• Journal of the Korea Society of Computer and Information
• /
• v.18 no.11
• /
• pp.39-49
• /
• 2013

In this paper, security mechanism of internal network(CAN) of vehicle is a very incomplete state and the possibility of external threats as a way to build a test environment that you can easily buy from the market by the vehicle's ECU(Electric Control Unit) to verify and obtain a CAN message. Then, by applying it to ECU of the real car to try to attack is proposed. A recent study, Anyone can see plain-text status of the CAN message in the vehicle. so that in order to verify the information is vulnerable to attack from outside, analyze the data in a vehicle has had a successful attack, but attack to reverse engineering in the stationary state and buying a car should attempt has disadvantages that spatial, financial, and time costs occurs. Found through the car's ECU CAN message is applied to a real car for Potential threats outside of the car to perform an experiment to verify and equipped with a wireless network environment, the experimental results, proposed method through in the car to make sure the attack is possible. As a result, reduce the costs incurred in previous studies and in the information absence state of the car, potential of vehicle's ECU attack looks.

• Clean Technology
• /
• v.27 no.4
• /
• pp.277-290
• /
• 2021

A supercapacitor, also called an ultracapacitor or an electrochemical capacitor, stores electrochemical energy by the adsorption/desorption of electrolytic ions or a fast and reversible redox reaction at the electrode surface, which is distinct from the chemical reaction of a battery. A supercapacitor features high specific power, high capacitance, almost infinite cyclability (~ 100,000 cycle), short charging time, good stability, low maintenance cost, and fast frequency response. Supercapacitors have been used in electronic devices to meet the requirements of rapid charging/discharging, such as for memory back-up, and uninterruptible power supply (UPS). Also, their use is being extended to transportation and large industry applications that require high power/energy density, such as for electric vehicles and power quality systems of smart grids. In power generation using intermittent power sources such as solar and wind, a supercapacitor is configured in the energy storage system together with a battery to compensate for the relatively slow charging/discharging time of the battery, to contribute to extending the lifecycle of the battery, and to improve the system power quality. This article provides a concise overview of the principles, mechanisms, and classification of energy storage of supercapacitors in accordance with the electrode materials. Also, it provides a review of the status of recent research and patent, product, and market trends in supercapacitor technology. There are many challenges to be solved to meet industrial demands such as for high voltage module technologies, high efficiency charging, safety, performance improvement, and competitive prices.

• 한국노년학
• /
• v.38 no.4
• /
• pp.963-979
• /
• 2018

The purpose of this study was to identify frailty profiles based on physical, psychological, and social domains of functioning and to examine the associated factors showing the differences among frailty profiles. Respondents were 70 years and older(n=403) and latent class analysis was applied to determine the optimal subgroups based on Tilberg Frailty Indicators which comprised of three domains(the physical, psychological, and social domain). Also, we performed multinominal logistic regression analysis to find out factors making differences among frailty profiles. Latent class analysis(LCA) identified three distinct types: multi-frail type(27.0%), psychologically frail type(26.8%), inadequate support type(46.2%). All three types had common difficulties in dealing with daily life problems and did not receive enough help with theses difficulties. Based on the results of the LCA three-class models, people in multi-frail type accumulated problems in physical and psychological domains and had partially social domain. On the other hands, psychologically frail type showed a relatively high anxiety disorder and depression. Lastly, people in inadequate support type reported the lack of helps, but they were relatively healthy. Comparing these groups with inadequate support type, people with multi-frail had lower educational level, poor nutritional management status and were less likely to participate in labor market. People in psychologically frail type were more likely to be male, to live in big cities rather than middle and small cities, and less likely to smoke. Based on these results, our results showed the multifaceted concept of frailty among Korean elderly people and we suggested several implications for preventing frail process.

