• The Journal of Society for e-Business Studies
• /
• v.26 no.2
• /
• pp.1-17
• /
• 2021

This paper elucidates the effect of characteristics of service quality on continuance usage intention of digital healthcare service using mediating factors of user expectation and user utility. First, we classified independent factors into three types such as service system characteristics, user characteristics, and healthcare service characteristics from the previous studies, and investigated the effect of three independent factors on continuance usage intention of digital healthcare service. Second, we analyzed the impact of two mediating factors, user expectation and user utility, on the continuance usage intention. We developed a research model that includes three types of independent factors, mediated factors of user expectation and user utility, and a dependent factor of continuance usage intention. We surveyed a total of 357 samples from digital healthcare service users and analyzed the research model. The research results significantly show that Characteristics of Users is essential factor impacting a dependent factor of Continuance Usage Intention. The results indicate the followings: (1) Characteristics of Users including the variables of Innovation impacts User Expectation, and User Expectation affects Users Utility, and Users Utility also affects Continuance Usage Intention. (2) Characteristics of Service Systems including the variables of Functionality, Compatibility, and Convenience and Characteristics of users of Innovation variable impact the mediating factor of User Expectation, and User Expectation also affects the factor of Continuance Usage Intention. (3) Characteristics of Healthcare Services including the variables of Reliability, Ease of Operation, Safety, and Accuracy impact User Utility, and User Utility also affects Continuance Usage Intention.

• Korea Journal of Hospital Management
• /
• v.10 no.4
• /
• pp.75-97
• /
• 2005

The research objective is to empirically investigate the compensation packages maximizing the utilities of internal customers by applying the market segmentation theory. Data was collected from four Korean hospitals in Seoul, Busan and Gyunggi-do. The research is designed to seek the compensation package maximizing the utility of doctors by mixture regression model, which has been applied as latent structure and other type of finite mixture models from various academic fields since early 1980s. The mixture regression model shows the optimal segments number and fuzzy classification for each observation by EM(expectation-maximization algorism). The finite mixture regression model is to unmix the sample, to identify the groups, and to estimate the parameters of the density function underlying the observed data within each group. The doctors were segmented into 5 groups by their preference for the compensation package. The results of this study imply that the utility of doctors increases with differentiated compensation package segmented by their preference.

• Journal of computational fluids engineering
• /
• v.10 no.1
• /
• pp.94-98
• /
• 2005

Accurate prediction of the fire-induced air velocity, temperature and smoke flow in underground utility tunnel becomes more important for the optimization of design and placement of heat and smoke detectors. In order to improve the safety of underground utility tunnel systems, the behaviors of fire-induced smoke flow and temperature distributions are investigated. Especially, two different cross-sectional shapes of tunnel, such as rectangular and circular types are modeled. Also, fire source is modeled as a volumetric heat source. Three-dimensional thermal-flow characteristics in an underground tunnel are solved by means of FVM using SIMPLE algorithm. The effects of shape geometry on the fire-induced flow characteristics are graphically depicted. It is desirable that heat and smoke detectors are installed on the cables and the top of the wall.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2003.05a
• /
• pp.972-975
• /
• 2003

The purpose of this study is to integrate Decision Theory Approach(DTA) and OR Theory Approach(OTA) systemically. and to develop Combination Theory Approach to build an optimal R&D project portfolio by strategies. To Integrate two approaches. Utility theory is introduced. Evaluation Results aye converted into utility values by the utility functions and the values are optimized by 0-1 programming. Scoring method and Integer programming is used to evaluation a correspondence with a goal and to allocation the limiting resources. And utility function is used to reflect the preference of decision makers on the project evaluation.

• Journal of the Korean Data and Information Science Society
• /
• v.23 no.2
• /
• pp.365-374
• /
• 2012

Weather derivatives designed to manage casual changes of weather, as opposed to catastrophic risks of weather, are relatively a new class of financial instruments. There are still many theoretical and practical challenges to the effective use of these instruments. The objective of this paper is to develop a pricing approach for valuing weather derivatives and presents a case study that is practical enough to be used by the risk managers of electrical utility firms. Utilizing daily average temperature data of Guangzhou, China from $1^{st}$ January 1978 to $31^{st}$ December 2010, this paper adopted a univariate time series model to describe weather behavior dynamics and calculates equilibrium prices for weather futures and options for an electrical utility firm in the region. The results imply that the risk premium is an important part of derivatives prices and the market price of risk affects option values much more than forward prices. It also demonstrates that weather innovation as well as weather risk management significantly affect the utility's financial outcomes.

