• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.287-294
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• 2021

In order to expand facility agriculture and reduce greenhouse construction costs in reclaimed land, a greenhouse foundation method that satisfies economic feasibility and structural safety at the same time is required. As an alternative, the allowable bearing capacity and settlement were reviewed when the DCM(Deep cement mixing) method was applied among the soft ground reinforcement methods. To examine the applicability of the greenhouse foundation, the allowable bearing capacity and settlement were calculated by applying the theory of Terzaghi, Meyerhof, Hansen, and Schmertmann. In case of the diameter of 800mm and the width and length of the foundation of 4m, the allowable bearing capacity was 179kN/m² and the settlement was 7.25mm, which satisfies the required bearing capacity and settlement standards. The calculation results were verified through FEM(Finite element method) analysis using the Mohr-Coulomb material model. The allowable bearing capacity was 169kN/m² and the settlement was 2.52mm. The bearing capacity showed an error of 5.6% compared to calculated value, and the settlement showed and error of 65.4%. Through theoretical calculations and FEM analysis, it was confirmed that the allowable bearing capacity and settlement satisfies the design criteria as a greenhouse foundation when the width and length of the foundation were 4m. Based on the verified design values, it is expected to be able to present the foundation design criteria for greenhouses through empirical tests such as bearing capacity tests and long-term settlement monitoring.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.5
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• pp.587-609
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• 2019

Short-and long-term stabilities of bentonite, favored material as buffer in geological repositories for high-level waste were reviewed in this paper in addition to alternative design concepts of buffer to mitigate the thermal load from decay heat of SF (Spent Fuel) and further increase the disposal efficiency. It is generally reported that the irreversible changes in structure, hydraulic behavior, and swelling capacity are produced due to temperature increase and vapor flow between $150{\sim}250^{\circ}C$. Provided that the maximum temperature of bentonite is less than $150^{\circ}C$, however, the effects of temperature on the material, structural, and mineralogical stability seems to be minor. The maximum temperature in disposal system will constrain and determine the amount of waste to be disposed per unit area and be regarded as an important design parameter influencing the availability of disposal site. Thus, it is necessary to identify the effects of high temperature on the performance of buffer and allow for the thermal constraint greater than $100^{\circ}C$. In addition, the development of high-performance EBS (Engineered Barrier System) such as composite bentonite buffer mixed with graphite or silica and multi-layered buffer (i.e., highly thermal-conductive layer or insulating layer) should be taken into account to enhance the disposal efficiency in parallel with the development of multilayer repository. This will contribute to increase of reliability and securing the acceptance of the people with regard to a high-level waste disposal.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.12
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• pp.1625-1632
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• 2009

Four lactating Holstein Friesian crossbred cows, with an average initial weight of 450 kg, 48${\pm}$12 days in milk and initial milk yield of 18 kg/h/d, were randomly arranged according to a 2${\times}$2 factorial arrangement in a 4${\times}$4 in Latin square design with 21-d period to investigate the effects of type of total mixed ration (TMR) and type of whole cottonseed (WCS) on intake, digestibility and milk production. The dietary treatments were i) TMR and WCS supplementation at 0.5 kg/h/d, ii) TMR and cracked WCS (cWCS) supplementation at 0.5 kg/h/d, iii) fermented TMR (FTMR) and WCS supplementation at 0.5 kg/h/d, and iv) FTMR and cWCS supplementation at 0.5 kg/h/d. Voluntary feed intake was 15.9, 15.2, 15.4 and 15.6 kg DM/d in dietary treatment 1, 2, 3 and 4, respectively. Digestibility of DM, OM, CP, EE, NDF and ADF were not significantly different among dietary treatments. Ruminal pH, $NH_{3}-N$ and volatile fatty acids in the rumen were also not significantly different among type of TMR or type of WCS. Blood urea-N concentration was not significantly different among dietary treatments. Ruminal bacteria population tended to increase but ruminal protozoa population tended to decrease with supplementation of cWCS, but they were not affected by FTMR. Milk yield and 3.5% FCM were not statistically different among treatments (16.6, 16.2, 17.0, 16.3 kg/d and 18.0, 18.6, 19.9 and 19.0 kg/d, respectively). Milk composition was not significantly different among dietary treatments. However, unsaturated fatty acids in milk fat in cows fed FTMR were lower (p<0.05) than in cows fed TMR. In conclusion, fermentation is a conceivable method to improve the quality of TMR for long-time storage and the cracking method is suitable to release the fat from cottonseed for enhancing fatty acid deposition in milk. Thus, the combination of FTMR and cWCS supplementation would be an alternative strategy to improve performance of lactating cows.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1730-1738
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• 2011

