• Proceedings of the Korean Operations and Management Science Society Conference
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• 2008.10a
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• pp.179-190
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• 2008

Consumers earn a number of points for every purchase and then they can exchange a specified number of points for a desired reward in a typical loyalty program. The immediate payoff of their effort given as points is not the real reward they actually care about. It is merely an instrument (or medium) which has no value in itself. In a real world, consumers frequently choose the option with a bigger medium even though the economic value of the option is not changed by the medium. We call it 'medium effect'. In this study we explored if the size of medium affects on consumers' preferences. For this we controlled the reward options with three types of medium (small, medium, big) and measured the magnitude of preference difference among the three types of reward options. In addition, we manipulated comparability of reward options with wine and gas discount coupon. We confirmed that choosing one of two wines was easier than that of the two gas coupons. 164 respondents were allocated into three experimental groups and one control group. In three experimental groups, the ratios of the focused reward option's medium to the compared reward option's medium were different. For example, the focused reward option has 10 million points whereas the compared reward option has 10 million points for 1 million won purchase amount in the first group. Then each respondent was asked to choose one of two loyalty programs (focused program vs. compared program) in two different conditions (comparability between reward options: easiness vs. difficulty). To compare the medium effects among the experiment conditions we used chi-squares tests. The empirical results show the medium effect increases and then decreases as the ratio of reward mileages/points to purchase amount increases. Additionally, they let us know that comparability of alternatives affects on the medium effects depending on the ratio of reward mileages/points to purchase amount.

• Fire Science and Engineering
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• v.29 no.6
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• pp.65-70
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• 2015

This research examines the removal efficiency of benzene, toluene, xylene (BTX) and total volatile organic compounds (TVOCs) by flowing VOCs, which are generated at a petrochemical complex in the Ulsan area, in a sliding arc plasma (SAP) reactor. The SAP reactor process is composed of 5 steps and the analysis was conducted using a BTX detector and TVOC measuring instrument. The removal efficiency of BTX was better at high concentration than at low concentration and the emitted TVOC concentration increased in later steps of the reactor. In addition, the removal efficiency improved, as the flow velocity increased. The maximum permissible concentration of TVOCs in the first step was about 481 ppm and showed over 94.83% efficiency when it was operated in the 2nd step at concentrations beyond 481 ppm. Therefore, there are many factors for improving the removal efficiency of SAP reactors at low concentration and measures should be prepared according to the application method for the various types of industrial reactors.

• Journal of Korean society of Dental Hygiene
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• v.14 no.6
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• pp.895-902
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• 2014

Objectives: The purpose of the study was to investigate the actual oral health status and dental fear level in the elderly. Methods: Data were collected by questionnaire interview method from June 15, 2013 to December 14, 2013. The subjects were elderly over 65 years old in Jeonbuk province. The study instrument was structured questionnaire including general characteristics of the subjects(3 questions), oral health management status(16 questions), Dental Fear Survey(DFS, 9 questions). Cronbach alphas were 0.804 and 0.959 in the study. Higher score of oral health management status showed good oral health care and higher DFS showed higher level of dental fear. Data were analyzed by t-test, one way ANOVA, post-hoc Scheffe test, and Pearson correlation analysis. Higher dental fear was defined below 33.3%. Results: Women tended to have better oral health than male. Women brush their teeth more frequently than male. Most of the elderly answered that it was important to brush teeth for 3 minutes, to use dental floss and to have oral health education(p<0.05). Score of dental fear level was similar in men and women. Those who were above 69 years old tended to have dental fear. Poor oral health condition was closely related to dental fear. Conclusions: The oral care in the elderly showed considerable differences between the groups and affected the dental fear. It is important to implement the nationwide dental care for the elderly in the future.

