• Journal of the Korean Society for Railway
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• v.15 no.3
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• pp.300-305
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• 2012

The saving of time, which is defined as the demand from passengers and the supply from the urban railway, must be balanced. The selected factors influencing on the balance are the traffic, customer contact facilities, the number of failures, customer complaints(VOC), passenger moving time and transfer stations. Also, the overall ratio of SMRT's 4 lines is generated by differentiating the rate of each attribute in each factor. This is not only to differentiate the stations with peculiar factors but also to standardize criteria of the personalized services. Furthermore, as part of standardization, standard drawings of facility management are prepared for the improvement on the management of human resource and material. The drawings include passenger moving lines, location of safety incidents and also indicate the rating of the factors in each station and overall evaluation rating. In conclusion, this thesis aims to improve customer satisfaction constantly by reducing passenger moving time, through the differentiated management of each station.

• Journal of the Korean Society for Railway
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• v.20 no.3
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• pp.349-355
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• 2017

Failures of railway systems can result in train delays or accidents, and therefore high reliability is required to ensure safety of railway systems. To improve reliability, railway systems are designed with redundant systems so that the standby system will continue to function normally even if the primary system fails. Generally, overall system reliability can be evaluated by the reliabilities of the parts of the whole system and the reliability of the redundant system considering common failures in case of each system is not conform physical, functional and process independent. In this study, the reliability of the hot-standby sparing system is analyzed the independent systems and dependent systems with common failures. The reliability for the standby system can be effectively analysed using Markov models, which can model the redundant configuration and the state transition.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.1507-1510
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• 2012

본 논문은 EPS(전자식 파워 스티어링)에 사용되는 Torque and Angle sensor 의 절대각 신뢰성 보증 방식에 관한 것으로, Inductive 방식의 센서에서 절대각 신호 신뢰성 보증에 대한 효과적인 방법을 제시한다. 전동식 파워 스티어링 시스템의 ECU(전자제어유닛)는 조타각도를 출력하는 2 개의 소자에서 버니어 알고리즘을 통해 360 도 이상의 멀티 조타각을 인식하게 된다. 토크&조향각 센서는 절대 조향각을 계산하는 1 개의 Hall IC 소자 신호와, 상대 조향각을 계산하는 ASIC 소자 신호를 사용하여 멀티 조타각을 인식한다. 인식된 조타각이 추가적인 검증 절차 없이 제어에 사용된다면, 센서의 이상 발생 시에 운전자의 조타감을 불편해질 수 있고, 나아가서는 차량사고의 위험을 발생시킬 수 있다.따라서 차량 거동 시 절대 조향각의 신뢰성 검증은 제어와 동시에 항상 요구되어야 한다. 특히, 유럽/미국 업계의 ISO 26262 표준 도입에 따라 절대 조향각의 높은 신뢰성이 요구된다. 본 논문에서는 이러한 요구사항을 만족하기 위해 측정된 절대각 신호를 기준으로 상대각 신호 2 개를 측정에 사용하고, Driving 시에도 절대각 기준의 신뢰도 향상을 위해 절대각 신호 1 개를 비교기로 사용한다. 최적화된 에러 기준을 근거로 절대 조향각 신호의 신뢰성을 보장하는 방법을 제안한다. 이러한 방법을 적용한다면, 정확하고 안정적으로 조타각을 결정함으로써 EPS 안전성 확보에 도움을 줄 수 있다.

• Korean Journal of Psychosomatic Medicine
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• v.24 no.1
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• pp.61-65
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• 2016

Currently, a variety of Information and Communication Technology(ICT) is being broadly utilized for mental health. Especially, mobile application is one of the effective ICT, and several applications have been developed after the spread of smartphones. The mobile-based mental health has several strengths, such as better treatment accessibility and easier check-ups of symptoms or daily activities by real-time monitoring. Better follow-ups of treatment course, more customized feedback and better transportability enable patients to be more adherent. However, there are some limitations of mobile technology about the mental health, such as technical troubles of electric errors, data safety problems and personal information extrusion. Therefore, full considerations should be given during the development and provision of the technology. Most of all, mental health specialists should actively participate in the development process by incorporation of evidence-based experiences and assurance of good clinical qualities.

