• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.6
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• pp.77-86
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• 2022

Various odor reduction systems are being operated at pig houses to improve livestock odor issues. However, the quantitative evaluation of odor reduction efficiency is not sufficiently conducted. The analysis of factors that affect the reduction efficiency also has not been sufficiently conducted. Therefore, in this study, the reduction efficiency of representative odor reduction facilities (bio-curtain, scrubber) operated by domestic pig houses was evaluated. The odor reduction efficiency was evaluated by sampling the air before and after the odor reduction facility in 6 pig houses. Livestock odors were evaluated for complex odors, ammonia, hydrogen sulfide, and VOC. To find factors for reduction efficiency, temperature, humidity, pH of washing resolution, type of washing water, and ventilation rate was measured. As a result, it was found that the scrubber system had the highest reduction efficiency. The reduction efficiency was found to be affected by the scrubber's washing resolution, filler, operating conditions, and size. Bio-curtains may have problems such as deterioration of fan performance due to ventilation fan load, groundwater pollution, and excessive use of groundwater.

• Culinary science and hospitality research
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• v.23 no.8
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• pp.17-26
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• 2017

This study compared and analyzed the importance-satisfaction regarding the selection attributes of the convenience store focusing on PB lunch box for consumers of 20s and 30s. According to the research results, the importance of factors such as easy purchase, time reduction, convenient intake were found to be high among the selection attributes of the convenience store PB lunchbox and those of factors such as confirmation of food ingredients, nutrition, and new taste were found to be relatively low. In addition, factors with high satisfaction included easy purchase, convenient intake, time reduction, while factors with low satisfaction were confirmation of food ingredients, nutrition and hygiene. The results of the IPA analysis were as follows: The $1^{st}$ quadrant (Keep up the good work) included convenience, time reduction, easy purchase, convenient intake, convenient cooking method, and convenient packing container Etc. $2^{nd}$ quadrant (possible overkill) includes origin labeling and the 3rd quadrant (low priority) includes packing container design, convenient storage, consistency of quality and taste, good taste, moderate amount, new taste, one meal, moderate quantity and quality, inexpensive intake, and hygiene Etc. $4^{th}$ quadrant was found to include no corresponding factors.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.3
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• pp.113-120
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• 2010

Reduction factor for installation damage required to calculate design strength of geogrid used in MSEW(mechanically stabilized earth wall) design is usually obtained in the field test simulating real construction condition. However, damages occurred in geogrid during backfill work are influenced by many factors such as polymer types, unit weight per area, backfill construction method and gradation of backfill material and field test considering these factors demand lots of time and costs. In this study, factors affecting installation damage are analyzed and empirical method to evaluate reduction factor for installation damage using maximum particle size in backfill material is suggested.

• Journal of Trauma and Injury
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• v.25 no.1
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• pp.7-16
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• 2012

Purpose: Cervical dislocations with locked facets account for more than 50% of all cervical injuries. Thus, investigating a suitable management of cervical locked facets is important. This study examined factors of close reduction failure in traumatically locked facets of the subaxial cervical spine patients to determine suitable surgical management. Methods: We retrospectively analyzed of the case histories of 28 patients with unilateral/bilateral cervical locked facets from Nov. 2004 to Dec. 2010. Based on MRI evaluation of disc status at the injury level, we found unilateral dislocations in 9 cases, and bilateral dislocations in 19 cases, The patients were investigated for neurologic recovery, closed reduction rate, factors of the close reduction barrier, fusion rate and period, spinal alignment, and complications. Results: The closed reduction failed in 23(82%) patients. Disc herniation was an obstacle to closed reduction (p=0.015) and was more frequent in cases involving a unilateral dislocation (p=0.041). The pedicle or facet fracture was another factor, although some patients showed aggravation of neurologic symptoms, most patients had improved by the last follow up. The kyphotic angle were statistically significant (p=0.043). Sixs patient underwent anterior decompression/fusion, and 15 patients underwent circumferential fusion, and 7 patients underwent posterior fusion. All patients were fused at 3 months after surgery. The complications were 1 case of CSF leakage and 1 case of esphageal fistula, 1 case of infection. Conclusion: We recommend closed reduction be performed as soon as possible after injury to maximize the potential for neurological recovery. Patients fot whom closed reduction of the cervical locked facets have a higher incidence of anatomic obstacles to reduction, including facet fractures and disc herniation. Immediate direct open anterior reduction or circumferential fixation/fusion of locked cervical facets is recommended as a treatment of choice for traumatic locked cervical facet patients after closed reduction failure.

