• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.20 no.2
• /
• pp.171-181
• /
• 2002

As the result of the analysis of the underground utility map made before, we could have divided the kind of errors into the two types, position error of geometric data and attribute error and knew the fact that mainly position error is derived from the process of detecting and surveying the underground utility, and attribute is inputting data. In this study we showed the way improving accuracy in detecting and surveying underground utility by field test, and the way to reduce attribute error by process refinement.

• Proceedings of the KIEE Conference
• /
• 2001.10a
• /
• pp.334-336
• /
• 2001

The photovoltaic power generation system has a great future as clean energy instead of fossil fuel which has many environmental problems such as exhausted gas or air pollution. In a utility interactive photovoltaic generation system, a three-phase inverter is used for the connection between the photovoltaic array and the utility. This paper presents a three phase inverter for photovoltaic power system with current controller, voltage controller PLL control system and the phase detector of interactive voltage by using do transformation. The proposed inverter system provides a sinusoidal are current for domestic loads and the utility line with unity power factor. The results of the operated from January to October show the system characteristics.

• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.1161-1165
• /
• 2004

The fundamental digital control of utility-connected PV inverter are presented with detailed analysis and simulation and experimental results. PLL controller using virtual two phase detector, current controller of DC-DC converter, dc link voltage controller and inverter current controller are discussed. The novel PLL controller using virtual two phase detector can detect the information of utility voltage instantaneously and is not sensitive to the noise. Current controller of DC-DC converter, dc link voltage controller and inverter current controller are the conventional methods. We have constructed utility-Connected PV Inverter and applied to those controllers. The simulation and experimental results demonstrate an excellent performance in the single-phase grid-connected operation.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.13 no.2
• /
• pp.473-493
• /
• 2019

5G vehicular communication is one of key enablers in next generation intelligent transportation system (ITS), that require ultra-reliable and low latency communication (URLLC). To meet this requirement, a new hybrid vehicular network structure which supports both centralized network structure and distributed structure is proposed in this paper. Based on the proposed network structure, a new vehicular network utility model considering the latency and reliability in vehicular networks is developed based on Euclidean norm theory. Building on the Pareto improvement theory in economics, a vehicular network uplink optimization algorithm is proposed to optimize the uplink utility of vehicles on the roads. Simulation results show that the proposed scheme can significantly improve the uplink vehicular network utility in vehicular networks to meet the URLLC requirements.

• Fashion & Textile Research Journal
• /
• v.16 no.1
• /
• pp.160-166
• /
• 2014

Patent and utility indicate international competitiveness in the knowledge-based society of the $21^{st}$century where both the quantity and quality of the nation's scientific intelligence and innovative technology represent key criteria to evaluate its strength. Thus, discerning the trends of patents is inevitable for further development. This research is centered on apprehending the technological current of the functional clothing of Korea, through an analysis of patents and utility models. The number of patent applications in Korea was low until the mid-1990s. However, it began to grow rapidly in the 2000s and the number of patents surpassed the number of utility starting in 2006. The technological level of invention in this field has been turned into a higher level. The IPC code with the strongest application was the field related to temperature controllable clothing (A41D 13/005), followed by surgeon or patient apparel related fields (A41D 13/12), and reflective or luminous safety devices (A41D 13/01).The main technological idea was to give functionality that could protect the human body from various hazards and represents the goal of various applied techniques. About 66% of domestic patent applications belong to individuals; however, the proportion of corporate or institutional applications(including universities) remains poor. Consequently, more systematic and long-term support for research on patents is required.

• The Korean Journal of Food And Nutrition
• /
• v.27 no.2
• /
• pp.310-317
• /
• 2014

The purposes of this study were to identify the relative importance attributes, deduct the ideal combination of total utility and establish the marketing strategies for quality improvement of foodservice at funeral halls of medical centers. Data were collected using self-administered questionnaires from 102 funeral foodservice employees and 71 chief mourners or the bereaved. According to the results from a conjoint analysis, among foodservice employees at funeral hall, the relatively important attributes were 'taste (52.84%)', 'menu variety (24.419%)' and 'price (22.741%)'; among chief mourners or the bereaved, they were 'taste (50.004%)', 'price (31.388%)' and 'menu variety (18.008%)'. The ideal combination of total utility was different between funeral foodservice employees and chief mourners or the bereaved; it was higher among chief mourners or the bereaved (1.211) compared to funeral foodservice employees (1.169). Thus, there should an endeavor to improve the foodservice quality in funeral halls of medical centers through better taste, low price and similar menu variety.

