• The Korean Journal of Food And Nutrition
• /
• v.22 no.1
• /
• pp.57-62
• /
• 2009

The current exploratory study attempted to investigate the levels of expected and perceived service quality of in-flight meals. A questionnaire was developed following extensive literature review and in-depth interviews. The survey was conducted on board a flight by international passengers and also by passengers in the trans lounge waiting for connecting flights between October 21, 2005 through October 30, 2005. Out of the 450 questionnaires administered, a total of 319 completed questionnaires were returned, yielding a response rate of 89.6%. The 20 items representing the service quality factor of in-flight meals were analyzed, resulting in four distinct dimensions-food quality, employee service, cleanliness and reliability. In all dimensions, customer expectation was higher than the perceived level of service and the service quality of Korean based airlines was higher than that compared to foreign based airlines. There were differences in the perceived service quality of in-flight meals according to the demographics of the respondents. The results of this study can be beneficial from a theoretical and practical point of view by providing empirical data that measures the service quality of in-flight meals.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.64 no.11
• /
• pp.1535-1542
• /
• 2015

An increasing number of electric vehicles (EVs) in power system affects its reliability in various aspects. Especially under high EV penetration level, new generating units are required to satisfy system's adequacy criterion. Wind power generation is expected to take the major portion of the new units due to environmental and economic issues. In this paper, the system reliability is analyzed using Loss of Load Expectation (LOLE) and Expected Energy Not Served (EENS) under each and both cases of increasing wind power generation and EVs. A probabilistic multi-state modeling method of wind turbine generator under various power output for adequate reliability evaluation is presented as well. EVs are modeled as loads under charging algorithm with Time-Of-Use (TOU) rates in order to incorporate EVs into hour-to-hour yearly load curve. With the expected load curve, the impact of EVs on the system adequacy is analyzed. Simulations show the reliability evaluation of increasing wind power capacity and number of EVs. With this method, system operator becomes capable of measuring appropriate wind power capacity to meet system reliability standard.

• Korean Journal of Materials Research
• /
• v.21 no.11
• /
• pp.623-627
• /
• 2011

This is a study on the distribution of acoustic emission parameters during a burst test for a type-II CNG vehicle fuel tank. A resonant AE sensor with a central frequency of 150 kHz was attached to the composite materials in the center of the fuel tank. The pressure was increased from 30 to 100% of the expected burst pressure and was maintained for 10 minutes at each level. Damage at 70% of expected burst pressure occurred by various damage mechanisms including fiber breakage and delamination, while that of below 60% only occurred by matrix crack initiation and growth. The count, duration and rise time of the AE signal at 60% of the expected burst pressure are distributed below 500, 5000 ${\mu}s$ and 300 ${\mu}s$, respectively. Then, at above 70% they increased with pressure by superimposing of individual AE signal generated at a nearby place. These results confirmed that the analysis of the distribution of AE parameters is an effective tool for estimating damage of a CNG fuel tank.

• Earthquakes and Structures
• /
• v.21 no.5
• /
• pp.505-514
• /
• 2021

A formulation based on structural reliability and cost effectiveness is proposed to provide recommendations to select the best retrofit strategy for schools with reinforced concrete frames and masonry walls, among three proposed alternatives. The cost calculation includes the retrofit cost and the expected costs of failure consequences. Also, the uncertainty of the seismic hazard is considered for each school site. The formulation identifies the potential failure modes, among shear and bending forces for beams, and flexure-compression forces for columns, for each school, and the seismic damages suffered by the schools after the earthquake of September 17, 2017 are taken into account to calibrate the damaged conditions per school. The school safety level is measured through its global failure probability, instead of only the local failure probability. The proposed retrofit alternatives are appraised in terms of the cost/benefit balance under future earthquakes, for the respective site seismic hazard, as opposed to the current practice of just restoring the structure original resistance. The best retrofit is the one that corresponds to the minimum value of the expected life cycle cost. The study, with further developments, may be used to develop general recommendations to retrofit schools located at seismic zones.

• The Journal of Industrial Distribution & Business
• /
• v.13 no.3
• /
• pp.13-24
• /
• 2022

Purpose: The purpose of this paper is to investigate key factors that affect customer dissatisfaction on public transportation system by highlighting the necessity of citizen participation and improved management of advanced technology for sustainability. Research questions applied in this study include following; i) how are factors on dissatisfaction related to types of transportation modes; ii) how do perceived proposed factors affect citizen dissatisfaction; iii) how do the improvement of public transportation service affect the level of expected satisfaction; and iv) how do expected satisfaction affect policy agreement and government trust. Research design, data and methodology: For qualitative research, civil opinions were collected and chi-square analysis was applied using keywords. For quantitative research, online survey was collected and factor and multiple regression analyses were applied. 3) Results: This study found that efficiency of operation system and safety on dissatisfaction showed significant in all three public transportation modes. This study found that perception of government policy and trust on government will increase as expected satisfaction increases. Conclusions: This study provides managerial and policy implications on society and policy makers by addressing necessity of improving strategies for public transportation system with the consideration of citizen relationship management and sustainable development.