• Korean Journal of Organic Agriculture
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• v.32 no.2
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• pp.161-182
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• 2024

The purpose of this study is to highlight overseas reductions as one of the measures to achieve Korea's 2030 NDCs, and to derive factors to promote overseas greenhouse gas reduction projects. To this end, a survey was first conducted on greenhouse gas management companies, which are the main entities for reducing greenhouse gas emissions. The contents of the survey are divided into three categories: awareness of greenhouse gas reduction projects, institutional and technical sectors, and government support and difficulties. Specifically, the perception section on greenhouse gas reduction projects examined the greenhouse gas reduction methods currently implemented or under consideration in the future. In the area of government support and difficulties, difficulties in promoting overseas greenhouse gas reduction projects were investigated. The results of the analysis using the probability selection model are as follows. First, the greater the greenhouse gas intensity, the degree of dedicated manpower, and the larger the size according to the company's business field, the higher the interest in overseas reduction projects. Second, there was discrimination in the method of reducing greenhouse gas emissions according to the size variables of the company, the degree of greenhouse gas intensity, the degree of having dedicated manpower, and the business field. Lastly, in the case of small businesses, difficulties in business promotion due to the lack of greenhouse gas reduction technology were found to be the biggest cause than other problems. Therefore, it is necessary to induce the reduction of greenhouse gas emissions by introducing foreign technologies to support greenhouse gas reduction technologies for small and medium-sized enterprises, and to provide support such as training courses for professional manpower and the operation of portals for information provision at the government level.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1994.10a
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• pp.49-58
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• 1994

The methods of estimation of VTS effectivenss are compared and the worldwide literature related to the VTS effectiveness is reviewed. The review suggests three potential approaches ; simulation ; synthesis of expert opinion and statistical analysis of casualties. this study adopted dissimilar approaches to estimate the VTS effectiveness to the earlier studies ; the combination of synthesis of expert opinion and causal analysis of casualty. The VTS effectiveness is derived by multiplying casualty rate reduction factors by the effect level of causal factors. The development of casualty rate reduction factors was based on the questionnaire survey and the evolution of effect levels was based on the causal analysis using functional block diagram. According to these procedures the maximum benefit to be obtained through the introduction of a VTS system was approximately 46 percent overall. The collision reduction rate was estimated to be approximately 50 percent for a VTS system with advanced radar surveillance. And 47 percent of groundings 36 percent of rammings and 21 percent of founderings could be reduced by the introduction of VTS. These figures are more or less the same to the earlier studies. The VTS effectiveness by the different causal factor groups was examined. VTS may reduce about 68 percent of causal factors classified as environmental conditions 40 percent of human factors and 35 percent of technical factors in collision accidents. As a whole 60 percent of environmental factors 41 percent of human factors and 20 percent of technical factors may be prevented by a VTS. The key variable of the effectiveness percentage is the value of weight coefficient $\delta$. Therefore differing values for this input was discussed and the impact that these variations have on the VS effectiveness noted. As the results of sensitivity analysis of VTS effectiveness by $\pm$10 percent the effectiveness is varied approximately three to seven percent by casualty type. And the value is changed roughly four to eight percent by a $\pm$10 percent variation by different sub-areas.

• Magazine of the Korea Concrete Institute
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• v.15 no.6
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• pp.22-29
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• 2003

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.5
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• pp.444-451
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• 2007

In this paper, we propose an improved reduction model and a reduction model-based hybrid smith-predictor fuzzy controller. The transient and steady-state responsed of the reduction model was evaluated. In tuning the controller, the parameters of PID and the factors fuzzy controllers were obtained from the reduced model and by using genetic algorithms, respectively. Simulation examples demonstrated a better performance of the proposed controller than conventional ones.

• Structural Engineering and Mechanics
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• v.45 no.5
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• pp.655-676
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• 2013

In this study, strength reduction factors and inelastic displacement ratios are investigated for SDOF systems with period range of 0.1-3.0 s considering soil structure interaction for earthquake motions recorded on soft soil. The effect of stiffness degradation on strength reduction factors and inelastic displacement ratios is investigated. The modified-Clough model is used to represent structures that exhibit significant stiffness degradation when subjected to reverse cyclic loading and the elastoplastic model is used to represent non-degrading structures. The effect of negative strain - hardening on the inelastic displacement and strength of structures is also investigated. Soil structure interacting systems are modeled and analyzed with effective period, effective damping and effective ductility values differing from fixed-base case. For inelastic time history analyses, Newmark method for step by step time integration was adapted in an in-house computer program. New equations are proposed for strength reduction factor and inelastic displacement ratio of interacting system as a function of structural period($\tilde{T}$, T) ductility (${\mu}$) and period lengthening ratio ($\tilde{T}$/T).

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.196-203
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• 2008

Durability of geosynthetics for soil reinforcement is accounted for creep and creep rupture, installation damage and weathering, chemical and biological degradation. Among these, the long-term creep properties have been considered as the most important factors which are directly related to the failure of geosynthetic-reinforced soil(GRS). However, the creep test methods and strain limits are too various to compare the test results with each other. The most widely used test methods are conventional creep test, time-temperature superposition and stepped isothermal method as accelerated creep tests. Recently developed design guidelines recommend that creep-rupture curve be used to determine the creep reduction factor($RF_{CR}$) which is a conservative approach. In this study, the different creep test methods were compared and the creep reduction factors were estimated at different creep strain limits of 10% of total creep strain and creep rupture. In order to minimize the impact of creep strain to the GRS structures, the various creep reduction factors using different creep test methods should be investigated and then the most appropriated one should be selected for incorporating into the design.