• Journal of the Society of Disaster Information
• /
• v.19 no.3
• /
• pp.665-672
• /
• 2023

Purpose: Underground utility tunnel is facility that is jointly house infrastructure such as electricity, water and gas in city, causing condensation problems due to lack of airflow. This paper aims to prevent electricity leakage fires caused by condensation by detecting whether the control panel door in the underground utility tunnel is open using a deep learning model. Method: YOLO, a deep learning object recognition model, is trained to recognize the opening and closing of the control panel door using video data taken by a robot patrolling the underground utility tunnel. To improve the recognition rate, image augmentation is used. Result: Among the image enhancement techniques, we compared the performance of the YOLO model trained using mosaic with that of the YOLO model without mosaic, and found that the mosaic technique performed better. The mAP for all classes were 0.994, which is high evaluation result. Conclusion: It was able to detect the control panel even when there were lights off or other objects in the underground cavity. This allows you to effectively manage the underground utility tunnel and prevent disasters.

• Journal of Electrical Engineering and Technology
• /
• v.12 no.4
• /
• pp.1484-1494
• /
• 2017

We present a two-stage inverter with high step-up conversion ratio engaging modified finite-set Model Predictive Control (MPC) for utility-integrated photovoltaic (PV) applications. The anticipated arrangement is fit for low power PV uses, the calculated efficiency at 150 W input power and 19 times boosting ratio was around 94%. The suggested high-gain dc-dc converter based on Cockcroft-Walton multiplier constitutes the first-stage of the offered structure, due to its high step-up ability. It can boost the input voltage up to 20 times. The 3S current-source inverter constitutes the second-stage. The 3S current-source inverter hires three semiconductor switches, in which one is functioning at high-frequency and the others are operating at fundamental-frequency. The high-switching pulses are varied in the procedure of unidirectional sine-wave to engender a current coordinated with the utility-voltage. The unidirectional current is shaped into alternating current by the synchronized push-pull configuration. The MPC process are intended to control the scheme and achieve the subsequent tasks, take out the Maximum Power (MP) from the PV, step-up the PV voltage, and introduces low current with low Total Harmonic Distortion (THD) and with unity power factor with the grid voltage.

• Nuclear Engineering and Technology
• /
• v.50 no.5
• /
• pp.794-800
• /
• 2018

The proliferation resistance (PR) of Th/U and Th/Pu fuels used in CANada Deuterium Uranium for the deep geological repository was assessed by combining the multiattribute utility analysis proposed by Chirayath et al., 2015 with the transport model of radionuclides in the repository and comparing with that of the used natural U fuel case. It was found that there was no significant advantage for Th/U and Th/Pu fuels from the viewpoint of the PR in the repository. It was also found that the PR values for used nuclear fuels in the repository of Th/U, Th/Pu, and natural U was comparable with those for enrichment and reprocessing facilities in the pressurized water reactor (PWR) nuclear fuel cycle. On the other hand, the PR values considering the transport of radionuclides in the repository were found to be slightly smaller than those without their transport after the used nuclear fuels started dissolving after 1,000 years.

• Journal of Information Processing Systems
• /
• v.17 no.2
• /
• pp.306-317
• /
• 2021

The unbalance between system ergodic sum rate and high fairness is one of the key issues affecting the performance of non-orthogonal multiple access (NOMA) system. To solve the problem, this paper proposes a power allocation algorithm to realize the ergodic sum rate maximization of NOMA system. The scheme is mainly achieved by the construction algorithm of fair model based on α fair utility function and the optimal solution algorithm based on the interior point method of penalty function. Aiming at the construction of fair model, the fair target is added to the traditional power allocation model to set the reasonable target function. Simultaneously, the problem of ergodic sum rate and fairness in power allocation is weighed by adjusting the value of α. Aiming at the optimal solution algorithm, the interior point method of penalty function is used to transform the fair objective function with unequal constraints into the unconstrained problem in the feasible domain. Then the optimal solution of the original constrained optimization problem is gradually approximated within the feasible domain. The simulation results show that, compared with NOMA and time division multiple address (TDMA) schemes, the proposed method has larger ergodic sum rate and lower Fairness Index (FI) values.

• International journal of advanced smart convergence
• /
• v.10 no.3
• /
• pp.41-50
• /
• 2021

The purpose of this study is to analyze various energy platforms using data in the US and to suggest directions and implications. Some of the leading energy platforms are selected and analyzed based on the opening platform model. We focus on the case analysis of the US utility companies. In case of the horizontal open platform, Green Button sponsor's 'Connect My Data (CMD)' driven by the government invites the utility companies to jointly develop the sponsor's data solution. In case of the vertical open platform, the certification program 'Share My Data (SMD)' allows backward compatibility, because the technical improvement is minimal. The utility companies benchmark Amazon's three-sided market mediation and prefer platform and category exclusivity. For the former, they have data analytics companies like Enervee, Opower and for the latter, they have electronics manufactures and energy service providers (ESPs) like Distributed Energy Resources (DERs). Based on this US case study, we suggest the energy platforms to open their platform for renewable energy supply, energy conservation, high-efficiency products, and residential DER dissemination. To successfully implement the government's energy transition policy, the US platforms should be benchmarked as a business model. Especially, it is needed for them to coordinate a platform ecosystem. To ensure trust in the products and services offered on the marketplace platform, platform's certification program is helpful.