\beta}^{\prime}$ and ${\gamma}_2$ phases were observed in the material in spite of no heat treatment due to quenching effect of a spin mold. However, their phases, that is, ${\beta}^{\prime}$ and ${\gamma}_2$ phases decreased gradually with increasing the holding time at a constant temperature of $500^{\circ}C$. The hardness more or less decreased with heat treatment, however its corrosion resistance was improved with the heat treatment. Furthermore, the longer holding time, the better corrosion resistance. In addition, when the holding time was 48hrs, its corrosion current density showed the lowest value. The pattern of corroded surface was nearly similar to that of the pitting corrosion, and this morphology was greatly observed in the case of no heat treatment. It is considered that ${\gamma}_2$ phase at the grain boundary was corroded preferentially as an anode. However, the pattern of general corrosion exhibited increasingly due to decreasing the ${\gamma}_2$ phase with heat treatment. Consequently, it is suggested that the corrosion resistance of Cu-7Al-2.5Si alloy can be improved with the heat treatment as a holding time for 48 hrs at $500^{\circ}C$.

• 한국화재소방학회논문지
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• 제27권3호
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• pp.85-93
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• 2013

본 연구에서는 소방대원이 수행하는 업무 중 중량물을 다루어야 하는 작업에 대한 분류 및 정량적 분석(NLE, 3DSSPP)을 수행하여 향후 소방대원의 중량물 관련 작업에 대한 위험도를 예측하고, 관련 위험도를 감소시키기 위한 기초 자료를 도출하고자 하였다. 도출된 위험도 등급은 위험도 점수가 3점부터 9점까지 총 7단계로 구성되었다. 가장 위험도가 높은 1등급은 나타나지 않았으며 인명구조 작업이 두 번째로 높은 2등급에 속하는 것으로 나타났다. 3등급은 파괴기구 활용, 환자 들어올리기작업 등으로 나타났다. 본 연구 결과들은 소방대원의 허리 부상을 포함하는 근골격계 질환 예방을 위한 작업방법 및 장비의 개선, 교육 프로그램의 개발에 기본 토대가 될 수 있다고 판단되며, 소방대원들의 근골격계 질환에 대한 지속적인 예방을 위해서는 본 연구의 골격을 토대로 한 추후 심층적인 조사와 연구가 시급하다고 사료된다.

• 대한조선학회 특별논문집
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• 대한조선학회 2017년도 특별논문집
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• pp.105-108
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• 2017

Condensation is one of the common issues which we can easily see in everyday life. For example, the surface of glasses with cold water is easily moisturized. This wet surface gives us uncomfortable feeling and is sometimes dangerous because it is slippery. As the safety on working space is one of the most important issue on offshore project, condensation is also important matter to take care of with precaution. Since the bottom of vessel or offshore facility is submersed in the water, the risk of having condensate on the steel surface is getting higher because sea water temperature is normally lower than ambient temperature. And if there is any electric equipment or person working in that space, condensation is normally not allowed. The pontoon of semi-submersible drilling rig is such a space which is submersed, with electric and mechanical equipments and person working periodically. To prevent condensation in pontoon, study was conducted by checking several cases.

• 한국기계가공학회지
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• 제17권4호
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• pp.137-142
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• 2018

Recycled synthetic resin materials produced from waste vinyl and waste plastic contain many foreign substances. Plastic products made from this recycled resin materials containing foreign substances are of poor quality, with reduced the strength and rigidity. Foreign substances include heavy metals, cement, foil, dyed paper and dust. In this study, the scratch-Dies process; which remove foreign sbustances, with precision and automation, through a three-stage mesh filter, is designed. The process is evaluated with finite element analysis according to vibration loading and make. After installing the manufactured equipment, recycled resin was producde, and its heavy metal content was evaluated. Recycled synthetic resin materials were also used plastic products and evaluate their strength. In addition, the change in production was assessed.