• Journal of Distribution Science
• /
• v.16 no.7
• /
• pp.5-16
• /
• 2018

Purpose - This study posits that sustainable mobility of the sharing economy plays a key role to consider environment benefits. The purpose of this study is to investigate the bicycle-sharing economy as an emerging and alternative mode of transportation service and provide managerial and policy implications. The bicycle-sharing economy is still at an early stage of introduction as a transportation mode, while the governmental sector is promoting public bicycle-sharing to encourage bicycle as a substitute for private cars. Research design, data, and methodology - This study analyzed the current status of bicycle sharing programs through a survey that was distributed randomly to users and non-users across the country. Using factor analysis, satisfaction and loyalty for the existing users and intention to use and expected satisfaction for the potential users were examined in relation to utility factors. Results - The results show that economic utility affects satisfaction for user, while storage, mobility, and economic utility affects intention to use for potential users. The findings of this study indicate that in order to promote a bicycle-sharing scheme, it would be better to focus on the scheme's economic advantage to be truly effective. Conclusions - The findings of the study could be applicable to future directions of the sharing economy as a means to achieve the sustainable development of society.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.25 no.1
• /
• pp.11-20
• /
• 2021

The seismic deformation method is conventionally used as a seismic design for a multi-utility tunnel in Korea. In the seismic deformation method, the soil ground's natural period is one of the most critical factors for calculating the ground displacement using cosine functions. Correction factors for the natural period and shear wave velocity have been used to consider the non-linearity of dynamic soil properties. However, the correction factors have been issued because the correction factors have not been sufficiently studied to consider Korea's regional conditions. This paper aims to evaluate the natural periods for the seismic deformation method considering Korea's ground conditions. Ground response analysis was performed using seven real earthquake records on twelve sites with different soil conditions where actual multi-utility tunnels are installed. As a result, natural periods of the sites were analyzed and new correction factors were proposed according to seismic performance and Korea's regional conditions.

• Computers and Concrete
• /
• v.29 no.2
• /
• pp.69-79
• /
• 2022

For long underground box utility tunnels, post-tensioned precast concrete is often used. Between precast tunnel segments, sealed waterproof flexible joints are often specified. Fault displacement can lead to excessive deformation of the joints, which can lead to reduction in waterproofing due to diminished contact pressure between the sealant strip and the tunnel segment. This paper authenticates utilization of a finite element model for a prefabricated tunnel fault-crossing founded on ABAQUS software. In addition, material parameter selection, contact setting and boundary condition are reviewed. Analyzed under normal fault action are: the influence of fault displacement; buried depth; soil friction coefficient, and angle of crossing at the fault plane. In addition, distribution characteristics of the utility tunnel structure for vertical and longitudinal/horizontal relative displacement at segmented interface for the top and bottom slab are analyzed. It is found that the effect of increase in fault displacement on the splice joint deformation is significant, whereas the effects of changes in burial depth, pipe-soil friction coefficient and fault-crossing angle on the overall tunnel and joint deformations were not so significant.

• Journal of Smart Tourism
• /
• v.4 no.1
• /
• pp.31-38
• /
• 2024

This study investigates the adoption of technology in smart tourist destinations, with a focus on the Baby Boomer generation. The objective is to analyze the perceived utility, intention to use, and risk perception of this generation regarding Information and Communication Technologies (ICT) in the context of smart tourist destinations. Data were collected through questionnaires administered to elderly groups belonging to the Baby Boomer generation in two Brazilian cities. Data analysis was conducted using statistical tools such as SPSS and Microsoft Excel, with an emphasis on regression analysis with moderation. The results indicate that when Baby Boomer tourists feel insecure about technology, they tend to not perceive its utility, impacting its acceptance. On the other hand, lower risk perceptions lead to an increase in perceived utility and, consequently, a greater intention to use technology in travel planning. The moderating role of risk perception in the relationship between perceived utility and intention to use is emphasized. The findings highlight the need for managers of smart destinations to consider the risks perceived by tourists, focus on diverse age groups, and implement strategies that address digital exclusion.