• 한국기계가공학회지
• /
• 제17권3호
• /
• pp.155-162
• /
• 2018

Delta robots are usually used for industrial manufacturing, but heavy weight and expensive price have been obstacles to rapid propagation of robots in the field. The goal of this research is to make light-weight and price-competitive delta robots. To reduce the weight, we used plastic material for the arm link, and to reduce the price, we used a step-motor as the main actuator. First we formulated the equations of inverse kinematics for the designed delta robot and then verified these equations by using multibody-dynamics simulation. An algorithm of motion control was developed and applied to the motion-processing unit using a timer-interrupt of 8 milliseconds. Finally, we tested the performance of the new delta robot by checking its control of motion along line segments.

• Journal of Ginseng Research
• /
• 제5권2호
• /
• pp.92-98
• /
• 1981

This experiment was carried out to inverstigate the characteristics of growth of ginseng Plant on field conditions as affected by seedling weight. Weight of seedling ranged from 0.4 to 1.8g were divided into seven classes at interval of 0.2g. The heavy seedlings showed superiority in stem length, stem diameter, leaf area, number of palmate leaf and leaflets and root weight in 2-,3-, and 4-age as compared to light ones. The heavy seedlings also showed superiority in the ratio of inflorescence appearance in 2-age and seed product in 4-age as compared to light ones, but there were no significant difference in the ratio of missing-plant and the cracking. of root. The differences of growth in field condition as affected by seedling weight were diminished as the age progressed, and the annual growth rates of root of light seedling were high in older plant.

• 한국항공운항학회지
• /
• 제21권1호
• /
• pp.62-67
• /
• 2013

Human Powered Aircraft (HPA) should be light in weight and have high efficiency because power source of propulsion is human muscles. Airframe structure takes up most of empty weight of aircraft, so weight reduction of structure is very important issue for HPA. In this paper, design/analysis/test procedures for ultra light weight structure of the HPA developed by Korea Aerospace Research Institute (KARI) are explained briefly. Structural design is conducted through case studies on HPA in the USA and Japan. Loads analysis is performed to calculate design loads which is needed for structural design and analysis. Structural analysis is conducted for structure sizing. Static strength test of main wing spar which is primary structure of wing is performed to verify structural integrity.

• 한국의류산업학회지
• /
• 제7권1호
• /
• pp.111-114
• /
• 2005

In this the study, polyester/cotton(P/C) blended fabrics with fine denier were developed to get the light weight compared with the traditional P/C blended fabrics. Moreover, the width of the fabrics was extended by the tenter during the final heat treatment to get the lower fabric density and lighter weight. Then, the physical properties of these fabrics were analysed. The results were as the follows: The developed fabrics had 22.6-31.6% lighter weight than the traditional fabrics with the same fabric width. The weight of fabric decreased drastically with the fabrics width down to 67.1 $g/m^2$. The fabric density for the warp direction decreased with the fabric width. The tenacity and the elongation of the developed fabrics was little lower than that of the traditional fabrics. The air permeability of the developed fabrics increased with that of the traditional fabrics. The stretch rate of the developed fabrics decreased with increasing the fabric width. Residual stretch rate of the developed fabrics was more stable than that of the traditional fabrics. Residual stretch rate of the developed fabrics increased with the fabric width, but the highest value was less than 5% which is quit stable.

• 한국건설순환자원학회논문집
• /
• 제4권4호
• /
• pp.356-362
• /
• 2016

경량 콘크리트는 기포제를 사용하여 건축자재의 경량화와 단열성을 추구하고 있다. 그러나 기포제의 사용은 콘크리트의 체적이 감소되고, 압축강도가 낮아지는 문제점이 있다. 본 연구에서는 별도의 기포제를 사용하지 않고 산업 부산물인 폐발포 폴리우레탄을 재활용하여 콘크리트의 경량화와 단열성을 확보하고자 한다. 그리고 콘크리트의 시공성과 재료분리를 방지하기 위해 소량의 혼화재를 사용한다. 이러한 혼화재의 혼입률이 폐발포 폴리우레탄이 혼입된 경량 콘크리트의 물성에 미치는 영향을 확인하고자 한다. 실험 결과, 두 개 회사의 혼화재 중에서 폐발포 폴리우레탄이 고르게 분산되는 것을 사용하였다. 혼화재의 혼입률을 다르게하여 배합한 결과는 혼화재의 혼입이 많을수록 콘크리트의 유동성이 감소된 반면, 콘크리트의 함수율과 압축강도는 소폭 증가하였다. 또한, 난연성능과 차음성능을 확보할 수 있는 것으로 나타났다.

