• Journal of Korean Society of Transportation
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• v.25 no.5
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• pp.183-193
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• 2007

Traditionally, a congestion charge based on first-best congestion pricing theory, namely, the theory of marginal cost pricing theory, is equal to the difference between marginal social cost and marginal private cost. It is charged on each link so as to derive a user equilibrium flow pattern to a system optimal one. Based on this theory this paper investigates on the characteristics of first-best congestion pricing of multiple user class on road with variable demand, and presents two methods for analysis of social and spatial equity. For these purposes, we study on the characteristics of first-best congestion pricing derived from system optimal in time and in monetary unit, and analyze equity from this congestion pricing with an example network.

• Journal of Convergence for Information Technology
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• v.10 no.7
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• pp.7-13
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• 2020

IoT which is the core IT of the 4^th industrial revolution, is providing various services from users in the conversion with other industries. The IoT convergence technology is leading the communication paradigm of communication environment in accordance with the increase of convenience for users. However, it is urgently needed to establish the security measures for the rapidly-developing IoT convergence technology. As IoT is closely related to digital ethics and personal information protection, other industries should establish the measures for coping with threatening elements in accordance with the introduction of IoT. In case when security incidents occur, there could be diverse problems such as information leakage, damage to image, monetary loss, and casualty. Thus, this paper suggests a certificate management technique for safe control over access in IoT-based Cloud convergence environment. This thesis designed the device/user registration, message communication protocol, and device renewal/management technique. On top of performing the analysis on safety in accordance with attack technique and vulnerability, in the results of conducting the evaluation of efficiency compared to the existing PKI-based certificate management technique, it showed about 32% decreased value.

• Korea Journal of Hospital Management
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• v.25 no.4
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• pp.60-75
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• 2020

Purpose: This study aims to develop a cost model for NRP (Nursing Residency Program) operation and ultimately provide evidence for financial factors for NRP operation in the future by simulating a cost model. Methodology: This study developed a model for the NRP education cost calculation model based on the review of Hansen's model, which has systematically reported on the development and operation of NRP, and discussions with nursing education experts at a university-affiliated hospital. With the simulation, it was intended to predict nurses' supply and demand in the long term and to calculate changes in long-term education costs. Findings: Firstly, turnover model, term model, cost model necessary for calculating a model for the NRP education cost calculation model was set up. Secondly, the simulation showed the following results; 1) the proportion of newly graduated nurses less than 5 years of working decreases gradually over time, which will make the composition of nurses more balanced. 2) In the first year of the partial introduction of NRP, the cost of training new nurses was about 2.1 times higher than before. After the introduction, the training cost in the 13th year began to be lesser than before the introduction, and in the 25th year, it decreased by 28.1% compared to before the introduction. Practical Implications: Firstly, NRP would be an effective way to solve the higher turnover and frequent departure of new nurses and the imbalance of nurses' composition. Secondly, although the costs of NRP are incurred in the early stages, in the end, NRP training costs are reduced compared to before the introduction of NRP. It is necessary to systematically understand the contribution effect of NRP by analyzing the economic value of NRP considering financial and non-monetary returns in the future and providing a basis for decision-making related to NRP implementation.

• Sleep Medicine and Psychophysiology
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• v.28 no.1
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• pp.34-42
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• 2021

Objectives: This study investigated sleep quality in female full-time homemakers and evaluated the relationship of sleep disturbance with psychological and socio-environmental factors. Methods: This cross-sectional study adopted a structured survey and sequential recruitment method for randomized participation of community-dwelling full-time female homemakers. Sleep quality and mental health were measured using the Korean version of the Pittsburgh Sleep Quality Index (K-PSQI), Korean version of the Beck Depression Inventory-II (K-BDI-II), Korean version of the Beck Anxiety Inventory (K-BAI), and Korean version of the Beck Hopelessness Scale (K-BHS). The willingness-to-pay (WTP) method was selected to measure the self-evaluated monetary value of household service work. The relationship among the main relevant factors was statistically analyzed through a mediation model. Results: A total of 166 participants were analyzed and classified having poor versus good sleep quality (poor : 24.1%, n = 40 ; good : 75.9%, n = 126 ; cut-off point = 9 on the K-PSQI). Significant between-group differences were observed in mental health status (K-BDI-II, p < 0.001 ; K-BAI, p < 0.001 ; K-BHS, p = 0.003). The moderated mediation model was verified, indicating that depression may mediate the association between nurturing burden and sleep disturbance. The path from nurturing burden to depression may be moderated by average monthly household income. Conclusion: A relatively high portion of full-time female homemakers may suffer from sleep disturbance and interactions between psychological and socio-environmental factors might determine sleep quality, suggesting the need for public health policies targeting improvement of sleep quality and mental health among full-time homemakers.

