• 산업경영시스템학회지
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• 제22권50호
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• pp.65-73
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• 1999

Most psychophysical studies in manual material handling (MMH) have paid more attention to two-handed MMH activities than to one-handed MMH activities. Also, studies are involved only with single MMH activities - lifting, lowering, carrying, holding, pushing or pulling. Very few studies are reported on the determination of workers' capacities for combinations of one-handed MMH activities (lifting a box, then carrying the box, and lowering the box). The objective of this study was to find the psychophysical and physiological responses of human subjects from a simulated industrial task involving one-handed and two-handed combined tasks. The capacities that were determined as the maximum acceptable weight workloads for 1 hr work period for one-handed and two-handed combined tasks - lifting a box from floor to knuckle height, carrying the box for 4.3 m, and lowering the box from knuckle to floor height - were determined psychophysically under three frequencies: six handlings per minute, one handling per minute and one handling per five minutes. In addition to maximum acceptable weight, heart rate and RPE values on wholebody, back, and arm were also measured as responses.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 추계학술대회 논문집(II)
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• pp.876-883
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• 2002

Electric vehicle body has to be subjected to uniform load and requires auxiliary equipment such as air pipe and electric wire pipe. Especially, the cross beam supports the weight of passenger and electrical equipments. a lightweight vehicle body is salutary to save operating costs and fuel consumption. Therefore this study is to perform the size and the shape optimization of crossbeam fur electric vehicle using the method of topology optimization to introduce the concept of homogenization based on optimality criteria method which is efficient for the problem having the number of design variables and a few boundary condition. this provides the method to determine the optimum position and shape of circular hole in the cross beam and then can achieve the optimal design to reduce weight.

• Journal of Pharmaceutical Investigation
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• 제30권4호
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• pp.295-297
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• 2000

A new method to evaluate erosion of biodegradable polymer, polyanhydrides, was developed. The polymer devices were prepared with the melt-casting method and weight loss was accurately measured after agitating the devices in buffers (pH 1-9), and removing the device at selected time intervals and freeze-drying the device. The erosion rate was estimated from the plot of the weight loss(%) of device as a function of time. The freeze-drying technique used in this study is particularly useful for estimating the erosion rate of biodegradable polymer.

• Elastomers and Composites
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• 제56권1호
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• pp.1-5
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• 2021

Tire and road wear particles (TRWPs) were collected from road dust and thermogravimetric analysis (TGA) was performed to measure the content of tire wear particles (TWPs) in the TRWPs. The TGA thermograms of TRWPs showed two weight loss steps associated with polymer decomposition including weight loss after 480℃ which may be due to road wear particles. Different samples gave different TGA thermograms because the types and contents of the road wear particles attached to the TWPs should be different from each other, and each TWP might have different composition. The TGA results of the model asphalt pavement wear particles, with (volatile organics + polymers + carbon black) : ash = 33.5 : 66.5, was applied to the TRWP results, and the TWP contents of TRWPs were found to be 50-65%. The zinc oxide content in the rubber compound was negligible.

• 한국작물학회지
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• 제25권4호
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• pp.81-85
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• 1980

Field experiment was conducted to determine the optimum harvesting time in winter rape (Brassica napus L.) by investigating the percent oil, 1, 000 seed weight, seed yield, dehiscent pod ratio and oil yield at 46, 50, 54, 58, 62, 66 and 70 days after flowering. Variation of all characters with days after flowering could be explained significantly by second degree polynomial equations. Percent oil and 1, 000 seed weight increased until 62 days after flowering and thereafter these traits decreased, while seed yield increased to 58 days after flowering and thereafter this trait decreased. This controversy was due to the drastic increase in dehiscent pods beyond 58 days after flowering which brought loss in seed yield. These results suggest that optimum harvesting time is 58 days after flowering and it should not be later than 60 days after flowering.

• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.304-310
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• 2011

The populations of major cities in Australia are increasing rapidly and facing an acute housing shortage. Traditional apartment procurement techniques involve lengthy lead-times and factory-based, or offsite manufactured (OSM) multi-storey apartment buildings may offer the opportunity to help fulfill the need by significantly reducing build times. Other advantages of OSM may include superior quality, low weight ratios, economies of scale achieved through repetition of prefabricated units, use on infill sites, sustainable design standards and better occupational health and safety. There are also positive labour and training implications, which may help to alleviate an industry-wide shortage of skills through use of semi-skilled labour. Previous uncertainties about the adoption of offsite due to the high capital costs and perception issues were generally based on pre-cast concrete structures, which are quite a different building type in terms of flexibility, construction, delivery and finishes. Identification of drivers and constraints assists in the determination of current industry status, allows for a benchmark to be established and future opportunities and directions for OSM to be determined.