• Journal of People, Plants, and Environment
• /
• v.22 no.4
• /
• pp.395-410
• /
• 2019

The purpose of this study was to investigate 199 subfertile women's interest in and needs for forest therapy programs according to their demographic characteristics in a subfertile clinic in Seoul to provide basic data. The results of this study were summarized as follows. First, the perception and experience of subfertile women about forest therapy were all low, but their intention to participate was generally positive. Second, the type of forest therapy preferred by subfertile women was a half-day small group that they can participate with their spouse during weekends. Third, subfertile women expected phytoncide (35.8%) and a high level of oxygen (29.9%) from forest therapy programs. Fourth, subfertile women expected physical and mental health such as improved blood circulation and immunity, and meditation opportunity from forest therapy. Fifth, subfertile women expected from forest therapists understanding and sympathy (62.2%). This study conducted a survey on 199 subfertile women only. Through follow-up studies that involve more subfertile subjects and a broader region, it will be possible to develop more effective forest therapy programs for promoting the physical and mental health of subfertile subjects.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.20 no.2
• /
• pp.109-123
• /
• 2024

The purpose of this study is to identify strategic insights for cyber universities to secure a competitive advantage based on market analysis grounded in customer needs and motivations. As a research method, we surveyed and analyzed college students using conjoint analysis, identified the importance of cyber university components, estimated the utility of each detailed level, and identified the configuration of cyber universities most preferred by potential customers. In the study results, the importance of attributes that appeared by analyzing all respondents was in the order of 'expected ourcoms after graduation', 'department characteristic', 'cyber university name', and 'learning management style'. Cluster analysis was performed, divided into two groups, and conjoint analysis was performed. For Cluster 1, the importance values of the components were 'expected outcomes after graduation,' 'learning management style,' 'cyber university name,' and 'department characteristics,' in that order. For Cluster 2, the importance values were 'expected outcomes after graduation,' 'department characteristics,' 'cyber university name,' and 'learning management style,' in that order. As an application of the research, As an application of the study, it is suggested that analyzing the preferences of potential customers in the entire group is not accurate; therefore, segmenting the groups for analysis and strategy formulation can be useful.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.7 no.3
• /
• pp.78-85
• /
• 2004

The non-planned development of the rural area surrounding the Metropolitan area has become a social problem. The land development program until now has an aspect of not combining the spacial plan and the environmental plan. The land use and city development system based on development should change into a form that combines developing the area and conserving the environment. Therefore, this research attempts to compare the results of the overlay analysis and the gravity matrix which are ways to evaluate the value land that has a high environmental conservation value. The research area is the town of Seonggeo-eup, Cheonan City, and the reason for selecting this area is because it is expected to be densely populated as a connected area to the Metropolitan and the development pressure, such as expanding the industrial area, is high due to convenient transportation. The environmental factors used in the research are the relative altitude, incline, age-class, natural degree of the ecology, classification of the land covering and the NDVI, and the research methods used are the overlay analysis of the GIS and the statistical method. The overlay analysis results showed level 1 13.2%, level 2 30.7%, level 3 47.4%, level 4 1.0%, level 5 2.4%, level 6 5.4% and so on. The gravity matrix was classified as level 1 27.0%, level 2 9.3%, level 3 58.2%, level 4 2.4%, level 5 2.3%, level 6 0.9% and so on. These results are more appropriate than current methods for plans that value the environment because the analyzed results of the gravity matrix have a tendency to highly condense the environmentally valuable area. Consequently, if the spacial and environmental plans combine and therefore expand the efficient use of the land in the current state where the nation's concern in environment is getting higher, it is thought that it will contribute highly on the development of the nation's life quality.

• Journal of the Society of Naval Architects of Korea
• /
• v.49 no.3
• /
• pp.239-246
• /
• 2012

It is the well-known fact that most part of goods transported are moved on the unfavorable ocean and even a small amount of accident on sea is extremely dangerous for human lives, financial losses, and social responsibility. Among the several causes of accidents, those by fire have occurred frequently and their damage has been highly serious. The aim of this paper is to assess the risk of fires due to oil leakage in the machinery space. To define the possible fire scenario, our team has performed the search of casualty database and reviewed the previous and various studies in the field. As a result, it is noted that the quantitative risk of the fire scenario have been evaluated on the ground of the FSA risk model. The expected frequency of a fire amounts to incidents during the life of a ship, and the expected financial damage amounts to 5,654 USD per a ship. By adopting Safety Instrumented System (SIS) introduced in IEC 61508 and IEC 61511, SIS model is designed to prevent oil leakage fire as a risk reduction method. It is concluded that System Integrity Level (SIL) 1 seems to be appropriate level of SIS.

• Journal of Internet Computing and Services
• /
• v.15 no.3
• /
• pp.91-100
• /
• 2014

While IT security investment of organizations has been increased, the amount of the monetary loss of organizations caused by IT security breaches did not decrease as much as their expectation. Also, from surveys, it was discovered that the poor usage of their security budget thwarted the improvement of the organization's security level. In this paper, to resolve the poor usage of security budget of organizations, we propose a comprehensive economic model for determining the optimal amount of investment in security solutions, including the proactive security solutions(PSSs) and the reactive security solutions(RSSs). Using the proposed analytical model under different parameters of security solutions, we show the optimal condition to maximize the expected net benefits from IT security investment of organizations. Also, we verify the common belief that the optimal level of investment in security solutions is an increasing function of vulnerability. Through simulations, we find the optimal level of IT security investment, given parameters of different characteristics of security solutions.