• KIPS Transactions on Software and Data Engineering
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• v.11 no.7
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• pp.283-290
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• 2022

Blockchain is a technology that secures integrity and transparency by distributing and storing transaction details within multiple node networks. Recently, research is being conducted to secure integrity by applying blockchain to Bill of Lading (B/L documents) of monetary value. In this paper, we study a blockchain-based bill of lading system to improve usability. The shippers register the issued bill of lading on the blockchain, and banks in each country read it to conduct L/C transactions. The consignees receive the goods after completing certification with a quick response code (QR) containing the bill of lading information. Through this, shippers enjoy merits in that they can shorten the time and cost of sending shipping documents by mail and prove the integrity of the documents. The consignees have the advantage of being able to check the documents at the same time as they are registered and trust the transaction. Finally, on the bank side, the security of shipping documents is ensured and verification can be done quickly.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.2
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• pp.207-211
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• 1981

The effect of plant populations - 16,667, 14,285, 12,499 or 10,7l4/10a on the agronomic characteristics of an aromatic tobacco, Sohyang was investigated for two years. The growth and number of suckers produced decreased as the population increased. The leaf area index (L.A.I) was higher in thinner planting, but there was no significant difference in weight per unit leaf area between treatments. Yield was highest, 1 24 kg/ l0a, in 16,667 plantings per l0a, but quality was not different among densitites tested. Similar trends were observed in monetary value per l0a. Concentrations of total alkaloids and nitrogen were low in denser planting, but no significant difference was observed in total sugar. The results suggest that about 16,000/10a more would be optimum number of plants for Sohyang.

• Fashion & Textile Research Journal
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• v.25 no.4
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• pp.449-459
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• 2023

This study focuses on online communities and the ritual conversations of users when participating in sharing activities. The study aims to understand the social and psychological phenomena that occur between users within the context of Erving Goffman's impression management theory. Case studies and a content analysis were conducted by collecting posts and comments related to fashion products in the sharing activities category on Naver Cafe "Family Sale." On the one hand, the study identified various disposition motives among givers, including a desire for recognition, self-expression, activation of the community, emotional sympathy, goodwill, play, and simple disposition. On the other hand, receivers' purchase motives included the need for a product, reciprocation based on a sense of belonging, play, gift-giving, and simple response. Analyzing the posts of givers and the comments of receivers of fashion products using impression management strategies and dramaturgical analysis, the study interpreted users' impression management and revealed propensities in fashion consumption: fashionability, conspicuousness, value orientation, and economic feasibility. Through ritual conversations, users managed to attain emotional stability on an individual level, while they reinforced collective bonds on a social level. They fulfilled their roles with their own narratives to achieve personal and collective goals in a non-face-to-face situations and non-monetary transactions. This study is significant in that it examines normative communication in an online community and user relationships to understand a recent phenomenon in the fashion industry.