• 한국응용곤충학회지
• /
• 제15권3호
• /
• pp.153-159
• /
• 1976

Sclerotinia sclerotiorum(Lib.) de Bary의 상치, 오이 및 유채의 3균주에 대하여 PDA를 기본부지로하여 광선이 이들의 균핵형성에 미치는 영향을 연구하였다. 광원으로서는 주광색 형광등을 사용하였다. 그 결과를 요약하면 다음과 같다. 1) 계속광처리에서 광도 480Lux까지는 광도가 증가함에 따라 증가했지만 성숙균핵의 건물중은 이와는 반대로 감소하였다. 그리고 800 Lux 처리에서는 균핵시원체의 유기가 크게 억제되었고 성숙균핵은 거의 형성되지 않았다. 2) 5000Lux의 고광도라 하더라도 48시의 단시간처리는 균핵시원체수 및 성숙균핵수를 증가시켰다. 그러나 성숙균핵의 건물중은 160 Lux에서만 다소 증가하는 경향이 있었다. 3) 광 shock 즉 1분간치의 계속광 48시간까지의 160 Lux, 500Lux 처리는 모두 균핵형성수와 건물중을 증가시켰는데 균핵형성수와 건물중을 증가시켰는데 균핵형성수는 500Lux에서 균핵건물중은 160Lux에서 더 높았다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제17권5호
• /
• pp.684-687
• /
• 2004

A study was conducted to determine the effect of live weight of pheasants on egg production and egg quality characteristics. A total of 48 ring-necked pheasants were divided into control, heavy, middle and light BW groups. Live weights of the control were 1,187 g, 1,352.92 g for heavy group, 1,247.92 g for middle group and 1,003.33 g for light group. Egg production of groups were found as 47.32, 42.82, 45.79 and 46.51% respectively, in 10 weeks of period. There were no statistical differences on egg production among the groups. The effect of live weight on egg weight, shape index, specific gravity, shell weight, shell thickness, Haugh Unit, yolk weight and albumen weight were found statistically significant (p<0.05). The effect of live weight on albumen index, membrane weight and membrane thickness were found not important (p>0.05). On the other hand, other important factors to be effective on the egg quality of pheasants should be investigated. As a result of this study, live weight of pheasant hens is not an important factor to obtain high egg production in pheasants. But, body conformation of breeding materials should be in good conditions.

• Animal Bioscience
• /
• 제36권5호
• /
• pp.731-739
• /
• 2023

Objective: This study was to evaluate the interaction of three different light-emitting diode (LED) light colors (white, green, and blue) and three intensities (5, 10, and 15 lx) on slaughter performance, meat quality and serum antioxidant capacity of broilers raised in three-layer cages. Methods: A total of 648 (8-days-old) male broiler chicks (Cobb-500) were randomly assigned in 3×3 factorially arranged treatments: three light colors (specifically, white, blue, and green) and three light intensities (namely, 5, 10, and 15 lx) for 35 days. Each treatment consisted of 6 replicates of 12 chicks. The test lasted for 35 days. Results: The semi-eviscerated weight percentage (SEWP) in 5 lx white was higher than that in 15 lx (p<0.01). The eviscerated weight percentage (EWP) (p<0.05) and water-loss percentage (WLP) (p<0.01) decreased in 10 lx white light than those in green light. Under blue light, the content of hypoxanthine (Hx) in muscle was lower than that under white and green light (p<0.01). The content of malondialdehyde (MDA) in 15 lx blue light was higher than that in 10 lx green light (p<0.05). Light color had an extremely significant effect on thigh muscle percentage, WLP, Hx, and crude protein content (p<0.01). Light intensity had a significant effect on SEWP (p<0.05), EWP (p<0.05), lightness (L^*) value (p<0.05), WLP (p<0.01), and the contents of superoxide dismutase (p<0.05), MDA (p<0.01), glutathione peroxidase (p<0.01). Conclusion: Using white LED light with 10 lx light intensity can significantly improve the chicken quality of caged Cobb broilers, improve the content of inosine acid in chicken breast and enhance the antioxidant capacity of the body. We suggest that the broiler farm can use 10 lx white LED light source for lighting in 8 to 42 days.

• 한국군사과학기술학회지
• /
• 제19권6호
• /
• pp.769-778
• /
• 2016

Technical approach on the modeling, simulation and experimentation methods, which are applied for developing a constructive simulation and engagement experimentation software for supporting light weight torpedo operational tactics study, is introduced. Conceptual modeling for the weapon engagement and simulation entities, mathematical models for the simulation elements, approach for the design of experimentations are described, and screen shots of the software are also presented as some example results of experimentation and analysis. It is found that the simulation and experimentation results are useful to support and fulfill the mission needs and requests. As a consequence, the technical approach is rated to be appropriate to accomplish the dedicated purpose of the simulation and experiments.

• 대한교통학회지
• /
• 제14권1호
• /
• pp.165-177
• /
• 1996

Recently, many local governments suffering from traffic congestion have plans to introduce light weight (mid-size) rail transit systems, since the systems' investment costs are known to be much less than heavy rail transits such as the subway in Seoul. Most of the governments expect private partners to be involved in the systems' constructions and operations mainly because of their financial difficulties. Since the governments do not have experiences of evaluating and selecting privately financed transportation systems, they may need an evaluation guideline. This paper discusses evaluation criteria, methodologies, and procedures which will be helpful to local governments faced with evaluating light weight rail transit systems proposed by private companies.