• Korean Journal of Labor Studies
• /
• v.24 no.2
• /
• pp.181-214
• /
• 2018

This study uses the youth panel survey (YP2007 2th ~ 9th) data of the Korea Employment Information Service to examine the phenomenon of subjective mismatch arising from the youth labor market and analyzed the determinants and wage effects of subjective mismatch. Overall, the analysis showed that the over-education and over-technology of both educational background and technical skill level in the Miss Match significantly decreased, while the lack of education and technology increased rather gradually. Next, the analysis of the determinants of downward employment(Excess of education and technology) showed that males were less likely to be downwardly employed(Excess of education and technology) than females, and in the status of workers, the probability of downward employment of regular and non-wage workers was lower than that of temporary/daily workers. Finally, as a result of estimating the wage effect of the mismatch based on the pooled OLS model and the Panel Fixed Effect model, the mismatch which has the greatest effect on the wage was found to be excessive education, and it has been estimated that youth employees who are over-educated have an average 6.7% lower wages than those who are not. After controlling for the unobserved individual characteristics, they were found to receive a lower wage of 3.2%, and it is estimated that 2.9% for the technical excess mismatch and 2.3% for the major mismatch receive lower wages than the reference group.

• The Journal of the Korea Contents Association
• /
• v.19 no.8
• /
• pp.473-482
• /
• 2019

People's leisure activities have increased due to changes in perception of social life. Camping cars are becoming popular due to the development of camping culture and traveling. However, there are not many users compared to the population of the camper due to the difficulty of economy and usability. Making it not easy to purchase or rent a camping car. Therefore, this study researches on camping service by combining shared services. It is aimed to provide a user centered camping shared service considering usage and economic efficiency. This study analyzed the concept, characteristics and current status of shared service and camping car with reference to domestic, overseas literature and internet data to provide basic data of camping car using shared service. In addition, through case study of shared vehicles, it is possible to grasp the current market. Integrate P2P, B2C, renting company and individuals to derive the design of A2P (All to People)service which connects and shares all. The user can have its own space available at the desired place and time. This study is a camping or unique mobile space service design that can be easily experienced in everyday life. It will reduce the strain of maintaining expenses and also process of pick up, return is freely making user-centered service design. This service design will lead to a diverse range of leisure activities and contribute to the upsweep of the camper industry.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.13 no.4
• /
• pp.2060-2077
• /
• 2019

Recently, mobile healthcare services have attracted significant attention because of the emerging development and supply of diverse wearable devices. Smartwatches and health bands are the most common type of mobile-based wearable devices and their market size is increasing considerably. However, simple value comparisons based on accumulated data have revealed certain problems, such as the standardized nature of health management and the lack of personalized health management service models. The convergence of information technology (IT) and biotechnology (BT) has shifted the medical paradigm from continuous health management and disease prevention to the development of a system that can be used to provide ground-based medical services regardless of the user's location. Moreover, the IT-BT convergence has necessitated the development of lifestyle improvement models and services that utilize big data analysis and machine learning to provide mobile healthcare-based personal health management and disease prevention information. Users' health data, which are specific as they change over time, are collected by different means according to the users' lifestyle and surrounding circumstances. In this paper, we propose a prediction model of user physical activity that uses data characteristics-based long short-term memory (DC-LSTM) recurrent neural networks (RNNs). To provide personalized services, the characteristics and surrounding circumstances of data collectable from mobile host devices were considered in the selection of variables for the model. The data characteristics considered were ease of collection, which represents whether or not variables are collectable, and frequency of occurrence, which represents whether or not changes made to input values constitute significant variables in terms of activity. The variables selected for providing personalized services were activity, weather, temperature, mean daily temperature, humidity, UV, fine dust, asthma and lung disease probability index, skin disease probability index, cadence, travel distance, mean heart rate, and sleep hours. The selected variables were classified according to the data characteristics. To predict activity, an LSTM RNN was built that uses the classified variables as input data and learns the dynamic characteristics of time series data. LSTM RNNs resolve the vanishing gradient problem that occurs in existing RNNs. They are classified into three different types according to data characteristics and constructed through connections among the LSTMs. The constructed neural network learns training data and predicts user activity. To evaluate the proposed model, the root mean square error (RMSE) was used in the performance evaluation of the user physical activity prediction method for which an autoregressive integrated moving average (ARIMA) model, a convolutional neural network (CNN), and an RNN were used. The results show that the proposed DC-LSTM RNN method yields an excellent mean RMSE value of 0.616. The proposed method is used for predicting significant activity considering the surrounding circumstances and user status utilizing the existing standardized activity prediction services. It can also be used to predict user physical activity and provide personalized healthcare based on the data collectable from mobile host devices.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.25 no.1
• /
• pp.11-16
• /
• 2019

