• Korean Journal of Construction Engineering and Management
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• v.23 no.4
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• pp.57-64
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• 2022

A plant factory is a facility that creates an artificial environment in a controlled space and produces plants systematically through automated facilities. However, automation in the cultivation process is insufficient compared to the internal environment control technology in plant factories. This causes the problem of an increase in operating costs due to the input of a large number of workers. Therefore, this study aims to evaluate economic feasibility by comparing before and after introducing automation in the cultivation process of plant factories. The target plant factory to be analyzed was selected, and the break-even point analysis method was used by comparing the cost required compared to the operating period. As a result, the break-even point was analyzed to be 3.4 years when automation was introduced into six processes for plant cultivation. Therefore, it can be judged that the introduction of automation is excellent in terms of economic feasibility when the target plant factory has been operated for more than 3.4 years. This study is expected to be used as basic data to analyze the economic feasibility of introducing automation in domestic and foreign plant factories.

• Culinary science and hospitality research
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• v.3
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• pp.165-179
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• 1997

Cost-volume-profit analysis shows the relationship between these factors. The figures expressed in a break-even chart can be used planning control and decision making. The relation ships can also be helpful in understanding how all costs must be covered in menu pricing. Involved in these relationship is the contribution to overhead and profit, or contribution ratio. This study used the food service operation of H hotel. Assumed the FC would be 10% of the High Volume, the VC would be 76% of the high volume. And in the CVP of individual meals, selected labor cost of the VC, assumed labor cost would be 35% of the volume.

• 한국전산유체공학회:학술대회논문집
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• 2003.10a
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• pp.17-18
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• 2003

Drop deformation in a cylindrical contraction geometry, characterized here by the formation of a thread of drop fluid in the contraction, is predicted using a Volume-of-Fluid numerical technique. The predicted drop shape is found to closely follow the observed deformation. A capillary instability in the developing drop thread in the contraction was predicted, in agreement with experimental observation.

• Journal of Korean Society for Quality Management
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• v.20 no.2
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• pp.118-128
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• 1992

The determination of appropriate buffer capacity is an important issue in the design of the advanced manufacturing systems and closely related to the system efficiency and flexibility. Work-in-process is usually not desirable. However, in reality, maintaining some capacity of buffer storage is inevitable in compensation for the machine blocking and break down. The objective of this paper is to present analytical methods and tools for the buffer capacity planning in the Flexible Manufacturing System Environments. The effects when machine blocking is critical factor are also discussed.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.8
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• pp.1203-1210
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• 2004

It was reported recently that the pump head degradation near the best efficiency point from single-phase flow to the break-down due to air entrainment became less in a screw-type centrifugal pump than in a general centrifugal pump. In this paper, I carried out internal pressure measurements and visualizations, and investigated the various physical phenomena occurring inside a screw-type centrifugal pump operated in air-water two-phase flow. The results could give some characteristics about the degradation of pump performance on air-water two-phase flow.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.862-867
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• 2004

In this paper, the crack properties of steel fiber reinforced concrete (SFHC) beams by experimental method are discussed. The major role played by the steel fiber occurs in the post-cracking zone, in which the fibers bridge across the cracked matrix. Because of its improved ability to break crack, SFRC has better crack properties than that of reinforced concrete (RC). Crack properties are influenced by longitudinal reinforcement ratio, volume and type of steel fiber, strength of concrete and the stress level. Crack width and crack number in the SFRC beams havebeen evaluated from experimental test data at various levels in the beams.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.1
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• pp.23-27
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• 1990

To elucidate the influence of nitrogen application rate on cool tolerance at the booting stage and respiratory activity of anther at the heading stage in the rice plants, the relationships among nitrogen content in the leaf blade and leaf sheath+culm at young microspore stage, cool tolerance at the booting stage and respiratory activity of anther at the heading stage were investigated for 3 rice cultivars-Yeomyungbyeo, Unbongbyeo and Milyang 23. Nitrogen content in the leaf blade at the young microspore stage was negatively correlated with respiratory rate of anther at the heading stage and fertility index, respectively. Respiratory activity of anther at the heading stage with 10ppm nitrogen application was higher than that of anther with 100ppm nitrogen application. On the Arrhenius plot of respiratory activity of anther at the heading stage, Yeomyungbyeo and Unbongbyeo showed a break at 18$^{\circ}C$ and 18.5$^{\circ}C$, respectively, with 100ppm nitrogen application, but did not show a break in respiratory activity of anther with 10ppm nitrogen application, while Milyang 23 showed a break at 20.5$^{\circ}C$ and 21$^{\circ}C$ with 10ppm and 100ppm nitrogen application, respectively. The highest correlation coefficient between fertility and respiratory rate of anther at the heading stage was shown at 20$^{\circ}C$ in the temperature range of 15$^{\circ}C$-30$^{\circ}C$.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.3
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• pp.279-284
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• 2012

Purpose: We measured the amplitude of accommodation using the push-up and push-away tests and near point of convergence (NPC) and investigated the accommodative insufficiency (AI) and convergence insufficiency (CI) in elementary school children of 12~13 years old. Methods: 88 students who aged 12~13 $12.63{\pm}0.51$ years old with more than 1.0 spectacle best corrected visual acuity were examined using push-up and push-away tests. The break and recovery points of NPC also were measured. Results: Mean amplitudes of accommodations using push-up and push-away tests were $11.52{\pm}2.50D$ and $10.06{\pm}1.97D$, respectively in right eye (P<0.001). Mean break and recovery points in NPC were $8.66{\pm}1.99cm$ and $10.98{\pm}2.06cm$. AI and CI showed 28.75% and 30.00% each. 48.75% was within normal range in both amplitudes of accommodations according to their age expected and convergence. Students having both AI and CI were 7.50%. Conclusions: A high correlation between the push-up test and push-away test was found in elementary school children (r=0.6025; P<0.05). Students having normal amplitude of accommodation by their age expected and normal convergence were 71.25% and 70.00%, respectively.

• The Journal of Engineering Geology
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• v.29 no.2
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• pp.153-162
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• 2019

Rapid variations in the geometry (i.e., thickness) of the refractor and low velocities affect greatly the imaging of the reflectors of land seismic data. Conventional solutions to obtain the weathering models utilizes first break picking method, which requires time consuming steps and causes the human error in picking the first arrivals. A new interferometric approach (interferometric refraction statics, IRS) which utilizes the first arrival signal (S/N enhanced by refraction convolution stack) instead of first break picking, is tested in this study to the synthetic data from the velocity structure provided by surface geophysics (refraction, MASW) and borehole geophysics (tomography, SPS logging) for the Cheongju granitic bodies. The results of IRS approach are found to be better than the ones from conventional first break picking in terms of continuities and horizontal resolution of the reflectors. The unresolved long-wavelength statics in brute stack are much removed by IRS weathering correction and the overlying refractors (the base of shallow weathering zone) are incidentally delineated in the refraction convolution stack.

• Journal of the Ergonomics Society of Korea
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• v.19 no.1
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• pp.63-76
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• 2000

In this study, the factors affecting reality aspect of virtual reality system were identified through Quality Function Deployment. The influence of some selected factors was evaluated in simulated performance test. It was shown that the factor of whether user can break through the objects in virtual space is the most sensitive to performance, followed by the factors of rotation angle and movement step. Also, the results implied that as more referents were provided to user, feeling of reality was enhanced.