• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.3
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• pp.345-351
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• 2017

A wind tunnel test for the scaled parachute models was performed to verify aerodynamic characteristics for practical usage of Korean low cost low altitude aerial delivery system. The cruciform shaped cargo parachute models for heavy and light weight were ejected into wind tunnel test section; and the drag forces acting on the models in steady condition were measured in accordance with velocity. Also, the maximum opening forces during inflation were obtained and captured by a high speed camera to analyze the inflation characteristics and evaluate the design of the low cost aerial delivery system. The results showed a reliable stability and met the design requirement of delivery operation system for R.O.K Air Force.

• KSBB Journal
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• v.31 no.4
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• pp.300-311
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• 2016

Recently gene delivery has been designed newly using bioactive biomaterial and applied in the various field by many researchers. In this study, we proposed a new gene delivery system which has the capability of targeting effect in the specific tissue and remarkably enhanced transfection efficiency. We investigated $^1H-NMR$ spectroscopy, particle size analyzer and gel retardation to confirm the correct preparation of gene delivery. Also, we identified the hemo-compatibility of gene delivery by hemolysis assay, non-cytotoxicity by MTT test and transfection efficiency. The uptake mechanism of the gene carrier was confirmed using inhibitor agent such as sodium azide, indomethacin, quercetin, colchicine, and chloropromazine. As a results, it was identified that gene carrier prepared by in this study entered in the cell by the microtubule-dependent, energy-dependent and clathrin-mediated endocytosis pathway.

• The Korean Journal of Food & Health Convergence
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• v.7 no.1
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• pp.7-15
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• 2021

This study aims to empirically analyze the differences between groups of customers who prefer delivery food, which is rapidly growing amid the COVID-19 pandemic, and those who prefer the traditional practice of visiting offline restaurants. Based on the eating out lifestyle, participants were divided into three groups: participants who prefer food delivery, those who prefer to visit restaurants, and those who favor both. The comparison of differences between the groups was analyzed. A total of 215 questionnaires were distributed, and reliability and validity were verified with a sample of 201 copies, excluding 14 unreliable respondents. Then, a multivariate analysis of variance was used to compare the groups. The results showed that regarding offline restaurants, the group of customers who prefer to visit restaurants valued their atmosphere, while the customers who prefer delivery food valued the reputation of the restaurant. Regarding delivery-specialized restaurants, the group of customers who prefer delivery placed greater value on coupon events and payment convenience than other groups. The results revealed that the difference between the customers who prefer to visit restaurants and those who prefer delivery food was identified through empirical analysis, which provides strategic implications for catering companies and restaurant industries during COVID-19 in Korea.

• Journal of the Korean Society for Precision Engineering
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• v.34 no.2
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• pp.101-106
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• 2017

The chemical mechanical planarization (CMP) process combines the chemical effect of slurry with the mechanical effect of abrasive (slurry)-wafer-pads The slurry delivery system has a notable effect on polishing results, because the slurry distribution is changed by the supply method. Thus, the investigation of slurry pumps and nozzles with regard to the slurry delivery system becomes important. This paper investigated the effect of a centrifugal slurry pump on a spray nozzle system in terms of uniform slurry supply under a rotating copper (Cu) wafer, based on experimental results and computational fluid dynamics (CFD). In conventional tools, the slurry is unevenly and discontinuously supplied to the pad, due to a pulsed flow caused by the peristaltic pump and distributed in a narrow area by the tube nozzle. Adopting the proposed slurry delivery system provides a higher uniformity and lowered shear stress than usual methods. Therefore, the newly developed slurry delivery system can improve the CMP performance.

