• Korean Journal of Organic Agriculture
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• v.7 no.1
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• pp.35-48
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• 1998

The total amount of dry matter for the green manure crops was great wheat> rye> barley> Italian ryegrass in that order. The green manure crope were verified to have the reducing effect of injury of successive croppingin peper, mainly reducing the occurance of the most important pepper disease, Phytophthora capsisi, and enhancing the pepper quality in the fruit length and diameter. The direct seeding using current commercial pepper variety was proved as not economical one. In the first year of compost application, the growth and yield of red pepper were rather somewhat decreasing compared with those of check plot applied with organic fertilizers. compst application increased the content of organic matter in soil, which suggested compost could be applied for the sustainable purposes. In preference analysis about taking the new technique, the smaller farmer's cultivation area the more they wanted to accept the LISA farming, compared with the conventional one, could be possible to save 12% in the inorganic fertilizer expenses but wasted 412% ant 163% in both organic fertilizer and operator labor expenses, respectively. At the same time, the LISA decreased 15% in production cost but increased 225% and 139% in organic fertilizer quantity and operator labor hours. Since there was a great deal of difference in technological and economic factors from two farming methods, LISA multi-goal decision modeling is further required.

• Journal of Mechanical Science and Technology
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• v.17 no.11
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• pp.1812-1819
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• 2003

This paper presents the effect of injection pressure on the atomization characteristics of high-pressure injector in a direct injection gasoline engine both experimentally and numerically. The atomization characteristics such as mean droplet size, mean velocity, and velocity distribution were measured by phase Doppler particle analyzer. The spray development, spray penetration, and global spray structure were visualized using a laser sheet method. In order to investigate the atomization process in more detail, the calculations with the LISA-DDB hybrid model were performed. The results provide the effect of injection pressure on the macroscopic and microscopic behaviors such as spray development, spray penetration, mean droplet size, and mean velocity distribution. It is revealed that the accuracy of prediction is promoted by using the LISA-DDB hybrid breakup model, comparing to the original LISA model or TAB model alone. And the characteristics of the primary and secondary breakups have been investigated by numerical approach.

• Journal of the Korea Society of Computer and Information
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• v.26 no.5
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• pp.31-38
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• 2021

This study empirically investigated the user's experience with based on the Technology Acceptance Model. According to the frequency analysis results, the usability for learning was evaluated relatively higher than that for appreciation from the perspective of perceived usefulness and the technical factors such as graphics and modeling raised the issue for the quality improvement. According to the results of the correlation analysis, the usability for learning correlated with the degree of satisfaction. In addition, all detailed factors of perceived ease of use positively influenced on the degree of satisfaction and the impact of the environmental factor on the degree of satisfaction was greatest. The degree of satisfaction with the VR application significantly correlated with the degree of immersion and behavioral intention to the VR application. Therefore, this study proved the suitability for the Technology Acceptance Model as a tool for evaluating a VR application.

• Journal of Korean Society of Archives and Records Management
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• v.21 no.3
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• pp.163-186
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• 2021

The purpose of this study is to analyze research trends on overseas business archives, compare them with domestic and related prior studies, and present the direction of the development of domestic business archives research. For the research analysis, bibliography from 493 papers was collected using four academic databases: Web of Science, Scopus, LISA (ProQuest), LISS (EBSCOhost). Following data collection, data analysis was conducted and focused on the publication status of related papers, major journals, research forms, and researcher information. In addition, unique words were extracted through the data processing of English abstracts, and the frequency of the key words was identified. Through topic modeling, this study extracted seven topics from the entire literature group, analyzed the publication trends of the papers corresponding to each topic, and examined the topics and representative papers of that topic. The names for these topics were assigned as "access and usability of business records'," "information/evidence value of business records," "importance and operational strategy of business archives," "record management as a business heritage," "management of business records in digital environments," "preservation and disposal of business records," and "historical value of business records." Based on the prior research and analysis results, this study proposed implications for the development and expansion of future research on the domestic business archives.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3467-3472
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• 2007

The effects of the wall geometry on the spray-wall impingement process of a hollow-cone fuel spray emerging from a high-pressure swirl injector of the Gasoline Direct Injection (GDI) engine were investigated by means of a numerical method. The ized Instability Sheet Atomization (LISA) & Aerodynamically Progressed Taylor Analogy Breakup (APTAB) model for spray atomization process and the Gosman model were applied to model the atomization and wall impingement process of the spray. The calculation results of spray characteristics, such as a spray development process and a radial distance after wall impingement, compared with the experimental ones by the Laser Induced Exciplex Fluorescence (LIEF) technique. It was found that the radial distance of the cavity angle of 90$^{circ]$ after wall impingement was the shortest and the ring shaped vortex was generated near the wall after spray-wall impingement process.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.6
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• pp.27-33
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• 2002

This paper presents the comparison of prediction accuracy of hybrid models. To obtain the experimental results fur comparing with the numerical results, the macroscopic and microscopic structures of the hollow-cone spray such as spray development process, spray penetration and the distribution of mean droplet size are investigated by using a shadowgraph technique and phase Doppler particle analyzer. Also, the numerical researches using various hybrid models are performed. LISA model and WAVE model are used for the primary breakup, and TAB, DDB, and RT model are used for the secondary breakup.

• Journal of ILASS-Korea
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• v.7 no.3
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• pp.1-6
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• 2002

In this study numerical and experimental study on the spray atomization characteristics of a GDI injector is performed. To carry out numerical analysis, four hybrid models that are composed of conical sheet disintegration model, LISA model, DDB model, and RT model are used. The experimental results to evaluate the prediction accuracy of hybrid models are obtained by using phase Doppler particle analyzer and spray visualization system. It is shown that the prediction accuracy of hybrid model concerning spray developing process and spray tip penetration is good for all hybrid models, but the hybrid breakup models show different prediction of accuracy in the case of local radial SMD distribution.

• Safety and Health at Work
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• v.12 no.2
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• pp.167-173
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• 2021

Background: Correctional officers (COs) experience elevated rates of mental and physical ill-health as compared with other general industry and public safety occupations. The purpose of this study was to investigate demographic, mental health, job tenure, and work-family characteristics and their prospective association to burnout within and between jail officers during one year of new employment. Methods: In 2016, newly hired jail officers (N = 144) completed self-reported surveys across four time points in a one-year prospective study at a Midwestern United States urban jail. Linear mixed-effects and growth modeling examined how work-family conflict (W-FC) and depressive symptoms relate to perceptions of burnout over time. Results: Jail officer burnout increased and was related to rises in W-FC and depression symptoms. Within-person variance for W-FC (B_pooled = .52, p < .001) and depression symptoms (B_pooled = .06, p < .01) were significant predictors of burnout. Less time on the job remained a significant predictor of burnout across all analyses (B_pooled = .03, p < .001). Conclusions: Results from this study indicate that burnout increased during the first year of new employment; and increased W-FC, higher depression, and brief tenure were associated with burnout among jail COs. Future study of correctional workplace health is needed to identify tailored, multilevel interventions that address burnout and W-FC prevention and early intervention among COs.