• Research in Community and Public Health Nursing
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• v.17 no.2
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• pp.195-209
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• 2006

Purpose: This study attempted to access the health promotion activities and employee's health promotion needs in workplaces. Methods: Subjects were 280 health care managers employed at small to large scale enterprises in national-wide areas of Korea. The instrument was a structured questionnaire included characteristics of workplace and respondents, health promotion activities, health promotion needs, and bottlenecks to operate programs. Data was analyzed using SAS 8.1 by applying $x^2-test$, t-test and ANOVA. Results: 1, 25.4% of the total workplaces employed health care managers. 2. Musculoskeletal management programs(49.6%) were the highest operating program. 3. The highest needs of health promotion programs were lifestyle management and disease prevention. 4. Health promotion activities were significantly different according to the type and size of workplaces. The programs were more frequently applied in manufacturing industries than non-manufacturing and in large-scale enterprises than small and middle-scale enterprises. 5. The needs of health promotion programs were high in non-manufacturing industries than manufacturing industries in all programs. 6. The major bottlenecks to operate programs were the difficulty in securing time, lack of budgets and lack of legal regulations. Conclusions: Health promotion activities were linked to their work environments including budgets, time, and law. Therefore, to operate effective health promotion programs in workplaces, various health promotion programs are required to be developed and systems for governmental support and management should be established.

• Journal of Aerospace System Engineering
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• v.16 no.4
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• pp.77-87
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• 2022

The Precision Aerial Delivery System is an instrument designed to improve the poor landing accuracy of aerial delivery system with conventional circular parachutes, and is equipped with an Airborne Guidance Unit to safely transport supplies to the desired destination. Currently, the landing accuracy of the PADS product is reported as CEP₅₀ 100m and also differs significantly, depending on the actual topography and weather environment. In this study, HILS was constructed based on the 6DOF nonlinear modeling of PADS to analyze the maneuver characteristics of Ram Air Parachute under wind environments. By using the new algorithm a precision soft landing algorithm including Energy Management and Final Approach is designed. HILS results show that it is possible to achieve a precise soft landing within CEP₅₀ 40m, and it can be exploited to develop an actual PADS drop test.

• Journal of Environmental Health Sciences
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• v.44 no.3
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• pp.205-216
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• 2018

Objectives: Scientific verification for health effects has been constantly demanded through the forest healing factors. In this study, phytoncide concentration which is one of the forest healing factors, was investigated according to stand density, season and visiting time, and analyzed correlation with micrometeorology factors. Methods: Total volatile organic compounds (TVOCs) and Natural volatile organic compounds (NVOCs) were collected using a measuring instrument which is connected to an air pump with the Tenax TA tube. The 32NVOCs were selected through the detailed criteria of adequacy assessment for recreational forest. The statistical analysis (correlation and stepwise regression analysis) was conducted between phytoncide concentration and micrometeorology factors. Results: NVOCs concentration linearly increased according to stand density. The high level showed in the summer (p<0.05), and there is no significant difference according to visiting hours of the Healing forest. NVOCs is a negative correlation with solar radiation, PAR and wind direction, and a positive correlation with relative humidity and temperature (p<0.01). NVOCs increased following the increase of humidity and temperature ($R^2=0.55$). Conclusions: Phytoncide linearly increased according to stand density, and showed the correlation significantly with microclimate factors. In future, these results will be utilized as a basic material to promote the generation of phytoncide, which positively influences human health promotion and manage the forest welfare space.

• Journal of the Korean Wood Science and Technology
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• v.36 no.2
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• pp.39-45
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• 2008

