• Journal of the Korean Wood Science and Technology
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• 제46권4호
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• pp.380-392
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• 2018

The importance of polysaccharides is increasing globally due to their role as a significant source of dietary prebiotics in the human diet. In the present study, in order to maximize the yield of crude polysaccharides from Pinus densiflora, response surface methodology (RSM) was used to optimize a two-stage extraction process consisting of steam explosion and water extraction. Three independent main variables, namely, the severity factor (Ro) for the steam explosion process, the water extraction temperature ($^{\circ}C$), and the ratio of water to raw material (v/w), were studied with respect to prebiotic sugar content. A Box-Behnken design was created on the basis of the results of these single-factor tests. The experimental data were fitted to a second-order polynomial equation for multiple regression analysis and examined using the appropriate statistical methods. The data showed that both the severity factor (Ro) and the ratio of water to material (v/w) had significant effects on the prebiotic sugar content. The optimal conditions for the two-stage process were as follows: a severity factor (Ro) of 3.86, a water extraction temperature of $89.66^{\circ}C$, and a ratio of water to material (v/w) of 39.20. Under these conditions, the prebiotic sugar content in the extract was 332.45 mg/g.

• 한국산학기술학회논문지
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• 제8권3호
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• pp.654-659
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• 2007

본 논문은 호텔기업이 많이 활용하고 있는 CRM의 운용성과를 측정하기 위한 측정 요인에 대한 연구를 하였다. 이를 위해 통계적인 방법인 요인분석(Factor Analysis)과 AHP(Analytic Hierarchy Process)분석 기법을 연계하여 분석하는 방법을 연구하였다. 요인분석은 서로 상관있는 변수들만을 그룹화하고, 상관도가 낮은 변수는 또 다른 그룹으로 묶는 결과를 도출한다. 그러나 요인분석은 요인의 분류 외에는 주요 정보를 제공하지 못한다. 그렇기 때문에 이를 극복하기 위해서 분산분석, 회귀분석 등 다른 통계분석 방법을 시도한다. 그러나 이러한 분석은 요인분석 결과와 연계되는 것이 아니라 독립적인 분석을 하게 되는 것이다. 그렇지만 호텔기업의 CRM 운용성과 분석에서는 요인의 중요도 분석이 중요하다. 따라서 AHP 분석기법을 연계하여 호텔기업의 CRM 운용 성과를 측정하기 위한 요인 분석방법에 대해 고찰하였다.

• Journal of Microbiology and Biotechnology
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• 제18권5호
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• pp.997-1003
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• 2008

Viral safety is a prerequisite for manufacturing clinical antihemophilic factor VIII concentrates from human plasma. With particular regard to the hepatitis A virus (HAV), a terminal dry-heat treatment ($100^{\circ}C$ for 30 min) process, following lyophilization, was developed to improve the virus safety of a solvent/detergent-treated antihemophilic factor VIII concentrate. The loss of factor VIII activity during dry-heat treatment was of about 5%. No substantial changes were observed in the physical and biochemical characteristics of the dry-heat-treated factor VIII compared with those of the factor VIII before dry-heat treatment. The dry-heat-treated factor VIII was stable for up to 24 months at $4^{\circ}C$. The dry-heat treatment after lyophilization was an effective process for inactivating viruses. The HAV, murine encephalomyocarditis virus (EMCV), and human immunodeficiency virus (HIV) were completely inactivated to below detectable levels within 10 min of the dry-heat treatment. Bovine herpes virus (BHV) and bovine viral diarrhea virus (BVDV) were potentially sensitive to the treatment. However porcine parvovirus (PPV) was slightly resistant to the treatment. The log reduction factors achieved during lyophilization and dry-heat treatment were ${\geq}5.55$ for HAV, ${\geq}5.87$ for EMCV, ${\geq}5.15$ for HIV, 6.13 for BHV, 4.46 for BVDV, and 1.90 for PPV. These results indicate that dry-heat treatment improves the virus safety of factor VIII concentrates, without destroying the activity. Moreover, the treatment represents an effective measure for the inactivation of non-lipid-enveloped viruses, in particular HAV, which is resistant to solvent/detergent treatment.

• Nuclear Engineering and Technology
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• 제21권4호
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• pp.321-331
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• 1989

방사성 폐기물 소각기술 개발 자립의 일환으로 한국에너지연구소에서는 실험용 방사성폐기물 소각공정을 설치하여 운전중에 있다. 이 공정은 소각경험의 습득 및 소각 특성 시험, 여과기의 성능시험 등을 위하여 설치되었다. 종이와 폴리에틸렌 모의폐기물을 소각하여 공정의 경제성과 운전성을 나타내는 감용비과 제염계수를 결정하였다. 제염계수로부터 소각설비의 허용 비방사능치를 얻어내고 설비의 감용비를 산출하는 방법을 기술하였다. 실험용 소각공정에서의 가연성 폐기물에 함유된 핵종에 대한 인수기준치를 상기방법을 이용하여 제시하여 보았다.

