• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.783-798
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• 2004

An e-business client application in ubiquitous mobile computing environment may become disconnected from the enterprise server due to broken communication connections caused by the limitation of mobile computing environments(limited battery life of the mobile device, low bandwidth communication, incomplete wireless communication infrastructure, etc). It Is even Possible that mobile client application Intentionally operates in disconnected mode to reduce communication cost and the power consumption of the mobile device. We use “data hoarding” as a means of providing local autonomy to allow transactions to be processed and committed on the mobile host despite of disconnection. The key problem to this approach is the synchronization problem that serialize potentially conflicting updates from disconnected clients on master objects of the server database. In this paper, we present a new transaction synchronizing method that splits a transaction into a set of independent component transactions and give the synchronization priority on each component taking the possibility of use and conflicts in the server into consideration. Synchronization is performed component by component based un synchronization priority. After the Preferred component of a no bile transaction succeeds in synchronization with the server, the mobile transaction can pre-commit at server. A pre-committed transaction's updated value is made visible at server before the final commit of the transaction. The synchronization of the component with low synchronization priority can be delayed in adaption to wireless bandwidth and computing resources. As a result, the availability of important data updated by mobile client is increased and it can maximize the utilization of the limited wireless bandwidth and computing resources.

• Nuclear Engineering and Technology
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• v.53 no.8
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• pp.2534-2546
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• 2021

Nuclear emergency preparedness and response is an essential part to ensure the safety of nuclear power plant (NPP). Key support technologies of nuclear emergency decision-making usually consist of accident diagnosis, source term estimation, accident consequence assessment, and protective action recommendation. Source term estimation is almost the most difficult part among them. For example, bad communication, incomplete information, as well as complicated accident scenario make it hard to determine the reactor status and estimate the source term timely in the Fukushima accident. Subsequently, it leads to the hard decision on how to take appropriate emergency response actions. Hence, this paper aims to develop a method for rapid source term estimation to support nuclear emergency decision making in pressurized water reactor NPP. The method aims to make our knowledge on NPP provide better support nuclear emergency. Firstly, this paper studies how to build a Bayesian network model for the NPP based on professional knowledge and engineering knowledge. This paper presents a method transforming the PRA model (event trees and fault trees) into a corresponding Bayesian network model. To solve the problem that some physical phenomena which are modeled as pivotal events in level 2 PRA, cannot find sensors associated directly with their occurrence, a weighted assignment approach based on expert assessment is proposed in this paper. Secondly, the monitoring data of NPP are provided to the Bayesian network model, the real-time status of pivotal events and initiating events can be determined based on the junction tree algorithm. Thirdly, since PRA knowledge can link the accident sequences to the possible release categories, the proposed method is capable to find the most likely release category for the candidate accidents scenarios, namely the source term. The probabilities of possible accident sequences and the source term are calculated. Finally, the prototype software is checked against several sets of accident scenario data which are generated by the simulator of AP1000-NPP, including large loss of coolant accident, loss of main feedwater, main steam line break, and steam generator tube rupture. The results show that the proposed method for rapid source term estimation under nuclear emergency decision making is promising.

• 한국사회정책
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• v.25 no.3
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• pp.279-303
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• 2018

Since the introduction of the Riester Pension Scheme, the controversy has continued in the policy studies and the political debates. This study evaluates the achievements and limitations of the German Riester pension scheme and tries to derive policy implications for South Korea. As a result of the analysis, the most worthwhile achievement of the Riester Pension is to strengthen the role of the private pension schemes. Unlike other private pension schemes, it included a large part of lower income households. It also opened a new perspective of utilizing private pension schemes to accomplish the goals of the family policy. Despite these attainments, it does not reach the promised coverage rate. It also was revealed that the higher income households have concluded more Riester Pension Contracts than the targeted lower-income households. Due to high administration fee and incomplete information problems, benefit levels are supposed to be much lower than expected. It concludes, above all, despite some achievements, the Riester Pension Scheme will not fill completely the gap of old age income security caused by the reduction of the public pension system. The German case provides fruitful lessons for Korea. The introduction of a subsidized personal pension scheme in South Korea can be realized only when some prerequisites would be satisfied such as the consolidation and maturing of public pension schemes and the strengthening of the transparency in the private pension market.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.653-659
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• 2018

The accurate prediction of construction cost is a key factor in a project's success. However, it is hard to predict the construction costs in the planning stages rapidly and precisely when drawings, specifications, construction cost calculation statements are incomplete, among other factors. Accurate construction-cost prediction in the planning stage of a project is also important for project feasibility studies and successful completion. Therefore, various techniques have been applied to accurately predict construction costs at an early stage when project information is limited. There are many factors that affect the construction cost prediction. This paper presents a construction-cost prediction method as multiple regression model with seven construction factors as independent variables. The method was used to predict the construction cost of a local housing union project, and the error rate was 4.87%. It is not possible to compare the cost of the project at the planning stage of the local housing union project, but it has high prediction accuracy compared to the unit price of an existing unit area. It is likely to be applied in construction-cost calculation work and to contribute to the establishment of the budget for the local housing union project.