Formaldehyde and volatile organic compounds (VOCs) are emitted from wood-based panels that have been made using wood particles, wood fiber, wood chips, formaldehyde-based resins and so on. In this study, we examined formaldehyde and total VOCs (TVOC) emission behaviors for plywood overlaid with water-soluble phenolic resin impregnated linerboard (PL), and two kinds of surface materials (decorative veneer and pre-impregnated finishing foil) that were adhered onto the PL that named DPL and PPL. EVA (ethyl vinyl acetate) was used to overlay the decorative veneer and pre-impregnated finishing foil on the plywood with water-soluble phenolic resin impregnated linerboard by a hot press instrument. The debonding test and accelerated aging test were conducted to assess their mechanical properties. Formaldehyde and TVOC emission concentrations were measured using the FLEC method and a VOC Analyzer, respectively. The debonding test results of PL, DPL and PPL were 1.2, 1.5, and $0.5N/mm^2$, respectively. The surface appearance of the samples were not changed after the accelerated aging test. The PL and DPL exhibited reduced formaldehyde and TVOC emission levels, respectively. In the case of PPL, the VOC value was relatively higher than those of PL and DPL.

• Journal of the Korean Dietetic Association
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• v.14 no.2
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• pp.139-151
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• 2008

Presently, media for sanitation education consisting of a sanitation manual and a CD-ROM intended for restaurant employers and employees was developed and evaluated. The sanitation manual consisted of five principles: prevention of foodborne illness, personal hygiene, control of food production, instrument and equipment cleaning and sanitation, and management of environmental sanitation. The CD-ROM was composed of animations detailed real-life examples of Salmonella, Staphylococcus aureus, and Norovirus foodborned illness outbreaks; slides summarizing the five principles of the manual; and a poster entitled You can prevent foodborne illness listing and describing the principles. A 15 question evaluation survey was developed to gauge the efficacy of the animations. The survey was divided into five sections on comprehension of the instructions, content organization concerning understanding, content organization concerning the information presented, content organization concerning retention of interest (concentration), and recommendations concerning concentration. Ranked on a 5-point scale the survey produced a mean value of 3.80$\pm$0.39 and individual scores of 3.92$\pm$0.45 (learning instruction), 3.86$\pm$0.48 (understanding), 3.82$\pm$0.52 (information), 3.75$\pm$0.49 (concentration), and 3.67$\pm$0.58 (concentration-recommendation). Overall, evaluation results of the animation were good and easy to understand, with only a few respondents electing to watch the animations more than once. In terms of continuous and recurring education, sanitation training programs should be easy to learn and contain sufficient and specific examples of the importance of sanitation in achieving food safety.

• Nuclear Engineering and Technology
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• v.48 no.5
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• pp.1206-1218
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• 2016

This article proposes a highly reliable power and communication system that guarantees the protection of essential instruments in a nuclear power plant under a severe accident. Both power and communication lines are established with not only conventional wired channels, but also the proposed wireless channels for emergency reserve. An inductive power transfer system is selected due to its robust power transfer characteristics under high temperature, high pressure, and highly humid environments with a large amount of scattered debris after a severe accident. A thermal insulation box and a glass-fiber reinforced plastic box are proposed to protect the essential instruments, including vulnerable electronic circuits, from extremely high temperatures of up to $627^{\circ}C$ and pressure of up to 5 bar. The proposed wireless power and communication system is experimentally verified by an inductive power transfer system prototype having a dipole coil structure and prototype Zigbee modules over a 7-m distance, where both the thermal insulation box and the glass-fiber reinforced plastic box are fabricated and tested using a high-temperature chamber. Moreover, an experiment on the effects of a high radiation environment on various electronic devices is conducted based on the radiation test having a maximum accumulated dose of 27 Mrad.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.1
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• pp.61-66
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• 2014

As a key technology of U-health, RFID can be applied to the hospitals in a variety of cases such as patient tracking, medical instrument management, and so on. However, adoption of RFID in healthcare does not reach expectations because of huge cost. Exact estimation of cost and effectiveness will boost adoption of RFID in healthcare. This study proposes a novel simulation technique to evaluate cost and effectiveness of RFID in hospital environment. To do this, this study proposes a technique for modeling patients' movements in a hospital. Based on the model, this study provides how to obtain tag event dataset by means of simulating identifications of RFID tags that are attached to patients.