• 한국기계가공학회지
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• 제7권4호
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• pp.155-160
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• 2008

End part of the brake tube formed with the shape of snake head is important for the braking of automobile in safety because it has to prevent crack, fracture and defects occurred during the forming process. Especially, the shape of tube end has influence on the ability of brake. Based on the procedure of process design, in this paper, the forming operation is done by finite element method and the design variables are analyzed by Taguchi method. Design variables such as the outer angle of tube end with the shape of snake head(A), the inner angle to make a hole at tube end with the shape of snake head(B) and the forming distance at tube end(C) are used. Optimization of design variables is performed to minimize the damage factor of the tube end occurred during the forming process. The value of damage factor of 0.327 was obtained under the optimal condition like $A=114^{\circ},\;B=80^{\circ}$ and C=5.3mm, respectively.

• 한국안전학회지
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• 제37권2호
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• pp.76-87
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• 2022

Lithium-ion batteries (LIBs) have attracted much interest for their high energy density (>150 mAh/g), high capacity, low self-discharge rate, and high coulombic efficiency. However, with the successful commercialization of LIBs, fire and explosion incidents are likely to increase. The thermal runaway is known as the major factor in battery-related accidents that can lead to a series of critical conditions. Considering this, recent studies have shown an increased interest in countering the safety issues associated with LIBs. Although safety standards for LIB use have recently been formulated, little attention has been paid to the safety around the manufacturing process for battery products. The present study introduces a risk assessment method suitable for assessing the safety of the LIB-manufacturing process. In the assessment method, a compensation parameter (Z-factor) is employed to correctly evaluate the process's safety on the basis of the type of material (e.g., metal anode, liquid electrolyte, solid-state electrolytes) utilized in a cell. The proposed method has been applied to an 18650 cell-manufacturing process, and three sub-processes have been identified as possibly vulnerable parts (risk index: >4). This study offers some crucial insights into the establishment of safety standards for battery-manufacturing processes.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제18권1호
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• pp.75-87
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• 2014

It is central to use a scale to measure a person's level of a construct in mathematics education research. This article explains a practical process through which a researcher rapidly can develop an instrument to measure the construct. The process includes research questioning, reviewing the literature, framing a background theory, treating the data, and reviewing the instrument. The statistical treatment of data includes normality analysis, item-total correlation analysis, reliability analysis, and factor analysis. A virtual example is given for better understanding of the process.

• 시스템엔지니어링학술지
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• 제15권2호
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• pp.87-97
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• 2019

This paper focuses on the SE concept based on the weapon system design, which is the lack of systematic research at the stage of military requirements creation prior to acquisition management phase. Influence factors were derived by focusing on the core issues that were at issue in the process of requirements analysis, requirements verification, and business management in recent years. Next, the impact factor was prioritized using the AHP technique and then alternatives were suggested. As a result, through the hierarchical analysis process, 'substantiation of necessity' was found to be the most important factor in the large category, and 'satisfaction of the operating concept' was the most important factor. In addition, as a result of calculating the final weight for each nutritional factor, it was analyzed in order of 'enemy threat response ability', 'response to operational environment change', 'performance considering operational environment', and 'guaranteed power generation'. The results of this analysis suggest which factors should be focused on, firstly, based on the concept of SE by the military and JCS.

• Child Health Nursing Research
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• 제26권3호
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• pp.338-347
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• 2020

Purpose: The Life Transition Scale (LTS) consists of 24 items that assess the life transition process of parents of autistic children. This study aimed to examine the validity and reliability of the LTS in parents of children with a wide spectrum of disabilities. Methods: Data were collected from 260 parents of children with disabilities through self-report questionnaires. Validity was examined using exploratory and confirmative factor analysis to determine the factor structures of the LTS; socio-demographic differences in LTS scores were examined using the t-test or ANOVA. Reliability was examined using Cronbach's α coefficient. Results: A four-factor structure was validated (χ²=640.0, p<.001, GFI=.81, RMSEA=.07, NNFI=.89, CFI=.89, PNFI=.74, Q [χ²/df]=2.60). The validity of the LTS was verified by exploratory factor analysis, with factor loading ranging from .30 to .80. There were significant differences in the accepting phase according to children's and parents' age and the type of disability, and in the wandering phase according to parental gender, educational level, job, and socioeconomic status. The Cronbach's αs for the reliability of each of the four structures were acceptable, within a range of .80~.90. Conclusion: The LTS is a valid and reliable measurement to assess the life transition process of parents with disabled children.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.398-406
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• 2007

Constructing high buildings is a global trend, and skyscrapers for residing are also increasing. But a period of works for finish construction is different depending on a company while a period of works for frame construction of skyscrapers for residing in the country is regular when considering a difference of a method of construction, and the increase of repeated construction for high buildings and number of related process for finish construction are stressing the importance of improving productivity through construction management and plan for works. Because there are many compositive factors affecting productivity other than technical factors, we should intensively study the way of improvement and prevention preferentially through analyzing factors affecting productivity. So in this study, we present important management factors for making systematic strategy and plan for improvement of productivity by finding factors affecting productivity depending on the degree of importance unifying factors affecting productivity of plan factor(internal factor of construction process) and management factor(outer factor of construction process).