• The Journal of the Korea Contents Association
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• v.20 no.12
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• pp.492-497
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• 2020

Today, banks around the world are making great efforts to adapt to the rapidly changing internal and external environment changes caused by the development of IT technology and to gain a competitive advantage in the market. In particular, in line with the rapid growth of smartphone usage, financial services are also provided in a variety of ways using Fintech, and one of the fastest growing areas is mobile simple payment. Mobile payment service is a financial service that pays the purchase price using a portable mobile device. As fintech, a convergence of financial services and information technology, it is recently used not only in financial services, but also in various industries. It is used in all fields where payment functions such as distribution are available. In the case of mobile cards, it shows that the usage rate of people in their 20s and 30s is increasing very much, so it can be said that the use of mobile payment services will continue to increase in the coming future. We know that simple payments are being used. However, it can be said that the research on the use of mobile payment services by these teenagers is somewhat incomplete. Therefore, this study investigated what factors are important for Korean teenagers to use mobile payment services. As a result, among the five hypotheses presented in this study, all hypotheses were adopted except for , which states that cash usage habits have no effect on innovation.

• Journal of Music and Human Behavior
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• v.18 no.1
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• pp.1-27
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• 2021

The purpose of this study was to investigate how primary caregivers of children with developmental disabilities aged 6 to 18 years perceived on tele-music programs in which their children participated during COVID-19. A total of 83 caregivers who voluntarily agreed to participate in this study responded to a survey either on-line or in person and 67 questionnaires were included in the final analysis after deleting 16 incomplete responses. The results showed that tele-music programs were rated somewhat suitable for distance learning but that there was still a need for adult assistance to help children with developmental disabilities participate in the program. When comparing the perceptions of caregivers who participated in remote general education versus who participated in tele-music program, significantly higher level of program engagement and positive responses from a child were perceived with tele-music program. The caregivers who participated in tele-music program showed significantly greater willingness to participate in tele-music therapy in the future than those who did not. The findings of this study presents information on how tele-music therapy has been implemented to children with disabilities and what can be considered for the the development of a tele-music therapy program.

• Journal of the Korean Geotechnical Society
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• v.23 no.11
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• pp.109-117
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• 2007

Uncertainty is pervasive in rock slope stability analysis due to various reasons and subsequently it may cause serious rock slope failures. Therefore, the importance of uncertainty has been recognized and subsequently the probability theory has been used to quantify the uncertainty since 1980's. However, some uncertainties, due to incomplete information, cannot be handled satisfactorily in the probability theory and the fuzzy set theory is more appropriate for those uncertainties. In this study the random variable is considered as fuzzy number and the fuzzy set theory is employed in rock slope stability analysis. However, the previous fuzzy analysis employed the approximate method, which is first order second moment method and point estimate method. Since previous studies used only the representative values from membership function to evaluate the stability of rock slope, the approximated analysis results have been obtained in previous studies. Therefore, the Monte Carlo simulation technique is utilized to evaluate the probability of failure for rock slope in the current study. This overcomes the shortcomings of previous studies, which are employed vertex method. With Monte Carlo simulation technique, more complete analysis results can be secured in the proposed method. The proposed method has been applied to the practical example. According to the analysis results, the probabilities of failure obtained from the fuzzy Monte Carlo simulation coincide with the probabilities of failure from the probabilistic analysis.

• Korea Science and Art Forum
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• v.24
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• pp.277-287
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• 2016

This study purpose is comparative analysis of environmental design checklist based on physical characteristics of the elders between Korea and Japan exhibition facilities. We were selected to represent the exhibition facilities in Korea and Japan and conducted field survey and understand the application status. The scope of the exhibition facilities space is entry, exhibition, public-service, educational activity and movement. And the elders physical characteristics are divided into 'sense(eye-sight, hearing, and feeling by touch)' / 'exercise (skeleton, movement, physical strength and muscular strength)'. Based on the checklist, we gave the score depending installation, part installation and uninstallation and then analyzed the average. The Results were as follows. First, Korea and Japan exhibition facilities are appear to similar and both above the average level. It is show that environment design reflects the physical characteristics of the elders. Second, exhibition space and educational activity space has lower score than other space, indicated most items are consist of the recommended. Most items appears as part of the preparation for this installed or uninstalled. Third, It showed that the installation is incomplete entries corresponding to the physical characteristics of the sensory area of the elderly (hearing). Therefore, there need to install additional information facilities such as voice, emergency call bell. Forth, the exhibition facilities appears differently depending on time of erecting and remodeling.