• Journal of the Korea Convergence Society
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• v.12 no.12
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• pp.83-91
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• 2021

For agricultural products, supply is irregular due to changes in meteorological conditions, and it has high price elasticity. For example, if the supply decreases by 10%, the price increases by 50%. Due to these fluctuations in the prices of agricultural products, the Korean government guarantees the safety of prices to producers through small merchants' auctions. However, when prices plummet due to overproduction, protection measures for producers are insufficient. Therefore, in this paper, we designed a business model that can be used in the electronic transaction system by predicting the price of agricultural products with an artificial intelligence algorithm. To this end, the trained model with the training pattern pairs and a predictive model was designed by applying ARIMA, SARIMA, RNN, and CNN. Finally, the agricultural product forecast price data was classified into short-term forecast and medium-term forecast and verified. As a result of verification, based on 2018 data, the actual price and predicted price showed an accuracy of 91.08%.

• Journal of Convergence for Information Technology
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• v.11 no.11
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• pp.66-74
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• 2021

With the development of the Internet, user authentication technology that proves me online is improving. Existing ID methods pose a threat of personal information leakage if the service provider manages personal information and security is weak, and the information subject is to the service provider. In this study, as online identification technology develops, we propose a DID-based self-authentication model to prevent the threat of leakage of personal information from a centralized format and strengthen sovereignty. The proposed model allows users to directly manage personal information and strengthen their sovereignty over information topics through VC issued by the issuing agency. As a research method, a self-authentication model that guarantees security and integrity is presented using a decentralized identifier method based on distributed ledger technology, and the security of the attack method is analyzed. Because it authenticates through DID Auth using public key encryption algorithms, it is safe from sniffing, man in the middle attack, and the proposed model can replace real identity card.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.2
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• pp.109-114
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• 2021

As various users increase in a network environment, it is difficult to protect sensitive and confidential information transmitted and received from attackers. Concealing bitwise secret data in an image using the LSB technique can be very vulnerable to attack. To solve this problem, a hybrid method that combines encryption and information hiding is used. Therefore, an effective method for users to securely protect secret messages and implement secret communication is required. A new approach is needed to improve security and imperceptibility to ensure image quality. In this paper, I propose an LSB steganography technique that hides Hangul messages in a cover image based on MSB and LSB. At this time, after separating Hangul into chosung, jungsung and jongsung, the secret message is applied with Exclusive-OR or Exclusive-NOR operation depending on the selected MSB. In addition, the calculated secret data is hidden in the LSB n bits of the cover image converted by Fibonacci technique. PSNR was used to confirm the effectiveness of the applied results. It was confirmed 41.517(dB) which is suitable as an acceptable result.

• Journal of the Korea Convergence Society
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• v.9 no.12
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• pp.207-216
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• 2018

In Korea, there has been no national research on the use of antipsychotics for people with intellectual disabilities(I.D); therefore, it is difficult to identify the problems or to find solutions for problems in using antipsychotics. So, the purpose of this study analyze research findings on the use of antipsychotics for people with I.D in Japan. This research method compared and analyzed the results of research published in the journal J-STAGE and Medical Online and studied a cohort results using data. The results of the analysis are as follows. First, many antipsychotic drugs are prescribed to people with I.D, but it is difficult to accurately assess the effectiveness of the treatments. Second, it is not easy to detect side effects. Third, the potential side effects of drug interactions have been raised. The results was emphasized the need of research that accurately evaluate the drugs in survey of actual situation to ensure more safe use of antipsychotics to peoples with I.D in Korea.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.6
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• pp.1585-1594
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• 2018

In recent years The importance of information security management for securing information collection and analysis, production and distribution is increasing. Companies are assured of confidence in information security through authentication of information Security Management System. However, level assessment and use of domains that make up the management system is limited. On the other hand, the security maturity model is able to diagnose the level of information protection of the enterprise step by step. It is also possible to judge the area to be improved urgently. It is a tool to support goal setting according to the characteristics and level of company. In this paper, C2M2, which is an example of security maturity model, is compared and analyzed with Korea Information Security Management System certification. Benchmark the model to check the level of information security management and derive the priority among the items that constitute the detailed area of information security measures of ISMS certification. It also look at ways to check the level of information security management step by step.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.3
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• pp.589-598
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• 2019

The amount of digital data a is explosively growing, and these data have large potential values. Countries and companies are creating various added values from vast amounts of data, and are making a lot of investments in data analysis techniques. The privacy problem that occurs in data analysis is a major factor that hinders data utilization. Recently, as privacy violation attacks on neural network models have been proposed. researches on artificial neural network technology that preserves privacy is required. Therefore, various privacy preserving artificial neural network technologies have been studied in the field of differential privacy that ensures strict privacy. However, there are problems that the balance between the accuracy of the neural network model and the privacy budget is not appropriate. In this paper, we study differential privacy techniques that preserve the performance of a model within a given privacy budget and is resistant to model inversion attacks. Also, we analyze the resistance of model inversion attack according to privacy preservation strength.