This study analyzed various packaging materials and types for frozen foods and the effects of packaging materials on temperature changes during frozen process. Pouches with different film thickness were prepared and placed in an IQF freezer, then the temperature inside pouches measured using a deep thermometer. The most common types of primary packaging for frozen foods in the market was plastic pouches with polyethylene or polyamide/polyethylene multilayer materials. The temperature change inside of packaging was delayed with film thickness increased. As the size of packaged food increased, the temperature change inside the food was slowed down. In addition, the pouches with air inside took more time to reach $-30^{\circ}C$ compared to pouches with less air during frozen process. This study provides information on packaging materials and types for frozen foods and preliminary data of temperature change by different types of packaging.

• Journal of the Economic Geographical Society of Korea
• /
• v.22 no.2
• /
• pp.160-177
• /
• 2019

In this study, we examined the distribution of dealers and the repair parts management system of a Japanese car manufacturer in the Chinese market in looking at the case of Toyota. We conducted our research by obtaining information from a GAC Toyota dealer about the current distribution of dealers and locations of warehouses throughout China, as well as the status of stocks and the distribution system for repair and maintenance parts. The results of our investigation showed that although GAC Toyota has 437 dealers throughout the country, there is an imbalance in distribution towards the coastal areas, after the population ratios and other measurements are factored in. Therefore, it can be said expansion towards the inland regions, where demand for automobiles has increased in recent years, has been stunted. On the other hand, there is a high correlation between gross GDP by region and the number of stores, and it can be pointed out that the company prioritizes the sale of high-priced vehicles in major coastal areas where the economy is large, rather than selling low-priced vehicles for inland consumers with a relatively small economic scale. The company also has difficulty in securing dealers that can provide sufficient after-sales service. According to the regulations of GAC Toyota, the company require dealers to have at least 1,500 repair and maintenance parts in stock. Also, when exchanging maintenance parts, GAC Toyota's emphasis is on increasing customer satisfaction by giving sufficient explanations for customers and obtaining consent from them. As a result, the company's dealers need financial resources to continue their business from a long-term perspective. However, it can be pointed out that such dealers are limited, and it is difficult to distribute profits among manufacturers and dealers.

• Journal of Digital Convergence
• /
• v.17 no.9
• /
• pp.97-104
• /
• 2019

With the development and spread of smart devices, the proportion of mobile shopping is gradually increasing, and the market for mobile gift certificates is also increasing. This study examines the usage status and acceptance attitude of mobile gift certificates for university students who are major customers of mobile gift certificates. Also, based on the extended integrated technology acceptance model (UTAUT2), the results of the analysis of the mediating effect of the intention of the user on the relationship between acceptance of mobile vouchers and recommendation intention were presented. As a result of the analysis, it was shown that the effort expectation, hedonic motivation, price utility, and habit had significant influence on the intention to use the mobile gift certificates. Also, the intention to use mobile gift certificates has mediating effects between effort expectation, hedonic motivation, price utility and recommendation intention. The results of this study can be applied to strategic marketing such as recruitment of new customers through mobile gift certificates while explaining customers' acceptance of technology to mobile gift vouchers or future prospective customers.

• Journal of the Korean Applied Science and Technology
• /
• v.36 no.1
• /
• pp.90-101
• /
• 2019

The study wanted to compare the use status of general beauty salons and men's hair salons for male customers managed by male practitioners and to check the impact of service quality awareness on satisfaction and loyalty. A total of 405 people were used as analysis materials. Principle Component Analysis was used to verify the reliability and validity of the measurement tool. Sub-factors of service quality recognition have derived expertise, affinity, reliability and persistence. The validity and reliability of satisfaction and loyalty were verified. Based on the results of this study, the differences in hair involvement in general beauty salons and men's specialty salons, service quality awareness, satisfaction and loyalty were identified. The relationship between professionalism, affinity, reliability, persistence by sub-factor of service quality awareness has been identified with satisfaction, loyalty and statistically significant positive (+). In addition, male professional beauty salons had positive effects on service quality awareness of satisfaction and loyalty. Service quality satisfaction has been confirmed to have a positive impact on loyalty. In this study, the beauty of the men through the significant marketing potential use as basic data on the market feed that the portraits.