• Journal of the Ergonomics Society of Korea
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• v.35 no.5
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• pp.465-472
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• 2016

Objective:This study is on the characteristics of motorcycle accidents occurring in the mail delivery process by skill level. Background: The tendency of delivery postmen's driving in a hurry may become the cause of accidents since there is a constraint that delivery should be completed within a limited time. Method: This study analyzed the traffic accident data of 259 delivery postmen, who had been approved as occupation-related industrial accident victims from 2009 to 2012, by their work experience in view of season, day of the week of an accident occurrence, accident occurrence time, accident cause, collision type, and driving situation. Results: Accident characteristics of delivery postmen show that the ratio of accidents occurring to those who had less than 10 years of work experience was high. There were many motorcycle collisions in winter and summer by season and an unexpected object, along with road condition, took up 70.7% of the accident sources. There were no differences in accident occurrence time, the day of the week, season, accident source, and collision type between the group of delivery postmen with less than 10 years of work experience and those with 10 years or more of work experience. However, there was a difference in distribution of driving condition. Conclusion and Applications: The results of this study can be used to present the policies or guidelines for the accident prevention of delivery postmen since the results show the characteristics of the injured and accident occurrence characteristics in relation with the delivery postmen's motorcycle collisions.

• Health Policy and Management
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• v.33 no.4
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• pp.479-488
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• 2023

Background: By applying the suggested criteria for needs-based chronic medical care and long-term care delivery system for the elderly, the current status of delivery system was identified and regional delivery systems were categorized according to quantity and quality of delivery system. Methods: National claims data were used for this study. All claims data of medical and long-term care uses by the elderly and all claims data from long-term care hospitals and nursing homes in 2016 were analyzed to categorize the regional medical and long-term care delivery system. The current status of the delivery system with a high possibility of transition to a needs-based appropriate delivery system was identified. The necessary and actual amount of regional supply was calculated based on their needs, and the structure of delivery systems was evaluated in terms of the needs-based quality of the system. Finally, all regions were categorized into 15 types of medical and care delivery systems for the elderly. Results: Of the total 55 regions, 89.1% of regions had an oversupply of elderly medical and care services compared to the necessary supply based on their needs. However, 69.1% of regions met the criteria for less than two types of needs groups, and 21.8% of regions were identified as regions where the numbers of institutions or regions with a high possibility of transition to an appropriate delivery system were below the average levels for all four needs groups. Conclusion: In order to establish an appropriate community-based integrated elderly care system, it is necessary to analyze the characteristics of the regional delivery system categories and to plan a needs-based delivery system regionally.

• Women's Health Nursing
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• v.8 no.3
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• pp.371-379
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• 2002

The purpose of the present study is to consider its effect on the childbirth of a woman. This is a quasi-experimental study with nonequivalent control group post-test design. The subjects of this study are 60 primiparas (30 in the control, and another 30 in the experimental group) who have had a regular prenatal care from February 5 to March 20, 2002, in an outpatient obstetrics and gynecology of S university medical center located in Seoul. The result is as follows: 1. The hours of labor pains in the entire delivery period: the average hours are 7 hr. 9 min. in the experimental group, and 10 hr. 39 min. in the control group. The hours of labor pains are shorter in the woman with a family delivery experience in LDR. The difference is statistically significant (t=-3.34, p=.001). 2. The degree of pains in the entire delivery period: the average degree is 7.38 in the experimental group, and 7.68 in the control group. The degree of labor pains are lower in the woman with a family delivery experience in LDR. But, the difference is statistically insignificant (t=-0.86, p=.396). 3. The perceptions of the delivery experience: the average score of the perception is 73.63 in the experimental group, and 63.57 in the control group. The women with a family delivery experience in LDR have more positive perception of the delivery procedure, and, the difference is statistically significant (t=4.65, p=.000). In summary of the above result, a family-participated delivery in LDR is proved to be an effective nursing intervention that shortens the hours spent in the delivery procedure and promotes positive perceptions of the delivery experience.