• Journal of Preventive Medicine and Public Health
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• v.56 no.5
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• pp.467-474
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• 2023

Objectives: Diabetes mellitus (DM) is a serious public health issue that places a heavy financial, social, and health-related burden on individuals, families, and healthcare systems. Self-reported health-related quality of life (HRQoL) is extensively used for monitoring the general population's health conditions and measuring the effectiveness of interventions. Therefore, this study investigated HRQoL and associated factors among patients with type 2 DM at a primary healthcare center in Indonesia. Methods: A cross-sectional study was conducted in Klaten District, Central Java, Indonesia, from May 2019 to July 2019. In total, 260 patients with DM registered with National Health Insurance were interviewed. HRQoL was measured with the EuroQol Group's validated Bahasa Indonesia version of the EuroQoL 5-Dimension 5-Level (EQ-5D-5L) with the Indonesian value set. Multivariate regression models were used to identify factors influencing HRQoL. Results: Data from 24 patients were excluded due to incomplete information. Most participants were men (60.6%), were aged above 50 years (91.5%), had less than a senior high school education (75.0%), and were unemployed (85.6%). The most frequent health problems were reported for the pain/discomfort dimension (64.0%) followed by anxiety (28.4%), mobility (17.8%), usual activities (10.6%), and self-care (6.8%). The average EuroQoL 5-Dimension (EQ-5D) index score was 0.86 (95% confidence interval [CI], 0.83 to 0.88). In the multivariate ordinal regression model, a higher education level (coefficient, 0.08; 95% CI, 0.02 to 0.14) was a significant predictor of the EQ-5D-5L utility score. Conclusions: Patients with diabetes had poorer EQ-5D-5L utility values than the general population. DM patients experienced pain/discomfort and anxiety. There was a substantial positive relationship between education level and HRQoL.

• Asia pacific journal of information systems
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• v.20 no.1
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• pp.127-140
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• 2010

The benefit that a consumer derives from the use of a good often depends on the number of other consumers purchasing the same goods or other compatible items. This property, which is known as network externality, is significant in many IT related industries. Over the past few decades, network externalities have been recognized in the context of physical networks such as the telephone and railroad industries. Today, as many products are provided as a form of system that consists of compatible components, the appreciation of network externality is becoming increasingly important. Network externalities have been extensively studied among economists who have been seeking to explain new phenomena resulting from rapid advancements in ICT (Information and Communication Technology). As a result of these efforts, a new body of theories for 'New Economy' has been proposed. The theoretical bottom-line argument of such theories is that technologies subject to network effects exhibit multiple equilibriums and will finally lock into a monopoly with one standard cornering the entire market. They emphasize that such "tippiness" is a typical characteristic in such networked markets, describing that multiple incompatible technologies rarely coexist and that the switch to a single, leading standard occurs suddenly. Moreover, it is argued that this standardization process is path dependent, and the ultimate outcome is unpredictable. With incomplete information about other actors' preferences, there can be excess inertia, as consumers only moderately favor the change, and hence are themselves insufficiently motivated to start the bandwagon rolling, but would get on it once it did start to roll. This startup problem can prevent the adoption of any standard at all, even if it is preferred by everyone. Conversely, excess momentum is another possible outcome, for example, if a sponsoring firm uses low prices during early periods of diffusion. The aim of this paper is to analyze the dynamics of the adoption process in markets exhibiting network effects by focusing on two factors; switching and agent heterogeneity. Switching is an important factor that should be considered in analyzing the adoption process. An agent's switching invokes switching by other adopters, which brings about a positive feedback process that can significantly complicate the adoption process. Agent heterogeneity also plays a important role in shaping the early development of the adoption process, which has a significant impact on the later development of the process. The effects of these two factors are analyzed by developing an agent-based simulation model. ABM is a computer-based simulation methodology that can offer many advantages over traditional analytical approaches. The model is designed such that agents have diverse preferences regarding technology and are allowed to switch their previous choice. The simulation results showed that the adoption processes in a market exhibiting networks effects are significantly affected by the distribution of agents and the occurrence of switching. In particular, it is found that both weak heterogeneity and strong network effects cause agents to start to switch early and this plays a role of expediting the emergence of 'lock-in.' When network effects are strong, agents are easily affected by changes in early market shares. This causes agents to switch earlier and in turn speeds up the market's tipping. The same effect is found in the case of highly homogeneous agents. When agents are highly homogeneous, the market starts to tip toward one technology rapidly, and its choice is not always consistent with the populations' initial inclination. Increased volatility and faster lock-in increase the possibility that the market will reach an unexpected outcome. The primary contribution of this study is the elucidation of the role of parameters characterizing the market in the development of the lock-in process, and identification of conditions where such unexpected outcomes happen.