• 한국환경보건학회지
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• 제29권4호
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• pp.27-34
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• 2003

Bisphenol A is used in the manufacture of epoxy, polycarbonate, and corrosion-resistant unsaturated polyester-styrene resins required for food packaging materials in industrial processing. Some reports indicated the possibility of harmful effects on rats. In this study was used a method for the determination of bisphenol A in blood according to the OSHA High Performance Liquid Chromatography (HPLC) guideline. The method involved blood extraction using methylene chloride. And it was evaluated developmental and teratogenic effects in pregnant rats and second generation. The results obtained were as follows. There was a significant increase in the body weights and treated groups F1 female in liver, spleen, kidney, but according to dose-response. F1 female rat's relative body weight and absolute body weight are not different. There was a significant increase liver, spleen, kidney organ weight and reproductive organ weight epididymis, prostate gland in F1 male rats. There was a proestrous in pregnant rat, group 200 $\mu\textrm{g}$/kg, 2000 $\mu\textrm{g}$/kg, 20,000 $\mu\textrm{g}$/kg. The effect on rat treated with bisphenol A decrease organ weight and reproductive organ weight. Identification and quantitation were performed with using HPLC C18 column and using at retention time 5.5 min. The results of the detection of bisphenol A were at 20,000 $\mu\textrm{g}$/kg in average 1 $\mu\textrm{g}$/ml, 200 $\mu\textrm{g}$/kg average in 0.9 $\mu\textrm{g}$/ml blood samples. From those results, it could be concluded that the effects of pregnant rat and second generation(F1) by bisphenol A treatment during lactational period were estrogenic and bisphenol A was remained in serum at low level.

• 생물환경조절학회지
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• 제29권4호
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• pp.381-387
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• 2020

작물의 생체중을 추정하기 위해 다양한 연구가 시도되었지만, 이미지를 활용하여 생체중을 추정한 예는 없었다. 최근 합성곱 신경망을 사용한 이미지 처리 연구가 늘고 있으며, 합성곱 신경망은 미가공 데이터를 그대로 사용할 수 있다. 본 연구에서는 합성곱 신경망을 이용하여 미가공 데이터 상태인 특정 시점의 파프리카 이미지를 입력으로 작물의 생체중을 추정하도록 학습하였다. 실험은 파프리카(Capsicum annuum L.)를 재배하는 온실에서 수행하였다. 합성곱 신경망의 출력값인 생체중은 파괴조사를 통해 수집한 데이터를 기반으로 회귀 분석하였다. 학습된 합성곱 신경망의 결정 계수(R²)의 최고값은 0.95로 나타났다. 생체중 추정값은 실제 측정값과 매우 유사한 경향성을 보여주었다.

• 인터넷정보학회논문지
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• 제4권1호
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• pp.39-52
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• 2003

사회 및 경제가 발전함에 따라 소프트웨어 품질에 관심이 많아지며 고품질의 소프트웨어 생산을 위한 노력이 많이 이루어지고 있다. 이러한 소프트웨어의 가치를 평가하기 위해 ISO/IEC 9126 등의 표준안들이 많이 제공되고 있지만, 이러한 표준안들은 소프트웨어 항목 특성 및 평가 프로세스의 모형만을 제시하고 있을 뿐 평가 시 측정되는 평가 항목의 가중치에 대한 언급은 없다. 이에 본 논문에서는 ISO/IEC 9126의 지침에 따라 소프트웨어의 품질을 평가함에 있어 평가 항목간의 중요도 관계를 나타내는 평가 항목 가중치를 객관적이고 정량적인 방법으로 산출하여 품질 평가의 신뢰성을 높이고자 한다. 이러한 평가 항목에 대한 가중치 계산 방법의 바탕이 되는 이론으로, 각각의 평가 항목에 대한 신뢰 함수를 사용하여 평가 기준의 불확실성을 제거할 수 있게 하는 Dempster-Shafer 이론을 사용하며 더 나아가 Dempster-Shafer이론의 결합 규칙의 문제점을 개선하여 상호 배타적인 가설들의 결합 문제에도 효율적으로 적용하였다. 또한 평가자들의 정성적 인 표현으로부터 기초확률할당함수 값을 도출하는 정량화 기법의 사용으로 보다 효율적인 가중치 결정 기법을 제안하였다.

• 한국임상약학회지
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• 제9권1호
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• pp.15-18
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• 1999

Ascertainment of accurate pharmacokinetic parameters for aminoglycoside dosing remains critical, as the serum drug concentration relates directly to both the therapeutic response and toxic effect. In the initial dosing of aminoglycosides, the volume of distribution is especially important because the dosage is calculated by multiplying the volume of distribution by the desired serum concentration. Aminoglycosides distribute into mainly the extracellular fluid and it has been reported that the volume of distribution is 0.25 L/kg. Penetration of polar aminoglycosides into adipose tissue occurs to some extent, but varies according to the degree of obesity. Therefore, dosages may be overestimated or underestimated according to the type of the dosing weight in overweight or underweight patients. Prior investigations have suggested various dosing weights which are multiplied by the popular volume of distribution to calculate the total volume of distribution. Based on other investigations, we calculated a new dosing weight which was applicable to all patients regardless of obesity in order to use the popular volume of distribution. We estimated IBW+$0.414^{\ast}$(TBW-IBW) as a new dosing weight with the SAS program. A new dosing weight is similar to those of other studies which examined in morbidly obese patients. Consequently we suggests that the dosing weight reported in morbidly obese patients can be extended to a broader patients population. But we found that the volume of distribution per kilogram from our patients was significantly larger than that for foreign patients(0.343L/kg vs 0.25 L/kg)(Kor. J. Clin. Pharm. 1999; 9(1): 15-18)