• Journal of The Geomorphological Association of Korea
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• v.27 no.3
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• pp.87-103
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• 2020

The purpose of this study is to evaluate the risk of cropland and man-made infrastructures in a landslide-prone area using a GIS-based method. To achieve this goal, a landslide inventory map was prepared based on aerial photograph analysis as well as field observations. A total of 550 landslides have been counted in the entire study area. For model analysis and validation, extracted landslides were randomly selected and divided into two groups. The landslide causative factors such as slope, aspect, curvature, topographic wetness index, elevation, forest type, forest crown density, geology, land-use, soil drainage, and soil texture were used in the analysis. Moreover, to identify the correlation between landslides and causative factors, pixels were divided into several classes and frequency ratio was also extracted. A landslide susceptibility map was constructed using a bayesian predictive model (BPM) based on the entire events. In the cross validation process, the landslide susceptibility map as well as observation data were plotted with a receiver operating characteristic (ROC) curve then the area under the curve (AUC) was calculated and tried to extract a success rate curve. The results showed that, the BPM produced 85.8% accuracy. We believed that the model was acceptable for the landslide susceptibility analysis of the study area. In addition, for risk assessment, monetary value (local) and vulnerability scale were added for each social thematic data layers, which were then converted into US dollar considering landslide occurrence time. Moreover, the total number of the study area pixels and predictive landslide affected pixels were considered for making a probability table. Matching with the affected number, 5,000 landslide pixels were assumed to run for final calculation. Based on the result, cropland showed the estimated total risk as US $ 35.4 million and man-made infrastructure risk amounted to US $ 39.3 million.

• Korean Journal of Environment and Ecology
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• v.26 no.2
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• pp.273-282
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• 2012

This study has estimated Gyeongju National Park's natural environment and cultural relic value in the same way and then been performed to compare the size of the value. Representative method to measure environmental property is contingent valuation methods, CVM. The variables and estimated models adopted for the calculation were same and the respondents were asked by distinguishing between the amount which they would pay to preserve the natural environment and that which they were willing to pay to preserve the cultural relics. As the result, WTP(Willing to pay), the amount that they were willing to pay to preserve the natural environment of Gyeongju National Park was 17,838 won per person and that to preserve the cultural relics appeared to be 316,248 won per person. Based on this, it was estimated that the value of the natural environment with which Gyeongju National Park provided annual visitors was 47 billion won and that the annual value of the cultural relics was 845.7 billion. If the natural environment and the cultural relics value elements are united, it can be estimated that the natural environment and cultural relic value got at the time of people's first visit to Gyeongju National Park is 334,086 won and that the annual value is 893.4 billion won. In this study, the value of the cultural relics has been estimated 18 times higher than that of the natural environment. This reason was that visitors judged that a total of 66 cultural properties including 11 national treasures, 23 treasures, 13 historic places, one historic sites and scenic spot and 18 local cultural properties, etc. which were distributed in Gyeongju National Park were worth far more than the natural environment. Based on the result of this study, the operating management plan of Gyeongju National Park should include a differentiated operation strategy through consultation with relevant experts by taking into account characteristics of the physical components.

• Journal of Communication Design
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• v.68
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• pp.278-288
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• 2019

The purpose of this study is to analyze the effects of risk and convenience on purchase intention in the IOT market, and I want to analyze the moderating effect of emotional consumption value. In this study, two products were selected from three product groups. There are three major methods of research. First, theoretical considerations. Second, survey analysis. Reliability analysis and factor analysis were performed using descriptive statistics using SPSS. Third, we measured changes of EEG according to in - depth interview and indirect experience. As a result of the hypothesis of this study, it was confirmed that convenience of use of IoT product influences purchase intention. Risk was predicted to have a negative effect on purchase intentions, but not significant in this study. This implies that IoT products tend to be neglected in terms of monetary loss such as cost of purchase, cost of use, and disposal cost when purchasing. In-depth interviews and EEG analysis revealed that there is a desire to purchase and try out the IoT product due to the nature of the product, the novelty of new technology, and the vague idea that it will benefit my life. The aesthetic, symbolic, and pleasure factors, which are sub - elements of emotional consumption value, were found to have a great influence. This is consistent with previous research showing that emotional consumption value has a positive effect on purchase intention. In-depth interviews and EEG analyzes also yielded the same results. This study has revealed that emotional consumption value affects the intention to purchase IoT products. It seems that companies producing IoT products need to concentrate on marketing with more emotional consumption value.