Personal Rapid Transit (PRT) has emerged as a promising alternative transportation mode for transit-oriented sustainable communities by creating compact and walkable environments with competitive construction and operational costs. This study seeks to capture the changes in travel mode choice behavior in response to the introduction of PRT to travelers who have no previous experience of using it. A critical issue in modeling the PRT mode choice is how to capture travelers' perception and evaluation of the unexperienced travel mode. The data used come from questionnaire surveys, in which RP (Revealed Preference) and SP (Stated Preference) data were collected in relation to travel mode choices with and without PRT systems. The questionnaire was designed especially for mitigating the potential bias in favor of or against choosing PRT. In addition, an efficient approach was proposed to reduce the number of SP questions by avoiding the complex fractional factorial design which tends to make it difficult for respondents to keep their attention throughout the survey. The analysis results show that the proposed approach is able to realistically capture the effects of explanatory variables on the travel mode choice. Discrete choice models are developed to predict travelers' mode choices under different choice scenarios by varying PRT system specifications and operational characteristics. PRT patronages are projected for two different test sites using the developed PRT mode choice models.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.4
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• pp.30-41
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• 2010

Research was initiated to investigate germination characteristics and germination pattern of creeping bentgrass (CB, Agrostis palustris Huds.). Seven varieties of CB were evaluated in the study. An alternative condition for a CB germination test required by International Seed Testing Association (ISTA) was applied in the experiment, consisting of 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$ (ISTA conditions). Daily and cumulative germination patterns were measured and analyzed on a daily basis. Significant differences were observed in germination pattern, days to the first germination, days to 50% germination, days to 85% germination, and germination percentage. Germination rates were different among the treatments at the end of study. There were significantly considerable variations in early germination characteristics and germination pattern among CB varieties. The first germination in all entries was initiated between 4 and 5 DAS (days after seeding) under ISTA conditions. Generally, the first germination percentage was 5 to 25%. However, such Penn-series varieties as Penn A-1, Penn A-4 and Penncross were much more vigorous over others, resulting in 50 to 75% in the first germination percentage. It took 4 to 10 DAS in reaching to days to the 50% germination, being 5 days in difference among the varieties. Days to the 85% germination were 5.90 to 11.75 DAS under ISTA conditions, being 5.85 days in variety difference. It means 1 to 2 days after days to 50% germination. Penn A-1 was the fastest variety, while T-1 the slowest one. Considering days to the first germination, days to 85% germination, and germination pattern etc, Penn A-1, Penn A-4, Penncross and L-93 were regarded as excellent varieties under ISTA conditions. From this study, in-depth information on germination characteristics and pattern would be usefully applied for golf course design and construction, when established with CB.

• Journal of Korea Water Resources Association
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• v.45 no.3
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• pp.317-329
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• 2012

It is increasing to make an efforts on preventing natural river environment and preserving natural river ecosystem as development is unavoidable. In the case of inconsistent river flow caused by reservoir development, fishway is an alternative to secure fish diversity and preserve existing river ecosystem but existing fishway was established without full study for their functions. In this study, hydraulic characteristics of natural fishway established on Beakje weir's right side were analyzed. The results show that the fishway has reasonable depth and velocity condition which inhabit condition is enough for a dominant species. For assessing the optimal design of fishway, the Weighted Usable Area (WUA) was calculated by using two dimensional numerical model under the ordinary flow condition. The comparison results for various pool widths in the fishway show that the designed width has maximum WUA for adult Zacco platypus but WUA is maximized with 1m wider pool width than designed width for spawning.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.11
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• pp.1600-1607
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• 2014

A total of 120 finishing pigs ([Yorkshire${\times}$Landrace]${\times}$Duroc) with an average body weight (BW) of $49.72{\pm}1.72kg$ were used in 12-wk trial to evaluate the effects of protected organic acids on growth performance, nutrient digestibility, fecal micro flora, meat quality and fecal gas emission. Pigs were randomly allotted to one of three dietary treatments (10 replication pens with 4 pigs per pen) in a randomly complete block design based on their initial BW. Each dietary treatment consisted of: Control (CON/basal diet), OA1 (basal diet+0.1% organic acids) and OA2 (basal diet+0.2% organic acids). Dietary treatment with protected organic acid blends linearly improved (p<0.001) average daily gain during 0 to 6 week, 6 to 12 week as well as overall with the increase in their inclusion level in the diet. The dry matter, N, and energy digestibility was higher (linear effect, p<0.001) with the increase in the dose of protected organic acid blends during 12 week. During week 6, a decrease (linear effect, p = 0.01) in fecal ammonia contents was observed with the increase in the level of protected organic acid blends on d 3 and d 5 of fermentation. Moreover, acetic acid emission decreased linearly (p = 0.02) on d7 of fermentation with the increase in the level of protected organic acid blends. During 12 weeks, linear decrease (p<0.001) in fecal ammonia on d 3 and d 5 and acetic acid content on d 5 of fermentation was observed with the increase in the level of protected organic acid blends. Supplementation of protected organic acid blends linearly increased the longissimus muscle area with the increasing concentration of organic acids. Moreover, color of meat increased (linear effect, quadratic effect, p<0.001, p<0.002 respectively) and firmness of meat showed quadratic effect (p = 0.003) with the inclusion of increasing level of protected organic acid in the diet. During the 6 week, increment in the level of protected organic acid blends decreased (linear effect, p = 0.01) Escherichia coli (E. coli) counts and increased (linear effect, p = 0.004) Lactobacillus counts. During 12-wk of experimental trial, feces from pigs fed diet supplemented with organic acid blends showed linear reduction (p<0.001) of E. coli counts and the tendency of linear increase (p = 0.06) in Lactobacillus count with the increase in the level of organic acid blends. In conclusion, 0.2% protected organic acids blends positively affected growth performance, nutrient digestibility, fecal gas emission and meat quality in finishing pigs without any adverse effects on blood parameters.