• 대한조선학회 특별논문집
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• 대한조선학회 2005년도 특별논문집
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• pp.211-215
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• 2005

The binary Al-Mg alloys are the basis for the 5000 series of non-heat-treatable aluminum alloys. In general, 5000 series of aluminum alleys have a high strength, good welding characteristics and a high resistance to corrosion, especially under the seawater. Thus the aluminum alloys are adopted in the hull material of hovercraft that is required light in weight as well as high strength. It is very important that the weldability problem of these alloys caused by high thermal conductivities welding deformation, porosity and so on. in this study, auto-welding equipment was applied for aluminum welding automation. Also, optimal welding data were studied by investigating welding characteristics for various shapes of weldment to use Al 5083 that is representative structural materials of the 5000 series of aluminum alloys.

• 한국음향학회지
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• 제42권2호
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• pp.143-151
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• 2023

본 논문은 표준 중량충격원을 이용한 건축물의 바닥충격음 차단성능을 측정하는 경우 측정불확도를 평가하는 방법을 다루었다. 반복 측정의 영향 이외에도 측정 위치의 영향, 가진 위치의 영향, 음압측정에 사용된 장비의 영향 및 충격원의 영향 등을 고려하였다. 평균 최대 바닥충격음 레벨 측정의 수학적 모델을 제시하고 요인별 불확도 평가방법을 제안하였으며, 제안한 방법을 실제 측정 결과에 적용하여 평균 최대 바닥충격음 레벨 및 측정불확도를 평가하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제17권12호
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• pp.1736-1740
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• 2004

Since the application of relatively high levels of heavy metals in the compost poses a potential hazard to plants and animals, the content of heavy metals in the compost with animal manure is important to know if it is as a fertilizer. Measurement of heavy metals content in the compost by chemical methods usually requires numerous reagents, skilled labor and expensive analytical equipment. The objective of this study, therefore, was to explore the application of near-infrared reflectance spectroscopy (NIRS), a nondestructive, cost-effective and rapid method, for the prediction of heavy metals contents in compost. One hundred and seventy two diverse compost samples were collected from forty-seven compost facilities located along the Han river in Korea, and were analyzed for Cr, As, Cd, Cu, Zn and Pb levels using inductively coupled plasma spectrometry. The samples were scanned using a Foss NIRSystem Model 6500 scanning monochromator from 400 to 2,500 nm at 2 nm intervals. The modified partial least squares (MPLS), the partial least squares (PLS) and the principal component regression (PCR) analysis were applied to develop the most reliable calibration model, between the NIR spectral data and the sample sets for calibration. The best fit calibration model for measurement of heavy metals content in compost, MPLS, was used to validate calibration equations with a similar sample set (n=30). Coefficient of simple correlation (r) and standard error of prediction (SEP) were Cr (0.82, 3.13 ppm), As (0.71, 3.74 ppm), Cd (0.76, 0.26 ppm), Cu (0.88, 26.47 ppm), Zn (0.84, 52.84 ppm) and Pb (0.60, 2.85 ppm), respectively. This study showed that NIRS is a feasible analytical method for prediction of heavy metals contents in compost.

• Radiation Oncology Journal
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• 제33권4호
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• pp.337-343
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• 2015

Purpose: The purpose of this report is to describe the proton therapy system at Samsung Medical Center (SMC-PTS) including the proton beam generator, irradiation system, patient positioning system, patient position verification system, respiratory gating system, and operating and safety control system, and review the current status of the SMC-PTS. Materials and Methods: The SMC-PTS has a cyclotron (230 MeV) and two treatment rooms: one treatment room is equipped with a multi-purpose nozzle and the other treatment room is equipped with a dedicated pencil beam scanning nozzle. The proton beam generator including the cyclotron and the energy selection system can lower the energy of protons down to 70 MeV from the maximum 230 MeV. Results: The multi-purpose nozzle can deliver both wobbling proton beam and active scanning proton beam, and a multi-leaf collimator has been installed in the downstream of the nozzle. The dedicated scanning nozzle can deliver active scanning proton beam with a helium gas filled pipe minimizing unnecessary interactions with the air in the beam path. The equipment was provided by Sumitomo Heavy Industries Ltd., RayStation from RaySearch Laboratories AB is the selected treatment planning system, and data management will be handled by the MOSAIQ system from Elekta AB. Conclusion: The SMC-PTS located in Seoul, Korea, is scheduled to begin treating cancer patients in 2015.