• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.469-478
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• 2019

Car-sharing services have been settled on as a new type of public transportation owing to their enhanced convenience, expanded awareness of practical consumption patterns, the inspiration for environmental conscientiousness, and the diffusion of smart phones following the economic crisis. With development of the market, many people have started using such services. However, security is still an issue. Damage is expected since IDs and passwords are required for log-in when renting and controlling the vehicles. The protocol suggested in this study uses bio-information, providing an optimized service, and convenient (but strong) authentication with various service-provider clouds registering car big data about users through brokers. If using the techniques suggested here, it is feasible to reduce the exposure of the bio-information, and to receive service from multiple service-provider clouds through one particular broker. In addition, the proposed protocol reduces public key operations and session key storage by 20% on mobile devices, compared to existing car-sharing platforms, and because it provides convenient, but strong, authentication (and therefore constitutes a secure channel), it is possible to proceed with secure communications. It is anticipated that the techniques suggested in this study will enhance secure communications and user convenience in the future car-sharing-service cloud environment.

• Journal of the Korea Computer Industry Society
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• v.5 no.1
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• pp.39-48
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• 2004

An IP address shortage problem is happening with a rapid propagation of the Internet and demands about a new IP address. Address translation technology as NAT is becoming use widely in order to solve these problems. NAT is an very useful If address translation technique that allows two connected networks to use different and incompatible IP address schemes. Rut it is difficult to use NAT particularly for applications that embeded IP addresses in data payloads or encrypted IP packet to guarantee End-to-End Security such as IPSec. In addition to rewiting the source/destination IP address in the packet, NAT must modify IP checksum every time, which could lead to considerablely performance decrease of the overall system in the process of address translation. RSIP is an alternative to solve these disadvantages and address shortage problems of NAT. Both NAT and RSIP divide networks into inside and outside addressing realms. NAT translates addresses between internal network and external network, but RSIP uses a borrowed external address for outside communications. RSIP server assigns a routable, public address to an RSIP client temporaily to communicate with public network outside the private network. In this paper, I will analyze NAT and RSIP gateway system, and then I will propose the Linux-based RSIP gateway for more efficient IP Address Translation in Intranet environments based on RSIP standard of IETF.

• Journal of Korean Public Health Nursing
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• v.12 no.2
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• pp.67-88
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• 1998

Present study was attempt to explore the relationship between perceived family support and depression and to emphasize the importance or needs of family support in psychological care especially among adolescents. Study subjects comprized of 308 high school students including vocational students in part, and data collection was done in the Kwangju City area in April. 1998. The Moos Family Environment Scale and the Zung's Self-Rating Depression Scale modified by investigators were used as measurement tools of 59 item questionnaire and in data analysis, statistical methods of T-test, ANOVA. and Pearson Correlation Coefficient were utilized. The study findings are as follows 1. The hypothesis of the study, 'the higher the degree of perceived family support among adolescents, the lower the level of depression', was supported (r=-0.4469, p<.001). 2. Some variables in demographic characteristics related to the degree of family support with statistical significance were school division of vacational vs non-vocational(t=-2.02, p<.05), age(f=5.47, p<.01), family monthly income (f=2.49, p<.05), mother's level of education (f=3.01. p<.05), residence at developmental stage (f=2.87, p<.05), personal problem of highest priority at present(f=7.73, p<.001), and family problem perceived by adolescents(f=7.38, p< .001). 3. Items In general characteristics related to the level of depression with statistical significance were sex(t=-2.91, p<.0l). mother's level of education(f=2.53. p<.05). residence at developmental stage (f=3.95. p<.0l). present personal problem of highest priority (f=3.68. p<.1l). and perceived in-family problem (f=4.58. p<.001). 4. The mean score of the degree of perceived family support was 61.26 $(SD=\pm14.45)$ in a range of 21.00 to 96.00 ; that of the level of depression. 43.74 $(SD=\pm8.04)$ in a range of 23.00 to 67.00. which demonstrated that the higher the degree of perceived family support, the lower the level of depression. In conclusion. it was found that the degree of family support perceived by adolescents is a variable affecting the level of depression. Based on the study outcome, further research suggestions can be made as such that repeated studies are needed in order to delineate the various factors affecting family support and depression, and a study involving family support implementation program is required as a nursing intervention for the development of emotional security among adolescents, perceived family support, depression, adolescence.

