• 한국유기농업학회지
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• 제19권4호
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• pp.435-461
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• 2011

This study was conducted field surveys and theoretical discussion whether small farmers thinks there are economics of scope in small organically grown cropslivestock farming cycling system. The discussions are summarized as follows. At the end of October 2011, the cycling agriculture farms are only a total of 15 farmers, 0.1% of total organic farms in Korea. The FMD disease, FTA, family farm structure, the importance of animal health and welfare, agricultural cycles, when considering the valuation of the multifunctionality, alternative agriculture is small farming cycling system. Organic agriculture is a 'cooperation-cycling-family farm' in the interaction it is important to understand. The two groups were surveyed. Group 1 is 6 farmers who practicing cycling farming system, and Group 2 is the 33 farmers who wish to cycling farming system. Interview survey and the survey results was obtained as follows. First, We find that there are strong economies of scope, due to a decreased costs have increased net profit. Second, the multifunctional values is realized also cycling farming system. Third, but some certification standards leads to high transaction cost. Thus, a small family farm who wishing to target organic livestock certification standards need to improve.

• 한국항해항만학회지
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• 제34권9호
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• pp.719-726
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• 2010

As the competition among the container terminals in Korea has become increasingly fierce, every terminal is striving to increase its investments constantly and lower its operational costs in order to maintain the competitive edge and provide satisfactory services to terminal users. The unreasoning behavior, however, has induced that substantial waste and inefficiency exists in container terminal production. Therefore, it is of great importance for the terminal to know whether it has fully used its existing infrastructures and that output has been maximized given the input. From this perspective, data envelopment analysis (DEA) provides a more appropriate benchmark. This study applies three models of DEA to acquire a variety of analytical results about the operational efficiency to the Korean container terminals. According to efficiency value analysis, this study first finds the reason of inefficiency. It is followed by identification of the potential areas of improvement for inefficient terminals by applying slack variable method and giving the projection results. Finally, return to scale approach is used to assess whether each terminal is in a state of increasing, decreasing, or constant return to scale. The results of this study can provide terminal managers with insight into resource allocation and optimization of the operating performance.

• Fibers and Polymers
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• 제7권2호
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• pp.146-157
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• 2006

Traditional spinning systems have reached profitability limits in developed countries due to high production costs and low system productivity. Pneumatic spinning is seen as a developing system, because productivity is much higher than conventional systems. This study evaluates one of the main problems to increase productivity in pneumatic spinning, where air mass-flow is dragged by the drafting cylinders. This flow interacts with the incoming fibres deviating them from their expected path. Via laser anemometry, airflow velocity distribution around drafting cylinders has been measured and it has been found that vorticity is created at the cylinder's inlet. Extensive CFD simulation on the air flow dragged by the cylinders has given a clear insight into the vortex created, producing valuable information on how cylinder design affects the vorticity created. Several drafting cylinder designs have been tested without giving any improvement in productivity. However, the use of a drafting cylinder with holes in it produced good results to the problem of air currents, strongly reducing them and therefore allowing a sharp increase in yarn quality, as well as an increase in productivity. An extensive study on vortex kinematics has been undertaken, bringing with it a better understanding of vortex creation, development and breakdown.

• 한국건축시공학회지
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• 제22권6호
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• pp.673-680
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• 2022

모듈러 건축은 시공 기간의 단축, 건축비용 절감 등의 여러 가지 장점에도 불구하고 국내 건설시장에서 좀처럼 탄력을 받지 못하고 있다. 이러한 원인에는 모듈러 내화 기술 적용의 한계도 있으나 무엇보다 내화구조 제도에 대한 접근성이 쉽지 않은 것이 주요 요인으로 간주되고 있다. 따라서 모듈러 건축 활성화를 위해 주요 저해요인인 내화구조 제도 현황과 문제점에 대해 고찰하였으며, 내화구조 제도적 개선 및 연구개발 방향에 대해 제시하고자 한다.