• Journal of Distribution Science
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• v.12 no.4
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• pp.47-54
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• 2014

Purpose - The postponement strategy, which delays the form, place, and production of products as late as possible, has been widely considered as a competitive supply chain management scheme in an era of mass customization and modular manufacturing. An interesting business phenomenon is that not all manufacturing/logistics firms choose the postponement strategy. Given that postponement is a counter-measure to speculation, which has some advantages under certain environments, the current imprudent inclination toward the postponement strategy may cause firms to lose the potential of the speculation strategy, an alternative strategy in supply chain management. Building on the logistics and manufacturing literature, this study examines characteristics of two contrasting strategies, postponement and speculation, and major factors favoring each strategy. Research design, data, and methodology - We apply the profiling approach to two business cases, HP printer and LG mobile phone. The profiling approach is a method of choosing a particular strategy aligned with environmental factors. While various approaches have been used to check the fit between a business strategy and environmental factors, the literature on manufacturing strategy and logistics has commonly adopted the profiling approach. Major factors used in profiling variables are derived from the literature. Two samples, HP printer and LG mobile phone, are selected, because they represent major characteristics appropriate for each strategy. The profiling is based on data from semi-organized interviews with managers. Results - The profiling approach shows that the postponement strategy is a suitable one for HP printers. Most factors, such as product life cycle, large production volume, low-price, product value, and monetary density, support delaying end products until as late as possible. Despite some exceptions, such as delivery time and economy of scale, our analysis states that the overall profile of HP printer is favorable for the postponement strategy. On the other hand, LG mobile phone may adapt the speculation strategy. Although it has large production volume and low delivery frequency, most characteristics support the speculation strategy for this product. An interesting finding is that, despite common perception that advanced technology products such as mobile telephones favor the postponement strategy, profiling proposes the speculation strategy for this product. Conclusions - Our analysis shows that speculation is not the universal option for supply chain management, and that, when choosing a specific strategy, one should consider many factors simultaneously. A major implication of our work is to emphasize the role of environmental factors such as supply chain variables in choosing an inventory strategy, and the importance of fit rather than solely strategic orientation. A theoretical contribution is to demonstrate the benefit of the simultaneous consideration of business variables in choosing specific strategies. For practitioners, our work leads us to consider the existence and the potential of speculation as a counter-measure to postponement. In addition, the comprehensive framework in this research may be instantly used in examining a practical strategy.

• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.4
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• pp.14-30
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• 2015

This paper attempted to analyze the hydraulic effects that the dredging can take as an alternative to reduce possible damages of flooding due to the overflow of river levee in meandering rivers, where riverbed aggradation, seepage and erosion may occur. In order to make a hydraulic analysis in a section of meandering rivers, a two-dimensional hydraulic analysis model, RMA-2, was selected. The GIS was applied to construct two-dimensional finite element grids to consider the hydraulic conditions before and after dredging. The water surface elevations, depths, velocities, and tractive forces were compared before and after the dredging. The difference of water surface elevation between the inside and outside of river was turned out to be the maximum value of 0.58m under the design flood condition. It could be evaluated that the tractive force at the bank decreased about 42 to 67% on average for all the sections. These results could give valuable information that the dredging of the stream channel at the meandering sections decreased the risk of overflow, seepage and erosion of the banks. The methodologies given in this study will contribute to mitigating the flood damages in the surrounding farmlands.

• Clean Technology
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• v.7 no.1
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• pp.13-25
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• 2001

With fast advancement of fine machineries and semiconductor industries in recent decades, the ultra-cleaning of organic chemicals, submicron particles from contaminated unit equipments and products such as silicon wafers becomes one of the most important steps for further advancement of such industries. To date, two kinds of ultra cleaning techniques are used; one is the wet-cleaning and the other is the dry cleaning. In case of wet cleaning, removal of organic contaminants and submicron particles is made by DIW with additives such as $H_2O_2$, $H_2SO_4$, HCl, $NH_4OH$ and HF, etc. While the wet cleaning method is most widely adopted for various occasions, it is inevitable to discharge significant amount of toxic waste waters in environment. Dry cleaning is an alternative method to mitigate environmental pollution of the wet cleaning with maintaining comparable degree of cleaning to the wet cleaning. Although there are various concept of dry cleaning have been devised, the dry cleaning with environmentally-benign solvent such as carbon dioxide proven to show high degree of cleaning from the contaminated porous surface as well as from the bare surface. Thus, special global attention has been placing on this technique since it has important advantages of simple process schemes and no environmentally concern, etc. Thus, this article critically reviews the state-of-the-art of the supercritical fluid drying with emphasis on the thermo-physical characteristics of the supercritical solvent, environmental gains compared to other dry cleaning methods, and the generic aspects of the basic design and processing engineering.