• Korean Chemical Engineering Research
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• v.58 no.3
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• pp.450-457
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• 2020

In the previous study, there was a big difference between the tendency of the delivery efficiency of Yo-Pro-1 and the expression efficiency of the CFP gene, but there was a problem that could not provide a clue to this problem. Therefore, this study aimed to present a clue to this problem by quantifying and comparing the delivery efficiency after labeling DNA using a fluorescent dye, which was one of the methods for quantifying biomolecules. As a fluorescent dye for labeling, Yo-Pro-1 was used, and the delivery efficiency of the fluorescent dye Yo-Pro-1 and the labeled DNA was compared. The delivery efficiency of Yo-Pro-1 and labeled DNA according to the voltage condition of the digital electroporation system was maximized at 96 V, and the delivery efficiency tended to decrease as the voltage increased further. In the comparison of the delivery efficiency of Yo-Pro-1 and labeled DNA according to the number of voltage application conditions, the delivery efficiency was maximized at the number of 8 voltage application times for both delivery materials, and the delivery efficiency tended to decrease as the number of voltage application increases further. Through the two results, it was confirmed that the delivery efficiency using Yo-Pro-1 in the digital electroporation system represents the delivery efficiency of the system well. In addition, through the results of this study, the difference between the tendency of the delivery efficiency of Yo-Pro-1 and the expression efficiency of the CFP gene shown in the preceding study was not the result of the difference in the delivery efficiency of the delivery material, but it can be predicted to be due to a problem with the expression process of the genetic material that had been delivered.

• Journal of Distribution Science
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• v.20 no.9
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• pp.97-107
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• 2022

Purpose: Online-To-Offline Food Delivery Services (O2O-FDS) is a new element in hotel supply chain that digitalizes traditional food delivery practices using new technologies. Targeting hotel guests, the present research is to explore the role of trust in the relationship between food delivery app on loyalty, price efficiency, and convenience. This new perspective is an essential value addition in the field of hotel marketing in relation to O2O-FDS. Research design, data and methodology: The present research conducted the mediator variable regression analysis as a main statistical methodology to identify the connections between three main constructs using total 244 South Korean participants that were recruited from the professional research company in Korea. Results: The statistical findings based on three steps of mediator regression approach strongly indicate that the trust of food delivery app in the hotel sector plays a moderating role in the relationship between price efficiency and convenience of food delivery app and customer loyalty of food delivery app in the hotel business. Conclusions: This research concludes that hotel practitioners must strive to provide adequate information on food delivery applications in order to increase price efficiency and convenience relative to traditional food and beverage services, influencing consumer trust in food delivery technology.

• Journal of the Korean Society of Safety
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• v.39 no.1
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• pp.55-61
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• 2024

In response to the COVID-19 pandemic, the logistics industry in Korea has rapidly been expanding, with offline demand concentrating on online platforms owing to the development of digital infrastructure. This has increased the workload of courier drivers considerably, along with labor intensity. A delivery driver died recently from overwork due to the continuous increase in delivery volume, which raises social concerns. Delivery drivers work long hours, (over 12 hours) and are greatly affected by weather conditions, such as snow, rain, heat waves, and cold waves. In addition, they lack a fixed workplace; perform atypical work handling workpieces of various sizes, weights, and shapes; and spend a large amount of time driving as part of their work. This work involves a high level of tension and requires attention and concentration. Despite the frequency of industrial accidents in the courier industry, studies on safety and health to quantitatively analyze and systematize the work of courier workers are very scarce. Therefore, to define the work process necessary for investigating the harmful factors in delivery service and the work analysis, this study conducted interviews and on-site surveys to analyze the unit work of the delivery service by targeting delivery workers. In other words, a framework of unit work for work analysis was presented to enable research and analysis by considering the aforementioned characteristics of the courier industry. The process was broadly divided into work, transport, storage, delay, and inspection. Work was divided into loading, sorting, unloading, and door subcategories, and transportation was divided into vehicle, cart, and walking subcategories as well as 10 small processes. Moreover, 22 unit works were again drawn by conducting field surveys and interviews. The risk of unit work derived from this study was ergonomically evaluated, and the ergonomic analysis revealed that uploading and transportation were the most dangerous. The results of this study could be used as basic data for preventing industrial accidents among courier workers, whose work has increased with the logistics volume and the development of the logistics industry.