• Journal of Internet Computing and Services
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• v.16 no.1
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• pp.91-100
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• 2015

Recently many companies began to feel the pressures of cost savings due to the global recession, so they have been interested in the Cloud Computing. Cloud Computing is one of using method of IT resources through the network. Users can borrow softwares or hardwares instead of buying them. Many people expect remarkable growth in Cloud Computing industry because of it's effectiveness. But Cloud Computing industry is still at an early stage. Especially, people who in the public sector hesitate to adopt Cloud Computing Services due to security issues and their conservative views. Also, they just have limited understanding, so we need to investigate what they really know and understand. Researches about the Cloud Computing generally focus on technical issues, so we can hardly find researches reference for decision making in considering the services. The study aims to investigate diverse factors for agencies' adoption decisions, such as benefits, costs, and risk in developing the most ideal type of cloud computing service for them, and performs priority analyses by applying ANP (Analytic Network Process). The results identify that features pertaining to the risk properties were considered the most significant factors. According to this research, the usage of private cloud computing services may prove to be appropriate for public environment in Korea. The study will hopefully provide the guideline to many governmental agencies and service providers, and assist the related authorities with cloud computing policy in coming up with the relevant regulations.

• Journal of Korea Port Economic Association
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• v.39 no.2
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• pp.59-76
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• 2023

In this study, we tried to find out port safety from various perspectives through news data that can be easily accessed by the general public and domestic academic journal data that reflects the insights of port researchers. Non-negative Matrix Factorization(NMF) based topic modeling was conducted using Python to derive the main topics for each data, and then semantic analysis was conducted for each topic. The news data mainly derived natural and environmental factors among port safety risk factors, and the academic journal data derived security factors, mechanical factors, human factors, environmental factors, and natural factors. Through this, the need for strategies to strengthen the safety of domestic ports, such as strengthening the resilience of port safety, improve safety awareness to broaden the public's view of port safety, and conduct research to develop the port industry environment into a safe and specialized mature port. As a result, this study identified the main factors to be improved and provided basic data to develop into a mature port with a port safety culture.

• Journal of Intelligence and Information Systems
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• v.26 no.2
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• pp.131-145
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• 2020

In line with the trend of industrial innovation, IoT technology utilized in a variety of fields is emerging as a key element in creation of new business models and the provision of user-friendly services through the combination of big data. The accumulated data from devices with the Internet-of-Things (IoT) is being used in many ways to build a convenience-based smart system as it can provide customized intelligent systems through user environment and pattern analysis. Recently, it has been applied to innovation in the public domain and has been using it for smart city and smart transportation, such as solving traffic and crime problems using CCTV. In particular, it is necessary to comprehensively consider the easiness of securing real-time service data and the stability of security when planning underground services or establishing movement amount control information system to enhance citizens' or commuters' convenience in circumstances with the congestion of public transportation such as subways, urban railways, etc. However, previous studies that utilize image data have limitations in reducing the performance of object detection under private issue and abnormal conditions. The IoT device-based sensor data used in this study is free from private issue because it does not require identification for individuals, and can be effectively utilized to build intelligent public services for unspecified people. Especially, sensor data stored by the IoT device need not be identified to an individual, and can be effectively utilized for constructing intelligent public services for many and unspecified people as data free form private issue. We utilize the IoT-based infrared sensor devices for an intelligent pedestrian tracking system in metro service which many people use on a daily basis and temperature data measured by sensors are therein transmitted in real time. The experimental environment for collecting data detected in real time from sensors was established for the equally-spaced midpoints of 4×4 upper parts in the ceiling of subway entrances where the actual movement amount of passengers is high, and it measured the temperature change for objects entering and leaving the detection spots. The measured data have gone through a preprocessing in which the reference values for 16 different areas are set and the difference values between the temperatures in 16 distinct areas and their reference values per unit of time are calculated. This corresponds to the methodology that maximizes movement within the detection area. In addition, the size of the data was increased by 10 times in order to more sensitively reflect the difference in temperature by area. For example, if the temperature data collected from the sensor at a given time were 28.5℃, the data analysis was conducted by changing the value to 285. As above, the data collected from sensors have the characteristics of time series data and image data with 4×4 resolution. Reflecting the characteristics of the measured, preprocessed data, we finally propose a hybrid algorithm that combines CNN in superior performance for image classification and LSTM, especially suitable for analyzing time series data, as referred to CNN-LSTM (Convolutional Neural Network-Long Short Term Memory). In the study, the CNN-LSTM algorithm is used to predict the number of passing persons in one of 4×4 detection areas. We verified the validation of the proposed model by taking performance comparison with other artificial intelligence algorithms such as Multi-Layer Perceptron (MLP), Long Short Term Memory (LSTM) and RNN-LSTM (Recurrent Neural Network-Long Short Term Memory). As a result of the experiment, proposed CNN-LSTM hybrid model compared to MLP, LSTM and RNN-LSTM has the best predictive performance. By utilizing the proposed devices and models, it is expected various metro services will be provided with no illegal issue about the personal information such as real-time monitoring of public transport facilities and emergency situation response services on the basis of congestion. However, the data have been collected by selecting one side of the entrances as the subject of analysis, and the data collected for a short period of time have been applied to the prediction. There exists the limitation that the verification of application in other environments needs to be carried out. In the future, it is expected that more reliability will be provided for the proposed model if experimental data is sufficiently collected in various environments or if learning data is further configured by measuring data in other sensors.