• 한국기계가공학회지
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• 제21권4호
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• pp.100-106
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• 2022

Topology optimization is applied for the optimal design of various products to ensure weight reduction and productivity improvement. Reducing the weight of the mold while maintaining its rigidity can ensure shortening of the production cycle, stabilization of the mold temperature, and reduction of mold material costs. In this study, a topology optimization technique was applied to the optimal design of the injection mold, and a topology-optimized model of the mold was obtained. First, the injection mold for the square specimens was modeled. Subsequently, a structural analysis was performed by implementing a load condition generated during the injection molding process. Topology optimization was performed based on the structural analysis results, and the models of the initial and topology-optimized designs were manufactured at 1/4 magnification using a 3D printer. Consequently, compared with the existing model, the weight of the topology-optimized model decreased by 9.8%, and the manufacturing time decreased by 7.61%.

• Journal of Animal Science and Technology
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• 제65권3호
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• pp.627-637
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• 2023

As the population and income levels rise, meat consumption steadily increases annually. However, the number of farms and farmers producing meat decrease during the same period, reducing meat sufficiency. Information and Communications Technology (ICT) has begun to be applied to reduce labor and production costs of livestock farms and improve productivity. This technology can be used for rapid pregnancy diagnosis of sows; the location and size of the gestation sacs of sows are directly related to the productivity of the farm. In this study, a system proposes to determine the number of gestation sacs of sows from ultrasound images. The system used the YOLOv7-E6E model, changing the activation function from sigmoid-weighted linear unit (SiLU) to a multi-activation function (SiLU + Mish). Also, the upsampling method was modified from nearest to bicubic to improve performance. The model trained with the original model using the original data achieved mean average precision of 86.3%. When the proposed multi-activation function, upsampling, and AutoAugment were applied, the performance improved by 0.3%, 0.9%, and 0.9%, respectively. When all three proposed methods were simultaneously applied, a significant performance improvement of 3.5% to 89.8% was achieved.

• 한국자동차공학회논문집
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• 제25권1호
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• pp.35-41
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• 2017

The use of engineering plastics in automotive components is increasing with the trend towards improving the car strength and reducing weight. Among the different choices of materials, engineering plastic emerged as the necessary material for achieving lower costs, reduced weight and improved production efficiency. To produce the automotive parts, it is important to predict defect and validation of injection molding prior to design. Injection molding analysis and structural analysis are widely applied as a part of the design process when developing automotive parts. Injection molding analysis, in particular, involves a highly complicated mechanism that requires deep knowledge of polymer properties as well as an analytic approach different from that used for a general isotropic material when the molded material is used as a structural material. This is because the parts made of polymer have pre-stress factors such as intrinsic deformation and residual stress. The most important factors for injection molded plastic products are injection molding condition and cavity design, taking into account ease of molding, mass production and application. Despite optimal injection molding conditions and cavity design, however, glass fiber orientation is critically linked to strength reduction. The application of injection molding and structural coupled analysis provides a low-cost solution for product molding and structural validation, all prior to the actual molding. The purpose of this study involves the validation, pre-study, and solution of defect in injection-molded polymer automotive parts using the simulation software for injection molding and structural coupled analysis. Finally, this thesis provides validation of an injection molding and structural coupled analytic mechanism that can demonstrate the effect of glass fiber orientation on mechanical strength. Design improvement ideas for the injection molded product of PPS (Poly Phenylene Sulfide)+40% glass fiber are also suggested.