• Journal of Internet Computing and Services
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• v.21 no.3
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• pp.1-9
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• 2020

Along with the growth of Blockchain, DApp (Distributed Application) is getting attention. As interest in DApp grows, market size continues to grow and many developers participate in development. Many developers are using API(Application Programming Interface) services to mediate Blockchain nodes, such as Infura, for DApp development. However, when using such a service, there is a serious risk that the API service operator can violate the user's privacy by 1 to 1 matching the account address of the Transaction executed by the DApp user with the IP address of the DApp user. It can have an adverse effect on the reliability of public Blockchains that need to provide users with a secure DApp service environment. The proposed Blockchain platform is expected to provide user privacy protection from API services and provide a reliable DApp use environment that existing Blockchain platforms did not provide. It is also expected to help to activate DApp and increase the number of DApp users, which has not been activated due to the risk of an existing privacy breach.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.4
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• pp.365-375
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• 2017

Approximately 250 marine pollution accidents involving oil and HNS spills are reported every year in the Republic of Korea. It is necessary that a strengthen of specialization of marine pollution response personnel on marine pollution response due to a diminution of damage when a major oil and HNS spill incident occurred, as in the case of the M/V Heibei Spirit and the M/V Maritime Maisie. In regard to this, the International Maritime Organization (IMO) has planned to revise the OPRC Model Training Course to strengthen expertise for oil spill incident responses. Through a comparison of curriculum with the Korea Coast Guard Academy (KCGA) program, a revised IMO Model Course and the OSRL training institute, this study recommends the following improvements for the education program of the KCGA in response to oil spills. This study suggests several options in line with this approach to revise the oil spill response education curriculum, exercise, discussions and making materials. Accreditation of the KCGA as an institute that provides an IMO Model training course developed according to the revised IMO Model Course material is proposed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.5
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• pp.389-401
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• 2016

This study attempted to present the monthly distribution of the inshore gill netters for the prevention of propeller failure caused by the damage of fishing gear by the merchant vessels in the West Sea. This study was conducted using the transmitting device of fishing location (V-Pass) data for 1 year in 2014. The grid intervals are $30minute{\times}30minute$ ($latitude{\times}longitude$) based on the section of the sea. A total of 56 sections were analyzed by constructing a grid. The results revealed that the section no. 194 with the highest density index showed no fishing gear damage accident. But the section no. 193 with a relatively lower density index showed more frequent fishing gear damage accident. It is because the section no. 193 is included in the main route of the merchant vessels. Based on this analysis, it is found that the fishing gears are not damaged in proportion to density index but risk of damage exists according to the main routes of merchant vessels. Therefore, for the safe navigation of the merchant vessels, notifying the waters of $34.5^{\circ}{\sim}35.5^{\circ}$ at latitude and $125.67^{\circ}{\sim}126^{\circ}$ at longitude, as a navigational warning area from May through September, will prevent marine accident, such as propeller failure and fishing gear damage. Accordingly, when the merchant vessels navigate in the section no. 193 and 203, the area of $34.5^{\circ}{\sim}35.5^{\circ}$ at latitude and $125.5^{\circ}{\sim}125.67^{\circ}$ at longitude is recommended for the safe navigation.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.2
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• pp.104-110
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• 2009

This study tries to give improvement directions of the law of oil spill focusing on the view that satisfying remuneration for victims should be considered. And it looks through the existing remuneration system provided by P&I Club and IOPC Fund. It also covers with issues related to remuneration in order to find the best for victims. The major contents of this study are as follows. First, the present law of compensation security to Marine oil pollution accident should be revised. Maximum value of remuneration needs to be raised and subjects liable to pay reparation need to be expanded. Second, in case the damage is widely different comparing to similar cases in foreign countries, it's hard to get complete remuneration from international corporations responsible for reparation. That's the reason the national emergency system for oil pollution must be established. Third, this study says the law that certainly defines a liability subject and that the liability is not necessarily caused by fault should be enacted. Last, it suggest that victims should have their object income data to facilitate establishment of the law of compensation for damages from marine oil pollution. To calculate proper remuneration, government should consider to choose one of public organizations as an investigator to damages and should collect accurate statistics relating to fishery. Furthermore, compensation system which can provide rapid reparation to victims needs to established by founding professional maritime organization of arbitration.