• 농업과학연구
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• 제32권2호
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• pp.107-126
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• 2005

The most limited production resource in Korea is land. During the period from 1995 to 2002, annual farm land area of 17,600ha have been converted to urban and industrial land. The self-sufficiency rate of rice, Korean staple food, is expected to be decreased from 97.5% in 2003 to 60-70% in 2020. Under such conditions, this study is aimed at first identifying multi-functional benefits of the reclamation projects such as agricultural production, industrial water supply, urban land supply, transportation effects, sightseeing effects and environmental values with and without the projects. To carry out the objectives, three existing tideland reclamation projects such as Daeho, Kumgang and Yongsangang irrigation project stage II were evaluated and Saemangeum tideland reclamation project which was jointly revaluated by environmental NGO and Govn't appointed specialists in 2000 was reviewed. According to this study results, tide land reclamation projects were showed financially and economically feasible and environmentally sustainable. The joint cost like estuary dam should be allocated based on the multi-functional benefits of the projects. To allocate the joint cost, legal and institutional improvement should adapt the joint cost allocation method as the specific cost-remaining benefit method. Korea has more than 402,000 ha of tidal flat of which 76,396ha have been reclaimed in 2003. To meet food security and to cope with shortage of land, phil-environmental reclamation projects should be continuously implemented and necessary tidal flats for protecting environmental ecosystem should be remained according to the detail survey results of reclaimable resources.

• Asian-Australasian Journal of Animal Sciences
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• 제22권2호
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• pp.162-167
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• 2009

Reproductive abilities in beef cattle herds are receiving increased attention due to recent rises in production costs. To achieve more efficient management, a measure of fertility, namely the number of calves produced at k yr of age ($NCP_k$), was developed and its genetic parameters were estimated from Japanese Black cows by restricted maximum likelihood procedures. The k examined were distributed from 2 to 10 yr of age and $NCP_2$ averaged 1.077 calves over 43,536 cows. The averages increased by approximately 0.9 calf with each additional 1 yr increment in k. Heritabilities of $NCP_k$ were estimated to be low ranging from 0.083 to 0.162, which seemingly suggested a difficulty of genetic improvement. However, large genetic variation and high accuracy were observed in predicted breeding values of $NCP_k$. For example, the breeding values of $NCP_7$ were predicted between -0.303 and +0.213 with average accuracy of 0.607 for cows with observations. Genetic correlations among different k were generally high and positive (0.474 to 0.995). The analyses showed that at least $NCP_4$ was required to maintain the genetic correlations of 0.8 or higher with subsequent $NCP_k$. Also $NCP_5$ maintained the genetic correlations of 0.9 or higher with subsequent $NCP_k$ The results suggested some possibilities for $NCP_k$ to be a selection criterion considering its genetic variation, high accuracy and consistency with subsequent performance.

• International Journal of Advanced Culture Technology
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• 제9권1호
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• pp.177-182
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• 2021

The fourth industrial revolution based on information and communication technology (ICT) becomes the center of society, and the overall industrial structure is also changing significantly. ICT refers to the hardware of information devices and the software technologies required for the operation and information management of these devices, and any means of collecting, producing, processing, preserving, communicating and utilizing them. ICT is integrated into industries and services or combined with new technologies in various fields such as robotics and nanotechnology to connect all products and services to the network. The development of ICT, which continuously creates new products and services, has spread to all sectors of the industry, affecting not only daily life but also the livestock sector recently. In agriculture, ICT technology can reduce production costs by efficiently managing labor and energy because it can improve quality and yield based on data on environmental and growth information such as temperature, humidity, light and soil. In particular, smart livestock is considered suitable for achieving livestock management goals because it can reduce labor force and improve productivity by remotely and automatically managing accurate information necessary for raising and breeding livestock with ICT devices. The purpose of this study is to propose the need for ICT technology by comparing farm productivity before and after ICT is introduced. The method of the study is to compare the productivity before and after the introduction of ICT in Korean beef farms, pig farms, and poultry farms. The effectiveness of the study proved the excellence of ICT technology through the production results before ICT introduction and the productivity improvement case of livestock farms that efficiently operated manpower management and reduced labor force after ICT introduction. The conclusion of this paper is to present the need for smart livestock through ICT adoption through case study results.